The Use of Salvage Chemotherapy for Patients with Relapsed Testicular Germ Cell Tumor (GCT) in Canada: A National Survey.

BACKGROUND: Although metastatic germ cell tumor (GCT) is highly curable with initial cisplatin-based chemotherapy (CT), 20-30% of patients relapse. Salvage CT options include conventional (CDCT) and high dose chemotherapy (HDCT), however definitive comparative data remain lacking. We aimed to characterize the contemporary practice patterns of salvage CT across Canada. METHODS: We conducted a 30-question online survey for Canadian medical and hematological oncologists with experience in treating GCT, assessing treatment availability, patient selection, and management strategies used for relapsed GCT patients. RESULTS: There were 30 respondents from 18 cancer centers across eight provinces. The most common CDCT regimens used were TIP (64%) and VIP (25%). HDCT was available in 13 centers (70%). The HDCT regimen used included carboplatin and etoposide for two cycles (76% in 7 centers), three cycles (6% in 2 centers), and the TICE protocol (11%, in 2 centers). "Bridging" CDCT was used by 65% of respondents. Post-HDCT treatments considered include surgical resection for residual disease (87.5%), maintenance etoposide (6.3%), and surveillance only (6.3%). CONCLUSIONS: HDCT is the most commonly used GCT salvage strategy in Canada. Significant differences exist in the treatment availability, selection, and delivery of HDCT, highlighting the need for standardization of care for patients with relapsed testicular GCT.

Testosterone suppression plus enzalutamide versus testosterone suppression plus standard antiandrogen therapy for metastatic hormone-sensitive prostate cancer (ENZAMET): an international, open-label, randomised, phase 3 trial.

BACKGROUND: The interim analysis of the ENZAMET trial of testosterone suppression plus either enzalutamide or standard nonsteroidal antiandrogen therapy showed an early overall survival benefit with enzalutamide. Here, we report the planned primary overall survival analysis, with the aim of defining the benefit of enzalutamide treatment in different prognostic subgroups (synchronous and metachronous high-volume or low-volume disease) and in those who received concurrent docetaxel. METHODS: ENZAMET is an international, open-label, randomised, phase 3 trial conducted at 83 sites (including clinics, hospitals, and university centres) in Australia, Canada, Ireland, New Zealand, the UK, and the USA. Eligible participants were males aged 18 years or older with metastatic, hormone-sensitive prostate adenocarcinoma evident on CT or bone scanning with 99mTc and an Eastern Cooperative Oncology Group performance status score of 0-2. Participants were randomly assigned (1:1), using a centralised web-based system and stratified by volume of disease, planned use of concurrent docetaxel and bone antiresorptive therapy, comorbidities, and study site, to receive testosterone suppression plus oral enzalutamide (160 mg once per day) or a weaker standard oral non-steroidal antiandrogen (bicalutamide, nilutamide, or flutamide; control group) until clinical disease progression or prohibitive toxicity. Testosterone suppression was allowed up to 12 weeks before randomisation and for up to 24 months as adjuvant therapy. Concurrent docetaxel (75 mg/m2 intravenously) was allowed for up to six cycles once every 3 weeks, at the discretion of participants and physicians. The primary endpoint was overall survival in the intention-to-treat population. This planned analysis was triggered by reaching 470 deaths. This study is registered with ClinicalTrials.gov, NCT02446405, ANZCTR, ACTRN12614000110684, and EudraCT, 2014-003190-42. FINDINGS: Between March 31, 2014, and March 24, 2017, 1125 participants were randomly assigned to receive non-steroidal antiandrogen (n=562; control group) or enzalutamide (n=563). The median age was 69 years (IQR 63-74). This analysis was triggered on Jan 19, 2022, and an updated survival status identified a total of 476 (42%) deaths. After a median follow-up of 68 months (IQR 67-69), the median overall survival was not reached (hazard ratio 0·70 [95% CI 0·58-0·84]; p<0·0001), with 5-year overall survival of 57% (0·53-0·61) in the control group and 67% (0·63-0·70) in the enzalutamide group. Overall survival benefits with enzalutamide were consistent across predefined prognostic subgroups and planned use of concurrent docetaxel. The most common grade 3-4 adverse events were febrile neutropenia associated with docetaxel use (33 [6%] of 558 in the control group vs 37 [6%] of 563 in the enzalutamide group), fatigue (four [1%] vs 33 [6%]), and hypertension (31 [6%] vs 59 [10%]). The incidence of grade 1-3 memory impairment was 25 (4%) versus 75 (13%). No deaths were attributed to study treatment. INTERPRETATION: The addition of enzalutamide to standard of care showed sustained improvement in overall survival for patients with metastatic hormone-sensitive prostate cancer and should be considered as a treatment option for eligible patients. FUNDING: Astellas Pharma.

Outcomes of patients with advanced non-clear cell renal cell carcinoma treated with first-line immune checkpoint inhibitor therapy.

BACKGROUND: Immune checkpoint inhibitors (ICI) have demonstrated impressive activity in metastatic clear-cell renal cell carcinoma (ccRCC) and have become standard treatment options for patients with advanced disease. Data supporting the effectiveness of ICI-based therapy in advanced non-clear cell RCC (nccRCC) is more limited. METHODS: We performed a retrospective analysis using the International Metastatic RCC Database Consortium (IMDC) to evaluate the outcomes of patients with advanced nccRCC. Patients were classified into three groups based on first-line therapy: ICI-based therapy (monotherapy or combination), vascular endothelial growth factor (VEGF) inhibitor monotherapy, or mammalian target of rapamycin (mTOR) inhibitor monotherapy. The primary outcome was overall survival (OS). Secondary outcomes were time to treatment failure (TTF) and objective response rate (ORR). We used the Kaplan-Meier method to compare OS and TTF between treatment groups and Cox proportional hazards models to adjust for prognostic covariates. RESULTS: We identified a total of 1145 patients with metastatic nccRCC. The most common subtype was papillary RCC (54.9%). For first-line therapy, 74.3% received VEGF monotherapy, 15% received mTOR monotherapy, and 10.7% received ICI-based therapy. Median OS in the ICI group was 28.6 months, versus 16.4 months in the VEGF group and 12.2 months in the mTOR group. Median TTF in the ICI group was 6.9 months, versus 5.0 months in the VEGF group and 3.9 months in the mTOR group. ORR was 27.2% in the ICI group, 14.5% in the VEGF group, and 9% in the mTOR group. After adjusting for the IMDC risk group, histological subtype, and age, the hazard ratio for OS was 0.57 (95% CI 0.42-0.78, p < 0.0001) for ICI versus VEGF and 0.50 (95% CI 0.36-0.71, p < 0.0001) for ICI versus mTOR. CONCLUSIONS: In advanced nccRCC, first-line ICI-based treatment appears to be associated with improved OS compared to VEGF and mTOR targeted therapy. These results should be confirmed in prospective randomised trials.

Health-Related Quality of Life in Metastatic, Hormone-Sensitive Prostate Cancer: ENZAMET (ANZUP 1304), an International, Randomized Phase III Trial Led by ANZUP.

PURPOSE: We previously reported that enzalutamide improved overall survival when added to standard of care in metastatic, hormone-sensitive prostate cancer. Here, we report its effects on aspects of health-related quality of life (HRQL). METHODS: HRQL was assessed with the European Organisation for Research and Treatment of Cancer core quality-of-life questionnaire and QLM-PR25 at weeks 0, 4, 12, and then every 12 weeks until progression. Scores from week 4 to 156 were analyzed with repeated measures modeling to calculate group means and differences. Deterioration-free survival was from random assignment until the earliest of death, clinical progression, discontinuation of study treatment, or a worsening of 10 points or more from baseline in fatigue, physical function, cognitive function, or overall health and quality of life (OHQL). HRQL scores range from 0 (lowest possible) to 100 (highest possible). RESULTS: HRQL was assessed in 1,042 of 1,125 participants (93%). Differences in means favored control over enzalutamide for fatigue (5.2, 95% CI, 3.6 to 6.9; P < .001), cognitive function (4.0, 95% CI, 2.5 to 5.5; P < .001), and physical function (2.6, 95% CI, 1.3 to 3.9; P < .001), but not OHQL (1.2, 95% CI, -0.2 to 2.7; P = .1). Deterioration-free survival rates at 3 years, and log-rank P values comparing the whole distributions, favored enzalutamide over control for OHQL (31% v 17%; P < .0001), cognitive function (31% v 20%; P = .001), and physical function (31% v 22%; P < .001), but not fatigue (24% v 18%; P = .16). The effects of enzalutamide on HRQL were independent of baseline characteristics. CONCLUSION: Enzalutamide was associated with worsening of self-reported fatigue, cognitive function, and physical function, but not OHQL. Enzalutamide was associated with improved deterioration-free survival for OHQL, physical function, and cognitive function because delays in disease progression outweighed early deteriorations in these aspects of HRQL.

Stereotactic Radiotherapy for Oligoprogression in Metastatic Renal Cell Cancer Patients Receiving Tyrosine Kinase Inhibitor Therapy: A Phase 2 Prospective Multicenter Study.

BACKGROUND: Despite the paucity of prospective evidence, stereotactic radiotherapy (SRT) is increasingly being considered in the setting of oligoprogression to delay the need to change systemic therapy. OBJECTIVE: To determine the local control (LC), progression-free survival (PFS), cumulative incidence of changing systemic therapy, and overall survival (OS) after SRT to oligoprogressive metastatic renal cell carcinoma (mRCC) lesions in patients who are on tyrosine kinase inhibitor (TKI) therapy. DESIGN, SETTING, AND PARTICIPANTS: A prospective multicenter study was performed to evaluate the use of SRT in oligoprogressive mRCC patients. Patients with mRCC who had previous stability or response after ≥3 mo of TKI therapy were eligible if they developed progression of five of fewer metastases. Thirty-seven patients with 57 oligoprogressive tumors were enrolled. INTERVENTION: Oligoprogressive tumors were treated with SRT, and the same TKI therapy was continued afterward. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Competing risk analyses and the Kaplan-Meir methodology were used to report the outcomes of interest. RESULTS AND LIMITATIONS: The median duration of TKI therapy prior to study entry was 18.6 mo; 1-yr LC of the irradiated tumors was 93% (95% confidence interval [CI] 71-98%). The median PFS after SRT was 9.3 mo (95% CI 7.5-15.7 mo). The cumulative incidence of changing systemic therapy was 47% (95% CI 32-68%) at 1 yr, with a median time to change in systemic therapy of 12.6 mo (95% CI 9.6-17.4 mo). One-year OS was 92% (95% CI 82-100%). There were no grade 3-5 SRT-related toxicities. CONCLUSIONS: LC of irradiated oligoprogressive mRCC tumors was high, and the need to change systemic therapy was delayed for a median of >1 yr. PATIENT SUMMARY: The use of stereotactic radiotherapy in metastatic kidney cancer patients, who develop growth of a few tumors while on oral targeted therapy, can significantly delay the need to change to the next line of drug therapy.

Overall Survival of Men with Metachronous Metastatic Hormone-sensitive Prostate Cancer Treated with Enzalutamide and Androgen Deprivation Therapy.

Men who initially present with localized prostate cancer and later develop metachronous metastases have a better prognosis than men with de novo metastatic disease and often have a low burden of disease on conventional imaging. Some have disease amenable to metastasis-directed therapy for lymph node or bone metastases, a strategy used by some because no documented overall survival (OS) benefit of combination systemic therapy in this setting. We report data for patients prospectively classified as "M0" at initial diagnosis from the interim analysis of the ENZAMET trial, with 34 mo of median follow-up for survivors. A total of 312 (28%) of the 1125 enrolled patients were classified as M0 at diagnosis, and 205 (66%) of the 312 patients had low-volume disease at study entry as per the CHAARTED criteria. The hazard ratio for OS, that is, HR(OS), was 0.56 (95% confidence interval [CI]: 0.29-1.06) with the addition of enzalutamide for all patients with metachronous metastatic hormone-sensitive prostate cancer, and for the low-volume subset the HR(OS) was 0.40 (95% CI: 0.16-0.97). The 3-yr OS was 83% without and 89% with enzalutamide for all patients with metachronous metastases, and 83% and 92%, respectively, for the low-volume subset. Intensification of hormonal therapy should strongly be considered for these men. PATIENT SUMMARY: Many men present with prostate cancer that has spread to distant sites beyond the prostate gland years after their initial diagnosis and treatment, while others have distant spread at the time the cancer is diagnosed. On average, men whose cancer comes back years after the initial diagnosis often survive much longer than men whose cancer has been found to spread to distant sites when it is first diagnosed. In this report, we demonstrate strong evidence for the first time that the survival of men whose cancer comes back years later is improved when drugs such as enzalutamide or apalutamide are added to testosterone suppression in this setting.

