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San Francisco Examiner
Three-drug mixture suppresses AIDS virus longer;
Lisa M. Krieger, Examiner Medical Writer
September 11, 1997
Two studies offer definitive evidence that an AIDS-fighting triple-drug cocktail suppresses the deadly virus for at least a year, delaying illness and prolonging life.

The three-drug regimen is far superior to a two- or one-drug regimen and should be the standard of care for the estimated 650,000 to 900,000 Americans living with HIV, scientists reported in Thursday's issue of the New England Journal of Medicine.

If the drugs show sustained effectiveness - as this evidence suggests - they could change HIV from a death warrant to a manageable chronic illness in some patients.

It is estimated that fewer than one-third of people living with HIV in the U.S. are taking the potent combination.

New AIDS treatments have prompted a flurry of Lazarus-like tales of patients who experienced a near-disappearance of virus and illness, as well as more cautionary stories of those who have received little benefit.

But the evidence - both pro and con - had not been put to a statistically rigorous test.

The two new studies offer some assurance that the effects of treatment can be both real and sustained, at least in some patients.

The new research also suggests that because the triple-combination regimen so sharply suppresses growth of HIV, it may slow or prevent the evolution of resistant viral strains. This holds out the promise of longer-term effective therapy.

The regimen is a potent combination of three antiviral medications, including the older AIDS drugs AZT and 3TC. It gets its real kick from the protease inhibitor indinavir, approved last year.

All three drugs are still, by normal standards of drug development, experimental. Those taking them are part of science projects.

"For the first time, we have definitive data documenting the effectiveness of this therapy for such a sustained period," said Dr. John Mellors of the Veterans Affairs Pittsburgh Health Care System and a researcher in one study.

One study found triple therapy cut the risk of infections, cancers and deaths by approximately half, compared to two-drug therapy.

Patients getting the triple therapy had a death rate of 1.4 percent over one year, compared to 3.1 percent in patients getting only two drugs. Of HIV patients on triple therapy, 6 percent progressed to AIDS; of those on two-drug therapy, 11 percent progressed, reported investigator Dr. Scott Hammer of Harvard Medical School.

The second study looked at patients' blood, rather than general health, and found that after one year, the triple therapy suppressed the virus to undetectable levels in 80 percent of those studied, reported Dr. Roy Gulick and his team from the New York University School of Medicine.

The triple therapy benefited patients who had previously taken AZT or those whose immune systems had already been severely damaged by HIV - two large groups of people that many thought might be beyond reach.

Used alone or in pairs, without protease inhibitors, the older drugs AZT and 3TC inhibit the virus but quickly lose their punch as mutant forms of HIV evolve that are immune to their effects.

The addition of a protease inhibitor, which intercepts the virus at a different stage in its life cycle, attacks the virus more completely - and prevents or delays emerging resistance.



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