安斯泰来与Medivation启动前列腺癌新药Xtandi IV期研究

安斯泰来（Astellas）和Medivation制药11月12日宣布，启动前列腺癌新药Xtandi（enzalutamide）的一项IV期试验PLATO，该研究在经enzalutamide治疗后病情恶化的化疗初治（chemotherapy-naïve）转移性前列腺癌成人患者中开展，将评价enzalutamide+醋酸阿比特龙（abiraterone acetate）+强的松（prednisone）相对于醋酸阿比特龙+强的松的疗效和安全性。

PLATO是一项全球性随机、双盲、安慰剂对照IV期研究，旨在招募约500名化疗初治（chemotherapy-naive）转移性去势前列腺癌患者。所有患者最初将接受enzalutamide治疗。经enzalutamide治疗后，病情恶化的患者，将随机接受醋酸阿比特龙+强的松治疗，或enzalutamide+醋酸阿比特龙+强的松治疗。该项研究的主要终点是疾病无进展生存期（PFS）。

该项研究将评估enzalutamide（160mg，每天口服一次）+醋酸阿比特龙（1000mg，每天口服一次）+强的松（5mg，每天口服2次）组合疗法，相对于安慰剂及同剂量醋酸阿比特龙和强的松组合疗法的疗效和安全性。

关于enzalutamide：

enzalutamide商品名为Xtandi，该药属于一类名为雄性激素抑制剂的新药，旨在干扰睾酮结合前列腺癌细胞的能力。睾酮是一种男性激素，能够激化前列腺癌细胞的生长。

Xtandi于今年8月31日获得了FDA批准，用于经激素疗法及化疗后癌症已扩散的男性前列腺癌患者的治疗。

英文原文：Astellas, Medivation Start Enzalutamide Phase 4 Trial - Quick Fact

SAN FRANCISCO, CA and NORTHBROOK, IL -- (Marketwired) -- 11/12/13 -- Astellas Pharma US, Inc., a U.S. subsidiary of Tokyo-based Astellas Pharma Inc. (TOKYO: 4503), and Medivation, Inc. (NASDAQ: MDVN) announced the initiation of a Phase 4 clinical trial, known as PLATO. The study will evaluate the efficacy and safety of continued treatment with enzalutamide plus abiraterone acetate and prednisone as compared to treatment with abiraterone acetate and prednisone alone in patients with chemotherapy-naïve metastatic prostate cancer whose disease has progressed following enzalutamide therapy.

"This Phase 4 study offers an important opportunity to help determine the potential clinical benefit of extending time on enzalutamide treatment by adding an additional therapy in patients with progressive chemotherapy-naïve metastatic prostate cancer," said David Hung, M.D., president and chief executive officer of Medivation, Inc. "This trial underscores our continued commitment to discovering how enzalutamide can be used most effectively to benefit prostate cancer patients across the disease continuum."

About the Phase 4 Study
The Phase 4 global randomized, double-blind, placebo-controlled trial is designed to enroll approximately 500 chemotherapy-naïve patients with metastatic castration-resistant prostate cancer. All enrolled patients will initially receive treatment with enzalutamide. Eligible patients with disease progression on enzalutamide will be randomized to treatment with enzalutamide plus abiraterone acetate and prednisone or to abiraterone acetate and prednisone. The primary endpoint of the trial is progression-free survival.

The trial will evaluate enzalutamide at a dose of 160 mg taken orally once daily in combination with abiraterone acetate at a dose of 1000 mg administered orally once daily and prednisone at a dose of 5 mg administered orally twice daily, versus placebo plus the same doses of abiraterone acetate and prednisone.

About Enzalutamide
Enzalutamide is an androgen receptor inhibitor that acts on different steps in the androgen receptor signaling pathway. Enzalutamide has been shown to competitively inhibit androgen binding to androgen receptors, and inhibit androgen receptor nuclear translocation and interaction with DNA.

About XTANDI® (enzalutamide) capsules
XTANDI is approved for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have previously received docetaxel.