FDA Delays Biohaven’s Approval Decision for Rare Disease Drug Troriluzole

The U.S. Food and Drug Administration (FDA) has postponed its decision on Biohaven Pharmaceuticals’ lead drug candidate, troriluzole, a potential treatment for a group of rare neurological conditions that damage nerve function. The company had anticipated a regulatory verdict by the end of September, following the completion of late-stage clinical trials. However, Biohaven announced that the FDA now requires additional time and input from an independent advisory committee, a move that adds uncertainty to the review process.

This development contradicts Biohaven’s previous communication. In its recent earnings report, the company stated that FDA officials had not mentioned the possibility of convening an advisory panel—a step usually taken when the agency has remaining questions about the safety, efficacy, or overall benefit-risk profile of a drug under review.

Troriluzole is Biohaven’s most advanced clinical candidate and is designed to metabolize into a molecule already approved in the U.S. and Europe to treat amyotrophic lateral sclerosis (ALS). Biohaven is positioning the drug as a therapy for a wider range of conditions, from the rare spinocerebellar ataxia (SCA) to more common illnesses like obsessive-compulsive disorder (OCD).

Key Developments and Market Impact

• Regulatory setback in the U.S.: The FDA’s request for an advisory committee adds months to the review process and suggests increased regulatory scrutiny.

• Unexpected reversal: Just days before the announcement, Biohaven reported no signs from the FDA of needing such a meeting.

• European withdrawal: In March, Biohaven withdrew its marketing application for troriluzole in Europe after the EMA indicated likely rejection and declined to grant a special designation with economic benefits.

• Market reaction: The European decision alone led to a $400 million loss in Biohaven’s market value. Combined with other setbacks, the stock is down roughly 15% over the past six months.

• Investor concerns: Analysts such as Leonid Timashev of RBC Capital Markets say the new delay raises doubts about the overall regulatory outlook for troriluzole and increases the chances of a rejection.

• Staffing issues at the FDA: Some believe the delay may also be partly attributed to internal staffing shortages at the FDA following recent layoffs.

If successful, troriluzole would become the first approved treatment for SCA and could mark a turning point for Biohaven, which has not brought a new therapy to market since it sold its migraine drug portfolio to Pfizer for $12 billion in 2022. The company has indicated it plans to reapply in Europe and remains committed to advancing its rare disease pipeline.