A single-arm phase II trial of pazopanib in patients with advanced non-small cell lung cancer with non-squamous histology with disease progression on bevacizumab containing therapy

Abstract

ObjectivesPlatinum-based chemotherapy with bevacizumab is a standard therapy for patients with stage IIIB/IV non-small cell lung cancer (NSCLC) with non-squamous (NS) histology. Mechanisms of resistance to bevacizumab include increased VEGF signaling or activation of VEGF receptors. Pazopanib is a multi-targeted VEGF receptor tyrosine kinase with single agent activity in NSCLC. Materials and methodsStage IIIB/IV patients with adequate organ function, who progressed on a bevacizumab containing therapy were eligible if it had been ≤8 weeks since the last bevacizumab treatment. The primary end-point was disease control rate (DCR), defined as partial or complete response, or stable disease for ≥12 weeks. Patients were assessed radiographically every 2 cycles (6 weeks). A Simon 2-stage design was used, and if in the first stage ≤4 of 17 patients experienced disease control the trial was to have been stopped for futility. An unplanned analysis was performed after 15 patients were evaluable secondary to slow accrual. ResultsBetween December 2010 and November 2013, 15 patients were treated on trial. The median age was 61 years (range 39–74), and all patients had stage IV disease. Of the 15 patients, 4 discontinued therapy prior to cycle 2 evaluation due to adverse events (n=3) and medical illness (n=1), 5 patients had progressive disease, 4 patients had stable disease for <12 weeks, and 2 patients had stable disease for ≥12 weeks. No responses were observed. The DCR observed was 13% (2/15), and the trial did not meet the criteria to proceed to the second stage. Episodes of grade 3 treatment related toxicities observed included: increased ALT (n=2), increased AST (n=1), anorexia (n=3), fatigue (n=3), hypertension (n=1), infection (n=1), mucositis (n=2), nausea (n=3), pericardial effusion (n=1), and vomiting (n=1). ConclusionPazopanib has limited activity in NSCLC-NS in patients who have experienced disease progression on bevacizumab.