Single­Dose Pharmacokinetics and Safety of the Oral Galectin­3 Inhibitor, Selvigaltin (GB1211), in Participants with Hepatic Impairment.

BACKGROUND AND OBJECTIVES: Selvigaltin (GB1211), an orally available small molecule galectin-3 inhibitor developed as a treatment for liver fibrosis and cirrhosis, was evaluated to assess the effect of hepatic impairment on its pharmacokinetics and safety to address regulatory requirements. METHODS: GULLIVER-2 was a Phase Ib/IIa three-part study. Parts 1 and 3 had single-dose, open-label designs assessing pharmacokinetics (plasma [total and unbound] and urine), safety, and tolerability of 100 mg oral selvigaltin in participants with moderate (Child-Pugh B, Part 1) or severe (Child-Pugh C, Part 3) hepatic impairment, compared with healthy-matched participants (n = 6 each). RESULTS: All participants received selvigaltin and completed the study. No adverse events were reported. The median time to reach maximum total plasma concentration following drug administration was of 3.49 and 4.00 h post-dose for Child-Pugh B and C participants, respectively; comparable with controls. Total plasma exposure was higher for participants with hepatic impairment compared with controls. Whilst maximum plasma concentration (Cmax) was unaffected in Child-Pugh B participants, area under the plasma concentration-time curve from time zero to infinity (AUC∞) increased by ~ 1.7-fold compared with controls, and half-life was prolonged (geometric mean 28.15 vs 16.38 h). In Child-Pugh C participants, Cmax increased by ~ 1.3-fold, AUC∞ increased by ~ 1.5-fold, and half-life was prolonged (21.05 vs 16.14 h). No trend was observed in plasma unbound fractions or urinary excretion of unchanged selvigaltin in either group. CONCLUSION: Hepatic impairment increased selvigaltin exposure without safety concerns. These data can inform dose recommendations for future clinical programmes. TRIAL REGISTRATION: Clinicaltrials.gov NCT05009680.

Relative bioavailability and food effect of the galectin-3 inhibitor selvigaltin (GB1211) administered as a tablet in healthy participants (GALBA-1).

PURPOSE: Overexpression of galectin-3, a ß-galactoside-binding lectin, is associated with fibrotic diseases and cancer. Selvigaltin is an oral galectin-3 inhibitor, previously administered as a 50 mg capsule. This study aimed to evaluate the relative bioavailability and food effect of selvigaltin as a 100 mg tablet in healthy volunteers. METHODS: In this single-dose, randomized, three-period, crossover study (GALBA-1; NCT05747573), participants received selvigaltin as a 100 mg tablet (under fasted and fed conditions) or as two 50 mg capsules (under fasted conditions). Primary endpoints included plasma and urine pharmacokinetic (PK) parameters. Secondary endpoints were safety and tolerability. RESULTS: Of the 13 enrolled participants, 12 completed the study. Under fasted conditions, geometric mean maximum observed plasma concentration (Cmax) and systemic exposure (AUC0─inf) of selvigaltin were 161.0% and 84.0% higher, respectively, after administration of a tablet vs. capsules. Under fed vs. fasted conditions, geometric mean Cmax of the selvigaltin tablet was 20.0% lower, whereas AUC0─inf was unaffected. Geometric mean percentage of total dose of selvigaltin excreted in urine over 0─96 h was 30.3% and 35.9% for the tablet under fasted and fed conditions, respectively, and 14.5% for the capsules. No treatment-emergent severe or serious adverse events or study discontinuations due to a treatment-emergent adverse event were reported. CONCLUSION: The tablet formulation of selvigaltin displayed higher bioavailability vs. the capsule formulation, with minimal effect of food on PK. Selvigaltin was well-tolerated during all treatments. These findings warrant further clinical development of the tablet formulation of selvigaltin without specific food restrictions. CLINICAL TRIAL REGISTRATION: NCT05747573; February 28, 2023.

An Inhaled Galectin-3 Inhibitor in COVID-19 Pneumonitis: A Phase Ib/IIa Randomized Controlled Clinical Trial (DEFINE).

