New River Pharmaceuticals Inc. has announced that the enrolment numbers have been met for the company's NRP104.303 study, which will examine the safety and efficacy of NRP104 as a treatment for attention-deficit/hyperactivity disorder (ADHD) in adult populations (ages 18-52). Randal Kirk, New River's chairman and CEO, and Krish Krishnan, CFO and COO, stated that the company expects to complete the study in Q4 2006, to announce top-line data in from the study in Q1 2007, and to file a supplemental new drug application for the adult indication in Q2 2007.

NRP104 (lisdexamfetamine dimesylate) is the subject of a collaboration agreement between New River and Shire plc. It is currently under review with the US Food and Drug Administration for the treatment of ADHD in pediatric populations (ages 6to12) with an October 6, 2006 PDUFA date.

The company also stated, that the desired safety and efficacy endpoints were met in the company's NRP104.302 study, a long-term, open-label and single-arm study of NRP104 in doses of 30mg, 50mg or 70mg per day in pediatric patients diagnosed with ADHD. A total of 293 patients with ADHD were enrolled in this multi-centre trial, the results of which were submitted to the FDA.

New River's management also provided an update on the company's other drug candidates in clinical development. The company announced that it expects to begin a pharmacokinetic (PK) clinical study of NRP409 later this month, with conclusion anticipated in Q1 2007. A derivative of tri-iodothyronine (T3), NRP409 is under development for the treatment of primary hypothyroidism.

With regard to NRP290, a derivative of hydrocodone, New River management stated that two PK clinical studies have been completed. In an effort to reduce the overall cost of goods sold, the company is also working on chemistry, manufacturing and controls (CMC) issues related to NRP290 synthesis. New River anticipates an End-of-phase-II meeting with the FDA following resolution of the CMC issues.