Passage BIO, Inc. 10-Q

Item 5. Other Information. 10b5-1 Trading Plans During the three months ended June 30, 2026, none of our directors or officers, as defined in Rule 16a-1(f), informed us of the adoption , modification or termination of a “Rule 10b5-1 trading agreement” or “non-Rule 10b5-1 trading agreement,” as those terms are defined in Regulation S-K, Item 408. 46 Table of Contents Item 6. Exhibits. The exhibits filed or furnished as part of this Quarterly Report on Form 10-Q are set forth on the Exhibit Index below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exhibit Number ​ ​ Description ​ ​ ​ Form ​ ​ ​ ​ File No. ​ ​ ​ Exhibit Filing Date ​ ​ ​ Filed/Furnished Herewith ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2.1 ˄ ​ Agreement and Plan of Merger and Reorganization among Passage Bio, Inc., Merger Sub, Inc. and Remix Therapeutics, Inc., dated as of June 24, 2026. ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4.1 ​ Form of Contingent Value Rights Agreement ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10.1 ​ Form of Support Agreement by and between Passage Bio, Inc. and certain stockholders of Remix Therapeutics, Inc. ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10.2 ​ Form of Support Agreement by and between Remix Therapeutics, Inc. and certain stockholders of Passage Bio, Inc. ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10.3 ​ Form of Lock-Up Agreement. ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10.4 ​ Form of Subscription Agreement among Remix Therapeutics, Inc. and the purchasers signatory thereto. ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10.5 ​ Form of Registration Rights Agreement among Remix Therapeutics, Inc., Passage Bio, Inc. and the purchasers signatory thereto. ​ 8-K ​ 001-39231 ​ June 24, 2026 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 31.1 ​ Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 31.2 ​ Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 32.1* ​ Certification of Principal Executive Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 32.2* ​ Certification of Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 47 Table of Contents 101.INS ​ Inline XBRL Instance Document ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 101.SCH ​ Inline XBRL Taxonomy Extension Schema Document ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 101.CAL ​ Inline XBRL Taxonomy Extension Calculation Linkbase Document ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 101.DEF ​ Inline XBRL Taxonomy Extension Definition Linkbase Document ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 101.LAB ​ Inline XBRL Taxonomy Extension Label Linkbase Document ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 101.PRE ​ Inline XBRL Taxonomy Extension Presentation Linkbase Document ​ ​ ​ ​ ​ ​ ​ X ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 104 ​ Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101) ​ ​ ​ ​ ​ ​ ​ X ​ ad ​ ​ ​ ​ ​ ​ * ​ This certification is deemed not filed for purposes of Section 18 of the Exchange Act or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act. ​ ˄ ​ The annexes, schedules and/or certain exhibits to this agreement have been omitted pursuant to Item 601(b)(2) or Item 601(a)(5) of Regulation S-K. ​ ​ ​ 48 Table of Contents SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. ​ ​ ​ ​ ​ ​ PASSAGE BIO, INC. ​ ​ ​ ​ Date: August 10, 2026 ​ By: /s/ William Chou, M.D. ​ ​ ​ William Chou, M.D. ​ ​ ​ President and Chief Executive Officer ​ ​ ​ ​ ​ ​ Date: August 10, 2026 ​ By: /s/ Kathleen Borthwick ​ ​ ​ Kathleen Borthwick ​ ​ ​ Chief Financial Officer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 49