0000950170-24-123331 | 10-Q | XBRL Viewer

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Strategic Investment	9 Months Ended
Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Strategic Investment	Note 6. Strategic Investment Astellas Terms of the Agreement On August 4, 2023 (the “Signing Date”), the Company entered into a series of agreements (collectively, the “Astellas Strategic Agreements”) with Astellas US, LLC (“Astellas”) as described below. Securities Purchase and Registration Rights Agreement Pursuant to a securities purchase agreement (the “Securities Purchase Agreement”), the Company agreed to issue and sell to Astellas in a private placement (the “Private Placement”) an aggregate of 8,333,333 shares (the “Shares”) of common stock, par value $0.0001 per share, of the Company, at a purchase price of $3.00 per Share, for aggregate gross proceeds of $25.0 million. The Private Placement closed on August 7, 2023 (the “Closing Date”). The Company also entered into a registration rights agreement with Astellas (the “Registration Rights Agreement”), pursuant to which the Company agreed to register the resale by Astellas of the Shares no later than the 250th day after the Closing Date. Strategic Rights Letter Agreement On the Signing Date, the Company also entered into a strategic rights letter agreement (the “Astellas Strategic Rights Letter”) with Astellas, pursuant to which, the Company agreed to the following: (i) grant Astellas the right to an observer seat on the Company’s board of directors, any committee of the Company’s board of directors, and the Company’s scientific advisory board; (ii) for a period of 18 months, grant Astellas a right of notification with respect to a Change in Control (as defined in the Astellas Strategic Rights Letter); (iii) during the period beginning on the Closing Date and ending on the 12-month anniversary of the Closing Date (the “Exclusivity Period”), not to (1) solicit, knowingly encourage, negotiate or otherwise enter into bona fide discussions about a Program Transaction (as defined below) with any third party, (2) provide access to any confidential information of the Company relating to P-MUC1C-ALLO1, the Company’s fully allogeneic CAR-T product candidate for multiple solid tumor indications (the “Program”), for purposes of knowingly facilitating a Program Transaction, or (3) enter into any letter of intent, contract or other commitment for a Program Transaction (a “Program Transaction” being an exclusive or co-exclusive license or co-promote or co-marketing arrangement or granting of commercial rights to sell, promote or market one or more products of the Program for any indication in the world); (iv) provide notice to Astellas (1) if the Company receives a bona fide proposal for a Change in Control transaction from a third party, unless such proposal is rejected by the Company’s board of directors, or (2) of the commencement of a process approved by the Company’s board of directors for a Change in Control, (3) if the Company receives a bona fide proposal for a Program Transaction from a third party unless the proposal is rejected by the Company’s board of directors (a “Program Transaction Proposal”) or, (4) following the Exclusivity Period, the commencement of substantive discussions for a Program Transaction with a third party in connection with a process approved by the Company’s board of directors for a Program Transaction (a “Program Process”). In connection with a notice related to (x) a Program Transaction Proposal, Astellas shall have a right of first refusal to provide a competing proposal that is in aggregate more favorable to the Company than the Program Transaction Proposal, and thereby have a right to negotiate exclusively a possible Program Transaction for a specified period and (y) a Program Process, Astellas shall have a right of first offer to negotiate a Program Transaction for a specified period before the Company engages with any third party in meaningful substantive discussions, in each case, in accordance with the procedures and subject to the conditions set forth in the Astellas Strategic Rights Letter. As partial consideration for the rights granted to Astellas under the Astellas Strategic Rights Letter, Astellas paid the Company a one-time payment in the amount of $25.0 million (the “Upfront Payment”). In connection with a Change in Control transaction or Program Transaction between the Company and Astellas, some, all or none of the Upfront Payment may be offset against payments owed by Astellas in a tiered basis to the Company dependent on certain factors set forth in the Astellas Strategic Rights Letter. The Astellas Strategic Rights Letter shall terminate upon the earliest to occur of (i) the 18-month anniversary of the Closing Date, (ii) such time that Astellas owns fewer than 8,000,000 shares of common stock (subject to adjustment for any stock splits, stock dividends or recapitalizations) and (iii) the consummation of a Change in Control. Revenue Recognition The Securities Purchase Agreement and the Registration Rights Agreement are not within the scope of ASC 606 and were accounted for as an equity issuance with the deemed fair value of the shares issued scoped out of the transaction price. See Note 10 for further detail of the equity issuance. The rights granted under the Astellas Strategic Rights Letter were assessed under ASC 606, as the agreement represents a contract with a customer. The rights were deemed to not transfer any control to Astellas but give Astellas a right in the future, as all or a portion of the Upfront Payment of $25.0 million is creditable to Astellas towards a future potential transaction within the restrictions and time frames specified in the letter. Therefore, the full amount allocated to the rights is treated as a non-refundable payment. The Company recorded the issuance of common stock at its estimated fair value on the date of issuance of $14.4 million, which reflects a discount for the lack of marketability (“DLOM”) of the shares. The DLOM was applied due to the inability to trade the shares until they are registered. The $10.6 million difference between the $25.0 million paid by Astellas for the Securities Purchase Agreement and the fair market value of shares issued was allocated to the rights granted under the Astellas Strategic Rights Letter for a total amount allocable of $35.6 million. The amount will be recognized when the likelihood of Astellas exercising its remaining rights becomes remote, or when the proportionate amount of the tiered creditable amounts expire. The Company recognized $11.9 million and $23.7 million of revenue from the Astellas Strategic Agreements for the three and nine months ended September 30, 2024, respectively. The Company has $11.9 million of deferred revenue on its condensed consolidated balance sheet as of September 30, 2024, expected to be recognized by February 2025.

Strategic Investment

9 Months Ended

Sep. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Strategic Investment

Note 6. Strategic Investment

Astellas

Terms of the Agreement

On August 4, 2023 (the “Signing Date”), the Company entered into a series of agreements (collectively, the “Astellas Strategic Agreements”) with Astellas US, LLC (“Astellas”) as described below.

Securities Purchase and Registration Rights Agreement

Pursuant to a securities purchase agreement (the “Securities Purchase Agreement”), the Company agreed to issue and sell to Astellas in a private placement (the “Private Placement”) an aggregate of 8,333,333 shares (the “Shares”) of common stock, par value $0.0001 per share, of the Company, at a purchase price of $3.00 per Share, for aggregate gross proceeds of $25.0 million. The Private Placement closed on August 7, 2023 (the “Closing Date”).

The Company also entered into a registration rights agreement with Astellas (the “Registration Rights Agreement”), pursuant to which the Company agreed to register the resale by Astellas of the Shares no later than the 250th day after the Closing Date.

Strategic Rights Letter Agreement

On the Signing Date, the Company also entered into a strategic rights letter agreement (the “Astellas Strategic Rights Letter”) with Astellas, pursuant to which, the Company agreed to the following: (i) grant Astellas the right to an observer seat on the Company’s board of directors, any committee of the Company’s board of directors, and the Company’s scientific advisory board; (ii) for a period of 18 months, grant Astellas a right of notification with respect to a Change in Control (as defined in the Astellas Strategic Rights Letter); (iii) during the period beginning on the Closing Date and ending on the 12-month anniversary of the Closing Date (the “Exclusivity Period”), not to (1) solicit, knowingly encourage, negotiate or otherwise enter into bona fide discussions about a Program Transaction (as defined below) with any third party, (2) provide access to any confidential information of the Company relating to P-MUC1C-ALLO1, the Company’s fully allogeneic CAR-T product candidate for multiple solid tumor indications (the “Program”), for purposes of knowingly facilitating a Program Transaction, or (3) enter into any letter of intent, contract or other commitment for a Program Transaction (a “Program Transaction” being an exclusive or co-exclusive license or co-promote or co-marketing arrangement or granting of commercial rights to sell, promote or market one or more products of the Program for any indication in the world); (iv) provide notice to Astellas (1) if the Company receives a bona fide proposal for a Change in Control transaction from a third party, unless such proposal is rejected by the Company’s board of directors, or (2) of the commencement of a process approved by the Company’s board of directors for a Change in Control, (3) if the Company receives a bona fide proposal for a Program Transaction from a third party unless the proposal is rejected by the Company’s board of directors (a “Program Transaction Proposal”) or, (4) following the Exclusivity Period, the commencement of substantive discussions for a Program Transaction with a third party in connection with a process approved by the Company’s board of directors for a Program Transaction (a “Program Process”). In connection with a notice related to (x) a Program Transaction Proposal, Astellas shall have a right of first refusal to provide a competing proposal that is in aggregate more favorable to the Company than the Program Transaction Proposal, and thereby have a right to negotiate exclusively a possible Program Transaction for a specified period and (y) a Program Process, Astellas shall have a right of first offer to negotiate a Program Transaction for a specified period before the Company engages with any third party in meaningful substantive discussions, in each case, in accordance with the procedures and subject to the conditions set forth in the Astellas Strategic Rights Letter.

As partial consideration for the rights granted to Astellas under the Astellas Strategic Rights Letter, Astellas paid the Company a one-time payment in the amount of $25.0 million (the “Upfront Payment”). In connection with a Change in Control transaction or Program Transaction between the Company and Astellas, some, all or none of the Upfront Payment may be offset against payments owed by Astellas in a tiered basis to the Company dependent on certain factors set forth in the Astellas Strategic Rights Letter.

