Quince Therapeutics (QNCX) 10-Q 14 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 06, 2023
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Registrant Name	Quince Therapeutics, Inc.
Entity Central Index Key	0001662774
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		42,868,947
Entity File Number	001-38890
Entity Tax Identification Number	90-1024039
Entity Address, Address Line One	601 Gateway Boulevard, Suite 1250.
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	910-5717
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Common Stock
Trading Symbol	QNCX
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.001 per share
Series A Junior Participating Preferred Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NASDAQ
Title of 12(b) Security	Series A Junior Participating Preferred Purchase Rights

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 21,632	$ 44,579
Short term investments	61,593	45,602
Prepaid expenses and other current assets	1,448	3,567
Note receivable	500	0
Total current assets	85,173	93,748
Assets held for sale	82	0
Property and equipment, net	5	393
Operating lease right-of-use assets, net	48	291
Long term investments	0	3,578
Intangible asset	0	5,900
Equity investments in Lighthouse Pharmaceuticals, Inc.	78	0
Total assets	85,386	103,910
Current liabilities:
Accounts payable	409	570
Accrued expenses and other current liabilities	1,844	2,499
Total current liabilities	2,253	3,069
Deferred tax liabilities	0	248
Total liabilities	2,253	3,317
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 authorized, no shares issued and outstanding as of September 30, 2023 and December 31, 2022	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized, 36,343,632 and 36,136,480 issued and outstanding as of September 30, 2023 and December 31, 2022, respectively	36	36
Additional paid in capital	393,331	389,105
Accumulated other comprehensive income (loss)	516	(289)
Accumulated deficit	(310,750)	(288,259)
Total stockholders’ equity	83,133	100,593
Total liabilities and stockholders’ equity	$ 85,386	$ 103,910

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	36,343,632	36,136,480
Common stock, shares outstanding	36,343,632	36,136,480

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 1,431	$ 2,451	$ 6,013	$ 22,410
General and administrative	4,663	4,344	12,786	22,461
Goodwill impairment charge	0	825	0	825
Intangible asset impairment charge	0	0	5,900	0
Total operating expenses	6,094	7,620	24,699	45,696
Loss from operations	(6,094)	(7,620)	(24,699)	(45,696)
Interest income	959	315	2,464	532
Other expense, net	(216)	(616)	(504)	(1,246)
Net loss before income tax benefit	(5,351)	(7,921)	(22,739)	(46,410)
Income tax benefit	0	0	248	284
Net loss	(5,351)	(7,921)	(22,491)	(46,126)
Other comprehensive income (loss):
Foreign currency translation adjustments	158	343	309	481
Unrealized gain (loss) on available for sales securities	101	(130)	496	(655)
Total comprehensive loss	$ (5,092)	$ (7,708)	$ (21,686)	$ (46,300)
Net loss per share - basic	$ (0.15)	$ (0.22)	$ (0.63)	$ (1.41)
Net loss per share - diluted	$ (0.15)	$ (0.22)	$ (0.63)	$ (1.41)
Weighted average shares of common stock outstanding - basic	36,073,040	35,612,749	35,941,234	32,758,132
Weighted average shares of common stock outstanding - diluted	36,073,040	35,612,749	35,941,234	32,758,132

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 at Dec. 31, 2021	$ 118,586	$ 30	$ 355,234	$ (79)	$ (236,599)
Beginning balance, shares at Dec. 31, 2021		30,074,412
Issuance of common stock in connection with open market sales agreement, net of issuance costs	608		608
Issuance of common stock in connection with open market sales agreement, net of issuance costs, shares		51,769
Issuance of common stock on exercise of stock options and vesting of restricted stock units	148		148
Issuance of common stock on exercise of stock options and vesting of restricted stock units, shares		484,125
Stock based compensation	14,986		14,986
Value of share Issued in connection with acquisition of Novosteo	16,503	$ 6	16,497
Share issuance in connection with acquisition of Novosteo Inc.		5,520,000
Foreign currency translation adjustment	481			481
Unrealized gain on available for sales investments	(655)			(655)
Net loss	(46,126)				(46,126)
Ending balance at Sep. 30, 2022	104,531	$ 36	387,473	(253)	(282,725)
Ending balance, shares at Sep. 30, 2022		36,130,306
Beginning balance at Jun. 30, 2022	111,532	$ 36	386,766	(466)	(274,804)
Beginning balance, shares at Jun. 30, 2022		35,977,688
Issuance of common stock on exercise of stock options and vesting of restricted stock units	13		13
Issuance of common stock on exercise of stock options and vesting of restricted stock units, shares		152,618
Stock based compensation	694		694
Foreign currency translation adjustment	343			343
Unrealized gain on available for sales investments	(130)			(130)
Net loss	(7,921)				(7,921)
Ending balance at Sep. 30, 2022	104,531	$ 36	387,473	(253)	(282,725)
Ending balance, shares at Sep. 30, 2022		36,130,306
Beginning balance at Dec. 31, 2022	100,593	$ 36	389,105	(289)	(288,259)
Beginning balance, shares at Dec. 31, 2022		36,136,480
Issuance of common stock on exercise of stock options and vesting of restricted stock units	110		110
Issuance of common stock on exercise of stock options and vesting of restricted stock units, shares		270,445
Restricted stock award retirement, shares		(63,293)
Restricted stock award retirement	(18)		(18)
Stock based compensation	4,134		4,134
Foreign currency translation adjustment	309			309
Unrealized gain on available for sales investments	496			496
Net loss	(22,491)				(22,491)
Ending balance at Sep. 30, 2023	83,133	$ 36	393,331	516	(310,750)
Ending balance, shares at Sep. 30, 2023		36,343,632
Beginning balance at Jun. 30, 2023	86,884	$ 36	391,990	257	(305,399)
Beginning balance, shares at Jun. 30, 2023		36,327,995
Issuance of common stock on exercise of stock options and vesting of restricted stock units	28		28
Issuance of common stock on exercise of stock options and vesting of restricted stock units, shares		70,394
Restricted stock award retirement, shares		(54,757)
Restricted stock award retirement	(18)		(18)
Stock based compensation	1,331		1,331
Foreign currency translation adjustment	158			158
Unrealized gain on available for sales investments	101			101
Net loss	(5,351)				(5,351)
Ending balance at Sep. 30, 2023	$ 83,133	$ 36	$ 393,331	$ 516	$ (310,750)
Ending balance, shares at Sep. 30, 2023		36,343,632

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Private Placement
Stock issuance costs	$ 19

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net Loss	$ (22,491)	$ (46,126)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock based compensation	4,134	14,986
Depreciation and amortization	18	162
Impairment loss on operating lease	66	136
Loss on disposal of fixed assets	71	77
Equity investment in Lighthouse Pharmaceuticals, Inc.	(78)	0
Non-cash goodwill impairment charge	0	825
Non-cash intangible impairment charge	5,900	0
Amortization of (discount) premium on available for sale investments	(1,313)	83
Change in deferred tax liabilities due to acquisition of Novosteo, Inc.	(248)	(284)
Changes in operating assets and liabilities, net of acquisitions:
Prepaid expenses and other current assets	2,272	2,396
Right of use assets and lease liabilities	192	0
Other assets	0	175
Accounts payable	(161)	(5,329)
Accrued expenses and other current liabilities	(576)	(5,304)
Net cash used in operating activities	(12,214)	(38,203)
Cash flow from investing activities:
Purchase of investments	(95,116)	(66,767)
Proceeds from maturities of investments	84,514	55,495
Cash acquired from Novosteo, Inc.	0	10,593
Note receivable	(500)	0
Proceeds from disposal of fixed assets	90	70
Purchase of property and equipment	(136)	(55)
Net cash used in investing activities	(11,148)	(664)
Cash flows from financing activities:
Payments of finance leases	(6)	(31)
Proceeds from issuance of common stock upon exercise of stock options	92	148
Proceeds from issuance of common stock in connection with open market sales agreement, net of issuance costs	0	608
Net cash provided by financing activities	86	725
Effect of exchange rate changes on cash	329	227
Net decrease in cash and cash equivalents	(22,947)	(37,915)
Cash and cash equivalents at beginning of period	44,579	69,724
Cash and cash equivalents at end of period	21,632	31,809
Supplemental disclosures of non-cash information:
Net assets acquired of Novosteo, Inc. in exchange for common stock	0	16,503
Right-of-use assets obtained in exchange for new operating lease liabilities	0	256
Right-of-use asset and financing lease liability reduction as a result of lease modification	(70)	0
Right-of-use asset and operating lease liability reduction as a result of lease modification	$ 0	$ (640)

