Galera Therapeutics (GRTX) 10-K 28 Mar 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Mar. 26, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Entity Registrant Name	Galera Therapeutics, Inc.
Entity Central Index Key	0001563577
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Title of 12(b) Security	Common Stock,$0.001 par value per share
Trading Symbol	GRTX
Security Exchange Name	NASDAQ
Entity Shell Company	false
Entity Common Stock Shares Outstanding		54,392,170
Entity File Number	001-39114
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	46-1454898
Entity Address, Address Line One	P.O. Box 134
Entity Address, City or Town	Malvern
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19355
City Area Code	610
Local Phone Number	725-1500
Document Annual Report	true
Document Transition Report	false
Entity Voluntary Filers	No
Document Fiscal Period Focus	FY
Entity Ex Transition Period	true
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction Flag	false
Entity Public Float			$ 129.8
Entity Well-known Seasoned Issuer	No
Auditor Name	KPMG LLP
Auditor Firm ID	185
Auditor Location	Philadelphia, Pennsylvania

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 18,257	$ 4,266
Short-Term Investments	0	27,331
Restricted cash	0	50
Refundable PDUFA fee	0	3,242
Prepaid expenses and other current assets	3,372	3,646
Total current assets	21,629	38,535
Property and equipment, net	71	438
Acquired intangible asset	2,258	2,258
Goodwill	881	881
Right-of-use lease assets	1,212	43
Other assets	90	1,881
Total Assets	26,141	44,036
Current Liabilities:
Accounts payable	1,375	3,581
Accrued expenses	3,449	9,754
Lease liabilities, current	133	44
Total current liabilities	4,957	13,379
Royalty purchase liability	151,049	139,635
Lease liabilities, net of current portion	1,117	0
Deferred tax liability	203	203
Total liabilities	157,326	153,217
Commitments (Note 9)
Stockholders’ Equity:
Preferred stock, $0.001 par value: 10,000,000 shares authorized; no shares issued and outstanding.	0	0
Common stock, $0.001 par value: 200,000,000 shares authorized; 54,392,170 and 28,510,066 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively	54	28
Additional paid-in capital	306,167	269,137
Accumulated other comprehensive loss	0	(22)
Accumulated deficit	(437,406)	(378,324)
Total stockholders’ equity	(131,185)	(109,181)
Total liabilities and stockholders' equity	$ 26,141	$ 44,036

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized (shares)	10,000,000	10,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	54,392,170	28,510,066
Common stock, shares outstanding	54,392,170	28,510,066

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating expenses:
Research and development	$ 24,115	$ 31,012
General and administrative	22,836	20,214
Restructuring costs	2,309	0
Loss from operations	(49,260)	(51,226)
Other income (expenses):
Interest income	1,595	506
Interest expense	(11,414)	(11,571)
Foreign currency loss	(3)	(1)
Loss before income tax benefit	(59,082)	(62,292)
Income tax benefit	0	70
Net loss	$ (59,082)	$ (62,222)
Net loss per share of common stock, basic	$ (1.33)	$ (2.3)
Net loss per share of common stock, diluted	$ (1.33)	$ (2.3)
Weighted-average shares of common stock outstanding, basic	44,549,285	27,086,664
Weighted-average shares of common stock outstanding, diluted	44,549,285	27,086,664

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ (59,082)	$ (62,222)
Unrealized gain (loss) on short-term investments	22	(8)
Comprehensive loss	$ (59,060)	$ (62,230)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (loss)	Accumulated Deficit
Balance at Dec. 31, 2021	$ (58,004)	$ 26	$ 258,086	$ (14)	$ (316,102)
Balance (in shares) at Dec. 31, 2021		26,458,767
Share-based compensation expense	7,164		7,164
Exercise of stock options	81		81
Exercise of stock options, shares		68,526
Sale Of Shares Under Open Market Sale Agrrement Shares		1,982,773
Sale of shares under Open Market Sale Agreement , net	3,808	$ 2	3,806
Unrealized gain (loss) on short-term investments	(8)			(8)
Net Income (Loss)	(62,222)				(62,222)
Balance at Dec. 31, 2022	$ (109,181)	$ 28	269,137	(22)	(378,324)
Balance (in shares) at Dec. 31, 2022	28,510,066	28,510,066
Share-based compensation expense	$ 5,560		5,560
Exercise of stock options	$ 188	$ 1	187
Exercise of stock options, shares	78,600	78,600
Exercise of common stock warrants	$ 2,009	$ 1
Exercise of common stock warrants, Share		1,020,000
Sale of common stock and common stock warrants in registered direct offering, net of issuance costs of $2,403	27,598	$ 14	27,584
Sale of common stock in initial public offering, net of issuance costs, shares		14,320,000
Sale Of Shares Under Open Market Sale Agrrement Shares		10,463,504
Sale of shares under Open Market Sale Agreement , net	1,701	$ 10	1,691
Unrealized gain (loss) on short-term investments	22			22
Net Income (Loss)	(59,082)				(59,082)
Balance at Dec. 31, 2023	$ (131,185)	$ 54	$ 306,167	$ 0	$ (437,406)
Balance (in shares) at Dec. 31, 2023	54,392,170	54,392,170

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Statement of Stockholders' Equity [Abstract]
Sale of common stock in initial public offering, issuance costs	$ 2,403

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating activities:
Net loss	$ (59,082)	$ (62,222)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	259	114
Noncash interest expense	11,414	11,571
Share-based compensation expense	5,560	7,164
Gain on disposal of property and equipment	(72)	0
Deferred tax liability	0	(70)
Changes in operating assets and liabilities:
Refundable PDUFA fee	3,242	(3,242)
Prepaid expenses and other current assets	514	2,529
Other assets	1,932	330
Accounts payable	(2,206)	(1,463)
Accrued expense	(6,305)	2,121
Other liabilities	(104)	(258)
Cash used in operating activities	(44,848)	(43,426)
Investing activities:
Purchases of short-term investments	(22,643)	(59,891)
Proceeds from sales of short-term investments	49,995	83,910
Purchase of property and equipment	(59)	(25)
Cash provided by investing activities	27,293	23,994
Financing activities:
Proceeds from the sale of common stock and common stock warrants in registered direct offering, net of issuance costs	27,598	0
Proceeds from the sale of common stock under the Open Market Sale Agreement, net of issuance costs	1,701	3,808
Proceeds from the exercise of common stock warrants	2,009	0
Proceeds from exercise of stock options	188	81
Cash provided by financing activities	31,496	3,889
Net increase (decrease) in cash, cash equivalents and restricted cash	13,941	(15,543)
Cash, cash equivalents and restricted cash at beginning of year	4,316	19,859
Cash, cash equivalents and restricted cash at end of year	18,257	4,316
Supplemental schedule of non-cash financing activities:
Right-of-use asset obtained in exchange for lease obligation	1,310	0
Sale of property and equipment in exchange for prepaid future services	$ 240	$ 0

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ (59,082)	$ (62,222)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	During the three months ended December 31, 2023 , no director or officer of the Company adopted or terminated a “ Rule 10b5-1 trading arrangement” or “ non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.
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

