Chemotherapy-naive Men Research Articles

Can RECIST response predict success in phase 3 trials in men with metastatic castration-resistant prostate cancer?

Intermediate endpoints are needed in early phase studies of men with metastatic castration-resistant prostate cancer (mCRPC) that can reliably predict success in phase 3 trials. Among men with measurable disease, objective response may provide information as to whether a treatment is likely to be successful. We conducted a systematic review of systemic agents that have proceeded to phase 3 trials in men with mCRPC and examined the relationship between improvements in measurable disease response in phase 2 trials and successful phase 3 trials leading to regulatory approval. Only trials that included men with radiographically measurable disease were included. We examined 31 eligible mCRPC phase 3 trials between 1992 and 2017 and 29 of the preceding phase 2 trials for RECIST responses. Measurable tumor responses in phase 2 trials were higher for successful therapies in phase 3 trials in chemotherapy-naive men with mCRPC, but were less correlated with success in trials investigating docetaxel combination regimens or the post chemotherapy mCRPC setting. Many failed agents did not produce higher than expected response rates over control arms; however, several agents such as anti-angiogenic therapies or orteronel produced higher than expected responses without survival benefit. Objective responses in men with mCRPC may be associated with prolonged survival, but this association is mechanism dependent and inconsistent across trials or disease states. These data support considering RECIST response as a supportive but not sole endpoint in phase 2 trials to support launching phase 3 trials.

Radiographic Progression-Free Survival as a Clinically Meaningful End Point in Metastatic Castration-Resistant Prostate Cancer

Drug development for metastatic castration-resistant prostate cancer has been limited by a lack of clinically relevant trial end points short of overall survival (OS). Radiographic progression-free survival (rPFS) as defined by the Prostate Cancer Clinical Trials Working Group 2 (PCWG2) is a candidate end point that represents a clinically meaningful benefit to patients. To demonstrate the robustness of the PCWG2 definition and to examine the relationship between rPFS and OS. PREVAIL was a phase 3, randomized, double-blind, placebo-controlled multinational study that enrolled 1717 chemotherapy-naive men with metastatic castration-resistant prostate cancer from September 2010 through September 2012. The data were analyzed in November 2016. Patients were randomized 1:1 to enzalutamide 160 mg or placebo until confirmed radiographic disease progression or a skeletal-related event and initiation of either cytotoxic chemotherapy or an investigational agent for prostate cancer treatment. Sensitivity analyses (SAs) of investigator-assessed rPFS were performed using the final rPFS data cutoff (May 6, 2012; 439 events; SA1) and the interim OS data cutoff (September 16, 2013; 540 events; SA2). Additional SAs using investigator-assessed rPFS from the final rPFS data cutoff assessed the impact of skeletal-related events (SA3), clinical progression (SA4), a confirmatory scan for soft-tissue disease progression (SA5), and all deaths regardless of time after study drug discontinuation (SA6). Correlations between investigator-assessed rPFS (SA2) and OS were calculated using Spearman ρ and Kendall τ via Clayton copula. In the 1717 men (mean age, 72.0 [range, 43.0-93.0] years in enzalutamide arm and 71.0 [range, 42.0-93.0] years in placebo arm), enzalutamide significantly reduced risk of radiographic progression or death in all SAs, with hazard ratios of 0.22 (SA1; 95% CI, 0.18-0.27), 0.31 (SA2; 95% CI, 0.27-0.35), 0.21 (SA3; 95% CI, 0.18-0.26), 0.21 (SA4; 95% CI, 0.17-0.26), 0.23 (SA5; 95% CI, 0.19-0.30), and 0.23 (SA6; 95% CI, 0.19-0.30) (P < .001 for all). Correlations of rPFS and OS in enzalutamide-treated patients were 0.89 (95% CI, 0.86-0.92) by Spearman ρ and 0.72 (95% CI, 0.68-0.77) by Kendall τ. Sensitivity analyses in PREVAIL demonstrated the robustness of the PCWG2 rPFS definition using additional measures of progression. There was concordance between central and investigator review and a positive correlation between rPFS and OS among enzalutamide-treated patients. clinicaltrials.gov Identifier: NCT01212991.

Development and validation of a prognostic model for overall survival in chemotherapy-naive men with metastatic castration-resistant prostate cancer (mCRPC) from the phase 3 prevail clinical trial.

5022 Background: Prognostic models require updating to reflect contemporary medical practice. In a post hoc analysis of the phase 3 PREVAIL trial (enzalutamide vs placebo), we identified prognostic factors for overall survival (OS) in chemotherapy-naive men with mCRPC. Methods: Patients were randomly divided 2:1 into training (n = 1159) and testing (n = 550) sets. Using the training set, 23 predefined candidate prognostic factors (including treatment) were analyzed in a multivariable Cox model with stepwise procedures and in a penalized Cox proportional hazards model using the adaptive least absolute shrinkage and selection operator (LASSO) penalty (data cutoff June 1, 2014). A multivariable model predicting OS was developed using the training set; the predictive accuracy was assessed in the testing set using time-dependent area under the curve (tAUC). The testing set was stratified based on risk score tertiles (low, intermediate, high), and OS was analyzed using Kaplan-Meier methodology. Results: Demographics, disease characteristics, and OS were balanced between the training and testing sets; median OS was 32.7 months for both datasets. There were no enzalutamide treatment-prognostic factor interactions (predictors). The final multivariable model included 11 prognostic factors: prostate-specific antigen, treatment, hemoglobin, neutrophil-lymphocyte ratio, liver metastases, time from diagnosis to randomization, lactate dehydrogenase, ≥ 10 bone metastases, pain, albumin, and alkaline phosphatase. The tAUC was 0.74 in the testing set. Median (95% confidence interval [CI]) OS for the low-, intermediate-, and high-risk groups (testing set) were not yet reached (NYR) (NYR–NYR), 34.2 months (31.5–NYR), and 21.1 months (17.5–25.0). The hazard ratios (95% CI) for OS in the low- and intermediate-risk groups vs the high-risk group were 0.20 (0.14–0.29) and 0.40 (0.30–0.53), respectively. Conclusions: Our validated prognostic model incorporates factors routinely collected in chemotherapy-naive men with mCRPC treated with enzalutamide and identifies subsets of men with widely differing survival times. Clinical trial information: NCT01212991.

