US regulators have approved Biocodex’ Diacomit for the treatment of seizures associated with Dravet syndrome (DS), a rare and difficult to treat form of epilepsy.

The decision allows physicians to prescribe the drug to patients two years of age and older taking clobazam.

The approval is based on two multicenter placebo-controlled trials, STICLO France and STICLO Italy, which both had a primary efficacy endpoint of responder rate, defined as the number of patients who experienced a greater than 50% decrease in the frequency (per 30 days) of generalized clonic or tonic-clonic seizures.

In STICLO France, the responder rate for patients receiving Diacomit (stiripentol) was 71%, compared to 5% for patients receiving placebo.

In STICLO Italy, the responder rate for patients receiving the drug was 67%, compared to 9.1% for patients receiving placebo.

The most common adverse reactions, occurring in at least 10% of Diacomit-treated patients and more frequently than on placebo, included somnolence (67%), decreased appetite (45%), agitation (27%), ataxia (27%), weight decreased (27%), hypotonia (24%), nausea (15%), tremor (15%), dysarthria (12%), and insomnia (12%).

Dravet syndrome, also known as severe myoclonic epilepsy in infancy (SMEI), is a catastrophic early onset epileptic syndrome thought to affect round 2,000 to 8,000 patients in the US.