2013年11月15日拜耳（Bayer）宣布，抗癌药物Xofigo（radium 223 dichloride，镭223二氯）已获欧盟委员会（EC）批准，用于有症状骨转移（symptomatic bone metastases ）及无已知内脏转移（no known visceral metastatic disease）的阉割性前列腺癌（CRPC）患者的治疗。
Xofigo的获批，是基于关键性III期ALSYMPCA研究的数据，该项研究中，与安慰剂相比，Xofigo显着改善了整体存活率（OS），同时延迟了首次有症状骨骼事件（SSE）的发生时间。
此前，Xofigo已于今年5月获得了FDA的批准，是首个α-粒子辐射放射性治疗药物。拜耳拥有Xofigo的全球独家销售权。在美国，拜耳与Algeta US公司共同推广该药。
临床试验中，Xofigo表现出了良好的安全性，该药以一种完全新颖的方式改善患者的预后。镭233发射的α粒子能够作用于骨转移的癌细胞，能够帮助改善患者的生存。
骨骼是体内转移性癌症影响的最常见部位，前列腺癌的骨转移尤其普遍。转移性前列腺癌中有约90%的患者发生骨转移。骨转移能够导致增加骨骼事件的发生频率，并已被证明是CRPC患者发病和致死的主要病因.
关于Xofigo：
Xofigo（radium 223 dichloride，镭223二氯）是一种α-粒子辐射放射性治疗药物，其活性部分（active moiety）模拟了钙离子（calcium），通过与骨骼中的羟基磷灰石（HAP）形成复合物，选择性地靶向骨骼，尤其是骨转移区域。镭233【α-发射器（80千电子伏/微米）】发射的高LET （linear energy transfer, 线性能量转移）射线，能够在邻近肿瘤细胞中引发高频率的双链DNA断裂，从而产生强效的细胞毒效应。对肿瘤微环境（包括骨细胞和破骨细胞）的额外效应，也有助于体内（in vivo）的疗效。
来自Xofigo的α粒子量程小于100微米（不到10个细胞直径），能够最大限度地减少对周围正常组织的伤害.

Bayer Receives Approval for New Cancer Drug Xofigo® in the EU
New treatment for adults with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastases / Xofigo significantly extended overall survival in Phase III ALSYMPCA study
Berlin, November 15, 2013 – Bayer HealthCare announced today that the European Commission (EC) has granted marketing authorisation for Xofigo® 1000 kBq/ml, solution for injection (radium Ra 223 dichloride) for the treatment of adults with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastases. This decision follows a positive recommendation from the European Committee for Medicinal Products for Human Use (CHMP) in September of this year. The approval of Xofigo is based on data from the pivotal Phase III ALSYMPCA (ALpharadin in SYMptomatic Prostate CAncer) trial.
“Bone metastases occur in the majority of men living with castration-resistant prostate cancer and can result in pain and even death. The profound impact of bone metastases should therefore be a key treatment consideration for this disease,” said Christopher Parker, M.D., Principal Investigator of the ALSYMPCA trial and Consultant Clinical Oncologist at The Royal Marsden NHS Foundation Trust, and Honorary Reader in Prostate Oncology at The Institute of Cancer Research, London. “Xofigo targets bone metastases, delivering a localized cytotoxic effect to offer patients prolonged survival, making it an exciting advance in the treatment of this cancer.”
“As the latest addition to Bayer’s growing oncology franchise and following a quick approval in the U.S., we are pleased that Xofigo is now available to patients in Europe,” said Kemal Malik, M.D., member of the Bayer HealthCare Executive Committee and Head of Global Development.
About Castration-Resistant Prostate Cancer (CRPC) and Bone Metastases
Prostate cancer is the second most commonly diagnosed malignancy in men worldwide. In 2008, an estimated 899,000 men were diagnosed with prostate cancer and 258,000 died from the disease worldwide. Prostate cancer is the sixth leading cause of death from cancer in men.
A majority of men with CRPC have symptomatic bone metastases. Once the cancer cells settle in the bone, they interfere with bone strength, often leading to pain, fracture and other complications that can significantly impair a man’s health. Bone metastases secondary to prostate cancer typically target the lumbar spine, vertebrae and pelvis. In fact, bone metastases are one of the main causes of morbidity and death in patients with CRPC.
About Xofigo® (radium Ra 223 dichloride)
Xofigo® is an alpha particle-emitting pharmaceutical. Xofigo’s active moiety mimics calcium and selectively targets bone, specifically areas of bone metastases, by forming complexes with the bone mineral hydroxyapatite. The high linear energy transfer of alpha emitters (80 keV/micrometer) leads to a high frequency of double-strand DNA breaks in adjacent tumour cells, resulting in a potent cytotoxic effect. Additional effects on the tumour microenvironment including osteoblasts and osteoclasts also contribute to the in vivo efficacy. The alpha particle range from Xofigo is less than 100 micrometers (less than 10 cell diameters), which minimises damage to the surrounding normal tissue.
Xofigo is approved in the U.S. for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastatic disease.
In September 2009, Bayer signed an agreement with Algeta ASA (Oslo, Norway) for the development and commercialization of Xofigo. Under the terms of this agreement, Bayer will develop, apply for health authority approvals worldwide and commercialize Xofigo globally. Algeta is co-promoting Xofigo with Bayer in the U.S.