0001564590-22-037398 | 10-Q | XBRL Viewer

Print Document View Excel Document

Stock-Based Compensation - Schedule of Assumptions Used to Determine the Fair Value of Options Granted (Details)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	1.30%	0.50%
Risk-free interest rate, maximum	3.40%	1.10%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	83.00%	82.20%
Expected term (years)	3 years	5 years 6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	92.20%	84.30%
Expected term (years)	6 years	6 years

Stock-Based Compensation - Schedule of Assumptions Used to Determine the Fair Value of Purchase Rights Issued Under ESPP (Details)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	1.30%	0.50%
Risk-free interest rate, maximum	3.40%	1.10%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	83.00%	82.20%
Expected term (years)	3 years	5 years 6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	92.20%	84.30%
Expected term (years)	6 years	6 years
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate		0.10%
Risk-free interest rate, minimum	0.60%
Risk-free interest rate, maximum	3.90%
Expected term (years)	6 months	6 months
2020 Employee Stock Purchase Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	84.40%	74.80%
2020 Employee Stock Purchase Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	101.50%	87.90%

Net Income (Loss) Per Share - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net income (loss)	$ 70,409	$ (43,036)	$ (58,057)	$ (42,424)	$ (45,705)	$ (38,314)	$ (30,684)	$ (126,443)
Numerator for basic net income (loss) per share stockholders	70,409			(42,424)			(30,684)	(126,443)
Numerator for diluted net income (loss) per share stockholders	$ 52,248			$ (42,424)			$ (48,845)	$ (126,443)
Denominator:
Denominator for basic net income (loss) per share - weighted-average common stock outstanding	76,287,421			62,298,243			67,235,865	62,144,595
Effect of dilutive securities:
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding	76,688,382			62,298,243			67,235,865	62,144,595
Net income (loss) per share, basic	$ 0.92			$ (0.68)			$ (0.46)	$ (2.03)
Net income (loss) per share, diluted	$ 0.92			$ (0.68)			$ (0.46)	$ (2.03)
Stock Options
Effect of dilutive securities:
Effect of dilutive securities	147,443
RSUs
Effect of dilutive securities:
Effect of dilutive securities	237,212
ESPP Shares
Effect of dilutive securities:
Effect of dilutive securities	16,306

Stock-Based Compensation - Summary of the Company's Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Balance, Shares \| shares	9,899,707
Granted, Shares \| shares	3,725,101
Exercised, Shares \| shares	(94,164)
Forfeited/Cancelled, Shares \| shares	(1,567,282)
Balance, Shares \| shares	11,963,362
Options vested and expected to vest as of September 30, 2022 \| shares	11,963,362
Options vested and exercisable as of September 30, 2022 \| shares	4,720,812
Balance, Weighted Average Exercise Price \| $ / shares	$ 9.57
Options Granted, Weighted Average Exercise Price \| $ / shares	3.67
Exercised, Weighted Average Exercise Price \| $ / shares	1.44
Forfeited/Cancelled, Weighted Average Exercise Price \| $ / shares	9.12
Balance, Weighted Average Exercise Price \| $ / shares	7.85
Options vested and expected to vest as of September 30, 2022 \| $ / shares	7.85
Options vested and exercisable as of September 30, 2022 \| $ / shares	$ 9.24
Balance, Weighted Average Remaining Contractual Term (Years)	8 years 4 months 20 days
Options vested and expected to vest as of September 30, 2022	8 years 4 months 20 days
Options vested and exercisable as of September 30, 2022	7 years 8 months 12 days
Balance,Aggregate Intrinsic Value \| $	$ 1,409
Options vested and expected to vest as of September 30, 2022 \| $	1,409
Options vested and exercisable as of September 30, 2022 \| $	$ 619

Commitments and Contingencies - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($) ft² Option	Sep. 30, 2021 USD ($)
Commitments And Contingencies [Line Items]
Operating leases, number of square feet \| ft²	110,000
Right-of-use asset obtained in exchange for operating lease liability	$ 4.4
Operating lease, number of options to extend term \| Option	2
Operating lease, extended term	5 years
Operating lease, option to extend	true
Operating lease, option to extend, description	Certain of the Company’s manufacturing, laboratory and office space lease agreements include two options to extend the term for a period of five years each.
Operating lease expense	$ 5.4	$ 4.7
Impairment of ROU asset	0.6
Operating lease, payments	$ 6.1
Operating lease, weighted-average remaining lease term	6 years 6 months
Operating lease, weighted -average discount rate	8.90%
Maximum
Commitments And Contingencies [Line Items]
Operating leases remaining lease terms	7 years 3 months 18 days
Operating lease remaining lease term dedicated to manufacturing suites	1 year 3 months 18 days

Nature of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Net loss	$ (70,409)	$ 43,036	$ 58,057	$ 42,424	$ 45,705	$ 38,314	$ 30,684	$ 126,443
Net cash used in operating activities							29,175	$ 111,016
Accumulated deficit	437,543						437,543		$ 406,859
Cash, cash equivalents and short-term investments	$ 279,000						$ 279,000

- 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

Stockholders' Equity - Additional Information (Details) - USD ($)	1 Months Ended	9 Months Ended
	Aug. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Jul. 31, 2020
Class Of Stock [Line Items]
Common stock, shares authorized		250,000,000	250,000,000
Common stock, par value		$ 0.0001	$ 0.0001
Common stock, voting rights		Each share of common stock is entitled to one vote.
Dividends declared		$ 0
Proceeds from public offering of common stock, net of issuance costs		$ 75,299,000
Common Stock
Class Of Stock [Line Items]
Warrants to purchase stock		93,518
Warrants to purchase stock		$ 4.28
Sale of common stock under an underwritten public offering	23,000,000
Sale of stock, price per share	$ 3.50
Shares sold pursuant to full exercise of underwriters' option to purchase additional shares	3,000,000
Proceeds from public offering of common stock, net of issuance costs	$ 75,300,000
2018 and 2019 Warrants \| Common Stock
Class Of Stock [Line Items]
Warrants to purchase stock		27,604
Warrants to purchase stock		$ 7.25
IPO
Class Of Stock [Line Items]
Common stock, shares authorized				250,000,000
Common stock, par value				$ 0.0001
Undesignated preferred stock, shares authorized				10,000,000
Undesignated preferred stock, par value				$ 0.0001

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	85,946,414	62,523,596
Common stock, shares outstanding	85,946,414	62,523,596

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2022
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Poseida Therapeutics, Inc. (the “Company” or “Poseida”) is a clinical-stage cell and gene therapy company advancing a new class of treatments for patients with cancer and rare diseases. The Company has discovered and is developing a broad portfolio of product candidates in a variety of indications based on its core proprietary platforms, including the Company’s non-viral piggyBac DNA Delivery System, Cas-CLOVER Site-specific Gene Editing System and nanoparticle- and AAV-based gene delivery technologies. The Company is subject to risks and uncertainties common to development-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s therapeutic development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales.
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements reflect the Company’s financial position, results of operations and cash flows, in conformity with generally accepted accounting principles in the United States of America (“GAAP”), for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. The accompanying condensed consolidated financial statements include the accounts of Poseida Therapeutics, Inc. and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. These unaudited condensed consolidated financial statements reflect all adjustments that are, in the opinion of management, necessary to fairly state the financial position and the results of its operations and cash flows for interim periods presented. Interim-period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, as filed with the Securities and Exchange Commission (“SEC”) on March 10, 2022 from which the Company derived its condensed consolidated balance sheet as of December 31, 2021.
Risk and Uncertainties	Risk and Uncertainties In March 2020, the World Health Organization made the assessment that a novel strain of coronavirus, SARS-CoV-2, a novel strain of coronavirus, commonly referred to as COVID-19 had become a global pandemic. The impact of this pandemic has been and may continue to be extensive in many aspects of society, which has resulted in and may continue to result in significant disruptions to the global economy, as well as businesses and capital markets around the world. Impacts to the Company’s business, some of which the Company has experienced to date, include, but are not limited to, temporary closures of its facilities or those of its vendors, disruptions or restrictions on its employees’ ability to travel, disruptions to or delays in ongoing laboratory experiments, preclinical studies, clinical trials, third-party manufacturing supply and other operations, the diversion of healthcare resources away from the conduct of clinical trials to focus on pandemic concerns, interruptions or delays in the operations of the U.S. Food and Drug Administration (“FDA”) or other regulatory authorities, and the Company’s ability to raise capital and conduct business development activities. Russia’s invasion of Ukraine and the retaliatory measures that have been taken, or could be taken in the future, by the United States, NATO, and other countries have created global security concerns that could result in a regional conflict and otherwise have a lasting impact on regional and global economies, any or all of which could disrupt the Company’s supply chain and adversely affect its ability to conduct ongoing and future clinical trials of the Company’s product candidates. The extent to which the ongoing conflict ultimately impacts the Company’s business is highly uncertain and cannot be predicted with confidence at this time.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, which include, but are not limited to, estimates related to revenue, accrued expenses, research and development expenses, stock-based compensation expense and deferred tax valuation allowances. The Company bases its estimates on historical experience and other market-specific or relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions.
Fair Value Measurements	Fair Value Measurements Certain financial instruments are required to be recorded at fair value. Other financial instruments, like cash are recorded at cost, which approximates fair value. Cash equivalents and short-term investments are comprised of available-for-sale securities, which are carried at fair value. Additionally, carrying amounts of accounts receivable, accounts payable and accrued liabilities approximate fair value because of the short maturity of those instruments. The carrying value of the Company’s term debt approximates its fair value due to its variable interest rate, which approximates a market interest rate.
Concentration of Business Risk	Concentration of Business Risk The Company operates in one reportable business segment and has two customers. The Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and materials for its development programs. These programs could be adversely affected by a significant interruption in these manufacturing services.
Leases	Leases The Company accounts for leases in accordance with Accounting Standards Codification Topic 842, Leases, (“ASC 842”). The Company determines if an arrangement is a lease at contract inception. A lease exists when a contract conveys the right to control the use of identified property, plant, or equipment for a period of time in exchange for consideration. The definition of a lease embodies two conditions: (1) there is an identified asset in the contract that is land or a depreciable asset (i.e., property, plant, and equipment), and (2) the Company has the right to control the use of the identified asset. Operating leases where the Company is the lessee are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, current and operating lease liabilities, non-current on its condensed consolidated balance sheets. The lease liabilities are initially and subsequently measured at the present value of the unpaid lease payments at the lease commencement date. ASC 842 requires a lessee to discount its unpaid lease payments using the interest rate implicit in the lease or, if that rate cannot be readily determined, its incremental borrowing rate. The rates implicit in the Company’s leases are not known, therefore, the incremental borrowing rate is used based on the information available at commencement date in determining the present value of lease payments. The Company’s incremental borrowing rate for a lease is the rate of interest it would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. The lease term for all of the Company’s leases includes the noncancelable period of the lease. Where the Company’s lease term is impacted by options to extend or terminate the lease, when it is reasonably certain that it will exercise such option, then the lease payments are included in the measurement of the lease asset or liability. The Company has elected not to recognize ROU assets and lease liabilities for all short-term leases that have a lease term of 12 months or less. The Company recognizes the lease payments associated with its short-term leases as an expense on a straight-line basis over the lease term. There are no variable lease payments associated with these leases. Additionally, the Company has elected to account for the lease and non-lease components together as a single lease component for its real estate asset class.
Revenue Recognition	Revenue Recognition The Company’s revenues to date have been generated primarily through collaboration and license agreements. The Company’s collaboration and license agreements may contain multiple elements including intellectual property licenses and research, and development services. Consideration the Company receives under these arrangements may include upfront payments, research and development funding, cost reimbursements, research, development, regulatory and commercial milestone payments, and royalty payments. The Company applies Accounting Standard Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”), issued by the Financial Accounting Standards Board (“FASB”) to account for its contracts with customers. Under ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration that the Company expects to be entitled to receive in exchange for these services and excludes sales incentives and amounts collected on behalf of third parties. The Company analyzes the nature of these performance obligations in the context of individual collaboration and license agreements in order to assess the distinct performance obligations. The Company evaluates its contracts with customers for proper classification in the consolidated statements of operations based on the nature of the underlying activity. Transactions with customers recorded in the Company’s consolidated statements of operations are recorded on either a gross or net basis, depending on the characteristics of the collaborative relationship. To determine revenue recognition for arrangements within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. The Company allocates the transaction price to individual performance obligations on their relative standalone selling price basis. Standalone selling prices are based on observable prices at which the Company separately sells the products or services. If a standalone selling price is not directly observable, then the Company estimates the standalone selling price considering market conditions and entity-specific factors including, but not limited to, features and functionality of the products and services. The Company receives payments from its collaborators based on terms established in each contract. Upfront payments and other payments may require deferral of revenue recognition to a future period until the Company satisfies its performance obligations under the contract.
Accounts Receivable and Allowance for Credit Losses	Accounts Receivable and Allowance for Credit Losses Accounts receivable primarily consist of amounts due from customers for services and payments due based on contractual terms. Accounts receivable are recorded when the right to consideration becomes unconditional. For research and development services, the Company generally bills its customers monthly or quarterly as the services are performed. Payment terms on invoiced amounts are typically 30 - 60 days. The Company recognizes estimated allowance for credit losses based on an assessment of a customer’s ability to pay, credit quality of the customer, age of receivable balances and current economic conditions. As of September 30, 2022 and December 31, 2021, the Company recorded no allowance for credit losses.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on short-term investments. Comprehensive gains (losses) have been reflected in the unaudited condensed consolidated statements of operations and comprehensive income (loss) for all periods presented.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these condensed consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In May 2021, the FASB issued ASU 2021-04, Earnings Per Share (Topic 260), Debt-Modifications and Extinguishments (Subtopic 470-50), Compensation- Stock Compensation (Topic 718), and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40) which provides guidance on modifications or exchanges of a freestanding equity-classified written call option that is not within the scope of another Topic. An entity should treat a modification of the terms or conditions or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange as an exchange of the original instrument for a new instrument ASU 2021-04 also provides further guidance on measuring the effect of a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange. ASU 2021-04 also provides guidance on the recognition of the effect of a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange on the basis of the substance of the transaction, in the same manner as if cash had been paid as consideration. The Company adopted ASU 2021-04 on January 1, 2022. The adoption of this standard had no impact on the Company’s condensed consolidated financial statements and disclosures. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments, which established ASC 326, Financial Instruments - Credit Losses. This ASU, along with subsequent amendments, improves financial reporting by requiring timely recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. This guidance will become effective for the Company beginning January 1, 2023, with early adoption permitted. The Company is currently evaluating the potential impact ASU 2016-13 may have on its financial position and results of operations upon adoption but does not expect the adoption will have a material impact on the Company’s consolidated financial statements and disclosures.

