FORM 10-Q QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIESEXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIESEXCHANGE ACT OF 1934 For the transition period from ___________ to___________Commission File Number 000-14656 REPLIGEN CORPORATION (Exact Name of Registrant as Specified in its Charter) 04-2729386(I.R.S. EmployerIdentification No.) Delaware(State or Other Jurisdiction ofIncorporation or Organization) 41 Seyon Street, Bldg. 1, Suite 100Waltham, MA(Address of Principal Executive Offices) 02453(Zip Code) (781) 250-0111Registrant’s Telephone Number, Including Area Code Securities registered pursuant to Section 12(b) of the Act: Common Stock, par value $0.01 per share RGEN Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15 (d) of the SecuritiesExchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file suchreports), and (2) has been subject to such filing requirements for the past 90 days.YesNo Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period thatthe registrant was required to submit such files).YesNo Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smallerreporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smallerreporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.: Large accelerated filerNon-accelerated filerEmerging growth company Accelerated filerSmaller reporting company If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act.):Yes☐No☒ The number of shares outstanding of the registrant’s common stock on May 1, 2026 was 56,407,740. Table of Contents PAGEPART I.FINANCIAL INFORMATION3Item 1.Financial Statements3Condensed Consolidated Balance Sheets as of March 31, 2026 and December 31, 2025 (Unaudited)3Condensed Consolidated Statements of Comprehensive (Loss) Income for the Three Months EndedMarch 31, 2026 and 2025 (Unaudited)4Condensed Consolidated Statements of Stockholders’ Equity for the Three Months Ended March 31,2026 and 2025 (Unaudited)5Condensed Consolidated Statements of Cash Flows for the Three Months Ended March 31, 2026 and2025 (Unaudited)6Notes to Unaudited Condensed Consolidated Financial Statements7Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations18Item 3.Quantitative and Qualitative Disclosures About Market Risk25Item 4.Controls and Procedures25PART II. OTHER INFORMATION26Item 1.Legal Proceedings26Item 1A.Risk Factors26Item 2.Unregistered Sales of Equity Securities and Use of Proceeds26Item 3.Defaults Upon Senior Securities26Item 4.Mine Safety Disclosures26Item 5.Other Information26Item 6.Exhibits27Signatures28 The accompanying notes are an integral part of these condensed consolidated financial statements. REPLIGEN CORPORATIONCONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME(Unaudited, amounts in thousands, except per share data) The accompanying notes are an integral part of these condensed consolidated financial statements. REPLIGEN CORPORATIONCONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY(Unaudited, amounts in thousands, except share data) The accompanying notes are an integral part of these condensed consolidated financial statements. REPLIGEN CORPORATIONCONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS(Unaudited, amounts in thousands) REPLIGEN CORPORATIONNOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS(Unaudited) 1.Summary of Significant Accounting Policies Basis of Presentation The condensed consolidated financial statements included herein have been prepared by Repligen Corporation (the “Company”,“Repligen”, “our” or “we”) in accordance with generally accepted accounting principles in the United States (“GAAP”) andpursuant to the rules and regulations of the United States (“U.S.”) Securities and Exchange Commission (“SEC”). Certaininformation and note disclosures normally included in the audited financial statements prepared in accordance with GAAP havebeen condensed or omitted pursuant to such rules and regulations. The information included within this Quarterly Report on Form10-Q should be read in conjunction with the audited consolidated financial statements and accomp