Effectiveness and safety of perampanel as early add-on treatment in patients with epilepsy and focal seizures in the routine clinical practice: Spain prospective study (PERADON)

Abstract Objective Perampanel (PER) has been shown to be effective as an adjunctive therapy for controlling refractory focal-onset seizures (FOS). However, the information as early add-on for the treatment of FOS in the clinical practice is still scarce and must be further assessed. Methods An observational prospective study was conducted to evaluate the effectiveness of early add-on PER, assessed as 50% responders (seizure frequency reduced by at least 50% during the last 3 months as compared with baseline) rate at 6 and 12 months, in patients with FOS in the routine clinical practice of Spain. Results One hundred and thirteen patients (mean age: 40.3 years, 51.3% male) with FOS received PER as early add-on (1st add-on: 37.2% and 2nd: 62.8%) for a mean exposure of 11 months (mean PER dose: 6.3 mg/day at month 12). At 6 months, 50.4% and 20.4% of the patients were responders and seizure-free (respectively) relative to baseline (3 months prior to PER initiation), and at 12 months, 68.1% and 26.5% of the patients were responders and seizure-free (respectively), relative to baseline (3 months prior to PER initiation). The retention rate at 6 and 12 months was 83.2% and 80.5%, respectively. The percentage of seizure-free patients at 12 months was significantly (p = 0.033) higher when PER was added as first vs. second add-on. The number of concomitant antiepileptic drugs (AEDs) was significantly reduced from baseline to 6 and 12 months (p = 0.001). Treatment was simplified in 23.9% of patients at the end of the observation period. Drug-related adverse events (AEs), most mild or moderate, were reported in 30.1% of patients, with irritability (8%) and dizziness (7.1%) as the most frequent ones. Conclusions This is the first observational, prospective study to evaluate efficacy and safety of early adjunctive treatment with PER in patients with focal epilepsy at 12 months. Perampanel demonstrated a good efficacy and safety profile when used at a median dose of 6 mg/day, regardless of the combination with other AEDs. Adverse events were mild or moderate, with dizziness being the most frequent one.