The Astellas Strategic Rights Letter shall terminate upon the earliest to occur of (i) the 18-month anniversary of the Closing Date, (ii) such time that Astellas owns fewer than 8,000,000 shares of common stock (subject to adjustment for any stock splits, stock dividends or recapitalizations) and (iii) the consummation of a Change in Control.

Revenue Recognition

The Securities Purchase Agreement and the Registration Rights Agreement are not within the scope of ASC 606 and were accounted for as an equity issuance with the deemed fair value of the shares issued scoped out of the transaction price. See Note 10 for further detail of the equity issuance. The rights granted under the Astellas Strategic Rights Letter were assessed under ASC 606, as the agreement represents a contract with a customer. The rights were deemed to not transfer any control to Astellas but give Astellas a right in the future, as all or a portion of the Upfront Payment of $25.0 million is creditable to Astellas towards a future potential transaction within the restrictions and time frames specified in the letter. Therefore, the full amount allocated to the rights is treated as a non-refundable payment.

The Company recorded the issuance of common stock at its estimated fair value on the date of issuance of $14.4 million, which reflects a discount for the lack of marketability (“DLOM”) of the shares. The DLOM was applied due to the inability to trade the shares until they are registered. The $10.6 million difference between the $25.0 million paid by Astellas for the Securities Purchase Agreement and the fair market value of shares issued was allocated to the rights granted under the Astellas Strategic Rights Letter for a total amount allocable of $35.6 million. The amount will be recognized when the likelihood of Astellas exercising its remaining rights becomes remote, or when the proportionate amount of the tiered creditable amounts expire.

The Company recognized $11.9 million and $23.7 million of revenue from the Astellas Strategic Agreements for the three and nine months ended September 30, 2024, respectively. The Company has $11.9 million of deferred revenue on its condensed consolidated balance sheet as of September 30, 2024, expected to be recognized by February 2025.

Composition of Certain Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2024

Balance Sheet Related Disclosures [Abstract]

Summary of Property and Equipment Net

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


	September 30,			December 31,
	2024			2023
Laboratory equipment	$	23,487		$	21,271
Leasehold improvements		14,172			14,113
Computer equipment and software		1,355			1,355
Furniture and fixtures		1,204			1,125
Total property and equipment		40,218			37,864
Less: Accumulated depreciation and amortization		(22,852	)		(18,809	)
Total property and equipment, net	$	17,366		$	19,055

Summary of Accrued Expenses and Other Liabilities

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


	September 30,		December 31,
	2024		2023
Contract research services	$	16,054	$	14,621
Payroll and related expense		9,320		13,076
Other		4,340		3,395
Total accrued expenses and other liabilities	$	29,714	$	31,092

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, 2024	Sep. 30, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	23,248,752	19,962,488
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	23,094,747	19,837,783
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
ESPP Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	32,883	3,583

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net loss	$ (35,410)	$ (98,081)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	4,048	4,179
Stock-based compensation	17,971	18,071
Accretion of discount on issued term debt	757	575
Accretion of discount on short-term investments, net	(5,455)	(6,218)
Write off of deferred CIRM grant liability		(3,992)
Changes in operating assets and liabilities:
Accounts receivable	(5,739)	415
Prepaid expenses and other current assets	(159)	1,596
Operating lease right-of-use assets	2,672	2,514
Other long-term assets	176	(30)
Accounts payable	1,930	302
Accrued expenses and other liabilities	(1,943)	(2,563)
Operating lease liabilities	(3,014)	(2,732)
Deferred revenue	37,887	22,541
Net cash provided by (used in) operating activities	13,721	(63,423)
Investing Activities:
Purchases of property and equipment	(1,794)	(2,757)
Purchases of short-term investments	(187,758)	(215,822)
Proceeds from maturities of short-term investments	180,000	210,000
Net cash used in investing activities	(9,552)	(8,579)
Financing Activities:
Proceeds from issuance of common stock under employee stock compensation plans	1,291	1,276
Payment of taxes related to net share settlement of equity awards	(592)	(494)
Proceeds from issuance of common stock through ATM offering, net of issuance costs		928
Proceeds from private placement of common stock		14,417
Net cash provided by financing activities	699	16,127
Net increase (decrease) in cash and cash equivalents	4,868	(55,875)
Cash and cash equivalents at beginning of period	44,472	81,378
Cash and cash equivalents at end of period	49,340	25,503
Non-cash operating, investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued liabilities	585	220
Supplemental disclosure of cash flow information:
Interest paid	$ 6,079	$ 5,786

Net Income (Loss) Per Share

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Net Income (Loss) Per Share

Note 13. 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, common stock options, restricted stock units and common stock from the ESPP, 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 income (loss) per share attributable to common stockholders is the same.

The following table sets forth 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,
	2024		2023			2024			2023
Numerator:
Net income (loss)	$	20,235	$	(31,778	)	$	(35,410	)	$	(98,081	)
Net income (loss) attributable to common stockholders	$	20,235	$	(31,778	)	$	(35,410	)	$	(98,081	)
Denominator:
Denominator for basic net income (loss) per share - weighted-average common stock outstanding		97,160,467		91,898,347			96,716,649			88,321,943
Effect of dilutive securities:
Common stock options		194,627		—			—			—
RSUs		847,279		—			—			—
ESPP shares		17,574		—			—			—
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding		98,219,947		91,898,347			96,716,649			88,321,943
Basic net income (loss) per share	$	0.21	$	(0.35	)	$	(0.37	)	$	(1.11	)
Diluted net income (loss) per share	$	0.21	$	(0.35	)	$	(0.37	)	$	(1.11	)

The Company excluded the following potential shares of common stock, 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,
	2024		2023
Outstanding stock options and RSUs		23,094,747		19,837,783
Warrants to purchase common stock		121,122		121,122
ESPP Shares		32,883		3,583
		23,248,752		19,962,488

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income tax expense	$ 43	$ 107	$ 43	$ 107
Effective tax rate	0.20%		(0.10%)
Federal tax rate			21.00%

- Definition

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

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+ Details

Composition of Certain Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense	$ 1,300	$ 1,400	$ 4,048	$ 4,179

Stockholders' Equity

9 Months Ended

Sep. 30, 2024

Equity [Abstract]

Stockholders' Equity

Note 10. 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

On August 4, 2023, the Company entered into the Securities Purchase Agreement with Astellas, pursuant to which the Company agreed to issue and sell to Astellas in the Private Placement an aggregate of 8,333,333 shares of common stock at a purchase price of $3.00 per Share, for aggregate gross proceeds of $25.0 million. The Private Placement closed on August 7, 2023. The Company recorded the issuance of common stock at its estimated fair value on the date of issuance of $14.4 million, which reflects a DLOM of the shares. The DLOM was applied due to the inability to trade the shares until they are registered. The issuance of the equity shares was recorded upon the delivery of the underlying shares, with the associated fair value recorded within equity on the Company’s condensed consolidated balance sheets.

At the Market Facility

In August 2021, the Company entered into a Controlled Equity OfferingSM Sales Agreement, which was amended and restated in August 2024 (the “Sales Agreement”) with Cantor Fitzgerald & Co. (“Cantor”) to sell shares of common stock, from time to time, through an “at the market offering” program having an aggregate offering price of up to $85.0 million through which Cantor would act as sales agent. During the nine months ended September 30, 2024, the Company did not issue any shares of common stock under the “at the market offering” program. During the nine months ended September 30, 2023, the Company issued and sold an aggregate of 119,000 shares of common stock under the “at the market offering” program at a weighted average price of $8.04 per share for net proceeds of approximately $0.9 million.

- Definition

The entire disclosure for equity.

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+ Details

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, 2024	Dec. 31, 2023
Collaborations And License Agreement [Line Items]
Beginning balance	$ 47,788	$ 41,056
Amounts received/invoiced	163,750	71,435
Revenue recognized	(125,863)	(64,703)
Ending balance	85,675	47,788
Roche Collaboration Agreement
Collaborations And License Agreement [Line Items]
Beginning balance	12,205	31,749
Amounts received/invoiced	113,750	30,741
Revenue recognized	(100,975)	(50,285)
Ending balance	24,980	12,205
Takeda Collaboration Agreement
Collaborations And License Agreement [Line Items]
Beginning balance		9,307
Amounts received/invoiced		5,111
Revenue recognized		(14,418)
Astellas Strategic Rights Letter
Collaborations And License Agreement [Line Items]
Beginning balance	35,583
Amounts received/invoiced		35,583
Revenue recognized	(23,722)
Ending balance	11,861	$ 35,583
Astellas Collaboration Agreement
Collaborations And License Agreement [Line Items]
Amounts received/invoiced	50,000
Revenue recognized	(1,166)
Ending balance	$ 48,834

Collaboration and License Agreements

9 Months Ended

Sep. 30, 2024

Collaborations And License Agreement [Line Items]

Collaboration and License Agreements

Note 8. California Institute of Regenerative Medicine Award

The Company has been awarded funding from the California Institute of Regenerative Medicine (“CIRM”) to develop certain internal programs. Under the terms of the funding, both CIRM and the Company have co-funded 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. As an alternative to revenue sharing, the Company has the option to convert any award to a loan, which such option the Company must exercise on or before ten business days after the U.S. Food and Drug Administration (“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 plus 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 accounts 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 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. In the third quarter of 2023, the Company decided not to pursue additional clinical or other development activities of the P-PSMA-101 program, which resulted in write off of the amount previously included in the deferred CIRM grant liability as the Company no longer intends to repay the award and which amount is included in other income in the accompanying consolidated statement of operations and comprehensive loss.

