Quince Therapeutics (QNCX) 10-Q 13 Nov 24 2024 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2024	Nov. 05, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-38890
Entity Registrant Name	Quince Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
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
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	QNCX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		44,001,643
Entity Central Index Key	0001662774
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 2,675	$ 20,752
Short-term investments	45,172	54,307
Prepaid expenses and other current assets	3,871	2,381
Total current assets	51,718	77,440
Property and equipment, net	208	234
Operating lease right-of-use assets	559	385
Goodwill	0	17,625
Intangible assets	64,528	63,672
Other assets	9,506	8,544
Total assets	126,519	167,900
Current liabilities:
Accounts payable	1,622	2,033
Short-term contingent consideration	0	4,103
Accrued expenses and other current liabilities	3,803	3,436
Total current liabilities	5,425	9,572
Long-term debt	14,899	13,429
Long-term operating lease liabilities	450	321
Long-term contingent consideration	54,788	53,603
Deferred tax liabilities	5,382	5,304
Other long-term liabilities	643	587
Total liabilities	81,587	82,816
Commitments and contingencies
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 September 30, 2024 and December 31, 2023, respectively.	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized, 43,276,606 and 42,973,215 issued and outstanding as of September 30, 2024 and December 31, 2023, respectively.	43	43
Additional paid in capital	405,484	401,638
Accumulated other comprehensive income	3,419	3,047
Accumulated deficit	(364,014)	(319,644)
Total stockholders’ equity	44,932	85,084
Total liabilities and stockholders’ equity	$ 126,519	$ 167,900

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Preferred stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	43,276,606	42,973,215
Common stock, shares outstanding (in shares)	43,276,606	42,973,215
Series A Preferred Stock
Preferred stock, shares authorized (in shares)	100,000	100,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating expenses:
Research and development	$ 4,916	$ 1,431	$ 12,765	$ 6,013
General and administrative	3,630	4,663	13,296	12,786
Goodwill impairment charge	0	0	17,130	0
Intangible asset impairment charge	0	0	0	5,900
Fair value adjustment for contingent consideration	(2,683)	0	2,082	0
Total operating expenses	5,863	6,094	45,273	24,699
Loss from operations	(5,863)	(6,094)	(45,273)	(24,699)
Fair value adjustment for long-term debt	(449)	0	(1,252)	0
Interest income	683	959	2,393	2,464
Other income (expense), net	150	(216)	(158)	(504)
Net loss before income tax benefit	(5,479)	(5,351)	(44,290)	(22,739)
Income tax (expense) benefit	(13)	0	(80)	248
Net loss	(5,492)	(5,351)	(44,370)	(22,491)
Other comprehensive loss:
Foreign currency translation adjustments	2,158	158	203	309
Unrealized gain (loss) on available-for-sale securities	174	101	169	496
Total comprehensive loss	$ (3,160)	$ (5,092)	$ (43,998)	$ (21,686)
Net loss per share - basic (in USD per share)	$ (0.13)	$ (0.15)	$ (1.03)	$ (0.63)
Net loss per share - diluted (in USD per share)	$ (0.13)	$ (0.15)	$ (1.03)	$ (0.63)
Weighted average shares of common stock outstanding - basic (in shares)	43,164,136	36,073,040	43,090,632	35,941,234
Weighted average shares of common stock outstanding - diluted (in shares)	43,164,136	36,073,040	43,090,632	35,941,234

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income / (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022		36,136,480
Beginning balance at Dec. 31, 2022	$ 100,593	$ 36	$ 389,105	$ (289)	$ (288,259)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of stock options and vesting of restricted stock units (in shares)		270,445
Issuance of common stock on exercise of stock options and vesting of restricted stock units	110		110
Restricted Stock award retirement (in shares)		(63,293)
Restricted stock award retirement	(18)		(18)
Stock based compensation	4,134		4,134
Foreign currency translation adjustment	309			309
Unrealized gain (loss) on available for sale investments	496			496
Net loss	(22,491)				(22,491)
Ending balance (in shares) at Sep. 30, 2023		36,343,632
Ending balance at Sep. 30, 2023	83,133	$ 36	393,331	516	(310,750)
Beginning balance (in shares) at Jun. 30, 2023		36,327,995
Beginning balance at Jun. 30, 2023	86,884	$ 36	391,990	257	(305,399)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of stock options and vesting of restricted stock units (in shares)		70,394
Issuance of common stock on exercise of stock options and vesting of restricted stock units	28		28
Restricted Stock award retirement (in shares)		(54,757)
Restricted stock award retirement	(18)		(18)
Stock based compensation	1,331		1,331
Foreign currency translation adjustment	158			158
Unrealized gain (loss) on available for sale investments	101			101
Net loss	(5,351)				(5,351)
Ending balance (in shares) at Sep. 30, 2023		36,343,632
Ending balance at Sep. 30, 2023	83,133	$ 36	393,331	516	(310,750)
Beginning balance (in shares) at Dec. 31, 2023		42,973,215
Beginning balance at Dec. 31, 2023	85,084	$ 43	401,638	3,047	(319,644)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of stock options and vesting of restricted stock units (in shares)		303,391
Issuance of common stock on exercise of stock options and vesting of restricted stock units	225		225
Stock based compensation	3,621		3,621
Foreign currency translation adjustment	203			203
Unrealized gain (loss) on available for sale investments	169			169
Net loss	(44,370)				(44,370)
Ending balance (in shares) at Sep. 30, 2024		43,276,606
Ending balance at Sep. 30, 2024	44,932	$ 43	405,484	3,419	(364,014)
Beginning balance (in shares) at Jun. 30, 2024		43,276,606
Beginning balance at Jun. 30, 2024	46,968	$ 43	404,360	1,087	(358,522)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation	1,124		1,124
Foreign currency translation adjustment	2,158			2,158
Unrealized gain (loss) on available for sale investments	174			174
Net loss	(5,492)				(5,492)
Ending balance (in shares) at Sep. 30, 2024		43,276,606
Ending balance at Sep. 30, 2024	$ 44,932	$ 43	$ 405,484	$ 3,419	$ (364,014)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities
Net Loss	$ (44,370)	$ (22,491)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock based compensation	3,621	4,134
Depreciation and amortization	170	18
Impairment loss on operating lease	0	66
Loss on disposal of fixed assets	0	71
Equity investment in Lighthouse, Inc.	0	(78)
Change in the fair value of contingent consideration liabilities	2,082	0
Change in fair value of long-term debt	1,252	0
Non-cash goodwill and intangible asset impairment charge	17,130	5,900
Amortization of discount on available-for-sale investments	(1,858)	(1,313)
Change in deferred tax liabilities due to acquisition of Novosteo, Inc.	0	(248)
Changes in operating assets and liabilities, net of acquisitions:
Prepaid expenses and other current assets	(2,025)	2,272
Right of use assets, operating leases and operating lease liabilities	(170)	192
Other assets	(292)	0
Accounts payable	(424)	(161)
Accrued expenses and other current liabilities	532	(576)
Net cash used in operating activities	(24,352)	(12,214)
Cash flow from investing activities:
Purchase of investments	(89,562)	(95,116)
Proceeds from maturities of investments	100,727	84,514
Note receivable	0	(500)
Proceeds from disposal of assets	0	90
Purchase of property and equipment	(124)	(136)
Net cash provided by investing activities	11,041	(11,148)
Cash flows from financing activities:
Payment of contingent consideration	(5,000)	0
Payments of finance leases	0	(6)
Proceeds from issuance of common stock upon exercise of stock options	225	92
Net cash provided by financing activities	(4,775)	86
Effect of exchange rate changes on cash	9	329
Net increase in cash and cash equivalents	(18,077)	(22,947)
Cash and cash equivalents at beginning of period	20,752	44,579
Cash and cash equivalents at end of period	2,675	21,632
Supplemental disclosures of non-cash information:
Right-of-use assets obtained in exchange for new operating lease liabilities	232	0
Right-of-use asset and financing lease liability reduction as a result of lease modification	$ 0	$ (70)

