Reuters：辉瑞乳腺癌新药palbociclib获FDA重大突破药物认定

美国审定机构指定辉瑞公司乳腺癌试验药物palbociclib为“重大突破药物”，公司股票应声上涨，其正在增长的癌症药物研发前景一片光明。JP摩根的分析称这种口服的抗癌药palbociclib能够为辉瑞公司带来50亿美元甚至更多的市场份额。这款药物可用于乳腺癌或其他类型癌症的治疗。
随着该药获得批准，辉瑞公司的股价应声上涨2.6个百分点，由于先前palbociclib的研究取得不错的临床结果，此次获得FDA特殊地位认定也是顺理成章的事情，现在辉瑞公司正在开展其III期临床研究。
美国食品药监局（FDA）称该药是一种突破性药物，能够提供比现在市场上的药物更加持久且有实质性改善的药效。公司预期加速该药的研发进程。Leerink Swann分析员Seamus Fernandez称palbociclib到2020年每年可带来24亿美元的销售额。他预言当前研究会证实palbociclib可延缓肿瘤生长并延长生存。
JPMorgan分析员Chris Schott称FDA的这一决定对辉瑞股票注入了强心剂并预言由于“突破性药物”指定的助推作用， palbociclib 将于2016年或更早一点获得批准。
在临床3期试验中，以局部晚期或转移性乳腺癌初治患者的试验对象，研究人员对Palbociclib以标准药物来曲唑为对照进行评估。辉瑞称稍早的中期试验的中期分析显示联合治疗的患者无症状恶化的平均时间为26.1个月，与之相比仅使用来曲唑的的患者这一数据为7.5个月。palbociclib的作用机理是通过组织CDK4和CDK6两种细胞周期蛋白依赖性激酶来起效。
辉瑞公司在过去的十年一直立志于研发出创新性的新药，其推出的肺癌药物Xalkori、肾癌的药物Inlyta和白血病治疗药Bosulif也确实为他赢回了不少市场。
与乳腺癌相关的拓展阅读：

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• Lancet Oncol：手术范围、超重或肥胖影响术后乳腺癌患者上臂淋巴水肿的发病率
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原文阅读：Pfizer cancer drug wins special status; shares jump
(Reuters) - U.S. regulators have granted a "breakthrough therapy" designation to an experimental Pfizer Inc treatment for breast cancer, lifting the company's shares and putting a spotlight on its growing cancer-drug portfolio.
Analysts from JPMorgan and Leerink Swann forecast the oral medicine, called palbociclib, could generate annual sales of $5 billion or more if it is approved for use against breast cancer as well as other types of cancer.
Pfizer, whose stock rose 2.6 percent, said the U.S. Food and Drug Administration conferred the special status on palbociclib based on impressive results seen in mid-stage trials. The drug is now being tested in a larger Phase III study.
The FDA created the "breakthrough therapy" designation earlier this year for medicines deemed likely to demonstrate "substantial improvement" over existing drugs. It is intended to speed development and regulatory review of such medicines.
Leerink Swann analyst Seamus Fernandez said palbociclib could generate annual sales of $2.4 billion by 2020 if it is approved for breast cancer. He predicted the current study would show palbociclib slows tumor growth and prolongs life.
JPMorgan analyst Chris Schott called the FDA decision a "clear positive for Pfizer shares" and predicted palbociclib will be approved by 2016 or sooner thanks to acceleration under the "breakthrough" designation.
Palbociclib is being tested in combination with a standard drug, letrozole, in a Phase III trial of patients undergoing initial treatment for locally advanced or metastatic breast cancer.
Pfizer said interim data from the earlier mid-stage trials showed patients on the combined therapy went an average 26.1 months without a worsening of symptoms, compared with 7.5 months for patients taking only letrozole.
Palbociclib works by blocking two enzymes: cyclin dependent kinases (CDK) 4 and 6.
Pfizer, which has struggled in the past decade to come up with important new medicines, has won respect with recent approvals of three cancer drugs: Xalkori for lung cancer, Inlyta for kidney cancer and Bosulif for leukemia.
Pfizer shares were up 77 cents to $29.88 in early-afternoon trade, outpacing a 1.2 percent rise for the ARCA Pharmaceutical Index of large U.S. and European drugmakers.