A Trial of the Efficacy and Safety of CVL-865 as Adjunctive Therapy in the Treatment of Focal Onset Seizures

The goal of this clinical trial is to learn if CVL-865, when taken regularly with other anti-seizure medicines, works to prevent seizures in adults with drug-resistant focal onset seizures. It will also learn about the safety of CVL-865. The main question it aims to answer is whether CVL-865, when taken regularly with other anti-seizure medicines, lowers the number of seizures in those with a diagnosis of epilepsy with drug-resistant focal onset seizures. This study has an 8-week Screening/Baseline Period, a 13-week Treatment Period (including a 2-week Titration Phase, an 8-week Maintenance Phase, and a 3-week Taper Phase), and a 4-week Safety Follow-Up Period. Participants will take CVL-865 or a placebo twice a day during the 10-13 week Treatment Period, visit the clinic every few weeks for checkups, tests, and surveys, and fill out an e-Diary.