Organization

Organization	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Description of Business Quince Therapeutics, Inc. is a late-stage biotechnology company dedicated to unlocking the power of a patient’s own biology for the treatment of rare diseases. The Company's proprietary AIDE technology platform is an innovative drug/device combination platform that uses an automated process to encapsulate a drug into a patient’s own red blood cells. Red blood cells have several characteristics that make them a potentially ideal vehicle for drug delivery and our AIDE technology is designed to harness many of these benefits to allow for new and improved therapeutic options for patients living with high unmet medical needs. The AIDE technology platform is believed to confer several benefits over conventional therapies which could be applied to a broad range of small or large molecule drugs and biologics. Our Phase 3 lead asset, EryDex, leverages the AIDE technology to encapsulate DSP into a patient’s own red blood cells, and is targeted to treat a rare pediatric neurodegenerative disease, A-T. By pioneering the encapsulation of drugs in a patient’s own red blood cells, we seek to advance proprietary therapeutics that hold the potential to redefine the standard of care and meaningfully improve the quality of life for patients with rare disease. 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 September 30, 2024, the Company had an accumulated deficit of $364.0 million. Since inception through September 30, 2024, 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 Company’s initial public offering (the “IPO”) and from the net proceeds of the private investment in public equity transaction (“PIPE Financing”). As of September 30, 2024, the Company had cash, cash equivalents, and short-term investments of $47.8 million, which it believes will be sufficient to fund its planned operations into the first quarter of 2026, a period that is at least 12 months from the date of the issuance of the accompanying unaudited consolidated financial statements. In connection with the acquisition of EryDel on October 20, 2023 (the “EryDel Acquisition”), the Company assumed an unsecured line of credit between EryDel and the European Investment Bank (the “EIB Loan”). As of September 30, 2024, the principal of 10.0 million euros ($11.2 million) was outstanding on the EIB Loan. The Debt Agreement requires the Company to maintain a minimum cash balance of 14.65 million euros ($16.4 million) until the outstanding obligations under the Debt Agreement, together with accrued interest and all other amounts accrued or outstanding under the agreement, is repaid in full (the “Minimum Cash Covenant”) Furthermore, the Company may at any time voluntarily prepay, in whole or in part, together with certain fees as set forth in the Debt Agreement, the outstanding obligations under the Debt Agreement. In the event of a default or a change in control, as specified in the Debt Agreement, EIB may, subject to certain grace periods, accelerate the outstanding obligations under the EIB Loan. In November 2024, the Company entered into an amendment (the “Amendment”) of the Debt Agreement with EIB which waives the Minimum Cash Covenant from January 1, 2025 and up to the earlier of December 31, 2025, or the date the Minimum Cash Covenant is restored. Under the terms of the Amendment, the Company agreed to amendments requiring monthly reporting of cash balances and additional limitations on certain permitted acquisitions. Additionally, during the waiver period, the Company agreed to convert 2% of the total 9% deferred interest on Tranches A and B to be payable quarterly, with the first payment due on March 31, 2025, and a one-time fee of 20,000 euros in connection with the Amendment. 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 product candidates.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Consolidation The accompanying condensed 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 unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and pursuant to the instructions of the SEC on Form 10-Q and Article 8 of Regulation S-X of the SEC. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the management’s opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of the results of operations and cash flows for the periods presented have been included. The condensed consolidated balance sheet as of September 30, 2024, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2024 and 2023, the condensed consolidated statements of stockholders’ equity for the three and nine months ended September 30, 2024 and 2023, the condensed consolidated statements of cash flows for the nine months ended September 30, 2024 and 2023, and the financial data and other financial information disclosed in the notes to the condensed consolidated financial statements are unaudited. These financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2023 included in the Company’s Form 10-K filed with the SEC on April 1, 2024. The results of operations for the nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period. Risks 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 potential 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. Use of Estimates The 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 business combinations 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, including 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 Euro and Australian Dollar. 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 condensed consolidated statements of operations and comprehensive loss. Significant Accounting Policies There have been no significant changes to the accounting policies during the nine months ended September 30, 2024, as compared to the significant accounting policies described in our Annual Report on Form 10-K for the year ended December 31, 2023. 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 the EryDel Acquisition. 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 Definite lived 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. The Company regularly reviews whether current conditions or events suggest that the carrying values of its acquired definite lived intangible assets might not be recoverable. When such conditions are identified, an estimate of the undiscounted future cash flows from these assets, or relevant asset groupings, is compared to their carrying value to determine if an impairment exists. If an impairment is identified, the loss is calculated as the difference between the carrying value of the intangible asset and its fair value, which is based on the net present value of the estimated future cash flows. Indefinite lived Intangible Assets Intangible assets with an indefinite useful life are not amortized. Intangible assets acquired in a business combination or an acquisition 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 indefinite lived 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. During the nine months ended September 30, 2024, the Company recognized a non-cash goodwill impairment charge of $17.1 million as the quantitative analysis resulted in the Company's fair value being significantly below its carrying value during the three months ended June 30, 2024. 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 three months ended September 30, 2024, the Company recorded a $2.7 million adjustment to decrease the fair value of its contingent consideration related to the acquisition of EryDel. During the nine months ended September 30, 2024, the Company recorded a net $2.1 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 original 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. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its 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 beginning after December 2024 under a prospective approach. Early adoption is permitted. The Company is evaluating the disclosure requirements related to the new standard. 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	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The fair value of the Company's financial instruments reflects the amounts that the Company estimates that it 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 condensed 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 three and nine months ended September 30, 2024 and 2023. 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 three and nine months ended September 30, 2024, 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 September 30, 2024 and December 31, 2023 are presented in the following tables (in thousands): Fair Value Measurements as of September 30, 2024 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 997 $ 997 $ — $ — Government and agency notes 45,172 — 45,172 — Total Assets $ 46,169 $ 997 $ 45,172 $ — Liabilities: Contingent consideration 54,788 — — 54,788 Long-term debt 14,899 — — 14,899 Total $ 69,687 $ — $ — $ 69,687 Fair Value Measurements as of 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: Contingent consideration 57,706 — — 57,706 Long-term debt 13,429 — — 13,429 Total $ 71,135 $ — $ — $ 71,135 The Company classifies certificates of deposit 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. Level 3 Assets and Liabilities 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 nine months ended September 30, 2024: (in thousands) Beginning Balance as of January 1, 2024 $ 57,706 Payout of contingent earnout based on milestone achievement (5,000) Change in fair value of contingent consideration 2,082 Ending Balance as of September 30, 2024 $ 54,788 During the three months ended June 30, 2024, the Company enrolled the first patient in the Phase 3 NEAT clinical trial. In accordance with the purchase agreement entered into in connection with EryDel Acquisition, the Company notified the former EryDel shareholders of this achievement within 45 days of achieving this milestone. During the three months ended September 30, 2024, the Company paid the cash milestone payment of $5 million to the former EryDel shareholders. The change in the fair value of the contingent consideration is primarily driven by the cash milestone payment of $5 million to the former EryDel shareholders, and the passage of time. The Company owes no further payments to EryDel shareholders for development-related milestones. The remaining potential contingent payments in connection with the EryDel Acquisition pertain to regulatory on market and sales milestones. The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related accrued earnout as of September 30, 2024 (in thousands except for percentages): September 30, 2024 Valuation Technique Unobservable Input Range (Input Used) Contingent consideration $ 54,788 Expected present value Probability of achieving 0% - 100% Long-term Debt The following table presents the changes in the fair value of the Level 3 EIB Loan for the nine months ended September 30, 2024: (in thousands) Beginning Balance as of January 1, 2024 $ 13,429 Change in fair value 1,252 Due to foreign currency translation 218 Ending Balance as of September 30, 2024 $ 14,899 The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related long term debt as of September 30, 2024 (in thousands except for percentages): September 30, 2024 Valuation Technique Unobservable Input Range (Input Used) EIB loan $ 14,899 Expected present value Credit quality of company 13%

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments The following tables categorize the fair values of cash, cash equivalents and investments measured at fair value on a recurring basis on our balance sheets (in thousands): September 30, 2024 December 31, 2023 Cash and cash equivalents: Cash $ 1,678 $ 1,521 Money market funds 997 4,285 Government and agency notes — 14,946 Total cash and cash equivalents $ 2,675 $ 20,752 Short-term investments: Certificates of deposit $ — $ 729 Government and agency notes 45,172 53,578 Total short-term investments $ 45,172 $ 54,307 The Company's investments are classified as available-for-sale securities. As of September 30, 2024, the weighted average remaining contractual maturities of available-for-sale securities was approximately 6 months. The unrealized gain (loss) activity related to the Company’s available-for-sale securities is included in the Company’s accumulated other comprehensive income. There were no significant realized gains or losses recognized on the sale or maturity of available-for-sale securities for the three and nine months ended September 30, 2024 and 2023, and as a result, the Company did not reclassify any amounts out of accumulated other comprehensive income. Based on the Company’s review of its available-for-sale securities, the Company has no available-for-sale securities in loss positions as of September 30, 2024. No other-than-temporary impairments on these securities were recognized for the three and nine months ended September 30, 2024 and 2023. The Company periodically assess its investment in available-for-sale securities for impairment losses and credit losses. The amount of credit losses are determined by comparing the difference between the present value of future cash flows expected to be collected on these securities and the amortized cost. Factors considered in assessing credit losses include the position in the capital structure, vintage and amount of collateral, delinquency rates, current credit support, and geographic concentration. There have been no impairment and credit losses related to available-for-sale securities for the three and nine months ended September 30, 2024 and 2023. 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 income, 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 condensed 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 condensed balance sheets. The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements as of September 30, 2024 Amortized Unrealized Unrealized Fair Value Money market funds $ 997 $ — $ — $ 997 Government and agency notes 45,013 159 — 45,172 Total cash equivalents and investments $ 46,010 $ 159 $ — $ 46,169 Classified as: Cash equivalents (original maturities within 90 days) $ 997 Short-term investments (maturities within one year) 45,172 Total cash equivalents and investments $ 46,169 Fair Value Measurements as of December 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses 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 one year) 54,307 Total $ 73,538

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2024
Balance Sheet Components [Abstract]
Balance Sheet Components	Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): September 30, 2024 December 31, 2023 Prepaid research and development expenses $ 1,415 $ 133 Short-term Italian research and development refundable tax credit 995 993 Prepaid insurance 841 809 Prepaid expenses 565 365 Other current assets 55 81 Total prepaid expenses and other current assets $ 3,871 $ 2,381 The Company 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 contributions (e.g., social contributions, VAT payables, registration fees, income and withholding taxes and other tax-related items that companies usually pay monthly). The Company recognized reductions to R&D expense of $0.4 million and $1.2 million for the three and nine months ended September 30, 2024 respectively, and $0 reductions for the three and nine months ended September 30, 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. During the three and nine months ended September 30, 2024, the Company received $0 refundable tax credit. During the first quarter of 2023, the Company received a refundable tax credit of $0.5 million, 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): September 30, 2024 December 31, 2023 Long-term Italian research and development refundable tax credit $ 4,074 $ 4,993 VAT receivable 5,354 3,463 Equity investments in Lighthouse Pharmaceuticals, Inc. 78 78 Assets held for sale — 10 Total other assets $ 9,506 $ 8,544 Property and Equipment, Net Property and equipment, net consist of the following (in thousands): September 30, 2024 December 31, 2023 Computer equipment $ 38 $ 36 Computer Software 30 30 Lab equipment 534 486 Leasehold improvement 36 36 Office furniture 237 153 Less: accumulated amortization and depreciation (667) (507) Property and equipment, net $ 208 $ 234 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): September 30, 2024 December 31, 2023 Personnel expenses $ 2,301 $ 2,340 Research and development expenses 1,063 564 Professional fees 140 211 Current portion of operating lease liabilities 101 64 Other 198 257 Total accrued expenses and other current liabilities $ 3,803 $ 3,436 For the nine months ended September 30, 2024 and 2023, the severance accrual activity were as follows (in thousands): 2024 2023 Beginning accrued severance $ 341 $ — Incurred during the period 41 770 Severance paid during the period (382) (309) Ending accrued severance $ — $ 461 On January 30, 2023, 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 Company's Board of Directors 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 $0.3 million was paid during the nine months ended September 30, 2024. The severance is to be 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 that was recorded in 2023.

