Investigator Perspectives on Emerging Concepts in the Management of Genitourinary CancersAR-V7 status and response to chemotherapy and/or endocrine therapy in mCRPC
1:42 minutes.
TRANSCRIPTION:
DR PETRYLAK: We know that in a patient, it’s about a 10% rate in castrate-resistant disease initially. It goes up after treatment with abiraterone or enzalutamide. If you’re positive for the splice variant, it’s unlikely you will respond to either enzalutamide or abiraterone, whether that’s as de novo resistance or acquired later on, when they do develop and convert from negative to positive. So that’s a good indication that they’re not going to respond. Now, whether it’s the V7 variant or whether it is actual androgen receptor levels is not clear at this point. DR LOVE: And I guess the thing that’s been really interesting has been I think the first time I saw this was at the ASCO GU meeting in 2015 and then published was the data with chemotherapy with docetaxel. DR PETRYLAK: Correct. And docetaxel seems to respond well in those patients who are V7-positive. DR LOVE: So globally in a more typical patient who progresses after responding to one, what’s the thinking in terms of response to the second one? DR PETRYLAK: Without having a marker, the way I look at is it’s the old adage: If you respond for a long period of time, you may be more likely to respond to something else. So I will give abi or enza, or vice versa, a shot in the second-line setting, if the patient has contraindications to chemotherapy or if they’ve had a good long response and they have good performance status and they’ve got time. I generally will not try that in rapidly progressing disease. |