PROTAC'ing the androgen receptor and other emerging therapeutics in prostate cancer.

INTRODUCTION: The androgen receptor (AR) is a critical driver of prostate cancer progression and the advent of androgen receptor pathway inhibitors (ARPIs) has transformed the treatment landscape of metastatic prostate cancer. However, resistance to ARPIs eventually develops via mutations in AR, AR overexpression, and alternative AR signaling which have required novel approaches to target effectively. AREAS COVERED: The mechanism of action and early clinical results of proteolysis targeting chimera (PROTAC) agents targeting AR are reviewed. Preclinical and early clinical data for other emerging AR-targeting therapeutics, including dual anti-androgen receptor inhibitors (DAARIs) and anitens that target the N-terminal domain (NTD) of AR, were also identified through literature search for agents which may circumvent resistance through AR splice variants and AR LBD mutations. The literature search utilized PubMed to identify articles that were relevant to this review from 2000 - 2024. EXPERT OPINION: PROTACs, DAARIs, and anitens represent novel and promising AR-targeting therapeutics that may become an important part of prostate cancer treatment in the future. Elucidating mechanisms of resistance, including ability of these agents to target full length AR, may yield further insights into maximal therapeutic efficacy aimed at silencing AR signaling.

Clinical implications of Wnt pathway genetic alterations in men with advanced prostate cancer.

BACKGROUND: Aberrant Wnt signaling has been implicated in prostate cancer tumorigenesis and metastasis in preclinical models but the impact of genetic alterations in Wnt signaling genes in men with advanced prostate cancer is unknown. METHODS: We utilized the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) clinical-genomic database for this retrospective analysis. Patients with activating mutations in CTNNB1 or RSPO2 or inactivating mutations in APC, RNF43, or ZNRF3 were defined as Wnt-altered, while those lacking such alterations were defined as Wnt non-altered. We compared patient characteristics and clinical outcomes as well as co-occurring genetic alterations according to Wnt alteration status. RESULTS: Of the 1498 patients included, 193 (12.9%) were Wnt-altered. These men had a statistically significant 2-fold increased prevalence of liver and lung metastases as compared with Wnt non-altered patients at the time of initial diagnosis, (4.66% v 2.15% ; 6.22% v 3.07%), first metastatic disease diagnosis (10.88% v 5.29%; 13.99% v 6.21%), and CRPC development (11.40% v 6.36%; 12.95% v 5.29%). Wnt alterations were associated with more co-occurring alterations in RB1 (10.4% v 6.2%), AR (38.9% vs 25.7%), SPOP (13.5% vs 4.1%), FOXA1 (6.7% vs 2.8%), and PIK3CA (10.9% vs 5.1%). We found no significant differences in overall survival or other clinical outcomes from initial diagnosis, first metastatic disease, diagnosis of CRPC, or with AR inhibition for mCRPC between the Wnt groups. CONCLUSIONS: Wnt-altered patients with prostate cancer have a higher prevalence of visceral metastases and are enriched in RB1, AR, SPOP, FOXA1, and PIK3CA alterations. Despite these associations, Wnt alterations were not associated with worse survival or treatment outcomes in men with advanced prostate cancer.

PSCA-CAR T cell therapy in metastatic castration-resistant prostate cancer: a phase 1 trial.

Despite recent therapeutic advances, metastatic castration-resistant prostate cancer (mCRPC) remains lethal. Chimeric antigen receptor (CAR) T cell therapies have demonstrated durable remissions in hematological malignancies. We report results from a phase 1, first-in-human study of prostate stem cell antigen (PSCA)-directed CAR T cells in men with mCRPC. The starting dose level (DL) was 100 million (M) CAR T cells without lymphodepletion (LD), followed by incorporation of LD. The primary end points were safety and dose-limiting toxicities (DLTs). No DLTs were observed at DL1, with a DLT of grade 3 cystitis encountered at DL2, resulting in addition of a new cohort using a reduced LD regimen + 100 M CAR T cells (DL3). No DLTs were observed in DL3. Cytokine release syndrome of grade 1 or 2 occurred in 5 of 14 treated patients. Prostate-specific antigen declines (>30%) occurred in 4 of 14 patients, as well as radiographic improvements. Dynamic changes indicating activation of peripheral blood endogenous and CAR T cell subsets, TCR repertoire diversity and changes in the tumor immune microenvironment were observed in a subset of patients. Limited persistence of CAR T cells was observed beyond 28 days post-infusion. These results support future clinical studies to optimize dosing and combination strategies to improve durable therapeutic outcomes. ClinicalTrials.gov identifier NCT03873805 .

