BURROUGHS WELLCOME's RETROVIR REDUCTION IN AIDS OPPORTUNISTIC

BURROUGHS WELLCOME's RETROVIR REDUCTION IN AIDS OPPORTUNISTIC infections compared to placebo is the most likely reason for a reduced mortality rate, according to the results of an efficacy study published in the July 23 issue of the New England Journal of Medicine. The study, which formed the basis for FDA approval of the drug last March for use in AIDS and ARC patients, found that the probability of survival for patients who recieved Retrovir for the 24 week trial was 98% compared to 78% for the placebo group. According to the study, "opportunistic infection did occur less frequently among subjects receiving AZT [Retrovir, azidothymidine] and is the most likely reason for the decreased death rate in this group." The study, conducted by Burroughs Wellcome and researchers at 12 medical centers, enrolled 282 patients between February and June 1986. Of that group, 160 had AIDS and 122 were diagnosed with AIDS-related complex (ARC). One hundred forty-five of the 282 patients were randomly assigned to receive AZT, while the remaining 137 subjects received placebo. Specifically, the AZT group included 85 AIDS patients and 60 ARC patients; the placebo group had 75 patients with AIDS and 62 with ARC. AZT "decreased mortality and the frequency of opportunistic infections in a well defined-group of subjects with AIDS or AIDS-related complex during a period of up to six months. The most striking difference between AZT and placebo recipients was a significantly lower incidence of death," the authors conclude. Also, after six weeks of AZT therapy there was no opportunistic infection among patients with ARC. Designed to last 24 weeks, the study "was terminated prematurely because there was a significant difference in mortality between the AZT and placebo recipients," according to the published results. Nineteen placebo recipients and one AZT recipient died during the study. An addendum to the report notes that "as of April 30, 1987, the mortality rate among the original 145 AZT recipients was 6.2% after 36 weeks of AZT therapy and 10.3% after 52 weeks." Mortality at nine months for the placebo group was 39.3%. "AZT administration was therefore associated with a fourfold-to-sixfold reduction in mortality rates in the study population at nine months," the study declares. Patients were eligible for the study if they had AIDS, accompanied by a first episode of Pneumocystis carinii pneumonia within the previous four months, or if they had advanced ARC. "Further studies will be needed to determine whether AZT will similarly benefit patients with other opportunistic infections fulfilling the definition of AIDS, or patients with less severe manifestations of HIV infection." The authors predicted that, because AZT delayed progression to AIDS and resulted in sustained increases in levels of CD4 cells in many ARC patients, "AZT may be particularly beneficial to patients with less severe HIV infection." In a separate report in the same issue of the New England Journal of Medicine, the authors said that AZT patients suffered nausea, myalgia, insomnia and severe headaches more frequently than those taking placebo. The major laboratory effects were anemia and neutropenia. Also, when taken with acetaminophen, AZT increased the frequency of neutropenia. "Since the present observations were made over only 24 weeks," the study noted, "the long-term benefits and toxic effects of AZT in this patient population still need to be defined."