Prognostic Value of Androgen Receptor Splice Variant 7 in the Treatment of Castration-resistant Prostate Cancer with Next generation Androgen Receptor Signal Inhibition: A Systematic Review and Meta-analysis

CTC-derived AR-V7 detection as a prognostic and predictive biomarker in advanced prostate cancer

“…AR-V7 is one of these candidates as a putative predictor of benefit to the newer ARS inhibitors, as demonstrated in several single-center trials and a recent meta-analysis, as discussed above 31,32,34,38,40 . These studies demonstrate in aggregate that the benefit of ARS inhibitors is limited to AR-V7(−) patients and very few patients with AR-V7(+) disease demonstrate benefit with abiraterone or enzalutamide.…”

“…To add further evidence of the prognostic impact of AR-V7 in patients with mCRPC treated with ARS inhibitors, a meta-analysis on this subject was recently published 40 . In the PFS and OS analysis, a total of eight trials encompassing 490 patients were included and demonstrated that both PFS and OS were better in AR-V7(−) than AR-V7(+) patients.…”

AR-V7 and treatment selection in advanced prostate cancer: are we there yet?

“…These studies have included different methods of evaluating the presence of AR-V7 in circulating tumor cells (CTCs); the two most accepted assays are the Johns Hopkins mRNA-based assay using the AdnaTest platform (2–4) and the EPIC Sciences protein-based assay developed in collaboration with Memorial Sloan Kettering Cancer Center (5). In aggregate, the published data including a recent meta-analysis (6), consistently demonstrate that the benefit of ARSi occurs predominantly in AR-V7 negative (–) CRPC patients while most AR-V7 positive (+) CRPC patients do not respond well or durably to abiraterone or enzalutamide. On the other hand, AR-V7 status appears to not correlate with efficacy of taxane-based chemotherapy, and the detection of AR-V7 does not preclude favorable responses to docetaxel or cabazitaxel (3,5,7).…”

Performance comparison of two androgen receptor splice variant 7 (AR‐V7) detection methods

“…Antonarakis et al [10] showed that detection of AR-V7 mRNA in circulating tumour cells (CTC) of patients with mCRPC was associated with non-response to next-generation ADT. Several subsequent confirmatory studies followed [3,[12][13][14] and importantly the response rates to taxane-based chemotherapy showed no significant difference between AR-V7positive vs -negative patients with mCRPC [3,10,[12][13][14][15][16]. These findings collectively argue for AR-V7 as a potential treatment selection biomarker in the setting of mCRPC ( Fig.…”

“…However, in our opinion the more meaningful comparison is that of response rates to the two therapeutic alternatives and projecting this on the tested population. Antonarakis et al recently reported that the response rate in AR‐V7‐positive patients to next‐generation ADT is ~27% (four of 15 patients), whereas the response rate to chemotherapy in AR‐V7‐positive patients is ~36% (19of 53 patients) . At first glance these numbers suggest a difference of ~9%; however, when applied to all tested patients, the net benefit from testing can be estimated around ~1.5% , which is considerably lower than currently portrayed.…”