Rationale: High circulating galectin-3 is associated with poor outcomes in patients with coronavirus disease (COVID-19). We hypothesized that GB0139, a potent inhaled thiodigalactoside galectin-3 inhibitor with antiinflammatory and antifibrotic actions, would be safely and effectively delivered in COVID-19 pneumonitis. Objectives: Primary outcomes were safety and tolerability of inhaled GB0139 as an add-on therapy for patients hospitalized with COVID-19 pneumonitis. Methods: We present the findings of two arms of a phase Ib/IIa randomized controlled platform trial in hospitalized patients with confirmed COVID-19 pneumonitis. Patients received standard of care (SoC) or SoC plus 10 mg inhaled GB0139 twice daily for 48 hours, then once daily for up to 14 days or discharge. Measurements and Main Results: Data are reported from 41 patients, 20 of which were assigned randomly to receive GB0139. Primary outcomes: the GB0139 group experienced no treatment-related serious adverse events. Incidences of adverse events were similar between treatment arms (40 with GB0139 + SoC vs. 35 with SoC). Secondary outcomes: plasma GB0139 was measurable in all patients after inhaled exposure and demonstrated target engagement with decreased circulating galectin (overall treatment effect post-hoc analysis of covariance [ANCOVA] over days 2-7; P = 0.0099 vs. SoC). Plasma biomarkers associated with inflammation, fibrosis, coagulopathy, and major organ function were evaluated. Conclusions: In COVID-19 pneumonitis, inhaled GB0139 was well-tolerated and achieved clinically relevant plasma concentrations with target engagement. The data support larger clinical trials to determine clinical efficacy. Clinical trial registered with ClinicalTrials.gov (NCT04473053) and EudraCT (2020-002230-32).

Phase 1 and 2 Randomized Clinical Studies Determine Lack of Efficacy for Anti-IL-17C Antibody MOR106 in Moderate-Severe Atopic Dermatitis.

Interleukin 17C (IL-17C) modulates epithelial inflammation and has a possible role in atopic dermatitis (AD) pathology. Four randomized clinical studies (Phase 1 and 2) investigated the safety, tolerability, efficacy, and pharmacokinetic profile of the anti-IL-17C monoclonal antibody MOR106 for up to 12 weeks (NCT03568071: n = 207 adults with moderate-severe AD; NCT03689829 Part 1: n = 32 healthy males; NCT03689829 Part 2: n = 44 adults with moderate-severe AD; and NCT03864627: n = 76 adults with moderate-severe AD). In these studies, MOR106 was either administered intravenously (i.v.) every 2 or 4 weeks at doses between 1-10 mg/kg, or subcutaneously (s.c.), either as a single dose or doses every 2 weeks at 320 mg. Overall, MOR106 was well-tolerated, and the safety profile was consistent with monoclonal antibodies approved for AD. Bioavailability following s.c. dosing was 55%, and steady-state drug levels were reached at 2-4 weeks. Ongoing studies were terminated following a futility analysis of the Phase 2 placebo-controlled dose-finding study (NCT03568071) due to a low probability for achieving the primary efficacy endpoint. Cumulatively, MOR106 demonstrated ineffectiveness for the treatment of AD, but its safety and pharmacokinetic characteristics warrant further drug development in other indications. Funding: sponsored by Galapagos NV; funded by Novartis AG.

Prognostic Association of Prostate-specific Antigen Decline with Clinical Outcomes in Men with Metastatic Castration-resistant Prostate Cancer Treated with Enzalutamide in a Randomized Clinical Trial.

BACKGROUND: In the PREVAIL study, enzalutamide provided significant improvements versus placebo in clinical outcomes in chemotherapy-naïve men with metastatic castration-resistant prostate cancer (mCRPC). The association of post-treatment prostate-specific antigen (PSA) decline with clinical outcomes may provide important prognostic information. OBJECTIVE: To evaluate associations between the magnitude of PSA decline from baseline to month 3 and clinical outcomes among enzalutamide recipients. DESIGN, SETTING, AND PARTICIPANTS: This was a post hoc retrospective analysis of PREVAIL, an international, randomized, double-blind, placebo-controlled phase 3 study. Men with mCRPC and no prior chemotherapy from the enzalutamide arm were included (n=872). Patients were grouped by confirmed maximal PSA decline from baseline to month 3 of treatment (n=795 evaluable). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary outcomes were overall survival and radiographic progression-free survival. Secondary outcomes included PSA progression-free survival, radiographic response, and degradation of Functional Assessment of Cancer Therapy-Prostate score, which were estimated using the Kaplan-Meier method. RESULTS AND LIMITATIONS: Following 3mo of enzalutamide treatment, 88% (701/795), 80% (639/795), and 39% (307/795) of patients had postbaseline confirmed maximal PSA declines of ≥30%, ≥50%, and ≥90%, respectively, whereas 12% (94/795) had no confirmed maximal PSA decline or a decline of <30%. Greater degrees of PSA decline within the first 3mo of enzalutamide treatment were increasingly associated with longer overall survival, time to PSA and radiographic progression, higher objective soft-tissue responses, and longer time to quality-of-life deterioration than no PSA decline or declines of <30% from baseline. PSA flares (rise followed by fall) after enzalutamide treatment were rare (<1%). CONCLUSIONS: The magnitude of PSA decline after 3mo of enzalutamide therapy was strongly associated with better clinical and patient-reported outcomes. This updated prognostic information is of clinical value to this patient population and their health care providers. PATIENT SUMMARY: We report that decreases in PSA levels are closely linked to better health and survival after 3mo of enzalutamide treatment in men with metastatic prostate cancer. The PREVAIL trial is registered at clinicaltrials.gov as NCT01212991.

