Department of Oncology, Karmanos Cancer Center, Wayne State University, Detroit, Michigan.
Department of Internal Medicine, University of Michigan, Ann Arbor.
JAMA Netw Open. 2021 Jan 4;4(1):e2034633. doi: 10.1001/jamanetworkopen.2020.34633.
Black patients have been underrepresented in prospective clinical trials of advanced prostate cancer. This study evaluated the efficacy of enzalutamide compared with bicalutamide, with planned subset analysis of Black patients with metastatic hormone-sensitive prostate cancer (mHSPC), which is a disease state responsive to androgen deprivation therapy (ADT).
To compare the efficacy of enzalutamide vs bicalutamide in combination with ADT in men with mHSPC, with a subset analysis of Black patients.
DESIGN, SETTING, AND PARTICIPANTS: In this randomized clinical trial, a phase 2 screening design enabled a nondefinitive comparison of the primary outcome by treatment. Patients were stratified by race (Black or other) and bone pain (present or absent). Accrual of at least 30% Black patients was required. This multicenter trial was conducted at 4 centers in the US. Men with mHSPC with no history of seizures and adequate marrow, renal, and liver function were eligible. Data analysis was performed from February 2019 to March 2020.
Participants were randomized 1:1 to receive oral enzalutamide (160 mg daily) or bicalutamide (50 mg daily) in addition to ADT.
The primary end point was the 7-month prostate-specific antigen (PSA) response (SMPR) rate, a previously accepted surrogate for overall survival (OS) outcome. Secondary end points included adverse reactions, time to PSA progression, and OS.
A total of 71 men (median [range] age, 65 [51-86] years) were enrolled; 29 (41%) were Black, 41 (58%) were White, and 1 (1%) was Asian. Thirty-six patients were randomized to receive enzalutamide, and 35 were randomized to receive bicalutamide. Twenty-six patients (37%) had bone pain and 37 patients (52%) had extensive disease. SMPR was achieved in 30 of 32 patients (94%; 95% CI, 80%-98%) taking enzalutamide and 17 of 26 patients (65%; 95% CI, 46%-81%) taking bicalutamide (P = .008) (difference, 29%; 95% CI, 5%-50%). Among Black patients, the SMPR was 93% (95% CI, 69%-99%) among those taking enzalutamide and 42% (95% CI, 19%-68%) among those taking bicalutamide (P = .009); among non-Black patients, the SMPR was 94% (95% CI, 74%-99%) among those taking enzalutamide and 86% (95% CI, 60%-96%) among those taking bicalutamide. The 12-month PSA response rates were 84% with enzalutamide and 34% with bicalutamide.
The findings of this randomized clinical trial comparing enzalutamide with bicalutamide suggest that enzalutamide is associated with improved outcomes compared with bicalutamide, in terms of the rate and duration of PSA response, in Black patients with mHSPC.
ClinicalTrials.gov Identifier: NCT02058706.
黑人患者在晚期前列腺癌的前瞻性临床试验中代表性不足。本研究评估了恩扎卢胺与比卡鲁胺相比的疗效，对转移性激素敏感前列腺癌（mHSPC）的黑人患者进行了计划的亚组分析，这是一种对雄激素剥夺疗法（ADT）有反应的疾病状态。
比较恩扎卢胺与比卡鲁胺联合 ADT 在 mHSPC 男性中的疗效，并对黑人患者进行亚组分析。
设计、地点和参与者：这是一项随机临床试验，采用 2 期筛选设计，通过治疗对主要结局进行非确定性比较。患者按种族（黑人或其他）和骨痛（存在或不存在）分层。需要至少 30%的黑人患者入组。这项多中心试验在美国的 4 个中心进行。患有 mHSPC 且无癫痫病史和足够的骨髓、肾脏和肝功能的男性有资格参加。数据分析于 2019 年 2 月至 2020 年 3 月进行。
参与者按 1:1 的比例随机接受口服恩扎卢胺（每日 160 毫克）或比卡鲁胺（每日 50 毫克）加 ADT。
主要终点是前列腺特异性抗原（PSA）反应（SMPR）率的 7 个月，这是先前接受的总生存（OS）结果的替代指标。次要终点包括不良反应、PSA 进展时间和 OS。
共纳入 71 名男性（中位[范围]年龄，65[51-86]岁）；29 名（41%）是黑人，41 名（58%）是白人，1 名（1%）是亚洲人。36 名患者随机接受恩扎卢胺治疗，35 名患者随机接受比卡鲁胺治疗。26 名患者（37%）有骨痛，37 名患者（52%）有广泛疾病。32 名接受恩扎卢胺治疗的患者中有 30 名（94%；95%CI，80%-98%）和 26 名接受比卡鲁胺治疗的患者中有 17 名（65%；95%CI，46%-81%）达到 SMPR（P=0.008）（差异，29%；95%CI，5%-50%）。在黑人患者中，接受恩扎卢胺治疗的患者 SMPR 为 93%（95%CI，69%-99%），接受比卡鲁胺治疗的患者为 42%（95%CI，19%-68%）（P=0.009）；在非黑人患者中，接受恩扎卢胺治疗的患者 SMPR 为 94%（95%CI，74%-99%），接受比卡鲁胺治疗的患者为 86%（95%CI，60%-96%）。恩扎卢胺治疗的 12 个月 PSA 反应率为 84%，比卡鲁胺治疗的为 34%。
这项比较恩扎卢胺与比卡鲁胺的随机临床试验结果表明，在黑人 mHSPC 患者中，与比卡鲁胺相比，恩扎卢胺在 PSA 反应的速度和持续时间方面与改善的结局相关。
ClinicalTrials.gov 标识符：NCT02058706。