Organization

Organization	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Note 1. Organization Description of Business Effective August 1, 2022, Cortexyme Inc. changed its name to Quince Therapeutics, Inc ("Quince" or the "Company"). The Company was incorporated in the State of Delaware in June 2012 and is headquartered in South San Francisco, California. From inception, the Company has been focused on novel therapeutic approaches to improve the lives of patients with major, unmet medical needs. The Company, previously named Cortexyme, Inc. (“Cortexyme”) was initially founded on the seminal discovery of the presence of Porphyromonas gingivalis ("P. gingivalis"), and its secreted toxic virulence factor proteases, called gingipains, in the relevant brain areas of both Alzheimer's and Parkinson's disease patients. In May 2022, the Company completed the acquisition of Novosteo, Inc. ("Novosteo"), a Delaware corporation, a privately held biotechnology company focused on targeted therapeutics to treat rare skeletal diseases, bone fractures and injury. The acquisition of Novosteo, in 2022 (the "Novosteo Acquisition"), and the addition of new executive management allowed us to strategically shift focus and prioritize the internal development of our innovative bone-targeting drug platform and lead preclinical compound NOV004 for development for rare skeletal diseases, bone fractures, and injury. Following the Novosteo Acquisition in August 2022, the Company changed the corporate name to Quince Therapeutics, Inc.. At that time, the Company also announced it intended to actively seek compelling clinical-stage assets available for in-licensing and acquisition to expand our development pipeline with a focus on acquiring, developing, and commercializing innovative therapeutics for patients suffering from debilitating and rare diseases. On January 30, 2023, the Company announced that it intended to prioritize capital resources toward the expansion of its development pipeline through opportunistic in-licensing and acquisition of clinical-stage assets targeting debilitating and rare diseases. The Company also plans to out-license its bone-targeting drug platform and precision bone growth molecule NOV004 designed for accelerated fracture repair in patients with bone fractures and osteogenesis imperfecta. On October 20, 2023, we completed our acquisition of EryDel S.p.A., (“EryDel”), a privately-held, late-stage biotechnology company (the “EryDel Acquisition”) with a Phase 3 lead asset, EryDex, that targets the treatment of a rare neurodegenerative disease, Ataxia-Telangiectasia ("A-T"), for which there are currently no approved treatments globally. The EryDel Acquisition was completed pursuant to that certain Stock Purchase Agreement, dated as of July 21, 2023, (the “Purchase Agreement”), by and among the Company, EryDel, EryDel Italy, Inc., holders of EryDel capital stock and the managers of EryDel (the “EryDel Shareholders”) and Shareholder Representative Services LLC, a Colorado limited liability company solely in its capacity as the representative, agent and attorney-in-fact of the EryDel Shareholders. Pursuant to the terms of the Purchase Agreement, the Company issued 6,525,315 shares of common stock of the Company to the EryDel Shareholders. Up to an additional 725,037 shares of the Company’s common stock may be issued to the EryDel Shareholders upon the first anniversary of the closing of the EryDel Acquisition. The EryDel Shareholders have a contingent right to receive up to an aggregate of $ 485,000,000 in potential cash payments, comprised of up to $ 5,000,000 upon the achievement of a specified development milestone, $ 25,000,000 at new drug application ("NDA") acceptance by the U.S. Food and Drug Administration ("FDA"), up to $ 60,000,000 upon the achievement of specified approval milestones, and up to $ 395,000,000 upon the achievement of specified on market and sales milestones, with no royalties paid to EryDel. Refer to Note 13 Subsequent Events for additional details. Novosteo, Inc. Acquisition On May 9, 2022, the Company entered into an Agreement and Plan of Merger and Reorganization (the “Merger Agreement”) with Novosteo, Quince Merger Sub I, Inc., a Delaware corporation and a wholly owned subsidiary of the Company, Quince Merger Sub II, LLC, a Delaware limited liability company and a wholly owned subsidiary of Company, Novosteo, and Fortis Advisors LLC, a Delaware limited liability company, solely in its capacity as the securityholders’ representative. The transaction closed on May 19, 2022. Pursuant to the terms of the Merger Agreement, at the closing of the Novosteo Acquisition, each outstanding share of capital stock of Novosteo was automatically cancelled and converted into the right to receive 0.0911 shares of common stock, par value $ 0.001 per share, of the Company. The Company issued 5,520,000 shares and assumed 507,108 outstanding Novosteo options after conversion with the awards, retaining the same vesting and other terms and conditions as in effect immediately prior to consummation of the Novosteo Acquisition. Pursuant to the Merger Agreement, upon the terms and subject to the conditions set forth therein, Merger Sub I merged with and into Novosteo (the “First Merger”), with Novosteo as the surviving entity in the First Merger (the “First Step Surviving Corporation”). Immediately following the First Merger, the First Step Surviving Corporation merged with and into Merger Sub II, with Merger Sub II surviving the Novosteo Acquisition. Merger Sub II was renamed Novosteo, LLC and is a wholly-owned single member limited liability corporation. Novosteo, LLC has a wholly owned subsidiary in Australia, Novosteo Pty Ltd. Sale of Legacy Portfolio On January 27, 2023, the Company sold its legacy small molecule protease inhibitor portfolio, including COR588, COR388, COR852, and COR803, pursuant to an asset purchase agreement with Lighthouse Pharmaceuticals, Inc., (the "Purchaser" or “Lighthouse”) an entity co-founded by Casey Lynch, former chief executive officer of Quince’s predecessor company Cortexyme, Inc. Upon the consummation of the transaction, the Company received shares of common stock of Purchaser (“Common Stock”) equal to seven and a half percent ( 7.5 %) of the currently issued and outstanding Common Stock. The issuance is governed by a Stock Issuance Agreement entered into by the Company and the Purchaser on January 27, 2023 (the “Stock Agreement”). Pursuant to the terms of the asset purchase agreement, the Company is eligible to receive milestone payments up to $ 150 million on a product by product basis for the achievement of certain regulatory approvals and global net sales thresholds. Additionally, the Company is eligible to receive certain sales-based royalty payments on a product by product basis, ranging from high single-digit to mid-teens of annual net sales related to the two existing clinical stage programs, and low single-digit royalties for the preclinical programs, and certain sublicense income on a product by product basis, either in addition to milestone payments and royalties prior to Phase 2 initiation for COR588 or COR388, or in lieu of milestones payments and royalties after initiation of Phase 2 for COR588 or COR388 or for the preclinical programs. 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, 2023, the Company had an accumulated deficit of $ 310.8 million. Since inception through September 30, 2023, the Company has funded operations primarily with the net proceeds from the issuance of convertible promissory notes, from the issuance of redeemable convertible preferred stock, from the net proceeds from the Company’s initial public offering (the “IPO”), a private investment in public equity transaction (“PIPE Financing”), and an at-the-market offering under an open market sales agreement. As of September 30, 2023, the Company had cash, cash equivalents, and short-term investments of $ 83.2 million, which it believes will be sufficient to fund its planned operations for a period of at least 12 months from the date of the issuance of the accompanying unaudited consolidated financial statements. The Company had no long-term investments as of September 30, 2023. Management expects to incur additional losses in the future to fund the Company's operations, advance clinical trials, 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 in-licensed or acquired clinical stage assets accordingly .

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. 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. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“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, 2023, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022, the condensed consolidated statements of stockholders’ equity for the three and nine months ended September 30, 2023 and 2022, the condensed consolidated statements of cash flows for the nine months ended September 30, 2023 and 2022, 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, 2022 included in the Company’s Form 10-K filed with the SEC on March 15, 2023. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2023 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 U.S. Food and Drug Administration ("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 the acquisition of Novosteo, Inc., including associated intangible assets and goodwill, accruals for research and development costs, useful lives of long-lived assets, stock-based compensation and related assumptions, the incremental borrowing rate for leases and income tax uncertainties, including a valuation allowance for deferred tax assets, eligibility of expenses for the Australia research and development refundable tax credits, impairment of intangible assets or goodwill, collectability of note receivable; 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 In April 2021, the Company established a wholly owned subsidiary in Australia, Cortexyme Australia, Pty Ltd. In addition, Novosteo, LLC has a wholly owned subsidiary in Australia, Novosteo Pty Ltd. The functional currency of two of the Company’s wholly-owned subsidiaries is the Australian Dollar. Its 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 income (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, 2023 , as compared to the significant accounting policies described in our Annual Report on Form 10-K. Business Combinations The Company accounts for business combinations using the acquisition method pursuant to the Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification (“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 Novosteo 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. Assets Held for Sale Assets held for sale represent lab equipment that have met the criteria of “held for sale” accounting, as specified by Accounting Standards Codification (“ASC”) 360, “Long-lived Assets.” As of September 30, 2023, there were $ 0.1 million of lab equipment that are recorded as assets held for sale. The effect of suspending depreciation on the equipment held for sale is immaterial to the results of operations. The assets held for sale are being marketed for sale and it is the Company’s intention to complete the sales of these assets within the upcoming year. Intangible Assets Intangible assets with a definite useful life are amortized on a straight-line basis over the estimated useful life of the related assets. Intangible assets with an indefinite useful life are not amortized. Intangible assets acquired in a business combination 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 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. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value. There are no unrealized gains or losses on the money market funds for the periods presented. Investments The Company’s marketable securities primarily consist of U.S. Government and corporate debt securities. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses during the periods presented. At each balance sheet date, the Company assesses available-for-sale debt securities in an unrealized loss position to determine whether the unrealized loss or any potential credit losses should be recognized in net income (loss). 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 through net income (loss). For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented. The Company excludes the applicable accrued interest from both the fair value and amortized costs basis of the Company’s available-for-sale securities for the purpose of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within prepaid and other assets on the balance sheets. The Company made an accounting policy election to (1) not measure an allowance for credit loss for accrued interest receivable, and (2) to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which the Company considers to be in the period in which it determines the accrued interest will not be collected. See Note 3 (Fair Value Measurements) for further information. 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 its 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 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. Equity Investments without Readily Determinable Fair Values Equity investments without readily determinable fair values include ownership rights that either (i) do not meet the definition of in-substance common stock or (ii) do not provide the Company with control or significant influence and these investments do not have readily determinable fair values. Equity investments without readily determinable fair values are recorded at cost, less any impairment, and adjusted for subsequent observable price changes as of the date that an observable transaction takes place and are recorded in other income (expense), net (See Note 4). Recent Accounting Pronouncements Adopted Financial Instruments—Credit Losses: In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments which amends the principles around the recognition of credit losses by mandating entities incorporate an estimate of current expected credit losses when determining the value of certain assets. The guidance also amends reporting around allowances for credit losses on available-for-sale marketable securities. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842): Effective Dates, which established that a one-time determination of the effective date for ASU 2016-13 would be based on the Company’s SEC reporting status as of November 15, 2019. The Company was a “smaller reporting company” as defined by Item 10 of Regulation S-K, and therefore, ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. This guidance helps to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in Topic 326 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company has adopted the new guidance as of January 1, 2023, and it did not have a material impact on its financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its financial statements: Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions (ASC 820); In June 2022, the FASB issued ASU No. 2022-03, " Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions ." This ASU clarifies that a contractual restriction on the sale of equity security should not be considered in measuring the fair value. In addition, the ASU requires specific disclosures related to contractual sale restrictions. The ASU is effective in January 2024 under a prospective approach. Early adoption is permitted. Adoption of this ASU is not expected to have a material impact on the Company's condensed consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements The Company measures and reports its cash equivalents and investments at fair value. Money market funds are measured at fair value on a recurring basis using quoted prices and are classified as Level 1. Investments are measured at fair value based on inputs other than quoted prices that are derived from observable market data and are classified as Level 2 inputs. 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, 2023 and December 31, 2022 are presented in the following tables (in thousands): Fair Value Measurements at September 30, 2023 Total Level 1 Level 2 Level 3 Money market funds $ 12,285 $ 12,285 $ — $ — Certificates of Deposit 1,465 — 1,465 — Government and agency notes 68,666 — 68,666 — Total $ 82,416 $ 12,285 $ 70,131 $ — Fair Value Measurements at December 31, 2022 Total Level 1 Level 2 Level 3 Money market funds $ 10,988 $ 10,988 $ — $ — Certificates of Deposit 6,102 — 6,102 — Repurchase Agreements 9,000 — 9,000 — Corporate notes 12,411 — 12,411 — Government and agency notes 50,766 — 50,766 — Municipal notes 506 — 506 — Total $ 89,773 $ 10,988 $ 78,785 $ — The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements at September 30, 2023 Amortized Unrealized Unrealized Fair Value Money market funds $ 12,285 $ — $ — $ 12,285 Certificates of Deposit 1,480 — ( 15 ) 1,465 Government and agency notes 68,712 4 ( 50 ) 68,666 Total cash equivalents and investments $ 82,477 $ 4 $ ( 65 ) $ 82,416 Classified as: Cash equivalents (original maturities within 90 days) $ 20,823 Short-term investments (maturities within one year) 61,593 Total cash equivalents and investments $ 82,416 Fair Value Measurements at December 31, 2022 Amortized Unrealized Unrealized Fair Value Money market funds $ 10,988 $ — $ — $ 10,988 Certificates of Deposit 6,237 1 ( 136 ) 6,102 Repurchase Agreements 9,000 — — 9,000 Corporate notes 12,575 — ( 164 ) 12,411 Government and agency notes 51,020 4 ( 258 ) 50,766 Municipal notes 510 — ( 4 ) 506 Total cash equivalents and investments $ 90,330 $ 5 $ ( 562 ) $ 89,773 Classified as: Cash equivalents (original maturities within 90 days) $ 40,593 Short-term investments (maturities within one year) 45,602 Long-term investments (maturities beyond one year) 3,578 Total cash equivalents and investments $ 89,773 As of September 30, 2023 , the remaining contractual maturities of available-for-sale securities was approximately 3 months. There have been no significant realized gains or losses on available-for-sale securities for the periods presented. The Company records its available-for-sale debt securities at fair value, with changes in fair value reported as a component of accumulated other comprehensive income (loss). We periodically assess our investment in available-for-sale securities for impairment losses and credit losses. The amount of credit losses is 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, 2023 and 2022. The table below summarizes the unrealized losses of the Company's investments in debt securities measured at fair value as of September 30, 2023 (in thousands): Less than twelve months Twelve months or greater Total Fair value Gross unrealized loss Fair value Gross unrealized loss Fair value Gross unrealized loss Certificates of deposit $ — $ — $ 1,465 $ ( 15 ) $ 1,465 $ ( 15 ) Government and agency notes 22,662 ( 5 ) 3,686 ( 45 ) 26,348 ( 50 ) Total cash equivalents and investments $ 22,662 $ ( 5 ) $ 5,151 $ ( 60 ) $ 27,813 $ ( 65 ) The investments are classified as available-for-sale securities. At September 30, 2023 and December 31, 2022 , the balance in the Company’s accumulated other comprehensive income (loss) was comprised primarily of activity related to the Company’s available-for-sale securities. There were no realized gains or losses recognized on the sale or maturity of available-for-sale securities for the three and nine months ended September 30, 2023 and as a result, the Company did no t reclassify any amounts out of accumulated other comprehensive income for the quarter. There were no transfers between Levels 1, 2 or 3 for the period presented. The table below summarizes the contractual maturities of the Company's investments in debt securities measured at fair value as of September 30, 2023 (in thousands): Maturities by Period Total Less Than 1 Year 1-5 Years 6-10 Years More Than 10 Years Fair value of debt securities $ 61,593 $ 61,593 $ — $ — $ —

