EL7.AI
StocksMedium•22 October 2026•
4 min read

Biohaven Ataxia Drug Resubmission Accepted for Review, Decision Targeted for Early 2027

Key Facts

1The FDA set the first quarter of 2027 as the target for regulatory action on the application.
2Biohaven said analyses of a study spanning 3 years showed a 50-70% slowdown in decline, equivalent to a 1.5-2.2-year delay in disease progression.
3Biohaven estimates that about 15,000 people in the United States and 24,000 in Europe and the United Kingdom have the disease.
4Biohaven targeted a roughly 60% reduction in annual direct research and development spending following the earlier rejection, excluding personnel costs and stock-based compensation.
5The FDA accepted for review the resubmitted application for approval of troriluzole to treat spinocerebellar ataxia.

Biohaven said the U.S. Food and Drug Administration had accepted for review its resubmitted application for approval of VYGLXIA, known generically as troriluzole, to treat spinocerebellar ataxia. The move returns the investigational treatment to regulatory review following an earlier rejection, while the drug remains unapproved in the United States for any therapeutic use. The company said in a filing with the U.S. Securities and Exchange Commission that the resubmission includes "new positive supportive analyses." That is Biohaven's description of the analyses it added to the filing, while the agency's announced action concerns acceptance of the application for review. Acceptance of the resubmission does not constitute authorization to market the drug or agency endorsement of its efficacy in treating the disease.

The agency had granted the application priority review during the previous assessment cycle, according to Biohaven's statement when the filing was accepted at the time. During that cycle, the FDA extended the review period by 3 months to allow time to fully examine additional information. The company submitted that information in response to agency requests, according to its statement on the extension. Biohaven then announced on November 4, 2025 that it had received a complete response letter regarding its application for approval of VYGLXIA to treat spinocerebellar ataxia. In its statement on the earlier rejection, the company said the FDA's objections concerned real-world evidence and studies that used external controls for comparison. Those objections included "potential bias, design flaws, lack of prespecification and unmeasured confounders," according to Biohaven's account of the agency's findings.

In its annual report filed with the U.S. Securities and Exchange Commission, Biohaven presented results from analyses of the drug's real-world study. It said the rate of decline among treated patients was 50-70% slower than among untreated patients. The study underlying that comparison spanned 3 years, according to the company's annual report. Biohaven estimated that this slowdown equated to a 1.5-2.2-year delay in disease progression over the study period. The company's reported result concerns the rate of decline relative to the untreated group, while the agency's earlier objections included the design of externally controlled studies and their potential for bias.

Troriluzole targets an inherited degenerative disease that causes a progressive decline in voluntary motor control, according to Biohaven's description of spinocerebellar ataxia. The disease is accompanied by atrophy of the cerebellum and brainstem, and its effects can progress to loss of the ability to walk. Its consequences also include difficulties with speech and swallowing, according to the company's statement on the previous review extension. In its statement published in May 2025, Biohaven estimated that about 15,000 people in the United States had the disease. It estimated the number in Europe and the United Kingdom at about 24,000, as part of its overview of the affected population. The investigational drug's primary mechanism of action, according to the company, is to reduce glutamate levels at synapses.

The earlier regulatory rejection had affected Biohaven's shares and its research and development spending plans. Investing.com reported in its coverage published in November 2025 that the stock fell 44% after the FDA issued the complete response letter. Following the rejection, Biohaven announced a reprioritization, targeting a roughly 60% reduction in annual direct research and development spending. That targeted reduction applies to direct spending, excluding personnel costs and stock-based compensation, according to the company's official statement. The spending reduction plan was thus among the measures Biohaven announced after the treatment's approval application faltered during the previous review.

In the current review cycle, the FDA plans to convene a meeting of the Peripheral and Central Nervous System Drugs Advisory Committee, according to Biohaven's filing. The meeting is intended to obtain outside views on the drug application before the agency. The company said the committee meeting date would be announced soon. The FDA set the first quarter of 2027 as the target for regulatory action on the resubmission. Troriluzole remains an investigational treatment unapproved in the United States as the application moves toward the committee meeting and the target decision date.