802NP302 Efficacy and Safety Study of BIIB074 in Participants With Trigeminal Neuralgia

Key Inclusion Criteria: * A diagnosis of trigeminal neuralgia (TN) for at least 3 months based on International Headache Society (IHS) diagnostic criteria. * Participant must have failed at least 1 prior standard of care pharmacologic treatment for TN (defined as an inadequate response or intolerance to treatment), as determined by the Investigator based on medical history. * Age ≥18 years at the time of informed consent. * Participants must have recorded their pain score in their eDiary on at least 5 days during the run-in period (Days -7 to -1). * Allowed concomitant medications must have been stable for at least 4 weeks prior to Day 1 of the dose-optimization period. The maximum dosage of carbamazepine allowed on Day 1 is 400 mg/day (or 600 mg/day for oxcarbazepine). Key Exclusion Criteria: * History or positive test result at Screening for hepatitis C virus antibody or current hepatitis B infection (defined as positive for hepatitis B surface antigen \[HBsAg\] and/or hepatitis B core antibody \[HBcAb\]). * Positive history of human immunodeficiency virus (HIV) or a positive HIV test at Screening. * Participants with facial pain other than TN. * Personal or family (first-degree relative) history of seizures (except for simple febrile convulsions) or clinically significant head injury. * Positive drug screen for drugs of abuse at Screening (amphetamine \[methamphetamines and 3,4-methylenedioxymethamphetamine\], phencyclidine, barbiturates, benzodiazepines, cocaine, opioi…