A Study of Oral Methylnaltrexone (MNTX) for the Treatment of Opioid-Induced Constipation (OIC) in Participants With Chronic, Non-Malignant Pain
Opioid-Induced Constipation
About this trial
This is an interventional treatment trial for Opioid-Induced Constipation focused on measuring Treatment of Opioid-Induced Constipation in Participants with Chronic, Non-Malignant Pain
Eligibility Criteria
Key Inclusion Criteria:
- History of chronic non-malignant pain (originating from a non-malignant source) with condition(s) underlying the chronic pain of greater than or equal to (≥) 2 months' duration before the screening visit.
- Taking oral, transdermal, intravenous (IV), or subcutaneous (SC) opioids for chronic non-malignant pain for ≥1 month.
- No known history of chronic constipation prior to the initiation of opioid therapy.
- Currently taking laxative therapy for ≥30 days and willing to discontinue all laxative therapy at the start of screening period and use only study-permitted rescue laxatives throughout the screening and double-blind treatment periods..
Key Exclusion Criteria:
- Prior treatment with oral MNTX.
- Prior treatment with SC MNTX within 30 days of screening.
- Women who are pregnant, breastfeeding, or plan to become pregnant during the study.
- Fecal incontinence, rectal prolapse, fecal ostomy or other clinically significant gastrointestinal disorders such as inflammatory bowel disease or clinically significant irritable bowel syndrome that would have made bowel movement assessment inaccurate.
- Current treatment with partial opioid agonists (for example; buprenorphine) or combination agonists/antagonists.
Sites / Locations
- PRA International
- PRA, Intl.
Arms of the Study
Arm 1
Arm 2
Arm 3
Arm 4
Experimental
Experimental
Experimental
Placebo Comparator
MNTX 150 mg
MNTX 300 mg
MNTX 450 mg
Placebo
Participants will receive methylnaltrexone (MNTX) 150 milligrams (mg) (1 tablet of MNTX 150 mg and 2 matching placebo tablets) orally once daily (QD) for 28 days (4 weeks), then MNTX tablets at a dose as needed (PRN) for remaining 56 days (8 weeks).
Participants will receive MNTX 300 mg (2 tablets of MNTX 150 mg each and 1 matching placebo tablet) orally QD for 28 days (4 weeks), then MNTX tablets at a dose PRN for remaining 56 days (8 weeks).
Participants will receive MNTX 450 mg (3 tablets of MNTX 150 mg each) orally QD for 28 days (4 weeks), then MNTX tablets at a dose PRN for remaining 56 days (8 weeks).
Participants will receive 3 tablets of placebo matched to MNTX orally QD for 84 days (12 weeks).