Experience of perampanel monotherapy beyond initial titration to achieve seizure freedom in patients with focal-onset seizures with newly diagnosed or currently untreated recurrent epilepsy: A post hoc analysis of the open-label Study 342 (FREEDOM).

OBJECTIVE: This post hoc analysis evaluated whether continued treatment with perampanel monotherapy beyond initial titration may be appropriate for patients with focal-onset seizures (FOS) with currently untreated epilepsy to achieve seizure freedom with an effective dose. METHODS: Study 342 (NCT03201900; FREEDOM) is a single-arm, open-label, Phase III study of perampanel monotherapy. Patients aged ≥12 years with untreated FOS received perampanel 4 mg/d in a 32-week Treatment Phase (6-week Titration and 26-week Maintenance Periods); in case of seizure(s) during Maintenance Period, patients could enter a 30-week Treatment Phase (4-week Titration and 26-week Maintenance Periods) to be up-titrated to perampanel 8 mg/d. The primary endpoint was seizure-freedom rate during Maintenance Period in the modified Intent-to-Treat (mITT) Analysis Set (patients who had ≥1 post-dose efficacy measurement during Maintenance Period); safety was monitored. This analysis of 4-mg/d efficacy data assessed the proportion of patients achieving seizure freedom during the Maintenance Period (responders) relative to patients with an early/later response (depending on seizure status during the Titration Period). RESULTS: In the mITT population (n = 73), 46 patients were 4-mg/d responders; of whom, 37 (80.4%) were early responders and nine (19.6%) were later responders. The mean (standard deviation) percent reductions in FOS frequency from baseline at the end of the 4-mg/d Titration Period were 100.0% (0.0%; early responders) and 46.3% (97.3%; later responders). Among the 27 4-mg/d nonresponders, nine (33.3%) patients who had an early response experienced seizure(s) during the subsequent 4-mg/d Maintenance Period. Safety outcomes were similar, regardless of responder status, without new safety concerns. SIGNIFICANCE: Some patients with untreated FOS may benefit from continued treatment beyond initial titration of perampanel monotherapy to achieve seizure freedom, suggesting that it may not be appropriate to make treatment decisions to discontinue or switch from perampanel monotherapy solely based on seizure response before an effective dose has been reached.

Efficacy and safety of perampanel monotherapy in patients with focal-onset seizures with newly diagnosed epilepsy or recurrence of epilepsy after a period of remission: The open-label Study 342 (FREEDOM Study).

OBJECTIVE: Our study assessed perampanel monotherapy in patients (aged ≥12 years) with focal-onset seizures (FOS) with or without focal to bilateral tonic-clonic seizures (FBTCS) in Japan and South Korea. METHODS: Study 342 (NCT03201900; FREEDOM) is a single-arm, open-label, Phase III study. Patients initially received perampanel in a 32-week 4-mg/d Treatment Phase (6-week Titration; 26-week Maintenance Periods). If they experienced a seizure during the 4-mg/d Maintenance Period, they could be up-titrated to 8 mg/d across an additional 30-week Treatment Phase (4-week Titration; 26-week Maintenance Periods). Primary endpoint was the seizure-freedom rate during the Maintenance Period (4 mg/d and last evaluated dose [4 or 8 mg/d]). Secondary endpoints included time to first seizure onset and to withdrawal during Maintenance. Treatment-emergent adverse events (TEAEs) were monitored. RESULTS: At data cutoff (February 28, 2019), 89 patients with FOS (84 [94.4%] with newly diagnosed epilepsy and 5 [5.6%] with recurrence of epilepsy after a period of remission) had received ≥1 perampanel dose; 16 patients discontinued during the 4-mg/d Titration Period, meaning 73 patients entered the 4-mg/d Maintenance Period and were included in the primary analysis set for efficacy. Seizure-freedom rate in the 26-week Maintenance Period was 46/73 (63.0%; 95% confidence interval [CI]: 50.9-74.0) at 4 mg/d and 54/73 (74.0%; 95% CI: 62.4-83.5) at 4 or 8 mg/d. Cumulative probability of seizure-onset and withdrawal rates during Maintenance was 30.8% (95% CI: 21.5-43.0) and 23.7% (95% CI: 15.4-35.3) at 4 mg/d, and 18.2% (95% CI: 11.0-29.3) and 23.3% (95% CI: 15.2-34.8) at 4 or 8 mg/d. Perampanel was generally well tolerated, and the most common TEAE was dizziness. SIGNIFICANCE: Perampanel monotherapy (4 to 8 mg/d) was efficacious and consistent with the known safety profile up to 26 weeks in patients (≥12 years) with primarily newly diagnosed FOS with or without FBTCS.

Long-term tolerability, safety and efficacy of adjunctive perampanel in the open-label, dose-ascending Study 231 and extension Study 233 in Japanese patients with epilepsy.

PURPOSE: To evaluate long-term tolerability, safety and efficacy of adjunctive perampanel in a Phase II, multicentre, open-label, dose-ascending Study 231 (NCT00849212) and its extension (Study 233; NCT00903786) in Japanese patients with refractory partial-onset seizures (POS), with/without secondarily generalised seizures. METHODS: In Study 231, patients received adjunctive perampanel ≤12 mg/day during a 10-week treatment period. Patients completing Study 231 could enter Study 233 (≤316-week treatment period). Assessments included monitoring of treatment-related treatment-emergent adverse events (TEAEs), median percent change in seizure frequency per 28 days, 50% responder and seizure-freedom rates. During Study 231, a pharmacokinetic analysis assessed the effects of enzyme-inducing antiepileptic drugs. RESULTS: Overall, 23/30 (76.7%) patients completed Study 231; 21/30 (70.0%) received perampanel ≥8 mg/day and 10/30 (33.3%) achieved a maximum tolerated dose of 12 mg/day. Median percent change in seizure frequency per 28 days was -35.0%. 50% responder rate was 37.0%; 4 (13.3%) patients achieved seizure freedom. Twenty-one patients entered Study 233. Mean duration of exposure was 195 weeks; 9 (42.9%) patients received perampanel for ≤208 weeks. Seizure control was sustained for 316 weeks in 3/21 (14.3%) patients; 2 achieved seizure freedom. Treatment-related TEAEs were tolerable; the most common was dizziness (Study 231, 53.3%; Study 233, 14.3%). Mean perampanel plasma concentrations were lower with concomitant carbamazepine vs non-inducers (152.7 ng/mL vs 389.4 ng/mL across perampanel groups); small patient numbers for non-inducers (n = 2) should be considered when interpreting these data. CONCLUSION: Adjunctive perampanel demonstrated a favourable safety profile and long-term tolerability in Japanese patients with refractory POS for ≤316 weeks.