Quince Therapeutics (QNCX) 10-K 1 Apr 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. 25, 2024	Jun. 30, 2023
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Registrant Name	Quince Therapeutics, Inc.
Entity Central Index Key	0001662774
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		43,215,233
Entity Public Float			$ 50
Entity File Number	001-38890
Entity Tax Identification Number	90-1024039
Entity Address, Address Line One	611 Gateway Boulevard, Suite 273
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	910-5717
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Documents Incorporated by Reference	Part III incorporates by reference certain information from the registrant’s definitive proxy statement (the “Proxy Statement”) relating to its 2024 Annual Meeting of Stockholders. The Proxy Statement will be filed with the United States Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Auditor Firm ID	243
Audior name	BDO USA, P.C.
Auditor location	San Jose, California
Common Stock
Trading Symbol	QNCX
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.001 per share
Series A Junior Participating Preferred Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NASDAQ
Title of 12(b) Security	Series A Junior Participating Preferred Purchase Rights

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 20,752	$ 44,579
Short term investments	54,307	45,602
Prepaid expenses and other current assets	2,381	3,567
Total current assets	77,440	93,748
Assets held for sale	10	0
Property and equipment, net	234	393
Operating lease right-of-use assets	385	291
Long term investments	0	3,578
Goodwill	17,625	0
Intangible asset	63,672	5,900
Other assets	8,456	0
Equity investments in Lighthouse Pharmaceuticals, Inc.	78	0
Total assets	167,900	103,910
Current liabilities:
Accounts payable	2,033	570
Short term contingent consideration	4,103	0
Accrued expenses and other current liabilities	3,436	2,499
Total current liabilities	9,572	3,069
Long - term debt	13,429	0
Long-term operating lease liabilities	321	0
Long term contingent consideration	53,603	0
Deferred tax liabilities	5,304	248
Other long-term liabilities	587	0
Total liabilities	82,816	3,317
Commitments and contingencies (See Note 8)
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 authorized (100,000 shares of which are designated as Series A Junior Participating Preferred Stock), no shares issued and outstanding as of December 31, 2023 and 2022, respectively	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized, 42,973,215 and 36,136,480 issued and outstanding as of December 31, 2023 and 2022, respectively	43	36
Additional paid in capital	401,638	389,105
Accumulated other comprehensive income (loss)	3,047	(289)
Accumulated deficit	(319,644)	(288,259)
Total stockholders’ equity	85,084	100,593
Total liabilities and stockholders’ equity	$ 167,900	$ 103,910

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares	42,973,215	36,136,480
Common stock, shares outstanding	42,973,215	36,136,480
Series A Preferred Stock
Preferred stock, shares authorized	100,000	100,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating expenses:
Research and development	$ 9,447	$ 25,178
General and administrative	17,695	26,012
Goodwill impairment charge	0	825
Intangible asset impairment charge	5,900	0
Fair value adjustment for contingent consideration	1,578	0
Total operating expenses	34,620	52,015
Loss from operations	(34,620)	(52,015)
Fair value adjustment for long-term debt	(338)	0
Interest income	3,478	1,068
Other expense, net	(102)	(997)
Net loss before income tax benefit	(31,582)	(51,944)
Income tax benefit	197	284
Net loss	(31,385)	(51,660)
Other comprehensive income (loss):
Foreign currency translation adjustments	2,789	248
Unrealized gain (loss) on available-for-sale securities	547	(458)
Total comprehensive loss	$ (28,049)	$ (51,870)
Net loss per share - basic	$ (0.84)	$ (1.54)
Net loss per share - diluted	$ (0.84)	$ (1.54)
Weighted average shares of common stock outstanding - basic	37,237,149	33,496,534
Weighted average shares of common stock outstanding - diluted	37,237,149	33,496,534

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income / (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ 118,586	$ 30	$ 355,234	$ (79)	$ (236,599)
Beginning balance, shares at Dec. 31, 2021		30,074,412
Issuance of common stock , net of issuance costs	608		608
Issuance of common stock , net of issuance costs, shares		51,769
Issuance of common stock on exercise of stock options and vesting of restricted stock units	148		148
Issuance of common stock on exercise of stock options and vesting of restricted stock units, shares		490,299
Stock based compensation	16,618		16,618
Value of share Issued in connection with acquisition	16,503	$ 6	16,497
Share issuance in connection with acquisition		5,520,000
Foreign currency translation adjustments	248			248
Unrealized gain (loss) on available for sale investments	(458)			(458)
Net loss	(51,660)				(51,660)
Ending balance at Dec. 31, 2022	100,593	$ 36	389,105	(289)	(288,259)
Ending balance, shares at Dec. 31, 2022		36,136,480
Issuance of common stock on exercise of stock options and vesting of restricted stock units	167		167
Issuance of common stock on exercise of stock options and vesting of restricted stock units, shares		374,713
Restricted stock award forfeiture	(18)		(18)
Restricted stock award forfeiture, Shares		(63,293)
Stock based compensation	5,220		5,220
Value of share Issued in connection with acquisition	7,171	$ 7	7,164
Share issuance in connection with acquisition		6,525,315
Foreign currency translation adjustments	2,789			2,789
Unrealized gain (loss) on available for sale investments	547			547
Net loss	(31,385)				(31,385)
Ending balance at Dec. 31, 2023	$ 85,084	$ 43	$ 401,638	$ 3,047	$ (319,644)
Ending balance, shares at Dec. 31, 2023		42,973,215

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Private Placement
Stock issuance costs	$ 19

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net Loss	$ (31,385)	$ (51,660)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash rent expense	0	(29)
Stock based compensation	5,220	16,618
Depreciation and amortization	322	204
Impairment loss on operating lease	66	136
Gain on sale of Legacy Assets	(78)	0
Loss on disposal of fixed assets	37	94
Change in the fair value of contingent consideration liabilities	1,578	0
Change in fair value of EIB loan	338	0
Non-cash goodwill impairment charge	0	825
Non-cash intangible impairment charge	5,900	0
Amortization of discount on available-for-sale investments	(2,019)	(113)
Change in deferred tax liabilities due to acquisition of Novosteo, Inc.	(248)	(284)
Changes in operating assets and liabilities, net of acquisitions:
Prepaid expenses and other current assets	4,246	2,580
Other assets	(9)	194
Accounts payable	(288)	(5,943)
Accrued expenses and other current liabilities	(1,972)	(6,660)
Net cash used in operating activities	(18,292)	(44,038)
Cash flow from investing activities:
Purchase of investments	(113,781)	(75,021)
Proceeds from maturities of investments	111,209	82,493
Cash acquired from Novosteo, Inc.	0	10,593
Advancement of notes receivable	(1,000)	0
Cash paid in acquisition of EryDel S.p.A. net of cash acquired	(2,116)	0
Proceeds from disposal of assets	90	70
Purchase of property and equipment	(160)	(133)
Net cash provided by (used in) investing activities	(5,758)	18,002
Cash flows from financing activities:
Payments of finance leases	(6)	(49)
Proceeds from issuance of common stock upon exercise of stock options	149	148
Proceeds from issuance of common stock in connection with open market sales agreement, net of issuance costs	0	608
Net cash provided by financing activities	143	707
Effect of exchange rate changes on cash	80	184
Net decrease in cash and cash equivalents	(23,827)	(25,145)
Cash and cash equivalents at beginning of period	44,579	69,724
Cash and cash equivalents at end of period	20,752	44,579
Supplemental disclosures of non-cash information:
Right-of-use assets obtained in exchange for new operating lease liabilities	0	411
Right-of-use asset and financing lease liability reduction as a result of lease modification	(70)	0
Right-of-use asset and operating lease liability reduction as a result of lease modification	0	(640)
EryDel
Supplemental disclosures of non-cash information:
Net assets acquired in exchange for common stock	63,732	0
Novosteo
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash goodwill impairment charge		800
Supplemental disclosures of non-cash information:
Net assets acquired in exchange for common stock	$ 0	$ 16,503

Organization

Organization	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Note 1. Organization Description of Business Effec tive August 1, 2022, Cortexyme Inc. changed its name to Quince Therapeutics, Inc (the "Company"). The Company was incorporated in the State of Delaware in June 2012 and is headquartered in South San Francisco, Californi a. From its inception, the Company has been focused on novel therapeutic approaches to improve the lives of patients diagnosed with Alzheimer’s and other degenerative diseases. The predecessor company, Cortexyme, Inc. was initially founded on the seminal discovery of the presence of Porphyromonas gingivalis, and its secreted toxic virulence factor proteases, called gingipains, in the relevant brain areas of both Alzheimer's and Parkinson's disease patients. In May 2022, the Company completed the acquisition of Novosteo focused on targeted therapeutics to treat rare skeletal diseases, bone fractures and injury. In 2023, the Company decided to discontinue the internal development of NOV004, which was acquired in the acquisition of Novosteo, and terminated the related license. On October 20, 2023, the Company completed the acquisition of EryDel, a privately held, late-stage biotechnology company with a Phase 3 lead asset, EryDex, that targets the potential treatment of a rare neurodegenerative disease, A-T. Novosteo Acquisition On May 9, 2022, the Company entered into an Agreement and Plan of Merger and Reorganization (the “Merger Agreement”) with Novosteo, Quince Merger Sub I, Inc., a Delaware corporation and a wholly owned subsidiary of the Company, Quince Merger Sub II, LLC, a Delaware limited liability company and a wholly owned subsidiary of Company, Novosteo, and Fortis Advisors LLC, a Delaware limited liability company, solely in its capacity as the securityholders’ representative. The transaction closed on May 19, 2022. Pursuant to the terms of the Merger Agreement, at the closing of the Novosteo Acquisition, each share of capital stock of Novosteo that was issued and outstanding immediately prior to the Effective Time was automatically cancelled and converted into the right to receive 0.0911 shares of common stock, par value $ 0.001 per share, of the Company. The Company issued 5,520,000 shares and assumed 507,108 outstanding Novosteo options after conversion with the awards, retaining the same vesting and other terms and conditions as in effect immediately prior to consummation of the Novosteo Acquisition. Pursuant to the Merger Agreement, upon the terms and subject to the conditions set forth therein, Merger Sub I merged with and into Novosteo (the “First Merger”), with Novosteo as the surviving entity in the First Merger (the “First Step Surviving Corporation”). Immediately following the First Merger, the First Step Surviving Corporation merged with and into Merger Sub II, with Merger Sub II surviving the Acquisition. Merger Sub II was renamed Novosteo, LLC and is a wholly-owned single member limited liability corporation. Sale of Legacy Portfolio On January 27, 2023, we sold our legacy small molecule protease inhibitor portfolio, including COR588, COR388, COR852, and COR803, pursuant to an asset purchase agreement with Lighthouse Pharmaceuticals, Inc., (the "Purchaser" or "Lighthouse") an entity co-founded by Casey Lynch, former chief executive officer of Cortexyme. Lighthouse is a variable interest entity but the Company is not the primary beneficiary. Upon the consummation of the transaction, we received shares of common stock of Purchaser (“Common Stock”) equal to seven and a half percent ( 7.5 %) of the currently issued and outstanding Common Stock. The issuance is governed by a Stock Issuance Agreement entered into by us and the Purchaser on January 27, 2023 (the “Stock Agreement”). Pursuant to the terms of the asset purchase agreement, we are eligible to receive milestone payments up to $ 150 million on a product by product basis for the achievement of certain regulatory approvals and global net sales thresholds. Additionally, we are eligible to receive certain sales-based royalty payments on a product by product basis, ranging from high single-digit to mid-teens of annual net sales related to the two existing clinical stage programs, and low single-digit royalties for the preclinical programs, and certain sublicense income on a product by product basis, either in addition to milestone payments and royalties prior to Phase 2 initiation for COR588 or COR388, or in lieu of milestones payments and royalties after initiation of Phase 2 for COR588 or COR388 or for the preclinical programs. EryDel Acquisition On October 20, 2023, we completed our acquisition of EryDel, a privately held, late-stage biotechnology company with a Phase 3 lead asset, EryDex, that targets the potential treatment of a rare neurodegenerative disease, A-T. The EryDel Acquisition was completed pursuant to that certain Stock Purchase Agreement, dated as of July 21, 2023. Pursuant to the terms of the Purchase Agreement, the Company issued 6,525,315 shares of its common stock to the EryDel Shareholders. Up to an additional 725,037 shares of the Company's common stock may be issued to the EryDel Shareholders upon the first anniversary of the closing of the EryDel Acquisition. The EryDel Shareholders have a contingent right to receive up to an aggregate of $ 485.0 million in potential cash payments, comprised of up to $ 5.0 million upon the achievement of a specified development milestone, $ 25.0 million at NDA acceptance by the FDA, up to $ 60.0 million upon the achievement of specified approval milestones, and up to $ 395.0 million upon the achievement of specified on market and sales milestones, with no royalties paid to EryDel. EryDel is a variable interest entity and the Company is the primary beneficiary and sole shareholder. Refer to Note 15 Business Combination for additional details. Liquidity and Capital Resources The Company has incurred losses and negative cash flows from operations since inception and expects to continue to generate operating losses for the foreseeable future. As of December 31, 2023, the Company had an accumulated deficit of $ 319.6 million. Since inception through December 31, 2023, the Company has funded operations primarily with the net proceeds from the issuance of convertible promissory notes, from the issuance of redeemable convertible preferred stock, from the net proceeds from the IPO and from the net proceeds from the PIPE Financing. As of December 31, 2023, the Company had cash, cash equivalents, and short-term investments of $ 75.1 million, which it believes will be sufficient to fund its planned operations for a period of at least 12 months from the date of the issuance of the accompanying consolidated financial statements. Management expects to incur additional losses in the future to fund the Company's operations and conduct product research and development and may need to raise additional capital to fully implement its business plan. The Company may raise additional capital through the issuance of equity securities, debt financings or other sources including out-licensing or partnerships, in order to further implement its business plan. However, if such financing is not available when needed and at adequate levels, the Company will need to reevaluate its operating plan and may be required to delay the development of its product candidates.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Basis of Consolidation The accompanying consolidated financial statements include the accounts of Quince Therapeutics, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated upon consolidation. Basis of Presentation The accompanying consolidated financial statements and the notes thereto have been prepared in accordance with accounting principles GAAP pursuant to the instructions of the SEC on Form 10-K through the rules and interpretive releases of the SEC under federal securities law. Use of Estimates T he preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and expenses, as well as related disclosure of contingent assets and liabilities. The most significant estimates used in the Company’s consolidated financial statements relate to the determination of the fair value of stock-based awards and other issuances, determination of the fair value of identifiable assets and liabilities in connection with the acquisition of Novosteo, Inc. and EryDel S.p.A., including associated intangible assets and goodwill, contingent consideration, accruals for research and development costs, useful lives of long-lived assets, stock-based compensation and related assumptions, the incremental borrowing rate for leases and income tax uncertainties, including a valuation allowance for deferred tax assets, eligibility of expenses for the Australia research and development refundable tax credits, impairment of intangible assets or goodwill; and contingencies. The Company bases its estimates on historical experience and on various other market specific and other relevant assumptions that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from the Company’s estimates. Foreign Currency Translation and Transactions The functional currency of the Company’s wholly-owned subsidiaries are the Australian Dollar and the Euro. The Company's financial results and financial position are translated into U.S. dollars using exchange rates at balance sheet dates for assets and liabilities and using average exchange rates for income and expenses. The resulting translation differences are presented as a separate component of accumulated other comprehensive loss, as a separate component of equity. Foreign currency transactions are translated into the functional currencies using the exchange rates prevailing at the dates of the transactions. Foreign exchange gains and losses, resulting from the settlement of such transactions and from the re-measurement of monetary assets and liabilities denominated in foreign currencies using exchange rates at balance sheet date and non-monetary assets and liabilities using historical exchange rates, are recognized in the consolidated statements of operations and comprehensive income. Risk and Uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s drug candidates, uncertainty of market acceptance of the Company’s drug candidates, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals and sole source suppliers. The Company’s drug candidates will require approvals from the FDA and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any drug candidate will receive the necessary approvals. Segments The Company operates and manages its business as one reportable and operating segment, which is the business of developing and commercializing therapeutics. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating and evaluating financial performance. All long-lived assets are maintained in Italy. Business Combinations The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. The Company accounts for business combinations using the acquisition method pursuant to the FASB ASC Topic 805. This method requires, among other things, that results of operations of acquired companies are included in the Company's financial results beginning on the respective acquisition dates, and that identifiable assets acquired and liabilities assumed are recognized at fair value as of the acquisition date. Intangible assets acquired in a business combination are recorded at fair value using one of three valuation approaches, the income approach, the market approach or the cost approach. The Company reviewed the three valuation approaches and determined the income approach was the most appropriate model to approximate fair value for both the Novosteo and EryDel Acquisitions. The income approach model requires assumptions about the timing and amount of future net cash flows, the cost of capital and terminal values from the perspective of a market participant. Any excess of the fair value of consideration transferred (the “Purchase Price”) over the fair values of the net assets acquired is recognized as goodwill. The fair value of identifiable assets acquired and liabilities assumed in certain cases may be subject to revision based on the final determination of fair value during a period of time not to exceed 12 months from the acquisition date. Legal costs, due diligence costs, business valuation costs and all other acquisition-related costs are expensed when incurred. Intangible Assets Intangible assets with a definite useful life are amortized on a straight-line basis over the estimated useful life of the related assets. Intangible assets with an indefinite useful life are not amortized. Intangible assets acquired in a business combination that are used in research and development activities (regardless of whether they have an alternative future use) shall be considered indefinite lived until the completion or abandonment of the associated research and development efforts. Intangible assets acquired in a business combination are initially recorded at fair value. During the period that those assets are considered indefinite lived, they shall not be amortized but shall be tested for impairment. Once the research and development efforts are completed or abandoned, the entity shall determine the useful life of the assets. An intangible asset shall be tested for impairment annually and more frequently if events or changes in circumstances indicate that it is more likely than not that the asset is impaired. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the intangible asset is less than its carrying amount, If that is the case, the Company performs a quantitative impairment test, and, if the carrying amount of the Company exceeds its fair value, then the Company will recognize an impairment charge for the amount by which its carrying amount exceeds its fair value, not to exceed the carrying amount of the intangible asset. Qualitative factors to be considered include but are not limited to: • Cost factors such as increases in raw materials, labor, or other costs that have a negative effect on future expected earnings and cash flows. • Legal/regulatory factors or progress and results of clinical trials. • Other relevant entity-specific events such as changes in management, key personnel, strategy, or customers; contemplation of bankruptcy; or litigation that could affect significant inputs used to determine the fair value of the indefinite-lived intangible asset. • Industry and market considerations such as a deterioration in the environment in which an entity operates, an increased competitive environment. • Macroeconomic conditions such as deterioration in general economic conditions, limitations on accessing capital, fluctuations in foreign exchange rates, or other developments in equity and credit markets that could affect significant inputs used to determine the fair value of the indefinite-lived intangible asset. Goodwill Goodwill represents the excess of the purchase price over the fair value of the net assets acquired as of the acquisition date. Goodwill has an indefinite useful life and is not amortized. The Company reviews its goodwill for impairment at least annually or whenever events or changes in circumstances indicate that the carrying amount of the Company may exceed its fair value. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the Company is less than its carrying amount, including goodwill. If that is the case, the Company performs a quantitative impairment test, and, if the carrying amount of the Company exceeds its fair value, then the Company will recognize an impairment charge for the amount by which its carrying amount exceeds its fair value, not to exceed the carrying amount of the goodwill. Contingent Consideration The Company determines the acquisition date fair value of contingent consideration using a discounted cash flow method, with significant inputs that are not observable in the market and thus represents a Level 3 fair value measurement as defined in ASC Topic 820, Fair Value Measurement. The significant inputs in the Level 3 measurement not supported by market activity included our probability assessments of expected future cash flows related to the Company's acquisition of EryDel in October 2023, during the contingent consideration period, appropriately discounted considering the uncertainties associated with the earnout obligation, and calculated in accordance with the terms of the definitive agreement. The liabilities for the contingent consideration are established at the time of the acquisition and will be evaluated on a quarterly basis based on additional information as it becomes available. Any change in the fair value adjustment is recorded in the earnings of that period. During the year ended December 31, 2023, the Company recorded a $ 1.6 million adjustment to increase the fair value of its contingent consideration related to the acquisition of EryDel. The adjustment is reflected within operating loss on the consolidated statement of operations and comprehensive loss . Changes in the fair value of the contingent consideration obligations may result from changes in probability assumptions with respect to the likelihood of achieving the various contingent payment obligations. Significant increases or decreases in the inputs noted above in isolation would result in a significantly lower or higher fair value measurement. Cash, Cash Equivalents and Investments The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash equivalents include marketable securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and at the end of each reporting period. Investments with original maturities beyond three months at the date of purchase and which mature at, or less than twelve months from the balance sheet date are classified as short-term investments. Investments with a maturity beyond twelve months from the balance sheet date are classified as long-term investments. Collectively, cash equivalents, short-term investments and long-term investments are considered available-for-sale and are recorded at fair value. Unrealized gains and losses are recorded as a component of other comprehensive loss in the consolidated statements of operations and included as a separate component of consolidated statements of stockholders’ equity (deficit). Realized gains and losses are included in interest income in the consolidated statements of operations and comprehensive loss. Premiums (discounts) are amortized (accreted) over the life of the related investment as an adjustment to yield using the straight-line interest method. Dividend and interest income are recognized when earned. These amounts are recorded in “interest income” in the consolidated statements of operations and comprehensive loss. Property and Equipment, Net Property and equipment are stated at cost and reduced by accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful lives of the respective assets. Depreciation and amortization begin at the time the asset is placed in service. Maintenance and repairs are charged to expense as incurred, and improvements are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in operations in the period realized. The useful lives of property and equipment are as follows: Computer equipment 3 years Lab equipment 2.5 to 5 years Finance lease right of use assets Shorter of estimated useful life or lease term Leasehold improvement Shorter of estimated useful life or lease term Office furniture 4 to 5 years Concentration of Credit Risk Cash equivalents, short-term and long-term investments are financial instruments that potentially subject the Company to concentrations of credit risk. The Company invests in money market funds, repurchase agreements, treasury bills and notes, government bonds, and corporate notes. The Company limits its credit risk associated with cash equivalents, short-term and long-term investments by placing them with banks and institutions it believes are highly credit worthy and in highly rated investments. However, cash balances in excess of Federal Deposit Insurance Corporation (FDIC) insured limit of $ 0.3 million are at risk. Impairment of Long-Lived Assets The Company reviews long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. An impairment charge would be recorded when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than its carrying amount. Impairment, if any, is assessed using discounted cash flows or other appropriate measures of fair value. The Company recognized impairment charges of $ 0.2 million related to the San Diego lease impairment loss and loss on disposal of fixed assets for the year ended December 31, 2022 . The Company recognized an impairment charge $ 0.1 million for the Purdue lease the year ended December 31, 2023 . Leases The Company determines if an arrangement includes a lease at inception. Right-of-use lease assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use lease asset includes any lease payments made and excludes lease incentives. Incremental borrowing rate is used in determining the present value of future payments. The Company applies a portfolio approach to the property leases to apply an incremental borrowing rate to leases with similar lease terms. The lease terms may include options to extend or terminate the lease. The Company recognizes the options to extend the lease as part of the right-of-use lease assets and lease liabilities only if it is reasonably certain that the option would be exercised. Lease expense for minimum lease payments is recognized on a straight-line basis over the non-cancelable lease term. Research and Development Expenses Research and development costs are expensed as incurred. Research and development expenses consist primarily of personnel costs for the Company’s research and product development employees. Also included are non-personnel costs such as professional fees payable to third parties for preclinical and clinical studies and research services, laboratory supplies and equipment maintenance, product licenses, and other consulting costs. The Company estimates preclinical and clinical study and research expenses based on the services performed, pursuant to contracts with CROs that conduct and manage preclinical and clinical studies and research services on its behalf. Expenses related to clinical studies are based on estimates of the services received and efforts expended pursuant to contracts with many research institutions, clinical research organizations and other service providers that conduct and manage clinical studies on the Company's behalf. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Generally, these agreements set forth the scope of work to be performed at a fixed fee or unit price. Payments under the contracts are mainly driven by time and materials incurred by these service providers. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered. Expenses related to clinical studies are generally recorded based on the timing of when services that have been performed on the Company’s behalf by the service providers, clinical trial budgets and in accordance with the contracts and related amendments. The determination of timing involves reviewing open contracts and purchase orders, communicating with applicable personnel to identify the timing of when services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The Company periodically confirms the accuracy of estimates with the service providers and makes adjustments if necessary. Examples of estimated clinical expenses include: • fees paid to CROs in connection with clinical studies; • fees paid to investigative sites in connection with clinical studies; • fees paid to contract manufacturers in connection with the production of clinical study materials; and • fees paid to vendors in connection with preclinical development activities. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the prepaid or accrual accordingly. Payments associated with licensing agreements to acquire exclusive licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternate commercial use are expensed as incurred. Patent Costs The Company has no historical data to support a probable future economic benefit for the arising patent applications, filing and prosecution costs. Therefore, patent costs are expensed as incurred. Stock-Based Compensation The Company accounts for stock-based compensation arrangements with employees in accordance with ASC 718, Compensation—Stock Compensation. Stock-based awards granted include stock options with service-based vesting. ASC 718 requires the recognition of compensation expense, using a fair value-based method, for costs related to all stock-based payments. The Company’s determination of the fair value of stock options with service-based vesting on the date of grant utilizes the Black-Scholes option-pricing model and is impacted by its common stock price as well as other variables including: but not limited to, expected term that options will remain outstanding, expected common stock price volatility over the term of the option awards, risk-free interest rates and expected dividends. The fair value of a stock-based award is recognized over the period during which an optionee is required to provide services in exchange for the option award, known as the requisite service period (usually the vesting period) on a straight-line basis. Stock-based compensation expense is recognized based on the fair value determined on the date of grant and is reduced for forfeitures as they occur. Stock options exercised are issued new shares of our common stock. Income Taxes The Company accounts for income taxes under the asset and liability method. Current income tax expense or benefit represents the amount of income taxes expected to be payable or refundable for the current year. Deferred income tax assets and liabilities are determined based on differences between the consolidated financial statement reporting and tax bases of assets and liabilities and net operating loss and credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all of the tax benefits will not be realized. The Company accounts for uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainty in Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available. The Company includes any penalties and interest expense related to income taxes as a component of other expense, net and interest expense, net, as necessary. Comprehensive Loss The Company is required to report all components of comprehensive loss, including net loss, in the consolidated financial statements in the period in which they are recognized. Comprehensive loss is defined as a change in equity of a business enterprise during a period, resulting from transactions and other events and circumstances from non-owner sources. The Company had an unrealized gain and loss from its available-for sale securities and cumulative translation adjustment during the years ended December 31, 2023 and December 31, 2022, respectively, which are considered other comprehensive loss. Net Loss per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and common share equivalents of potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation and common stock options are considered to be potentially dilutive securities. Because the Company reported a net loss for the years ended December 31, 2023 and December 31, 2022 , and the inclusion of the potentially dilutive securities would be antidilutive, diluted net loss per share is the same as basic net loss per share for both periods. Recent Accounting Pronouncements Adopted Financial Instruments—Credit Losses: In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments which amends the principles around the recognition of credit losses by mandating entities incorporate an estimate of current expected credit losses when determining the value of certain assets. The guidance also amends reporting around allowances for credit losses on available-for-sale marketable securities. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842): Effective Dates, which established that a one-time determination of the effective date for ASU 2016-13 would be based on the Company’s SEC reporting status as of November 15, 2019. The Company was a “smaller reporting company” as defined by Item 10 of Regulation S-K, and therefore, ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. This guidance helps to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in Topic 326 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company has adopted the new guidance as of January 1, 2023, and it did not have a material impact on its consolidated financial statements and related disclosures. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive loss, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the statement of operations and comprehensive loss. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the balance sheets. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its consolidated financial statements: Improvements to Income Tax Disclosures (ASC 740); In December 2023, the FASB issued ASU No. 2023-09, "Improvements to Income Tax Disclosures." This ASU establishes new income tax disclosure requirements in addition to modifying and eliminating certain existing requirements. Under this ASU, entities must consistently categorize and provide greater disaggregation of information in the rate reconciliation. They must also further disaggregate income taxes paid. The ASU is effective in December 2024 under a prospective approach. Early adoption is permitted. Adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. Accounting Standard Update 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”): In November 2023, the FASB issued ASU 2023-07, which is intended to improve reportable segment disclosure requirements, primarily through additional disclosures about significant segment expenses, including for single reportable segment entities. The standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. The Company is evaluating the disclosure requirements related to the new standard. All other newly issued accounting pronouncements not yet effective have been deemed either immaterial or not applicable.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements The fair value of the Company's financial instruments reflects the amounts that the company estimates would receive in connection with the sale of an asset or pay in connection with the transfer of a liability in an orderly transaction between market participants at the measurement date (exit price). The Company discloses and recognizes the fair value of the assets and liabilities using a hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to valuations based upon unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to valuations based upon unobservable inputs that are significant to the valuation (Level 3 measurements). The guidance establishes three levels of the fair value hierarchy as follows: Level 1 - Inputs that reflect unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 - Inputs other than quoted prices that are observable for the assets or liability either directly or indirectly, including inputs in markets that are not considered to be active. Level 3 - Inputs that are unobservable. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company's financial instruments are carried in the accompanying consolidated balance sheets at amounts that approximate fair value. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the years ended December 31, 2023 and December 31, 2022. The Company elected the fair value option for the EIB Loan assumed as part of the EryDel Acquisition. The Company adjusted the EIB Loan to fair value through the change in fair value of debt in the accompanying consolidated statements of operations and comprehensive loss. Subsequent unrealized gains and losses on items for which the fair value option is elected are reported in earnings. The Company will breakout any change in value due to credit loss in accumulated other comprehensive loss. For the year ended December 31, 2023 there was no change in value due to credit loss. Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of December 31, 2023 and 2022 are presented in the following tables (in thousands): Fair Value Measurements at December 31, 2023 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 4,285 $ 4,285 $ — $ — Certificates of Deposit 729 — 729 — Government and agency notes 68,524 3,971 64,553 — Total assets $ 73,538 $ 8,256 $ 65,282 $ — Liabilities: Accrued earnout 57,706 — — 57,706 Long-term debt 13,429 — — 13,429 Total liabilities $ 71,135 $ — $ — $ 71,135 Fair Value Measurements at December 31, 2022 Total Level 1 Level 2 Level 3 Money market funds $ 10,988 $ 10,988 $ — $ — Certificates of Deposit 6,102 — 6,102 — Repurchase Agreements 9,000 — 9,000 — Corporate notes 12,411 — 12,411 — Government and agency notes 50,766 — 50,766 — Municipal notes 506 — 506 — Total $ 89,773 $ 10,988 $ 78,785 $ — The Company classifies corporate notes, certificates of deposit, repurchase agreements, municipal notes, and government and agency notes as Level 2 investments as the Company uses quoted prices for similar assets sourced from certain third-party pricing services. The third-party pricing services generally utilize industry standard valuation models for which all significant inputs are observable, either directly or indirectly, to estimate the price or fair value of the securities. The primary input generally includes reported trades of or quotes on the same or similar securities. The Company does not make additional judgments or assumptions made to the pricing data sourced from the third-party pricing services. Contingent Consideration The following table reflects the changes in present value of acquisition related accrued earnouts of contingent consideration liability using significant unobservable inputs (Level 3) for the year ended December 31, 2023 follows: (in thousands) Beginning Balance as of January 1, 2023 $ — Acquisition date fair value of contingent consideration 56,128 Change in fair value of contingent consideration 1,578 Ending Balance as of December 31, 2023 $ 57,706 The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related accrued earnout as of December 31, 2023: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value at Valuation Unobservable Input Range (Input Used) December 31, Technique 2023 Accrued earnout $ 57,706 Expected present Probability of achieving earnout 0 % - 100 % value objectives per the purchase agreement Long-term Debt The following table presents the changes in the fair value of the Level 3 EIB Debt: (in thousands) Beginning Balance as of January 1, 2023 $ — Acquisition of EIB Debt 12,564 Change in fair value 338 Due to foreign currency translation 527 Ending Balance as of December 31, 2023 $ 13,429 The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related long term debt as of December 31, 2023: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value at Valuation Unobservable Input Discount Rate (Input Used) December 31, Technique 2023 EIB loan $ 13,429 Expected present Credit quality of company 13 % value and credit spreads for comparable debt

