FDA panel backs epilepsy drug Potiga

A US Food and Drug Administration (FDA) panel has unanimously voted in favour of GlaxoSmithKline's (GSK) and Valeant Pharmaceutical's epilepsy drug, Potiga (ezogabine) as being an effective treatment for patients with partial onset seizures.

The drug is aimed at controlling epileptic seizures when other medicines fail. 

Of the votes cast, all also thought the urinary side-effects were manageable. In studies, 5 per cent of patients reported trouble with urination or related issues, higher than the 3 per cent with a placebo. Symptoms included an inability to urinate or to fully empty the bladder.

But nearly all cases of side-effects were reversible with treatment, GSK and Valent said. Similarly, panel members held that urinary retention risk could be "mitigated by patient monitoring." 

The panel voted 11-0 with two abstentions that monitoring for urinary problems would help minimise side effects. It also voted 13-0 that Potiga was effective for use with other epilepsy drugs in patients who still have seizures with current therapy.

The votes move the drug closer to the US market as the FDA usually follows panel recommendations when deciding whether to clear new drugs. A final decision is expected August 30. If approved, analysts have forecasted peak annual sales from $200m to $800m.

About three million Americans have epilepsy, a brain disorder that causes seizures. While seizures can be controlled with medication, an estimated 30 per cent of those suffering do not find adequate treatment. Potiga works differently to other approved epilepsy drugs by targeting potassium channels in the brain.