Genomic Hallmarks and Structural Variation in Metastatic Prostate Cancer.

While mutations affecting protein-coding regions have been examined across many cancers, structural variants at the genome-wide level are still poorly defined. Through integrative deep whole-genome and -transcriptome analysis of 101 castration-resistant prostate cancer metastases (109X tumor/38X normal coverage), we identified structural variants altering critical regulators of tumorigenesis and progression not detectable by exome approaches. Notably, we observed amplification of an intergenic enhancer region 624 kb upstream of the androgen receptor (AR) in 81% of patients, correlating with increased AR expression. Tandem duplication hotspots also occur near MYC, in lncRNAs associated with post-translational MYC regulation. Classes of structural variations were linked to distinct DNA repair deficiencies, suggesting their etiology, including associations of CDK12 mutation with tandem duplications, TP53 inactivation with inverted rearrangements and chromothripsis, and BRCA2 inactivation with deletions. Together, these observations provide a comprehensive view of how structural variations affect critical regulators in metastatic prostate cancer.

Rucaparib or Physician's Choice in Metastatic Prostate Cancer.

BACKGROUND: In a phase 2 study, rucaparib, an inhibitor of poly(ADP-ribose) polymerase (PARP), showed a high level of activity in patients who had metastatic, castration-resistant prostate cancer associated with a deleterious BRCA alteration. Data are needed to confirm and expand on the findings of the phase 2 study. METHODS: In this randomized, controlled, phase 3 trial, we enrolled patients who had metastatic, castration-resistant prostate cancer with a BRCA1, BRCA2, or ATM alteration and who had disease progression after treatment with a second-generation androgen-receptor pathway inhibitor (ARPI). We randomly assigned the patients in a 2:1 ratio to receive oral rucaparib (600 mg twice daily) or a physician's choice control (docetaxel or a second-generation ARPI [abiraterone acetate or enzalutamide]). The primary outcome was the median duration of imaging-based progression-free survival according to independent review. RESULTS: Of the 4855 patients who had undergone prescreening or screening, 270 were assigned to receive rucaparib and 135 to receive a control medication (intention-to-treat population); in the two groups, 201 patients and 101 patients, respectively, had a BRCA alteration. At 62 months, the duration of imaging-based progression-free survival was significantly longer in the rucaparib group than in the control group, both in the BRCA subgroup (median, 11.2 months and 6.4 months, respectively; hazard ratio, 0.50; 95% confidence interval [CI], 0.36 to 0.69) and in the intention-to-treat group (median, 10.2 months and 6.4 months, respectively; hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001 for both comparisons). In an exploratory analysis in the ATM subgroup, the median duration of imaging-based progression-free survival was 8.1 months in the rucaparib group and 6.8 months in the control group (hazard ratio, 0.95; 95% CI, 0.59 to 1.52). The most frequent adverse events with rucaparib were fatigue and nausea. CONCLUSIONS: The duration of imaging-based progression-free survival was significantly longer with rucaparib than with a control medication among patients who had metastatic, castration-resistant prostate cancer with a BRCA alteration. (Funded by Clovis Oncology; TRITON3 ClinicalTrials.gov number, NCT02975934.).

Quality of life outcomes for patients with metastatic castration-resistant prostate cancer and pretreatment prognostic score.

BACKGROUND: A prognostic risk score (Halabi score) in metastatic castration-resistant prostate cancer (mCRPC) accurately predicts overall survival, but its association with quality of life (QOL) has not been defined. We hypothesize that a higher pretreatment Halabi score is associated with worse QOL outcomes over time in mCRPC patients. METHODS: Patient-level data from the docetaxel plus prednisone control arm of Mainsail, a Phase 3 clinical trial in mCRPC were accessed via ProjectDataSphere. Pretreatment Halabi score included disease-related factors: metastatic site, opioid use, Eastern Cooperative Oncology Group performance status (ECOG-PS), alkaline phosphatase, albumin, hemoglobin, lactic acid dehydrogenase, and PSA, with higher score indicating worse survival. Three QOL scales were created: Functional Assessment of Cancer Therapy-Prostate (FACT-P, higher score = better QOL), Brief Pain Inventory-Short Form Severity score (BPI-SFSS, higher score = higher pain severity), and BPI-SF Interference score (BPI-SFIS, higher score = greater pain interference). Mixed linear model was used to estimate the associations between Halabi score and QOL scores assessed at different time points (baseline, 2 months, and 6 months). RESULTS: This analysis included 412 mCRPC patients (median age = 68 years, 82% white, 5% Black, median log PSA = 4.4 ng/mL). After multivariable adjustment, Halabi score was significantly associated with QOL scores at all time points. At 6 months, multivariable adjusted FACT-P decreased by 10.0 points (worsening), BPI-SFSS increased by 0.8 points (worsening), and BPI-SFIS increased by 0.9 points (worsening) for each unit increase in Halabi risk score. In multivariable analysis of individual components, ECOG-PS, site of metastasis, and opioid use were significantly associated with worse QOL scores at baseline. CONCLUSIONS: Chemotherapy-naïve mCRPC patients with poorer Halabi prognostic risk scores have poorer QOL and greater pain intensity and interference at baseline and during follow-up.