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Cash, Cash Equivalents and Investments	Note 4. Cash, Cash Equivalents and Investments The following tables categorize the fair values of cash, cash equivalents, short-term investments and long-term investments measured at fair value on a recurring basis on our balance sheets (in thousands): September 30, 2023 December 31, 2022 Cash and cash equivalents: Cash $ 809 $ 3,986 Money market funds 12,285 10,988 Repurchase agreements — 9,000 Government and agency notes 8,538 20,605 Total cash and cash equivalents $ 21,632 $ 44,579 Short-term investments: Certificates of deposit $ 1,465 $ 5,390 Municipal notes — 506 Corporate notes — 12,411 Government and agency notes 60,128 27,295 Total short-term investments $ 61,593 $ 45,602 Long-term investments Certificates of deposit $ — $ 712 Government and agency notes — 2,866 Total long-term investments $ — $ 3,578 Equity investments without readily determinable fair values assessed under the measurement alternative Equity investments without readily determinable fair value include ownership rights that either (i) do not meet the definition of in-substance common stock or (ii) do not provide the Company with control or significant influence and these investments do not have readily determinable fair values. During the nine months ended September 30, 2023, the Company received approximate ly $ 78,000 in equity investments witho ut readily determinable fair values of Lighthouse in exchange for the Legacy Assets. As of September 30, 2023 , the Company has no t recorded any cumulative upward adjustments or cumulative impairments for its equity investments without readily determinable fair values.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2023
Balance Sheet Components [Abstract]
Balance Sheet Components	Note 5. Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, 2023 2022 Prepaid expenses $ 270 $ 223 Prepaid insurance 1,037 977 Prepaid research and development expenses 49 1,088 Australia research and development refundable tax credit — 1,003 Other current assets 92 276 Total prepaid expenses and other current assets $ 1,448 $ 3,567 Cortexyme Australia, Pty, Ltd is eligible to obtain a cash refund from the Australian Taxation Office for eligible R&D expenditures under the Australian R&D Tax Incentive Program (the “Australian Tax Incentive”). The Australian Tax Incentive is recognized as a reduction to R&D expense when there is reasonable assurance that the relevant expenditure has been incurred, the amount can be reliably measured and the Australian Tax Incentive will be received. The Company received a refundable tax credit of $ 0.5 million in the second quarter of 2023, which reduced prepaid expenses and other current assets by $ 0.5 million as of June 30, 2023. The Company recognized reductions to R&D expense of $ 0 for the three and nine months ended September 30, 2023 and $ 0.1 million and $ 0.5 million reductions to R&D expense for the three and nine months ended September 30, 2022. Novosteo Pty, Ltd is eligible to obtain a cash refund from the Australian Taxation Office for eligible R&D expenditures under the Australian Tax Incentive as well. The Company received a refundable tax credit of $ 0.5 million in the first quarter of 2023, which reduced prepaid expenses and other current assets by $ 0.5 million as of March 31, 2023. Notes Receivable Notes receivables consist of the following (in thousands): September 30, 2023 December 31, 2022 Notes receivable 500 — Total Notes receivable $ 500 $ — On August 30, 2023, EryDel Italy, Inc., an indirect wholly owned subsidiary of the Company, entered into that certain promissory note, (the “Promissory Note”) with EryDel S.p.A. (“EryDel”), pursuant to which EryDel Italy, Inc. promised to make advances to EryDel of up to $ 1.0 million. Under the terms of the Promissory Note, the principal amount of the note shall be made available in two tranches, an initial tranche, in an aggregate amount of $ 500,000 , with an interest rate of 5.07 % per annum, and a second tranche, up to an aggregate amount of $ 500,000 , with an annual interest rate equal to Applicable Federal Rate for Annual Compounding Short-Term Debt Instruments as at the funding date of such tranche, to be funded to EryDel during the period commencing September 1, 2023 to October 31, 2023. The first tranche was made during the three months ended September 30, 2023 . Interest receivable as of September 30, 2023 was approximately $ 1,300 . The Promissory Note will mature on July 1, 2024, provided that, subject to certain conditions, in the event that the closing date occurs under the Stock Purchase Agreement on or before December 31, 2023, or the Stock Purchase Agreement is terminated for any reason other than by the Company in certain specified circumstances, all obligations of EryDel and EryDel Italy, Inc. under the Promissory Note shall be deemed to be paid and discharged in full, all unfunded commitments of EryDel Italy, Inc. to make advances under the Promissory Note shall be terminated, and all other obligations of EryDel shall be deemed terminated. For additional details, refer to Note 13 Subsequent Events. Assets Held for Sale Assets held for sale consist of the following (in thousands): September 30, 2023 December 31, 2022 Assets held for sale $ 82 $ — Total assets held for sale $ 82 $ — In response to the reprioritization of its pipeline following the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities the Company reclassified the equipment on consignment of $ 0.1 million to Assets held for sale. Property and Equipment, Net Property and equipment, net consist of the following (in thousands): September 30, December 31, 2023 2022 Computer equipment $ 18 $ 18 Lab equipment — 415 Finance lease right of use assets — 124 Leasehold improvement — 21 Less: accumulated amortization and depreciation ( 13 ) ( 185 ) Property and equipment, net $ 5 $ 393 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, 2023 2022 Personnel expenses $ 1,366 $ 1,130 Professional fees 225 234 Research and development expenses 41 497 Current portion of operating lease liabilities 61 377 Current portion of finance lease liability — 76 Other 151 185 Total accrued expenses and other current liabilities $ 1,844 $ 2,499 Below is the severance accrual activity included in the personnel expenses in the above table related to a cost reduction program during the period ended September 30, 2023 (in thousands): For the Nine Months 2023 Beginning accrued severance $ — Incurred during the period 770 Severance paid during the period ( 309 ) Ending accrued severance 461 In response to the reprioritization of the Company's pipeline following the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities, the Board approved a cost reduction program to reorganize operations and allow continued support for the needs of the business. Under the cost reduction program, the Company lowered headcount through a reduction in workforce. The Company recognized the severance and related expenses 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 $ 475,000 , 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 $ 140,000 .

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Leases	Note 6. Leases Real Estate Operating Leases In June 2022, the Company entered into a Sublease Agreement to rent office space in South San Francisco, California. The Sublease Agreement commenced on June 18, 2022 and ends on November 30, 2023. The total payments under the term of the lease are expected to be approximately $ 271,000 . The Company paid a security deposit of $ 17,000 which is included in Prepaid Expenses and Other Current Assets on the September 30, 2023 condensed consolidated balance sheets. At the commencement of the lease, the Company recorded an operating lease right of use asset and liability of $ 256,000 . On October 31, 2023, the Company signed a lease agreement for a smaller office space in South San Francisco, California. The total payments under the new lease are expected to be approximately $ 22,000 for the year. The lease will commence on November 30, 2023 and end on November 30, 2024. In October 2022, the Company entered into a lease agreement to rent space in West Lafayette, Indiana. The lease agreement amended the original lease to transfer liability to the Company due to the Novosteo Acquisition. The lease agreement is for 15 months, which commenced on October 1, 2022 and ends on December 31, 2023. The total payments under the term of the lease are expected to be approximately $ 151,000 . At the commencement of the lease, the Company recorded an operating lease right of use asset and liability of $ 145,000 . In December 2022, the Company entered into an amendment to the lease agreement of the rental space in West Lafayette to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company will pay rent monthly for the additional space. The Company recorded an operating lease right of use asset and liability of $ 10,000 . In February 2023, as a result of the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities, the Company entered into a sublease agreement as the lessor for the majority of the West Lafayette facility. The lease commenced on March 17, 2023 and ends on December 31, 2023. The sublessee paid the Company a security deposit of $ 6,000 which is included in Accrued expenses and other current liabilities on the September 30, 2023 condensed consolidated balance sheets. Under the terms of the sublease, the Company is entitled to receive a total rental income that is expected to offset rent expense of $ 57,000 . As a result of this decision and the sublease agreement, the Company recorded an impairment loss of approximately $ 66,000 which is included in other expense, net per statements of operations and comprehensive loss for the nine months ended September 30, 2023 condensed consolidated statement of operations and comprehensive loss. The Company recognizes lease expense on a straight-line basis over the term of its operating lease. As of September 30, 2023, total future rent expense from all real estate operating leases of $ 48,000 will be recognized over the remaining term of 2 to 3 months on a straight-line basis over the respective lease period. Clinical Equipment Financing Lease As part of the Novosteo Acquisition, the Company acquired a financing lease for certain lab equipment. The Company recognizes the depreciation expense in research and development expenses in the condensed consolidated statements of operations and comprehensive loss and recognizes expense on a straight-line basis starting when the equipment is placed into service until the end of the remaining contract term of 18 months. Amortization expense of the financing lease right of use asset for the nine months ended September 30, 2023 was $ 6,000 . In February 2023, as a result of the decision to discontinue internal development of NOV004 and to pursue out-licensing opportunities, the Company exercised its purchase option for the financed equipment in order to resell and this equipment is currently held on consignment and is included in Assets held for sale on the September 30, 2023 condensed consolidated balance sheets. As a result of this action, the Company reduced the Finance lease ROU asset and Finance lease liability by approximately $ 70,000 . Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): September 30, 2023 December 31, 2022 Operating lease right of use asset, net $ 48 $ 291 Short-term operating lease liability 61 377 $ 61 $ 377 Finance lease right of use asset — 124 Finance lease accumulated amortization — ( 50 ) Total finance lease right of use asset, net $ — $ 74 Weighted average remaining lease term Operating leases 0.2 years 0.9 years Finance leases — 1.0 year Weighted average discount rate Operating leases 6.70 % 5.71 % Finance leases — % 4.45 % Year ended December 31, Operating Lease Operating Lease Year ended December 31, 2023 (excluding the nine months ended September 30, 2023) $ 62 $ 388 Total lease payments 62 388 Less: imputed interest ( 1 ) ( 11 ) Total remaining lease liability $ 61 $ 377

