Cartesian Therapeutics Inc

On December 23, 2024, Christopher Jewell, our Chief Scientific Officer, adopted a trading plan intended to satisfy the conditions under Rule 10b5-1(c) of the Exchange Act. Dr. Jewell’s plan provides for the exercise of vested stock options and the potential associated sale of up to 15,000 shares of our common stock until and including December 31, 2025. The foregoing exercises or sales, if any, will be made in accordance with the prices and formulas set forth in the plan and such plan terminates on the earlier of the date all the shares under the plan are sold and December 31, 2025.

During the fiscal quarter ended December 31, 2024, no other officer or director, as defined in Rule 16a-1(f) of the Exchange Act, informed us of theadoption, modification ortermination of any “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement,” as those terms are defined in Item 408 of Regulation S-K .