APOLLO-2: A Randomized, Placebo and Active-Controlled Phase III Study Investigating Oliceridine (TRV130), a G Protein-Biased Ligand at the μ-Opioid Receptor, for Management of Moderate to Severe Acute Pain Following Abdominoplasty.

[OBJECTIVES] The clinical utility of conventional IV opioids is limited by the occurrence of opioid-related adverse events. Oliceridine is a novel G protein-biased μ-opioid receptor agonist designed to provide analgesia with an improved safety and tolerability profile. This phase III, double-blind, randomized trial (APOLLO-2 [NCT02820324]) evaluated the efficacy and safety of oliceridine for acute pain following abdominoplasty.

[METHODS] Patients received a loading dose of either placebo, oliceridine (1.5 mg), or morphine (4 mg), followed by demand doses via patient-controlled analgesia (0.1, 0.35, or 0.5 mg oliceridine; 1 mg morphine; or placebo) with a 6-minute lockout interval. The primary endpoint was the proportion of treatment responders over 24 hours for oliceridine regimens compared to placebo. Secondary outcomes included a predefined composite measure of respiratory safety burden (RSB, representing the cumulative duration of respiratory safety events) and the proportion of treatment responders vs. morphine.

[RESULTS] A total of 401 patients were treated with study medication. Effective analgesia was observed for all oliceridine regimens, with responder rates of 61.0%, 76.3%, and 70.0% for the 0.1-, 0.35-, and 0.5-mg regimens, respectively, compared with 45.7% for placebo (all P < 0.05) and 78.3% for morphine. Oliceridine 0.35- and 0.5-mg demand dose regimens were equi-analgesic to morphine using a noninferiority analysis. RSB showed a dose-dependent increase across oliceridine regimens (mean hours [standard deviation], 0.1 mg: 0.43 [1.56]; 0.35 mg: 1.48 [3.83]; 0.5 mg: 1.59 [4.26]; all comparisons not significant at P > 0.05 vs. placebo: 0.60 [2.82]). The RSB measure for morphine was 1.72 (3.86) (P < 0.05 vs. placebo). Gastrointestinal adverse events increased in a dose-dependent manner across oliceridine demand dose regimens (0.1 mg: 49.4%; 0.35 mg: 65.8%; 0.5 mg: 78.8%; vs. placebo: 47.0%; and morphine: 79.3%). In comparison to morphine, the proportion of patients experiencing nausea or vomiting was lower with the 2 equi-analgesic dose regimens of 0.35 and 0.5 mg oliceridine.

[CONCLUSIONS] Oliceridine is a safe and effective IV analgesic for the relief of moderate to severe acute postoperative pain in patients undergoing abdominoplasty. Since the low-dose regimen of 0.1 mg oliceridine was superior to placebo but not as effective as the morphine regimen, safety comparisons to morphine are relevant only to the 2 equi-analgesic dose groups of 0.35 and 0.5 mg, which showed a favorable safety and tolerability profile regarding respiratory and gastrointestinal adverse effects compared to morphine. These findings support that oliceridine may provide a new treatment option for patients with moderate to severe acute pain where an IV opioid is warranted.