Roche Ltd And Takeda Pharmaceuticals USA Inc.

Collaborations And License Agreement [Line Items]

Collaboration and License Agreements

Note 7. 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 Tier 1 Program activities beyond the specified reimbursement cap, Roche is obligated to reimburse all costs incurred for the program. For each Tier 2 Program, the Company will perform research and development activities either through selection of a development candidate for Investigational New Drug Application (“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 are conducting 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 could extend the existing work being performed under the initial term, and/or 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.

Effective November 7, 2023, the Roche Collaboration Agreement was amended to, among other things: (i) reallocate certain existing manufacturing-related fees payable to the Company by Roche to add new manufacturing process development and implementation transfer fees for each of our existing Tier 1 Programs; and (ii) reallocate amounts in certain development milestone payments payable to us by Roche at market rates for each Tier 1 Program. The amendment also provided for the ability for the existing two-year research program to be extended for an additional 18 months with the payment of a $15.0 million milestone.

Effective August 14, 2024, the Roche Collaboration Agreement was amended to include additional activities to be conducted by the Company. The additional activities will be funded by Roche with an initial scope that covers expanded Tier 1 Program activities. In addition, the consideration of certain of the Company’s existing performance obligations related to the Tier 1 Programs were modified.

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. The licenses associated with the Tier 1 Programs were delivered at the beginning of the agreement term and deemed capable of being distinct as the Company concluded that Roche has the knowledge and capabilities to continue development work and fully utilize the licenses without the Company’s involvement.

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. In addition, the Company achieved incremental developmental milestones aggregating to $65.0 million through September 30, 2024, of which, $20.0 million was achieved in the third quarter of 2024. In accordance with ASC 606, the Company determined that the achieved milestones represented an increase in the initial transaction price in the form of the receipt of variable consideration that was previously constrained. The Company recognized revenue associated with these milestones in an amount equal to the proportional percentage of the actual costs incurred under the related program since its inception as a percentage of the total costs expected to be incurred over the expected term of the program. The remaining unrecognized revenue associated with these milestones is included within deferred revenue and is being recognized as revenue over the expected term of the related program. All other future potential milestone payments were excluded from the estimated total transaction price as they were considered constrained until the underlying event is attained. The Company also earns variable consideration attributed to development cost reimbursement associated with some of the Company’s research and development efforts. Variable consideration related to development cost reimbursement increases the transaction price for the associated performance obligations and is recognized as the underlying services are provided.

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 judgment and make estimates of future expenditures. If the Company’s estimates or judgments 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. In connection with the August 14, 2024 amendment to the Roche Collaboration Agreement, the Company adjusted the transaction price based on estimated variable consideration of the performance obligations to account for a change in pricing associated with one component of the Tier 1 Program activities. This resulted in an increase in proportional cumulative performance of the underlying performance obligation and recognition of an additional $15.2 million in revenue in the third quarter of 2024.

Astellas

Terms of the Agreement

In April 2024, the Company and Xyphos Biosciences, Inc. (“Xyphos”), a wholly-owned subsidiary of Astellas Pharma Inc., entered into a collaboration and license agreement (the “Astellas Collaboration Agreement”), pursuant to which the Company granted to Xyphos (i) an exclusive license under certain Company intellectual property to conduct activities under two research plans, to create one Company-developed CAR-T construct to form the basis of two convertibleCAR® product candidates targeting solid tumors, which will be generated by using both parties’ platform technology (each a “Research Product”), where each Research Product will bind to a human tumor-associated antigen, and may also bind to a human antigen associated with a tumor microenvironment, (ii) an exclusive license under certain Company intellectual property after certain conditions are satisfied to develop, and commercialize up to two Research Products that have been designated as licensed products following receipt of the applicable IND-enabling data package, and (iii) after certain conditions are satisfied, an exclusive license under certain Company intellectual property to manufacture the products once manufacturing technology transfer has been completed.

For each research plan, the Company will perform research and development activities through the generation of an IND-enabling data package and Xyphos is obligated to fully reimburse the Company for full-time equivalent costs and expenses incurred by the Company in its performance of certain activities, up to an agreed annual cap. Xyphos may request that the Company transfer the manufacturing process for a product to Xyphos, or that, subject to the payment of a fee, the Company manufacture the Allo-T Cells forming part of such product for use in the first Phase 1 trial of such product.

In consideration for the rights granted to Xyphos under the Astellas Collaboration Agreement, the Company received an upfront payment of $50.0 million, $6.0 million of which was advanced for the Company’s costs and expenses for its research and development activities. In addition, the Company could also receive up to $550.0 million in potential development and sales milestone payments and contingency payments. The Company is further entitled to receive, on a product-by-product basis, tiered royalty payments up to the low teens as a percentage of net sales of licensed products. Royalties will be payable, on a product-by-product basis, during the period commencing on the first commercial sale of a product in a country until the latest of (a) the expiration of the licensed patents covering such product in such country, (b) the expiration of regulatory exclusivity for such product in such country and (c) a certain period of time following such first commercial sale of such product in such country.

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

Revenue Recognition

At contract inception, the Company has identified six distinct performance obligations under the Astellas Collaboration Agreement: (i) a material right for the option to obtain a commercial license for the first product candidate, (ii) a material right for the option to obtain a commercial license for the second product candidate, (iii) research and development efforts for the first product candidate, (iv) research and development efforts for the second product candidate, (v) process development and other target agnostic activities to support production of cell manufacturing, and (vi) manufacturing of both product candidates during the research term.

In order to determine the transaction price, the Company evaluated all the payments to be received during the term of the Astellas Collaboration Agreement. The development and sales milestone payments and certain payments were considered variable consideration and 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 Astellas Collaboration Agreement was $63.8 million, which consists of the upfront payment of $50.0 million, which includes the $6.0 million advanced for the Company's costs and expenses for its research and development activities, as well as estimated incremental research and development costs over the duration of the research term of $13.8 million to be reimbursed by Astellas. As a practical alternative to estimating the standalone selling price when the goods or services are both (i) similar to the original goods and services in the contract and (ii) provided in accordance with the terms of the original contract, the Company allocated the total amount of variable consideration expected to be received from the customer to the total goods or services expected to be provided to the customer.

In assessing whether the options under the Astellas Collaboration Agreement represent material rights, the Company considered if there was additional consideration the Company would be entitled to upon the option exercise and the standalone selling price of the underlying goods and services. For the material rights identified as performance obligations above, the Company concluded that each

of the options to obtain commercial licenses provided Astellas with a discount that it otherwise would not have received without entering into the Astellas Collaboration Agreement.

The material rights for the commercial licenses will be recognized upon the first to occur: once the licenses are exercised or once the rights expire, which is estimated to occur at the end of the research term. The remaining performance obligations will be recognized on a proportionate 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 for these performance obligations 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 judgment and make estimates of future expenditures. If the Company’s estimates or judgments 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

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 transposon-based, 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. Under the Takeda Collaboration Agreement, the Company received an upfront payment of $45.0 million and R&D reimbursement payments during the term of the agreement.

On May 31, 2023, the Company received written notice from Takeda of its election to terminate the Takeda Collaboration Agreement, effective July 30, 2023 (the “Termination Date”). Until the Termination Date, the parties performed their respective obligations under the Collaboration Agreement and upon the Termination Date, the Company’s exclusivity obligations under the Collaboration Agreement terminated. In addition, the licenses granted to Takeda by the Company, and the licenses granted to the Company by Takeda to perform research activities under the Collaboration Agreement terminated.

Deferred Revenue Reconciliation

While the Company’s entry into the Astellas Strategic Rights Letter was a strategic investment, for purposes of recognizing the remaining amount, it has been determined to be revenue, and as such, reference to remaining deferred revenue for these agreements is included in the following table. There were no contract assets as of September 30, 2024 related to the Roche Collaboration Agreement, Takeda Collaboration Agreement, Astellas Strategic Rights Letter, or Astellas Collaboration Agreement. A contract asset of $30.0 million for the Roche Collaboration Agreement was netted against deferred revenue for the year ended December 31, 2023. There were no contract assets as of December 31, 2023 related to the Takeda Collaboration Agreement or Astellas Strategic Rights Letter.

