Martin Boegemann

Enzalutamide in castration-resistant prostate cancer patients progressing after docetaxel and abiraterone.

BACKGROUND Abiraterone, an androgen synthesis inhibitor, has been successfully used in the treatment of castration-resistant prostate cancer (CRPC) for 2 yr. Enzalutamide is a second-generation nonsteroidal antiandrogen that has recently been approved for the same indication. OBJECTIVE This is the first study to evaluate the effectiveness of enzalutamide after failure of abiraterone. DESIGN, SETTING, AND PARTICIPANTS Thirty-five patients were identified as having received sequential therapy with abiraterone followed by enzalutamide. All patients had undergone prior docetaxel chemotherapy, and no patient had received ketoconazole. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Posttreatment changes in prostate-specific antigen (PSA) were used to determine the activity of enzalutamide in patients who had received prior abiraterone. RESULTS AND LIMITATIONS The median duration of abiraterone treatment was 9.0 mo (range: 2.0-19.0 mo). Of the 35 patients, 16 (45.7%) achieved a >50% decline in PSA, and 14 (40%) had a rising PSA as the best response. The median duration of subsequent enzalutamide treatment was 4.9 mo (Kaplan-Meier estimate; 95% confidence interval [CI], 2.4-7.4). Seven of 16 CRPC patients who were initially abiraterone-sensitive (43.8%) and 3 of 19 CRPC patients who were initially abiraterone-insensitive (15.8%) showed a >50% PSA decline while taking enzalutamide. Of the 35 patients, 17 (48.6%) were primarily enzalutamide-resistant and showed a rising PSA as the best response. Median time to progression was 4.0 mo (95% CI, 2.0-6.0) for 18 of 35 patients with at least one declining PSA value while taking enzalutamide (51.4%). Of the 17 patients who were assessable radiologically, only 1 (2.9%) attained a confirmed partial response. Small sample size was the major limitation. CONCLUSIONS Enzalutamide treatment achieved only a modest response rate in patients progressing after abiraterone. Although cross-resistance between abiraterone and enzalutamide was a common phenomenon, it was not inevitable, and a small but significant number of patients showed significant benefit from sequential treatment.

Enzalutamide Antitumour Activity Against Metastatic Castration-resistant Prostate Cancer Previously Treated with Docetaxel and Abiraterone: A Multicentre Analysis

BACKGROUND The degree of antitumour activity of enzalutamide following disease progression on docetaxel and abiraterone remains controversial. OBJECTIVE To examine the effect of enzalutamide in patients progressing following taxane-based chemotherapy and abiraterone. DESIGN, SETTING, AND PARTICIPANTS Metastatic castration-resistant prostate cancer patients entering one of four European compassionate use programmes of enzalutamide. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The primary end point was overall survival (OS). Secondary end points were association between OS and posttreatment prostate-specific antigen (PSA) kinetics, patient characteristics, and progression-free survival, respectively. Kaplan-Meier survival analysis and Cox proportional hazard analysis were performed. RESULTS AND LIMITATIONS We identified 137 patients who prior to enzalutamide had progressed following a median of eight cycles of docetaxel and seven courses of abiraterone. The median time on enzalutamide was 3.2 mo; median OS from the time patients started enzalutamide was 8.3 mo (95% confidence interval, 6.8-9.8). Only 45 (38%) and 22 (18%) patients had PSA declines (unconfirmed) >30% and 50%, respectively. Patients who had more than 30% or 50% falls in PSA had improved survival compared with patients who had no such PSA fall (11.4 mo vs 7.1 mo; p=0.001 and 12.6 vs 7.4 mo; p=0.007, respectively). Poor performance status and low haemoglobin was negatively associated with OS. CONCLUSIONS Median OS on enzalutamide following disease progression on taxane-based chemotherapy and abiraterone was modest, but patients who experience a PSA decline >30% or 50%, respectively, with enzalutamide in this setting had longer survival. PATIENT SUMMARY Enzalutamide produces modest prostate-specific antigen (PSA) responses in patients progressing following chemotherapy and abiraterone. Despite a modest PSA response, survival may still be improved.

Expression of AR-V7 in Circulating Tumour Cells Does Not Preclude Response to Next Generation Androgen Deprivation Therapy in Patients with Castration Resistant Prostate Cancer

The androgen receptor splice variant AR-V7 has recently been discussed as a predictive biomarker for nonresponse to next-generation androgen deprivation therapy (ADT) in patients with castration-resistant prostate cancer. However, we recently identified one patient showing a response from abiraterone despite expression of AR-V7 in his circulating tumour cells (CTC). Therefore, we precisely assessed the response in a cohort of 21 AR-V7 positive castration-resistant prostate cancer patients who had received therapy with abiraterone or enzalutamide. We detected a subgroup of six AR-V7 positive patients showing benefit from either abiraterone or enzalutamide. Their progression free survival was 26 d (censored) to 188 d. Four patients displayed a prostate-specific antigen decrease of >50%. When analysing prior therapies, we noticed that only one of the six patients had received next-generation ADT prior to CTC collection. As a result, we conclude that AR-V7 status in CTC cannot entirely predict nonresponse to next generation ADT and AR-V7-positive patients should not be systematically denied abiraterone or enzalutamide treatment, especially as effective alternative treatment options are still limited. PATIENT SUMMARY A subgroup of patients can benefit from abiraterone and/or enzalutamide despite detection of AR-V7 splice variants in their circulating tumour cells.

