USFDA Imposes Partial Clinical Hold on Biohaven's Epilepsy Drug Over Rodent Findings

The US ⁠Food and ⁠Drug Administration imposed the hold on September 4, citing insufficient information to assess ​the potential human risk from a metabolite - a substance produced when the body breaks down ​a drug - identified during rodent testing.Biohaven said the finding's significance to humans was uncertain and it could be specific to rodents. The ​company also voluntarily extended the enrollment pause ⁠to sites ‌outside the U.S.

BHV-7000 is being developed to treat refractory focal epilepsy, in which seizures start in one area of ⁠the brain and persist despite treatment with at least two suitable anti-seizure medicines.

More than 600 patients already ​assigned to treatment can continue receiving the drug, Biohaven said.

One fully enrolled late-stage trial remains on track to report results in the second half of 2026. Enrollment in another is paused, while existing patients and those in a related extension study will continue treatment.

RBC Capital Markets analysts said though the partial hold adds development and safety risk, these may be resolved relatively ​quickly given ​the drug's safety ⁠record in more than 1,200 participants and additional animal data expected within weeks.

Biohaven said it disclosed the findings to SK Biopharmaceuticals before an August 26 ​deal granting it worldwide rights to BHV-7000 and related drugs. The deal remains subject to a U.S. antitrust filing.

William Blair analysts said the pause would likely delay a potential U.S. approval application and extend Xenon Pharmaceuticals' lead with its rival experimental epilepsy drug, azetukalner.