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Note 7. Stock-Based Compensation The Company operates three stock plans as of September 30, 2023. • 2019 Equity Incentive Plan (Quince) • 2019 Equity Incentive Plan (Novosteo) • 2022 Inducement Plan (Quince) 2019 Equity Incentive Plan (Quince) On December 4, 2014, the Company’s stockholders approved the 2014 Stock Plan (“2014 Plan”), and on April 25, 2019 amended, restated and re-named the 2014 Plan as the 2019 Equity Incentive Plan (the “Quince 2019 Plan”), which became effective as of May 7, 2019, the day prior to the effectiveness of the registration statement filed in connection with the IPO. The remaining shares available for issuance under the 2014 Plan were added to the shares reserved for issuance under the Quince 2019 Plan. The Quince 2019 Plan provides for the grant of stock options (including incentive stock options and non-qualified stock options), stock appreciation rights, restricted stock, RSUs, performance units, and performance shares to the Company’s employees, directors, and consultants. As of September 30, 2023, the maximum aggregate number of shares that remain available for issuance under the Quince 2019 Plan is 10,036,489 shares of the Company’s common stock. In addition, the number of shares available for issuance under the Quince 2019 Plan will be annually increased on the first day of each 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 Board, the Quince 2019 Plan will automatically terminate on April 23, 2029. As of September 30, 2023, the Company had 4,964,784 shares available for future issuance under the Quince 2019 Plan. Stock Options Activity for service-based stock options under the Quince 2019 Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2022 3,319,711 $ 16.07 4.77 $ 65 Options granted 2,162,958 1.04 — — Options exercised ( 258,705 ) 0.42 — 240 Options cancelled / forfeited ( 1,915,786 ) 18.35 — — Balance at September 30, 2023 3,308,178 $ 6.15 8.15 $ 245 Options vested and expected to vest as of September 30, 2023 3,308,178 6.15 8.15 245 Options exercisable as of September 30, 2023 1,122,154 $ 13.46 6.56 $ 61 For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $ 615,000 and $ 1,993,000 , 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, 2023, total unamortized employee stock-based compensation was $ 3.8 million, which is expected to be recognized over the remaining estimated vesting period of 2.37 years. Performance Stock Options (“PSOs”) There was no activity or balance of any PSOs from the 2019 plan for the nine months ended September 30, 2023. For the three and nine months ended September 30, 2023 , the Company recognized stock-based compensation expense of $ 0 related to these PSOs. For the three and nine months ended September 30, 2022, the Company recognized stock-based compensation expense of $ 0 and $ 2,044,000 , respectively, related to these PSOs. As of September 30, 2023 and December 31, 2022 , there was no remaining unamortized stock-based compensation related to PSOs. Restricted Stock Units (“RSUs”) The following table summarizes activity under the Company’s RSUs from the Quince 2019 Plan and related information: Restricted Stock Units Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 30,876 $ 4.30 RSUs granted — — RSUs vested ( 8,713 ) 4.30 RSUs cancelled ( 19,188 ) 4.30 Unvested - September 30, 2023 2,975 $ 4.30 The fair value of the RSUs is determined on the grant date based on the fair value of the Company’s common stock. The fair value of the RSUs is recognized as expense ratably over the vesting period of two years . The total grant date fair value of the RSUs vested during the three and nine months ended September 30, 2023 was $ 6,400 and $ 37,500 , respectively. The aggregate intrinsic value of the shares of the RSUs vested during the three and nine months ended September 30, 2023 was $ 2,000 and $ 9,900 , respectively. For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $ 6,000 and $ 31,000 respectively, related to these RSUs. As of September 30, 2023, total unamortized stock-based compensation related to RSUs was $ 11,000 , which is expected to be recognized over the remaining estimated vesting period of 0.42 years. 2019 Equity Incentive Plan (Novosteo) On May 19, 2022, in accordance with the term of the Merger Agreement, the Company assumed the 2019 Novosteo, 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 and adjusted into the right to purchase 0.0911 shares of common stock. Each such converted stock option will continue to be subject to substantially the same terms and conditions as applied to the corresponding Novosteo stock option prior to the Novosteo 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. As of September 30, 2023, the Company had 143,022 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 Weighted Weighted Aggregate (In thousands) Balance at December 31, 2022 503,105 $ 0.55 9.23 $ 44 Options granted — — — — Options exercised ( 3,027 ) 0.55 — 3 Options cancelled / forfeited ( 37,848 ) 0.55 — — Balance at September 30, 2023 462,230 $ 0.55 5.75 $ 263 Options vested and expected to vest as of September 30, 2023 462,230 0.55 5.75 263 Options exercisable as of September 30, 2023 219,190 0.55 4.58 125 For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $ 96,000 and $ 226,000 , respectively, related to options granted to employees and non-employees for the 2019 Novosteo plan. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the condensed consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of September 30, 2023, total unamortized employee stock-based compensation was $ 0.5 million, which is expected to be recognized over the remaining estimated vesting period of 2.48 years. On May 19, 2022, in accordance with the term of the Merger Agreement, the Company assumed a number of restricted stock awards ("RSAs") agreements with certain employees. Each outstanding Novosteo RSA was converted into a corresponding RSA with the number of shares underlying such RSA adjusted into 0.0911 shares of common stock. Each such converted RSA will continue to be subject to substantially the same terms and conditions as applied to the corresponding Novosteo RSA prior to the Novosteo Acquisition. Restricted Stock Awards (“RSAs”) Restricted Stock Awards Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 427,401 $ 3.30 RSAs granted — — RSAs vested ( 164,008 ) 3.30 RSAs cancelled ( 63,294 ) 3.30 Unvested - September 30, 2023 200,099 $ 3.30 For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $ 167,000 and $ 415,000 , respectively, related to restricted stock awards. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the condensed consolidated statement of operations and comprehensive loss for stock-based compensation arrangements. As of September 30, 2023 , total unamortized employee stock-based compensation was $ 0.6 million, which is expected to be recognized over the remaining estimated vesting period of 1.99 years. 2022 Inducement Plan On May 9, 2022, the Board approved 4,000,000 shares of the Registrant’s common stock that may be offered or issued under the Quince Therapeutics, Inc. 2022 Inducement Plan (the “2022 Inducement Plan”). The 2022 Inducement Plan was adopted by the independent members of the Board without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. In accordance with rule awards under those plans may only be made to an employee who has not previously been an employee or member of the Board or of any board of directors of any parent or subsidiary of the Company, or following a bona fide period of non-employment by the Company or a parent or subsidiary, if he or she is granted such award in connection with his or her commencement of employment with the Company or a subsidiary and such grant is an inducement material to his or her entering into employment with the Company or such subsidiary. The terms and conditions of the 2022 Inducement Plan are substantially similar to those of the Quince 2019 Plan. As of September 30, 2023, the Company had 301,245 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 Weighted Weighted Aggregate (In thousands) Balance at December 31, 2022 3,742,255 $ 2.98 9.39 $ — Options granted — — — — Options exercised — — — — Options cancelled / forfeited ( 43,500 ) 2.98 — — Balance at September 30, 2023 3,698,755 $ 2.98 5.52 $ — Options vested and expected to vest as of September 30, 2023 3,698,755 2.98 5.52 — Options exercisable as of September 30, 2023 1,673,844 2.98 4.11 — For the three and nine months ended September 30, 2023, the Company recognized stock-based compensation expense of $ 447,000 and $ 1,469,000 , respectively, related to options granted to employees and non-employees for the 2022 Inducement plan. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the condensed consolidated statement of operations and comprehensive for stock-based compensation arrangements. As of September 30, 2023, total unamortized employee stock-based compensation was $ 3.5 million, which is expected to be recognized over the remaining estimated vesting period of 2.64 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, 2023 and 2022 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, 2023 2022 2023 2022 General and administrative expense $ 945 $ 1,289 $ 3,014 $ 8,988 Research and development expense 386 ( 595 ) 1,120 5,998 Total stock-based compensation $ 1,331 $ 694 $ 4,134 $ 14,986 Employee Stock Purchase Plan On April 24, 2019, the Board 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 1,494,530 shares of common stock for issuance under the 2019 ESPP. In addition, the number of shares reserved for issuance under the 2019 ESPP will be increased automatically on the first day of each fiscal year for a period of up to ten years , starting with the 2020 fiscal year, by a number equal to the least 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 Board. 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. Rights Plan On April 5, 2023, the Board declared a dividend of one preferred share purchase right (a “Right”) for each outstanding share of the common stock, par value $ 0.001 per share (the “Common Shares”), of the Company. The dividend is effective as of April 17, 2023 (the “Record Date”) with respect to stockholders of record on that date. The Rights will also attach to new Common Shares issued after the Record Date. Each Right entitles 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. The descriptions and terms of the Rights are set forth in a Rights Agreement, dated as of April 5, 2023 (the “Rights Agreement"), between the Company and American Stock Transfer & Trust Company, LLC. The Rights will expire on April 5, 2024 , unless the Rights are earlier redeemed or exchanged by the Company.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Note 8. Related Party Transactions David Lamond, Chairperson of the Board was a director and an equity holder in Novosteo, Inc. which Quince acquired on May 19, 2022. The shares of Novosteo, Inc. beneficially owned by Mr. Lamond were automatically canceled and converted into the right to receive shares of Quince common stock in accordance with the terms of the Merger Agreement. The respective boards of directors of Quince and Novosteo have approved the Merger Agreement, and the Novosteo’s stockholders adopted the Merger Agreement upon recommendation of the Novosteo board of directors. Mr. Lamond was not part of either company's special committees that evaluated the Novosteo Acquisition and recused himself from board meetings where the Novosteo Acquisition was discussed. Dirk Thye, M.D., Chief Executive Officer, is an investor in Morphimmune Inc. and Philip Low, Ph.D, a former Board member of Quince Therapeutics, Inc., is a co-founder and Board member of Morphimmune Inc. During the nine months ended September 30, 2023 , the Company sold certain lab equipment to Morphimmune Inc. for $ 80,000 as well as signed a sublease with Morphimmune as the sublessee with total payments of approximately $ 57,000 for the lease term of March 17, 2023 through December 31, 2023.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Note 9. Income Taxes The Company has a history of losses and expects to record a loss in 2023. The Company accounts for income taxes under ASC Topic 740 – Income Taxes . A valuation allowance is provided for significant deferred tax assets when it is more likely than not that such assets will not be realized through future operations. Future tax benefits which may arise as a result of these losses have not been recognized in these financial statements, as their realization is determined not likely to occur and accordingly, the Company has maintained a valuation allowance for the future deferred tax assets. The Company recorded a discrete tax benefit of $ 0.2 million in the nine months ended September 30, 2023 due to the release of valuation allowance in connection with the write down of the in-process research and development ("IPR&D") intangible asset related to NOV004. As a result of the impairment, the Company reversed the Deferred tax liabilities associated with the intangible asset resulting in the tax benefit of $ 0.2 million as of March 31, 2023.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	Note 10. Net Loss Per Share The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the period presented due to their anti-dilutive effect: September 30, 2023 2022 Stock options issued and outstanding 7,469,163 8,398,987 Restricted stock units 2,975 173,113 Restricted stock awards 200,099 466,750 Total 7,672,237 9,038,850

