SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One)☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the fiscal year ended December 31, 2025OR☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the transition period fromtoCommission File Number 001-38890 Quince Therapeutics, Inc.(Exact name of registrant as specified in its charter) Securities registered pursuant to Section 12(b) of the Act: Securities registered pursuant to Section 12(g) of the Act:None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YES☐NO☒ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. YES☐NO☒ Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during thepreceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past90 days. YES☒NO☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of RegulationS-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). YES☒NO☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerginggrowth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2of the Exchange Act. Large accelerated filer☐Non-accelerated filer☒Emerging growth company☐ Accelerated filer☐Smaller reporting company☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revisedfinancial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal controlover financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issuedits audit report.☐ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflectthe correction of an error to previously issued financial statements.☐Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YES☐NO☒ The aggregate market value of the common stock held by non-affiliates of the registrant as of June 30, 2025 (the last business day of the registrant’s most recentlycompleted second fiscal quarter) was approximately $64.0 million, based on the closing price of the registrant’s common stock, as reported by the Nasdaq GlobalSelect Market on June 30, 2025 of $1.65 per share. As of April 9, 2026, the registrant had 163,007,943 shares of common stock, $0.001 par value per share, outstanding.DOCUMENTS INCORPORATED BY REFERENCE Part III incorporates by reference certain information from the registrant’s definitive proxy statement (the “Proxy Statement”) relating to its 2026 Annual Meeting ofStockholders. The Proxy Statement will be filed with the United States Securities and Exchange Commission within 120 days after the end of the fiscal year towhich this report relates. Table of Contents PART I Item 1.BusinessItem 1A.Risk FactorsItem 1B.Unresolved Staff CommentsItem 1C.CybersecurityItem 2.PropertiesItem 3.Legal ProceedingsItem 4.Mine Safety Disclosures PART II Item 5.Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of EquitySecurities45Item 6.Reserved45Item 7.Management’s Discussion and Analysis of Financial Condition and Results of Operations46Item 7A.Quantitative and Qualitative Disclosures About Market Risk57Item 8.Financial Statements and Supplementary Data58Item 9.Changes in and Disagreements With Accountants on Accounting and Financial Disclosure95Item 9A.Controls and Procedures95Item 9B.Other Information96Item 9C.Disclosure Regarding Foreign Jurisdictions that Prevent Inspections96 PART III Item 10.Directors, Executive Officers and Corporate Governance97Item 11.Executive Compensation97Item 12.Security Ownership of Certain Beneficial Owners a