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Cash, Cash Equivalents and Investments	Note 4: Cash, Cash Equivalents and Investments The following tables categorize the fair values of cash, cash equivalents, short-term investments and long-term investments measured at fair value on a recurring basis on our balance sheets (in thousands): December 31, 2023 2022 Cash and cash equivalents: Cash $ 1,521 $ 3,986 Money market funds 4,285 10,988 Repurchase agreements — 9,000 Government and agency notes 14,946 20,605 Total cash and cash equivalents $ 20,752 $ 44,579 Short-term investments: Certificates of deposit $ 729 $ 5,390 Municipal notes — 506 Corporate notes — 12,411 Government and agency notes 53,578 27,295 Total short-term investments $ 54,307 $ 45,602 Long-term investments Certificates of deposit $ — $ 712 Government and agency notes — 2,866 Total long-term investments $ — $ 3,578 The investments are classified as available-for-sale securities. As of December 31, 2023, the weighted average remaining contractual maturities of available-for-sale securities was approximately 2 months . At December 31, 2023 and 2022 , the unrealized gain (loss) activity related to the Company’s available-for-sale securities is included in the Company’s accumulated other comprehensive loss. There were no significant realized gains or losses recognized on the sale or maturity of available-for-sale securities for the years ended December 31, 2023 and 2022 and as a result, the Company did no t reclassify any amounts out of accumulated other comprehensive loss. Based on the Company’s review of its available-for-sale securities, the Company has a limited number of available-for-sale securities in insignificant loss positions as of December 31, 2023. No other-than-temporary impairments on these securities were recognized for the years ended as of December 31, 2023 and 2022. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive loss, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the statement of operations and comprehensive loss. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the balance sheets. The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements at December 31, 2023 Amortized Unrealized Unrealized Fair Value Money market funds $ 4,285 $ — $ — $ 4,285 Certificates of Deposit 735 — ( 6 ) 729 Government and agency notes 68,528 13 ( 17 ) 68,524 Total cash equivalents and investments $ 73,548 $ 13 $ ( 23 ) $ 73,538 Classified as: Cash equivalents (original maturities within 90 days) $ 19,231 Short-term investments (maturities within 1 year) 54,307 Total cash equivalents and investments $ 73,538 Fair Value Measurements at December 31, 2022 Amortized Unrealized Unrealized Fair Value Money market funds $ 10,988 $ — $ — $ 10,988 Certificates of Deposit 6,237 1 ( 136 ) 6,102 Repurchase Agreements 9,000 — — 9,000 Corporate notes 12,575 — ( 164 ) 12,411 Government and agency notes 51,020 4 ( 258 ) 50,766 Municipal notes 510 — ( 4 ) 506 Total cash equivalents and investments $ 90,330 $ 5 $ ( 562 ) $ 89,773 Classified as: Cash equivalents (original maturities within 90 days) $ 40,593 Short-term investments (maturities within 1 year) 45,602 Long-term investments (maturities beyond 1 year) 3,578 Total cash equivalents and investments $ 89,773 The table below summarizes the unrealized losses of the Company's investments in debt securities measured at fair value as of December 31, 2023 (in thousands): Less than twelve months Twelve months or greater Total Fair value Gross unrealized loss Fair value Gross unrealized loss Fair value Gross unrealized loss Certificates of deposit $ — $ — $ 729 $ ( 6 ) $ 729 $ ( 6 ) Government and agency notes 3,966 — 2,975 ( 17 ) 6,941 ( 17 ) Total cash equivalents and investments $ 3,966 $ — $ 3,704 $ ( 23 ) $ 7,670 $ ( 23 ) There were no transfers between Levels 1, 2 or 3 for the period presented. The table below summarizes the contractual maturities of the Company's investments in debt securities measured at fair value as of December 31, 2023 (in thousands): Maturities by Period Total Less Than 1 Year 1-5 Years 6-10 Years More Than 10 Years Fair value of debt securities $ 54,307 $ 54,307 $ — $ — $ —

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2023
Balance Sheet Components [Abstract]
Balance Sheet Components	Note 5: Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2023 2022 Prepaid expenses $ 365 $ 223 Prepaid insurance 809 977 Prepaid research and development expenses 133 1,088 Australia research and development refundable tax credit — 1,003 Short-term Italian research and development refundable tax credit 993 — Other current assets 81 276 Total prepaid expenses and other current assets $ 2,381 $ 3,567 EryDel is eligible to obtain an R&D tax credit as companies in Italy that invest in eligible research and development activities, regardless of the legal form and economic sector in which they operate, can benefit from a R&D tax credit. Such tax credits can only be used to offset payments of certain taxes and c ontributions (e.g., social contributions, VAT payables, registration fees, income and withholding taxes and all other tax-related items that companies usually pay monthly). The Company recognized reductions to R&D expense of $ 0.2 million and $ 0 for the years ended December 31, 2023 and 2022, respectively. Cortexyme Australia, Pty, Ltd, a wholly-owned subsidiary of the company is eligible to obtain a cash refund from the Australian Taxation Office for eligible R&D expenditures under the Australian R&D Tax Incentive Program (the “Australian Tax Incentive”). The Australian Tax Incentive is recognized as a reduction to R&D expense when there is reasonable assurance that the relevant expenditure has been incurred, the amount can be reliably measured and that the Australian Tax Incentive will be received. The Company recognized reductions to R&D expense of $ 0 and $ 0.6 million for the years ended December 31, 2023 and 2022 , respectively. The Company received a refundable tax credit of $ 0.5 million in the year ended December 31, 2023 , which reduced prepaid expenses and other current assets by $ 0.5 million as of December 31, 2023. Novosteo Pty, Ltd, a wholly-owned subsidiary of Novosteo, LLC, is eligible to obtain a cash refund from the Australian Taxation Office for eligible R&D expenditures under the Australian Tax Incentive as well. The Company received a refundable tax credit of $ 0.5 million in the first quarter of 2023, which reduced prepaid expenses and other current assets by $ 0.5 million as of March 31, 2023. Other Assets Other assets consisted of the following (in thousands): December 31, 2023 2022 VAT receivable $ 3,463 $ — Long-term Italian research and development refundable tax credit 4,993 — Total other assets $ 8,456 $ — Assets Held for Sale Assets held for sale consist of the following (in thousands): December 31, 2023 2022 Assets held for sale $ 10 $ — Total assets held for sale $ 10 $ — Property and equipment, net Property and equipment, net consisted of the following (in thousands): December 31, 2023 2022 Computer equipment $ 36 $ 18 Computer software 30 — Lab equipment 486 415 Finance lease right of use assets — 124 Leasehold improvement 36 21 Office furniture 153 — Less: accumulated amortization and depreciation ( 507 ) ( 185 ) Property and equipment, net $ 234 $ 393 Depreciation and amortization expense for property and equipment was $ 0.3 million and $ 0.2 million for the years ended December 31, 2023 and 2022, respectively. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): December 31, 2023 2022 Personnel expenses $ 2,340 $ 1,130 Professional fees 211 234 Research and development expenses 564 497 Current portion of operating lease liabilities 64 377 Current portion of finance lease liability — 76 Other 257 185 Total accrued expenses and other current liabilities $ 3,436 $ 2,499 Below is the severance accrual activity included in the personnel expenses in the above table related to a cost reduction program during the years ended December 31, 2023 and December 31, 2022 (in thousands): For the year 2023 2022 Beginning accrued severance $ — $ — Incurred during the period 770 3,942 Severance paid during the period ( 429 ) ( 3,942 ) Ending accrued severance $ 341 $ — In response to the reprioritization of the Company's pipeline following the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities, the Board approved a cost reduction program to reorganize operations and allow continued support for the needs of the business. Under the cost reduction program, the Company lowered headcount through a reduction in workforce. The Company recognized the severance of $ 0.3 million and related expenses of $ 0.1 million over the requisite employment obligation period. The reduction in force was completed in April 2023. On August 4, 2023, the Company entered into a transition and separation agreement with Karen Smith, M.D., Ph.D., (the “Separation Agreement”) in connection with Dr. Smith’s transition and departure from the Company as the Company's Chief Medical Officer, effective as of September 1, 2023. Pursuant to the Separation Agreement, the Company is required to pay cash severance, equal to her annual salary, in the aggregate amount of $ 0.5 million, of which $ 0.1 million was recognized during the year ended December 31, 2023 . The severance is paid on regular payroll schedule through the third quarter of 2024. Additionally, pursuant to the Separation Agreement, the Company paid an additional cash bonus severance payment equal to 100 % of Dr. Smith’s target annual bonus opportunity for 2023 on a prorated basis, an additional cash severance payment equal to 12 months’ of the monthly premiums for health care continuation benefits, and provided for 50 % accelerated vesting with respect to Dr. Smith’s equity award. The acceleration of 612,141 options and 54,757 RSAs resulted in a stock-based compensation expense of approximately $ 0.1 million.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	Note 6. Leases Real Estate Operating Leases In June 2022, the Company entered into a Sublease Agreement to rent office space in South San Francisco, California. The Sublease Agreement commenced on June 18, 2022 and ended on November 30, 2023. The total payments under the term of the lease were approximately $ 0.3 million. The Company paid a security deposit of $ 17,000 which is included in Prepaid Expenses and Other Current Assets on the December 31, 2023 consolidated balance sheets and the deposit was refunded in January 2024. At the commencement of the lease, the Company recorded an operating lease right of use asset and liability of $ 0.3 million. On October 31, 2023, the Company signed a lease agreement for a smaller office space in South San Francisco, California. The total payments under the new lease are expected to be approximately $ 22,000 for the year. The lease commenced on November 30, 2023 and will end on November 30, 2024. In October 2022, the Company entered into a lease agreement to rent space in West Lafayette, Indiana. The lease agreement amended the original lease to transfer liability to the Company due to the Novosteo Acquisition. The lease agreement is for 15 months, which commenced on October 1, 2022 and ended on December 31, 2023. The total payments under the term of the lease were approximately $ 0.2 million. At the commencement of the lease, the Company recorded an operating lease right of use asset and liability of $ 0.1 million. In December 2022, the Company entered into an amendment to the lease agreement of the rental space in West Lafayette to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company will pay rent monthly for the additional space. The Company recorded an operating lease right of use asset and liability of $ 10,000 . In February 2023, as a result of the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities, the Company entered into a sublease agreement as the lessor for the majority of the West Lafayette facility. The lease commenced on March 17, 2023 and ended on December 31, 2023. The sublessee paid the Company a security deposit of $ 6,000 which is included in Accrued expenses and other current liabilities on the December 31, 2023 consolidated balance sheet. Under the terms of the sublease, the Company is entitled to receive a total rental income that is expected to offset rent expense of $ 57,000 . As a result of this decision and the sublease agreement, the Company recorded an impairment loss of approximately $ 66,000 which is included in other expense, net per the consolidated statement of operations and comprehensive loss for the year ended December 31, 2023. In October 2023, as part of the EryDel Acquisition the Company acquired operating leases in which the Company recorded an operating lease right of use asset and liability in total of $ 0.4 million. This includes a lease agreement renting office space in Bresso, in the Province of Milan, Italy. The Lease Agreement commenced on September 1, 2016, and will end on August 31, 2028. At acquisition date, the Company recorded an operating lease right of use asset and liability of $ 0.1 million. This also includes a lease agreement renting office space in Medolla, in the Province of Modena, Italy. The Lease Agreement commenced on June 18, 2018, with a duration of 12 years , until January 31, 2030. At acquisition date, the Company recorded an operating lease right of use asset and liability of $ 0.2 million. The acquired lease agreements also included other operating leases two of which are car leases and the other a printing press which in total the Company recorded an operating lease right of use asset and liability of $ 31,000 . In January 2024, the above-mentioned Lease Agreement for the office space in Medolla (Italy) was renegotiated. The new Lease Agreement commenced on February 1, 2024, and will end on January 31, 2036, substituting the Lease Agreement commenced in June 2018. The Company recognizes lease expense on a straight-line basis over the term of its operating lease. As of December 31, 2023, total future rent expense from all real estate operating leases of $ 0.4 million will be recognized over the remaining term of 29 to 73 months on a straight-line basis over the respective lease period. Clinical Equipment Financing Lease As part of the Novosteo Acquisition, the Company acquired a financing lease for certain lab equipment. The Company recognizes the amortization expense in research and development expenses in the consolidated statements of operations and comprehensive loss and recognizes expense on a straight-line basis starting when the equipment is placed into service until the end of the remaining contract term of 18 months. Amortization expense of the financing lease right of use asset for the year ended December 31, 2023 was $ 6,000 . Amortization expense of the financing lease right of use asset for the year ended December 31, 2022 was $ 50,000 . In February 2023, as a result of the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities, the Company exercised its purchase option for the financed equipment in order to resell and this equipment is currently held on consignment and is included in assets held for sale on the December 31, 2023 consolidated balance sheet. As a result of this action, the Company reduced the Finance lease ROU asset and Finance lease liability by approximately $ 70,000 . Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): December 31, 2023 December 31, 2022 Operating lease right of use asset, net $ 385 $ 291 Short-term operating lease liability 64 377 Long-term operating lease liability 321 — $ 385 $ 377 Finance lease right of use asset — 124 Finance lease accumulated amortization — ( 50 ) Total finance lease right of use asset, net $ — $ 74 Weighted average remaining lease term Operating leases 5.4 years 0.9 years Finance leases — 1.0 year Weighted average discount rate Operating leases 7.95 % 5.71 % Finance leases — % 4.45 % Year ended December 31, Operating Lease 2024 91 2025 91 2026 88 2027 81 2028 69 Thereafter 48 Total lease payments 469 Less: imputed interest ( 83 ) Total remaining lease liability $ 385 Lease costs for the years ended December 31, 2023 and 2022 were approximately: Years ended December 31, 2023 2022 Lease costs: Finance lease amortization of right of use assets $ 6 $ 50 Operating lease costs 266 572 Short-term lease costs 96 75 Total lease costs $ 368 $ 697

