Protective Effect of Mangafodipir Against Oxaliplatin Neurotoxicity

Overview

Oxaliplatin is a major antitumor agent but its use is limited by potentially disabling neurotoxicity, characterized by a sensitive defect in the extremities.Mangafodipir is a MRI contrast agent with antioxidant properties. Our previous laboratory works showed that mangafodipir is able to prevent hematologic toxicity of several chemotherapy agents, including oxaliplatin and to increase their antitumor activity. Preliminary clinical data suggested that mangafodipir could prevent oxaliplatin neurotoxicity.The primary purpose of the present study is to assess the protective effect of mangafodipir in patients who have a already moderate oxaliplatin neuropathy and in whom the continuation of this treatment is desirable because of significant antitumor effect.

Phase 2 study aiming to assess the protective effect of mangafodipir against the oxaliplatine neuropathy.Population: Cancer patient who have a mild (grade 2) oxaliplatin neuropathy and in whom the continuation of oxaliplatin for at least 4 infusions is desirable will be include, whatever the location of the primitive tumor and the use of others anticancer agents.Treatment: Mangafodipir (0.5 ml/kg) is administered as a 30 minutes infusion just after each administration of oxaliplatin. The oxaliplatin dose (85 to 100 mg/m²) and the length of the infusion (2 hours) are the same that before the inclusion and modifications are not authorized during all the study participation. Primary objective: Neuropathy are clinically evaluated according to NCI-CTC criteria before each mangafodipir and oxaliplatin and thereafter one month after the last infusion. The primary criteria is the worst grade of oxaliplatin neuropathy experienced by each patient. The improvement of neuropathy is defined as a decrease by at least one grade of the severity of the neuropathy for at least 2 months. Hypothesis: at least 50% of patients will experience an improvement or a stabilization of the oxaliplatin neuropathy while receiving the mangafodipir - oxaliplatin association.Treatment discontinuation: the treatment will be stopped if the neuropathy worsened by at least one grade, in case of tumor progression, intolerable toxicity, and patient wish. Number of patients: it will be determined according to a simplified Gehan procedure: The inclusions will be stopped if no objective response (neuropathy improvement) is observed among the first 9 evaluable patients. If at least one response is observed, 16 more evaluable patients will be include. The total number of patients will be between 9 and 30 patients, including non evaluable patients. Pharmacokinetic: Serum and intra- erythrocytes manganese concentration will be evaluated before each mangafodipir infusion in order to detect accumulation Pharmacodynamic: plasmatic total antioxidant activity, superoxide dismutase activity and lipid peroxidation will be assessed at the first cycle: before and after the administration of oxaliplatin and just after the perfusion of mangafodipir.