Abstracts

Rationale: In the US and Europe, perampanel is approved for focal-onset seizures (FOS), with/without focal to bilateral tonic-clonic seizures (FBTCS), in patients aged ≥ 4 years (US: monotherapy/adjunctive; Europe, adjunctive), and generalized tonic-clonic seizures (GTCS) in patients aged ≥ 12 (≥ 7, Europe) years (adjunctive). Here, we present final results from the AMPA study (NCT04257604; Study 501), which evaluated the effectiveness and safety of adjunctive perampanel in patients with FOS (with/without FBTCS) in a real-life clinical setting in Italy.

Methods: The AMPA study was a multicenter, prospective, real-life, observational study of perampanel as adjunctive therapy in adult and adolescent patients aged ≥ 12 years with FOS, with or without FBTCS. Patients with insufficiently controlled seizures while receiving 1–3 anti-seizure medications (ASMs) were prescribed adjunctive perampanel in line with the approved indication; the treating physician’s decision to prescribe perampanel was made before and independently of their decision to include the patient in the study. Seizure diaries and treatment-emergent adverse events (TEAEs) were verified at study visits (baseline and after 3, 6, and 12 months of treatment). The primary endpoint was percentage change in seizure frequency per 28 days at 6 months (secondary endpoint, Month 12); other secondary efficacy and safety measures included 50% and 75% responder and seizure-freedom rates, retention rates, and monitoring of TEAEs up to 12 months.

Results: Overall, 234 patients received adjunctive perampanel (Safety Analysis Set; mean [range] age, 38.6 [12–84] years; female, 51.3%); 135 (57.7%) patients completed the study. Perampanel was added to a median (range) of 2 (0–5) concomitant ASMs; the most common concomitant ASMs at baseline were carbamazepine (33.8% [n=79]) and levetiracetam (17.9% [n=42]). The mean (standard deviation [SD]) modal dose of adjunctive perampanel was 5.8 (2.5) mg/day. Median reductions from baseline in seizure frequency at Months 6 and 12 were 55.4% (95% confidence interval [CI], 46.7%–66.7%) and 69.2% (95% CI, 58.8%–76.1%), respectively, for FOS (with/without FBTCS) and 100.0% (95% CI, 93.3%–100.0%) and 100.0% (84.9%–100.0%) for FBTCS. The 50% and 75% responder rates increased over the course of treatment to 63.5% and 44.5%, respectively, for FOS (with/without FBTCS), and to 81.3% and 68.8% for FBTCS at Month 12; the seizure-freedom and retention rates were 18.8% and 57.3%, respectively, for FOS (with/without FBTCS) (Table 1). Overall, 132 (56.4%; Table 2) patients experienced TEAEs; most were mild to moderate. The most common treatment-related TEAEs were dizziness/vertigo (19.7% [n=46]); somnolence (8.1% [n=19]); and irritability (7.3% [n=17]).

Conclusions: Final results from this prospective real-world study suggest that adjunctive perampanel is effective in patients aged ≥ 12 years with FOS (with/without FBTCS); no new safety signal raised.

Funding: Please list any funding that was received in support of this abstract.: Eisai S.r.l.