Organization and description of

Organization and description of business	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and description of business	1. Organization and description of business Galera Therapeutics, Inc. was incorporated as a Delaware corporation on November 19, 2012 (inception) and together with its subsidiaries (the Company, or Galera) is a biopharmaceutical company that was historically focused on developing a pipeline of novel, proprietary therapeutics that have the potential to transform radiotherapy in cancer. The Company's lead product candidate, avasopasem manganese (avasopasem), was being developed for the reduction of severe oral mucositis (SOM) in patients with head and neck cancer (HNC), the reduction of esophagitis in patients with lung cancer, and the reduction of cisplatin-induced kidney damage in patients with cancer. The Company’s second product candidate, rucosopasem manganese (rucosopasem), was in development to augment the anti-cancer efficacy of stereotactic body radiation therapy (SBRT) in patients with non-small cell lung cancer (NSCLC) and locally advanced pancreatic cancer (LAPC). The U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) have granted orphan drug designation and orphan medicinal product designation, respectively, to rucosopasem for the treatment of pancreatic cancer. In August 2023, the Company announced that it had received a Complete Response Letter (CRL) from the FDA regarding the Company’s New Drug Application (NDA) for avasopasem for radiotherapy-induced SOM in patients with HNC undergoing standard-of-care treatment. In the CRL, the FDA communicated that results from an additional clinical trial will be required for resubmission. During the Type A meeting held in September 2023, and in the subsequently received meeting minutes, the FDA reiterated the need for a second Phase 3 trial to support resubmission of the NDA. It is not feasible to conduct an additional trial with the Company’s current resources. In connection with the CRL, the Company wound down its commercial readiness efforts for avasopasem, reduced headcount across several departments and began to pursue strategic alternatives. The reduction in force, which was approved by the Company’s board of directors, reduced the Company’s workforce by 22 employees, or approximately 70 %, as of August 9, 2023 (the Workforce Reduction). The decision was based on cost-reduction initiatives intended to reduce operating expenses. In October 2023, the Company halted its Phase 2b GRECO-2 trial of rucosopasem in patients with LAPC, following a futility analysis of the trial, which indicated that the trial was unlikely to succeed as designed. At the same time, the Company also halted its Phase 1/2 GRECO-1 trial of rucosopasem in patients with NCSLC. In October 2023, the Company also announced that it had engaged Stifel, Nicolaus & Company, Inc. (Stifel), as its financial advisor, to assist in reviewing strategic alternatives with the goal of maximizing value for its stockholders. Such alternatives may include a merger, sale, divestiture of assets, licensing, or other strategic transaction. If the Company is unable to undertake any strategic alternative, it may be required to cease operations altogether. Liquidity The Company has incurred recurring losses and negative cash flows from operations since inception and has an accumulated deficit of $ 437.4 million as of December 31, 2023. The Company expects its existing cash and cash equivalents as of December 31, 2023 will enable the Company to fund its operating expenses and capital expenditure requirements into the second quarter of 2025. The Company’s future capital requirements will depend on the results of its ongoing strategic evaluation. If the Company is unable to undertake any strategic alternative, its board of directors may decide to pursue a dissolution and liquidation of the Company. In December 2020, the Company filed an S-3 registration statement with the Securities and Exchange Commission (SEC) which covered the offering, issuance and sale of up to $ 200.0 million in Company securities, which included an Open Market Sale Agreement with Jefferies LLC (the Sales Agreement) covering the offering, issuance and sale of up to a maximum aggregate offering price of $ 50.0 million of the Company’s common stock, which could be utilized to raise funding for future operating expenses and capital expenditure requirements. During the year ended December 31, 2023 , the Company sold approximately 10.5 million shares of common stock and received net proceeds of $ 1.7 million pursuant to the Sales Agreement. The S-3 expired on December 1, 2023, and therefore no further sales are available under the Sales Agreement. On February 17, 2023, the Company completed a registered direct offering, which resulted in the issuance and sale of 14,320,000 shares of its common stock and warrants to purchase up to 14,320,000 shares of common stock at a combined offering price of $ 2.095 per share and accompanying warrant, generating gross proceeds of $ 30.0 million. The warrants have an exercise price of $ 1.97 per share of common stock, are exercisable immediately following their issuance and will expire five years from the date of issuance. The Company received net proceeds of approximately $ 27.6 million from this offering, after deducting placement agent fees and offering expenses.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. Basis of presentation and significant accounting policies Basis of presentation and consolidation The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (U.S. GAAP). Any reference in these notes to applicable guidance is meant to refer to U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) of the Financial Accounting Standards Board (FASB). The consolidated financial statements include the accounts of Galera Therapeutics, Inc. and its wholly owned subsidiaries, Galera Therapeutics Australia Pty Ltd (Galera Australia) and Galera Labs, LLC. All intercompany accounts and transactions have been eliminated in consolidation. The Company has determined the functional currency of Galera Australia to be the U.S. dollar. The Company records remeasurement gains and losses on monetary assets and liabilities, such as accounts payable, which are not denominated in U.S. dollars in the statements of operations. The Company manages its operations as a single reportable segment for the purposes of assessing performance and making operating decisions. Use of estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are periodically reviewed and the effects of revisions are reflected in the consolidated financial statements in the period they are determined to be necessary. Significant areas that require management’s estimates include the share-based compensation assumptions, royalty purchase liability assumptions and accrued research and development expenses. Fair value of financial instruments Management believes that the carrying amounts of the Company’s financial instruments, including accounts payable and accrued expenses, approximate fair value due to the short-term nature of those instruments. Short-term investments are recorded at their estimated fair value. The royalty purchase liability is accounted for as debt and interest is accreted over the expected repayment period. Based on the outcome from the Company’s discussions with the FDA reiterating the need for an additional Phase 3 trial to support resubmission of the avasopasem NDA, the Company is exploring potential strategic alternatives for the development of avasopasem as it is not feasible to conduct an additional clinical trial with the Company’s current resources. Due to the uncertainty of obtaining regulatory approval and successful commercialization of avasopasem, it is impractical to determine the fair value of the debt. Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations 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 believes it is not exposed to significant risk on its cash and cash equivalents. The Company had no short-term investments as of December 31, 2023. Cash and cash equivalents The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash and cash equivalents as of December 31, 2023 and 2022 consisted of bank deposits, U.S. Treasury obligations and a money market mutual fund invested in U.S. Treasury obligations. Restricted cash Restricted cash represented collateral provided under a commercial credit card agreement entered into with TD Bank, N.A. during July 2022. Restricted cash was $ 50,000 as of December 31, 2022. The Company has recorded this deposit and accumulated interest thereon as restricted cash on its consolidated balance sheet. In October 2023, the commercial credit card agreement was terminated by the Company and the bank removed the restriction on the cash. Refundable PDUFA fee In December 2022, the Company paid a $ 3.2 million Prescription Drug User Fee Act (PDUFA) fee to the FDA in conjunction with the filing of its NDA for avasopasem. The Company requested and was granted a small business waiver of this PDUFA fee from the FDA. The Company received the refund of the PDUFA fee from the FDA in May 2023. Short-term investments Short-term investments consisted of debt securities with a maturity of greater than three months when acquired. The Company classified its short-term investments at the time of purchase as available-for-sale securities. Short-term investments were $ 27.3 million, net of unrealized losses of $ 8,000 , as of December 31, 2022 . Available-for-sale securities are carried at fair value. Unrealized gains and losses on available-for-sale securities are reported in accumulated other comprehensive income (loss), a component of stockholders’ equity (deficit), until realized. The Company had no short-term investments as of December 31, 2023. Property and equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives ranging from three to five years . Leasehold improvements are amortized over the shorter of their economic lives or the remaining lease term. The costs of maintenance and repairs are expensed as incurred. Improvements and betterments that add new functionality or extend the useful life of the asset are capitalized. Impairment of long-lived assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, then an impairment charge is recognized for the amount by which the carrying value of the asset exceeds the estimated fair value of the asset. As of December 31, 2023 , the Company believes that no revision of the remaining useful lives or write-down of long-lived assets is required. Goodwill and acquired intangible asset In November 2012, the Company completed a Series A redeemable convertible preferred stock (Series A) financing with venture capital investors and simultaneously acquired Galera Therapeutics, LLC (LLC), a limited liability company incorporated in Missouri in 2009. LLC was renamed Galera Labs, LLC in January 2013 and operates as a wholly-owned subsidiary of the Company. The Company applied the purchase method of accounting under which the consideration given to the LLC members and noteholders was allocated to the fair value of the net assets assumed from the LLC at the date of the acquisition. The sole intangible asset acquired represented the fair value of in-process research and development (IPR&D) which has been recorded on the accompanying consolidated balance sheets as an indefinite life intangible asset. A deferred tax liability was recorded for the difference between the fair value of the acquired IPR&D and its tax basis of zero which was recognized as goodwill in applying the purchase method of accounting. Intangible assets related to IPR&D are considered indefinite-lived intangible assets and, along with goodwill, are not amortized, but are assessed for impairment annually or more frequently if impairment indicators exist. For those compounds that reach commercialization, the IPR&D assets will be amortized over their estimated useful lives. If the associated research and development effort related to IPR&D is abandoned, the related assets will be written-off and the Company will record a noncash impairment loss on its consolidated statements of operations. For the years ended December 31, 2023 and 2022 , the Company determined that there was no impairment to goodwill or IPR&D. The Company believes it has sufficient future cash flows to support the value of its goodwill and IPR&D. The Company will continue to evaluate its timelines for commercialization and probability of success of development of its IPR&D assets. Further reductions to probabilities of success, decrease in market share, additional development and commercial launch delays, increases in underlying discount rates, or any decision to undertake any strategic alternative that the Company has initiated, have the potential to result in future goodwill or IPR&D impairments. Royalty purchase liability In November 2018, the Company entered into an Amended and Restated Purchase and Sale Agreement (the Royalty Agreement), with Clarus IV Galera Royalty AIV, L.P., Clarus IV-A, L.P., Clarus IV-B, L.P., Clarus IV-C, L.P. and Clarus IV-D, L.P. (collectively, Blackstone or Blackstone Life Sciences). Pursuant to the Royalty Agreement, Blackstone agreed to pay up to $ 80.0 million (the Royalty Purchase Price) in four tranches of $ 20.0 million each upon the achievement of specific Phase 3 clinical trial patient enrollment milestones. The Company received the first tranche of the Royalty Purchase Price in November 2018, the second tranche of the Royalty Purchase Price in April 2019, and the third tranche of the Royalty Purchase Price in February 2020, in each case in connection with the achievement of the first three milestones, respectively. The proceeds received have been recorded as long-term debt obligations. Interest expense on such obligation is imputed by estimating risk adjusted future royalty payments over the term of the Royalty Agreement which takes into consideration the probability of obtaining FDA approval. Other significant assumptions include adjustments to estimated gross revenues to arrive at net product sales from which a royalty payment can be estimated. The non-cash interest expense recorded increases the balance of the royalty obligation. The royalty obligation will be reduced when royalty payments are made, if any. In May 2020, the Company entered into Amendment No. 1 to the Royalty Agreement (the Amendment) with Clarus IV Galera Royalty AIV, L.P. (the Blackstone Purchaser). The Blackstone Purchaser is affiliated with Blackstone Life Sciences, the successor in interest to Clarus Ventures. The Amendment increased the Royalty Purchase Price by $ 37.5 million to $ 117.5 million, by increasing the fourth tranche from $ 20.0 million to $ 37.5 million, which was received in July 2021, and adding a new $ 20.0 million tranche upon the achievement of an additional clinical enrollment milestone, which was received in June 2021. The Company accounted for the Amendment as a debt modification and is amortizing fees paid to the Blackstone Purchaser related to the Amendment over the estimated term of the royalty purchase liability utilizing the effective-interest method. Actual royalty payments are highly uncertain and may change depending on a number of factors, including the Company’s ability to obtain FDA approval, successfully commercialize the Company’s product candidates and the timing of future royalty payments. The Company imputes interest expense on the royalty purchase obligations based on such factors at each reporting period. As these factors change, the Company will adjust its estimate of the imputed interest expense accordingly. Given the uncertainty of obtaining future avasopasem revenue based on the FDA reiterating the need for an additional Phase 3 trial for NDA resubmission, the Company’s inability to conduct an additional trial with its current resources, and its focus on exploring strategic alternatives for the development of avasopasem, coupled with the Company’s decision in October 2023 to discontinue its clinical trials of rucosopasem, the Company suspended accreting interest on the royalty purchase liability and amortizing the fees paid to the Blackstone Purchaser related to the Amendment at the end of October 2023. Leases At lease commencement, the Company records a lease liability based on the present value of lease payments over the expected lease term including any options to extend the lease that the Company is reasonably certain to exercise. The Company calculates the present value of lease payments using an incremental borrowing rate as the Company’s leases do not provide an implicit interest rate. The Company’s incremental borrowing rate for a lease is the rate of interest it would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. At the lease commencement date, the Company records a corresponding right-of-use lease asset based on the lease liability, adjusted for any lease incentives received and any initial direct costs paid to the lessor prior to the lease commencement date. The Company may enter into leases with an initial term of 12 months or less (short-term leases). For short-term leases, the Company records the rent expense on a straight-line basis and does not record the leases on the balance sheet. The Company had no short-term leases as of December 31, 2023 and 2022. After lease commencement, the Company measures its leases as follows: (i) the lease liability based on the present value of the remaining lease payments using the discount rate determined at lease commencement, and (ii) the right-of-use lease asset based on the remeasured lease liability, adjusted for any unamortized lease incentives received, any unamortized initial direct costs and the cumulative difference between rent expense and amounts paid under the lease agreement. Any lease incentives received and any initial direct costs are amortized on a straight-line basis over the expected lease term. Rent expense is recorded on a straight-line basis over the expected lease term. Research and development expenses Research and development costs are expensed as incurred and consist primarily of funds paid to third parties for the provision of services for product candidate development, clinical and preclinical development and related supply and manufacturing costs, and regulatory compliance costs. The Company accrues and expenses preclinical studies and clinical trial activities performed by third parties based upon estimates of the proportion of work completed over the term of the individual trial and patient enrollment rates in accordance with agreements with clinical research organizations and clinical trial sites. The Company determines the estimates by reviewing contracts, vendor agreements and purchase orders, and through discussions with internal clinical personnel and external service providers as to the progress or stage of completion of trials or services and the agreed-upon fee to be paid for such services. However, actual costs and timing of clinical trials are highly uncertain, subject to risks and may change depending upon a number of factors, including the Company’s clinical development plan. Management makes estimates of the Company’s accrued expenses as of each balance sheet date in the Company’s consolidated financial statements based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed or services are performed. Share-based compensation The Company measures share-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. Estimating the fair value of share-based awards requires the input of subjective assumptions, including the expected life of the options and stock price volatility. The Company accounts for forfeitures of stock option awards as they occur. The Company uses the Black-Scholes option pricing model to value its stock option awards. The assumptions used in estimating the fair value of share-based awards represent management’s estimate and involve inherent uncertainties and the application of management’s judgment. As a result, if factors change and management uses different assumptions, share-based compensation expense could be materially different for future awards. The expected life of the stock options is estimated using the “simplified method,” as the Company has limited historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses comparable public companies as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option. Employee Benefit Plan The Company sponsors a 401(k) defined contribution plan for its employees. Employee contributions are voluntary. The Company matches employee contributions in an amount equal to 100 % of the first 4 % of eligible compensation, and such employer contributions are immediately vested. During each of the years ended December 31, 2023 and 2022 , the Company provided matching contributions of $ 0.3 million. Income taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, and operating loss and credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes the benefit of an uncertain tax position that it has taken or expects to take on its income tax return if such a position is more likely than not to be sustained. Net loss per share The Company uses the two-class method to compute net income per common share during periods the Company realizes net income and has securities that entitle the holder to participate in dividends and earnings of the Company. The two-class method is not applicable during periods with a net loss, as the participating securities are not obligated to fund losses. Basic loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as stock options and common stock warrants, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: December 31, 2023 2022 Stock options 5,739,488 5,783,185 Common stock warrants 13,850,661 550,661 19,590,149 6,333,846 Recent Accounting Pronouncements In August 2020, FASB issued ASU 2020-06, “Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity,” which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. The ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, and it also simplifies the diluted earnings per share calculation in certain areas. This guidance is effective for fiscal years beginning after December 15, 2023, including interim periods therein. Early adoption is permitted. The Company adopted this ASU on January 1, 2023. There was no impact to the Company's consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In November 2023, FASB issued ASU 2023-07, “Improvements to Reportable Segment Disclosures,” which improves reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The guidance is effective for the Company beginning in the annual reporting period ending December 31, 2024 and interim periods beginning in fiscal year 2025. Early adoption is permitted. The Company is assessing the impact of adopting this guidance on its consolidated financial statements. In December 2023, FASB issued ASU 2023-09, “Improvements to Income Tax Disclosures,” which enhances the transparency and decision usefulness of income tax disclosures. The guidance is effective for the Company’s annual reporting period ending December 31, 2025. Early adoption is permitted. The Company is assessing the impact of adopting this guidance on its consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair value measurements The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines fair value based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels: • Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. • Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. • Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at measurement date. The following table presents the Company’s assets and liabilities that are measured at fair value on a recurring basis (amounts in thousands): December 31, 2023 (Level 1) (Level 2) (Level 3) Assets Money market funds and U.S. Treasury obligations $ 17,964 $ — $ — December 31, 2022 (Level 1) (Level 2) (Level 3) Assets Money market funds and U.S. Treasury obligations $ 3,467 $ — $ — Short-term investments U.S. government agency securities $ — $ 8,172 $ — U.S. Treasury obligations 19,159 — — Total short-term investments $ 19,159 $ 8,172 $ — There were no changes in valuation techniques during the years ended December 31, 2023 and 2022 . The Company’s short-term investment instruments classified using Level 1 inputs within the fair value hierarchy are classified as such because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The fair value of Level 2 securities is estimated based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term on the assets or liabilities.