Leases

Leases	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Leases	Leases 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. In January 2024, the above-mentioned Lease Agreement for the office space in Medolla was renegotiated. The new Lease Agreement includes an additional space and commenced on February 1, 2024, and will end on January 31, 2036, substituting the Lease Agreement commenced in June 2018. The Company recorded an additional $0.2 million of operating lease right of use asset and liability during the nine months ended September 30, 2024. The Company recognizes lease expense on a straight-line basis over the term of its operating lease. During the nine months ended September 30, 2024 and 2023, the Company recorded rent expense of $0.1 million. Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): September 30, 2024 December 31, 2023 Assets: Operating lease right of use asset, net $ 559 $ 385 Liabilities: Short-term operating lease liability 101 64 Long-term operating lease liability 450 321 Total lease liabilities $ 551 $ 385 Other information: Weighted average remaining lease term 4.9 years 5.4 years Weighted average discount rate 9.11 % 7.95 % Future minimum lease payments under lease agreements as of September 30, 2024, were as follows (in thousands): Fiscal Year 2024 (remainder of the year) $ 35 2025 140 2026 136 2027 130 2028 and thereafter 214 Total lease payments 655 Less: imputed interest (104) Total remaining lease liability $ 551

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity On April 5, 2023, the Company’s Board of Directors declared a dividend of one preferred share purchase right (a “Right”) for each outstanding share of the common stock of the Company. The dividend was effective as of April 17, 2023 (the “Record Date”) with respect to stockholders of record on that date. The Rights also attached to shares of common stock issued after the Record Date. Each Right entitled the registered holder to purchase from the Company one one-thousandth of a share of Series A Junior Participating Preferred Stock, par value $0.001 per share, (the “Preferred Shares”), of the Company at a price of $6.00 per one one-thousandth of a Preferred Share, subject to adjustment. On April 5, 2024, the Rights Plan and the Rights issued thereunder expired.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company operates three stock plans as of September 30, 2024: • 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. As of September 30, 2024, the maximum aggregate number of shares that may be issued under the 2019 Plan is 11,755,418 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 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 Board may determine. The Quince 2019 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 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. As of September 30, 2024, the Company had 2,288,074 shares available for future issuance under the Quince 2019 Plan. Stock Options Stock options under the 2019 Plan may be granted for periods of up to 10 years and at prices no less than 100% of the fair market value of the shares on the date of grant. 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 Options and Unvested Shares Weighted Average Exercise Price Weighted average remaining contractual life (years) Aggregate intrinsic value (In thousands) Balance as of December 31, 2023 4,267,178 $ 5.00 8.85 $ 197 Options granted 3,602,500 1.26 — — Options exercised (155,311) 0.93 — 65 Options cancelled / forfeited (165,861) 13.06 — — Balance as of September 30, 2024 7,548,506 $ 3.12 8.72 $ 5 Options vested and expected to vest as of September 30, 2024 7,548,506 3.12 8.72 5 Options exercisable as of September 30, 2024 2,062,912 $ 7.86 7.76 $ — For the three and nine months ended September 30, 2024, the Company recognized stock-based compensation expense of $0.7 million and $2.2 million, respectively, related to options granted to employees and non-employees. For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $0.6 million and $2.0 million, respectively, 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 condensed consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of September 30, 2024, total unamortized employee stock-based compensation was $5.5 million, which is expected to be recognized over the remaining estimated vesting period of 2.74 years. Restricted Stock Units (“RSUs”) 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, 2023 1,488 $ 4.30 RSUs granted — — RSUs vested (1,488) 4.30 RSUs cancelled — — Unvested - September 30, 2024 — $ — 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. For the three and nine months ended September 30, 2024, the Company recognized stock-based compensation expense of $0 and $4.4 thousand, respectively, related to these RSUs. For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $6.4 thousand and $37.5 thousand respectively, related to these RSUs. As of September 30, 2024, total unamortized stock-based compensation related to RSUs was $0. 2019 Equity Incentive Plan (Novosteo) On May 19, 2022, in accordance with the term of the Merger Agreement, the Company assumed the 2019 Novosteo, Inc. 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 on the exchange ratio of 0.0911. Each such converted stock option continues 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 fair market value of the shares on the date of grant. 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. As of September 30, 2024, the Company had 246,797 shares available for future issuance under the 2019 Novosteo Plan. Activity for service-based stock options under the 2019 Novosteo Plan is as follows: Number of Options and Unvested Shares Weighted Average Exercise Price Weighted average remaining contractual life (years) Aggregate intrinsic value (In thousands) Balance as of December 31, 2023 310,431 $ 0.55 8.23 $ 155 Options granted — — — — Options exercised (146,592) 0.55 — 94 Options cancelled / forfeited — — — — Balance as of September 30, 2024 163,839 $ 0.55 7.48 $ 37 Options vested and expected to vest as of September 30, 2024 163,839 0.55 7.48 37 Options exercisable as of September 30, 2024 47,426 $ 0.55 7.48 $ 11 For the three and nine months ended September 30, 2024, the Company recognized stock-based compensation expense of $48.7 thousand and $145.6 thousand, respectively, related to options granted to employees and non-employees for the 2019 Novosteo Plan. For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $96.0 thousand and $226.0 thousand, 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 condensed consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of September 30, 2024, total unamortized employee stock-based compensation was $288.1 thousand, which is expected to be recognized over the remaining estimated vesting period of 1.48 years. On May 19, 2022, in accordance with the term of the Merger Agreement, the Company assumed a number of restricted stock award ("RSA") 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, 2023 175,763 $ 3.30 RSAs granted — — RSAs vested (73,010) 3.30 RSAs cancelled — — Unvested - September 30, 2024 102,753 $ 3.30 For the three and nine months ended September 30, 2024, the Company recognized stock-based compensation expense of $0.1 million and $0.2 million, respectively, related to restricted stock awards. For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $0.2 million and $0.4 million, respectively, related to restricted stock awards. The compensation expense is allocated on a departmental basis, based on the classification of the award holder. No income tax benefits have been recognized in the condensed consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of September 30, 2024, total unamortized employee stock-based compensation was $0.3 million, which is expected to be recognized over the remaining estimated vesting period of 0.99 years. 2022 Inducement Plan On May 9, 2022, the Company's Board of Directors approved 4,000,000 shares of common stock that may be offered or issued under the Quince Therapeutics, Inc. 2022 Inducement Plan (the "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 (“Nasdaq Rule 5635(c)(4)”). In accordance with Nasdaq Rule 5635(c)(4), awards under those plans may only be made to an employee who has not previously been an employee or member of the Board of Directors 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 fair market value of the shares on the date of grant. Options granted to employees may have different performance goals or other vesting provisions (including continued employment) in accordance with the applicable 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 from the date of termination or expiration of the option, whichever is earlier. As of September 30, 2024, the Company had 1,666,694 shares available for future issuance under the 2022 Inducement Plan. Activity for service-based stock options under the 2022 Inducement Plan is as follows: Number of Options and Unvested Shares Weighted Average Exercise Price Weighted Aggregate intrinsic value (In thousands) Balance as of December 31, 2023 2,333,306 $ 2.98 8.40 — Options granted — — — — Options exercised — — — — Options cancelled / forfeited — — — — Balance as of September 30, 2024 2,333,306 $ 2.98 7.65 — Options vested and expected to vest as of September 30, 2024 2,333,306 2.98 7.65 — Options exercisable as of September 30, 2024 1,361,094 $ 2.98 7.65 — For the three and nine months ended September 30, 2024, the Company recognized stock-based compensation expense of $0.3 million and $1.0 million, respectively, related to options granted to employees for the 2022 Inducement Plan. For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $0.4 million and $1.5 million, respectively, related to options granted to 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 condensed consolidated statement of operations and comprehensive for stock-based compensation arrangements. As of September 30, 2024, total unamortized employee stock-based compensation was $2.2 million, which is expected to be recognized over the remaining estimated vesting period of 1.64 years. Stock-Based Compensation Expense The following table summarizes employee and non-employee stock-based compensation expense for the three and nine months ended September 30, 2024 and 2023 and the allocation within the condensed consolidated statements of operations and comprehensive loss (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 General and administrative expense $ 786 $ 945 $ 3,096 $ 3,014 Research and development expense 338 386 525 1,120 Total stock-based compensation $ 1,124 $ 1,331 $ 3,621 $ 4,134 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 Internal Revenue Code (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 1,924,262 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.

