0000950170-22-016882 | 10-Q | XBRL Viewer | 4D Molecular Therapeutics INC

The Company	6 Months Ended
Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The Company 4D Molecular Therapeutics, Inc. (the “Company”) was formed as a limited liability company in September 2013 under the name 4D Molecular Therapeutics, LLC. The Company changed its name and converted into a corporation which was incorporated in the state of Delaware in March 2015. The Company is a clinical-stage gene therapy company pioneering the development of product candidates using its targeted and evolved adeno-associated virus (“AAV”) vectors. Initial Public Offering In December 2020, the Company sold and issued 9,660,000 shares of common stock at a price to the public of $23.00 per share, which included shares sold upon the underwriters’ exercise of their overallotment option to purchase 1,260,000 additional shares. The Company received an aggregate of $204.7 million in net proceeds, after deducting underwriting discounts and commissions, and offering costs. Upon the closing of the Company’s initial public offering in December 2020 (the “IPO”), all outstanding shares of redeemable convertible preferred stock automatically converted into 11,575,984 shares of common stock. Subsequent to the closing of the IPO, there were no shares of redeemable convertible preferred stock outstanding. Follow On Public Offering In November 2021, the Company completed its second underwritten public offering ("Follow-on Offering") in which 4,750,000 shares of the Company's common stock were sold at an offering price of $25.00 per share pursuant to an effective Registration Statement on Form S-1. The net proceeds from the Follow-on Offering were $111.1 million, after deducting underwriting discounts and commissions and offering expenses. Liquidity The Company has incurred significant losses and negative cash flows from operations and had an accumulated deficit of $261.4 million as of June 30, 2022. The Company believes that its cash and cash equivalents and marketable securities as of June 30, 2022 are sufficient for the Company to fund planned operations for at least one year from the issuance date of these unaudited condensed financial statements. The Company has historically financed its operations primarily through the sale of equity securities, and to a lesser extent, from cash received pursuant to its collaboration and license agreements. To date, none of the Company’s product candidates have been approved for sale, and therefore, the Company has not generated any revenue from product sales. Management expects operating losses and negative cash flows from operations to continue for the foreseeable future. The Company plans to raise additional funding as required based on the status of its clinical trials and projected cash flows. There can be no assurance that, in the event the Company requires additional financing, such financing will be available on terms acceptable to the Company, if at all. Failure to generate sufficient cash flows from operations, raise additional capital and reduce discretionary spending should additional capital not become available could have a material adverse effect on the Company’s ability to achieve its business objectives.

The Company

6 Months Ended

Jun. 30, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. The Company

4D Molecular Therapeutics, Inc. (the “Company”) was formed as a limited liability company in September 2013 under the name 4D Molecular Therapeutics, LLC. The Company changed its name and converted into a corporation which was incorporated in the state of Delaware in March 2015. The Company is a clinical-stage gene therapy company pioneering the development of product candidates using its targeted and evolved adeno-associated virus (“AAV”) vectors.

Initial Public Offering

In December 2020, the Company sold and issued 9,660,000 shares of common stock at a price to the public of $23.00 per share, which included shares sold upon the underwriters’ exercise of their overallotment option to purchase 1,260,000 additional shares. The Company received an aggregate of $204.7 million in net proceeds, after deducting underwriting discounts and commissions, and offering costs.

Upon the closing of the Company’s initial public offering in December 2020 (the “IPO”), all outstanding shares of redeemable convertible preferred stock automatically converted into 11,575,984 shares of common stock. Subsequent to the closing of the IPO, there were no shares of redeemable convertible preferred stock outstanding.

Follow On Public Offering

In November 2021, the Company completed its second underwritten public offering ("Follow-on Offering") in which 4,750,000 shares of the Company's common stock were sold at an offering price of $25.00 per share pursuant to an effective Registration Statement on Form S-1. The net proceeds from the Follow-on Offering were $111.1 million, after deducting underwriting discounts and commissions and offering expenses.

Liquidity

The Company has incurred significant losses and negative cash flows from operations and had an accumulated deficit of $261.4 million as of June 30, 2022. The Company believes that its cash and cash equivalents and marketable securities as of June 30, 2022 are sufficient for the Company to fund planned operations for at least one year from the issuance date of these unaudited condensed financial statements. The Company has historically financed its operations primarily through the sale of equity securities, and to a lesser extent, from cash received pursuant to its collaboration and license agreements. To date, none of the Company’s product candidates have been approved for sale, and therefore, the Company has not generated any revenue from product sales. Management expects operating losses and negative cash flows from operations to continue for the foreseeable future. The Company plans to raise additional funding as required based on the status of its clinical trials and projected cash flows. There can be no assurance that, in the event the Company requires additional financing, such financing will be available on terms acceptable to the Company, if at all. Failure to generate sufficient cash flows from operations, raise additional capital and reduce discretionary spending should additional capital not become available could have a material adverse effect on the Company’s ability to achieve its business objectives.

Research and Collaboration Arrangements - CFF - Additional Information (Details 1) - CFF - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-07-01	Jun. 30, 2022
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, estimated performance period	2 years
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, estimated performance period	4 years

Commitments and Contingencies

6 Months Ended

Jun. 30, 2022

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

9. Commitments and Contingencies

Operating Lease Commitments

5980 Horton Street Building Lease

In May 2015, the Company executed a lease agreement for office and laboratory space in Emeryville, California. In January 2016, the Company executed the first amendment to the lease agreement for additional rentable office and laboratory space which extended the lease term to March 31, 2023 and updated the option to renew the lease at market rent from the prior additional term of three years to five years. In October 2018, the Company executed a second amendment to extend the lease to September 2026. Additionally, the second amendment provided a tenant improvement allowance of $0.2 million, which was paid to the Company in November 2018.

The 5980 Horton Street Building Lease is considered an operating lease under ASC 842 as it does not meet the criteria of a finance lease. As of June 30, 2022, the operating lease right-of-use asset and operating lease liability were $1.7 million and $2.1 million, respectively. As of December 31, 2021, the operating lease right-of-use asset and operating lease liability were $1.9 million and $2.3 million, respectively. The discount rate used to determine the lease liability was 7.5%.

5858 Horton Street Building Lease and Expansion

In October 2018, the Company executed a second lease agreement for additional office and laboratory space in Emeryville, California. The new lease has an initial term of 87 months beginning on the rent commencement date with the option to renew the lease for one additional term of five years at market rent. The Company did not have to pay rent until October 2019. This lease agreement also provided for a tenant improvement allowance of $0.4 million, which was paid to the Company in December 2019. The Company amortizes the tenant improvement allowance on a straight-line basis over the remaining term of the lease as a reduction of rent expense.

In May 2019, the Company amended the second lease agreement executed in October 2018 to add additional office, manufacturing and laboratory space (the “Expansion”). The amendment extended the term of the lease to December 31, 2029. The Company did not have to pay rent until December 2019. The lease agreement also included a tenant improvement allowance, which was increased to $2.3 million in February 2021 pursuant to a second amendment to the second lease agreement. As of June 30, 2022 the Company has received $1.9 million of this tenant improvement allowance. The tenant improvement allowance funds improvements to the additional office, manufacturing and laboratory space, which the Company has determined to be lessee owned. The allowance is treated as a reduction of lease payments used to measure the lease liability.

The 5858 Horton Street Building Lease and Expansion are considered operating leases under ASC 842 as they do not meet the criteria of a finance lease. As of June 30, 2022, the operating lease right-of-use asset and operating lease liability were $12.1 million and $14.9 million, respectively. As of December 31, 2021, the operating lease right-of-use asset and operating lease liability were $12.6 million and $14.2 million, respectively. The discount rate used to determine the lease liability was 7.8%.

Neither of the leases include a general option for the Company to terminate the leases.

The following table summarizes the components of lease expense for the three and six months ended June 30, 2022 and 2021 (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Operating lease cost	$	697	$	697	$	1,393	$	1,237
Variable lease cost		246		241		557		476
Total	$	943	$	938	$	1,950	$	1,713

Variable lease payments include amounts relating to common area maintenance and are recognized in the condensed statements of operations as incurred.

The following table summarizes supplemental information related to operating leases:


	June 30, 2022			December 31, 2021
Weighted-average remaining lease term (in years):		7.1			7.6
Weighted-average discount rate:		7.8	%		7.8	%

The following table summarizes the maturities of lease liabilities as of June 30, 2022 (in thousands):


2022 (remaining six months)	$	1,119
2023		3,058
2024		3,149
2025		3,244
2026		3,135
Thereafter		8,688
Total future minimum lease payments		22,393
Less: Amount representing interest		(5,395	)
Present value of future minimum lease payments		16,998
Less: Current portion of operating lease liabilities		2,596
Long-term portion of operating lease liabilities	$	14,402

Indemnification Agreements

In the ordinary course of business, the Company enters into agreements that may include indemnification provisions, such as with vendors and other parties. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently maintains directors’ and officers’ liability insurance that would generally enable it to recover a portion of any future amounts paid. The Company believes the estimated fair value of its indemnification agreements in excess of applicable insurance coverage is not material.

Legal Proceedings

From time to time, the Company may become involved in legal proceedings arising from the ordinary course of its business. If applicable, the Company records a legal liability when it believes that it is both probable that a liability may be imputed, and the amount of the liability can be reasonably estimated. Significant judgment by the Company is required to determine both probability and the estimated amount.

There are no material legal proceedings outstanding at June 30, 2022. See Note 12 for details of a settlement with a former employee in April 2021.

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment	$ 27,294	$ 19,716
Less: Accumulated depreciation and amortization	(6,197)	(5,325)
Property and equipment, net	21,097	14,391
Machinery and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	9,224	5,971
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	15,886	2,527
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	565	566
Office Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	188	165
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Total property and equipment	616	421
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment	$ 815	$ 10,066

Stock-based Compensation - Summary of Stock Options Activity (Details) - shares	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Number of Shares Available for Grant, Balances at December 31, 2021	2,690,097
Number of Shares Available for Grant, Options authorized	1,611,226
Number of Shares Available for Grant, Options granted	(1,497,137)
Number of Shares Available for Grant, Options expired	55,438
Number of Shares Available for Grant, Options forfeited	211,301
Number of Shares Available for Grant, Balances at June 30, 2022	3,070,925
Number of Shares Underlying Outstanding Options, Balances at December 31, 2021	3,881,274
Number of Shares Underlying Outstanding Options, granted	1,497,137
Number of Shares Underlying Outstanding Options, exercised	(90,802)
Number of Shares Underlying Outstanding Options, expired	(55,438)
Number of Shares Underlying Outstanding Options, forfeited	(211,301)
Number of Shares Underlying Outstanding Options, Balances at June 30, 2022	5,020,870
Number of Shares Underlying Outstanding Options, Options exercisable at June 30, 2022	2,012,208
Number of Shares Underlying Outstanding Options, Options vested and expected to vest at June 30, 2022	5,020,870

Stock-based Compensation - Summary of Stock-based Compensation Expense for Employees and Nonemployees by Function (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 4,322	$ 3,816	$ 8,255	$ 6,145
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,343	1,895	4,493	3,008
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,979	$ 1,921	$ 3,762	$ 3,137

Stock-based Compensation - Schedule of Assumptions Used in Black-Scholes Valuation Model to Estimate Fair Value of Stock Options (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	80.60%	82.80%	80.00%	82.80%
Expected volatility, maximum	81.30%	84.30%	81.30%	84.30%
Risk-free interest rate, minimum	2.70%	1.00%	1.50%	0.60%
Risk-free interest rate, maximum	3.60%	1.10%	3.60%	1.10%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	5 years 10 months 24 days	5 years 9 months 18 days	5 years 10 months 24 days	5 years 9 months 18 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days	6 years 3 months 18 days

401(K) Plan

6 Months Ended

Jun. 30, 2022

Retirement Benefits [Abstract]

401(K) Plan

16. 401(k) Plan

In 2014, the Company adopted a 401(k) plan for all employees who have met certain eligibility requirements. The 401(k) plan allows employees to make pre-tax and post-tax contributions up to the maximum allowable amount set by the Internal Revenue Service. The Company made contributions to the 401(k) plan for all eligible participants and recorded contribution expenses of $0.3 million and $0.1 million for the three months ended June 30, 2022 and 2021. For the six months ended June 30, 2022 and 2021, the Company recorded contribution expenses of $0.5 million and $0.3 million, respectively.

