Update on Phase 2 of KYSA-6, an Open-label, Single-arm, Multicenter Phase 2/3 Study of Miv-cel (Mivocabtagene Autoleucel; KYV-101), a Fully Human CD19 Chimeric Antigen Receptor (CAR) T-cell Therapy in Generalized Myasthenia Gravis (gMG)
Marinos Dalakas1, Srikanth Muppidi2, Michael Hunter3, Sarah Hoffmann4, Tobias Hegelmaier5, Jeremias Motte6, Ralf Gold6, Charlotte Schubert7, Bradley Hunter8, Marie Luise Hütter-Krönke9, Christian Schultze-Florey10, Roland Schroers11, Francis Ayuk12, Justin Chou13, Xue Han13, John Sun13, Shouvonik Sengupta13, Christine Bryant13, Linus Sun13, Dena Grayson13, Naji Gehchan13, Aiden Haghikia5
1Department of Neurology, Thomas Jefferson University, 2Department of Neurology, Stanford Healthcare, 3Department of Neuromuscular Medicine, Intermountain Medical Center, 4Department of Neurology with Experimental Neurology and Neuroscience Clinical Research Center (NCRC), Charité-Universitätsmedizin Berlin, 5Department of Neurology with Clinical Neurophysiology, Hannover Medical School, 6Department of Neurology, Ruhr University Bochum, 7Institute of Neuroimmunology and Multiple Sclerosis and Department of Neurology, University Medical Center Hamburg-Eppendorf, 8Department of Hematology Oncology, Blood and Marrow Transplantation, Intermountain LDS Hospital, 9Department of Hematology, Oncology and Cancer Immunology, Charité Universitätsmedizin Berlin, 10Department of Hematology, Hemostaseology, Oncology and Stem Cell Transplantation, Hannover Medical School, 11Department of Hematology and Oncology, Ruhr University Bochum, 12Department for Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf, 13Kyverna Therapeutics, Inc.
Objective:
Evaluate clinical outcomes with miv-cel in patients with gMG in Phase 2 of KYSA-6 (NCT06193889).
Background:
gMG is a neuromuscular autoimmune disease typically causing substantial disability. Novel therapies that provide greater absolute reduction in MG Activities of Daily Living (MG-ADL) to minimize or eliminate disease symptoms are needed. Miv-cel is a fully human, autologous CD19 CAR T-cell therapy with CD28 costimulation, designed for potency and tolerability.
Design/Methods:
Adults (18-75y) with gMG (MGFA class IIb-IV), history of AChR or MuSK autoantibodies, MG-ADL score ≥6, and ≥2 immunosuppressant/immunomodulator failures, received low-dose lymphodepletion and a single infusion of 1×108 CAR T cells.
Results:
As of February 25, 2026, 7 patients were dosed (mean [range]: age 46.1y [21-62]; MG-ADL 10.6 [7-16]; quantitative MG [QMG] 16.9 [9-28]). Median follow-up was 10.2 months (range, 3.3-16.0). All patients had robust CAR T-cell expansion and B-cell depletion. With a single dose, all patients had ≥3-point MG-ADL improvement versus baseline; 57% achieved minimal symptom expression (MG-ADL ≤1) at their last follow-up. At 24-weeks (n=6), miv-cel treatment resulted in 8.5-point (range, 7-13) and 11.3-point (range, 5-27) mean reductions from baseline in MG-ADL and QMG scores, respectively. All 7 patients became immunotherapy-free (86% at last follow-up). No ICANS or high-grade CRS occurred.
Conclusions:
These findings support the potential of a single dose of miv-cel to deliver durable, drug-free, disease-free remission in patients with moderate to severe gMG. Miv-cel treatment resulted in robust, sustained improvements in disease severity with an acceptable safety profile, and eliminated background immunosuppressants in the majority of patients. Phase 3 is ongoing.
Generative AI Usage
No, did not use generative AI in the drafting or editing in this abstract.
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