Neuroprotective Effect of Reduced Glutathione on Oxaliplatin-Based Chemotherapy in Advanced Colorectal Cancer: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

PURPOSE: We performed a randomized, double-blind, placebo-controlled trial to assess the efficacy of glutathione (GSH) in the prevention of oxaliplatin-induced neurotoxicity. PATIENTS AND METHODS: Fifty-two patients treated with a bimonthly oxaliplatin-based regimen were randomized to receive GSH (1,500 mg/m² over a 15-minute infusion period before oxaliplatin) or normal saline solution. Clinical neurologic evaluation and electrophysiologic investigations were performed at baseline and after four (oxaliplatin dose, 400 mg/m²), eight (oxaliplatin dose, 800 mg/m²), and 12 (oxaliplatin dose, 1,200 mg/m²) cycles of treatment. RESULTS: At the fourth cycle, seven patients showed clinically evident neuropathy in the GSH arm, whereas 11 patients in the placebo arm did. After the eighth cycle, nine of 21 assessable patients in the GSH arm suffered from neurotoxicity compared with 15 of 19 in the placebo arm. With regard to grade 2 to 4 National Cancer Institute common toxicity criteria, 11 patients experienced neuropathy in the placebo arm compared with only two patients in the GSH arm (P = .003). After 12 cycles, grade 2 to 4 neurotoxicity was observed in three patients in the GSH arm and in eight patients in the placebo arm (P = .004). The neurophysiologic investigations (sural sensory nerve conduction) showed a statistically significant reduction of the values in the placebo arm but not in the GSH arm. The response rate was 26.9% in the GSH arm and 23.1% in the placebo arm, showing no reduction in activity of oxaliplatin. CONCLUSION: This study provides evidence that GSH is a promising drug for the prevention of oxaliplatin-induced neuropathy, and that it does not reduce the clinical activity of oxaliplatin.