Enzalutamide in Men with Nonmetastatic, Castration-Resistant Prostate Cancer.

BACKGROUND: Men with nonmetastatic, castration-resistant prostate cancer and a rapidly rising prostate-specific antigen (PSA) level are at high risk for metastasis. We hypothesized that enzalutamide, which prolongs overall survival among patients with metastatic, castration-resistant prostate cancer, would delay metastasis in men with nonmetastatic, castration-resistant prostate cancer and a rapidly rising PSA level. METHODS: In this double-blind, phase 3 trial, we randomly assigned, in a 2:1 ratio, men with nonmetastatic, castration-resistant prostate cancer and a PSA doubling time of 10 months or less who were continuing androgen-deprivation therapy to receive enzalutamide (at a dose of 160 mg) or placebo once daily. The primary end point was metastasis-free survival (defined as the time from randomization to radiographic progression or as the time to death without radiographic progression). RESULTS: A total of 1401 patients (median PSA doubling time, 3.7 months) underwent randomization. As of June 28, 2017, a total of 219 of 933 patients (23%) in the enzalutamide group had metastasis or had died, as compared with 228 of 468 (49%) in the placebo group. The median metastasis-free survival was 36.6 months in the enzalutamide group versus 14.7 months in the placebo group (hazard ratio for metastasis or death, 0.29; 95% confidence interval, 0.24 to 0.35; P<0.001). The time to the first use of a subsequent antineoplastic therapy was longer with enzalutamide treatment than with placebo (39.6 vs. 17.7 months; hazard ratio, 0.21; P<0.001; such therapy was used in 15% vs. 48% of patients) as was the time to PSA progression (37.2 vs. 3.9 months; hazard ratio, 0.07; P<0.001; progression occurred in 22% vs. 69% of patients). At the first interim analysis of overall survival, 103 patients (11%) receiving enzalutamide and 62 (13%) receiving placebo had died. Adverse events of grade 3 or higher occurred in 31% of the patients receiving enzalutamide, as compared with 23% of those receiving placebo. CONCLUSIONS: Among men with nonmetastatic, castration-resistant prostate cancer with a rapidly rising PSA level, enzalutamide treatment led to a clinically meaningful and significant 71% lower risk of metastasis or death than placebo. Adverse events were consistent with the established safety profile of enzalutamide. (Funded by Pfizer and Astellas Pharma; PROSPER ClinicalTrials.gov number, NCT02003924 .).

Radiographic Progression-Free Survival as a Clinically Meaningful End Point in Metastatic Castration-Resistant Prostate Cancer: The PREVAIL Randomized Clinical Trial.

Importance: 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. Objective: To demonstrate the robustness of the PCWG2 definition and to examine the relationship between rPFS and OS. Design, Setting, and Participants: 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. Interventions: 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. Main Outcomes and Measures: 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. Results: 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. Conclusions and Relevance: 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. Trial Registration: clinicaltrials.gov Identifier: NCT01212991.

The association between health-related quality-of-life scores and clinical outcomes in metastatic castration-resistant prostate cancer patients: Exploratory analyses of AFFIRM and PREVAIL studies.

