SHM Converge Scientific Abstract ePoster Gallery-Impact of Subgroups on Methylnaltrexone Efficacy/Safety in Advanced Illness

Pdf Summary

This post hoc analysis pooled data from two randomized, double-blind, placebo-controlled trials of methylnaltrexone (MNTX) in 363 adults with advanced illness and opioid-induced constipation (OIC). The goal was to see whether baseline characteristics affected MNTX’s safety and efficacy. Patients were generally older (mean age 66), mostly had cancer, had poor functional status, used high opioid doses, and were already taking laxatives.<br /><br />The main efficacy outcome was rescue-free laxation (RFL) within 4 or 24 hours after the first dose. Across all examined subgroups—age, cancer status, ECOG performance status, opioid dose, and laxative type—MNTX led to significantly higher RFL rates than placebo. Benefits were consistent regardless of whether patients were older or younger than 65, had cancer or noncancer illness, had ECOG score 2 or higher, used different opioid dose ranges, or were taking osmotic agents, stimulants, or stool softeners.<br /><br />Safety findings were also generally similar across subgroups. Overall treatment-emergent adverse event rates were comparable between MNTX and placebo. Gastrointestinal adverse events were common in both groups, but abdominal pain occurred more often with MNTX. This was expected and typically mild to moderate, often occurring with a laxation response. No major safety differences were identified based on baseline characteristics.<br /><br />Overall, the analysis suggests that MNTX is an effective and generally well-tolerated treatment for OIC in patients with advanced illness, and its benefit appears consistent across a wide range of demographic and clinical subgroups.

Asset Subtitle

Bobbie Sue Brown

Meta Tag

Author List Bobbie Sue Brown, Eric D. Shah, Nancy Stambler, Neel Mehta

Category Research

Concept Opioid-Induced Constipation

Concept Methylnaltrexone

Concept Selective Peripheral Mu-Receptor Antagonist

Concept Rescue-Free Laxation

Concept Advanced Illness

Distinguished Non-Finalist

Presenter Organization Salix Pharmaceuticals

Presenting Author Bobbie Sue Brown

Track Patient Safety

Keywords

methylnaltrexone

opioid-induced constipation

advanced illness

randomized controlled trials

rescue-free laxation

safety and efficacy

placebo-controlled

cancer patients

baseline characteristics

laxative use

Opioid-Induced Constipation

Methylnaltrexone

Selective Peripheral Mu-Receptor Antagonist

Rescue-Free Laxation

Advanced Illness