Net Loss Per Share Attributable to Common Stockholders - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator
Net loss	$ (28,086)	$ (7,589)	$ (54,424)	$ (23,995)
Denominator
Weighted-average shares outstanding used in computing net loss per share, basic	32,324,392	26,739,149	32,263,015	26,715,014
Weighted-average shares outstanding used in computing net loss per share, diluted	32,324,392	26,739,149	32,263,015	26,715,014
Net loss per share, basic	$ (0.87)	$ (0.28)	$ (1.69)	$ (0.90)
Net loss per share, diluted	$ (0.87)	$ (0.28)	$ (1.69)	$ (0.90)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1448-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1337-109256

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e4984-109258

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 15
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e3842-109258

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1252-109256

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 52
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e4984-109258

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
-Paragraph 15
-URI https://asc.fasb.org/extlink&oid=128363288&loc=d3e3842-109258

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1252-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1337-109256

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1448-109256

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 11
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1377-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

+ Details

Property and Equipment, Net (Tables)

6 Months Ended

Jun. 30, 2022

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment, Net

Property and equipment, net, consisted of the following (in thousands):


	June 30, 2022			December 31, 2021
Machinery and equipment	$	9,224		$	5,971
Leasehold improvements		15,886			2,527
Furniture and fixtures		565			566
Office equipment		188			165
Computer equipment and software		616			421
Construction in progress		815			10,066
Total property and equipment		27,294			19,716
Less: Accumulated depreciation and amortization		(6,197	)		(5,325	)
Property and equipment, net	$	21,097		$	14,391

Related Party Transactions - Additional Information (Details)	1 Months Ended		3 Months Ended		6 Months Ended
	Mar. 31, 2021 USD ($)	Apr. 30, 2019 USD ($) Agreement	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
UC Regents \| SRAs
Related Party Transaction [Line Items]
Number of sponsored research agreements entered \| Agreement		2
Agreement term		3 years
Amount due to related party		$ 1,500,000
UC Regents \| SRAs and Machine Learning SRA
Related Party Transaction [Line Items]
Accounts payable, related party			$ 0.0		$ 0.0		$ 0.0
UC Regents \| Machine Learning SRA
Related Party Transaction [Line Items]
Agreement term	3 years
Amount due to related party	$ 1,400,000
Payment to related party					$ 400,000
Agreement terminated					2022-03
David Schaffer, Ph.D. \| Consulting Services and Services as Board of Director
Related Party Transaction [Line Items]
Related party expenses			$ 0	$ 31,000	$ 0	$ 63,000

Fair Value Measurements - Summary of Changes in Fair Value of Level 3 Financial Instruments (Details) - Derivative Liability - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 214	$ 122
Change in fair value included in other income (expense), net	$ 8	$ 85
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Income [Extensible List]	Other expense, net	Other expense, net
Ending Balance	$ 222	$ 207

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net loss	$ (54,424)	$ (23,995)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	8,255	6,145
Vesting of common stock warrants	44	44
Change in fair value of derivative liability	8	85
Depreciation and amortization	872	753
Amortization of right-of-use assets	741	737
Net amortization (accretion) of premium (discount) on marketable securities	1,051	0
Changes in operating assets and liabilities
Accounts receivable	47	268
Prepaid expenses and other current assets	2,660	653
Accounts payable	(1,454)	(172)
Accrued and other liabilities	(422)	(904)
Deferred revenue	(1,382)	(14,454)
Operating lease liabilities	550	(737)
Net cash used in operating activities	(43,454)	(31,577)
Cash flows from investing activities
Purchase of marketable securities	(65,879)	0
Maturities of marketable securities	77,716	0
Acquisition of property and equipment	(8,479)	(1,379)
Net cash provided by (used in) investing activities	3,358	(1,379)
Cash flows from financing activities
Payment of offering costs	(360)	(946)
Proceeds from the exercise of stock options and warrants	939	919
Net cash provided by (used in) financing activities	579	(27)
Net decrease in cash and cash equivalents	(39,517)	(32,983)
Cash and cash equivalents, beginning of period	153,001	276,726
Cash and cash equivalents, end of period	113,484	243,743
Supplemental disclosures of noncash investing and financing information
Decrease in right-of-use assets due to reduction in operating lease liabilities upon modification	0	(478)
Issuance of common stock warrant to settle liability	0	1,146
Purchases of property and equipment in accounts payable and accrued and other liabilities	$ 1,298	$ 347

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Basis of Presentation

The accompanying unaudited condensed financial statements have been prepared in accordance with United States Generally Accepted Accounting Principles (“U.S. GAAP”) and the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim reporting.

Our condensed balance sheet for the year ended December 31, 2021 was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. Certain information and note disclosures normally included in annual financial statements prepared in accordance with U.S. GAAP

have been condensed or omitted. Accordingly, the unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 filed with the SEC.

The accompanying financial information for the three and six months ended June 30, 2022 and 2021 are unaudited. The unaudited condensed financial statements have been prepared on the same basis as the annual audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of June 30, 2022 and December 31, 2021 and its results of operations and cash flows for the six months ended June 30, 2022 and 2021. The results for interim periods are not necessarily indicative of the results expected for the full fiscal year or any other periods.

Use of Estimates and Judgements

The preparation of the condensed financial statements in conformity with U.S. GAAP requires management to make estimates and judgements that affect the reported amounts of assets, liabilities, revenue and expenses and disclosure of contingent assets and liabilities as of the date of the financial statements. Such estimates include the determination of useful lives for property and equipment, the contract term, transaction price and costs of collaboration agreements, as well as estimates of the fair value of common stock (prior to the IPO), stock options, derivative instrument and income tax uncertainties. Actual results could differ from those estimates.

Due to the coronavirus (“COVID-19”) pandemic, there has been uncertainty and disruption in the global economy and financial markets. The Company is not aware of any specific event or circumstance that would require an update to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of June 30, 2022. While there was not a material impact to the Company's unaudited condensed financial statements as of June 30, 2022, these estimates may change, as new events occur and additional information is obtained, as well as other factors related to the COVID-19 pandemic that could result in material impacts to the unaudited condensed financial statements in future reporting periods.

Segment Information

The Company operates and manages its business as one reportable and operating segment. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on a company-wide basis for purposes of allocating resources and assessing financial performance.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents, marketable securities and accounts receivable. The Company’s cash is held at two financial institutions in the United States of America. The Company’s cash equivalents are invested in money market funds. The Company also invests in U.S. Treasuries, U.S. Government sponsored agency, commercial paper and corporate bonds. The Company has not experienced any losses on its deposits of cash and cash equivalents. Such deposits may, at times, exceed federally insured limits.

The Company’s partners in collaboration and license agreements who represent 10% or more of the Company’s total revenue are as follows:


	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Customer A	*	98%	*	96%
Customer B	99%	*	98%	*
Total	99%	98%	98%	96%

* Less than 10%

The Company’s partners in collaboration and license agreements who represent 10% or more of the Company’s total accounts receivable are as follows:


	June 30, 2022	December 31, 2021
Customer A	0%	100%
Total	0%	100%

The Company’s total revenues by geographic region, based on the location of the customer, are as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Netherlands	$	160	$	267	$	1,352	$	659
Switzerland		—		14,297		—		15,902
United States		2		16		30		19
Total revenue	$	162	$	14,580	$	1,382	$	16,580

Cash and Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents consist of money market funds.

Marketable Securities

Marketable securities consist of commercial paper, corporate bonds, U.S. Treasuries and U.S. Government sponsored agency and are included in current and noncurrent assets. The Company classifies its marketable securities as available-for-sale and carries them at fair value on its condensed balance sheet. Fair value is estimated using independent pricing sources based on quoted prices in active markets for similar securities. Unrealized gains and losses on the marketable securities are reported as a component of stockholders' equity in accumulated other comprehensive loss. The amortized cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest income on the condensed statements of operations. Realized gains and losses are included in interest income on the condensed statements of operations.

The Company periodically evaluates its marketable securities to assess whether those with unrealized loss positions are other than temporarily impaired. The Company considers various factors in determining whether to recognize an impairment charge. If the Company determines that the decline in an investment's fair value is other-than-temporary, the difference is recognized as an impairment loss in the condensed statements of operations.

Other Risks and Uncertainties

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, suppliers for key raw materials, contract manufacturing organizations (“CMOs”) and contract research organizations (“CROs”), compliance with government regulations and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies, clinical trials and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance and reporting.

There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained or maintained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from other

pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, consultants and other third parties (including for clinical trials and some aspects of research and preclinical testing).

The extent of the impact of the COVID-19 pandemic on the Company’s business will depend upon the duration and spread of the outbreak and the extent and severity of the impact on the Company’s clinical trial activities, research activities and suppliers, all of which are uncertain and cannot be predicted. The extent to which the coronavirus outbreak may materially impact the Company’s financial condition, liquidity or results of operations is uncertain.

Fair Value Measurements

The Company applies fair value accounting for all financial assets and liabilities and nonfinancial assets and liabilities that are recognized or disclosed at fair value in the unaudited condensed financial statements on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability.

As a basis for considering such assumptions, a three-level fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

•

Level 1 — Observable inputs that reflect unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date.

•

Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•

Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company accounts for transfers of financial instruments between levels of the fair value hierarchy on the date of the event or change in circumstance that caused the transfer.

Common Stock Warrants

The Company accounts for common stock warrants which meet the definition of a derivative as liabilities if the warrant requires net cash settlement or gives the holder the option of net cash settlement. The Company accounts for common stock warrants as equity if the contract requires physical settlement or net physical settlement or if the Company has the option of physical settlement or net physical settlement. Common stock warrants classified as liabilities are initially recorded at fair value and remeasured at fair value each condensed balance sheet date with the offset adjustments recorded in other income (expense), net within the condensed statements of operations. Common stock warrants classified as equity are initially measured at fair value on the grant date and are not subsequently remeasured.

Leases

On December 31, 2021, the Company adopted Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842), ("ASC 842") using the alternative modified transition method effective as of January 1, 2021. As a result, the Company has retrospectively changed its previously issued unaudited condensed financial statements as of June 30, 2021 and for the three and six months ended June 30, 2021 as presented within the Company's June 30, 2021 Quarterly Report on Form 10-Q to reflect the adoption of ASC 842 on January 1, 2021. The condensed financial statements for the three and six months ended June 30, 2021 presented herein differ from the Company's condensed financial statements included in the Company's June 30, 2021 Quarterly Report on Form 10-Q as those unaudited condensed financial statements were prepared using the former accounting standard referred to as ASC Topic 840, Leases.

The impact of adoption on ASC 842 on the condensed statements of operations for the six months ended June 30, 2021 was immaterial. The following table summarizes the effect of the adoption of ASC 842 on the condensed statement of cash flows for the six months ended June 30, 2021 (in thousands):


	Pre ASC 842					After ASC 842
	Six Months Ended		ASC 842			Six Months Ended
	June 30, 2021		Adjustments			June 30, 2021
Adjustments to reconcile net loss to net cash used in operating activities
Amortization of right-of-use assets	$	—	$	737		$	737
Changes in operating assets and liabilities
Operating lease liabilities		—		(737	)		(737	)
Supplemental disclosures of noncash investing and financing information
Decrease in right-of-use assets due to reduction in operating lease liabilities upon modification		—		(478	)		(478	)

At contract inception, the Company determines if an arrangement is or contains a lease. A contract is or contains a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. If determined to be or contain a lease, the lease is assessed for classification as either an operating or finance lease at the lease commencement date, defined as the date on which the leased asset is made available for use by the Company, based on the economic characteristics of the lease.

A right-of-use asset represents the economic benefit conveyed to the Company by the right to use the underlying asset over the lease term. A lease liability represents the obligation to make lease payments arising from the lease. Operating lease right-of-use assets represent the Company's right to use an underlying asset for the lease term and operating lease liabilities represent the Company's obligation to make payments arising from the lease. Operating right-of-use assets and liabilities are recognized at the commencement date of the lease and are measured at the present value of the fixed payments due over the expected lease term less the present value of any incentives, rebates, or abatements the Company expects to receive from the lessor. The Company records amortization of operating right-of-use assets and accretion of lease liabilities as a single lease cost on a straight-line basis over the lease term. No lease renewal options are recognized as part of the right-of-use assets and lease liabilities.

The Company's operating leases are presented in the condensed balance sheets as operating lease right-of-use assets, classified as noncurrent assets, and operating lease liabilities, classified as current and noncurrent based on the discounted lease payments to be made within the preceding twelve months.

As the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate to discount lease payments. The incremental borrowing rate represents an estimated rate of interest that the Company would have to pay to borrow equivalent funds on a collateralized basis at the lease commencement date.

Revenue Recognition

The Company determines revenue recognition for arrangements within the scope of Accounting Standards Update 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASC 606") by performing the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation.

The Company’s revenue is primarily derived through its license, research, development and commercialization agreements. The terms of these types of agreements may include (i) licenses to the

Company’s technology, (ii) research and development services, and (iii) services or obligations in connection with participation in research or steering committees. Payments to the Company under these arrangements typically include one or more of the following: nonrefundable upfront and license fees, research funding, milestone and other contingent payments to the Company for the achievement of defined collaboration objectives and certain preclinical, clinical, regulatory and sales-based events, as well as royalties on sales of any commercialized products. Arrangements that include upfront payments are recorded as deferred revenue upon receipt or when due and are recognized as revenue as the performance conditions are met. The event-based milestone payments, royalties and cost reimbursements represent variable consideration, and the Company uses the most likely amount method to estimate this variable consideration. Royalty payments are recognized when earned or as the sales occur. The Company records cost reimbursements as accounts receivable when right to consideration is unconditional.

A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account in ASC 606. The Company allocates the total transaction price to each performance obligation based on the estimated standalone selling price and recognizes revenue when, or as, the performance obligation is satisfied. The Company includes the unconstrained amount of estimated variable consideration in the transaction price. At the end of each reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjusts its estimate of the overall transaction price.

Significant management judgment is required to determine the level of effort required under an arrangement and the period over which the Company expects to complete its performance obligations under the arrangement. Changes in these estimates can have a material effect on revenue recognized.

Embedded Derivative

Embedded derivatives that are required to be bifurcated from the underlying host instrument are accounted for and valued as a separate financial instrument. An embedded derivative exists in the award agreement with the Cystic Fibrosis Foundation (“CFF”). As described in Note 14, the embedded derivative has been bifurcated and is classified as a liability on the condensed balance sheets and is separately accounted for at its fair value. The derivative liability is subject to remeasurement to fair value each reporting period. Changes in the fair value of the derivative liability are recognized as a component of other income (expense), net within the condensed statements of operations.

Net Loss Per Share, Basic and Diluted

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potentially dilutive common shares outstanding for the period. For purposes of this calculation, stock options to acquire shares of common stock and common stock warrants are considered potentially dilutive common shares, but have been excluded from the calculation of diluted net loss per share as their effect is antidilutive.

Recent Accounting Pronouncement

New Accounting Pronouncement Not Yet Adopted

As an “emerging growth company,” the Jumpstart Our Business Startups Act (“JOBS Act”) allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. The Company has elected to use this extended transition period under the JOBS Act. The adoption dates discussed below reflect this election.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, as clarified in subsequent amendments. ASU 2016-13 changes the impairment model for certain financial instruments. The new model is a forward-looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade

receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. In October 2019, the FASB voted to delay the effective date of this standard. Topic 326 will be effective for the Company for fiscal years beginning after December 15, 2022. Early adoption is permitted. The Company is in the process of evaluating the impact of this new guidance on its condensed financial statements.

Accrued and Other Current Liabilities (Tables)

6 Months Ended

Jun. 30, 2022

Payables and Accruals [Abstract]

Summary of Accrued and Other Current Liabilities

Accrued and other current liabilities consisted of the following (in thousands):


	June 30, 2022		December 31, 2021
Payroll and related expenses	$	2,933	$	3,994
Accrued clinical and preclinical study costs		1,255		407
Consulting and professional		1,227		1,573
Other accrued expenses		748		1,770
Total accrued and other current liabilities	$	6,163	$	7,744

Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Stock Options Activity

The following table summarizes the stock options activity for the six months ended June 30, 2022:


	Number of Shares Available for Grant			Number of Shares Underlying Outstanding Options
Balances at December 31, 2021		2,690,097			3,881,274
Options authorized		1,611,226			—
Options granted		(1,497,137	)		1,497,137
Options exercised		—			(90,802	)
Options expired		55,438			(55,438	)
Options forfeited		211,301			(211,301	)
Balances at June 30, 2022		3,070,925			5,020,870
Options exercisable at June 30, 2022					2,012,208
Options vested and expected to vest at June 30, 2022					5,020,870

Schedule of Assumptions Used in Black-Scholes Valuation Model to Estimate Fair Value of Stock Options

The Company estimates the fair value of stock options using the Black-Scholes option pricing model. The fair value of employee and nonemployee options is recognized on a straight-line basis over the requisite service period of the awards. The fair value of the Company’s stock options was estimated using the following assumptions for the three and six months ended June 30, 2022 and 2021.


	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Expected term	5.9 - 6.1 years	5.8 - 6.1 years	5.9 - 6.1 years	5.8 - 6.3 years
Expected volatility	80.6% - 81.3%	82.8% - 84.3%	80.0% - 81.3%	82.8% - 84.3%
Risk-free interest rate	2.7% - 3.6%	1.0% - 1.1%	1.5% - 3.6%	0.6% - 1.1%
Expected dividend yield	—%	—%	—%	—%

Summary of Stock-based Compensation Expense for Employees and Nonemployees by Function

The following table is a summary of stock-based compensation expense incurred for employees and nonemployees by function (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	2,343	$	1,895	$	4,493	$	3,008
General and administrative		1,979		1,921		3,762		3,137
Total stock-based compensation expense	$	4,322	$	3,816	$	8,255	$	6,145

Summary of Significant Accounting Policies - Additional Information (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2022 Financial_Institution Segment	Dec. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments	1
Number of operating segments	1
Number of financial institutions cash is held \| Financial_Institution	2
Accounting Standards Update [Extensible Enumeration]		Accounting Standards Update 2016-02 [Member]
Change in accounting principle accounting standards update, adopted		true
Change in accounting principle accounting standards update, adoption date		Jan. 01, 2021

- Definition

Indicates amendment to accounting standards.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (f)(2)
-URI https://asc.fasb.org/extlink&oid=128097895&loc=SL121327923-165333

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(2)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (f)(1)
-URI https://asc.fasb.org/extlink&oid=128097895&loc=SL121327923-165333

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=128097895&loc=SL121327923-165333

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 832
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128342835&loc=SL128342857-244232

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (d)(3)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (b)(1)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iv)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iii)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (b)(2)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (h)(1)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 32: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(2)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (d)(2)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(3)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 38: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL122150809-237846

Reference 42: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 43: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(1)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 44: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 45: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497

Reference 46: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 47: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 48: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497

Reference 49: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 50: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 51: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 52: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 53: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(i)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 54: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 55: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 56: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 57: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (e)(3)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 58: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(03)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 59: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 60: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)(2)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 61: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(01)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 62: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 63: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 832
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128342835&loc=SL128342857-244232

Reference 64: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 65: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(3)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 66: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 67: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 68: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

+ Details

- Definition

Indicates (true false) whether accounting standards update was adopted.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 20
-Section 65
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=121483254&loc=SL120254523-199619

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120254519-210437

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL120154346-209984

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL122150809-237846

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(2)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 832
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128342835&loc=SL128342857-244232

+ Details

- Definition

Date accounting standards update was adopted, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 832
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128342835&loc=SL128342857-244232

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(2)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(3)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL122150809-237846

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL120154346-209984

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 65
-Paragraph 3
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 20
-Section 65
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=121483254&loc=SL120254523-199619

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120254519-210437

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984

+ Details

Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Schedule of Concentration of Risk

The Company’s partners in collaboration and license agreements who represent 10% or more of the Company’s total revenue are as follows:


	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Customer A	*	98%	*	96%
Customer B	99%	*	98%	*
Total	99%	98%	98%	96%

* Less than 10%

The Company’s partners in collaboration and license agreements who represent 10% or more of the Company’s total accounts receivable are as follows:


	June 30, 2022	December 31, 2021
Customer A	0%	100%
Total	0%	100%

Schedule of Revenues by Geographic Region

The Company’s total revenues by geographic region, based on the location of the customer, are as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Netherlands	$	160	$	267	$	1,352	$	659
Switzerland		—		14,297		—		15,902
United States		2		16		30		19
Total revenue	$	162	$	14,580	$	1,382	$	16,580

Schedule of Impact of Adoption of New Accounting Standard

The following table summarizes the effect of the adoption of ASC 842 on the condensed statement of cash flows for the six months ended June 30, 2021 (in thousands):


	Pre ASC 842					After ASC 842
	Six Months Ended		ASC 842			Six Months Ended
	June 30, 2021		Adjustments			June 30, 2021
Adjustments to reconcile net loss to net cash used in operating activities
Amortization of right-of-use assets	$	—	$	737		$	737
Changes in operating assets and liabilities
Operating lease liabilities		—		(737	)		(737	)
Supplemental disclosures of noncash investing and financing information
Decrease in right-of-use assets due to reduction in operating lease liabilities upon modification		—		(478	)		(478	)

Derivative Liability - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Change in control discount rate	15.00%	14.00%
Estimated fair value of derivative liability	$ 0.2	$ 0.2
Minimum
Derivative [Line Items]
Change of control payment	$ 0.0	$ 0.0
Change in control event percentage	4.80%	4.80%
Maximum
Derivative [Line Items]
Change of control payment	$ 10.6	$ 10.6
Change in control event percentage	17.20%	17.20%

Related Party Transactions

6 Months Ended

Jun. 30, 2022

Related Party Transactions

15. Related Party Transactions

During the three months and six months ended June 30, 2021, the Company paid $31,000 and $63,000, respectively, to David Schaffer, Ph.D., a co-founder, and former director and Chief Scientific Advisor of the Company for consulting services while Dr. Schaffer was a director. The Company made no payments to Dr. Schaffer during the three and six months ended June 30, 2022. In April 2019, the Company entered into two sponsored research agreements (“SRAs”) with the UC Regents to conduct research in a research facility on the U.C. Berkeley campus, under the direction of Dr. Schaffer. The SRAs have a three year term ending in May 2022. Under the SRAs, the Company has an option to license (on a royalty-bearing basis) all intellectual property generated under the SRAs. Any patent prosecution costs incurred under the SRAs will also be borne by the Company. The Company can terminate the SRAs for

convenience and without cause with 60 days’ notice. The total amount the Company is committed to pay to the UC Regents under the SRAs is $1.5 million, which was fully paid as of June 30, 2022. In March 2021, the Company entered into another sponsored research agreement with the UC Regents to conduct research in laboratories on the U.C. Berkeley campus that are under the direction of Dr. Schaffer and another U.C. Berkeley professor covering investigations into how machine learning approaches may enhance AAV capsid engineering (the “Machine Learning SRA”). Pursuant to the Machine Learning SRA, the Company committed to pay the UC Regents a total of $1.4 million, of which $0.4 million was paid as of June 30, 2022. The Machine Learning SRA has a three-year term ending in 2024. Any patent prosecution costs incurred under the SRAs will also be borne by the Company. The Company can terminate the SRAs for convenience and without cause with 60 days’ notice. While the Machine Learning SRA is between the Company and the UC Regents, the payments under the SRA will be used to fund the lab under the direction of Dr. Schaffer. As of June 30, 2022 and December 31, 2021, accounts payable related to the SRAs and Machine Learning SRA was $0.0 million. The Machine Learning SRA was terminated by the Company in March 2022. As of February 2022, the SRAs ceased to be related party transactions upon the resignation of Dr. Schaffer from the board of directors of the Company.

Fair Value Measurements - Fair Value Hierarchy for Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value on Recurring Basis - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	$ 242,950	$ 198,984
Liabilities	222	214
Derivative Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	222	214
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	26,456	37,535
Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	61,092	94,864
US Treasuries
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	58,399	30,029
US Government Sponsored Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	2,189
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	94,814	36,556
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	94,814	36,556
Level 1 \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	94,814	36,556
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	148,136	162,428
Level 2 \| Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	26,456	37,535
Level 2 \| Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	61,092	94,864
Level 2 \| US Treasuries
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	58,399	30,029
Level 2 \| US Government Sponsored Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	2,189
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	222	214
Level 3 \| Derivative Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	$ 222	$ 214

Summary of Significant Accounting Policies - Schedule of Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Line Items]
Total revenue	$ 162	$ 14,580	$ 1,382	$ 16,580
Netherlands
Disaggregation Of Revenue [Line Items]
Total revenue	160	267	1,352	659
Switzerland
Disaggregation Of Revenue [Line Items]
Total revenue	0	14,297	0	15,902
United States
Disaggregation Of Revenue [Line Items]
Total revenue	$ 2	$ 16	$ 30	$ 19

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9031-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9038-108599

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 235
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-URI https://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 22: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

+ Details

Accrued and Other Current Liabilities - Summary of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Payroll and related expenses	$ 2,933	$ 3,994
Accrued clinical and preclinical study costs	1,255	407
Consulting and professional	1,227	1,573
Other accrued expenses	748	1,770
Total accrued and other current liabilities	$ 6,163	$ 7,744

Common Stock (Tables)

6 Months Ended

Jun. 30, 2022

Equity [Abstract]

Schedule of Common Share Reserved for Future Issuance

As of June 30, 2022 and December 31, 2021, the Company has reserved common stock, on an as-converted basis, for future issuance as follows:


	June 30, 2022		December 31, 2021
Issuance of common stock under the 2020 Equity Incentive Award Plan		3,070,925		2,690,097
Issuance of common stock under the Employee Stock Purchase Plan		462,195		498,747
Exercise of options issued and outstanding		5,020,870		3,881,274
Exercise of common stock warrants		53,669		53,669
Total common stock reserved for future issuance		8,607,659		7,123,787

Marketable Securities - Additional Information (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($) Security
Debt Securities, Available-for-sale [Line Items]
Number of marketable securities unrealized loss position more than one year \| Security		0
Other-than-temporary impairment on investment in debt securities available-for-sale \| $	$ 0	$ 0
Maximum Maturity Period of Marketable Securities		2 years

