Temporal Profile of Treatment-Emergent Adverse Events in Adult Asian Patients with Focal-Onset Seizures During Adjunctive Brivaracetam Treatment: Post Hoc Analysis of a Phase 3, Randomized Trial.

INTRODUCTION

We assessed the time course of treatment-emergent adverse events (TEAEs) in adult Asian patients (in Thailand, Japan, China, Philippines, Malaysia, Singapore, and Taiwan) with focal-onset seizures (FOS) during adjunctive brivaracetam (BRV) treatment.

METHODS

Post hoc analysis of EP0083/NCT03083665, a Phase 3, randomized, double-blind, placebo (PBO)-controlled trial that evaluated BRV 50 and 200 mg/day in adult Asian patients (≥ 16-80 years) with FOS. Following an 8-week prospective baseline, patients were randomized 1:1:1 to PBO, BRV 50 mg, or BRV 200 mg and entered a 12-week treatment period.

RESULTS

Overall, 448 patients (mean age 34.5 years; 53.8% female) received ≥ 1 dose of trial medication (PBO/BRV 50 mg/BRV 200 mg: n = 149/151/148 [Safety Set]). The overall incidence of TEAEs was similar across treatment arms (53.6-58.1%), and most TEAEs were mild in intensity (45.0-48.3%). Patients discontinuing BRV because of TEAEs (1.3% BRV 50 mg; 2.7% BRV 200 mg) discontinued during the first 5 weeks of treatment (for PBO, discontinuations due to TEAEs [3.4%] took place between weeks 1-8). The incidence of drug-related TEAEs was 18.1% in patients receiving PBO, 24.5% in those on BRV 50 mg/day, and 39.2% for BRV 200 mg/day; however, most were of mild intensity and did not lead to BRV discontinuation. The incidence of TEAEs and drug-related TEAEs was highest during the first week of adjunctive BRV treatment and decreased thereafter. The onset of drug-related somnolence and dizziness occurred mainly during the first week of treatment.

CONCLUSION

In Asian adults with FOS, most drug-related TEAEs were mild in intensity, indicating that adjunctive BRV had a favorable tolerability profile when initiated at a potentially therapeutic dose without titration. The incidence of drug-related TEAEs including somnolence and dizziness was highest during the first week of adjunctive BRV treatment, abating thereafter. These tolerability data could help inform patient monitoring and treatment decisions when prescribing BRV.

TRIAL REGISTRATION: ClinicalTrials.gov NCT03083665.