California Institute of Regenerative Medicine Awards - Additional Information (Details) - CIRM $ in Millions	1 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2022 Time
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue sharing multiple \| Time		9
Period to exercise loan option upon food and drug administration authorization		10 days
Repayment period		10 days
Repayment of awards percentage		60.00%
P-PSMA-101 program
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Award received \| $	$ 4.0
LIBOR
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Debt instrument basis spread on variable rate		10.00%

Composition of Certain Balance Sheet Components - Summary of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Contract research services	$ 11,094	$ 12,292
Payroll and related expense	7,504	8,760
Other	3,475	2,488
Total accrued expenses and other liabilities	$ 22,073	$ 23,540

Stockholders' Equity

9 Months Ended

Sep. 30, 2022

Equity [Abstract]

Stockholders' Equity

Note 9. Stockholders’ Equity

Authorized Shares

In connection with the completion of the Company’s initial public offering in July 2020, the Company amended its certificate of incorporation to authorize 250,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share, that may be issued from time to time by the Company’s board of directors in one or more series. Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the Company’s board of directors. Since the Company’s inception, there have been no dividends declared.

Warrants

Pursuant to the Amended Loan Agreement, the Company issued Oxford (i) in 2017, a warrant to purchase 93,518 shares of common stock at an exercise price of $4.28 per share, which will expire in 2027 unless earlier exercised and (ii) in 2018 and 2019, warrants to purchase an aggregate of 27,604 shares of common stock at an exercise price of $7.25 per share, which will expire in 2028 and 2029, respectively, unless earlier exercised.

Sale of Common Stock

In August 2022, the Company completed the sale of an aggregate of 23,000,000 shares of its common stock in an underwritten public offering, at a price of $3.50 per share, including 3,000,000 shares sold pursuant to the full exercise of the underwriters' option to purchase additional shares. The net proceeds to the Company from the offering were approximately $75.3 million after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company.

- 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

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net loss	$ (30,684)	$ (126,443)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	3,817	3,369
Loss on disposal of property and equipment	205	3
Stock-based compensation	14,378	12,355
Accretion of discount on issued term debt	637	484
Amortization (accretion) on investment securities, net	(474)	133
Changes in operating assets and liabilities:
Accounts receivable	(38,467)
Prepaid expenses and other current assets	(184)	(2,096)
Operating lease right-of-use assets	3,602	2,699
Other long-term assets	606	(228)
Accounts payable	(5,536)	2,882
Accrued expenses and other liabilities	(1,536)	(1,906)
Operating lease liabilities	(3,796)	(2,268)
Deferred revenue	28,257
Net cash used in operating activities	(29,175)	(111,016)
Investing Activities:
Purchases of property and equipment	(3,664)	(2,421)
Proceeds from sale of property and equipment	12
Purchases of short-term investments	(143,792)
Proceeds from maturities of short-term investments	30,000	225,000
Net cash provided by (used in) investing activities	(117,444)	222,579
Financing Activities:
Net proceeds from issuance of common stock under employee stock compensation plans	1,252	2,282
Proceeds from public offering of common stock, net of issuance costs	75,299
Payment of debt issuance costs	(1,450)
Proceeds from term debt	30,000
Net cash provided by financing activities	105,101	2,282
Net increase (decrease) in cash and cash equivalents	(41,518)	113,845
Cash and cash equivalents at beginning of period	206,325	83,966
Cash and cash equivalents at end of period	164,807	197,811
Non-cash operating, investing and financing activities:
Purchases of property and equipment in accounts payable and accrued liabilities	68	58
Deferred offering costs incurred but not yet paid		115
Supplemental disclosure of cash flow information:
Interest paid	$ 3,470	$ 2,041

Term Debt

9 Months Ended

Sep. 30, 2022

Debt Instruments [Abstract]

Term Debt

Note 8. Term Debt

In 2017, the Company entered into a loan and security agreement with Oxford Finance LLC (“Oxford”), which was subsequently amended (“Amended Loan Agreement”), pursuant to which the Company borrowed $20.0 million under a Term A loan and $10.0 million under a Term B loan.

In February 2022, the Company entered into a new Loan and Security Agreement (“2022 Loan Agreement”) with Oxford. Pursuant to the terms of the 2022 Loan Agreement, the Company borrowed $60.0 million in term loans (the “Term Loans”), of which $31.6 million was used to repay the balance outstanding under the Amended Loan Agreement, including $0.2 million of accrued interest. Under the 2022 Loan Agreement the interest-only period is through April 1, 2025, followed by 23 equal monthly payments of principal and applicable interest. In September 2022, a qualifying equity event, as defined in the 2022 Loan Agreement, was achieved which extended the interest-only period through April 1, 2026, followed by 11 equal monthly payments of principal and applicable interest. As a result, all amounts outstanding under the 2022 Loan Agreement will mature on February 1, 2027 (the “Maturity Date”). In connection with the repayment of the balance outstanding under the Amended Loan Agreement, the Company incurred amendment and final payment fees of $1.5 million previously due on the earlier of (i) the maturity date, (ii) acceleration of any Term A or Term B loans, or (iii) the prepayment of the Term A or Term B loans.

The Company accounted for this amendment as debt modification in accordance with ASC Topic 470, Debt because the modification was not considered substantial.

The balance outstanding under the 2022 Loan Agreement bears interest at a floating per annum rate equal to 7.83% plus the greater of (a) the 30-day U.S. Dollar (USD) LIBOR rate and (b) 0.11%. The interest rate applicable to the Term Loans as of September 30, 2022 was 10.38% per annum. The 2022 Loan Agreement includes a provision addressing replacement of LIBOR with an alternate benchmark rate, which may include the Secured Overnight Financing Rate, when LIBOR is phased out. LIBOR is scheduled to be phased out in June 2023. Consistent with the Amended Loan Agreement, the Company is required to make a final payment fee of 7.5% of the principal balance outstanding, payable on the earlier of (i) the Maturity Date, (ii) acceleration of any Term Loan, or (iii) the prepayment of the Term Loan. As of September 30, 2022, there was $60.0 million outstanding under the Term Loans. In connection with the Amended Loan Agreement, the Company previously incurred debt issuance costs of $1.6 million, which have been recorded as a debt discount and are being accreted to interest expense over the term of the Term Loans. Interest on the Term Loans, consisting of the stated interest rate, final payment fee and amortization of the discount, is being recognized under the effective interest method using a rate of 12.05%. As of September 30, 2022, the balance of the unamortized debt discount was $1.8 million. The balance of the accrued final payment fee was $2.0 million as of September 30, 2022 and is presented as other long-term liability in the accompanying condensed consolidated balance sheet.

