Cubist Enrolls First Patient in Phase 3 Efficacy Studies Evaluating Bevenopran for the Treatment of Opioid-Induced Constipation

Cubist Pharmaceuticals Inc. today announced the initiation of Phase 3 efficacy studies of bevenopran (previously known as CB-5945) in patients with chronic non-cancer pain and opioid-induced constipation (OIC).

The Phase 3 program ASCENT includes three identically-designed studies that will enroll approximately 600 patients each (1800 total) designed to evaluate the efficacy and safety of bevenopran (0.25 mg orally twice daily) vs. placebo. The ASCENT program also includes a 1400-patient one-year placebo-controlled safety study which was initiated in October 2012.

“Effective management of OIC is extremely important for the millions of patients who need opioids to manage chronic non-cancer pain and there are limited treatment options currently available” said Steven Gilman Ph.D. Executive Vice President of Research and Development and Chief Scientific Officer of Cubist Pharmaceuticals. “We believe bevenopran has the potential to be an important option for managing constipation and related symptoms in patients taking chronic opioids for pain management.”

The primary endpoint of the studies is the proportion of spontaneous bowel movement (SBM) responders over a 12-week treatment period. The Phase 3 efficacy trials also include as a secondary endpoint a patient reported outcome (PRO) measurement tool that was developed and validated using data from the Phase 2 studies of bevenopran. This measure known as Chronic Opioid-Related Gastrointestinal Symptoms Scale (CORGISS) assesses GI symptoms associated with chronic opioid therapy.

About Opioid-Induced Constipation (OIC) and bevenopran

The American Pain Foundation estimates that nine percent of the U.S. adult population suffers from moderate to severe non-cancer related chronic painwhich is commonly defined as pain that lasts longer than the usual course of an injury or illness. Long-term management of chronic pain often includes treatment with opioid analgesics. Many people receiving this treatment will develop constipation as well as other associated gastrointestinal complications. This is believed to be the result of the stimulation of mu opioid receptors in the gastrointestinal tract by opioid analgesics. The stimulation of these peripheral mu opioid receptors disrupts regulation of motility secretion and absorption. Bevenopran is a peripherally acting mu opioid receptor antagonist drug candidate that is intended to block the adverse effects of opioid analgesics on the gastrointestinal tract without compromising the pain relief caused by opioid action in the central nervous system.

About Cubist

Cubist Pharmaceuticals Inc. is a biopharmaceutical company focused on the research development and commercialization of pharmaceutical products that address significant unmet medical needs in the acute care environment. Cubist is headquartered in Lexington Mass. Additional information can be found on Cubist’s website at