Belgium’s UCB says that its follow-up to the blockbuster epilepsy drug Keppra has entered late-stage clinical trials.

Phase III clinical trials of Rikelta (brivaracetam) are underway as an adjunctive therapy in patients with refractory partial-onset epilepsy, the company noted, saying that some 1,300 patients, aged between 16 and 70, years, will take part. Two studies are designed to evaluate the efficacy and safety of the treatment (5, 20 and 50mg/day or 20, 50 and 100mg/day) over 12 weeks in patients with partial onset epilepsy, not fully controlled despite treatment with one or two other drugs, while a third study will evaluate the safety and tolerability of Rikelta in patients with uncontrolled partial onset or primary generalised seizures.

The first results from these studies are expected in the third quarter of 2009 and Iris Loew-Friedrich, global head of development at UCB, noted that “up to 30% of patients can be resistant to current antiepileptic medications” and the firm’s research efforts “aim to support this significant unmet medical need”. UCB added that Rikelta has “distinct pharmacological differences as well as having some structural similarity” to Keppra (levetiracetam), adding that brivaracetam was shown to have a 10-fold higher affinity for synaptic vesicle protein 2A than the older drug, which means that it is more potent than the latter in controlling seizure activity.

The importance of having a follow-up to Keppra is evident given that the latter is a major earner for UCB. Half-year 2007 sales of the drug, which is the market leader in Europe as well as in the USA, leapt 36% to 498 million euros and US turnover of the drug were approximately $742 million for the 12 months ending June 30. Now, however, generic competition is looming very large and the Belgian firm recently settled a patent dispute with Mylan in a deal which could see the US firm its copycat version of levetiracetam from November 1 next year.