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2023
Business Combinations [Abstract]
Business Combination	Note 11. Business Combination On May 19, 2022, the Company completed the Novosteo Acquisition. Pursuant to the terms of the Merger Agreement, at the closing of the Novosteo Acquisition (the “Effective Time”), each share of capital stock of Novosteo (the “Novosteo Capital Stock”) that was issued and outstanding immediately prior to the Effective Time was automatically cancelled and converted into the right to receive 0.0911 shares of common stock, par value $ 0.001 per share, of the Company (the “Company Common Stock”). These shares included options to purchase an aggregate of 507,108 shares of the Company Common Stock upon conversion of the outstanding Novosteo options based on the Company Option Exchange Ratio (as defined in the Merger Agreement), with the awards retaining the same vesting and other terms and conditions as in effect immediately prior to consummation of the Novosteo Acquisition. These options, as well as 519,216 unvested restricted shares were concluded to be post-combination expense and were excluded from purchase consideration. The transaction costs associated with the Novosteo Acquisition were approximately $ 1.1 million and were recorded in general and administrative expense. The acquisition date fair value of the consideration transferred for Novosteo was approximately $ 16,502,587 , which consisted of 5,000,784 shares at $ 3.30 per share. The Company accounted for the Novosteo Acquisition as a business combination in accordance with ASC Topic 805, Business Combinations ("ASC 805"). The Company applied the acquisition method, which requires the identifiable assets acquired and liabilities assumed be recorded at fair value with limited exceptions. The following table summarizes the fair values of the identifiable assets acquired and liabilities assumed as of the date of acquisition (in thousands): May 19, 2022 Identifiable assets acquired and liabilities assumed: Cash and cash equivalents $ 10,593 Prepaid expenses and other current assets 1,040 ROU asset 124 Property and equipment 279 Intangible assets 5,900 Accounts payable and accrued liabilities ( 1,726 ) Deferred tax liabilities ( 532 ) Net assets acquired $ 15,678 Goodwill $ 825 The final determination of the fair value of assets and liabilities was completed within the one-year measurement period as required by ASC 805. The excess of the fair value of purchase consideration over the fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill, which is primarily attributed to the assembled workforce and expanded market opportunities, for which there is no basis for U.S. income tax purposes. Goodwill amounts are not amortized but are rather tested for impairment at least annually, see Note 12 for this assessment. Goodwill is not deductible for tax purposes. The Intangible asset balance above is attributable to in-process research and development with an indefinite useful life. The amounts of Novosteo's net loss was $ 2.7 million and $ 5.2 million, respectively, included in the Company's condensed consolidated statement of operations and comprehensive loss for the three and nine months ended September 30, 2022. The amount of Novosteo's revenue was $ 0 for both the three and nine months ended September 30, 2022. The unaudited pro forma revenue and net loss of the combined entity had the acquisition date been January 1, 2022 are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 Revenue $ — $ 262 Net loss ( 7,921 ) ( 47,057 )

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Note 12. Intangible Assets The intangible asset acquired as a result of the Novosteo Acquisition consists of in-process research and development ("IPR&D") related to NOV004, the Company's bone targeting molecule designed to accelerate fracture repair. The value of the IPR&D was determined using discounted probable future cash flows. Significant assumptions used in determining the value of the intellectual property include the initiation of clinical trials and NDA approval with respect to NOV004, probability of reaching various phases of development, costs and cost of goods sold, and the risk adjusted discount rate applied to the cash flows. All intangible assets acquired in a business combination that are used in research and development activities are capitalized as indefinite-lived intangible assets. During the period that those assets are considered indefinite lived, they are not amortized but are tested for impairment. Once the research and development efforts are completed, the asset will be amortized over its remaining useful life. If the research and development efforts are abandoned, the intangible asset will be expensed in that period. The following table provides details of the carrying amount of our indefinite-lived intangible asset (in thousands): As of September 30, 2023 Unamortized intangible assets: In-process research and development $ 5,900 Impairment charge ( 5,900 ) Balance as of September 30, 2023 — In January 2023, the Company decided to discontinue the internal development of NOV004 and pursue out-licensing opportunities. As a result, several of the assumptions used in determining the initial fair value have changed including discount rate and expected cash flows and thus triggered the need for an interim impairment assessment as required under ASC 350. 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 three months ended March 31, 2023. Goodwill 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. There was no amount related to goodwill reflected on the condensed consolidated balance sheet for the Company as of September 30, 2023 and December 31, 2022. In 2022, management 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 our assessment that the Company's market capitalization was significantly below its carrying value and a further quantitative analysis was conducted to determine to the extent, if any, the Company's carrying value exceeded its fair value as of September 30, 2022. The quantitative analysis used fair value based on market capitalization adjusted for control premium based on market co mparable transactions. This quantitative analysis resulted in the Company's fair value being significantly below its carrying value, resulting in a non-cash goodwill impairment charge of $ 0.8 million being recorded during the year ended December 31, 2022.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Note 13. Subsequent Events On October 20, 2023, the Company completed its acquisition of EryDel S.p.A., a privately-held, late-stage biotechnology company with a lead Phase 3 lead asset, EryDex, that targets the treatment of a rare neurodegenerative disease, Ataxia-Telangiectasia, for which there are currently no approved treatments globally. The Company will account 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. The accounting for the acquisition is incomplete as of the date of this Quarterly Report on Form 10-Q. The EryDel Acquisition was pursuant to that certain Stock Purchase Agreement, dated as of July 21, 2023, by and among the Company, EryDel, EryDel Italy, Inc., holders of EryDel capital stock and the managers of EryDel and Shareholder Representative Services LLC, a Colorado limited liability company solely in its capacity as the representative, agent and attorney-in-fact of the EryDel Shareholders. Pursuant to the terms of the Purchase Agreement, the Company issued 6,525,315 shares of common stock of the Company, approximately equivalent to $ 6.5 million, to the EryDel Shareholders, resulting in the EryDel Shareholders owning approximately 15.2 % of the outstanding common stock of the Company. Up to an additional 725,037 shares of the Company’s common stock may be issued to the EryDel Shareholders upon the first anniversary of the closing of the EryDel Acquisition. The EryDel Shareholders have a contingent right to receive up to an aggregate of $ 485,000,000 in potential cash payments, comprised of up to $ 5,000,000 upon the achievement of a specified development milestone, $ 25,000,000 at NDA acceptance by the FDA, up to $ 60,000,000 upon the achievement of specified approval milestones, and up to $ 395,000,000 upon the achievement of specified on market and sales milestones, with no royalties paid to EryDel. In connection with the closing of the EryDel Acquisition, Quince, together with its wholly owned subsidiaries, EryDel Italy, Inc., a Delaware corporation, and EryDel US, Inc., a Delaware corporation (each a “Quince Party” and together, collectively, the “Quince Parties”), have agreed to guarantee the obligations of EryDel, a company with shares incorporated under the laws of Italy, in respect of a $ 31.8 million unsecured credit facility (the “EIB Facility”) evidenced by the Finance Contract, dated as of July 24, 2020 (the “Existing Finance Contract” and, as amended by the Amendment, the “Amended Finance Contract”), by and between EryDel, as borrower, and the European Investment Bank, as lender (the “Lender”), by entering into (i) an Accession, Amendment and Restatement Agreement, dated as of October 20, 2023 (the “Amendment”), which amends and restates the Existing Finance Contract and joins each Quince Party thereto as a guarantor of the obligations of EryDel thereunder, and (ii) an Autonomous First Demand Guarantee (Garanzia Autonoma a Prima Richiesta) by each Quince Party respectively in favor of the Lender (collectively, the “Guarantees”). As of October 20, 2023, approximately $ 10.6 million has been disbursed to EryDel. The outstanding principal amount under the EIB Facility will become due and payable at maturity on August 11, 2026 and bears interest at a fixed rate of 9.00 % per annum. The EIB Facility may be voluntarily prepaid at any time with at least 60 days ’ prior notice, subject to a prepayment penalty. Pursuant to the EIB Facility, each Quince Party will (i) make representations and warranties to EIB that are customary for facilities similar to the EIB Facility and (ii) become bound by customary affirmative and negative covenants, subject to customary exceptions. Quince, but not the other Quince Parties, will become subject to a requirement under the EIB Facility to maintain a certain minimum unrestricted balance of cash or cash equivalents during the term of the EIB Facility. A failure by a Quince Party to comply with any of the covenants applicable to it under the EIB Facility will, either immediately or after the passage of time in the case of those covenants that are subject to a grace period, constitute an event of default under the EIB Facility. Pursuant to the Guarantees, each Quince Party has agreed to guarantee EryDel’s obligations under the EIB Facility, which must be paid to EIB within five (5) business days of written demand therefor from EIB. Under the Promissory Note entered into on August 30, 2023, discussed in Note 5 Balance Sheet Components, EryDel Italy, Inc. provided the second tranche on October 17, 2023 in an amount of $ 500,000 with 5.22 % annual interest to EryDel. On October 24, 2023, in connection with the EryDel Acquisition, the outstanding principal and accrued interest due under the Promissory Note of approximately $ 1.0 million in the aggregate was deemed to be paid and discharged in full.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
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.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“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, 2023, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022, the condensed consolidated statements of stockholders’ equity for the three and nine months ended September 30, 2023 and 2022, the condensed consolidated statements of cash flows for the nine months ended September 30, 2023 and 2022, 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, 2022 included in the Company’s Form 10-K filed with the SEC on March 15, 2023. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2023 or for any other future annual or interim period.
Risks and Uncertainties	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 U.S. Food and Drug Administration ("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	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 the acquisition of Novosteo, Inc., including associated intangible assets and goodwill, accruals for research and development costs, useful lives of long-lived assets, stock-based compensation and related assumptions, the incremental borrowing rate for leases and income tax uncertainties, including a valuation allowance for deferred tax assets, eligibility of expenses for the Australia research and development refundable tax credits, impairment of intangible assets or goodwill, collectability of note receivable; 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 In April 2021, the Company established a wholly owned subsidiary in Australia, Cortexyme Australia, Pty Ltd. In addition, Novosteo, LLC has a wholly owned subsidiary in Australia, Novosteo Pty Ltd. The functional currency of two of the Company’s wholly-owned subsidiaries is the Australian Dollar. Its 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 income (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	Significant Accounting Policies There have been no significant changes to the accounting policies during the nine months ended September 30, 2023 , as compared to the significant accounting policies described in our Annual Report on Form 10-K.
Business Combinations	Business Combinations The Company accounts for business combinations using the acquisition method pursuant to the Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification (“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 Novosteo 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.
Assets Held For Sale	Assets Held for Sale Assets held for sale represent lab equipment that have met the criteria of “held for sale” accounting, as specified by Accounting Standards Codification (“ASC”) 360, “Long-lived Assets.” As of September 30, 2023, there were $ 0.1 million of lab equipment that are recorded as assets held for sale. The effect of suspending depreciation on the equipment held for sale is immaterial to the results of operations. The assets held for sale are being marketed for sale and it is the Company’s intention to complete the sales of these assets within the upcoming year.
Intangible Assets	Intangible Assets Intangible assets with a definite useful life are amortized on a straight-line basis over the estimated useful life of the related assets. Intangible assets with an indefinite useful life are not amortized. Intangible assets acquired in a business combination 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 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.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value. There are no unrealized gains or losses on the money market funds for the periods presented.
Investments	Investments The Company’s marketable securities primarily consist of U.S. Government and corporate debt securities. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses during the periods presented. At each balance sheet date, the Company assesses available-for-sale debt securities in an unrealized loss position to determine whether the unrealized loss or any potential credit losses should be recognized in net income (loss). 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 through net income (loss). For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented. The Company excludes the applicable accrued interest from both the fair value and amortized costs basis of the Company’s available-for-sale securities for the purpose of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within prepaid and other assets on the balance sheets. The Company made an accounting policy election to (1) not measure an allowance for credit loss for accrued interest receivable, and (2) to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which the Company considers to be in the period in which it determines the accrued interest will not be collected. See Note 3 (Fair Value Measurements) for further information.
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 its 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 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.
Equity Investments without Readily Determinable Fair Values	Equity Investments without Readily Determinable Fair Values Equity investments without readily determinable fair values include ownership rights that either (i) do not meet the definition of in-substance common stock or (ii) do not provide the Company with control or significant influence and these investments do not have readily determinable fair values. Equity investments without readily determinable fair values are recorded at cost, less any impairment, and adjusted for subsequent observable price changes as of the date that an observable transaction takes place and are recorded in other income (expense), net (See Note 4).
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Adopted Financial Instruments—Credit Losses: In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments which amends the principles around the recognition of credit losses by mandating entities incorporate an estimate of current expected credit losses when determining the value of certain assets. The guidance also amends reporting around allowances for credit losses on available-for-sale marketable securities. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842): Effective Dates, which established that a one-time determination of the effective date for ASU 2016-13 would be based on the Company’s SEC reporting status as of November 15, 2019. The Company was a “smaller reporting company” as defined by Item 10 of Regulation S-K, and therefore, ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. This guidance helps to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in Topic 326 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company has adopted the new guidance as of January 1, 2023, and it did not have a material impact on its financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its financial statements: Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions (ASC 820); In June 2022, the FASB issued ASU No. 2022-03, " Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions ." This ASU clarifies that a contractual restriction on the sale of equity security should not be considered in measuring the fair value. In addition, the ASU requires specific disclosures related to contractual sale restrictions. The ASU is effective in January 2024 under a prospective approach. Early adoption is permitted. Adoption of this ASU is not expected to have a material impact on the Company's condensed consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities to Fair Value Measurements on Recurring Basis	Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of September 30, 2023 and December 31, 2022 are presented in the following tables (in thousands): Fair Value Measurements at September 30, 2023 Total Level 1 Level 2 Level 3 Money market funds $ 12,285 $ 12,285 $ — $ — Certificates of Deposit 1,465 — 1,465 — Government and agency notes 68,666 — 68,666 — Total $ 82,416 $ 12,285 $ 70,131 $ — Fair Value Measurements at December 31, 2022 Total Level 1 Level 2 Level 3 Money market funds $ 10,988 $ 10,988 $ — $ — Certificates of Deposit 6,102 — 6,102 — Repurchase Agreements 9,000 — 9,000 — Corporate notes 12,411 — 12,411 — Government and agency notes 50,766 — 50,766 — Municipal notes 506 — 506 — Total $ 89,773 $ 10,988 $ 78,785 $ —
Summary of Available-for-Sale Securities	The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements at September 30, 2023 Amortized Unrealized Unrealized Fair Value Money market funds $ 12,285 $ — $ — $ 12,285 Certificates of Deposit 1,480 — ( 15 ) 1,465 Government and agency notes 68,712 4 ( 50 ) 68,666 Total cash equivalents and investments $ 82,477 $ 4 $ ( 65 ) $ 82,416 Classified as: Cash equivalents (original maturities within 90 days) $ 20,823 Short-term investments (maturities within one year) 61,593 Total cash equivalents and investments $ 82,416 Fair Value Measurements at December 31, 2022 Amortized Unrealized Unrealized Fair Value Money market funds $ 10,988 $ — $ — $ 10,988 Certificates of Deposit 6,237 1 ( 136 ) 6,102 Repurchase Agreements 9,000 — — 9,000 Corporate notes 12,575 — ( 164 ) 12,411 Government and agency notes 51,020 4 ( 258 ) 50,766 Municipal notes 510 — ( 4 ) 506 Total cash equivalents and investments $ 90,330 $ 5 $ ( 562 ) $ 89,773 Classified as: Cash equivalents (original maturities within 90 days) $ 40,593 Short-term investments (maturities within one year) 45,602 Long-term investments (maturities beyond one year) 3,578 Total cash equivalents and investments $ 89,773
Summary of Unrealized Losses of Company's Investments in Debt Securities Measured at Fair Value	The table below summarizes the unrealized losses of the Company's investments in debt securities measured at fair value as of September 30, 2023 (in thousands): Less than twelve months Twelve months or greater Total Fair value Gross unrealized loss Fair value Gross unrealized loss Fair value Gross unrealized loss Certificates of deposit $ — $ — $ 1,465 $ ( 15 ) $ 1,465 $ ( 15 ) Government and agency notes 22,662 ( 5 ) 3,686 ( 45 ) 26,348 ( 50 ) Total cash equivalents and investments $ 22,662 $ ( 5 ) $ 5,151 $ ( 60 ) $ 27,813 $ ( 65 )
Schedule of the Ccontractual Maturities of our Investments in Debt Securities Measured at Fair Value	The table below summarizes the contractual maturities of the Company's investments in debt securities measured at fair value as of September 30, 2023 (in thousands): Maturities by Period Total Less Than 1 Year 1-5 Years 6-10 Years More Than 10 Years Fair value of debt securities $ 61,593 $ 61,593 $ — $ — $ —

