An Open Label Trial to Evaluate the Efficacy and Safety of PRAX-628 in Adults With Focal Onset or Tonic-Clonic Seizures

Inclusion Criteria: * A diagnosis of focal onset seizures or idiopathic generalized tonic clonic seizures. * Evidence by computed tomography (CT) or magnetic resonance imaging (MRI) in the past that has ruled out a progressive cause of epilepsy. * Participant must have been receiving stable doses of allowable ASMs (a minimum of 1 and a maximum of 3 ASMs). * Participant and/or caregiver (if applicable) self-reports at least 2 countable focal onset seizures per month for focal onset patients, or 1 countable generalized tonic-clonic seizure per month in the 3 months immediately prior to the Screening/Observation Period for PGTCS patients. Exclusion Criteria: * History of pseudo or psychogenic seizures, or cluster seizures only, within the 12-month period preceding study entry where the individual seizures cannot be counted, or an episode of convulsive status epilepticus requiring hospitalization and intubation in the 12 months prior to Screening. * Planned epilepsy surgery during the course of the clinical trial. * History of neurosurgery for seizures \<1 year prior to enrollment, or radiosurgery \<2 years prior to enrollment. * Schizophrenia and obsessive-compulsive disorder, or other serious mental health disorders. * Active suicidal plan/intent in the past 6 months, or a history of suicide attempt in the last 2 years, or more than 1 lifetime suicide attempt. * Participants with a history of malignancy, myeloproliferative or lymphoproliferative disorders within the past 5 y…