Clinical outcomes in patients with metastatic castrate-resistant prostate cancer treated with abiraterone with or without ongoing androgen deprivation therapy: A retrospective case-control study.

INTRODUCTION: Abiraterone and concurrent androgen deprivation therapy (ADT) are used in the treatment of patients with metastatic castration-resistant prostate cancer. Recently, it has been suggested that the use of abiraterone alone (without ADT) may have comparable efficacy to abiraterone with ongoing ADT. Here, we sought to assess the impact of ADT cessation in patients beginning abiraterone for castration-resistant prostate cancer. METHODS: We identified 39 patients at our institution who received abiraterone alone (with discontinuation of ADT) between 2011 and 2022. We then procured a comparable group of 39 patients (matched by age, Gleason score, and prostate-specific antigen [PSA] level) who received abiraterone with ongoing ADT during the same period. We assessed and compared clinical outcomes in the two groups (abiraterone-alone vs. abiraterone-ADT) with respect to PSA response rates, PSA progression-free survival, and overall survival. Results were adjusted using Cox proportional-hazards multivariable models. RESULTS: The median PSA before treatment initiation was 12.7 (range: 0.2-199) ng/mL in the abiraterone-alone group and 15.5 (range: 0.6-212) ng/mL in the abiraterone-ADT group. Use of abiraterone alone adequately suppressed testosterone levels in 35/37 (94.6%) patients. Patients receiving abiraterone alone had a median PSA reduction of 80.2% versus 79.5% in patients receiving abiraterone plus ADT. The median PSA progression-free survival in patients receiving abiraterone alone was 27.4 versus 25.8 months in patients receiving abiraterone plus ADT (hazard ratio [HR] 1.10; 95% confidence interval [CI] 0.65-1.71; p = 0.82). In addition, abiraterone alone was associated with an overall survival of 3.6 versus 3.1 years in patients receiving abiraterone plus ADT (HR 0.90; 95% CI 0.50-1.62; p = 0.72). There were no differences in PFS or OS between groups after performing Cox multivariable regression analyses. CONCLUSION: Use of abiraterone alone was associated with comparable clinical outcomes to patients who received abiraterone together with ADT. Further prospective studies are warranted to evaluate the impact of abiraterone alone on treatment outcomes and cost savings.

Comprehensive genomic profiling of penile squamous cell carcinoma and the impact of human papillomavirus status on immune-checkpoint inhibitor-related biomarkers.

BACKGROUND: Advanced penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy with limited success of immune-checkpoint inhibitors (ICIs). Approximately half of pSCC cases are associated with human papillomavirus (HPV) infection. METHODS: Evaluation was done retrospectively of the landscape of somatic alterations and ICI-related biomarkers in pSCC by using the Caris Life Sciences data set with the aim to establish signatures for HPV-dependent oncogenesis. The pSCC tumors were analyzed by using next-generation sequencing (NGS) of DNA and RNA. Programmed death ligand 1 (PD-L1) expression was evaluated by immunohistochemistry (IHC). Microsatellite instability (MSI) was tested by fragment analysis, IHC (SP142; ≥1%), and NGS. Tumor mutational burden (TMB)-high was defined as ≥10 mutations/Mb. HPV16/18 status was determined by using whole-exome sequencing (WES) when available. Significance was adjusted for multiple comparisons (q value < .05). RESULTS: NGS of the overall cohort (N = 108) revealed TP53 (46%), CDKN2A (26%), and PIK3CA (25%) to be the most common mutations. Overall, 51% of tumors were PD-L1+, 10.7% had high TMB, and 1.1% had mismatch repair-deficient (dMMR)/MSI-high status. Twenty-nine patients had their HPV status made available by WES (HPV16/18+, n = 13; HPV16/18-, n = 16). KMT2C mutations (33% vs. 0%) and FGF3 amplifications (30.8% vs. 0%) were specific to HPV16/18+ tumors, whereas CDKN2A mutations (0% vs. 37.5%) were exclusive to HPV16/18- tumors. TMB-high was exclusively found in the HPV16/18+ group (30.8%). The two groups had comparable PD-L1 and dMMR/MSI-H status. CONCLUSIONS: In a large and comprehensive NGS-based evaluation of somatic alterations in pSCC, HPV16/18+ versus HPV16/18- pSCCs were molecularly distinct tumors. Our finding that TMB-high is exclusive to HPV16/18+ tumors requires confirmation in larger data sets. PLAIN LANGUAGE SUMMARY: Penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy in the advanced setting, with poor prognosis and little success with immune-checkpoint inhibitors (ICIs) in an unselected patient approach. Human papillomavirus (HPV) infection is a known risk factor for pSCC; its impact on genomic tumor profiling is less defined. Using next-generation sequencing, we explored the genetic landscape and ICI-related biomarkers of pSCC and HPV-driven oncogenic molecular signatures. Our results indicate that HPV-positive and HPV-negative pSCCs are molecularly distinct tumors. Increased tumor mutational burden is associated with HPV-positive tumors, and could serve as a biomarker for predicting therapeutic response to ICI-based therapies. Our results support the growing literature indicating that HPV status in pSCC can be used to guide patient stratification in ICI-based clinical trials.

