Antiepileptic Drug Perampanel (Fycompa) Meets Primary Endpoints in Phase III Trial
Treatment is approved in U.S. for adjunctive therapy of partial-onset seizures
A phase III trial of perampanel (Fycompa, Eisai Co., Ltd.), an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, has met its primary endpoints in patients with primary generalized tonic-clonic (PGTC) seizures — one of the most severe forms of generalized seizures.
The double-blind, randomized, placebo-controlled, parallel-group study evaluated the efficacy and safety of adjunctive therapy with perampanel in 164 patients aged 12 years and older with uncontrolled PGTC seizures receiving one to a maximum of three anti-epileptic drugs. The patients were randomly assigned to receive perampanel or placebo.
Perampanel significantly reduced the frequency of PGTC seizures and improved responder rates (i.e., the percentage of patients who experienced a 50% or greater reduction in PGTC seizure frequency), the study’s two primary outcome measures, compared with placebo. The most common adverse events were dizziness, fatigue, headache, irritability, and somnolence.
Based on the results of this study, an application is expected to be submitted to the FDA during the first half of 2014 for an indication expansion to include the adjunctive treatment of PGTC seizures. Fycompa (perampanel) is currently approved in the U.S. as an adjunctive treatment for partial-onset seizures (with or without secondary generalized seizures) in patients with epilepsy aged 12 years and older.
Perampanel is a selective, noncompetitive AMPA receptor antagonist that reduces neuronal hyperexcitation associated with seizures by targeting glutamate activity at postsynaptic AMPA receptors.
Epilepsy reportedly affects 2.2 million people in the U.S. and more than 50 million people worldwide. The disorder is broadly categorized by seizure type, with partial-onset seizures accounting for approximately 60% of epilepsy cases and generalized seizures accounting for approximately 40%. PGTC seizures are one of the most common and most severe forms of generalized seizures, accounting for approximately 60% of generalized epilepsy and approximately 20% of all epilepsy cases.
For most patients, a PGTC seizure begins with a loss of consciousness without prior warning symptoms and a sudden contraction of the tonic muscles, causing the patient to fall down (tonic phase). This is followed by violent convulsions (clonic phase) until the muscles relax. Although the seizures generally last only a few minutes, the patient will often feel confused, groggy, or drowsy for a short period before returning to normal.
Source: Eisai Co., Ltd.; June 17, 2014.