VANCOUVER, Canada — Aggressive treatment with multiple drugs can convert deadly AIDS into a chronic, manageable disorder like diabetes, said newly confident scientists and doctors who wrapped up the 11th International Conference on AIDS here Thursday.
Researcher after researcher reported virtually identical results, each offering evidence that his particular combination of drugs reduced levels of HIV--the virus that causes AIDS--in patients to the point of being undetectable and have sustained those reductions in studies begun about a year ago.
"There is now very compelling evidence that combination therapy . . . improves clinical outcome," said conference co-chair Dr. Martin T. Schechter of the University of British Columbia, one of several presenters Thursday. "It is unequivocal that combination therapy has now replaced monotherapy [use of only one drug] as the standard of care."
Further, it appears not to matter which "drug cocktails" are given to patients as long as they involve a combination of medicines from each of two classes of drugs as part of an aggressive treatment program, and as long as correct doses are administered consistently. Differing combinations of drugs from those two classes were used in the half-dozen major studies presented this week--without affecting results, the experts said.
The new point of comparison among AIDS drugs, said Dr. Roy Gullick of the New York University Medical Center, "may no longer be which drugs are most effective but which have the fewest side effects."
As long as the virus cannot reproduce, it cannot mutate to become resistant to the drugs, noted Dr. Joepe Lange of the University of Amsterdam in the Netherlands.
Earlier studies have shown that a reduction in the level of HIV is associated with an improvement in symptoms and a longer life span.
Critics, AIDS activists and scientists from developing countries complained that the drugs, which can cost $16,000 a year, are too expensive for many Americans and for most of the rest of the world. But their voices were largely lost in the drumbeat of enthusiasm.
Asked whether physicians should begin using the new drugs, Dr. Martin Markowitz of the Aaron Diamond AIDS Institute in New York summarized the attitude of most researchers here, saying: "Go for it!"
The growing consensus among clinicians is that the virus should be attacked vigorously as soon as possible after patients become infected with the human immunodeficiency virus. Markowitz reported on nine patients who began treatment with AZT, 3TC and ritonavir, one of a new class of drugs called "protease inhibitors," within 90 days after they were found to be HIV-positive.
A year after treatment began, HIV is now undetectable in all their bloodstreams, Markowitz said, adding, "It's very encouraging data." But he cautioned that HIV can linger in the brain and in other tissue, and it will be another year or two before he can say the virus has been eradicated from their bodies.
The treatments have also worked in advanced patients. Gullick reported on 97 patients who had been treated with AZT for an average of 2.5 years and had already developed AIDS when the NYU team began treating them. A combination of AZT, 3TC and the protease inhibitor indinavir has made the virus undetectable in the blood of 90% of these patients, Gullick said, and the results have been sustained for 60 weeks.
"We have really not seen that magnitude and duration of effect before," he said.
In general, studies show that results are not as good when protease inhibitors are not used.
Dr. William Cameron of Canada's University of Ottawa reported the long-awaited results of the first studies to use a combination of two protease inhibitors, ritonavir and saquinavir. His team found that the mixture reduced HIV levels so far that they could no longer be detected.
The pairing had additional benefits. Ritonavir blocks enzymes that would normally clear saquinavir from the body, permitting saquinavir to be used in lower doses and less frequently than is possible in other combinations. The lower doses and less frequent use reduce both side effects and cost, he said.
The side effects from other regimens can be a serious problem, particularly early in therapy. Christopher Murray, an HIV-positive member of Gay Men's Health Crisis from the Bronx, N.Y., said he suffered diarrhea, nausea, fatigue and headaches when he began triple-drug therapy about six months ago. "I was really knocked out," he noted.
Some side effects have persisted, he said, but the trade-off is that doctors have been unable to detect any HIV in his blood since two weeks after the treatment began.
Murray is one of the lucky patients whose insurance will pay for the drugs. Only 29% of HIV-positive people have private insurance, according to Gary Rose of the AIDS Action Council in Washington, D.C. An additional 50% to 60% are covered by Medicaid, which, in many states, limits patients to three prescriptions per month.