Tolerability of Olaparib Combined with Abiraterone in Patients with Metastatic Castration-resistant Prostate Cancer: Further Results from the Phase 3 PROpel Trial.

BACKGROUND: The PROpel study (NCT03732820) demonstrated a statistically significant progression-free survival benefit with olaparib plus abiraterone versus placebo plus abiraterone in the first-line metastatic castration-resistant prostate cancer (mCRPC) setting, irrespective of homologous recombination repair mutation status. OBJECTIVE: We report additional safety analyses from PROpel to increase clinical understanding of the adverse-event (AE) profiles of olaparib plus abiraterone versus placebo plus abiraterone. DESIGN, SETTING, AND PARTICIPANTS: A randomised (1:1), double-blind, placebo-controlled trial was conducted at 126 centres in 17 countries (October 2018-January 2020). Patients had mCRPC and no prior systemic mCRPC treatment. INTERVENTION: Olaparib (300 mg bid) or placebo with abiraterone (1000 mg od) plus prednisone/prednisolone (5 mg bid). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The data cut-off date was July 30, 2021. Safety was assessed by AE reporting (Common Terminology Criteria for Adverse Events v4.03) and analysed descriptively. RESULTS AND LIMITATIONS: The most common AEs (all grades) for olaparib plus abiraterone versus placebo plus abiraterone were anaemia (46.0% vs 16.4%), nausea (28.1% vs 12.6%), and fatigue (27.9% vs 18.9%). Grade ≥3 anaemia occurred in 15.1% versus 3.3% of patients in the olaparib plus abiraterone versus placebo plus abiraterone arm. The incidences of the most common AEs for olaparib plus abiraterone peaked early, within 2 mo, and were managed typically by dose modifications or standard medical practice. Overall, 13.8% versus 7.8% of patients discontinued treatment with olaparib plus abiraterone versus placebo plus abiraterone because of an AE; 3.8% versus 0.8% of patients discontinued because of anaemia. More venous thromboembolism events were observed in the olaparib plus abiraterone arm (any grade, 7.3%; grade ≥3, 6.8%) than in the placebo plus abiraterone arm (any grade, 3.3%; grade ≥3, 2.0%), most commonly pulmonary embolism (6.5% vs 1.8% for olaparib plus abiraterone vs placebo plus abiraterone). CONCLUSIONS: Olaparib plus abiraterone has a manageable and predictable safety profile. PATIENT SUMMARY: The PROpel trial showed that in patients who had not received any previous treatment for metastatic castration-resistant prostate cancer, olaparib combined with abiraterone was more effective in delaying progression of the disease than abiraterone alone. Most side effects caused by combining olaparib with abiraterone could be managed with supportive care methods, by pausing olaparib administration for a short period of time and/or by reducing the dose of olaparib.

Pembrolizumab Plus Olaparib for Patients With Previously Treated and Biomarker-Unselected Metastatic Castration-Resistant Prostate Cancer: The Randomized, Open-Label, Phase III KEYLYNK-010 Trial.

PURPOSE: There is an unmet need for therapeutic options that prolong survival for patients with heavily pretreated, metastatic castration-resistant prostate cancer (mCRPC). The phase III, open-label KEYLYNK-010 study evaluated pembrolizumab plus olaparib versus a next-generation hormonal agent (NHA) for biomarker-unselected, previously treated mCRPC. METHODS: Eligible participants had mCRPC that progressed on or after abiraterone or enzalutamide (but not both) and docetaxel. Participants were randomly assigned (2:1) to pembrolizumab plus olaparib or NHA (abiraterone or enzalutamide). The dual primary end points were radiographic progression-free survival (rPFS) by blinded independent central review per Prostate Cancer Working Group-modified RECIST 1.1 and overall survival (OS). Time to first subsequent therapy (TFST) was a key secondary end point. Safety and objective response rate (ORR) were secondary end points. RESULTS: Between May 30, 2019, and July 16, 2021, 529 participants were randomly assigned to pembrolizumab plus olaparib and 264 to NHA. At final rPFS analysis, median rPFS was 4.4 months (95% CI, 4.2 to 6.0) with pembrolizumab plus olaparib and 4.2 months (95% CI, 4.0 to 6.1) with NHA (hazard ratio [HR], 1.02 [95% CI, 0.82 to 1.25]; P = .55). At final OS analysis, median OS was 15.8 months (95% CI, 14.6 to 17.0) and 14.6 months (95% CI, 12.6 to 17.3), respectively (HR, 0.94 [95% CI, 0.77 to 1.14]; P = .26). At final TFST analysis, median TFST was 7.2 months (95% CI, 6.7 to 8.1) versus 5.7 months (95% CI, 5.0 to 7.1), respectively (HR, 0.86 [95% CI, 0.71 to 1.03]). ORR was higher with pembrolizumab plus olaparib versus NHA (16.8% v 5.9%). Grade ≥3 treatment-related adverse events occurred in 34.6% and 9.0% of participants, respectively. CONCLUSION: Pembrolizumab plus olaparib did not significantly improve rPFS or OS versus NHA in participants with biomarker-unselected, heavily pretreated mCRPC. The study was stopped for futility. No new safety signals occurred.