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


	Roche Collaboration Agreement			Takeda Collaboration Agreement			Astellas Strategic Rights Letter			Astellas Collaboration Agreement			Total
Balance as of December 31, 2022	$	31,749		$	9,307		$	—		$	—		$	41,056
Amounts received/invoiced		30,741			5,111			35,583			—			71,435
Revenue recognized		(50,285	)		(14,418	)		—			—			(64,703	)
Balance as of December 31, 2023	$	12,205		$	—		$	35,583		$	—		$	47,788
Amounts received/invoiced		113,750			—			—			50,000			163,750
Revenue recognized		(100,975	)		—			(23,722	)		(1,166	)		(125,863	)
Balance as of September 30, 2024	$	24,980		$	—		$	11,861		$	48,834		$	85,675

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, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Net Income (Loss) Attributable to Parent [Abstract]
Net income (loss)	$ 20,235	$ (31,371)	$ (24,274)	$ (31,778)	$ (27,456)	$ (38,847)	$ (35,410)	$ (98,081)
Net income (loss) attributable to common stockholders, Basic	20,235			(31,778)			(35,410)	(98,081)
Net income (loss) attributable to common stockholders, Diluted	$ 20,235			$ (31,778)			$ (35,410)	$ (98,081)
Denominator:
Denominator for basic net income (loss) per share - weighted-average common stock outstanding	97,160,467			91,898,347			96,716,649	88,321,943
Effect of dilutive securities:
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding	98,219,947			91,898,347			96,716,649	88,321,943
Basic net income (loss) per share	$ 0.21			$ (0.35)			$ (0.37)	$ (1.11)
Diluted net income (loss) per share	$ 0.21			$ (0.35)			$ (0.37)	$ (1.11)
Employee Stock Option
Effect of dilutive securities:
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding	194,627
RSUs
Effect of dilutive securities:
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding	847,279
ESPP Shares
Effect of dilutive securities:
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding	17,574

Net Income (Loss) Per Share (Tables)

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

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

The following table sets forth 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,
	2024		2023			2024			2023
Numerator:
Net income (loss)	$	20,235	$	(31,778	)	$	(35,410	)	$	(98,081	)
Net income (loss) attributable to common stockholders	$	20,235	$	(31,778	)	$	(35,410	)	$	(98,081	)
Denominator:
Denominator for basic net income (loss) per share - weighted-average common stock outstanding		97,160,467		91,898,347			96,716,649			88,321,943
Effect of dilutive securities:
Common stock options		194,627		—			—			—
RSUs		847,279		—			—			—
ESPP shares		17,574		—			—			—
Denominator for diluted net income (loss) per share - adjusted weighted-average common stock outstanding		98,219,947		91,898,347			96,716,649			88,321,943
Basic net income (loss) per share	$	0.21	$	(0.35	)	$	(0.37	)	$	(1.11	)
Diluted net income (loss) per share	$	0.21	$	(0.35	)	$	(0.37	)	$	(1.11	)

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


	Nine Months Ended September 30,
	2024		2023
Outstanding stock options and RSUs		23,094,747		19,837,783
Warrants to purchase common stock		121,122		121,122
ESPP Shares		32,883		3,583
		23,248,752		19,962,488

Collaboration and License Agreements (Tables)

9 Months Ended

Sep. 30, 2024

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			Astellas Strategic Rights Letter			Astellas Collaboration Agreement			Total
Balance as of December 31, 2022	$	31,749		$	9,307		$	—		$	—		$	41,056
Amounts received/invoiced		30,741			5,111			35,583			—			71,435
Revenue recognized		(50,285	)		(14,418	)		—			—			(64,703	)
Balance as of December 31, 2023	$	12,205		$	—		$	35,583		$	—		$	47,788
Amounts received/invoiced		113,750			—			—			50,000			163,750
Revenue recognized		(100,975	)		—			(23,722	)		(1,166	)		(125,863	)
Balance as of September 30, 2024	$	24,980		$	—		$	11,861		$	48,834		$	85,675

Nature of Business and Basis of Presentation

9 Months Ended

Sep. 30, 2024

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 therapy and genetic medicines 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 its non-viral, transposon-based DNA delivery system, Cas-CLOVER Site-specific Gene Editing System and nanoparticle-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 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 realize 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, 2024, the Company incurred a net loss of $35.4 million and positive cash flows from operations of $13.7 million. The Company expects it will continue to incur net losses and will incur negative cash flows from operations for at least the next several years. As of September 30, 2024, the Company had an accumulated deficit of $629.7 million.

The Company expects that its cash, cash equivalents and short-term investments as of September 30, 2024 of $230.9 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 subsidiary. 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, 2023, as filed with the Securities and Exchange Commission (“SEC”) on March 7, 2024 from which the Company derived its condensed consolidated balance sheet as of December 31, 2023. We have reclassified certain amounts previously reported in our financial statements to conform to the current presentation.

Risk and Uncertainties

Global events such as the conflict in the Middle East, 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 any such ongoing or future conflict ultimately impacts the Company’s business is highly uncertain and cannot be predicted with confidence at this time.

Stockholders' Equity - Additional Information (Details) - USD ($)		1 Months Ended	9 Months Ended
	Aug. 04, 2023	Aug. 31, 2021	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	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 issuance of common stock through ATM offering, net of issuance costs				$ 928,000
Common stock issued and sold			97,411,571		95,636,553
Common Stock
Class Of Stock [Line Items]
Warrants to purchase stock			93,518
Warrants to purchase stock			$ 4.28
Common Stock \| Astellas \| Securities Purchase Agreement
Class Of Stock [Line Items]
Discount for lack of marketability of shares, at fair value on date of issuance	$ 14,400,000
Common Stock \| 2018 and 2019 Warrants
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
At the Market Facility \| Common Stock \| Sales Agreement \| Cantor Fitzgerald & Co.
Class Of Stock [Line Items]
Proceeds from issuance of common stock through ATM offering, net of issuance costs				$ 900,000
Aggregate offering price		$ 85,000,000
Weighted average price per share				$ 8.04
Common stock issued and sold			0	119,000
Private Placement \| Common Stock \| Astellas \| Securities Purchase Agreement
Class Of Stock [Line Items]
Common stock, par value	$ 0.0001
Sale of common stock under an underwritten public offering	8,333,333
Sale of stock, price per share	$ 3
Proceeds from issuance of common stock through ATM offering, net of issuance costs	$ 25,000,000

Composition of Certain Balance Sheet Components - Summary of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Contract research services	$ 16,054	$ 14,621
Payroll and related expense	9,320	13,076
Other	4,340	3,395
Total accrued expenses and other liabilities	$ 29,714	$ 31,092

California Institute of Regenerative Medicine Award - Additional Information (Details) - CIRM $ in Millions	1 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2024 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%

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [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, 2024:


	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (thousands)
Balance at January 1, 2024		14,909,912		$	6.84
Granted		3,910,132			3.80
Exercised		(39,476	)		2.74
Forfeited/Cancelled		(1,259,350	)		5.46
Balance at September 30, 2024		17,521,218		$	6.27		7.12	$	696
Options vested and expected to vest as of September 30, 2024		17,521,218		$	6.27		7.12	$	696
Options vested and exercisable as of September 30, 2024		10,312,322		$	7.55		6.08	$	500

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

The fair value of options granted is estimated at the date of grant using the Black-Scholes option pricing model. Forfeitures are accounted for as incurred as a reversal of any share-based compensation expense related to options that will not vest. 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,
	2024	2023
Risk-free interest rate	4.0%	4.0%
Expected volatility	80.8%	82.6%
Expected term (years)	5.7	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, 2024:


	Shares			Weighted Average Grant Date Fair Value
Balance at January 1, 2024		4,555,099		$	4.35
Granted		2,808,838			3.51
Vested		(1,318,974	)		4.30
Forfeited/Cancelled		(471,434	)		4.11
Balance at September 30, 2024		5,573,529		$	3.96

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 were as follows:


	Nine Months Ended September 30,
	2024	2023
Risk-free interest rate	4.9%	5.3%
Expected volatility	91.0%	87.1%
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,
	2024		2023		2024		2023
Research and development	$	3,160	$	3,097	$	9,327	$	9,258
General and administrative		1,799		2,020		8,644		8,813
Total stock-based compensation expense	$	4,959	$	5,117	$	17,971	$	18,071

Financial Instruments

9 Months Ended

Sep. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Financial Instruments

Note 4. Financial Instruments

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


	Maturity	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
At September 30, 2024:
Money market funds	1 year or less	$	46,605	$	—	$	—		$	46,605
U.S. government agency securities and treasuries	1 year or less		181,136		377		(1	)		181,512
Total		$	227,741	$	377	$	(1	)	$	228,117

At December 31, 2023:
Money market funds	1 year or less	$	37,590	$	—	$	—		$	37,590
U.S. government agency securities and treasuries	1 year or less		167,604		158		(32	)		167,730
Total		$	205,194	$	158	$	(32	)	$	205,320

The Company has classified all of its short-term investments as available-for-sale as the sale of such securities may be required prior to maturity to implement management strategies, and therefore, they are carried at fair value. No available-for-sale debt securities held as of September 30, 2024 and December 31, 2023, had remaining maturities greater than one year. Unrealized gains and losses on available-for-sale securities are included as a component of comprehensive loss. As of September 30, 2024, none of the Company’s securities were in material unrealized loss positions.

The Company reviews its investment holdings at the end of each reporting period and evaluates any unrealized losses using the expected credit loss model to determine if the unrealized loss is a result of a credit loss or other factors. The Company also evaluates its investment holdings for impairment using a variety of factors including the Company’s intent to sell the underlying securities prior to maturity and whether it is more likely than not that the Company would be required to sell the securities before the recovery of their

amortized basis. As of September 30, 2024, none of the available-for-sale securities have been in an unrealized loss position for greater than 12 months. During the nine months ended September 30, 2024 and 2023, the Company did not recognize any impairment or realized gains or losses on sales of investments, and the Company did not record an allowance for, or recognize, any expected credit losses.