Cash, Cash Equivalents and In_2

Cash, Cash Equivalents and Investments (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis	The following tables categorize the fair values of cash, cash equivalents, short-term investments and long-term investments measured at fair value on a recurring basis on our balance sheets (in thousands): September 30, 2023 December 31, 2022 Cash and cash equivalents: Cash $ 809 $ 3,986 Money market funds 12,285 10,988 Repurchase agreements — 9,000 Government and agency notes 8,538 20,605 Total cash and cash equivalents $ 21,632 $ 44,579 Short-term investments: Certificates of deposit $ 1,465 $ 5,390 Municipal notes — 506 Corporate notes — 12,411 Government and agency notes 60,128 27,295 Total short-term investments $ 61,593 $ 45,602 Long-term investments Certificates of deposit $ — $ 712 Government and agency notes — 2,866 Total long-term investments $ — $ 3,578

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2023
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, December 31, 2023 2022 Prepaid expenses $ 270 $ 223 Prepaid insurance 1,037 977 Prepaid research and development expenses 49 1,088 Australia research and development refundable tax credit — 1,003 Other current assets 92 276 Total prepaid expenses and other current assets $ 1,448 $ 3,567
Schedule of Notes Receivable	Notes receivables consist of the following (in thousands): September 30, 2023 December 31, 2022 Notes receivable 500 — Total Notes receivable $ 500 $ — On August 30, 2023, EryDel Italy, Inc., an indirect wholly owned subsidiary of the Company, entered into that certain promissory note, (the “Promissory Note”) with EryDel S.p.A. (“EryDel”), pursuant to which EryDel Italy, Inc. promised to make advances to EryDel of up to $ 1.0 million.
Schedule of Assets Held for Sale	Assets held for sale consist of the following (in thousands): September 30, 2023 December 31, 2022 Assets held for sale $ 82 $ — Total assets held for sale $ 82 $ —
Schedule of Property and Equipment, Net	Property and equipment, net consist of the following (in thousands): September 30, December 31, 2023 2022 Computer equipment $ 18 $ 18 Lab equipment — 415 Finance lease right of use assets — 124 Leasehold improvement — 21 Less: accumulated amortization and depreciation ( 13 ) ( 185 ) Property and equipment, net $ 5 $ 393
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, 2023 2022 Personnel expenses $ 1,366 $ 1,130 Professional fees 225 234 Research and development expenses 41 497 Current portion of operating lease liabilities 61 377 Current portion of finance lease liability — 76 Other 151 185 Total accrued expenses and other current liabilities $ 1,844 $ 2,499
Summary of Accrued Severance and Related Expenses	Below is the severance accrual activity included in the personnel expenses in the above table related to a cost reduction program during the period ended September 30, 2023 (in thousands): For the Nine Months 2023 Beginning accrued severance $ — Incurred during the period 770 Severance paid during the period ( 309 ) Ending accrued severance 461

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): September 30, 2023 December 31, 2022 Operating lease right of use asset, net $ 48 $ 291 Short-term operating lease liability 61 377 $ 61 $ 377 Finance lease right of use asset — 124 Finance lease accumulated amortization — ( 50 ) Total finance lease right of use asset, net $ — $ 74 Weighted average remaining lease term Operating leases 0.2 years 0.9 years Finance leases — 1.0 year Weighted average discount rate Operating leases 6.70 % 5.71 % Finance leases — % 4.45 % Year ended December 31, Operating Lease Operating Lease Year ended December 31, 2023 (excluding the nine months ended September 30, 2023) $ 62 $ 388 Total lease payments 62 388 Less: imputed interest ( 1 ) ( 11 ) Total remaining lease liability $ 61 $ 377

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Summary of Employee and Non-Employee Stock-Based Compensation Expense	The following table summarizes employee and non-employee stock-based compensation expense for the three and nine months ended September 30, 2023 and 2022 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, 2023 2022 2023 2022 General and administrative expense $ 945 $ 1,289 $ 3,014 $ 8,988 Research and development expense 386 ( 595 ) 1,120 5,998 Total stock-based compensation $ 1,331 $ 694 $ 4,134 $ 14,986
Service Based Stock Options
Summary of Stock Options Activity	Activity for service-based stock options under the Quince 2019 Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2022 3,319,711 $ 16.07 4.77 $ 65 Options granted 2,162,958 1.04 — — Options exercised ( 258,705 ) 0.42 — 240 Options cancelled / forfeited ( 1,915,786 ) 18.35 — — Balance at September 30, 2023 3,308,178 $ 6.15 8.15 $ 245 Options vested and expected to vest as of September 30, 2023 3,308,178 6.15 8.15 245 Options exercisable as of September 30, 2023 1,122,154 $ 13.46 6.56 $ 61
Service Based Stock Options | Novosteo
Summary of Stock Options Activity	Activity for service-based stock options under the 2019 Novosteo Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2022 503,105 $ 0.55 9.23 $ 44 Options granted — — — — Options exercised ( 3,027 ) 0.55 — 3 Options cancelled / forfeited ( 37,848 ) 0.55 — — Balance at September 30, 2023 462,230 $ 0.55 5.75 $ 263 Options vested and expected to vest as of September 30, 2023 462,230 0.55 5.75 263 Options exercisable as of September 30, 2023 219,190 0.55 4.58 125
Service Based Stock Options | 2022 Inducement Plan
Summary of Stock Options Activity	Activity for service-based stock options under the 2022 Inducement Plan is as follows: Number of Weighted Weighted Aggregate (In thousands) Balance at December 31, 2022 3,742,255 $ 2.98 9.39 $ — Options granted — — — — Options exercised — — — — Options cancelled / forfeited ( 43,500 ) 2.98 — — Balance at September 30, 2023 3,698,755 $ 2.98 5.52 $ — Options vested and expected to vest as of September 30, 2023 3,698,755 2.98 5.52 — Options exercisable as of September 30, 2023 1,673,844 2.98 4.11 —
Restricted Stock Units (RSUs)
Summary of Stock Options Activity	The following table summarizes activity under the Company’s RSUs from the Quince 2019 Plan and related information: Restricted Stock Units Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 30,876 $ 4.30 RSUs granted — — RSUs vested ( 8,713 ) 4.30 RSUs cancelled ( 19,188 ) 4.30 Unvested - September 30, 2023 2,975 $ 4.30
Restricted Stock Awards (RSAs)
Summary of Stock Options Activity	Restricted Stock Awards (“RSAs”) Restricted Stock Awards Outstanding Number of Shares Weighted Average Grant Date Fair Value Unvested - December 31, 2022 427,401 $ 3.30 RSAs granted — — RSAs vested ( 164,008 ) 3.30 RSAs cancelled ( 63,294 ) 3.30 Unvested - September 30, 2023 200,099 $ 3.30

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
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 period presented due to their anti-dilutive effect: September 30, 2023 2022 Stock options issued and outstanding 7,469,163 8,398,987 Restricted stock units 2,975 173,113 Restricted stock awards 200,099 466,750 Total 7,672,237 9,038,850

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2023
Business Combinations [Abstract]
Schedule of fair values of assets acquired and liabilities assumed	May 19, 2022 Identifiable assets acquired and liabilities assumed: Cash and cash equivalents $ 10,593 Prepaid expenses and other current assets 1,040 ROU asset 124 Property and equipment 279 Intangible assets 5,900 Accounts payable and accrued liabilities ( 1,726 ) Deferred tax liabilities ( 532 ) Net assets acquired $ 15,678 Goodwill $ 825
Schedule of Revenue and Net Loss of the Combined Entity	Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 Revenue $ — $ 262 Net loss ( 7,921 ) ( 47,057 )

