|
|
作者：路透社 来自：路透社 发布时间：2004-3-17 |
|
|
| |
 葛兰素史克（GlaxoSmithKline，GSK）2月11日表示，已开始对一种前景看好的爱滋病毒（HIV）新药中期测试。该药的前期测试资料于当日早些时候公布，结果令人鼓舞。辉瑞（Pfizer，PFE）也已经完成了一种类似药物的二期（中期）测试；而先灵（Schering-Plough，SGP）计划很快开始其类似新药的二期测试，该药原理为阻断HIV进入人体细胞。葛兰素新药873140的一期测试资料是2月11日在逆转录病毒和机会性感染大会（Conference on Retroviruses and Opportunistic Infections）旧金山年会上公布的。与辉瑞和先灵的新药一样，葛兰素新药的原理为阻断在某类白血球细胞表面发现的CCR5蛋白受体，而这类白细胞上面还覆盖着另一种CD4蛋白的受体。“我们的新药几乎完全阻断了CCR5受体；无论测试者服用的剂量如何，阻断率都达到95-100%，”葛兰素负责该药开发的项目主管拉方（Stephen LaFon）谈到一期测试结果时说。拉方表示，在有关HIV对新药抗药性的试管研究中，该病毒抗药性的发展“非常缓慢”。他说，如果接下来的测试取得成功，葛兰素计划在2007年的年中寻求美国主管部门批准该药。 Glaxo Begins Phase 2 Trial of New Type of HIV DrugWed February 11, 2004 06:25 PM ETNEW YORK (Reuters) - GlaxoSmithKline Plc said on Wednesday it has begun a mid-stage trial of a promising new type of HIV pill, following positive data from a previous study of the medicine that were described earlier in the day.Pfizer Inc. has already completed Phase II, or mid-stage, trials of a similar medicine and Schering-Plough Corp. plans to soon begin Phase II trials of its own such experimental drug meant to prevent HIV from entering human cells.Data from the Phase I trial of Glaxo's drug, called 873140, were presented on Wednesday at the annual meeting of the Conference on Retroviruses and Opportunistic Infections in San Francisco.Stephen LaFon, Glaxo's project leader for the medicine, said his company earlier this month began enrolling patients for the follow-up Phase II trial, whose results are expected to be announced later this year.Like the Pfizer and Schering-Plough pills, it works by blocking receptors to the CCR5 protein found on the surface of a certain type of white blood cell that is also covered with receptors to a second protein called CD4.HIV, the virus that causes AIDS, invades the white blood cells through a two-step process of latching onto a CD4 receptor and then grabbing hold of a CCR5 receptor.By binding to the CCR5 receptor, and thereby blocking that doorway, the three rival drugmakers hope their drugs will effectively prevent HIV from slipping inside the white blood cells and turning them into factories for making copies of itself.LeFon said Glaxo's Phase I trial involved 40 people who had never been infected with the virus that causes AIDS. They were given varying doses of 873140 twice daily for 7 days. Their white blood cells were then analyzed to see how well the drug bound to -- and presumably thereby blocked -- the CCR5 receptors found in great numbers on their surfaces."Our drug pretty much completely blocked the CCR5 receptors, by 95 to 100 percent, regardless of the dose used," LeFon said in an interview.Moreover, he said most of the receptors remained bound more than 24 hours, providing optimism the Glaxo drug might only have to be administered once daily if it is eventually approved.Pfizer plans within the next few months to begin Phase III trials of its medicine, called UK-427,857.Schering-Plough Corp. on Monday said it had completed a Phase I trial of its CCR5 blocker, called SCH-D, and that it caused a 50-fold reduction in the amount of virus in HIV-infected patients.That is similar to the efficacy seen with Pfizer's drug. It is also in line with the impressive viral reductions achieved with standard HIV treatments, all of which, by contrast, work by preventing HIV from replicating once the virus has already gotten inside CD4 white blood cells.A high percentage of people taking HIV drugs eventually fail to benefit from the medicines as the virus mutates and becomes resistant to the treatments.LeFon said the virus was "very slow" in test-tube studies to develop resistance to Glaxo's drug, although it remains unclear whether that favorable trend will hold up in clinical trials.He said Glaxo aims to seek U.S. approval for its drug in mid-2007, if it succeeds in upcoming trials. |
|