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended						6 Months Ended
	Feb. 28, 2021	Dec. 31, 2019	May 31, 2019	Nov. 30, 2018	Oct. 31, 2018	May 31, 2015	Jun. 30, 2022	Dec. 31, 2021	Jan. 31, 2016
Commitment And Contingencies [Line Items]
Operating lease right-of-use ("ROU") assets							$ 13,821	$ 14,562
Operating lease liability							16,998
5980 Horton Street Building Lease
Commitment And Contingencies [Line Items]
Lease extended term date						Mar. 31, 2023
Tenant improvement allowance				$ 200
Operating lease right-of-use ("ROU") assets							1,700	1,900
Operating lease liability							2,100	$ 2,300
Operating lease, discount rate								7.50%
Lease extended term period					2026-09
5858 Horton Street Building Lease and Expansion
Commitment And Contingencies [Line Items]
Lease extended term date			Dec. 31, 2029
Maximum tenant improvement allowance available	$ 2,300
Tenant improvement allowance		$ 400					1,900
Operating lease right-of-use ("ROU") assets							12,100	$ 12,600
Operating lease liability							$ 14,900	$ 14,200
Operating lease, discount rate								7.80%
Lease initial term					87 months
Lease option to renew term description							The new lease has an initial term of 87 months beginning on the rent commencement date with the option to renew the lease for one additional term of five years at market rent.
Lease existence of option to renew term					true
Lease renewal term					5 years
Maximum \| 5980 Horton Street Building Lease
Commitment And Contingencies [Line Items]
Lease renewal term									5 years
Minimum \| 5980 Horton Street Building Lease
Commitment And Contingencies [Line Items]
Lease renewal term									3 years

Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (28,086)	$ (7,589)	$ (54,424)	$ (23,995)
Other comprehensive loss:
Net unrealized loss on marketable securities	(406)	0	(1,404)	0
Total Comprehensive loss	$ (28,492)	$ (7,589)	$ (55,828)	$ (23,995)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669619-108580

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669625-108580

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

+ Details

Research and Collaboration Arrangements - Additional Information (Details 1)	Jan. 31, 2014
uniQure \| uniQure Agreement \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-07-01
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, estimated performance period	4 years

Net Loss Per Share Attributable to Common Stockholders

6 Months Ended

Jun. 30, 2022

Earnings Per Share [Abstract]

Net Loss Per Share Attributable to Common Stockholders

13. Net Loss Per Share, Basic and Diluted

The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data):


	Three Months Ended June 30,						Six Months Ended June 30,
	2022			2021			2022			2021
Numerator
Net loss	$	(28,086	)	$	(7,589	)	$	(54,424	)	$	(23,995	)
Denominator
Weighted-average shares outstanding used in computing net loss per share, basic and diluted		32,324,392			26,739,149			32,263,015			26,715,014
Net loss per share, basic and diluted	$	(0.87	)	$	(0.28	)	$	(1.69	)	$	(0.90	)

The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive:


	June 30,
	2022		2021
Options issued and outstanding		5,020,870		4,238,519
ESPP shares expected to be issued		—		111,589
Common stock warrants		53,669		98,669
Total		5,074,539		4,448,777

Stock-based Compensation

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation

11. Stock-based Compensation

2020 Equity Incentive Award Plan

In December 2020, the Company adopted the 2020 Incentive Award Plan (“2020 Plan”), which became effective on December 10, 2020. The 2020 Plan initially reserved 2,606,546 shares of common stock for the issuance of stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance bonus awards, performance stock units, dividend equivalents or other stock or cash based award granted to employees, directors and consultants of the Company. The number of shares reserved for future issuance under the 2020 Plan will increase annually on the first day of each fiscal year beginning in 2021 and ending in 2030 by the lesser of (i) 5% of the shares of common stock outstanding (on an as converted basis) on the last day of the immediately preceding fiscal year and (ii) such number of shares of common stock as determined by the Company's board of directors, provided, however, no more than 18,000,000 shares of the Company's common stock may be issued upon the exercise of incentive stock options. In 2022, an additional 1,611,226 shares of the Company's common stock became available for issuance under the 2020 Plan, as a result of the operation of the automatic annual increase provision. All options are exercisable over a period not to exceed the contractual term of ten years from the date the stock options were issued. As of June 30, 2022 there were 2,902,219 shares available for grant under the 2020 Plan.

2015 Equity Incentive Plan

Following the effectiveness of the 2020 Plan, the Company will not make any further grants under the 2015 Equity Incentive Plan (the "2015 Plan"). However, the 2015 Plan continues to govern the terms of options that remain outstanding under the 2015 Plan. All outstanding grants under the 2015 Plan that are repurchased, forfeited, expire or are returned back to the 2015 Plan are not available for grant under the 2020 Plan.

The 2015 Plan provided for grants of stock options, stock appreciation rights, restricted stock and restricted stock unit awards to employees, directors and consultants of the Company. As of June 30, 2022, options to purchase 2,371,439 shares of the Company's common stock were outstanding under the 2015 Plan. All options are exercisable over a period not to exceed the contractual term of ten years from the date the stock options were issued and are granted at prices not less than the estimated fair market value of the Company’s common stock on the grant date as determined by the Company's board of directors. If an

individual owns stock representing more than 10% of the Company’s outstanding shares, the exercise price of each share shall be at least 110% of the fair market value on the date of grant.

Employee Stock Purchase Plan

In December 2020, the Company adopted the 2020 Employee Stock Purchase Plan (the “2020 ESPP”). Under the 2020 ESPP, 252,337 shares of the Company's common stock were initially reserved for employee purchases of the Company's common stock under terms and provisions established by the Company's board of directors and approved by the Company's stockholders. The number of shares reserved for future issuance under the 2020 ESPP will increase annually on the first day of each fiscal year beginning in 2021 and ending in 2030 by the lesser of (i) 1% of the shares of the Company's common stock outstanding (on an as converted basis) on the last day of the immediately preceding fiscal year and (ii) such number of shares of common stock as determined by the Company's board of directors, provided, however, no more than 15,000,000 shares of the Company's common stock may be issued under the 2020 ESPP. On March 28, 2022, an additional 25,000 shares of the Company's common stock became available for future issuance under the 2020 ESPP, as a result of the operation of this automatic annual increase provision.

Under the 2020 ESPP the Company's employees may purchase common stock through payroll deductions at a price equal to 85% of the lower of the fair market value of the stock at the beginning of the offering period or at the end of each applicable purchase period. The 2020 ESPP provides for a series of overlapping 24-month offering periods comprised of four six-month purchase periods. The initial offering period under the ESPP is longer than 24 months, commencing February 15, 2021 and ending on May 14, 2023. Contributions under the 2020 ESPP are limited to a maximum of 15% of an employee's eligible compensation.

Stock Options

The following table summarizes the stock options activity for the six months ended June 30, 2022:


	Number of Shares Available for Grant			Number of Shares Underlying Outstanding Options
Balances at December 31, 2021		2,690,097			3,881,274
Options authorized		1,611,226			—
Options granted		(1,497,137	)		1,497,137
Options exercised		—			(90,802	)
Options expired		55,438			(55,438	)
Options forfeited		211,301			(211,301	)
Balances at June 30, 2022		3,070,925			5,020,870
Options exercisable at June 30, 2022					2,012,208
Options vested and expected to vest at June 30, 2022					5,020,870


	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Expected term	5.9 - 6.1 years	5.8 - 6.1 years	5.9 - 6.1 years	5.8 - 6.3 years
Expected volatility	80.6% - 81.3%	82.8% - 84.3%	80.0% - 81.3%	82.8% - 84.3%
Risk-free interest rate	2.7% - 3.6%	1.0% - 1.1%	1.5% - 3.6%	0.6% - 1.1%
Expected dividend yield	—%	—%	—%	—%

Expected Term. The expected term for employee options is calculated using the simplified method as the Company does not have sufficient historical information to provide a basis for this estimate. The

simplified method is based on the average of the vesting tranches and the contractual life of each grant. The expected term for nonemployee options is the contractual term of the options.

Expected Volatility. The expected volatility is based on a mix of the Company's historical volatility and the historical volatility of comparable companies with similar attributes to the Company, including industry, stage of life cycle, size and financial leverage. For each grant, the Company measured historical volatility over a period equivalent to the expected term.

Risk-free Interest Rate. The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues whose term is similar in duration to the expected term of the respective stock option.

Expected Dividend Yield. The Company has not paid and does not anticipate paying any dividends on its common stock in the future. Accordingly, the Company has estimated the dividend yield to be zero.

Stock-Based Compensation Expense

The following table is a summary of stock-based compensation expense incurred for employees and nonemployees by function (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	2,343	$	1,895	$	4,493	$	3,008
General and administrative		1,979		1,921		3,762		3,137
Total stock-based compensation expense	$	4,322	$	3,816	$	8,255	$	6,145

Research and Collaboration Arrangements - Summary of Deferred Revenue (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue	$ 3,708	$ 5,090
uniQure
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue	2,309	3,661
CFF
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total deferred revenue	$ 1,399	$ 1,429

Research and Collaboration Arrangements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2014	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Aug. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized				$ 1,400,000	$ 14,000,000.0
Deferred revenue		$ 3,708,000		3,708,000		$ 5,090,000
Accounts receivable		0		0		47,000
uniQure
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue		2,309,000		2,309,000		3,661,000
Accounts receivable		$ 0		0		0
uniQure \| uniQure Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Increase in revenue recognized related to performance obligations partially satisfied in the beginning of the current year				$ 1,300,000
Collaborative arrangement, initial research term	3 years
Upfront payments received	$ 200,000
Options to purchase ordinary shares	609,744
Ordinary shares vesting period	3 years
Fair value of options	$ 10,600,000
uniQure \| uniQure Agreement \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent payments entitled to receive for achievement of research and development milestones	$ 5,000,000.0
Deferred revenue, estimated performance period		2 years		2 years
uniQure \| uniQure Agreement \| Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue, estimated performance period		1 year		1 year
uniQure \| Amended uniQure Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 200,000	$ 300,000	$ 1,400,000	$ 700,000
Fair value of non monetary consideration of intellectual property right							$ 5,100,000
Remaining performance obligations		$ 2,500,000		$ 2,500,000		$ 3,700,000
uniQure \| Amended uniQure Agreement \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent payments eliminated							$ 5,000,000.0

Research and Collaboration Arrangements - Roche Agreement - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues		$ 162,000	$ 14,580,000	$ 1,382,000	$ 16,580,000
Roche \| 2017 Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable upfront payments received	$ 21,000,000.0
Contingent payment for each nominated product beyond the first three	1,000,000.0
Maximum contingent payment upon exercise of the option to convert a product	30,000,000.0
Maximum development milestone payments	223,000,000.0
Development milestone payments relating to Choroideremia	86,000,000.0
Maximum sales-based milestone payments	$ 123,000,000.0
Non-refundable development milestone payments				10,000,000.0
Collaborative arrangement adjustment to transaction price					8,500,000
Revenues		0	$ 14,300,000	0	$ 15,900,000
Deferred revenue		0		0		$ 0
Accounts receivable		0		0		0
Remaining performance obligations		$ 0		$ 0		$ 0

401(K) Plan - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
2014 401(k) Plan
Defined Contribution Plan Disclosure [Line Items]
Employer contribution	$ 0.3	$ 0.1	$ 0.5	$ 0.3

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Stockholders' Equity, beginning balances at Dec. 31, 2020	$ 256,387	$ 3	$ 392,063		$ (135,679)
Stockholders' Equity, beginning balances (in shares) at Dec. 31, 2020		26,681,983
Issuance of common stock upon exercise of stock options	99		99
Issuance of common stock upon exercise of stock options (in shares)		12,396
Stock-based compensation expense	2,329		2,329
Vesting of common stock warrants issued for services	22		22
Net loss	(16,406)				(16,406)
Stockholders' Equity, ending balances at Mar. 31, 2021	242,431	$ 3	394,513		(152,085)
Stockholders' Equity, ending balances (in shares) at Mar. 31, 2021		26,694,379
Stockholders' Equity, beginning balances at Dec. 31, 2020	256,387	$ 3	392,063		(135,679)
Stockholders' Equity, beginning balances (in shares) at Dec. 31, 2020		26,681,983
Net loss	(23,995)
Stockholders' Equity, ending balances at Jun. 30, 2021	240,646	$ 3	400,317		(159,674)
Stockholders' Equity, ending balances (in shares) at Jun. 30, 2021		26,891,857
Stockholders' Equity, beginning balances at Mar. 31, 2021	242,431	$ 3	394,513		(152,085)
Stockholders' Equity, beginning balances (in shares) at Mar. 31, 2021		26,694,379
Issuance of common stock upon exercise of stock options and warrants	820		820
Issuance of common stock upon exercise of stock options and warrants (in shares)		197,478
Stock-based compensation expense	3,816		3,816
Issuance of common stock warrant	1,146		1,146
Vesting of common stock warrants issued for services	22		22
Net loss	(7,589)				(7,589)
Stockholders' Equity, ending balances at Jun. 30, 2021	240,646	$ 3	400,317		(159,674)
Stockholders' Equity, ending balances (in shares) at Jun. 30, 2021		26,891,857
Stockholders' Equity, beginning balances at Dec. 31, 2021	319,107	$ 3	526,523	$ (423)	(206,996)
Stockholders' Equity, beginning balances (in shares) at Dec. 31, 2021		32,224,524
Issuance of common stock upon exercise of stock options	330		330
Issuance of common stock upon exercise of stock options (in shares)		39,541
Stock-based compensation expense	3,933		3,933
Vesting of common stock warrants issued for services	22		22
Net unrealized loss on marketable securities	(998)			(998)
Net loss	(26,338)				(26,338)
Stockholders' Equity, ending balances at Mar. 31, 2022	296,056	$ 3	530,808	(1,421)	(233,334)
Stockholders' Equity, ending balances (in shares) at Mar. 31, 2022		32,264,065
Stockholders' Equity, beginning balances at Dec. 31, 2021	$ 319,107	$ 3	526,523	(423)	(206,996)
Stockholders' Equity, beginning balances (in shares) at Dec. 31, 2021		32,224,524
Issuance of common stock upon exercise of stock options (in shares)	90,802
Net loss	$ (54,424)
Stockholders' Equity, ending balances at Jun. 30, 2022	272,517	$ 3	535,761	(1,827)	(261,420)
Stockholders' Equity, ending balances (in shares) at Jun. 30, 2022		32,376,878
Stockholders' Equity, beginning balances at Mar. 31, 2022	296,056	$ 3	530,808	(1,421)	(233,334)
Stockholders' Equity, beginning balances (in shares) at Mar. 31, 2022		32,264,065
Issuance of common stock upon exercise of stock options	138		138
Issuance of common stock upon exercise of stock options (in shares)		51,261
Stock-based compensation expense	4,322		4,322
Issuance of common stock - 2020 ESPP	471		471
Issuance of common stock - 2020 ESPP (in shares)		61,552
Vesting of common stock warrants issued for services	22		22
Net unrealized loss on marketable securities	(406)			(406)
Net loss	(28,086)				(28,086)
Stockholders' Equity, ending balances at Jun. 30, 2022	$ 272,517	$ 3	$ 535,761	$ (1,827)	$ (261,420)
Stockholders' Equity, ending balances (in shares) at Jun. 30, 2022		32,376,878

