February 6, 2001 CHICAGO (AP) - A new generation of AIDS medicines in development may outwit HIV's uncanny ability to grow resistant to standard drugs.
The drugs are a form of protease inhibitor, the main ingredient of drug cocktails that have revolutionized the treatment of AIDS.
A main drawback of these drugs is they lose power when the virus evolves mutant forms that are impervious to them. Once this happens, AIDS becomes much more difficult to treat.
Several variations of a new protease inhibitor are being developed by Tibotec of Rockville, Md., that seem able to attack these resistant viruses. They were described Monday at the Eighth Annual Retrovirus Conference in Chicago.
The drugs look promising in test tube studies, but testing in people has just begun, and no one knows if they will work and be safe.
Nevertheless, Dr. David Ho of the Aaron Diamond AIDS Research Center in New York City said, "We have for the first time a very, very powerful protease inhibitor that could suppress resistant virus. That's pretty impressive."
John Erickson of Tibotec said one prototype, code-named TMC-126, demonstrates an extraordinary capability to block the virus from replicating in the test tube, and it works across a broad spectrum of HIV strains that are resistant to many different protease inhibitors.
In addition, the drug appears to suppress the development of new varieties of resistant virus. Erickson described the combination of these two features as "resistance-repellence."
Protease is an essential viral enzyme necessary for the virus to commandeer human cells, forcing them to make new copies of HIV.
Erickson said TMC-126 appears to work by binding especially tightly to protease and yet being flexible enough to attack slightly different forms of the enzyme.
He said that if the drug passes testing, it could be used to help AIDS patients who have failed other treatments as well as be front-line therapy for those with newly diagnosed infections.
Copyright 2001 The Associated Press. All rights reserved.
