Why did a promising heart drug fail? Doomed drug highlights complications of meddling with cholesterol. 1.The failure of a high-profile cholesterol drug has thrown a spotlight on the complicated machinery that regulates cholesterol levels. But many researchers remain confident that drugs to boost levels of good cholesterol are still one of the most promising means to combat spiralling heart disease. 2.Drug company Pfizer announced on 2 December that it was cancelling all clinical trials of torcetrapib, a drug designed to raise heart-protective high-density lipoproteins (HDLs). In a trial of 15000 patients, a safety board found that more people died or suffered cardiovascular problems after taking the drug plus a cholesterol-lowering statin than those in a control group who took the statin alone. 3.The news came as a kick in the teeth to many cardiologists because earlier tests in animals and people suggested it would lower rates of cardiovascular disease. There have been no red flags to my knowledge, says John Chapman, a specialist in lipoproteins and atherosclerosis at the National Institute for Health and Medical Research (INSERM) in Paris who has also studied torcetrapib. This cancellation came as a complete shock. 4.Torcetrapib is one of the most advanced of a new breed of drugs designed to raise levels of HDLs, which ferry cholesterol out of artery-clogging plaques to the liver for removal from the body. Specifically, torcetrapib blocks a protein called cholesterol ester transfer protein (CETP), which normally transfers the cholesterol from high-density lipoproteins to low density, plaque-promoting ones. Statins, in contrast, mainly work by lowering the bad low-density lipoproteins. Under pressure 5.Researchers are now trying to work out why and how the drug backfired, something that will not become clear until the clinical details are released by Pfizer. One hint lies in evidence from earlier trials that it slightly raises blood pressure in some patients. It was thought that this mild problem would be offset by the heart benefits of the drug. But it is possible that it actually proved fatal in some patients who already suffered high blood pressure. If blood pressure is the explanation, it would actually be good news for drug developers because it suggests that the problems are specific to this compound. Other prototype drugs that are being developed to block CETP work in a slightly different way and might not suffer the same downfall. 6.But it is also possible that the whole idea of blocking CETP is flawed, says Moti Kashyap, who directs atherosclerosis research at the VA Medical Center in Long Beach, California. When HDLs excrete cholesterol in the liver, they actually rely on LDLs for part of this process. So inhibiting CETP, which prevents the transfer of cholesterol from HDL to LDL, might actually cause an abnormal and irreversible accumulation of cholesterol in the body. Youre blocking a physiologic mechanism to eliminate cholesterol and effectively constipating the pathway, says Kashyap. Going up 7.Most researchers remain confident that elevating high density lipoproteins levels by one means or another is one of the best routes for helping heart disease patients. But HDLs are complex and not entirely understood. One approved drug, called niacin, is known to both raise HDL and reduce cardiovascular risk but also causes an unpleasant sensation of heat and tingling. Researchers are exploring whether they can bypass this side effect and whether niacin can lower disease risk more than statins alone. Scientists are also working on several other means to bump up high-density lipoproteins by, for example, introducing synthetic HDLs. The only thing we know is dead in the water is torcetrapib, not the whole idea of raising HDL, says Michael Miller, director of preventive cardiology at the University of Maryland Medical Center, Baltimore.
执政新词展现中共领导集体把握时局定力[1]
2019年12月英语四级作文预测:社会实践
扎克伯格“雾霾跑步”真是拼了!
体坛英语资讯:Italys Laporta wins Hainan Open European Challenge Tour
围棋“人机大战”上演
体坛英语资讯:Wu Xi scores twice as Suning beat Hebei 4-1 in Chinese CSL
2019年12月英语四级作文范文:邀请参加晚会
美国发型大赛决赛,媒体称画风过于刺激
天价“学区房”
体坛英语资讯:ITTF CEO expects to deepen cooperation with Chinese Table Tennis Association
央行正探索“利率走廊”机制
国内英语资讯:Improving governance system important for Chinas modernization: expert
澳大利亚遭遇历史级丛林大火,考拉纷纷逃亡
2017年中国“私募股权投资”创新高
袁贵仁谈中国教育发展水平
做起来,灵魂保健操
鼓励家庭成员“合葬”
“弹性学制”和“休学创业”
“保姆黑名单”规范市场
国内英语资讯:Chinese vice president meets Kissinger
国际英语资讯:AU expresses deep concern over UKs continued colonial administration of Chagos Archipelago
杨传堂:网约车对传统出租车行业带来巨大冲击
哭!夏天还没到就开始流行A4腰了!
2019年12月英语四级作文模板:环境健康角度
“主权信用评级”
国内英语资讯:Chinese state councilor calls for upholding multilateralism, free trade at G20 Foreign Minis
亚马逊推电子书“包月服务”
苹果应用商店下架并封禁电子烟app
权威声音:多部委“一把手”密集回应经济民生热点[1]
国内英语资讯:Beijing accelerates 5G coverage
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |