1399P Androgen receptor (AR) alterations on circulating tumor DNA (ctDNA) sequencing and response to the first-line androgen-receptor targeted agent (ARAT) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

Abstract

AR gene alterations, detected by ctDNA sequencing, in the first line mCRPC setting were associated with worse outcomes on ARATs (abiraterone and enzalutamide) in a phase 2 trial (PMID: 29367197). Our objective was to correlate AR alterations with outcomes in real-world patients with treatment naïve mCRPC treated with ARATs, and to assess outcomes based on the presence of AR amplification (ARamp) versus AR mutation (ARmut).