Prepaid Expenses And Other Curr

Prepaid Expenses And Other Current Assets	12 Months Ended
	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses And Other Current Assets	4. Prepaid expenses and other current assets Prepaid expenses and other current assets consist of (amounts in thousands): December 31, December 31, 2023 2022 Prepaid clinical expenses $ 1,450 $ 1,359 Prepaid insurance 1,302 1,396 Other prepaid expenses and other current assets 620 891 $ 3,372 $ 3,646

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and equipment Property and equipment consist of (amounts in thousands): December 31, December 31, 2023 2022 Laboratory equipment $ — $ 1,398 Computer hardware and software 305 292 Leasehold improvements 46 270 Furniture and fixtures 179 179 Property and equipment, gross 530 2,139 Less: Accumulated depreciation and amortization ( 459 ) ( 1,701 ) Property and equipment, net $ 71 $ 438 Depreciation and amortization expense was $ 0.3 million and $ 0.1 million for the years ended December 31, 2023 and 2022, respectively. In 2023, the Company wrote off $ 0.3 million of leasehold improvements related to the previous office space for which the lease expired in February 2023. In addition, the Company wrote off $ 1.4 million of laboratory equipment that was either sold, exchanged in a barter transaction for future services, or otherwise disposed of in 2023.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued Expenses	6. Accrued expenses Accrued expenses consist of (amounts in thousands): December 31, December 31, 2023 2022 Compensation and related benefits $ 121 $ 2,655 Restructuring costs 443 — Research and development expenses 2,672 6,764 Professional fees and other expenses 213 335 $ 3,449 $ 9,754

Royalty Purchase Liability

Royalty Purchase Liability	12 Months Ended
	Dec. 31, 2023
Royalty Purchase Liability [Abstract]
Royalty Purchase Liability	7. Royalty purchase liability Pursuant to the Royalty Agreement, Blackstone agreed to pay up to $ 80.0 million (the Royalty Purchase Price) in four tranches of $ 20.0 million each upon the achievement of specific Phase 3 clinical trial patient enrollment milestones. The Company received the first tranche of the Royalty Purchase Price in November 2018, the second tranche of the Royalty Purchase Price in April 2019, and the third tranche of the Royalty Purchase Price in February 2020, in each case in connection with the achievement of the first three milestones, respectively. In May 2020, the Company entered into Amendment No. 1 to the Royalty Agreement (the Amendment) with Clarus IV Galera Royalty AIV, L.P. (the Blackstone Purchaser). The Blackstone Purchaser is affiliated with Blackstone Life Sciences, the successor in interest to Clarus Ventures. The Amendment increased the Royalty Purchase Price by $ 37.5 million, to $ 117.5 million by increasing the fourth tranche from $ 20.0 million to $ 37.5 million and adding a new $ 20.0 million tranche upon the achievement of an additional clinical enrollment milestone. The Company accounted for the Amendment as a debt modification and is amortizing fees paid to the Blackstone Purchaser related to the Amendment over the estimated term of the royalty purchase liability utilizing the effective-interest method. In June 2021, the Company received the new tranche ($ 20.0 million) under the Amendment in connection with the enrollment of the first patient in a Phase 2b trial of rucosopasem in combination with SBRT in patients with locally advanced pancreatic cancer, which the Company refers to as the GRECO-2 trial. Also in June 2021, the Company completed enrollment in its ROMAN trial, thereby achieving the milestone associated with the fourth tranche ($ 37.5 million) under the Amendment, which was received in July 2021. The Company accounts for the Royalty Agreement as a debt instrument. The $ 117.5 million in proceeds received as of December 31, 2023 have been recorded as a liability on the accompanying consolidated balance sheets. Interest expense is imputed based on the estimated royalty repayment period described below, which takes into consideration the probability and timing of obtaining FDA approval and the potential future revenue from commercializing its product candidates, and which results in a corresponding increase in the liability balance. The Company updated the assumptions underlying the calculation of interest expense on the royalty purchase liability based on the CRL received from the FDA in August 2023 on the Company's NDA for avasopasem for radiotherapy-induced SOM. The Company recognized $ 11.4 million and $ 11.6 million in noncash interest expense during the years ended December 31, 2023 and 2022, respectively. The Company suspended recognizing interest expense on the royalty purchase liability after October 2023, as the result of the uncertainty of any future royalties following its decision to discontinue the rucosopasem GRECO trials and that it is not feasible with its current resources for the Company to conduct another Phase 3 trial of avasopasem. Pursuant to the Royalty Agreement and the Amendment, in connection with the payment of each tranche of the Royalty Purchase Price, the Company has agreed to sell, convey, transfer and assign to Blackstone all of its right, title and interest in a high single-digit percentage of (i) worldwide net sales of avasopasem and rucosopasem (collectively, the Products) and (ii) all amounts received by the Company or its affiliates, licensees and sublicensees with respect to Product-related damages (collectively, the Product Payments) during the Royalty Period. The Royalty Period means, on a Product-by-Product and country-by-country basis, the period of time commencing on the commercial launch of such Product in such country and ending on the latest to occur of (i) the 12th anniversary of such commercial launch, (ii) the expiration of all valid claims of the Company’s patents covering such Product in such country, and (iii) the expiration of regulatory data protection or market exclusivity or similar regulatory protection afforded by the health authorities in such country, to the extent such protection or exclusivity effectively prevents generic versions of such Product from entering the market in such country. The Royalty Agreement and the Amendment will remain in effect until the date on which the aggregate amount of the Product Payments paid to Blackstone exceeds a fixed single-digit multiple of the actual amount of the Royalty Purchase Price received by the Company, unless earlier terminated pursuant to the mutual written agreement of the Company and Blackstone. If no Products are commercialized, the Company would not have an obligation to make Product Payments to Blackstone, which is the sole mechanism for repaying the liability. Upon execution of the Amendment, the Company issued common stock warrants to the Blackstone Purchaser, each of which became exercisable upon the receipt by the Company of the applicable specified milestone payment. The issued warrants expire six years after the initial exercise dates, as follows: Shares Exercise Price Initial Exercise Date Expiration Date New Milestone Warrant 293,686 $ 13.62 6/7/2021 6/6/2027 Fourth Milestone Warrant 256,975 $ 13.62 7/19/2021 7/18/2027 The warrants are equity-classified and were valued at $ 4.7 million at the time of issuance using the Black-Scholes option pricing model. The warrants were recorded as a discount to the royalty purchase liability. The Company amortizes the debt discount to interest expense over the estimated term of the royalty purchase liability utilizing the effective-interest method. The Company suspended amortizing the debt discount to interest expense after October 2023, as the result of the uncertainty of any future royalties following its decision to discontinue the rucosopasem GRECO trials and that it is not feasible with its current resources for the Company to conduct another Phase 3 trial of avasopasem.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	8. Leases The Company has a non-cancelable operating lease for office and laboratory space in Malvern, Pennsylvania which, as of December 31, 2023 , has a remaining lease term of approximately 6.8 years . The discount rate used to account for the Company’s operating lease is the Company’s estimated incremental borrowing rate of 5.4 %. Supplemental balance sheet information related to leases was as follows: December 31, December 31, 2023 2022 Operating Leases Right-of-use lease assets $ 1,212 $ 43 Lease liabilities, current 133 44 Lease liabilities, net of current portion 1,117 — Total operating lease liabilities $ 1,250 $ 44 The components of lease expense were as follows: Year ended 2023 2022 Operating lease costs Operating lease rental expense $ 191 $ 267 Total operating lease expense $ 191 $ 267 Supplemental cash flow information related to leases was as follows: Year ended 2023 2022 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for operating leases $ 150 $ 266 Right-of-use assets obtained in exchange for lease obligation Operating leases 1,310 — Our operating lease liabilities as of December 31, 2023 will mature, as follows (amounts in thousands): 2024 195 2025 217 2026 220 2027 224 2028 and after 633 Total 1,489 Less: imputed interest ( 239 ) $ 1,250

