HIV locked out

2019-03-08 05:19:03

By Nell Boyce in Washington DC A NEW type of drug that shuts the door HIV uses to enter cells is just as potent as current AIDS treatments, a first clinical trial suggests. Existing drugs such as AZT and protease inhibitors stop the virus replicating by blocking key enzymes. But with the creeping threat of drug resistance doctors know more drugs are needed. So some researchers tried a different tactic and designed a synthetic peptide called T-20 that blocks the fusion of the virus with cell membranes of the white blood cells it infects—the process that allows HIV’s RNA inside. The first test on people suggests the drug has potential, says Michael Kilby of the University of Alabama at Birmingham. Kilby’s team tested T-20 in 16 HIV-infected adults. Patients receiving the highest intravenous dose for two weeks had a near 100-fold drop in blood virus levels with no significant side effects (Nature Medicine, vol 4, p 1302). “It’s a very important proof of concept that you can inhibit fusion,” says Robert Schooley, an AIDS expert at the University of Colorado in Denver. “The fact that this can be done in vivo squelches a lot of scepticism about this approach,” says Kilby. But like other peptides T-20 cannot be absorbed in oral form, which limits its usefulness. “It’s going to be awfully hard to develop an oral drug based on a peptide,