This Phase 2/3 multicenter, randomized, placebo-controlled, double-blind study will evaluate the safety and efficacy of JZP926 capsule in participants aged ≥ 10 years with Juvenile Myoclonic Epilepsy (JME). The study will assess the efficacy of JZP926 capsule as an adjunctive treatment in reducing the frequency of myoclonic seizure days when compared with placebo, as well as the effect of JZP926 capsule on non-seizure endpoints.