Impact of darolutamide on local symptoms: pre-planned and post hoc analyses of the ARAMIS trial.

OBJECTIVE: To assess, the effect of darolutamide (a structurally distinct androgen receptor inhibitor) on urinary and bowel symptoms, using data from the phase III ARAMIS trial (NCT02200614) that showed darolutamide significantly reduced the risk of metastasis and death versus placebo. PATIENTS AND METHODS: Patients with non-metastatic castration-resistant prostate cancer (nmCRPC) were randomised 2:1 to darolutamide (n = 955) or placebo (n = 554). Local symptom control was assessed by first prostate cancer-related invasive procedures and post hoc analyses of time to deterioration in quality of life (QoL) using total urinary and bowel symptoms, and individual questions for these symptoms from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Prostate Cancer Module subscales and Functional Assessment of Cancer Therapy-Prostate prostate cancer subscale. Prostate-specific antigen (PSA) responses were correlated with urinary and bowel adverse events (AEs). RESULTS: Fewer patients receiving darolutamide (4.7%) versus placebo (9.6%) underwent invasive procedures, and time to first procedure was prolonged with darolutamide (hazard ratio 0.42, 95% confidence interval 0.28-0.62). Darolutamide significantly (P < 0.01) delayed worsening of QoL for total urinary and bowel symptoms versus placebo, mostly attributed by individual symptoms of urinary frequency, associated pain, and interference with daily activities. AEs of urinary retention and dysuria were less frequent with darolutamide, and greater PSA response (≥90%, ≥50% and <90%, <50%) among darolutamide-treated patients was associated with lower incidences of urinary retention (2.2%, 4.2%, 5.1%) and dysuria (0.5%, 3.2%, 5.1%), respectively. CONCLUSIONS: Darolutamide demonstrated a positive impact on local disease recurrence and symptom control in patients with nmCRPC, delayed time to deterioration in QoL related to urinary and bowel symptoms, and a favourable safety profile showing similar incidence of urinary- and bowel-related AEs compared with placebo.

Transcriptional profiling identifies an androgen receptor activity-low, stemness program associated with enzalutamide resistance.

The androgen receptor (AR) antagonist enzalutamide is one of the principal treatments for men with castration-resistant prostate cancer (CRPC). However, not all patients respond, and resistance mechanisms are largely unknown. We hypothesized that genomic and transcriptional features from metastatic CRPC biopsies prior to treatment would be predictive of de novo treatment resistance. To this end, we conducted a phase II trial of enzalutamide treatment (160 mg/d) in 36 men with metastatic CRPC. Thirty-four patients were evaluable for the primary end point of a prostate-specific antigen (PSA)50 response (PSA decline ≥50% at 12 wk vs. baseline). Nine patients were classified as nonresponders (PSA decline <50%), and 25 patients were classified as responders (PSA decline ≥50%). Failure to achieve a PSA50 was associated with shorter progression-free survival, time on treatment, and overall survival, demonstrating PSA50's utility. Targeted DNA-sequencing was performed on 26 of 36 biopsies, and RNA-sequencing was performed on 25 of 36 biopsies that contained sufficient material. Using computational methods, we measured AR transcriptional function and performed gene set enrichment analysis (GSEA) to identify pathways whose activity state correlated with de novo resistance. TP53 gene alterations were more common in nonresponders, although this did not reach statistical significance (P = 0.055). AR gene alterations and AR expression were similar between groups. Importantly, however, transcriptional measurements demonstrated that specific gene sets-including those linked to low AR transcriptional activity and a stemness program-were activated in nonresponders. Our results suggest that patients whose tumors harbor this program should be considered for clinical trials testing rational agents to overcome de novo enzalutamide resistance.

Management of Patients with Metastatic Castration-Sensitive Prostate Cancer in the Real-World Setting in the United States.