Efficacy and safety of enzalutamide in patients 75 years or older with chemotherapy-naive metastatic castration-resistant prostate cancer: results from PREVAIL

Prostate cancer disproportionately affects older men. Because age affects treatment decisions, it is important to understand the efficacy and tolerability of therapies for advanced prostate cancer in elderly men. This analysis describes efficacy and safety outcomes in men aged ≥75 years who received enzalutamide, an androgen receptor inhibitor, in the phase III PREVAIL trial. PREVAIL was a randomised, double-blind, multinational study of oral enzalutamide 160 mg/day (N = 872) versus placebo (N = 845) in chemotherapy-naive men with metastatic castration-resistant prostate cancer. Overall survival (OS) and radiographic progression-free survival (rPFS) were coprimary end points. Subgroup analysis of men aged ≥75 years (elderly) and men aged <75 years was pre-specified for the coprimary end points and adverse events (AEs). Among 609 elderly patients (35%) who participated in PREVAIL, median treatment duration was 16.6 and 5.0 months in the enzalutamide and placebo arms, respectively. In the elderly subgroup, OS was greater with enzalutamide than with placebo [32.4 months (95% confidence interval (CI) 27.7-not yet reached] versus 25.1 months (95% CI 22.6-28.0); hazard ratio (HR) = 0.61 (95% CI 0.47-0.79); P = 0.0001], as was rPFS [not yet reached (95% CI 12.3-not yet reached) versus 3.7 months (95% CI 3.6-5.3); HR = 0.17 (95% CI 0.12-0.24); P < 0.0001]. Irrespective of treatment assignment, incidence of AEs was similar between the two age groups, except for an overall higher incidence of falls among elderly patients than younger patients [84/609 (13.8%) versus 62/1106 (5.6%)] and among elderly patients receiving enzalutamide than those receiving placebo [61/317 (19.2%) versus 23/292 (7.9%)]. Elderly men benefited from treatment with enzalutamide in terms of OS and rPFS. Enzalutamide was well tolerated in the elderly subgroup and those aged <75 years. Age and enzalutamide treatment were associated with a higher incidence of falls. NCT01212991, ClinicalTrials.gov.

15 years of The Lancet Oncology

The 15th year of The Lancet Oncology provides an excellent juncture at which to review progress made in the lifespan of the journal. Advances in cancer care can be illustrated by highlighting articles published during three distinct eras: at the journal's launch in 2000, during the first year it accepted original research papers in 2005, and the current issues from 2015. The Lancet Oncology's preview issue discussed the importance of biochemical relapse of prostate cancer, defined on the basis of a rising prostate-specific antigen in the absence of symptoms or confirmatory diagnostic studies. 1 Tannock I Eradication of a disease: how we cured asymptomatic prostate cancer. Lancet Oncol. 2000; 1: 17-19 Summary Full Text Full Text PDF PubMed Google Scholar At a time of few treatment options, a concern was raised that biomarker-based relapse merely provided a lead-time bias, resulting in increased patient anxiety without an opportunity for intervention. Fast forward to 2015, and the journal published results of a study in the asymptomatic castrate-resistant metastatic prostate setting showing an overall survival benefit and additive quality-of-life outcome compared with placebo for the androgen antagonists abiraterone and enzalutamide, respectively. 2 Ryan CJ Smith MR Fizazi K et al. 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. Lancet Oncol. 2015; 16: 152-160 Summary Full Text Full Text PDF PubMed Scopus (955) Google Scholar , 3 Loriot Y Miller K Sternberg CN et al. Effect of enzalutamide on health-related quality of life, pain, and skeletal-related events in asymptomatic and minimally symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer (PREVAIL): results from a randomised, phase 3 trial. Lancet Oncol. 2015; 16: 509-521 Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar Diagnostic advances typically precede effective therapies, leading to the conundrum of how to address minimal residual disease. This gap persists today with ever more sensitive diagnostic procedures. One contemporary example is liquid biopsy using circulating tumour DNA to monitor genomic changes in response to therapy. 4 Tabernero J Lenz H-J Siena S et al. Analysis of circulating DNA and protein biomarkers to predict the clinical activity of regorafenib and assess prognosis in patients with metastatic colorectal cancer: a retrospective, exploratory analysis of the CORRECT trial. Lancet Oncol. 2015; 16: 937-948 Summary Full Text Full Text PDF PubMed Scopus (246) Google Scholar Whether acting on mutational variants detected in blood improves clinical outcomes remains to be determined.

