On the back of positive late-stage data, Eisai says it plans to submit its epilepsy drug Zonegran to European regulators as a first-line monotherapy for the neurological condition.

Zonegran (zonisamide) is already licensed as adjunctive therapy in the treatment of partial seizures in adult epilepsy patients. However, the Japanese drugmaker says a new Phase III study showed the treatment is effective and well tolerated in newly-diagnosed epilepsy patients when used as monotherapy.

The trial compared once-daily zonisamide with twice-daily controlled-release carbamazepine in 582 adults with newly-diagnosed partial epilepsy. The data met the criteria of noninferiority in terms of the proportion of patients who were seizure-free at six months: 79.4% of zonisamide-treated patients and 83.7% of those on carbamazepine.

Eisai noted that the 12-month results were consistent with those at six months. The firm quoted Michel Baulac, at the Hopital de la Pitie-Salpetriere in Paris, as saying that "less than 50% of our patients have their seizures controlled by their first antiepileptic drug, and only a further 10-12% will achieve seizure-freedom from alternative drugs given as monotherapies".

It is therefore important to develop new options, he adds, and "zonisamide would be a promising addition in the monotherapy armamentarium". It also has the benefit of once-daily dosing "that may help reduce the pill-burden a person with epilepsy experiences".