Eisai: first AMPA antagonist grows treatment options for refractory epilepsy.
Eisai: first AMPA antagonist grows treatment options for refractory epilepsy
Perampanel has become the first AMPA receptor antagonist to gain approval for the adjunctive treatment of partial-onset seizures. Despite underwhelming clinical trial data and relatively late market entry, perampanel’s novel class, convenient dosing regimen, and preferable side-effect profile will support its uptake in the refractory patient population.
On June 27, 2012, the European Commission approved Fycompa (perampanel) as an adjunctive treatment of partial-onset seizures, with or without secondary generalization, in people with epilepsy aged 12 years and older. Initial EU launch of perampanel will take place in the UK in September 2012. Perampanel is also pending approval for the same indication in the US with an expected PDUFA date of October 2012. The product remains under Phase III development in Japan for the adjunctive treatment of partial-onset epilepsy.
Perampanel’s EU approval in epilepsy is welcome news for Eisai in view of the regulatory hurdles the drug has experienced in the US and the discontinuation of its development in three neurological indications: neuropathic pain, multiple sclerosis, and migraine prophylaxis. As an orally available and novel selective alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, perampanel represents the very first of this novel class to become available for use in epilepsy, thereby conferring an important product differentiator in an increasingly competitive market.
Although perampanel’s clinical trial data are not groundbreaking, the drug has demonstrated good efficacy in the treatment of drug-resistant epilepsy, a segment of the epilepsy population characterized by a high level of unmet need. As such, Datamonitor believes that upon launch, perampanel will represent a useful treatment option to the 20-30% of epilepsy patients who suffer from drug-resistant epilepsy.
However, as a late entrant to the epilepsy market, perampanel will launch into an increasingly competitive space. The product’s anticipated UK launch in September 2012 will come 16 months after the launch of another first-in-class product, Trobalt (ezogabine/retigabine; Valeant), in the EU. Ezogabine’s strong efficacy profile and earlier market entry will have enabled the drug to obtain a strong foothold in the treatment-refractory segment of the epilepsy market, providing direct competition to the uptake of perampanel. Nevertheless, Datamonitor believes that perampanel’s once-daily dosing and beneficial safety profile will be an advantage over ezogabine’s three times daily dosing and side effects of dizziness, somnolence, and headache. Moreover, unlike ezogabine, perampanel benefits from approval in the adolescent population, affording it a key advantage in targeting the younger patient populations. Datamonitor anticipates that perampanel will capture a sizable proportion of the treatment-refractory epilepsy patient population, and forecasts peak epilepsy-specific revenues of $193m across the seven major markets (the US, Japan, France, Germany, Italy, Spain, and the UK) by 2019.
However, perampanel’s commercial potential extends beyond refractory epilepsy. Eisai is keen to expand perampanel’s potential indications and is investigating the compound in pediatric and primary generalized tonic-clonic seizures as well as use as a monotherapy. If successful in obtaining these indications, the drug has the potential to boost its patient population and ultimately its commercial success.