Biohaven’s attempts to redefine itself as a post-migraine company are continuing to encounter headaches, with the company expressing “deep disappointment” at the FDA’s refusal to review the brain disorder drug troriluzole.
Even according to Biohaven’s description, the FDA’s reasoning is straightforward—as the drug has previously failed a phase 3 trial in spinocerebellar ataxia, the regulator “would not permit a substantive review.”
In the phase 3 study readout in May 2022, an unexpected lack of disease progression among trial participants over the nearly one-year follow-up period hindered the impact of the drug. Despite failing the trial, CEO Vlad Coric, M.D., said at the time that the company looked forward to sharing genotype data with regulators and “working with the FDA to address the high unmet need in this patient population.”
Coric wasn’t the only one who remained upbeat on the drug’s chances, with Mizuho Securities analysts also pointing out last year that there are no treatment options for the disease. If Biohaven was able to find positive results for the subgroup as it planned to do, the analysts noted at the time, troriluzole could still find a niche market.
It was with this mindset that Biohaven submitted troriluzole for approval to the FDA last month. The new drug application was specifically for patients with the genotype SCA3, who the company said had demonstrated “consistent treatment benefits.” This group represents the most common form of SCA and accounted for 41% of the population of the failed phase 3 trial.
Despite the agency's refusal to review the application, Biohaven “is committed to working closely with the FDA to bring troriluzole to people with SCA3 as quickly as possible given no therapy is currently approved for this ultra-rare genetic disorder.”
The company was given the option to request a Type A meeting with the regulator within 30 days, and Biohaven said it will take up this offer to “comprehensively address FDA's concerns cited in the refusal to file letter.” These letters are issued when the agency determines that an application has significant deficiencies.
“As a physician, I am deeply disappointed by the FDA's decision not to review the submitted NDA, and not to give complete consideration of all available data that we believe show disease-modifying effects for this genetic disorder that has no approved treatments,” Coric said in this morning’s release.
“We believe the NDA package is compelling and shows that treatment with troriluzole leads to clinically meaningful treatment benefits, including significantly delaying disease progression and reduction in falls,” the CEO added. “We stand by these data and analyses.”
Luckily, Biohaven’s fortunes don’t rest on troriluzole. The company has been making efforts to flesh out its neuroscience pipeline since relaunching after the sale of its migraine program to Pfizer for more than $11 billion in 2022. Most recently, that has meant licensing a neuroinflammation drug from China’s Highlightll Pharmaceuticals. The company also tried to soften the blow of the FDA’s decision this morning by highlighting positive interim data from its lead investigational epilepsy candidate BHV-7000 in healthy volunteers.
Biohaven’s shares were down 16% to $20 in pre-market trading Thursday from a Wednesday closing price $23.80. Still, it marks a relatively small dent in an overall positive year for Biohaven’s stock, which entered 2023 at just $13.50.