A Study to Evaluate the Efficacy and Safety of Perampanel Monotherapy in Untreated Participants With Focal Onset Seizures With or Without Focal to Bilateral Tonic-clonic Seizures

Inclusion Criteria:

1. Male and female, age 4 years or older

2. Diagnosis of epilepsy with FOS with or without FBTCS according to the InternationalLeague Against Epilepsy (ILAE) Classification of Epileptic Seizures (2017),established by clinical history and an electroencephalogram (EEG)

3. Newly diagnosed or recurrent epilepsy with at least 2 unprovoked seizures (excludingfocal non-motor seizures) separated by a minimum of 24 hours in the 1 year beforeVisit 1 (baseline)

Exclusion Criteria:

1. Focal non-motor seizures only

2. Generalized epilepsies or seizures such as absences and/or myoclonic seizures, orLennox Gastaut syndrome

3. History of status epilepticus within 1 year before Visit 1 (baseline)

4. History of psychogenic non-epileptic seizures within 5 years before Visit 1 (baseline)

5. Progressive central nervous system (CNS) disease (including degenerative CNSdiseases, progressive tumors, and dementia), or clinically significant psychologicalor neurological disorders

6. History of suicidal ideation/attempt within 5 years before Visit 1 (baseline)

7. Evidence of clinically significant active hepatic disease, or other clinicallysignificant disease (example, cardiac, respiratory, gastrointestinal, renal disease)that in the opinion of the investigators could affect the participant safety orinterfere with the study assessments

8. History of any type of brain or central nervous system surgery within 1 year beforeVisit 1 (baseline)

9. Newly started ketogenic diet or has been on ketogenic diet for less than 5 weeksbefore Visit 1 (baseline)

10. Multiple drug allergies or a severe drug reaction to anti-epileptic drugs (AEDs),including dermatological (example, Stevens-Johnson syndrome), hematological, ororgan toxicity reactions

11. Hypersensitive to perampanel or ingredients of this drug

12. Participant with genetic problems including galactose intolerance, Lapp lactasedeficiency, or glucose-galactose malabsorption

13. Use of intermittent rescue medication on 2 or more occasions within 4 weeks beforeVisit 1 (baseline)

14. History of receiving any AED (except for occasional use less than 2 weeks of AEDs asrescue treatment), antipsychotics, or anti-anxiety drugs within 12 weeks beforeVisit 1 (baseline)

15. History of receiving any AED (including rescue treatment) for more than 2 weeks intotal within 2 years before Visit 1 (baseline)

16. Has received prior treatment with perampanel

17. Females of child bearing potential who are breastfeeding or pregnant at Visit 1 (baseline), or who do not consent to employ contraception

18. Currently enrolled in another clinical study or have used any investigationaldrug/biologics or device within 28 days or 5*half-life, whichever is longer

19. Participant who did not consent to having at least 2 weeks of washout period beforeVisit 2, if known to take Cytochrome P4503A (CYP3A) inducing drugs or foods on Visit 1 (including, but not limited to the following) - Carbamazepine, enzalutamide,mitotane, phenytoin, phenobarbital, amobarbital, secobarbital, rifabutin,rifampicin, food containing St. John's Wort (hypericum perforatum), bosentan,efavirenz, etravirine, modafinil, armodafinil, rufinamide, nevirapine,oxcarbazepine, and glucocorticoid (except for topical use)