Association of genetic markers in angiogenesis- or exposure-related genes with overall survival in pazopanib (P) treated patients (Pts) with advanced renal cell carcinoma.

Abstract

303 Background: Pazopanib, an oral tyrosine kinase inhibitor of VEGFR, PDGFR and c-Kit, has been approved for the treatment of advanced renal cell cancer (RCC). Interindividual variability in response and survival is observed among advanced RCC pts treated with P. Our previous analyses showed that germline variants in angiogenesis (IL8, HIF1A, VEGFA)- and exposure (NR1IR)-related genes may predict progression free survival and/or response rate to P monotherapy (ASCO 2010 abstract 4520). This study sought to test the hypothesis that differences in overall survival (OS) can be explained, at least in part, by germline genetic variants in angiogenesis- and/or exposure-related genes. Methods: Twenty-seven functional polymorphisms within 13 genes were evaluated in 241 P treated pts with advanced RCC from a phase III study (ESMO 2010 abstract LBA22) and a single arm Phase II study. Genetic association with OS was analyzed using the Cox proportional hazards model. Results: Six polymorphisms in IL8, FGFR2, VEGFA, FLT4, and NR1I2 showed nominally significant association with OS (p≤0.05). A median OS of 29.6 months was observed in pts carrying wild-type IL8 2767 AA genotype (n=68, 31%), compared to 14.8 months in those with the TT variant genotype (n=36, 16%) (HR (95%CI) = 2.3 (1.4, 3.9) for TT vs. AA, p=0.002]. The median OS for pts who were heterozygous for this IL8 polymorphism was 23.9 months (n=119, 53%). The FGFR2 IVS2 + 906C>T variant TT genotype was associated with inferior OS compared with the wild-type CC genotype (median OS, 21.4 vs. 28.0 months, HR (95%CI) = 2.0 (1.2, 3.2), p=0.009). Similarly, shorter OS was observed for the VEGFA −1154G>A variant AA genotype compared with the wild-type GG genotype [median OS, 16.7 vs. 25.3 months, HR (95%CI) = 2.2 (1.3, 3.6), p=0.004]. The variant genotypes of the NR1IR (−25385C>T) and FLT4 (1480A>G) polymorphisms were also associated with reduced OS (p<0.05). Conclusions: Germline variants in angiogenesis- and exposure-related genes may be associated with survival outcome for P monotherapy in pts with advanced RCC. These associations are considered exploratory and require confirmation in an independent dataset. [Table: see text]