TransCode Therapeutics, Inc.

Item 3.03 Material Modification to Rights of Securityholders. To the extent required by Item 3.03 of Form 8-K, the information contained in Item 5.03 of this Current Report on Form 8-K is incorporated by reference into this Item 3.03.

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. Amendment and Restatement of Certificate of Designation As previously disclosed, on March 2, 2026, TransCode Therapeutics, Inc. (the “Company”) filed a Certificate of Designation of Preferences, Rights and Limitations of Series C Non-Voting Convertible Preferred Stock (the “Prior Certificate”) with the Secretary of State of the State of Delaware in connection with the Exclusive Licensing Agreement dated as of March 2, 2026, (the “Licensing Agreement”) by and between the Company and Unleash Immuno Oncolytics, Inc., a Delaware corporation (“Unleash”), and that certain Equity Issuance and Registration Rights Agreement dated as of March 2, 2026, (the “Unleash Registration Rights Agreement”) by and between the Company and Unleash. On July 16, 2026, upon obtaining the consent of a majority of the holders of the Company’s Series C Non-Voting Convertible Preferred Stock, par value $0.0001 per share (“Series C Preferred Stock”), and the approval of the Company’s Board of Directors, the Company filed an Amended and Restated Certificate of Designation of Preferences, Rights and Limitations of Series C Non-Voting Convertible Preferred Stock (the “Amended and Restated Certificate of Designation”) with the Secretary of State of the State of Delaware. The Amended and Restated Certificate of Designation amended Section 6.3.3 of the Prior Certificate to increase the beneficial ownership limitation applicable to holders of Series C Preferred Stock from 4.99% to 9.99%. In addition, the Amended and Restated Certificate of Designation includes certain non-substantive revisions to the Prior Certificate consisting solely of corrections to scrivener’s errors. The Amended and Restated Certificate of Designation effected no other changes to the Prior Certificate other than the foregoing, and no additional securities were issued or sold in connection with the filing. The foregoing description of the Amended and Restated Certificate of Designation does not purport to be complete and is qualified in its entirety by reference to the full text of the Amended and Restated Certificate of Designation, a copy of which is filed as Exhibit 3.1 to this Current Report on Form 8-K and is incorporated herein by reference.