PURPOSE: This study provides a contemporary assessment of the treatment patterns, health care resource utilization (HRU) and costs among metastatic castration-sensitive prostate cancer (mCSPC) patients in the U.S. MATERIALS AND METHODS: Adults with mCSPC were selected from Optum's de-identified Clinformatics® Data Mart Database (Commercial insurance/Medicare Advantage [COM/MA]; January 1, 2014-July 31, 2019) or Medicare Fee-for-Service (FFS; January 1, 2014-December 31, 2017). The index date was the first metastatic disease diagnosis date on/after the first prostate cancer diagnosis (without prior evidence of castration resistance). Patients were observed for 12 months pre-index (baseline) through their mCSPC period (from index until castration resistance or followup end). First-line (1L) mCSPC therapy was assessed during the mCSPC period; all-cause HRU and health plan-paid costs per-patient-per-year (PPPY) were measured during baseline and mCSPC periods. RESULTS: Among 6,517 COM/MA and 13,324 Medicare-FFS mCSPC patients over ∼10 months (median mCSPC period), 38% and 48% remained untreated/deferred treatment, and 45% and 46% received 1L androgen deprivation therapy (ADT) monotherapy, respectively. 1L abiraterone acetate and docetaxel were used among 7% and 6% of COM/MA and 1% and 2% of Medicare-FFS patients, respectively. HRU increased from baseline to mCSPC period, resulting in increased health plan-paid costs from $21,201 to $108,767 in COM/MA and from $16,819 to $69,639 PPPY in Medicare-FFS. CONCLUSIONS: This study highlights the limited use of newer therapies that improve survival in men with mCSPC in the U.S. HRU and costs increased substantially after onset of metastasis. Given the emergence of newer effective mCSPC therapies, further evaluation of future real-world mCSPC treatment patterns and outcomes is warranted.

Optimizing the management of castration-resistant prostate cancer patients: A practical guide for clinicians.

BACKGROUND: Advanced prostate cancer (PC) patients, especially those with metastatic prostate cancer (mPC), often require complex management pathways. Despite the publication of clinical practice guidelines by leading urological and oncological organizations that provide a substantial and comprehensive framework, there are numerous clinical scenarios that are not always addressed, especially as new treatments become available, new imaging modalities are developed, and advances in genetic testing continue. METHODS: A 14-member expert review panel comprised of urologists and medical oncologists were chosen to provide guidance on addressing specific topics and issues regarding metastatic castration-resistant prostate cancer (mCRPC) patients. Panel members were chosen based upon their experience and expertise in the management of PC patients. Four academic members (two urologists and two medical oncologists) of the panel served as group leaders; the remaining eight panel members were from Large Urology Group Practice Association (LUGPA) practices with proven experience in leading their advanced PC clinics. The panel members were assigned to four separate working groups, each assigned a specific mCRPC topic to review and discuss with the entire panel. RESULTS: This article describes the practical recommendations of an expert panel on the management of mCRPC patients. The target reading audience for this publication is all providers (urologists, medical oncologists, radiation oncologists, or advanced practice providers) who evaluate and manage advanced PC patients, regardless of their practice setting. CONCLUSION: The panel has provided recommendations for managing mCRPC with regard to specific issues: (a) biomarker monitoring and the role of genetic and molecular testing; (b) rationale, current strategies, and optimal sequencing of the various approved therapies, including hormonal therapy, cytotoxic chemotherapy, radiopharmaceuticals and immunotherapy; (c) adverse event management and monitoring; and (d) imaging advanced PC patients. These recommendations seek to complement national guidelines, not replace them, and a discussion of where the panel agreed or disagreed with national guidelines is included.

Differential use of medical versus surgical androgen deprivation therapy for patients with metastatic prostate cancer.

BACKGROUND: Surgical and medical androgen deprivation therapy (ADT) strategies are comparable in their ability to suppress serum testosterone levels as treatment in patients with metastatic prostate cancer but differ with regard to cost and impact on quality of life. Medical ADT is associated with better long-term quality of life due to the flexibility of possible therapy interruption but comes with a higher cumulative cost. In the current study, the authors examined whether surgical ADT (ie, bilateral orchiectomy) was used differentially by race/ethnicity and other social factors. METHODS: The authors identified patients with metastatic disease at the time of diagnosis through the California Cancer Registry. The association between race/ethnicity and receipt of surgical ADT was modeled using multivariable Firth logistic regression adjusting for age, Gleason score, prostate-specific antigen level, clinical tumor and lymph node classification, neighborhood socioeconomic status (SES), insurance, marital status, comorbidities, initial treatment (radiotherapy, chemotherapy), location of care, rural/urban area of residence, and year of diagnosis. RESULTS: The authors examined a total of 10,675 patients with metastatic prostate cancer, 11.4% of whom were non-Hispanic black, 8.4% of whom were Asian/Pacific Islander, 18.5% of whom were Hispanic/Latino, and 60.5% of whom were non-Hispanic white. In the multivariable model, patients found to be more likely to receive surgical ADT were Hispanic/Latino (odds ratio [OR], 1.32; 95% confidence interval [95% CI], 1.01-1.72), were from a low neighborhood SES (OR, 1.96; 95% CI, 1.34-2.89) or rural area (OR, 1.49; 95% CI, 1.15-1.92), and had Medicaid/public insurance (OR, 2.21; 95% CI, 1.58-3.10). Patients with military/Veterans Affairs insurance were significantly less likely to receive surgical ADT compared with patients with private insurance (OR, 0.34; 95% CI, 0.13-0.88). CONCLUSIONS: Race/ethnicity, neighborhood SES, and insurance status appear to be significantly associated with receipt of surgical ADT. Future research will need to characterize other differences in initial treatments among men with advanced prostate cancer based on race/ethnicity and aim to better understand what factors drive the association between surgical ADT among men of Hispanic origin or those from areas with low neighborhood SES.

