Cartesian Therapeutics, Inc.

SPECIAL MEETING OF STOCKHOLDERS

To Be Held on March 27, 2024

INFORMATION CONCERNING SOLICITATION AND VOTING

This proxy statement contains information about the special meeting of stockholders of Cartesian Therapeutics, Inc. (the “Special Meeting”), which will be held on March 27, 2024 at 9:00 a.m., Eastern Time by virtual meeting online at www.virtualshareholdermeeting.com/RNAC2024SM for the following purposes. The board of directors of Cartesian Therapeutics, Inc. (the “Board of Directors”) is using this proxy statement to solicit proxies for use at the Special Meeting. In this proxy statement, the terms “Cartesian,” “the Company,” “we,” “us,” and “our” refer to Cartesian Therapeutics, Inc. (the “Company”). The mailing address of our principal executive offices is Cartesian Therapeutics, Inc., 704 Quince Orchard Road, Gaithersburg, MD 20878.

All properly submitted proxies will be voted in accordance with the instructions contained in those proxies. If no instructions are specified, the proxies will be voted in accordance with the recommendation of our Board of Directors with respect to each of the matters set forth in the accompanying Notice of Special Meeting of Stockholders (“Notice of Meeting”). You may revoke your proxy at any time before it is exercised at the meeting by giving our corporate secretary written notice to that effect.

At the Special Meeting, our stockholders will be asked to approve:

After careful consideration, the Board of Directors has approved the proposals referred to above, and has determined that they are advisable, fair and in the best interests of Cartesian’s stockholders. Accordingly, the Board of Directors recommends that stockholders vote “FOR” each of the proposals set forth above.

Your vote is important. Whether or not you attend the Special Meeting, it is important that your shares be represented and voted at the Special Meeting. Therefore, you are urged to promptly vote and submit your proxy by phone, via the Internet, or, if you received paper copies of these materials, by signing, dating and returning the enclosed proxy card in the enclosed envelope, which requires no postage if mailed in the United States. If you have previously received our Notice of Internet Availability of Proxy Materials (the “Internet Notice”), then instructions regarding how you can vote are contained in that notice. If you have received a proxy card, then instructions regarding how you can vote are contained on the proxy card. If you decide to attend the virtual Special Meeting, you will be able to vote your shares electronically, even if you have previously submitted your proxy.

This proxy statement is dated February 14, 2024 and is first being mailed to stockholders on or about February 14, 2024.