Defining cisplatin eligibility in patients with muscle-invasive bladder cancer.

The current treatment paradigm for muscle-invasive bladder cancer (MIBC) consists of cisplatin-based neoadjuvant chemotherapy followed by local definitive therapy, or local definitive therapy alone for cisplatin-ineligible patients. Given that MIBC has a high propensity for distant relapse and is a chemotherapy-sensitive disease, under-utilization of chemotherapy is associated with suboptimal cure rates. Cisplatin eligibility criteria are defined for patients with metastatic bladder cancer by the Galsky criteria, which include creatinine clearance ≥60 ml/min. However, consensus is still lacking regarding cisplatin eligibility criteria in the neoadjuvant, curative MIBC setting, which continues to represent a substantial barrier to the standardization of patient care and clinical trial design. Jiang and colleagues accordingly suggest an algorithm for assessing cisplatin eligibility in patients with MIBC. Instead of relying on an absolute renal function threshold, their algorithm emphasizes a multidisciplinary and patient-centred approach. They also propose mitigation strategies to minimize the risk of cisplatin-induced nephrotoxicity in selected patients with impaired renal function. This new framework is aimed at reducing the inappropriate exclusion of some patients from cisplatin-based neoadjuvant chemotherapy (which leads to under-treatment) and harmonizing clinical trial design, which could lead to improved overall outcomes in patients with MIBC.

Efficacy and Safety of nab-Paclitaxel vs Paclitaxel on Survival in Patients With Platinum-Refractory Metastatic Urothelial Cancer: The Canadian Cancer Trials Group BL.12 Randomized Clinical Trial.

IMPORTANCE: Treatment options for platinum-refractory metastatic urothelial cancer (mUC) are limited, and outcomes remain poor. Nab-paclitaxel is an albumin-bound formulation of paclitaxel showing promising activity and tolerability in a prior single-arm trial. OBJECTIVES: To evaluate the efficacy and safety of nab-paclitaxel vs paclitaxel in platinum-refractory mUC. DESIGN, SETTING, AND PARTICIPANTS: In this investigator-initiated, open-label, phase 2 randomized clinical trial conducted across Canada and Australia from January 2014 to April 2017, eligible patients had histologically confirmed, radiologically evident mUC of the urinary tract. Mixed histologic findings, except small cell, were permitted provided UC was the predominant histologic finding. All patients had received platinum-based chemotherapy either in the metastatic setting or were within 12 months of perioperative chemotherapy. Patients with prior taxane chemotherapy were not included. Patients had an Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0 to 2 and adequate organ function. INTERVENTIONS: Patients were randomized to nab-paclitaxel, 260 mg/m2, or paclitaxel, 175 mg/m2, every 3 weeks. MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival (PFS). RESULTS: Among 199 patients, median age was 67 (range, 24-88) years; 144 (72%) were men; 167 (84%) were ECOG PS 0-1; 59 (30%) had liver metastases; and 110 (55%) were within 6 months of prior platinum-based chemotherapy. At a median follow-up of 16.4 months, there was no significant difference between nab-paclitaxel vs paclitaxel for median PFS (3.4 months vs 3.0 months; hazard ratio [HR], 0.92; 90% CI, 0.68-1.23; 1-sided P = .31). Median overall survival was 7.5 months for nab-paclitaxel vs 8.8 months for paclitaxel (HR, 0.95; 90% CI, 0.70-1.30; 1-sided P = .40); and objective response rate (ORR) was 22% for nab-paclitaxel vs 25% for paclitaxel (P = .97). Grade 3/4 adverse events were more frequent with nab-paclitaxel (64/97 [66%]) compared with paclitaxel (45/97 [46%]), P = .009; but peripheral sensory neuropathy was similar (all grades, 72/97 [74%] vs 64/97 [66%]; grade 3/4, 7/97 [7%] vs 3/97 [3%]; P = .27). There were no apparent differences in scores for health-related quality of life. CONCLUSIONS AND RELEVANCE: In this open-label, phase 2 randomized clinical trial of patients with platinum-refractory mUC, nab-paclitaxel had similar efficacy to paclitaxel; but worse toxic effects. The ORR with either taxane, however, was higher than previously reported and similar to those reported for the immune checkpoint inhibitors, suggesting that the taxanes remain a reasonable option in this setting. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02033993.

