Eisai reported positive data from a Phase III trial evaluating the antiepilepsy drug Zonegran® (zonisamide) as adjunctive therapy in pediatric patients with partial-onset seizures. The placebo-controlled CATZ study included 207 patients aged 6–17 years with partial-onset seizures, who were already taking one or two antiepileptic drugs. Participants were randomized to receive either Zonegran or placebo in addition to their existing medications.
The primary endpoint was the proportion of patients who responded to therapy by a 50% or more reduction in seizure frequency after 12 weeks of maintenance therapy. The results showed that 50.5% of patients responded positively to the addition of Zonegran, compared with a response rate of 31% among placebo patients.
Eisai has developed Zonegran under license from Sumitomo Pharma. The drug is one of three antiepileptic drugs marketed by Eisai in Europe. Zebinix® (eslicarbazepine acetate), licensed from BIAL, is approved as an adjunctive therapy in adult patients with partial-onset seizures, with or without secondary generalization. Inovelon™ (rufinamide; tradenamed Banzel in the U.S.) is approved as adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients aged four years and older. Phase III trials in Japan are ongoing for the LGS indicaton, with regulatory submission planned for the first half of 2012.
Eisai’s epilepsy pipeline also includes the AMPA-type glutamate receptor antagonist E2007 (perampanel). A regulatory submission for use of the drug as an adjunctive therapy in epilepsy patients with partial seizures was accepted for regulatory review in Europe in June. Eisai submitted a regulatory application for E2007 to FDA in May, but the agency requested additional information, including reformatting of certain datasets. The firm says it is now working to prepare for resubmission.
A Phase III study investigating E2007 as a potential treatment for generalized seizures in patients with epilepsy is in addition currently under way in the U.S., Europe, and Japan, and the drug is separately undergoing Phase II development as a potential treatment for neuropathic pain, multiple sclerosis, and migraine prophylaxis. Eisai says further studies are similarly planned to evaluate perampanel as monotherapy for partial-onset seizures and other forms of epilepsy such as Lennox-Gastaut syndrome.