SWOG S0722: phase II study of mTOR inhibitor everolimus (RAD001) in advanced malignant pleural mesothelioma (MPM).

INTRODUCTION

The PI3K/Akt/mammalian target of rapamycin pathway is activated in a majority of malignant pleural mesotheliomas (MPM). We evaluated the activity of everolimus, an oral mammalian target of rapamycin inhibitor, in patients with unresectable MPM.

METHODS

MPM patients who had received at least one but no more than two prior chemotherapy regimens, which must have been platinum-based, were treated with 10 mg of everolimus daily. The primary endpoint was 4-month progression-free survival (PFS) by RECIST 1.1.

RESULTS

A total of 59 evaluable patients were included in the analysis. The median duration of treatment was 2 cycles (56 days). Overall response rate was 2% [95% confidence interval (CI): 0-12%] by RECIST 1.1 and 0% (0-10%) by modified RECIST for MPM. The 4-month PFS rate was 29% (95% CI: 17-41%) by RECIST 1.1, and 27% (95% CI: 16-39%) by modified RECIST. The median PFS was 2.8 months (95% CI: 1.8-3.4) by RECIST 1.1. The median overall survival was 6.3 months (95% CI: 4.0-8.0). There was no difference in PFS among patients who received one or two prior chemotherapy regimens (p = 0.74). There was no difference in overall survival between patients with epithelioid histology versus other types (p = 0.47). The most common toxicities were fatigue (59%), hypertriglyceridemia (44%), anemia (42%), oral mucositis (34%), nausea (32%), and anorexia (32%). The most common grade 3 to 4 toxicities were fatigue (10.2%), anemia (6.8%), and lung infection (6.8%).

CONCLUSION

Everolimus has limited clinical activity in advanced MPM patients. Additional studies of single-agent everolimus in advanced MPM are not warranted.