Plasma AR Copy Number Changes and Outcome to Abiraterone and Enzalutamide.

Introduction: Plasma androgen receptor (AR) copy number (CN) status identifies castration-resistant prostate cancer (CRPC) patients with worse outcome on abiraterone/enzalutamide. However, the impact of AR CN changes on clinical outcome in CRPC is unknown. Materials and Methods: Plasma samples from 73 patients treated with abiraterone or enzalutamide were collected at baseline and at the time of progression disease (PD). Droplet digital polymerase chain reaction was used to assess AR CN status. Results: We showed that 11 patients (15.1%) changed AR CN status from baseline to PD (9 patients from normal to gain, 2 from gain to normal). Patients changing AR CN status from normal at baseline to gain at PD had intermediate median overall survival (OS) of 20.5 months (95% CI = 8.0-44.2) between those who remained AR CN normal from baseline to PD (27.3 months [95% CI = 21.9-34.4]) and those who remained AR CN gain from baseline to PD (9.1 months [95% CI = 3.8-14.5], p < 0.0001). Patients changing AR CN from normal at baseline to gain at PD had a median progression-free survival (PFS) of 9.2 months (95% CI = 2.0-14.7), patients who remained AR CN normal had a median PFS of 9.1 months (95% CI = 7.2-10.1), and patients who remained AR CN gain had a median PFS of 5.4 (95% CI = 3.6-6.5, p = 0.0005). Both OS and PFS were not significantly different between patients with AR CN that changes from normal to gain and patients with stable AR CN normal. Conclusions: We showed that CRPC patients changing AR CN status from baseline to progression time point had intermediate OS and we suggested that AR CN evaluation at baseline could be the most informative for clinical outcome of CRPC patients treated with abiraterone or enzalutamide. Larger prospective studies are warranted.

Enzalutamide for the treatment of nonmetastatic castration-resistant prostate cancer.

INTRODUCTION: Enzalutamide is the first characterized second-generation nonsteroidal androgen receptor inhibitor (ARi). Its efficacy has been established in several clinical trials evaluating its role in different settings of prostate cancer. Recently, enzalutamide has been approved for the treatment of nonmetastatic castration-resistant prostate cancer (nmCRPC). AREAS COVERED: In this paper, the authors describe the chemical structure and pharmacologic characteristics of enzalutamide, providing a summary of clinical trials evaluating its efficacy and safety in prostate cancer patients. EXPERT OPINION: Enzalutamide adds to the growing arsenal of ARi used in nmCRPC. An improvement in metastasis-free survival was observed with the use of these new treatment options; recently released preliminary data report also an OS benefit. These novel agents are generally well tolerated, but their safety profiles differ slightly. Since head-to-head comparisons between ARi in nmCRPC are lacking, the adverse events profile, as well as drug availability, costs, and considerations on treatment-sequencing, would most likely influence the selection of the individual agent in this setting. Further research is needed to improve treatment selection and clarify many unsolved issues. Abbreviations ARi: nonsteroidal androgen receptor inhibitor; nmCRPC: nonmetastatic castration resistant prostate cancer; ADT: androgen deprivation therapy; OS: overall survival; PSA: prostate specific antigen; FDA: Food and Drug Administration; AR: Androgen Receptor; MFS: metastasis free survival; PSA-DT: PSA doubling time; HR: hazard ratio; CI: confidence interval; AEs: adverse events; mCRPC: metastatic castration resistant prostate cancer; mHSPC: metastatic hormone-sensitive prostate cancer; rPFS: radiographic progression-free survival; OR: odds ratio.

The Interplay between Inflammation, Anti-Angiogenic Agents, and Immune Checkpoint Inhibitors: Perspectives for Renal Cell Cancer Treatment.

Treatment options for metastatic renal cell carcinoma (RCC) have been expanding in the last years, from the consolidation of several anti-angiogenic agents to the approval of immune checkpoint inhibitors (ICIs). The rationale for the use of immunomodulating agents derived from the observation that RCC usually shows a diffuse immune-cell infiltrate. ICIs target Cytotoxic T Lymphocytes Antigen 4 (CTLA-4), programmed death 1 (PD-1), or its ligand (PD-L1), showing promising therapeutic efficacy in RCC. PD-L1 expression is associated with poor prognosis; however, its predictive role remains debated. In fact, ICIs may be a valid option even for PD-L1 negative patients. The establishment of valid predictors of treatment response to available therapeutic options is advocated to identify those patients who could benefit from these agents. Both local and systemic inflammation contribute to tumorigenesis and development of cancer. The interplay of tumor-immune status and of cancer-related systemic inflammation is pivotal for ICI-treatment outcome, but there is an unmet need for a more precise characterization. To date, little is known on the role of inflammation markers on PD-1 blockade in RCC. In this paper, we review the current knowledge on the interplay between inflammation markers, PD-1 axis, and anti-angiogenic agents in RCC, focusing on biological rationale, implications for treatment, and possible future perspectives.

Plasma Androgen Receptor in Prostate Cancer.

The therapeutic landscape of prostate cancer has expanded rapidly over the past 10 years, and there is now an even greater need to understand the biological mechanisms of resistance and to develop noninvasive biomarkers to guide treatment. The androgen receptor (AR) is known to be involved in the pathogenesis and progression of prostate cancer. Recently, highly sensitive next-generation sequencing and PCR-based methods for analyzing androgen receptor gene (AR) copy numbers (CN) and mutations in plasma were established in cell-free DNA (cfDNA) of patients with castration-resistant prostate cancer (CRPC) treated with different drugs. The study of cfDNA holds great promise for improving treatment in CRPC, especially in the advanced stage of the disease. Recent findings showed the significant association of plasma AR aberrations with clinical outcome in CRPC patients treated with AR-directed therapies, whereas no association was observed in patients treated with taxanes. This suggests the potential for using plasma AR as a biomarker for selecting treatment, i.e., hormone therapy or chemotherapy, and the possibility of modulating taxane dose. In recent years, plasma AR status has also been investigated in association with novel agents, such as 177Lu-PSMA radioligand therapy and PARP inhibitors. This review will focus on AR testing in plasma that may have clinical utility for treatment selection in advanced prostate cancer.