Would you use AR-V7 testing to decide second-line androgen receptor-axis-targeted therapy vs chemotherapy for patients who with metastatic castration-resistant prostate cancer?

In our PROPHECY multicenter AR-V7 validation trial, we compared the JHU AR-V7 CTC RNA test against the Epic/Genomic Sciences nuclear protein CTC AR-V7 test. Both tests, when positive, were strongly associated with lack of PSA response, short PFS, and short OS in men with mCRPC receiving abiraterone ...

Next generation AR therapy remains a critical therapy option for most patients with mCRPC. As some patients who test AR-V7 positive still respond to these agents and a psa 4-6 weeks after starting one of these drugs will provide "early" clinical information regarding response I do not use AR-V7 test...

Yes, I use the Johns Hopkins AR-V7 test (since it is available at my institution!) in two settings. In the first-line (treatment-naive) mCRPC setting, I use the test to determine who NOT to treat initially with Abi or Enza. Only 8-10% of patients will have a positive JHU AR-V7 test in this setting; ...