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【原创】“万络”魂断美利坚
纽约（路透社）讯，美国默克公司已于9月30日在一项研究中证实了服用关节药万络（VIOXX）会增加心肌梗死与中风的危险后, 宣布在全世界范围内撤回这个被百万患者使用的药物。
默克说，它是在审评一项进行了三年的结肠癌试验的数据后决定撤回该药的。
该试验被设计用于评估标准剂量25mg 万络在预防结肠息肉中的作用，有时这些息肉会变成癌（一些研究者认为关节中的炎症也可能与结肠癌有关）。
默克宣称，在试验的前18个月，并未发现心肌梗死和中风的情况，但随后却发生了。
在新闻发布会上，默克承认，“在该项研究中，与服用安慰剂的患者相比，服用万络的病人在服药18个月后患上心肌梗死和中风等心血管疾病的可能性较大。” 建议“正在使用万络的患者应与他们的医生联系，停止使用万络并选择其他可能的治疗方法”。
万络和辉瑞公司的西乐葆（Celebrex）及BEXTRA均被设计用于治疗炎症和疼痛，作用机制是抑制导致炎症的蛋白COX-2。与标准的非甾体抗炎药（NSAID）药如阿斯匹林和布洛芬相比，疗效相当但极少发生溃疡和胃肠道反应。
美国FDA的一项近期研究数据显示，服用万络会增加血栓的形成，从而导致心肌梗死和中风。服用万络的患者发生心肌梗死和突发心脏猝死的几率比服用辉瑞公司的关节炎药CELEBREX增加50%。
消息一经公示，默克的股价立马下降15%，而销售两个与万络竞争的抗关节炎药（西乐葆和BEXTRA）的辉瑞公司股价却上升了5%（由于这两个药品尚未发现与心肌梗死和中风有关，故而医生转向这些药品而导致这些药品的销量上升）。
Cathay金融分析家Sena Lund评论道，这对默克是一个沉重的打击，因为尽管万络由于安全问题近几年销售疲软，毕竟是关系到默克未来增长的五个拳头产品之一。
1999年上市的万络，单在美国就已经开出了9千1百万个处方（在某些国家以CEOXX的商品名销售）。2003年世界销售额达25.5亿美元（在某些国家以CEOXX为商品名销售）。
默克首席执政官Raymond Gilmartin说，“考虑到还有其它的治疗方法以及这次研究数据带来的问题，我们认为主动召回万络是负责任的行为。”
默克宣布将继续在47个国家销售更新的COX-2抑制剂ARCOXIA。但美国执法机构担心它与万络同样会导致心肌梗死和中风的危险，因此至今未下达批准指令。
Arthritis drug Vioxx being pulled
Thursday, September 30, 2004 Posted: 9:59 AM EDT (1359 GMT)
NEW YORK (Reuters) -- The arthritis drug Vioxx, used by millions of people around the world, is being pulled off the market after a study confirmed long-standing concerns that it raises the risk of heart attack and stroke, the manufacturer, Merck & Co., said today.
"Patients who are currently taking Vioxx should contact their health care providers to discuss discontinuing use of Vioxx and possible alternative treatments," Merck said.
The company said it was withdrawing the drug following a review of data from a three-year colon cancer trial.
"In this study, there was an increased relative risk for confirmed cardiovascular events, such as heart attack and stroke, beginning after 18 months of treatment in the patients taking Vioxx compared to those taking placebo," Merck said in a press release.
Worldwide sales of Vioxx totaled $2.55 billion last year. Since the introduction of the drug in 1999, 91 million Vioxx prescriptions have been written in the United States alone. The drug is sold in some countries under the name Ceoxx.
Merck shares plunged 15 percent in pre-market trading after the announcement. Shares of Pfizer Inc., which sells two rival arthritis drugs, rose 5 percent.
"It's a major blow for Merck," said Sena Lund, an analyst at Cathay Financial. "It was one of their five key drivers for future growth."
Vioxx sales have been flat in recent years amid safety concerns. Clinical trial data have shown the drug increased the incidence of blood clots tied to strokes and heart attacks.
A recent study by the U.S. Food and Drug Administration suggested patients taking Vioxx faced a 50 percent greater risk of heart attacks and sudden cardiac death than those taking Pfizer's Celebrex arthritis treatment.
Sales of the Pfizer arthritis drugs Celebrex and Bextra have steadily grown as doctors have turned to those drugs, which have not been linked to heart attack and stroke.
The colon cancer trial was designed to evaluate the effectiveness of the standard 25-milligram Vioxx dose in preventing recurrence of colon polyps. Such polyps sometimes become cancerous.
Vioxx was used in the colon cancer trial because some researchers theorize that inflammation, present in arthritis, may be linked to colon cancer.
Merck said the heart attacks and strokes were not spotted during the first 18 months of the trial but became apparent later.
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作者:admin@医学,生命科学 2010-12-13 17:11
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