Marketable Securities

6 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

4. Marketable Securities

Marketable securities, which are classified as available-for-sale, consisted of the following as of June 30, 2022 and December 31, 2021 (in thousands):


	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value as of June 30, 2022
Short-term marketable securities:
Commercial paper	$	21,544	$	—	$	(74	)	$	21,470
Corporate bonds		48,438		—		(703	)		47,735
US Treasuries		59,076		—		(677	)		58,399
Total short-term marketable securities	$	129,058	$	—	$	(1,454	)	$	127,604
Long-term marketable securities:
Commercial paper	$	5,098	$	—	$	(111	)	$	4,987
Corporate bonds		13,608		—		(252	)		13,356
US Government sponsored agency		2,199		—		(10	)		2,189
Total long-term marketable securities	$	20,905	$	—	$	(373	)	$	20,532


	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value as of December 31, 2021
Short-term marketable securities:
Commercial paper	$	32,471	$	—	$	(4	)	$	32,467
Corporate bonds		57,315		—		(79	)		57,236
US Treasuries		5,082		—		(9	)		5,073
Total short-term marketable securities	$	94,868	$	—	$	(92	)	$	94,776
Long-term marketable securities:
Commercial paper	$	5,089	$	—	$	(21	)	$	5,068
Corporate bonds		37,821		—		(193	)		37,628
US Treasuries		25,073		—		(117	)		24,956
Total long-term marketable securities	$	67,983	$	—	$	(331	)	$	67,652

All marketable securities held as of June 30, 2022 and December 31, 2021 had contractual maturities of less than two years. There was an immaterial realized loss on marketable securities for the six-month period ended June 30, 2022. None of the Company's investments in marketable securities has been in an unrealized loss position for more than one year. The Company determined that it has the ability and intent to hold all marketable securities that have been in a continuous loss position until maturity or recovery, thus there has been no recognition of any other-than-temporary impairment in the three and six months ended June 30, 2022.

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

Use of Estimates and Judgements

Segment Information

Concentration of Credit Risk

The Company’s partners in collaboration and license agreements who represent 10% or more of the Company’s total revenue are as follows:


	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Customer A	*	98%	*	96%
Customer B	99%	*	98%	*
Total	99%	98%	98%	96%

* Less than 10%

The Company’s partners in collaboration and license agreements who represent 10% or more of the Company’s total accounts receivable are as follows:


	June 30, 2022	December 31, 2021
Customer A	0%	100%
Total	0%	100%

The Company’s total revenues by geographic region, based on the location of the customer, are as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Netherlands	$	160	$	267	$	1,352	$	659
Switzerland		—		14,297		—		15,902
United States		2		16		30		19
Total revenue	$	162	$	14,580	$	1,382	$	16,580

Cash and Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents consist of money market funds.

Marketable Securities

Other Risks and Uncertainties

Fair Value Measurements

As a basis for considering such assumptions, a three-level fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

•

Level 1 — Observable inputs that reflect unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date.

•

Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company accounts for transfers of financial instruments between levels of the fair value hierarchy on the date of the event or change in circumstance that caused the transfer.

Common Stock Warrants

Leases


	Pre ASC 842					After ASC 842
	Six Months Ended		ASC 842			Six Months Ended
	June 30, 2021		Adjustments			June 30, 2021
Adjustments to reconcile net loss to net cash used in operating activities
Amortization of right-of-use assets	$	—	$	737		$	737
Changes in operating assets and liabilities
Operating lease liabilities		—		(737	)		(737	)
Supplemental disclosures of noncash investing and financing information
Decrease in right-of-use assets due to reduction in operating lease liabilities upon modification		—		(478	)		(478	)

Revenue Recognition

The Company’s revenue is primarily derived through its license, research, development and commercialization agreements. The terms of these types of agreements may include (i) licenses to the

Embedded Derivative

Net Loss Per Share, Basic and Diluted

Recent Accounting Pronouncement

New Accounting Pronouncement Not Yet Adopted

Research and Collaboration Arrangements - CFF - Additional Information (Details) - CFF	1 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($) Installment	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement total amount of award	$ 3,500,000
Collaborative arrangement achieved milestones		$ 1,800,000	$ 1,800,000
Number of installments to pay actual award \| Installment	3
Actual award payment period upon first commercial sale of product	4 years
Continuous period where the Company ceases to develop or commercialize any product	180 days
Deferred revenue		1,400,000	1,400,000
Accounts receivable		0	0
Aggregate amount of transaction price allocated to remaining performance obligation		$ 1,400,000	$ 1,400,000
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Expected payments percentage to equal actual award received	600.00%
Future sales-based milestone payments percentage	300.00%
Royalties percentage on actual award received	600.00%

Common Stock

6 Months Ended

Jun. 30, 2022

Equity [Abstract]

Common Stock

10. Common Stock

As of June 30, 2022 and December 31, 2021, the Company’s certificate of incorporation authorized the Company to issue 300,000,000 shares of common stock, at the par value of $0.0001 per share. The holder of each share of common stock is entitled to one vote per share.

Common stockholders are entitled to dividends, if and when declared by the board of directors. To date, no dividends on common stock have been declared by the board of directors.

As of June 30, 2022 and December 31, 2021, the Company has reserved common stock, on an as-converted basis, for future issuance as follows:


	June 30, 2022		December 31, 2021
Issuance of common stock under the 2020 Equity Incentive Award Plan		3,070,925		2,690,097
Issuance of common stock under the Employee Stock Purchase Plan		462,195		498,747
Exercise of options issued and outstanding		5,020,870		3,881,274
Exercise of common stock warrants		53,669		53,669
Total common stock reserved for future issuance		8,607,659		7,123,787

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI https://asc.fasb.org/topic&trid=2208762

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=SL126733271-114008

+ Details

Common Stock - Schedule of Common Share Reserved for Future Issuance (Details) - shares	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock reserved	8,607,659	7,123,787
2020 Equity Incentive Award Plan
Class Of Stock [Line Items]
Common stock reserved	3,070,925	2,690,097	2,606,546
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Common stock reserved	462,195	498,747
Options Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved	5,020,870	3,881,274
Common Stock Warrants
Class Of Stock [Line Items]
Common stock reserved	53,669	53,669

Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2022

Commitments and Contingencies Disclosure [Abstract]

Summary of Components of Lease Expense

The following table summarizes the components of lease expense for the three and six months ended June 30, 2022 and 2021 (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Operating lease cost	$	697	$	697	$	1,393	$	1,237
Variable lease cost		246		241		557		476
Total	$	943	$	938	$	1,950	$	1,713

Summary of Supplemental Information Related to Leases

The following table summarizes supplemental information related to operating leases:


	June 30, 2022			December 31, 2021
Weighted-average remaining lease term (in years):		7.1			7.6
Weighted-average discount rate:		7.8	%		7.8	%

Summary of Future Minimum Commitments Under Lease Contracts

The following table summarizes the maturities of lease liabilities as of June 30, 2022 (in thousands):


2022 (remaining six months)	$	1,119
2023		3,058
2024		3,149
2025		3,244
2026		3,135
Thereafter		8,688
Total future minimum lease payments		22,393
Less: Amount representing interest		(5,395	)
Present value of future minimum lease payments		16,998
Less: Current portion of operating lease liabilities		2,596
Long-term portion of operating lease liabilities	$	14,402

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 0.5	$ 0.4	$ 0.9	$ 0.8

Research and Collaboration Arrangements (Tables)

6 Months Ended

Jun. 30, 2022

Research And Collaboration Arrangements [Abstract]

Summary of Collaboration and License Revenue

Collaboration and license revenue for each period was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
uniQure	$	160	$	267	$	1,352	$	659
Roche		—		14,297		—		15,902
CFF		2		16		30		19
Total revenue	$	162	$	14,580	$	1,382	$	16,580

Summary of Deferred Revenue

Deferred revenue is summarized as follows (in thousands):


	June 30, 2022		December 31, 2021
uniQure	$	2,309	$	3,661
CFF		1,399		1,429
Total deferred revenue	$	3,708	$	5,090

Marketable Securities - Summary of Available for Sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	$ 129,058	$ 94,868
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,454)	(92)
Fair Value	127,604	94,776
Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	20,905	67,983
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(373)	(331)
Fair Value	20,532	67,652
Commercial Paper \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	21,544	32,471
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(74)	(4)
Fair Value	21,470	32,467
Commercial Paper \| Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	5,098	5,089
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(111)	(21)
Fair Value	4,987	5,068
Corporate Bonds \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	48,438	57,315
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(703)	(79)
Fair Value	47,735	57,236
Corporate Bonds \| Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	13,608	37,821
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(252)	(193)
Fair Value	13,356	37,628
US Treasuries \| Short-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	59,076	5,082
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(677)	(9)
Fair Value	58,399	5,073
US Treasuries \| Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis		25,073
Gross Unrealized Gains		0
Gross Unrealized Losses		(117)
Fair Value		$ 24,956
US Government Sponsored Agency \| Long-term Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	2,199
Gross Unrealized Gains	0
Gross Unrealized Losses	(10)
Fair Value	$ 2,189

Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue:
Collaboration and license revenue	$ 162	$ 14,580	$ 1,382	$ 16,580
Total revenue	162	14,580	1,382	16,580
Operating expenses:
Research and development (includes $0 and $262 for the three months ended June 30, 2022 and 2021, respectively, and $134 and $410 for the six months ended June 30, 2022 and 2021, respectively, attributable to related parties)	20,422	15,223	39,819	27,992
General and administrative	8,166	6,953	16,381	12,496
Total operating expenses	28,588	22,176	56,200	40,488
Loss from operations	(28,426)	(7,596)	(54,818)	(23,908)
Other income (expense):
Interest income	340	7	440	14
Other expense, net	(0)	(0)	(46)	(101)
Total other income (expense), net	340	7	394	(87)
Net loss	$ (28,086)	$ (7,589)	$ (54,424)	$ (23,995)
Net loss per share, basic	$ (0.87)	$ (0.28)	$ (1.69)	$ (0.90)
Net loss per share, diluted	$ (0.87)	$ (0.28)	$ (1.69)	$ (0.90)
Weighted-average shares outstanding used in computing net loss per share, basic	32,324,392	26,739,149	32,263,015	26,715,014
Weighted-average shares outstanding used in computing net loss per share, diluted	32,324,392	26,739,149	32,263,015	26,715,014

Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of Available for Sale Securities

Marketable securities, which are classified as available-for-sale, consisted of the following as of June 30, 2022 and December 31, 2021 (in thousands):


	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value as of June 30, 2022
Short-term marketable securities:
Commercial paper	$	21,544	$	—	$	(74	)	$	21,470
Corporate bonds		48,438		—		(703	)		47,735
US Treasuries		59,076		—		(677	)		58,399
Total short-term marketable securities	$	129,058	$	—	$	(1,454	)	$	127,604
Long-term marketable securities:
Commercial paper	$	5,098	$	—	$	(111	)	$	4,987
Corporate bonds		13,608		—		(252	)		13,356
US Government sponsored agency		2,199		—		(10	)		2,189
Total long-term marketable securities	$	20,905	$	—	$	(373	)	$	20,532


