Kyverna’s Miv-Cel Shows 1-Year Data Ahead Of Q4 BLA

With a rolling BLA submission targeted for completion in Q4 2026, Kyverna Therapeutics has released one-year data from KYSA-8 and updated longer-term data from KYSA-6, findings that will anchor the regulatory package for mivocabtagene autoleucel (miv-cel) in stiff person syndrome (SPS) and generalized myasthenia gravis (gMG). For manufacturing and QA leads already tracking autologous CAR-T process validation demands, the 100-plus patient treatment history across Kyverna's autoimmune programs signals that the established manufacturing process has been stress-tested at a scale relevant to pre-approval inspection readiness.

In the 26-patient KYSA-8 phase 2 registrational cohort, median improvement on the Timed 25-Foot Walk reached 49% at month 12, up from 46% at week 16 (P <.0001). Ninety-five percent of patients sustained a clinically meaningful response, defined as greater than 20% reduction from baseline, and 92% remained free of chronic immunotherapies through the one-year assessment. Of the 12 patients who required a walking aid before treatment, 67% no longer needed assistance at latest follow-up. No high-grade CRS or ICANS were reported, a safety profile that reduces the post-infusion monitoring burden relevant to clinical site operations.

In the seven-patient KYSA-6 phase 2 cohort for gMG, all patients achieved clinically meaningful improvement in MG-ADL and QMG scores at week 24, with mean reductions of 8.3 and 11.7 points respectively. Among the five patients reaching one year or longer follow-up, improvement was maintained, and 57% achieved minimal symptom expression defined as an MG-ADL score of 0 to 1.

Miv-cel is a fully human, autologous CD19-directed CAR T-cell therapy incorporating CD28 co-stimulation. It holds FDA Regenerative Medicine Advanced Therapy (RMAT) designation across three indications: SPS, gMG, and non-active secondary progressive multiple sclerosis. No FDA-approved therapy currently exists for SPS, a rare progressive autoimmune disorder in which up to 80% of patients develop mobility loss, a regulatory context that will shape the benefit-risk framing within the BLA submission.

For regulatory affairs leads preparing for the submission window, the consistency of functional outcomes across a single-dose regimen, without ongoing immunosuppression, provides a clinically coherent narrative for the SPS indication. The absence of an approved comparator also removes the need for an active-controlled trial design, though it places greater weight on the registrational single-arm data from KYSA-8.

Completion of the rolling BLA for SPS in Q4 2026 will mark the first measurable checkpoint for assessing whether Kyverna's manufacturing process documentation and clinical dataset meet FDA's threshold for a formal review cycle.

Source: CGTLive via Kyverna Therapeutics announcement, September 24, 2026.