Treatment Patterns, Clinical Outcomes, Health Care Resource Utilization and Costs in Older Patients With Metastatic Castration-Resistant Prostate Cancer in the United States: An Analysis of SEER-Medicare Data.

BACKGROUND: Prostate cancer (PC) is more likely to develop in men ≥65 years old than in those <65 years old. This study aimed to generate real-world evidence on treatment patterns, clinical outcomes, health care resource utilization (HCRU), and costs among older patients with metastatic castration-resistant PC (mCRPC). MATERIALS AND METHODS: A claims algorithm based on treatments expected for mCRPC was used to identify men ≥65 years old with mCRPC in the SEER-Medicare data between 2007 and 2019. The index date was defined as the date of the start of first-line therapy (1L). Treatment patterns and all-cause and PC-specific HCRU and costs were measured in the 12 months preindex period and the postindex follow-up period. Time to next treatment or death (TNTD) and overall survival (OS) were assessed in the follow-up period. RESULTS: A total of 4758 patients met the eligibility criteria and received 1L treatment. Among these 1L patients, 57.4% subsequently received second-line (2L) treatment; among patients receiving 2L treatment, 49.3% subsequently received third-line (3L) treatment. Abiraterone, enzalutamide, and docetaxel were most common regimens in 1L (41.9%, 22.0%, 22.0%, respectively), 2L (33.3%, 32.7%, 13.6%, respectively), and 3L (17.9%, 25.1%, 22.3%, respectively). On average, patients had 1.2 inpatient admissions, 1.1 emergency room visits, and 27.6 outpatient visits per year during follow-up. The mean total all-cause and PC-related costs during the follow-up period were $111,060 and $99,540 per-patient-per-year, respectively. Median TNTD was 9.3, 6.5, and 5.7 months for 1L, 2L, and 3L, respectively. Median OS from the start of 1L treatment for mCRPC was 21.5 months. DISCUSSION: Among older patients with mCRPC, high attrition from 1L to subsequent lines of therapy was observed. Median TNTD was <1 year and median OS was <2 years. These results highlight a need to introduce more effective mCRPC therapies in 1L to improve clinical outcomes for older patients.

Coffee Intake, Caffeine Metabolism Genotype, and Survival Among Men with Prostate Cancer.

BACKGROUND: Coffee intake may lower prostate cancer risk and progression, but postdiagnosis outcomes by caffeine metabolism genotype are not well characterized. OBJECTIVE: To evaluate associations between coffee intake, caffeine metabolism genotype, and survival in a large, multicenter study of men with prostate cancer. DESIGN, SETTING, AND PARTICIPANTS: Data from The PRACTICAL Consortium database for 5727 men with prostate cancer from seven US, Australian, and European studies were included. The cases included had data available for the CYP1A2 -163C>A rs762551 single-nucleotide variant associated with caffeine metabolism, coffee intake, and >6 mo of follow-up. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariable-adjusted Cox proportional hazards models across pooled patient-level data were used to compare the effect of coffee intake (categorized as low [reference], high, or none/very low) in relation to overall survival (OS) and prostate cancer-specific survival (PCSS), with stratified analyses conducted by clinical disease risk and genotype. RESULTS AND LIMITATIONS: High coffee intake appeared to be associated with longer PCSS (hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.68-1.08; p = 0.18) and OS (HR 0.90, 95% CI 0.77-1.07; p = 0.24), although results were not statistically significant. In the group with clinically localized disease, high coffee intake was associated with longer PCSS (HR 0.66, 95% CI 0.44-0.98; p = 0.040), with comparable results for the group with advanced disease (HR 0.92, 95% CI 0.69-1.23; p = 0.6). High coffee intake was associated with longer PCSS among men with the CYP1A2 AA (HR 0.67, 95% CI 0.49-0.93; p = 0.017) but not the AC/CC genotype (p = 0.8); an interaction was detected (p = 0.042). No associations with OS were observed in subgroup analyses (p > 0.05). Limitations include the nominal statistical significance and residual confounding. CONCLUSIONS: Coffee intake was associated with longer PCSS among men with a CYP1A2 -163AA (*1F/*1F) genotype, a finding that will require further replication. PATIENT SUMMARY: It is likely that coffee intake is associated with longer prostate cancer-specific survival in certain groups, but more research is needed to fully understand which men may benefit and why.

