As expected, regulators in the USA have rejected Eisai's bid to expand approval of Dacogen but have accepted the resubmission of the Japanese drugmaker's epilepsy drug perampanel.

First up, the US Food and Drug Administration has issued a complete response letter to Eisai for its supplemental New Drug Application for Dacogen (decitabine) for injection for patients with acute myeloid leukaemia (AML). It was seeking to get approval for the drug in adults aged 65 or older who are not considered candidates for induction therapy.

The FDA declined to approve the NDA because the pre-specified analysis of the primary endpoint in the Phase III, 500-patient study did not demonstrate statistically significant superiority over the control arm. The decision comes a month after the agency's Oncologic Drugs Advisory Committee voted 10 to 3 with one person abstaining that the data did not support a favourable benefit-risk profile for the treatment of AML.

Dacogen is already approved in the USA for the treatment of patients with myelodysplastic syndromes. Astex Pharmaceuticals licensed the drug to Eisai which in turn sold rights outside of North America to Johnson and Johnson and the latter's Janssen unit submitted a file for Dacogen as a treatment for AML in Europe in May last year.

Better news for Eisai came on the news that the FDA has accepted for review Eisai’s resubmission of perampanel (also known as E2007) for the treatment of partial-onset seizures associated with epilepsy. The original NDA was rejected in July 2011, when the FDA requested "reformatting and reanalyses of some datasets in the dossier to assist with a substantive review".

Eisai noted at the time that no new studies were required for perampanel, a first-in-class highly selective non-competitive AMPA-type glutamate receptor antagonist.