Sequential chemotherapy with cisplatin/gemcitabine (CG) followed by mitoxantrone/methotrexate/mitomycin (MMM) in patients with malignant pleural mesothelioma. A multicenter Italian Phase II Study (SITMP1)

Purpose: We performed a multicenter phase II trial to evaluate the impact on the activity, efficacy, symptom control and safety of using two active regimens in a sequential schedule (cisplatin/gemcitabine followed by mitoxantrone/methotrexate/mitomycin) as first-line chemotherapy for unresectable malignant pleural mesothelioma (MPM). Patients and methods: A total of 54 patients received cisplatin 75 mg/m² on day 1 and gemcitabine 1200 mg/m² on days 1 and 8, every 3 weeks for four courses (CG regimen) followed by mitoxantrone 10 mg/m² on day 1, methotrexate 35 mg/m² on day 1 and mitomycin 7 mg/m² on day 1, every 3 weeks with mitomycin in alternate cycles for four courses (MMM regimen). Results: We observed 3 complete responses (CRs) (5.6%) and 13 partial responses (PRs) (24.0%), with an overall response rate (ORR) of 29.6% (95% confidence interval, 17-42%), 33 stable disease (SD) (61.1%) and 5 progressive disease (PD) (9.2%). Median time to progression (TTP) was 9.5 months (range, 2-23). Median overall survival (OS) was 13 months (range, 3-33); 1-year survival rate was 63%. The treatment produced a good symptom control, with an improvement during chemotherapy in dyspnea and pain in 52.9 and 48.3% of patients, respectively. The major toxicity observed was hematological. Grades 3-4 NCI-CTC v 2.0 toxicity with the CG regimen included: neutropenia (11.1%), anemia (1.9%), thrombocytopenia (7.4%), vomiting (11.1%) and with the MMM regimen: neutropenia (35.2%), anemia (5.5%), thrombocytopenia (7.4%) and stomatitis (1.9%). Conclusion: This phase II study with the sequential approach of two active regimens showed a good disease control in MPM, with symptom improvement and only mild toxicity.