US FDA pauses new enrollment in Biohaven's epilepsy drug trials

Sept. 10 (Reuters) - Biohaven said on Thursday the U.S. FDA had imposed a partial clinical hold, pausing new patient enrollment in trials of its experimental epilepsy drug after rodent findings, sending its shares down more than 13% in premarket trading.

• The U.S. 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 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.
• More than 1,200 participants have received BHV-7000, which has generally been safe and well tolerated, the company said. Further animal data expected in the coming weeks will assess whether the finding is relevant to human safety, it added.
• 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 has not closed and remains subject to a U.S. antitrust filing.