HLA-B*57:01 Confers Susceptibility to Pazopanib-Associated Liver Injury in Patients With Cancer.

Purpose: Pazopanib is an effective treatment for advanced renal cell carcinoma and soft-tissue sarcoma. Transaminase elevations have been commonly observed in pazopanib-treated patients. We conducted pharmacogenetic analyses to explore mechanistic insight into pazopanib-induced liver injury. Experimental Design: The discovery analysis tested association between four-digit HLA alleles and alanine aminotransferase (ALT) elevation in pazopanib-treated patients with cancer from eight clinical trials (N = 1,188). We conducted confirmatory analysis using an independent dataset of pazopanib-treated patients from 23 additional trials (N = 1,002). Genome-wide association study (GWAS) for transaminase elevations was also conducted. Results: The discovery study identified an association between HLA-B*57: 01 carriage and ALT elevation [P = 5.0 x 10(-5) for maximum on-treatment ALT (MaxALT); P = 4.8 x 10(-4) for time to ALT > 3 x upper limit of normal (ULN) event; P = 4.1 x 10(-5) for time to ALT > 5 x ULN event] that is significant after adjustment for number of HLA alleles tested. We confirmed these associations with time to ALT elevation event (P = 8.1 x 10(-4) for ALT > 3 x ULN, P = 9.8 x 10(-3) for ALT > 5 x ULN) in an independent dataset. In the combined data, HLA-B*57: 01 carriage was associated with ALT elevation (P = 4.3 x 10(-5) for MaxALT, P = 5.1 x 10(-6) for time to ALT > 3 x ULN event, P = 5.8 x 10(-6) for time to ALT > 5 x ULN event). In HLA-B*57: 01 carriers and noncarriers, frequency of ALT > 3 x ULN was 31% and 19%, respectively, and frequency of ALT > 5 x ULN was 18% and 10%, respectively. GWAS revealed a possible borderline association, which requires further evaluation. Conclusions: These data indicate that HLA-B*57: 01 carriage confers higher risk of ALT elevation in patients receiving pazopanib and provide novel insight implicating an immune-mediated mechanism for pazopanib-associated hepatotoxicity in some patients. (C) 2015 AACR.