Pharmacokinetics, Antitumor Activity, and Safety of ODM-201 in Patients with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer: An Open-label Phase 1 Study

BackgroundODM-201 is a novel second-generation androgen receptor inhibitor for the treatment of metastatic castration-resistant prostate cancer (mCRPC). ObjectiveTo evaluate the pharmacokinetics of ODM-201 tablet products and preliminary long-term safety, tolerability, and antitumor activity of ODM-201 in chemotherapy-naive men with mCRPC. Design, setting, and participantsThirty patients were enrolled in this open-label phase 1 trial. Patients received a single 600-mg dose of ODM-201 in capsules with food and one 600-mg dose of ODM-201 tablet product (TabA or TabB) with food and in the fasted state in a random order. In the extension, patients received 600mg twice daily ODM-201 taken with food in capsules. Outcome measurements and statistical analysisWe analyzed the pharmacokinetics of ODM-201 tablet formulations. Safety and tolerability were assessed until disease progression or an intolerable adverse event (AE). Antitumor activity was assessed by prostate-specific antigen (PSA) levels and imaging. Results and limitationsThe capsule:TabA ratio of area under the concentration-time curve from time zero to the last sample at 48h was 1.06 (90% confidence interval [CI], 0.91–1.24); the capsule:TabB ratio was 0.97 (90% CI, 0.82–1.14). At week 12, 25 of 30 patients (83%) had a PSA response (≥50% reduction from baseline). Median time to radiographic progression was 66 wk (95% CI, 41–79). Most common AEs were fatigue (n=4 [13%]) and nausea (n=4 [13%]). ConclusionsThe study showed that the tablet formulation of ODM-201 had similar pharmacokinetics compared with the capsule. Treatment with a 600-mg twice daily dose of ODM-201 provided anticancer activity and was well tolerated in men with chemotherapy-naive mCRPC. Patient summaryThe findings of this study showed that ODM-201 is well tolerated and provided antitumor activity in chemotherapy-naive patients with metastatic castration-resistant prostate cancer (mCRPC) and that the 300-mg tablet formulation can be used in further clinical studies. A phase 3 trial with ODM-201 600mg twice daily in patients with non-mCRPC is ongoing.

Effect of enzalutamide on health-related quality of life, pain, and skeletal-related events in asymptomatic and minimally symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer (PREVAIL): results from a randomised, phase 3 trial

Enzalutamide significantly increased overall survival and radiographic progression-free survival compared with placebo in the PREVAIL trial of asymptomatic and minimally symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer. We report the effect of enzalutamide on health-related quality of life (HRQoL), pain, and skeletal-related events observed during this trial. In this phase 3, double-blind trial, patients were randomly assigned (1:1) to receive enzalutamide 160 mg/day (n=872) or placebo (n=845) orally. HRQoL was assessed at baseline and during treatment using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and EQ-5D questionnaires. Pain status was assessed at screening, baseline, week 13, and week 25 with the Brief Pain Inventory Short Form (BPI-SF). The primary analysis of HRQoL data used a mixed-effects model to test the difference between least square means change from baseline at week 61. We assessed change from baseline, percentage improvement, and time to deterioration in HRQoL and pain, the proportion of patients with a skeletal-related event, and time to first skeletal-related event. Analysis was done on the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01212991. Median treatment duration was 16·6 months (IQR 10·1-21·1) in the enzalutamide group and 4·6 months (2·8-9·7) in the placebo group. The mixed-effects model analyses showed significant treatment differences in change from baseline to week 61 with enzalutamide compared with placebo for most FACT-P endpoints and EQ-5D visual analogue scale. Median time to deterioration in FACT-P total score was 11·3 months (95% CI 11·1-13·9) in the enzalutamide group and 5·6 months (5·5-5·6) in the placebo groups (hazard ratio [HR] 0·62 [95% CI 0·54-0·72]; p<0·0001). A significantly greater proportion of patients in the enzalutamide group than in the placebo group reported clinically meaningful improvements in FACT-P total score (327 [40%] of 826 vs 181 [23%] of 790), in EQ-5D utility index (224 [28%] of 812 vs 99 [16%] of 623), and visual analogue scale (218 [27%] of 803 vs 106 of [18%] 603; all p<0·0001). Median time to progression in BPI-SF pain at its worst was 5·7 months (95% CI 5·6-5·7) in the enzalutamide group and 5·6 months (5·4-5·6) in the placebo group (HR 0·62 [95% CI 0·53-0·74]; p<0·0001). Progression of pain at its worst was less common in the enzalutamide group than in the placebo group at week 13 (220 [29%] of 769 vs 257 [42%] of 610; p<0·0001), but not at week 25 (225 [32%] of 705 vs 135 [38%] of 360; p=0·068). 278 (32%) of 872 patients in the enzalutamide group and 309 (37%) of 845 patients in the placebo group had experienced a skeletal-related event by data cutoff. Median time to first skeletal-related events in the enzalutamide group was 31·1 months (95% CI 29·5-not reached) and 31·3 months (95% CI 23·9-not reached) in the placebo group (HR 0·72 [95% CI 0·61-0·84]; p<0·0001). In addition to improving overall survival relative to placebo, enzalutamide significantly improves patient-related outcomes and delays occurrence of first skeletal-related event in chemotherapy-naive men with metastatic castration-resistant prostate cancer. Astellas Pharma and Medivation.