BACKGROUND: Our exploratory analysis examined the association between health-related quality of life (HRQoL) (baseline and change over time) and clinical outcomes (overall survival [OS]/radiographic progression-free survival [rPFS]) in metastatic castration-resistant prostate cancer (mCRPC). METHODS: HRQoL, OS and rPFS were assessed in phase III trials comparing enzalutamide with placebo in chemotherapy-naïve (PREVAIL; NCT01212991) or post-chemotherapy (AFFIRM; NCT00974311) mCRPC. HRQoL was assessed using the Functional Assessment of Cancer Therapy-Prostate (FACT-P). Multivariate analyses evaluated the prognostic significance of baseline and time-dependent scores after adjusting for treatment and clinical/demographic variables. Hazard ratios (HRs) and 95% confidence intervals (CIs) represented the hazard of rPFS or OS per minimally important difference (MID) score change in HRQoL variables. RESULTS: In baseline and time-dependent multivariate analyses, OS was independently associated with multiple HRQoL measures across both studies. In time-dependent analyses, a 10-point (upper bound of MID range) increase (improvement) in FACT-P total score was associated with reductions in mortality risk of 19% in AFFIRM (HR 0.81 [95% CI 0.78-0.84]) and 21% in PREVAIL (HR 0.79 [0.76-0.83]). For baseline analyses, a 10-point increase in FACT-P total score was associated with reductions in mortality risk of 12% (HR 0.88 [0.84-0.93]) and 10% (HR 0.90 [0.86-0.95]) in AFFIRM and PREVAIL, respectively. rPFS was associated with a subset of HRQoL domains in both studies. CONCLUSION: Several baseline HRQoL domains were prognostic for rPFS and OS in patients with mCRPC, and this association was maintained during treatment, indicating that changes in HRQoL are informative for patients' expected survival.

Clinical Outcomes of Chemotherapy Naïve Men with Metastatic Castration Resistant Prostate Cancer and Low Baseline Prostate Specific Antigen Treated with Enzalutamide vs Placebo.

PURPOSE: Metastatic castration resistant prostate cancer with low baseline prostate specific antigen represents an early stage in the natural history of castration resistant prostate cancer progression (low volume disease), low prostate specific antigen producing disease or disease that is less dependent on androgen receptor biology (high volume disease). We analyzed outcomes in men with low prostate specific antigen and a high disease burden who received the oral androgen receptor inhibitor enzalutamide in the PREVAIL (Safety and Efficacy Study of Oral MDV3100 in Chemotherapy-Naive Patients with Progressive Metastatic Prostate Cancer) study. MATERIALS AND METHODS: In this exploratory analysis low baseline prostate specific antigen was defined as less than 10 ng/ml. Post hoc analyses included radiographic progression-free and overall survival in the once daily enzalutamide and placebo arms. Patients were stratified post hoc by high volume disease, defined as more than 4 bone metastases and/or visceral disease, and low volume disease, defined as 4 or fewer bone metastases with no visceral disease. RESULTS: Of 1,717 patients enrolled in PREVAIL 242 (14.1%) had low baseline prostate specific antigen, including 110 with high volume disease. Enzalutamide decreased the risk of radiographic progression relative to placebo in patients with low baseline prostate specific antigen (HR 0.20, 95% CI 0.10-0.42). This decrease was irrespective of tumor burden (high volume disease HR 0.17, 95% CI 0.06-0.51 and low volume disease HR 0.25, 95% CI 0.09-0.70). Median overall survival was not reached in patients with low baseline prostate specific antigen in either treatment arm. CONCLUSIONS: Chemotherapy naïve men with metastatic castration resistant prostate cancer and low baseline prostate specific antigen irrespective of disease burden may benefit from enzalutamide. This indicates that targeting the androgen receptor signaling pathway is a therapeutic option in similar patients.

Health-related quality of life effects of enzalutamide in patients with metastatic castration-resistant prostate cancer: an in-depth post hoc analysis of EQ-5D data from the PREVAIL trial.

BACKGROUND: The effect of enzalutamide on health-related quality of life (HRQoL) in the PREVAIL trial in chemotherapy-naïve men with metastatic castration-resistant prostate cancer was analyzed using the generic EQ-5D instrument. METHODS: Patients received oral enzalutamide 160 mg/day (n = 872) or placebo (n = 845). EQ-5D index and EQ-5D visual analogue scale (EQ-5D VAS) scores were evaluated at baseline, week 13, and every 12 weeks until week 61 due to sample size reduction thereafter. Changes on individual dimensions were assessed, and Paretian Classification of Health Change (PCHC) and time-to-event analyses were conducted. RESULTS: With enzalutamide, EQ-5D index and EQ-5D VAS scores declined more slowly versus placebo and time to diverge from full health was prolonged. Average decline in EQ-5D index (-0.042 vs. -0.070; P < .0001) and EQ-5D VAS (-1.3 vs. -4.4; P < .0001) was significantly smaller with enzalutamide. There were significant (P < .05) between-group differences favoring enzalutamide in Pain/Discomfort to week 37, Anxiety/Depression at week 13, and Usual Activities at week 25, but no significant differences for Mobility and Self-care. The PCHC analysis showed more enzalutamide patients reporting improvement than placebo patients at weeks 13, 25, and 49 (all P < .05) and week 37 (P = .0512). Enzalutamide was superior (P ≤ .0003) to placebo for time to diverge from full health and time to first deterioration on Pain/Discomfort and Anxiety/Depression dimensions. CONCLUSIONS: This in-depth post hoc analysis showed that enzalutamide delayed HRQoL deterioration and had beneficial effects on several HRQoL domains, including Pain/Discomfort and the proportion of patients in full health, compared with placebo, and may help to support future analyses of this type. TRIAL REGISTRATION: NCT01212991.

