Sorafenib in malignant mesothelioma (MM): A phase II trial of the Cancer and Leukemia Group B (CALGB 30307)

Abstract

Listen

Translate article

7707 Background: Systemic chemotherapy with cisplatin/pemetrexed is the approved first line treatment regimen for patients with MM. There is no approved second line therapy. In addition, many patients, especially those >70, cannot tolerate combination chemotherapy. Angiogenesis inhibitors have emerged as attractive potential therapies for MM and SU5416 and PTK787 have previously demonstrated single agent activity. We examined the efficacy of sorafenib, an inhibitor of VEGFR2 and PDGFR-b, in chemotherapy naïve and previously treated patients with MM. Methods: This was an open label single arm phase II study of sorafenib in chemotherapy naïve and previously pemetrexed treated patients with MM. Primary end point was response rate (RR). Secondary objectives were 3-month failure free and overall survival (FFS and OS). Forty-four (44) eligible patients were expected to enroll to differentiate a RR of <5% versus >20%, with a Type I error of 0.0675 and a power of 0.955 Results: Between 10/04 and 8/05, 51 patients were enrolled and treated with sorafenib 400 mg bid. One cycle was defined as 28 days; restaging occurred every 2 cycles. Baseline demographics: M/F (36/15); Median age (69; range 36–88; 45% >70); Histology (epithelial/sarcomatoid/mixed/unknown: 37/4/8/2); pleural/peritoneal MM (46/5); ECOG PS 0/1 (11/40); chemo-naive/prior chemo (20/31). Grade 3/4 toxicities occurring in >10% of patients: Fatigue (12 (25%); 11/1) and hand-foot reaction (6 (13%); 6/0). No study related deaths occurred. Estimates of RR and FFS are based on 47 patients with available follow-up data. Response: CR: 0; PR 2: 4% (95% CI; 1- 14%); SD 28 (60%); PD 11 (23%); unevaluable 6 (14%). Three month FFS was 78%; median FFS was 3.7 months and median OS was 10.7 months. The median FFS were 3.6 and 3.6 months and the median OS were 4.9 and 14.6 months in chemo naïve and previously treated patients, respectively. Conclusions: Sorafenib demonstrated modest activity in this phase II trial but did not meet its primary endpoint. The improved outcome in previously treated patients likely reflects patient selection. Ongoing correlative science studies including expression of p-ERK 1/2, baseline VEGF and PDGF levels, are being performed to help identify patient subsets who may benefit (PR or SD) from sorafenib. No significant financial relationships to disclose.