Repeat Next-Generation Sequencing Testing on Progression in Men With Metastatic Prostate Cancer Can Identify New Actionable Alterations.

PURPOSE: There are limited data available on the real-world patterns of molecular testing in men with advanced prostate cancer. We thus sought to evaluate next-generation sequencing (NGS) testing in the United States, focused on single versus serial NGS testing, the different disease states of testing (hormone-sensitive v castration-resistant, metastatic vs nonmetastatic), tissue versus plasma circulating tumor DNA (ctDNA) assays, and how often actionable data were found on each NGS test. METHODS: The Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort clinical-genomic database was used for this retrospective analysis, including 1,597 patients across 15 institutions. Actionable NGS data were defined as including somatic alterations in homologous recombination repair genes, mismatch repair deficiency, microsatellite instability (MSI-high), or a high tumor mutational burden ≥10 mut/MB. RESULTS: Serial NGS testing (two or more NGS tests with specimens collected more than 60 days apart) was performed in 9% (n = 144) of patients with a median of 182 days in between test results. For the second NGS test and beyond, 82.1% (225 of 274) of tests were from ctDNA assays and 76.1% (217 of 285) were collected in the metastatic castration-resistant setting. New actionable data were found on 11.1% (16 of 144) of second NGS tests, with 3.5% (5 of 144) of tests detecting a new BRCA2 alteration or MSI-high. A targeted therapy (poly (ADP-ribose) polymerase inhibitor or immunotherapy) was given after an actionable result on the second NGS test in 31.3% (5 of 16) of patients. CONCLUSION: Repeat somatic NGS testing in men with prostate cancer is infrequently performed in practice and can identify new actionable alterations not present with initial testing, suggesting the utility of repeat molecular profiling with tissue or blood of men with metastatic castration-resistant prostate cancer to guide therapy choices.

Three- and Seven-month Prostate-specific Antigen Levels as Prognostic Markers for Overall Survival in Metastatic Hormone-sensitive Prostate Cancer: Results from SWOG S1216, a Phase 3 Randomized Trial of Androgen Deprivation Plus Orteronel or Bicalutamide.

BACKGROUND: A robust decrease in prostate-specific antigen (PSA) in response to androgen deprivation therapy (ADT) has been evaluated as a prognostic factor in patients with metastatic hormone-sensitive prostate cancer (mHSPC) since 2006, but the treatment of mHSPC has since evolved to include intensified therapy. OBJECTIVE: We assessed the association of PSA levels at 3 (PSA-3mo) and 7 (PSA-7mo) mo with overall survival (OS) in patients with mHSPC treated with ADT combined with either bicalutamide or orteronel in the S1216 phase 3 clinical trial. DESIGN, SETTING, AND PARTICIPANTS: PSA responses to treatment of patients in the S1216 trial were categorized as: complete response (CR) if PSA was ≤0.2 ng/ml, partial response if PSA was >0.2 and ≤4 ng/ml, and no response (NR) if PSA was >4 ng/ml. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: A Cox analysis (adjusted for treatment arm and three stratification factors: performance status, severity of disease, and early vs late induction) was used for OS association. While PSA-7mo association was a prespecified objective, PSA-3mo association was also evaluated. RESULTS AND LIMITATIONS: A total of 1251 and 1231 patients from the S1216 study were evaluable for PSA-3mo and PSA-7mo, respectively. A PSA-7mo CR was associated with improved OS compared with NR (HR: 0.20; p < 0.0001). A PSA-3mo CR showed a similar association to NR (HR: 0.34; p < 0.0001). The association of a PSA response with survival did not differ by treatment arm at either time point. CONCLUSIONS: The PSA-3mo and PSA-7mo responses were strongly associated with OS; taken with other emerging prognostic biomarkers, these markers may allow for early identification of patients at the highest risk of death, aid with counseling in clinical practice, and permit design of future clinical trials targeting these patients. PATIENT SUMMARY: A low prostate-specific antigen level at 3 or 7 mo after starting treatment for metastatic hormone-sensitive prostate cancer predicts longer survival regardless of the first treatment given with androgen deprivation therapy.

