Comparison of PFS and safety for Asian compared to North American and European populations in the phase III trial of pazopanib versus sunitinib in patients with treatment-naive RCC (COMPARZ).

Abstract

366 Background: Pazopanib (P) and sunitinib (S) are multi-kinase angiogenesis inhibitors that positively impact progression-free survival (PFS) in patients (pts) with metastatic renal cell carcinoma (mRCC) (NEJM 2007 356:115; JCO 2009 29:475). The safety profile of multi-kinase angiogenesis inhibitors has been shown to vary depending upon ethnic background (Oncology 2011 80:395). Methods: Treatment naïve pts with clear cell mRCC and measurable disease were randomized 1:1 to P, 800mg QD continuous dosing or S, 50 mg QD for 4 weeks followed by 2 weeks off treatment. Primary endpoint was PFS. A subgroup analysis compared PFS (Cox analysis with treatment as only covariate) and AEs between the Asian, North American (NA), and European (EU) populations. Of the 1,110 pts 367 were from Asia (188 P, 179 S). Results: PFS in the Asian subgroup was consistent with NA and EU. HR (95% CI): Asia 1.07 (0.81, 1.42); NA 1.18 (0.90, 1.53); EU 1.03 (0.79, 1.36). Median PFS mos (95% CI) P: Asia 8.4 (8.3,11.1); EU 8.5 (8.0, 11.0); NA 8.3 (6.6, 11.0); S: Asia 11.1 (8.2, 14.3); EU 9.0 (8.1, 12.9); NA 10.5 (8.2, 13.4). AEs in >25% of pts in any arm in any region and a difference of 15% between any region within an arm are shown. Conclusions: In both arms, PFS in the Asian population was similar to NA and EU. In the Asian population increased incidences of hematotoxicity, hypertension, HFS, LFT increase, proteinuria, and decreased incidences of GI symptoms, headache were observed in both arms. Consistent with NA and EU, more frequent AEs in the Asian population (>10% difference between arms): ALT increase (P); HFS, thrombocytopenia, neutropenia (S). [Table: see text]