Impact of next-generation hormonal agents on treatment patterns among patients with metastatic hormone-sensitive prostate cancer: a real-world study from the United States, five European countries and Japan.

BACKGROUND: Until five years ago, the metastatic hormone-sensitive prostate cancer (mHSPC) treatment landscape was dominated by the use of androgen deprivation therapy (ADT) alone. However, novel hormonal agents (NHAs) and chemotherapy are now approved for male patients with mHSPC. This study aimed to understand the impact NHA approvals had on mHSPC real-world treatment patterns and to identify the key factors associated with NHA or chemotherapy (± ADT) usage vs ADT alone. METHODS: Data were collected from the Adelphi Prostate Cancer Disease Specific Programme (DSP)™, a point-in-time survey of physicians and their consulting patients conducted in the United States (US), five European countries (France, Germany, Italy, Spain, and the United Kingdom), and Japan between January and August 2020. Data were analysed using descriptive statistics for individual countries, regions, and all countries combined. Pairwise analyses were used to further investigate differences between treatment groups at global level. RESULTS: 336 physicians provided data on 1195 mHSPC patients. Globally, at data collection, the most common mHSPC regimen initiated first was ADT alone (47%), followed by NHAs (± ADT) (31%, of which 21% was abiraterone, 8% was enzalutamide, and 2% was apalutamide) and chemotherapy (± ADT) (19%). The highest rates of ADT alone usage were observed in Japan (78%) and Italy (66%), and the lowest in Spain (34%) and in the US (36%). Our results showed that clinical decision making was driven by patient fitness, compliance, tolerance of adverse events, and balance of impact on quality of life vs overall survival. CONCLUSIONS: This real-world survey offered early insights into the evolving mHSPC treatment paradigm. It showed that in 2020, ADT alone remained the most common initial mHSPC therapy, suggesting that physicians may prefer using treatments which they are familiar and have experience with, despite clinical trial evidence of improved survival with NHAs or chemotherapy (± ADT) vs ADT alone. Results also indicated that physicians prescribed specific mHSPC treatments primarily based on the following criteria: patient preference, disease burden/severity, and the performance status and comorbidities of the patient. To fully appreciate the rapidly changing mHSPC treatment landscape and monitor NHA uptake, additional real-world studies are required.

Real-World Treatment Patterns in Metastatic Castration-Resistant Prostate Cancer Across Europe (France, Germany, Italy, Spain, and the United Kingdom) and Japan.

INTRODUCTION: Prostate cancer (PC) is the second most common cancer, and the fifth most common cause of cancer-related mortality among male patients, worldwide. In Europe and Japan, the incidence of PC in men in 2020 exceeded that of lung cancer. Although national and regional clinical guidelines for the treatment of metastatic castration-resistant prostate cancer (mCRPC) are available in Europe and Japan, a literature review did not identify a published comparison of differing guidelines, but identified a lack of studies reporting treatment patterns of approved mCRPC treatments in Europe and Japan in normal clinical practice. The objective of this real-world study was to compare national treatment guidelines and real-world treatment for mCRPC in Europe and Japan. METHODS: Physician-reported demographics, clinical characteristics, and treatment data of patients with mCRPC were drawn from the Adelphi Prostate Cancer Disease Specific Programme™, conducted in five European countries and Japan (2020) and analysed descriptively. RESULTS: All current treatment guidelines recommended the use of novel hormonal agents (NHA-abiraterone/enzalutamide) and chemotherapy (mainly docetaxel), with some intercountry differences, with NHA rechallenge accepted in Germany, Italy and Japan, but not in France, Spain or the United Kingdom. Overall, 271 physicians provided data for 1753 patients. At 1st-line (1L), the most common treatment was NHAs followed by (→) chemotherapy, in all countries. Chemotherapy was the most common 2nd-line (2L) treatment, except in Japan, where 2L NHA use was preferred, and Spain, where both were used equally. NHA â†’ chemotherapy and chemotherapy â†’ NHA were the first and second usual 1L â†’ 2L sequence in most countries, except for France, where the second most common sequence was NHA â†’ NHA, and Japan, with androgen deprivation therapy alone â†’ NHA. CONCLUSION: Real-world mCRPC treatment patterns largely reflected national guidelines. It is expected that guidelines and treatment patterns will change with the development of new treatment options.