Long-term Debt

Long-term Debt	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Long-term Debt	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 million euro; and tranche D, 10.0 million euro. Each tranche is subject to conditions precedent related to the Company’s business and capitalization. As of September 30, 2024, 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 September 30, 2024, principal of 10.0 million euros ($11.2 million) was outstanding on the EIB Loan and it is recorded as Long-term debt on the condensed consolidated balance sheet at fair value with imputed interest of 9.0% included. The Debt Agreement requires the Company to maintain a minimum cash balance of 14.65 million euros ($16.4 million) until the outstanding obligations under the Debt Agreement, together with accrued interest and all other amounts accrued or outstanding under the agreement, is repaid in full (the “Minimum Cash Covenant”) . Furthermore, the Company may at any time voluntarily prepay, in whole or in part, together with certain fees as set forth in the Debt Agreement, the outstanding obligations under the Debt Agreement. In the event of a default or a change in control, as specified in the Debt Agreement, EIB may, subject to certain grace periods, accelerate the outstanding obligations under the EIB Loan. In November 2024, the Company entered into an amendment (the “Amendment”) of the Debt Agreement with EIB which waives the Minimum Cash Covenant from January 1, 2025 and up to the earlier of December 31, 2025, or the date the Minimum Cash Covenant is restored. Under the terms of the Amendment, the Company agreed to amendments requiring monthly reporting of cash balances and additional limitations on certain permitted acquisitions. Additionally, during the waiver period, the Company agreed to convert 2% of the total 9% deferred interest on Tranches A and B to be payable quarterly, with the first payment due on March 31, 2025, and a one-time fee of 20,000 euros in connection with the Amendment. 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 expense, net in the condensed 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 as of September 30, 2024 was determined using a discounted cash flow analysis discounted at the market yield. The significant inputs used to measure the market yield as of September 30, 2024 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 September 30, 2024, the fair value of the EIB Loan is $14.9 million, which includes a fair value adjustment of $1.3 million and foreign currency translation of $0.2 million during the nine months ended September 30, 2024. Future minimum principal payments, as of September 30, 2024 are as follows (in thousands): Quarter ended September 30, 2024 Amount 2024 $ — 2025 — 2026 11,190 2027 and thereafter — Total future payments 11,190 Imputed interest and fair value adjustments 3,709 Total Debt as of September 30, 2024 $ 14,899

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded $13.0 thousand and $80.0 thousand of tax expense for the three and nine months ended September 30, 2024, respectively, primarily related to foreign withholding tax and interest on the uncertain tax position liability. The Company has a history of losses and expects to incur a loss for 2024. The Company maintains a full valuation allowance against its net deferred tax assets as the Company believes it is not more likely than not that the benefit will be realized. The primary difference between the effective tax rate and the statutory tax rate relates to the change in valuation allowance.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic and diluted net loss per common share is determined by dividing the net loss by the weighted-average common shares outstanding during the period, as follows (net loss in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net loss $ (5,492) $ (5,351) $ (44,370) $ (22,491) Denominator: Weighted average common shares outstanding 43,164,136 36,073,040 43,090,632 35,941,234 Net loss per share, basic and diluted $ (0.13) $ (0.15) $ (1.03) $ (0.63) The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the periods presented because including them would have been antidilutive: September 30, 2024 2023 Stock options issued and outstanding 10,045,651 7,469,163 Restricted stock units — 2,975 Restricted stock awards 102,753 200,099 Total 10,148,404 7,672,237

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2024
Business Combination and Asset Acquisition [Abstract]
Business Combination	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 – or has the potential to become – a standard of care if there were not corticosteroid-related safety concerns. 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”) were withheld by the Company until October 2024 for general representations and warranties. The Company has included the total fair value of the stock consideration within additional-paid-in capital and common stock. In October 2024, upon the first anniversary of the closing of the EryDel Acquisition (the “Holdback Release Date”), and in accordance with the purchase agreement entered into in connection with EryDel Acquisition, the Indemnity Holdback Shares were released to the EryDel shareholders. As of the Holdback Release Date, no indemnification claims were made by the Company. No further stock consideration is available for issuance and no additional shares will be issued in connection with the EryDel Acquisition. 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 enrollment of the first patient in the Phase 3 NEAT clinical trial, which was paid in the third quarter of 2024, $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. During the three months ended June 30, 2024, the Company enrolled the first patient in the Phase 3 NEAT clinical trial. During the three months ended September 30, 2024, the Company paid the cash milestone payment of $5 million to the former EryDel shareholders in accordance with the purchase agreement entered into in connection with EryDel Acquisition. 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): Preliminary Purchase Price Allocation Assets acquired: 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 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 trade name intangible assets was $0.5 million. The trade name 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 13 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.

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets EryDel Intangible Assets The following table provides details of the carrying amount of the Company's indefinite-lived intangible asset (in thousands): September 30, 2024 In-process research and development: Balance as of December 31, 2023 $ 63,197 Impairment charge — Foreign currency translation adjustments 867 Balance as of September 30, 2024 $ 64,064 The following table provides details of the carrying amount of the Company's finite-lived intangible asset (in thousands, except useful life): As of September 30, 2024 As of December 31, 2023 Useful life Cost Accumulated Amortization Net Carrying Value Cost Accumulated Amortization Net Carrying Value Finite life intangible assets: Trade name 21 years $ 460 $ (22) $ 438 $ 460 $ (4) $ 456 Impairment charge — — Foreign currency translation adjustments 26 19 Total $ 464 $ 475 The Company performs annual impairment reviews of its intangible assets during the fourth fiscal quarter or more frequently if appropriate. As of September 30, 2024, the Company did not incur any impairment losses related to its EryDel intangible assets. Novosteo Intangible Assets In January 2023, the Company decided to abandon 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. And so, the Company performed a fair value assessment of the Intellectual Property as of March 31, 2023, and based upon this assessment, the fair value was determined to be significantly below its carrying value and resulted in an asset impairment charge of $5.9 million during the nine months ended September 30, 2023. Goodwill 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 evaluates goodwill at least annually, as well as whenever events or changes in circumstances suggest that the carrying amount may not be recoverable. As of June 30, 2024, the Company performed an impairment evaluation of goodwill 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 the 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 June 30, 2024. 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 $17.1 million being recorded during the nine months ended September 30, 2024. The following table summarizes the changes in the carrying amount of goodwill (in thousands): Balance as of December 31, 2023 $ 17,625 Impairment charge (17,130) Foreign currency translation adjustments (495) Balance as of September 30, 2024 $ —

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On the Holdback Release Date, and in accordance with the purchase agreement entered into, the Indemnity Holdback Shares were released to the EryDel shareholders. As of the Holdback Release Date, no indemnification claims were made by the Company. No further stock consideration is available for issuance and no additional shares will be issued in connection with the EryDel Acquisition.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Consolidation	Basis of Consolidation The accompanying condensed 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 unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and pursuant to the instructions of the SEC on Form 10-Q and Article 8 of Regulation S-X of the SEC. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the management’s opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of the results of operations and cash flows for the periods presented have been included. The condensed consolidated balance sheet as of September 30, 2024, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2024 and 2023, the condensed consolidated statements of stockholders’ equity for the three and nine months ended September 30, 2024 and 2023, the condensed consolidated statements of cash flows for the nine months ended September 30, 2024 and 2023, and the financial data and other financial information disclosed in the notes to the condensed consolidated financial statements are unaudited. These financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2023 included in the Company’s Form 10-K filed with the SEC on April 1, 2024. The results of operations for the nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period.
Risks and Uncertainties	Risks and Uncertainties
Use of Estimates	Use of Estimates The 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 business combinations 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, including 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 Euro and Australian Dollar. 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 condensed consolidated statements of operations and comprehensive loss.
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 the EryDel Acquisition. 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 Definite lived 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. The Company regularly reviews whether current conditions or events suggest that the carrying values of its acquired definite lived intangible assets might not be recoverable. When such conditions are identified, an estimate of the undiscounted future cash flows from these assets, or relevant asset groupings, is compared to their carrying value to determine if an impairment exists. If an impairment is identified, the loss is calculated as the difference between the carrying value of the intangible asset and its fair value, which is based on the net present value of the estimated future cash flows. Indefinite lived Intangible Assets Intangible assets with an indefinite useful life are not amortized. Intangible assets acquired in a business combination or an acquisition 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 indefinite lived 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. During the nine months ended September 30, 2024, the Company recognized a non-cash goodwill impairment charge of $17.1 million as the quantitative analysis resulted in the Company's fair value being significantly below its carrying value during the three months ended June 30, 2024.
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 three months ended September 30, 2024, the Company recorded a $2.7 million adjustment to decrease the fair value of its contingent consideration related to the acquisition of EryDel. During the nine
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments The Company considers all highly liquid investments with original 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.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its 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 beginning after December 2024 under a prospective approach. Early adoption is permitted. The Company is evaluating the disclosure requirements related to the new standard. 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 (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024 and December 31, 2023 are presented in the following tables (in thousands): Fair Value Measurements as of September 30, 2024 Total Level 1 Level 2 Level 3 Assets: Money market funds $ 997 $ 997 $ — $ — Government and agency notes 45,172 — 45,172 — Total Assets $ 46,169 $ 997 $ 45,172 $ — Liabilities: Contingent consideration 54,788 — — 54,788 Long-term debt 14,899 — — 14,899 Total $ 69,687 $ — $ — $ 69,687 Fair Value Measurements as of 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: Contingent consideration 57,706 — — 57,706 Long-term debt 13,429 — — 13,429 Total $ 71,135 $ — $ — $ 71,135
Schedule of Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	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 nine months ended September 30, 2024: (in thousands) Beginning Balance as of January 1, 2024 $ 57,706 Payout of contingent earnout based on milestone achievement (5,000) Change in fair value of contingent consideration 2,082 Ending Balance as of September 30, 2024 $ 54,788 The following table presents the changes in the fair value of the Level 3 EIB Loan for the nine months ended September 30, 2024: (in thousands) Beginning Balance as of January 1, 2024 $ 13,429 Change in fair value 1,252 Due to foreign currency translation 218 Ending Balance as of September 30, 2024 $ 14,899
Schedule of Quantitative Information About 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 September 30, 2024 (in thousands except for percentages): September 30, 2024 Valuation Technique Unobservable Input Range (Input Used) Contingent consideration $ 54,788 Expected present value Probability of achieving 0% - 100% The following table summarizes the quantitative information including the unobservable inputs related to the Company's acquisition related long term debt as of September 30, 2024 (in thousands except for percentages): September 30, 2024 Valuation Technique Unobservable Input Range (Input Used) EIB loan $ 14,899 Expected present value Credit quality of company 13%

