Following the announcement of positive clinical trial data for its primary therapeutic candidate, Descartes-08, shares of Cartesian Therapeutics, Inc. (NASDAQ: RNAC) saw significant increases in after-hours trading. After rising 2.99% during normal market hours to settle at $10.67, RNAC shares increased 7.59% to close at $11.48 in extended trading.
Encouraging 12-Month Outcomes in MG Trial
The market reaction was fueled by Cartesian Therapeutics’ recent announcement of 12-month efficacy and safety results from its Phase 2b clinical trial of Descartes-08, a novel treatment for generalized myasthenia gravis (MG). Participants who received a single six-week outpatient regimen of Descartes-08 demonstrated sustained symptom relief at the 12-month mark.
Dr. Tuan Vu of the University of South Florida originally talked about his findings at the 24th Annual Needham Virtual Healthcare Conference. He then presented them at the 2025 American Academy of Neurology Annual Meeting in San Diego.
Therapeutic Promise of Descartes-08
Descartes-08 is a B-cell maturation antigen (BCMA)-targeting autologous CAR-T treatment that is specifically created for outpatient delivery without the need for chemotherapy beforehand. Descartes-08 achieved its primary aim and showed a good safety profile in the randomized, double-blind, placebo-controlled study that included 36 patients with MG who had received extensive pretreatment.
Updated data revealed that among 15 participants in the primary efficacy group, 12 completed 12-month follow-ups, with several demonstrating durable therapeutic responses. Notably, participants with no prior exposure to biologic treatments showed compelling results: an average 7.1-point reduction in MG-ADL scores, with 57% maintaining minimal symptom expression through one year.
Pathway to Phase 3 and Regulatory Progress
These findings strengthen Descartes-08’s position as a potential outpatient therapeutic capable of delivering long-lasting relief for MG patients. The therapy’s performance may set a new standard for care, particularly due to its convenience and absence of preconditioning chemotherapy.
The U.S. Food and Drug Administration has granted Cartesian Therapeutics a Special Protocol Assessment (SPA), certifying that the suggested design for its Phase 3 AURORA study is appropriate to support a subsequent biologics license application. It is still planned for Cartesian Therapeutics (RNAC) to start the pivotal study in 2025’s second quarter.
