Search

Background: Androgen receptor splice variant 7 (AR-V7) in circulating tumor cells (CTCs) from patients with metastatic castration-resistant prostate cancer (mCRPC) was recently demonstrated to be associated with resistance to abiraterone and enzalutamide. Cabazitaxel might, however, remain effective in AR-V7-positive patients. Objective: To investigate the association between AR-V7 expression in CTCs and resistance to cabazitaxel. Design, setting, and participants: We selected patients with mCRPC from the multicenter, randomized, phase 2, randomized, open-label, multicenter study in mCRPC on the pharmacodynamic effects of budesonide on cabazitaxel (Jevtana) (CABARESC). Before the start of the first and third cabazitaxel cycle, CTCs were enumerated using the CellSearch System. In patients with >= 10 CTCs in 7.5 ml blood at baseline, the expression of AR-V7 was assessed by quantitative polymerase chain reaction. Outcome measures and statistical analysis: The primary end point was the association between the AR-V7 status and the CTC response rate (decrease to fewer than five CTCs in 7.5 ml blood during treatment). Secondary end points were the prostate-specific antigen (PSA) response rate (RR) and overall survival (OS). Analyses were performed using chi-square and log-rank tests. Results and limitations: AR-V7 was detected in 16 of 29 patients (55%) with >= 10 CTCs and was more frequently found in abiraterone pretreated patients (5 of 5 [100%] treated vs 7 of 20 [35%] untreated; p = 0.009). We found no differences in CTC and PSA RRs. The presence of AR-V7 in CTCs was not associated with progression-free survival (hazard ratio [HR]: 0.8; 95% confidence interval [CI], 0.4-1.8) or overall survival (HR 1.6; 95% CI, 0.6-4.4). Conclusions: The response to cabazitaxel seems to be independent of the AR-V7 status of CTCs from mCRPC patients. Consequently, cabazitaxel might be a valid treatment option for patients with AR-V7-positive CTCs. Patient summary: Tools are needed to select specific treatments for specific patients at specific times. The presence of the gene AR-V7 in CTCs has been associated with resistance to antiandrogen receptor treatments. We investigated whether this holds true for cabazitaxel, but we found cabazitaxel to be effective independent of the presence of AR-V7. (C) 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Context In patients with advanced and metastatic urological cancers, clinical outcome may be improved by immune checkpoint inhibitors (ICIs). Objective To systematically review relevant literature on efficacy and safety of ICIs in patients with advanced and metastatic urothelial cell cancer (UCC), renal cell cancer (RCC), and prostate cancer. Evidence acquisition Relevant databases, including Medline, Embase, and the Cochrane Library, were searched up to March 16, 2017. A narrative review of randomized clinical trials (RCTs) was performed. Evidence synthesis Six RCTs were included for the systematic review. In platinum-pretreated UCC, efficacy of pembrolizumab was superior to chemotherapy, with longer median overall survival (OS; 10.3 vs 7.4 mo), a higher objective response rate (ORR; 21.1% vs 11.4%, p=0.001), and a lower adverse event rate (60.9% vs 90.2%). Three RCTs assessed the safety and efficacy of nivolumab in advanced RCC. The median OS (25.0 vs 19.6 mo) and the ORR (25% vs 5%) were higher in patients treated with nivolumab compared with second-line everolimus. In all three studies, the safety profile of nivolumab was favorable. In patients with metastatic castration-resistant prostate cancer, two RCTs were identified, which did not show significant benefits for ipilimumab over placebo. In UCC and RCC, there was no conclusive association between programmed cell death receptor ligand 1 (PD-L1) expression in tumor tissue and clinical outcome during pembrolizumab and nivolumab treatment, respectively. Conclusion In metastatic UCC and RCC, pembrolizumab and nivolumab have superior efficacy and safety to second-line chemotherapy and everolimus, respectively. No beneficial effect of ipilimumab was observed in prostate cancer patients. PD-L1 expression status is currently not suitable as a predictive marker for treatment outcome. Patient summary Immune checkpoint inhibitors are able to reactivate the immune system against tumor cells. In second-line setting, pembrolizumab and nivolumab are safe and confer survival benefit in advanced urothelial cell and renal cell cancer, respectively.