Weekly systemic combination of cisplatin and interferon alpha 2a in diffuse malignant pleural mesothelioma.

The treatment of diffuse malignant pleural mesothelioma (DMPM) remains grim. Neither surgery, radiotherapy nor chemotherapy can be considered as a standard therapy. Immunotherapy with interferon (IFN) in combination with chemotherapy may be an interesting new approach. In 13 consecutive patients with DMPM, we used a weekly combination of cisplatin (CDDP) (60 mg/m2; day 2) and IFN alpha 2a (6 MU/day; days 1-4) in a protocol of two cycles of 4 weeks on/4 weeks off followed by 3 weeks on/3 weeks off. Total treatment duration was thus 25 weeks. In responders, IFN as maintenance monotherapy was continued for a further 6 months. There were nine males and four females with an average age of 65.3 years (range 51-72 years). Eleven had epithelial, one had mixed and one had a sarcomatoid form of DMPM. Five patients were classified as stage II, six as stage III and two as stage IV, as per the International Mesothelioma Interest Group. Thirty-five cycles were administered with a median of three cycles/patient (range 0.75-4). The median total cumulative dose of CDDP was 596 mg/m2 (range 114-861) and that of IFN alpha 2a was 264 MU (range 72-336). Four patients received IFN maintenance therapy, one for 3 months and three for 6 months. One patient had a complete response, four had a partial response, six had a stable disease and the disease progressed in one. One patient was non evaluable for response. All patients were assessable for toxicity. Hematological toxicity was the most frequently observed but was manageable (grade 3 anemia in five patients, grade 3 thrombocytopenia in three patients, grade 3 neutropenia in five patients). Grade 1 renal toxicity was observed in six patients, grade 2-3 asthenia in six patients and an average 5-kg weight loss was noted in nine patients. In conclusion, systemic combination of CDDP and IFN alpha 2a in large doses is effective at the expense of non-negligible toxicity.