Commitments

Commitments	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments	9. Commitments Executive employment agreements The Company has entered into employment agreements with certain key executives, providing for compensation and severance in certain circumstances, such as a change in control, as described in the respective agreements. Legal matters The Company is subject from time to time to various claims and legal actions arising during the ordinary course of its business. Management believes that there are currently no claims or legal actions that would reasonably be expected to have a material adverse effect on the Company’s results of operations, financial condition or cash flows.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders' Equity (Deficit)	10. Stockholders' Equity (Deficit) Equity offerings In February 2023, the Company completed a registered direct offering, which resulted in the issuance and sale of 14,320,000 shares of its common stock and warrants to purchase up to 14,320,000 shares of common stock at a combined offering price of $2.095 per share and accompanying warrant, and received net proceeds of $27.6 million after deducting placement agent fees and offering expenses. The warrants are equity-classified, have an exercise price of $1.97 per share of common stock, are exercisable immediately following their issuance, and will expire five years from the date of issuance. In the event the Company’s board of directors approves a fundamental transaction (defined as a merger, sale of substantially all assets, tender offer or share exchange), warrant holders may elect to exercise their warrants and receive cash consideration equal to a Black-Scholes option value, as defined in the warrant agreement, in lieu of other consideration received by the common shareholders. During the year ended December 31, 2023 , warrants were exercised in exchange for 1,020,000 shares of common stock resulting in proceeds of $ 2.0 million. Warrants to purchase up to 13,300,000 shares of common stock remain unexercised as of December 31, 2023. In December 2020, the Company entered into the Sales Agreement with Jefferies LLC (Jefferies) as sales agent, pursuant to which it could, from time to time, issue and sell common stock with an aggregate value of up to $ 50.0 million in “at-the-market” (ATM) offerings under the Company’s Registration Statement on Form S-3 (File No. 333-251061) filed with the SEC on December 1, 2020. Sales of common stock pursuant to the Sales Agreement were made in sales deemed to be an “at the market offering” as defined in Rule 415(a) of the Securities Act, including sales made directly through the Nasdaq Global Market or on any other existing trading market for the Company’s common stock. The Company was required to pay Jefferies a commission equal to three percent of the gross sales proceeds and provided Jefferies with customary indemnification rights. During the years ended December 31, 2023 and 2022 , 10,463,504 and 1,982,773 shares were sold under the Sales Agreement, respectively, at a weighted average price per share of $ 0.20 and $ 2.00 , respectively. Net proceeds to the Company after deducting fees, commissions and other expenses related to the offering were $ 1.7 million and $ 3.8 million, respectively, for the years ended December 31, 2023 and 2022. The S-3 expired on December 1, 2023, and therefore no further sales are available under the Sales Agreement. Share-based compensation Equity Incentive Plan In November 2012, the Company adopted the Galera Therapeutics, Inc. Equity Incentive Plan (the Prior Plan). The Prior Plan provided for the grant of incentive stock options, nonstatutory stock options, restricted stock awards, and stock appreciation rights. In connection with the adoption of the 2019 Plan (as defined below), the Company ceased issuing awards under the Prior Plan. As a result, no shares remain available for issuance under the Prior Plan; however, the Prior Plan continues to govern awards that are outstanding under it. The total number of shares subject to outstanding awards under the Prior Plan as of December 31, 2023 was 1,665,268 . 2019 Incentive Award Plan In connection with the Company’s Initial Public Offering (IPO) in November 2019, the Company’s board of directors adopted and the Company’s stockholders approved the Galera Therapeutics, Inc. 2019 Incentive Award Plan (the 2019 Plan), which became effective upon the effectiveness of the registration statement on Form S-1 for the IPO. Upon effectiveness of the 2019 Plan, the Company ceased granting new awards under the Prior Plan. The 2019 Plan provides for the grant of incentive stock options, nonstatutory stock options, restricted stock awards, restricted stock units, stock appreciation rights and other stock-based awards. The number of shares of common stock initially available for issuance under the 2019 Plan was 1,948,970 shares of common stock plus the number of shares subject to awards outstanding under the Prior Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company on or after the effective date of the 2019 Plan. In addition, the number of shares of common stock available for issuance under the 2019 Plan is subject to an annual increase on the first day of each calendar year beginning on January 1, 2020 and ending on and including January 1, 2029 equal to the lesser of (i) 4 % of the Company’s outstanding shares of common stock on the final day of the immediately preceding calendar year, and (ii) such smaller number of shares of common stock as determined by the Company’s board of directors . As of December 31, 2023 , there were 2,535,043 shares avail able for future issuance under the 2019 Plan, including 1,140,402 shares added pursuant to this provision effective January 1, 2023. Pursuant to this provision, the Company added an additional 2,175,686 shares to the total shares available for issuance under the 2019 Plan effective January 1, 2024. The maximum number of shares of common stock that may be issued under the 2019 Plan upon the exercise of incentive stock options is 14,130,029 . In November 2019, the Company’s board of directors adopted and the Company’s stockholders approved the Galera Therapeutics, Inc. 2019 Employee Stock Purchase Plan (the ESPP). The ESPP allows employees to buy Company stock through after-tax payroll deductions at a discount from market value. The number of shares of common stock initially available for issuance under the ESPP was 243,621 shares of common stock. In addition, the number of shares of common stock available for issuance under the ESPP is subject to an annual increase on the first day of each calendar year beginning on January 1, 2020 and ending on and including January 1, 2029 equal to the lesser of (i) 1 % of the Company’s outstanding shares of common stock on the final day of the immediately preceding calendar year and (ii) such smaller number of shares of common stock as determined by the Company’s board of directors, provided that not more than 3,288,886 shares of common stock may be issued under the ES PP. As of December 31, 2023 , there were 1,291,184 shares av ailable for issuance under the ESPP, including 285,100 shares added pursuant to this provision effective January 1, 2023. Pursuant to this provision, the Company added an additional 543,921 shares to the total shares available for issuance under the ESPP effective January 1, 2024. 2023 Employment Inducement Award Plan On April 28, 2023, the Company's board of directors adopted the Galera Therapeutics, Inc. 2023 Employment Inducement Award Plan (Inducement Plan), which became effective on such date without stockholder approval pursuant to Rule 5635(c)(4) of The Nasdaq Stock Market LLC listing rules (Rule 5635(c)(4)). The Inducement Plan provides for the grant of nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock-based awards. In accordance with Rule 5635(c)(4), awards under the Inducement Plan may only be granted to persons who (a) were not previously an employee or director of the Company, or (b) are commencing employment with the Company following a bona fide period of non-employment, in either case as an inducement material to the individual’s entering into employment with the Company. A total of 1,500,000 shares of common stock was reserved for issuance under the Inducement Plan. Any shares subject to awards previously granted under the Inducement Plan that expire, terminate or are otherwise surrendered, canceled, or forfeited, in a manner that results in the Company (i) acquiring the shares covered by the award at a price not greater than the price (as adjusted to reflect any equity restructuring) paid by the participant for such shares or (ii) not issuing any shares covered by the award, the unused shares covered by such awards will again be available for award grants under the Inducement Plan. As of December 31, 2023 , there were 1,500,000 shares available for issuance under the Inducement Plan. Share-based compensation expense was as follows for the years ended December 31, 2023 and 2022 (in thousands): Year ended 2023 2022 Research and development $ 1,675 $ 2,596 General and administrative 3,885 4,568 $ 5,560 $ 7,164 The following table summarizes the activity related to stock option grants for the year ended December 31, 2023: Shares Weighted Weighted- Outstanding at January 1, 2023 5,783,185 $ 6.86 6.8 Granted 2,424,844 2.13 Exercised ( 78,600 ) 2.39 Forfeited ( 2,389,941 ) 4.64 Outstanding at December 31, 2023 5,739,488 $ 5.85 6.6 Vested and exercisable at December 31, 2023 3,878,156 $ 7.07 5.5 Vested and expected to vest at December 31, 2023 5,739,488 $ 5.85 6.6 The Company's stock option awards vest based on the terms in the governing agreements and generally vest over four years and have a term of 10 years . As of December 31, 2023 , the unrecognized compensation cost was $ 4.3 million and will be recognized over an estimated weighted-average remaining amortization period of 1.9 years. The aggregate intrinsic value of options outstanding and options exercisable as of December 31, 2023 were zero. Options granted during the years ended December 31, 2023 and 2022 had weighted-average grant-date fair values of $ 1.68 and $ 1.57 per share, respectively. The fair value of options is estimated using the Black-Scholes option pricing model, which takes into account inputs such as the exercise price, the estimated fair value of the underlying common stock at the grant date, expected term, expected stock price volatility, risk-free interest rate and dividend yield. The fair value of stock options granted during the years ended December 31, 2023 and 2022 was determined using the methods and assumptions discussed below. • The expected term of employee stock options with service-based vesting is determined using the “simplified” method, as prescribed in SEC’s Staff Accounting Bulletin (SAB) No. 107, whereby the expected life equals the arithmetic average of the vesting term and the original contractual term of the option due to the Company’s lack of sufficient historical data. The expected term of nonemployee options is equal to the contractual term. • The expected stock price volatility is based on historical volatilities of comparable public entities within the Company’s industry which were commensurate with the expected term assumption as described in SAB No. 107. • The risk-free interest rate is based on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the expected term. • The expected dividend yield is 0 % because the Company has not historically paid, and does not expect for the foreseeable future to pay, a dividend on its common stock. • The Company’s board of directors has determined the per share value of the Company’s common stock based on the closing price as reported by the NASDAQ Global Market on the date of the grant. The grant date fair value of each option grant was estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions: Year ended 2023 2022 Expected term (in years) 6.2 6.2 Expected stock price volatility 95.4 % 92.7 % Risk-free interest rate 4.05 % 2.07 % Expected dividend yield 0 % 0 %