The Company has an option to repay the outstanding debt under the 2022 Loan Agreement at any time in increments of $5.0 million, subject to a prepayment fee of 1.00% if the Term Loans are prepaid on or prior to February 22, 2024, after which no prepayment penalty would be applied.

The Company may use the proceeds from the Term Loans solely for its working capital requirements and to fund its general business operations. The Company’s obligations under the 2022 Loan Agreement are secured by a first priority security interest in substantially all of its current and future assets, other than its intellectual property. In addition, the Company has also agreed not to encumber its intellectual property assets, except as permitted by the 2022 Loan Agreement. While any amounts are outstanding under the 2022 Loan Agreement, the Company is subject to a number of affirmative and restrictive covenants, including covenants regarding dispositions of property, business combinations or acquisitions, among other customary covenants. The Company is also restricted from declaring dividends or making other distributions or payments on its capital stock in excess of $0.3 million per calendar year, subject to limited exceptions. As of September 30, 2022, the Company was in compliance with all covenants under the 2022 Loan Agreement.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI https://asc.fasb.org/topic&trid=2208564

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 6: 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(c))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1E
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2022

Commitments And Contingencies Disclosure [Abstract]

Summary of Maturities of Lease Liabilities

As of September 30, 2022, maturities of lease liabilities were as follows (in thousands):

Year ending December 31,
2022 (remaining 3 months)	$	1,729
2023		7,057
2024		6,188
2025		6,374
2026		5,107
Thereafter		16,260
Total future lease payments		42,715
Imputed interest		(10,244	)
Total lease liability balance		32,471
Less current portion of lease liability		6,737
Lease liability, net of current portion	$	25,734

Composition of Certain Balance Sheet Components - Summary of Property and Equipment Net (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment	$ 34,579	$ 31,187
Less: Accumulated depreciation and amortization	(12,831)	(9,137)
Total property and equipment, net	21,748	22,050
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	17,312	14,192
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	14,007	13,910
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Total property and equipment	2,263	2,137
Furniture, Fixtures and Other
Property Plant And Equipment [Line Items]
Total property and equipment	$ 997	$ 948

Commitments and Contingencies - Summary of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
2022 (remaining 3 months)	$ 1,729
2023	7,057
2024	6,188
2025	6,374
2026	5,107
Thereafter	16,260
Total future lease payments	42,715
Imputed interest	(10,244)
Total lease liability balance	32,471
Less current portion of lease liability	6,737	$ 6,337
Lease liability, net of current portion	$ 25,734	$ 25,504

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Income Taxes [Line Items]
Income tax expense	$ 252	$ 252
Effective income tax rate	0.40%	(0.80%)
Federal statutory income tax rate, percent		21.00%
Domestic
Income Taxes [Line Items]
Tax cuts and jobs act capitalize and amortize research and development expenditures period		5 years
Foreign
Income Taxes [Line Items]
Tax cuts and jobs act capitalize and amortize research and development expenditures period		15 years

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Fair Value Measurement - Schedule of Company's Valuation Hierarchy of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets:
Cash and cash equivalents	$ 164,807	$ 206,325
Recurring Basis \| Level 1
Assets:
Short-term investments	114,178
Total	151,822	176,102
Recurring Basis \| Level 1 \| Money Market Funds and U.S. Government Agency Treasuries
Assets:
Cash and cash equivalents	$ 37,644
Recurring Basis \| Level 1 \| Money Market Fund
Assets:
Cash and cash equivalents		$ 176,102

Stock-Based Compensation - Summary of Restricted Stock Unit (RSU) Activity (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted, Shares \| shares	2,594,471
Forfeited/Cancelled, Shares \| shares	(221,544)
Balance, Shares \| shares	2,372,927
Granted, Weighted Average Grant Date Fair Value \| $ / shares	$ 3.67
Forfeited/Cancelled, Weighted Average Grant Date Fair Value \| $ / shares	3.52
Balance, Weighted Average Grant Date Fair Value \| $ / shares	$ 3.68

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	9 Months Ended
	Jul. 31, 2020	Sep. 30, 2022	Sep. 30, 2021	Feb. 28, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted		$ 2.63	$ 6.32
Aggregate intrinsic value of options exercised		$ 0.1	$ 3.2
Cash received from options exercised		0.1	$ 1.7
Unrecognized compensation cost		$ 34.0
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period over which cost expected to be recognized		2 years 8 months 12 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period over which cost expected to be recognized		3 years 3 months 18 days
Vesting period		4 years
Unrecognized compensation cost		$ 7.4
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock reserved for issuance	11,183,476
Share-based compensation award term	10 years
Percentage increase of outstanding number of shares of common stock	5.00%
Inducement Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock issuable				2,000,000
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock reserved for issuance	615,000
Share-based compensation award term	10 years
Percentage increase of outstanding number of shares of common stock	1.00%
Share-based compensation shares issued in period	1,230,000
Offering period of common stock	six months
Percentage of the fair market value per share of common stock	85.00%
Initial purchase period, commenced	2021-03
Total shares purchased by employees		328,654
Net proceeds from share purchase by employees		$ 1.1
2020 Employee Stock Purchase Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of annual compensation	15.00%
Number of shares purchased	3,000

Collaborations and License Agreements (Tables)

9 Months Ended

Sep. 30, 2022

Collaborations And License Agreement [Abstract]

Summary of Reconciliation of Closing Balance of Deferred Revenue Related to agreements

A reconciliation of the closing balance of deferred revenue related to the agreements is as follows (in thousands):

	Roche Collaboration Agreement			Takeda Collaboration Agreement			Total
Balance as of December 31, 2020	$	—		$	—		$	—
Amounts received/invoiced		—			45,000			45,000
Revenue recognized		—			(31,238	)		(31,238	)
Balance as of December 31, 2021	$	—		$	13,762		$	13,762
Amounts received/invoiced		146,533			2,165			148,698
Revenue recognized		(114,109	)		(6,332	)		(120,441	)
Balance as of September 30, 2022	$	32,424		$	9,595		$	42,019

Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2022 USD ($) Segment Customer	Dec. 31, 2021 USD ($)
Accounting Policies [Abstract]
Number of reportable segment \| Segment	1
Number of customer \| Customer	2
Variable lease, payments	$ 0
Description of payment terms	Payment terms on invoiced amounts are typically 30 - 60 days
Allowance for credit loss	$ 0	$ 0

Income Taxes

9 Months Ended

Sep. 30, 2022

Income Tax Disclosure [Abstract]

Income Taxes

Note 13. Income Taxes

Beginning in 2022, the Tax Cuts and Jobs Act of 2017 requires taxpayers to capitalize and amortize research and development expenditures over five years for domestic research and 15 years for foreign research pursuant to Section 174 of the Internal Revenue Code of 1986, as amended. Although the U.S. Congress is considering legislation that would defer the amortization requirement to later years, the Company has no assurance that the provision will be repealed or otherwise modified. As a result, the Company recorded income tax expense of $0.3 million for the three and nine months ended September 30, 2022. Additionally, the Company’s effective tax rate for the three and nine months ended September 30, 2022, was 0.4% and (0.8)%, respectively. This rate differed from the federal tax rate of 21% primarily due to the inability to benefit the Company’s financial reporting loss for income tax purposes, as well as the limitation on the use of previously unbenefited tax losses and credits carried forward from prior years to fully offset current year taxable income resulting from the requirement to capitalize research and development costs for federal income tax purposes.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI https://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: 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(h)(2))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Fair Value Measurement

9 Months Ended

Sep. 30, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurement

Note 5. Fair Value Measurement

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants as of the measurement date. Applicable accounting guidance provides an established hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs that market participants would use in valuing the asset or liability and are developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the factors that market participants would use in valuing the asset or liability. There are three levels of inputs that may be used to measure fair value:

•

Level 1 — Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities

•

Level 2 — Significant other observable inputs other than Level 1 prices such as quoted prices in markets that are not active, or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability

•

Level 3 — Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity)

The Company classifies its money market funds and U.S. treasury securities, which are valued based on quoted market prices in active markets with no valuation adjustment, as Level 1 assets within the fair value hierarchy.

The following table summarizes the Company’s valuation hierarchy for its financial assets and liabilities measured at fair value on a recurring basis (in thousands):

	Level 1		Level 2		Level 3
September 30, 2022:
Assets:
Money market funds and U.S. government agency treasuries(1)	$	37,644	$	—	$	—
Short-term investments		114,178		—		—
Total	$	151,822	$	—	$	—

December 31, 2021:
Assets:
Money market funds(1)	$	176,102	$	—	$	—
Total	$	176,102	$	—	$	—

(1) Included in cash and cash equivalents in the accompanying condensed consolidated balance sheets.

- 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

Financial Instruments - Summary of Amortized Cost and Fair Value of Securities Available-for-Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Securities, Amortized Cost/Cost	$ 151,966	$ 176,102
Available-for-Sale Securities, Unrealized Gains	1
Available-for-Sale Securities , Unrealized Losses	(145)
Available-for-Sale Securities, Fair Value	151,822	176,102
Money Market Fund
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Securities, Amortized Cost/Cost	37,644	176,102
Available-for-Sale Securities, Fair Value	37,644	$ 176,102
U.S. Government Agency Securities and Treasuries
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Securities, Amortized Cost/Cost	114,322
Available-for-Sale Securities, Unrealized Gains	1
Available-for-Sale Securities , Unrealized Losses	(145)
Available-for-Sale Securities, Fair Value	$ 114,178

Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2022

Fair Value Disclosures [Abstract]

Schedule of Company's Valuation Hierarchy of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table summarizes the Company’s valuation hierarchy for its financial assets and liabilities measured at fair value on a recurring basis (in thousands):

	Level 1		Level 2		Level 3
September 30, 2022:
Assets:
Money market funds and U.S. government agency treasuries(1)	$	37,644	$	—	$	—
Short-term investments		114,178		—		—
Total	$	151,822	$	—	$	—

December 31, 2021:
Assets:
Money market funds(1)	$	176,102	$	—	$	—
Total	$	176,102	$	—	$	—

(1) Included in cash and cash equivalents in the accompanying condensed consolidated balance sheets.

