Eisai has presented new data on its epilepsy drugs, notably for its investigational drug perampanel and Zonegran.

The Japanese drugmaker outlined the progress it is making at the International Epilepsy Congress in Rome. First up, a Phase III study showed that perampanel, 8mg and 12mg, produced statistically-significant reductions in median seizure frequency compared to placebo among patients having partial-onset seizures while receiving treatment with one to three other epilepsy drugs.

In Study 305, the response rates (defined as 50% or greater reduction in seizure frequency) were 14.7% for placebo, 33.3% for 8mg and 33.9% for 12mg. The most commonly reported treatment-emergent adverse events in 10% or more of patients included dizziness, fatigue, headache and somnolence.

Perampanel, a highly selective non-competitive AMPA-type glutamate receptor antagonist, was accepted for review by the European Medicines Agency in June.

Zonegran for children

Eisai also unveiled preliminary results from a new Phase III 207-patient paediatrics study which showed that Zonegran (zonisamide) is more effective than placebo and well tolerated in children with partial-onset seizures treated with one or two other anti-epileptic drugs.

The percentage of patients who completed the study was comparable between the zonisamide and placebo groups (86.9% of those on Zonegran and 90% patients on placebo). The results showed that significantly more patients responded positively to treatment with zonisamide (50.5%) versus treatment with placebo (31.0%).

Commenting on the study, Renzo Guerrini, professor at the Children’s Hospital Anna Meyer, University of Florence, Italy, said: “There are a large proportion of children who do not get complete seizure control and have to take more than one type of anti-epileptic to reduce seizures". He added that "we know zonisamide is already a successful add-on treatment and is also very effective in newly diagnosed adults with epilepsy. I welcome these study results as they indicate that the paediatric population could stand to significantly benefit too.”

Zebinix presentations

Eisai and partner Bial of Portugal also presented 25 abstracts at the meeting in  Rome on Zebinix (eslicarbazepine) "highlighting an extensive development programme". The presentations evaluated the use of Zebinix as monotherapy, its efficacy and safety in children with partial-onset seizures, its cognitive effects when used as an add-on therapy in the latter and its potential for use in elderly patients with partial-onset seizures.

Eugen Trinka of the University of Salzburg, said "we know from previous clinical trials and ongoing clinical practice that eslicarbazepine is an effective add-on therapy for adults with partial-onset seizures, with or without secondary generalisation that is easy to titrate, is well tolerated and offers once-daily dosing". He added that these results, "together with the extensive clinical trial programme, highlight the potential that Zebinix has to improve seizure control and expand its use in epilepsy".

Zebinix is approved in Europe as adjunctive therapy for use in adults with partial-onset seizures with or without secondary generalisation. In the USA, however, Bial and North American partner Sanofi received a complete response letter from the US Food and Drug Administration for the drug last year.

RA drug iguratimod filed in Japan

Meantime, Eisai and Toyama Chemical Co have submitted a marketing authorisation application  for T-614 (iguratimod), an anti-rheumatic agent being jointly developed in Japan by the two companies.

T-614 is a novel disease modifying anti-rheumatic drug originally discovered by Toyama and an MAA was previously submitted in 2003. However, the application was temporarily withdrawn in 2009 in order to conduct an additional clinical study which subsequently confirmed with statistical significance the efficacy of the agent as an add-on therapy for use with the standard of care, methotrexate.