Perampanel for the treatment of epilepsy; Longitudinal actuarial analysis and dose responses based on monthly outcomes

Abstract Purpose: To explore the retention rates and the efficacy and tolerability of perampanel (PER) by using monthly real life data for a period of 12 months. Methods: Longitudinal outcomes of (PER) usage were assessed using actuarial statistics in an observational nonrandomised multicentre study of 181 people with epilepsy (PWE) refractory to first and second line drugs. Graded seizure outcomes, toxicity and the dose of PER were recorded for each month. Results: PWE were followed for a mean of 15.1 months. The total cumulative probability for retention on PER at 12 months was 61.7% and for ≥50% improvement was 38.2%. Most improvements in seizure control occurred soon after initiation of PER, 17% by one month, 32% by six months and 38% by twelve months, and mostly at low doses 53% on 2 mg and 90% up to 6 mg. Improvements, when they occurred, were sustained. The most common side effects were neuropsychiatric, occurring in 28%. The emergence of side effects did not appear to be dose related. Although people with intellectual disability (ID) were more likely to remain on PER they did not show improved seizure control and also reported more side effects. Patients treated with VNS and PER had a worse outcome. Conclusion: Overall around a third of people showed a useful, response to PER therapy. The response to PER is noted usually early in the treatment and for the majority of the patients for doses up to 8 mg.