The dose-finding study was a randomized, placebo-controlled, double-blind, multicenter, multinational clinical trial that evaluated the efficacy and safety of four different doses (one, two, five or 10mg BID) of preladenant compared to placebo in the treatment of patients with moderate to severe Parkinson’s disease with motor fluctuations and dyskinesias.
All patients were on a stable regimen of standard treatments with L-Dopa and other adjunctive treatments, such as dopamine agonists and/or entacapone, but were still experiencing motor fluctuations and dyskinesias. The previous treatment was continued throughout the trial, in which the study medication was given as an adjunctive therapy.
A total of 253 patients were randomized into the trial, with the treatment Phase lasting 12 weeks. Preladenant was statistically significantly more effective than the control group at the doses of five and 10mg BID, respectively, in reducing the ‘off’-time, the primary endpoint of the trial.
In addition, preladenant significantly increased the ‘on’-time at the same doses of five and 10mg BID, a secondary endpoint of the study. Importantly, this improvement in ‘on’-time was not associated with a proportional overall increase in dyskinesias, the company said.
The company expects to report the results of this trial in June 2009. The company also added that it is continuing a Phase II extension trial with preladenant and preparing for the initiation of its Phase III clinical development program in Parkinson’s disease.
Ismail Kola, chief scientific officer of Schering-Plough, said: “We are very excited about these compelling Phase II data that show statistically significant and clinically relevant effects on both ‘off’- and ‘on’-times in Parkinson’s patients who, while continuing on current therapies, came into the study still experiencing profound motor fluctuations that make simple daily tasks extremely burdensome.”