Kyverna Therapeutics said updated phase 2 data for mivocabtagene autoleucel, or miv-cel, in generalized myasthenia gravis showed responses that deepened and held through a year after one treatment, as the company pushes the therapy into phase 3.
The company said 7 patients with moderate-to-severe gMG were treated with a single dose of 1×10^8 CAR T cells. At the February 25 data cutoff, median follow-up was 10.2 months, with a range of 3.3 to 16.0 months.
At 24 weeks, mean MG-ADL scores fell 8.5 points and mean QMG scores fell 11.3 points from baseline. Kyverna said those were deeper than in the prior interim analysis. Deep responses were seen as early as 2 weeks, and in the 3 patients with follow-up available to 52 weeks, those responses were maintained through that point.
Every patient in the study posted at least a 3-point reduction in both MG-ADL and QMG. Five of the 7 patients, or 57%, reached minimal symptom expression at their last follow-up, defined as an MG-ADL score of 0 or 1. All 7 patients also achieved a clinically meaningful response on MG Composite, with a mean 16-point reduction at 24 weeks.
The treatment also appeared to reduce dependence on other therapies. Kyverna said 100% of patients were free of nonsteroidal immunosuppressants, high-dose steroids above 10 mg, and FcRn and complement inhibitors through week 24.
On the biomarker side, the company said all patients showed robust CAR T-cell expansion and deep B-cell depletion, with reduced autoantibody levels at week 12 and preserved humoral immunity. Safety data showed no high-grade cytokine release syndrome and no immune effector cell-associated neurotoxicity syndrome. Two patients had transient grade 3 or 4 neutropenia, which fully resolved.
Kyverna said Kysa-6 is now an FDA-aligned registrational phase 2/3 trial, and phase 3 enrollment is underway at 14 active clinical sites across three geographies. The company said it will also present updated phase 2 data from Kysa-8 in stiff person syndrome at the same meeting. Today the company's shares have moved 2.03% to a price of $8.03. For the full picture, make sure to review Kyverna Therapeutics's 8-K report.