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Long-term Debt	Note 7. Long-term Debt In connection with the acquisition of EryDel on October 20, 2023 , the Company assumed an unsecured line of credit between EryDel and the European Investment Bank (the "EIB Loan"). The EIB Loan was amended and restated as of the acquisition date. The EIB Loan provides for maximum borrowings of 30.0 million euro through four tranches; tranche A, 3.0 million euro; tranche B, 7.0 million euro; tranche C, 10.0 mi llion euro; and tranche D, 10.0 million euro. Each tranche is subject to conditions precedent related to the Company’s business and capitalization. The unused portions of each tranche may be canceled by the Company at any time, subject to a cancellation fee. As of December 31, 2023, only tranches A and B have been drawn. All amounts due under tranche A and B are payable on their maturity date of August 2026. Tranche C and D are payable in equal installments of principal together with all amounts outstanding under the tranches on the repayment dates specified in the relevant Disbursement Offer. The first Repayment Date of tranche C shall fall not earlier than twelve months from the Disbursement Date of such tranche. The last Repayment Date of tranche C and tranche D shall fall not later than 5 years from the Disbursement Date of tranche C and tranche D, respectively. The EIB Loan bears interest at fixed rates for each tranche and is payable on the maturity date for each Tranche. The fixed rates range from 7.0 % to 9.0 % per annum. As of December 31, 2023, principal of 10.0 million euros ($ 11.0 million) was outstanding on the EIB Loan and it is recorded as Long-term debt on the consolidated balance sheet at fair value with imputed interest of 9.0 % included. The Company may voluntarily prepay, in whole or in part with a prepayment premium. In the event of an occurrence of an event of default or a change in control, as specified in the Debt Agreement, the Company will be required to prepay the outstanding EIB Debt. The Debt Agreement includes a provision for additional remuneration to be paid in addition to interest. The amount of additional remuneration to be paid is equal to 2.5 % of revenue up to 125.0 million euros, plus 1.85 % of revenue between 125.0 and 250.0 million euros , plus 1.0 % of revenue in excess of 250.0 million euros, multiplied by a varying percentage based on how many tranches have been drawn. The varying percentage is equal to 30.0 % in the event tranche A has been drawn, 50.0 % in the event tranche A and B have been drawn, 80.0 % in the event tranche A, B and C have been drawn, and 100.0 % in the event all four tranches have been drawn. The additional remuneration is payable for seven years , during the period January 1, 2026, through December 31, 2032. In the event of an occurrence of an event of default or prepayment, the Company may be required to pay an additional remuneration buyout fee. The Company elected to account for the EIB Loan at fair value, which requires the EIB Loan to be recorded at fair value at issuance and at the end of each reporting period. Gains or losses upon remeasurement are to be recorded in other income (expense) in the consolidated statements of operations and comprehensive income. The Company presents separately in other comprehensive income the portion of the total change in the fair value of the EIB Loan that results from a change in instrument-specific credit risk. The EIB Loan’s fair value at the date it was assumed adjusted its carrying value based on using a discounted cash flow analysis with a discount rate based on a yield curve that was adjusted for credit rating. The change in fair value at December 31, 2023 was determined using a discounted cash flow analysis discounted at the market yield. The significant inputs used to measure the market yield at December 31, 2023 relative to the date the EIB Loan was assumed was the change in credit quality of the Company, the change in credit spreads for comparable debt instruments, and the change in the risk-free rate. As of December 31, 2023, the fair value of the EIB Loan is valued at $ 13.4 million, which includes a fair value adjustment of $ 0.3 million and foreign currency translation of $ 0.5 million, from the amount recorded at fair value on the date of the EryDel Acquisition of $ 12.6 million. Future minimum principal payments, as of December 31, 2023 are as follows (in thousands): Year Ending December 31, Amount 2024 $ — 2025 — 2026 11,053 2027 and thereafter — Total future minimum payments 11,053 Imputed interest 2,376 Total Debt as of December 31, 2023 $ 13,429

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 8. Commitments and Contingencies Legal Matters The Company’s industry is characterized by frequent claims and litigation, including claims regarding intellectual property. As a result, the Company may be subject to various legal proceedings from time to time. The results of any future litigation cannot be predicted with certainty, and regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. Management is not aware of any pending or threatened litigation. Indemnification As permitted under Delaware law and in accordance with the Company’s bylaws, the Company indemnifies its officers and directors for certain events or occurrences while the officer or director is or was serving in such capacity. The Company is also party to indemnification agreements with its directors. The Company believes the fair value of the indemnification rights and agreements is minimal. Accordingly, the Company has not recorded any liabilities for these indemnification rights and agreements as of December 31, 2023 and 2022. Contingencies From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made, and such expenditures can be reasonably estimated.

Equity Incentive Plans

Equity Incentive Plans	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Equity Incentive Plans	Note 9. Equity Incentive Plans The Company operates three stock plans as of December 31, 2023. • 2019 Equity Incentive Plan (Quince) • 2019 Equity Incentive Plan (Novosteo) • 2022 Inducement Plan (Quince) 2019 Equity Incentive Plan (Quince) On December 4, 2014, the Company’s stockholders approved the 2014 Stock Plan (“2014 Plan”), and on April 25, 2019 amended, restated and re-named the 2014 Plan as the 2019 Equity Incentive Plan (the “Quince 2019 Plan”), which became effective as of May 7, 2019, the day prior to the effectiveness of the registration statement filed in connection with the IPO. The remaining shares available for issuance under the 2014 Plan were added to the shares reserved for issuance under the Quince 2019 Plan. The Quince 2019 Plan provides for the grant of stock options (including incentive stock options and non-qualified stock options), stock appreciation rights, restricted stock, RSUs, performance units, and performance shares to the Company’s employees, directors, and consultants. The maximum aggregate number of shares that may be issued under the Quince 2019 Plan is 10,036,489 shares of the Company’s common stock. In addition, the number of shares available for issuance under the Quince 2019 Plan will be annually increased on the first day of each of its fiscal years beginning with fiscal 2020, by an amount equal to the least of (i) 2,146,354 shares of common stock; (ii) 4 % of the outstanding shares of its common stock as of the last day of its immediately preceding fiscal year; and (iii) such other amount as the Company’s Board of Directors may determine. The Quince 2019 Plan may be amended, suspended or terminated by the Company’s Board of Directors at any time, provided such action does not impair the existing rights of any participant, subject to stockholder approval of any amendment to the Quince 2019 Plan as required by applicable law or listing requirements. Unless sooner terminated by the Company’s Board of Directors, the 2019 Plan will automatically terminate on April 23, 2029. Stock Options S tock options under the 2019 Plan may be granted for periods of up to 10 years and at prices no less than 100 % of the estimated fair value of the shares on the date of grant as determined by the board of directors. If, at the time of grant, the optionee directly owns stocks representing more than 10 % of the voting power of all our outstanding capital stock, the exercise price for these options must be at least 110 % of the fair value of the underlying common stock. Stock options granted to employees and non-employees generally have a maximum term of ten years and vest over four years from the vesting commencement date, of which 25 % vest on the one-year anniversary of the vesting commencement date, and 75 % vest in equal monthly installments over the remaining three years or monthly vesting over 3 to 4 years. We may grant options with different vesting terms from time to time. Unless an employee's or non-employee's termination is due to cause, disability or death, upon termination of service, any unexercised vested options will be forfeited at the end of the three months from the termination date or expiration of the option, whichever is earlier. Activity for service-based stock options under the Quince 2019 Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2021 5,571,293 $ 28.70 8.26 $ 15,687 Options granted 2,051,058 8.13 — — Options exercised ( 102,152 ) 1.45 — — Options cancelled / forfeited ( 4,200,488 ) 29.30 — — Balance at December 31, 2022 3,319,711 $ 16.07 4.77 $ 65 Options granted 3,346,958 1.03 — — Options exercised ( 258,705 ) 0.42 — — Options cancelled / forfeited ( 2,140,786 ) 16.52 — — Balance at December 31, 2023 4,267,178 $ 5.00 8.85 $ 197 Options vested and expected to vest as of December 31, 2023 4,267,178 5.00 8.85 197 Options exercisable at December 31, 2023 1,109,464 $ 14.09 7.32 $ 34 Aggregate intrinsic value represents the difference between the Company’s estimated fair value of its common stock as of their respective balance sheet dates and the exercise price of outstanding options. The total intrinsic value of the Quince 2019 Plan options exercised was $ 0.3 million and $ 1.4 million for the years ended December 31, 2023 and 2022, respectively. The weighted-average grant date fair value of options granted during the years ended December 31, 2023 and 2022 was $ 0.82 and $ 6.05 per share, respectively. The total estimated grant date fair value of options vested during each of the years ended December 31, 2023 and 2022 was $ 11.1 million and $ 31.8 million, respectively. In 2023 and 2022 , the Company recognized $ 2.6 million and $ 11.4 million, respectively, of stock-based compensation expense related to options granted to employees and non-employees. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of December 31, 2023, total unamortized employee stock-based compensation was $ 4.0 million, which is expected to be recognized over the remaining estimated vesting period of 2.55 years. Restricted Stock Units RSUs are share awards that entitle the holder to receive freely tradable shares of the Company’s common stock upon vesting. The fair value of RSUs is based upon the closing sales price of the Company’s common stock on the grant date. RSUs granted to employees generally vest over a 2 – 4 year period. The following table summarizes activity under the Company’s RSUs from the Quince 2019 Plan and related information: Restricted Stock Units Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 30,876 $ 4.30 RSUs granted — — RSUs vested ( 10,200 ) 4.30 RSUs cancelled ( 19,188 ) 4.30 Unvested - December 31, 2023 1,488 $ 4.30 The fair value of the RSUs is determined on the grant date based on the fair value of the Company’s common stock. The fair value of the RSUs is recognized as expense ratably over the vesting period of two years . The total grant date fair value of the RSUs vested during the years ended December 31, 2023 and 2022 was $ 44,000 and $ 1,700,000 , respectively. The aggregate intrinsic value of the shares of the RSUs vested during the years ended December 31, 2023 and December 31, 2022 were $ 11,000 and $ 1.1 million, respectively . For the years ended December 31, 2023 and 2022, the Company recognized stock-based compensation expense of $ 37,000 and $ 1,337,000 , respectively, related to these RSUs. As of December 31, 2023, the total unamortized stock-based compensation related to RSUs was $ 4,000 , which is expected to be recognized over the remaining estimated vesting period of 0.17 years. 2019 Equity Incentive Plan (Novosteo) On May 19, 2022, in accordance with the term of the Merger Agreement, the Company assumed the 2019 Novosteo Equity Incentive Plan (the "2019 Novosteo Plan"). The 2019 Novosteo Plan provides for the grant of stock options (including incentive stock options and non-qualified stock options), stock appreciation rights, restricted stock, RSUs, performance units, and performance shares to the Novosteo legacy employees. On the closing date, each outstanding Novosteo stock option granted under Novosteo’s equity compensation plans was converted into a corresponding stock option with the number of shares underlying such option and the applicable exercise price adjusted based and adjusted into the right to purchase 0.0911 shares of common stock. Each such converted stock option will continue to be subject to substantially the same terms and conditions as applied to the corresponding Novosteo stock option prior to the Acquisition. The maximum aggregate number of shares that may be issued under the 2019 Novosteo Plan is 544,985 shares of the Company’s common stock. The 2019 Novosteo Plan may be amended, suspended or terminated by the Board at any time, provided such action does not impair the existing rights of any participant, subject to stockholder approval of any amendment to the 2019 Novosteo Plan as required by applicable law or listing requirements. Unless sooner terminated by the Board, the 2019 Novosteo Plan will automatically terminate on May 20, 2029. Stock options under the 2019 Novosteo Plan may be granted for periods of up to 10 years and at prices no less than 100 % of the estimated fair value of the shares on the date of grant as determined by the board of directors. If, at the time of grant, the optionee directly owns stocks representing more than 10 % of the voting power of all our outstanding capital stock, the exercise price for these options must be at least 110 % of the fair value of the underlying common stock. Stock options granted to employees and non-employees generally have a maximum term of ten years and vest over four years from the vesting commencement date, of which 25 % vest on the one-year anniversary of the vesting commencement date, and 75 % vest in equal monthly installments over the remaining three years or monthly vesting over 3 to 4 years. We may grant options with different vesting terms from time to time. Unless an employee's or non-employee's termination is due to cause, disability or death, upon termination of service, any unexercised vested options will be forfeited at the end of the three months from the termination date or expiration of the option, whichever is earlier. Activity for service-based stock options under the 2019 Novosteo Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2021 — $ — — $ — Options assumed 507,648 0.55 — — Options exercised — — — — Options cancelled / forfeited ( 4,543 ) 0.55 — — Balance at December 31, 2022 503,105 $ 0.55 9.23 $ 44 Options granted — — — — Options exercised ( 105,808 ) 0.55 — 40 Options cancelled / forfeited ( 86,866 ) 0.55 — — Balance at December 31, 2023 310,431 $ 0.55 8.23 $ 155 Options vested and expected to vest as of December 31, 2023 310,431 0.55 8.23 155 Options exercisable as of December 31, 2023 135,812 $ 0.55 8.23 $ 68 For the years ended December 31, 2023 and 2022, the Company recognized stock-based compensation expense of $ 275,000 and $ 245,000 , respectively, related to options granted to employees and non-employees for the 2019 Novosteo plan. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of December 31, 2023, total unamortized employee stock-based compensation was $ 0.4 million, which is expected to be recognized over the remaining estimated vesting period of 2.23 years. The total aggregate intrinsic value of the Novosteo 2019 Plan options exercised was $ 427,000 and $ 0 for the years ended December 31, 2023 and 2022. The weighted-average grant date fair value of options granted during the years ended December 31, 2023 and 2022 was $ 0 and $ 2.51 per share, respectively. The total estimated grant date fair value of options vested during the years ended December 31, 2023 and 2022 was $ 0.3 million and $ 0.3 million, respectively. On May 19, 2022, in accordance with the term of the Merger Agreement, the Company assumed a number of RSAs agreements with certain employees. Each outstanding Novosteo RSA was converted into a corresponding RSA with the number of shares underlying such RSA adjusted into 0.0911 shares of common stock. Each such converted RSA will continue to be subject to substantially the same terms and conditions as applied to the corresponding Novosteo RSA prior to the Acquisition. Restricted Stock Awards Restricted Stock Awards Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 427,401 $ 3.30 RSAs issued — — RSAs vested ( 188,344 ) 3.30 RSAs cancelled ( 63,293 ) 3.30 Unvested - December 31, 2023 175,764 $ 9.90 For the years ended December 31, 2023 and 2022, the Company recognized stock-based compensation expense of $ 496,000 and $ 338,000 , respectively, related to restricted stock awards. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of December 31, 2023, total unamortized employee stock-based compensation was $ 0.6 million, which is expected to be recognized over the remaining estimated vesting period of 1.74 years. 2022 Inducement Plan On May 9, 2022, the Company's board of directors approved 4,000,000 shares of the Registrant’s common stock that may be offered or issued under the Quince Therapeutics, Inc. 2022 Inducement Plan. The 2022 Inducement Plan was adopted by the independent members of the Board without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. In accordance with rule awards under those plans may only be made to an employee who has not previously been an employee or member of the Board or of any board of directors of any parent or subsidiary of the Company, or following a bona fide period of non-employment by the Company or a parent or subsidiary, if he or she is granted such award in connection with his or her commencement of employment with the Company or a subsidiary and such grant is an inducement material to his or her entering into employment with the Company or such subsidiary. The terms and conditions of the 2022 Inducement Plan are substantially similar to those of the Quince 2019 Plan. Options under the 2022 Inducement Plan may be granted for periods of up to 10 years at prices no less than 100 % of the estimated fair value of the shares on the date of grant as determined by the board of directors. Options granted to employees may have different performance goals or other vesting provisions (including continued employment) in accordance with Award Agreement. Unless an employee's termination service is due to disability or death, upon termination of service, any unexercised vested options will be forfeited at the end of the three months or expiration of the option, whichever is earlier. Activity for service-based stock options under the 2022 Inducement Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2021 — $ — — $ — Options granted 3,744,255 2.98 — — Options exercised — — — — Options cancelled / forfeited ( 2,000 ) 2.98 — — Balance at December 31, 2022 3,742,255 $ 2.98 9.39 $ — Options granted — — — — Options exercised — — — — Options cancelled / forfeited ( 1,408,949 ) 2.98 — — Balance at December 31, 2023 2,333,306 $ 2.98 8.39 $ — Options vested and expected to vest as of December 31, 2023 2,333,306 2.98 8.39 — Options exercisable as of December 31, 2023 923,599 $ 2.98 8.39 $ — For the years ended December 31, 2023 and 2022, the Company recognized stock-based compensation expense of $ 1,802,000 and $ 1,293,000 , respectively, related to options granted to employees and non-employees for the 2022 Inducement plan. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of December 31, 2023, total unamortized employee stock-based compensation was $ 3.2 million, which is expected to be recognized over the remaining estimated vesting period of 2.39 years. The total aggregate intrinsic value of the 2022 Inducement Plan options exercised was $ 0 for both the years ended December 31, 2023 and 2022. The weighted-average grant date fair value of options granted during the years ended December 31, 2023 and 2022 was $ 0.00 and $ 2.26 per share, respectively. The total estimated grant date fair value of options vested during the years ended December 31, 2023 and 2022 was $ 2.1 million and $ 0 , respectively. Stock-Based Compensation Expense The following table summarizes employee and non-employee stock-based compensation expense for the years ended December 31, 2023 and 2022 and the allocation within the consolidated statements of operations and comprehensive loss (in thousands): 2023 2022 General and administrative expense $ 4,003 $ 10,225 Research and development expense 1,217 6,393 Total stock-based compensation $ 5,220 $ 16,618 The Company estimates the fair value of its service-based stock option awards utilizing the Black-Scholes option pricing model, which is dependent upon several variables, such as expected term, volatility, risk-free interest rate, and expected dividends. Each of these inputs is subjective and generally requires significant judgment to determine. Stock-based compensation is measured at the grant date based on the fair value of the award and is recognized as expense, over the requisite service period, which is generally the vesting period of the respective award. The Company recognizes compensation on a straight-line basis over the requisite vesting period for each award. Forfeitures are recognized as they occur. The following weighted average assumptions were used to calculate the fair value of stock-based compensation for the years ended December 31, 2023 and 2022: 2023 2022 Expected volatility 106.36 % 89.98 % Expected dividend yield — % — % Expected term (in years) 6.22 6.23 Risk-free interest rate 4.01 % 2.67 % Expected Term — The Company has opted to use the “simplified method” for estimating the expected term of options, whereby the expected term equals the arithmetic a verage of the vesting term and the original contractual term of the option (generally 10 years). The expected term was estimated using the simplified method for employee stock options since the Company does not have adequate historical exercise data to estimate the expected term. Expected Volatility—Due to the Company’s limited operating history and a lack of company specific historical and implied volatility data, the Company has based its estimate of expected volatility on the historical volatility of its own stock and the stock of companies within its defined peer group. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. Risk-Free Interest Rate — The risk-free rate assumption is based on the U.S. Treasury instruments with maturities similar to the expected term of the Company’s stock options. Expected Dividend — The Company has not issued any dividends in its history and does not expect to issue dividends over the life of the options and therefore has estimated the dividend yield to be zero . Fair value of Common Stock — The board of directors uses the closing price of stock on the date of grant to determine the fair value. The board of directors intends all options granted to be exercisable at a price per share not less than the estimated per share fair value of common stock underlying those options on the date of grant. Employee Stock Purchase Plan On April 24, 2019, the Company’s Board of Directors adopted its 2019 Employee Stock Purchase Plan (“2019 ESPP”), which was subsequently approved by the Company’s stockholders and became effective on May 7, 2019, the day immediately prior to the effectiveness of the registration statement filed in connection with the IPO. The 2019 ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Code for U.S. employees. In addition, the 2019 ESPP authorizes grants of purchase rights that do not comply with Section 423 of the Code under a separate non-423 component for non-U.S. employees and certain non-U.S. service providers. The Company has reserved 1,494,530 shares of common stock for issuance under the 2019 ESPP. In addition, the number of shares reserved for issuance under the 2019 ESPP will be increased automatically on the first day of each fiscal year for a period of up to ten years , starting with the 2020 fiscal year, by a number equal to the lesser of: (i) 536,589 shares; (ii) 1 % of the shares of common stock outstanding on the last day of the prior fiscal year; or (iii) such lesser number of shares determined by the Company’s Board of Directors. The 2019 ESPP is expected to be implemented through a series of offerings under which participants are granted purchase rights to purchase shares of the Company’s common stock on specified dates during such offerings. The Company has not yet approved an offering under the 2019 ESPP.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Common Stock	Note 10. Common Stock Equity Transactions , whereby the Company may sell up to $ 150.0 million in aggregate proceeds of common stock from time to time, through Jefferies as our sales agent. During the years ended December 31, 2023 and 2022 , the Company sold zero and 51,769 shares of common stock, respectively, under this agreement and received net proceeds of $ 0 and $ 0.6 million, respectively. Common Stock The Company had reserved shares of common stock for future issuance as follows: December 31, 2023 2022 Options issued and outstanding under the Quince 2019 Stock Plan 4,267,178 3,319,711 Shares available for issuance under Quince 2019 Stock Plan 4,005,784 3,747,309 Shares available for issuance under the Employee Stock Purchase Plan 1,494,530 1,133,165 Options issued and outstanding under the Novosteo 2019 Plan 310,431 503,105 Shares available for issuance under Novosteo 2019 Plan 246,797 41,880 Options issued and outstanding under the 2022 Inducement Plan 2,333,306 3,742,255 Shares available for issuance under 2022 Inducement Plan 1,666,694 257,745 Total 14,324,720 12,745,170 The Company is authorized to issue 100,000,000 shares of common stock with a par value of $ 0.001 per share. Each share of common stock is entitled to one vote . The holders of common stock are also entitled to receive dividends whenever funds are legally available and when and if declared by the board of directors, subject to the prior rights of holders of any preferred stock that may be outstanding at the time. The Company has never declared any dividends on common stock. As of December 31, 2023 and 2022, the Company had 42,973,215 and 36,136,480 shares of common stock issued and outstanding, respectively. In addition, in April 2023, we implemented the Rights Agreement, also called a “poison pill,” that may have the effect of discouraging or preventing a change of control by, among other things, making it uneconomical for a third party to gain control of us through open market accumulation of shares without paying all stockholders an appropriate control premium or without the consent of our board of directors. The Rights will expire on April 5, 2024 , unless the Rights are earlier redeemed or exchanged by the Company.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Note 11. Related Party Transactions David Lamond, Chairperson of the Board of Quince Therapeutics, Inc. was a director and an equity holder in Novosteo which Quince acquired on May 19, 2022. The shares of Novosteo beneficially owned by Mr. Lamond were automatically cancelled and converted into the right to receive shares of Quince common stock in accordance with the terms of the Merger Agreement. The respective boards of directors of Quince and Novosteo approved the Merger Agreement, and the Novosteo’s stockholders adopted the Merger Agreement upon recommendation of the Novosteo board of directors. Mr. Lamond was not part of either company's special committees that evaluated the Novosteo Acquisition and recused himself from board meetings where the Novosteo Acquisition was discussed. Dirk Thye, M.D., Chief Executive Officer, is an investor in Morphimmune Inc. and Philip Low, Ph.D, a former Board member of Quince Therapeutics, Inc., is a co-founder and Board member of Morphimmune Inc. During the year ended December 31, 2023 , the Company sold certain lab equipment to Morphimmune Inc. for $ 80,000 as well as signed a sublease with Morphimmune as the sublessee with total payments of approximately $ 57,000 for the lease term of March 17, 2023 through December 31, 2023.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Note 12. Income taxes The components of the Company's loss before income taxes were as follows (in thousands): Year ended December 31, 2023 2022 United States $ ( 27,375 ) $ ( 48,191 ) International ( 4,207 ) ( 3,753 ) Total $ ( 31,582 ) $ ( 51,944 ) The components of the Company's benefit for income taxes were as follows: Year ended December 31, (in thousands) 2023 2022 Current expense (benefit): Federal $ — $ — State — — Foreign 61 — Total current expense (benefit): 61 — Deferred expense (benefit): Federal ( 248 ) 284 State — — Foreign ( 10 ) — Total deferred expense (benefit): ( 258 ) 284 Total income tax expense (benefit) $ ( 197 ) $ 284 The provision for income taxes differs from the amount expected by applying the federal statutory rate to the loss before taxes as follows: Year ended December 31, 2023 2022 Federal statutory income tax rate 21.00 % 21.00 % State income taxes 4.47 0.89 Income tax credits 1.07 1.49 Stock based compensation ( 26.35 ) ( 0.82 ) Non-deductible expenses and others ( 1.25 ) ( 3.38 ) Change in valuation allowance 1.68 ( 18.63 ) 0.62 % 0.55 % As of December 31, 2023 and 2022, the components of the Company’s deferred tax assets are as follows (in thousands): Year ended December 31, 2023 2022 Deferred tax asset: Federal and State net operating loss carryforwards $ 81,881 $ 49,481 Stock based compensation 2,401 9,667 Other accruals 527 515 Capitalized research and development expense 3,220 3,094 Tax credits 8,343 7,970 Disallowed interest expense carryforward 1,043 — Gross deferred tax asset 97,415 70,727 Valuation allowance ( 85,111 ) ( 69,692 ) Total deferred tax assets 12,304 1,035 Deferred tax liabilities: Property and equipment — ( 11 ) Capitalized leases — ( 32 ) IP R&D ( 17,608 ) ( 1,239 ) Gross deferred tax liabilities ( 17,608 ) ( 1,282 ) Net deferred tax liabilities $ ( 5,304 ) $ ( 247 ) Deferred income taxes reflect the net tax effects of (a) temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, and (b) operating losses and tax credit carryforwards. The Company’s accounting for deferred taxes involves the evaluation of a number of factors concerning the realizability of its net deferred tax assets. The Company primarily considered such factors as its history of operating losses, the nature of the Company’s deferred tax assets, and the timing, likelihood and amount, if any, of future taxable income during the periods in which those temporary differences and carryforwards become deductible. At present, the Company does not believe that it is more likely than not that the deferred tax assets will be realized; accordingly, a full valuation allowance has been established and a deferred tax liability has been recorded as shown in the accompanying balance sheets. The valuation allowance increased by approximately $ 15.4 million and $ 11.1 million, respectively for the years ended December 31, 2023 and 2022. At December 31, 2023, the Company has federal net operating loss carryforwards of approximately $ 238.4 million of which $ 222.6 million will not expire and $ 15.8 million begin expiring in 2034 . The Company also has state net operating loss carryforwards of approximately $ 34.2 million which begin to expire in 2034 . Additionally, the Company has federal tax credits of approximately $ 9.8 million which begin to expire in 2036 and state tax credits of approximately $ 2.9 million which do not expire. At December 31, 2023, the Company has foreign net operating loss carryforwards, primarily in Italy, of approximately $ 121.1 million, which have no expiration date. Use of the net operating loss and credit carryforwards may be subject to a substantial annual limitation due to the ownership change provisions of U.S. tax law and similar state provisions. The annual limitation may result in the expiration of net operating losses and credits before use. Pursuant to the Code Sections 382 and 383, annual use of a company’s U.S. NOL and research and development credit carryforwards may be limited if there is a cumulative change in ownership of greater than 50 % within a three-year period. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. If limited, the related tax asset would be removed from the deferred tax asset schedule with a corresponding reduction in the valuation allowance. The Company has completed such an analysis pursuant to Sections 382 and 383 in prior years which determined that ownership changes occurred on December 22, 2015 and May 13, 2019, which had no impact on the NOLs available to offset future income. The Company has rolled forward the analysis through December 31, 2023 and no additional ownership changes have occurred. The Company follows the provisions of the FASB ASC 740-10, Accounting for Uncertainty in Income Taxes. ASC 740-10 prescribes a comprehensive model for the recognition, measurement, presentation and disclosure in the consolidated financial statements of uncertain tax positions that have been taken or expected to be taken on a tax return. It is the Company’s policy to include penalties and interest related to income tax matters in income tax expense. The Company is subject to taxation in the United States, Australia, and Italy . Because of the net operating loss and research credit carryforwards, all of the Company’s tax years, from 2013 to 2023 , remain open to U.S. federal, California, other state tax examinations. The Company's Australian subsidiaries remain open to examination from their inception to 2023. The Company’s Italian subsidiary remain open to examination from their inception to 2023. The majority of our unrecognized tax benefits would not impact our effective tax rate due to a valuation allowance offsetting our deferred tax assets. T he impact on our effective tax rate of recognizing unrecognized tax benefits is approximately $ 0.5 million. There were interest and penalties of $ 0.1 million and $ 0 accrued at December 31, 2023 and 2022, respectively. The Company does not expect that our uncertain tax positions will materially change in the next twelve months. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Year ended December 31, 2023 2022 Beginning balance $ 3,688 $ 3,249 Additions for tax positions taken in a prior year 200 — Additions for tax positions taken in a current year 451 439 Ending balance $ 4,339 $ 3,688