Tumor Mutational Burden in Metastatic Castration-Resistant Prostate Cancer and Response to Checkpoint Inhibition.

This single-center cohort study assesses the association of tumor mutational burden status in patients with metastatic castration-resistant prostate cancer and response to immune checkpoint inhibitor therapy.

Immuno-Oncology Advances in Genitourinary Cancers.

Immuno-oncology (IO) has made monumental gains in the past decade in the genitourinary space. In this review, we highlight advances with IO in renal cell carcinoma where it now has become standard-of-care frontline therapy in the metastatic setting but also discuss challenges with the initial approach. In urothelial carcinoma, we discuss the growing use of IO including exciting recent updates with IO-based regimens that may soon become the new standard of care. We further discuss difficulties with IO in prostate cancer, germ cell tumors, and penile squamous cell carcinoma. Finally, we highlight advances in IO approaches beyond checkpoint inhibition including the role of the gut microbiome and T-cell redirecting therapies.

Assessment of eligibility criteria in renal cell carcinoma trials evaluating systemic therapy.

OBJECTIVES: To characterise the restrictiveness of eligibility criteria in contemporary renal cell carcinoma (RCC) trials, using recommendations from the American Society of Clinical Oncology (ASCO)-Friends of Cancer Research (FCR) initiative. METHODS: vPhase I-III trials assessing systemic therapies in patients with RCC starting between 30 June 2012 and 30 June 2022 were identified. Eligibility criteria regarding brain metastases, prior or concurrent malignancies, hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, and human immunodeficiency virus (HIV) infection were identified and stratified into three groups: exclusion, conditional inclusion, and not reported. Descriptive statistics were used to determine the frequency of eligibility criteria. Fisher's exact test or chi-square test were used to calculate their associations with certain trial characteristics. RESULTS: A total of 423 RCC trials were initially identified of which 112 (26.5%) had sufficient accessible information. Exclusion of patients with HIV infection, HBV/HCV infection, brain metastases, and prior or concurrent malignancies were reported in 74.1%, 53.6%, 33.0%, and 8.0% of trials, respectively. In the context of HIV and HBV/HCV infection, patients were largely excluded from trials evaluating immunotherapy (94.4% and 77.8%, respectively). In addition, brain metastases were excluded in trials assessing targeted therapy (36.4%), combined therapy (33.3%), and immunotherapy (22.2%). Exclusion of patients with prior or concurrent malignancies was less frequently reported, accounting for 9.1%, 8.3%, and 5.6% targeted therapy, combined therapy and immunotherapy trials, respectively. CONCLUSION: A substantial proportion of RCC trials utilise restrictive eligibility criteria, excluding patients with fairly prevalent comorbidities. Implementing the ASCO-FCR recommendations will ensure resulting data are more inclusive and aligned with patient populations in the real-world.

Xaluritamig, a STEAP1 × CD3 XmAb 2+1 Immune Therapy for Metastatic Castration-Resistant Prostate Cancer: Results from Dose Exploration in a First-in-Human Study.

Xaluritamig (AMG 509) is a six-transmembrane epithelial antigen of the prostate 1 (STEAP1)-targeted T-cell engager designed to facilitate lysis of STEAP1-expressing cancer cells, such as those in advanced prostate cancer. This first-in-human study reports monotherapy dose exploration for patients with metastatic castration-resistant prostate cancer (mCRPC), primarily taxane pretreated. Ninety-seven patients received ≥1 intravenous dose ranging from 0.001 to 2.0 mg weekly or every 2 weeks. MTD was identified as 1.5 mg i.v. weekly via a 3-step dose. The most common treatment-related adverse events were cytokine release syndrome (CRS; 72%), fatigue (45%), and myalgia (34%). CRS occurred primarily during cycle 1 and improved with premedication and step dosing. Prostate-specific antigen (PSA) and RECIST responses across cohorts were encouraging [49% PSA50; 24% objective response rate (ORR)], with greater frequency at target doses ≥0.75 mg (59% PSA50; 41% ORR). Xaluritamig is a novel immunotherapy for prostate cancer that has shown encouraging results supporting further development. SIGNIFICANCE: Xaluritamig demonstrated encouraging responses (PSA and RECIST) compared with historical established treatments for patients with late-line mCRPC. This study provides proof of concept for T-cell engagers as a potential treatment for prostate cancer, validates STEAP1 as a target, and supports further clinical investigation of xaluritamig in prostate cancer. See related commentary by Hage Chehade et al., p. 20. See related article by Nolan-Stevaux et al., p. 90. This article is featured in Selected Articles from This Issue, p. 5.

