IPX159 is an oral controlled-release formulation of a small molecule that has an established pharmacological and safety profile for non-RLS use outside the US.
The multicenter, randomized, double-blind, placebo-controlled, Phase IIb study is intended to assess the safety and efficacy of IPX159.
The trial will randomize around 120 adult subjects who will receive either IPX159 or placebo and will be treated for up to 11 weeks.
Impax Pharmaceuticals chief scientific officer Suneel Gupta said the advancement of the trial will help the drug candidate establish its clinical profile in moderate to severe RLS patients.
"We look forward to reporting the results from this study and providing an update on the program in mid-2013," Gupta added.