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	Note 13. Net Loss per Share The following table sets forth the computation of basic and diluted net loss per share (in thousands except for share and per share amounts): December 31, 2023 2022 Numerator: Net loss $ ( 31,385 ) $ ( 51,660 ) Denominator: Weighted average common shares outstanding 37,237,149 33,496,534 Net loss per share, basic and diluted $ ( 0.84 ) $ ( 1.54 ) The following outstanding potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: December 31, 2023 2022 Stock options issued and outstanding 6,910,915 7,565,071 Restricted stock units 1,488 30,876 Restricted stock awards 175,764 427,401 Total 7,088,167 8,023,348

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Employee Benefit Plan	Note 14. Employee Benefit Plan The Company sponsors a 401(k) defined contribution plan for its US employees. This plan provides for pre-tax and post-tax contributions for all US employees . Employee contributions are voluntary. Employees may contribute up to 100 % of their annual compensation to this plan, as limited by an annual maximum amount as determined by the Internal Revenue Service. The Company may match employee contributions, and may make profit sharing contributions, in amounts to be determined at the Company’s sole discretion . The amount of contributions that the Company made to the 401(k) Plan during the years ended December 31, 2023 and 2022 was $ 0.1 million and $ 0.2 million, respectively. The Company has defined benefit plans, regulated by the Italian laws in which the Company’s non-US employees participate in. The benefits due to employees under the defined benefit plans are calculated based on the employee compensation and the duration of the employment relationship and are paid to the employee upon termination of the employment relationship or retirement. The costs of the defined benefit plans reported in the Company’s consolidated statements of operations and comprehensive loss is determined by an actuarial calculation performed on an annual basis. The actuarial valuation is performed using the “Projected Unit Credit Method” based on the employees’ expected date of separation or retirement.

