Material Agreement (Form 8-K)

On September 30, 2025, TransCode Therapeutics, Inc. (the "Company") and The General Hospital Corporation d/b/a Massachusetts General Hospital (the "Licensor") entered into the Second Amendment to Exclusive Patent License Agreement (the "Second Amendment") to that certain Exclusive Patent License Agreement, dated October 26, 2018, and amended by the First Amendment to Exclusive Patent License Agreement, dated October 30, 2020, (as so amended, the "MGH License"). Pursuant to the Second Amendment, effective August 15, 2025, the timelines for the pre-sales requirements for Patent Family 1 (as defined in the MGH License) were updated, and the requirements and timelines for the pre-sales requirements for Patent Family 2 (as defined in the MGH License) were updated. In addition, the aggregate dollar amount of one-time milestone payments the Company shall pay the Licensor upon certain milestones was increased from $1,550,000 to $2,950,000 for each patent family; and the individual amounts for therapeutic product- or processes-related milestone payments were updated.

The foregoing description of the Second Amendment does not purport to be complete and is subject to, and qualified in its entirety by reference to, the complete text of the Second Amendment, which will be filed with the Securities and Exchange Commission as an exhibit to the Company's Quarterly Report on Form 10-Q for the quarter ended September 30, 2025.