The Effects of Aplindore on the Treatment of Signs and Symptoms of Restless Legs Syndrome

The purpose of this study is to assess the efficacy and tolerability of single doses of aplindore compared to placebo in RLS. Patients will be required to spend 5-8 nights in a sleep laboratory. This includes 1 adaptation night, 1 placebo night, and 3-6 drug treatment nights. Ascending doses of active drug will be administered on study nights 3 through 5 to determine the maximum well tolerated efficacious dose (defined as a decrease in Periodic Limb Movement Index (PLMI) of at least 50% from placebo baseline). If an efficacious dose cannot be identified the Investigator in consultation with the sponsor may decide to examine higher doses in up to 3 additional PSG nights in an attempt to identify a tolerable efficacious dose. This study will utilize up to 24 evaluable patients, each meeting International Classification of Sleep Disorders (ICSD-2) diagnostic criteria for primary RLS who are not currently taking any RLS medication including DAs ( and L-dopa) or who are able to discontinue their RLS medication at least 5 half-lives prior to the adaptation night.