This study is to assess the efficacy, safety, and tolerability of the investigational drug UCB0942in adult subjects with drug-resistant focal epilepsy across multiple centers in Europe.

The study will include a Screening Visit, a Prospective Outpatient Baseline Period (2 to 3 weeks), an Inpatient Period (3 weeks), an Outpatient Period (8 weeks of treatment and 2 weeks of taper), and a Safety Follow-Up Period (4 weeks). The total study duration after screening will be 19 to 20 weeks. Approximately 6 months after the last visit subjects will be asked to return for an additional visit.

Inclusion Criteria:

• Subject is an adult (18 years of age or more)
• Subject is able to understand the study and the ICF as assessed by the Investigator. Subjects with known mental retardation (defined as IQ below 70) are not eligible to participate. Subject and/or caregiver is considered reliable and capable of adhering to the protocol (eg, able to understand and complete diaries), visit schedule, and the medication intake scheme as instructed according to the judgment of the Investigator
• Subject fulfills ILAE (1989) criteria for focal epilepsy; clinical semiology should be described and fulfill criteria for focal seizures; there will have been an electroencephalogram (EEG) reading compatible with focal epilepsy in the last 5 years; the subject has no seizures that are not focal by the new ILAE criteria; a brain MRI (magnetic resonance imaging) or head CT (computed tomography) to be performed before randomization, if no such scan was performed in the last 5 years, and a report is available. If a scan was performed within the last 5 years but the epilepsy has not been stable since the last scan, a new scan should be obtained
• Subject has failed to achieve seizure control with ≥4 appropriately chosen Antiepileptic Drug (AED) regimens of adequate dose and duration, including the current treatment, as documented in medical records and per Investigator assessment of patient report
• Subject is currently treated with a stable dose of at least 1 AED for the 4 weeks prior to the Screening Visit (Visit 1) and throughout the duration of the Treatment Period with or without additional concurrent vagus nerve stimulation (VNS) or other neurostimulation treatments. The VNS must have been in place for at least 12 months with constant settings for at least 3 months and the battery life of unit anticipated to extend for the duration of study prior to the Screening Visit and throughout the duration of the study
• During the 4 weeks prior to Screening (Historical Baseline Period), subject must report to have had an average of at least 4 spontaneous and observable focal seizures per week ("focal seizures" refers to partial-onset seizures of type IA1, IB, and IC, but does not include type IA2, IA3, or IA4 seizures), and cannot have had any seizure-free period longer than 3 days (based on Investigator assessment of subject report and seizure diaries if available). The cut-off seizure frequency (4 seizures per week) and maximum seizure-free interval (3 days) must be maintained during the 2-week Prospective Outpatient Baseline Period
• Female subjects of nonchildbearing potential (premenarcheal, postmenopausal for at least 2 years, bilateral oophorectomy or tubal ligation, and complete hysterectomy) are eligible. Female subjects of childbearing potential are eligible if they use medically accepted contraceptive methods. Oral or depot contraceptive treatment with at least ethinylestradiol 30 μg per intake used with an additional barrier contraception method, monogamous relationship with vasectomized or female partner, or double-barrier contraception are acceptable methods. The subject must understand the consequences and potential risks of inadequately protected sexual activity, be educated about and understand the proper use of contraceptive methods, and undertake to inform the Investigator of any potential change in status. Abstinence will be considered as an acceptable method of contraception if the Investigator can document that the subject agrees to be compliant when it is in line with the preferred and usual lifestyle of the subject
• Male subjects confirm that during the study period and for a period of 3 months after the final dose, when having sexual intercourse with a woman of childbearing potential, he will use a barrier contraceptive (eg, condom) and that the respective partner will use an additional contraceptive method

Exclusion Criteria:

• Subject has participated in another study of an investigational medication (or medical device) within the last 30 days or is currently participating in another study of an investigational medication (or a medical device)
• Subject has a known hypersensitivity to any components of UCB0942 formulation or to similar drugs (LEV, BRV, or benzodiazepines), or a history of drug or other allergy that, in the opinion of the Investigator or UCB Study Physician, contraindicates her/his participation
• Subject has a current or past psychiatric condition that, in the opinion of the Investigator, could compromise his/her safety or ability to participate in this study including a history of schizophrenia, schizoaffective disorder, bipolar disorder, or severe unipolar depression. The presence of potential psychiatric exclusion criteria will be determined based on screening with the BPRS plus the Mini International Neuropsychiatric Interview (MINI)
• Subject has taken other (non-AED) prescription, nonprescription, dietary (eg, grapefruit or passion fruit), or herbal products that are potent inducers or inhibitors of the CYP3A4 pathway for 2 weeks (or 5 half-lives, whichever is longer) prior to the Baseline Visit
• Subject is currently treated with carbamazepine, phenytoin, primidone, or phenobarbital or any other drug known to induce CYP3A4 liver enzymes; Subject is taking tiagabine, felbamate, or vigabatrin; Subject is taking benzodiazepines, zolpidem, zaleplon, or zopiclone >3 times per week for any indication
• Subject has a clinically significant abnormality on echocardiography at Screening or a history of rheumatic heart disease or other known valvular abnormalities
• Subjects with a history of hypersensitivity reactions or autoimmune disease
• Female subject who is pregnant or breastfeeding