Cash, Cash Equivalents and In_2

Cash, Cash Equivalents and Investments (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Schedule 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 and investments measured at fair value on a recurring basis on our balance sheets (in thousands): September 30, 2024 December 31, 2023 Cash and cash equivalents: Cash $ 1,678 $ 1,521 Money market funds 997 4,285 Government and agency notes — 14,946 Total cash and cash equivalents $ 2,675 $ 20,752 Short-term investments: Certificates of deposit $ — $ 729 Government and agency notes 45,172 53,578 Total short-term investments $ 45,172 $ 54,307
Schedule of Available-for-Sale Securities	The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements as of September 30, 2024 Amortized Unrealized Unrealized Fair Value Money market funds $ 997 $ — $ — $ 997 Government and agency notes 45,013 159 — 45,172 Total cash equivalents and investments $ 46,010 $ 159 $ — $ 46,169 Classified as: Cash equivalents (original maturities within 90 days) $ 997 Short-term investments (maturities within one year) 45,172 Total cash equivalents and investments $ 46,169 Fair Value Measurements as of December 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses 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 one year) 54,307 Total $ 73,538

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2024
Balance Sheet Components [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): September 30, 2024 December 31, 2023 Prepaid research and development expenses $ 1,415 $ 133 Short-term Italian research and development refundable tax credit 995 993 Prepaid insurance 841 809 Prepaid expenses 565 365 Other current assets 55 81 Total prepaid expenses and other current assets $ 3,871 $ 2,381
Schedule of Other Assets	Other assets consisted of the following (in thousands): September 30, 2024 December 31, 2023 Long-term Italian research and development refundable tax credit $ 4,074 $ 4,993 VAT receivable 5,354 3,463 Equity investments in Lighthouse Pharmaceuticals, Inc. 78 78 Assets held for sale — 10 Total other assets $ 9,506 $ 8,544
Schedule of Property and Equipment, Net	Property and equipment, net consist of the following (in thousands): September 30, 2024 December 31, 2023 Computer equipment $ 38 $ 36 Computer Software 30 30 Lab equipment 534 486 Leasehold improvement 36 36 Office furniture 237 153 Less: accumulated amortization and depreciation (667) (507) Property and equipment, net $ 208 $ 234
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): September 30, 2024 December 31, 2023 Personnel expenses $ 2,301 $ 2,340 Research and development expenses 1,063 564 Professional fees 140 211 Current portion of operating lease liabilities 101 64 Other 198 257 Total accrued expenses and other current liabilities $ 3,803 $ 3,436
Schedule of Accrued Severance and Related Expenses	For the nine months ended September 30, 2024 and 2023, the severance accrual activity were as follows (in thousands): 2024 2023 Beginning accrued severance $ 341 $ — Incurred during the period 41 770 Severance paid during the period (382) (309) Ending accrued severance $ — $ 461

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Schedule of Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): September 30, 2024 December 31, 2023 Assets: Operating lease right of use asset, net $ 559 $ 385 Liabilities: Short-term operating lease liability 101 64 Long-term operating lease liability 450 321 Total lease liabilities $ 551 $ 385 Other information: Weighted average remaining lease term 4.9 years 5.4 years Weighted average discount rate 9.11 % 7.95 %
Schedule of Future Minimum Lease Payments Under Lease Agreements	Future minimum lease payments under lease agreements as of September 30, 2024, were as follows (in thousands): Fiscal Year 2024 (remainder of the year) $ 35 2025 140 2026 136 2027 130 2028 and thereafter 214 Total lease payments 655 Less: imputed interest (104) Total remaining lease liability $ 551

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Options Activity	Activity for service-based stock options under the Quince 2019 Plan is as follows: Number of Options and Unvested Shares Weighted Average Exercise Price Weighted average remaining contractual life (years) Aggregate intrinsic value (In thousands) Balance as of December 31, 2023 4,267,178 $ 5.00 8.85 $ 197 Options granted 3,602,500 1.26 — — Options exercised (155,311) 0.93 — 65 Options cancelled / forfeited (165,861) 13.06 — — Balance as of September 30, 2024 7,548,506 $ 3.12 8.72 $ 5 Options vested and expected to vest as of September 30, 2024 7,548,506 3.12 8.72 5 Options exercisable as of September 30, 2024 2,062,912 $ 7.86 7.76 $ — Activity for service-based stock options under the 2019 Novosteo Plan is as follows: Number of Options and Unvested Shares Weighted Average Exercise Price Weighted average remaining contractual life (years) Aggregate intrinsic value (In thousands) Balance as of December 31, 2023 310,431 $ 0.55 8.23 $ 155 Options granted — — — — Options exercised (146,592) 0.55 — 94 Options cancelled / forfeited — — — — Balance as of September 30, 2024 163,839 $ 0.55 7.48 $ 37 Options vested and expected to vest as of September 30, 2024 163,839 0.55 7.48 37 Options exercisable as of September 30, 2024 47,426 $ 0.55 7.48 $ 11 Activity for service-based stock options under the 2022 Inducement Plan is as follows: Number of Options and Unvested Shares Weighted Average Exercise Price Weighted Aggregate intrinsic value (In thousands) Balance as of December 31, 2023 2,333,306 $ 2.98 8.40 — Options granted — — — — Options exercised — — — — Options cancelled / forfeited — — — — Balance as of September 30, 2024 2,333,306 $ 2.98 7.65 — Options vested and expected to vest as of September 30, 2024 2,333,306 2.98 7.65 — Options exercisable as of September 30, 2024 1,361,094 $ 2.98 7.65 —
Schedule of Nonvested Restricted Stock Shares 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, 2023 1,488 $ 4.30 RSUs granted — — RSUs vested (1,488) 4.30 RSUs cancelled — — Unvested - September 30, 2024 — $ — Restricted Stock Awards Restricted Stock Awards Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2023 175,763 $ 3.30 RSAs granted — — RSAs vested (73,010) 3.30 RSAs cancelled — — Unvested - September 30, 2024 102,753 $ 3.30
Schedule of Employee and Non-Employee Stock-Based Compensation Expense	The following table summarizes employee and non-employee stock-based compensation expense for the three and nine months ended September 30, 2024 and 2023 and the allocation within the condensed consolidated statements of operations and comprehensive loss (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 General and administrative expense $ 786 $ 945 $ 3,096 $ 3,014 Research and development expense 338 386 525 1,120 Total stock-based compensation $ 1,124 $ 1,331 $ 3,621 $ 4,134

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of Future minimum principal payments	Future minimum principal payments, as of September 30, 2024 are as follows (in thousands): Quarter ended September 30, 2024 Amount 2024 $ — 2025 — 2026 11,190 2027 and thereafter — Total future payments 11,190 Imputed interest and fair value adjustments 3,709 Total Debt as of September 30, 2024 $ 14,899

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	Basic and diluted net loss per common share is determined by dividing the net loss by the weighted-average common shares outstanding during the period, as follows (net loss in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net loss $ (5,492) $ (5,351) $ (44,370) $ (22,491) Denominator: Weighted average common shares outstanding 43,164,136 36,073,040 43,090,632 35,941,234 Net loss per share, basic and diluted $ (0.13) $ (0.15) $ (1.03) $ (0.63)
Schedule of Outstanding Potentially Dilutive Ordinary Shares Excluded from Calculation of Diluted Net Loss Per Share	The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the periods presented because including them would have been antidilutive: September 30, 2024 2023 Stock options issued and outstanding 10,045,651 7,469,163 Restricted stock units — 2,975 Restricted stock awards 102,753 200,099 Total 10,148,404 7,672,237

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2024
Business Combination and Asset Acquisition [Abstract]
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): Preliminary Purchase Price Allocation Assets acquired: 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

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
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): September 30, 2024 In-process research and development: Balance as of December 31, 2023 $ 63,197 Impairment charge — Foreign currency translation adjustments 867 Balance as of September 30, 2024 $ 64,064
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): As of September 30, 2024 As of December 31, 2023 Useful life Cost Accumulated Amortization Net Carrying Value Cost Accumulated Amortization Net Carrying Value Finite life intangible assets: Trade name 21 years $ 460 $ (22) $ 438 $ 460 $ (4) $ 456 Impairment charge — — Foreign currency translation adjustments 26 19 Total $ 464 $ 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, 2023 $ 17,625 Impairment charge (17,130) Foreign currency translation adjustments (495) Balance as of September 30, 2024 $ —

Organization (Details)