Docetaxel and prednisone with or without lenalidomide in chemotherapy-naive patients with metastatic castration-resistant prostate cancer (MAINSAIL): a randomised, double-blind, placebo-controlled phase 3 trial

Patients with metastatic castration-resistant prostate cancer have few treatment options. We investigated the safety and efficacy of lenalidomide, an immunomodulatory agent with anti-angiogenic properties, in combination with docetaxel and prednisone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer. In this randomised, double-blind, placebo-controlled, phase 3 study, we randomly assigned chemotherapy-naive patients with progressive metastatic castration-resistant prostate cancer in a 1:1 ratio to receive docetaxel (75 mg/m(2)) on day 1 and prednisone (5 mg twice daily) on days 1-21 and either lenalidomide (25 mg) or placebo once daily on days 1-14 of each 21 day treatment cycle. Permuted block randomisation was done with an interactive voice response system and stratified by Eastern Cooperative Oncology Group performance status, geographic region, and type of disease progression. Clinicians, patients, and investigators were masked to treatment allocation. The primary endpoint was overall survival. Efficacy analysis was by intention to treat. Patients who received at least one dose of study drug were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT00988208. 1059 patients were enrolled and randomly assigned between Nov 11, 2009, and Nov 23, 2011 (533 to the lenalidomide group and 526 to the control group), and 1046 patients received study treatment (525 in the lenalidomide group and 521 in the placebo group). At data cutoff (Jan 13, 2012) after a median follow-up of 8 months (IQR 5-12), 221 patients had died: 129 in the lenalidomide group and 92 in the placebo group. Median overall survival was 17·7 months (95% CI 14·8-18·8) in the lenalidomide group and not reached in the placebo group (hazard ratio [HR] 1·53, 95% CI 1·17-2·00, p=0·0017). The trial was subsequently closed early due to futility. The number of deaths that occurred during treatment or less than 28 days since the last dose were similar in both groups (18 [3%] of 525 patients in the lenalidomide group vs 13 [2%] of 521 patients). 109 (21%) patients in the lenalidomide group and 78 (15%) in the placebo group died more than 28 days from last dose, mainly due to disease progression. At least one grade 3 or higher adverse event was reported in 381 (73%) of 525 patients receiving lenalidomide and 303 (58%) of 521 patients receiving placebo. Grade 3-4 neutropenia (114 [22%] for lenalidomide vs 85 [16%] for placebo), febrile neutropenia (62 [12%] vs 23 [4%]), diarrhoea (37 [7%] vs 12 [2%]), pneumonia (24 [5%] vs five [1%]), dyspnoea (22 [4%] vs nine [2%]), asthenia (27 [5%] vs 17 [3%]), and pulmonary embolism (32 [6%] vs seven [1%]) occurred more frequently in the lenalidomide group than in the placebo group. Overall survival with the combination of lenalidomide, docetaxel, and prednisone was significantly worse than with docetaxel and prednisone for chemotherapy-naive men with metastatic, castration-resistant prostate cancer. Further research with this treatment combination is not warranted. Celgene Corporation.

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

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. 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. 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%]). 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. Janssen Research & Development.

767P - Response Rates and Outcomes with Enzalutamide for Patients with Metastatic Castration Resistant Prostate Cancer and Visceral Disease in the Prevail Trial

ABSTRACT Aim: In the PREVAIL trial, enzalutamide, an androgen receptor signaling inhibitor, significantly improved overall survival (OS) (HR, 071; p Methods: PREVAIL was a Phase 3 multinational, double-blind study in chemotherapy-naive men with asymptomatic or mildly symptomatic mCRPC. Co-primary endpoints were OS and rPFS. Best soft tissue objective response, a secondary endpoint, was defined as partial or complete response (PR or CR) per RECIST 1.1 criteria in patients with measurable disease at baseline. Results: A total of 1717 men were randomized (1715 treated) including 1513 (88.1%) without and 204 (11.9%) with visceral disease at screening (139 lung, 74 liver and 9 both). Patients with visceral disease had higher baseline median PSA than those without visceral disease (72.5 ng/mL and 46.8 ng/mL, respectively), worse performance status (38.2% and 31.1% ECOG PS = 1), and higher rates of lymph node disease (57.8% and 49.8%), but similar rates of bone disease (80.4% and 83.7%). Adverse event rates were similar to the full study population. Conclusions: Visceral metastases were permitted in the PREVAIL trial of men with chemotherapy-naive mCRPC. Enzalutamide was active in this small group of patients; post-hoc analyses showed benefit vs placebo on OS, rPFS, and secondary endpoints. Response rates were higher for lung vs liver metastases. These results support androgen receptor signaling as an important target in prostate cancer with visceral metastases. Response Rates and Study Outcomes in PREVAIL Total Visceral Disease Cohort Lung and/or Liver (n = 204) Median (months) Enzalutamide/Placebo HR (95% CI) rPFS NYR/3.6 0.28 (0.16, 0.49) OS 27.8/22.8 0.82 (0.55, 1.23) Time to cytotoxic chemotherapy 22.6/6.6 0.30 (0.20, 0.45) Time to PSA progression (PCWG2 criteria) 11.1/2.9 0.16 (0.10, 0.26) Time to first skeletal-related event 29.5/NYR 0.69 (0.43, 1.11) Visceral Disease Cohort With Baseline Measurable Soft Tissue Disease * Liver Lung Enzalutamide (N= 31) Placebo (N= 28) Enzalutamide (N= 25) Placebo (N= 36) Best Objective Response (95% CI) 29.0% (14.2-48.0) 0.0 (0.0 - 12.3) 60.0% (38.7-78.9) 0.0% (0.0- 9.7) Complete Response 6.5% 0.0% 8.0% 0.0% Partial Response 22.6% 0.0% 52.0% 0.0% * Defined as at least one target lesion per RECIST 1.1. Disclosure: C. Higano: Consultant: Astellas/Medivation, Bayer, Dendreon, Johnson & Johnson Research Funding: Alegra, Aragon, Astellas/Medivation, Dendreon, Sanofi; S. Chowdhury: Advisory Board/Lectures: Astellas, Janssen Cilag, Sanofi-Aventis, Dendreon Speaker: GSK; Y. Loriot: Consultant/Advisory: Astellas Research Funding: Astellas Other: Sanofi, Cellgene, Bayer, Jansen; C.N. Sternberg: Honoraria: Astellas, Johnson & Johnson, Ipsen, Bayer, Millenium; J.S. de Bono: Astellas/Medivation; B. Tombal: Advisor: Medivation, Astellas, Ferring Speaker: Astellas, Ferring; F.G. Perabo: Employee: Astellas Pharma; D. Forer, S. Noonberg and H. Mansbach: Employee: Medivation; T. Beer: Research Funding: Astellas/Medivation, Janssen Consultant: Janssen. All other authors have declared no conflicts of interest.

