CAR T Therapy Shows Promise in Treating Autoimmune Conditions

Bristol Myers Squibb and Cabaletta Bio have reported encouraging results from their Phase I/II clinical trials investigating resecabtagene autoleucel (rese-cel), a CAR T therapy, for the treatment of various autoimmune conditions. The data, presented at the 2025 American College of Rheumatology congress, demonstrate the potential of this innovative approach in addressing immune dysfunction beyond its established use in cancer treatment.

Positive Outcomes in Lupus and Myositis Trials

In the RESET-SLE trial, three patients with systemic lupus erythematosus (SLE) achieved disease remission after rese-cel treatment, with at least three months of follow-up. A fourth participant with lupus nephritis experienced a complete renal response. These results have prompted Cabaletta to initiate a dose-escalation cohort in this trial, scheduled to begin next year.

The RESET-Myositis trial, involving six patients with dermatomyositis (DM) or antisynthetase syndrome (ASyS), showed that four evaluable patients demonstrated "moderate or major improvement" after 16 weeks of treatment. Notably, these improvements occurred without the use of immunomodulators, which analysts from William Blair suggest de-risks an upcoming registrational cohort for DM.

Promising Results in Systemic Sclerosis

The RESET-SSc trial, focusing on systemic sclerosis (SSc), reported data from four patients with at least three months of follow-up. Initial results indicate that rese-cel treatment led to clinical improvements without the need for immunomodulator or steroid treatment. This suggests that the CAR T candidate may effectively "reset" the immune system in SSc patients.

Expanding Horizons for CAR T Therapy

While CAR T therapies have primarily been confined to cancer treatment, with all FDA-approved products in this class indicated for malignancies, these recent studies point to the potential of this approach in addressing autoimmune diseases. The immunosuppressant-free profile of rese-cel is particularly noteworthy, as it may offer a new treatment paradigm for patients with autoimmune conditions.

David Chang, Cabaletta's Chief Medical Officer, stated that the company is preparing for a registrational trial of rese-cel in myositis. Additionally, the partners are working to align with the FDA this year on pivotal study designs for lupus and systemic sclerosis.

As the pharmaceutical industry continues to explore novel applications for CAR T therapy, these early results from Bristol Myers Squibb and Cabaletta Bio represent a significant step forward in the potential treatment of autoimmune diseases, offering hope for patients with conditions that have traditionally been challenging to manage.