Eisai has suffered a setback with the news that its investigational severe sepsis treatment eritoran has failed in a late-stage trial.

The Japanese drugmaker says that it will not file for regulatory approval of eritoran in the USA, the European Union and Japan by the end of the fiscal year ending March 31, as previously planned. The decision is based on preliminary findings from the 2,000-patient Phase III ACCESS study, which did not meet its primary endpoint of 28-day all-cause mortality.

Eisai added that it would "continue its analysis of the eritoran clinical trial data and determine next steps". In March last year, an independent data monitoring committee said the firm needed to enrol another 500 patients to take the number up to 2,000, a move which put back regulatory submissions that were originally planned for mid-2010.

It is a blow for Eisai coming a couple of months after the Alzheimer's disease drug Aricept (donepezil), co-marketed with Pfizer and far and away Eisai’s biggest earner, lost patent protection in the USA. Analyst peak sales forecasts for eritoran had ranged between $1-$2 billion.

Epilepsy drug filed

Better news came with the announcement that Eisai will submit simultaneuous applications in the USA and the European Union this quarter for the anti-epileptic perampanel. Based on the results of three Phase III studies, the drug, a first-in-class, highly selective non-competitive AMPA-type glutamate receptor antagonist, will be filed for adjunctive treatment of partial seizures in patients with epilepsy.

The Tokyo-based company already markets Zonegran (zonisamide) and Zebinix (eslicarbazepine) as adjunctive therapies in adults with partial-onset seizures, with or without secondary generalisation in Europe. It also has Inovelon (rufinamide) for the treatment of seizures associated with Lennox-Gastaut Syndrome.