Nature of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (20,235)	$ 31,371	$ 24,274	$ 31,778	$ 27,456	$ 38,847	$ 35,410	$ 98,081
Net cash provided by (used in) operating activities							13,721	$ (63,423)
Accumulated deficit	629,701						629,701		$ 594,291
Cash, cash equivalents and short-term investments	$ 230,900						$ 230,900

- Definition

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

+ References

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+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Stock-Based Compensation - Summary of Restricted Stock Unit (RSU) Activity (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance, Shares \| shares	4,555,099
Granted, Shares \| shares	2,808,838
Vested, Shares \| shares	(1,318,974)
Forfeited/Cancelled, Shares \| shares	(471,434)
Balance, Shares \| shares	5,573,529
Balance, Weighted Average Grant Date Fair Value \| $ / shares	$ 4.35
Granted, Weighted Average Grant Date Fair Value \| $ / shares	3.51
Vested, Weighted Average Grant Date Fair Value \| $ / shares	4.3
Forfeited/Cancelled, Weighted Average Grant Date Fair Value \| $ / shares	4.11
Balance, Weighted Average Grant Date Fair Value \| $ / shares	$ 3.96

Income Taxes

9 Months Ended

Sep. 30, 2024

Income Tax Disclosure [Abstract]

Income Taxes

Note 14. Income Taxes

The Company follows guidance under ASC Topic 740-270 Income Taxes, which requires that an estimated annual effective tax rate is applied to year-to-date ordinary income (loss). At the end of each interim period, the Company estimates the effective tax rate expected to be applicable for the full fiscal year. The tax effect of discrete items is recorded in the quarter in which the discrete events occur.

The Company recorded income tax expense of $43 thousand for the three and nine months ended September 30, 2024, yielding an effective tax rate of 0.2% and (0.1)% for the three and nine months ended September 30, 2024, respectively. These rates differed from the federal tax rate of 21% primarily due to the Company’s inability to benefit from its financial reporting loss for income tax purposes, as well as the limitation on the Company’s 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 tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
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	97,411,571	95,636,553
Common stock, shares outstanding	97,411,571	95,636,553

Commitments and Contingencies - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) ft² Option	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Oct. 31, 2021 ft²
Commitments And Contingencies [Line Items]
Operating leases, number of square feet \| ft²	110,000
ROU asset	$ 19,054		$ 21,726
Lease liability	$ 23,819
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	The lease agreements include two options to extend the term for a period of 5 years each.
Operating lease expense	$ 4,300	$ 4,400
Operating lease, payments	$ 4,600
Operating lease, weighted-average remaining lease term	5 years
Operating lease, weighted -average discount rate	8.90%
Research and Administrative Activities
Commitments And Contingencies [Line Items]
Operating leases, number of square feet \| ft²				23,000
Lease Expires on December 31, 2029
Commitments And Contingencies [Line Items]
Operating leases, number of square feet \| ft²	87,000

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue:
Collaboration revenue	$ 71,748	$ 9,352	$ 125,863	$ 39,708
Operating expenses:
Research and development	41,914	37,482	130,382	114,727
General and administrative	10,092	8,092	32,072	28,576
Total operating expenses	52,006	45,574	162,454	143,303
Income (loss) from operations	19,742	(36,222)	(36,591)	(103,595)
Other income (expense):
Interest expense	(2,295)	(2,236)	(6,807)	(6,404)
Other income, net	2,831	6,787	8,031	12,025
Net income (loss) before income tax	20,278	(31,671)	(35,367)	(97,974)
Income tax expense	(43)	(107)	(43)	(107)
Net income (loss)	20,235	(31,778)	(35,410)	(98,081)
Other comprehensive income (loss):
Unrealized gain (loss) on short-term investments	458	80	250	(51)
Comprehensive income (loss)	$ 20,693	$ (31,698)	$ (35,160)	$ (98,132)
Net income (loss) per share attributable to common stockholders, basic	$ 0.21	$ (0.35)	$ (0.37)	$ (1.11)
Net income (loss) per share attributable to common stockholders, diluted	$ 0.21	$ (0.35)	$ (0.37)	$ (1.11)
Weighted-average number of shares outstanding, basic	97,160,467	91,898,347	96,716,649	88,321,943
Weighted-average number of shares outstanding, diluted	98,219,947	91,898,347	96,716,649	88,321,943
Collaboration Revenue
Revenue:
Collaboration revenue	$ 71,748	$ 9,352	$ 125,863	$ 39,708

Stock-Based Compensation - Schedule of Assumptions Used to Determine the Fair Value of Options Granted (Details)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	4.00%	4.00%
Expected volatility	80.80%	82.60%
Expected term (years)	5 years 8 months 12 days	6 years

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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Reference 24: http://www.xbrl.org/2003/role/disclosureRef
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2024 Customer Segment
Accounting Policies [Abstract]
Number of reportable segment \| Segment	1
Number of customer \| Customer	2

Financial Instruments - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Debt securities, available-for-sale, unrealized loss position	$ 0
Debt securities, available-for-sale, unrealized loss position for greater than 12 months	0
Gain (loss) on sale of investments	0	$ 0
Allowance for credit loss	$ 0	$ 0

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 4,959	$ 5,117	$ 17,971	$ 18,071
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3,160	3,097	9,327	9,258
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,799	$ 2,020	$ 8,644	$ 8,813

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2024	Nov. 01, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
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		97,465,024

Commitments and Contingencies

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Note 12. Commitments and Contingencies

Operating Leases

As of September 30, 2024, the Company had operating leases consisting of approximately 110,000 square feet of manufacturing, laboratory and office space in San Diego, California, including 87,000 square feet under a lease that expires on December 31, 2029, which contains a clinical manufacturing facility adjacent to office and laboratory space. The lease agreements include two options to extend the term for a period of 5 years each.

In October 2021, the Company entered into a sublease agreement for a facility in San Diego, California consisting of approximately 23,000 square feet to be used for research and administrative activities. The lease term commenced in March 2022 and will expire on December 31, 2025.

During the nine months ended September 30, 2024 and 2023, the Company recognized $4.3 million and $4.4 million, respectively, of operating lease expense. During the nine months ended September 30, 2024, the Company paid $4.6 million for its operating leases. As of September 30, 2024, the weighted-average remaining lease term and weighted-average discount rate for operating leases were 5.0 years and 8.9%, respectively.

As of September 30, 2024, maturities of lease liabilities were as follows (in thousands):


Year ending December 31,
2024 (remaining three months)	$	1,564
2025		6,374
2026		5,107
2027		5,260
2028		5,418
Thereafter		5,581
Total future lease payments		29,304
Imputed interest		(5,485	)
Total lease liability balance		23,819
Less current portion of lease liability		6,085
Lease liability, net of current portion	$	17,734

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.

California Institute of Regenerative Medicine Award

9 Months Ended

Sep. 30, 2024

Collaborative Arrangement [Abstract]

Collaboration and License Agreements

Note 8. California Institute of Regenerative Medicine Award

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2024
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Poseida Therapeutics, Inc. (the “Company” or “Poseida”) is a clinical-stage cell therapy and genetic medicines 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 its non-viral, transposon-based DNA delivery system, Cas-CLOVER Site-specific Gene Editing System and nanoparticle-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 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 realize 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 subsidiary. 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, 2023, as filed with the Securities and Exchange Commission (“SEC”) on March 7, 2024 from which the Company derived its condensed consolidated balance sheet as of December 31, 2023. We have reclassified certain amounts previously reported in our financial statements to conform to the current presentation.
Risk and Uncertainties	Risk and Uncertainties Global events such as the conflict in the Middle East, 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 any such ongoing or future 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.
Cash, Cash Equivalents and Short-term Investments	Cash, Cash Equivalents and Short-term Investments The Company considers all highly liquid investments purchased with original final maturities of 90 days or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with financial institutions and marketable securities. Investments with a remaining maturity when purchased of greater than three months are classified as short-term investments in the consolidated balance sheet and consist primarily of U.S. Treasury and other government agency obligations. As the Company’s entire investment portfolio is considered available for use in current operations, the Company classifies all investments as available-for-sale and as current assets, even though the stated maturity date may be one year or more beyond the current consolidated balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary.
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.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to a significant concentration of credit risk, consist primarily of cash and cash equivalents and short-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits and investments are held. The Company invests exclusively in securities issued by the U.S. government or U.S. government agencies, or in money-market funds. The Company maintains an investment policy with investment objectives to preserve principal, achieve liquidity requirements, and safeguard funds. For these reasons, management believes that the Company is not exposed to significant credit risk.
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. 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 and comprehensive loss based on the nature of the underlying activity. Transactions with customers recorded in the Company’s consolidated statements of operations and comprehensive loss 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. For each agreement entered into, including licenses granted upon the exercise of license options, the Company determines the contract term for purposes of applying the requirements of ASC 606. Generally, the Company’s agreements are terminable at the option of the licensee with advance notice. The Company evaluates these termination rights to determine the contract term and whether a substantive termination penalty would be incurred by the licensee upon termination. If the licensee incurs a substantive termination penalty upon termination, the contract term for revenue recognition purposes is generally equal to the stated term of the agreement, which many times is equal to the research term. Alternatively, if the licensee does not incur a substantive termination penalty upon termination, the contract term for revenue recognition purposes may be shorter than the stated term of the agreement, in which case the termination rights may be accounted for as contract renewal options. The determination of whether a substantive termination penalty is associated with the termination rights requires significant judgment. In making this determination, the Company considers, among other things, the nature of the rights that would be returned to the Company upon termination, exclusivity rights, stage of development of the licensed products, payment terms, including the amount and timing of non-refundable or guaranteed payments, and the business purpose of the termination rights granted. If the customer options are determined to represent a material right, the material right is recognized as a separate performance obligation at the outset of the arrangement. The Company allocates the transaction price to material rights based on the standalone selling price. As a practical alternative to estimating the standalone selling price when the goods or services are both (i) similar to the original goods and services in the contract and (ii) provided in accordance with the terms of the original contract, the Company allocates the total amount of consideration expected to be received from the customer to the total goods or services expected to be provided to the customer. 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.
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.