Gemcitabine and cisplatin plus nivolumab as organ-sparing treatment for muscle-invasive bladder cancer: a phase 2 trial.

Cystectomy is a standard treatment for muscle-invasive bladder cancer (MIBC), but it is life-altering. We initiated a phase 2 study in which patients with MIBC received four cycles of gemcitabine, cisplatin, plus nivolumab followed by clinical restaging. Patients achieving a clinical complete response (cCR) could proceed without cystectomy. The co-primary objectives were to assess the cCR rate and the positive predictive value of cCR for a composite outcome: 2-year metastasis-free survival in patients forgoing immediate cystectomy or

Biomarker-Directed Therapy in Black and White Men With Metastatic Castration-Resistant Prostate Cancer.

Importance: Black men have higher incidence and mortality from prostate cancer. Whether precision oncology disparities affect Black men with metastatic castration-resistant prostate cancer (mCRPC) is unknown. Objective: To compare precision medicine data and outcomes between Black and White men with mCRPC. Design, Setting, and Participants: This retrospective cohort study used data collected by the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) consortium, a multi-institutional registry with linked clinicogenomic data, from April 2020 to December 2021. Participants included Black and White patients with mCRPC with molecular data. Data were analyzed from December 2021 to May 2023. Exposures: Database-reported race and ethnicity. Main Outcomes and Measures: The primary outcome was the frequency of actionable molecular data, defined as the presence of mismatch repair deficiency (MMRD) or high microsatellite instability (MSI-H), homologous recombination repair deficiency, or tumor mutational burden of 10 mutations per megabase or greater. Secondary outcomes included the frequency of other alterations, the type and timing of genomic testing performed, and use of targeted therapy. Efficacy outcomes were prostate-specific antigen response rate, site-reported radiographic response, and overall survival. Results: A total of 962 eligible patients with mCRPC were identified, including 204 Black patients (21.2%; median [IQR] age at diagnosis, 61 [55-67] years; 131 patients [64.2%] with Gleason scores 8-10; 92 patients [45.1%] with de novo metastatic disease) and 758 White patients (78.8%; median [IQR] age, 63 [57-69] years; 445 patients [58.7%] with Gleason scores 8-10; 310 patients [40.9%] with de novo metastatic disease). Median (IQR) follow-up from mCRPC was 26.6 (14.2-44.7) months. Blood-based molecular testing was more common in Black men (111 men [48.7%]) than White men (317 men [36.4%]; P < .001). Rates of actionable alterations were similar between groups (65 Black men [32.8%]; 215 White men [29.1%]; P = .35), but MMRD or MSI-H was more common in Black men (18 men [9.1]) than White men (36 men [4.9%]; P = .04). PTEN alterations were less frequent in Black men than White men (31 men [15.7%] vs 194 men [26.3%]; P = .003), as were TMPRSS alterations (14 men [7.1%] vs 155 men [21.0%]; P < .001). No other differences were seen in the 15 most frequently altered genes, including TP53, AR, CDK12, RB1, and PIK3CA. Matched targeted therapy was given less frequently in Black men than White men (22 men [33.5%] vs 115 men [53.5%]; P = .008). There were no differences in response to targeted therapy or survival between the two cohorts. Conclusions and Relevance: This cohort study of men with mCRPC found higher frequency of MMRD or MSI-H and lower frequency of PTEN and TMPRSS alterations in Black men compared with White men. Although Black men received targeted therapy less frequently than White men, no differences were observed in clinical outcomes.

The new era of prostate-specific membrane antigen-directed immunotherapies and beyond in advanced prostate cancer: a review.

The lack of success in prostate cancer from immune checkpoint inhibitors, which is likely multifactorial, has led to the development and investigation of a number of other novel immunotherapeutic techniques, including antibody-drug conjugates, T-cell redirected bispecific therapies, cancer vaccines and chimeric antigen receptor T-cell therapies. Prostate-specific membrane antigen (PSMA) is a tumour-associated antigen (TAA) that is highly expressed in metastatic prostate cancer and has been validated as an effective target for radionuclide treatment. But while PSMA has thus far been the 'front runner' target for these novel immunotherapeutic techniques, it may not be the ideal target for immunotherapy and there are other potential targetable TAAs that will require further exploration. This review will focus on these various PSMA-directed therapies, as well as other potential targets for immunotherapy beyond PSMA.

