Merck KGAA discontinues sarizotan after drug misses Ph III efficacy endpoints in PADDY-1/2

German drugmaker Merck KGaA says it will discontinue the development of its drug candidate sarizotan after it failed to demonstrate efficacy in two Phase III clinical trials in advanced Parkinson's disease patients suffering from dyskinesia.

The placebo-controlled, double-blind PADDY-1 and PADDY-2 evaluations were performed in 15 countries worldwide featuring over 1,000 PD sufferers with disabling dyskinesia, a problem encountered after prolonged use of the common PD therapeutic, L-DOPA.

According to the Darmstadt-headquartered firm, the treatment duration in the trials was six months and the first endpoint reached after three months. 1mg strength sarizotan tablets were administered twice-daily and the primary variable of efficacy, defined as 25% improvement over placebo, was based on the Unified Parkinson's Disease Rating Scale, also including measures of severity as well as duration of dyskinesia.