PENWEST LAUNCHES STUDY OF CONTROLLED-RELEASE NALBUPHINE

Penwest Pharmaceuticals has begun a Phase I safety study of a nalbuphine hydrochloride extended-release tablet formulation, Nalbuphine ER, that the company is developing for the treatment of pain. Nalbuphine ER employs Penwest's TIMERx controlled-release drug-delivery technology. It is designed to be administered as a twice-daily tablet.

The primary objective of the Phase I safety study is to evaluate the safety and tolerability of the drug in healthy subjects of escalating dosage levels during multiple-dose steady-state administration. The secondary objective is to evaluate the pharmacokinetics of nalbuphine during steady-state administration and the effect of different dosage levels on typical opioid-related side effects.

The study will follow a randomized, sequential, dose-escalation design, with a planned total enrollment of 32 healthy adult subjects in two separate alternating cohorts. The study will examine a total of four dosage levels. Each subject will receive treatment at two different dose levels sequentially, with a number of days at each dosage level until steady state plasma concentrations are achieved.

"We believe that, combined with the single dose safety and efficacy data we already have, this study will give us the information necessary to advance to the Phase II program we intend to begin in the first half of this year," Alan Joslyn, Penwest's senior vice president for R&D, said.