Cartesian's CAR-T Pushes Beyond Cancer into Autoimmune Frontier

FREDERICK, Md. – January 09, 2026 – Cartesian Therapeutics is charting an ambitious course to repurpose a powerful cancer-fighting tool for autoimmune diseases, signaling a potential paradigm shift in treatment for chronic conditions. The clinical-stage biotech company today announced significant progress across its pipeline, centered on its lead candidate, Descartes-08, an innovative RNA-based CAR-T cell therapy. With a pivotal trial in myasthenia gravis well underway, a newly accepted plan to study myositis, and a pediatric trial now initiated, Cartesian is rapidly advancing a therapy designed to be safer and more accessible than conventional cell treatments.

The company's momentum is underscored by recent validation from the scientific community. Its ongoing Phase 3 trial for myasthenia gravis was named by Nature Medicine as one of the "Eleven clinical trials that will shape medicine in 2026," and two new peer-reviewed articles in the same prestigious journal detail the therapy's unique mechanism and promising long-term patient data. This confluence of clinical progress, regulatory milestones, and scientific backing positions Cartesian at the forefront of applying cell therapy beyond its oncology origins.

A New Paradigm for Autoimmune Treatment

At the heart of Cartesian's strategy is Descartes-08, an autologous CAR-T therapy that targets B-cell maturation antigen (BCMA), a protein expressed on the plasma cells that produce disease-causing autoantibodies. Unlike conventional DNA-based CAR-T therapies, which carry risks of genomic integration and require harsh preconditioning chemotherapy, Descartes-08 is engineered with RNA. This design allows for transient, controlled activity, eliminating the need for lymphodepleting chemotherapy and enabling administration in an outpatient setting.

"Following a year marked by significant progress advancing our autoimmune-focused pipeline, we are entering 2026 with strong momentum," said Carsten Brunn, Ph.D., President and Chief Executive Officer of Cartesian, in a statement. "Given the favorable safety profile observed in Descartes-08 supporting outpatient administration, we are confident that Descartes-08 could represent a meaningful addition to the MG treatment landscape.”

This confidence is backed by robust clinical data. Enrollment is on track for the Phase 3 AURORA trial, a randomized, double-blind study evaluating Descartes-08 in approximately 100 patients with generalized myasthenia gravis (MG), a debilitating neuromuscular autoimmune disease. The trial's design—six once-weekly outpatient infusions—is a stark contrast to the inpatient hospitalizations required for traditional CAR-T.

Furthermore, a new publication in Nature Medicine reiterates the deep and durable responses observed in the company's Phase 2b trial. Through 12 months of follow-up, patients showed significant improvement. Notably, in a subset of patients who had not received prior biologic therapies, 57% achieved minimal symptom expression by Month 6 and maintained it through Month 12. These patients also saw a median reduction in their daily prednisone dose of 55% by the one-year mark, a critical achievement for a population often reliant on long-term steroids with burdensome side effects. Crucially, no instances of severe toxicities like cytokine release syndrome (CRS) or neurotoxicity (ICANS), which can plague conventional CAR-T, have been reported.

Expanding the Frontier: Myositis and Pediatric Trials

Building on its success in myasthenia gravis, Cartesian is expanding the reach of Descartes-08 into other autoimmune conditions with high unmet needs. The company announced that the U.S. Food and Drug Administration (FDA) has accepted its Investigational New Drug (IND) application to study the therapy in myositis, a group of rare diseases causing chronic muscle inflammation and weakness.

The planned Phase 2 TRITON trial, set to begin in the first half of 2026, will employ a seamless adaptive design. This modern trial structure includes a planned interim analysis after the first ten participants, which could allow the study to be expanded into a single pivotal trial, potentially accelerating the path to approval. Myositis affects an estimated 80,000 people in the U.S. and remains a significantly underserved market, with patients often cycling through treatments that offer limited relief.

Cartesian is also addressing the needs of younger patients with the initiation of its Phase 1/2 HELIOS trial for Descartes-08 in children and young adults. The trial will focus on autoimmune diseases including juvenile dermatomyositis (JDM), a rare and severe disorder marked by skin rashes and muscle inflammation that can affect multiple organ systems. The FDA has already granted Descartes-08 Rare Pediatric Disease Designation for JDM, a status that can lead to a priority review voucher upon approval, incentivizing development for rare childhood diseases.

Strategic Vision and Financial Fortitude

Cartesian's ambitious clinical expansion is supported by a solid financial foundation. The company stated it expects its current cash resources to fund planned operations into mid-2027, a runway sufficient to complete the pivotal Phase 3 MG trial and initiate the Phase 2 myositis study. This financial stability is crucial in the capital-intensive biotech sector and provides a buffer against market volatility. While the company's stock (NASDAQ: RNAC) has seen fluctuations, some analysts remain highly bullish, with an average price target suggesting significant upside and a "Strong Buy" consensus reflecting confidence in its long-term strategy.

That strategy extends beyond Descartes-08. The company is actively exploring next-generation delivery platforms, including in-vivo CAR-T, which aims to engineer therapeutic cells directly within the patient's body. This futuristic approach could one day eliminate the need for external cell manufacturing altogether, making treatments more scalable and accessible.

This forward-looking vision is bolstered by the recent appointment of Adrian Bot, M.D., Ph.D., to Cartesian's Board of Directors. Dr. Bot is a veteran of the cell therapy space, having pioneered CAR-T at Kite Pharma and, more recently, serving as Chief Scientific Officer at Capstan Therapeutics. Capstan made headlines with its own novel in-vivo CAR-T technology, leading to its recent acquisition by AbbVie. Dr. Bot's expertise provides Cartesian with invaluable insight as it navigates the next frontier of cell and gene therapy.

Reshaping the Market and Patient Lives

The work being done by Cartesian represents more than just scientific innovation; it offers a glimmer of hope for patients burdened by chronic autoimmune diseases. Conditions like myasthenia gravis and myositis often force patients to rely on a cocktail of immunosuppressants and steroids, which carry a heavy toll of side effects and may not fully control debilitating symptoms like muscle weakness and profound fatigue. Diagnostic delays, which can average three years for MG, further compound the physical and psychosocial burden.

Industry experts and patient advocates have long highlighted the need for therapies that not only manage symptoms but also offer a better safety profile and quality of life. By "retuning" the immune system rather than broadly suppressing it, Descartes-08 aims to do just that. The ability to receive a potentially transformative therapy through a series of outpatient visits without the need for debilitating chemotherapy could fundamentally change the treatment experience. As Cartesian pushes its versatile RNA cell therapy platform through late-stage trials and into new disease areas, it is not just developing a product, but potentially defining a new, more patient-friendly standard of care for autoimmune disease.