Pilot trial of a patient-specific cutaneous electrostimulation device (MC5-A Calmare^®) for chemotherapy-induced peripheral neuropathy

Context: Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting and persistent consequence of numerous classes of antineoplastic agents, affecting up to 30%-40% of patients. To date, there is no effective prevention or therapy. An evolving hypothesis for reducing CIPN pain involves direct nerve stimulation to reduce the pain impulse. Objectives: To evaluate the impact on CIPN associated with the MC5-A Calmare^® therapy device. Methods: The MC5-A Calmare^® therapy device is designed to generate a patient-specific cutaneous electrostimulation to reduce the abnormal pain intensity. Sixteen patients from one center received one-hour interventions daily over 10 working days. Results: Of 18 patients, 16 were evaluable. The mean age of the patients was 58.6 years - four men and 14 women - and the duration of CIPN was three months to eight years. The most common drugs were taxanes, platinums, and bortezomib (Velcade, Millenium Pharmaceuticals, Cambridge MA). At the end of the study (Day 10), a 20% reduction in numeric pain scores was achieved in 15 of 16 patients. The pain score fell 59% from 5.81 ± 1.11 before treatment to 2.38 ± 1.82 at the end of 10 days (P < 0.0001 by paired t-test). A daily treatment benefit was seen with a strong statistically significant difference between the pre- and post-daily pain scores (P < 0.001). Four patients had their CIPN reduced to zero. A repeated-measures analysis using the scores from all 10 days confirmed these results. No toxicity was seen. Some responses have been durable without maintenance. Conclusion: Patient-specific cutaneous electrostimulation with the MC5-A Calmare^® device appears to dramatically reduce pain in refractory CIPN patients with no toxicity. Further studies are underway to define the benefit, mechanisms of action, and optimal schedule.