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2023
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 our indefinite-lived intangible asset (in thousands): As of September 30, 2023 Unamortized intangible assets: In-process research and development $ 5,900 Impairment charge ( 5,900 ) Balance as of September 30, 2023 —

Organization - Additional Infor

Organization - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				9 Months Ended
	Oct. 20, 2023	Aug. 04, 2023	Jan. 27, 2023	Sep. 30, 2023	Dec. 31, 2022	May 09, 2022
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Entity incorporation date				2012-06
Accumulated deficit				$ (310,750)	$ (288,259)
Cash, cash equivalents, and short-term investments				83,200
Long term investments				$ 0	$ 3,578
Common stock, par value				$ 0.001	$ 0.001
Common stock, shares issued				36,343,632	36,136,480
Stock Agreement
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of issued and outstanding Common Stock			7.50%
Milestone payments			$ 150,000
Ery Del | Subsequent Event
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock, shares issued	6,525,315
Additional common stock shares issued	725,037
Aggregate potential cash payments under contigent rights	$ 485,000,000
Amount payable upon achievement of specified milestone	5,000,000
NDA acceptance under contigent consideration	25,000,000
Milestone achievement related to market and sales	395,000,000
Ery Del | Subsequent Event | Approval Milestones
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Milestone payment	$ 60,000,000
Restricted Stock Awards (RSAs)
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Unvested restricted shares				200,099	427,401
Accelerated vesting, number of options		54,757
Merger Agreement
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Automatically cancelled and converted common stock						0.0911
Common stock, par value						$ 0.001
Common stock, shares issued						5,520,000
Options outstanding assumed						507,108

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Realized gains or losses on the sale or maturity of available-for-sale securities	$ 0
Lab Equipment
Summary Of Significant Accounting Policies [Line Items]
Asset Held-for-Sale	100,000
Money market funds
Summary Of Significant Accounting Policies [Line Items]
Unrealized gains or loss	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	$ 82,416	$ 89,773
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	12,285	10,988
Certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	1,465	6,102
Repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		9,000
Corporate notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		12,411
Government and agency notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	68,666	50,766
Municipal notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		506
Level 1
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	12,285	10,988
Level 1 | Money market funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	12,285	10,988
Level 1 | Certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	0	0
Level 1 | Repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		0
Level 1 | Corporate notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		0
Level 1 | Government and agency notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	0	0
Level 1 | Municipal notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		0
Level 2
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	70,131	78,785
Level 2 | Money market funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	0	0
Level 2 | Certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	1,465	6,102
Level 2 | Repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		9,000
Level 2 | Corporate notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		12,411
Level 2 | Government and agency notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	68,666	50,766
Level 2 | Municipal notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		506
Level 3
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	0	0
Level 3 | Money market funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	0	0
Level 3 | Certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	0	0
Level 3 | Repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		0
Level 3 | Corporate notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		0
Level 3 | Government and agency notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	$ 0	0
Level 3 | Municipal notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 82,477	$ 90,330
Unrealized Gains	4	5
Unrealized Losses	(65)	(562)
Financial assets and liabilities	82,416	89,773
Cash equivalents (maturities within 90 days)	20,823	40,593
Short-term investments (maturities within one year)	61,593	45,602
Long-term investments (maturities beyond one year)	0	3,578
Total cash equivalents and investments	82,416	89,773
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	12,285	10,988
Unrealized Gains	0	0
Unrealized Losses	0	0
Financial assets and liabilities	12,285	10,988
Certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,480	6,237
Unrealized Gains	0	1
Unrealized Losses	(15)	(136)
Financial assets and liabilities	1,465	6,102
Repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		9,000
Unrealized Gains		0
Unrealized Losses		0
Financial assets and liabilities		9,000
Corporate notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		12,575
Unrealized Gains		0
Unrealized Losses		(164)
Financial assets and liabilities		12,411
Government and agency notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	68,712	51,020
Unrealized Gains	4	4
Unrealized Losses	(50)	(258)
Financial assets and liabilities	$ 68,666	50,766
Municipal notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		510
Unrealized Gains		0
Unrealized Losses		(4)
Financial assets and liabilities		$ 506

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Available-for-sale securities loss position for more than 120 days	$ 22,662,000		$ 22,662,000
Weighted average remaining contractual maturities of available-for-sale securities			3 months
Impairment charges	0	$ 0	$ 0	$ 0
Realized gains or losses recognized on the sale or maturity of available-for-sale securities	0		0
Fair value assets level 1 to level 2	0		0
Fair value assets level 2 to level 1	$ 0		0		$ 0
Fair value assets transfers into level 3			0
Fair value assets transfers out of level 3			$ 0

Fair Value Measurements - sum_2

Fair Value Measurements - summarizes the unrealized losses of the Company's investments in debt securities measure (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, Less than twelve months	$ 22,662
Gross unrealized loss, Less than twelve months	5
Fair value,Twelve months or greater	5,151
Gross unrealized loss, Twelve months or greater	60
Fair value, Total	27,813
Gross unrealized loss, total	65
Certificates of Deposit [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, Less than twelve months
Gross unrealized loss, Less than twelve months
Fair value,Twelve months or greater	1,465
Gross unrealized loss, Twelve months or greater	15
Fair value, Total	1,465
Gross unrealized loss, total	15
US Government Corporations and Agencies Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, Less than twelve months	22,662
Gross unrealized loss, Less than twelve months	5
Fair value,Twelve months or greater	3,686
Gross unrealized loss, Twelve months or greater	45
Fair value, Total	26,348
Gross unrealized loss, total	$ 50

Fair Value Measurements - sum_3

Fair Value Measurements - summarizes the contractual maturities of the Company's investments in debt securities measured at fair value (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Fair Value Disclosures [Abstract]
Total	$ 61,593
Less Than 1 Year	61,593
1-5 Years	0
6-10 Years	0
More Than 10 Years	$ 0

Cash, Cash Equivalents and In_3

Cash, Cash Equivalents and Investments - Summary of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	$ 21,632	$ 44,579
Short term investments	61,593	45,602
Long term investments	0	3,578
Fair Value on Recurring | Cash
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	809	3,986
Fair Value on Recurring | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	12,285	10,988
Fair Value on Recurring | Repurchase agreements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	0	9,000
Fair Value on Recurring | Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	1,465	5,390
Long term investments	0	712
Fair Value on Recurring | Municipal notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	0	506
Fair Value on Recurring | Corporate notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	0	12,411
Fair Value on Recurring | Government and agency notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	8,538	20,605
Short term investments	60,128	27,295
Long term investments	$ 0	$ 2,866

Cash, Cash Equivalents and In_4

Cash, Cash Equivalents and Investments - Additional Information (Details)	Sep. 30, 2023 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cumulative upward adjustments	$ 0
Cumulative impairments	0
Lighthouse Inc
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments without readily determinable fair values	$ 78,000

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 270	$ 223
Prepaid insurance	1,037	977
Prepaid research and development expenses	49	1,088
Australia research and development refundable tax credit	0	1,003
Other current assets	92	276
Total prepaid expenses and other current assets	$ 1,448	$ 3,567

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Aug. 04, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Aug. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Reductions in Research and Development Expense		$ 0	$ 100	$ 0	$ 500
Australia research and development refundable tax credit		0		0					$ 1,003
Prepaid expenses and other current assets		1,448		1,448					$ 3,567
Consignment Equipment		100		100
Cash severance payments	$ 475,000
Share based compensation accelerated vesting percentage	50%
Additional cash bonous severance percentage	100%
Total stock-based compensation	$ 140,000	1,331	$ 694	4,134	$ 14,986
Option [Member]
Restructuring Cost and Reserve [Line Items]
Accelerated vesting, number of options	612,141
Restricted Stock Awards (RSAs)
Restructuring Cost and Reserve [Line Items]
Accelerated vesting, number of options	54,757
Ery Del
Restructuring Cost and Reserve [Line Items]
Notes Payable to Related Party						$ 1,000
Promissory note aggregate principal amount		$ 500,000		$ 500,000
Promissory note interest rate		5.07%		5.07%
Promissrory note interest receivable		$ 1,300		$ 1,300
Novosteo
Restructuring Cost and Reserve [Line Items]
Australia research and development refundable tax credit								$ 500
Prepaid expenses and other current assets								$ 500
Cortexyme Australia [Member]
Restructuring Cost and Reserve [Line Items]
Australia research and development refundable tax credit							$ 500
Prepaid expenses and other current assets							$ 500

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Notes Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Notes Receivable Abstract
Notes receivable	$ 500	$ 0
Total Notes receivable	$ 500	$ 0

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Assets Held for Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Assets Held For Sale	$ 82	$ 0
Novosteo [Member]
Restructuring Cost and Reserve [Line Items]
Assets Held For Sale	$ 82	$ 0

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Less: accumulated amortization and depreciation	$ (13)	$ (185)
Property and equipment, net	5	393
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment	18	18
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment	0	415
Finance Lease Right of Use Assets
Property Plant And Equipment [Line Items]
Property and equipment	0	124
Leasehold Improvement
Property Plant And Equipment [Line Items]
Property and equipment	$ 0	$ 21

Balance Sheet Components - Sc_5

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Personnel expenses	$ 1,366	$ 1,130
Professional fees	225	234
Research and development expenses	41	497
Current portion of operating lease liabilities	61	377
Current portion of finance lease liability	0	76
Other	151	185
Total accrued expenses and other current liabilities	$ 1,844	$ 2,499

Balance Sheet Components - Summ

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

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)			3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Feb. 28, 2023
Lessee Lease Description [Line Items]
Operating lease liability			$ 61,000			$ 61,000		$ 377,000
Future rent expense						$ 48,000,000
Finance lease amortized period on equipment service						18 months
Amortization expense of the financing lease right of use asset						$ 6,000,000
Impairment charges			$ 0	$ 0		$ 0	$ 0
Finance Lease, Liability, Total									$ 70,000,000
Minimum
Lessee Lease Description [Line Items]
Operating lease remaining term on a straight-line basis						3 months
Maximum
Lessee Lease Description [Line Items]
Operating lease remaining term on a straight-line basis						2 months
South San Francisco, California
Lessee Lease Description [Line Items]
Operating lease payments					$ 271,000,000
Operating lease liability					256,000
Security deposit paid					$ 17,000,000
South San Francisco, California | Subsequent Event
Lessee Lease Description [Line Items]
Operating lease payments	$ 22,000,000
West Lafayette
Lessee Lease Description [Line Items]
Lease agreement period		15 months
Operating lease payments		$ 151,000,000
Operating lease liability		$ 145,000,000
Right-of-use assets obtained in exchange for new operating lease liabilities								$ 10,000,000
Impairment charges						$ 66,000,000
Loan proceeds used to offset rent expense, utility costs and mortgage interest expense						57,000,000
West Lafayette | Accrued Expenses And Other Current Liabilities [Member]
Lessee Lease Description [Line Items]
Security deposit paid						$ 6,000,000

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease right-of-use assets, net	$ 48	$ 291
Short-term operating lease liability	61	377
Operating lease liability	61	377
Finance lease right of use asset	$ 0	$ 124
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Finance lease accumulated amortization		$ (50)
Total finance lease right of use asset, net	$ 0	$ 74
Weighted average remaining lease term
Operating leases	2 months 12 days	10 months 24 days
Finance leases		1 year
Weighted average discount rate
Operating leases	6.70%	5.71%
Finance leases	0%	4.45%
Operating Lease, Liability, Payment, Due [Abstract]
2022 (excluding the nine months ended September 30, 2022)	$ 62	$ 388
Total lease payments	62	388
Less: imputed interest	(1)	(11)
Operating lease liability	$ 61	$ 377