Perceptions of COVID-19 Vaccination in Patients with Genitourinary Cancers: A Survey Study.

Since the approval of the COVID-19 vaccines, their safety and efficacy has been widely demonstrated in patients with cancer. However, there remain patients with reservations regarding vaccination. We aimed to assess genitourinary cancer patients' perceptions of the vaccines as well as barriers and influencers of decision-making through the completion of a questionnaire. While vaccine-associated concerns were observed, most patients with genitourinary cancers were willing to receive the vaccine. Moving forward, differing strategies could be considered to enhance patient education on the utility of vaccination in the setting of cancer and beyond.

Dietary Interventions in Cancer Treatment and Response: A Comprehensive Review.

Chemotherapy and radiotherapy are first-line treatments in the management of advanced solid tumors. Whereas these treatments are directed at eliminating cancer cells, they cause significant adverse effects that can be detrimental to a patient's quality of life and even life-threatening. Diet is a modifiable risk factor that has been shown to affect cancer risk, recurrence, and treatment toxicity, but little information is known how diet interacts with cancer treatment modalities. Although dietary interventions, such as intermittent fasting and ketogenic diets, have shown promise in pre-clinical studies by reducing the toxicity and increasing the efficacy of chemotherapeutics, there remains a limited number of clinical studies in this space. This review surveys the impact of dietary interventions (caloric restriction, intermittent and short-term fasting, and ketogenic diet) on cancer treatment outcomes in both pre-clinical and clinical studies. Early studies support a complementary role for these dietary interventions in improving patient quality of life across multiple cancer types by reducing toxicity and perhaps a benefit in treatment efficacy. Larger, phase III, randomized clinical trials are ultimately necessary to evaluate the efficacy of these dietary interventions in improving oncologic or quality of life outcomes for patients that are undergoing chemotherapy or radiotherapy.

Cabozantinib in combination with atezolizumab in patients with metastatic castration-resistant prostate cancer: results from an expansion cohort of a multicentre, open-label, phase 1b trial (COSMIC-021).

BACKGROUND: Patients with metastatic castration-resistant prostate cancer have few treatment options after novel hormonal therapy (eg, abiraterone or enzalutamide). We aimed to evaluate cabozantinib, a tyrosine kinase inhibitor with immunomodulatory properties, in combination with the PD-L1 inhibitor atezolizumab in metastatic castration-resistant prostate cancer. METHODS: COSMIC-021 is an ongoing, multicentre, open-label, phase 1b study with a dose-escalation stage followed by tumour-specific expansion stages. Expansion cohort 6 in metastatic castration-resistant prostate cancer was enrolled at 42 cancer research centres in France, Italy, the Netherlands, Spain, and the USA. Eligible patients were aged 18 years or older and had metastatic castration-resistant prostate cancer with radiographic soft tissue progression following treatment with either enzalutamide or abiraterone, or both; measurable soft tissue disease per Response Evaluation Criteria In Solid Tumours (RECIST) version 1.1; and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received oral cabozantinib 40 mg per day and intravenous atezolizumab 1200 mg once every 3 weeks. Study treatment continued until progressive disease or unacceptable toxicity. All enrolled patients were assessed for efficacy and safety. The primary endpoint was objective response rate per RECIST version 1.1 as assessed by the investigator. This study is registered with ClinicalTrials.gov, NCT03170960. FINDINGS: Between April 24, 2018, and Aug 31, 2020, 132 patients were enrolled and received at least one dose of study treatment. At data cutoff (Feb 19, 2021), median duration of follow-up was 15·2 months (IQR 9·6-21·7). Objective response rate was 23% (95% CI 17-32; 31 of 132 patients), with three (2%) confirmed complete responses and 28 (21%) confirmed partial responses. 72 (55%) of 132 patients had grade 3-4 treatment-related adverse events, with the most common being pulmonary embolism (11 [8%] patients), diarrhoea (nine [7%]), fatigue (nine [7%]), and hypertension (nine [7%]). There was one grade 5 treatment-related adverse event (dehydration). 74 (56%) of 132 patients had serious adverse events of any causality. 28 (21%) of 132 patients had treatment-related adverse events leading to discontinuation of either study drug. INTERPRETATION: Cabozantinib plus atezolizumab showed promising antitumour activity in patients with metastatic castration-resistant prostate cancer after novel hormonal therapy with an acceptable safety profile, supporting further evaluation of this combination. FUNDING: Exelixis.

