
- The troriluzole clinical development program encompassed the first industry clinical trials to generate data showing therapeutic potential in patients with spinocerebellar ataxia (SCA), a rare genetic, inherited, life-threatening neurodegenerative disease with no treatment options.
- Compelling data from troriluzole's new drug application (NDA) included: a 3-year real-world evidence study (Study 206-RWE) showing slowing of SCA disease progression by 50-70% in troriluzole-treated patients compared to matched untreated external controls; > 50% risk reduction in AEs of falls in troriluzole-treated subjects compared to placebo from the safety analysis of the 1-year, double-blind, placebo controlled Study -206; and multiple supportive analyses showing a delay in becoming wheelchair bound or losing the ability to walk, decreased gait impairment as measured by f-SARA and objective video-based kinematic analysis, and improvement in overall functioning as assessed by the clinician global impression (CGI) scale.
- The FDA issued a complete response letter (CRL) despite Study 206-RWE being reviewed by FDA and achieving statistical significance in the study's prespecified primary and secondary outcome efficacy endpoints. FDA cited issues that can be inherent to real-world evidence and external control studies including potential bias, design flaws, lack of pre-specification and unmeasured confounding factors.
- Prior to 206-RWE protocol finalization, study approval and topline data analysis, the FDA provided feedback on the study's statistical analysis plan and study protocol that were incorporated into the IRB approved study. The FDA official meeting minutes (March 8, 2024) from discussion of the RWE study included the statement, "a large and robust treatment effect would be needed to overcome the biases of an externally controlled trial, in order for it to be used as the primary basis for substantial evidence for effectiveness."
- Biohaven believes the statistical significance and clinical meaningfulness achieved on the primary endpoint and eight consecutive secondary endpoints in 206-RWE, which included consistent results across two separate, independent, third-party run, multi-center, external controls from the largest natural history studies of SCA in the United States and Europe, clearly met criteria of "a large and robust treatment effect."
- Troriluzole received Orphan and Fast Track designation as well as a Priority Review acceptance of the NDA; FDA subsequently delayed the PDUFA date by 3 months during the review period. There was no communication of the need for an Advisory Committee meeting at acceptance of the Priority Review; however, a few months later the FDA informed Biohaven that an Advisory Committee was being planned but then cancelled it weeks before the anticipated meeting, preventing qualified clinical experts the opportunity to publicly weigh in on their opinion of what is a large and robust treatment effect and after the Company spent significant resources preparing for the Advisory Committee.
- Compelling data from troriluzole's new drug application (NDA) included: a 3-year real-world evidence study (Study 206-RWE) showing slowing of SCA disease progression by 50-70% in troriluzole-treated patients compared to matched untreated external controls; > 50% risk reduction in AEs of falls in troriluzole-treated subjects compared to placebo from the safety analysis of the 1-year, double-blind, placebo controlled Study -206; and multiple supportive analyses showing a delay in becoming wheelchair bound or losing the ability to walk, decreased gait impairment as measured by f-SARA and objective video-based kinematic analysis, and improvement in overall functioning as assessed by the clinician global impression (CGI) scale.
- In the CRL, the FDA recommended that Biohaven meet with the Division to discuss the evidence that will be needed to support a future NDA for the treatment of SCA with troriluzole. Following receipt of the CRL today, Biohaven is in the process of formally requesting a meeting as soon as possible given the large number of patients who are currently being treated in the expanded access program.
- Biohaven remains committed to working with the FDA to find a path forward for its NDA for VYGLXIA and plans to meet with the FDA to discuss potential next steps.
- Given the CRL, Biohaven is initiating strategic portfolio and cost-optimization measures to prioritize 3 key, late-stage, clinical programs with the greatest potential for value generation:
- Key areas of focus over the near term include: 1) Clinical-stage, lead extracellular degraders for IgA nephropathy (BHV-1400) and Graves' disease (BHV-1300); 2) Opakalim, Kv7 ion channel activator, pivotal trials in adult focal epilepsy and depression; and 3) Taldefgrobep alfa, myostatin-activin pathway inhibitor for obesity and SMA.
- Restructuring of business priorities underway to achieve an approximately 60% reduction in annual direct R&D spend (which excludes personnel and SBC), will result in delay of non-priority programs.
- New data will be presented from several of Biohaven's priority programs at an annual healthcare conference in January 2026.
NEW HAVEN, Conn., Nov. 4, 2025 /PRNewswire/ -- Biohaven Ltd. (NYSE: BHVN) ("Biohaven"), a global clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of life-changing therapies to treat a broad range of rare and common diseases, today announced that it has received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) for the New Drug Application (NDA) seeking approval of VYGLXIA (troriluzole) for the treatment of spinocerebellar ataxia (SCA).
Share this article