	Amortized Cost Basis		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value as of December 31, 2021
Short-term marketable securities:
Commercial paper	$	32,471	$	—	$	(4	)	$	32,467
Corporate bonds		57,315		—		(79	)		57,236
US Treasuries		5,082		—		(9	)		5,073
Total short-term marketable securities	$	94,868	$	—	$	(92	)	$	94,776
Long-term marketable securities:
Commercial paper	$	5,089	$	—	$	(21	)	$	5,068
Corporate bonds		37,821		—		(193	)		37,628
US Treasuries		25,073		—		(117	)		24,956
Total long-term marketable securities	$	67,983	$	—	$	(331	)	$	67,652

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Fair Value Hierarchy for Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis

The following tables represent the Company’s fair value hierarchy for financial assets and financial liabilities measured at fair value on a recurring basis as of June 30, 2022 and December 31, 2021 (in thousands):


	Basis for Fair Value Measurements						Fair Value as of
	Level 1		Level 2		Level 3		June 30, 2022
Assets
Money market funds	$	94,814	$	—	$	—	$	94,814
Commercial paper		—		26,456		—		26,456
Corporate bonds		—		61,092		—		61,092
US Treasuries		—		58,399		—		58,399
US Government sponsored agency				2,189				2,189
Total	$	94,814	$	148,136	$	—	$	242,950
Liabilities
Derivative liability	$	—	$	—	$	222	$	222
Total	$	—	$	—	$	222	$	222


	Basis for Fair Value Measurements						Fair Value as of
	Level 1		Level 2		Level 3		December 31, 2021
Assets
Money market funds	$	36,556	$	—	$	—	$	36,556
Commercial paper		—		37,535		—		37,535
Corporate bonds		—		94,864		—		94,864
US Treasuries		—		30,029		—		30,029
Total	$	36,556	$	162,428	$	—	$	198,984
Liabilities
Derivative liability	$	—	$	—	$	214	$	214
Total	$	—	$	—	$	214	$	214

Summary of Changes in Fair Value of Level 3 Financial Instruments

The following tables set forth a summary of the changes in the fair value of the Company’s Level 3 financial instrument during the six-month periods ended June 30, 2022 and 2021 (in thousands):


	Derivative Liability
Balance as of December 31, 2021	$	214
Change in fair value included in other income (expense), net		8
Balance as of June 30, 2022	$	222


	Derivative Liability
Balance as of December 31, 2020	$	122
Change in fair value included in other income (expense), net		85
Balance as of June 30, 2021	$	207

Net Loss Per Share Attributable to Common Stockholders - Outstanding Potentially Dilutive Securities Excluded From Computation of Diluted Net Loss Per Share (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	5,074,539	4,448,777
Options Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	5,020,870	4,238,519
ESPP Shares Expected to be Issued
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	0	111,589
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	53,669	98,669

Derivative Liability

6 Months Ended

Jun. 30, 2022

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Liability

14. Derivative Liability

The Company identified an embedded derivative resulting from the change of control provision in the CFF Agreement. Embedded derivatives that are required to be bifurcated from the underlying host instrument are accounted for and valued as separate financial instruments. At the inception of the derivative in 2017, the Company recognized this derivative as a liability, and revenue was reduced by the initial fair value of the derivative liability. The Company remeasures the derivative liability to fair value at each reporting period and records the change in fair value of the derivative liability as other income (expense), net. The Company uses a present value analysis with multiple scenarios, which incorporates assumptions and estimates to value the derivative instrument. The Company assesses these assumptions and estimates on a periodic basis as additional information impacting the assumptions is obtained. Estimates and assumptions impacting the fair value measurement include the change of control payment to CFF (range of $0.0 million to $10.6 million at June 30, 2022 and December 31, 2021), the probability of a change of control event, the probability of the product achieving development or commercial status at time of change of control (range of 4.8% to 17.2% at June 30, 2022 and December 31, 2021) and the discount rate (15.0% and 14.0% at June 30, 2022 and December 31, 2021, respectively). The Company determined the estimated fair value of this liability as of the inception date of the CFF Agreement and concluded that the amount was immaterial. The Company determined the fair value of this derivative liability was $0.2 million as of June 30, 2022 and December 31, 2021.

Condensed Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Prepaid expenses to related parties	$ 0	$ 285
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares, issued	32,376,878	32,224,524
Common stock, shares, outstanding	32,376,878	32,224,524

Summary of Significant Accounting Policies - Summary of Adoption of ASC 842 on condensed statement of cash flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Summary Of Significant Accounting Policies [Line Items]
Amortization of right-of-use assets	$ 741	$ 737
Operating lease liabilities	550	(737)
Decrease in right-of-use assets due to reduction in operating lease liabilities upon modification	$ 0	(478)
Revision of Prior Period, Accounting Standards Update, Adjustment \| ASC 842 Adjustments
Summary Of Significant Accounting Policies [Line Items]
Amortization of right-of-use assets		737
Operating lease liabilities		(737)
Decrease in right-of-use assets due to reduction in operating lease liabilities upon modification		$ (478)

License Arrangements

6 Months Ended

Jun. 30, 2022

License Arrangements [Abstract]

License Arrangements

8. License Arrangements

The Company has exclusive, worldwide license agreements (the “UC Agreements”) with the Regents of the University of California (the “UC Regents”) relating to the use of certain patents and intellectual property surrounding its core technologies, including Therapeutic Vector Evolution. Pursuant to each of the UC Agreements executed prior to January 2019, the Company was obligated to pay a (i) non-refundable license fee of $5,000 upon execution, (ii) a non-refundable license fee of $5,000 each year thereafter, until sales of a licensed product are made and royalties are paid to the UC Regents, (iii) reimbursement of domestic and foreign patent filing, prosecution and maintenance fees, and (iv) either $50,000 or issuance of a 3% equity interest in the Company upon the closing of the first qualified financing at the option of the UC Regents. The Company’s first qualified financing occurred in 2015 and at the election of the UC Regents, the Company issued the UC Regents in January 2016 an amount of common stock equal to 6% of the equity interests in the Company pursuant to the applicable clause in each of the UC Agreements.

Pursuant to an agreement with the UC Regents executed in January 2019 the Company paid a non-refundable license fee of $50,000 to the UC Regents upon execution of the agreement. The Company is obligated to pay a non-refundable license fee of $5,000 on the one-year anniversary of the contract effective date and each year thereafter, until sales of a licensed product are made and royalties are paid to the UC Regents.

In addition, the Company is obligated to make certain contingent payments including (i) development milestones up to $3.1 million, (ii) low single digit royalties on the net sales of its developed products that consists of a minimum annual royalty of up to $0.1 million per year for the term of the Agreement beginning in the first calendar year after the year in which net sales first occurred and (iii) sublicense consideration in the mid-teens to the mid-twenties range on any future sublicensing arrangements the Company may enter into with third-party licensees.

In July 2021, the Company entered into an exclusive license agreement with the UC Regents and the Trustees of the University Pennsylvania to license intellectual property related to certain vectors. In July 2021, the Company paid a non-refundable license fee of $100,000 to the UC Regents upon execution of the agreement. The Company is obligated to pay a non-refundable license maintenance fee of $10,000 on the one-year anniversary of the contract effective date and each year thereafter, except years for which the Company has paid royalties on the net sales of a licensed product. In addition, the Company is obligated to make certain contingent payments including (i) development milestones up to $3.9 million, (ii) low single digit percentage rate royalties on the net sales of its licensed products that consists of a minimum annual

royalty of up to $0.1 million per year for the term of the Agreement beginning in the first calendar year after the year in which net sales first occurred and (iii) sublicense consideration in the mid-single digits to the low twenties percentage rate range on any future sublicensing arrangements the Company may enter into with third-party licensees.

During each of the three and six months ended June 30, 2022 and 2021, the Company incurred immaterial expenses under the provisions of the outstanding license arrangements.

Commitments and Contingencies -Summary of Supplemental Information Related to Leases - (Details)	Jun. 30, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Weighted-average remaining lease term (in years)	7 years 1 month 6 days	7 years 7 months 6 days
Weighted-average discount rate	7.80%	7.80%

Property and Equipment, Net

6 Months Ended

Jun. 30, 2022

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

5. Property and Equipment, Net

Property and equipment, net, consisted of the following (in thousands):


	June 30, 2022			December 31, 2021
Machinery and equipment	$	9,224		$	5,971
Leasehold improvements		15,886			2,527
Furniture and fixtures		565			566
Office equipment		188			165
Computer equipment and software		616			421
Construction in progress		815			10,066
Total property and equipment		27,294			19,716
Less: Accumulated depreciation and amortization		(6,197	)		(5,325	)
Property and equipment, net	$	21,097		$	14,391

All property and equipment are maintained in the United States. Depreciation expense was $0.5 million and $0.4 million for the three months ended June 30, 2022 and 2021, respectively, and $0.9 million and $0.8 million for the six months ended June 30, 2022 and 2021, respectively.

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2022	Aug. 08, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	4D Molecular Therapeutics, Inc.
Entity Central Index Key	0001650648
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		32,382,378
Entity Interactive Data Current	Yes
Entity File Number	001-39782
Entity Tax Identification Number	47-3506994
Entity Address, Address Line One	5858 Horton Street #455
Entity Address, City or Town	Emeryville
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94608
City Area Code	(510)
Local Phone Number	505-2680
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	FDMT
Security Exchange Name	NASDAQ

Research and Collaboration Arrangements - Summary of Collaboration and License Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue	$ 162	$ 14,580	$ 1,382	$ 16,580
Collaboration and License Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue	162	14,580	1,382	16,580
Collaboration and License Revenue \| uniQure
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue	160	267	1,352	659
Collaboration and License Revenue \| Roche
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue	0	14,297	0	15,902
Collaboration and License Revenue \| CFF
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue	$ 2	$ 16	$ 30	$ 19

- Definition

+ References

+ Details

Research and Collaboration Arrangements - CRF Agreement - Additional Information (Details) - USD ($)	1 Months Ended	6 Months Ended
	Nov. 30, 2015	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable		$ 0	$ 47,000
CRF Agreement \| CRF
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement, initial research term	2 years
Collaborative arrangement contribution upon development milestone	$ 2,500,000
Collaborative arrangement additional research term	3 years
Collaborative arrangement achieved milestones		0
Deferred revenue		0	$ 0
Accounts receivable		$ 0		$ 0

Fair Value Measurements - Additional Information (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Assets, Level 1 and Level 2 transfers	$ 0	$ 0
Assets, Transfers into Level 3	0	0
Assets, Transfers out of Level 3	0	0
Liabilities, Level 1 and Level 2 transfers	0	0
Liabilities, Transfers into Level 3	0	0
Liabilities, Transfers out of Level 3	$ 0	$ 0

Net Loss Per Share Attributable to Common Stockholders (Tables)

6 Months Ended

Jun. 30, 2022

Earnings Per Share [Abstract]

Computation of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data):


	Three Months Ended June 30,						Six Months Ended June 30,
	2022			2021			2022			2021
Numerator
Net loss	$	(28,086	)	$	(7,589	)	$	(54,424	)	$	(23,995	)
Denominator
Weighted-average shares outstanding used in computing net loss per share, basic and diluted		32,324,392			26,739,149			32,263,015			26,715,014
Net loss per share, basic and diluted	$	(0.87	)	$	(0.28	)	$	(1.69	)	$	(0.90	)

Outstanding Shares of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share


	June 30,
	2022		2021
Options issued and outstanding		5,020,870		4,238,519
ESPP shares expected to be issued		—		111,589
Common stock warrants		53,669		98,669
Total		5,074,539		4,448,777

Condensed Statements of Operations (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Research and development expense, related party	$ 0	$ 262	$ 134	$ 410

License Arrangements - Additional Information (Details) - UC Agreements - USD ($)	1 Months Ended		6 Months Ended
	Jul. 31, 2021	Jan. 31, 2016	Jun. 30, 2022	Jan. 31, 2019	Dec. 31, 2018
Research And Development Arrangement Contract To Perform For Others [Line Items]
Non-refundable license fee payable upon execution					$ 5,000
Non-refundable license fee payable upon execution every year thereafter until sales of a licensed product and payment of royalties					5,000
Amount obligated to pay upon closing first qualified financing at option of UC Regents					$ 50,000
Percentage of equity interest upon closing of first qualified financing at option of UC Regents					3.00%
Percentage of equity interests issued as common stock		6.00%
Amount paid non-refundable license fee	$ 100,000			$ 50,000
Non-refundable license fee payable annually	10,000			$ 5,000
Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Contingent payments development milestones	3,900,000		$ 3,100,000
Minimum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Annual royalty	$ 100,000		$ 100,000

Commitments and Contingencies- Summary of Components of Lease Expense - (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 697	$ 697	$ 1,393	$ 1,237
Variable lease cost	246	241	557	476
Lease, Cost, Total	$ 943	$ 938	$ 1,950	$ 1,713

Fair Value Measurements

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements


	Basis for Fair Value Measurements						Fair Value as of
	Level 1		Level 2		Level 3		June 30, 2022
Assets
Money market funds	$	94,814	$	—	$	—	$	94,814
Commercial paper		—		26,456		—		26,456
Corporate bonds		—		61,092		—		61,092
US Treasuries		—		58,399		—		58,399
US Government sponsored agency				2,189				2,189
Total	$	94,814	$	148,136	$	—	$	242,950
Liabilities
Derivative liability	$	—	$	—	$	222	$	222
Total	$	—	$	—	$	222	$	222


	Basis for Fair Value Measurements						Fair Value as of
	Level 1		Level 2		Level 3		December 31, 2021
Assets
Money market funds	$	36,556	$	—	$	—	$	36,556
Commercial paper		—		37,535		—		37,535
Corporate bonds		—		94,864		—		94,864
US Treasuries		—		30,029		—		30,029
Total	$	36,556	$	162,428	$	—	$	198,984
Liabilities
Derivative liability	$	—	$	—	$	214	$	214
Total	$	—	$	—	$	214	$	214

Level 3 Inputs

The fair value of the derivative liability is based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The fair value of the derivative liability was determined using a present value analysis with multiple scenarios. In determining the fair value of the derivative liability, the inputs impacting fair value include the change of control payment to CFF, the probability of a change of control event, the product status at time of a change of control event and the discount rate. See Note 14 for further discussion on the embedded derivative.