The percentage of prostate-specific antigen (PSA) isoform [-2]proPSA and the Prostate Health Index improve the diagnostic accuracy for clinically relevant prostate cancer at initial and repeat biopsy compared with total PSA and percentage free PSA in men aged ≤65 years.

To prospectively test the diagnostic accuracy of the percentage of prostate specific antigen (PSA) isoform [–2]proPSA (%p2PSA) and the Prostate Health Index (PHI), and to determine their role for discrimination between significant and insignificant prostate cancer at initial and repeat prostate biopsy in men aged ≤65 years.

Prognostic Value of PD-1 and PD-L1 Expression in Patients with High Grade Upper Tract Urothelial Carcinoma

Purpose: We investigated the prognostic value of PD‐1 and PD‐L1 expression in patients with high grade upper tract urothelial carcinoma. Materials and Methods: Tissue microarrays of 423 patients treated with extirpative surgery for high grade upper tract urothelial carcinoma from the International Upper Tract Urothelial Carcinoma collaboration were stained for PD‐1 and PD‐L1 using antibodies, including Cell Marque™ NAT105 diluted 1:250 and prediluted E1L3N® via immunohistochemistry. A 1% or greater staining rate of tumor infiltrating lymphocytes (PD‐1) and tumor cells (PD‐L1) was considered positive. Univariate and multivariate analyses were performed to assess independent prognosticators of survival outcomes. Results: Median patient age was 70.0 years and median followup was 37.0 months. PD‐1 and PD‐L1 were positive in 37.2% and 26.2% of patients, respectively. PD‐1 positivity was significantly associated with adverse pathological characteristics while PD‐L1 positivity was associated with favorable pT stage. On univariate analysis PD‐1 expression was associated with worse recurrence‐free, cancer specific and overall survival. On multivariate analysis PD‐1 expression was an independent prognosticator of cancer specific survival (HR 1.7, 95% CI 1.03–2.66, p = 0.039) and overall survival (HR 1.5, 95% CI 1.05–2.24, p = 0.029) but not recurrence‐free survival (HR 1.4, 95% CI 0.9–2.16, p = 0.139). On univariate analysis PD‐L1 expression was not significantly associated with survival outcomes. However, on multivariate analysis in patients with organ confined disease (pT2 or less, pN0/x and cM0), PD‐L1 positivity was an independent prognosticator of recurrence‐free survival (HR 0.2, 95% CI 0.06–0.98, p = 0.046) and overall survival (HR 0.3, 95% CI 0.11–0.63, p = 0.003). Conclusions: PD‐1 positivity of tumor‐infiltrating lymphocytes was associated with adverse pathological criteria and independent prognostication of worse survival outcomes. PD‐L1 positivity of tumor cells was an independent prognosticator of favorable survival outcomes in cases of organ confined disease.

Spotlight on atezolizumab and its potential in the treatment of advanced urothelial bladder cancer

Metastatic urothelial carcinoma of the bladder is an aggressive malignancy with poor prognosis, reflecting a lack of effective systemic therapies. The current standard of care includes multiagent platinum-based chemotherapy; however a majority of patients do not respond to treatment and most eventually succumb to disease. Recently, renewed interest in immunotherapy in the form of immune-checkpoint inhibition has gained widespread attention for a number of malignancies. Atezolizumab, an anti-PDL1 antibody, has been shown to be effective in a subset of patients previously treated with or unfit for platinum-based chemotherapy, and has shown durable responses with a good tolerability profile. We review the mechanism of action and clinical evidence of atezolizumab for metastatic urothelial bladder cancer, and discuss this drug within the context of ongoing developments in this dynamic field of immunooncology.

Novel AR-V7 detection in whole blood samples in patients with prostate cancer: not as simple as it seems

performed with EpCAM (epithelial cell adhesion molecule) based approaches [12]. This might be even more interesting since more insights are gained into biology of non-EpCAM positive tumor cells—cells which might have shifted to a mesenchymal rather than an epithelial phenotype and thus, might escape an EpCAM enrichment strategy [13]. Moreover, focussing on AR-V7 mRNA from CTCs origin only presumably excludes significance of AR-V7 transcripts originated from extracellular vesicles, which might exhibit clinical biomarker validity as well [14]. Another advantage of the whole blood RNA extraction method is the missing necessity of special processing, presumably allowing higher reproducibility among different laboratories. However, results of these studies are highly diverse. Therefore, we would like to sound a note of caution. In the study of Liu et al. the authors separated the blood sample by using CD45-antibody coupled magnetic beads to discriminate between leukocytes which do not express AR-V7 (CD45+) as well as the remaining cell population in which AR-V7 positive tumor cells are supposed to be present (CD45−). However, the authors detected AR-V7 in CD45+ samples and explained this phenomenon by cross contamination due to non-specific binding of the CD45 antibody to tumor cells, aberrant expression of CD45 by tumor cells or leukocyte/CTC clusters. In the study by Todenhöfer et al. the authors used blood samples from pre-treated CRPC patients (n = 64) as well as healthy donors of similar sex and age comparable to prostate cancer patients, i.e. men ≥50 years of age which had serum PSA value <1 ng/ml as well as no clinical signs of prostate cancer [10]. The authors performed RNA extraction followed by cDNA synthesis and gene-specific pre-amplification. Subsequently, they used quantitative real time RT-PCR (qPCR) to detect AR-V7 as well as other prostate cancer marker genes, e.g. Dear Editor,

Prospects and progress of immunotherapy for bladder cancer

ABSTRACT Introduction: With recent advances in immunooncology and the introduction of checkpoint inhibitors into clinical practice for many cancers, the treatment landscape of urothelial carcinoma has changed dramatically and will continue to change further. Currently, a number of compounds and combinations are under investigation in numerous clinical trials and various clinical scenarios for bladder cancer. Areas covered: In this review, the authors provide an overview of the history and rationale for immunotherapy in bladder cancer. They also provide the currently available data evaluating checkpoint inhibitors for bladder cancer, and discuss ongoing trials and future perspectives for urothelial carcinoma treatment. Expert opinion: The introduction of checkpoint inhibitors into the management of bladder cancer marks a significant milestone for this disease. Checkpoint inhibitors have the potential to impact patients across multiple disease states from non-muscle-invasive disease to metastatic tumors refractory to conventional treatment. That being said, validated biomarkers, including genetic signatures, to accurately predict response, and the establishment of optimal sequencing and combination of these immunotherapeutic agents with chemo/radiotherapy are urgently needed.

Influence of Statins on Survival Outcome in Patients with Metastatic Castration Resistant Prostate Cancer Treated with Abiraterone Acetate.

Objective Even though the exact mechanism is largely unknown until now, statins are supposed to improve survival outcomes in various malignancies. For prostate cancer however, statins are known to compete with dehydroepiandrosterone (DHEAS) for the transport into the cytosol both using the cell by the Solute Carrier Transporter and thus diminish the cellular uptake of DHEAS as a precursor of androgens. Abiraterone inhibits CYP17A1 and thus effectively decreases the production of all relevant androgens including DHEAS. In this study we examined whether statins still affect survival outcome in patients with metastatic castration resistant prostate cancer (mCRPC) when treated with Abiraterone. Patients and Methods 108 men with mCRPC treated with Abiraterone from 02/2010 to 07/2015 with (n = 21) or without (n = 87) concomitant treatment with statins were investigated. Progression free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier-estimates and univariate Cox-regression analysis. The influence on best clinical benefit under Abiraterone treatment was analyzed with bivariate and multivariate logistic regression analysis. Results PSA-decline ≥ 50% was not significantly different in both groups (57 vs. 53%; p = 0.73). The median PFS (9 vs. 10 months; p = 0.97) and OS (14 vs. 18 months; p = 0.77) did not differ significantly between those men treated with and without concomitant statin therapy, respectively. Accordingly, there was no improvement for best clinical benefit in patients using statins (odds ratio: 1.2 (CI: 0.4–4.2); p = 0.76). Conclusion Use of statins as concomitant medication did not improve survival outcomes or best clinical benefit in men with mCRPC treated with Abiraterone.

The Role of the Neutrophil to Lymphocyte Ratio for Survival Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Abiraterone

The purpose of this study was to examine the prognostic capability of baseline neutrophil-to-lymphocyte-ratio (NLR) and NLR-change under Abiraterone in metastatic castration-resistant prostate cancer patients. The impact of baseline NLR and change after eight weeks of treatment on progression-free survival (PFS) and overall survival (OS) was analyzed using Kaplan-Meier-estimates and Cox-regression. 79 men with baseline NLR <5 and 17 with NLR >5 were analyzed. In baseline analysis of PFS NLR >5 was associated with non-significantly shorter median PFS (five versus 10 months) (HR: 1.6 (95%CI:0.9–2.8); p = 0.11). After multivariate adjustment (MVA), ECOG > 0–1, baseline LDH>upper limit of normal (UNL) and presence of visceral metastases were independent prognosticators. For OS, NLR >5 was associated with shorter survival (seven versus 19 months) (HR: 2.3 (95%CI:1.3–4.0); p < 0.01). In MVA, ECOG > 0–1 and baseline LDH > UNL remained independent prognosticators. After 8 weeks of Abiraterone NLR-change to <5 prognosticated worse PFS (five versus 12 months) (HR: 4.1 (95%CI:1.1–15.8); p = 0.04). MVA showed a trend towards worse PFS for NLR-change to <5 (p = 0.11). NLR-change to <5 led to non-significant shorter median OS (seven versus 16 months) (HR: 2.3 (95%CI:0.7–7.1); p = 0.15). MVA showed non-significant difference for OS. We concluded baseline NLR <5 is associated with improved survival. In contrast, in patients with baseline NLR >5, NLR-change to <5 after eight weeks of Abiraterone was associated with worse survival and should be interpreted carefully.