At What Cost to Clinical Trial Enrollment? A Retrospective Study of Patient Travel Burden in Cancer Clinical Trials.

BACKGROUND: Recent literature suggests that living in a rural setting may be associated with adverse cancer outcomes. This study examines the burden of travel from home to cancer center for clinical trial (CT) enrollees. MATERIALS AND METHODS: Patients from the University of California San Francisco Clinical Trial Management System database who enrolled in a cancer CT for a breast, genitourinary, or gastrointestinal malignancy between 1993 and 2014 were included. Cancer type, household zip code, race/ethnicity, phase of study, study sponsor, and year of signed consent were exported. Distance traveled from home to center was calculated using a GoogleMaps application programming interface. The relationships of distance with phase of CT, household income, and race/ethnicity were examined. RESULTS: A total of 1,600 patients were enrolled in breast (55.8%), genitourinary (29.4%), or gastrointestinal (14.9%) cancer CTs. The overall median unidirectional distance traveled from home to study site was 25.8 miles (interquartile range [IQR] 11.5-75.3). Of the trial sponsors examined, principal investigator (56.4%), industry (22.2%), cooperative group (11.6%), and National Institutes of Health (NIH; 9.8%), the longest distance traveled was for NIH-sponsored trials, with a median of 39.4 miles (p < .001). Phase I (8.4%) studies had the longest distance traveled, with a median of 41.2 miles (IQR 14.5-101.0 miles; p = .001). White patients (83%) traveled longer compared with black patients (4.4%), with median distances of 29.9 and 13.9 miles, respectively (p < .001). Patients from lower-income areas (n = 799) traveled longer distances compared with patients from higher-income areas (n = 773; 58.3 vs. 17.8 miles, respectively; p < .001). A multivariable linear model where log10 (distance) was the outcome and adjusting for the exported variables and income revealed that cancer type, year of consent, race/ethnicity, and income were significantly associated with distance traveled. CONCLUSION: This study found that the burden of travel is highest among patients enrolled in NIH-sponsored trials, phase I studies, or living in low-income areas. These data suggest that travel burden for cancer CT participants may be significant. IMPLICATIONS FOR PRACTICE: This study is one of the first to measure travel distance for patients in cancer clinical trials using a real-world GoogleMaps calculator. Out-of-pocket expenses such as travel are not typically covered by health care payers; therefore, patients may face considerable cost to attend each study visit. Using a single-center clinical trials enrollment database, this study found that the burden of travel is highest for patients enrolled in National Institutes of Health-sponsored trials and phase I studies, as well as for patients living in low-income areas. Results suggest that a significant proportion of patients enrolled in clinical trials face a substantial travel burden.

A Phase II Trial of Selinexor, an Oral Selective Inhibitor of Nuclear Export Compound, in Abiraterone- and/or Enzalutamide-Refractory Metastatic Castration-Resistant Prostate Cancer.

LESSONS LEARNED: In abiraterone- and/or enzalutamide-refractory metastatic castration-resistant prostate cancer (mCRPC) patients, selinexor led to prostate-specific antigen and/or radiographic responses in a subset of patients, indicating clinical activity in this indication.Despite twice-a-week dosing and maximal symptomatic management, selinexor was associated with significant anorexia, nausea, and fatigue in mCRPC patients refractory to second-generation anti-androgen therapies, limiting further clinical development in this patient population.This study highlights the challenge of primary endpoint selection for phase II studies in the post-abiraterone and/or post-enzalutamide mCRPC space. BACKGROUND: Selinexor is a first-in-class selective inhibitor of nuclear export compound that specifically inhibits the nuclear export protein Exportin-1 (XPO-1), leading to nuclear accumulation of tumor suppressor proteins. METHODS: This phase II study evaluated the efficacy and tolerability of selinexor in patients with metastatic castration-resistant prostate cancer (mCRPC) refractory to abiraterone and/or enzalutamide. RESULTS: Fourteen patients were enrolled. Selinexor was initially administered at 65 mg/m2 twice a week (days 1 and 3) and was subsequently reduced to 60 mg flat dose twice a week (days 1 and 3), 3 weeks on, 1 week off, to improve tolerability. The median treatment duration was 13 weeks. At a median follow-up of 4 months, two patients (14%) had ≥50% prostate-specific antigen (PSA) decline, and seven patients (50%) had any PSA decline. Of eight patients with measurable disease at baseline, two (25%) had a partial response and four (50%) had stable disease as their best radiographic response. Five patients (36%) experienced serious adverse events (SAEs; all unrelated to selinexor), and five patients (36%) experienced treatment-related grade 3-4 AEs. The most common drug-related adverse events (AEs) of any severity were anorexia, nausea, weight loss, fatigue, and thrombocytopenia. Three patients (21%) came off study for unacceptable tolerability. CONCLUSION: Selinexor demonstrated clinical activity and poor tolerability in mCRPC patients refractory to second-line anti-androgenic agents.

