In each study, aplindore demonstrated highly significant efficacy and was well tolerated. Neurogen believes aplindore’s dopamine partial agonist controlled release profile may be better tolerated, with fewer side effects and greater dosing flexibility, than existing drugs to treat restless legs syndrome (RLS) and Parkinson’s disease.
The RLS study was a placebo-controlled, single-blind, multi-center study designed to assess the efficacy, safety and tolerability of single doses of aplindore compared to placebo. The primary efficacy endpoint was the mean change in the periodic limb movement index (PLMI) during sleep from baseline to the highest achieved aplindore dose.
In this study, aplindore achieved statistically significant results versus placebo at all doses tested. In addition, aplindore was well tolerated with an incidence of adverse events similar to placebo in doses up to 0.2mg.
As planned, an interim analysis on the primary efficacy endpoint was conducted when a sufficient number of evaluable patients was reached (n=19). Results of this interim analysis indicated a significant reduction (p<0.0001) in the mean PLMI at a level higher than the pre-specified criterion (alpha=0.01) for stopping the study. On the basis of these results, the study was terminated following the interim analysis. The same outcomes and conclusion were also reached when a sensitivity analysis was performed including all patients treated with aplindore (n=26). The Parkinson's study was a dose-ranging, randomized, double-blind, placebo-controlled, parallel design exploratory study of the safety, tolerability, efficacy and pharmacokinetics of aplindore in patients with early stage Parkinson's disease. The primary objective was to evaluate in five separate groups of patients the safety and tolerability of aplindore given twice a day over two weeks in varying titration schedules and across different dose ranges. Aplindore achieved statistically significant results versus placebo in each of the three lowest dose regimens tested. In addition, aplindore was generally well tolerated and there were no withdrawals due to adverse events and no serious adverse events.