Cartesian initiates Phase 3 mRNA CAR-T trial in myasthenia gravis

Cartesian Therapeutics has shared promising long-term results from a Phase 2b study of its mRNA CAR-T therapy for myasthenia gravis, indicating that the therapy's benefits extend beyond the initial three-month period. The study included 12 patients, and the average decline in the Myasthenia Gravis Composite (MGC) score, a 60-point measure of disease activity, was over six points at six months. Four of these patients showed minimal symptoms at this mark. Two patients from the primary analysis were lost to follow-up.

Additionally, the company retreated three patients, two of whom continued to show minimal symptoms two years post-treatment. The third patient, who was retreated more recently, showed a six-point improvement in their MGC score two months after the retreatment.

James Howard, the lead investigator from the University of North Carolina School of Medicine, highlighted the significance of the therapy's durability. He noted during an analyst call that while targeted therapies over the past five to six years have been effective, they required continual dosing to maintain their effects. The ability to treat patients less frequently while still providing a sustained quality of life and prolonged benefit is particularly rewarding.

In July, Cartesian announced that the Phase 2b study achieved its primary goal, with 10 of 14 patients showing a minimum five-point improvement in their MGC scores. In comparison, only three out of 12 patients in the placebo group reached this level of improvement.

Looking ahead, Cartesian is preparing for its pivotal Phase 3 study, named AURORA. This trial will include around 100 myasthenia gravis patients who have specific autoantibodies in their blood. The company plans to initiate this trial in the first half of the upcoming year.

Interest in CAR-T cell therapies for myasthenia gravis is growing, with other companies like Kyverna Therapeutics and Cabaletta Bio also developing treatments. Unlike Cartesian's therapy, these companies' treatments resemble traditional CAR-T therapies, involving preconditioning chemotherapy and potential immunotherapy-related side effects.

Besides cell therapy approaches, the competitive landscape for myasthenia gravis treatments includes companies like argenx, UCB, Johnson & Johnson, and Immunovant, which are either marketing new therapies or developing drugs for the condition.