United Press International - Tuesday, 11 July 2000
Michael Smith, UPI Science News

"Eradication is not possible," said Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases (NIAID).

That means, Fauci told a plenary session of the conference, that researchers must turn to ways of making current drug therapies work better, at a lower cost in price and side-effects. One possible approach, he said, is to interrupt therapy for short periods of time.

Fauci's conclusion was echoed by David Ho of the Aaron Diamond AIDS Research Institute in New York, one of the leaders only a few years ago in proclaiming that then-new drugs might wipe out HIV, the virus that causes AIDS.

But discoveries over the past couple of years have shown that HIV can hide in lymph tissue and perhaps elsewhere in the body, and rebound when so-called "highly active antiretroviral therapy" (HAART) is stopped, he said.

The hope that HAART could wipe out HIV, Ho said, was based on two ideas, both later proved to be wrong: That the drugs would completely stop the virus from reproducing and that there were no "compartments" in the body where the virus could hide.

The admission that a cure is still not in sight came as researchers for the Centers for Disease Control reported Tuesday that HAART is not as effective in suppressing the reproduction of HIV as scientists had earlier hoped.

Researcher Scott Holmberg said HAART is effective for more than 12 months in only about one-third of patients. Others, Holmberg said, must regularly change their drug regimes in order to maintain low blood levels of HIV, which means that drug options "are increasingly being exhausted by the people who need them."

Fauci said the first hints that HAART was not wiping out HIV came in 1997, when several research groups found they could find the virus, even in patients who had been on the therapy for up to three years and who had no detectable level of HIV in their blood.

"That was the first sign we were not eradicating HIV," Fauci said.

The next step was to try to attack the "reservoirs" in which HIV hides, he said, but even when that seemed successful, the virus rebounded when HAART was stopped. The rebound occurred even in two patients who seemed to have no detectable virus in any part of their body, he said.

"The virus has the uncanny ability to re-establish a reservoir," Fauci said. "Even our most rigorous attempts to reduce or eliminate the reservoir had been unsuccessful."

But, he said, there were experimental hints that HIV took some time to rebound after HAART was stopped, which suggested that deliberately interrupting therapy for defined periods might not cause any harm.

On the positive side, he said, carefully scheduled interrupted treatments would also be cheaper, have fewer side-effects and be easier for patients to follow.

In early data from NIAID tests on human subjects, Fauci said, interrupting therapy -- either one week on, one week off or two months on, one off -- appears to control the virus as well as constant treatment, while reducing the cost.

He said it's still too early to know whether there will be fewer side-effects, but the test subjects are excited about avoiding the "extraordinary burden" of the pill-intensive therapy, in which patients must take as many as 40 pills a day.

But he added that physicians shouldn't move too quickly: "Don't try this until the trial is complete," Fauci said.

One fear in interrupting therapy is that the virus will be able to recover and perhaps evolve strains resistant to the drugs. But Fauci said that fear only applies to "sub-optimal therapy," in which patients don't follow treatment plans, and is unlikely to arise in his interrupted therapy.

The CDC's Holmberg, analyzing medical data from more than 1,600 AIDS patients across the United States, found that HAART use has climbed from 4 percent at the end of 1995 to 87 percent in late 1999. At the same time, AIDS deaths dropped by more than 90 percent.

But HAART failed to keep virus levels low for more than a year in 64 percent of patients, Holmberg said. Those who changed their drug regime -- because the virus became resistant or because side-effects were too extreme -- were less likely to keep HIV levels low.

The conference was interrupted briefly in mid-afternoon Tuesday by piercing whistles and air-horns wielded about 20 demonstrators from the AIDS activist group ACT- UP. The demonstrators, chanting "Greed costs lives, pills cost pennies," were protesting the lack of affordable drugs in the developing world.

The protest was the first non-sanctioned demonstration at this conference;

Sunday, South African groups organized a 5,000-strong protest march from Durban City Hall to the conference center. Earlier AIDS conferences have had their proceedings repeatedly interrupted by protests.
000711
UP000716

Always watch for outdated information. This article first appeared in 2000. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 2000. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .