Differences in real-world outcomes by risk classification for localized prostate cancer patients after radiation therapy

BACKGROUND

Limited real-world evidence exists on the long-term clinical outcomes of patients with localized prostate cancer (LPC) who received external beam radiation therapy (EBRT) as the initial treatment. This study evaluated clinical outcomes of US patients with high-risk LPC (HR-LPC) and low/intermediate-risk LPC (LIR-LPC) who received EBRT.

METHODS

This retrospective study using Surveillance, Epidemiology, and End Results-Medicare linked data from 2012 to 2019 included patients ≥ 65 years old who received EBRT as initial therapy. Baseline patient characteristics were summarized, metastasis-free survival (MFS), overall survival, and time to initiation of advanced prostate cancer treatment were compared using Kaplan-Meier (KM) and adjusted Cox proportional hazard (PH) models. 5-year survival probabilities stratified by race/ethnicity (non-Hispanic [NH] White, NH Black, NH Asian, and Hispanic) were assessed.

RESULTS

Of 11,313 eligible patients, 41% (n = 4600) had HR-LPC and 59% (n = 6713) had LIR-LPC. Patient characteristics for both groups were comparable, with mean age at EBRT initiation > 70 years, 86% white, and mean follow-up time >40 months. More patients in the HR-LPC than LIR-LPC groups (78% vs 34%) had concurrent androgen deprivation therapy use and for a longer duration (median 10.4 months vs. 7.4 months). A higher proportion of HR-LPC patients developed metastasis, died, or received advanced prostate cancer treatment. Adjusted Cox PH survival analyses showed significantly (p < 0.0001) higher risk of mortality (hazard ratios [HR], 1.57 [1.38, 2.34]), metastasis or death (HR, 1.97 [1.78, 2.17]), and advanced prostate cancer therapy use (HR, 2.57 [2.11, 3.14]) for HR-LPC than LIR-LPC patients. Within 5 years after the initial EBRT treatment, 18%-26% of patients with HR-LPC are expected to have died or developed metastasis. The 5-year MFS rate in the HR-LPC group was lower than the LIR-LPC group across all racial/ethnic subgroups. NH Black patients with HR-LPC had the highest all-cause mortality rate and lowest rate of receiving advanced prostate cancer treatment, compared to other racial/ethnic subgroups.

CONCLUSIONS

This real-world study of clinical outcomes in patients with LPC treated with EBRT suggests substantial disease burden in patients with HR-LPC and highlights the need for additional treatment strategies to improve clinical outcomes in patients with HR-LPC.

A US real-world study of treatment patterns and outcomes in localized or locally advanced prostate cancer patients

PURPOSE

Men with localized or locally advanced prostate cancer (LPC/LAPC) are at risk of progression after radiotherapy (RT) or radical prostatectomy (RP). Using real-world data, we evaluated patient characteristics, treatment patterns, and outcomes in LPC/LAPC.

METHODS

Optum claims and electronic health records (EHR) data from January 2010 to December 2021 were queried for men with LPC/LAPC who received primary RT, RP, or androgen deprivation therapy alone within 180 days after diagnosis. Survival outcomes were analyzed using descriptive statistics and Kaplan-Meier curves. Real-world overall survival (rwOS) was compared in patients with and without evidence of disease (i.e., disease recurrence, metastasis, diagnosis of castration-resistant PC) at defined time points.

RESULTS

61,772 and 62,361 men in claims and EHR cohorts met the inclusion criteria. Median follow-up was 719 and 901 days, respectively. Most men received primary RT (51.0% claims, 35.0% EHR) or RP (39.4% claims, 53.8% EHR). Survival was greatest among men treated with RP, followed by RT. Adjusted for age and comorbidity, rwOS was shorter among men with evidence of disease within 1, 3, 4, and 5 years after primary treatment than those without at the same time points.

CONCLUSION

Real-world claims and EHR data show that survival among men with LPC/LAPC differs by primary treatment and time point of disease recurrence thereafter. Poor outcomes in men with LPC/LAPC who progress early indicate an unmet medical need for more effective primary treatment. If validated for surrogacy, no evidence of disease at specific time points could represent an intermediate efficacy endpoint in future 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.

Efficacy and safety exposure-response relationships of apalutamide in patients with metastatic castration-sensitive prostate cancer: results from the phase 3 TITAN study

PURPOSE

Apalutamide plus androgen-deprivation therapy (ADT) has been approved for treatment of patients with metastatic castration-sensitive prostate cancer (mCSPC) based on data from phase 3 TITAN study. This analysis was conducted to describe pharmacokinetics of apalutamide and N-desmethyl-apalutamide and explore relationships between apalutamide exposure and selected clinical efficacy and safety observations.

METHODS

1052 patients were randomized to apalutamide + ADT (n = 525) or placebo + ADT (n = 527). A previously developed population pharmacokinetic model was applied. Cox regression analysis investigated the relationships between apalutamide exposure and overall survival (OS; n = 1004) and radiographic progression-free survival (rPFS; n = 1003). Logistic regression analysis assessed the relationships between apalutamide exposure and selected clinically relevant adverse events (n = 1051).

RESULTS

Apalutamide + ADT treatment was efficacious in extending rPFS and OS versus placebo + ADT. Within a relatively narrow apalutamide exposure range (coefficient of variation: 22%), no statistical association was detected between rPFS, OS and apalutamide exposure quartiles. Incidence of skin rash and pruritus increased significantly with increasing apalutamide exposure.

CONCLUSIONS

Differences in apalutamide exposure were not associated with clinically relevant differences in rPFS or OS in patients with mCSPC. Patients with increased apalutamide exposure are more likely to develop skin rash and pruritus. Dose reductions may improve these adverse events, based on an individual risk-benefit approach.

Concomitant use of oral anticoagulants in patients with advanced prostate cancer receiving apalutamide: A post-hoc analysis of TITAN and SPARTAN studies

Apalutamide, an androgen receptor signaling inhibitor, in combination with androgen-deprivation therapy (ADT), is approved for treatment of patients with nonmetastatic castration-resistant prostate cancer and metastatic castration-sensitive prostate cancer, based on the data from the phase 3 SPARTAN and TITAN studies respectively. Apalutamide is an inducer of cytochrome P450 enzymes and P-glycoprotein, which are involved in the metabolism of oral anticoagulants (OACs) and may thus have potential drug-drug interactions when co-administered with OACs. Concomitant use of certain OACs such as apixaban, rivaroxaban, edoxaban, dabigatran, and warfarin was allowed in the SPARTAN and TITAN studies. A post-hoc analysis was conducted to evaluate the incidence of treatment-emergent thrombotic and embolic adverse events (AEs) in patients receiving concomitant OACs with apalutamide + ADT or placebo + ADT in both the studies. Anticoagulants were identified by WHO Drug Anatomical Therapeutic Chemical level 4 classifications. Thrombotic and embolic AEs were coded using the Medical Dictionary for Regulatory Activities Version 22.1. Data were analyzed from patients receiving concurrent OACs among all treated patients in SPARTAN (apalutamide + ADT: 95/803 [11.8%]; placebo + ADT: 48/398 [12.1%]) and TITAN (apalutamide + ADT: 31/524 [5.9%]; placebo + ADT: 28/527 [5.3%]). No consequential differences were observed in the occurrence of thrombotic and embolic events between apalutamide + ADT and placebo + ADT groups receiving concomitant OACs in SPARTAN (11.6% vs 12.5%) or TITAN (19.4% vs 21.4%). Grade 3/4 thrombotic and embolic AEs observed in patients receiving concomitant OACs with apalutamide + ADT or placebo + ADT were 6 (6.3%) vs 5 (10.4%) in SPARTAN and 3 (9.7%) vs 1 (3.6%) in TITAN. This analysis suggests that when necessary, concomitant OACs can be used with apalutamide with appropriate monitoring.

The Oral Gonadotropin-releasing Hormone Receptor Antagonist Relugolix as Neoadjuvant/Adjuvant Androgen Deprivation Therapy to External Beam Radiotherapy in Patients with Localised Intermediate-risk Prostate Cancer: A Randomised, Open-label, Parallel-group Phase 2 Trial

BACKGROUND

External beam radiotherapy (EBRT) with neoadjuvant/adjuvant androgen deprivation therapy (ADT) is an established treatment option to prolong survival for patients with intermediate- and high-risk prostate cancer (PCa). Relugolix, an oral gonadotropin-releasing hormone (GnRH) receptor antagonist, was evaluated in this clinical setting in comparison with degarelix, an injectable GnRH antagonist.

OBJECTIVE

To evaluate the safety and efficacy of relugolix to achieve and maintain castration.

DESIGN, SETTING, AND PARTICIPANTS

A phase 2 open-label study was conducted in 103 intermediate-risk PCa patients undergoing primary EBRT and neoadjuvant/adjuvant ADT between June 2014 and December 2015.

INTERVENTION

Patients randomly assigned (3:2) to 24-wk treatment with either daily oral relugolix or 4-wk subcutaneous depot degarelix (reference control).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the rate of effective castration (testosterone <1.73nmol/l) in relugolix patients between 4 and 24 wk of treatment. Secondary endpoints included rate of profound castration (testosterone <0.7nmol/l), prostate-specific antigen (PSA) levels, prostate volume, quality of life (QoL) assessed using the Aging Males' Symptoms scale, and the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life (30-item EORTC core questionnaire [EORTC QLQ-C30] and 25-item EORTC prostate cancer module [EORTC QLQ-PR25]) questionnaires, and safety. No formal statistical comparisons with degarelix were planned.

RESULTS AND LIMITATIONS

Castration rates during treatment were 95% and 82% with relugolix and 89% and 68% with degarelix for 1.73 and 0.7nmol/l thresholds, respectively. Median time to castration in the relugolix arm was 4 d. During treatment, PSA levels and prostate volumes were reduced in both groups. Three months after discontinuing treatment, 52% of men on relugolix and 16% on degarelix experienced testosterone recovery (statistical significance of differences not tested). Mean and median QoL scores improved following treatment discontinuation. The most common adverse event was hot flush (relugolix 57%; degarelix 61%). Lack of blinding was a potential limitation.

CONCLUSIONS

Relugolix achieved testosterone suppression to castrate levels within days and maintained it over 24 wk with a safety profile consistent with its mechanism of action.

PATIENT SUMMARY

Oral once-daily relugolix may be a novel oral alternative to injectable androgen deprivation therapies.

Double-Blind, Randomized, Placebo-controlled Studies Evaluating Apaziquone (E09, Qapzola™) Intravesical Instillation Post Transurethral Resection of Bladder Tumors for the Treatment of Low-risk Non-Muscle Invasive Bladder Cancer

Background

Guidelines recommend a single postoperative instillation of intravesical chemotherapy within 24 hours of transurethral resection of bladder tumors (TURBT) in patients with low- and intermediate-risk non-muscle invasive bladder cancer (NMIBC) to reduce recurrence risk.

Objective

To evaluate the 2-year recurrence rate (2-YRR) of bladder cancer in randomized patients with Ta, G1-G2 histology who receive TURBT plus apaziquone versus TURBT plus placebo.

Methods

Two nearly identical Phase 3, multinational, randomized, double-blind, placebo-controlled trials were conducted in patients with histologically confirmed Ta, G1-G2 NMIBC (Target Population) to evaluate the efficacy/safety of a single instillation of apaziquone post-TURBT. A single intravesical instillation of apaziquone (4 mg/40 mL) or placebo was administered within 6 hours post-TURBT. The primary and secondary efficacy endpoints were 2-YRR and time to recurrence (TTR) respectively.

Results

Overall, 1614 patients were enrolled, including 1146 patients in the Target Population. Individually, the two studies did not meet statistical significance for 2-YRR (38.0% vs 44.6% ; 39.7% vs. 46.3%). Because apaziquone is rapidly metabolized in blood, a post hoc subgroup analysis was performed by time window of drug instillation post-TURBT. Patients who had drug instilled in the time window 60±30 minutes post-TURBT demonstrated 20.3% and 20.8% reduction in 2-YRR and 56% (HR = 0.44) and 45% (HR = 0.55) reduction in hazards for TTR in two studies respectively. Apaziquone was well tolerated with minimal toxicity.

Conclusions

Two identical Phase 3 studies supported the safety of apaziquone (4 mg/40 mL) administered as a single intravesical instillation post-TURBT and identified efficacy when instilled within 60±30-minutes time interval which requires further study.

How I Do It: Hydrogel spacer placement in men scheduled to undergo prostate radiotherapy

Hydrogel spacer placement between the prostate and rectum in men scheduled to undergo prostate radiotherapy is an emerging technique well suited for urologists. The hydrogel spacer reduces rectal injury during radiotherapy by displacing the rectum away from the high dose region. Following radiotherapy the hydrogel spacer then liquifies, is absorbed, and then clears via renal filtration in approximately 6 months. Herein we describe the appropriate patients eligible for this procedure, and the application technique we use in our clinic.

Validating the total illness burden index for prostate cancer (TIBI-CaP) in men with castration-resistant prostate cancer: data from TRUMPET

AIM

To validate the total illness burden index for prostate cancer (TIBI-CaP) in castration-resistant prostate cancer (CRPC) patients.

PATIENTS & METHODS

Baseline comorbidity scores collected using the TIBI-CaP were compared with the baseline patient-reported health-related quality of life using the SF-12v2 and FACT-P questionnaires in 302 patients enrolled in the Treatment Registry for Outcomes in CRPC Patients (TRUMPET).

RESULTS

Baseline TIBI-CaP scores were negatively correlated with all baseline SF-12v2 domain/composite (p < 0.001) and FACT-P subscale/total (p < 0.020) scores. There was a significant decreasing linear trend in SF12v2 and FACT-P scores over the categories based on TIBI-CaP quartiles of comorbidity burden (from 'least' to 'severe').

CONCLUSION

The TIBI-CaP is a valid measure of comorbidity burden in patients with CRPC in the real world.

Decipher test impacts decision making among patients considering adjuvant and salvage treatment after radical prostatectomy: Interim results from the Multicenter Prospective PRO-IMPACT study

BACKGROUND

Patients with prostate cancer and their providers face uncertainty as they consider adjuvant radiotherapy (ART) or salvage radiotherapy (SRT) after undergoing radical prostatectomy. The authors prospectively evaluated the impact of the Decipher test, which predicts metastasis risk after radical prostatectomy, on decision making for ART and SRT.

METHODS

A total of 150 patients who were considering ART and 115 who were considering SRT were enrolled. Providers submitted a management recommendation before processing the Decipher test and again at the time of receipt of the test results. Patients completed validated surveys on prostate cancer (PCa)‐specific decisional effectiveness and PCa‐related anxiety.

RESULTS

Before the Decipher test, observation was recommended for 89% of patients considering ART and 58% of patients considering SRT. After Decipher testing, 18% (95% confidence interval [95% CI], 12%‐25%) of treatment recommendations changed in the ART arm, including 31% among high‐risk patients; and 32% (95% CI, 24%‐42%) of management recommendations changed in the salvage arm, including 56% among high‐risk patients. Decisional Conflict Scale (DCS) scores were better after viewing Decipher test results (ART arm: median DCS before Decipher, 25 and after Decipher, 19 [P<.001]; SRT arm: median DCS before Decipher, 27 and after Decipher, 23 [P<.001]). PCa‐specific anxiety changed after Decipher testing; fear of PCa disease recurrence in the ART arm (P = .02) and PCa‐specific anxiety in the SRT arm (P = .05) decreased significantly among low‐risk patients. Decipher results reported per 5% increase in 5‐year metastasis probability were associated with the decision to pursue ART (odds ratio, 1.48; 95% CI, 1.19‐1.85) and SRT (odds ratio, 1.41; 95% CI, 1.09‐1.81) in multivariable logistic regression analysis.

CONCLUSIONS

Knowledge of Decipher test results was associated with treatment decision making and improved decisional effectiveness among men with PCa who were considering ART and SRT. Cancer 2017;123:2850–59. © 2017 American Cancer Society.

Use of the Decipher test appears to result in a change in treatment decision making in a substantial percentage of men with prostate cancer who are considering adjuvant or salvage radiotherapy after radical prostatectomy. Decisional effectiveness improves for both patients and providers with use of the Decipher test.

Continued Benefit to Rectal Separation for Prostate Radiation Therapy: Final Results of a Phase III Trial

PURPOSE

SpaceOAR, a Food and Drug Administration-approved hydrogel intended to create a rectal-prostate space, was evaluated in a single-blind phase III trial of image guided intensity modulated radiation therapy. A total of 222 men were randomized 2:1 to the spacer or control group and received 79.2 Gy in 1.8-Gy fractions to the prostate with or without the seminal vesicles. The present study reports the final results with a median follow-up period of 3 years.

METHODS AND MATERIALS

Cumulative (Common Terminology Criteria for Adverse Events, version 4.0) toxicity was evaluated using the log-rank test. Quality of life (QOL) was examined using the Expanded Prostate Cancer Index Composite (EPIC), and the mean changes from baseline in the EPIC domains were tested using repeated measures models. The proportions of men with minimally important differences (MIDs) in each domain were tested using repeated measures logistic models with prespecified thresholds.

RESULTS

The 3-year incidence of grade ≥1 (9.2% vs 2.0%; P=.028) and grade ≥2 (5.7% vs 0%; P=.012) rectal toxicity favored the spacer arm. Grade ≥1 urinary incontinence was also lower in the spacer arm (15% vs 4%; P=.046), with no difference in grade ≥2 urinary toxicity (7% vs 7%; P=0.7). From 6 months onward, bowel QOL consistently favored the spacer group (P=.002), with the difference at 3 years (5.8 points; P<.05) meeting the threshold for a MID. The control group had a 3.9-point greater decline in urinary QOL compared with the spacer group at 3 years (P<.05), but the difference did not meet the MID threshold. At 3 years, more men in the control group than in the spacer group had experienced a MID decline in bowel QOL (41% vs 14%; P=.002) and urinary QOL (30% vs 17%; P=.04). Furthermore, the control group were also more likely to have experienced large declines (twice the MID) in bowel QOL (21% vs 5%; P=.02) and urinary QOL (23% vs 8%; P=.02).

CONCLUSIONS

The benefit of a hydrogel spacer in reducing the rectal dose, toxicity, and QOL declines after image guided intensity modulated radiation therapy for prostate cancer was maintained or increased with a longer follow-up period, providing stronger evidence for the benefit of hydrogel spacer use in prostate radiation therapy.

Treatment registry for outcomes in patients with castration-resistant prostate cancer (TRUMPET): a methodology for real-world evidence and research

AIM

This study seeks to improve the understanding of treatment patterns and associated health-related quality of life (HRQoL), clinical outcomes and healthcare utilization in US patients with castration-resistant prostate cancer (CRPC).

PATIENTS & METHODS

Treatment Registry for Outcomes in CRPC Patients (TRUMPET) is a US-based, prospective, observational multicenter registry (NCT02380274) involving patients with CRPC and their caregivers. Patients initiating their first active treatment course will be enrolled from urology and medical oncology practices, with data captured up to 4 years.

RESULTS

Information on prescribing patterns, HRQoL, clinical outcomes and healthcare utilization will be collected.

CONCLUSION

TRUMPET will enable scientific understanding of disease management in terms of HRQoL, clinical outcomes and healthcare utilization in clinical practice for patients with CRPC.

Enzalutamide Versus Bicalutamide in Castration-Resistant Prostate Cancer: The STRIVE Trial

PURPOSE

Enzalutamide, a potent oral androgen receptor inhibitor, improves survival in men with metastatic castration-resistant prostate cancer (CRPC) before and after chemotherapy. Bicalutamide, a nonsteroidal antiandrogen, is widely used to treat men with nonmetastatic or metastatic CRPC. The efficacy and safety of these drugs were compared in this randomized, double-blind, phase II study of men with CRPC.

PATIENTS AND METHODS

A total of 396 men with nonmetastatic (n = 139) or metastatic (n = 257) CRPC were randomly assigned to enzalutamide 160 mg per day (n = 198) or bicalutamide 50 mg per day (n = 198). Androgen deprivation therapy was continued in both arms. The primary end point was progression-free survival (PFS).

RESULTS

Enzalutamide reduced the risk of progression or death by 76% compared with bicalutamide (hazard ratio [HR], 0.24; 95% CI, 0.18 to 0.32; P < .001). Median PFS was 19.4 months with enzalutamide versus 5.7 months with bicalutamide. Enzalutamide resulted in significant improvements in all key secondary end points: time to prostate-specific antigen progression (HR, 0.19; 95% CI, 0.14 to 0.26; P < .001); proportion of patients with a ≥ 50% prostate-specific antigen response (81% v 31%; P < .001); and radiographic PFS in metastatic patients (HR, 0.32; 95% CI, 0.21 to 0.50; P < .001). Beneficial effects with enzalutamide were observed in both nonmetastatic and metastatic subgroups. The observed adverse event profile was consistent with that from phase III enzalutamide trials.

CONCLUSION

Enzalutamide significantly reduced risk of prostate cancer progression or death compared with bicalutamide in patients with nonmetastatic or metastatic CRPC.

Safety of long-term denosumab therapy: results from the open label extension phase of two phase 3 studies in patients with metastatic breast and prostate cancer

Purpose

Zoledronic acid (ZA) or denosumab treatment reduces skeletal-related events; however, the safety of prolonged therapy has not been adequately studied. Here, we describe safety results of extended denosumab therapy in patients with bone metastases from the open-label extension phase of two phase 3 trials.

Methods

Patients with metastatic breast or prostate cancer received subcutaneous denosumab 120 mg Q4W or intravenous ZA 4 mg Q4W in a double-blinded fashion. Denosumab demonstrated superior efficacy in the blinded treatment phase; thus, patients were offered open-label denosumab for up to an additional 2 years.

Results

Cumulative median (Q1, Q3) denosumab exposure was 19.1 (9.2, 32.2) months in the breast cancer trial (n = 1019) and 12.0 (5.6, 21.3) months in the prostate cancer trial (n = 942); 295 patients received denosumab for >3 years. No new safety signals were identified during the open-label phase, or among patients who switched from ZA to denosumab. During the blinded treatment phase, exposure-adjusted subject incidences of osteonecrosis of the jaw (ONJ) were 49 (1.9 %) and 31 (1.2 %) in the denosumab and ZA groups, respectively. In total, 32 (6.9 %) and 25 (5.5 %) new cases of ONJ (not adjusted for exposure) were reported for patients continuing and switching to denosumab, respectively. The incidences of hypocalcemia were 4.3 and 3.1 %, in patients continuing and switching to denosumab, respectively.

Conclusion

These results describe the safety profile of denosumab after long-term exposure, or after switching to denosumab from ZA. No new safety signals were identified. Hypocalcemia rates were similar in the blinded treatment and open-label phases. ONJ rates increased with increasing exposure to antiresorptives, consistent with previous reports.

Bone-related Parameters are the Main Prognostic Factors for Overall Survival in Men with Bone Metastases from Castration-resistant Prostate Cancer

BACKGROUND

Previous studies have reported on prognostic factors for castration-resistant prostate cancer (CRPC); however, most of these studies were conducted before docetaxel chemotherapy was approved for CRPC.

OBJECTIVE

To evaluate the prognostic value of multiple parameters in men with bone metastases due to CRPC using a contemporary dataset.

DESIGN, SETTING, AND PARTICIPANTS

The analysis included 1901 patients with metastatic CRPC enrolled in an international, multicenter, randomized, double-blind phase 3 trial conducted between May 2006 and October 2009.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

We developed multivariate validated Cox proportional hazards models and nomograms to estimate 12-mo and 24-mo survival probabilities and median survival time.

RESULTS AND LIMITATIONS

The median (95% confidence interval) overall survival was 20 (18, 21) mo. The final model included 12 of the 15 potential prognostic variables evaluated (concordance index 0.72). Seven bone-related variables were associated with longer survival in the final model: alkaline phosphatase ≤143 U/l (p<0.0001); bone-specific alkaline phosphatase (BSAP) <146 U/l (p<0.0001); corrected urinary N-telopeptide (uNTx) ≤50 nmol/mmol (p=0.0008); mild or no pain (Brief Pain Inventory-Short Form [BPI-SF] score ≤4) (p<0.0001); no previous skeletal-related event (SRE; p=0.0002); longer time from initial diagnosis to first bone metastasis (p<0.0001); and longer time from first bone metastasis to randomization (p<0.0001). Other significant predictors of improved survival included prostate-specific antigen (PSA) level <10 ng/ml (p<0.0001), hemoglobin >128g/l (p<0.0001), absence of visceral metastases (p<0.0001), Eastern Co-operative Oncology Group (ECOG) score ≤1 (p=0.017), and younger age (p=0.008). Nomograms were generated based on the parameters included in the final validated models (with/without uNTx and BSAP). One limitation was that lactate dehydrogenase (LDH) levels, a known prognostic factor, were not available in this study.

CONCLUSIONS

Bone-related parameters are strong prognostic variables for overall survival in patients with bone metastases from CRPC.

PATIENT SUMMARY

Survival time is variable in patients with bone metastases from prostate cancer. We found that factors related to bone help to predict how long a patient will live.

Safety and efficacy of a patient-controlled bladder management system for treating urinary retention in men

AIMS

The CymActive™ Bladder Management System (BMS) is a self-retaining, intraurethral catheter with a patient-controlled magnetic valve that allows cyclical bladder filling and emptying, without external appliances. We determined the safety and efficacy of the BMS in men with urinary retention who required catheterization for more than 7 days.

METHODS

Men requiring continuous drainage, bladder capacity less than 300 ml, history of prostatic or urethral surgery, or urethral length outside of defined limits, were excluded. Data were collected from patient diaries and weekly visits during catheterization for up to 30 days. The primary composite endpoint assessed four outcomes: placement, post-void residual volume (PVR) of 75 ml or less, adverse device-related events requiring early removal, and removal.

RESULTS

Nine of 23 patients met all four criteria: eight of 18 non-neurogenic (7/11 prior Foley users and 1/7 without Foley experience) and one of five neurogenic spinal cord injury (SCI) patients. Secondary outcomes in non-neurogenic patients included: 17/18 successful insertions; of these, 16/17 average PVR of 75 ml; successful valve openings and closings ≥ 95% of more than 1,400 voids; and minimal leakage. Four of five SCI patients discontinued within 7 days. Cystourethroscopy after removal revealed no marked inflammation or mucosal changes.

CONCLUSIONS

This pilot study demonstrated the BMS is potentially useful, convenient, and safe for appropriate patients. A follow-up study will better define the characteristics of patients who benefit from this device and examine whether the use of antimuscarinic agents improves outcomes. Neurourol. Urodynam. 35:630-635, 2016. © 2015 Wiley Periodicals, Inc.

A multi-institutional prospective trial in the USA confirms that the 4Kscore accurately identifies men with high-grade prostate cancer

BACKGROUND

The 4Kscore combines measurement of four kallikreins in blood with clinical information as a measure of the probability of significant (Gleason ≥7) prostate cancer (PCa) before prostate biopsy.

OBJECTIVE

To perform the first prospective evaluation of the 4Kscore in predicting Gleason ≥7 PCa in the USA.

DESIGN, SETTING, AND PARTICIPANTS

Prospective enrollment of 1012 men scheduled for prostate biopsy, regardless of prostate-specific antigen level or clinical findings, was conducted at 26 US urology centers between October 2013 and April 2014.

INTERVENTION

The 4Kscore.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was Gleason ≥7 PCa on prostate biopsy. The area under the receiver operating characteristic curve, risk calibration, and decision curve analysis (DCA) were determined, along with comparisons of probability cutoffs for reducing the number of biopsies and their impact on delaying diagnosis.

RESULTS AND LIMITATIONS

Gleason ≥7 PCa was found in 231 (23%) of the 1012 patients. The 4Kscore showed excellent calibration and demonstrated higher discrimination (AUC 0.82) and net benefit compared to a modified Prostate Cancer Prevention Trial Risk Calculator 2.0 model and standard of care (biopsy for all men) according to DCA. A possible reduction of 30-58% in the number biopsies was identified with delayed diagnosis in only 1.3-4.7% of Gleason ≥7 PCa cases, depending on the threshold used for biopsy. Pathological assessment was performed according to the standard of care at each site without centralized review.

CONCLUSION

The 4Kscore showed excellent diagnostic performance in detecting significant PCa. It is a useful tool in selecting men who have significant disease and are most likely to benefit from a prostate biopsy from men with no cancer or indolent cancer.

PATIENT SUMMARY

The 4Kscore provides each patient with an accurate and personalized measure of the risk of Gleason ≥7 cancer to aid in decision-making regarding the need for prostate biopsy.

Denosumab and bone-metastasis-free survival in men with castration-resistant prostate cancer: results of a phase 3, randomised, placebo-controlled trial

BACKGROUND

Bone metastases are a major cause of morbidity and mortality in men with prostate cancer. Preclinical studies suggest that osteoclast inhibition might prevent bone metastases. We assessed denosumab, a fully human anti-RANKL monoclonal antibody, for prevention of bone metastasis or death in non-metastatic castration-resistant prostate cancer.

METHODS

In this phase 3, double-blind, randomised, placebo-controlled study, men with non-metastatic castration-resistant prostate cancer at high risk of bone metastasis (prostate-specific antigen [PSA] ≥8·0 μg/L or PSA doubling time ≤10·0 months, or both) were enrolled at 319 centres from 30 countries. Patients were randomly assigned (1:1) via an interactive voice response system to receive subcutaneous denosumab 120 mg or subcutaneous placebo every 4 weeks. Randomisation was stratified by PSA eligibility criteria and previous or ongoing chemotherapy for prostate cancer. Patients, investigators, and all people involved in study conduct were masked to treatment allocation. The primary endpoint was bone-metastasis-free survival, a composite endpoint determined by time to first occurrence of bone metastasis (symptomatic or asymptomatic) or death from any cause. Efficacy analysis was by intention to treat. The masked treatment phase of the trial has been completed. This trial was registered at ClinicalTrials.gov, number NCT00286091.

FINDINGS

1432 patients were randomly assigned to treatment groups (716 denosumab, 716 placebo). Denosumab significantly increased bone-metastasis-free survival by a median of 4·2 months compared with placebo (median 29·5 [95% CI 25·4-33·3] vs 25·2 [22·2-29·5] months; hazard ratio [HR] 0·85, 95% CI 0·73-0·98, p=0·028). Denosumab also significantly delayed time to first bone metastasis (33·2 [95% CI 29·5-38·0] vs 29·5 [22·4-33·1] months; HR 0·84, 95% CI 0·71-0·98, p=0·032). Overall survival did not differ between groups (denosumab, 43·9 [95% CI 40·1-not estimable] months vs placebo, 44·8 [40·1-not estimable] months; HR 1·01, 95% CI 0·85-1·20, p=0·91). Rates of adverse events and serious adverse events were similar in both groups, except for osteonecrosis of the jaw and hypocalcaemia. 33 (5%) patients on denosumab developed osteonecrosis of the jaw versus none on placebo. Hypocalcaemia occurred in 12 (2%) patients on denosumab and two (<1%) on placebo.

INTERPRETATION

This large randomised study shows that targeting of the bone microenvironment can delay bone metastasis in men with prostate cancer.

FUNDING

Amgen Inc.

Denosumab versus zoledronic acid for treatment of bone metastases in men with castration-resistant prostate cancer: a randomised, double-blind study

BACKGROUND

Bone metastases are a major burden in men with advanced prostate cancer. We compared denosumab, a human monoclonal antibody against RANKL, with zoledronic acid for prevention of skeletal-related events in men with bone metastases from castration-resistant prostate cancer.

METHODS

In this phase 3 study, men with castration-resistant prostate cancer and no previous exposure to intravenous bisphosphonate were enrolled from 342 centres in 39 countries. An interactive voice response system was used to assign patients (1:1 ratio), according to a computer-generated randomisation sequence, to receive 120 mg subcutaneous denosumab plus intravenous placebo, or 4 mg intravenous zoledronic acid plus subcutaneous placebo, every 4 weeks until the primary analysis cutoff date. Randomisation was stratified by previous skeletal-related event, prostate-specific antigen concentration, and chemotherapy for prostate cancer within 6 weeks before randomisation. Supplemental calcium and vitamin D were strongly recommended. Patients, study staff, and investigators were masked to treatment assignment. The primary endpoint was time to first on-study skeletal-related event (pathological fracture, radiation therapy, surgery to bone, or spinal cord compression), and was assessed for non-inferiority. The same outcome was further assessed for superiority as a secondary endpoint. Efficacy analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00321620, and has been completed.

