Repligen Corp美股招股说明书(2026-09-04版)

MERGER PROPOSAL—YOUR VOTE IS VERY IMPORTANT Dear BioLife Solutions, Inc. Stockholder: On July21, 2026, BioLife Solutions, Inc., a Delaware corporation (“BioLife” or the “Company”), entered into an Agreement and Plan of Merger(the “Merger Agreement”) by and among, BioLife, Repligen Corporation, a Delaware corporation (“Repligen”), Bravo Merger Sub I, Inc., a Delawarecorporation and wholly owned subsidiary of Repligen (“Merger Sub I”) and Bravo Merger Sub II, LLC, a Delaware limited liability company andwholly owned subsidiary of Repligen (“Merger Sub II”). Pursuant to the Merger Agreement, and subject to the satisfaction or waiver of the conditionsspecified therein, Merger Sub I will be merged with and into BioLife (the “First Merger”), with BioLife surviving the First Merger as a direct, whollyowned subsidiary of Repligen (the “Surviving Company”), and immediately following the First Merger, the Surviving Company will be merged withand into Merger Sub II (the “Second Merger,” and, together with the First Merger, the “Mergers”), with Merger Sub II surviving the Second Merger as adirect, wholly owned subsidiary of Repligen. If the Mergers are completed, each share of BioLife’s common stock, par value $0.001 per share (“BioLife Common Stock”), issued andoutstanding immediately prior to the time at which the First Merger becomes effective upon filing of the certificate of merger with respect to the FirstMerger (other than the shares of BioLife Common Stock that are held by BioLife in treasury or owned by Repligen, Merger Sub I or Merger Sub II, andshares of BioLife Common Stock with respect to which appraisal rights have been properly exercised and perfected, and have not been withdrawn, inaccordance with Delaware law) shall be converted automatically into the right to receive (A) 0.1442 validly issued, fully paid and nonassessable sharesof common stock, par value $0.01 per share, of Repligen (“Repligen Common Stock”) (such shares of Repligen Common Stock, the “StockConsideration”) and (B) $11.25 in cash, without interest (the “Cash Consideration” and together with the Stock Consideration, the “MergerConsideration”). No fractional shares of Repligen Common Stock will be issued in the Mergers, and stockholders of BioLife will receive cash in lieu ofany fractional shares as part of the Merger Consideration, as specified in the Merger Agreement. At the special meeting of BioLife’s stockholders to be held virtually on October5, 2026 (the “BioLife Special Meeting”), BioLife’s stockholderswill be asked to vote on (i)a proposal to adopt the Merger Agreement (the “Merger Proposal”), (ii) a proposal to approve, on a non-binding, advisorybasis, the compensation that may be paid or become payable to certain named executive officers of BioLife in connection with the Mergers (the“Compensation Proposal”), and (iii)a proposal to approve the adjournment from time to time of the BioLife Special Meeting, if necessary, to solicitadditional proxies if there are not sufficient votes to approve the Merger Proposal (the “Adjournment Proposal”). Only holders of record of BioLife Common Stock on September3, 2026 (including shares of BioLife Common Stock held through a bank, brokeror other nominee that is a stockholder of record of BioLife) are entitled to attend and vote at the BioLife Special Meeting, or any adjournment orpostponement thereof. Your vote is very important, regardless of the number of shares of BioLife Common Stock you own. BioLife cannot complete the Mergersunless the BioLife stockholders approve the Merger Proposal. Whether or not you expect to attend the BioLife Special Meeting, please voteyour shares of BioLife Common Stock as promptly as possible by (1)accessing the internet website specified on your proxy card, (2)calling thetoll-free number specified on your proxy card, or (3)signing and returning all proxy cards that you receive in the postage-paid envelopeprovided, so that your shares of BioLife Common Stock may be represented and voted at the BioLife Special Meeting. If your shares of BioLifeCommon Stock are held in “street name” by a bank, broker or other nominee, please follow the instructions on the voting instruction formprovided by the record holder. If you are a BioLife stockholder, please note that a failure to vote your shares of BioLife Common Stock mayresult in a failure to establish a quorum for the BioLife Special Meeting. Table of Contents BioLife’s board of directors (the “BioLife Board”), with Mr.Tony Hunt recused and not participating in the deliberations or vote for thereasons described in the section of this proxy statement/prospectus entitled “The Mergers—Recommendation of the BioLife Board of Directors;BioLife’s Reasons for the Merger,” beginning on page59, has unanimously among the remaining directors participating in the meeting(i)determined that the Merger Agreement and the transactions contemplated thereby, including the Mergers, are fair to, and in the bestinterests of, BioLife