Efficacy and safety of controlled-release oxycodone/naloxone versus controlled-release oxycodone in Korean patients with cancer-related pain: a randomized controlled trial.

BACKGROUND: Controlled-release oxycodone/naloxone (OXN-CR) maintains the effect of opioid-induced analgesia through oxycodone while reducing the occurrence rate of opioid-induced constipation through naloxone. The present study was designed to assess the non-inferiority of OXN-CR to controlled-release oxycodone (OX-CR) for the control of cancer-related pain in Korean patients. METHODS: In this randomized, open-labeled, parallel-group, phase IV study, we enrolled patients aged 20 years or older with moderate to severe cancer-related pain [numeric rating scale (NRS) pain score ≥4] from seven Korean oncology/hematology centers. Patients in the intention-to-treat (ITT) population were randomized (1:1) to OXN-CR or OX-CR groups. OXN-CR was administered starting at 20 mg/10 mg per day and up-titrated to a maximum of 80 mg/40 mg per day for 4 weeks, and OX-CR was administered starting at 20 mg/day and up-titrated to a maximum of 80 mg/day for 4 weeks. The primary efficacy endpoint was the change in NRS pain score from baseline to week 4, with non-inferiority margin of -1.5. Secondary endpoints included analgesic rescue medication intake, patient-reported change in bowel habits, laxative intake, quality of life (QoL), and safety assessments. RESULTS: Of the ITT population comprising 128 patients, 7 with missing primary efficacy data and 4 who violated the eligibility criteria were excluded from the efficacy analysis. At week 4, the mean change in NRS pain scores was not significantly different between the OXN-CR group (n = 58) and the OX-CR group (n = 59) (-1.586 vs. -1.559, P = 0.948). The lower limit of the one-sided 95% confidence interval (-0.776 to 0.830) for the difference exceeded the non-inferiority margin (P < 0.001). The OXN-CR and OX-CR groups did not differ significantly in terms of analgesic rescue medication intake, change in bowel habits, laxative intake, QoL, and safety assessments. CONCLUSIONS: OXN-CR was non-inferior to OX-CR in terms of pain reduction after 4 weeks of treatment and had a similar safety profile. Studies in larger populations of Korean patients with cancer-related pain are needed to further investigate the effectiveness of OXN-CR for long-term pain control and constipation alleviation. Trial registration ClinicalTrials.gov NCT01313780, registered March 8, 2011.

Intravenous Oxycodone versus Intravenous Morphine in Cancer Pain: A Randomized, Open-Label, Parallel-Group, Active-Control Study.

Objective: To compare efficacy and safety of intravenous continuous infusion of oxycodone with morphine in patients with cancer pain. Methods: A 5-day, randomized, open-label, exploratory study at 6 sites in the Republic of Korea. Sixty-six adults aged ≥19 years with moderate-to-severe cancer pain (Numeric Rating Scale [NRS] ≥ 4) were enrolled. The study group received intravenous (IV) oxycodone, and the comparator group received IV morphine which were titrated depending on pain intensity. The efficacy endpoint is change in average NRS score from baseline to Day 5. Other assessments included worst, current, and average pain intensity; patient satisfaction; medication dose; and adverse events. Results: Both groups achieved >50% reduction in average pain intensity: from "moderate" at baseline (oxycodone versus morphine: 6.0 ± 1.8 versus 5.9 ± 1.4) to "mild" at Day 5 (2.5 ± 1.8 versus 2.8 ± 1.6). While this reduction was similar between groups (3.5 ± 2.2 versus 3.1 ± 1.8, P value = 0.562), oxycodone achieved faster pain relief (average pain: 3.0 ± 1.6 versus 3.9 ± 1.6, P value = 0.020) on Day 2 and significant NRS reductions for worst pain on Day 2 (P value = 0.045) and current pain on Day 2 (P value = 0.035) and Day 5 (P value = 0.020) compared to morphine. Patient satisfaction, adverse events, and adverse drug reactions were similar for both groups. Conclusions: For Asian patients with cancer pain, IV oxycodone is faster acting and showed similar analgesic efficacy and safety profiles as IV morphine. This trial is registered with Clinicaltrials.gov NCT02660229.