Safety and effectiveness of pemetrexed in patients with malignant pleural mesothelioma based on all-case drug-registry study

Background Pemetrexed in combination with cisplatin (Pem/Cis) is the only approved chemotherapeutic regimen for malignant pleural mesothelioma (MPM). At the time of launch, limited safety information was available. The purpose of this postmarketing all-case registry study was to investigate the safety and effectiveness of pemetrexed in patients with MPM.Methods From January 2007 to May 2008, MPM patients to be treated with pemetrexed in Japan were registered to this study to monitor its safety and effectiveness. Supply of pemetrexed was restricted to institutions with experienced medical oncologists based on predetermined criteria.Results Of 953 patients registered, data from 903 patients were eligible for analysis. Most patients were male, with median age of 65 years and 68.5% had a history of asbestos exposure. More than 90% of patients received the first cycle of Pem/Cis treatment; median number of treatment cycles was 4.0. Treatment-associated death was reported in 0.8% of patients. The incidence of Interstitial lung disease (ILD) associated with Pem/Cis during the observation period was 0.9%. The frequency of ILD in patients with pre-existing asbestosis was higher than that in patients without it. For tumor response, the overall response rate was 25.0% (95% confidence interval (CI): 22.2–28.0%). The six-month survival rate estimated by the Kaplan–Meier method was 75.9%.Conclusions This large scale all case registry study appeared to have enrolled a major portion of Japanese MPM patients. Treatment with pemetrexed was generally well tolerated and showed safety and effectiveness comparable to prior clinical trials.