2013年7月25日讯 /生物谷BIOON/ --默沙东（Merck & Co）7月24日宣布，FDA已接受审查其抗凝血剂vorapaxar的上市申请（MA)，该药旨在用于既往有心脏病发作病史但无中风病史的患者，预防心脏病发作和中风。

默沙东于2009年通过收购竞争对手先灵葆雅（Schering-Plough）获得vorapaxar，该药一度被认为是一个潜在的重磅产品，有望成为华法林（warfarin）有前途的接班人。

但vorapaxar的前景在2011年枯萎，一个安全委员会监督一项涉及26000例患者的研究TRA-2P时称，该药不适合那些已遭受过一次中风的患者，因为该药使出血风险升高。一些分析师称，该药物估计永远不会出现在销售代表手中。

默沙东之后被允许在心脏病发作或被诊断为腿部动脉堵塞但病情稳定的患者中继续推进该项研究。有中风病史的患者从该试验中被排除。

该项研究的目的是观察，vorapaxar是否能在更有限的患者群体中安全地用于预防心脏病发作和中风。

尽管现已完成的试验和一个单独的早期研究TRACER试验的数据均好坏参半，但默沙东去年夏天称，将继续寻求vorapaxar的获批。

但一些分析师警告称，即便vorapaxar获批，由于出血风险，该药应用的患者数量可能十分有限。（生物谷Bioon.com）

英文原文：FDA accepts review of long-delayed Merck blood clot drug

July 24 - Merck & Co. on Wednesday said U.S. regulators had accepted its marketing application for the blood clot drug vorapaxar, aimed at preventing heart attacks and strokes in patients who have already had a heart attack but who have no history of stroke.

The experimental drug, acquired by Merck through its 2009 acquisition of rival U.S. drugmaker Schering-Plough Corp., was once considered a potential blockbuster product.

But its prospects wilted in 2011 when a safety committee overseeing a 26,000-patient study, called TRA-2P, said the new type of anti-platelet drug was not appropriate for patients who had already suffered a stroke because the drug raised bleeding risk.

Merck was allowed to press ahead with the trial, one of the largest heart-drug studies ever conducted, among patients who were in stable condition after having heart attacks or being diagnosed with clogged leg arteries. Patients who had suffered strokes were excluded from the trial.

The study's aim was to see if vorapaxar could prevent heart attack and stroke in that more-limited patient population and whether it could do so safely, given the drug's established bleeding risk.

Despite mixed results of the now-completed trial and the drug's failure in a separate earlier study called TRACER, Merck last summer said it would seek approval of vorapaxar.

"Despite the use of standard therapy, there continues to be residual risk of additional heart attacks in these patients," Merck spokeswoman Pam Eisele said on Wednesday, citing the need for new drugs like vorapaxar, which works through a different mechanism than existing medicines.

But some analysts have cautioned that even if approved, it would likely be used by a limited number of patients because of the bleeding risk.

Merck shares slipped 0.6 percent to $47.63 in morning trading on the New York Stock Exchange.