Cartesian Therapeutics Inc. (Nasdaq: RNAC) reported additional Phase 2 retreatment data for Descartes-08 on September 29, 2026, showing sustained reductions in myasthenia gravis symptoms among five patients followed for 12 months after receiving a second treatment course.
Descartes-08 is an investigational autologous CAR-T therapy targeting B-cell maturation antigen, or BCMA. Unlike conventional DNA-based CAR-T therapies, Cartesian’s treatment uses messenger RNA and is designed for outpatient administration without lymphodepleting chemotherapy.
The retreatment analysis included five patients whose symptoms returned at least 12 months after their initial Descartes-08 treatment. The median interval between completing the original course and beginning retreatment was 16.6 months. Each patient received another six once-weekly infusions.
At Month 12 following retreatment, the five patients recorded an average 6.6-point reduction from baseline on the Myasthenia Gravis Activities of Daily Living scale. The average reduction on the Myasthenia Gravis Composite was 15 points.
All five patients achieved clinically meaningful reductions on both measures. Four maintained a clinically meaningful MG-ADL reduction through Month 12.
Cartesian reported no serious adverse events during retreatment and no cases of cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, cytopenias or hypogammaglobulinemia. Adverse events were described as transient and mild.
The results nevertheless come from an uncontrolled case series involving only five patients. The small sample cannot establish how frequently patients will benefit from retreatment or whether the reported safety profile will be reproduced in a larger population.
“These data strengthen our conviction in Descartes-08 as we approach topline results from our Phase 3 AURORA trial,” President and CEO Carsten Brunn said.
The retreatment findings build on a randomized Phase 2b study published in Nature Medicine. In that trial, 66.7% of Descartes-08 recipients in the primary efficacy population achieved at least a five-point improvement on the Myasthenia Gravis Composite at Month 3, compared with 27.3% of placebo recipients.
The ongoing Phase 3 AURORA trial is expected to enroll approximately 100 patients with acetylcholine receptor antibody-positive generalized myasthenia gravis. Participants receive Descartes-08 or placebo as six weekly infusions. The primary endpoint evaluates the proportion of patients achieving at least a three-point MG-ADL improvement at Month 4.
Cartesian expects topline AURORA results during the first quarter of 2027 and plans a biologics license application for mid-2027, subject to the trial’s outcome.
The company reported US$149.3 million in cash, cash equivalents and restricted cash as of June 30, 2026. It expects its current resources to support planned operations into 2028, although it used US$43.2 million in operating activities during the first half of 2026 and has not generated product-sales revenue.
Upcoming Catalysts
- Phase 3 AURORA topline results expected in the first quarter of 2027
- Potential Descartes-08 BLA filing in mid-2027
- Phase 2 TRITON myositis data expected during the first half of 2027
- Phase 1/2 HELIOS pediatric data expected during the first half of 2027
Sources
- Cartesian reports Descartes-08 retreatment data — September 29, 2026
- Descartes-08 randomized Phase 2b study — Nature Medicine
- Cartesian second-quarter 2026 financial results
- Cartesian Form 10-Q for the quarter ended June 30, 2026 — SEC
- Cartesian announces FDA Special Protocol Assessment agreement for AURORA
Editorial Disclosure
This article is based entirely on publicly available information, including company announcements, an SEC filing, a peer-reviewed publication and publicly available clinical information. Securities discussed or referenced include Cartesian Therapeutics Inc. (Nasdaq: RNAC). Biotech Stocks Daily has not received compensation from Cartesian Therapeutics, its management, investor relations representatives or any third party for this specific article. Biotech Stocks Daily may have current or past paid business relationships with other companies, which do not influence the content or conclusions of this article. No staff member or principal of Biotech Stocks Daily holds a position in any security mentioned at the time of publication.
Sources used include Cartesian’s September 29, 2026 retreatment announcement, its August 2026 financial update, its SEC Form 10-Q for the quarter ended June 30, 2026, the published Phase 2b study in Nature Medicine and the company’s FDA Special Protocol Assessment announcement. The new retreatment results were supplied by Cartesian and have not been independently validated by Biotech Stocks Daily.
The retreatment analysis involved five patients and did not include a concurrent control group. Results from this small case series cannot establish the safety or efficacy of Descartes-08 or predict the outcome of the Phase 3 AURORA trial. Comparisons with patients’ original treatment courses are not equivalent to randomized comparisons against placebo or an active treatment.
Descartes-08 remains investigational and has not been approved by the FDA or any other regulatory authority. RMAT and Orphan Drug designations do not constitute approval or establish that the treatment is safe or effective. The FDA’s Special Protocol Assessment concerns the acceptability of the Phase 3 trial design and does not guarantee favorable results, acceptance of a future application or approval.
Financial information reflects Cartesian’s position as of June 30, 2026 and is reported in U.S. dollars. The company has not generated revenue from product sales and expects continued development expenses. Its reported cash balance included restricted cash, debt financing and proceeds raised through an at-the-market equity program. Debt creates repayment obligations, while equity sales may dilute existing shareholders. The company’s projected cash runway into 2028 is a forward-looking estimate.
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