Association of single nucleotide polymorphisms (SNPs) in CYP17A1 and SLCO2B1 genes and clinical outcome in metastatic castration-resistant prostate cancer patients treated with abiraterone acetate: results of the ABIGENE prospective study.

358Background: Abiraterone acetate (AA), a CYP17A1 inhibitor, has been approved in the treatment of metastatic castration-resistant prostate cancer (mCRPC). Germline polymorphisms in genes involved in androgen biosynthesis or transport may influence response and survival in this setting. Methods: ABIGENE is a multicentric prospective non-randomized pharmacogenetic study (NCT01858441). The primary objective was to investigate the association between 13 SNPs in genes related to AA pharmacology (CYP17A1, SLCO2B1 and SLCO2B3) and radiographic progression-free survival (rPFS), according to PCWG2 criteria, in pts with mCRPC treated with first-line AA + prednisone. The main secondary objectives were to evaluate the impact of these SNPs on radiographic and PSA response, overall survival (OS) and toxicity. SNPs were detected in blood samples before starting AA and analyzed by pyrosequencing or PCR-RFLP methods. Kaplan-Meyer’s curves with log-rank tests and cox regression models were used to identify relationships ...