The IMAAGEN Study: Effect of Abiraterone Acetate and Prednisone on Prostate Specific Antigen and Radiographic Disease Progression in Patients with Nonmetastatic Castration Resistant Prostate Cancer.

PURPOSE: We evaluated the use of abiraterone acetate (1,000 mg) plus prednisone (5 mg) in patients with high risk, nonmetastatic, castration resistant prostate cancer. MATERIALS AND METHODS: Patients considered at high risk for progression to metastatic disease (prostate specific antigen 10 ng/ml or greater, or prostate specific antigen doubling time 10 months or less) received abiraterone acetate plus prednisone daily in 28-day cycles. The primary study end point was the proportion of patients in whom a 50% or greater prostate specific antigen reduction was achieved during cycles 1 to 6. Secondary end points included time to prostate specific antigen progression, time to radiographic evidence of disease progression and safety. RESULTS: Of the 131 enrolled patients 44 (34%) remained on treatment with a median followup of 40.0 months. Median age was 72 years (range 48 to 90). Of the patients 82.4% were white and 14.5% were black. Median screening prostate specific antigen was 11.9 ng/dl and median prostate specific antigen doubling time was 3.4 months. Prostate specific antigen was significantly reduced (p <0.0001) with a 50% or greater prostate specific antigen reduction in 86.9% of cases and a 90% or greater reduction in 59.8%. Median time to prostate specific antigen progression was 28.7 months (95% CI 21.2-38.2). Median time to radiographic evidence of disease progression was not reached but on sensitivity analysis in 15 patients it was estimated to be 41.4 months (95% CI 27.6-not estimable). Baseline testosterone 12.5 ng/dl or greater and a 90% or greater prostate specific antigen reduction at cycle 3 were associated with longer time to prostate specific antigen progression and radiographic evidence of disease progression. Outcomes in black patients were similar to those in other patients. Adverse events, grade 3 or greater adverse events and serious adverse events were reported in 96.2%, 61.1% and 43.5% of patients, respectively. CONCLUSIONS: In patients with high risk, nonmetastatic, castration resistant prostate cancer treatment with abiraterone acetate plus prednisone demonstrated a significant 50% or greater prostate specific antigen reduction with encouraging results for the secondary end points, including the safety of 5 mg prednisone.

Prediction of overall survival for patients with metastatic castration-resistant prostate cancer: development of a prognostic model through a crowdsourced challenge with open clinical trial data.

BACKGROUND: Improvements to prognostic models in metastatic castration-resistant prostate cancer have the potential to augment clinical trial design and guide treatment strategies. In partnership with Project Data Sphere, a not-for-profit initiative allowing data from cancer clinical trials to be shared broadly with researchers, we designed an open-data, crowdsourced, DREAM (Dialogue for Reverse Engineering Assessments and Methods) challenge to not only identify a better prognostic model for prediction of survival in patients with metastatic castration-resistant prostate cancer but also engage a community of international data scientists to study this disease. METHODS: Data from the comparator arms of four phase 3 clinical trials in first-line metastatic castration-resistant prostate cancer were obtained from Project Data Sphere, comprising 476 patients treated with docetaxel and prednisone from the ASCENT2 trial, 526 patients treated with docetaxel, prednisone, and placebo in the MAINSAIL trial, 598 patients treated with docetaxel, prednisone or prednisolone, and placebo in the VENICE trial, and 470 patients treated with docetaxel and placebo in the ENTHUSE 33 trial. Datasets consisting of more than 150 clinical variables were curated centrally, including demographics, laboratory values, medical history, lesion sites, and previous treatments. Data from ASCENT2, MAINSAIL, and VENICE were released publicly to be used as training data to predict the outcome of interest-namely, overall survival. Clinical data were also released for ENTHUSE 33, but data for outcome variables (overall survival and event status) were hidden from the challenge participants so that ENTHUSE 33 could be used for independent validation. Methods were evaluated using the integrated time-dependent area under the curve (iAUC). The reference model, based on eight clinical variables and a penalised Cox proportional-hazards model, was used to compare method performance. Further validation was done using data from a fifth trial-ENTHUSE M1-in which 266 patients with metastatic castration-resistant prostate cancer were treated with placebo alone. FINDINGS: 50 independent methods were developed to predict overall survival and were evaluated through the DREAM challenge. The top performer was based on an ensemble of penalised Cox regression models (ePCR), which uniquely identified predictive interaction effects with immune biomarkers and markers of hepatic and renal function. Overall, ePCR outperformed all other methods (iAUC 0·791; Bayes factor >5) and surpassed the reference model (iAUC 0·743; Bayes factor >20). Both the ePCR model and reference models stratified patients in the ENTHUSE 33 trial into high-risk and low-risk groups with significantly different overall survival (ePCR: hazard ratio 3·32, 95% CI 2·39-4·62, p<0·0001; reference model: 2·56, 1·85-3·53, p<0·0001). The new model was validated further on the ENTHUSE M1 cohort with similarly high performance (iAUC 0·768). Meta-analysis across all methods confirmed previously identified predictive clinical variables and revealed aspartate aminotransferase as an important, albeit previously under-reported, prognostic biomarker. INTERPRETATION: Novel prognostic factors were delineated, and the assessment of 50 methods developed by independent international teams establishes a benchmark for development of methods in the future. The results of this effort show that data-sharing, when combined with a crowdsourced challenge, is a robust and powerful framework to develop new prognostic models in advanced prostate cancer. FUNDING: Sanofi US Services, Project Data Sphere.

