Biohaven reports an FDA partial clinical hold on BHV-7000 new enrollment while keeping pivotal epilepsy trial data readouts on track.

Announced mere weeks after Biohaven sold off rights to the therapy, opakalim, the halt affects a study some analysts believe is necessary to support a potential approval.

Biohaven stock plummeted Thursday after the company paused enrollment in a midstage study of its seizure treatment.