Real-world homologous recombination repair mutation testing in metastatic castration-resistant prostate cancer in the USA, Europe and Japan.

Aim: To assess homologous recombination repair mutation (HRRm) testing patterns in metastatic castration-resistant prostate cancer. Methods: A point-in-time, international survey conducted January-August 2020. Results: Three-quarters of physicians (oncologists, urologists, specialist surgeons) globally reported access to genetic/genomic testing and just over half were HRRm testers. Surveyed physicians reported HRRm testing and positivity rates for 1913 patients, which were 18.1% and 33.7%, respectively. Of patients tested (n = 347), the most common HRR genes tested were BRCA (91.6%) and ATM (47.3%). Conclusion: Overall testing rates were low, with physicians mostly testing patients they considered higher risk. Increased awareness and education are needed to encourage broader testing, to understand familial risk and to identify patients with worse outcomes or those eligible for life-prolonging treatments.

Metastatic castration-resistant prostate cancer (mCRPC) is cancer that has spread beyond the prostate gland and that no longer responds to hormone therapy. Genetic testing is now recommended for patients with mCRPC to help doctors understand familial risk and identify patients who may benefit from new treatments. The authors asked doctors questions about their patients, such as their age, symptoms and genetic testing. The authors found that overall genetic testing rates were low, with doctors mostly testing patients they thought were at higher risk of developing cancer. Increased doctor awareness and education are needed to encourage more genetic testing in mCRPC patients. However, doctors claimed that the cost of these tests was a challenge to conducting genetic testing.

Genetic Factors Associated with Prostate Cancer Conversion from Active Surveillance to Treatment.

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion (MAST3, p = 6.9×10-7 and GAB2, p = 2.0×10-6). Moreover, increasing values of a previously validated 269-variant genetic risk score (GRS) for PC was positively associated with conversion (e.g., comparing the highest to the two middle deciles gave a hazard ratio [HR] = 1.13; 95% Confidence Interval [CI]= 0.94-1.36); whereas, decreasing values of a 36-variant GRS for prostate-specific antigen (PSA) levels were positively associated with conversion (e.g., comparing the lowest to the two middle deciles gave a HR = 1.25; 95% CI, 1.04-1.50). These results suggest that germline genetics may help inform and individualize the decision of AS-or the intensity of monitoring on AS-versus treatment for the initial management of patients with low-risk PC.

Beyond Frontline Therapy with Abiraterone and Enzalutamide in Metastatic Castration-Resistant Prostate Cancer: A Real-World US Study.

BACKGROUND: Real-world evidence suggest that next generation hormonal agents (NHAs) abiraterone and enzalutamide were preferred as first-line (1L) therapies for metastatic castration-resistant prostate cancer (mCRPC) in the United States (US) pre-2020, with chemotherapies, particularly docetaxel, being preferred in subsequent lines (2L+). This real-world study described patient characteristics, treatment patterns, time on treatment (ToT) and overall survival (OS) among patients with mCRPC treated with 2L and 3L docetaxel post-NHAs in the mCRPC setting. METHODS: Adults with confirmed adenocarcinoma mCRPC diagnosis and ≥1 month of follow-up post-diagnosis were selected from a US electronic health record-derived oncology de-identified database (01/2013-03/2019). Based on the observed line of therapy sequences post-mCRPC diagnosis, patients who received NHA therapy in 1L and docetaxel therapy in 2L were included in the 2L docetaxel cohort, and patients who received NHA therapy in both 1L and 2L and docetaxel therapy in 3L were included in the 3L docetaxel cohort. ToT and OS were evaluated using Kaplan-Meier analysis. RESULTS: Among 5,213 patients with mCRPC, 278 and 166 were included in the 2L and the 3L docetaxel cohorts, respectively (median age: 73 years for both cohorts). ADT was the most used class of medication pre-mCRPC (>75%). For the 2L cohort, the most common sequence post-mCRPC was 1L abiraterone â†’ 2L docetaxel (52.5%), while the median ToT and OS post-2L start were 4.1 and 10.5 months, respectively; for the 3L cohort, the most common sequence post-mCRPC was 1L abiraterone â†’ 2L enzalutamide â†’ 3L docetaxel (67.5%), while the median ToT and OS post-3L start were 3.8 and 8.7 months, respectively. CONCLUSIONS: This real-world study provides novel data on patients treated with docetaxel post-NHAs in a mCRPC setting and highlights the critical unmet need for developing more effective treatment options in this population.