A Phase I Study of Abiraterone Acetate Combined with BEZ235, a Dual PI3K/mTOR Inhibitor, in Metastatic Castration Resistant Prostate Cancer.

LESSONS LEARNED: The combination of standard dose abiraterone acetate and BEZ235, a pan-class I PI3K and mTORC1/2 inhibitor, was poorly tolerated in men with progressive mCRPC.Although the clinical development of BEZ235 has been discontinued in prostate cancer, agents that more selectively target PI3K-AKT-mTOR signaling may have a more favorable therapeutic index and should continue to be explored. BACKGROUND: Androgen receptor (AR) and phosphatidylinositol-3 kinase (PI3K) signaling are two commonly perturbed pathways in prostate cancer. Preclinical data have shown that the two pathways compensate for each other when one is inhibited, and combined inhibition of AR and PI3K signaling may be a viable strategy to prevent or overcome castration resistance. METHODS: This phase I study evaluated the safety and tolerability of abiraterone acetate and prednisone combined with BEZ235, a dual PI3K and mTORC1/2 inhibitor, in men with progressive metastatic castration resistant prostate cancer (mCRPC) who have not received prior chemotherapy. RESULTS: Six patients (n = 6) were treated at the starting dose level of abiraterone acetate 1,000 mg with prednisone 5 mg twice daily and BEZ235 200 mg twice daily in a 3 + 3 dose escalation design. The study was terminated early because three of the six patients (50%) experienced dose-limiting toxicities: grade 3 mucositis, grade 3 hypotension, and grade 4 dyspnea and pneumonitis. All six patients had previously progressed on abiraterone/prednisone. The median treatment duration was 27 days (range: 3-130 days). No prostate-specific antigen (PSA) decline or objective response were observed. CONCLUSION: The combination of standard-dose abiraterone/prednisone with BEZ235 200 mg twice daily was poorly tolerated in patients with mCRPC. The on-target and off-target effects of dual PI3K and mTORC inhibition likely contributed to the unacceptable toxicity profile. The Oncologist 2017;22:503-e43.

Treatment strategies in low-volume metastatic castration-resistant prostate cancer.

PURPOSE OF REVIEW: There are currently limited data to guide the optimal management of patients with low-volume metastatic castration-resistant prostate cancer (mCRPC). In this review, we critically assess the most relevant clinical data, and discuss opportunities for advancing therapeutic options in this patient population. RECENT FINDINGS: Over the past decade, treatment options for mCRPC have expanded beyond taxanes to include abiraterone/prednisone, enzalutamide, sipuleucel-T, and radium-223. However, only a subset of patients in the landmark phase 3 studies would meet criteria consistent with low-volume mCRPC, and optimal treatment approach for this patient population is unclear. There is emerging evidence that mCRPC patients who harbor low-volume or indolent disease may derive the most benefit from immunotherapy. Whereas prospective data are lacking, stereotactic body radiation appears to be well tolerated and effective for local control of metastases in oligometastatic CRPC. SUMMARY: Prospective studies are needed to establish optimal therapeutic approaches in carefully selected low-volume mCRPC patients. Advances in functional imaging and molecular profiling should provide opportunities to optimize patient selection for effective treatment strategies.

DNA Repair Deficiency Is Common in Advanced Prostate Cancer: New Therapeutic Opportunities.

UNLABELLED: : Advances in DNA sequencing technology have created a wealth of information regarding the genomic landscape of prostate cancer. It had been thought that BRCA1 and BRCA2 mutations were associated with only a small fraction of prostate cancer cases. However, recent genomic analysis has revealed that germline or somatic inactivating mutations in BRCA1 or BRCA2, or other genes involved in the homologous recombination (HR) pathway of DNA repair collectively occur in as much as 20%-25% of advanced prostate cancers. A synthetic lethal therapeutic approach using poly(ADP-ribose) polymerase inhibitor therapy has been developed for BRCA mutant- and HR deficient-related cancers (those with "BRCAness") and is being studied in multiple clinical trials. This article discusses the current understanding of the genomic landscape of prostate cancer, focusing on the occurrence of DNA repair mutations and the therapeutic opportunities that this presents. IMPLICATIONS FOR PRACTICE: This review aims to update oncologists about the increased understanding of the genomes of prostate cancers and, in particular, the prevalence of mutations in DNA repair genes. These observations provide potential new therapeutic opportunities for the use of poly(ADP-ribose) polymerase inhibitors and other therapies, especially in advanced forms of the disease. Of note is the recent U.S. Food and Drug Administration breakthrough therapy designation of olaparib for the treatment of BRCA1/2- or ATM-mutated metastatic castration-resistant prostate cancer. The implications of this new knowledge for clinical practice now and in the future are discussed.