Enzalutamide in men with chemotherapy-naive metastatic prostate cancer (mCRPC): Results of phase III PREVAIL study.

LBA1^ Background: Enzalutamide, an orally administered androgen receptor inhibitor, improved overall survival (OS) in men with mCRPC who had received prior docetaxel therapy (Scher et al, NEJM 367:13, 2012). This study examined whether enzalutamide could prolong OS and radiographic progression-free survival (rPFS) in asymptomatic or mildly symptomatic chemotherapy-naive men with mCRPC. Methods: In this randomized, double-blind, placebo-controlled, multinational phase 3 study (NCT01212991), chemotherapy-naive patients with mCRPC were stratified by site and randomized 1:1 to enzalutamide 160 mg/day or placebo. OS and rPFS were co-primary endpoints and analyzed for the intent-to-treat population. Planned sample size was 1,680 with 765 deaths to achieve 80% power to detect a target OS hazard ratio (HR) of 0.815 with a type I error rate of 0.049 and a single interim analysis at 516 (67%) deaths. The co-primary endpoint of rPFS had sufficient power to detect a target HR of 0.57 and a type I error rate of 0.001 with a minimum of 410 events. Results: A total of 1,717 men were randomized (1,715 treated) between September 2010 and September 2012. The interim analysis at 539 deaths showed a statistically significant benefit of enzalutamide over placebo with a 30% reduction in risk of death (OS: HR 0.70; 95% CI: 0.59-0.83; P&lt; 0.0001) and an 81% reduction in risk of radiographic progression or death (rPFS: HR 0.19; 95% CI: 0.15-0.23; P&lt; 0.0001). At the time of the analysis, 28% of enzalutamide patients and 35% of placebo patients had died. Estimated median OS was 32.4 months (mo) (95% CI, 31.5–upper limit not yet reached [NYR]) in the enzalutamide arm vs 30.2 mo (95% CI, 28–upper limit NYR) in the placebo arm. Median rPFS was NYR (95% CI: 13.8–upper limit NYR) in the enzalutamide arm vs 3.9 mo (95% CI: 3.7-5.4) in the placebo arm. Seizure events were reported in two patients. The Independent Data Monitoring Committee considered the benefit-risk ratio to favor enzalutamide and recommended stopping the study and crossing placebo patients to enzalutamide. Secondary endpoints and safety analysis will be presented. Conclusions: Treatment with enzalutamide significantly improves OS and rPFS in men with chemotherapy-naive mCRPC. Clinical trial information: NCT01212991.

Docetaxel and dasatinib or placebo in men with metastatic castration-resistant prostate cancer (READY): a randomised, double-blind phase 3 trial

