Abstract
Purpose
Pazopanib and lapatinib are tyrosine kinase inhibitors that target vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit or epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/neu), respectively. In cervical cancer, EGFR and HER2/neu overexpression and high microvascular density correlate with survival.
Patients and Methods
Patients with measurable stage IVB persistent/recurrent cervical carcinoma not amenable to curative therapy and at least one prior regimen in the metastatic setting were randomly assigned in a ratio of 1:1:1 to pazopanib at 800 mg once daily, lapatinib at 1,500 mg once daily, or lapatinib plus pazopanib combination therapy (lapatinib at 1,000 mg plus pazopanib at 400 mg once daily or lapatinib at 1,500 mg plus pazopanib at 800 mg once daily). Therapy continued until progression or withdrawal because of adverse events (AEs). Primary end point was progression-free survival (PFS), and secondary end points were overall survival (OS), response rate (RR), and safety. The futility boundary was crossed at the planned interim analysis for combination therapy compared with lapatinib therapy, and the combination was discontinued.
Results
Of 230 patients enrolled, 152 were randomly assigned to the monotherapy arms: pazopanib (n = 74) or lapatinib (n = 78). Most patients (62%) had recurrent cancer. Pazopanib improved PFS (hazard ratio [HR], 0.66; 90% CI, 0.48 to 0.91; P = .013) and OS (HR, 0.67; 90% CI, 0.46 to 0.99; P = .045). Median OS was 50.7 weeks and 39.1 weeks and RRs were 9% and 5% for pazopanib and lapatinib, respectively. The only grade 3 AE > 10% was diarrhea (11% pazopanib and 13% lapatinib). Grade 4 AEs were 9% (lapatinib) and 12% (pazopanib).
Conclusion
This study confirms the activity of antiangiogenesis agents in advanced and recurrent cervical cancer and demonstrates the benefit of pazopanib based on the prolonged PFS and favorable toxicity profile.