Effect of Visceral Disease Site on Outcomes in Patients With Metastatic Castration-resistant Prostate Cancer Treated With Enzalutamide in the PREVAIL Trial.

BACKGROUND: The Multinational Phase 3, Randomized, Double-Blind, Placebo-Controlled Efficacy and Safety Study of Oral MDV3100 in Chemotherapy-Naive Patients With Progressive Metastatic Prostate Cancer Who Have Failed Androgen Deprivation Therapy (PREVAIL) trial was unique as it included patients with visceral disease. This analysis was designed to describe outcomes for the subgroup of men from PREVAIL with specific sites of visceral disease to help clinicians understand how these patients responded to enzalutamide prior to chemotherapy. PATIENTS AND METHODS: Prespecified analyses examined the coprimary endpoints of radiographic progression-free survival (rPFS) and overall survival (OS) only. All other efficacy analyses were post hoc. The visceral subgroup was divided into liver or lung subsets. Patients with both liver and lung metastases were included in the liver subset. RESULTS: Of the 1717 patients in PREVAIL, 204 (12%) had visceral metastases at screening (liver only or liver/lung metastases, n = 74; lung only metastases, n = 130). In patients with liver metastases, enzalutamide was associated with an improvement in rPFS (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.22-0.90) but not OS (HR, 1.04; 95% CI, 0.57-1.87). In patients with lung metastases only, the HR for rPFS (0.14; 95% CI, 0.06-0.36) and the HR for OS (0.59; 95% CI, 0.33-1.06) favored enzalutamide over placebo. Patients with liver metastases had worse outcomes than those with lung metastases, regardless of treatment. Enzalutamide was well tolerated in patients with visceral disease. CONCLUSIONS: Enzalutamide is an active first-line treatment option for men with asymptomatic or mildly symptomatic chemotherapy-naive metastatic castration-resistant prostate cancer and visceral disease. Patients with lung-only disease fared better than patients with liver disease, regardless of treatment.

Clinical outcomes and survival surrogacy studies of prostate-specific antigen declines following enzalutamide in men with metastatic castration-resistant prostate cancer previously treated with docetaxel.

BACKGROUND: In the AFFIRM trial, enzalutamide significantly increased overall survival (OS) for men with metastatic castration-resistant prostate cancer (mCRPC) after chemotherapy versus placebo and significantly decreased prostate-specific antigen (PSA) levels. The goal of this post hoc analysis was to associate levels of PSA decline from baseline after enzalutamide with clinical outcomes in the postchemotherapy mCRPC setting. METHODS: Men in the AFFIRM trial (n = 1199) were grouped by maximal PSA decline in the first 90 days of treatment. Kaplan-Meier estimates evaluated the association of defined PSA changes from baseline with OS, progression-free survival (PFS), radiographic PFS (rPFS), and pain response. Each PSA decline category was assessed for OS surrogacy using Prentice criteria, proportion of treatment effect explained (PTE), and proportion of variation explained. RESULTS: Men treated with enzalutamide had improved OS (hazard ratio, 0.63; P < .001) and higher rates of PSA decline (odds ratio, >19.0; P < .001) versus placebo. PSA declines of any, ≥30%, ≥50%, and ≥90% with enzalutamide were strongly associated with greater OS, PSA PFS, rPFS (P < .001), and pain response (P < .026) versus PSA increase/no decline. Any, ≥30%, and ≥50% declines in PSA resulted in the PTE range of 1.07-1.29, where treatment was no longer significant after adjustment for decline measures (P > .20). CONCLUSIONS: PSA declines of any, ≥30%, and ≥50% following enzalutamide were associated with greater clinical and pain response and improvements in PFS and OS. Surrogacy of PSA decline for OS was not fully established, possibly due to lack of PSA declines with placebo, and discordant results between PSA and imaging responses over time, and because some declines were not durable due to rapid resistance development. However, a lack of PSA decline by 90 days following enzalutamide treatment was a poor prognosis indicator in this setting. Conclusions from sensitivity analyses of maximal PSA decline from baseline over the entire treatment period are consistent with PSA declines restricted to the first 90 days. Cancer 2017;123:2303-2311. © 2017 American Cancer Society.