Src kinase-mediated interactions between prostate cancer cells and osteoclasts might promote bone metastasis. Dasatinib inhibits tyrosine kinases, including Src kinases. Data suggests that dasatinib kinase inhibition leads to antitumour activity, affects osteoclasts, and has synergy with docetaxel, a first-line chemotherapy for metastatic castration-resistant prostate cancer. We assessed whether dasatinib plus docetaxel in chemotherapy-naive men with metastatic castration-resistant prostate cancer led to greater efficacy than with docetaxel alone. In this double-blind, randomised, placebo-controlled phase 3 study, we enrolled men of 18 years or older with chemotherapy-naive, metastatic, castration-resistant prostate cancer, and adequate organ function from 186 centres across 25 countries. Eligible patients were randomly assigned (1:1) via an interactive voice response system to receive docetaxel (75 mg/m(2) intravenously every 3 weeks, plus oral prednisone 5 mg twice daily), plus either dasatinib (100 mg orally once daily) or placebo until disease progression or unacceptable toxicity. Randomisation was stratified by Eastern Cooperative Oncology Group performance status (0-1 vs 2), bisphosphonate use (yes vs no), and urinary N-telopeptide (uNTx) value (<60 μmol/mol creatinine vs ≥60 μmol/mol creatinine). All patients, investigators, and personnel involved in study conduct and data analyses were blinded to treatment allocation. The primary endpoint was overall survival, analysed by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00744497. Between Oct 30, 2008, and April 11, 2011, 1522 eligible patients were randomly assigned to treatment; 762 patients were assigned to dasatinib and 760 to placebo. At final analysis, median follow-up was 19·0 months (IQR 11·2-25·1) and 914 patients had died. Median overall survival was 21·5 months (95% CI 20·3-22·8) in the dasatinib group and 21·2 months (20·0-23·4) in the placebo group (stratified hazard ratio [HR] 0·99, 95·5% CI 0·87-1·13; p=0·90). The most common grade 3-4 adverse events included diarrhoea (58 [8%] patients in the dasatinib group vs 27 [4%] patients in the placebo group), fatigue (62 [8%] vs 42 [6%]), and asthenia (40 [5%] vs 23 [3%]); grade 3-4 pleural effusions were uncommon (ten [1%] vs three [<1%]). The addition of dasatinib to docetaxel did not improve overall survival for chemotherapy-naive men with metastatic castration-resistant prostate cancer. This study does not support the combination of dasatinib and docetaxel in this population of patients. Bristol-Myers Squibb.

Abiraterone acetate plus prednisone versus prednisone alone in chemotherapy-naive men with metastatic castration-resistant prostate cancer: patient-reported outcome results of a randomised phase 3 trial

Abiraterone acetate plus prednisone significantly improves radiographic progression-free survival in asymptomatic or mildly symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer compared with prednisone alone. We describe analyses of data for patient-reported pain and functional status in a preplanned interim analysis of a phase 3 trial. Between April 28, 2009, and June 23, 2010, patients with progressive, metastatic castration-resistant prostate cancer were enrolled into a multinational, double-blind, placebo-controlled trial. Patients were eligible if they were asymptomatic (score of 0 or 1 on item three of the Brief Pain Inventory Short Form [BPI-SF] questionnaire) or mildly symptomatic (score of 2 or 3) and had not previously received chemotherapy. Patients were randomly assigned (1:1) to receive oral abiraterone (1 g daily) plus prednisone (5 mg twice daily) or placebo plus prednisone in continuous 4-week cycles. Pain was assessed with the BPI-SF questionnaire, and health-related quality of life (HRQoL) with the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire. We analysed data with prespecified criteria for clinically meaningful pain progression and deterioration in HRQoL. All patients who underwent randomisation were included in analyses. 1088 patients underwent randomisation: 546 were assigned to abiraterone plus prednisone and 542 to placebo plus prednisone. At the time of the second prespecified interim analysis, median follow-up was 22·2 months (IQR 20·2-24·8). Median time to progression of mean pain intensity was longer in patients assigned to abiraterone plus prednisone (26·7 months [95% CI 19·3-not estimable]) than in those assigned to placebo plus prednisone (18·4 months [14·9-not estimable]; hazard ratio [HR] 0·82, 95% CI 0·67-1·00; p=0·0490), as was median time to progression of pain interference with daily activities (10·3 months [95% CI 9·3-13·0] vs 7·4 months [6·4-8·6]; HR 0·79, 95% CI 0·67-0·93; p=0·005). Median time to progression of worst pain was also longer with abiraterone plus prednisone (26·7 months [95% CI 19·4-not estimable]) than with placebo plus prednisone (19·4 months [16·6-not estimable]), but the difference was not significant (HR 0·85, 95% CI 0·69-1·04; p=0·109). Median time to HRQoL deterioration was longer in patients assigned to abiraterone plus prednisone than in those assigned to placebo plus prednisone as assessed by the FACT-P total score (12·7 months [95% CI 11·1-14·0] vs 8·3 months [7·4-10·6]; HR 0·78, 95% CI 0·66-0·92; p=0·003) and by the score on its prostate-cancer-specific subscale (11·1 months [8·6-13·8] vs 5·8 months [5·5-8·3]; HR 0·70, 95% CI 0·60-0·83; p<0·0001). Abiraterone plus prednisone delays patient-reported pain progression and HRQoL deterioration in chemotherapy-naive patients with metastatic castration-resistant prostate cancer. These results provide further support for the efficacy of abiraterone in this population.

Once-daily Dasatinib: Expansion of Phase II Study Evaluating Safety and Efficacy of Dasatinib in Patients With Metastatic Castration-resistant Prostate Cancer

