Vinorelbine and Gemcitabine As Second- or Third-line Therapy for Malignant Pleural Mesothelioma

Objectives: Pemetrexed-cisplatin is the only FDA-approved regimen for malignant pleural mesothelioma (MPM), and the impact on survival is modest. No drugs have been shown to improve survival as second-line therapy, yet vinorelbine and gemcitabine are prescribed based on the results of small phase II trials. To augment the existing limited data, we examined our institutional experience with vinorelbine and gemcitabine in patients with previously treated MPM.

Materials And Methods: We reviewed charts of patients with MPM treated with vinorelbine and/or gemcitabine as second- or third-line therapy between 2003 and 2010. Toxicity was graded according to the Common Terminology Criteria for Adverse Events Version 4.0. CT scans were reviewed with a reference radiologist according to modified RECIST criteria.

Results: Sixty patients were identified: 33 treated with vinorelbine, 15 gemcitabine, and 12 both agents. Eighty-three percent initially received pemetrexed-platinum. Toxicity was substantial: 46% experienced at least one episode of grade 3-4 toxicity. Of 56 patients evaluable radiologically, there was 1 partial response (gemcitabine) giving a response rate of 2% (95% CI: 0-10%). Forty-six percent had stable disease. Median progression free survival was 1.7 months for vinorelbine and 1.6 months for gemcitabine. Median overall survival was 5.4 and 4.9 months, respectively.

Conclusions: Response to second- or third-line vinorelbine or gemcitabine is rare. The high rate of stable disease warrants the continued use of these agents in this setting, though the impact on survival is questionable. These data justify the choice of placebo control arms in randomized trials of novel agents in previously treated patients.