HIV Digest	HIV Digest Archive

Salvage therapy represents the last hope for an estimated 40,000 US patients for whom standard AIDS drug regimens no longer work. While some physicians put their salvage patients back on older drugs, other doctors attempt to gain access to experimental treatments.

In 2004, AIDS killed 15,798 Americans, a steep decline from 51,000 deaths in 1995. Twenty-two approved AIDS drugs are now on the market, but even with the best treatment, "We've only changed the slope of the disease progression, not halted it altogether, and eventually they do run out of options," said Dr. Daniel Kurtizkes, an associate professor of medicine at Harvard Medical School.

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Many patients now on salvage therapy have been HIV-positive for more than two decades. Some took AZT when it was approved in 1987. Many switched to new drugs as they came out, believing this to be the best strategy. But by the time protease inhibitors were introduced in 1996, these patients "already had high-level resistance," said Dr. Steven Deeks of San Francisco General Hospital and the University of California-San Francisco. It now seems that rapid switching of single drugs encouraged the development of drug-resistant virus.

People on drug cocktails who still aggressively switch to new drugs are perpetuating the problem, Deeks said. "We need to stop switching so aggressively. We need to hold still until we have a number of new families of drugs," he said. He counsels returning to old drugs like AZT or 3TC to stabilize patients until two or three novel drugs can be prescribed in an all-new cocktail.

The experimental drugs furthest along in development include TMC114, a new protease inhibitor from Johnson & Johnson's Tibotec; new integrase inhibitors from Gilead and Merck; entry inhibitors from Pfizer and Schering-Plough that block the CCR5 co-receptor; and Tanox's IV monoclonal antibody to block HIV's entry through the CD4 receptor on human immune cells.

Editor's Note: from the Wall Street Journal