Pipeline and Clinical Trials - Cartesian Therapeutics is pioneering mRNA cell therapies for autoimmunity, with multiple anticipated near-term catalysts[5] - Phase 3 AURORA study of Descartes-08 for Myasthenia Gravis (MG) is expected to commence in 1H25[8] - An open-label Phase 2 trial of Descartes-08 in Systemic Lupus Erythematosus (SLE) is ongoing, with data readout expected in 2H25[8] - A Phase 2 pediatric basket trial, including juvenile SLE, juvenile MG, and other conditions, is expected to initiate in 2H25[8, 12] - Dosing is underway in a first-in-human Phase 1 dose escalation trial for Descartes-15, a next-generation mRNA CAR-T candidate[8] Descartes-08 Efficacy and Safety - In a Phase 2b trial, participants treated with Descartes-08 maintained deep and durable responses over 12 months[16] - At Month 4, participants in the primary efficacy dataset experienced an average MG-ADL reduction of 5.5 points[23] - 33% of participants achieved minimum symptom expression at Month 6[23] - 80% of participants reaching Month 12 maintained a clinically meaningful response[23] - In participants with no prior exposure to biologics, the average MG-ADL reduction was 6.6 points at Month 4[26] - 57% of participants with no prior exposure to biologics achieved minimum symptom expression at Month 6[26] - 100% of participants with no prior exposure to biologics reaching Month 12 maintained a clinically meaningful response[26] - The safety profile of Descartes-08 supports outpatient administration, with no new types of adverse events reported[16, 28] Financial Position - Cartesian Therapeutics has a strong balance sheet with approximately $220.9 million as of September 30, 2024[9] - This is expected to support planned operations, including completion of the planned Phase 3 trial of Descartes-08 for MG, into mid-2027[9]

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q þ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _______ to _______ Commission File Number: 001-37798 For the quarterly period ended March 31, 2025 Cartesian Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 26-1622110 (I.R.S. Empl ...

Exhibit 99.1 Cartesian Therapeutics Reports First Quarter 2025 Financial Results and Provides Business Update Initiation of Phase 3 AURORA trial of Descartes-08 in myasthenia gravis expected in 2Q25; deep and sustained benefits observed through Month 12 after a single course of therapy in Phase 2b trial Preliminary data from Phase 2 trial of Descartes-08 in systemic lupus erythematosus expected in 2H25 Initiation of Phase 2 pediatric basket trial of Descartes-08 in select autoimmune indications expected in ...