Eligibility Criteria and Endpoints in Metastatic Renal Cell Carcinoma Trials.

OBJECTIVES: Treatments for metastatic renal cell carcinoma (mRCC) are often compared across trials, but trial eligibility criteria and endpoints differ. In an effort to better align trials, the Definition for the Assessment of Time to event Endpoints in CANcer trials (DATECAN) project published recommendations in 2015 to be used in mRCC clinical trial design. We analyzed mRCC trial criteria to determine if DATECAN's recommendations were followed. MATERIALS AND METHODS: We compared eligibility criteria across 29 phase 3 mRCC trials conducted between 2003 and 2019. We then evaluated endpoints used in 10 phase 3 trials activated between 2015 and 2019 to determine their compliance with DATECAN's recommendations. RESULTS: Among the 29 trials, performance status, renal function, and disease characteristics differed in terms of requirements and measures used. In terms of endpoints, the 10 trials did not entirely follow DATECAN's recommendations. In total, 7/10 trials' primary endpoint was progression-free survival (PFS) as recommended; 4/9 trials used PFS as an endpoint but did not publish their definition of PFS, and the 5 that did, included "death from any cause" instead of DATECAN's recommendation of "death from kidney cancer." CONCLUSIONS: Key eligibility criteria were somewhat inconsistent across the phase 3 mRCC trials studied. Endpoints in the newer trials did not align with DATECAN's recommendations. Not only is greater standardization needed to facilitate meta-analyses and cross-trial comparisons, but as evident from lack of adherence to DATECAN's recommendations, greater promotion and adoption of recommendations are needed to better harmonize trial design.

Optimizing management of advanced urothelial carcinoma: A review of emerging therapies and biomarker-driven patient selection.

INTRODUCTION: Advanced urothelial carcinoma has been challenging to treat due to limited treatment options, poor response rates, and poor long-term survival. New treatment options hold the promise of improved outcomes for these patients. METHODS: A multidisciplinary working group drafted a management algorithm for advanced urothelial carcinoma using "consensus development conference" methodology. A targeted literature search identified new and emerging treatments for inclusion in the management algorithm. Published clinical data were considered during the algorithm development process, as well as the risks and benefits of the treatment options. Biomarkers to guide patient selection in clinical trials for new treatments were incorporated into the algorithm. RESULTS: The advanced urothelial carcinoma management algorithm includes newly approved first-line anti-programmed death receptor-1 (PD1)/ programmed death-ligand 1 (PD-L1) therapies, a newly approved anti-fibroblast growth factor receptors (FGFR) therapy, and an emerging anti-Nectin 4 therapy, which have had encouraging results in phase 2 trials for second-line and third-line therapy, respectively. This algorithm also incorporates suggestions for biomarker testing of PD-L1 expression and FGFR gene alterations. CONCLUSIONS: Newly approved and emerging therapies are starting to cover an unmet need for more treatment options, better response rates, and improved overall survival in advanced urothelial carcinoma. The management algorithm provides guidance on how to incorporate these new options, and their associated biomarkers, into clinical practice.

Cost-effectiveness analysis of metformin with enzalutamide in the metastatic castrate-resistant prostate cancer setting.

INTRODUCTION: Enzalutamide (Enza) is an effective treatment for metastatic castrate-resistant prostate cancer (mCPRC). However, Enza is not cost-effective (CE) at willingness to pay (WTP) thresholds from $0-$125 000/quality adjusted life years (QALYs) and is therefore a strain on valuable health care dollars. Metformin (Met) is inexpensive (~$8.00/month) and is thought to improve prostate cancer specific and overall survival compared to those not taking Met. We hypothesized that there must be an added effect Met could provide that would make Enza CE thereby alleviating this financial strain on government health care budgets. MATERIALS AND METHODS: We constructed a Markov model and performed a threshold analysis to narrow in on the added effect needed to make such a combination therapy cost-effective at various WTP thresholds. RESULTS: At a WTP threshold of $50 000/QALY Enza + Met is unlikely to be CE unless it increases Enza's efficacy by more than 30%. At a WTP threshold of $100 000, Enza + Met could be CE barring Met adds 18.73% to the efficacy of Enza. CONCLUSIONS: Enza + Met is unlikely to be CE at WTP thresholds less than $100 000/QALY; these results make sense because a therapy that is not CE at these WTP thresholds by itself is unlikely to be CE with an adjuvant therapy that keep a patient on such a treatment for even longer. Finally, our model suggests that the mCRPC setting is not the optimal place to trial adding Met as the relative costs are high and utility values low.