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes The Company’s loss before income taxes for the years ended December 31, 2023 and 2022 is as follows (in thousands): Year ended December 31, 2023 2022 Domestic $ ( 59,067 ) $ ( 62,281 ) Foreign ( 15 ) ( 11 ) $ ( 59,082 ) $ ( 62,292 ) The Company’s tax benefit for the years ended December 31, 2023 and 2022 is summarized as follows (in thousands): Year ended December 31, 2023 2022 Current Federal $ — $ — State — — Foreign — — — — Deferred: Federal — — State — ( 70 ) Foreign — — — ( 70 ) Total income tax benefit $ — $ ( 70 ) A reconciliation of the federal income tax rate to the Company’s effective tax rate is as follows: Year ended December 31, 2023 2022 Rate reconciliation: Federal tax benefit at statutory rate 21.0 % 21.0 % State tax, net of federal benefit 3.1 3.1 Net operating loss carryforwards 0.4 0.1 Change in tax rate — ( 9.6 ) Sale of royalty interest ( 4.1 ) ( 3.9 ) Research and development 5.2 ( 0.8 ) Change in valuation allowance ( 24.4 ) ( 9.1 ) Share-based compensation ( 0.5 ) ( 0.6 ) Other ( 0.7 ) ( 0.1 ) Total provision — % 0.1 % The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities were as follows (in thousands): December 31, 2023 2022 Deferred tax assets Net operating loss carryforwards $ 48,957 $ 41,697 Share-based compensation 4,518 3,731 Research and development credits 10,382 7,287 Capitalized research and development expenses 9,701 6,354 Accrued expenses and other 107 82 Gross deferred tax assets 73,665 59,151 Valuation allowance ( 72,861 ) ( 58,424 ) Net deferred tax asset 804 727 Deferred tax liabilities Accrued expenses and other ( 424 ) ( 348 ) Acquired in-process research and development ( 583 ) ( 582 ) Net deferred tax liabilities $ ( 203 ) $ ( 203 ) In assessing the need for a valuation allowance, the Company may utilize indefinite-lived deferred tax liabilities from an intangible asset as a future source of income. The Company’s acquired IPR&D intangible asset can be utilized as a source of income arising from the future reversal of temporary difference that can be offset against post 2017 indefinite-lived net operating losses (NOLs). Therefore, the Company is permitted to offset the indefinite-lived deferred tax liability up to the 80 percent limitation for NOLs generated subsequent to January 1, 2018. Beginning in 2022, the 2017 Tax Cuts and Jobs Act requires taxpayers to capitalize research and development expenses with amortization periods over five and fifteen years , depending on where the research is conducted. The Company has $ 22 million of research and development costs being capitalized in 2023. However, given the Company has a valuation allowance against its deferred tax assets, including the capitalized research and development costs, the enacted provision does not have a material impact on the consolidated financial statements. The valuation allowance increased by $ 14.4 million and $ 5.6 million for the years ended December 31, 2023 and 2022, respectively. The following table summarizes carryforwards of federal, state and foreign NOLs as of December 31, 2023 and 2022, respectively (in thousands): December 31, 2023 2022 Combined NOL Carryforwards: Federal $ 191,315 $ 162,335 State 213,784 184,382 Foreign 1,745 1,716 As of December 31, 2023 , the Company had federal and state net operating losses of $ 191.3 million and $ 213.8 million, respectively, which will begin expiring in 2032. The Company also had foreign net operating loss carryforwards of $ 1.7 million which do not expire. As of December 31, 2023 , the Company also had federal, state, and foreign research and development tax credit carryforwards of $ 10.4 million. The federal and state research and development tax credit carryforwards will begin to expire in 2032 and 2037, respectively, unless previously utilized. The foreign research and development tax credit carryforwards do not have an expiration date. The NOL and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. In general, under Section 382 of the Code, a corporation that undergoes an “ownership change,” generally defined as a greater than 50 % change by value in its equity ownership over a three-year period, is subject to limitations on its ability to utilize its pre change tax credits as well as its net operating losses (NOLs) to offset future taxable income. During 2021, the Company conducted a Section 382 study and determined that approximately $ 63.7 million in NOLs and $ 2.7 million in research and development tax credits are limited by Section 382 as of December 31, 2021. As a result of the Section 382 analysis, approximately $ 1.4 million of research and development tax credits are scheduled to expire unused due to the annual Section 382 limitation and therefore were written off in 2021. There has been no subsequent Section 382 analysis performed, therefore it is possible that additional limitations on the Company’s NOLs and research and development tax credits may exist if an ownership change has occurred since 2021. Future changes in the Company’s stock ownership, some of which might be beyond its control, could result in an ownership change under Section 382 of the Code, further limiting the Company’s ability to utilize a material portion of the NOLs and research and development tax credits. The Company will recognize interest and penalties related to uncertain tax positions as income tax expense. As of December 31, 2023 , the Company had no accrued interest and penalties related to uncertain tax positions and no amounts have been recognized in the Company's statements of operations. Due to NOL and tax credit carryforwards that remain unutilized, income tax returns from 2020 through 2022 remain subject to examination by the taxing jurisdictions. The NOLs remain subject to review until utilized.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2023
Related Party Transactions [Abstract]
Related Party Transactions	12. Related Party Transactions IntellectMap provides IT-advisory services to the Company. The chief executive officer of IntellectMap is the brother of the Company’s chief executive officer. Fees incurred by the Company with respect to IntellectMap during the years ended December 31, 2023 and 2022 were $ 0.3 million and $ 0.2 million, respectively.

Restructuring charges

Restructuring charges	12 Months Ended
	Dec. 31, 2023
Restructuring Charges [Abstract]
Restructuring charges	13. Restructuring charges On August 9, 2023, the Company announced a plan to reduce expenses and extend its cash runway. In connection with this plan, the Company's board of directors approved the Workforce Reduction. The decision was based on cost-reduction initiatives intended to reduce operating expenses. The Company incurred a $ 2.3 million charge in the third quarter of 2023 in connection with the Workforce Reduction, primarily consisting of severance payments, employee benefits and related costs. The following table summarizes the restructuring balances at December 31, 2023 (in thousands): 2023 Balance, January 1 $ — Current year restructuring costs 2,309 Payment of employee severance and related costs ( 1,866 ) Balance, December 31 $ 443

