Pazopanib improved PFS in advanced, metastatic renal cell cancer

Pazopanib demonstrated significant improvement in PFS and tumor response rates in patients with treatment-naïve renal cell cancer when compared with placebo. The data, which were the basis for pazopanib’s FDA approval in late 2009, were recently published in the Journal of Clinical Oncology.

“These findings further support the continued evaluation of the efficacy, safety and effect on quality-of-life of pazopanib in this patient population,” researchers wrote.

The phase-3 clinical trial included 435 treatment-naive (n=233) and cytokine-pretreated patients (n=202) with advanced or metastatic renal cell cancer randomly assigned to once-daily oral pazopanib (Votrient, GlaxoSmithKline) or placebo.

Primary endpoint was PFS; secondary endpoints were OS, tumor response rate and safety.

Overall PFS was 9.2 months with pazopanib vs. 4.2 months with placebo (HR=0.46; 95% CI, 0.34-0.62; P<.0001). Improvements were also seen for patients assigned pazopanib within a subgroup analysis of both treatment-naive and cytokine-pretreated patients.

In addition, data from a subgroup analysis indicated PFS was improved regardless of MSKCC risk category, age, sex or ECOG performance status (P<.001).

Further, the tumor response rate was 30% with pazopanib vs. 3% with placebo (P<.001); median duration of response for pazopanib was 58.7 weeks.

The most commonly reported adverse events in the treatment arm were diarrhea (52%), hypertension (40%), hair color changes (38%), nausea (26%), anorexia (22%) and vomiting (21%).

Despite the FDA warning that pazopanib has been associated with heart rhythm irregularities and that patients on pazopanib be monitored with periodic electrocardiograms and blood tests to monitor electrolytes, the researchers report “there was no evidence of clinically important differences in quality of life for pazopanib vs. placebo.”

Sternberg CN. J Clin Oncol. 2010; 10.1200/JCO.2009.23.9764.