Adjusting Overall Survival Estimates after Treatment Switching: a Case Study in Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: If patients in oncology trials receive subsequent therapy, standard intention-to-treat (ITT) analyses may inaccurately estimate the overall survival (OS) effect of the investigational product. In this context, a post-hoc analysis of the phase 3 PREVAIL study was performed with the aim to compare enzalutamide with placebo in terms of OS, adjusting for potential confounding from switching to antineoplastic therapies that are not part of standard metastatic castration-resistant prostate cancer (mCRPC) treatment pathways in some jurisdictions. METHODS: The PREVAIL study, which included 1717 chemotherapy-naïve men with mCRPC randomized to treatment with enzalutamide 160 mg/day or placebo, was stopped after a planned interim survival analysis revealed a benefit in favor of enzalutamide. Data from this cutoff point were confounded by switching from both arms and so were evaluated in terms of OS using two switching adjustment methods: the two-stage accelerated failure time model (two-stage method) and inverse probability of censoring weights (IPCW). RESULTS: Following adjustment for switching to nonstandard antineoplastic therapies by 14.8 (129/872 patients) and 21.3% (180/845 patients) of patients initially randomized to enzalutamide and placebo, respectively, the two-stage and IPCW methods both resulted in numerical reductions in the hazard ratio (HR) for OS [HR 0.66, 95% confidence interval (CI) 0.57-0.81 and HR 0.63, 95% CI 0.52-0.75, respectively] for enzalutamide compared to placebo versus the unadjusted ITT analysis (HR 0.71, 95% CI 0.60-0.84). These results suggest a slightly greater effect of enzalutamide on OS than originally reported. CONCLUSION: In the PREVAIL study, switching to nonstandard antineoplastic mCRPC therapies resulted in the ITT analysis of primary data underestimating the benefit of enzalutamide on OS.

Efficacy and safety of enzalutamide versus bicalutamide for patients with metastatic prostate cancer (TERRAIN): a randomised, double-blind, phase 2 study.

BACKGROUND: Enzalutamide is an oral androgen-receptor inhibitor that has been shown to improve survival in two placebo-controlled phase 3 trials, and is approved for patients with metastatic castration-resistant prostate cancer. The objective of the TERRAIN study was to compare the efficacy and safety of enzalutamide with bicalutamide in patients with metastatic castration-resistant prostate cancer. METHODS: TERRAIN was a double-blind, randomised phase 2 study, that recruited asymptomatic or minimally symptomatic men with prostate cancer progression on androgen-deprivation therapy (ADT) from academic, community, and private health-care provision sites across North America and Europe. Eligible patients were randomly assigned (1:1) via an interactive voice response system to receive enzalutamide 160 mg/day or bicalutamide 50 mg/day, both taken orally, in addition to ADT, until disease progression. Patients were stratified by a permutated block method (block size of four), by whether bilateral orchiectomy or receipt of luteinising hormone-releasing hormone agonist or antagonist therapy started before or after the diagnosis of metastases, and by study site. Participants, investigators, and those assessing outcomes were masked to group assignment. The primary endpoint was progression-free survival, analysed in all randomised patients. Safety outcomes were analysed in all patients who received at least one dose of study drug. The open-label period of the trial is in progress, wherein patients still on treatment at the end of the double-blind treatment period were offered open-label enzalutamide at the discretion of the patient and study investigator. This trial is registered with ClinicalTrials.gov, number NCT01288911. FINDINGS: Between March 22, 2011, and July 11, 2013, 375 patients were randomly assigned, 184 to enzalutamide and 191 to bicalutamide. 126 (68%) and 168 (88%) patients, respectively, discontinued their assigned treatment before study end, mainly due to progressive disease. Median follow-up time was 20·0 months (IQR 15·0-25·6) in the enzalutamide group and 16·7 months (10·2-21·9) in the bicalutamide group. Patients in the enzalutamide group had significantly improved median progression-free survival (15·7 months [95% CI 11·5-19·4]) compared with patients in the bicalutamide group (5·8 months [4·8-8·1]; hazard ratio 0·44 [95% CI 0·34-0·57]; p<0·0001). Of the most common adverse events, those occurring more frequently with enzalutamide than with bicalutamide were fatigue (51 [28%] of 183 patients in the enzalutamide group vs 38 [20%] of 189 in the bicalutamide group), back pain (35 [19%] vs 34 [18%]), and hot flush (27 [15%] vs 21 [11%]); those occurring more frequently with bicalutamide were nausea (26 [14%] vs 33 [17%]), constipation (23 [13%] vs 25 [13%]), and arthralgia (18 [10%] vs 30 [16%]). The most common grade 3 or worse adverse events in the enzalutamide or bicalutamide treatment groups, respectively, were hypertension (13 [7%] vs eight [4%]), hydronephrosis (three [2%] vs seven [4%]), back pain (five [3%] vs three [2%]), pathological fracture (five [3%] vs two [1%]), dyspnoea (four [2%] vs one [1%]), bone pain (one [1%] vs four [2%]), congestive cardiac failure (four [2%] vs two [1%]), myocardial infarction (five [3%] vs none), and anaemia (four [2%] vs none]). Serious adverse events were reported by 57 (31%) of 183 patients and 44 (23%) of 189 patients in the enzalutamide and bicalutamide groups, respectively. One of the nine deaths in the enzalutamide group was thought to be possibly related to treatment (due to systemic inflammatory response syndrome) compared with none of the three deaths in the bicalutamide group. INTERPRETATION: The data from the TERRAIN trial support the use of enzalutamide rather than bicalutamide in patients with asymptomatic or mildly symptomatic metastatic castration-resistant prostate cancer. FUNDING: Astellas Pharma, Inc and Medivation, Inc.

