Cubist Pharmaceuticals has commenced patient enrolment in its Phase III CB-5945 ascent study for the treatment of opioid-induced constipation (OIC).
The multicentre, long-term safety study is one of four registrational studies conducted in patients with chronic non-cancer pain.
The randomised (1:1), double-blind, placebo-controlled study is designed to evaluate CB-5945 (0.25mg twice a day) and will enrol 1,400 eligible patients in the US and Canada.
Cubist chief scientific officer Dr Steve Gilman said that for millions of people with chronic non-cancer pain, opioid-induced constipation is a debilitating side effect.
"We are excited to begin the robust Phase III development program for CB-5945 and hope one day to make this important therapy available for patients," Gilman said.
The safety of CB-5945 (0.25mg twice a day) compared with placebo over a one-year treatment period is the primary objective of the study, while the effects of the candidate on quality of life is a secondary objective.
A total of nearly 3,200 patients are expected to be enrolled in the Phase III programme.
CB-5945 is a potent, peripherally acting mu opioid receptor antagonist designed to block the adverse effects of opioid analgesics on the gastrointestinal tract without affecting the centrally mediated pain relief.