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 20,235	$ (31,371)	$ (24,274)	$ (31,778)	$ (27,456)	$ (38,847)	$ (35,410)	$ (98,081)

- Definition

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

+ References

+ Details

Stock-Based Compensation - Schedule of Assumptions Used to Determine the Fair Value of Purchase Rights Issued Under ESPP (Details)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	4.00%	4.00%
Expected volatility	80.80%	82.60%
Expected term (years)	5 years 8 months 12 days	6 years
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	4.90%	5.30%
Expected volatility	91.00%	87.10%
Expected term (years)	6 months	6 months

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Jul. 31, 2020	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Feb. 28, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted		$ 2.75	$ 3.42
Aggregate intrinsic value of options exercised		$ 35	$ 100
Cash received from options exercised		100	$ 100
Unrecognized compensation cost		$ 20,100
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 6 months
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		2 years 8 months 12 days
Vesting period		4 years
Unrecognized compensation cost		$ 16,800
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				3,517,105	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%
Total shares purchased by employees		568,023
Net proceeds from share purchase by employees		$ 1,200
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

Financial Instruments - Summary of Amortized Cost and Fair Value of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Securities, Amortized Cost	$ 227,741	$ 205,194
Available-for-Sale Securities, Unrealized Gains	377	158
Available-for-Sale Securities , Unrealized Losses	(1)	(32)
Available-for-Sale Securities, Fair Value	$ 228,117	$ 205,320
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Available-for-Sale Securities, Amortized Cost	$ 46,605	$ 37,590
Available-for-Sale Securities, Fair Value	$ 46,605	$ 37,590
U.S. Government Agency Securities and Treasuries
Schedule Of Available For Sale Securities [Line Items]
Maturity	1 year or less	1 year or less
Available-for-Sale Securities, Amortized Cost	$ 181,136	$ 167,604
Available-for-Sale Securities, Unrealized Gains	377	158
Available-for-Sale Securities , Unrealized Losses	(1)	(32)
Available-for-Sale Securities, Fair Value	$ 181,512	$ 167,730

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

Composition of Certain Balance Sheet Components - Summary of Property and Equipment Net (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Total property and equipment	$ 40,218	$ 37,864
Less: Accumulated depreciation and amortization	(22,852)	(18,809)
Total property and equipment, net	17,366	19,055
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	23,487	21,271
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	14,172	14,113
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Total property and equipment	1,355	1,355
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	$ 1,204	$ 1,125

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 49,340	$ 44,472
Short-term investments	181,512	167,730
Accounts receivable	14,749	9,010
Prepaid expenses and other current assets	5,103	5,263
Total current assets	250,704	226,475
Property and equipment, net	17,366	19,055
Operating lease right-of-use assets	19,054	21,726
Intangible assets, net	1,320	1,320
Goodwill	4,228	4,228
Other long-term assets	905	1,081
Total assets	293,577	273,885
Current liabilities:
Accounts payable	5,197	3,267
Accrued expenses and other liabilities	29,714	31,092
Operating lease liabilities, current	6,085	5,951
Deferred revenue, current	37,273	31,008
Total current liabilities	78,269	71,318
Term debt	58,908	58,590
Deferred revenue, noncurrent	48,402	16,780
Operating lease liabilities, non-current	17,734	20,882
Other long-term liabilities	3,053	2,614
Total liabilities	206,366	170,184
Commitments and Contingencies (Note 12)
Stockholders’ equity:
Common stock, $0.0001 par value: 250,000,000 shares authorized at September 30, 2024 and December 31, 2023; 97,411,571 and 95,636,553 shares issued and outstanding at September 30, 2024 and December 31, 2023, respectively	10	10
Additional paid-in capital	716,526	697,856
Accumulated other comprehensive income	376	126
Accumulated deficit	(629,701)	(594,291)
Total stockholders’ equity	87,211	103,701
Total liabilities and stockholders’ equity	$ 293,577	$ 273,885

Term Debt - Additional Information (Details) $ in Millions		1 Months Ended	9 Months Ended
Term Debt - Additional Information (Details) $ in Millions	Jul. 01, 2023	Feb. 28, 2022 USD ($) Months	Sep. 30, 2024 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Debt issuance costs			$ 1.1
Debt instrument final payment fee accrued			3.0
Capital stock in excess		$ 0.3
2022 Loan Agreement
Debt Instrument [Line Items]
Debt instrument maturity date		Feb. 01, 2027
Debt instrument basis spread on variable rate	7.83%
Debt instrument interest rate during period	0.10%
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 initial interest-only period was 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 \| Months		23
Debt instrument repayment additional number of monthly payments due period extension \| Months		11
Amended Loan Agreement
Debt Instrument [Line Items]
Long-term debt				$ 30.0
Amount used to repay outstanding debt		$ 31.6
Payment of accrued interest		0.2
Debt instrument, fee amount		$ 1.5
Debt issuance costs			1.5
Term Loans
Debt Instrument [Line Items]
Long-term debt			$ 60.0
Debt instrument basis spread on variable rate			13.13%
Interest rate recognized under effective interest method			14.61%
Term Loans \| 2022 Loan Agreement
Debt Instrument [Line Items]
Debt instrument basis spread on variable rate	7.94%	7.83%
Debt instrument floating per annum rate	1-Month CME Term Secured Overnight Financing Rate (“SOFR”)	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

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, 2024	Dec. 31, 2023
Assets:
Cash and cash equivalents	$ 49,340	$ 44,472
Recurring Basis \| Level 1
Assets:
Total	228,117	205,320
Recurring Basis \| Level 1 \| U.S. government agency securities and treasuries
Assets:
Total	181,512	167,730
Recurring Basis \| Level 1 \| Money Market Funds
Assets:
Cash and cash equivalents	$ 46,605	$ 37,590

Stock-Based Compensation - Summary of the Company's Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares
Share-Based Payment Arrangement [Abstract]
Balance, Shares \| shares	14,909,912
Granted, Shares \| shares	3,910,132
Exercised, Shares \| shares	(39,476)
Forfeited/Cancelled, Shares \| shares	(1,259,350)
Balance, Shares \| shares	17,521,218
Options vested and expected to vest as of September 30, 2024 \| shares	17,521,218
Options vested and exercisable as of September 30, 2024 \| shares	10,312,322
Balance, Weighted Average Exercise Price \| $ / shares	$ 6.84
Options Granted, Weighted Average Exercise Price \| $ / shares	3.8
Exercised, Weighted Average Exercise Price \| $ / shares	2.74
Forfeited/Cancelled, Weighted Average Exercise Price \| $ / shares	5.46
Balance, Weighted Average Exercise Price \| $ / shares	6.27
Options vested and expected to vest as of September 30, 2024 \| $ / shares	6.27
Options vested and exercisable as of September 30, 2024 \| $ / shares	$ 7.55
Balance, Weighted Average Remaining Contractual Term (Years)	7 years 1 month 13 days
Options vested and expected to vest as of September 30, 2024	7 years 1 month 13 days
Options vested and exercisable as of September 30, 2024	6 years 29 days
Balance,Aggregate Intrinsic Value \| $	$ 696
Options vested and expected to vest as of September 30, 2024 \| $	696
Options vested and exercisable as of September 30, 2024 \| $	$ 500

Fair Value Measurement

9 Months Ended

Sep. 30, 2024

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
At September 30, 2024:
Assets:
Money market funds	$	46,605	$	—	$	—
U.S. government agency securities and treasuries		181,512		—		—
Total	$	228,117	$	—	$	—

At December 31, 2023:
Assets:
Money market funds	$	37,590	$	—	$	—
U.S. government agency securities and treasuries		167,730		—		—
Total	$	205,320	$	—	$	—

- 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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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-Name Accounting Standards Codification
-Section 55
-Paragraph 107
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Commitments and Contingencies - Summary of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
2024 (remaining three months)	$ 1,564
2025	6,374
2026	5,107
2027	5,260
2028	5,418
Thereafter	5,581
Total future lease payments	29,304
Imputed interest	(5,485)
Total lease liability balance	23,819
Less current portion of lease liability	6,085	$ 5,951
Lease liability, net of current portion	$ 17,734	$ 20,882

Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2024

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
At September 30, 2024:
Assets:
Money market funds	$	46,605	$	—	$	—
U.S. government agency securities and treasuries		181,512		—		—
Total	$	228,117	$	—	$	—

At December 31, 2023:
Assets:
Money market funds	$	37,590	$	—	$	—
U.S. government agency securities and treasuries		167,730		—		—
Total	$	205,320	$	—	$	—

