A Study to Evaluate the Safety and Tolerability of Intravenous Brivaracetam (BRV) as Replacement for Oral Brivaracetam in Japanese Subjects >=16 Years of Age With Partial Seizures With or Without Secondary Generalization

Inclusion criteria

• Subject has, in the opinion of the Investigator, adequate seizure control for participation in the study, and is willing and able to comply with all study requirements including hospitalization, multiple blood draws, and intravenous (iv) injection
• Female subjects without childbearing potential (postmenopausal for at least 2 years, bilateral oophorectomy or tubal ligation, complete hysterectomy) are eligible. Female subjects with childbearing potential are eligible if they use a medically accepted contraceptive method
• Japanese subject is currently enrolled in EP0085 [NCT03250377] receiving oral brivaracetam (BRV) for the treatment of partial seizures and has been enrolled for at least 8 weeks prior to entry into EP0118
• Subject has been on a stable twice daily dosage regimen of BRV 50 mg/day to 200 mg/day for the 4 weeks prior to entry into EP0118
• Subject has been receiving concomitant antiepileptic drug (AED(s)) at doses that have remained stable for the 4 weeks (12 weeks for phenobarbital, phenytoin, and primidone) prior to entry into EP0118
• Subject has been receiving drugs with possible central nervous system (CNS) effects at doses that have remained stable for the 4 weeks prior to entry into EP0118, if applicable
• Subject has been receiving drugs that significantly influence the metabolism of BRV at doses that have remained stable for the 4 weeks prior to entry into EP0118, if applicable
• Subject has had stable vagal nerve stimulation (VNS) settings for the 4 weeks prior to entry into EP0118, if applicable

Exclusion criteria

• Subject is receiving an investigational medicinal product (IMP) or unapproved medication other than oral BRV, or using an experimental medical device
• Subject has previously been treated with intravenous (iv) brivaracetam (BRV)
• Subject has a known hypersensitivity to any components of the investigational medicinal product (IMP) or comparative drugs as stated in this protocol
• Subject has a confirmed clinically relevant abnormality by electrocardiogram (ECG)
• Subject has a severe medical, neurological, or psychiatric disorder, or abnormal laboratory values which may have an impact on the safety of the subject
• Subject has demonstrated poor compliance with the visit schedule or medication intake in previous BRV studies
• Subject has planned participation in any other clinical study of another IMP or device during this study
• Subject is a pregnant or lactating female
• Subject has any medical condition which, in the Investigator's opinion, warrants exclusion
• Subject has a lifetime history of suicide attempt (including an active attempt, interrupted attempt, or aborted attempt), or has suicidal ideation in the past 6 months as indicated by a positive response ("Yes") to either Question 4 or Question 5 of the Columbia-Suicide Severity Rating Scale (C-SSRS) "Since Last Visit" at Screening
• Subject has >2x upper limit of normal (ULN) of any of the following prior to Day 1 (from liver function assessment in EP0085): alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), or >ULN total bilirubin (>=1.5x ULN total bilirubin if known Gilbert's syndrome)