Organization (Details) € in Thousands, $ in Thousands	Nov. 13, 2024 USD ($)	Nov. 13, 2024 EUR (€)	Sep. 30, 2024 USD ($)	Sep. 30, 2024 EUR (€)	Dec. 31, 2023 USD ($)
Line of Credit Facility [Line Items]
Accumulated deficit			$ 364,014		$ 319,644
Cash, cash equivalents, and short-term investments			47,800
Long-term debt			14,899		$ 13,429
Line of Credit | EIB loan
Line of Credit Facility [Line Items]
Long-term debt			11,200	€ 10,000
Minimum cash balance			$ 16,400	€ 14,650
Line of Credit | EIB loan | Subsequent Event
Line of Credit Facility [Line Items]
Percentage of deferred interest converted	2%	2%
Deferred interest percent	9%	9%
Payment of one-time amendment fee	$ 20	€ 20

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($)
Accounting Policies [Abstract]
Number of reportable segment | segment			1
Number of operating segment | segment			1
Impairment charge | $	$ 0	$ 0	$ 17,130	$ 0
Fair value adjustment for contingent consideration | $	$ (2,683)	$ 0	$ 2,082	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Millions	3 Months Ended
	Sep. 30, 2024 USD ($)
Ery Del
Business Acquisition [Line Items]
Payment for contingent consideration	$ 5

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets:
Debt securities, fair value	$ 46,169	$ 73,538
Total	46,169	73,538
Liabilities:
Contingent consideration	54,788	57,706
Long-term debt	14,899	13,429
Total	69,687	71,135
Money market funds
Assets:
Debt securities, fair value	997	4,285
Certificates of deposit
Assets:
Debt securities, fair value		729
Government and agency notes
Assets:
Debt securities, fair value	45,172	68,524
Level 1
Assets:
Total	997	8,256
Liabilities:
Contingent consideration	0	0
Long-term debt	0	0
Total	0	0
Level 1 | Money market funds
Assets:
Debt securities, fair value	997	4,285
Level 1 | Certificates of deposit
Assets:
Debt securities, fair value		0
Level 1 | Government and agency notes
Assets:
Debt securities, fair value	0	3,971
Level 2
Assets:
Total	45,172	65,282
Liabilities:
Contingent consideration	0	0
Long-term debt	0	0
Total	0	0
Level 2 | Money market funds
Assets:
Debt securities, fair value	0	0
Level 2 | Certificates of deposit
Assets:
Debt securities, fair value		729
Level 2 | Government and agency notes
Assets:
Debt securities, fair value	45,172	64,553
Level 3
Assets:
Total	0	0
Liabilities:
Contingent consideration	54,788	57,706
Long-term debt	14,899	13,429
Total	69,687	71,135
Level 3 | Money market funds
Assets:
Debt securities, fair value	0	0
Level 3 | Certificates of deposit
Assets:
Debt securities, fair value		0
Level 3 | Government and agency notes
Assets:
Debt securities, fair value	$ 0	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Changes in Present Value of Acquisition Related Accrued Earnouts of Contingent Consideration Liability (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Payout of contingent earnout based on milestone achievement	$ (5,000)
Change in fair value of contingent consideration	(2,683)	$ 0	$ 2,082	$ 0
Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance as of January 1, 2024			57,706
Ending Balance as of September 30, 2024	$ 54,788		$ 54,788

Fair Value Measurements - Sch_3

Fair Value Measurements - Schedule of Quantitative Information about Fair Value Measurements (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Contingent consideration
Schedule Of Available For Sale Securities [Line Items]
Fair value measurements	$ 54,788
Contingent consideration | Minimum
Schedule Of Available For Sale Securities [Line Items]
Input used	0
Contingent consideration | Maximum
Schedule Of Available For Sale Securities [Line Items]
Input used	1
EIB loan
Schedule Of Available For Sale Securities [Line Items]
Fair value measurements	$ 14,899
Input used	0.13

Fair Value Measurements - Sch_4

Fair Value Measurements - Schedule of Fair Value of the Level 3 EIB Debt (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Debt Instrument, Fair Value [Roll Forward]
Beginning Balance as of January 1, 2024	$ 13,429
Ending Balance as of September 30, 2024	14,899
Level 3
Debt Instrument, Fair Value [Roll Forward]
Beginning Balance as of January 1, 2024	13,429
Change in fair value	1,252
Due to foreign currency translation	218
Ending Balance as of September 30, 2024	$ 14,899

Cash, Cash Equivalents and In_3

Cash, Cash Equivalents and Investments - Schedule of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	$ 46,169	$ 73,538
Total	46,169	73,538
Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	997	19,231
Short-Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	45,172	54,307
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	997	4,285
Government and agency notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	45,172	68,524
Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value		729
Fair Value on Recurring | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	2,675	20,752
Fair Value on Recurring | Short-Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	45,172	54,307
Fair Value on Recurring | Cash | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash	1,678	1,521
Fair Value on Recurring | Money market funds | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	997	4,285
Fair Value on Recurring | Government and agency notes | Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	0	14,946
Fair Value on Recurring | Government and agency notes | Short-Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	45,172	53,578
Fair Value on Recurring | Certificates of deposit | Short-Term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities, fair value	$ 0	$ 729

Cash, Cash Equivalents and In_4

Cash, Cash Equivalents and Investments - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Weighted average remaining contractual maturities of available-for-sale securities			6 months
Realized gains or losses on the sale or maturity of available-for-sale securities	$ 0	$ 0	$ 0	$ 0
Amounts reclassify out of accumulated other comprehensive loss	0	0	0	0
Impairment charges	$ 0	$ 0	$ 0	$ 0

Cash, Cash Equivalents and In_5

Cash, Cash Equivalents and Investments - Schedule of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 46,010	$ 73,548
Unrealized Gains	159	13
Unrealized Losses	0	(23)
Fair Value	46,169	73,538
Cash and Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Fair Value	997	19,231
Short-Term Investments
Schedule Of Available For Sale Securities [Line Items]
Fair Value	45,172	54,307
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	997	4,285
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	997	4,285
Government and agency notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	45,013	68,528
Unrealized Gains	159	13
Unrealized Losses	0	(17)
Fair Value	$ 45,172	68,524
Certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		735
Unrealized Gains		0
Unrealized Losses		(6)
Fair Value		$ 729

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Components [Abstract]
Prepaid research and development expenses	$ 1,415	$ 133
Short-term Italian research and development refundable tax credit	995	993
Prepaid insurance	841	809
Prepaid expenses	565	365
Other current assets	55	81
Total prepaid expenses and other current assets	$ 3,871	$ 2,381

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended		12 Months Ended
	Aug. 04, 2023	Sep. 30, 2024	Sep. 30, 2023	Apr. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Balance Sheet Components [Line Items]
Reductions in research and development expense		$ 400	$ 0			$ 1,200	$ 0
Reduction in prepaid expenses and other current assets						(2,025)	2,272
Cash severance payments	$ 500			$ 300
Expenses related to employment obligation				$ 100
Severance costs recognized						300
Additional cash bonus severance percentage	100%
Share based compensation accelerated vesting percentage	50%
Stock-based compensation expense related to options granted		1,124	$ 1,331			3,621	$ 4,134	$ 100
Option
Balance Sheet Components [Line Items]
Accelerated vesting, number of options								612,141
Restricted Stock Awards
Balance Sheet Components [Line Items]
Accelerated vesting, number of options								54,757
Novosteo
Balance Sheet Components [Line Items]
Proceeds from income tax refunds		$ 0			$ 500	$ 0
Reduction in prepaid expenses and other current assets					$ 500

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Components [Abstract]
Long-term Italian research and development refundable tax credit	$ 4,074	$ 4,993
VAT receivable	5,354	3,463
Equity investments in Lighthouse Pharmaceuticals, Inc.	78	78
Assets held for sale	0	10
Total other assets	$ 9,506	$ 8,544

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Components [Line Items]
Less: accumulated amortization and depreciation	$ (667)	$ (507)
Property and equipment, net	208	234
Computer equipment
Balance Sheet Components [Line Items]
Property and equipment	38	36
Computer Software
Balance Sheet Components [Line Items]
Property and equipment	30	30
Lab equipment
Balance Sheet Components [Line Items]
Property and equipment	534	486
Leasehold improvement
Balance Sheet Components [Line Items]
Property and equipment	36	36
Office furniture
Balance Sheet Components [Line Items]
Property and equipment	$ 237	$ 153

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Components [Abstract]
Personnel expenses	$ 2,301	$ 2,340
Research and development expenses	1,063	564
Professional fees	140	211
Current portion of operating lease liabilities	101	64
Other	198	257
Total accrued expenses and other current liabilities	$ 3,803	$ 3,436

Balance Sheet Components - Sc_5

Balance Sheet Components - Schedule of Accrued Severance (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Balance Sheet Components [Roll Forward]
Beginning accrued severance	$ 341	$ 0
Incurred during the period	41	770
Severance paid during the period	(382)	(309)
Ending accrued severance	$ 0	$ 461

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands		9 Months Ended
	Oct. 31, 2023 USD ($) lease	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Lessee Lease Description [Line Items]
Operating lease asset		$ 559		$ 385
Operating lease liability		551		$ 385
Rent expenses (less than)		100	$ 100
Car
Lessee Lease Description [Line Items]
Number of lease agreements acquired | lease	2
Ery Del | Other Operating Leases
Lessee Lease Description [Line Items]
Operating lease asset	$ 200
Operating lease liability	200
Bresso, Italy | Ery Del
Lessee Lease Description [Line Items]
Operating lease asset	400
Operating lease liability	400
Medolla, Italy
Lessee Lease Description [Line Items]
Operating lease asset		200
Operating lease liability		$ 200
Medolla, Italy | Ery Del
Lessee Lease Description [Line Items]
Operating lease asset	100
Operating lease liability	$ 100
Lease agreement period	12 years

