Kyverna's CAR T Therapy Shows Promising Results in Myasthenia Gravis, Signaling Shift in Autoimmune Treatment

Kyverna Therapeutics has reported groundbreaking results from its Phase II study of KYV-101, a CAR T cell therapy for generalized myasthenia gravis (gMG), potentially revolutionizing treatment approaches for autoimmune diseases.

100% Response Rate Sets New Efficacy Standard

In a significant development for the field of autoimmune disorders, Kyverna Therapeutics announced a 100% response rate in patients with gMG treated with KYV-101. The Phase II portion of the KYSA-6 study, involving six patients with moderate to severe gMG who had previously failed immunosuppressant therapies, demonstrated clinically meaningful improvements in activities of daily living at 36 weeks post-treatment.

William Blair analysts have hailed these results as establishing "a new efficacy standard in the field," positioning KYV-101 as a potentially game-changing therapy compared to current treatments and other late-stage assets. The remarkable efficacy has also significantly de-risked the planned Phase III trial, according to the analysts.

Reduced Treatment Burden and Safety Profile

Beyond efficacy, KYV-101 showed promise in reducing the overall treatment burden for gMG patients. All treated patients were able to discontinue non-steroidal immunosuppressants, high-dose steroids, and other therapies after 24 weeks of treatment. This finding suggests that KYV-101 could offer a more streamlined and potentially less burdensome treatment approach for gMG patients.

The safety profile of KYV-101 appears favorable, with the therapy being well-tolerated overall. Notably, there were no documented cases of high-grade cytokine release syndrome or immune effector cell–associated neurotoxicity syndrome, both of which are common concerns with CAR T therapies. One patient developed grade 4 neutropenia, which was expected and improved to grade 1 by the data cutoff.

Expanding Horizons for CAR T in Autoimmune Diseases

Kyverna's success with KYV-101 in gMG is part of a broader trend of applying CAR T cell therapies, traditionally used in cancer treatment, to autoimmune disorders. Other companies, including Cabaletta Bio, Bristol Myers Squibb, CRISPR Therapeutics, and Autolus Therapeutics, are also exploring CAR T platforms for various autoimmune conditions.

Cabaletta Bio recently reported promising efficacy signals for its cell therapy rese-cel in multiple autoimmune indications, including dermatomyositis, systemic lupus erythematosus, systemic sclerosis, and antisynthetase syndrome. The company is planning to advance rese-cel into a registrational study for myositis and is seeking FDA alignment on trial designs for lupus and systemic sclerosis.

As Kyverna prepares to initiate enrollment for the Phase III portion of the KYSA-6 study by the end of this year, the pharmaceutical industry watches closely. The potential success of KYV-101 and similar therapies could mark a paradigm shift in the treatment of autoimmune diseases, offering new hope to patients who have exhausted conventional treatment options.