Efficacy and safety of oxycodone/naloxone as add‐on therapy to gabapentin or pregabalin for the management of chemotherapy‐induced peripheral neuropathy in Korea

Abstract Aims To investigate the efficacy and safety of oxycodone/naloxone in patients with chemotherapy‐induced peripheral neuropathy (CIPN) inadequately controlled with pregabalin or gabapentin. Methods This 4‐week, multicenter, interventional, single‐arm phase IV study included 72 Korean patients with CIPN inadequately controlled with pregabalin or gabapentin (Numeric Rating Scale 0–10; NRS ≥4 at baseline). In addition to pregabalin or gabapentin at existing doses, patients received 20/10 mg/day oxycodone/naloxone (up‐titrated to 80/40 mg/day as needed). The primary endpoint was change in NRS score after 4 weeks. Secondary endpoints included Functional Assessment of Cancer Therapy/Gynecologic Oncology Group‐Neurotoxicity (FACT/GOG‐NTX) scores and safety assessments. Results The mean ± standard deviation (SD) dose of oxycodone/naloxone was 23.3 ± 7.5 mg/day. At week 4, NRS score reduction was 1.29 ± 1.84 points (21.4% reduction; P < 0.0001). Patients on taxane‐based chemotherapy experienced a significantly smaller mean change in NRS score at week 4 compared to patients on other chemotherapy (−0.63 ± 1.54 [ n = 30] vs. −1.83 ± 1.00 [ n = 36]; P = 0.0072). Although there were no significant changes in FACT/GOG‐NTX total scores, improvements were observed in the neurotoxicity subscale measuring numbness/tingling of hands (mean ± SD change: −0.27 ± 1.04; P = 0.0427) and feet (−0.60 ± 1.09; P < 0.0001). Forty‐two (58.3%) patients reported adverse events. There were no clinically significant changes in laboratory tests or vital signs. Conclusion Oxycodone/naloxone added to pregabalin or gabapentin provided additional pain relief and symptom control in Korean patients with CIPN, without clinically significant safety concerns.