New River Pharmaceuticals Inc. has announced the results from the Phase 3 trial on its lead investigational new drug candidate under development, NRP104.

The study compared the efficacy, duration of action and incidence of adverse events of three doses of NRP104 to placebo in the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in 285 patients aged 6 to 12 years old.

The primary efficacy endpoint in this study was the ADHD Rating Scale (ADHD-RS). The secondary endpoint was the Conners' Parent Rating Scale (CPRS), assessed in the morning, afternoon and evening. The study results indicated that each of the NRP104 doses demonstrated robust efficacy when compared to placebo on both primary and secondary endpoints (p values <0.0001).

"We continue to be pleased with NRP104's performance in clinical trials," said Suma Krishnan, New River's vice president of product development. "Our other Phase 3 trial, a long-term safety study, is ongoing. We remain confident that we will be able to file a new drug application for NRP104 as a treatment for paediatric ADHD by the end of 2005."

In January 2005, New River reached an agreement to collaborate with Shire Pharmaceuticals Group plc on the worldwide development and commercialization of NRP104.