Erlotinib plus bevacizumab in previously treated patients with malignant pleural mesothelioma.

Background: We conducted a phase 2, multicenter, open-label study of erlotinib plus bevacizumab in patients with malignant pleural mesothelioma who had previously received 1 prior chemotherapy regimen. These agents have activity in non-small cell lung cancer, but their role in mesothelioma is unclear. The primary endpoint is response rate. Secondary endpoints include time to progression, survival, and toxicity.

Methods: Eligible patients with mesothelioma who had previously received 1 chemotherapy regimen were treated with erlotinib 150 mg per os daily and bevacizumab 15 mg/kg administered intravenously on Day 1 of a 21-day cycle. Treatment continued until disease progression or development of significant toxicity. Tumor response was assessed after every 2 cycles using previously established mesothelioma response criteria from Byrne and Nowak.

Results: Twenty-four eligible patients initiated therapy with erlotinib and bevacizumab between February 2004 and October 2006. There were no complete or partial responses, although 12 patients achieved stable disease for at least 2 cycles of treatment. The median time to progression was 2.2 months (95% confidence interval [CI], 1.4 months-5.9 months). The median survival was 5.8 months (95% CI, 2.8 months-10.1 months). The most common toxicities were rash and diarrhea. There were no treatment-related deaths, intracranial bleeding, or hemoptysis.

Conclusions: The combination of erlotinib and bevacizumab was tolerated reasonably well, but there was no evidence of radiographic response. This study demonstrates the feasibility of conducting trials in mesothelioma patients who have failed first-line therapy. More therapeutic studies with effective agents are needed for these patients.