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.).

Changes to design and analysis elements of research plans during randomised controlled trials in Australia.

OBJECTIVES: To investigate the frequency and legitimacy of substantive changes to the research plans of published randomised controlled trials (RCTs) undertaken in Australia. DESIGN: Comparison of methodology and analysis plans for RCTs specified in protocol documents (full protocols, published protocol articles, statistical analysis plans, Australian New Zealand Clinical Trials Registry [ANZCTR] registration entries) and described in publications of primary results. SETTING, PARTICIPANTS: 181 RCTs registered with the ANZCTR, 1 September 2007 - 31 December 2013, for which primary results had been published. MAIN OUTCOME MEASURE: Changes made to research plan, both overall and by specific item (primary outcome, analysis set, eligibility criteria, sample size, primary analysis method, and treatment arms included in the primary comparison in multi-arm trials); trial characteristics associated with changes. RESULTS: Protocol documents were available for 124 of 181 eligible RCTs (69%; 46 publicly available, 78 provided by trial groups on request). Full audit of RCTs with protocols found clear or probable changes in 111 trials (90%), for 101 of which (91%) it was unclear whether changes had been made blinded to treatment outcomes. After seeking clarification from investigators, changes to 78 trials were confirmed (63%), for 61 of which (78%) changes were made blinded to treatment outcomes. Any change was less likely for trials with publicly available protocols than for trials for which we needed to request protocols (odds ratio, 0.22; 95% CI, 0.06-0.77). Limited reviews of trials without protocols identified that changes had been made to 42 of 57 trials (74%). CONCLUSION: Changes to RCT study plans in Australia are both frequent and usually made appropriately blinded to treatment outcomes. However, the documentation of changes made to RCT protocols should be formalised to improve transparency.

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.

Reacting to prognostic covariate imbalance in randomised controlled trials.

Clinical trialists may regard an observed imbalance on a prognostic covariate as sufficiently troubling to warrant action. OBJECTIVE: To elucidate the issues associated with selecting, and switching between, an unadjusted versus an adjusted analysis in response to an observed covariate imbalance. STUDY DESIGN AND SETTING: Simulation study performed under the null hypothesis of no treatment effect using data from a large secondary prevention trial of statin therapy. The operating characteristics of three reaction strategies to baseline imbalances observed post-hoc were assessed. RESULTS: Unadjusted analyses produced valid p-values irrespective of chance imbalance on a prognostic covariate. Switching to an adjusted analysis introduced no bias when the decision was made without knowledge of the direction of the imbalance. When the decision was based on the direction of the imbalance, the risk of incorrectly declaring the experimental treatment superior was inflated (by up to 48% in the scenarios investigated). CONCLUSION: Overreaction to baseline imbalances observed post-hoc is unwarranted and we support adherence to the ICH guideline recommendations on the use of covariates. A legitimate case for switching to an adjusted analysis prior to finalisation of the statistical analysis plan (SAP) could nevertheless be potentially made provided that the direction of an observed covariate imbalance is unknown. Investigators should avoid reviewing the distribution of baseline characteristics across randomised groups in an unblinded fashion, for open-label and blinded studies alike, prior to finalisation of the SAP. WHAT IS NEW: ICH guidelines on adjustment for covariates in RCT analyses appropriately advise against overreaction to baseline imbalances observed post-hoc. CONSORT reporting guidelines nevertheless place an emphasis on comparability of baseline characteristics across randomised groups. We demonstrate through a series of simulation studies why the ICH guidance is sound, but that a switch to an adjusted analysis in reaction to an observed prognostic covariate imbalance could legitimately be made provided that, when reaching the decision, treatment allocation is masked, and the direction of the imbalance is unknown. Trialists should therefore consider preserving the masking of actual treatment assignment when assessing the distribution of baseline characteristics across randomised groups.

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.

Changes to aspects of ongoing randomised controlled trials with fixed designs.

BACKGROUND: Despite careful planning, changes to some aspects of an ongoing randomised clinical trial (RCT), with a fixed design, may be warranted. We sought to elucidate the distinction between legitimate versus illegitimate changes to serve as a guide for less experienced clinical trialists and other stakeholders. METHODS: Using data from a large trial of statin therapy for secondary prevention, we generated a set of simulated trial datasets under the null hypothesis (H0) and a set under an alternative hypothesis (H1). Through analysis of these simulated trials, we assessed the performance of the strategy of changing aspects of the design/analysis with knowledge of treatment allocation (illegitimate) versus the strategy of making changes without knowledge of treatment allocation (legitimate). Performance was assessed using the type 1 error, as well as measures of absolute and relative bias in the treatment effect. RESULTS: Illegitimate changes led to a relative bias of 61% under H1, and a type 1 error rate under H0 of 23%-well in excess of the 5% significance level targeted. Legitimate changes produced unbiased estimates under H1 and did not inflate the type 1 error rate under H0. CONCLUSIONS: Changes to pre-specified aspects of the design and analysis of an ongoing RCT may be a necessary response to unforeseen circumstances. Such changes risk introducing a bias if undertaken with knowledge of treatment allocation. Legitimate changes need to be adequately documented to provide assurance to all stakeholders of their validity.

Comparing patients' and clinicians' assessment of outcomes in a randomised trial of sentinel node biopsy for breast cancer (the RACS SNAC trial).

The RACS sentinel node biopsy versus axillary clearance (SNAC) trial compared sentinel-node-based management (SNBM) and axillary lymph-node dissection (ALND) for breast cancer. In this sub study, we sought to determine whether patient ratings of arm swelling, symptoms, function and disability or clinicians' measurements were most efficient at detecting differences between randomized groups, and therefore, which of these outcome measures would minimise the required sample sizes in future clinical trials. 324 women randomised to SNBM and 319 randomised to ALND were included. The primary endpoint of the trial was percentage increase in arm volume calculated from clinicians' measurements of arm circumference at 10 cm intervals. Secondary endpoints included reductions in range of motion and sensation (both measured by clinicians); and, patients' ratings of arm swelling, symptoms and quality of life, using the European Organisation for Research and Treatment of Cancer Breast Cancer Module (EORTC QLM-BR23), the body image after breast cancer questionnaire (BIBC) and the SNAC study specific scales (SSSS). The relative efficiency (RE, the squared ratio of the test statistics, with 95% confidence intervals calculated by bootstrapping) was used to compare these measures in detecting differences between the treatment groups. Patients' self-ratings of arm swelling were generally more efficient than clinicians' measurements of arm volume in detecting differences between treatment groups. The SSSS arm symptoms scale was the most efficient (RE = 7.1) The entire SSSS was slightly less so (RE = 4.6). Patients' ratings on single items were 3-5 times more efficient than clinicians' measurements. Primary endpoints based on patient-rated outcome measures could reduce the required sample size in future surgical trials.

What Survival Benefits are Needed to Make Adjuvant Sorafenib Worthwhile After Resection of Intermediate- or High-Risk Renal Cell Carcinoma? Clinical Investigators' Preferences in the SORCE Trial.

BACKGROUND: Decisions about adjuvant therapy involve trade-offs between possible benefits and harms. OBJECTIVE: We sought to determine the survival benefits that clinical investigators would judge as sufficient to warrant treatment with adjuvant sorafenib in the SORCE trial after nephrectomy for apparently localised renal cell carcinoma (RCC). METHODS: A subset of clinical investigators in the SORCE trial completed a validated questionnaire that elicited the minimum survival benefits they judged sufficient to warrant one year of adjuvant sorafenib in scenarios with hypothetical baseline survival times of 5 years and 15 years, and baseline survival rates at 5 years of 65% and 85%. RESULTS: The 100 participating SORCE investigators had a median age of 42 years, and 74 were male. For one year of sorafenib versus no therapy, the median benefits in survival times the investigators judged sufficient to warrant treatment were an extra nine months beyond five years and an extra 12 months beyond 15 years; the median benefits in survival rates were an extra 5% beyond baseline survival rates of both 65% and 85% at five years. The patients recruited in the SORCE trial by these investigators judged smaller benefits sufficient to warrant adjuvant sorafenib for both survival rate scenarios (p≤0.0001). The survival benefits the investigators judged sufficient to warrant one year of adjuvant therapy with sorafenib for RCC were similar to those of other clinicians considering three months of adjuvant chemotherapy for lung cancer, but smaller than those of clinicians considering six months of adjuvant chemotherapy for breast cancer. CONCLUSION: SORCE investigators judged larger benefits necessary to warrant adjuvant sorafenib than their patients. The benefits required by the investigators were similar or smaller than those other clinicians considered sufficient to warrant adjuvant chemotherapy for other cancers. Clinicians should recognise that their patients and colleagues may have preferences that differ from their own when considering the potential benefits and harms of adjuvant treatment.