Evaluation of the Efficacy and Safety of ADL5945 Once Daily for the Treatment of Opioid-induced Constipation in Adults Taking Opioid Therapy for Chronic Noncancer Pain

Key Inclusion Criteria

• be a man or woman aged 18 to 75 years, inclusive, at the time of screening
• have a body weight ≥45 kilograms (kg) and a body mass index (BMI) ≤40 kilograms per square meter (kg/m^2)
• be taking a stable daily dose of opioids of ≥30-milligrams (mg) morphine-equivalent total -daily dose for chronic noncancer pain for ≥30 days before screening
• have opioid-induced constipation (OIC) by history. Additionally, based on the data collected during the 1-week screening period, participants must have <3 spontaneous bowel movements (SBMs) per week and have experienced ≥1 other bowel movement (BM) symptom (that is, straining to pass a stool, lumpy hard stools or small pellets, or sense of incomplete evacuation after passing a stool) for ≥25% of the total BMs
• be willing to discontinue use of all laxatives and stool softeners during the study period except as allowed by the protocol

Key Exclusion Criteria

• be pregnant, lactating, or planning to become pregnant during the study
• have aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen, or serum creatinine results ≥2 times the upper limit of normal
• have a recent history of myocardial infarction (MI) or unstable angina
• have an active malignancy of any type
• be taking opioids primarily for fibromyalgia
• be taking methadone as a maintenance medication (participants taking methadone for pain may be enrolled)
• be taking intrathecal opioids for the management of pain
• be taking tramadol, tapentadol, or any mixed agonist/antagonist opioid analgesics as the sole opioid for analgesia
• be taking any μ-opioid receptors (MOR) antagonist, including opioids in combination with naloxone, naltrexone, or methylnaltrexone bromide
• be taking medical marijuana
• have gastrointestinal (GI) or pelvic disorders known to affect bowel transit, produce GI obstruction, or contribute to bowel dysfunction
• have taken antispasmodics, antidiarrheals, or prokinetics within 7 days before the start of the screening week
• be taking nonopioid medications known to cause constipation
• be taking antidiarrheals and have an incidence or a history of intermittent diarrhea or loose stools
• be unwilling to abstain from grapefruit and grapefruit-containing products
• have a history of alcoholism or illicit drug dependence or abuse within 5 years before screening
• have positive results on a urine drug screen (excluding opioids) that indicate illicit drug use