KEYNOTE-641: a Phase III study of pembrolizumab plus enzalutamide for metastatic castration-resistant prostate cancer.

Current treatment options for men with metastatic castration-resistant prostate cancer (mCRPC) are noncurative, and median survival upon development of mCRPC is approximately 3 years. The novel hormonal agent enzalutamide has an established role in the mCRPC treatment paradigm, and emerging evidence suggests potential synergism with enzalutamide and the PD-1 inhibitor pembrolizumab in men with mCRPC. Here, we describe the design and rationale for the multicenter, randomized, double-blind, Phase III KEYNOTE-641 study, which will be conducted to compare the efficacy and safety of pembrolizumab plus enzalutamide with that of enzalutamide plus placebo in mCRPC. Clinical trial registration: NCT03834493 (ClinicalTrials.gov).

Adherence to the Mediterranean diet and grade group progression in localized prostate cancer: An active surveillance cohort.

BACKGROUND: The Mediterranean diet (MD) may be beneficial for men with localized prostate cancer (PCa) on active surveillance (AS) because of its anti-inflammatory, antilipidemic, and chemopreventive properties. This study prospectively investigated adherence to the MD with Gleason score progression and explored associations by diabetes status, statin use, and other factors. METHODS: Men with newly diagnosed PCa on an AS protocol (n = 410) completed a baseline food frequency questionnaire, and the MD score was calculated across 9 energy-adjusted food groups. Cox proportional hazards models were fit to evaluate multivariable-adjusted associations of the MD score with progression-free survival; progression was defined as an increase in the Gleason grade group (GG) score over a biennial monitoring regimen. RESULTS: In this cohort, 15% of the men were diabetic, 44% of the men used statins, and 76 men progressed (median follow-up, 36 months). After adjustments for clinical factors, higher adherence to the MD was associated with a lower risk of GG progression among all men (hazard ratio [HR] per 1-unit increase in MD score, 0.88; 95% confidence interval [CI], 0.77-1.01), non-White men (HR per 1-unit increase in MD score, 0.64; 95% CI, 0.45-0.92; P for interaction = .07), and men without diabetes (HR per 1-unit increase in MD score, 0.82; 95% CI, 0.71-0.96; P for interaction = .03). When joint effects of the MD score and statin use were examined, a similar risk reduction was observed among men with high MD scores who did not use statins in comparison with men with low/moderate MD scores with no statin use. CONCLUSIONS: The MD is associated with a lower risk of GG progression in men on AS, and this is consistent with prior reports about the MD and reduced cancer morbidity and mortality.

Systematic Literature Review of the Epidemiology of Advanced Prostate Cancer and Associated Homologous Recombination Repair Gene Alterations.

PURPOSE: To characterize the global epidemiology of metastatic castration-sensitive prostate cancer (mCSPC), nonmetastatic castration-resistant prostate cancer (nmCRPC) and metastatic castration-resistant prostate cancer (mCRPC). Additionally, to assess the prevalence of homologous recombination repair gene alterations (HRRm) and their prognostic impact in advanced disease setting. MATERIALS AND METHODS: A systematic literature review of real-world evidence published from January 2009 through May 2019 was conducted to assess global epidemiology and clinical practice trends for mCSPC, nmCRPC, mCRPC and HRRm; 4,732 papers were systematically screened for inclusion. Ten conference proceedings from 2014 through 2019 were reviewed. RESULTS: Of the screened articles 22 relevant publications were identified for this paper. Six publications reported global epidemiology of advanced prostate cancer. The prevalence of nmCRPC was estimated as 1.1% to 12.3% of prostate cancer cases and for mCRPC 1.2% to 2.1% of prostate cancer cases. No mCSPC prevalence was captured. Sixteen publications investigated HRRm prevalence in advanced prostate cancer with the majority conducted in mCRPC assessed using next-generation sequencing of tissue and germline samples. In mCRPC, the highest prevalence HRRm in both germline (3.3%-6.0%) and somatic (5.0%-15.1%) was BRCA2. Five publications reported the prognostic impact of HRRm in advanced prostate cancer. CONCLUSIONS: Published real-world evidence quantifying the prevalence of advanced prostate cancer and HRRm beyond mCRPC is sparse. Published data on HRRm, specifically BRCA2, are consistent with published clinical trial data for poly (ADP-ribose) polymerase inhibitors in mCRPC. In mCRPC, real-world evidence suggests that patients with HRRm have different clinical outcomes to noncarriers. More data are needed to better understand real-world patient segmentation and clinical outcomes for biomarkers given increasing interest in profiling.

The Association of Periprostatic Fat and Grade Group Progression in Men with Localized Prostate Cancer on Active Surveillance.