To determine the activity and tolerability of 100-mg once-daily (QD) dasatinib in patients with metastatic castration-resistance prostate cancer (CRPC). Dasatinib, an oral Src family kinase inhibitor, has demonstrated both preclinical and clinical activity with twice-daily dosing in patients with metastatic CRPC. Chemotherapy-naive men with metastatic CRPC and increasing prostate-specific antigen levels were treated with dasatinib 100 mg QD. The primary measurement was a composite lack of disease progression, according to the Prostate Cancer Working Group 2 criteria, determined every 12 weeks during the study. The other analyses included changes in the prostate-specific antigen level, bone lesions, soft tissue disease, and bone turnover markers (urine N-telopeptide and bone alkaline phosphatase). The present trial was designed before the publication of the recent Prostate Cancer Working Group 2 criteria; however, the analyses are presented to conform to the updated guidelines. A total of 48 patients received dasatinib. A lack of disease progression was observed in 21 patients (44%) at week 12 and in 8 (17%) at week 24. Urine N-telopeptide was reduced by ≥40% from baseline in 22 (51%) of 43 patients, and bone alkaline phosphatase was decreased in 26 (59%) of 44 patients. Dasatinib was well-tolerated, with only 6 patients (13%) with drug-related grade 3-4 adverse events and 3 (6%) with grade 3 adverse events. The most common treatment-related adverse events (≥20%) were fatigue, nausea, diarrhea, headache, and anorexia. Dasatinib 100 mg QD has a favorable safety profile and maintains a similar degree of activity as the previously reported twice-daily dosing schedules. These data support additional study of dasatinib 100 mg QD for metastatic CRPC.

Weekly Administration of Docetaxel and Epirubicin as First-Line Treatment for Hormone-Refractory Prostate Carcinoma

Androgen-independent prostate carcinoma (AICP) is one of the tumors that continue to respond poorly to chemotherapy. Recently, protocols based on the use of docetaxel have significantly improved survival for patients in this disease. In other types of neoplastic disease, combined therapy with taxanes and anthracycline derivatives has been shown to produce additive effects in terms of growth inhibition, and superior tolerability when associated with weekly administration schedules. These findings prompted us to examine the tolerability and efficacy of weekly treatment of AICP with docetaxel (DOX) plus epirubicin (EPI). We enrolled 35 chemotherapy-naive men with AICP (mean age 72 years, range 68-77) and normal hepatic, renal, and cardiac function. The chemotherapy protocol provided for the IV administration of DOX (30 mg/m2) and EPI (30 mg/m2) on days 1, 8, and 15 every 28 days. Treatment was continued for 6 months or until disease progression and/or unacceptable toxicity was observed. Serum levels of prostate-specific antigen (PSA) were monitored in all patients, and reductions from baseline values of >50% were considered indicative of positive responses to treatment. Thirty-four patients were included in the analysis of toxicity, and objective responses to treatment were assessed in the 28 patients with measurable lesions. Nineteen patients (56%) experienced PSA reductions of >50% that persisted for more than 4 weeks. The response to therapy was classified as complete in 1 of the 28 patients (4%) with measurable disease (at the lymph node level). Thirteen others (13/28, 46%) had partial responses, in nine (32%) the disease remained unchanged, and progression was observed in the remaining five (18%); overall response rate was 50% (CR + PR). Of the 27 patients with pain at the time of enrollment, 16 (59%) experienced pain reduction during treatment. The median time to disease progression was 11.7 months (95% CI: 7.7-15.7) while the median survival time was 18.7 months (95% CI: 12.3-25.1). During the study, four patients developed grade 3 anemia and leukopenia, which was reversible in all cases. Lower grades of asthenia, nausea, vomiting, diarrhea, and peripheral edema were also observed. There were no cases of cardiotoxic effects. Alopecia was frequent but reversible in all cases. The results of this preliminary study indicate that the combined administration of DOX and EPI for treatment of AIPC is effective and well tolerated. The weekly administration of the drug combination appears to be a promising approach to the treatment of these tumors.

Randomized, Double-Blinded Phase II Evaluation of Docetaxel with or without Doxercalciferol in Patients with Metastatic, Androgen-Independent Prostate Cancer

Docetaxel is standard of care for androgen-independent prostate cancer (AIPC). Doxercalciferol (1 alpha-hydroxyvitamin D2) had modest activity in phase I/II trials. Preclinical data support combining vitamin D analogues with docetaxel to treat AIPC. Chemotherapy-naive men with metastatic AIPC were randomized 1:1 to receive, on a 4-week cycle, docetaxel (35 mg/m2 i.v., days 1, 8, and 15) with or without doxercalciferol (10 microg orally, days 1-28). The primary end point was prostate-specific antigen (PSA) response. Secondary end points were progression-free survival, overall survival, objective response, and toxicity. Survival was analyzed as intent to treat. Seventy patients were randomized. Median follow-up was 17.6 months (range, 3.3-45.2). PSA response rate was 46.7% [95% confidence interval (95% CI), 30-64] in the doxercalciferol arm and 39.4% (95% CI, 25-56) with placebo (P = 0.560). Median progression-free survival in the doxercalciferol arm was 6.17 months (95% CI, 4.20-10.7) versus 6.20 months (95% CI, 4.83-9.07) with placebo (P = 0.764). Median overall survival in the doxercalciferol arm was 17.8 months (95% CI, 14.9-23.6) versus 16.4 months (95% CI, 11.9-23.8) with placebo (P = 0.383). Twenty-four patients in the doxercalciferol arm and 23 in the placebo arm were evaluable for objective response. No complete responses were observed. Partial objective response rate was 12.5% with doxercalciferol versus 8.7% with placebo (P = 0.672). Rate of grade > or =3 toxicity was 46% with doxercalciferol versus 42% with placebo (P = 0.785). Daily doxercalciferol with weekly docetaxel did not enhance PSA response rate or survival. Toxicity was similar between arms. Despite the disappointing results of this study, other vitamin D analogues remain under active investigation.