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of presentation and consolidation The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (U.S. GAAP). Any reference in these notes to applicable guidance is meant to refer to U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) of the Financial Accounting Standards Board (FASB). The consolidated financial statements include the accounts of Galera Therapeutics, Inc. and its wholly owned subsidiaries, Galera Therapeutics Australia Pty Ltd (Galera Australia) and Galera Labs, LLC. All intercompany accounts and transactions have been eliminated in consolidation. The Company has determined the functional currency of Galera Australia to be the U.S. dollar. The Company records remeasurement gains and losses on monetary assets and liabilities, such as accounts payable, which are not denominated in U.S. dollars in the statements of operations. The Company manages its operations as a single reportable segment for the purposes of assessing performance and making operating decisions.
Use of Estimates	Use of estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are periodically reviewed and the effects of revisions are reflected in the consolidated financial statements in the period they are determined to be necessary. Significant areas that require management’s estimates include the share-based compensation assumptions, royalty purchase liability assumptions and accrued research and development expenses.
Fair Value of Financial Instruments	Fair value of financial instruments Management believes that the carrying amounts of the Company’s financial instruments, including accounts payable and accrued expenses, approximate fair value due to the short-term nature of those instruments. Short-term investments are recorded at their estimated fair value. The royalty purchase liability is accounted for as debt and interest is accreted over the expected repayment period. Based on the outcome from the Company’s discussions with the FDA reiterating the need for an additional Phase 3 trial to support resubmission of the avasopasem NDA, the Company is exploring potential strategic alternatives for the development of avasopasem as it is not feasible to conduct an additional clinical trial with the Company’s current resources. Due to the uncertainty of obtaining regulatory approval and successful commercialization of avasopasem, it is impractical to determine the fair value of the debt.
Concentrations of Credit Risk	Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations 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 believes it is not exposed to significant risk on its cash and cash equivalents. The Company had no short-term investments as of December 31, 2023.
Cash and Cash Equivalents	Cash and cash equivalents The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash and cash equivalents as of December 31, 2023 and 2022 consisted of bank deposits, U.S. Treasury obligations and a money market mutual fund invested in U.S. Treasury obligations.
Restricted Cash	Restricted cash Restricted cash represented collateral provided under a commercial credit card agreement entered into with TD Bank, N.A. during July 2022. Restricted cash was $ 50,000 as of December 31, 2022. The Company has recorded this deposit and accumulated interest thereon as restricted cash on its consolidated balance sheet. In October 2023, the commercial credit card agreement was terminated by the Company and the bank removed the restriction on the cash.
Refundable PDUFA Fee	Refundable PDUFA fee In December 2022, the Company paid a $ 3.2 million Prescription Drug User Fee Act (PDUFA) fee to the FDA in conjunction with the filing of its NDA for avasopasem. The Company requested and was granted a small business waiver of this PDUFA fee from the FDA. The Company received the refund of the PDUFA fee from the FDA in May 2023.
Short-Term Investments	Short-term investments Short-term investments consisted of debt securities with a maturity of greater than three months when acquired. The Company classified its short-term investments at the time of purchase as available-for-sale securities. Short-term investments were $ 27.3 million, net of unrealized losses of $ 8,000 , as of December 31, 2022 . Available-for-sale securities are carried at fair value. Unrealized gains and losses on available-for-sale securities are reported in accumulated other comprehensive income (loss), a component of stockholders’ equity (deficit), until realized. The Company had no short-term investments as of December 31, 2023.
Property and Equipment	Property and equipment Property and equipment are recorded at cost and depreciated using the straight-line method over their estimated useful lives ranging from three to five years . Leasehold improvements are amortized over the shorter of their economic lives or the remaining lease term. The costs of maintenance and repairs are expensed as incurred. Improvements and betterments that add new functionality or extend the useful life of the asset are capitalized.
Impairment of Long-Lived Assets	Impairment of long-lived assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, then an impairment charge is recognized for the amount by which the carrying value of the asset exceeds the estimated fair value of the asset. As of December 31, 2023 , the Company believes that no revision of the remaining useful lives or write-down of long-lived assets is required.
Goodwill and Acquired Intangible Asset	Goodwill and acquired intangible asset In November 2012, the Company completed a Series A redeemable convertible preferred stock (Series A) financing with venture capital investors and simultaneously acquired Galera Therapeutics, LLC (LLC), a limited liability company incorporated in Missouri in 2009. LLC was renamed Galera Labs, LLC in January 2013 and operates as a wholly-owned subsidiary of the Company. The Company applied the purchase method of accounting under which the consideration given to the LLC members and noteholders was allocated to the fair value of the net assets assumed from the LLC at the date of the acquisition. The sole intangible asset acquired represented the fair value of in-process research and development (IPR&D) which has been recorded on the accompanying consolidated balance sheets as an indefinite life intangible asset. A deferred tax liability was recorded for the difference between the fair value of the acquired IPR&D and its tax basis of zero which was recognized as goodwill in applying the purchase method of accounting. Intangible assets related to IPR&D are considered indefinite-lived intangible assets and, along with goodwill, are not amortized, but are assessed for impairment annually or more frequently if impairment indicators exist. For those compounds that reach commercialization, the IPR&D assets will be amortized over their estimated useful lives. If the associated research and development effort related to IPR&D is abandoned, the related assets will be written-off and the Company will record a noncash impairment loss on its consolidated statements of operations. For the years ended December 31, 2023 and 2022 , the Company determined that there was no impairment to goodwill or IPR&D. The Company believes it has sufficient future cash flows to support the value of its goodwill and IPR&D. The Company will continue to evaluate its timelines for commercialization and probability of success of development of its IPR&D assets. Further reductions to probabilities of success, decrease in market share, additional development and commercial launch delays, increases in underlying discount rates, or any decision to undertake any strategic alternative that the Company has initiated, have the potential to result in future goodwill or IPR&D impairments.
Royalty Purchase Liability	Royalty purchase liability In November 2018, the Company entered into an Amended and Restated Purchase and Sale Agreement (the Royalty Agreement), with Clarus IV Galera Royalty AIV, L.P., Clarus IV-A, L.P., Clarus IV-B, L.P., Clarus IV-C, L.P. and Clarus IV-D, L.P. (collectively, Blackstone or Blackstone Life Sciences). Pursuant to the Royalty Agreement, Blackstone agreed to pay up to $ 80.0 million (the Royalty Purchase Price) in four tranches of $ 20.0 million each upon the achievement of specific Phase 3 clinical trial patient enrollment milestones. The Company received the first tranche of the Royalty Purchase Price in November 2018, the second tranche of the Royalty Purchase Price in April 2019, and the third tranche of the Royalty Purchase Price in February 2020, in each case in connection with the achievement of the first three milestones, respectively. The proceeds received have been recorded as long-term debt obligations. Interest expense on such obligation is imputed by estimating risk adjusted future royalty payments over the term of the Royalty Agreement which takes into consideration the probability of obtaining FDA approval. Other significant assumptions include adjustments to estimated gross revenues to arrive at net product sales from which a royalty payment can be estimated. The non-cash interest expense recorded increases the balance of the royalty obligation. The royalty obligation will be reduced when royalty payments are made, if any. In May 2020, the Company entered into Amendment No. 1 to the Royalty Agreement (the Amendment) with Clarus IV Galera Royalty AIV, L.P. (the Blackstone Purchaser). The Blackstone Purchaser is affiliated with Blackstone Life Sciences, the successor in interest to Clarus Ventures. The Amendment increased the Royalty Purchase Price by $ 37.5 million to $ 117.5 million, by increasing the fourth tranche from $ 20.0 million to $ 37.5 million, which was received in July 2021, and adding a new $ 20.0 million tranche upon the achievement of an additional clinical enrollment milestone, which was received in June 2021. The Company accounted for the Amendment as a debt modification and is amortizing fees paid to the Blackstone Purchaser related to the Amendment over the estimated term of the royalty purchase liability utilizing the effective-interest method. Actual royalty payments are highly uncertain and may change depending on a number of factors, including the Company’s ability to obtain FDA approval, successfully commercialize the Company’s product candidates and the timing of future royalty payments. The Company imputes interest expense on the royalty purchase obligations based on such factors at each reporting period. As these factors change, the Company will adjust its estimate of the imputed interest expense accordingly. Given the uncertainty of obtaining future avasopasem revenue based on the FDA reiterating the need for an additional Phase 3 trial for NDA resubmission, the Company’s inability to conduct an additional trial with its current resources, and its focus on exploring strategic alternatives for the development of avasopasem, coupled with the Company’s decision in October 2023 to discontinue its clinical trials of rucosopasem, the Company suspended accreting interest on the royalty purchase liability and amortizing the fees paid to the Blackstone Purchaser related to the Amendment at the end of October 2023.
Leases	Leases At lease commencement, the Company records a lease liability based on the present value of lease payments over the expected lease term including any options to extend the lease that the Company is reasonably certain to exercise. The Company calculates the present value of lease payments using an incremental borrowing rate as the Company’s leases do not provide an implicit interest rate. The Company’s incremental borrowing rate for a lease is the rate of interest it would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. At the lease commencement date, the Company records a corresponding right-of-use lease asset based on the lease liability, adjusted for any lease incentives received and any initial direct costs paid to the lessor prior to the lease commencement date. The Company may enter into leases with an initial term of 12 months or less (short-term leases). For short-term leases, the Company records the rent expense on a straight-line basis and does not record the leases on the balance sheet. The Company had no short-term leases as of December 31, 2023 and 2022. After lease commencement, the Company measures its leases as follows: (i) the lease liability based on the present value of the remaining lease payments using the discount rate determined at lease commencement, and (ii) the right-of-use lease asset based on the remeasured lease liability, adjusted for any unamortized lease incentives received, any unamortized initial direct costs and the cumulative difference between rent expense and amounts paid under the lease agreement. Any lease incentives received and any initial direct costs are amortized on a straight-line basis over the expected lease term. Rent expense is recorded on a straight-line basis over the expected lease term.
Research and Development Expenses	Research and development expenses Research and development costs are expensed as incurred and consist primarily of funds paid to third parties for the provision of services for product candidate development, clinical and preclinical development and related supply and manufacturing costs, and regulatory compliance costs. The Company accrues and expenses preclinical studies and clinical trial activities performed by third parties based upon estimates of the proportion of work completed over the term of the individual trial and patient enrollment rates in accordance with agreements with clinical research organizations and clinical trial sites. The Company determines the estimates by reviewing contracts, vendor agreements and purchase orders, and through discussions with internal clinical personnel and external service providers as to the progress or stage of completion of trials or services and the agreed-upon fee to be paid for such services. However, actual costs and timing of clinical trials are highly uncertain, subject to risks and may change depending upon a number of factors, including the Company’s clinical development plan. Management makes estimates of the Company’s accrued expenses as of each balance sheet date in the Company’s consolidated financial statements based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed or services are performed.
Share-Based Compensation	Share-based compensation The Company measures share-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. Estimating the fair value of share-based awards requires the input of subjective assumptions, including the expected life of the options and stock price volatility. The Company accounts for forfeitures of stock option awards as they occur. The Company uses the Black-Scholes option pricing model to value its stock option awards. The assumptions used in estimating the fair value of share-based awards represent management’s estimate and involve inherent uncertainties and the application of management’s judgment. As a result, if factors change and management uses different assumptions, share-based compensation expense could be materially different for future awards. The expected life of the stock options is estimated using the “simplified method,” as the Company has limited historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses comparable public companies as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option.
Employee Benefit Plan	Employee Benefit Plan The Company sponsors a 401(k) defined contribution plan for its employees. Employee contributions are voluntary. The Company matches employee contributions in an amount equal to 100 % of the first 4 % of eligible compensation, and such employer contributions are immediately vested. During each of the years ended December 31, 2023 and 2022 , the Company provided matching contributions of $ 0.3 million.
Income Taxes	Income taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, and operating loss and credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes the benefit of an uncertain tax position that it has taken or expects to take on its income tax return if such a position is more likely than not to be sustained.
Net Loss Per Share	Net loss per share The Company uses the two-class method to compute net income per common share during periods the Company realizes net income and has securities that entitle the holder to participate in dividends and earnings of the Company. The two-class method is not applicable during periods with a net loss, as the participating securities are not obligated to fund losses. Basic loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as stock options and common stock warrants, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: December 31, 2023 2022 Stock options 5,739,488 5,783,185 Common stock warrants 13,850,661 550,661 19,590,149 6,333,846
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2020, FASB issued ASU 2020-06, “Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity,” which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. The ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, and it also simplifies the diluted earnings per share calculation in certain areas. This guidance is effective for fiscal years beginning after December 15, 2023, including interim periods therein. Early adoption is permitted. The Company adopted this ASU on January 1, 2023. There was no impact to the Company's consolidated financial statements.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In November 2023, FASB issued ASU 2023-07, “Improvements to Reportable Segment Disclosures,” which improves reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The guidance is effective for the Company beginning in the annual reporting period ending December 31, 2024 and interim periods beginning in fiscal year 2025. Early adoption is permitted. The Company is assessing the impact of adopting this guidance on its consolidated financial statements. In December 2023, FASB issued ASU 2023-09, “Improvements to Income Tax Disclosures,” which enhances the transparency and decision usefulness of income tax disclosures. The guidance is effective for the Company’s annual reporting period ending December 31, 2025. Early adoption is permitted. The Company is assessing the impact of adopting this guidance on its consolidated financial statements.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Dilutive Securities Excluded from Computation of Diluted Weighted Average Shares of Common Stock Outstanding	The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: December 31, 2023 2022 Stock options 5,739,488 5,783,185 Common stock warrants 13,850,661 550,661 19,590,149 6,333,846

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents the Company’s assets and liabilities that are measured at fair value on a recurring basis (amounts in thousands): December 31, 2023 (Level 1) (Level 2) (Level 3) Assets Money market funds and U.S. Treasury obligations $ 17,964 $ — $ — December 31, 2022 (Level 1) (Level 2) (Level 3) Assets Money market funds and U.S. Treasury obligations $ 3,467 $ — $ — Short-term investments U.S. government agency securities $ — $ 8,172 $ — U.S. Treasury obligations 19,159 — — Total short-term investments $ 19,159 $ 8,172 $ —

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	12 Months Ended
	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Schedule Of Prepaid Expenses And Other Current Assets	Prepaid expenses and other current assets consist of (amounts in thousands): December 31, December 31, 2023 2022 Prepaid clinical expenses $ 1,450 $ 1,359 Prepaid insurance 1,302 1,396 Other prepaid expenses and other current assets 620 891 $ 3,372 $ 3,646

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consist of (amounts in thousands): December 31, December 31, 2023 2022 Laboratory equipment $ — $ 1,398 Computer hardware and software 305 292 Leasehold improvements 46 270 Furniture and fixtures 179 179 Property and equipment, gross 530 2,139 Less: Accumulated depreciation and amortization ( 459 ) ( 1,701 ) Property and equipment, net $ 71 $ 438

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of (amounts in thousands): December 31, December 31, 2023 2022 Compensation and related benefits $ 121 $ 2,655 Restructuring costs 443 — Research and development expenses 2,672 6,764 Professional fees and other expenses 213 335 $ 3,449 $ 9,754

Royalty purchase liability (Tab

Royalty purchase liability (Tables)	12 Months Ended
	Dec. 31, 2023
Royalty Purchase Liability [Abstract]
Schedule of Common Stock Warrants	Upon execution of the Amendment, the Company issued common stock warrants to the Blackstone Purchaser, each of which became exercisable upon the receipt by the Company of the applicable specified milestone payment. The issued warrants expire six years after the initial exercise dates, as follows: Shares Exercise Price Initial Exercise Date Expiration Date New Milestone Warrant 293,686 $ 13.62 6/7/2021 6/6/2027 Fourth Milestone Warrant 256,975 $ 13.62 7/19/2021 7/18/2027

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Summary of Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows: December 31, December 31, 2023 2022 Operating Leases Right-of-use lease assets $ 1,212 $ 43 Lease liabilities, current 133 44 Lease liabilities, net of current portion 1,117 — Total operating lease liabilities $ 1,250 $ 44
Summary of Lease Costs and Other Information	The components of lease expense were as follows: Year ended 2023 2022 Operating lease costs Operating lease rental expense $ 191 $ 267 Total operating lease expense $ 191 $ 267
Summary of Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases was as follows: Year ended 2023 2022 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for operating leases $ 150 $ 266 Right-of-use assets obtained in exchange for lease obligation Operating leases 1,310 —
Lessee Operating Lease Liability Maturity	Our operating lease liabilities as of December 31, 2023 will mature, as follows (amounts in thousands): 2024 195 2025 217 2026 220 2027 224 2028 and after 633 Total 1,489 Less: imputed interest ( 239 ) $ 1,250