Strategic Investment - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended		12 Months Ended
	Aug. 04, 2023	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Strategic Investment [Line Items]
Common stock, par value		$ 0.0001	$ 0.0001		$ 0.0001
Aggregate gross proceeds				$ 928
Non-refundable upfront payment	$ 35,600
Revenue recognized			$ (125,863)		$ (64,703)
Astellas
Strategic Investment [Line Items]
Revenue recognized		$ 11,900	23,700
Deferred revenue recognized		$ 11,900	11,900
Securities Purchase Agreement \| Astellas \| Common Stock
Strategic Investment [Line Items]
Discount for lack of marketability of shares, at fair value on date of issuance	$ 14,400
Securities Purchase Agreement \| Astellas \| Private Placement \| Common Stock
Strategic Investment [Line Items]
Sale of stock, number of shares issued	8,333,333
Common stock, par value	$ 0.0001
Sale of stock, price per share	$ 3
Aggregate gross proceeds	$ 25,000
Astellas Strategic Rights Letter Agreement
Strategic Investment [Line Items]
Revenue recognized			$ (23,722)
Astellas Strategic Rights Letter Agreement \| Astellas
Strategic Investment [Line Items]
Proceeds from rights granted	$ 25,000
Maximum number of shares owned at time of termination	8,000,000
Discount for lack of marketability of shares, at fair value on date of issuance	$ 14,400
Proceeds from shares allocated to non-refundable upfront payment	$ 10,600

Collaborations and License Agreements - Additional Information (Details)		1 Months Ended			3 Months Ended		9 Months Ended
	Nov. 07, 2023 USD ($)	Apr. 30, 2024 USD ($) Plan	Jul. 31, 2022 USD ($) Program PerformanceObligation	Oct. 31, 2021 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Collaborations And License Agreement [Line Items]
Additional revenue from performance obligation					$ 71,748,000	$ 9,352,000	$ 125,863,000	$ 39,708,000
Roche Collaboration Agreement
Collaborations And License Agreement [Line Items]
Number of collaboration programs \| Program			6
Number of early-stage existing programs \| Program			2
Research collaboration period	2 years		2 years
Research collaboration extension period	18 months		18 months
Upfront cash payment from collaboration agreement			$ 110,000,000
Collaboration revenue receivable terms			10 years
Number of performance obligations \| PerformanceObligation			6
Milestone payments	$ 15,000,000
Contract Assets					0		0
Additional revenue from performance obligation					15,200,000
Roche Collaboration Agreement \| Roche Ltd
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement			$ 110,000,000
Transaction price			185,000,000
Incremental developmental milestones					20,000,000
Incremental developmental milestones aggregate amount					65,000,000		65,000,000
Contract Assets									$ 30,000,000
Roche Collaboration Agreement \| Tier 1 Programs
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable			1,500,000,000
Development, regulatory and net sales milestones			1,400,000,000
Roche Collaboration Agreement \| Tier 1 Programs \| Roche Ltd
Collaborations And License Agreement [Line Items]
Future research funding			40,000,000
Milestone payments			35,000,000.0
Roche Collaboration Agreement \| Tier 2 Programs
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable			1,100,000,000
Development, regulatory and net sales milestones			1,000,000,000
Roche Collaboration Agreement \| Collaboration Programs
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable			2,900,000,000
Roche Collaboration Agreement \| Licensed Products
Collaborations And License Agreement [Line Items]
Fees and milestone payments receivable			$ 415,000,000
Takeda Collaboration Agreement
Collaborations And License Agreement [Line Items]
Contract Assets					0		0		0
Astellas Strategic Rights Letter
Collaborations And License Agreement [Line Items]
Contract Assets					0		0		$ 0
Collaborative Arrangement \| Takeda Pharmaceuticals USA, Inc.
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement				$ 45,000,000
Astellas Collaboration Agreement
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement		$ 50,000,000
Contract Assets					$ 0		$ 0
Number of research plans \| Plan		2
Astellas Collaboration Agreement \| Research and Development
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement		$ 6,000,000
Astellas Collaboration Agreement \| Maximum
Collaborations And License Agreement [Line Items]
Development, regulatory and net sales milestones		550,000,000
Astellas Collaboration Agreement \| Astellas Pharma Inc.
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement		50,000,000
Transaction price		63,800,000
Research and development costs reimbursed		13,800,000
Astellas Collaboration Agreement \| Astellas Pharma Inc. \| Research and Development
Collaborations And License Agreement [Line Items]
Upfront cash payment from collaboration agreement		$ 6,000,000

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Financial Instruments - (Tables)

9 Months Ended

Sep. 30, 2024

Investments, Debt and Equity Securities [Abstract]

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

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


	Maturity	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
At September 30, 2024:
Money market funds	1 year or less	$	46,605	$	—	$	—		$	46,605
U.S. government agency securities and treasuries	1 year or less		181,136		377		(1	)		181,512
Total		$	227,741	$	377	$	(1	)	$	228,117

At December 31, 2023:
Money market funds	1 year or less	$	37,590	$	—	$	—		$	37,590
U.S. government agency securities and treasuries	1 year or less		167,604		158		(32	)		167,730
Total		$	205,194	$	158	$	(32	)	$	205,320

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-9

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
-Paragraph 2
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

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-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

+ Details

Stock-Based Compensation

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Note 11. Stock-Based Compensation

In July 2020, the Company’s board of directors and stockholders approved and adopted the Company’s 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. Under the Inducement Plan approved in February 2022, the maximum number of shares of common stock initially approved to be issued was 2,000,000 shares. In December 2023, the Compensation Committee of the Company’s board of directors approved an amendment to the Inducement Plan which increased the pool to a maximum of 3,517,105 shares.

Stock Options

The following is a summary of the Company’s stock option activity for the nine months ended September 30, 2024:


	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (thousands)
Balance at January 1, 2024		14,909,912		$	6.84
Granted		3,910,132			3.80
Exercised		(39,476	)		2.74
Forfeited/Cancelled		(1,259,350	)		5.46
Balance at September 30, 2024		17,521,218		$	6.27		7.12	$	696
Options vested and expected to vest as of September 30, 2024		17,521,218		$	6.27		7.12	$	696
Options vested and exercisable as of September 30, 2024		10,312,322		$	7.55		6.08	$	500

The weighted-average grant date fair value of options granted during the nine months ended September 30, 2024 and 2023 was $2.75 and $3.42, respectively. The aggregate intrinsic value of options exercised was $35 thousand and $0.1 million during each of the nine months ended September 30, 2024 and 2023, respectively, determined as of the date of exercise. The Company received $0.1 million in cash from options exercised during each of the nine months ended September 30, 2024 and 2023.

As of September 30, 2024, total unrecognized compensation cost related to stock options was $20.1 million, and the weighted-average period over which this cost is expected to be recognized was approximately 2.5 years.


	Nine Months Ended September 30,
	2024	2023
Risk-free interest rate	4.0%	4.0%
Expected volatility	80.8%	82.6%
Expected term (years)	5.7	6.0
Dividend yield	—	—

Restricted Stock Units

The following is a summary of the Company’s restricted stock unit (“RSU”) activity for the nine months ended September 30, 2024:


	Shares			Weighted Average Grant Date Fair Value
Balance at January 1, 2024		4,555,099		$	4.35
Granted		2,808,838			3.51
Vested		(1,318,974	)		4.30
Forfeited/Cancelled		(471,434	)		4.11
Balance at September 30, 2024		5,573,529		$	3.96

RSU awards are share awards that, upon vesting, will deliver to the holder shares of the Company’s common stock. The RSUs granted to employees and non-employee directors vest up to four years from the grant date. The grant-date fair value is recognized as compensation expense over the vesting period. As of September 30, 2024, total unrecognized compensation cost related to RSUs was $16.8 million, and the weighted-average period over which this cost is expected to be recognized was approximately 2.7 years.

2020 Employee Stock Purchase Plan

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. During the nine months ended September 30, 2024, a total of 568,023 shares were purchased by the Company’s employees under the 2020 ESPP resulting in net proceeds of $1.2 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 were as follows:


	Nine Months Ended September 30,
	2024	2023
Risk-free interest rate	4.9%	5.3%
Expected volatility	91.0%	87.1%
Expected term (years)	0.5	0.5
Dividend yield	—	—


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	3,160	$	3,097	$	9,327	$	9,258
General and administrative		1,799		2,020		8,644		8,813
Total stock-based compensation expense	$	4,959	$	5,117	$	17,971	$	18,071

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Summary of Maturities of Lease Liabilities

As of September 30, 2024, maturities of lease liabilities were as follows (in thousands):


Year ending December 31,
2024 (remaining three months)	$	1,564
2025		6,374
2026		5,107
2027		5,260
2028		5,418
Thereafter		5,581
Total future lease payments		29,304
Imputed interest		(5,485	)
Total lease liability balance		23,819
Less current portion of lease liability		6,085
Lease liability, net of current portion	$	17,734

