Vatalanib in Malignant Mesothelioma: a Phase II Trial by the Cancer and Leukemia Group B (CALGB 30107)

Introduction: The Cancer and Leukemia Group B (CALGB) conducted a multi-center phase II trial to evaluate the efficacy and safety of vatalanib in previously untreated patients with malignant mesothelioma and to evaluate potential biomarkers of disease response (CALGB 30107).

Methods: Treatment consisted of vatalanib 1250 mg given orally once daily. CT scans were obtained at baseline and every 6 weeks thereafter. Baseline serum levels of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), thrombospondin-1 (TSP-1), and mesothelin were obtained. The primary endpoint was 3-month progression-free survival (PFS).

Results: Forty-seven patients enrolled at 19 centers. The median age was 75 years, and the majority of patients (79%) had an ECOG performance status of 1. Tumors were classified as epithelial (77%), sarcomatoid (10%), or mixed (9%) histology. Toxicity was mild; the most common grade 3/4 adverse events were neutropenia (2%), nausea (15%), elevated alanine aminotransferase (11%), hypertension (2%), and gastrointestinal bleeding (2%). Partial responses were observed in 6% of patients and stable disease in 72% of patients. The 3-month PFS rate was 55% (95% CI: 40%, 68%). The median PFS was 4.1 months. Median overall survival was 10.0 months. There was no correlation between serum levels of VEGF, PDGF, TSP-1, or mesothelin and treatment response, PFS, or survival.

Conclusions: Vatalanib as a single agent with this dose and schedule does not warrant further study in this disease.