Eisai ends perampanel PD late-stage program

Japanese drugmaker Eisai has discontinued the late-stage development of the Parkinson's disease indication for its ampakine drug candidate E2007 (perampanel). The Tokyo-headquartered firm says it will focus efforts on its first-in-class, orally-administered, selective non-competitive AMPA-type glutamate receptor antagonist for neuropathic pain and epilepsy.

The company recently completed the second Phase III trial of perampanel in PD. The 20-week, double-blind, placebo-controlled study compared 2mg and 4mg doses of the drug to placebo, but did not show a significant difference in the primary endpoint of reduction of off time, which is when signs and symptoms of PD return as the effect of levodopa wears off. After analyzing the data, Eisai decided to discontinue the program and not pursue submissions for this indication, noting that the two other ongoing indications, epilepsy and neuropathic pain, have different pathophysiology from PD and are supported by a different scientific rationale.

Eisai says it is preparing to initiate global Phase III studies with perampanel as add-on therapy in refractory partial seizures in the first quarter of fiscal-year 2008. The regulatory submission is planned for fiscal-year 2012. A Phase II study of the agent in painful diabetic neuropathy completed enrollment in March and top-line results are expected this September, with a submission for PDN planned in fiscal-year 2010. A Phase II study in post-herpetic neuralgia was initiated in January 2008.