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)		3 Months Ended		9 Months Ended
	Aug. 04, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Apr. 05, 2023	Dec. 31, 2022	May 19, 2022	May 09, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted	$ 140,000,000	$ 1,331,000	$ 694,000	$ 4,134,000	$ 14,986,000
Income tax benefits recognized				0
Unamortized employee stock-based compensation		$ 3,800,000		$ 3,800,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 4 months 13 days
Common stock, par value		$ 0.001		$ 0.001			$ 0.001
Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized employee stock-based compensation		$ 500,000		$ 500,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 5 months 23 days
Common stock, par value								$ 0.001
Warrant exercise price number of shares converted								$ 0.0911
Number of shares, Cancelled and converted								0.0911
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted		0	$ 0	$ 0	$ 2,044,000,000
Unamortized employee stock-based compensation		0		0			$ 0
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted		6,000,000		31,000,000
Unamortized employee stock-based compensation		11,000,000		$ 11,000,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				5 months 1 day
Total fair value of shares vested		6,400,000		$ 37,500,000
Aggregate intrinsic value		2,000,000		$ 9,900,000
Restricted Stock Units (RSUs) | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based awards vesting period				2 years
Restricted Stock Awards (RSAs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized employee stock-based compensation		600,000		$ 600,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				1 year 11 months 26 days
Restricted Stock Awards (RSAs) | Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Warrant exercise price number of shares converted								$ 0.0911
Employees And Non Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted		615,000		$ 1,993,000
Employees And Non Employees | Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted		96,000,000		226,000,000
Employees And Non Employees | Restricted Stock Awards (RSAs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted		$ 167,000,000		$ 415,000,000
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan		10,036,489		10,036,489
Increase in number of shares available for issuance as proportion of shares of common stock		2,146,354		2,146,354
Percentage of common stock outstanding				4%
Common stock reserved for issuance		4,964,784		4,964,784
2019 Plan | Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan								544,985
2019 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares available for issuance as proportion of shares of common stock		536,589		536,589
Percentage of common stock outstanding				1%
Common stock reserved for issuance		1,494,530		1,494,530
Maximum period for common stock shares reserved for future issuance				10 years
2019 ESPP | Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		143,022		143,022
2022 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares available for issuance as proportion of shares of common stock									4,000,000
Common stock reserved for issuance		301,245		301,245
Unamortized employee stock-based compensation		$ 3,500,000		$ 3,500,000
Unamortized employee stock-based compensation expected to recognized over remaining estimated vesting period				2 years 7 months 20 days
2022 Inducement Plan | Employees And Non Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted		$ 447,000,000		$ 1,469,000,000
Rights Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Rights outstanding, maturity date						Apr. 05, 2024
Rights Plan [Member] | Series A Preferred Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, par value						$ 0.001
Rights Plan [Member] | Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, par value						0.001
Rights Plan [Member] | Preferred Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, par value						$ 6

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Activity for Service-based Stock Options (Details) - Service Based Stock Options - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance	3,319,711
Number of Options and Unvested Shares, granted	2,162,958
Number of Options and Unvested Shares, exercised	(258,705)
Number of Options and Unvested Shares, cancelled / forfeited	(1,915,786)
Number of Options and Unvested Shares, ending balance	3,308,178	3,319,711
Number of Options and Unvested Shares, vested and expected to vest	3,308,178
Number of Options and Unvested Shares, exercisable	1,122,154
Weighted Average Exercise Price, beginning balance	$ 16.07
Weighted Average Exercise Price, granted	1.04
Weighted Average Exercise Price, exercised	0.42
Weighted Average Exercise Price, exercised, cancelled / forfeited	18.35
Weighted Average Exercise Price, ending balance	6.15	$ 16.07
Weighted Average Exercise Price, vested and expected to vest	6.15
Weighted Average Exercise Price, exercisable	$ 13.46
Weighted average remaining contractual life	8 years 1 month 24 days	4 years 9 months 7 days
Weighted average remaining contractual life, vested and expected to vest	8 years 1 month 24 days
Weighted average remaining contractual life, exercisable	6 years 6 months 21 days
Aggregate intrinsic value	$ 245	$ 65
Aggregate intrinsic value, exercised	240
Aggregate intrinsic value, vested and expected to vest	245
Aggregate intrinsic value, exercisable	$ 61
2022 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance	3,742,255
Number of Options and Unvested Shares, cancelled / forfeited	(43,500)
Number of Options and Unvested Shares, ending balance	3,698,755	3,742,255
Number of Options and Unvested Shares, vested and expected to vest	3,698,755
Number of Options and Unvested Shares, exercisable	1,673,844
Weighted Average Exercise Price, beginning balance	$ 2.98
Weighted Average Exercise Price, exercised, cancelled / forfeited	2.98
Weighted Average Exercise Price, ending balance	2.98	$ 2.98
Weighted Average Exercise Price, vested and expected to vest	2.98
Weighted Average Exercise Price, exercisable	$ 2.98
Weighted average remaining contractual life	5 years 6 months 7 days	9 years 4 months 20 days
Weighted average remaining contractual life, vested and expected to vest	5 years 6 months 7 days
Weighted average remaining contractual life, exercisable	4 years 1 month 9 days
Novosteo
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance	503,105
Number of Options and Unvested Shares, exercised	(3,027)
Number of Options and Unvested Shares, cancelled / forfeited	(37,848)
Number of Options and Unvested Shares, ending balance	462,230	503,105
Number of Options and Unvested Shares, vested and expected to vest	462,230
Number of Options and Unvested Shares, exercisable	219,190
Weighted Average Exercise Price, beginning balance	$ 0.55
Weighted Average Exercise Price, exercised	0.55
Weighted Average Exercise Price, exercised, cancelled / forfeited	0.55
Weighted Average Exercise Price, ending balance	0.55	$ 0.55
Weighted Average Exercise Price, vested and expected to vest	0.55
Weighted Average Exercise Price, exercisable	$ 0.55
Weighted average remaining contractual life	5 years 9 months	9 years 2 months 23 days
Weighted average remaining contractual life, vested and expected to vest	5 years 9 months
Weighted average remaining contractual life, exercisable	4 years 6 months 29 days
Aggregate intrinsic value	$ 263	$ 44
Aggregate intrinsic value, exercised	3
Aggregate intrinsic value, vested and expected to vest	263
Aggregate intrinsic value, exercisable	$ 125

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Options (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Outstanding, Number of Shares, Unvested, Beginning Balance | shares	30,876
Number of Shares, vested | shares	(8,713)
Number of Shares, Cancelled | shares	(19,188)
Outstanding, Number of Shares, Unvested, Ending Balance | shares	2,975
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Beginning Balance | $ / shares	$ 4.3
Weighted-Average Grant Date Fair Value, vested | $ / shares	4.3
Weighted-Average Grant Date Fair Value, cancelled | $ / shares	4.3
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Ending Balance | $ / shares	$ 4.3
Restricted Stock Awards (RSAs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Outstanding, Number of Shares, Unvested, Beginning Balance | shares	427,401
Number of Shares, vested | shares	(164,008)
Number of Shares, Cancelled | shares	(63,294)
Outstanding, Number of Shares, Unvested, Ending Balance | shares	200,099
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Beginning Balance | $ / shares	$ 3.3
Weighted-Average Grant Date Fair Value, vested | $ / shares	3.3
Weighted-Average Grant Date Fair Value, cancelled | $ / shares	3.3
Outstanding, Weighted-Average Grant Date Fair Value, Unvested, Ending Balance | $ / shares	$ 3.3

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Employee and Non-Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Aug. 04, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 140,000	$ 1,331	$ 694	$ 4,134	$ 14,986
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation		945	1,289	3,014	8,988
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation		$ 386	$ (595)	$ 1,120	$ 5,998

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - Morphimmune Inc. $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Related Party Transaction [Line Items]
Operating lease payments	$ 57,000
Lab Equipment
Related Party Transaction [Line Items]
Proceeds from sale of property, plant, and equipment	$ 80,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2023	Sep. 30, 2023
In Process Research and Development [Member]
Income Taxes [Line Items]
Net discrete tax adjustments	$ 0.2	$ 0.2

Net Loss Per Share - Schedule o

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, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	7,672,237	9,038,850
Stock Options Issued and Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	7,469,163	8,398,987
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	2,975	173,113
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	200,099	466,750

Business Combination - Addition

Business Combination - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	May 19, 2022	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Common stock, par value				$ 0.001	$ 0.001
Net loss		$ (7,921)	$ (47,057)
Revenue		0	262
Novosteo [Member]
Business Acquisition [Line Items]
Number of shares, Cancelled and converted	0.0911
Common stock, par value	$ 0.001
Aggregate purchase of common stock shares	507,108
Unvested restricted shares	519,216
Business acquisition, transaction costs	$ 1,100
Payment to acquire business	$ 16,502,587
Shares issued for acquisition	5,000,784
Net loss		2,700	5,200
Revenue		$ 0	$ 0
Share price	$ 3.3

Business Combination - Schedule

Business Combination - Schedule of fair values of assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	May 19, 2022
Business Combinations [Abstract]
Cash and cash equivalents			$ 10,593
Prepaid expenses and other current assets			1,040
ROU asset			124
Property and equipment			279
In-process research and development	$ 5,900		5,900
Accounts payable and accrued liabilities			(1,726)
Deferred tax liabilities			(532)
Net assets acquired			15,678
Goodwill	$ 0	$ 0	$ 825

Business Combination - Schedu_2

Business Combination - Schedule of Revenue and Net Loss of the Combined Entity (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Business Acquisition, Pro Forma Information [Abstract]
Revenue	$ 0	$ 262
Net loss	$ (7,921)	$ (47,057)

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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	May 19, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
In-process research and development	$ 5,900		$ 5,900		$ 5,900
Impairment charge	0	$ 0	(5,900)	$ 0
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 0		$ 0

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	May 19, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill		$ 0		$ 0	$ 825
Non-cash goodwill impairment charge	$ 5,900	$ 0	$ 825	$ 800

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands	Oct. 20, 2023	Oct. 24, 2023	Oct. 17, 2023	Sep. 30, 2023	Dec. 31, 2022
Subsequent Event [Line Items]
Common stock, shares issued				36,343,632	36,136,480
Common stock, shares issued value	$ 6,500			$ 36	$ 36
Ery Del [Member]
Subsequent Event [Line Items]
Outstanding principal and accrued interest due under promisory note		$ 1,000
Subsequent Event [Member] | Ery Del [Member]
Subsequent Event [Line Items]
Common stock, shares issued	6,525,315
Percentage of common stock share outstanding owned	15.20%
Additional common stock shares issued	725,037
Amount payable upon achievement of specified milestone	$ 5,000,000
Aggregate potential cash payments under contigent rights	485,000,000
NDA acceptance under contigent consideration	25,000,000
Milestone achievement related to market and sales	395,000,000
Amount disbursed to EryDel	$ 10,600
Interest rate during the period	9%
Interest rate period	60 days
Promissory note aggregate principal amount			$ 500,000
Promissory note interest rate			5.22%
Subsequent Event [Member] | Ery Del [Member] | Approval Milestones [Member]
Subsequent Event [Line Items]
Milestone payment	$ 60,000,000
Subsequent Event [Member] | Ery Del [Member] | EIB Facility [Member]
Subsequent Event [Line Items]
Unsecured credit facility	$ 31,800