Cytoreductive Nephrectomy in Metastatic Papillary Renal Cell Carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium.

BACKGROUND: There is evidence that cytoreductive nephrectomy (CN) may be beneficial in metastatic renal cell carcinoma (mRCC). This has been studied predominantly in clear-cell RCC, with more limited data on the role of CN in patients with papillary histology. OBJECTIVE: To determine the benefit of CN in synchronous metastatic papillary RCC. DESIGN, SETTING, AND PARTICIPANTS: Using the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) database, a retrospective analysis was performed for patients with papillary mRCC treated with or without CN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Median overall survival (OS) and progression-free survival (PFS) were determined for both patient groups. Cox regression analysis was performed to control for imbalances in individual IMDC risk factors. RESULTS AND LIMITATIONS: In total, 647 patients with papillary mRCC were identified, of whom 353 had synchronous metastatic disease. Of these, 109 patients were treated with CN and 244 were not. The median follow-up was 57.1mo (95% confidence interval [CI] 32.9-77.8) and the OS from the start of first-line targeted therapy for the entire cohort was 13.2mo (95% CI 12.0-16.1). Median OS for patients with CN was 16.3mo, compared to 8.6mo (p<0.0001) in the no-CN group. When adjusted for individual IMDC risk factors, the hazard ratio (HR) of death for CN was 0.62 (95% CI 0.45-0.85; p=0.0031). Limitations include the retrospective nature of the analysis. CONCLUSIONS: The use of CN in patients with mRCC and papillary histology appears to be associated with better survival compared to no CN after adjustment for risk criteria. Selection of appropriate candidates for CN is crucial. A clinical trial in this rare population may not be possible. PATIENT SUMMARY: In a population of patients with advanced papillary kidney cancer, we found that surgical removal of the primary kidney tumor was associated with better overall survival.

Enzalutamide with Standard First-Line Therapy in Metastatic Prostate Cancer.

BACKGROUND: Enzalutamide, an androgen-receptor inhibitor, has been associated with improved overall survival in men with castration-resistant prostate cancer. It is not known whether adding enzalutamide to testosterone suppression, with or without early docetaxel, will improve survival in men with metastatic, hormone-sensitive prostate cancer. METHODS: In this open-label, randomized, phase 3 trial, we assigned patients to receive testosterone suppression plus either open-label enzalutamide or a standard nonsteroidal antiandrogen therapy (standard-care group). The primary end point was overall survival. Secondary end points included progression-free survival as determined by the prostate-specific antigen (PSA) level, clinical progression-free survival, and adverse events. RESULTS: A total of 1125 men underwent randomization; the median follow-up was 34 months. There were 102 deaths in the enzalutamide group and 143 deaths in the standard-care group (hazard ratio, 0.67; 95% confidence interval [CI], 0.52 to 0.86; P = 0.002). Kaplan-Meier estimates of overall survival at 3 years were 80% (based on 94 events) in the enzalutamide group and 72% (based on 130 events) in the standard-care group. Better results with enzalutamide were also seen in PSA progression-free survival (174 and 333 events, respectively; hazard ratio, 0.39; P<0.001) and in clinical progression-free survival (167 and 320 events, respectively; hazard ratio, 0.40; P<0.001). Treatment discontinuation due to adverse events was more frequent in the enzalutamide group than in the standard-care group (33 events and 14 events, respectively). Fatigue was more common in the enzalutamide group; seizures occurred in 7 patients in the enzalutamide group (1%) and in no patients in the standard-care group. CONCLUSIONS: Enzalutamide was associated with significantly longer progression-free and overall survival than standard care in men with metastatic, hormone-sensitive prostate cancer receiving testosterone suppression. The enzalutamide group had a higher incidence of seizures and other toxic effects, especially among those treated with early docetaxel. (Funded by Astellas Scientific and Medical Affairs and others; ENZAMET (ANZUP 1304) ANZCTR number, ACTRN12614000110684; ClinicalTrials.gov number, NCT02446405; and EU Clinical Trials Register number, 2014-003190-42.).