A phase 2, double-blind, randomized, placebo-controlled, dose-escalation study to evaluate the efficacy, safety, and tolerability of naloxegol in patients with opioid-induced constipation.

Abstract Naloxegol (previously known as NKTR-118) is a peripherally acting μ-opioid receptor antagonist engineered using polymer conjugate technology in development as an oral, once-daily agent for the treatment of opioid-induced constipation (OIC). Eligible patients with OIC (n = 207), defined as P  = 0.0020] and 3.3 vs 0.5 [ P  = 0.0001], respectively). The increase in SBMs vs placebo was maintained over 4 weeks for naloxegol 25 mg (3.0 vs 0.8 [ P  = 0.0022]) and 50 mg (3.5 vs 1.0 [ P