Experimental Drug May Block Common AIDS Infection, Newspaper Says With PM-AIDS Antibiotic-Number

LOS ANGELES (AP) _ An experimental drug may delay or block a blood infection found in people with advanced cases of AIDS, a researcher says.

Preliminary test results with the drug, rifabutin, were so positive that on March 6 the U.S. Food and Drug Administration cleared the way for AIDS patients with severely impaired immune systems to receive the drug, the Los Angeles Times reported today.

Rifabutin has been effective in delaying or blocking the onset of a blood infection called Mycobacterium avium complex, or MAC, said Beverley Wynne, the project leader for rifabutin at Adria Laboratories of Dublin, Ohio, where the drug is made.

MAC bacteria are related to the tuberculosis germ, and cause severe illness in people with advanced AIDS. About 75,000 people in the United States have AIDS.

An AIDS expert at UC San Francisco said an effective drug to fight MAC would be a significant step forward.

''Over a quarter of the people in the late stages of human immunodeficiency virus disease are ultimately developing symptomatic MAC disease,'' said Dr. Harry Hollander, who was not involved in the Adria research.

A study of 590 AIDS patients that began in February 1990 found rifabutin nearly halved the rate at which patients developed the MAC infection.

As of November, 14.4 percent of the patients receiving a placebo developed MAC infections, while 8.2 percent of the patients given rifabutin developed MAC.

Results of a second study have not been released.

The results were so significant that both studies were stopped and all participants were given rifabutin, Wynne said.

The company, which released the first study's results after the Times inquired about it, said it wanted to avoid prematurely promoting the drug. The company is a division of Erbamont Inc.

Adria officials said more test data will be presented Monday when the federally funded AIDS Clinical Trials Group meets in Washington, and at the international AIDS meeting in Amsterdam in July.