FINDINGS

1904 patients were randomised, of whom 950 assigned to denosumab and 951 assigned to receive zoledronic acid were eligible for the efficacy analysis. Median duration on study at primary analysis cutoff date was 12·2 months (IQR 5·9-18·5) for patients on denosumab and 11·2 months (IQR 5·6-17·4) for those on zoledronic acid. Median time to first on-study skeletal-related event was 20·7 months (95% CI 18·8-24·9) with denosumab compared with 17·1 months (15·0-19·4) with zoledronic acid (hazard ratio 0·82, 95% CI 0·71-0·95; p = 0·0002 for non-inferiority; p = 0·008 for superiority). Adverse events were recorded in 916 patients (97%) on denosumab and 918 patients (97%) on zoledronic acid, and serious adverse events were recorded in 594 patients (63%) on denosumab and 568 patients (60%) on zoledronic acid. More events of hypocalcaemia occurred in the denosumab group (121 [13%]) than in the zoledronic acid group (55 [6%]; p<0·0001). Osteonecrosis of the jaw occurred infrequently (22 [2%] vs 12 [1%]; p = 0·09).

INTERPRETATION

Denosumab was better than zoledronic acid for prevention of skeletal-related events, and potentially represents a novel treatment option in men with bone metastases from castration-resistant prostate cancer.

FUNDING

Amgen.

A randomized phase III trial of denosumab versus zoledronic acid in patients with bone metastases from castration-resistant prostate cancer

LBA4507

Background: Bone metastases from hormone-refractory (castration-resistant) prostate cancer (CRPC) are associated with RANKL-mediated osteoclast activation resulting in bone destruction and skeletal-related events (SRE). Denosumab is a fully human monoclonal antibody against RANKL. This phase III, randomized, double-blind, active-controlled trial compared the efficacy and safety of denosumab vs. zoledronic acid (ZA) in patients with metastatic CRPC.

Methods: Patients (n = 1,901) with CRPC and at least 1 bone metastasis, but no prior IV bisphosphonate use, received either SC denosumab 120 mg and IV placebo (n = 950), or SC placebo and IV ZA 4 mg (n = 951) adjusted for creatinine clearance every 4 weeks. All patients were instructed to take supplemental calcium and vitamin D. The primary endpoint was time to first on-study SRE, defined as pathologic fracture, radiation or surgery to bone, or spinal cord compression.

Results: Denosumab significantly delayed the time to first on-study SRE compared with ZA, (HR 0.82 ; 95% CI: 0.71, 0.95 ; p = 0.008.) The median time to first on-study SRE was 20.7 mo denosumab vs. 17.1 mo ZA, a difference of 3.6 months. Denosumab also significantly delayed the time to first and subsequent on-study SRE (multiple event analysis) (HR 0.82 ; 95% CI: 0.71, 0.94 ; p = 0.004). Greater suppression of the bone turnover markers uNTx and BSAP occurred in denosumab patients compared with ZA (p < 0.0001 for both). Overall, adverse event (AE) rates (97% each) and serious AEs (63% denosumab, 60% ZA) were similar, irrespective of potential relationship to study drugs. AEs of hypocalcemia were reported in 13% and 6% of denosumab and ZA patients. Osteonecrosis of the jaw occurred in 22 (2.3%) denosumab compared with 12 (1.3%) ZA patients (p = 0.09). Overall survival (HR 1.03 ; 95% CI: 0.91, 1.17 ; p = 0.65) and time to cancer progression (HR 1.06; 95% CI: 0.95, 1.18; p = 0.30) were similar between treatment arms.

Conclusions: Denosumab demonstrated superiority over ZA in delaying or preventing SREs in patients with bone metastases from CRPC. Adverse events were consistent in both treatment groups with those previously reported in advanced cancer populations.

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The role of germinal epithelium and spermatogenesis in the privileged survival of intratesticular grafts

The testis is an immunologically privileged site. Since earlier studies excluded testicular steroid production as an essential factor, the present study evaluates the role of germ cells and spermatogenesis in the privileged survival of allografts within the testis. We used a Sertoli cell-only testis model and adolescent unilateral cryptorchidism in inbred rats to eliminate germ cells and spermatogenesis selectively. Parathyroid allografts were implanted into these sites, normal testes and beneath the renal capsule (a nonprivileged site) in appropriately matched controls. With at least 15 rats in each group, privileged allograft survival was shown to be unaffected by eliminating germ cells and spermatogenesis (p less than .005). Experimental evidence suggests the presence of an active process which incidentally permits privileged allograft survival within the testis, but which exists teleologically to protect the developing sperm from autoimmune attack. This is in addition to the passive anatomical separation provided by the blood-testis barrier. Our cumulative data strongly implicates the Sertoli cell in this process.