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of the Company's Stock Option Activity

The following is a summary of the Company’s stock option activity for the nine months ended September 30, 2022:

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (thousands)
Balance at January 1, 2022		9,899,707		$	9.57
Granted		3,725,101			3.67
Exercised		(94,164	)		1.44
Forfeited/Cancelled		(1,567,282	)		9.12
Balance at September 30, 2022		11,963,362		$	7.85		8.39	$	1,409
Options vested and expected to vest as of September 30, 2022		11,963,362		$	7.85		8.39	$	1,409
Options vested and exercisable as of September 30, 2022		4,720,812		$	9.24		7.70	$	619

Schedule of Assumptions Used to Determine the Fair Value of Options Granted

The Company uses the Black-Scholes option pricing model to estimate the fair value of each option grant on the date of grant or any other measurement date. The assumptions that the Company used to determine the fair value of options granted to employees, non-employees and directors were as follows:

	Nine Months Ended September 30,
	2022		2021
Risk-free interest rate	1.3%–3.4%		0.5%–1.1%
Expected volatility	83.0%–92.2%		82.2%–84.3%
Expected term (years)	3.0–6.0		5.5–6.0
Dividend yield		—		—

Summary of Restricted Stock Unit (RSU) Activity

The following is a summary of the Company’s restricted stock unit (“RSU”) activity for the nine months ended September 30, 2022:

	Shares			Weighted Average Grant Date Fair Value
Balance at January 1, 2022		—		$	—
Granted		2,594,471			3.67
Vested		—			—
Forfeited/Cancelled		(221,544	)		3.52
Balance at September 30, 2022		2,372,927		$	3.68

Schedule of Assumptions Used to Determine the Fair Value of Purchase Rights Issued Under ESPP

The assumptions that the Company used to determine the fair value of the purchase rights issued to employees during the nine months ended September 30, 2022 and 2021 were as follows:

	Nine Months Ended September 30,
	2022		2021
Risk-free interest rate	0.6% - 3.9%			0.1	%
Expected volatility	84.4 - 101.5%		74.8 - 87.9%
Expected term (years)		0.5		0.5
Dividend yield		—		—

Schedule of Stock-Based Compensation Expense

The Company recorded total stock-based compensation expense related to stock options, RSUs and the ESPP in the following expense categories of the accompanying condensed consolidated statements of operations and comprehensive income (loss) (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	2,056	$	2,049	$	7,132	$	5,966
General and administrative		2,221		2,102		7,246		6,389
Total stock-based compensation expense	$	4,277	$	4,151	$	14,378	$	12,355

Financial Instruments - (Tables)

9 Months Ended

Sep. 30, 2022

Investments Debt And Equity Securities [Abstract]

Summary of Amortized Cost and Fair Value of Securities Available-for-Sale

The following table summarizes the amortized cost and fair value of securities available-for-sale (in thousands):

	Amortized Cost/Cost		Unrealized Gains		Unrealized Losses			Fair Value
September 30, 2022:
Money market fund	$	37,644	$	—	$	—		$	37,644
U.S. government agency securities and treasuries		114,322		1		(145	)		114,178
Total	$	151,966	$	1	$	(145	)	$	151,822

December 31, 2021:
Money market fund	$	176,102	$	—	$	—		$	176,102
Total	$	176,102	$	—	$	—		$	176,102

Net Income (Loss) Per Share

9 Months Ended

Sep. 30, 2022

Earnings Per Share [Abstract]

Net Income (Loss) Per Share

Note 12. Net Income (Loss) Per Share

Basic net income (loss) per share is computed by dividing net income (loss) attributable to common stockholders for the period by the weighted-average number of common shares outstanding during the period. Diluted net income (loss) per share reflects the additional dilution from potential issuances of common stock, such as stock issuable pursuant to the exercise of stock options and from purchases under the ESPP, as well as from the possible exercise of the outstanding warrants.

The Company’s potentially dilutive securities, which include warrants to purchase common stock and common stock options, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same.

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

	Three Months Ended September 30,					Nine Months Ended September 30,
	2022		2021			2022			2021
Numerator:
Net income (loss)	$	70,409	$	(42,424	)	$	(30,684	)	$	(126,443	)
Numerator for basic and diluted net income (loss) per share stockholders	$	70,409	$	(42,424	)	$	(30,684	)	$	(126,443	)
Denominator:
Denominator for basic net income (loss) per share - weighted-average common stock outstanding		76,287,421		62,298,243			67,235,865			62,144,595
Effect of dilutive securities:
Common stock options		147,443		—			—			—
RSUs		237,212		—			—			—
ESPP shares		16,306		—			—			—
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding		76,688,382		62,298,243			67,235,865			62,144,595
Basic net income (loss) per share	$	0.92	$	(0.68	)	$	(0.46	)	$	(2.03	)
Diluted net income (loss) per share	$	0.92	$	(0.68	)	$	(0.46	)	$	(2.03	)

The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:

	Nine Months Ended September 30,
	2022		2021
Outstanding stock options and RSUs		14,336,289		8,456,838
Warrants to purchase common stock		121,122		121,122
		14,457,411		8,577,960

Net Income (Loss) Per Share - Schedule of Anti-Dilutive Securities Excluded From Computation of Diluted Net Loss per Share Attributable to Common Stockholders (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	14,457,411	8,577,960
Outstanding Stock Options and RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	14,336,289	8,456,838
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	121,122	121,122

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 164,807	$ 206,325
Short-term investments	114,178
Accounts receivable	38,467
Prepaid expenses and other current assets	7,677	7,548
Total current assets	325,129	213,873
Property and equipment, net	21,748	22,050
Operating lease right-of-use assets	27,000	26,177
Intangible assets	1,320	1,320
Goodwill	4,228	4,228
Other long-term assets	1,056	1,661
Total assets	380,481	269,309
Current liabilities:
Accounts payable	3,426	8,961
Accrued expenses and other liabilities	22,073	23,540
Operating lease liabilities, current	6,737	6,337
Deferred revenue, current	16,732	4,497
Total current liabilities	48,968	43,335
Operating lease liabilities, non-current	25,734	25,504
Term debt	58,162	29,357
Deferred CIRM grant liability	3,992	3,992
Deferred revenue, noncurrent	25,287	9,265
Deferred tax liability	55	55
Other long-term liabilities	1,970	1,590
Total liabilities	164,168	113,098
Commitments and Contingencies (Note 11)
Stockholders’ equity:
Common stock, $0.0001 par value: 250,000,000 shares authorized at September 30, 2022 and December 31, 2021; 85,946,414 and 62,523,596 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	9	6
Additional paid-in capital	653,991	563,064
Accumulated other comprehensive loss	(144)
Accumulated deficit	(437,543)	(406,859)
Total stockholders’ equity	216,313	156,211
Total liabilities and stockholders’ equity	$ 380,481	$ 269,309

California Institute of Regenerative Medicine Awards

9 Months Ended

Sep. 30, 2022

Collaborative Arrangement [Abstract]

Collaboration and License Agreements

Note 7. California Institute of Regenerative Medicine Award

The Company has been awarded funding from California Institute of Regenerative Medicine (“CIRM”) to develop certain internal programs. Under the terms of the funding both CIRM and the Company co-fund specified programs, under which funding is

provided in developmental milestones determined as a part of the award. The Company is obligated to share potential future revenues for the related programs with CIRM. The percentage of revenues due to CIRM in the future is dependent on the amount of the award received and whether revenue is generated from product sales or through license fees. The maximum revenue sharing amount the Company may be required to pay to CIRM is equal to nine times the total amount awarded and paid to the Company. The Company has the option to decline any and all future grant amounts awarded by CIRM. As an alternative to revenue sharing, the Company has an option to convert any award to a loan, which such option the Company must exercise on or before ten business days after the FDA notifies the Company that it has accepted the Company’s application for marketing authorization. In the event the Company exercises its right to convert any award to a loan, it would be obligated to repay the loan within ten business days of making such election. Repayment amounts due to CIRM vary dependent on when the award is converted to a loan, ranging from 60% of the award granted to the full amount received and interest at the rate of the three-month LIBOR rate plus 10% per annum. Since the Company may be required to repay some or all of the amounts awarded by CIRM, the Company accounted for this award as a liability as the Company’s intention is to convert the award into a loan. Given the uncertainty in amounts due upon repayment, the Company has recorded amounts received without any discount or interest recorded, upon determination of amounts that would become due, the Company will adjust the amount of the liability accordingly.

In September 2018, the Company was granted an award in the amount of $4.0 million from CIRM to support the Company’s preclinical studies for its P-PSMA-101 program. The Company received the full amount of the award based on achievement of specific developmental milestones. The amount of the award is presented as a deferred CIRM grant liability in the accompanying condensed consolidated balance sheets.

Composition of Certain Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2022

Balance Sheet Related Disclosures [Abstract]

Summary of Property and Equipment Net

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

	September 30, 2022			December 31, 2021
Laboratory equipment	$	17,312		$	14,192
Leasehold improvements		14,007			13,910
Computer equipment and software		2,263			2,137
Furniture, fixtures and other		997			948
Total property and equipment		34,579			31,187
Less: Accumulated depreciation and amortization		(12,831	)		(9,137	)
Total property and equipment, net	$	21,748		$	22,050

Summary of Accrued Expenses and Other Liabilities

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

	September 30, 2022		December 31, 2021
Contract research services	$	11,094	$	12,292
Payroll and related expense		7,504		8,760
Other		3,475		2,488
Total accrued expenses and other liabilities	$	22,073	$	23,540

Net Income (Loss) Per Share (Tables)

9 Months Ended

Sep. 30, 2022

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share

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

	Three Months Ended September 30,					Nine Months Ended September 30,
	2022		2021			2022			2021
Numerator:
Net income (loss)	$	70,409	$	(42,424	)	$	(30,684	)	$	(126,443	)
Numerator for basic and diluted net income (loss) per share stockholders	$	70,409	$	(42,424	)	$	(30,684	)	$	(126,443	)
Denominator:
Denominator for basic net income (loss) per share - weighted-average common stock outstanding		76,287,421		62,298,243			67,235,865			62,144,595
Effect of dilutive securities:
Common stock options		147,443		—			—			—
RSUs		237,212		—			—			—
ESPP shares		16,306		—			—			—
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding		76,688,382		62,298,243			67,235,865			62,144,595
Basic net income (loss) per share	$	0.92	$	(0.68	)	$	(0.46	)	$	(2.03	)
Diluted net income (loss) per share	$	0.92	$	(0.68	)	$	(0.46	)	$	(2.03	)

Schedule of Anti-Dilutive Securities Excluded From Computation of Diluted Net Loss per Share Attributable to Common Stockholders

	Nine Months Ended September 30,
	2022		2021
Outstanding stock options and RSUs		14,336,289		8,456,838
Warrants to purchase common stock		121,122		121,122
		14,457,411		8,577,960