PURPOSE: Evidence suggests that visceral fat quantity may be associated with post-prostatectomy outcomes and risk of prostate cancer related death. We evaluated whether increased fat volume, normalized to prostate size, is associated with decreased risk of disease progression. MATERIALS AND METHODS: Patients enrolled on a prospective active surveillance trial for at least 6 months who had magnetic resonance imaging within 2 years of enrollment were eligible. The surveillance protocol included a standardized followup regimen consisting of biennial prostate specific antigen and examination and yearly biopsy. Clinicopathological characteristics were collected at baseline. Three fat measurements were taken using prostate magnetic resonance imaging, including subcutaneous, linear periprostatic (pubic symphysis to prostate) and volumetrically defined periprostatic. Progression was defined as increase in Gleason grade group. Multivariable Cox proportional hazards models were used to evaluate fat volumes normalized by prostate size (stratified into tertiles). RESULTS: A total of 175 patients were included in the study. Average age was 62.5 years (SD 7.4) and average prostate specific antigen was 5.4 ng/dl (SD 3.9). Median followup was 42 months (IQR 18-60) and 50 patients (28.6%) had progression. Compared to the lowest tertile, the highest tertile of volumetric periprostatic fat measurement (HR 2.63, 95% CI 1.23-5.60, p=0.01) and linear periprostatic fat measurement (HR 2.30, 95% CI 1.01-5.22, p=0.05) were associated with worsened progression-free survival, while subcutaneous fat measurement (p=0.97) was not. Importantly, the model did not substantively change when accounting for patient body mass index and other factors. CONCLUSIONS: Increased periprostatic fat volume, normalized to prostate size, may be associated with shortened progression-free survival in men with prostate cancer on active surveillance.

A Phase 2 Trial of Abiraterone Followed by Randomization to Addition of Dasatinib or Sunitinib in Men With Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Resistance to novel androgen signaling inhibition and metastatic castration-resistant prostate cancer (mCRPC) progression is likely dependent on tumor microenvironment interactions. The Src pathway and neoangiogenesis have been implicated in prostate cancer progression. We studied the effect of adding the targeted agents dasatinib and sunitinib to abiraterone acetate (AA) in men with mCRPC. PATIENTS AND METHODS: In this open-label randomized phase 2 study, mCRPC patients received AA. At resistance to AA, they were randomized 1:1 to combination with dasatinib or sunitinib. At second progression, patients crossed over. The primary end point was time to treatment failure (TTF), defined as time to progression or death. Secondary end points included overall survival and safety. RESULTS: From March 2011 to February 2015, a total of 179 patients were enrolled and 132 subsequently randomized. Median TTF was 5.7 months in the dasatinib group and 5.5 months in the sunitinib group. There was no difference between the two groups in terms of TTF (hazard ratio, 0.85; 95% confidence interval, 0.59-1.22). Median overall survival from study entry was 26.3 months in the dasatinib group and 27.7 months in the sunitinib group (hazard ratio, 1.02; 95% confidence interval, 0.71-1.47). Grade 3 or higher adverse events related to study medication were more frequent with sunitinib (n = 44, 46%) compared to dasatinib (n = 26, 24%). At data cutoff, 7 patients were experiencing a continuous response to AA, with a median duration of treatment of 5.7 years. CONCLUSION: There is no difference in overall survival and TTF between dasatinib and sunitinib combined with abiraterone in the treatment of patients with bone mCRPC.

Caveolin-1-mediated sphingolipid oncometabolism underlies a metabolic vulnerability of prostate cancer.

Plasma and tumor caveolin-1 (Cav-1) are linked with disease progression in prostate cancer. Here we report that metabolomic profiling of longitudinal plasmas from a prospective cohort of 491 active surveillance (AS) participants indicates prominent elevations in plasma sphingolipids in AS progressors that, together with plasma Cav-1, yield a prognostic signature for disease progression. Mechanistic studies of the underlying tumor supportive onco-metabolism reveal coordinated activities through which Cav-1 enables rewiring of cancer cell lipid metabolism towards a program of 1) exogenous sphingolipid scavenging independent of cholesterol, 2) increased cancer cell catabolism of sphingomyelins to ceramide derivatives and 3) altered ceramide metabolism that results in increased glycosphingolipid synthesis and efflux of Cav-1-sphingolipid particles containing mitochondrial proteins and lipids. We also demonstrate, using a prostate cancer syngeneic RM-9 mouse model and established cell lines, that this Cav-1-sphingolipid program evidences a metabolic vulnerability that is targetable to induce lethal mitophagy as an anti-tumor therapy.

