Phase II proof-of-concept study of pazopanib monotherapy in treatment-naive patients with stage I/II resectable non-small-cell lung cancer

Abstract

Purpose: Patients with early-stage, resectable, non-small-cell lung cancer (NSCLC) are at risk for recurrent disease, and 5-year survival rates do not exceed 75%. Angiogenesis inhibitors have shown clinical activity in patients with late-stage NSCLC, raising the possibility that targeting the vascular endothelial growth factor pathway in earlier-stage disease may be beneficial. This proof-of-concept study examined safety and efficacy of short-term, preoperative pazopanib monotherapy in patients with operable stage I/II NSCLC.

Patients and methods: Patients scheduled for resection received oral pazopanib 800 mg/d for 2 to 6 weeks preoperatively. Tumor response was measured by high-resolution computed tomography, permitting estimation of change in tumor volume and diameter. Gene-expression profiling was performed on 77 pre- and post-treatment lung samples from 34 patients.

Results: Of 35 patients enrolled, 33 (94%) had clinical stage I NSCLC and two (6%) had clinical stage II NSCLC. Median treatment duration was 16 days (range, 3 to 29 days). Thirty patients (86%) achieved tumor-volume reduction after pazopanib treatment. Two patients achieved tumor-volume reduction > or = 50%, and three patients had partial response according to Response Evaluation Criteria in Solid Tumors. Pazopanib was generally well tolerated. The most common adverse events included grade 2 hypertension, diarrhea, and fatigue. One patient developed pulmonary embolism 11 days after surgery. Several pazopanib target genes and other angiogenic factors were dysregulated post-treatment.

Conclusion: Short-duration pazopanib was generally well tolerated and demonstrated single-agent activity in patients with early-stage NSCLC. Several target genes were dysregulated after pazopanib treatment, validating target-specific response and indicating a persistent pazopanib effect on lung cancer tissue. Further clinical evaluation of pazopanib in NSCLC is planned.