Investigating an mRNA CAR T-cell Therapy, Known as Descartes-08, as a Potential Approach to Treat Myasthenia Gravis

Inclusion Criteria: * Patient must be at least 18 years of age. * Patient must have generalized myasthenia gravis (gMG), Myasthenia Gravis Foundation of America (MGFA) clinical classification grades 2-4 at the time of Sscreening. * MG-Activities of Daily Living (MG ADL) total score ≥ 6. * Concomitant immunosuppressive drugs must be deemed necessary by the investigator. The dose must be stable for a minimum of 8 weeks prior to Baseline visit. * If a patient is using corticosteroids, the daily dose should not exceed 40 mg/day of prednisone equivalent. The dose must have been stable for a minimum of 8 weeks prior to Baseline visit. * Acetylcholine receptor autoantibody (anti-nAChR) titer or anti-AChR cluster antibody must be above the reference laboratory upper normal limit (UNL) and documented within the past 10 years of screening. * Patient must be willing to return for all study visits. * Patient must be able to give written informed consent. * Women of childbearing potential must agree to use highly effective birth control from Screening until 14 days post last dose of Descartes-08, Exclusion Criteria: * Major chronic illness that is not well managed at the time of study entry and in the opinion of the investigator may increase the risk to the patient. * Diagnosis of gMG within 12 months of screening. * No history of systemic treatment for gMG other than acetylcholine esterase inhibitors. * Diagnosis of a neuromuscular disease other than gMG. * Patient is pregnant or lact…