Genetic variants in epithelial-mesenchymal transition genes as predictors of clinical outcomes in localized prostate cancer.

BACKGROUND: Epithelial-mesenchymal transition (EMT) plays a pivotal role in the progression of prostate cancer (PCa). However, little is known about genetic variants in the EMT pathway as predictors of aggressiveness, biochemical recurrence (BCR) and disease reclassification in localized PCa. PATIENTS AND METHODS: In this multistage study, we evaluated 5186 single nucleotide polymorphisms (SNPs) from 264 genes related to EMT pathway to identify SNPs associated with PCa aggressiveness and BCR in the MD Anderson PCa (MDA-PCa) patient cohort (N = 1762), followed by assessment of the identified SNPs with disease reclassification in the active surveillance (AS) cohort (N = 392). RESULTS: In the MDA-PCa cohort, 312 SNPs were associated with high D'Amico risk (P < 0.05), among which, 14 SNPs in 10 genes were linked to BCR risk. In the AS cohort, 2 of 14 identified SNPs (rs76779889 and rs7083961) in C-terminal Binding Proteins 2 gene were associated with reclassification risk. The associations of rs76779889 with different endpoints were: D'Amico high versus low, odds ratio [95% confidence interval (CI)] = 2.89 (1.32-6.34), P = 0.008; BCR, hazard ratio (HR) (95% CI) = 2.88 (1.42-5.85), P = 0.003; and reclassification, HR (95% CI) = 2.83 (1.40-5.74), P = 0.004. For rs7083961, the corresponding risk estimates were: D'Amico high versus low, odds ratio (95% CI) = 1.69 (1.12-2.57), P = 0.013; BCR, HR (95% CI) = 1.87 (1.15-3.02), P = 0.011 and reclassification, HR (95% CI) = 1.72 (1.09-2.72), P = 0.020. There were cumulative effects of these two SNPs on modulating these endpoints. CONCLUSION: Genetic variants in EMT pathway may influence the risks of localized PCa's aggressiveness, BCR and disease reclassification, suggesting their potential role in the assessment and management of localized PCa.

A candidate androgen signalling signature predictive of response to abiraterone acetate in men with metastatic castration-resistant prostate cancer.

BACKGROUND: The unmet need for predictive biomarkers emerged from the unpredictable pattern of response to androgen signalling inhibition in metastatic castration-resistant prostate cancer (mCRPC). Here, we report on the testing of a previously identified candidate androgen signalling signature associated with response to androgen signalling inhibition. PATIENTS AND METHODS: We report on the outcome of the first module of a phase II trial on abiraterone acetate (AA) followed by combination with dasatinib or sunitinib. Bone marrow biopsies (BMBs) with matched bone marrow aspirate and blood samples were collected at baseline and upon progression. End-points included assessment of a prespecified molecular signature consisting of nuclear androgen receptor (AR) overexpression, cytochrome P450, family 17, subfamily A, polypeptide 1 (CYP17) expression, and AR-C-/N terminal expression ratio of ≥0.8 by immunohistochemistry (IHC) in patients with benefit versus primary resistance to AA (i.e. progression within 4 months). Tumour markers also included v-ets avian erythroblastosis virus E26 oncogene homologue (ERG), androgen receptor splice variant (ARV7) by IHC and steroids by liquid chromatography-tandem mass spectrometry. RESULTS: Of 170 patients accrued from 03/2011 to 02/2015, 44 (26%) were primary resistant to AA. Forty-eight patients had tumour infiltrated BMB at baseline. Pretreatment androgen signalling signature was linked to benefit from AA (p < 0.001). Presence of ERG was associated with benefit (p = 0.05), whereas nuclear ARV7 presence and 20 or more bone lesions at baseline with primary resistance (p = 0.04 and p = 0.0006, respectively). CONCLUSION: Testing of a prespecified androgen signalling signature was highly supportive of its predictive value in maximal androgen deprivation strategies in mCRPC. Further validation is under way. TRIAL REGISTRATION: ClinicalTrials.gov NCT01254864.

Determining Clinically Based Factors Associated With Reclassification in the Pre-MRI Era using a Large Prospective Active Surveillance Cohort.

