Kyverna completes its miv-cel BLA submission for stiff person syndrome, seeks FDA priority review and deprioritizes its KYV-102 programme.
Written By: Aabha Dey, BPharm
Reviewed By: Pharmacally Editorial Team
Kyverna Therapeutics announced on November 12, 2026, that it had completed its rolling Biologics License Application (BLA) submission to the US Food and Drug Administration (FDA) for miv-cel (mivocabtagene autoleucel, KYV-101), an investigational CD19-targeted CAR T-cell therapy for stiff person syndrome (SPS). The company is requesting priority review under the therapy’s Regenerative Medicine Advanced Therapy (RMAT) designation, with a potential US commercial launch in 2027.
Alongside the regulatory milestone, Kyverna announced that it had elected to deprioritize its KYV-102 programme as it concentrates on advancing miv-cel across its late-stage neurological indications. The company also plans to continue lifecycle-management activities for miv-cel to broaden patient access and reduce treatment costs.
KYSA-8 Clinical Results Support BLA Submission
The BLA is supported by results from KYSA-8, a registrational, open-label, single-arm Phase 2 trial evaluating miv-cel in adults with SPS who had inadequate responses to previous immunomodulatory treatments.
Of 27 enrolled patients, 26 received a single infusion. The primary efficacy endpoint assessed changes in the Timed 25-Foot Walk (T25FW) test at Week 16. The published analysis reported a 45.6% median improvement in walking performance, corresponding to a median reduction of 4.8 seconds (p<0.001).
Improvements were also observed across secondary measures, including disability, stiffness, hypersensitivity and ambulation. The findings were published in JAMA Neurology on November 9, 2026, providing peer-reviewed clinical evidence ahead of the BLA completion announcement.
One-Year Follow-up Indicates Sustained Functional Benefits
In September 2026, Kyverna reported additional KYSA-8 results based on a July 2026 database lock. At Month 12, patients demonstrated a 49% median improvement in T25FW performance (p<0.0001).
Among the key findings, 95% of initial responders maintained clinically meaningful improvement at one year. More than one-third of patients completed the walking test in under five seconds, while eight of the 12 patients who initially required walking assistance no longer needed it. Additionally, 92% remained free from chronic SPS immunotherapies at 12 months.
Improvements across secondary clinical measures were also maintained, with reported p-values ranging from less than 0.0001 to 0.0003. These findings suggest that a single infusion may provide sustained functional benefits, although longer-term follow-up remains necessary.
Safety Profile and CAR T-Cell Mechanism
Miv-cel is a fully human, autologous CD19-targeted CAR T-cell therapy incorporating CD28 co-stimulation. It involves collecting a patient’s T cells, genetically modifying them to recognise CD19-expressing B cells and reinfusing the engineered cells.
In SPS, autoantibodies, particularly those targeting glutamic acid decarboxylase 65 (GAD65), are associated with impaired inhibitory neurotransmission. By depleting CD19-expressing B cells, miv-cel aims to modify the underlying autoimmune response and potentially promote immune resetting.
The published KYSA-8 primary analysis reported cytokine release syndrome (CRS) in 24 of 26 patients (92.3%), with all cases limited to Grade 1 or 2. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in three patients (11.5%), all Grade 1. No cases of immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS) were observed.
The study also reported three treatment-related serious adverse events, which resolved without sequelae. In its subsequent one-year update, Kyverna reported no high-grade CRS or ICANS and no IEC-HS cases. Although encouraging, these findings require continued evaluation in larger populations and longer follow-up.
KYV-102 De-prioritization Reflects Portfolio Reprioritization
The KYV-102 decision represents an additional strategic development in Kyverna’s November 12 announcement. Rather than announcing programme termination, the company stated that it had elected to deprioritize KYV-102 while focusing on accelerating its late-stage neurological indications with miv-cel.
The company intends to continue lifecycle-management activities for miv-cel, with the stated objectives of broadening patient access and reducing costs. This positions miv-cel as the central development and potential commercialisation priority within its current neurological autoimmune portfolio.
Beyond SPS, Kyverna is advancing miv-cel in generalized myasthenia gravis (gMG) through the registrational KYSA-6 programme, with Phase 3 enrolment expected to conclude by mid-2027. An investigator-initiated Phase 1 study at Stanford University is also evaluating miv-cel in progressive multiple sclerosis. The FDA has granted RMAT designation for miv-cel in non-active secondary progressive multiple sclerosis.
Regulatory Outlook and Clinical Implications
The completed BLA submission marks a significant regulatory milestone for miv-cel. RMAT designation supports expedited development and regulatory interactions but does not automatically confer priority review or marketing approval. The FDA must still assess the submitted clinical, manufacturing and safety data.
If approved, miv-cel could become the first FDA-approved CAR T-cell therapy for an autoimmune disease and the first disease-specific FDA-approved treatment for SPS. However, KYSA-8 involved only 26 treated patients and lacked a randomised control group, limiting comparisons with existing treatments.
The combination of sustained clinical improvements and reduced reliance on chronic immunotherapies supports further investigation of single-dose CAR T-cell treatment in autoimmune neurological diseases. At the same time, Kyverna’s decision to deprioritize KYV-102 indicates a more concentrated development strategy around miv-cel as the company prepares for potential commercialisation.
Reference
Kyverna Therapeutics Announces Completion of BLA Submission for Miv-cel in Stiff Person Syndrome and Reports Third Quarter 2026 Financial Results, Kyverna Therapeutics, 12 November 2026
About the Writer
Aabha Dey (LinkedIn) is a Pharmacy Bachelor from Delhi Pharmaceutical Sciences and Research University (DIPSAR), New Delhi. She has a strong interest in pharmacology, clinical research and medical writing, with practical exposure through internships in hospital practice, scientific and journal writing, and medical coding.
Her academic interests include pharmacovigilance, drug development, regulatory affairs and evidence-based healthcare communication. She is particularly interested in scientific research and translating complex pharmaceutical and clinical information into clear, accurate and accessible content.