Electrochemotherapy with intravenous bleomycin in the local treatment of skin melanoma metastases

Background: Electrochemotherapy (ECT) combines chemotherapy and electroporation to increase drug uptake. Its role in cutaneous melanoma metastasis treatment is not well defined; indeed, few studies have been reported, without complete follow-up data. Aim: To prospectively evaluate clinical activity and tolerability of ECT with i.v. bleomycin, and to analyze the response increase associated to repeated sessions, in the largest series of cutaneous melanoma metastases reported to date (n = 233). Patients and Methods: 14 stage III relapsed/refractory patients were enrolled according to European Standard Operating Procedures of Electrochemotherapy (ESOPE) guidelines and treated under general sedation using the Cliniporator™ pulse generator. Results: A response was obtained in 13/14 patients (93%) after the first ECT, with a complete regression (CR) in 7 (50%). Seven patients underwent a second and three a third ECT on newly appearing and residual lesions, all achieving a response. Overall, a response was obtained in 93% metastases, with lower response rates in >1 cm² lesions. The CR rate was 58%; none of the CR nodules relapsed. The repeated ECT sessions gave rise to a new response in 21/29 (72%) re-treated lesions. The local tumor control rate was 74.5% at 2 years. Conclusion: ECT is a safe procedure, easily performed in terms of toxicities and cost-effectiveness ratios, and constitutes a therapeutic tool for relapsed/refractory cutaneous melanoma patients. The repeated ECT sessions are associated with a response increase in re-treated lesions which could allow to overcome the reduced activity in >1 cm² sized metastases.