In a main study involving 139 patients aged between 4 and 30 years (three quarters of them below 17 years old) Inovelon caused a reduction in the number and severity of seizures. All of the patients had Lennox-Gastaut syndrome that was not controlled despite continuous treatment for at least four weeks with up to three other anti-epileptic medicines. The study compared the effects of adding Inovelon tablets or adding placebo (a dummy treatment) to the other medicines the patients were taking. The main measures of effectiveness were the change in the number of seizures in the four weeks after Inovelon or placebo was added, compared with the four weeks before it was added, as well as the change in severity of seizures assessed on a 7?point scale by the patient’s parent or guardian.

Patients taking Inovelon had a 35.8% reduction in the total number of seizures, falling from an average of 290 seizures in the four-week period before Inovelon was started. There was a 1.6% reduction in the patients who added placebo to their existing treatment.

Patients adding Inovelon also had a 42.5% reduction in the number of ‘tonic-atonic’ seizures (a common type of fit in patients with Lennox-Gastaut syndrome that often involves the patient dropping to the floor), compared with a 1.9% increase in those adding placebo.

An improvement in the severity of seizures was reported for about half of the patients adding Inovelon, compared with a third of those adding placebo.

A study involving 37 children aged 1 to 4 years was inconclusive because of its small size and because it was not designed to show benefit. However, other analyses showed that doses based on body weight in children aged 1 to 4 years produced similar levels of the medicine in the body to those seen with standard doses in older patients. Given that the disease behaves the same way in both age groups, Inovelon could therefore be expected to act similarly in children aged 1 to 4 years.

The company also presented the results of a study showing that the oral suspension produced the same levels of the active substance in the blood as the tablets.