OBJECTIVE: To report biopsy-related and oncologic outcomes in a large prospective active surveillance cohort that was initiated in the premagnetic resonance imaging era and to additionally identify clinical factors associated with disease reclassification in order to inform future studies designed to improve enrollment and follow-up on active surveillance. METHODS: Patients were prospectively enrolled at a single institution from 2006 to 2014 and followed until 2016. Men with Gleason 6 or 7 disease were eligible, and those with >6 months follow-up were included in the analysis. Patients were risk stratified based on clinical/pathologic criteria, including based on a combination of baseline and confirmatory biopsy tumor characteristics. Reclassification-free survival, based on tumor volume increase or Gleason score increase, was analyzed using multivariable Cox proportional hazards models. RESULTS: Of 825 enrolled patients, 682 met inclusion criteria. Median follow-up was 40 months (range 6.6-126.8). Disease was reclassified in 249 (36.5%), and 157 (23.0%) underwent treatment. A single positive core with a negative confirmatory biopsy was significantly associated with time to reclassification (median not met vs 43 months, log rank test P <.001). Composite tumor length, defined as the combined tumor length between baseline and confirmatory biopsies, was associated with shorter Gleason upgrade-free survival (hazard ratio 1.24, 95% confidence interval 1.11-1.40, P <.001) in multivariable analysis. CONCLUSION: Baseline stratification using clinical factors including tumor length may refine risk stratification and offer the foundation on which new systems that incorporate modalities such as magnetic resonance imaging may be based.

Pembrolizumab for Treatment-Refractory Metastatic Castration-Resistant Prostate Cancer: Multicohort, Open-Label Phase II KEYNOTE-199 Study.

PURPOSE: Pembrolizumab has previously shown antitumor activity against programmed death ligand 1 (PD-L1)-positive metastatic castration-resistant prostate cancer (mCRPC). Here, we assessed the antitumor activity and safety of pembrolizumab in three parallel cohorts of a larger mCRPC population. METHODS: The phase II KEYNOTE-199 study included three cohorts of patients with mCRPC treated with docetaxel and one or more targeted endocrine therapies. Cohorts 1 and 2 enrolled patients with RECIST-measurable PD-L1-positive and PD-L1-negative disease, respectively. Cohort 3 enrolled patients with bone-predominant disease, regardless of PD-L1 expression. All patients received pembrolizumab 200 mg every 3 weeks for up to 35 cycles. The primary end point was objective response rate per RECIST v1.1 assessed by central review in cohorts 1 and 2. Secondary end points included disease control rate, duration of response, overall survival (OS), and safety. RESULTS: Two hundred fifty-eight patients were enrolled: 133 in cohort 1, 66 in cohort 2, and 59 in cohort 3. Objective response rate was 5% (95% CI, 2% to 11%) in cohort 1 and 3% (95% CI, < 1% to 11%) in cohort 2. Median duration of response was not reached (range, 1.9 to ≥ 21.8 months) and 10.6 months (range, 4.4 to 16.8 months), respectively. Disease control rate was 10% in cohort 1, 9% in cohort 2, and 22% in cohort 3. Median OS was 9.5 months in cohort 1, 7.9 months in cohort 2, and 14.1 months in cohort 3. Treatment-related adverse events occurred in 60% of patients, were of grade 3 to 5 severity in 15%, and led to discontinuation of treatment in 5%. CONCLUSION: Pembrolizumab monotherapy shows antitumor activity with an acceptable safety profile in a subset of patients with RECIST-measurable and bone-predominant mCRPC previously treated with docetaxel and targeted endocrine therapy. Observed responses seem to be durable, and OS estimates are encouraging.

Consistent Biopsy Quality and Gleason Grading Within the Global Active Surveillance Global Action Plan 3 Initiative: A Prerequisite for Future Studies.

Within the Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative, 25 centers across the globe collaborate to standardize active surveillance (AS) protocols for men with low-risk prostate cancer (PCa). A centralized PCa AS database, comprising data of more than 15000 patients worldwide, was created. Comparability of the histopathology between the different cohorts was assessed by a centralized pathology review of 445 biopsies from 15 GAP3 centers. Grade group 1 (Gleason score 6) in 85% and grade group ≥2 (Gleason score ≥7) in 15% showed 89% concordance at review with moderate agreement (κ=0.56). Average biopsy core length was similar among the analyzed cohorts. Recently established highly adverse pathologies, including cribriform and/or intraductal carcinoma, were observed in 3.6% of the reviewed biopsies. In conclusion, the centralized pathology review of 445 biopsies revealed comparable histopathology among the 15 GAP3 centers with a low frequency of high-risk features. This enables further data analyses-without correction-toward uniform global AS guidelines for men with low-risk PCa. PATIENT SUMMARY: Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative combines data from 15000 men with low-risk prostate cancer (PCa) across the globe to standardize active surveillance protocols. Histopathology review confirmed that the histopathology was consistent with low-risk PCa in most men and comparable between different centers.