There were no transfers between Level 1, 2 and 3 during the periods presented.

The following tables set forth a summary of the changes in the fair value of the Company’s Level 3 financial instrument during the six-month periods ended June 30, 2022 and 2021 (in thousands):


	Derivative Liability
Balance as of December 31, 2021	$	214
Change in fair value included in other income (expense), net		8
Balance as of June 30, 2022	$	222


	Derivative Liability
Balance as of December 31, 2020	$	122
Change in fair value included in other income (expense), net		85
Balance as of June 30, 2021	$	207

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Accrued and Other Current Liabilities

6 Months Ended

Jun. 30, 2022

Payables and Accruals [Abstract]

Accrued and Other Current Liabilities

6. Accrued and Other Current Liabilities

Accrued and other current liabilities consisted of the following (in thousands):


	June 30, 2022		December 31, 2021
Payroll and related expenses	$	2,933	$	3,994
Accrued clinical and preclinical study costs		1,255		407
Consulting and professional		1,227		1,573
Other accrued expenses		748		1,770
Total accrued and other current liabilities	$	6,163	$	7,744

Research and Collaboration Arrangements

6 Months Ended

Jun. 30, 2022

Research And Collaboration Arrangements [Abstract]

Research and Collaboration Arrangements

7. Research and Collaboration Arrangements

Collaboration and license revenue for each period was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
uniQure	$	160	$	267	$	1,352	$	659
Roche		—		14,297		—		15,902
CFF		2		16		30		19
Total revenue	$	162	$	14,580	$	1,382	$	16,580

Deferred revenue is summarized as follows (in thousands):


	June 30, 2022		December 31, 2021
uniQure	$	2,309	$	3,661
CFF		1,399		1,429
Total deferred revenue	$	3,708	$	5,090

The total amount of revenue in the six months ended June 30, 2022, which was included in deferred revenue at January 1, 2022, was $1.4 million. The total amount of revenue in the six months ended June 30, 2021, which was included in deferred revenue at January 1, 2021, was $14.0 million.

uniQure

In January 2014, the Company and uniQure biopharma B.V. (“uniQure”) entered into a Collaboration and License Agreement (the “uniQure Agreement”) to collaborate on the discovery and non-clinical research activities related to the Company’s Therapeutic Vector Evolution platform in order to generate and validate vectors for gene delivery to treat diseases within the central nervous system and liver (together, the “uniQure Field”).

The uniQure Agreement provided uniQure with a research license as well as an exclusive development and commercialization license for each project variant selected for further development. The initial research term was three years and uniQure exercised a one-time option to extend the research term for an additional year to January 2018. Once the Company’s research plan concluded, uniQure was solely responsible for the continued development, manufacturing and commercialization of the project variants as potential product candidates. The Company was also required to work exclusively with uniQure in the uniQure Field (the “uniQure Exclusivity Clause”). Pursuant to the uniQure Agreement, the Company received upfront payments of $0.2 million and was entitled to receive (i) contingent payments for the achievement of research and development milestones of up to $5.0 million for each licensed product selected under the arrangement, and (ii) royalties in the single digit percentage rate range on future sales of the potential product candidates and sublicense consideration in the low teens to low thirties percentage rate range on any future sublicensing arrangements. In connection with the performance obligations under the uniQure Agreement, the founders of 4D Molecular Therapeutics, LLC received equity options to purchase an aggregate of 609,744 of uniQure ordinary shares that vested over the initial three-year term of the agreement.

The upfront payment of $0.2 million was recorded as deferred revenue and was recognized on a ratable basis over the estimated performance period of four years. Payments and reimbursements for research costs were recognized on an as-incurred basis. The options to purchase uniQure shares were deemed to be a noncash component of the arrangement consideration as the vesting of options is linked to the uniQure Agreement and there is a requirement for the holders of the options to provide services under the uniQure Agreement. The fair value of the uniQure options, which was estimated to be $10.6 million, was recognized ratably as revenue over the estimated performance period of four years and the associated compensation expense related to the stock options was recorded as research and development expense.

In August 2019, the Company and uniQure entered into an Amended and Restated Collaboration and License Agreement (the “Amended uniQure Agreement”), which amended and restated the uniQure Agreement, and a separate Collaboration and License Agreement (the “Second uniQure Agreement”). Under these agreements, the Company agreed to transfer incremental rights and services to uniQure in exchange for uniQure eliminating the uniQure Exclusivity Clause and transferring other rights back to the Company.

Under the Amended uniQure Agreement, uniQure continues to have an exclusive license to select AAV capsid variants (the “Selected Variants”) in the uniQure Field. uniQure continues to be solely responsible, at its cost, to develop and commercialize the compounds and products containing the Selected Variants. The amended uniQure Agreement eliminated the uniQure Exclusivity Clause in the uniQure Agreement. Furthermore, the contingent payments that the Company was entitled to receive from uniQure for the achievement of research and development milestones of up to $5.0 million for each licensed product selected under the uniQure Agreement were eliminated and sublicense consideration on any future sublicensing arrangements was reduced from the low teens to low thirties percentages to mid-single digit to mid-twenties percentages.

Under the Second uniQure Agreement, the parties agreed to research and develop new AAV capsid variants (the “New Variants”) that are not Selected Variants that affect certain targets selected by uniQure (the “uniQure Targets”) in the uniQure Field. The Company is solely responsible, at its cost, for the research of the New Variants. The Company granted uniQure an exclusive license to a certain number of the New Variants (the “uniQure New Variants”) that affect the uniQure Targets. uniQure is solely responsible, at its cost, to develop and commercialize the compounds and products containing the uniQure New Variants that affect the uniQure Targets (the “Licensed Products”). The Company retains all rights to New Variants in the uniQure Field that affect targets other than the uniQure Targets.

Under both the Amended uniQure Agreement and the Second uniQure Agreement, uniQure will be required to pay the Company royalties on worldwide annual net sales of Licensed Products at a mid-single digit percentage rate, subject to certain specified reductions. uniQure will also be required to pay the Company sublicensing consideration for sublicensing the Company’s intellectual property rights licensed under the Amended uniQure Agreement or the Second uniQure Agreement to third parties at a rate between the mid-single digit to mid-twenties. The Company has reciprocal obligations, at the same percentage rates as uniQure, to pay uniQure royalties and sublicensing consideration for sublicensing certain intellectual property rights licensed under the Amended uniQure Agreement or the Second uniQure Agreement to third parties.

The Company concluded that the Amended uniQure Agreement and the Second uniQure Agreement should be accounted for as one combined contract but separate from the uniQure Agreement given that the incremental licensed intellectual property rights and research and development services are distinct from the rights and services previously transferred to uniQure under the uniQure Agreement and the transaction price increased by an amount that equals the standalone selling price of the incremental rights and services to be transferred to uniQure under the Amended uniQure Agreement and Second uniQure Agreement.

Neither party was required to pay monetary consideration in connection with the execution of the Amended uniQure Agreement or the Second uniQure Agreement or for subsequent performance by the parties under those agreements, notwithstanding the potential future royalty and sublicense consideration described above. The fair value of the non-monetary consideration given by uniQure to the Company, for the intellectual property right was $5.1 million. This intellectual property right is considered to be an in-process research and development asset with no alternative future use and, accordingly, was written off as acquired in-process research and development expense in the year ended December 31, 2019.

The incremental transaction price described in the paragraph above was recorded as deferred revenue given that the Company identified one single combined performance obligation under ASC 606, which includes the licenses to the New Variants, research services and participation in the joint steering committee (“JSC”). Revenue is recognized using the input method based on actual costs incurred as a percentage of total budgeted costs as the Company completes its performance obligation. Based on the current estimated timelines, the deferred revenue is expected to be recognized as revenue over approximately one to two years from June 30, 2022.

The Company determined the transaction price using the risk adjusted net present value analysis (“rNPV”) methodology to value the elimination of the uniQure exclusivity clause and other material rights received by the Company, including the potential royalties the Company would receive from uniQure. The rNPVs incorporate estimates and assumptions including the number of products the Company and uniQure would develop, the risk-adjusted probability of successfully developing a biopharmaceutical product, the probability that uniQure will develop a product, the research and development costs, the potential worldwide sales and associated commercialization costs, corporate tax rate, and discount rate.

During the three months ended June 30, 2022 and 2021, the Company recognized revenue of $0.2 million and $0.3 million under both of the Amended uniQure Agreement and the Second uniQure Agreement, respectively. During the six months ended June 30, 2022 and 2021, the Company recognized revenue of $1.4 million and $0.7 million under both of the Amended uniQure Agreement and the Second uniQure Agreement, respectively. During the six months ended June 30, 2022 the decrease in total budgeted costs for the remaining performance obligation resulted in a $1.3 million increase in revenue recognized related to the performance obligation partially satisfied prior to January 1, 2022. As of June 30, 2022 and December 31, 2021, deferred revenue relating to uniQure was $2.3 million and $3.7 million, respectively. There were no amounts due from uniQure under the uniQure Agreement, Amended uniQure Agreement or Second uniQure Agreement as of June 30, 2022 and December 31, 2021. As of June 30, 2022 and December 31, 2021, the aggregate amount of the transaction price allocated to the remaining performance obligation was $2.5 million and $3.7 million, respectively.

CRF

In November 2015, the Company entered into a research funding and collaboration agreement (the “CRF Agreement”) with the Choroideremia Research Foundation (“CRF”), a non-profit organization dedicated to finding a cure for choroideremia, a rare inherited disorder that causes progressive vision loss, ultimately leading to complete blindness. The goal of the CRF Agreement is for CRF to contribute funding to help with the advancement of the Company’s choroideremia research program. The Company is responsible for all decision making and execution of any and all of the related activities to be completed in its sole discretion. The initial term of the CRF Research Plan is two years. The agreement includes contribution by the Company to CRF of up to $2.5 million upon certain development or approval milestones. The overall arrangement has automatic extensions of up to three additional years. As of June 30, 2022, no milestones have been achieved.

Revenue was fully recognized for this agreement in the year ended December 31, 2017. There was no deferred revenue relating to the CRF Agreement as of June 30, 2022 and December 31, 2021. No amount was due from or to CRF under the CRF Agreement as of June 30, 2022 and 2021.

Roche

In November 2017, the Company entered into a collaboration and license agreement with F. Hoffmann-La Roche Ltd and Hoffmann-La Roche Inc. (together, “Roche”) to discover and develop products containing optimized next generation AAV Vectors focused on ophthalmological diseases and disorders excluding select criteria (the “2017 Roche Agreement”). The Company and Roche both had the ability to nominate products to discover, develop and commercialize.

At the effective date of the 2017 Roche Agreement, choroideremia was designated a Roche product class and the 4D-110 product was licensed to Roche. The Company was responsible for conducting research and development services prior to pivotal clinical studies, and Roche was responsible for conducting subsequent development and commercialization activities. In addition, Roche agreed to pay for research and development services at the agreed upon full-time employee rate for work performed for choroideremia under the 2017 Roche Agreement, and certain external costs, except for the costs associated with the manufacturing work for choroideremia.

Under the 2017 Roche Agreement, Roche had an option exercisable prior to pivotal clinical studies, to license 4D-125 (for the treatment of XLRP), which was not exercised.

Pursuant to the 2017 Roche Agreement, the Company received a non-refundable upfront payment of $21.0 million as consideration. In addition, the Company was entitled to contingent payments including (i) $1.0 million for each Roche nominated product beyond the first three, (ii) up to $30.0 million upon exercise of the option to convert a product the Company nominated and developed prior to pivotal clinical studies, (iii) development milestone payments of up to $223.0 million, of which $86.0 million related to choroideremia and the rest related to other licensed products; and (iv) sales-based milestones of up to $123.0 million in connection with licensed products. Through June 30, 2022, the Company received $10.0 million for development milestone payments that are non-refundable. The 2017 Roche Agreement also included provisions that entitled the Company to receive royalty payments ranging from the mid-single digits to the mid-teens for the net sales of the licensed products, in each case subject to the reductions in accordance with the terms of the agreement.

