Electrochemotherapy with bleomycin. The first clinical experience in malignant melanoma patients

Abstract

Electrochemotherapy offers a new approach to increase chemotherapeutic drug delivery. Exposure of cells or tissues to electric pulses potentiates the antitumor effectiveness of bleomycin and cisplatin, as demonstrated in vitro and in vivo on murine tumor models and in clinical trials in head and neck carcinoma patients. To determine the antitumor effectiveness of electrochemotherapy with bleomycin in malignant melanoma patients, cutaneous and subcutaneous tumor nodules were treated with electric pulses after intravenous administration of bleomycin. Nodules of various sizes were treated with single or multiple treatment. Also, antitumor effectiveness of electrochemotherapy with bleomycin was evaluated after several runs of electrochemotherapy treatment in the same patient with an interval of at least three weeks. The treatment effect was not dependent only on the tumor size, but also on the even distribution of the electric field for electropermeabilization of the nodules. Therefore, nodules which were treated either with a single or several runs of electric pulses, and were completely covered by the treatment, regressed within two to three weeks after therapy. Electrochemotherapy was equally effective in the same patient when it was repeated after a three weeks interval. In reported 2 malignant melanoma patients complete response was achieved in 22 out of 24 nodules treated. The preliminary results demonstrate that electrochemotherapy with bleomycin is effective in eradicating cutaneous and subcutaneous tumor lesions of malignant melanoma. Therefore, electrochemotherapy with bleomycin offers a successful approach to the treatment of cutaneous and subcutaneous tumor lesions in patients, without side effects and with high response rate. The treatment is applicable in nodules of varying sizes, since the nodules can be treated with multiple electric pulses to cover the whole tumor area and electrochemotherapy can be safely repeated several times.