New CAR-T Therapy Data Show Encouraging Results in Dermatomyositis

EULAR Announcement

Researchers from Cabaletta Bio recently shared new clinical results from the ongoing RESET-Myositis study evaluating rese-cel (formerly CABA-201), an investigational CAR-T cell therapy for patients with autoimmune diseases, including dermatomyositis (DM).

While CAR-T therapies were originally developed for cancer, researchers are now exploring whether they can “reset” the immune system in autoimmune diseases by targeting B cells that contribute to inflammation and tissue damage.

Encouraging Results in Dermatomyositis

Among the dermatomyositis patients treated with rese-cel:

• 5 of 6 patients (83%) achieved a moderate-to-major improvement in disease activity by Week 16
• These improvements occurred without ongoing immunomodulatory medications
• Patients were able to discontinue their immunosuppressive therapies before treatment and maintain their responses after receiving a single infusion of rese-cel

The study uses the Total Improvement Score (TIS), a standard measure commonly used in myositis clinical trials to assess changes in disease activity.

First Juvenile Dermatomyositis Patient Reported

The company also reported results from the first patient with juvenile dermatomyositis (JDM) treated in the program.

According to the announcement:

• The patient achieved a moderate TIS response
• Improvement was maintained through the latest follow-up at 32 weeks
• Cabaletta expects JDM to be included in a future regulatory submission for the myositis program

Although this represents only a single patient, the result is encouraging and supports continued investigation of CAR-T therapies in pediatric myositis.

What Makes This Different?

Unlike traditional treatments that often require ongoing therapy, rese-cel is designed as a one-time autologous CAR-T treatment.

The process involves:

1. Collecting a patient’s own T cells
2. Engineering those cells to target CD19-positive B cells
3. Re-infusing the modified cells back into the patient

Researchers hope this approach may provide a deeper and more durable immune reset than currently available therapies.

Important Things to Remember

These results come from a small number of patients, and the study is still ongoing.

While the early findings are encouraging, rese-cel remains an investigational therapy and has not been approved by the FDA for myositis.

Additional patients, longer follow-up, and larger studies will be needed to determine:

• How durable responses are over time
• Which patients benefit most
• The long-term safety profile
• Whether results can be reproduced in larger populations

Why This Matters to the Myositis Community

For many years, treatment options for myositis have relied on broad immunosuppression. CAR-T therapies represent a fundamentally different approach aimed at resetting the immune system rather than continuously suppressing it.

The ongoing RESET-Myositis study includes patients with:

• Dermatomyositis (DM)
• Anti-synthetase syndrome (ASyS)
• Immune-mediated necrotizing myopathy (IMNM)

As research continues, the myositis community will be watching closely to see whether CAR-T therapies can become a new treatment option for patients living with these rare autoimmune diseases.

For additional details, please  can review Cabaletta’s full announcement:
https://www.cabalettabio.com/news-media/press-releases/detail/149/cabaletta-bio-announces-new-rese-cel-data-and-development