The FINANCIAL — GlaxoSmithKline (GSK) plc announced that the pivotal Phase III study COMPARZ has met its primary endpoint.
In the open-label, head-to-head study, pazopanib demonstrated non-inferiority to sunitinib in terms of progression free survival. Patients in the study were treated for advanced renal cell carcinoma (mRCC) with a component of clear cell histology and had received no prior systemic therapy for advanced or metastatic renal cell carcinoma. As GlaxoSmithKline reported, the findings were presented by lead investigator, Robert J. Motzer, MD, of the Memorial Sloan-Kettering Cancer Center during the 1 October Presidential Symposium of the ESMO 2012 Congress of the European Society for Medical Oncology held in Vienna, Austria.
In the study, 1110 patients were randomised to receive treatment with either pazopanib or sunitinib at their respective, approved treatment doses (pazopanib – 800mg/daily; sunitinib – 50 mg/daily for 4 weeks followed by 2 weeks off treatment). Treatment was continued in both arms until patients showed signs of disease progression, unacceptable toxicity, or voluntarily withdrew from study. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response, health-related quality of life (QoL), safety, symptom burden and medical resource utilisation.
According to results based on independent review, COMPARZ showed that the Votrient vs sunitinib hazard ratio for PFS was 1.047 (95% CI 0.898, 1.220); predefined criterion for non-inferiority was the upper bound of a two-sided 95% CI of 1.25. Median PFS was 8.4 months (95% CI 8.3, 10.9) for pazopanib compared to sunitinib at 9.5 months (95% CI 8.3, 11.1). The secondary endpoint of objective response rate showed an ORR of 31% in the pazopanib arm compared to 25% in the sunitinib arm, (p = 0.032). Analysis of overall survival data showed that the Votrient vs sunitinib hazard ratio for OS was 0.908 (95% CI 0.762, 1.082; p-value = 0.275).
Study findings also showed there was a statistically significant outcome in favour of pazopanib for 11 of the 14 domains from four Quality of Life (QoL) instruments which included measures of fatigue, mouth and throat soreness, as well as hand and foot soreness among other measures.
The most common adverse events (≥ 30%, all grades) in this study for pazopanib compared to sunitinib, respectively, included: diarrhoea (63% vs. 57%); fatigue (55% vs. 63%); hypertension (46% vs. 41%); nausea (45% vs. 46%); decreased appetite (37% vs. 37%); ALT increase (31% vs. 18%); hair color changes (30% vs. 10%); hand-foot syndrome (29% vs. 50%); taste alteration (26% vs. 36%); and, thrombocytopenia (10% vs. 34%).
42% of patients in the pazopanib arm and 41% in the sunitinib arm had serious adverse events (AE). Serious AEs occurring in 3% or more of patients in the pazopanib arm were ALT increase and AST increase. Serious AEs occurring in 3% or more of patients in the sunitinib arm were pyrexia and thrombocytopenia.
13 subjects (2%) had fatal AEs in the pazopanib arm and 19 subjects (3%) in the sunitinib arm had fatal AEs. There was no predominant fatal event. 11 subjects had fatal AEs that were considered drug-related by Investigator assessment: 3 (<1%) in the pazopanib arm and 8 (1%) in the sunitinib arm.
“We are pleased with the results of the COMPARZ study and look forward to sharing our findings with the physicians who treat advanced renal cell carcinoma,” said Paolo Paoletti, MD, President of GSK Oncology. “There has been limited information on the direct comparison of therapeutic agents such as pazopanib and sunitinib and we undertook the study in hopes of providing insights that will support the treatment decisions physicians make.”