Ninth Amendment to License Agreement, dated March 17, 2023, between Prime Medicine, Inc. and MIL 21E, LLC

This Nineth Amendment to License Agreement (“Nineth Amendment”) is dated March 17, 2023 (“Effective Date”) and entered into by and between Prime Medicine, Inc. (“Licensee”) and MIL 21E, LLC (“Licensor”).

WHEREAS, Licensor and Licensee are parties to a certain License Agreement dated March 16, 2020, as amended by that certain First Amendment to License Agreement dated August 17, 2020, as amended by that certain Second Amendment to License Agreement dated October 21, 2020, as amended by that certain Third Amendment to License Agreement dated May 24, 2021, as amended by that certain Fourth Amendment to License Agreement dated July 27, 2021, as amended by that certain Fifth Amendment to License Agreement dated December 20, 2021, as amended by that certain Sixth Amendment to License Agreement dated April 5, 2022, as amended by that certain Seventh Amendment to License Agreement dated May 27, 2022, as amended by that certain Eighth Amendment dated June 21, 2022 (collectively “License Agreement”);

WHEREAS, Licensee warrants and represents that, to the best of its knowledge, Licensor has fulfilled its obligations under the License Agreement and is not in default of any covenants or obligations contained in the License Agreement;

WHEREAS, Licensor and Licensee desire to amend the License Agreement in certain respects as set forth herein; and,

WHEREAS, all capitalized terms contained herein shall, unless otherwise defined in this Nineth Amendment, have the same meaning as set forth in the License Agreement.

NOW THEREFORE, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties agree that the License Agreement agree as follows:

The parties acknowledge and agree to extend the Lab Bench Expiration Date such that it shall now be defined as December 14, 2023.

For the avoidance of doubt Licensee shall pay Licensor the Lab Bench Premises Fee, in addition to all other fees due pursuant to the License Agreement, through the Lab Bench Expiration Date as defined in this Nineth Amendment, all as shown on Schedule A attached hereto.

IN WITNESS WHEREOF, Licensor and Licensee have duly executed this Nineth Amendment as of the Effective Date.