The federal government Friday approved the experimental AIDS drug AZT for marketing in the United States, making it the first drug licensed in this country to treat the deadly disease.
Dr. Robert E. Windom, assistant secretary for health at the Health and Human Services Department, emphasized that AZT, to be sold under the trade name Retrovir, is not a cure for AIDS. But he said the action "means that significant medical relief will be available to thousands of those afflicted with this dreaded disease."
Windom said that licensing of the drug, which was recently approved for sale in France and Britain, "marks an important step but by no means a final victory in our ongoing war against AIDS."
AZT, or azidothymidine, is expected to be expensive, costing each patient as much as $10,000 a year.
Final approval of AZT, first administered to AIDS patients in human studies begun in July, 1985, came in record time, the result of a decision by the Food and Drug Administration to consider AIDS drugs as a top regulatory priority. Typically, the process takes an average of 8 1/2 years from the earliest studies to licensing.
"The agency will continue to follow up on post-marketing studies so that we can understand as much as possible about this drug," FDA Commissioner Frank Young said in an interview. "Nevertheless, we feel it is clearly appropriate to approve the drug at this time. New products will be passed through the regulatory process with as much compassion and dedication as humanly possible."
In another departure from usual procedures, distribution of AZT will be tightly controlled by its manufacturer, the Burroughs Wellcome Co., to ensure that only patients with AIDS and AIDS-related complex (ARC) who meet certain criteria can receive it, although the criteria appear flexible. Traditionally, once a drug is licensed by the FDA, there are no restrictions on how physicians prescribe it.
Must Submit Data
Under a program designed by the company, physicians with candidate patients will be asked to submit data about them to a special coordinating center staffed by a panel of physicians. This committee will evaluate the information and decide whether the patients qualify for AZT. Each patient approved for the drug will be assigned a specific number that will be written by the physician on the prescription, which can be filled at any pharmacy.
The criteria include an episode of pneumocystis carinii pneumonia, a parasite-induced respiratory infection common to AIDS patients, or a count of 200 or fewer so-called T-4 "helper" cells per cubic millimeter of blood. The T-4 cells, a critical part of the body's immune system, are the primary target of the AIDS virus. A normal count is 1,000 to 3,000.
Researchers said Friday that the T-4 cell requirement probably would include most patients with full-fledged AIDS and probably would enable many more patients to qualify for AZT than originally had been thought.
Supplies of the drug are expected to be limited, however, and company officials said Friday that they expect to have "adequate drug by April 1 to meet the needs of at least 15,000 patients and 30,000 by the end of 1987."
14,000 Patients Survive
Of the nearly 33,000 AIDS patients reported in this country since 1981, about 14,000 are still alive. AIDS patients typically survive no more than two years, and those who suffer repeated bouts of pneumocystis carinii pneumonia often die within 35 to 40 weeks of diagnosis.
Further, it has been estimated that there are as many as 200,000 to 300,000 individuals suffering from ARC, an associated AIDS disorder characterized by a different set of symptoms, which are often as debilitating as AIDS with as high a death rate.
AZT has been shown to be effective in prolonging the short-term survival of AIDS and ARC patients and decreasing the number and severity of opportunistic infections. However, the drug can cause toxic side effects, the most serious being bone marrow suppression that decreases the production of white and red blood cells.
Bone marrow suppression required that AZT either be discontinued, or its dose reduced, in 34% of those patients who have received it, the company said. The long-term effects of the drug are not known.
Concern Voiced on Cost
Nevertheless, AIDS researchers who have studied AZT and others applauded approval of the drug, though many expressed concern about its cost.
"A lot of people should be happy about this," said Dr. Robert T. Schooley, an AIDS specialist at Massachusetts General Hospital who has studied AZT. "We still have a lot to learn about this drug . . . but two very important things have been established: The first is that a drug that inhibits growth of the virus can have a beneficial effect for patients, and the second is that we can learn this fact in a relatively short period of time with a focused, well-planned research effort."
Dr. Michael Gottlieb, who has studied AZT at UCLA, called the approval "a milestone" and said it "offers encouragement that the system can respond in a time of medical urgency."
But Rep. Henry A. Waxman (D-Los Angeles), chairman of the House Energy and Commerce subcommittee on health, said: "We've got to figure out how to get it to patients who need it and won't be able to pay for it."
Additional Funds Sought
Waxman said he has asked the House Appropriations Committee to "add money immediately" to the supplemental appropriations bill to assist AIDS patients this year in purchasing the drug. Further, he said, he has asked the House Budget Committee "to put aside $60 million for fiscal year 1988, either to have Medicaid pay for the drug or to set up some other pool for purchase of the drug by those who can't afford it."
The AZT approval process was accelerated last September after a double-blind, placebo-controlled clinical trial--meaning that a second group of patients was taking a medically worthless placebo as a control--of 281 patients was halted when the early results showed that the drug had a significant impact on prolonging life.
An independent scientific monitoring board said 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. Since then, about 4,500 patients have received the drug without charge on an experimental basis.
At the time the study was stopped, 19 patients from the placebo group of 137 had died, compared to only one from the group of 144 who had been given the drug. As of February, a total of 35 patients from the original placebo group had died, compared to a total of 11 from the original group receiving the drug, the company said.
Destroys Immune System
AIDS destroys the body's immune system, leaving it powerless against certain cancers and otherwise rare infections. The virus can also invade the central nervous system, causing severe neurological disorders. It is commonly transmitted through anal and vaginal sexual intercourse, through the sharing of unsterilized hypodermic needles, and by woman to fetus during pregnancy.
In this country, AIDS has primarily afflicted homosexual and bisexual men, intravenous drug users and their sexual partners.
AZT, originally derived from fish sperm but now synthetically produced, works by playing a chemical trick on the virus that causes AIDS. It was originally developed in 1964 by Dr. Jerome Horowitz of the Michigan Cancer Foundation as a possible treatment for cancer.