Wall Street Journal Examines Pharmaceutical Companies’ Efforts To Develop HIV Entry Inhibitors

The Wall Street Journal on Wednesday examined how several pharmaceutical companies are "rushing" to develop antiretroviral entry inhibitor drugs, which "block" HIV before it enters human cells rather than fighting it once inside the cells. Entry inhibitors have shown positive results in early clinical testing, and long-term studies are ongoing, according to the Journal. Drug companies Pfizer and GlaxoSmithKline currently are conducting clinical trials with experimental entry inhibitors that block HIV from "docking" with a human cell's CCR5 receptor, which is where HIV latches onto a cell to enter it, the Journal reports. HIV that uses as an entry point another receptor, called CXCR-4, is less common and more prevalent in advanced stages of HIV, according to the Journal (Hovey, Wall Street Journal, 1/5). Previous studies have shown that people who lack CCR5 receptors because of genetic mutations rarely contract HIV (Kaiser Daily HIV/AIDS Report, 10/15/04). GSK is developing CCR5-blocking compounds with Schering-Plough. The compounds have had no harmful side effects in early studies, and the companies hope to begin Phase III testing later this year and file for FDA approval in 2007, according to an unnamed GSK spokesperson, the Journal reports. Pfizer's experimental CCR5 inhibitor, called UK-427, has entered Phase III trials, according to the Joseph Feczko, the company's drug development chief. Canadian biotechnology company AnorMED is developing an experimental CXCR-4 inhibitor that it hopes will have completed a Phase II study by early 2006, Gary Bridger, the company's chief scientific officer, said, according to the Journal (Wall Street Journal, 1/5).