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

PURPOSE: Enzalutamide, a potent oral androgen receptor inhibitor, improves survival in men with metastatic castration-resistant prostate cancer (CRPC) before and after chemotherapy. Bicalutamide, a nonsteroidal antiandrogen, is widely used to treat men with nonmetastatic or metastatic CRPC. The efficacy and safety of these drugs were compared in this randomized, double-blind, phase II study of men with CRPC. PATIENTS AND METHODS: A total of 396 men with nonmetastatic (n = 139) or metastatic (n = 257) CRPC were randomly assigned to enzalutamide 160 mg per day (n = 198) or bicalutamide 50 mg per day (n = 198). Androgen deprivation therapy was continued in both arms. The primary end point was progression-free survival (PFS). RESULTS: Enzalutamide reduced the risk of progression or death by 76% compared with bicalutamide (hazard ratio [HR], 0.24; 95% CI, 0.18 to 0.32; P < .001). Median PFS was 19.4 months with enzalutamide versus 5.7 months with bicalutamide. Enzalutamide resulted in significant improvements in all key secondary end points: time to prostate-specific antigen progression (HR, 0.19; 95% CI, 0.14 to 0.26; P < .001); proportion of patients with a ≥ 50% prostate-specific antigen response (81% v 31%; P < .001); and radiographic PFS in metastatic patients (HR, 0.32; 95% CI, 0.21 to 0.50; P < .001). Beneficial effects with enzalutamide were observed in both nonmetastatic and metastatic subgroups. The observed adverse event profile was consistent with that from phase III enzalutamide trials. CONCLUSION: Enzalutamide significantly reduced risk of prostate cancer progression or death compared with bicalutamide in patients with nonmetastatic or metastatic CRPC.

Development of enzalutamide for metastatic castration-resistant prostate cancer.

Prostate cancer is the most prevalent cancer among men in the Western world and a leading cause of cancer-related death among men. Within 5 years of initial diagnosis, approximately 10-20% of men will progress to metastatic castration-resistant prostate cancer (mCRPC). Often characterized by increased prostate-specific antigen and androgen receptor (AR) activity despite castrate levels of testosterone, mCRPC has a poor prognosis and causes significant deterioration in quality of life. Enzalutamide is an AR inhibitor approved to treat mCRPC in both post- and pre-chemotherapy settings on the basis of results from two phase III randomized, placebo-controlled trials, AFFIRM and PREVAIL, respectively. Enzalutamide significantly prolonged overall survival (hazard ratio (HR), AFFIRM 0.63, 95% confidence interval (CI) 0.53-0.75, P < 0.001; PREVAIL 0.71, 95% CI 0.60-0.84, P < 0.001) and radiographic progression (HR, AFFIRM 0.40, 95% CI 0.35-0.47, P < 0.001; PREVAIL 0.19, 95% CI 0.15-0.23, P < 0.001), and significantly improved quality of life. With an acceptable safety profile, enzalutamide is one of several emerging alternative options for men with mCRPC. Studies are ongoing to explore potential benefits of enzalutamide in earlier stages of prostate cancer and in breast cancer.

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.

BACKGROUND: 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. METHODS: 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. FINDINGS: 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). INTERPRETATION: 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. FUNDING: Astellas Pharma and Medivation.

