AZT Found to Delay AIDS in Those Free of Symptoms

Announcing a significant advance in the battle against AIDS, federal health officials said Thursday that the antiviral drug AZT has been shown to delay onset of the disease in certain groups of infected patients who have not yet developed symptoms.

“What we have learned . . . provides real hope for the millions of people worldwide who are infected with HIV (human immunodeficiency virus),” said Health and Human Services Secretary Louis W. Sullivan. “We are indeed entering the period when AIDS may become a treatable disease.”

The announcement came just two weeks after another AZT study showed that the drug arrests the progression of the disease in individuals experiencing initial symptoms of infection.

Together, the findings could benefit about 600,000 of the estimated 1.5 million infected individuals in this country, health officials said.

Dr. Anthony Fauci, chief of AIDS activities for the National Institutes of Health, said the AZT findings have “the broadest impact” of any of the therapeutic advances shown in recent years to prolong the lives of patients with AIDS or HIV infection.

Fauci said the findings are an important step toward the goal of moving AIDS from “an inevitably fatal disease” to “a disease that can be controlled over time” through early treatment after infection.

Moreover, Sullivan said, the latest information “underlines anew the need for people to voluntarily undergo HIV testing and counseling” so they can fully benefit from treatment.

“Every person who has reason to believe or suspect that he or she has been exposed to the virus should seek testing and counseling,” Sullivan said. He also cautioned that “AZT is not a cure and, indeed, even those who are under AZT treatment remain capable of transmitting the disease.”

AZT, or zidovudine, was approved by the Food and Drug Administration in 1987 for the treatment of fully developed AIDS. The two recent studies present the first real evidence that the drug can be effective in the earliest stages of disease.

In the latest study, infected individuals who had impaired immune systems but no symptoms and who took AZT developed AIDS or severe AIDS-related complex at half the rate of those who took a medically inert placebo.

The study--the largest AIDS clinical trial ever conducted--began two years ago and was coordinated by Paul Volderding, an AIDS specialist at San Francisco General Hospital.

The trial compared high and low doses of AZT against a placebo in 3,200 people who were infected with the virus but had not developed symptoms.

Of the 3,200 volunteers, 1,300 initially had abnormally low counts of T4 cells in their blood, indicating that their immune systems had been damaged. Those participants had fewer than 500 T4 cells per cubic millimeter of blood, contrasted with a normal range of 800 to 1,200. T4 cells are the primary targets of the AIDS virus.

The 1,300 participants with low T4 cell counts were divided equally into three groups. One group received a medically worthless placebo; a second group received a high dose of AZT, and the third group was given a low dose of the drug.

In the placebo group, 38 individuals developed AIDS or severe AIDS-related complex, contrasted with only 17 in the low-dose AZT group and 19 in the high-dose AZT group.

On Wednesday, an independent board of scientists monitoring the study decided that the placebo arm of the trials should be halted for participants with low T4 cell counts and that those people should be offered AZT because of its potentially therapeutic effects.

Officials said the three-group approach will continue for participants whose T4 counts are above 500, “since the study has shown that short-term risk of developing AIDS is negligible in persons with higher T4 counts.”

Officials said progression of the disease was about the same in patients receiving the low dose of 500 milligrams of AZT per day or the higher dose of 1,500 milligrams per day.

Reinforcing the study results of two weeks ago, they said that side effects associated with AZT were minimal, indicating that the drug can be better tolerated early in the disease. AZT has proved to be extremely toxic in many people with fully developed AIDS.

Although the results of both studies were dramatic, officials emphasized that AZT is not considered an AIDS cure and it remains unclear how long the disease can be slowed or delayed.

Although AIDS organizations, lawmakers and others cheered the results of the latest study, many expressed concern that AZT--which can cost a patient from $8,000 to $12,000 a year--will be inaccessible to many who need it.

“This announcement is great news for those people with good insurance,” said Rep. Henry A. Waxman (D-Los Angeles), chairman of the House Energy and Commerce subcommittee on health. “We have to find a way to get this drug to all who need it.”

Sullivan said he ordered the Medicare system Thursday to begin reimbursing for AZT, although it is unclear who would benefit from the directive. Medicare is available only to individuals older than 65, final-stage kidney disease patients and those who have been disabled for 29 months under Social Security regulations. Fully developed AIDS is considered a disability, but AIDS infection is not.

The administration of AZT, which is manufactured by Burroughs Wellcome Co. of Research Triangle Park, N.C., is not covered by all private health insurance programs and is covered by Medicaid only under certain circumstances.

“This research news is tremendously encouraging,” said Sen. Edward M. Kennedy (D-Mass.), chairman of the Senate Labor and Human Resources Committee.

Jean McGuire, executive director of the AIDS Action Council, said the news “marks a major turning point in the AIDS epidemic. For the first time, there is hope at the asymptomatic stage that progression to serious AIDS manifestations may be delayed.”