Collaborations and License Agreements - Additional Information (Details) $ in Millions	1 Months Ended			9 Months Ended
	Sep. 30, 2022 USD ($) Program	Jul. 31, 2022 USD ($) PerformanceObligation	Oct. 31, 2021 USD ($) Program	Sep. 30, 2022 USD ($) Program
Roche Collaboration Agreement
Collaborations And License Agreement [Line Items]
Number of collaboration programs \| Program	6			6
Number of early-stage existing programs \| Program	2			2
Research collaboration period		2 years
Research collaboration extension period		18 months
Upfront cash payment from collaboration agreement	$ 110.0
Collaboration revenue receivable terms		10 years
Number of performance obligations \| PerformanceObligation		6
Roche Collaboration Agreement \| Roche Ltd
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement				$ 110.0
Transaction price				185.0
Roche Collaboration Agreement \| Tier 1 Programs
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable		$ 1,500.0
Development, regulatory and net sales milestones		1,400.0
Roche Collaboration Agreement \| Tier 1 Programs \| Roche Ltd
Collaborations And License Agreement [Line Items]
Future research funding				40.0
Milestone payments	$ 35.0			$ 35.0
Roche Collaboration Agreement \| Tier 2 Programs
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable		1,100.0
Development, regulatory and net sales milestones		1,000.0
Roche Collaboration Agreement \| Collaboration Programs
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable		2,900.0
Roche Collaboration Agreement \| Licensed Products
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable		$ 415.0
Collaborative Arrangement \| Takeda Pharmaceuticals U S A Inc
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement			$ 45.0
Collaboration revenue receivable terms			10 years
Number of initially developing gene therapy programs \| Program			6
Number of option to add additional gene therapy programs \| Program			2
Prepaid research funding			$ 5.0
Minimum upfront and preclinical milestone payments receivable			82.5
Maximum clinical development, regulatory and commercial milestone payments receivable			435.0
Collaborative Arrangement \| Takeda Pharmaceuticals U S A Inc \| Minimum
Collaborations And License Agreement [Line Items]
Collaboration agreement revenue receivable			2,700.0
Collaborative Arrangement \| Takeda Pharmaceuticals U S A Inc \| Maximum
Collaborations And License Agreement [Line Items]
Collaboration agreement revenue receivable			$ 3,600.0

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2022	Nov. 08, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Trading Symbol	PSTX
Entity Registrant Name	Poseida Therapeutics, Inc.
Entity Central Index Key	0001661460
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Security12b Title	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-39376
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	47-2846548
Entity Address, Address Line One	9390 Towne Centre Drive
Entity Address, Address Line Two	Suite 200
Entity Address City Or Town	San Diego
Entity Address State Or Province	CA
Entity Address Postal Zip Code	92121
City Area Code	858
Local Phone Number	779-3100
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		85,949,385

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues:
Collaboration revenue	$ 116,306		$ 120,441
Operating expenses:
Research and development	35,137	$ 32,524	118,995	$ 97,627
General and administrative	9,389	9,066	28,171	26,306
Total operating expenses	44,526	41,590	147,166	123,933
Income (loss) from operations	71,780	(41,590)	(26,725)	(123,933)
Other income (expense):
Interest expense	(1,775)	(837)	(4,395)	(2,518)
Other income, net	656	3	688	8
Net income (loss) before income tax	70,661	(42,424)	(30,432)	(126,443)
Income tax expense	(252)		(252)
Net income (loss)	70,409	(42,424)	(30,684)	(126,443)
Other comprehensive expense:
Unrealized loss on short-term investments	(12)	(1)	(144)	(5)
Comprehensive income (loss)	$ 70,397	$ (42,425)	$ (30,828)	$ (126,448)
Net income (loss) per share, basic	$ 0.92	$ (0.68)	$ (0.46)	$ (2.03)
Net income (loss) per share, diluted	$ 0.92	$ (0.68)	$ (0.46)	$ (2.03)
Weighted-average number of shares outstanding, basic	76,287,421	62,298,243	67,235,865	62,144,595
Weighted-average number of shares outstanding, diluted	76,688,382	62,298,243	67,235,865	62,144,595
Collaboration Revenue
Revenues:
Collaboration revenue	$ 116,306		$ 120,441

Collaboration and License Agreements - Summary of Reconciliation of Closing Balance of Deferred Revenue Related to agreements (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Collaborations And License Agreement [Line Items]
Beginning balance	$ 13,762
Amounts received/invoiced	148,698	$ 45,000
Revenue recognized	(120,441)	(31,238)
Ending balance	42,019	13,762
Roche Collaboration Agreement
Collaborations And License Agreement [Line Items]
Amounts received/invoiced	146,533
Revenue recognized	(114,109)
Ending balance	32,424
Takeda Collaboration Agreement
Collaborations And License Agreement [Line Items]
Beginning balance	13,762
Amounts received/invoiced	2,165	45,000
Revenue recognized	(6,332)	(31,238)
Ending balance	$ 9,595	$ 13,762

Composition of Certain Balance Sheet Components

9 Months Ended

Sep. 30, 2022

Balance Sheet Related Disclosures [Abstract]

Composition of Certain Balance Sheet Components

Note 3. Composition of Certain Balance Sheet Components

Property and equipment, net

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

	September 30, 2022			December 31, 2021
Laboratory equipment	$	17,312		$	14,192
Leasehold improvements		14,007			13,910
Computer equipment and software		2,263			2,137
Furniture, fixtures and other		997			948
Total property and equipment		34,579			31,187
Less: Accumulated depreciation and amortization		(12,831	)		(9,137	)
Total property and equipment, net	$	21,748		$	22,050

Depreciation and amortization expense associated with property and equipment was $1.4 million and $3.8 million for the three and nine months ended September 30, 2022, respectively and $1.2 million and $3.4 million for the three and nine months ended September 30, 2021, respectively.

Accrued expenses and other liabilities

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

	September 30, 2022		December 31, 2021
Contract research services	$	11,094	$	12,292
Payroll and related expense		7,504		8,760
Other		3,475		2,488
Total accrued expenses and other liabilities	$	22,073	$	23,540

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Note 2. Summary of Significant Accounting Policies

Use of Estimates

The preparation of consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, which include, but are not limited to, estimates related to revenue, accrued expenses, research and development expenses, stock-based compensation expense and deferred tax valuation allowances. The Company bases its estimates on historical experience and other market-specific or relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions.

Fair Value Measurements

Certain financial instruments are required to be recorded at fair value. Other financial instruments, like cash are recorded at cost, which approximates fair value. Cash equivalents and short-term investments are comprised of available-for-sale securities, which are carried at fair value. Additionally, carrying amounts of accounts receivable, accounts payable and accrued liabilities approximate fair value because of the short maturity of those instruments. The carrying value of the Company’s term debt approximates its fair value due to its variable interest rate, which approximates a market interest rate.

Concentration of Business Risk

The Company operates in one reportable business segment and has two customers. The Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and materials for its development programs. These programs could be adversely affected by a significant interruption in these manufacturing services.

Leases

The Company accounts for leases in accordance with Accounting Standards Codification Topic 842, Leases, (“ASC 842”). The Company determines if an arrangement is a lease at contract inception. A lease exists when a contract conveys the right to control the use of identified property, plant, or equipment for a period of time in exchange for consideration. The definition of a lease embodies two conditions: (1) there is an identified asset in the contract that is land or a depreciable asset (i.e., property, plant, and equipment), and (2) the Company has the right to control the use of the identified asset.

Operating leases where the Company is the lessee are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, current and operating lease liabilities, non-current on its condensed consolidated balance sheets. The lease liabilities are initially and subsequently measured at the present value of the unpaid lease payments at the lease commencement date.

ASC 842 requires a lessee to discount its unpaid lease payments using the interest rate implicit in the lease or, if that rate cannot be readily determined, its incremental borrowing rate. The rates implicit in the Company’s leases are not known, therefore, the incremental borrowing rate is used based on the information available at commencement date in determining the present value of lease payments. The Company’s incremental borrowing rate for a lease is the rate of interest it would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms.

The lease term for all of the Company’s leases includes the noncancelable period of the lease. Where the Company’s lease term is impacted by options to extend or terminate the lease, when it is reasonably certain that it will exercise such option, then the lease payments are included in the measurement of the lease asset or liability.

The Company has elected not to recognize ROU assets and lease liabilities for all short-term leases that have a lease term of 12 months or less. The Company recognizes the lease payments associated with its short-term leases as an expense on a straight-line basis over the lease term. There are no variable lease payments associated with these leases. Additionally, the Company has elected to account for the lease and non-lease components together as a single lease component for its real estate asset class.

Revenue Recognition

The Company’s revenues to date have been generated primarily through collaboration and license agreements. The Company’s collaboration and license agreements may contain multiple elements including intellectual property licenses and research, and development services. Consideration the Company receives under these arrangements may include upfront payments, research and development funding, cost reimbursements, research, development, regulatory and commercial milestone payments, and royalty payments.

The Company applies Accounting Standard Codification Topic 606, Revenue from Contracts with Customers (“ASC 606”), issued by the Financial Accounting Standards Board (“FASB”) to account for its contracts with customers. Under ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration that the Company expects to be entitled to receive in exchange for these services and excludes sales incentives and amounts collected on behalf of third parties. The Company analyzes the nature of these performance obligations in the context of individual collaboration and license agreements in order to assess the distinct performance obligations. The Company evaluates its contracts with customers for proper classification in the consolidated statements of operations based on the nature of the underlying activity. Transactions with customers recorded in the Company’s consolidated statements of operations are recorded on either a gross or net basis, depending on the characteristics of the collaborative relationship.

To determine revenue recognition for arrangements within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. The Company allocates the transaction price to individual performance obligations on their relative standalone selling price basis. Standalone selling prices are based on observable prices at which the Company separately sells the products or services. If a standalone selling price is not directly observable, then the Company estimates the standalone selling price considering market conditions and entity-specific factors including, but not limited to, features and functionality of the products and services.

The Company receives payments from its collaborators based on terms established in each contract. Upfront payments and other payments may require deferral of revenue recognition to a future period until the Company satisfies its performance obligations under the contract.

Accounts Receivable and Allowance for Credit Losses

Accounts receivable primarily consist of amounts due from customers for services and payments due based on contractual terms. Accounts receivable are recorded when the right to consideration becomes unconditional. For research and development services, the Company generally bills its customers monthly or quarterly as the services are performed. Payment terms on invoiced amounts are typically 30 - 60 days. The Company recognizes estimated allowance for credit losses based on an assessment of a customer’s ability to pay, credit quality of the customer, age of receivable balances and current economic conditions. As of September 30, 2022 and December 31, 2021, the Company recorded no allowance for credit losses.

