Effectiveness of perampanel as the only adjunctive anti-seizure medication in adults: Final results from the observational PERPRISE study in Germany.

Objective: The PERPRISE study (Study 509; NCT04202159) was a prospective, observational, non-interventional study in a real-world setting in Germany. This study was conducted to evaluate the effectiveness of perampanel as the only adjunctive treatment for 12 months in patients aged ≥18 years with focal to bilateral tonic-clonic seizures (FBTCS) or generalized tonic-clonic seizures (GTCS) in clinical practice.

Methods: Adult patients with FBTCS or GTCS received perampanel as an adjunctive therapy to anti-seizure medication (ASM) monotherapy (add-on therapy) or as a substitute for one ASM in dual therapy (substitution therapy) per the approved indication. The primary endpoint was the 12-month retention rate of perampanel; the secondary endpoints were the 6-month retention rate, seizure freedom for FBTCS or GTCS at 12 months, and safety and tolerability. Exploratory endpoints included efficacy assessments by seizure type at 6 and 12 months and patient-reported outcomes.

Results: Of the 185 patients enrolled in the study, 183 patients were included in the full analysis set (add-on, 86 patients; substitution, 96 patients; missing, 1 patient). The 12-month retention rate was 66.7% (add-on, 67.4%; substitution, 66.7%); the 6-month retention rate was 80.3% (add-on, 82.6%; substitution, 78.1%). At 12 months, the seizure-freedom rate for FBTCS or GTCS was 42.3% (add-on, 51.7%; substitution, 35.1%). Treatment-emergent adverse events (TEAEs) occurred in 44.0% of patients; 6.0% of patients reported serious TEAEs, and 16.5% of patients withdrew from the study due to TEAEs. Treatment with perampanel did not adversely affect cognitive function in patients with FBTCS or GTCS, and improvements in quality of life were reported by patients at both 6 and 12 months following perampanel initiation.

Significance: Findings from the PERPRISE study suggest that perampanel as an only adjunctive therapy is associated with favorable retention rates and good tolerability in patients with FBTCS or GTCS in a real-world clinical setting in Germany.

Plain Language Summary: Patients with epilepsy often take multiple treatments to control their seizures. It is important to look at how well they work in everyday life. This study looked at adult patients in Germany taking perampanel added to one other epilepsy treatment. After 1 year, 58 of 137 patients suffering from the most severe type of seizure were free of them. Side effects occurred in 80 patients (most commonly dizziness, fatigue, and nausea) and caused 30 of them to withdraw from treatment. Perampanel was effective and did not seem to negatively affect patients' thinking ability or quality of life.