Open-Label Phase II Study Evaluating the Efficacy and Safety of Two Doses of Pertuzumab in Castrate Chemotherapy-Naive Patients With Hormone-Refractory Prostate Cancer

To determine the prostate-specific antigen (PSA) 50% decline rate within 24 weeks of starting treatment with single-agent pertuzumab in castrate patients with hormone-refractory prostate cancer (HRPC). Two independent Simon's two-stage designs were used to evaluate two doses of pertuzumab administered intravenously once every 3 weeks. An interim analysis of the first 23 assessable patients in the first cohort treated at 420 mg (loading dose of 840 mg) allowed termination of additional enrollment if three patients had a 50% decline in PSA after all patients had completed at least three cycles of therapy or withdrew due to insufficient therapeutic response, death, or study-related toxicity before completing three cycles. A second cohort of patients treated at 1,050 mg could be enrolled with the same design, and if more than three patients had a 50% decline in PSA, 27 more patients would be treated at 1,050 mg. Sixty-eight castrate, chemotherapy-naive men with HRPC were enrolled. A total of 35 patients were treated at 420 mg; no PSA declines 50% were observed at the interim analysis and recruitment was stopped. A total of 33 patients were then treated at 1,050 mg, and no PSA declines 50% were observed at the interim analysis. Pertuzumab was well tolerated. Pertuzumab has no clinically significant single-agent activity in castrate patients with HRPC at either of the tested dose levels. This may reflect the continued presence of significant levels of intraprostatic androgen driving androgen receptor signaling.

299 POSTER Randomized phase II trial of irofulven/prednisone, irofulven/capecitabine/prednisone, or mitoxantrone/prednisone in hormone refractory prostate cancer (HRPC) patients failing first-line docetaxel: preliminary results

The majority of patients with metastatic castration-resistant prostate cancer (mCRPC) will have disease progression of a uniformly fatal disease. mCRPC is driven by both activated androgen receptors and elevated intratumoural androgens; however, the current standard of care is therapy that targets a single androgen signalling mechanism. We aimed to investigate the combination treatment using apalutamide plus abiraterone acetate, each of which suppresses the androgen signalling axis in a different way, versus standard care in mCRPC.ACIS was a randomised, placebo-controlled, double-blind, phase 3 study done at 167 hospitals in 17 countries in the USA, Canada, Mexico, Europe, the Asia-Pacific region, Africa, and South America. We included chemotherapy-naive men (aged ≥18 years) with mCRPC who had not been previously treated with androgen biosynthesis signalling inhibitors and were receiving ongoing androgen deprivation therapy, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and a Brief Pain Inventory-Short Form question 3 (ie, worst pain in the past 24 h) score of 3 or lower. Patients were randomly assigned (1:1) via a centralised interactive web response system with a permuted block randomisation scheme (block size 4) to oral apalutamide 240 mg once daily plus oral abiraterone acetate 1000 mg once daily and oral prednisone 5 mg twice daily (apalutamide plus abiraterone–prednisone group) or placebo plus abiraterone acetate and prednisone (abiraterone–prednisone group), in 28-day treatment cycles. Randomisation was stratified by presence or absence of visceral metastases, ECOG performance status, and geographical region. Patients, the investigators, study team, and the sponsor were masked to group assignments. An independent data-monitoring committee continually monitored data to ensure ongoing patient safety, and reviewed efficacy data. The primary endpoint was radiographic progression-free survival assessed in the intention-to-treat population. Safety was reported for all patients who received at least one dose of study drug. This study is completed and no longer recruiting and is registered with ClinicalTrials.gov, number NCT02257736.982 men were enrolled and randomly assigned from Dec 10, 2014 to Aug 30, 2016 (492 to apalutamide plus abiraterone–prednisone; 490 to abiraterone–prednisone). At the primary analysis (median follow-up 25·7 months [IQR 23·0–28·9]), median radiographic progression-free survival was 22·6 months (95% CI 19·4–27·4) in the apalutamide plus abiraterone–prednisone group versus 16·6 months (13·9–19·3) in the abiraterone–prednisone group (hazard ratio [HR] 0·69, 95% CI 0·58–0·83; p<0·0001). At the updated analysis (final analysis for overall survival; median follow-up 54·8 months [IQR 51·5–58·4]), median radiographic progression-free survival was 24·0 months (95% CI 19·7–27·5) versus 16·6 months (13·9–19·3; HR 0·70, 95% CI 0·60–0·83; p<0·0001). The most common grade 3–4 treatment-emergent adverse event was hypertension (82 [17%] of 490 patients receiving apalutamide plus abiraterone–prednisone and 49 [10%] of 489 receiving abiraterone–prednisone). Serious treatment-emergent adverse events occurred in 195 (40%) patients receiving apalutamide plus abiraterone–prednisone and 181 (37%) patients receiving abiraterone–prednisone. Drug-related treatment-emergent adverse events with fatal outcomes occurred in three (1%) patients in the apalutamide plus abiraterone–prednisone group (2 pulmonary embolism, 1 cardiac failure) and five (1%) patients in the abiraterone–prednisone group (1 cardiac failure and 1 cardiac arrest, 1 mesenteric arterial occlusion, 1 seizure, and 1 sudden death).Despite the use of an active and established therapy as the comparator, apalutamide plus abiraterone–prednisone improved radiographic progression-free survival. Additional studies to identify subgroups of patients who might benefit the most from combination therapy are needed to further refine the treatment of mCRPC.Janssen Research & Development.