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2023
Business Combinations [Abstract]
Business Combination	Note 15. Business Combination EryDel business combination On October 20, 2023, the Company completed its acquisition of EryDel, a privately held, late-stage biotechnology company with a lead Phase 3 lead asset, EryDex, that targets the potential treatment of a rare neurodegenerative disease, A-T. The acquisition will drive Quinces’ next stage of growth, as EryDel’s proprietary drug-device combination technology platform and promising late-stage clinical asset represents an opportunity for the Company to expand into several debilitating rare diseases where chronic corticosteroid treatment is the standard of care – or could be in the absence of long-term corticosteroid toxicity. The Company accounted for this acquisition in accordance with ASC 805, Business Combinations, which requires the assets acquired and the liabilities assumed to be measured at fair value at the date of the acquisition. As part of the acquisition of EryDel, the Company recorded deferred tax liability of $ 5.1 million and uncertain tax position liability of $ 0.5 million against Goodwill. The acquisition date fair value of the consideration transferred for EryDel was approximately $ 66.9 million, which consisted of the following (in thousands): Fair Value of Consideration Cash $ 2,615 Quince Therapeutics common stock ( 7,250,352 shares) 7,164 Contingent consideration 56,128 Settlement of preexisting notes receivable 1,000 Fair value of total consideration transferred $ 66,907 The fair value of the Company’s common stock was determined based on the closing market price of the Company’s common stock of $ 0.989 per share on the acquisition date. The aggregate stock consideration consists of 6,525,315 shares of Company’s common stock issued at closing and 725,037 shares of common stock (the “Indemnity Holdback Shares”) withheld by the Company for general representations and warranties. The Indemnity Holdback Shares will be issued to the EryDel Shareholders upon the first anniversary of the closing of the acquisition, subject to reduction for any indemnification claims, if any. Any indemnification claims after the acquisition date will result in an adjustment to the consideration transferred if the indemnification claim is made before the end of the measurement period. Any indemnification claim after the end of the measurement period will be recognized in the Company’s consolidated statements of operations and comprehensive loss. The Company has included the total fair value of the stock consideration within additional-paid-in capital and common stock. The contingent consideration arrangement requires the Company to pay $ 485.0 million of additional consideration in cash, comprised of up to $ 5.0 million upon the achievement of a specified development milestone, $ 25.0 million at NDA acceptance, up to $ 60.0 million upon the achievement of specified approval milestones, and up to $ 395.0 million upon the achievement of specified on market and sales milestones. The Company estimated the fair value of the contingent consideration using a probability-weighted discounted cash flow model. This fair value measurement is based on significant inputs not observable in the market and thus represents a Level 3 measurement as defined in ASC 820. The key assumptions in applying the income approach are as follows: 15 % discount rate, probability of achievement, 0 % to 100 %, each of the milestones and future revenues from commercialization over the contingent consideration period. No contingent consideration is payable unless and until the milestones are achieved. The fair value of each milestone after the acquisition is reassessed, with the subsequent change in fair value recorded in the Company’s consolidated statements of operations and comprehensive loss. As of December 31, 2023, there were no significant changes in the range of outcomes for the contingent consideration recognized as a result of the EryDel acquisition. Prior to the acquisition the Company had a preexisting relationship with EryDel. The Company had advanced $ 1.0 million to EryDel pursuant to a promissory note agreement. At the date of the acquisition, the Company had notes receivable due from EryDel of $ 1.0 million, including interest receivable of $ 1,300 . As a result of the EryDel Acquisition, the promissory note between EryDel Italy and EryDel was effectively settled and recognized as additional consideration. The following table summarizes the allocation of the consideration paid for EryDel to the estimated fair value of the assets acquired and liabilities assumed at the acquisition date, with the excess recorded to goodwill (in thousands): Assets acquired: Preliminary Purchase Price Allocation Cash $ 560 Tax assets 10,187 Other current assets 644 Property and equipment, net 238 Operating lease right-of-use assets, net 383 Other non-current assets 14 Intangible assets 61,096 Goodwill 16,929 Total assets acquired 90,051 Liabilities assumed: Trade payables ( 1,685 ) Accrued expenses and other current liabilities ( 2,943 ) Debt, non-current ( 12,564 ) Other non-current liabilities ( 854 ) Deferred tax liability ( 5,098 ) Total liabilities assumed ( 23,144 ) Fair value of total consideration transferred $ 66,907 The purchase price allocation is preliminary and may change as a result of additional information obtained regarding assets acquired and liabilities assumed and revisions of estimates of fair values of intangible assets and related deferred tax assets and liabilities. The Company will finalize its valuation and the allocation of the purchase price, along with required retrospective adjustments, if any, within a year following the acquisition date. The fair value of identifiable Acquired IPR&D intangible assets was $ 60.6 million. IPR&D was determined using the Multi-Period Excess Earnings Method ("MPEEM") under the income approach. MPEEM calculates the economic benefits by determining the income attributable to an intangible asset after the returns are subtracted for contributory assets such as working capital, assembled workforce, and fixed assets. The resulting after-tax net earnings were discounted at 16.6 %, a rate commensurate with the risk inherent in the economic benefit projections of the assets. The probability-weighted, projected cash flows were calculated based on projections of revenues and expenses related to the asset and were assumed to extend through a multi-year projection period. The IPR&D has an indefinite useful life, and as such, is not amortized but rather tested for impairment at least annually. The fair value of tradename intangible assets was $ 0.5 million. The tradename intangible assets were derived using the relief from royalties method under the income approach, utilizing royalty rate of 0.3 %. This approach is used to estimate the cost savings that accrue for the owner of an intangible asset who would otherwise have to pay royalties or licensing fees on revenues earned through the use of the asset if they had not owned the rights to use the assets. The probability-weighted, net after-tax royalty savings are calculated for each year in the remaining economic life of the intangible asset and discounted to present value using a discount rate of 16.6 %. The trademark has a useful life of 21 years . The trademark is amortized on a straight-line basis over the useful life. The excess of the fair value of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill, which is primarily attributed to the assembled workforce and expanded global market opportunities. None of the goodwill is expected to be deductible for income tax purposes. Goodwill is not amortized but is tested for impairment at least annually, refer to Note 16 for this assessment. The transaction costs associated with the acquisition were approximately $ 2.5 million, of which $ 2.3 million were recorded in general and administrative expenses and $ 0.2 million were recorded in research and development expenses in the consolidated statement of operations and comprehensive loss. The Company has included the financial results of EryDel in the consolidated financial statements from the date of acquisition. From October 21, 2023 through December 31, 2023, the Company recognized no revenue and a net loss of $ 3.7 million attributable to EryDel. The following unaudited pro forma information gives effect to the acquisition of EryDel as if it had been completed on January 1, 2022 (the beginning of the comparable prior reporting period), including pro forma adjustments primarily related to amortization of acquired intangible assets, tax benefit from release of the valuation allowance and the inclusion of acquisition-related expenses reflected in the revenue and net loss (in thousands): For the year ended December, 31 2023 2022 Revenue $ — $ — Net Loss ( 40,265 ) ( 67,580 ) The 2023 supplemental pro forma earnings were adjusted to exclude $ 2.5 million of acquisition-related costs incurred in 2023, the 2022 pro forma earnings were adjusted to include these charges. Novosteo business combination On May 19, 2022, the Company completed the Novosteo Acquisition. Pursuant to the terms of the Merger Agreement, at the closing of the Novosteo Acquisition (the “Effective Time”), each share of capital stock of Novosteo (the “Novosteo Capital Stock”) that was issued and outstanding immediately prior to the Effective Time was automatically cancelled and converted into the right to receive 0.0911 shares of common stock, par value $ 0.001 per share, of the Company (the “Company Common Stock”). These shares included options to purchase an aggregate of 507,108 shares of the Company Common Stock upon conversion of the outstanding Novosteo options based on the Company Option Exchange Ratio (as defined in the Merger Agreement), with the awards retaining the same vesting and other terms and conditions as in effect immediately prior to consummation of the Acquisition. These options, as well as 519,216 unvested restricted shares were concluded to be post-combination expense and were excluded from purchase consideration. The Company has included the financial results of Novosteo in the consolidated financial statements from the date of the Acquisition and recorded immaterial amounts of expenses and earnings since the period from May 19, 2022 through December 31, 2023 . The transaction costs associated with the Acquisition were approximately $ 1.1 million and were recorded in general and administrative expense. The acquisition date fair value of the consideration transferred for Novosteo was approximately $ 16,502,587 , which consisted of 5,000,784 shares at $ 3.30 per share. The Company accounted for the Acquisition as a business combination in accordance with ASC 805. The Company applied the acquisition method, which requires the identifiable assets acquired and liabilities assumed be recorded at fair value with limited exceptions. The following table summarizes the fair values of the identifiable assets acquired and liabilities assumed as the final determination of the date of acquisition (in thousands): May 19, 2022 Identifiable assets acquired and liabilities assumed: Cash and cash equivalents $ 10,593 Prepaid expenses and other current assets 1,040 ROU asset 124 Property and equipment 279 In-process Research and Development 5,900 Accounts payable and accrued liabilities ( 1,726 ) Deferred tax liabilities ( 532 ) Net assets acquired 15,678 Goodwill $ 825 The final determination of the fair value of assets and liabilities have been completed within the one-year measurement period as required by ASC 805. As part of the valuation analysis, the fair value of the intangible assets was estimated by discounting forecasted risk adjusted cash flows at a rate that approximated the cost of capital of a market participant. Management's forecast of future cash flows was based on the income approach. Significant estimates, all of which are considered Level 3 inputs, were used in the fair value methodology, including the Company's forecast regarding its future operations and likeliness of obtaining approval to sell its products, as well as other market conditions. The Company recorded no measurement period adjustments for the years ended December 31, 2023 and 2022. All subsequent adjustments will be recorded to earnings. The excess of the fair value of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill, which is primarily attributed to the assembled workforce and expanded market opportunities, for which there is no basis for U.S. income tax purposes. Goodwill amounts are not amortized but are rather tested for impairment at least annually, see Note 16 for this assessment. Goodwill is not deductible for tax purposes. The Intangible asset balance above is attributable to in-process research and development with an indefinite useful life. The amounts of Novosteo's net loss was $ 9.4 million included in the Company's consolidated statement of operations and comprehensive loss for the year ended year ended December 31, 2022 . The amount of Novosteo's revenue was $ 0 for the year ended December 31, 2022 . The unaudited pro forma revenue and net loss of the combined entity had the acquisition date been January 1, 2021 are as follow s (in thousands): For the year ended December 31, 2022 Revenue $ 262 Net loss ( 52,592 ) The 2022 supplemental pro forma earnings were adjusted to exclude $ 2.2 million of acquisition-related costs incurred in 2022, the 2021 pro forma earnings were adjusted to include these charges. The Company’s consolidated statements of operations and comprehensive loss for the year ended December 31, 2022 include immaterial net revenue and net loss attributable to the Acquisition.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Note 16. Intangible Assets EryDel Intangible Assets The following table provides details of the carrying amount of the Company's indefinite-lived intangible asset (in thousands): As of December 31, 2023 Unamortized intangible assets: In-process research and development $ 60,636 Impairment charge — Foreign currency translation adjustments 2,561 Balance as of December 31, 2023 $ 63,197 The following table provides details of the carrying amount of the Company's finite-lived intangible asset (in thousands, except useful life): For the year ended December 31, Useful life 2023 Finite life intangible assets: Trade name 21 years $ 460 Impairment charge — Intangible asset amortization ( 4 ) Foreign currency translation adjustments 19 Balance as of December 31, 2023 $ 475 The Company performs annual impairment reviews of its intangible assets during the fourth fiscal quarter or more frequently if appropriate. The Company did not incur any impairment losses related to its EryDel intangible assets during the year ended December 31, 2023. Novosteo Intangible Assets The intangible asset acquired as a result of the Novosteo Acquisition consists of in-process research and development ("IPR&D") related to NOV004, the Company's bone targeting molecule designed to accelerate fracture repair. The value of the IPR&D was determined using discounted probable future cash flows. Significant assumptions used in determining the value of the intellectual property include the initiation of clinical trials and NDA approval with respect to NOV004, probability of reaching various phases of development, costs and cost of goods sold, and the risk adjusted discount rate applied to the cash flows. The following table provides details of the carrying amount of the Company's indefinite-lived intangible asset (in thousands): As of December 31, 2023 Unamortized intangible assets: In-process research and development $ 5,900 Impairment charge ( 5,900 ) Balance as of December 31, 2023 $ — In January 2023, the Company decided to discontinue the internal development of NOV004 and pursue out-licensing opportunities. As a result, several of the assumptions used in determining the initial fair value have changed including discount rate and expected cash flows and thus triggered the need for an interim impairment assessment as required under ASC 350. As a result, the fair value was determined to be significantly below its carrying value and the Company recognized an impairment charge of $ 5.9 million during the year ended December 31, 2023. On December 22, 2023, the Company, following its prior decision to discontinue internal development of NOV004, approved that certain Mutual Termination of License Agreement (the “Termination Agreement”) by and between the Company and Purdue Research Foundation ("PRF") to terminate the License Agreement dated June 3, 2020, as amended on March 17, 2022, July 22, 2022, and June 23, 2023 (the “License Agreement”). Under the License Agreement, the Company obtained from PRF an exclusive worldwide license under certain bone fracture repair related patents and technology developed by Purdue University, including patents claiming NOV004 and related compounds and use of such compounds in the treatment of bone fractures. Under the Termination Agreement, the License Agreement was terminated effective as of October 31, 2023. The Company agreed to reimburse PRF for certain fees and costs incurred in connection with the prosecution of the licensed patents prior to termination. The Company also agreed to assign to PRF certain documents and materials developed by the Company in connection with the development of the licensed product under the License Agreement, subject to the Company’s retained right to use such documents and materials for internal research purpose. Goodwill The following table summarizes the changes in the carrying amount of goodwill (in thousands): Balance as of December 31, 2021 $ — Additions (a) 825 Impairment charge ( 825 ) Balance as of December 31, 2022 — Additions (a) 16,929 Foreign currency translation adjustments 696 Balance as of December 31, 2023 $ 17,625 (a) Goodwill additions related to the acquisition of Novosteo in second quarter of 2022 and the acquisition of EryDel in the fourth quarter of 2023 (see Note 15). There was no amount related to goodwill related to the Novosteo acquisition reflected on the consolidated balance sheet for the Company as of December 31, 2022 . In 2022, management performed an impairment evaluation of goodwill related to the Novosteo acquisition after assessing qualitative factors that indicated a possible impairment of goodwill. Under the qualitative assessment, management considers relevant events and circumstances including but not limited to macroeconomic conditions, industry and market considerations, overall Company performance and events directly affecting the Company. It was noted during our assessment that the Company's market capitalization was significantly below its carrying value and a further quantitative analysis was conducted to determine to the extent, if any, the Company's carrying value exceeded its fair value as of September 30, 2022. The quantitative analysis used fair value based on market capitalization adjusted for control premium based on market comparable transactions. This quantitative analysis resulted in the Company's fair value being significantly below its carrying value, resulting in a non-cash goodwill impairment charge of $ 0.8 million being recorded during the year ended December 31, 2022. As part of the EryDel Acquisition, the Company recorded goodwill, the excess of the fair value of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired. The Company performed its annual qualitative test for goodwill in the fourth quarter of 2023, the Company concluded that no impairment exists for the year ended December 31, 2023.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Consolidation	Basis of Consolidation The accompanying consolidated financial statements include the accounts of Quince Therapeutics, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated upon consolidation.
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements and the notes thereto have been prepared in accordance with accounting principles GAAP pursuant to the instructions of the SEC on Form 10-K through the rules and interpretive releases of the SEC under federal securities law.
Use of Estimates	Use of Estimates T he preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and expenses, as well as related disclosure of contingent assets and liabilities. The most significant estimates used in the Company’s consolidated financial statements relate to the determination of the fair value of stock-based awards and other issuances, determination of the fair value of identifiable assets and liabilities in connection with the acquisition of Novosteo, Inc. and EryDel S.p.A., including associated intangible assets and goodwill, contingent consideration, accruals for research and development costs, useful lives of long-lived assets, stock-based compensation and related assumptions, the incremental borrowing rate for leases and income tax uncertainties, including a valuation allowance for deferred tax assets, eligibility of expenses for the Australia research and development refundable tax credits, impairment of intangible assets or goodwill; and contingencies. The Company bases its estimates on historical experience and on various other market specific and other relevant assumptions that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from the Company’s estimates.
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions The functional currency of the Company’s wholly-owned subsidiaries are the Australian Dollar and the Euro. The Company's financial results and financial position are translated into U.S. dollars using exchange rates at balance sheet dates for assets and liabilities and using average exchange rates for income and expenses. The resulting translation differences are presented as a separate component of accumulated other comprehensive loss, as a separate component of equity. Foreign currency transactions are translated into the functional currencies using the exchange rates prevailing at the dates of the transactions. Foreign exchange gains and losses, resulting from the settlement of such transactions and from the re-measurement of monetary assets and liabilities denominated in foreign currencies using exchange rates at balance sheet date and non-monetary assets and liabilities using historical exchange rates, are recognized in the consolidated statements of operations and comprehensive income.
Risk and Uncertainties	Risk and Uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s drug candidates, uncertainty of market acceptance of the Company’s drug candidates, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals and sole source suppliers. The Company’s drug candidates will require approvals from the FDA and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any drug candidate will receive the necessary approvals.
Segments	Segments The Company operates and manages its business as one reportable and operating segment, which is the business of developing and commercializing therapeutics. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating and evaluating financial performance. All long-lived assets are maintained in Italy.
Business Combinations	Business Combinations The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. The Company accounts for business combinations using the acquisition method pursuant to the FASB ASC Topic 805. This method requires, among other things, that results of operations of acquired companies are included in the Company's financial results beginning on the respective acquisition dates, and that identifiable assets acquired and liabilities assumed are recognized at fair value as of the acquisition date. Intangible assets acquired in a business combination are recorded at fair value using one of three valuation approaches, the income approach, the market approach or the cost approach. The Company reviewed the three valuation approaches and determined the income approach was the most appropriate model to approximate fair value for both the Novosteo and EryDel Acquisitions. The income approach model requires assumptions about the timing and amount of future net cash flows, the cost of capital and terminal values from the perspective of a market participant. Any excess of the fair value of consideration transferred (the “Purchase Price”) over the fair values of the net assets acquired is recognized as goodwill. The fair value of identifiable assets acquired and liabilities assumed in certain cases may be subject to revision based on the final determination of fair value during a period of time not to exceed 12 months from the acquisition date. Legal costs, due diligence costs, business valuation costs and all other acquisition-related costs are expensed when incurred.
Intangible Assets	Intangible Assets Intangible assets with a definite useful life are amortized on a straight-line basis over the estimated useful life of the related assets. Intangible assets with an indefinite useful life are not amortized. Intangible assets acquired in a business combination that are used in research and development activities (regardless of whether they have an alternative future use) shall be considered indefinite lived until the completion or abandonment of the associated research and development efforts. Intangible assets acquired in a business combination are initially recorded at fair value. During the period that those assets are considered indefinite lived, they shall not be amortized but shall be tested for impairment. Once the research and development efforts are completed or abandoned, the entity shall determine the useful life of the assets. An intangible asset shall be tested for impairment annually and more frequently if events or changes in circumstances indicate that it is more likely than not that the asset is impaired. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the intangible asset is less than its carrying amount, If that is the case, the Company performs a quantitative impairment test, and, if the carrying amount of the Company exceeds its fair value, then the Company will recognize an impairment charge for the amount by which its carrying amount exceeds its fair value, not to exceed the carrying amount of the intangible asset. Qualitative factors to be considered include but are not limited to: • Cost factors such as increases in raw materials, labor, or other costs that have a negative effect on future expected earnings and cash flows. • Legal/regulatory factors or progress and results of clinical trials. • Other relevant entity-specific events such as changes in management, key personnel, strategy, or customers; contemplation of bankruptcy; or litigation that could affect significant inputs used to determine the fair value of the indefinite-lived intangible asset. • Industry and market considerations such as a deterioration in the environment in which an entity operates, an increased competitive environment. • Macroeconomic conditions such as deterioration in general economic conditions, limitations on accessing capital, fluctuations in foreign exchange rates, or other developments in equity and credit markets that could affect significant inputs used to determine the fair value of the indefinite-lived intangible asset.
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of the net assets acquired as of the acquisition date. Goodwill has an indefinite useful life and is not amortized. The Company reviews its goodwill for impairment at least annually or whenever events or changes in circumstances indicate that the carrying amount of the Company may exceed its fair value. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the Company is less than its carrying amount, including goodwill. If that is the case, the Company performs a quantitative impairment test, and, if the carrying amount of the Company exceeds its fair value, then the Company will recognize an impairment charge for the amount by which its carrying amount exceeds its fair value, not to exceed the carrying amount of the goodwill.
Contingent Consideration	Contingent Consideration The Company determines the acquisition date fair value of contingent consideration using a discounted cash flow method, with significant inputs that are not observable in the market and thus represents a Level 3 fair value measurement as defined in ASC Topic 820, Fair Value Measurement. The significant inputs in the Level 3 measurement not supported by market activity included our probability assessments of expected future cash flows related to the Company's acquisition of EryDel in October 2023, during the contingent consideration period, appropriately discounted considering the uncertainties associated with the earnout obligation, and calculated in accordance with the terms of the definitive agreement. The liabilities for the contingent consideration are established at the time of the acquisition and will be evaluated on a quarterly basis based on additional information as it becomes available. Any change in the fair value adjustment is recorded in the earnings of that period. During the year ended December 31, 2023, the Company recorded a $ 1.6 million adjustment to increase the fair value of its contingent consideration related to the acquisition of EryDel. The adjustment is reflected within operating loss on the consolidated statement of operations and comprehensive loss . Changes in the fair value of the contingent consideration obligations may result from changes in probability assumptions with respect to the likelihood of achieving the various contingent payment obligations. Significant increases or decreases in the inputs noted above in isolation would result in a significantly lower or higher fair value measurement.
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash equivalents include marketable securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and at the end of each reporting period. Investments with original maturities beyond three months at the date of purchase and which mature at, or less than twelve months from the balance sheet date are classified as short-term investments. Investments with a maturity beyond twelve months from the balance sheet date are classified as long-term investments. Collectively, cash equivalents, short-term investments and long-term investments are considered available-for-sale and are recorded at fair value. Unrealized gains and losses are recorded as a component of other comprehensive loss in the consolidated statements of operations and included as a separate component of consolidated statements of stockholders’ equity (deficit). Realized gains and losses are included in interest income in the consolidated statements of operations and comprehensive loss. Premiums (discounts) are amortized (accreted) over the life of the related investment as an adjustment to yield using the straight-line interest method. Dividend and interest income are recognized when earned. These amounts are recorded in “interest income” in the consolidated statements of operations and comprehensive loss.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at cost and reduced by accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful lives of the respective assets. Depreciation and amortization begin at the time the asset is placed in service. Maintenance and repairs are charged to expense as incurred, and improvements are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in operations in the period realized. The useful lives of property and equipment are as follows: Computer equipment 3 years Lab equipment 2.5 to 5 years Finance lease right of use assets Shorter of estimated useful life or lease term Leasehold improvement Shorter of estimated useful life or lease term Office furniture 4 to 5 years
Concentration of Credit Risk	Concentration of Credit Risk Cash equivalents, short-term and long-term investments are financial instruments that potentially subject the Company to concentrations of credit risk. The Company invests in money market funds, repurchase agreements, treasury bills and notes, government bonds, and corporate notes. The Company limits its credit risk associated with cash equivalents, short-term and long-term investments by placing them with banks and institutions it believes are highly credit worthy and in highly rated investments. However, cash balances in excess of Federal Deposit Insurance Corporation (FDIC) insured limit of $ 0.3 million are at risk.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. An impairment charge would be recorded when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than its carrying amount. Impairment, if any, is assessed using discounted cash flows or other appropriate measures of fair value. The Company recognized impairment charges of $ 0.2 million related to the San Diego lease impairment loss and loss on disposal of fixed assets for the year ended December 31, 2022 . The Company recognized an impairment charge $ 0.1 million for the Purdue lease the year ended December 31, 2023 .
Leases	Leases The Company determines if an arrangement includes a lease at inception. Right-of-use lease assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use lease asset includes any lease payments made and excludes lease incentives. Incremental borrowing rate is used in determining the present value of future payments. The Company applies a portfolio approach to the property leases to apply an incremental borrowing rate to leases with similar lease terms. The lease terms may include options to extend or terminate the lease. The Company recognizes the options to extend the lease as part of the right-of-use lease assets and lease liabilities only if it is reasonably certain that the option would be exercised. Lease expense for minimum lease payments is recognized on a straight-line basis over the non-cancelable lease term.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred. Research and development expenses consist primarily of personnel costs for the Company’s research and product development employees. Also included are non-personnel costs such as professional fees payable to third parties for preclinical and clinical studies and research services, laboratory supplies and equipment maintenance, product licenses, and other consulting costs. The Company estimates preclinical and clinical study and research expenses based on the services performed, pursuant to contracts with CROs that conduct and manage preclinical and clinical studies and research services on its behalf. Expenses related to clinical studies are based on estimates of the services received and efforts expended pursuant to contracts with many research institutions, clinical research organizations and other service providers that conduct and manage clinical studies on the Company's behalf. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Generally, these agreements set forth the scope of work to be performed at a fixed fee or unit price. Payments under the contracts are mainly driven by time and materials incurred by these service providers. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered. Expenses related to clinical studies are generally recorded based on the timing of when services that have been performed on the Company’s behalf by the service providers, clinical trial budgets and in accordance with the contracts and related amendments. The determination of timing involves reviewing open contracts and purchase orders, communicating with applicable personnel to identify the timing of when services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The Company periodically confirms the accuracy of estimates with the service providers and makes adjustments if necessary. Examples of estimated clinical expenses include: • fees paid to CROs in connection with clinical studies; • fees paid to investigative sites in connection with clinical studies; • fees paid to contract manufacturers in connection with the production of clinical study materials; and • fees paid to vendors in connection with preclinical development activities. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the prepaid or accrual accordingly. Payments associated with licensing agreements to acquire exclusive licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternate commercial use are expensed as incurred.
Patents Costs	Patent Costs The Company has no historical data to support a probable future economic benefit for the arising patent applications, filing and prosecution costs. Therefore, patent costs are expensed as incurred.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation arrangements with employees in accordance with ASC 718, Compensation—Stock Compensation. Stock-based awards granted include stock options with service-based vesting. ASC 718 requires the recognition of compensation expense, using a fair value-based method, for costs related to all stock-based payments. The Company’s determination of the fair value of stock options with service-based vesting on the date of grant utilizes the Black-Scholes option-pricing model and is impacted by its common stock price as well as other variables including: but not limited to, expected term that options will remain outstanding, expected common stock price volatility over the term of the option awards, risk-free interest rates and expected dividends. The fair value of a stock-based award is recognized over the period during which an optionee is required to provide services in exchange for the option award, known as the requisite service period (usually the vesting period) on a straight-line basis. Stock-based compensation expense is recognized based on the fair value determined on the date of grant and is reduced for forfeitures as they occur. Stock options exercised are issued new shares of our common stock.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method. Current income tax expense or benefit represents the amount of income taxes expected to be payable or refundable for the current year. Deferred income tax assets and liabilities are determined based on differences between the consolidated financial statement reporting and tax bases of assets and liabilities and net operating loss and credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all of the tax benefits will not be realized. The Company accounts for uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainty in Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available. The Company includes any penalties and interest expense related to income taxes as a component of other expense, net and interest expense, net, as necessary.
Comprehensive Loss	Comprehensive Loss The Company is required to report all components of comprehensive loss, including net loss, in the consolidated financial statements in the period in which they are recognized. Comprehensive loss is defined as a change in equity of a business enterprise during a period, resulting from transactions and other events and circumstances from non-owner sources. The Company had an unrealized gain and loss from its available-for sale securities and cumulative translation adjustment during the years ended December 31, 2023 and December 31, 2022, respectively, which are considered other comprehensive loss.
Net Loss per Share	Net Loss per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and common share equivalents of potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation and common stock options are considered to be potentially dilutive securities. Because the Company reported a net loss for the years ended December 31, 2023 and December 31, 2022 , and the inclusion of the potentially dilutive securities would be antidilutive, diluted net loss per share is the same as basic net loss per share for both periods.
Recent Accounting Pronouncements Adopted	Recent Accounting Pronouncements Adopted Financial Instruments—Credit Losses: In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments which amends the principles around the recognition of credit losses by mandating entities incorporate an estimate of current expected credit losses when determining the value of certain assets. The guidance also amends reporting around allowances for credit losses on available-for-sale marketable securities. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842): Effective Dates, which established that a one-time determination of the effective date for ASU 2016-13 would be based on the Company’s SEC reporting status as of November 15, 2019. The Company was a “smaller reporting company” as defined by Item 10 of Regulation S-K, and therefore, ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. This guidance helps to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in Topic 326 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company has adopted the new guidance as of January 1, 2023, and it did not have a material impact on its consolidated financial statements and related disclosures. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive loss, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the statement of operations and comprehensive loss. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the balance sheets. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its consolidated financial statements: Improvements to Income Tax Disclosures (ASC 740); In December 2023, the FASB issued ASU No. 2023-09, "Improvements to Income Tax Disclosures." This ASU establishes new income tax disclosure requirements in addition to modifying and eliminating certain existing requirements. Under this ASU, entities must consistently categorize and provide greater disaggregation of information in the rate reconciliation. They must also further disaggregate income taxes paid. The ASU is effective in December 2024 under a prospective approach. Early adoption is permitted. Adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. Accounting Standard Update 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”): In November 2023, the FASB issued ASU 2023-07, which is intended to improve reportable segment disclosure requirements, primarily through additional disclosures about significant segment expenses, including for single reportable segment entities. The standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. The Company is evaluating the disclosure requirements related to the new standard. All other newly issued accounting pronouncements not yet effective have been deemed either immaterial or not applicable.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Schedule of Useful Lives of Property and Equipment	The useful lives of property and equipment are as follows: Computer equipment 3 years Lab equipment 2.5 to 5 years Finance lease right of use assets Shorter of estimated useful life or lease term Leasehold improvement Shorter of estimated useful life or lease term Office furniture 4 to 5 years