The Company identified a single combined performance obligation for the license, research services and participation in the JSC and concluded that Roche’s option did not represent a material right. The Company’s contract with Roche did not include a significant financing component. The Company further concluded that the transaction price should not include the variable consideration related to development milestones as they were considered to be constrained as it was probable that the inclusion of such variable consideration could result in a significant reversal of cumulative revenue in the future. The Company excluded any consideration related to sales-based milestones, including royalties, which would be recognized when the related sales occur. The transaction price and estimated period of performance are re-evaluated at each reporting period and adjusted as needed to reflect changes in the scope of the project, reimbursable expenses and other conditions affecting variable consideration.

In June 2021, the Company received from Roche notice of termination without cause of the 2017 Roche Agreement. The licenses granted by the Company to Roche under the 2017 Roche Agreement terminated in their entirety on September 16, 2021. Therefore, as of September 16, 2021, Roche no longer has a license for 4D-110 for the treatment of choroideremia or any other product class, and the Company is no longer entitled to receive any further milestones or royalties from Roche. In July 2021, the Company notified Roche of the Company’s election to continue development of choroideremia. As a result, in accordance with the terms of the agreement, all rights to 4D-110 data and intellectual property generated under the collaboration reverted to the Company. Under the 2017 Roche Agreement, if the Company is required to initiate a new Phase 1/2a clinical trial for 4D-110, the Company would not owe any royalty to Roche on net sales of 4D-110. If, however, the Company moves directly to a pivotal trial of 4D-110, without first being required to conduct a new Phase 1/2a clinical trial, the Company must pay Roche a mid-single digits percentage royalty on the net sales of 4D-110.

As a result of the termination of the 2017 Roche Agreement, an adjustment of $8.5 million was made to the transaction price for the six months ended June 30, 2021. During the three and six months ended June 30, 2021, the Company recognized revenue of $14.3 million and $15.9 million, respectively. The Company did not recognize any revenue under the 2017 Roche Agreement during the three and six months ended June 2022. As of June 30, 2022 and December 31, 2021, there was no deferred revenue and no accounts receivable from Roche relating to the 2017 Roche Agreement. As of December 31, 2021, the Company had no remaining performance obligation under the 2017 Roche Agreement.

CFF

In September 2016, the Company entered into an award agreement for the Optimized Adeno-Associated Virus for Lung Epithelia Gene Delivery Development Program with CFF, a non-profit organization dedicated to finding a cure for cystic fibrosis, an inherited disorder that causes disease in the pulmonary airways leading to morbidity and mortality. Under this agreement, CFF contributes funding to help advance the Company’s CF research program. The agreement was subsequently amended in September 2017, August 2018 and February 2021 (all four agreements are collectively referred to as the “CFF Agreement”). The total amount of the award under the CFF Agreement is $3.5 million. As of June 30, 2022 and December 31, 2021, the Company achieved milestones totaling $1.8 million, under the CFF Agreement. The remaining award amount will be paid by CFF based on the achievement of certain development milestones by the Company.

The Company expects to make payments to CFF equal to six times the actual award received by the Company in three installments within the first four years of the first commercial sale of a product developed under this agreement. The Company also has agreed to make future sales-based milestone payments to CFF of up to three times the actual award received upon achieving specified commercialization milestones with respect to the first of any product developed utilizing any compound covered under the CFF Agreement. The CFF Agreement also requires the Company to pay to CFF royalties of a mid-single digit percentage, up to six times the actual award received, on any amounts received by the Company from the sale, license or transfer to a third-party of rights in the technology developed as a result of this collaboration. Any such royalty payments shall be credited against the payments owed by the Company upon first commercial sale. In the event of a change of control of the Company, CFF will receive certain payments, depending on the timing of the change of control and the size of the transaction.

To date, the Company has not developed a commercial product in connection with the CFF Agreement, and it has not licensed, sold or otherwise transferred to another party the product developed under the CFF Agreement or the underlying technology.

If at any time prior to the first commercial sale of a product developed as a result of the CFF Agreement, the Company ceases to use commercially reasonable efforts to develop or commercialize any product under the CFF Agreement for a continuous period of 180 consecutive days and fails to present a reasonable plan to resume commercially reasonable efforts, the Company will grant to CFF an irrevocable, exclusive worldwide interruption license under all of the Company’s interest in the research plan technology to exploit such product. Any third-party license granted by the Company shall be subject to such interruption license.

Under ASC 606, the Company identified one performance obligation within the CFF grant agreement for research activities. The Company’s contract with CFF does not include a significant financing component.

The Company concluded that the transaction price should not include the variable consideration related to future research milestones as they were considered to be constrained as it is probable that the inclusion of such variable consideration could result in a significant reversal of cumulative revenue in the future. The Company re-evaluates the transaction price and estimated period of performance at each reporting date.

Revenue recognized during the three and six months ended June 30, 2022 and 2021 was immaterial. As of June 30, 2022 and December 31, 2021, deferred revenue relating to the CFF Agreement was $1.4 million. There were no accounts receivable from CFF under the CFF Agreement as of June 30, 2022 and December 31, 2021. As of June 30, 2022 and December 31, 2021, the aggregate amount of the transaction price allocated to the remaining performance obligation was $1.4 million. Based on current timelines, the deferred revenue is expected to be recognized as revenue over the next two to four years as the Company performs research services through the completion of IND-enabling studies.

The obligation to make payments to CFF upon a change of control meets the definition of an embedded derivative that is required to be bifurcated and separately accounted for as a derivative liability. See Note 14 for further discussion of the embedded derivative.

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 113,484	$ 153,001
Marketable securities	127,604	94,776
Accounts receivable	0	47
Prepaid expenses and other current assets (includes $0 and $285 at June 30, 2022 and December 31, 2021, respectively, attributable to related parties)	5,435	8,456
Total current assets	246,523	256,280
Marketable securities, long-term	20,532	67,652
Property and equipment, net	21,097	14,391
Operating lease right-of-use assets	13,821	14,562
Other assets	963	602
Total assets	302,936	353,487
Current liabilities
Accounts payable	3,316	4,764
Accrued and other current liabilities	6,163	7,744
Deferred revenue	2,256	2,599
Operating lease liabilities, current portion	2,596	1,231
Total current liabilities	14,331	16,338
Deferred revenue, net of current portion	1,452	2,491
Derivative liability	222	214
Long-term portion of operating lease liabilities	14,402	15,217
Other liabilities	12	120
Total liabilities	30,419	34,380
Commitments and contingencies (Note 9)
Stockholders’ equity
Common stock, $0.0001 par value, 300,000,000 shares authorized at June 30, 2022 and December 31, 2021; 32,376,878 and 32,224,524 shares issued and outstanding at June 30, 2022 and December 31, 2021, respectively	3	3
Additional paid-in-capital	535,761	526,523
Accumulated other comprehensive loss	(1,827)	(423)
Accumulated deficit	(261,420)	(206,996)
Total stockholders’ equity	272,517	319,107
Total liabilities and stockholders’ equity	$ 302,936	$ 353,487

Summary of Significant Accounting Policies - Schedule of Concentration of Risk (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Revenue \| Customer Concentration Risk \| Customer A
Concentration Risk [Line Items]
Concentration risk, percentage		98.00%		96.00%
Revenue \| Customer Concentration Risk \| Customer B
Concentration Risk [Line Items]
Concentration risk, percentage	99.00%		98.00%
Revenue \| Customer Concentration Risk \| Customer
Concentration Risk [Line Items]
Concentration risk, percentage	99.00%	98.00%	98.00%	96.00%
Accounts Receivable \| Credit Concentration Risk \| Customer A
Concentration Risk [Line Items]
Concentration risk, percentage			0.00%		100.00%
Accounts Receivable \| Credit Concentration Risk \| Customer
Concentration Risk [Line Items]
Concentration risk, percentage			0.00%		100.00%

Common Stock - Additional Information (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Equity [Abstract]
Common stock, shares authorized	300,000,000	300,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock voting rights	one vote per share
Common stock dividend	$ 0	$ 0

Commitments and Contingencies - Summary of Future Minimum Commitments Under Lease Contracts (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
2022 (remaining six months)	$ 1,119
2023	3,058
2024	3,149
2025	3,244
2026	3,135
Thereafter	8,688
Total future minimum lease payments	22,393
Less: Amount representing interest	(5,395)
Present value of future minimum lease payments	16,998
Less: Current portion of operating lease liabilities	2,596	$ 1,231
Long-term portion of operating lease liabilities	$ 14,402	$ 15,217

Common Stock Warrants

6 Months Ended

Jun. 30, 2022

Equity [Abstract]

Common Stock Warrants

12. Common Stock Warrants

In 2016, the Company issued a warrant for 45,000 shares of the Company’s common stock to a service provider with an exercise price of $1.14 per share, of which 15,000 warrant shares become exercisable upon completion of an offering of securities in a private placement by the Company with net proceeds in excess of $25.0 million and 30,000 warrant shares become exercisable upon completion of an IPO by the Company. The fair value of the warrant was determined at the issuance date using the Black-Scholes option pricing model. 15,000 of these warrant shares became exercisable upon the completion of the Series B financing in 2018 and 30,000 of these warrants became exercisable upon completion of the IPO in 2020. All 45,000 shares of this warrant were exercised in October 2021.

In May 2018, the Company issued a warrant for 23,669 shares of the Company’s common stock to a service provider with an exercise price of $3.19 per share. The fair value of the warrant was determined at the issuance date using the Black-Scholes option pricing model, expires in 2025 and upon issuance was fully vested.

In December 2020, the Company issued a warrant for 30,000 shares of the Company’s common stock to a service provider with an exercise price of $18.00 per share. This warrant vests over a period of four years and expires in 2027. The fair value of the warrant was determined at the issuance date using the Black-Scholes option pricing model.

In April 2021, the Company issued a warrant for 40,000 shares of the Company’s common stock to a former employee with an exercise price of $9.41 per share as a result of a settlement agreement with such former employee. The warrant was exercised in May 2021.

There was no material expense related to the above warrant shares during the three and six months ended June 30, 2022 and 2021.

Common Stock Warrants - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 30, 2021	May 31, 2018	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2016	Dec. 31, 2018
Class Of Warrant Or Right [Line Items]
Number of warrants issued	40,000	23,669					30,000	45,000
Exercise price	$ 9.41	$ 3.19					$ 18.00	$ 1.14
Warrant shares become exercisable								45,000
Warrant expiration year		2025					2027
Warrant shares, expense recognized			0	0	0	0
Warrant vesting period							4 years
Warrant exercised month and year	2021-05							2021-10
Series B Financing
Class Of Warrant Or Right [Line Items]
Warrant shares become exercisable									15,000
Private Placement
Class Of Warrant Or Right [Line Items]
Warrant shares become exercisable								15,000
Proceeds from offering of securities in a private placement								$ 25.0
Initial Public Offering
Class Of Warrant Or Right [Line Items]
Warrant shares become exercisable							30,000

The Company - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended
	Nov. 30, 2021	Dec. 31, 2020	Jun. 30, 2022	Dec. 31, 2021
Organization And Nature Of Business [Line Items]
Outstanding shares of redeemable convertible preferred stock		0
Accumulated deficit			$ 261,420	$ 206,996
Common Stock \| Initial Public Offering
Organization And Nature Of Business [Line Items]
Number of shares sold and issued		9,660,000
Stock sold and issued price per share		$ 23.00
Aggregate net proceeds, after deducting underwriting discounts and commissions and offering costs		$ 204,700
Number shares issued upon conversion of redeemable convertible preferred shares		11,575,984
Common Stock \| Excess of Overallotment Option
Organization And Nature Of Business [Line Items]
Number of shares sold and issued		1,260,000
Common Stock \| Follow-On Offering
Organization And Nature Of Business [Line Items]
Number of shares priced under public offering	4,750,000
Stock sold and issued price per share	$ 25.00
Aggregate net proceeds, after deducting underwriting discounts and commissions and offering costs	$ 111,100

Stock-based Compensation - Additional Information (Details) - shares	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2020	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Mar. 28, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance		8,607,659		8,607,659		7,123,787
Number of shares available for grant		3,070,925		3,070,925		2,690,097
Number of options outstanding		5,020,870		5,020,870		3,881,274
Expected dividend yield		0.00%	0.00%	0.00%	0.00%
2020 Equity Incentive Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance	2,606,546	3,070,925		3,070,925		2,690,097
Number of shares authorized and reserved for issuance		1,611,226		1,611,226
Percentage of aggregate number of shares of common stock outstanding reserved for future issuance				5.00%		5.00%
Number of shares available for grant		2,902,219		2,902,219
2020 Equity Incentive Award Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant		18,000,000		18,000,000		18,000,000
Options exercisable period				10 years		10 years
2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options exercisable period				10 years
Number of options outstanding		2,371,439		2,371,439
Minimum percentage of outstanding shares held by individual				10.00%
Exercise price as percentage of fair market value, minimum				110.00%
2020 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized and reserved for issuance	252,337						25,000
Percentage of aggregate number of shares of common stock outstanding reserved for future issuance				1.00%
Employee purchase price of common stock as percentage of fair market value	85.00%
Common stock overlapping offering period	24 months
Duration of purchase period	6 months
Percentage of maximum contributions of employee's eligible compensation	15.00%
2020 ESPP \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant		15,000,000		15,000,000