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Summary of Share-based Compensation Expense	Share-based compensation expense was as follows for the years ended December 31, 2023 and 2022 (in thousands): Year ended 2023 2022 Research and development $ 1,675 $ 2,596 General and administrative 3,885 4,568 $ 5,560 $ 7,164
Summary of Activity Related to Stock Option Grants	The following table summarizes the activity related to stock option grants for the year ended December 31, 2023: Shares Weighted Weighted- Outstanding at January 1, 2023 5,783,185 $ 6.86 6.8 Granted 2,424,844 2.13 Exercised ( 78,600 ) 2.39 Forfeited ( 2,389,941 ) 4.64 Outstanding at December 31, 2023 5,739,488 $ 5.85 6.6 Vested and exercisable at December 31, 2023 3,878,156 $ 7.07 5.5 Vested and expected to vest at December 31, 2023 5,739,488 $ 5.85 6.6
Summary of Fair Value of Each Option Grant Estimated Throughout Year Using Black-Scholes Option-pricing Model	The grant date fair value of each option grant was estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions: Year ended 2023 2022 Expected term (in years) 6.2 6.2 Expected stock price volatility 95.4 % 92.7 % Risk-free interest rate 4.05 % 2.07 % Expected dividend yield 0 % 0 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Summary of Company's Loss Before Income Taxes	The Company’s loss before income taxes for the years ended December 31, 2023 and 2022 is as follows (in thousands): Year ended December 31, 2023 2022 Domestic $ ( 59,067 ) $ ( 62,281 ) Foreign ( 15 ) ( 11 ) $ ( 59,082 ) $ ( 62,292 )
Summary of Company's Tax Provision (Benefit)	The Company’s tax benefit for the years ended December 31, 2023 and 2022 is summarized as follows (in thousands): Year ended December 31, 2023 2022 Current Federal $ — $ — State — — Foreign — — — — Deferred: Federal — — State — ( 70 ) Foreign — — — ( 70 ) Total income tax benefit $ — $ ( 70 )
Summary of Effective Tax Rate of Reconciliation of Federal Income Tax Rate	A reconciliation of the federal income tax rate to the Company’s effective tax rate is as follows: Year ended December 31, 2023 2022 Rate reconciliation: Federal tax benefit at statutory rate 21.0 % 21.0 % State tax, net of federal benefit 3.1 3.1 Net operating loss carryforwards 0.4 0.1 Change in tax rate — ( 9.6 ) Sale of royalty interest ( 4.1 ) ( 3.9 ) Research and development 5.2 ( 0.8 ) Change in valuation allowance ( 24.4 ) ( 9.1 ) Share-based compensation ( 0.5 ) ( 0.6 ) Other ( 0.7 ) ( 0.1 ) Total provision — % 0.1 %
Schedule of Significant Portions of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities were as follows (in thousands): December 31, 2023 2022 Deferred tax assets Net operating loss carryforwards $ 48,957 $ 41,697 Share-based compensation 4,518 3,731 Research and development credits 10,382 7,287 Capitalized research and development expenses 9,701 6,354 Accrued expenses and other 107 82 Gross deferred tax assets 73,665 59,151 Valuation allowance ( 72,861 ) ( 58,424 ) Net deferred tax asset 804 727 Deferred tax liabilities Accrued expenses and other ( 424 ) ( 348 ) Acquired in-process research and development ( 583 ) ( 582 ) Net deferred tax liabilities $ ( 203 ) $ ( 203 )
Summary of Carryforwards of Federal, State and Foreign NOLs and Tax Credits	The following table summarizes carryforwards of federal, state and foreign NOLs as of December 31, 2023 and 2022, respectively (in thousands): December 31, 2023 2022 Combined NOL Carryforwards: Federal $ 191,315 $ 162,335 State 213,784 184,382 Foreign 1,745 1,716

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Dilutive Securities Excluded from Computation of Diluted Weighted Average Shares of Common Stock Outstanding	The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: December 31, 2023 2022 Stock options 5,739,488 5,783,185 Common stock warrants 13,850,661 550,661 19,590,149 6,333,846

Restructuring charges (Tables)

Restructuring charges (Tables)	12 Months Ended
	Dec. 31, 2023
Restructuring Charges [Abstract]
Summary of Restructuring balances	The following table summarizes the restructuring balances at December 31, 2023 (in thousands): 2023 Balance, January 1 $ — Current year restructuring costs 2,309 Payment of employee severance and related costs ( 1,866 ) Balance, December 31 $ 443

Organization and description _2

Organization and description of business - Additional Information (Detail) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 17, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) shares	Aug. 09, 2023 Employees	Dec. 31, 2022 USD ($)
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of reduction in company's current workforce employees | Employees			22
Workforce Reduction Rate			70%
Proceeds from common stock offering	$ 30,000
Accumulated deficit		$ (437,406)		$ (378,324)
Common stock offering price	2.095%
Exercise price | $ / shares	$ 1.97
Net Proceeds from Common Stock and Warrants	$ 27,600
Sale of common stock in initial public offering, net of issuance costs, shares | shares	14,320,000
Open Market Sale Agreement [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Proceeds from common stock offering		$ 1,700
Sale of common stock in initial public offering, net of issuance costs, shares | shares		10,500,000
Open Market Sale Agreement [Member] | Jefferies L L C [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Maximum Offering Issuance And Sale Expense Covered In Company Securities		$ 200,000
Registration Payment Arrangement, Maximum Potential Consideration		$ 50,000

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Nov. 30, 2018	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2021	May 31, 2020
Summary Of Significant Accounting Policies [Line Items]
Restricted cash			$ 50,000
Refundable PDUFA Fee		$ 0	3,242,000
Impairment to goodwill		0	0
Total agreed amount of royalty purchase price		151,049,000	139,635,000
Other Short-Term Investments		$ 0
Property And Equipment Depreciation Methods		straight-line method
Defined Contribution Plan, Employer Matching Contribution, Percent		100%
Percentage Of Employee Eligible For Compensation And Employer Contribution		4%
Defined Contribution Plan, Employer Discretionary Contribution Amount		$ 300,000	300,000
Royalty Agreements [Member]
Summary Of Significant Accounting Policies [Line Items]
Total agreed amount of royalty purchase price	$ 80,000,000
Royalty purchase price		$ 117,500,000
Outstanding amount of royalty agreement					$ 20,000,000
Amended Royalty Agreements
Summary Of Significant Accounting Policies [Line Items]
Total agreed amount of royalty purchase price					117,500,000
Outstanding amount of royalty agreement					37,500,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives		3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives		5 years
U.S. Treasury Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt Securities, Available-for-Sale, Unrealized Loss			8,000,000
Other Short-Term Investments			$ 27,300,000
Fifth Tranche | Royalty Agreements [Member]
Summary Of Significant Accounting Policies [Line Items]
Outstanding amount of royalty agreement				$ 20,000,000
Fifth Tranche | Amended Royalty Agreements
Summary Of Significant Accounting Policies [Line Items]
Outstanding amount of royalty agreement					$ 20,000,000
First Tranche | Royalty Agreements [Member]
Summary Of Significant Accounting Policies [Line Items]
Royalty purchase price	$ 20,000,000

Basis of Presentation and Sig_5

Basis of Presentation and Significant Accounting Policies - Dilutive Securities Excluded from Computation of Diluted Weighted Average Shares of Common Stock (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities excluded from computation of earnings per share	19,590,149	6,333,846
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities excluded from computation of earnings per share	5,739,488	5,783,185
Common Stock Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities excluded from computation of earnings per share	13,850,661	550,661

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Level 1 [Member] | Money Market Funds and U.S. Treasury Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents and restricted cash equivalents	$ 17,964	$ 3,467
Level 1 [Member] | US Government Corporations and Agencies Securities [Member]
Marketable securities:
Marketable securities		0
Level 1 [Member] | Short-Term Investments [Member]
Marketable securities:
Total		19,159
Level 1 [Member] | U.S. Treasury Securities [Member]
Marketable securities:
Marketable securities		19,159
Level 2 [Member] | Money Market Funds and U.S. Treasury Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents and restricted cash equivalents	0	0
Level 2 [Member] | US Government Corporations and Agencies Securities [Member]
Marketable securities:
Marketable securities		8,172
Level 2 [Member] | Short-Term Investments [Member]
Marketable securities:
Total		8,172
Level 2 [Member] | U.S. Treasury Securities [Member]
Marketable securities:
Marketable securities		0
Level 3 [Member] | Money Market Funds and U.S. Treasury Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents and restricted cash equivalents	$ 0	0
Level 3 [Member] | US Government Corporations and Agencies Securities [Member]
Marketable securities:
Marketable securities		0
Level 3 [Member] | Short-Term Investments [Member]
Marketable securities:
Total		0
Level 3 [Member] | U.S. Treasury Securities [Member]
Marketable securities:
Marketable securities		$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Changes in valuation techniques	$ 0	$ 0

Prepaid Expenses And Other Cu_3

Prepaid Expenses And Other Current Assets - Schedule of Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid clinical expenses	$ 1,450	$ 1,359
Prepaid insurance	1,302	1,396
Other prepaid expenses and other current assets	620	891
Total	$ 3,372	$ 3,646

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 530	$ 2,139
Less: accumulated depreciation and amortization	(459)	(1,701)
Property and equipment, net	71	438
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	0	1,398
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	305	292
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	46	270
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 179	$ 179

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Table]
Depreciation and amortization expense	$ 259	$ 114
Laboratory Equipment [Member]
Property, Plant and Equipment [Table]
Property, Plant and Equipment, Disposals	1,400
Leasehold Improvements [Member]
Property, Plant and Equipment [Table]
Property, Plant and Equipment, Disposals	$ 300

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Compensation and related benefits	$ 121	$ 2,655
Restructuring costs	443	0
Research and development expenses	2,672	6,764
Professional fees and other expenses	213	335
Total accrued expenses	$ 3,449	$ 9,754

Royalty Purchase Liability - Ad

Royalty Purchase Liability - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2018	Dec. 31, 2023	Dec. 31, 2022	Jul. 31, 2021	Jun. 30, 2021	May 31, 2020
Royalty Purchase Liability [Line Items]
Royalty purchase liability		$ 151,049	$ 139,635
Noncash interest expense		11,414	11,571
Total agreed amount of royalty purchase price		$ 151,049	139,635
Warrant expiration term		6 years
Fair value of equity classified warrants		$ 4,700
Royalty Agreements
Royalty Purchase Liability [Line Items]
Royalty purchase liability	$ 80,000
Royalty purchase price		117,500
Noncash interest expense		$ 11,400	$ 11,600
Outstanding amount of royalty agreement						$ 20,000
Total agreed amount of royalty purchase price	80,000
Royalty Agreements | First Tranche
Royalty Purchase Liability [Line Items]
Royalty purchase price	$ 20,000
Royalty Agreements | Fourth Tranche
Royalty Purchase Liability [Line Items]
Outstanding amount of royalty agreement				$ 37,500
Royalty Agreements | Fifth Tranche
Royalty Purchase Liability [Line Items]
Outstanding amount of royalty agreement					$ 20,000
Amended Royalty Agreements
Royalty Purchase Liability [Line Items]
Royalty purchase liability						117,500
Outstanding amount of royalty agreement						37,500
Total agreed amount of royalty purchase price						117,500
Amended Royalty Agreements | Fifth Tranche
Royalty Purchase Liability [Line Items]
Outstanding amount of royalty agreement						$ 20,000