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities to Fair Value Measurements on Recurring Basis	Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of December 31, 2023 and 2022 are presented in the following tables (in thousands): Fair Value Measurements at December 31, 2023 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 4,285 $ 4,285 $ — $ — Certificates of Deposit 729 — 729 — Government and agency notes 68,524 3,971 64,553 — Total assets $ 73,538 $ 8,256 $ 65,282 $ — Liabilities: Accrued earnout 57,706 — — 57,706 Long-term debt 13,429 — — 13,429 Total liabilities $ 71,135 $ — $ — $ 71,135 Fair Value Measurements at December 31, 2022 Total Level 1 Level 2 Level 3 Money market funds $ 10,988 $ 10,988 $ — $ — Certificates of Deposit 6,102 — 6,102 — Repurchase Agreements 9,000 — 9,000 — Corporate notes 12,411 — 12,411 — Government and agency notes 50,766 — 50,766 — Municipal notes 506 — 506 — Total $ 89,773 $ 10,988 $ 78,785 $ —
Schedule of Changes in Present Value of Acquisition Related Accrued Earnouts of Contingent Consideration Liability	The following table reflects the changes in present value of acquisition related accrued earnouts of contingent consideration liability using significant unobservable inputs (Level 3) for the year ended December 31, 2023 follows: (in thousands) Beginning Balance as of January 1, 2023 $ — Acquisition date fair value of contingent consideration 56,128 Change in fair value of contingent consideration 1,578 Ending Balance as of December 31, 2023 $ 57,706
Summary of Quantitative Information About Level 3 Fair Value Measurements	The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related accrued earnout as of December 31, 2023: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value at Valuation Unobservable Input Range (Input Used) December 31, Technique 2023 Accrued earnout $ 57,706 Expected present Probability of achieving earnout 0 % - 100 % value objectives per the purchase agreement The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related long term debt as of December 31, 2023: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value at Valuation Unobservable Input Discount Rate (Input Used) December 31, Technique 2023 EIB loan $ 13,429 Expected present Credit quality of company 13 % value and credit spreads for comparable debt
Fair value of the Level 3 EIB Debt	The following table presents the changes in the fair value of the Level 3 EIB Debt: (in thousands) Beginning Balance as of January 1, 2023 $ — Acquisition of EIB Debt 12,564 Change in fair value 338 Due to foreign currency translation 527 Ending Balance as of December 31, 2023 $ 13,429

Cash, Cash Equivalents and In_2

Cash, Cash Equivalents and Investments (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Summary of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis	The following tables categorize the fair values of cash, cash equivalents, short-term investments and long-term investments measured at fair value on a recurring basis on our balance sheets (in thousands): December 31, 2023 2022 Cash and cash equivalents: Cash $ 1,521 $ 3,986 Money market funds 4,285 10,988 Repurchase agreements — 9,000 Government and agency notes 14,946 20,605 Total cash and cash equivalents $ 20,752 $ 44,579 Short-term investments: Certificates of deposit $ 729 $ 5,390 Municipal notes — 506 Corporate notes — 12,411 Government and agency notes 53,578 27,295 Total short-term investments $ 54,307 $ 45,602 Long-term investments Certificates of deposit $ — $ 712 Government and agency notes — 2,866 Total long-term investments $ — $ 3,578
Summary of Available-for-Sale Securities	The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements at December 31, 2023 Amortized Unrealized Unrealized Fair Value Money market funds $ 4,285 $ — $ — $ 4,285 Certificates of Deposit 735 — ( 6 ) 729 Government and agency notes 68,528 13 ( 17 ) 68,524 Total cash equivalents and investments $ 73,548 $ 13 $ ( 23 ) $ 73,538 Classified as: Cash equivalents (original maturities within 90 days) $ 19,231 Short-term investments (maturities within 1 year) 54,307 Total cash equivalents and investments $ 73,538 Fair Value Measurements at December 31, 2022 Amortized Unrealized Unrealized Fair Value Money market funds $ 10,988 $ — $ — $ 10,988 Certificates of Deposit 6,237 1 ( 136 ) 6,102 Repurchase Agreements 9,000 — — 9,000 Corporate notes 12,575 — ( 164 ) 12,411 Government and agency notes 51,020 4 ( 258 ) 50,766 Municipal notes 510 — ( 4 ) 506 Total cash equivalents and investments $ 90,330 $ 5 $ ( 562 ) $ 89,773 Classified as: Cash equivalents (original maturities within 90 days) $ 40,593 Short-term investments (maturities within 1 year) 45,602 Long-term investments (maturities beyond 1 year) 3,578 Total cash equivalents and investments $ 89,773
Summary of Unrealized Losses of Company's Investments in Debt Securities Measured at Fair Value	The table below summarizes the unrealized losses of the Company's investments in debt securities measured at fair value as of December 31, 2023 (in thousands): Less than twelve months Twelve months or greater Total Fair value Gross unrealized loss Fair value Gross unrealized loss Fair value Gross unrealized loss Certificates of deposit $ — $ — $ 729 $ ( 6 ) $ 729 $ ( 6 ) Government and agency notes 3,966 — 2,975 ( 17 ) 6,941 ( 17 ) Total cash equivalents and investments $ 3,966 $ — $ 3,704 $ ( 23 ) $ 7,670 $ ( 23 )
Schedule of the Ccontractual Maturities of our Investments in Debt Securities Measured at Fair Value	The table below summarizes the contractual maturities of the Company's investments in debt securities measured at fair value as of December 31, 2023 (in thousands): Maturities by Period Total Less Than 1 Year 1-5 Years 6-10 Years More Than 10 Years Fair value of debt securities $ 54,307 $ 54,307 $ — $ — $ —

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2023
Balance Sheet Components [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2023 2022 Prepaid expenses $ 365 $ 223 Prepaid insurance 809 977 Prepaid research and development expenses 133 1,088 Australia research and development refundable tax credit — 1,003 Short-term Italian research and development refundable tax credit 993 — Other current assets 81 276 Total prepaid expenses and other current assets $ 2,381 $ 3,567
Schedule of Other Assets	Other assets consisted of the following (in thousands): December 31, 2023 2022 VAT receivable $ 3,463 $ — Long-term Italian research and development refundable tax credit 4,993 — Total other assets $ 8,456 $ —
Schedule of Assets Held for Sale	Assets held for sale consist of the following (in thousands): December 31, 2023 2022 Assets held for sale $ 10 $ — Total assets held for sale $ 10 $ —
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): December 31, 2023 2022 Computer equipment $ 36 $ 18 Computer software 30 — Lab equipment 486 415 Finance lease right of use assets — 124 Leasehold improvement 36 21 Office furniture 153 — Less: accumulated amortization and depreciation ( 507 ) ( 185 ) Property and equipment, net $ 234 $ 393
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): December 31, 2023 2022 Personnel expenses $ 2,340 $ 1,130 Professional fees 211 234 Research and development expenses 564 497 Current portion of operating lease liabilities 64 377 Current portion of finance lease liability — 76 Other 257 185 Total accrued expenses and other current liabilities $ 3,436 $ 2,499
Summary of Accrued Severance and Related Expens	Below is the severance accrual activity included in the personnel expenses in the above table related to a cost reduction program during the years ended December 31, 2023 and December 31, 2022 (in thousands): For the year 2023 2022 Beginning accrued severance $ — $ — Incurred during the period 770 3,942 Severance paid during the period ( 429 ) ( 3,942 ) Ending accrued severance $ 341 $ —

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Supplemental Balance Sheet Information Related To Leases	Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): December 31, 2023 December 31, 2022 Operating lease right of use asset, net $ 385 $ 291 Short-term operating lease liability 64 377 Long-term operating lease liability 321 — $ 385 $ 377 Finance lease right of use asset — 124 Finance lease accumulated amortization — ( 50 ) Total finance lease right of use asset, net $ — $ 74 Weighted average remaining lease term Operating leases 5.4 years 0.9 years Finance leases — 1.0 year Weighted average discount rate Operating leases 7.95 % 5.71 % Finance leases — % 4.45 % Year ended December 31, Operating Lease 2024 91 2025 91 2026 88 2027 81 2028 69 Thereafter 48 Total lease payments 469 Less: imputed interest ( 83 ) Total remaining lease liability $ 385
Summary of Lease Costs	Lease costs for the years ended December 31, 2023 and 2022 were approximately: Years ended December 31, 2023 2022 Lease costs: Finance lease amortization of right of use assets $ 6 $ 50 Operating lease costs 266 572 Short-term lease costs 96 75 Total lease costs $ 368 $ 697

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of Future Minimum Principal Payments	Future minimum principal payments, as of December 31, 2023 are as follows (in thousands): Year Ending December 31, Amount 2024 $ — 2025 — 2026 11,053 2027 and thereafter — Total future minimum payments 11,053 Imputed interest 2,376 Total Debt as of December 31, 2023 $ 13,429

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2023
Summary of Employee and Non-Employee Stock-Based Compensation Expense	The following table summarizes employee and non-employee stock-based compensation expense for the years ended December 31, 2023 and 2022 and the allocation within the consolidated statements of operations and comprehensive loss (in thousands): 2023 2022 General and administrative expense $ 4,003 $ 10,225 Research and development expense 1,217 6,393 Total stock-based compensation $ 5,220 $ 16,618
Service Based Stock Options
Summary of Stock Options Activity	Activity for service-based stock options under the Quince 2019 Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2021 5,571,293 $ 28.70 8.26 $ 15,687 Options granted 2,051,058 8.13 — — Options exercised ( 102,152 ) 1.45 — — Options cancelled / forfeited ( 4,200,488 ) 29.30 — — Balance at December 31, 2022 3,319,711 $ 16.07 4.77 $ 65 Options granted 3,346,958 1.03 — — Options exercised ( 258,705 ) 0.42 — — Options cancelled / forfeited ( 2,140,786 ) 16.52 — — Balance at December 31, 2023 4,267,178 $ 5.00 8.85 $ 197 Options vested and expected to vest as of December 31, 2023 4,267,178 5.00 8.85 197 Options exercisable at December 31, 2023 1,109,464 $ 14.09 7.32 $ 34
Summary of Weighted Average Assumptions to Calculate the Fair Value of Stock-Based Compensation	The following weighted average assumptions were used to calculate the fair value of stock-based compensation for the years ended December 31, 2023 and 2022: 2023 2022 Expected volatility 106.36 % 89.98 % Expected dividend yield — % — % Expected term (in years) 6.22 6.23 Risk-free interest rate 4.01 % 2.67 %
Service Based Stock Options | Novosteo [Member]
Summary of Stock Options Activity	Activity for service-based stock options under the 2019 Novosteo Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2021 — $ — — $ — Options assumed 507,648 0.55 — — Options exercised — — — — Options cancelled / forfeited ( 4,543 ) 0.55 — — Balance at December 31, 2022 503,105 $ 0.55 9.23 $ 44 Options granted — — — — Options exercised ( 105,808 ) 0.55 — 40 Options cancelled / forfeited ( 86,866 ) 0.55 — — Balance at December 31, 2023 310,431 $ 0.55 8.23 $ 155 Options vested and expected to vest as of December 31, 2023 310,431 0.55 8.23 155 Options exercisable as of December 31, 2023 135,812 $ 0.55 8.23 $ 68
Service Based Stock Options | 2022 Inducement Plan
Summary of Stock Options Activity	Activity for service-based stock options under the 2022 Inducement Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2021 — $ — — $ — Options granted 3,744,255 2.98 — — Options exercised — — — — Options cancelled / forfeited ( 2,000 ) 2.98 — — Balance at December 31, 2022 3,742,255 $ 2.98 9.39 $ — Options granted — — — — Options exercised — — — — Options cancelled / forfeited ( 1,408,949 ) 2.98 — — Balance at December 31, 2023 2,333,306 $ 2.98 8.39 $ — Options vested and expected to vest as of December 31, 2023 2,333,306 2.98 8.39 — Options exercisable as of December 31, 2023 923,599 $ 2.98 8.39 $ —
Restricted Stock Awards
Summary of Stock Options Activity	Restricted Stock Awards Restricted Stock Awards Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 427,401 $ 3.30 RSAs issued — — RSAs vested ( 188,344 ) 3.30 RSAs cancelled ( 63,293 ) 3.30 Unvested - December 31, 2023 175,764 $ 9.90
Restricted Stock Units
Summary of Stock Options Activity	The following table summarizes activity under the Company’s RSUs from the Quince 2019 Plan and related information: Restricted Stock Units Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 30,876 $ 4.30 RSUs granted — — RSUs vested ( 10,200 ) 4.30 RSUs cancelled ( 19,188 ) 4.30 Unvested - December 31, 2023 1,488 $ 4.30

Common Stock (Tables)

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Future Issuance	The Company had reserved shares of common stock for future issuance as follows: December 31, 2023 2022 Options issued and outstanding under the Quince 2019 Stock Plan 4,267,178 3,319,711 Shares available for issuance under Quince 2019 Stock Plan 4,005,784 3,747,309 Shares available for issuance under the Employee Stock Purchase Plan 1,494,530 1,133,165 Options issued and outstanding under the Novosteo 2019 Plan 310,431 503,105 Shares available for issuance under Novosteo 2019 Plan 246,797 41,880 Options issued and outstanding under the 2022 Inducement Plan 2,333,306 3,742,255 Shares available for issuance under 2022 Inducement Plan 1,666,694 257,745 Total 14,324,720 12,745,170

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Loss Before Income Taxes	The components of the Company's loss before income taxes were as follows (in thousands): Year ended December 31, 2023 2022 United States $ ( 27,375 ) $ ( 48,191 ) International ( 4,207 ) ( 3,753 ) Total $ ( 31,582 ) $ ( 51,944 )
Schedule of Components of Benefit for Income Taxes	The components of the Company's benefit for income taxes were as follows: Year ended December 31, (in thousands) 2023 2022 Current expense (benefit): Federal $ — $ — State — — Foreign 61 — Total current expense (benefit): 61 — Deferred expense (benefit): Federal ( 248 ) 284 State — — Foreign ( 10 ) — Total deferred expense (benefit): ( 258 ) 284 Total income tax expense (benefit) $ ( 197 ) $ 284
Schedule of Provision for Income Taxes Differs From the Amount Expected by Applying the Federal Statutory Rate to Loss Before Taxes	The provision for income taxes differs from the amount expected by applying the federal statutory rate to the loss before taxes as follows: Year ended December 31, 2023 2022 Federal statutory income tax rate 21.00 % 21.00 % State income taxes 4.47 0.89 Income tax credits 1.07 1.49 Stock based compensation ( 26.35 ) ( 0.82 ) Non-deductible expenses and others ( 1.25 ) ( 3.38 ) Change in valuation allowance 1.68 ( 18.63 ) 0.62 % 0.55 %
Schedule of Components of Deferred Tax Assets	As of December 31, 2023 and 2022, the components of the Company’s deferred tax assets are as follows (in thousands): Year ended December 31, 2023 2022 Deferred tax asset: Federal and State net operating loss carryforwards $ 81,881 $ 49,481 Stock based compensation 2,401 9,667 Other accruals 527 515 Capitalized research and development expense 3,220 3,094 Tax credits 8,343 7,970 Disallowed interest expense carryforward 1,043 — Gross deferred tax asset 97,415 70,727 Valuation allowance ( 85,111 ) ( 69,692 ) Total deferred tax assets 12,304 1,035 Deferred tax liabilities: Property and equipment — ( 11 ) Capitalized leases — ( 32 ) IP R&D ( 17,608 ) ( 1,239 ) Gross deferred tax liabilities ( 17,608 ) ( 1,282 ) Net deferred tax liabilities $ ( 5,304 ) $ ( 247 )
Schedule of Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Year ended December 31, 2023 2022 Beginning balance $ 3,688 $ 3,249 Additions for tax positions taken in a prior year 200 — Additions for tax positions taken in a current year 451 439 Ending balance $ 4,339 $ 3,688

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of basic and diluted net loss per share (in thousands except for share and per share amounts): December 31, 2023 2022 Numerator: Net loss $ ( 31,385 ) $ ( 51,660 ) Denominator: Weighted average common shares outstanding 37,237,149 33,496,534 Net loss per share, basic and diluted $ ( 0.84 ) $ ( 1.54 )
Schedule of Outstanding Potentially Dilutive Ordinary Shares Excluded from Calculation of Diluted Net Loss Per Share	The following outstanding potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: December 31, 2023 2022 Stock options issued and outstanding 6,910,915 7,565,071 Restricted stock units 1,488 30,876 Restricted stock awards 175,764 427,401 Total 7,088,167 8,023,348

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2023
Business Acquisition [Line Items]
Schedule of Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the fair values of the identifiable assets acquired and liabilities assumed as the final determination of the date of acquisition (in thousands): May 19, 2022 Identifiable assets acquired and liabilities assumed: Cash and cash equivalents $ 10,593 Prepaid expenses and other current assets 1,040 ROU asset 124 Property and equipment 279 In-process Research and Development 5,900 Accounts payable and accrued liabilities ( 1,726 ) Deferred tax liabilities ( 532 ) Net assets acquired 15,678 Goodwill $ 825
Schedule of Revenue and Net Loss of the Combined Entity	The unaudited pro forma revenue and net loss of the combined entity had the acquisition date been January 1, 2021 are as follow s (in thousands): For the year ended December 31, 2022 Revenue $ 262 Net loss ( 52,592 )
Ery Del [Member]
Business Acquisition [Line Items]
Schedule of Fair Value of the Total Purchase Consideration Transferred	The acquisition date fair value of the consideration transferred for EryDel was approximately $ 66.9 million, which consisted of the following (in thousands): Fair Value of Consideration Cash $ 2,615 Quince Therapeutics common stock ( 7,250,352 shares) 7,164 Contingent consideration 56,128 Settlement of preexisting notes receivable 1,000 Fair value of total consideration transferred $ 66,907
Schedule of Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the allocation of the consideration paid for EryDel to the estimated fair value of the assets acquired and liabilities assumed at the acquisition date, with the excess recorded to goodwill (in thousands): Assets acquired: Preliminary Purchase Price Allocation Cash $ 560 Tax assets 10,187 Other current assets 644 Property and equipment, net 238 Operating lease right-of-use assets, net 383 Other non-current assets 14 Intangible assets 61,096 Goodwill 16,929 Total assets acquired 90,051 Liabilities assumed: Trade payables ( 1,685 ) Accrued expenses and other current liabilities ( 2,943 ) Debt, non-current ( 12,564 ) Other non-current liabilities ( 854 ) Deferred tax liability ( 5,098 ) Total liabilities assumed ( 23,144 ) Fair value of total consideration transferred $ 66,907
Schedule of Revenue and Net Loss of the Combined Entity	The following unaudited pro forma information gives effect to the acquisition of EryDel as if it had been completed on January 1, 2022 (the beginning of the comparable prior reporting period), including pro forma adjustments primarily related to amortization of acquired intangible assets, tax benefit from release of the valuation allowance and the inclusion of acquisition-related expenses reflected in the revenue and net loss (in thousands): For the year ended December, 31 2023 2022 Revenue $ — $ — Net Loss ( 40,265 ) ( 67,580 )

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Schedule of Intangible Assets [Line Items]
Schedule of Carrying Amount of Finite-Lived Intangible Asset	The following table provides details of the carrying amount of the Company's finite-lived intangible asset (in thousands, except useful life): For the year ended December 31, Useful life 2023 Finite life intangible assets: Trade name 21 years $ 460 Impairment charge — Intangible asset amortization ( 4 ) Foreign currency translation adjustments 19 Balance as of December 31, 2023 $ 475
Schedule carrying amount of goodwill	The following table summarizes the changes in the carrying amount of goodwill (in thousands): Balance as of December 31, 2021 $ — Additions (a) 825 Impairment charge ( 825 ) Balance as of December 31, 2022 — Additions (a) 16,929 Foreign currency translation adjustments 696 Balance as of December 31, 2023 $ 17,625 (a) Goodwill additions related to the acquisition of Novosteo in second quarter of 2022 and the acquisition of EryDel in the fourth quarter of 2023 (see Note 15).
Ery Del [Member]
Schedule of Intangible Assets [Line Items]
Schedule of Carrying Amount of Indefinite-Lived Intangible Asset	The following table provides details of the carrying amount of the Company's indefinite-lived intangible asset (in thousands): As of December 31, 2023 Unamortized intangible assets: In-process research and development $ 60,636 Impairment charge — Foreign currency translation adjustments 2,561 Balance as of December 31, 2023 $ 63,197
Novosteo [Member]
Schedule of Intangible Assets [Line Items]
Schedule of Carrying Amount of Indefinite-Lived Intangible Asset	The following table provides details of the carrying amount of the Company's indefinite-lived intangible asset (in thousands): As of December 31, 2023 Unamortized intangible assets: In-process research and development $ 5,900 Impairment charge ( 5,900 ) Balance as of December 31, 2023 $ —

