Exhibit 99.1 Cartesian Therapeutics Reports Full Year 2023 Financial Results and Provides Business Update Topline data from Phase 2b study of Descartes-08, the Company’s potential first-in-class mRNA CAR- T cell therapy, in myasthenia gravis (MG) remains on track for mid-2024 On track to initiate Phase 2 study of Descartes-08 in systemic lupus erythematosus (SLE) in 1H24 as well as Phase 2 basket studies in additional autoimmune indications in 2H24 Following recent IND clearance, planning underway for first ...