Royalty purchase liability - Sc

Royalty purchase liability - Schedule of Common Stock Warrants (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Feb. 17, 2023
Class of Warrant or Right [Line Items]
Exercise price		$ 1.97
New Milestone Warrant
Class of Warrant or Right [Line Items]
Class of warrant, shares issued	293,686
Exercise price	$ 13.62
Initial Exercise Date	Jun. 07, 2021
Expiration Date	Jun. 06, 2027
Fourth Milestone Warrant
Class of Warrant or Right [Line Items]
Class of warrant, shares issued	256,975
Exercise price	$ 13.62
Initial Exercise Date	Jul. 19, 2021
Expiration Date	Jul. 18, 2027

Collaborations - Additional Inf

Collaborations - Additional Information (Detail) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Common stock, par value	$ 0.001	$ 0.001

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Lessee Lease Description [Line Items]
Operating Lease, Liability, Noncurrent	$ 1,117	$ 0
Lessee, Operating Lease, Remaining Lease Term	6 years 9 months 18 days
Lessee, Operating Lease, Discount Rate	5.40%
Right-of-use lease assets	$ 1,212	43
Operating lease, liability	$ 1,250	$ 44

Leases - Summary of Balance She

Leases - Summary of Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Right-of-use lease assets	$ 1,212	$ 43
Lease liabilities, current	133	44
Lease liabilities, net of current portion	1,117	0
Total operating lease liabilities	$ 1,250	$ 44

Leases - Summary of Components

Leases - Summary of Components of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease rental expense	$ 191	$ 267
Total operating lease expense	$ 191	$ 267

Leases - Summary of Supplementa

Leases - Summary of Supplemental Cash Flow Information Related to Lease (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating cash flows from operating leases	$ 150	$ 266
Right Of Use Assets Obtained In Exchange For Lease Obligations [Abstract]
Operating leases	$ 1,310	$ 0

Leases - Summary of Operating L

Leases - Summary of Operating Leases Liabilities Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
2024	$ 195
2025	217
2026	220
2027	224
2028 and after	633
Total	1,489
Less: imputed interest	(239)
Operating lease, liability	$ 1,250	$ 44

Commitments (Additional Informa

Commitments (Additional Information) (Details)	Dec. 31, 2023 Claim
Commitments and Contingencies Disclosure [Abstract]
Number of pending claims or legal actions	0

Stockholders' Equity (Deficit_2

Stockholders' Equity (Deficit) - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended		12 Months Ended
	Jan. 01, 2024	Feb. 17, 2023	Jan. 01, 2023	Dec. 31, 2020	Nov. 30, 2019	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Purchased for Award						13,300,000
Stock Issued During Period Shares of Common Stock Warrants Exercised						1,020,000
Stock Issued During Period Value Common Stock Warrants Exercised						$ 2,000
Expected dividend yield						0%	0%
Unrecognized equity-based compensation expense related to restricted stock						$ 4,300
Weighted average period of unrecognized compensation costs						1 year 10 months 24 days
Weighted average grant date fair value per share						$ 1.68	$ 1.57
Proceeds from issuance of common stock		$ 30,000
At-the-market Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate value of common stock sale under ATM offering				$ 50,000
Commission to agent as percentage of ATM offering proceeds						3%
Sale Of Shares Under Open Market Sale Agrrement Shares						10,463,504	1,982,773
Weighted Average Price Of Shares Purchase						$ 0.2	$ 2
Proceeds from issuance of common stock						$ 1,700	$ 3,800
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance						2,535,043
Sale Of Shares Under Open Market Sale Agrrement Shares						10,463,504	1,982,773
2023 Employment Inducement Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining vesting period						4 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Terms of Award						10 years
2023 Employment Inducement Award Plan [Member] | April Twenty Eight, Two Thousand Twenty Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance						1,500,000
2019 Incentive Award Plan | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance					1,948,970
Percentage of cumulative increase in number of shares for future issuance					4%
Shares available for issuance	2,175,686		1,140,402			1,291,184
2019 Employee Stock Purchase Plan | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of cumulative increase in number of shares for future issuance					1%
Shares available for issuance	543,921				285,100
Shares of Common stock initially available for issuance under the ESPP					243,621
2012 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of Common stock initially available for issuance under the ESPP						1,500,000
Aggregate Intrinsic Value, Outstanding						$ 1,665,268
Maximum [Member] | 2019 Incentive Award Plan | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Payment Award Terms Of Award					14,130,029
Maximum [Member] | 2019 Employee Stock Purchase Plan | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Payment Award Terms Of Award					3,288,886

Stockholders' Equity (Deficit_3

Stockholders' Equity (Deficit) - Schedule of Equity-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 5,560	$ 7,164
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	1,675	2,596
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense	$ 3,885	$ 4,568

Stockholders' Equity (Deficit_4

Stockholders' Equity (Deficit) - Summary of Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Number of Options, Outstanding, Beginning Balance	5,783,185
Number of options, Granted	2,424,844
Number of options, Exercised	(78,600)
Number of options, Forfeited	(2,389,941)
Number of Options, Outstanding, Ending Balance	5,739,488	5,783,185
Number of Options, Exercisable	3,878,156
Number of Options, expected to vest	5,739,488
Weighted Average Exercise Price per Share, Outstanding, Beginning Balance	$ 6.86
Weighted Average Exercise Price per Share, Granted	2.13
Weighted Average Exercise Price per Share, Exercised	2.39
Weighted Average Exercise Price per Share, Forfeited	4.64
Weighted Average Exercise Price per Share, Outstanding, Ending Balance	5.85	$ 6.86
Weighted Average Exercise Price per Share, Exercisable	7.07
Weighted Average Exercise Price per Share, expected to vest	$ 5.85
Weighted Average Remaining Contractual Term, Outstanding	6 years 7 months 6 days	6 years 9 months 18 days
Weighted Average Remaining Contractual Term, Exercisable	5 years 6 months
Weighted Average Remaining Contractual Term, Expected to vest	6 years 7 months 6 days

Stockholders' Equity (Deficit_5

Stockholders' Equity (Deficit) - Summary of Fair Value of Each Option Grant Estimated Throughout Year Using Black-Scholes Option-pricing Model (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Expected term (in years)	6 years 2 months 12 days	6 years 2 months 12 days
Expected volatility of underlying stock	95.40%	92.70%
Risk-free interest rate	4.05%	2.07%
Expected dividend yield	0%	0%

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Domestic	$ (59,067)	$ (62,281)
Foreign	(15)	(11)
Loss before income tax benefit	$ (59,082)	$ (62,292)

Income Taxes - Summary of Com_2

Income Taxes - Summary of Company's Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Current - Federal	$ 0	$ 0
Current - State	0	0
Current - Foreign	0	0
Current - Total	0	0
Deferred - Federal	0	0
Deferred - State	0	(70)
Deferred - Foreign	0	0
Deferred - Total	0	(70)
Total income tax benefit	$ 0	$ 70

Income Taxes - Summary of Effec

Income Taxes - Summary of Effective Tax Rate of Reconciliation of Federal Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal tax benefit at statutory rate	21%	21%
State tax, net of federal benefit	3.10%	3.10%
Net operating loss carryforwards	0.40%	0.10%
Change in tax rate	0%	(9.60%)
Sale of royalty interest	(4.10%)	(3.90%)
Research and development	5.20%	(0.80%)
Change in valuation allowance	(24.40%)	(9.10%)
Share-based compensation	(0.50%)	(0.60%)
Other	(0.70%)	(0.10%)
Total provision	0%	0.10%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Percentage of maximum offset indefinite lived deferred tax liability for net operating loss	80%
Research and development costs	$ 22,000
Tax credit carryforward, amount			$ 63,700
Increase in valuation allowance	14,400	$ 5,600
Loss from operations	$ (49,260)	(51,226)
Tax credit carryforward, amount	50%
Accrued interest and penalties	$ 0
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Amortization periods, capitalized research and development expenses	5 years
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Amortization periods, capitalized research and development expenses	15 years
Federal
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 10,400
Operating Loss Carryforwards	191,315	162,335
Loss from operations	191,300
State
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	10,400
Operating Loss Carryforwards	213,784	184,382
Loss from operations	213,800
Foreign
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	10,400
Operating Loss Carryforwards	1,745	$ 1,716
Research and Development
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 10,400		1,400
Research and Development | Foreign
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount			$ 2,700

Income Taxes - Summary of Carry

Income Taxes - Summary of Carryforwards of Federal, State and Foreign NOLs and Tax Credits (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Federal
Operating Loss Carryforwards [Line Items]
Combined NOL Carryforwards	$ 191,315	$ 162,335
State
Operating Loss Carryforwards [Line Items]
Combined NOL Carryforwards	213,784	184,382
Foreign
Operating Loss Carryforwards [Line Items]
Combined NOL Carryforwards	$ 1,745	$ 1,716

Income Taxes - Schedule of Sign

Income Taxes - Schedule of Significant Portions of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets
Net operating loss carryforwards	$ 48,957	$ 41,697
Share-based compensation	4,518	3,731
Research & development credits	10,382	7,287
Capitalized research and development expenses	9,701	6,354
Accrued expenses and other	107	82
Gross deferred tax assets	73,665	59,151
Valuation allowance	(72,861)	(58,424)
Net deferred tax asset	804	727
Deferred tax liabilities
Accrued expenses and other	(424)	(348)
Acquired in-process research and development	(583)	(582)
Net deferred tax liabilities	$ (203)	$ (203)

Loss Per Share - Schedule of Ba

Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Income (Loss)	$ (59,082)	$ (62,222)

Loss Per Share - Potential Dilu

Loss Per Share - Potential Dilutive Securities Excluded from Computation of Diluted Net Loss Per Common Share (Detail) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from computation of diluted net loss per common share	19,590,149	6,333,846

401(k) Plan - Additional Inform

401(k) Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution of employee contribution, percent	100%
Employer discretionary contribution amount	$ 0.3	$ 0.3

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
IntellectMap
Related Party Transaction [Line Items]
Advisory services fees	$ 0.3	$ 0.2

Restructuring charges (Addition

Restructuring charges (Additional Information) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Restructuring Charges [Abstract]
Incured Restructuring Charges	$ 2.3

Restructuring charges - Summary

Restructuring charges - Summary of Restructuring balances (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Restructuring Charges [Abstract]
Balance, January 1	$ 0
Current year restructuring costs	2,309
Payment of employee severance and related costs	(1,866)
Balance, December 31	$ 443