Biotechnology US clinical-stage US autoimmune drug developer Kyverna Therapeutics saw its shares leap more than 23% to $10.82 after its announced positive top-line data from KYSA-8, its registrational Phase II trial of mivocabtagene autoleucel (‘miv-cel’), formerly KYV-101), a fully human, autologous CD19-targeting CAR T-cell therapy with CD28 co-stimulation, in stiff person syndrome (SPS). 16 December 2025