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AIDSWEEK: Studies show mixed results for drug combo




 

THIS WEEK, researchers from New York University reported that a triple combination of anti-AIDS drugs was still keeping the virus in check in some patients after two years, twice as long as previously reported.

The study, released at a scientific meeting in Toronto, suggests that at least in some people the new AIDS drug cocktails may have lasting effectiveness.

But a second study reported by UC-San Francisco's Dr. Steven Deeks found that the therapy worked in only half of HIV patients, reinforcing the view that the regimen is not foolproof.

The two reports paint a mixed picture of where the AIDS epidemic is headed. While many patients have prospects for a healthy future, others are in dire need of newer and better treatments.

The seemingly conflicting outcomes of the two studies reflect the differences in their subjects and treatment approach.

The first study involved patients in a rigorously controlled clinical trial who had not yet been exposed to many drugs. They were given two new drugs at once, to go along with the AZT they already were taking.

The second study looked at patients in a public clinic who, in general, had been sicker to start with, had more severely damaged immune systems, carried higher levels of the AIDS virus, had already been through a long series of ineffective single-drug treatments for HIV and may not have adhered perfectly to the treatment schedule.

Although a genetic comparison of the viruses in the two different groups of patients has not been performed, it is likely that the HIV carried by those in the first group is vulnerable to therapies, while the virus in the second group is resistant, said scientists at the conference.

Patients in both trials were on triple-combination therapy: AZT, 3TC and one of a new class of anti-HIV agents called protease inhibitors. In the first trial, sponsored by Merck & Co., the protease inhibitor used was indinavir, known by the trade name Crixivan. In the second trial, a variety of different protease inhibitors was used.

The first study found that after taking the three drugs for 100 weeks, 22 of 28 (79 percent) patients still had no detectable HIV in their blood, said Dr. Roy Gulick, assistant professor of clinical medicine at the New York University School of Medicine.

"This shows that you really can control HIV infection in a lot of patients for as long as two years," Gulick said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy in Toronto.

"The million-dollar question is: How long will this last?" he said.

The study is significant because it offers the longest look yet at the effectiveness of the triple therapy in suppressing HIV to immeasurable levels.

Equally encouraging, Gulick said, is evidence that the three-drug cocktail helped patients rebuild the immune systems that let them ward off disease. Patients taking the drug cocktail experienced a rapid rise in CD4 immune cells over the first six months, then a slower continued rise in cells during the 1-1/4 years that followed.

Although the patients have no signs of HIV in their blood, Gulick said it was premature to conclude that the drugs had completely wiped out the patients' infection. It is likely, he said, that traces of virus still remain hidden in certain immune-system cells.

The second study, also reported at the medical conference Monday, found that many patients outside carefully controlled clinical settings didn't fare nearly as well. After just six months, the triple-drug therapy failed in 53 percent of "real world" patients in San Francisco.

"The public has gotten the feeling that the epidemic is over, that these drugs are having this tremendous effect, with people who were on their death bed doing great," said Deeks, the author of the study. "Many people are going back to work . . . and in all likelihood they're going to live forever as long as they continue to take their drugs.

"But there's a whole group of patients - up to half - now showing evidence of drug failure. Those people in all likelihood are not going to respond very well to other protease inhibitors, and we as researchers have to be very vigilant and develop other options for those people," Deeks said.

Dr. Jerome Groopman, chief of experimental medicine at Boston's Beth Israel-Deaconess Medical Center, agreed: "It's a real advance, but it's not a cure. . . . If that misconception makes us passive about developing new drugs, we'll have set ourselves back."

News briefs

*Two-thirds of all Americans infected with HIV already know it. Researchers from the U.S. Centers for Disease Control and Prevention estimate that about 775,000 Americans carry HIV, and at least 500,000 have been tested and know their status.

*Researchers have statistically linked declining AIDS death rates with the use of combination therapies.

The first weak protease inhibitor became available in late 1995, and in 1996 there arrived two stronger ones that are now mainstays of treatment. In an analysis of almost 3,000 patients, Dr. Scott Holmberg of the CDC found that through 1995, the death rate among these patients averaged 7 percent every three months, but by the third quarter of 1996 the death rate had fallen to 3 percent. In the final three months of 1996, it was just 2 percent.

*The U.S. Food and Drug Administration has approved the first pill that combines two popular AIDS drugs, AZT and 3TC.

People infected with HIV now have to take more than a dozen pills a day. This new pill, called Combivir by manufacturer Glaxo Wellcome, will cut six pills out of the daily regimen.

The toll

James Tetzlaff, an artist, photographer and graphic designer with Design Vectors in San Francisco . . . Edward P. Schottman, 45, who loved all aspects of the arts, from grand opera to full-body Japanese tattoo . . . Joseph Taro Vega, 46, a singer and active member of a Bay Area cabaret who produced the local shows "A Whole Lotta Bessie in Me," "Fascination" and "Surviving the Crunch," in St. Louis . . . Scott M. Woods, 45, who enjoyed baking, biking, skating and collecting records, in Concord.

. . . . . .Date

. . . . . .reported. . Cases. . . Deaths

S.F.. . . .9/1 . . . . 24,611 . . 16,878

Calif.. . .9/1 . . . .102,574 . . 65,463

U.S.. . . .9/1 . . . .581,429 . .362,004

WHO(rprtd) 9/1 . . .8,400,000 . 6,400,000

Figures are cumulative since June 1981. Government officials now compile and release statistics quarterly, not monthly.

To contribute to AIDSweek, call (415) 777-7867. AIDSweek columns are available on the Internet at www.examiner.com / aidsweek / aidsweek.html



 


Copyright © 1997 -The Bangkok Pos, Publisher. All rights reserved to San Francisco Examiner. All rights reserved. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the San Francisco Examiner, Permissions Desk, 110 Fifth Street, P.O. Box 7260, San Franciso, CA 94120.San Francisco Examiner

Information in this article was accurate in October 1, 1997. The state of the art may have changed since the publication date. This material is designed to support, not replace, the relationship that exists between you and your doctor. Always discuss treatment options with a doctor who specializes in treating HIV.