Dive Brief:
- Biohaven Pharmaceutical, the neuroscience-focused drug developer which recently received an almost $12 billion buyout offer from Pfizer, said Monday that one of its experimental medicines failed a late-stage clinical trial testing it in patients with certain genetic disorders that impair muscle control.
- According to Biohaven, the medicine did not perform significantly better than a placebo when used to treat these disorders, known as spinocerebellar ataxia. After 48 weeks, the study found "minimal" change in both groups on a scale used to assess the severity of ataxia cases, results that Biohaven pinned on "less than expected disease progression."
- However, the company noted a "numerical treatment benefit" in a subset of study participants who have the most common form of spinocerebellar ataxia. That benefit, combined with positive safety and tolerability data, are encouraging to Biohaven, which now plans to share the subgroup data with regulators and work with the Food and Drug Administration to "address the high unmet need in this patient population."
Dive Insight:
Biohaven's migraine drugs are what attracted the buyout offer from Pfizer earlier this month. One, Nurtec ODT, has already been approved to both prevent the intense headaches and treat them as they occur.
A strong marketing push that's included celebrity endorsements, NASCAR placements and TikTok ads has helped propel sales of Nurtec ODT and keep it competitive with similar medicines sold by much larger drugmakers like AbbVie. Since coming to market, at least 2 million prescriptions of Nurtec ODT have been written. And over the first three months of this year, Biohaven recorded $124 million in net revenue from the drug.
The Connecticut-based company may soon have a second migraine product, as the FDA just agreed to review an approval application for a medicine called zavegepant. A verdict from the agency is expected in the first quarter of next year.
Unlike Nurtec ODT, which is taken orally, zavegepant comes as a nasal spray designed to relieve migraine pain in as little as 15 minutes. Pfizer estimates that Nurtec ODT and zavegepant, if approved, would create a migraine treatment franchise capable of generating more than $6 billion in peak annual sales.
Per terms of its acquisition, Biohaven's non-migraine assets will be spun into a new company that retains Biohaven's name and leadership. Among those assets is troriluzole, a so-called prodrug of riluzole, a compound which provides some protection to nerve cells and is often given to patients with amyotrophic lateral sclerosis.
Biohaven has evaluated troriluzole across a range of diseases, including Alzheimer's and generalized anxiety disorder. But currently, the drug is in late-stage trials for obsessive compulsive disorder as well as spinocerebellar ataxia.
High-level results released Monday show that, in that latter disease, patients declined about the same regardless of whether they received Biohaven's drug or a placebo. At the start of the study, both groups had an average score of 4.9 on that 16-point scale, which measures ataxia severity and gives higher scores to patients with more advanced disease. After nearly a year of testing, the average scores were 5.1 in the troriluzole group and 5.2 in the placebo group, meaning the study did not meet its primary goal.
Biohaven, though, said there were some positive findings. An after-the-fact analysis, for example, showed participants with the most common form of spinocerebellar ataxia experienced a "numerical benefit" in scores when given troriluzole as opposed to a placebo.
Biohaven also highlighted how troriluzole-treated patients demonstrated "minimal" disease progression over the course of the trial. Across all the participants who were able to walk at the study's onset, the relative risk of falling was reduced by approximately 58% in the troriluzole group, according to Biohaven.
"The importance of morbidity related to falls in this patient population cannot be overstated," said Jeremy Schmahmann, a neurology professor at Harvard Medical School and the founding director of the Ataxia Center at Massachusetts General Hospital.
Schmahmann added that the reduction in falls seen in Biohaven's trial, along with the subgroup data, indicates that patients with this more common type of spinocerebellar ataxia "are experiencing a clinically meaningful improvement in ataxia symptoms on troriluzole treatment."
Still, the comparison on the rate of falls is not listed as a goal of the study on a federal database of clinical trials, while after-the-fact, or "post-hoc," analyses can be misleading and introduce bias.
Spinocerebellar ataxia are a group of disorders that cause progressive loss in muscle control and premature death. They're characterized by the loss of balance and coordination and, eventually, challenges with walking, talking and swallowing. To date, there are no FDA-approved treatments for spinocerebellar ataxia.