FDA Advised to Approve AIDS Drug : AZT Clears Major Hurdle With Panel’s Recommendation
WASHINGTON — The experimental AIDS drug AZT cleared a critical regulatory obstacle Friday when a federal advisory committee recommended that the Food and Drug Administration approve the drug for marketing in this country.
If approved by the agency, which is expected to follow the panel’s recommendation, AZT would become the first drug in the nation licensed to treat the usually fatal disease.
The committee urged, however, that the distribution of the drug be “tightly controlled” by its manufacturer, Burroughs Wellcome Co., and that “thorough and extensive” post-approval monitoring be conducted “to resolve important questions about possible adverse effects and efficacy associated with AZT’s long-term use.”
Frequently Follows Advice
While the FDA is not bound by the recommendation of its advisory committee, made up of independent experts in infectious diseases, the agency frequently follows its advice and is expected to act within the next few months.
The FDA has established an accelerated process for considering all promising AIDS drugs, noting the urgency created by the nature of the deadly disease. AIDS patients typically survive no longer than two years.
AZT, or azidothymidine, has been studied thus far only on AIDS patients with early pneumocystis carinii pneumonia, a respiratory infection caused by a parasite, and on those with severe AIDS-Related Complex, an associated--and sometimes fatal--condition.
The committee recommended that the drug be prescribed only for those conditions until further studies can demonstrate the drug’s impact on other manifestations of AIDS.
Survival Prolonged
The committee said in a statement that the data from the company’s study demonstrates “AZT’s ability to prolong the short-term survival” of AIDS patients with recently diagnosed pneumocystis and certain patients with advanced ARC.
“These and other data indicate . . . that AZT is reasonably safe and effective for this specific indication,” the committee said.
Dr. David Barry, vice president for research at Burroughs Wellcome, said he estimated that at least 15,000 patients would be eligible for the drug, although the figure could actually be much higher. Currently, there are about 13,000 living AIDS patients. Individuals suffering from ARC, however, have been estimated as high as 20 times that number.
Barry would not predict how much the drug would cost once it reached the market. “It will be expensive because it’s expensive to make,” he said.
Strict Distribution Sought
Anticipating a potential shortage of AZT once it is approved, the company also proposed a strict distribution system to ensure that patients who most need the drug receive it, a plan later endorsed by the committee in its recommendation. The drug will be allocated only through company-designated pharmacies and physicians whose patients fit the criteria, Barry said.
Only eight patients have died from an original group of 145 who have been receiving the drug in a clinical study that began last spring, the company said.
The study, initially a double-blind, placebo-controlled clinical trial--meaning that a second group of patients was taking a medically worthless placebo as a control--was halted Sept. 20 when the early results were so encouraging. An independent scientific monitoring board determined that medical ethics demanded that members of the placebo group be given the drug and that it be made more widely available to other AIDS patients.
At the time the study was stopped, 19 patients on the placebo had died, compared to one taking the drug.
32 in Group Died
Since then, a total of 32 patients from the original placebo study group have died, most of them during the early weeks after the study was stopped. Seven more of the initial AZT recipients have died.
“We would be the first to agree that AZT does not stop death in all patients,” Barry said. “The question is whether the mortality rate is lower in patients on the drug.”
Company officials and AZT researchers told the committee that patients on AZT have experienced fewer and less severe episodes of opportunistic infections, have gained weight and had improved neurological functions, such as memory and “mental speed.” While the long-term effects on AZT are not known, the most toxic side effect thus far appears to be a significant decrease in the production of red and white blood cells.
AIDS, or acquired immune deficiency syndrome, is caused by a virus that destroys the immune system, making the individual powerless against otherwise rare infections and cancers. It can also invade the central nervous system, causing severe neurological disorders.
It is transmitted through anal and vaginal sexual intercourse, through the sharing of unsterilized hypodermic needles and by mother to child during pregnancy.
In this country, AIDS has primarily afflicted homosexual and bisexual men, intravenous drug users and their sexual partners. As of Monday, 29,435 Americans had contracted AIDS, of whom 16,667 had died.
