EX-32.1 5 exhibit321_3312026.htm EX-32.1
Exhibit 32.1
CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
In connection with the Quarterly Report on Form 10-Q of Cartesian Therapeutics, Inc. (the “Company”) for the period ended March 31, 2026 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), each of the undersigned officers of the Company hereby certifies, pursuant to 18 U.S.C. Section 1350, that to his knowledge:
1. The Quarterly Report on Form 10-Q of the Company for the period ended March 31, 2026 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and
2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

April 30, 2026 |  | /s/ Carsten Brunn, Ph.D.
|  | Carsten Brunn, Ph.D.
|  | President, Chief Executive Officer and Chairman of the Board
|  | (Principal Executive Officer)

April 30, 2026 |  | /s/ Blaine Davis
|  | Blaine Davis
|  | Chief Financial Officer
|  | (Principal Financial Officer)