On June 22, 2015, the US Food and Drug Administration (FDA) approved an expanded indication for perampanel hydrate (Fycompa; Eisai), an oral antiepileptic drug. This new indication allows the use of perampanel hydrate as an adjunctive treatment for primary generalized tonic-clonic (PGTC) seizures in patients with epilepsy aged ≥12 years.1 The FDA approval was based on new data from a phase 3 clinical trial showing a significant reduction in the frequency of PGTC seizures and freedom from seizures with perampanel hydrate versus placebo.1-3
Perampanel hydrate, a first-in-class α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist, was initially approved in 2012 as an adjunctive treatment for partial-onset seizures with or without secondarily generalized seizures in patients with epilepsy aged ≥12 years. Perampanel hydrate was launched in the United States in January 2014.1
The recommended starting dosage of perampanel hydrate in patients with PGTC who are not receiving concomitant enzyme-inducing antiepileptic drugs is 2 mg once daily, taken orally at bedtime. The dose should be increased by increments of 2 mg once daily and no more than at weekly intervals. The recommended maintenance dose in patients who are not taking enzyme-inducing antiepileptic drugs is 8 mg once daily, at bedtime. The maintenance dose of this drug can be increased to a maximum of 12 mg once daily.2
The prescribing information for perampanel hydrate includes a boxed warning regarding the risk for serious or life-threatening psychiatric and behavioral adverse reactions, including aggression, hostility, irritability, and homicidal ideation.2 In 2013, perampanel hydrate was placed into Schedule III of the US Controlled Substances Act, because it has central nervous system depressant and hallucinogenic properties.4
Study 332: Efficacy and Safety
The approval was based on new data from Study 332, a placebo-controlled, multicenter, phase 3 clinical trial.1,2 A total of 162 patients aged ≥12 years with PGTC seizures despite treatment with up to 3 antiepileptic drugs were randomized to perampanel hydrate or placebo.2 Patients were titrated during 4 weeks to 8 mg daily or to the highest tolerated dose, followed by 13 weeks of maintenance, for a total of 17 weeks.2
The primary end point was the change from baseline in the frequency of PGTC seizures during 4 weeks of the treatment period compared with the baseline period. Seizure frequency was reduced by 76% with perampanel hydrate versus 38% with placebo (P <.001).2 In addition, 31% of patients who received perampanel hydrate were free of seizures during the 13-week maintenance period versus 12% of patients who received placebo.1
The most common adverse events for perampanel hydrate included dizziness (32%), fatigue (15%), headache (12%), somnolence (11%), and irritability (11%). Overall, 7% of patients who took perampanel hydrate had weight gain versus 4% of patients who took placebo. Adverse reactions that led to the discontinuation of the drug were vomiting (2%) and dizziness (2%).2
Epilepsy is the fourth most common neurologic disorder after migraine, stroke, and Alzheimer's disease.5 An estimated 1.3 million to 2.8 million Americans have this condition.5 An epileptic seizure is an episode of abnormal electrical activity in the brain.6 Seizures are classified as partial or generalized seizures.
Generalized seizures can be further classified as atonic, tonic, clonic, tonic-clonic, myoclonic, or absence, based on clinical symptoms and electroencephalogram abnormalities.6 A tonic seizure is the rigid contracture of muscles, including respiratory muscles, and is usually brief. The clonic component is characterized by rhythmic shaking. A PGTC seizure, also known as a grand mal seizure, is one of the most severe forms of epileptic seizures.6
References
1. Eisai. U.S. FDA approves Eisai's antiepileptic agent Fycompa as adjunctive treatment for primary generalized tonic-clonic seizures. Press release. June 22, 2015. www.eisai.com/news/news201543.html. Accessed February 15, 2016.
2. Fycompa (perampanel) tablets [prescribing information]. Woodcliff Lake, NJ: Eisai; June 2015.
3. French JA, Krauss GL, Wechsler RT, et al. Perampanel for tonic-clonic seizures in idiopathic generalized epilepsy: a randomized trial. Neurology. 2015;85:950-957.
4. FDAnews. DEA places Eisai's Fycompa into Schedule III. December 4, 2013. www.fdanews.com/articles/160829-dea-places-eisais-fycompa-into-schedule-iii. Accessed March 2, 2016.
5. Shafer PO, Sirven JI. Epilepsy statistics. www.epilepsy.com/learn/epilepsy-statistics. Accessed March 2, 2016.
6. Mayo Clinic staff. Epilepsy. www.mayoclinic.org/diseases-conditions/epilepsy/symptoms-causes/dxc-20117207. Accessed March 2, 2016.