Introduction: Previously published results from a randomized phase III study of pemetrexed plus cisplatin in patients with malignant pleural mesothelioma (MPM) demonstrated a significant survival benefit and higher response rate compared with cisplatin. Although pemetrexed was under review by regulatory agencies, an International Expanded Access Program (EAP) provided more than 3000 mesothelioma patients with access to single-agent pemetrexed or pemetrexed in combination with cisplatin or carboplatin in 13 countries. This manuscript reports the safety and efficacy data from the nonrandomized open-label study in chemonaïve patients receiving pemetrexed plus platinum under the EAP.
Methods: Patients with histologically confirmed MPM, not amenable to curative surgery, received pemetrexed 500 mg/m in combination with either cisplatin 75 mg/m or carboplatin AUC 5, once every 21 days with standard premedication. Efficacy data were recorded at the end of study participation.
Results: A total of 1704 chemonaïve patients received pemetrexed plus cisplatin (n = 843) or pemetrexed plus carboplatin (n = 861) and were evaluated for safety. The efficacy evaluable population consisted of 745 patients in the pemetrexed plus cisplatin group and 752 patients in the pemetrexed plus carboplatin group for whom physician-reported tumor response was available. The pemetrexed plus cisplatin group demonstrated a response rate of 26.3% compared with 21.7% for the pemetrexed plus carboplatin group, with similar 1-year survival rates (63.1% versus 64.0%) and median time to progressive disease (7 months versus 6.9 months). The most common grade 3/4 hematologic toxicity was neutropenia in 23.9% of the pemetrexed plus cisplatin group and 36.1% of the pemetrexed plus carboplatin group.
Conclusion: This large EAP confirmed the activity of pemetrexed plus cisplatin and pemetrexed plus carboplatin in chemonaïve patients with MPM, demonstrating clinically similar time to progressive disease and 1-year survival rates.