Comparative Efficacy of Tapentadol versus Tapentadol Plus Duloxetine in Patients with Chemotherapy-Induced Peripheral Neuropathy (CIPN): A Randomized Non-Inferiority Clinical Trial

SIMPLE SUMMARY: Chemotherapy-induced peripheral neuropathy (CIPN) is a common complication due to treatment with anti-cancer agents. Our aim was therefore to assess the non-inferiority of the analgesic effect and safety of tapentadol alone compared to duloxetine plus tapentadol administered to patients with chemotherapy-induced peripheral neuropathy. The use of tapentadol is a safe and effective analgesic therapy in patients with CIPN. Positive effects of tapentadol were noted on the patients’ quality-of-life assessments. ABSTRACT: Introduction: Chemotherapy-induced peripheral neuropathy (CIPN) is a common complication due to treatment with many commonly used anti-cancer agents. CIPN is a mainly sensory neuropathy that can be characterized by the appearance of motor and autonomic alterations. Clinicians may offer duloxetine (DLX) for patients with cancer experiencing CIPN. Our aim was to assess the non-inferiority of the analgesic effect and safety of tapentadol (TP) alone compared to duloxetine plus tapentadol administered to patients with CIPN. Methods: A total of 114 patients were enrolled in the study and randomized to receive tapentadol in a dosage of 50 to 500 mg/day (n = 56) or tapentadol plus duloxetine in a dosage of 60 to 120 mg/day (n = 58) for a period of 4 weeks. We evaluated the analgesia efficacy, defined as a decrease in pain on the NRS between the first administration and 28 days later. Secondary endpoints included analgesia efficacy at 28 and 42 days, defined by a decrease in DN4 and LEPs, decrease in quality of life, and the incidence of any serious or non-serious adverse events after the first administration. Results: In this randomized, double-blind trial comparing TP and TP plus DLX for CIPN management, TP was feasible and non-inferior to the association with DLX as far as the reduction of pain after chemotherapy at 28 days is concerned. Scores on other rating scales evaluating the quality of life, anxiety and depression, and the characteristics of pain revealed similar improvements associated with tapentadol versus duloxetine at these time points. Conclusion: The use of TP is a safe and effective analgesic therapy in patients with CIPN. Positive effects of TP were noted on the patients’ quality-of-life assessments.