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
ASSETS
Operating lease right-of-use assets	$ 559	$ 385
Liabilities:
Short-term operating lease liability	101	64
Long-term operating lease liabilities	450	321
Total remaining lease liability	$ 551	$ 385
Other information:
Weighted average remaining lease term (in years)	4 years 10 months 24 days	5 years 4 months 24 days
Weighted average discount rate (as percent)	9.11%	7.95%
Operating Lease, Liability, Payment, Due [Abstract]
2024 (remainder of the year)	$ 35
2025	140
2026	136
2027	130
2028 and thereafter	214
Total lease payments	655
Less: imputed interest	(104)
Total remaining lease liability	$ 551	$ 385

Stockholders' Equity (Details)

Stockholders' Equity (Details) - $ / shares	Apr. 05, 2023	Sep. 30, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Preferred stock, par value (in USD per share)		$ 0.001	$ 0.001
Rights Plan | Preferred Stock
Class of Stock [Line Items]
Warrants to purchase common stock (in dollars per share)	$ 6,000
Rights Plan | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividends (in shares)	1
Preferred stock, par value (in USD per share)	$ 0.001
Preferred Stock, subject to adjustment (in shares)	0.001

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information - General (Details)	Sep. 30, 2024 plan
Share-Based Payment Arrangement [Abstract]
Number of stock plans	3

Stock-Based Compensation - 2019

Stock-Based Compensation - 2019 Equity Incentive Plan (Quince) - General (Details) - 2019 Plan	9 Months Ended
	Sep. 30, 2024 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan	11,755,418
Increase in number of shares available for issuance as proportion of shares of common stock (in shares)	2,146,354
Percentage of common stock outstanding	4%
Common stock reserved for issuance (in shares)	2,288,074

Stock-Based Compensation - 20_2

Stock-Based Compensation - 2019 Equity Incentive Plan (Quince) - Stock Options (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 04, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights	50%
Total stock-based compensation		$ 1,124	$ 1,331	$ 3,621	$ 4,134	$ 100
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award grant period				10 years
Voting rights in percentage				0.10
Stock based awards vesting period				4 years
Options, stock-based compensation not yet recognized		5,500		$ 5,500
2019 Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation		700	600	2,200	2,000
Income tax benefits recognized		$ 0	$ 0	$ 0	$ 0
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 8 months 26 days
2019 Plan | One Year Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period				1 year
Award vesting rights				25%
2019 Plan | Three Year Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period				3 years
Award vesting rights				75%
2019 Plan | Minimum
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				3 months
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)				100%
Stock options granted maximum period				10 years
Monthly installments over the remaining vesting period				4 years

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Activity for Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
2019 Plan
Number of Options and Unvested Shares
Number of Options and Unvested Shares, beginning balance (in shares)	4,267,178
Options granted (in shares)	3,602,500
Options exercised (in shares)	(155,311)
Options cancelled / forfeited (in shares)	(165,861)
Number of Options and Unvested Shares, ending balance (in shares)	7,548,506	4,267,178
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in USD per share)	$ 5
Options granted (in USD per share)	1.26
Options exercised (in USD per share)	0.93
Options cancelled / forfeited (in USD per share)	13.06
Weighted Average Exercise Price, ending balance (in USD per share)	$ 3.12	$ 5
Stock Options Additional Disclosures
Weighted average remaining contractual life (in years)	8 years 8 months 19 days	8 years 10 months 6 days
Aggregate intrinsic value	$ 5	$ 197
Options exercised	$ 65
Options vested and expected to vest (in shares)	7,548,506
Options exercisable (in shares)	2,062,912
Options vested and expected to vest (in USD per share)	$ 3.12
Options exercisable (in USD per share)	$ 7.86
Options vested and expected to vest as of September 30, 2024	8 years 8 months 19 days
Options exercisable as of September 30, 2024	7 years 9 months 3 days
Options vested and expected to vest as of September 30, 2024	$ 5
Options exercisable as of September 30, 2024	$ 0
2019 Novosteo Plan | Stock Options
Number of Options and Unvested Shares
Number of Options and Unvested Shares, beginning balance (in shares)	310,431
Options granted (in shares)	0
Options exercised (in shares)	(146,592)
Options cancelled / forfeited (in shares)	0
Number of Options and Unvested Shares, ending balance (in shares)	163,839	310,431
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in USD per share)	$ 0.55
Options granted (in USD per share)	0
Options exercised (in USD per share)	0.55
Options cancelled / forfeited (in USD per share)	0
Weighted Average Exercise Price, ending balance (in USD per share)	$ 0.55	$ 0.55
Stock Options Additional Disclosures
Weighted average remaining contractual life (in years)	7 years 5 months 23 days	8 years 2 months 23 days
Aggregate intrinsic value	$ 37	$ 155
Options exercised	$ 94
Options vested and expected to vest (in shares)	163,839
Options exercisable (in shares)	47,426
Options vested and expected to vest (in USD per share)	$ 0.55
Options exercisable (in USD per share)	$ 0.55
Options vested and expected to vest as of September 30, 2024	7 years 5 months 23 days
Options exercisable as of September 30, 2024	7 years 5 months 23 days
Options vested and expected to vest as of September 30, 2024	$ 37
Options exercisable as of September 30, 2024	$ 11
2022 Inducement Plan | Stock Options
Number of Options and Unvested Shares
Number of Options and Unvested Shares, beginning balance (in shares)	2,333,306
Options granted (in shares)	0
Options exercised (in shares)	0
Options cancelled / forfeited (in shares)	0
Number of Options and Unvested Shares, ending balance (in shares)	2,333,306	2,333,306
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in USD per share)	$ 2.98
Options granted (in USD per share)	0
Options exercised (in USD per share)	0
Options cancelled / forfeited (in USD per share)	0
Weighted Average Exercise Price, ending balance (in USD per share)	$ 2.98	$ 2.98
Stock Options Additional Disclosures
Weighted average remaining contractual life (in years)	7 years 7 months 24 days	8 years 4 months 24 days
Aggregate intrinsic value	$ 0	$ 0
Options vested and expected to vest (in shares)	2,333,306
Options exercisable (in shares)	1,361,094
Options vested and expected to vest (in USD per share)	$ 2.98
Options exercisable (in USD per share)	$ 2.98
Options vested and expected to vest as of September 30, 2024	7 years 7 months 24 days
Options exercisable as of September 30, 2024	7 years 7 months 24 days
Options vested and expected to vest as of September 30, 2024	$ 0
Options exercisable as of September 30, 2024	$ 0

Stock-Based Compensation - RSUs

Stock-Based Compensation - RSUs (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 1,124,000	$ 1,331,000	$ 3,621,000	$ 4,134,000	$ 100,000
Unamortized employee stock-based compensation	0		0
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 48,700	$ 6,400	$ 145,600	$ 37,500
Minimum | Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period			2 years
Maximum | Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period			4 years

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of RSUs and RSAs (Details)	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Restricted Stock Units
Number of Shares
Outstanding, Number of Shares, Unvested, Beginning Balance (in shares) | shares	1,488
Granted (in shares) | shares	0
Vested (in shares) | shares	(1,488)
Cancelled (in shares) | shares	0
Outstanding, Number of Shares, Unvested, Ending Balance (in shares) | shares	0
Weighted Average Grant Date Fair Value
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Beginning Balance (in USD per share) | $ / shares	$ 4.30
Granted (in USD per share) | $ / shares	0
Vested (in USD per share) | $ / shares	4.30
Cancelled (in USD per share) | $ / shares	0
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Ending Balance (in USD per share) | $ / shares	$ 0
Restricted Stock Awards
Number of Shares
Outstanding, Number of Shares, Unvested, Beginning Balance (in shares) | shares	175,763
Granted (in shares) | shares	0
Vested (in shares) | shares	(73,010)
Cancelled (in shares) | shares	0
Outstanding, Number of Shares, Unvested, Ending Balance (in shares) | shares	102,753
Weighted Average Grant Date Fair Value
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Beginning Balance (in USD per share) | $ / shares	$ 3.30
Granted (in USD per share) | $ / shares	0
Vested (in USD per share) | $ / shares	3.30
Cancelled (in USD per share) | $ / shares	0
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Ending Balance (in USD per share) | $ / shares	$ 3.30

Stock-Based Compensation - 20_3

Stock-Based Compensation - 2019 Equity Incentive Plan (Novosteo) (Details)			3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 04, 2023	May 19, 2022 $ / shares shares	Sep. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights	50%
Total stock-based compensation			$ 1,124,000	$ 1,331,000	$ 3,621,000	$ 4,134,000	$ 100,000
Unamortized employee stock-based compensation			$ 0		$ 0
2019 Novosteo Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan | shares		544,985
Common stock reserved for issuance (in shares) | shares			246,797		246,797
Options, stock-based compensation not yet recognized			$ 288,100		$ 288,100
2019 Novosteo Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Warrants to purchase common stock (in dollars per share) | $ / shares		$ 0.0911
Award grant period		10 years
Rate of purchase price of stock on fair value (as a percent)		100%
Voting rights in percentage		0.10
Stock options granted maximum period		10 years
Stock based awards vesting period		4 years
Total stock-based compensation			0	96,000	$ 4,400	226,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period					1 year 5 months 23 days
2019 Novosteo Plan | Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation			100,000	$ 200,000	$ 200,000	$ 400,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period					11 months 26 days
Stock award conversion ratio		0.0911
Unamortized employee stock-based compensation			$ 300,000		$ 300,000
2019 Novosteo Plan | One Year Anniversary | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights		25%
2019 Novosteo Plan | Three Year Anniversary | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights		75%
2019 Novosteo Plan | Maximum | Stock Options
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
2019 Novosteo Plan | Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Monthly installments over the remaining vesting period		3 years