Comprehensive Income (Loss)

Comprehensive income (loss) is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on short-term investments. Comprehensive gains (losses) have been reflected in the unaudited condensed consolidated statements of operations and comprehensive income (loss) for all periods presented.

Emerging Growth Company Status

The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably

opts out of the extended transition period provided in the JOBS Act. As a result, these condensed consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.

Recently Adopted Accounting Pronouncements

In May 2021, the FASB issued ASU 2021-04, Earnings Per Share (Topic 260), Debt-Modifications and Extinguishments (Subtopic 470-50), Compensation- Stock Compensation (Topic 718), and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40) which provides guidance on modifications or exchanges of a freestanding equity-classified written call option that is not within the scope of another Topic. An entity should treat a modification of the terms or conditions or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange as an exchange of the original instrument for a new instrument ASU 2021-04 also provides further guidance on measuring the effect of a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange. ASU 2021-04 also provides guidance on the recognition of the effect of a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange on the basis of the substance of the transaction, in the same manner as if cash had been paid as consideration. The Company adopted ASU 2021-04 on January 1, 2022. The adoption of this standard had no impact on the Company’s condensed consolidated financial statements and disclosures.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments, which established ASC 326, Financial Instruments - Credit Losses. This ASU, along with subsequent amendments, improves financial reporting by requiring timely recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. This guidance will become effective for the Company beginning January 1, 2023, with early adoption permitted. The Company is currently evaluating the potential impact ASU 2016-13 may have on its financial position and results of operations upon adoption but does not expect the adoption will have a material impact on the Company’s consolidated financial statements and disclosures.

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 4,277	$ 4,151	$ 14,378	$ 12,355
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,056	2,049	7,132	5,966
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 2,221	$ 2,102	$ 7,246	$ 6,389

Commitments and Contingencies

9 Months Ended

Sep. 30, 2022

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

Note 11. Commitments and Contingencies

Operating Leases

As of September 30, 2022, the Company had operating leases for manufacturing, laboratory and office space in San Diego, California consisting of approximately 110,000 square feet with remaining lease terms of up to 7.3 years. During the nine months ended September 30, 2022, the Company recorded an ROU asset of $4.4 million and a corresponding lease liability related to a sublease of a laboratory and office space facility, which commenced during the period. Certain of the Company’s manufacturing, laboratory and office space lease agreements include two options to extend the term for a period of five years each. Additionally, the Company had operating leases for dedicated manufacturing suites at its contract manufacturers with remaining lease terms of up to 1.3 years.

During the nine months ended September 30, 2022 and 2021, the Company recognized $5.4 million and $4.7 million, respectively, of operating lease expense, including a $0.6 million impairment of an ROU asset during the nine months ended September 30, 2022. During the nine months ended September 30, 2022, the Company paid $6.1 million for its operating leases. As of September 30, 2022, the weighted-average remaining lease term and weighted-average discount rate for operating leases were 6.5 years and 8.9%, respectively.

As of September 30, 2022, maturities of lease liabilities were as follows (in thousands):

Year ending December 31,
2022 (remaining 3 months)	$	1,729
2023		7,057
2024		6,188
2025		6,374
2026		5,107
Thereafter		16,260
Total future lease payments		42,715
Imputed interest		(10,244	)
Total lease liability balance		32,471
Less current portion of lease liability		6,737
Lease liability, net of current portion	$	25,734

Indemnification Agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, contract research organizations, business partners and other parties with respect to certain matters including, but not limited to, losses arising from breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and certain of its executive 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. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. The Company has not incurred any material costs as a result of such indemnifications and is not currently aware of any indemnification claims.

Legal Contingencies

In the ordinary course of business, the Company may face claims brought by third parties against the Company. The Company believes that there are currently no lawsuits, threats of litigation, or asserted or unasserted claims pending that could, individually or in the aggregate, have a material adverse effect on the Company’s results of operations or financial condition.

Term Debt - Additional Information (Details) $ in Millions	1 Months Ended	9 Months Ended
Term Debt - Additional Information (Details) $ in Millions	Feb. 28, 2022 USD ($) Month	Sep. 30, 2022 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Debt issuance costs		$ 1.8
Debt instrument final payment fee accrued		$ 2.0
Capital stock in excess	$ 0.3
2022 Loan Agreement
Debt Instrument [Line Items]
Debt instrument maturity date	Feb. 01, 2027
2022 Loan Agreement \| Oxford
Debt Instrument [Line Items]
Long-term debt	$ 60.0
Long-term debt		In February 2022, the Company entered into a new Loan and Security Agreement (“2022 Loan Agreement”) with Oxford. Pursuant to the terms of the 2022 Loan Agreement, the Company borrowed $60.0 million in term loans (the “Term Loans”), of which $31.6 million was used to repay the balance outstanding under the Amended Loan Agreement, including $0.2 million of accrued interest. Under the 2022 Loan Agreement the interest-only period is through April 1, 2025, followed by 23 equal monthly payments of principal and applicable interest. In September 2022, a qualifying equity event, as defined in the 2022 Loan Agreement, was achieved which extended the interest-only period through April 1, 2026, followed by 11 equal monthly payments of principal and applicable interest. As a result, all amounts outstanding under the 2022 Loan Agreement will mature on February 1, 2027 (the “Maturity Date”).
Debt instrument repayment number of month \| Month	23
Debt instrument repayment additional number of monthly payments due period extension \| Month	11
Amended Loan Agreement
Debt Instrument [Line Items]
Amount used to repay outstanding debt	$ 31.6
Payment of accrued interest	0.2
Debt instrument, fee amount	$ 1.5
Debt issuance costs		$ 1.6
Term A Loan \| Amended Loan Agreement
Debt Instrument [Line Items]
Long-term debt			$ 20.0
Term B Loan \| Amended Loan Agreement
Debt Instrument [Line Items]
Long-term debt			$ 10.0
Term Loans
Debt Instrument [Line Items]
Long-term debt		$ 60.0
Interest rate recognized under effective interest method		12.05%
Term Loans \| 2022 Loan Agreement
Debt Instrument [Line Items]
Debt instrument basis spread on variable rate	7.83%	10.38%
Debt instrument floating per annum rate		30-day U.S. Dollar (USD) LIBOR
Debt instrument interest rate during period	0.11%
Debt instrument, final payment fee percentage	7.50%
Repayment of outstanding debt	$ 5.0
Term Loans \| 2022 Loan Agreement \| Loan Prepayment
Debt Instrument [Line Items]
Debt instrument, final payment fee percentage	1.00%
Debt instrument term loan prepaid Period description		on or prior to February 22, 2024

Collaborations and License Agreements

9 Months Ended

Sep. 30, 2022

Collaborations And License Agreement [Line Items]

Collaboration and License Agreements

Note 7. California Institute of Regenerative Medicine Award

Roche Ltd And Takeda Pharmaceuticals USA Inc.

Collaborations And License Agreement [Line Items]

Collaboration and License Agreements

Note 6. Collaboration and License Agreements

Roche

Terms of the Agreement

In July 2022, the Company entered into a collaboration and license agreement (the “Roche Collaboration Agreement”) with F. Hoffmann-La Roche Ltd and Hoffmann-La Roche Inc. (collectively, “Roche”), pursuant to which the Company granted to Roche: (i) an exclusive, worldwide license under certain Company intellectual property to develop, manufacture and commercialize allogeneic CAR-T cell therapy products from each of the Company’s existing P-BCMA-ALLO1 and P-CD19CD20-ALLO1 programs (each a “Tier 1 Program”); (ii) an exclusive option to acquire an exclusive, worldwide license under certain Company intellectual property to develop, manufacture and commercialize allogeneic CAR-T cell therapy products from each of the Company’s existing P-BCMACD19-ALLO1 and P-CD70-ALLO1 programs (each, a “Tier 2 Program”); (iii) an exclusive license under certain Company intellectual property to develop, manufacture and commercialize allogeneic CAR-T cell therapy products from the up to six Collaboration Programs (as defined below) designated by Roche; (iv) an option for a non-exclusive, commercial license under certain limited Company intellectual property to develop, manufacture and commercialize certain Roche proprietary cell therapy products for up to three solid tumor targets to be identified by Roche (“Licensed Products”); and (v) the right of first offer for two (2) early-stage existing programs within hematologic malignancies. The Roche Collaboration Agreement became effective in September 2022 upon expiration of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended.

For each Tier 1 Program, the Company will perform development activities through a Phase 1 dose escalation clinical trial, and Roche is obligated to reimburse a specified percentage of certain costs incurred by the Company in its performance of such activities, up to a specified reimbursement cap for each Tier 1 Program. For each Tier 2 Program, the Company will perform research and development activities either through selection of a development candidate for IND-enabling studies or, subject to Roche’s election and payment of an option maintenance fee, through completion of a Phase 1 dose escalation clinical trial. In addition, for each Tier 2 Program for which Roche exercises its option for an exclusive license, Roche is obligated to pay an option exercise fee. For each Tier 1 Program and Tier 2 Program, the Company will perform manufacturing activities until the completion of a technology transfer to Roche.

The parties will conduct an initial two-year research program to explore and preclinically test a specified number of agreed-upon next generation therapeutic concepts relating to allogeneic CAR-T cell therapies. Subject to Roche’s election and payment of a specified fee, the parties would subsequently conduct a second research program of 18 months under which the parties would explore and preclinically test a specified number of additional agreed-upon next generation therapeutic concepts relating to allogeneic CAR-T therapies. Roche may designate up to six heme malignancy-directed, allogeneic CAR-T programs from the two research programs, for each of which the Company will perform research and development activities through selection of a development candidate for IND-enabling activities (each, a “Collaboration Program”). Upon its designation of each Collaboration Program, Roche is obligated to pay a designation fee. After the Company’s completion of lead optimization activities for a Collaboration Program, Roche may elect to transition such program to Roche with a payment to the Company or terminate it. Alternatively, Roche may elect, for a limited number of Collaboration Programs, to have the Company conduct certain additional development and manufacturing activities through the completion of a Phase 1 dose escalation clinical trial, in which case Roche will pay certain milestones and reimburse a specified percentage of the Company’s costs incurred in connection with such development

and manufacturing activities. For each Collaboration Program, the Company will perform manufacturing activities until the completion of a technology transfer to Roche.

