Biohaven rebounds with Phase 3 win, seeks FDA approval after previous rejection

Biohaven is advancing towards seeking FDA approval for its drug candidate, troriluzole, in the fourth quarter, following promising new data indicating the drug significantly slows disease progression in an ultra-rare disorder. This development comes after the FDA declined to review the drug last year.

In 2022, troriluzole failed a phase 3 trial for spinocerebellar ataxia, a degenerative disease affecting coordination and speech. Despite this setback, Biohaven continued monitoring the patients involved. The latest analysis involves 63 patients who were treated with troriluzole for three years. These patients' outcomes were compared to those recorded in external real-world assessments.

The results are encouraging. Patients on troriluzole showed significantly better performance on the f-SARA scale, which measures key functions like gait, stance, sitting, and speech, than their counterparts in the U.S. Clinical Research Consortium for the Study of Cerebellar Ataxia (CRC-SCA). Specifically, the progression rate for patients on troriluzole was 50% slower compared to CRC-SCA participants. Additionally, they exhibited a 70% slower progression rate than participants in a European natural history study. Biohaven interprets this 50% to 70% slowdown as a 1.5 to 2.2-year delay in disease progression over the three-year period.

Moreover, troriluzole outperformed control groups at one and two years of treatment, achieving statistically superior outcomes on nine primary and secondary endpoints, according to Biohaven.

With these results, Biohaven is preparing to apply for FDA approval in the fourth quarter. The company aims to commercialize troriluzole in the U.S. by next year, considering the drug's eligibility for priority review. Concurrently, troriluzole is under regulatory review in the European Union.

Despite the promising data, there are questions regarding the validity of the control comparisons. There is scrutiny over whether the external controls were appropriately matched to the treated patients based on initial health conditions and whether the control outcomes accurately reflect current care standards.

Biohaven asserts that patients from the CRC-SCA study were rigorously matched to those in the troriluzole trial based on baseline characteristics using propensity score matching. CRC-SCA started enrolling patients in 2010 and remains open for recruitment, while the European study collected data from 2005 to 2009.

As the FDA prepares to review the data, there may be further examination of these external controls. Nonetheless, the positive news has been well-received by investors, with Biohaven's shares increasing by 15% to $46.50 in premarket trading.

In addition to spinocerebellar ataxia, troriluzole is also being explored as a treatment for obsessive-compulsive disorder (OCD). Biohaven is nearing key data releases from two phase 3 clinical trials in this indication.

Overall, Biohaven's latest findings put it in a strong position to move forward with FDA approval and potentially bring a new treatment option to patients with spinocerebellar ataxia, while also progressing its development in OCD.