PD-L1 blockade restores CAR T cell activity through IFN-γ-regulation of CD163+ M2 macrophages.

BACKGROUND: The immune suppressive tumor microenvironment (TME) that inhibits T cell infiltration, survival, and antitumor activity has posed a major challenge for developing effective immunotherapies for solid tumors. Chimeric antigen receptor (CAR)-engineered T cell therapy has shown unprecedented clinical response in treating patients with hematological malignancies, and intense investigation is underway to achieve similar responses with solid tumors. Immunologically cold tumors, including prostate cancers, are often infiltrated with abundant tumor-associated macrophages (TAMs), and infiltration of CD163+ M2 macrophages correlates with tumor progression and poor responses to immunotherapy. However, the impact of TAMs on CAR T cell activity alone and in combination with TME immunomodulators is unclear. METHODS: To model this in vitro, we utilized a novel co-culture system with tumor cells, CAR T cells, and polarized M1 or M2 macrophages from CD14+ peripheral blood mononuclear cells collected from healthy human donors. Tumor cell killing, T cell activation and proliferation, and macrophage phenotypes were evaluated by flow cytometry, cytokine production, RNA sequencing, and functional blockade of signaling pathways using antibodies and small molecule inhibitors. We also evaluated the TME in humanized mice following CAR T cell therapy for validation of our in vitro findings. RESULTS: We observed inhibition of CAR T cell activity with the presence of M2 macrophages, but not M1 macrophages, coinciding with a robust induction of programmed death ligand-1 (PD-L1) in M2 macrophages. We observed similar PD-L1 expression in TAMs following CAR T cell therapy in the TME of humanized mice. PD-L1, but not programmed cell death protein-1, blockade in combination with CAR T cell therapy altered phenotypes to more M1-like subsets and led to loss of CD163+ M2 macrophages via interferon-γ signaling, resulting in improved antitumor activity of CAR T cells. CONCLUSION: This study reveals an alternative mechanism by which the combination of CAR T cells and immune checkpoint blockade modulates the immune landscape of solid tumors to enhance therapeutic efficacy of CAR T cells.

First-line Systemic Treatment of Recurrent Prostate Cancer After Primary or Salvage Local Therapy: A Systematic Review of the Literature.

CONTEXT: Several studies have investigated selection and sequencing of systemic agents to manage recurrent prostate cancer following local definitive treatment. OBJECTIVE: To define the incidence of recurrent prostate cancer in different countries, and systematically review management options and efficacy of first-line systemic therapies for patients with prostate cancer previously treated with definitive radical prostatectomy or radiation therapy. EVIDENCE ACQUISITION: We performed a systematic review of studies published from January 2010 to December 2021 in MEDLINE, EMBASE, or ClinicalTrials.gov according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Quality was assessed using the Grades of Recommendation, Assessment, Development and Evaluation methodology. The potential regional burdens of recurrent prostate cancer were estimated by analyzing various regional registry data. EVIDENCE SYNTHESIS: A total of 40 studies met the inclusion criteria and an additional landmark study published after the query was included in this review. Patients with metastatic recurrent disease derive benefit from the addition of androgen receptor signaling inhibitors to androgen deprivation therapy, while docetaxel should be reserved for patients with a high-volume metastatic burden by conventional imaging. Patients with biochemical-only recurrent disease benefit from continuous or intermittent androgen deprivation therapy if they possess high-risk features such as short prostate-specific antigen doubling time or high serum prostate-specific antigen. Current limitations to the published literature include no consideration of contemporary positron emission tomography imaging for evaluating metastatic recurrence or burden and few quality of life assessments. CONCLUSIONS: This systematic review summarizes the findings and recommendations for first-line systemic therapy for patients with recurrent prostate cancer following local therapy. PATIENT SUMMARY: We performed a systematic evaluation and summary of all studies published within the past decade on the topic of medications used to treat prostate cancer after it has recurred following radiation therapy or surgery. This review can be used to inform guidelines for prostate cancer management.