In consideration for the rights granted to Roche under the Roche Collaboration Agreement, the Company received an upfront payment of $110.0 million. In addition, subject to Roche exercising its Tier 2 Program options, designating Collaboration Programs, and exercising its option for the Licensed Products commercial license and further contingent on, among other things, achieving specified objectives, the Company is eligible to receive up to (i) $1.5 billion in aggregate payments for Tier 1 Programs comprised of research funding, feasibility fees and $1.4 billion in development, regulatory and net sales milestones, (ii) $1.1 billion in aggregate payments for Tier 2 Programs comprised of option exercise and maintenance fees and $1.0 billion in development, regulatory and net sales milestones, (iii) $2.9 billion in aggregate payments for the Collaboration Programs comprised of certain reimbursements, fees and milestone payments; and (iv) $415.0 million in payments for the Licensed Products comprised of certain reimbursements, fees and milestone payments.

The Company is further entitled to receive, on a product-by-product basis, tiered royalty payments in the mid-single to low double digits on net sales of products from the Tier 1 Programs, optioned Tier 2 Programs and Collaboration Programs and in the low to mid-single digits for Licensed Products, in each case, subject to certain customary reductions and offsets. Royalties will be payable, on a product-by-product and country-by-country basis, until the latest of the expiration of the licensed patents covering such product in such country or ten years from first commercial sale of such product in such country.

The Roche Collaboration Agreement will continue in effect on a product-by-product and country-to-country basis until there is no remaining royalty or other payment obligations. The Roche Collaboration Agreement includes standard termination provisions, including for material breach or insolvency and for Roche’s convenience. Certain of these termination rights can be exercised with respect to a particular product or license, as well as with respect to the entire Roche Collaboration Agreement.

Revenue Recognition

At contract inception, the Company has identified six performance obligations under the Roche Collaboration Agreement: (i) licenses associated with the Tier 1 Programs, (ii) research and development efforts for the Tier 1 Programs, (iii) clinical drug supply for the Tier 1 Programs, (iv) manufacturing process development program for the Tier 1 Programs, (v) research and development efforts for the Tier 2 programs, and (vi) research and development efforts for the Collaboration Programs. The Company concluded that Roche’s options within the Roche Collaboration Agreement do not represent material rights and are not considered performance obligations as they do not contain a significant and incremental discount.

In order to determine the transaction price, the Company evaluated all the payments to be received during the term of the Roche Collaboration Agreement. Certain milestones and additional fees were considered variable consideration, which were not included in the initial transaction price based on the most likely amount method. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company determined that the transaction price at the inception of the Roche Collaboration Agreement was $185.0 million, which consists of the upfront payment of $110.0 million, future research funding for the Tier 1 Programs of $40.0 million and a $35.0 million milestone achieved in September 2022 for the Tier 1 Programs. As of September 30, 2022, all other future potential milestone payments were excluded from the estimated total transaction price as they were considered constrained.

The performance obligation associated with the licenses for the Tier 1 Programs was satisfied as of the effective date of the Roche Collaboration Agreement. All other performance obligations will be recognized on a proportional basis as the underlying services are provided based on actual costs incurred as a percentage of total estimated costs. The Company determined that the cost-based input method most faithfully depicts the pattern in which these performance obligations are satisfied. Any cumulative effect of revisions to estimated costs to complete the Company’s performance obligation will be recorded in the period in which changes are identified and amounts can be reasonably estimated. This approach requires the Company to use significant judgement and make estimates of future expenditures. If the Company’s estimates or judgements change over the course of the collaboration, they may affect the timing and amount of revenue that it recognizes in the current and future periods.

Takeda

Terms of the Agreement

In October 2021, the Company entered into a collaboration and license agreement (the “Takeda Collaboration Agreement”) with Takeda Pharmaceuticals USA, Inc. (“Takeda”), pursuant to which the Company granted to Takeda a worldwide exclusive license under the Company’s certain platform technologies including piggyBac, Cas-CLOVER, biodegradable DNA and RNA nanoparticle delivery technology and other proprietary genetic engineering platforms to research, develop, manufacture and commercialize gene therapy products for certain indications, including Hemophilia A. The parties are collaborating to initially develop up to six in vivo gene therapy programs and Takeda also has an option to add two additional programs to the collaboration. The Company is obligated to perform research activities to the extent requested by Takeda up to the candidate selection stage, after which Takeda is obligated to assume responsibility for further development, manufacturing and commercialization of each program.

Under the Takeda Collaboration Agreement, the Company received an upfront payment of $45.0 million, of which $5.0 million represents prepaid research funding. Takeda is obligated to provide funding for all collaboration program development costs; provided that the Company is obligated to perform certain platform development activities at its own cost. Under the Takeda Collaboration Agreement, the Company is eligible to receive preclinical milestone payments that could potentially exceed $82.5 million in the aggregate if preclinical milestones for all six programs are achieved. The Company is also eligible to receive future clinical development, regulatory and commercial milestone payments of $435.0 million in the aggregate per target, with a total potential deal value over the course of the collaboration of up to $2.7 billion, if milestones for all six programs are achieved and up to $3.6 billion if the milestones related to the two optional programs are also achieved. The Company is entitled to receive tiered royalty payments on net sales in the mid-single to low double digits, subject to certain standard reductions and offsets. Royalties will be payable, on a product-by-product and country-by-country basis, until the latest of the expiration of the licensed patents covering such product in such country, ten years from first commercial sale of such product in such country, or expiration of regulatory exclusivity for such product in such country.

Revenue Recognition

The promised goods and services under the Takeda Collaboration Agreement were accounted for as following separate performance obligations: (i) development and commercialization licenses for initial two indications, (ii) separate material rights associated with four additional licenses Takeda has an option to acquire individually, (iii) platform technology enhancement services, and (iv) research and development services.

The Company recognizes revenue from platform technology enhancement services, which are delivered over time, based on the amount of incurred development expenses reimbursed by the customer as a percentage of total expected reimbursable expenses associated with the contract. As of September 30, 2022, all future potential milestone payments were excluded from the estimated total transaction price as they were considered constrained.

There are no contract assets as of September 30, 2022 or December 31, 2021 related to the Roche Collaboration Agreement or Takeda Collaboration Agreement. A reconciliation of the closing balance of deferred revenue related to the agreements is as follows (in thousands):

	Roche Collaboration Agreement			Takeda Collaboration Agreement			Total
Balance as of December 31, 2020	$	—		$	—		$	—
Amounts received/invoiced		—			45,000			45,000
Revenue recognized		—			(31,238	)		(31,238	)
Balance as of December 31, 2021	$	—		$	13,762		$	13,762
Amounts received/invoiced		146,533			2,165			148,698
Revenue recognized		(114,109	)		(6,332	)		(120,441	)
Balance as of September 30, 2022	$	32,424		$	9,595		$	42,019

Nature of Business and Basis of Presentation

9 Months Ended

Sep. 30, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of Business and Basis of Presentation

Note 1. Nature of Business and Basis of Presentation

Nature of Operations

Poseida Therapeutics, Inc. (the “Company” or “Poseida”) is a clinical-stage cell and gene therapy company advancing a new class of treatments for patients with cancer and rare diseases. The Company has discovered and is developing a broad portfolio of product candidates in a variety of indications based on its core proprietary platforms, including the Company’s non-viral piggyBac DNA Delivery System, Cas-CLOVER Site-specific Gene Editing System and nanoparticle- and AAV-based gene delivery technologies.

The Company is subject to risks and uncertainties common to development-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s therapeutic development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales.

Liquidity and Capital Resources

The Company has experienced net losses and negative cash flows from operations since its inception and has relied on its ability to fund its operations primarily through equity and debt financings and strategic collaborations. For the nine months ended September 30, 2022, the Company incurred a net loss of $30.7 million and negative cash flows from operations of $29.2 million. The Company expects to continue to incur net losses and negative cash flows from operations for at least the next several years. As of September 30, 2022, the Company had an accumulated deficit of $437.5 million.

The Company expects that its cash, cash equivalents and short-term investments as of September 30, 2022 of $279.0 million will be sufficient to fund its operations for at least the next twelve months from the date of issuance of these condensed consolidated financial statements. In the long term, the Company will need additional financing to support its continuing operations and pursue its business strategy. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through a combination of equity offerings, debt financings, collaborations, strategic alliances, and licensing arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed on favorable terms or at all. The inability to raise capital as and when needed would have a negative impact on the Company’s financial condition and its ability to pursue its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so.

Basis of Presentation and Consolidation

The accompanying condensed consolidated financial statements reflect the Company’s financial position, results of operations and cash flows, in conformity with generally accepted accounting principles in the United States of America (“GAAP”), for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. The accompanying condensed consolidated financial statements include the accounts of Poseida Therapeutics, Inc. and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. These unaudited condensed consolidated financial statements reflect all adjustments that are, in the opinion of management, necessary to fairly state the financial position and the results of its operations and cash flows for interim periods presented. Interim-period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, as filed with the Securities and Exchange Commission (“SEC”) on March 10, 2022 from which the Company derived its condensed consolidated balance sheet as of December 31, 2021.

Risk and Uncertainties

In March 2020, the World Health Organization made the assessment that a novel strain of coronavirus, SARS-CoV-2, a novel strain of coronavirus, commonly referred to as COVID-19 had become a global pandemic. The impact of this pandemic has been and may continue to be extensive in many aspects of society, which has resulted in and may continue to result in significant disruptions to the global economy, as well as businesses and capital markets around the world.

Impacts to the Company’s business, some of which the Company has experienced to date, include, but are not limited to, temporary closures of its facilities or those of its vendors, disruptions or restrictions on its employees’ ability to travel, disruptions to

or delays in ongoing laboratory experiments, preclinical studies, clinical trials, third-party manufacturing supply and other operations, the diversion of healthcare resources away from the conduct of clinical trials to focus on pandemic concerns, interruptions or delays in the operations of the U.S. Food and Drug Administration (“FDA”) or other regulatory authorities, and the Company’s ability to raise capital and conduct business development activities.

Russia’s invasion of Ukraine and the retaliatory measures that have been taken, or could be taken in the future, by the United States, NATO, and other countries have created global security concerns that could result in a regional conflict and otherwise have a lasting impact on regional and global economies, any or all of which could disrupt the Company’s supply chain and adversely affect its ability to conduct ongoing and future clinical trials of the Company’s product candidates. The extent to which the ongoing conflict ultimately impacts the Company’s business is highly uncertain and cannot be predicted with confidence at this time.

CONSOLIDATED STATEMENTS OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) $ in Thousands	3 Months Ended
	Sep. 30, 2022 USD ($)
Statement Of Stockholders Equity [Abstract]
Public offering, net of issuance costs	$ 5,223

Financial Instruments

9 Months Ended

Sep. 30, 2022

Investments Debt And Equity Securities [Abstract]

Financial Instruments

Note 4. Financial Instruments

The following table summarizes the amortized cost and fair value of securities available-for-sale (in thousands):

	Amortized Cost/Cost		Unrealized Gains		Unrealized Losses			Fair Value
September 30, 2022:
Money market fund	$	37,644	$	—	$	—		$	37,644
U.S. government agency securities and treasuries		114,322		1		(145	)		114,178
Total	$	151,966	$	1	$	(145	)	$	151,822

December 31, 2021:
Money market fund	$	176,102	$	—	$	—		$	176,102
Total	$	176,102	$	—	$	—		$	176,102

No available-for-sale debt securities held as of September 30, 2022 and December 31, 2021 had remaining maturities greater than one year. At September 30, 2022, the Company did not have any securities in material unrealized loss positions.