Abiraterone in metastatic prostate cancer without previous chemotherapy.

BACKGROUND: Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. METHODS: In this double-blind study, we randomly assigned 1088 patients to receive abiraterone acetate (1000 mg) plus prednisone (5 mg twice daily) or placebo plus prednisone. The coprimary end points were radiographic progression-free survival and overall survival. RESULTS: The study was unblinded after a planned interim analysis that was performed after 43% of the expected deaths had occurred. The median radiographic progression-free survival was 16.5 months with abiraterone-prednisone and 8.3 months with prednisone alone (hazard ratio for abiraterone-prednisone vs. prednisone alone, 0.53; 95% confidence interval [CI], 0.45 to 0.62; P<0.001). Over a median follow-up period of 22.2 months, overall survival was improved with abiraterone-prednisone (median not reached, vs. 27.2 months for prednisone alone; hazard ratio, 0.75; 95% CI, 0.61 to 0.93; P=0.01) but did not cross the efficacy boundary. Abiraterone-prednisone showed superiority over prednisone alone with respect to time to initiation of cytotoxic chemotherapy, opiate use for cancer-related pain, prostate-specific antigen progression, and decline in performance status. Grade 3 or 4 mineralocorticoid-related adverse events and abnormalities on liver-function testing were more common with abiraterone-prednisone. CONCLUSIONS: Abiraterone improved radiographic progression-free survival, showed a trend toward improved overall survival, and significantly delayed clinical decline and initiation of chemotherapy in patients with metastatic castration-resistant prostate cancer. (Funded by Janssen Research and Development, formerly Cougar Biotechnology; ClinicalTrials.gov number, NCT00887198.).

Abiraterone acetate plus prednisone versus placebo plus prednisone in chemotherapy-naive men with metastatic castration-resistant prostate cancer (COU-AA-302): final overall survival analysis of a randomised, double-blind, placebo-controlled phase 3 study.

BACKGROUND: Abiraterone acetate plus prednisone significantly improved radiographic progression-free survival compared with placebo plus prednisone in men with chemotherapy-naive castration-resistant prostate cancer at the interim analyses of the COU-AA-302 trial. Here, we present the prespecified final analysis of the trial, assessing the effect of abiraterone acetate plus prednisone on overall survival, time to opiate use, and use of other subsequent therapies. METHODS: In this placebo-controlled, double-blind, randomised phase 3 study, 1088 asymptomatic or mildly symptomatic patients with chemotherapy-naive prostate cancer stratified by Eastern Cooperative Oncology performance status (0 vs 1) were randomly assigned with a permuted block allocation scheme via a web response system in a 1:1 ratio to receive either abiraterone acetate (1000 mg once daily) plus prednisone (5 mg twice daily; abiraterone acetate group) or placebo plus prednisone (placebo group). Coprimary endpoints were radiographic progression-free survival and overall survival analysed in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT00887198. FINDINGS: At a median follow-up of 49.2 months (IQR 47.0-51.8), 741 (96%) of the prespecified 773 death events for the final analysis had been observed: 354 (65%) of 546 patients in the abiraterone acetate group and 387 (71%) of 542 in the placebo group. 238 (44%) patients initially receiving prednisone alone subsequently received abiraterone acetate plus prednisone as crossover per protocol (93 patients) or as subsequent therapy (145 patients). Overall, 365 (67%) patients in the abiraterone acetate group and 435 (80%) in the placebo group received subsequent treatment with one or more approved agents. Median overall survival was significantly longer in the abiraterone acetate group than in the placebo group (34.7 months [95% CI 32.7-36.8] vs 30.3 months [28.7-33.3]; hazard ratio 0.81 [95% CI 0.70-0.93]; p=0.0033). The most common grade 3-4 adverse events of special interest were cardiac disorders (41 [8%] of 542 patients in the abiraterone acetate group vs 20 [4%] of 540 patients in the placebo group), increased alanine aminotransferase (32 [6%] vs four [<1%]), and hypertension (25 [5%] vs 17 [3%]). INTERPRETATION: In this randomised phase 3 trial with a median follow-up of more than 4 years, treatment with abiraterone acetate prolonged overall survival compared with prednisone alone by a margin that was both clinically and statistically significant. These results further support the favourable safety profile of abiraterone acetate in patients with chemotherapy-naive metastatic castration-resistant prostate cancer. FUNDING: Janssen Research & Development.