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	ATM Offering	Private Placement	Common Stock	Common Stock ATM Offering	Common Stock Private Placement	Additional Paid-in Capital	Additional Paid-in Capital ATM Offering	Additional Paid-in Capital Private Placement	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2022	$ 187,595			$ 9			$ 658,596			$ (149)	$ (470,861)
Beginning balance, Shares at Dec. 31, 2022				85,964,161
Issuance of common stock under employee stock compensation plans, net of tax withholdings	258						258
Issuance of common stock under employee stock compensation plans, net of tax withholdings, Shares				675,726
Issuance of common stock, net of issuance cost		$ 928						$ 928
Issuance of common stock, net of issuance cost, Shares					119,000
Stock-based compensation expense	7,480						7,480
Unrealized gain (loss) on available-for-sale securities	151									151
Net income (loss)	(38,847)										(38,847)
Ending balance at Mar. 31, 2023	157,565			$ 9			667,262			2	(509,708)
Ending balance, Shares at Mar. 31, 2023				86,758,887
Beginning balance at Dec. 31, 2022	187,595			$ 9			658,596			(149)	(470,861)
Beginning balance, Shares at Dec. 31, 2022				85,964,161
Unrealized gain (loss) on available-for-sale securities	(51)
Net income (loss)	(98,081)
Ending balance at Sep. 30, 2023	123,660			$ 10			692,792			(200)	(568,942)
Ending balance, Shares at Sep. 30, 2023				95,573,526
Beginning balance at Mar. 31, 2023	157,565			$ 9			667,262			2	(509,708)
Beginning balance, Shares at Mar. 31, 2023				86,758,887
Issuance of common stock under employee stock compensation plans, net of tax withholdings, Shares				119,454
Stock-based compensation expense	5,474						5,474
Unrealized gain (loss) on available-for-sale securities	(282)									(282)
Net income (loss)	(27,456)										(27,456)
Ending balance at Jun. 30, 2023	135,301			$ 9			672,736			(280)	(537,164)
Ending balance, Shares at Jun. 30, 2023				86,878,341
Issuance of common stock under employee stock compensation plans, net of tax withholdings	523						523
Issuance of common stock under employee stock compensation plans, net of tax withholdings, Shares				361,852
Issuance of common stock, net of issuance cost			$ 14,417			$ 1			$ 14,416
Issuance of common stock, net of issuance cost, Shares						8,333,333
Stock-based compensation expense	5,117						5,117
Unrealized gain (loss) on available-for-sale securities	80									80
Net income (loss)	(31,778)										(31,778)
Ending balance at Sep. 30, 2023	123,660			$ 10			692,792			(200)	(568,942)
Ending balance, Shares at Sep. 30, 2023				95,573,526
Beginning balance at Dec. 31, 2023	103,701			$ 10			697,856			126	(594,291)
Beginning balance, Shares at Dec. 31, 2023				95,636,553
Issuance of common stock under employee stock compensation plans, net of tax withholdings	(43)						(43)
Issuance of common stock under employee stock compensation plans, net of tax withholdings, Shares				1,161,456
Stock-based compensation expense	5,383						5,383
Unrealized gain (loss) on available-for-sale securities	(173)									(173)
Net income (loss)	(24,274)										(24,274)
Ending balance at Mar. 31, 2024	84,594			$ 10			703,196			(47)	(618,565)
Ending balance, Shares at Mar. 31, 2024				96,798,009
Beginning balance at Dec. 31, 2023	103,701			$ 10			697,856			126	(594,291)
Beginning balance, Shares at Dec. 31, 2023				95,636,553
Unrealized gain (loss) on available-for-sale securities	250
Net income (loss)	(35,410)
Ending balance at Sep. 30, 2024	87,211			$ 10			716,526			376	(629,701)
Ending balance, Shares at Sep. 30, 2024				97,411,571
Beginning balance at Mar. 31, 2024	84,594			$ 10			703,196			(47)	(618,565)
Beginning balance, Shares at Mar. 31, 2024				96,798,009
Issuance of common stock under employee stock compensation plans, net of tax withholdings, Shares				282,808
Stock-based compensation expense	7,629						7,629
Unrealized gain (loss) on available-for-sale securities	(35)									(35)
Net income (loss)	(31,371)										(31,371)
Ending balance at Jun. 30, 2024	60,817			$ 10			710,825			(82)	(649,936)
Ending balance, Shares at Jun. 30, 2024				97,080,817
Issuance of common stock under employee stock compensation plans, net of tax withholdings	742						742
Issuance of common stock under employee stock compensation plans, net of tax withholdings, Shares				330,754
Stock-based compensation expense	4,959						4,959
Unrealized gain (loss) on available-for-sale securities	458									458
Net income (loss)	20,235										20,235
Ending balance at Sep. 30, 2024	$ 87,211			$ 10			$ 716,526			$ 376	$ (629,701)
Ending balance, Shares at Sep. 30, 2024				97,411,571

- Definition

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

+ References

+ Details

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References + Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

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+ Details

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2024
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. Cash, Cash Equivalents and Short-term Investments The Company considers all highly liquid investments purchased with original final maturities of 90 days or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist of deposits with financial institutions and marketable securities. Investments with a remaining maturity when purchased of greater than three months are classified as short-term investments in the consolidated balance sheet and consist primarily of U.S. Treasury and other government agency obligations. As the Company’s entire investment portfolio is considered available for use in current operations, the Company classifies all investments as available-for-sale and as current assets, even though the stated maturity date may be one year or more beyond the current consolidated balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. 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. Concentration of Credit Risk Financial instruments, which potentially subject the Company to a significant concentration of credit risk, consist primarily of cash and cash equivalents and short-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits and investments are held. The Company invests exclusively in securities issued by the U.S. government or U.S. government agencies, or in money-market funds. The Company maintains an investment policy with investment objectives to preserve principal, achieve liquidity requirements, and safeguard funds. For these reasons, management believes that the Company is not exposed to significant credit risk. 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. 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 and comprehensive loss based on the nature of the underlying activity. Transactions with customers recorded in the Company’s consolidated statements of operations and comprehensive loss 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. For each agreement entered into, including licenses granted upon the exercise of license options, the Company determines the contract term for purposes of applying the requirements of ASC 606. Generally, the Company’s agreements are terminable at the option of the licensee with advance notice. The Company evaluates these termination rights to determine the contract term and whether a substantive termination penalty would be incurred by the licensee upon termination. If the licensee incurs a substantive termination penalty upon termination, the contract term for revenue recognition purposes is generally equal to the stated term of the agreement, which many times is equal to the research term. Alternatively, if the licensee does not incur a substantive termination penalty upon termination, the contract term for revenue recognition purposes may be shorter than the stated term of the agreement, in which case the termination rights may be accounted for as contract renewal options. The determination of whether a substantive termination penalty is associated with the termination rights requires significant judgment. In making this determination, the Company considers, among other things, the nature of the rights that would be returned to the Company upon termination, exclusivity rights, stage of development of the licensed products, payment terms, including the amount and timing of non-refundable or guaranteed payments, and the business purpose of the termination rights granted. If the customer options are determined to represent a material right, the material right is recognized as a separate performance obligation at the outset of the arrangement. The Company allocates the transaction price to material rights based on the standalone selling price. As a practical alternative to estimating the standalone selling price when the goods or services are both (i) similar to the original goods and services in the contract and (ii) provided in accordance with the terms of the original contract, the Company allocates the total amount of consideration expected to be received from the customer to the total goods or services expected to be provided to the customer. 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. 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.

Term Debt

9 Months Ended

Sep. 30, 2024

Debt Instruments [Abstract]

Term Debt

Note 9. 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 a total amount of $30.0 million.

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 initial interest-only period was 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 Amended Loan Agreement loans, or (iii) the prepayment of any Amended Loan Agreement 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 initially bore 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 2022 Loan Agreement included a provision addressing replacement of LIBOR with an alternate benchmark rate, when LIBOR was phased out in June 2023. Effective July 1, 2023, the balance outstanding under the 2022 Loan Agreement bears interest at a floating per annum rate equal to the greater of (a) 7.94% and (b) the sum of (i) the 1-Month CME Term Secured Overnight Financing Rate (“SOFR”) on the last business day of the month that immediately precedes the month in which the interest will accrue, (ii) 0.10% and (iii) 7.83%. The interest rate applicable to the Term Loans as of September 30, 2024 was 13.13% per annum. 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, 2024, there was $60.0 million of the principal balance outstanding under the Term Loans. In connection with the Amended Loan Agreement, the Company previously incurred debt issuance costs of $1.5 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 14.61%. As of September 30, 2024, the balance of the unamortized debt discount was $1.1 million. The balance of the accrued final payment fee was $3.0 million as of September 30, 2024 and is presented within other long-term liabilities 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, with no prepayment penalty.

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, 2024, 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

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+ Details

Composition of Certain Balance Sheet Components

9 Months Ended

Sep. 30, 2024

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,			December 31,
	2024			2023
Laboratory equipment	$	23,487		$	21,271
Leasehold improvements		14,172			14,113
Computer equipment and software		1,355			1,355
Furniture and fixtures		1,204			1,125
Total property and equipment		40,218			37,864
Less: Accumulated depreciation and amortization		(22,852	)		(18,809	)
Total property and equipment, net	$	17,366		$	19,055

Depreciation and amortization expense associated with property and equipment was $1.3 million and $4.0 million for the three and nine months ended September 30, 2024, respectively, and $1.4 million and $4.2 million for the three and nine months ended September 30, 2023, respectively.

Accrued expenses and other liabilities

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


	September 30,		December 31,
	2024		2023
Contract research services	$	16,054	$	14,621
Payroll and related expense		9,320		13,076
Other		4,340		3,395
Total accrued expenses and other liabilities	$	29,714	$	31,092