Long-term Efficacy and Safety of Enzalutamide Monotherapy in Hormone-naïve Prostate Cancer: 1- and 2-Year Open-label Follow-up Results.

BACKGROUND: Enzalutamide is an androgen receptor inhibitor with a demonstrated overall survival benefit in metastatic castration-resistant prostate cancer. A phase 2 study of enzalutamide monotherapy in patients with hormone-naïve prostate cancer (HNPC) showed a high response rate for the prespecified primary endpoint (ie, prostate-specific antigen [PSA] response at week 25), regardless of metastases at baseline, and favorable tolerability. OBJECTIVE: To determine the long-term efficacy and safety of enzalutamide monotherapy at 1 and 2 yr. DESIGN, SETTING, AND PARTICIPANTS: Open-label, single-arm study in patients with HNPC and noncastrate testosterone (≥230 ng/dl). INTERVENTION: Oral enzalutamide 160mg/d until disease progression or unacceptable toxicity. OUTCOME MEASUREMENTS AND ANALYSIS: PSA response (≥80% decline from baseline) assessed at 1 yr (49 wk) and 2 yr (97 wk). RESULTS AND LIMITATIONS: The median (range) age was 73 (48-86) yr and 26 patients (39%) presented with metastases at study entry. Of 67 patients enrolled, 45 (67%) remained on enzalutamide at week 97. For patients remaining on therapy, the PSA response rate at week 97 was 100% (95% confidence interval 92-100%). Of 26 patients with metastases at baseline, 13 (50%) had a complete and four (15.4%) had a partial response as best overall tumor response up to 97 wk on treatment. There was overall maintenance of total-body bone mineral density (BMD) and moderate changes in lean and fat body mass at 49 and 97 wk. The most common adverse events were gynecomastia, nipple pain, fatigue, and hot flushes. The study limitations include lack of a control group and of endocrine, glycemic, and lipid data at 97 wk. CONCLUSIONS: Long-term enzalutamide monotherapy in men with noncastrate HNPC is associated with large sustained reductions in PSA, signals indicating a favorable tumor response, and favorable safety/tolerability profile, with relatively small negative effects on total-body BMD. PATIENT SUMMARY: In this long-term follow-up of the efficacy and safety of enzalutamide monotherapy in patients with hormone-naïve prostate cancer, enzalutamide maintained long-term reductions in prostate-specific antigen, with a minimal impact on total-body bone mineral density. TRIAL REGISTRATION: NCT01302041.

Enzalutamide in metastatic prostate cancer before chemotherapy.

BACKGROUND: Enzalutamide is an oral androgen-receptor inhibitor that prolongs survival in men with metastatic castration-resistant prostate cancer in whom the disease has progressed after chemotherapy. New treatment options are needed for patients with metastatic prostate cancer who have not received chemotherapy, in whom the disease has progressed despite androgen-deprivation therapy. METHODS: In this double-blind, phase 3 study, we randomly assigned 1717 patients to receive either enzalutamide (at a dose of 160 mg) or placebo once daily. The coprimary end points were radiographic progression-free survival and overall survival. RESULTS: The study was stopped after a planned interim analysis, conducted when 540 deaths had been reported, showed a benefit of the active treatment. The rate of radiographic progression-free survival at 12 months was 65% among patients treated with enzalutamide, as compared with 14% among patients receiving placebo (81% risk reduction; hazard ratio in the enzalutamide group, 0.19; 95% confidence interval [CI], 0.15 to 0.23; P<0.001). A total of 626 patients (72%) in the enzalutamide group, as compared with 532 patients (63%) in the placebo group, were alive at the data-cutoff date (29% reduction in the risk of death; hazard ratio, 0.71; 95% CI, 0.60 to 0.84; P<0.001). The benefit of enzalutamide was shown with respect to all secondary end points, including the time until the initiation of cytotoxic chemotherapy (hazard ratio, 0.35), the time until the first skeletal-related event (hazard ratio, 0.72), a complete or partial soft-tissue response (59% vs. 5%), the time until prostate-specific antigen (PSA) progression (hazard ratio, 0.17), and a rate of decline of at least 50% in PSA (78% vs. 3%) (P<0.001 for all comparisons). Fatigue and hypertension were the most common clinically relevant adverse events associated with enzalutamide treatment. CONCLUSIONS: Enzalutamide significantly decreased the risk of radiographic progression and death and delayed the initiation of chemotherapy in men with metastatic prostate cancer. (Funded by Medivation and Astellas Pharma; PREVAIL ClinicalTrials.gov number, NCT01212991.).