Organization - Additional Infor

Organization - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Oct. 20, 2023	Jan. 27, 2023	Dec. 31, 2023	Dec. 31, 2022	May 09, 2022
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock, par value			$ 0.001	$ 0.001
Common stock, shares			42,973,215	36,136,480
NDA Acceptance Under Contigent Consideration	$ 25,000
Entity incorporation date			2012-06
Accumulated deficit			$ (319,644)	$ (288,259)
Cash, cash equivalents, and short-term investments			$ 75,100
Stock Agreement
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of issued and outstanding Common Stock		7.50%
Milestone payments		$ 150,000
Approval Milestones
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Milestone Payment	$ 60,000
Ery Del [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock, shares	6,525,315
Additional common stock shares issued	725,037
Aggregate potential cash payments under contigent rights	$ 485,000
Amount payable upon achievement of specified milestone.	5,000
NDA Acceptance Under Contigent Consideration	25,000
Milestone achievement related to market and sales	395,000
Ery Del [Member] | Approval Milestones
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Milestone Payment	$ 60,000
Merger Agreement
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Automatically cancelled and converted common stock					0.0911
Common stock, par value					$ 0.001
Common stock, shares					5,520,000
Options outstanding assumed					507,108

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) Segment
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segment | Segment	1
Number of operating segment | Segment	1
Impairment charges	$ 0.1
Company's limit for FDIC	0.3
Ery Del [Member]
Summary Of Significant Accounting Policies [Line Items]
Fair value of contingent consideration related to acquisition	1.6
San Diego, California
Summary Of Significant Accounting Policies [Line Items]
Asset impairment charge related to lease impairment loss and loss on disposal of fixed assets	$ 0.2

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Useful Lives of Property and Equipment (Details)	Dec. 31, 2023
Computer Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	3 years
Lab Equipment | Minimum
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	2 years 6 months
Lab Equipment | Maximum
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	5 years
Finance Lease Right of Use Assets
Property Plant And Equipment [Line Items]
Useful Estimated lives of property and equipment	us-gaap:UsefulLifeShorterOfTermOfLeaseOrAssetUtilityMember
Leasehold Improvement
Property Plant And Equipment [Line Items]
Useful Estimated lives of property and equipment	us-gaap:UsefulLifeShorterOfTermOfLeaseOrAssetUtilityMember
Office Furniture | Minimum
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	4 years
Office Furniture | Maximum
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	5 years

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]
Fair value assets level 1 to level 2	$ 0	$ 0
Fair value assets level 2 to level 1	0	0
Fair value assets transfers into level 3	0	0
Fair value assets transfers out of level 3	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Financial assets	$ 73,538	$ 89,773
Financial liabilites	71,135
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets	4,285	10,988
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets	729	6,102
Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets		9,000
Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		12,411
Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets	68,524	50,766
Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		506
Accrued Earnout
Schedule Of Available For Sale Securities [Line Items]
Financial liabilites	57,706
Long-term debt
Schedule Of Available For Sale Securities [Line Items]
Financial liabilites	13,429
Level 1
Schedule Of Available For Sale Securities [Line Items]
Financial assets	8,256	10,988
Financial liabilites	0
Level 1 | Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets	4,285	10,988
Level 1 | Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets	0	0
Level 1 | Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets		0
Level 1 | Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		0
Level 1 | Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets	3,971	0
Level 1 | Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		0
Level 1 | Accrued Earnout
Schedule Of Available For Sale Securities [Line Items]
Financial liabilites	0
Level 2
Schedule Of Available For Sale Securities [Line Items]
Financial assets	65,282	78,785
Financial liabilites	0
Level 2 | Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets	0	0
Level 2 | Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets	729	6,102
Level 2 | Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets		9,000
Level 2 | Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		12,411
Level 2 | Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets	64,553	50,766
Level 2 | Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		506
Level 2 | Accrued Earnout
Schedule Of Available For Sale Securities [Line Items]
Financial liabilites	0
Level 3
Schedule Of Available For Sale Securities [Line Items]
Financial assets	0	0
Financial liabilites	71,135
Level 3 | Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets	0	0
Level 3 | Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets	0	0
Level 3 | Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets		0
Level 3 | Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		0
Level 3 | Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets	0	0
Level 3 | Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets		$ 0
Level 3 | Accrued Earnout
Schedule Of Available For Sale Securities [Line Items]
Financial liabilites	57,706
Level 3 | Long-term debt
Schedule Of Available For Sale Securities [Line Items]
Financial liabilites	$ 13,429

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Changes in Present Value of Acquisition Related Accrued Earnouts of Contingent Consideration Liability (Details) - Level 3 $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance as of January 1, 2023	$ 0
Acquisition date fair value of contingent consideration	56,128
Change in fair valuie of contingent consideration	1,578
Accrued earnout liability as of December 31, 2023	$ 57,706

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Quantitative Information About Level 3 Fair Value Measurements (Details) - Level 3 $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Fair Value Measurements related to accrued earnout	$ 57,706	$ 0
Accrued Earnout
Debt Securities, Available-for-Sale [Line Items]
Fair Value Measurements related to accrued earnout	$ 57,706
Accrued Earnout | Maximum
Debt Securities, Available-for-Sale [Line Items]
Input Used	100
Accrued Earnout | Minimum
Debt Securities, Available-for-Sale [Line Items]
Input Used	0
EIB loan
Debt Securities, Available-for-Sale [Line Items]
Fair Value Measurements related to accrued earnout	$ 13,429
Input Used	13

Fair Value Measurements - Fair

Fair Value Measurements - Fair value of the Level 3 EIB Debt (Details) - Level 3 $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Beginning Balance as of January 1, 2023	$ 0
Acquisition of EIB Debt	12,564
Change in fair value	338
Due to foreign currency translation	527
Ending Balance as of December 31, 2023	$ 13,429

Cash, Cash Equivalents and In_3

Cash, Cash Equivalents and Investments - Summary of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	$ 20,752	$ 44,579
Short term investments	54,307	45,602
Long term investments	0	3,578
Fair Value on Recurring | Cash
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	1,521	3,986
Fair Value on Recurring | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	4,285	10,988
Fair Value on Recurring | Repurchase Agreements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	0	9,000
Fair Value on Recurring | Certificates of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	729	5,390
Long term investments	0	712
Fair Value on Recurring | Municipal Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	0	506
Fair Value on Recurring | Corporate Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	0	12,411
Fair Value on Recurring | Government and Agency Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	14,946	20,605
Short term investments	53,578	27,295
Long term investments	$ 0	$ 2,866

Cash, Cash Equivalents and In_4

Cash, Cash Equivalents and Investments - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Weighted average remaining contractual maturities of available-for-sale securities	2 months
Realized gains or losses on the sale or maturity of available-for-sale securities	$ 0	$ 0
Amounts reclassify out of accumulated other comprehensive loss	0
Fair value assets level 1 to level 2	0	0
Fair value assets level 2 to level 1	$ 0	$ 0

Cash, Cash Equivalents and In_5

Cash, Cash Equivalents and Investments - Summary of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 73,548	$ 90,330
Unrealized Gains	13	5
Unrealized Losses	(23)	(562)
Financial assets and liabilities	73,538	89,773
Cash equivalents (original maturities within 90 days)	19,231	40,593
Short-term investments (maturities within 1 year)	54,307	45,602
Long-term investments (maturities beyond 1 year)	0	3,578
Total cash equivalents and investments	73,538	89,773
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	4,285	10,988
Unrealized Gains	0	0
Unrealized Losses	0	0
Financial assets and liabilities	4,285	10,988
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	735	6,237
Unrealized Gains	0	1
Unrealized Losses	(6)	(136)
Financial assets and liabilities	729	6,102
Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		9,000
Unrealized Gains		0
Unrealized Losses		0
Financial assets and liabilities		9,000
Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		12,575
Unrealized Gains		0
Unrealized Losses		(164)
Financial assets and liabilities		12,411
Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	68,528	51,020
Unrealized Gains	13	4
Unrealized Losses	(17)	(258)
Financial assets and liabilities	$ 68,524	50,766
Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		510
Unrealized Gains		0
Unrealized Losses		(4)
Financial assets and liabilities		$ 506

Cash, Cash Equivalents and In_6

Cash, Cash Equivalents and Investments - Summary of Unrealized Losses of Company's Investments in Debt Securities Measured at Fair Value (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, Less than twelve months	$ 3,966
Gross unrealized loss, Less than twelve months	0
Fair value,Twelve months or greater	3,704
Gross unrealized loss, Twelve months or greater	(23)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Total	7,670
Gross unrealized loss, total	(23)
Certificates of Deposit [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, Less than twelve months	0
Gross unrealized loss, Less than twelve months	0
Fair value,Twelve months or greater	729
Gross unrealized loss, Twelve months or greater	(6)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Total	729
Gross unrealized loss, total	(6)
US Government Corporations and Agencies Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, Less than twelve months	3,966
Gross unrealized loss, Less than twelve months	0
Fair value,Twelve months or greater	2,975
Gross unrealized loss, Twelve months or greater	(17)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Total	6,941
Gross unrealized loss, total	$ (17)

Cash, Cash Equivalents and In_7

Cash, Cash Equivalents and Investments - Schedule of the Ccontractual Maturities of our Investments in Debt Securities Measured at Fair Value (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Fair Value Disclosures [Abstract]
Total	$ 54,307
Less Than 1 Year	54,307
1-5 Years	0
6-10 Years	0
More Than 10 Years	$ 0

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Components [Line Items]
Prepaid expenses	$ 365	$ 223
Prepaid insurance	809	977
Prepaid research and development expenses	133	1,088
Other current assets	81	276
Total prepaid expenses and other current assets	2,381	3,567
Australia
Balance Sheet Components [Line Items]
Australia research and development refundable tax credit	0	1,003
Italy
Balance Sheet Components [Line Items]
Australia research and development refundable tax credit	$ 993	$ 0

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Aug. 04, 2023	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2023
Prepaid expenses and other current assets		$ 2,381	$ 3,567
Depreciation		300	200
Cash severance payments	$ 500	300
Severance costs recognized		100
Expenses related to employment obligation		100
Additional cash bonous severance percentage	100%
Share based compensation accelerated vesting percentage	50%
Total stock-based compensation	$ 100	5,220	16,618
Option [Member]
Accelerated vesting, number of options	612,141
Restricted Stock Awards
Accelerated vesting, number of options	54,757
Novosteo [Member]
Prepaid expenses and other current assets				$ 500
Australia research and development refundable tax credit				$ 500
Cortexyme Australia
Reductions in research and development expense		0	600
Prepaid expenses and other current assets		500
Australia research and development refundable tax credit		500
Ery Del [Member]
Reductions in research and development expense		$ 200	$ 0

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Components [Line Items]
VAT receivable	$ 3,463	$ 0
Total other assets	8,456	0
Italy
Balance Sheet Components [Line Items]
Long term Italian research and development refundable tax credit	$ 4,993	$ 0

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Assets Held for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Assets Held for Sale	$ 10	$ 0
Novosteo [Member]
Restructuring Cost and Reserve [Line Items]
Assets Held for Sale	$ 10	$ 0

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Less: accumulated amortization and depreciation	$ (507)	$ (185)
Property and equipment, net	234	393
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment	36	18
Computer Software
Property Plant And Equipment [Line Items]
Property and equipment	30	0
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment	486	415
Finance Lease Right of Use Assets
Property Plant And Equipment [Line Items]
Property and equipment	0	124
Leasehold Improvement
Property Plant And Equipment [Line Items]
Property and equipment	36	21
Office Furniture
Property Plant And Equipment [Line Items]
Property and equipment	$ 153	$ 0

Balance Sheet Components - Sc_5

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Personnel expenses	$ 2,340	$ 1,130
Professional fees	211	234
Research and development expenses	564	497
Current portion of operating lease liabilities	64	377
Current portion of finance lease liability	0	76
Other	257	185
Total accrued expenses and other current liabilities	$ 3,436	$ 2,499

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Severance and Related Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Components [Abstract]
Beginning accrued severance	$ 0	$ 0
Incurred during the period	770	3,942
Severance paid during the period	(429)	(3,942)
Ending accrued severance	$ 341	$ 0

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)			6 Months Ended	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022	Jun. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Oct. 20, 2023	Feb. 28, 2023
Lessee Lease Description [Line Items]
Operating lease liability				$ 385,000	$ 377,000
Operating lease asset				385,000	291,000
Future rent expense				$ 400,000
Finance lease amortized period on equipment service				18 months
Finance lease amortization of right of use assets				$ 6,000	50,000
Finance Lease, Liability, Total							$ 70,000
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]							Accrued Liabilities, Current
Impairment charges				$ 100,000
EryDel
Lessee Lease Description [Line Items]
Operating lease liability						$ 31,000
Operating lease asset						31,000
EryDel | Other Operating Leases
Lessee Lease Description [Line Items]
Operating lease liability						200,000
Operating lease asset						200,000
Minimum
Lessee Lease Description [Line Items]
Operating lease remaining term on a straight-line basis				29 months
Maximum
Lessee Lease Description [Line Items]
Operating lease remaining term on a straight-line basis				73 months
South San Francisco
Lessee Lease Description [Line Items]
Operating lease payments	$ 22,000		$ 300,000
Operating lease liability			300,000
Operating lease asset			300,000
Security deposit paid			$ 17,000
West Lafayette
Lessee Lease Description [Line Items]
Lease agreement period		15 months
Operating lease payments		$ 200,000
Operating lease liability		$ 100,000
Loan proceeds used to offset rent expense, utility costs and mortgage interest expense				$ 57,000
Right-of-use assets obtained in exchange for new operating lease liabilities					$ 10,000
Impairment charges				66,000
West Lafayette | Accrued Expenses And Other Current Liabilities
Lessee Lease Description [Line Items]
Security deposit paid				$ 6,000
Bresso, Italy | EryDel
Lessee Lease Description [Line Items]
Operating lease liability						400,000
Operating lease asset						$ 400,000
Medolla, Italy | EryDel
Lessee Lease Description [Line Items]
Lease agreement period						12 years
Operating lease liability						$ 100,000
Operating lease asset						$ 100,000

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease right-of-use assets	$ 385	$ 291
Short-term operating lease liability	$ 64	$ 377
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Long-term operating lease liabilities	$ 321	$ 0
Operating lease liability	385	377
Finance lease right of use asset	0	124
Finance lease accumulated amortization	0	(50)
Total finance lease right of use asset, net	$ 0	$ 74
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Weighted average remaining lease term
Operating leases	5 years 4 months 24 days	10 months 24 days
Finance leases		1 year
Weighted average discount rate
Operating leases	7.95%	5.71%
Finance leases	0%	4.45%
2024	$ 91
2025	91
2026	88
2027	81
2028	69
Thereafter	48
Total lease payments	469
Less: imputed interest	(83)
Operating lease liability	$ 385	$ 377

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Lease costs:
Finance lease amortization of right of use assets	$ 6,000	$ 50,000
Operating lease costs	266,000	572,000
Short-term lease costs	96,000	75,000
Total lease costs	$ 368,000	$ 697,000

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Details) - 12 months ended Dec. 31, 2023 € in Millions, $ in Millions	EUR (€)	USD ($)	USD ($)
EIB loan
Debt Instrument [Line Items]
Fair value of the EIB Loan | $			$ 13.4
Debt, Fair value adjustment | $		$ 0.3
Ery Del [Member]
Debt Instrument [Line Items]
Acquisition date	Oct. 20, 2023	Oct. 20, 2023
Maximum borrowings	€ 30
Loan restated term	The EIB Loan was amended and restated as of the acquisition date. The EIB Loan provides for maximum borrowings of 30.0 million euro through four tranches; tranche A, 3.0 million euro; tranche B, 7.0 million euro; tranche C, 10.0 million euro; and tranche D, 10.0 million euro. Each tranche is subject to conditions precedent related to the Company’s business and capitalization.	The EIB Loan was amended and restated as of the acquisition date. The EIB Loan provides for maximum borrowings of 30.0 million euro through four tranches; tranche A, 3.0 million euro; tranche B, 7.0 million euro; tranche C, 10.0 million euro; and tranche D, 10.0 million euro. Each tranche is subject to conditions precedent related to the Company’s business and capitalization.
Repayment terms	The unused portions of each tranche may be canceled by the Company at any time, subject to a cancellation fee. As of December 31, 2023, only tranches A and B have been drawn. All amounts due under tranche A and B are payable on their maturity date of August 2026. Tranche C and D are payable in equal installments of principal together with all amounts outstanding under the tranches on the repayment dates specified in the relevant Disbursement Offer. The first Repayment Date of tranche C shall fall not earlier than twelve months from the Disbursement Date of such tranche. The last Repayment Date of tranche C and tranche D shall fall not later than 5 years from the Disbursement Date of tranche C and tranche D, respectively. The EIB Loan bears interest at fixed rates for each tranche and is payable on the maturity date for each Tranche. The fixed rates range from 7.0% to 9.0% per annum. As of December 31, 2023, principal of 10.0 million euros ($11.0 million) was outstanding on the EIB Loan and it is recorded as Long-term debt on the consolidated balance sheet at fair value with imputed interest of 9.0% included.	The unused portions of each tranche may be canceled by the Company at any time, subject to a cancellation fee. As of December 31, 2023, only tranches A and B have been drawn. All amounts due under tranche A and B are payable on their maturity date of August 2026. Tranche C and D are payable in equal installments of principal together with all amounts outstanding under the tranches on the repayment dates specified in the relevant Disbursement Offer. The first Repayment Date of tranche C shall fall not earlier than twelve months from the Disbursement Date of such tranche. The last Repayment Date of tranche C and tranche D shall fall not later than 5 years from the Disbursement Date of tranche C and tranche D, respectively. The EIB Loan bears interest at fixed rates for each tranche and is payable on the maturity date for each Tranche. The fixed rates range from 7.0% to 9.0% per annum. As of December 31, 2023, principal of 10.0 million euros ($11.0 million) was outstanding on the EIB Loan and it is recorded as Long-term debt on the consolidated balance sheet at fair value with imputed interest of 9.0% included.
Outstanding amount of line of credit	€ 10	$ 11
Imputed interest on borrowings	9%		9%
Remuneration payable period	7 years	7 years
Fair value of EIB Loan | $			$ 12.6
Foreign currency translation adjustment in fair value | $			$ 0.5
Ery Del [Member] | Minimum
Debt Instrument [Line Items]
Disbursement period	12 months	12 months
Fixed interest rate	7%		7%
Ery Del [Member] | Maximum
Debt Instrument [Line Items]
Disbursement period	5 years	5 years
Fixed interest rate	9%		9%
Ery Del [Member] | Equal to 2.5%
Debt Instrument [Line Items]
Provision for additional remuneration paid based on revenue percentage	2.50%	2.50%
Ery Del [Member] | Equal to 2.5% | Maximum
Debt Instrument [Line Items]
Revenues	€ 125
Ery Del [Member] | Plus 1.85%
Debt Instrument [Line Items]
Provision for additional remuneration paid based on revenue percentage	1.85%	1.85%
Ery Del [Member] | Plus 1.85% | Minimum
Debt Instrument [Line Items]
Revenues	€ 125
Ery Del [Member] | Plus 1.85% | Maximum
Debt Instrument [Line Items]
Revenues	€ 250
Ery Del [Member] | Plus 1.0%
Debt Instrument [Line Items]
Provision for additional remuneration paid based on revenue percentage	1%	1%
Ery Del [Member] | Plus 1.0% | Minimum
Debt Instrument [Line Items]
Revenues	€ 250
Ery Del [Member] | Tranche A
Debt Instrument [Line Items]
Maximum borrowings	€ 3
Drawn percentage	30%	30%
Ery Del [Member] | Tranche B
Debt Instrument [Line Items]
Maximum borrowings	€ 7
Ery Del [Member] | Tranche C
Debt Instrument [Line Items]
Maximum borrowings	10
Ery Del [Member] | Tranche D
Debt Instrument [Line Items]
Maximum borrowings	€ 10
Ery Del [Member] | Tranche A and B
Debt Instrument [Line Items]
Drawn percentage	50%	50%
Ery Del [Member] | Tranche A,B and C
Debt Instrument [Line Items]
Drawn percentage	80%	80%
Ery Del [Member] | Tranche A,B,Cand D
Debt Instrument [Line Items]
Drawn percentage	100%	100%

Long-term Debt - Schedule of Fu

Long-term Debt - Schedule of Future Minimum Principal Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
2024	$ 0
2025	0
2026	11,053
2027 and thereafter	0
Total future minimum payments	11,053
Imputed interest	2,376
Total Debt as of December 31, 2023	$ 13,429	$ 0

