Descartes-08: Sustained Efficacy in Myasthenia Gravis as Cartesian Prepares for Phase III Trial

Therapy Overview:
Descartes-08 is an autologous mRNA CAR-T therapy developed by Cartesian Therapeutics, targeting generalized myasthenia gravis (gMG) and leveraging RNA modifications to improve safety and avoid preconditioning chemotherapy69.

Phase II Results: The therapy demonstrated sustained clinical benefits for 12 months in gMG patients after a single six-week course of treatment. Improvements included:

A 4.8-point reduction in the Myasthenia Gravis Activities of Daily Living (MG-ADL) score at 12 months.
A stronger response in biologic-naïve patients, with an average reduction of 7.1 points in MG-ADL and 57% achieving near-complete symptom control910.

Safety Profile:
Descartes-08 was shown to be well-tolerated without dose-limiting toxicities, cytokine release syndrome, or neurotoxicity, offering the convenience of outpatient administration7910.

Regulatory Designations:
The therapy has received Orphan Drug Designation and Regenerative Medicine Advanced Therapy (RMAT) Designation from the FDA, supporting its expedited development910.

Next Steps:
Cartesian is set to initiate the Phase III AURORA trial in the second quarter of 2025, marking a critical step toward potential FDA approval for gMG treatment. The trial design has already been approved under the FDA's Special Protocol Assessment process910.

Broader Implications:
The success of Descartes-08 highlights the potential for mRNA-engineered CAR-T therapies to safely treat autoimmune diseases, moving beyond the current scope of oncology-focused CAR-T therapies67.

Sources:

6. https://endpts.com/cartesian-tees-up-phase-3-mrna-car-t-study-in-myasthenia-gravis/

7. https://www.ucihealth.org/news/2023/06/rna-cell-therapy

9. https://www.biospace.com/press-releases/cartesian-therapeutics-descartes-08-observed-to-provide-deep-and-sustained-benefits-through-month-12-after-a-single-course-of-therapy-in-phase-2b-myasthenia-gravis-trial

10. https://www.globenewswire.com/news-release/2025/04/08/3057465/0/en/Cartesian-Therapeutics-Descartes-08-Observed-to-Provide-Deep-and-Sustained-Benefits-Through-Month-12-After-a-Single-Course-of-Therapy-in-Phase-2b-Myasthenia-Gravis-Trial.html