Stock-Based Compensation - 2022

Stock-Based Compensation - 2022 Inducement Plan (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	May 09, 2022	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation		$ 1,124	$ 1,331	$ 3,621	$ 4,134	$ 100
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 (in shares)	4,000,000
Award grant period	10 years
Rate of purchase price of stock on fair value (as a percent)	100%
Common stock reserved for issuance (in shares)		1,666,694		1,666,694
Total stock-based compensation		$ 300		$ 1,000
Options, stock-based compensation not yet recognized		$ 2,200		$ 2,200
2022 Inducement Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation			$ 400		$ 1,500
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				1 year 7 months 20 days

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 1,124	$ 1,331	$ 3,621	$ 4,134	$ 100
General and administrative expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	786	945	3,096	3,014
Research and development expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 338	$ 386	$ 525	$ 1,120

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee Stock Purchase Plan (Details) - 2019 ESPP	Apr. 24, 2019 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance (in shares)	1,924,262
Maximum period for common stock shares reserved for future issuance	10 years
Increase in number of shares available for issuance as proportion of shares of common stock (in shares)	536,589
Percentage of common stock outstanding	1%

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Details) € in Thousands, $ in Thousands				9 Months Ended
	Nov. 13, 2024 USD ($)	Nov. 13, 2024 EUR (€)	Oct. 20, 2023 EUR (€)	Sep. 30, 2024 USD ($)	Sep. 30, 2024 EUR (€)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Long-term debt | $				$ 14,899		$ 13,429
Ery Del
Debt Instrument [Line Items]
Foreign currency translation adjustment in fair value | $				200
Line of Credit | Ery Del
Debt Instrument [Line Items]
Provision for additional remuneration paid based on revenue up to 125 Million Euros, percentage			2.50%
Provision for additional remuneration paid based on revenue between 125 Million and 250 Million Euros, percentage			1.85%
Provision for additional remuneration paid based on revenue greater than 250 Million Euros, percentage			1%
Remuneration payable period			7 years
Line of Credit | Minimum
Debt Instrument [Line Items]
Disbursement period			12 months
Line of Credit | Maximum
Debt Instrument [Line Items]
Disbursement period			5 years
EIB loan
Debt Instrument [Line Items]
Fair value of the EIB Loan | $				14,900
Fair value adjustment | $				1,300
EIB loan | Line of Credit
Debt Instrument [Line Items]
Maximum borrowings			€ 30,000
Long-term debt				$ 11,200	€ 10,000
Imputed interest				9%	9%
Minimum cash balance				$ 16,400	€ 14,650
EIB loan | Line of Credit | Ery Del
Debt Instrument [Line Items]
Drawn percentage			100%
EIB loan | Line of Credit | Subsequent Event
Debt Instrument [Line Items]
Percentage of deferred interest converted	2%	2%
Deferred interest percent	9%	9%
Payment of one-time amendment fee	$ 20	€ 20
EIB loan | Line of Credit | Minimum
Debt Instrument [Line Items]
Fixed interest rate			7%
EIB loan | Line of Credit | Maximum
Debt Instrument [Line Items]
Fixed interest rate			9%
European Bank Loan, Tranche A, Tranche B, Tranche C | Line of Credit | Ery Del
Debt Instrument [Line Items]
Drawn percentage			80%
EIB Loan, Tranche A and Tranche B | Line of Credit | Ery Del
Debt Instrument [Line Items]
Drawn percentage			50%
EIB Loan, Tranche A | Line of Credit
Debt Instrument [Line Items]
Maximum borrowings			€ 3,000
EIB Loan, Tranche A | Line of Credit | Ery Del
Debt Instrument [Line Items]
Drawn percentage			30%
EIB Loan, Tranche B | Line of Credit
Debt Instrument [Line Items]
Maximum borrowings			€ 7,000
EIB Loan Tranche C | Line of Credit
Debt Instrument [Line Items]
Maximum borrowings			10,000
EIB Loan ,Tranche D | Line of Credit
Debt Instrument [Line Items]
Maximum borrowings			€ 10,000

Long-term Debt - Schedule of Fu

Long-term Debt - Schedule of Future Minimum Principal Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
2024	$ 0
2025	0
2026	11,190
2027 and thereafter	0
Total future payments	11,190
Imputed interest and fair value adjustments	3,709
Total Debt as of September 30, 2024	$ 14,899	$ 13,429

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income tax expense	$ 13	$ 0	$ 80	$ (248)

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	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net loss	$ (5,492)	$ (5,351)	$ (44,370)	$ (22,491)
Denominator:
Weighted average shares of common stock outstanding - basic (in shares)	43,164,136	36,073,040	43,090,632	35,941,234
Weighted average shares of common stock outstanding - diluted (in shares)	43,164,136	36,073,040	43,090,632	35,941,234
Net loss per share - basic (in USD per share)	$ (0.13)	$ (0.15)	$ (1.03)	$ (0.63)
Net loss per share - diluted (in USD per share)	$ (0.13)	$ (0.15)	$ (1.03)	$ (0.63)

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	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share (in shares)	10,148,404	7,672,237
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 (in shares)	10,045,651	7,469,163
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share (in shares)	0	2,975
Restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share (in shares)	102,753	200,099

Business Combination - Addition

Business Combination - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	Oct. 20, 2023 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) shares	Dec. 31, 2023 shares
Business Acquisition [Line Items]
Share price (in USD per share) | $ / shares	$ 0.989
Common stock, shares issued (in shares) | shares		43,276,606	42,973,215
NDA acceptance under contingent consideration	$ 25,000
Business combination discount rate	15%
Specified Approval Milestones
Business Acquisition [Line Items]
Milestone payment	$ 60,000
Ery Del
Business Acquisition [Line Items]
Deferred tax liability	5,098
Uncertain tax position liability	500
Fair value of total consideration transferred	$ 66,907
Common stock, shares issued (in shares) | shares	6,525,315
Common stock withheld (in shares) | shares	725,037
Maximum amount of future consideration payment	$ 485,000
Amount payable upon achievement of specified milestone.	5,000
Milestone achievement related to market and sales	$ 395,000
Payment for contingent consideration		$ 5,000
Discounted earning after tax	16.60%
Intangible assets	$ 61,096
Royalty rate utilized	0.30%
Discount rate	16.60%
Finite-lived intangible assets useful life	21 years
Goodwill expected to be deductible	$ 0
Business acquisition, transaction costs	2,500
Ery Del | General and administrative expense
Business Acquisition [Line Items]
Business acquisition, transaction costs	2,300
Ery Del | Research and development expense
Business Acquisition [Line Items]
Business acquisition, transaction costs	200
Ery Del | Trade Names
Business Acquisition [Line Items]
Intangible assets	500
Ery Del | IPR&D
Business Acquisition [Line Items]
Identifiable intangible assets	$ 60,600
Ery Del | Probability of Achievement | Minimum | Contingent consideration
Business Acquisition [Line Items]
Input used	0
Ery Del | Probability of Achievement | Maximum | Contingent consideration
Business Acquisition [Line Items]
Input used	1

Business Combination - Schedule

Business Combination - Schedule of Fair Value of the Total Purchase Consideration Transferred (Details) - Ery Del $ in Thousands	Oct. 20, 2023 USD ($) shares
Business Acquisition [Line Items]
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
Quince Therapeutics common stock (in shares) | shares	7,250,352

Business Combination - Schedu_2

Business Combination - Schedule of Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Oct. 20, 2023
Assets acquired:
Goodwill	$ 0	$ 17,625
Ery Del
Assets acquired:
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

Intangible Assets - Schedule of

Intangible Assets - Schedule of Carrying Amount of Indefinite Lived Intangible Asset (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
In-process research and development:
Impairment charge	$ 0	$ 0	$ 0	$ (5,900)
IPR&D
In-process research and development:
Balance as of December 31, 2023			63,197
Impairment charge			0	$ (5,900)
Foreign currency translation adjustments			867
Balance as of September 30, 2024	$ 64,064		$ 64,064

Intangible Assets - Schedule _2

Intangible Assets - Schedule of Carrying Amount of Finite-Lived Intangible Asset (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Net Carrying Value	$ 464	$ 475
Impairment charge	0	0
Foreign currency translation adjustments	$ 26	19
Trade Names
Finite-Lived Intangible Assets [Line Items]
Useful life	21 years
Cost	$ 460	460
Accumulated Amortization	(22)	(4)
Net Carrying Value	$ 438	$ 456

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Intangible asset impairment charge	$ 0	$ 0	$ 0	$ 5,900
Impairment charge	$ 0	$ 0	17,130	0
IPR&D
Finite-Lived Intangible Assets [Line Items]
Intangible asset impairment charge			$ 0	$ 5,900

Intangible Assets - Schedule Ca

Intangible Assets - Schedule Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Goodwill [Roll Forward]
Balance as of December 31, 2023			$ 17,625
Impairment charge	$ 0	$ 0	(17,130)	$ 0
Foreign currency translation adjustments			(495)
Balance as of September 30, 2024	$ 0		$ 0

Subsequent Events (Details)

Subsequent Events (Details) - Line of Credit - EIB loan - Subsequent Event € in Thousands, $ in Thousands	Nov. 13, 2024 EUR (€)	Nov. 13, 2024 USD ($)
Subsequent Event [Line Items]
Percentage of deferred interest converted	2%	2%
Deferred interest percent	9%	9%
Payment of one-time amendment fee	€ 20	$ 20