Efficacy and Safety Study of CB-5945 for the Treatment of Opioid-Induced Constipation

A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Study to Evaluate the Efficacy and Safety of CB-5945 for the Treatment of Opioid-Induced Constipation in Adults Taking Opioid Therapy for Chronic Non-Cancer Pain

The purpose of this study is to evaluate the safety and efficacy of CB-5945 for the treatment of opioid-induced constipation (OIC) in adults taking opioid therapy for chronic non-cancer pain.

This is a multicenter, double-blind, placebo-controlled, parallel-group study in participants with OIC taking opioid therapy for chronic non-cancer pain. Approximately 600 participants (300 participants per treatment group) with OIC will be randomized at approximately 75 study centers to receive either oral 0.25 mg CB-5945 BID or oral matching placebo BID for the 12-week double-blind treatment period, followed by a 4-week follow-up period. All randomized participants will be evaluated for clinical response for duration of their study participation. All participants will be followed for safety for 4 weeks after last dose of the study medication, regardless of when they discontinue study medication. The clinical study report for this study includes pooled results for studies 5945-OIC-12-02 (NCT01901302) 5945-OIC-12-03 (NCT01901328), and 5945-OIC-12-04 (NCT01901341).

Key Inclusion Criteria:

• Is taking a stable daily dose of opioids of ≥30 mg morphine equivalent total daily dose (METDD) for chronic non-cancer pain
• Has constipation that is caused by the chronic use of opioids
• Is willing to use only the study provided laxative(s) and to discontinue use of all other laxatives, enemas, stool softeners, and other medications to treat constipation (e.g., lubiprostone) from Screening until the last study assessment

Key Exclusion Criteria:

• Has gastrointestinal (GI) or pelvic disorders known to affect bowel transit (for example [e.g.], obstruction) or contribute to bowel dysfunction
• Has evidence of intestinal obstruction
• Has a history of rectal bleeding not due to hemorrhoids or fissures within 6 months of screening
• Has an active malignancy of any type (participants with a history of successfully treated malignancy >5 years before the scheduled administration of study medication and participants with treated basal or squamous cell cancer may be enrolled)
• Is taking antispasmodics (e.g., dicyclomine), antidiarrheals (e.g., loperamide), prokinetics (e.g., metoclopramide), or locally acting chloride channel activators (e.g., lubiprostone)
• Is taking non-opioid medications known to cause constipation (e.g., iron sulfate therapy, tricyclic antidepressants)