Oliceridine Exhibits Improved Tolerability Compared to Morphine at Equianalgesic Conditions: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials

INTRODUCTION: In the management of postoperative acute moderate-to-severe pain, opioids remain an important component. However, conventional opioids have a narrow therapeutic index and are associated with dose-limiting opioid-related adverse events (ORAEs) that can result in worse patient outcomes. Oliceridine, a new intravenous µ-opioid receptor agonist, is shown in nonclinical studies to be biased for G protein signaling (achieving analgesia) with limited recruitment of β-arrestin (associated with ORAEs). In two phase 3 randomized controlled studies of patients with moderate-to-severe acute pain following hard or soft tissue surgery, in which analgesia was measured using Sum of Pain Intensity Differences (SPID) from baseline over 48 and 24 h (SPID-48 and -24 respectively, oliceridine at demand doses of 0.1, 0.35, or 0.5 mg was highly effective compared to placebo, with a favorable safety profile compared to morphine. This exploratory analysis was conducted to determine whether the safety benefits seen with oliceridine persisted when adjusted for equal levels of analgesia compared to morphine. METHODS: Presence of at least one treatment-emergent ORAE (based on Medical Dictionary for Regulatory Activities [MedDRA]-coded events: hypoxemia, nausea, vomiting, sedation, pruritus, or dizziness) was used as the composite safety endpoint. A logistic regression model was utilized to compare oliceridine (pooled regimens) versus morphine, after controlling for analgesia (using SPID-48 or SPID-24 with pre-rescue scores carried forward 6 h). This analysis excluded patients receiving placebo and was repeated for each study and for pooled data. RESULTS: At a given level of SPID-48 or SPID-24, patients receiving oliceridine were less likely to experience the composite safety endpoint. Although not statistically significant at the 0.05 level in the soft tissue model, the odds ratio (OR) showed a consistent numerical trend for oliceridine, being approximately half that observed with morphine in both the hard (OR 0.499; 95% confidence interval [CI] 0.255, 0.976; p = 0.042) and soft (OR 0.542; 95% CI 0.250, 1.175; p = 0.121) tissue studies. Results from the pooled data were consistent with those observed in the individual studies (OR 0.507; 95% CI 0.304, 0.844; p = 0.009). CONCLUSION: Findings from this exploratory analysis suggest that at comparable levels of analgesia, patients receiving oliceridine were less likely to experience the composite safety endpoint consisting of ORAEs compared to patients treated with morphine. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40122-021-00299-0.