Passage BIO, Inc.

proxy statement of Passage Bio that will constitute a prospectus with respect to shares of Passage Bio stock to be issued in the proposed transaction (the “Proxy Statement/Prospec tus ”). Passage Bio may also file other documents with the SEC regarding the proposed transaction. This document is not a substitute for the Proxy Statement/Prospectus or any other document which Passag e B io may file with the SEC. INVESTORS AND SECURITYHOLDERS OF PASSAGE BIO AND REMIX ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT WILL BE FILED BY PASSAGE BI O WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PRO POS ED TRANSACTION AND RELATED MATTERS. Passage Bio and Remix stockholders will also be able to obtain free copies of the Proxy Statement/Prospectus (when available) and oth er documents containing important information about Passage Bio, Remix and the proposed transaction that will be filed with the SEC by Passage Bio through the website maintained by the SEC at www.sec.gov . Copies of the documents filed with the SEC by Passage Bio will also be available free of charge on Passage Bio’s website at www.passagebio.com or by contacting Passage Bio’s investor relations department by email at investors@passagebio.com. No Offer or Solicitation This presentation does not constitute an offer to sell or the solicitation of an offer to buy any securities nor a solicitati on of any vote or approval with respect to the proposed transaction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as a men ded, and otherwise in accordance with applicable law. Participants in the Solicitation Passage Bio, Remix and their respective directors and executive officers may be deemed to be “participants” (as defined in Se cti on 14(a) of the Securities Exchange Act of 1934) in the solicitation of proxies from Passage Bio’s stockholders in connection with the proposed transaction. Information regarding the persons who may, under SE C rules, be deemed participants in the solicitation of proxies from Passage Bio’s stockholders in connection with the proposed transaction will be set forth in the Proxy Statement/Prospectus on Form S - 4 f or the proposed transaction, which is expected to be filed with the SEC by Passage Bio. Information regarding Passage Bio’s directors and executive officers is also available in Passage Bio’s most rec ent Annual Report on Form 10 - K and in its definitive proxy statement for its 2026