The Company reviews its investment portfolio to identify and evaluate investments that have an indication of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. The Company does not intend to sell any investments prior to recovery of their amortized cost basis for any investments in an unrealized loss position.

Stock-Based Compensation

9 Months Ended

Sep. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

Note 10. Stock-Based Compensation

In July 2020, the Company’s board of directors and stockholders approved and adopted the 2020 Equity Incentive Plan (the “2020 Plan”). Under the 2020 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other stock or cash-based awards to individuals who are current employees, officers, directors or consultants of the Company. A total of 11,183,476 shares of common stock were approved to be initially reserved for issuance under the 2020 Plan. The number of shares that remained available for issuance under the Company’s previous equity incentive plan as of the effective date of the 2020 Plan and shares subject to outstanding awards under the Company’s previous equity incentive plan as of the effective date of the 2020 Plan that are subsequently canceled, forfeited or repurchased by the Company are added to the shares reserved under the 2020 Plan. The number of shares of common stock available for issuance under the 2020 Plan is automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31 of the preceding calendar year or such lesser amount as determined by the Company’s board of directors.

In February 2022, the Company’s board of directors approved and adopted the 2022 Inducement Plan (the “Inducement Plan”). Under the Inducement Plan, the Company may grant nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards and other awards to individuals not previously employees or non-employee directors of the Company, as an inducement toward entering into employment with the Company. The maximum number of shares of common stock that may be issued under the Inducement Plan is 2,000,000 shares.

The following is a summary of the Company’s stock option activity for the nine months ended September 30, 2022:

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (thousands)
Balance at January 1, 2022		9,899,707		$	9.57
Granted		3,725,101			3.67
Exercised		(94,164	)		1.44
Forfeited/Cancelled		(1,567,282	)		9.12
Balance at September 30, 2022		11,963,362		$	7.85		8.39	$	1,409
Options vested and expected to vest as of September 30, 2022		11,963,362		$	7.85		8.39	$	1,409
Options vested and exercisable as of September 30, 2022		4,720,812		$	9.24		7.70	$	619

The weighted-average grant date fair value of options granted during the nine months ended September 30, 2022 and 2021 was $2.63 and $6.32, respectively. The aggregate intrinsic value of options exercised during the nine months ended September 30, 2022 and 2021 was $0.1 million and $3.2 million, respectively, determined as of the date of exercise. The Company received $0.1 million and $1.7 million in cash from options exercised during the nine months ended September 30, 2022 and 2021, respectively.

As of September 30, 2022, total unrecognized compensation cost related to stock options was $34.0 million, and the weighted-average period over which this cost is expected to be recognized was approximately 2.7 years.

	Nine Months Ended September 30,
	2022		2021
Risk-free interest rate	1.3%–3.4%		0.5%–1.1%
Expected volatility	83.0%–92.2%		82.2%–84.3%
Expected term (years)	3.0–6.0		5.5–6.0
Dividend yield		—		—

The following is a summary of the Company’s restricted stock unit (“RSU”) activity for the nine months ended September 30, 2022:

	Shares			Weighted Average Grant Date Fair Value
Balance at January 1, 2022		—		$	—
Granted		2,594,471			3.67
Vested		—			—
Forfeited/Cancelled		(221,544	)		3.52
Balance at September 30, 2022		2,372,927		$	3.68

RSU awards are share awards that, upon vesting, will deliver to the holder shares of the Company’s common stock. The RSUs vest over four years from the grant date. The grant-date fair value is recognized as compensation expense over the vesting period. As of September 30, 2022, total unrecognized compensation cost related to RSUs was $7.4 million, and the weighted-average period over which this cost is expected to be recognized was approximately 3.3 years.

In July 2020, the Company’s board of directors and stockholders approved and adopted the 2020 Employee Stock Purchase Plan (the “ESPP”), which became effective as of the pricing of the Company’s initial public offering. A total of 615,000 shares of common stock were approved to be initially reserved for issuance under the ESPP. The number of shares of common stock available for issuance under the ESPP is automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lessor of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31 of the preceding calendar year, (ii) 1,230,000 shares of common stock or (iii) such lesser amount as determined by the Company’s board of directors. Under the 2020 ESPP, substantially all employees can elect to have up to 15% of their annual compensation withheld to purchase up to 3,000 shares of common stock per purchase period, subject to certain limitations. The shares of common stock can be purchased over an offering period of six months and at a price of 85% of the fair market value per share of common stock on the first trading day of the applicable offering period or on the exercise date of the applicable offering period, whichever is less. Under applicable accounting guidance, the 2020 ESPP is classified as a compensatory plan. The initial purchase period commenced in March 2021. During the nine months ended September 30, 2022, a total of 328,654 shares were purchased by the Company’s employees under the 2020 ESPP resulting in net proceeds of $1.1 million.

The Company uses the Black-Scholes pricing model to estimate the fair value of the purchase rights issued under the ESPP on each offering date. The assumptions that the Company used to determine the fair value of the purchase rights issued to employees during the nine months ended September 30, 2022 and 2021 were as follows:

	Nine Months Ended September 30,
	2022		2021
Risk-free interest rate	0.6% - 3.9%			0.1	%
Expected volatility	84.4 - 101.5%		74.8 - 87.9%
Expected term (years)		0.5		0.5
Dividend yield		—		—

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	2,056	$	2,049	$	7,132	$	5,966
General and administrative		2,221		2,102		7,246		6,389
Total stock-based compensation expense	$	4,277	$	4,151	$	14,378	$	12,355

Composition of Certain Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense	$ 1,400	$ 1,200	$ 3,817	$ 3,369

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 261,968	$ 6	$ 543,842	$ 5	$ (281,885)
Beginning balance, Shares at Dec. 31, 2020		61,860,897
Issuance of common stock under employee stock compensation plans	360		360
Issuance of common stock under employee stock compensation plans, Shares		265,839
Stock-based compensation expense	3,462		3,462
Unrealized gain (loss) on available-for-sale investments	10			10
Net income (loss)	(38,314)				(38,314)
Ending balance at Mar. 31, 2021	227,486	$ 6	547,664	15	(320,199)
Ending balance, Shares at Mar. 31, 2021		62,126,736
Beginning balance at Dec. 31, 2020	261,968	$ 6	543,842	5	(281,885)
Beginning balance, Shares at Dec. 31, 2020		61,860,897
Unrealized gain (loss) on available-for-sale investments	(5)
Net income (loss)	(126,443)
Ending balance at Sep. 30, 2021	150,157	$ 6	558,479		(408,328)
Ending balance, Shares at Sep. 30, 2021		62,469,819
Beginning balance at Mar. 31, 2021	227,486	$ 6	547,664	15	(320,199)
Beginning balance, Shares at Mar. 31, 2021		62,126,736
Issuance of common stock under employee stock compensation plans	67		67
Issuance of common stock under employee stock compensation plans, Shares		39,431
Stock-based compensation expense	4,742		4,742
Unrealized gain (loss) on available-for-sale investments	(14)			(14)
Net income (loss)	(45,705)				(45,705)
Ending balance at Jun. 30, 2021	186,576	$ 6	552,473	1	(365,904)
Ending balance, Shares at Jun. 30, 2021		62,166,167
Issuance of common stock under employee stock compensation plans	1,855		1,855
Issuance of common stock under employee stock compensation plans, Shares		303,652
Stock-based compensation expense	4,151		4,151
Unrealized gain (loss) on available-for-sale investments	(1)			(1)
Net income (loss)	(42,424)				(42,424)
Ending balance at Sep. 30, 2021	150,157	$ 6	558,479		(408,328)
Ending balance, Shares at Sep. 30, 2021		62,469,819
Beginning balance at Dec. 31, 2021	156,211	$ 6	563,064		(406,859)
Beginning balance, Shares at Dec. 31, 2021		62,523,596
Issuance of common stock under employee stock compensation plans	681		681
Issuance of common stock under employee stock compensation plans, Shares		181,130
Stock-based compensation expense	4,867		4,867
Net income (loss)	(58,057)				(58,057)
Ending balance at Mar. 31, 2022	103,702	$ 6	568,612		(464,916)
Ending balance, Shares at Mar. 31, 2022		62,704,726
Beginning balance at Dec. 31, 2021	156,211	$ 6	563,064		(406,859)
Beginning balance, Shares at Dec. 31, 2021		62,523,596
Unrealized gain (loss) on available-for-sale investments	(144)
Net income (loss)	(30,684)
Ending balance at Sep. 30, 2022	216,313	$ 9	653,991	(144)	(437,543)
Ending balance, Shares at Sep. 30, 2022		85,946,414
Beginning balance at Mar. 31, 2022	103,702	$ 6	568,612		(464,916)
Beginning balance, Shares at Mar. 31, 2022		62,704,726
Issuance of common stock under employee stock compensation plans	32		32
Issuance of common stock under employee stock compensation plans, Shares		24,000
Stock-based compensation expense	5,234		5,234
Unrealized gain (loss) on available-for-sale investments	(132)			(132)
Net income (loss)	(43,036)				(43,036)
Ending balance at Jun. 30, 2022	65,800	$ 6	573,878	(132)	(507,952)
Ending balance, Shares at Jun. 30, 2022		62,728,726
Issuance of common stock under employee stock compensation plans	540		540
Issuance of common stock under employee stock compensation plans, Shares		217,688
Issuance of common stock from public offering	75,299	$ 3	75,296
Issuance of common stock from public offering, net of issuance costs, Shares		23,000,000
Stock-based compensation expense	4,277		4,277
Unrealized gain (loss) on available-for-sale investments	(12)			(12)
Net income (loss)	70,409				70,409
Ending balance at Sep. 30, 2022	$ 216,313	$ 9	$ 653,991	$ (144)	$ (437,543)
Ending balance, Shares at Sep. 30, 2022		85,946,414

- Definition

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

+ References

+ Details

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI https://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-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 8: http://www.xbrl.org/2009/role/commonPracticeRef
-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

+ Details

Financial Instruments - Additional Information (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Debt securities, available-for-sale, noncurrent	$ 0	$ 0
Debt securities, available-for-sale, unrealized loss position	$ 0