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details) - USD ($)				12 Months Ended
	Aug. 04, 2023	May 19, 2022	May 09, 2022	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights	50%
Common stock reserved for issuance				14,324,720	12,745,170
Total intrinsic value of options exercised				$ 300,000	$ 1,400,000
Weighted average grant date fair value of options granted				$ 0.82	$ 6.05
Total estimated grant date fair value of options vested				$ 11,100,000	$ 31,800,000
Stock-based compensation expense related to options granted	$ 100,000			5,220,000	16,618,000
Income tax benefits recognized				0
Unamortized employee stock-based compensation				$ 4,000,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 6 months 18 days
Dividend yield				0%
One Year Anniversary [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights		25%		25%
Three Year Anniversary [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights		75%		75%
Novosteo [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total intrinsic value of options exercised				$ 427,000	$ 0
Weighted average grant date fair value of options granted				$ 0	$ 2.51
Total estimated grant date fair value of options vested				$ 300,000	$ 300,000
Unamortized employee stock-based compensation				$ 400,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 2 months 23 days
Number of shares, Cancelled and converted		0.0911
Warrants to purchase common stock, per share		$ 0.0911
Arithmetic Average
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term				10 years
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period				2 years
Total fair value of shares vested				$ 44,000	1,700,000
Aggregate intrinsic value				11,000	1,100,000
Stock-based compensation expense related to options granted				37,000	1,337,000
Unamortized employee stock-based compensation				$ 4,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 months 1 day
Number of Shares, Surrendered				19,188
Restricted Stock Units | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period				2 years
Restricted Stock Units | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period				4 years
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized employee stock-based compensation				$ 600,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				1 year 8 months 26 days
Number of Shares, Surrendered				63,293
Restricted Stock Awards | Novosteo [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		0.0911
Employees and Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted				$ 2,600,000	11,400,000
Employees and Non-Employees | Novosteo [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted				275,000	245,000
Employees and Non-Employees | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted				$ 496,000	338,000
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan				10,036,489
Increase in number of shares available for issuance as proportion of shares of common stock				2,146,354
Percentage of common stock outstanding				4%
Award grant period				10 years
Rate of purchase price of stock on fair value (as a percent)				100%
Voting rights in percentage				10
Stock based awards vesting period				4 years
2019 Plan | Novosteo [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan		544,985
2019 Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Monthly installments over the remaining vesting period				3 years
2019 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Rate of purchase price of stock on fair value (as a percent)				110%
Stock options granted maximum period				ten years
Monthly installments over the remaining vesting period				4 years
2019 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares available for issuance as proportion of shares of common stock				536,589
Percentage of common stock outstanding				1%
Common stock reserved for issuance				1,494,530
Maximum period for common stock shares reserved for future issuance				10 years
2022 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares available for issuance as proportion of shares of common stock			4,000,000
Award grant period			10 years
Rate of purchase price of stock on fair value (as a percent)			100%
Total intrinsic value of options exercised				$ 0	$ 0
Weighted average grant date fair value of options granted				$ 0	$ 2.26
Total estimated grant date fair value of options vested				$ 2,100,000	$ 0
Unamortized employee stock-based compensation				$ 3,200,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 4 months 20 days
2022 Inducement Plan | Employees and Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted				$ 1,802,000	$ 1,293,000
2019 Novosteo Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award grant period		10 years
Rate of purchase price of stock on fair value (as a percent)		100%
Voting rights in percentage		10
Stock options granted maximum period		ten years
Stock based awards vesting period		4 years
2019 Novosteo Plan [Member] | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Monthly installments over the remaining vesting period		3 years
2019 Novosteo Plan [Member] | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Rate of purchase price of stock on fair value (as a percent)		110%
Monthly installments over the remaining vesting period		4 years

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Activity for Service-based Stock Options (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate Intrinsic Value	$ 300,000	$ 1,400,000
2022 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate Intrinsic Value	0	0
Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate Intrinsic Value	$ 427,000	$ 0
Service Based Stock Options | 2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance	3,319,711	5,571,293
Number of Options and Unvested Shares, granted	3,346,958	2,051,058
Number of Options and Unvested Shares, exercised	(258,705)	(102,152)
Number of Options and Unvested Shares, Options cancelled / forfeited	(2,140,786)	(4,200,488)
Number of Options and Unvested Shares, ending balance	4,267,178	3,319,711	5,571,293
Number of Options and Unvested Shares, vested and expected to vest	4,267,178
Number of Options and Unvested Shares, exercisable	1,109,464
Weighted Average Exercise Price, beginning balance	$ 16.07	$ 28.7
Weighted Average Exercise Price, granted	1.03	8.13
Weighted Average Exercise Price, exercised	0.42	1.45
Weighted Average Exercise Price, cancelled/forfeited	16.52	29.3
Weighted Average Exercise Price, ending balance	5	$ 16.07	$ 28.7
Weighted Average Exercise Price, vested and expected to vest	5
Weighted Average Exercise Price, exercisable	$ 14.09
Weighted Average Remaining Contractual Life	8 years 10 months 6 days	4 years 9 months 7 days	8 years 3 months 3 days
Weighted Average Remaining Contractual Life, vested and expected to vest	8 years 10 months 6 days
Weighted Average Remaining Contractual Life, exercisable	7 years 3 months 25 days
Aggregate Intrinsic Value	$ 197,000	$ 65,000	$ 15,687,000
Aggregate Intrinsic Value, vested and expected to vest	197,000
Aggregate Intrinsic Value, exercisable	$ 34,000
Service Based Stock Options | 2022 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance	3,742,255
Number of Options and Unvested Shares, granted		3,744,255
Number of Options and Unvested Shares, Options cancelled / forfeited	(1,408,949)	(2,000)
Number of Options and Unvested Shares, ending balance	2,333,306	3,742,255
Number of Options and Unvested Shares, vested and expected to vest	2,333,306
Number of Options and Unvested Shares, exercisable	923,599
Weighted Average Exercise Price, beginning balance	$ 2.98
Weighted Average Exercise Price, granted		$ 2.98
Weighted Average Exercise Price, cancelled/forfeited	2.98	2.98
Weighted Average Exercise Price, ending balance	2.98	$ 2.98
Weighted Average Exercise Price, vested and expected to vest	2.98
Weighted Average Exercise Price, exercisable	$ 2.98
Weighted Average Remaining Contractual Life	8 years 4 months 20 days	9 years 4 months 20 days
Weighted Average Remaining Contractual Life, vested and expected to vest	8 years 4 months 20 days
Weighted Average Remaining Contractual Life, exercisable	8 years 4 months 20 days
Service Based Stock Options | Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance	503,105
Number of Options and Unvested Shares, assumed		507,648
Number of Options and Unvested Shares, exercised	(105,808)
Number of Options and Unvested Shares, Options cancelled / forfeited	(86,866)	(4,543)
Number of Options and Unvested Shares, ending balance	310,431	503,105
Number of Options and Unvested Shares, vested and expected to vest	310,431
Number of Options and Unvested Shares, exercisable	135,812
Weighted Average Exercise Price, beginning balance	$ 0.55
Weighted Average Exercise Price, assumed		$ 0.55
Weighted Average Exercise Price, exercised	0.55
Weighted Average Exercise Price, cancelled/forfeited	0.55	0.55
Weighted Average Exercise Price, ending balance	0.55	$ 0.55
Weighted Average Exercise Price, vested and expected to vest	0.55
Weighted Average Exercise Price, exercisable	$ 0.55
Weighted Average Remaining Contractual Life	8 years 2 months 23 days	9 years 2 months 23 days
Weighted Average Remaining Contractual Life, vested and expected to vest	8 years 2 months 23 days
Weighted Average Remaining Contractual Life, exercisable	8 years 2 months 23 days
Aggregate Intrinsic Value	$ 155,000	$ 44,000
Aggregate intrinsic value, exercised	40,000
Aggregate Intrinsic Value, vested and expected to vest	155,000
Aggregate Intrinsic Value, exercisable	$ 68,000

Equity Incentive Plans - Summ_2

Equity Incentive Plans - Summary of Restricted Stock Options (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Restricted Stock Units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Outstanding, Number of Shares, Unvested, Beginning Balance | shares	30,876
Number of Shares, vested | shares	(10,200)
Number of Shares, cancelled | shares	(19,188)
Outstanding, Number of Shares, Unvested, Ending Balance | shares	1,488
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 4.3
Weighted-Average Grant Date Fair Value, vested | $ / shares	4.3
Weighted-Average Grant Date Fair Value, cancelled | $ / shares	4.3
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Ending Balance | $ / shares	$ 4.3
Restricted Stock Awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Outstanding, Number of Shares, Unvested, Beginning Balance | shares	427,401
Number of Shares, vested | shares	(188,344)
Number of Shares, cancelled | shares	(63,293)
Outstanding, Number of Shares, Unvested, Ending Balance | shares	175,764
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 3.3
Weighted-Average Grant Date Fair Value, vested | $ / shares	3.3
Weighted-Average Grant Date Fair Value, cancelled | $ / shares	3.3
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Ending Balance | $ / shares	$ 9.9

Equity Incentive Plans - Summ_3

Equity Incentive Plans - Summary of Employee and Non-Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands		12 Months Ended
	Aug. 04, 2023	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 100	$ 5,220	$ 16,618
General and Administrative Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation		4,003	10,225
Research and Development Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation		$ 1,217	$ 6,393

Equity Incentive Plans - Summ_4

Equity Incentive Plans - Summary of Weighted Average Assumptions to Calculate the Fair Value of Stock-Based Compensation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0%
Service Based Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	106.36%	89.98%
Expected dividend yield	0%	0%
Expected term (in years)	6 years 2 months 19 days	6 years 2 months 23 days
Risk-free interest rate	4.01%	2.67%

Common Stock - Additional Infor

Common Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Dec. 23, 2021	Dec. 31, 2023	Dec. 31, 2022	Apr. 30, 2023
Subsidiary, Sale of Stock [Line Items]
Proceeds from issuance of common stock		$ 0	$ 608
Common stock, shares authorized		100,000,000	100,000,000
Common stock, par value		$ 0.001	$ 0.001
Common stock, shares		42,973,215	36,136,480
Common stock, shares outstanding		42,973,215	36,136,480
Common stock, voting rights		Each share of common stock is entitled to one vote
Rights Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Rights outstanding, maturity date				Apr. 05, 2024
Open Market Sales Agreement | Jefferies
Subsidiary, Sale of Stock [Line Items]
Proceeds from issuance of common stock	$ 150,000	$ 0	$ 600
Issuance of stock (in shares)		0	51,769

Common Stock - Schedule of Rese

Common Stock - Schedule of Reserved Shares of Common Stock for Future Issuance (Details) - shares	Dec. 31, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Total	14,324,720	12,745,170
Options Issued and Outstanding Under The Quince 2019 Stock Plan
Class Of Stock [Line Items]
Total	4,267,178	3,319,711
Shares Available for Issuance Under Quince 2019 Stock Plan
Class Of Stock [Line Items]
Total	4,005,784	3,747,309
Shares Available for Issuance Under Employee Stock Purchase Plan
Class Of Stock [Line Items]
Total	1,494,530	1,133,165
Options Issued and Outstanding Under The Novosteo 2019 Plan
Class Of Stock [Line Items]
Total	310,431	503,105
Shares Available for Issuance Under Novosteo 2019 Plan
Class Of Stock [Line Items]
Total	246,797	41,880
Options Issued and Outstanding Under the 2022 Inducement Plan
Class Of Stock [Line Items]
Total	2,333,306	3,742,255
Shares Available for Issuance Under 2022 Inducement Plan
Class Of Stock [Line Items]
Total	1,666,694	257,745

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - Morphimmune Inc. [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Related Party Transaction [Line Items]
Operating lease payments	$ 57,000
Lab Equipment
Related Party Transaction [Line Items]
Proceeds from sale of property, plant, and equipment	$ 80,000

Income Taxes - Schedule of Loss

Income Taxes - Schedule of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
United States	$ (27,375)	$ (48,191)
International	(4,207)	(3,753)
Total	$ (31,582)	$ (51,944)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Benefit for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Current expense (benefit):
Federal	$ 0	$ 0
State	0	0
Foreign	61	0
Total current expense (benefit)	61	0
Deferred expense (benefit):
Federal	(248)	284
State	0	0
Foreign	(10)	0
Total deferred expense (benefit)	(258)	284
Total income tax expense (benefit)	$ (197)	$ 284

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes Differs From the Amount Expected by Applying the Federal Statutory Rate to Loss Before Taxes (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21%	21%
State income taxes	4.47%	0.89%
Income tax credits	1.07%	1.49%
Stock based compensation	(26.35%)	(0.82%)
Non-deductible expenses and others	(1.25%)	(3.38%)
Change in valuation allowance	1.68%	(18.63%)
Effective income tax rate	0.62%	0.55%

Income Taxes - Schedule of Co_2

Income Taxes - Schedule of Components of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax asset:
Federal and State net operating loss carryforwards	$ 81,881	$ 49,481
Stock based compensation	2,401	9,667
Other accruals	527	515
Capitalized research and development expense	3,220	3,094
Tax credits	8,343	7,970
Disallowed interest expense carryforward	1,043	0
Gross deferred tax asset	97,415	70,727
Valuation allowance	(85,111)	(69,692)
Total deferred tax assets	12,304	1,035
Deferred tax liabilities:
Property and equipment	0	(11)
Capitalized leases	0	(32)
IP R&D	(17,608)	(1,239)
Gross deferred tax liabilities	(17,608)	(1,282)
Net deferred tax liabilities	$ (5,304)	$ (247)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Taxes [Line Items]
Valuation allowances increased	$ 15.4	$ 11.1
Unrecognized tax benefits that would impact the effective tax rate	0.5
Interest or penalties accrued	$ 0.1	$ 0
Earliest Tax Year | California State Tax Examinations
Income Taxes [Line Items]
Open tax year	2013
Latest Tax Year | California State Tax Examinations
Income Taxes [Line Items]
Open tax year	2023
U.S. Federal
Income Taxes [Line Items]
Operating loss carryforwards	$ 238.4
Operating loss carryforwards, not subject to expiration	222.6
Operating loss carryforwards, subject to expiration	$ 15.8
Operating loss carryforwards begin to expire	2034
Tax credit carryforwards	$ 9.8
Tax credits carryforwards begin to expire	2036
U.S. Federal | Earliest Tax Year
Income Taxes [Line Items]
Open tax year	2013
U.S. Federal | Latest Tax Year
Income Taxes [Line Items]
Open tax year	2023
State
Income Taxes [Line Items]
Operating loss carryforwards	$ 34.2
Operating loss carryforwards begin to expire	2034
Tax credit carryforwards	$ 2.9
Foreign Tax Authority
Income Taxes [Line Items]
Operating loss carryforwards	$ 121.1
Internal Revenue Code
Income Taxes [Line Items]
Period of cumulative change in ownership	3 years
Minimum | Internal Revenue Code
Income Taxes [Line Items]
Cumulative change in ownership percentage	50%

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Beginning balance	$ 3,688	$ 3,249
Additions for tax positions taken in a prior year	200	0
Additions for tax positions taken in a current year	451	439
Ending balance	$ 4,339	$ 3,688

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Numerator:
Net loss	$ (31,385)	$ (51,660)
Denominator
Weighted average shares of common stock outstanding - basic	37,237,149	33,496,534
Weighted average shares of common stock outstanding - diluted	37,237,149	33,496,534
Net loss per share - basic	$ (0.84)	$ (1.54)
Net loss per share - diluted	$ (0.84)	$ (1.54)

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Outstanding Potentially Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share (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 calculation of earnings per share, amount	7,088,167	8,023,348
Stock Options Issued and Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	6,910,915	7,565,071
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	1,488	30,876
Restricted Stock Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	175,764	427,401

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Percentage of employee contribution of their annual compensation	100%
Contributions	$ 100	$ 200
Defined contribution plan name	401(k)
Defined Contribution Plan, Plan Name [Extensible List]	us-gaap:QualifiedPlanMember

Business Combination - Addition

Business Combination - Additional Information (Details)			2 Months Ended	12 Months Ended
	Oct. 20, 2023 USD ($) $ / shares shares	May 19, 2022 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Business Acquisition [Line Items]
Deferred tax liability		$ 532,000
Common stock, par value | $ / shares			$ 0.001	$ 0.001	$ 0.001
NDA Acceptance Under Contigent Consideration	$ 25,000,000
Business Combination Discount Rate	15%
Revenue					$ 262,000
Net loss					(52,592,000)
Acquisition related costs				$ 2,500,000	$ 2,200,000
Common stock, shares | shares			42,973,215	42,973,215	36,136,480
Measurement period adjustments				$ 0	$ 0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total		$ 5,900,000
Specified Approval Milestones [Member]
Business Acquisition [Line Items]
Milestone Payment	$ 60,000,000
Novosteo [Member]
Business Acquisition [Line Items]
Number of shares, Cancelled and converted | shares		0.0911
Common stock, par value | $ / shares		$ 0.001
Aggregate purchase of common stock shares | shares		507,108
Unvested restricted shares | shares		519,216
Business acquisition, transaction costs		$ 1,100,000
Revenue					0
Net loss					9,400,000
Payment to acquire business		$ 16,502,587,000
Shares issued for acquisition | shares		5,000,784
Share Price | $ / shares		$ 3.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total			$ 5,900,000	5,900,000
Ery Del [Member]
Business Acquisition [Line Items]
Deferred tax liability	5,098,000
Uncertain tax position liability	500,000
Fair value of total consideration transferred	66,907,000
Maximum amount of future consideration payment	485,000,000
Amount payable upon achievement of specified milestone.	5,000,000
Milestone achievement related to market and sales	395,000,000
Notes Receivable on the date of acquisition	1,000,000
Payments made for acquisition of Promissory Notes Agreement	1,000,000
Interest receivable	1,300,000
Business acquisition, transaction costs	2,500,000
Revenue			0	0	0
Net loss			3,700,000	(40,265,000)	$ (67,580,000)
Payment to acquire business	$ 56,128,000
Shares issued for acquisition | shares	7,250,352
Share Price | $ / shares	$ 0.989
Common stock, shares | shares	6,525,315
Common Stock withheld | shares	725,037
Dicounted earning after tax	16.60%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total	$ 61,096,000		$ 60,636,000	$ 60,636,000
Royalty rate utilizing under income approach	0.30%
Discounted value to present value of intangible assets	16.60%
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life	21 years
Ery Del [Member] | Probability Of Achievement [Member] | Maximum | Contingent Consideration [Member]
Business Acquisition [Line Items]
Input Used			100	100
Ery Del [Member] | Probability Of Achievement [Member] | Minimum | Contingent Consideration [Member]
Business Acquisition [Line Items]
Input Used			0	0
Ery Del [Member] | In Process Research and Development [Member]
Business Acquisition [Line Items]
Fair value of identifiable intangible assets	$ 60,600,000
Ery Del [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total	500,000
Ery Del [Member] | General and Administrative Expense [Member]
Business Acquisition [Line Items]
Business acquisition, transaction costs	2,300,000
Ery Del [Member] | Research and Development Expense [Member]
Business Acquisition [Line Items]
Business acquisition, transaction costs	$ 200,000

Business Combination - Summary

Business Combination - Summary of Total Purchase Consideration Transferred (Details) - Ery Del [Member] $ in Thousands	Oct. 20, 2023 USD ($)
Business Acquisition [Line Items]
Cash	$ 2,615
Quince Therapeutics common stock (7,250,352 shares)	7,164
Contigent consideration	56,128
Settlement of preexisting notes receivable	1,000
Fair value of total consideration transferred	$ 66,907

Business Combination - Summar_2

Business Combination - Summary of Total Purchase Consideration Transferred (Parenthetical) (Details)	Oct. 20, 2023 shares
Ery Del [Member]
Business Acquisition [Line Items]
Quince Therapeutics common stock, Shares	7,250,352

Business Combination - Schedule

Business Combination - Schedule of Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Oct. 20, 2023	Dec. 31, 2022	May 19, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Cash and cash equivalents				$ 10,593
Property and equipment				279
ROU asset				124
In-process research and development				5,900
Goodwill	$ 17,625		$ 0	825	$ 0
Prepaid expenses and other current assets				1,040
Accounts payable and accrued liabilities				(1,726)
Deferred tax liabilities				(532)
Net assets acquired				$ 15,678
Ery Del [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 560
Tax assets		10,187
Other current assets		644
Property and equipment		238
ROU asset		383
Other non-current assets		14
In-process research and development	$ 60,636	61,096
Goodwill		16,929
Total assets acquired		90,051
Trade payables		(1,685)
Accrued expenses and other current liabilities		(2,943)
Debt, non-current		(12,564)
Other non-current liabilities		(854)
Deferred tax liabilities		(5,098)
Total liabilities assumed		(23,144)
Net assets acquired		$ 66,907

Business Combination - Schedu_2

Business Combination - Schedule of Revenue and Net Loss of the Combined Entity (Details) - USD ($)	2 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Revenue			$ 262,000
Net loss			(52,592,000)
Ery Del [Member]
Business Acquisition [Line Items]
Revenue	$ 0	$ 0	0
Net loss	$ 3,700,000	$ (40,265,000)	$ (67,580,000)

Intangible Assets - Schedule of

Intangible Assets - Schedule of Carrying Amount of Indefinite Lived Intangible Asset (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Oct. 20, 2023	May 19, 2022
Indefinite-Lived Intangible Assets [Line Items]
In-process research and development				$ 5,900
Impairment charge	$ (5,900)	$ 0
Ery Del [Member]
Indefinite-Lived Intangible Assets [Line Items]
In-process research and development	60,636		$ 61,096
Impairment charge	0
Foreign curency translation adjustments	2,561
Indefinite-Lived Intangible Assets (Excluding Goodwill), Total	63,197
Novosteo [Member]
Indefinite-Lived Intangible Assets [Line Items]
In-process research and development	5,900
Impairment charge	(5,900)
Indefinite-Lived Intangible Assets (Excluding Goodwill), Total	$ 0

Intangible Assets - Schedule _2

Intangible Assets - Schedule of Carrying Amount of Finite Lived Intangible Asset (Details) - Ery Del [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Finite-Lived Intangible Assets [Line Items]
Impairment charge	$ 0
Intangible asset amortization	(4)
Foreign curency translation adjustments	19
Finite-Lived Intangible Assets, Net, Total	475
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets	$ 460
Useful life	21 years

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	May 19, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Intangible asset impairment charge	$ 5,900,000	$ 0
Goodwill	17,625,000	0	$ 825,000	$ 0
Non-cash goodwill impairment charge	0	825,000
Novosteo [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset impairment charge	$ 5,900,000
Goodwill		0
Non-cash goodwill impairment charge		$ 800,000

Intangible Assets - Schedule ca

Intangible Assets - Schedule carrying amount of goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Beginning Balance	$ 0	$ 0
Additions	16,929	825
Impairment charge		(825)
Foreign curency translation adjustments	696
Goodwill, Ending Balance	$ 17,625	$ 0