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New York Times
A New Therapy Approach: Cancer as a Model for AIDS
LAWRENCE K. ALTMAN, Special to The New York Times
June 13, 1989
LEAD: The 5,000 reports at the international AIDS meeting here focused on how AIDS has become a chronic disease that partly responds to some therapies, but for which it will take years to develop an effective treatment or vaccine.

The 5,000 reports at the international AIDS meeting here focused on how AIDS has become a chronic disease that partly responds to some therapies, but for which it will take years to develop an effective treatment or vaccine.

In jammed lectures and in discussions in thronged hallways, many experts spoke of managing AIDS like cancer and other chronic diseases with "cocktails" of several new and existing drugs.

Dr. Samuel Broder, head of the National Cancer Institute in Bethesda, Md., said that researchers were expanding their studies on AIDS patients with two chemical cousins of AZT, or azidothymidine. AZT is now the only drug licensed in the United States for treating acquired immune deficiency syndrome. The experimental drugs are DDI (dideoxyinosine) and DDC (dideoxycytidine). In tests, some patients who could not tolerate AZT were able to take one of these agents. Leukemia Therapy a Model

Dr. Broder said that in seeking cures for AIDS, researchers "should borrow a page from the history of curative therapy in childhood leukemias." Cancer, of course, is different in that it is not a transmissible infection. In seeking a therapy for leukemia, doctors found that no one drug cured a child and that some were dangerous when given alone. But doctors eventually learned how to combine drugs to cure many cases of leukemia.

Many people "predicted with a certainty that is exasperating" that there would be no progress with leukemia, Dr. Broder said. "They were as wrong then as those who say that we will not make progress against AIDS are wrong now."

In using the word cure, Dr. Broder said he did not necessarily mean ridding the body of the human immunodeficiency virus that causes AIDS. Rather, he said he used the term in a statistical sense, the way doctors speak of people who are free of cancer for five years as being cured.

Dr. June E. Osborn, dean of the University of Michigan School of Public Health, told the 11,800 participants from 89 countries that "it is not for lack of trying" that a cure is not in sight. She also warned that one of the major therapeutic gains so far was threatened because there are signs that the virus is developing resistance to AZT. Small Steps Forward

A few advances were reported at the meeting. But even the most dramatic, like Dr. Jonas Salk's report on an experimental vaccine that protected two chimpanzees, represented small steps toward the goal of prevention. While Dr. Salk held out hope that someday the vaccine might help prevent an AIDS infection from progressing to the disease, he also said it might have to be used in combination with AZT or other therapies.

The overwhelming majority of reports concerned scientific nuances, incremental increases in knowledge and affirmed results of earlier studies and experiments.

Despite these gains, the death toll from AIDS remains high. In the United States alone, the Centers for Disease Control estimates that more than 54,000 people have died because of the disease.

Many participants expressed concern that health officials throughout the world were not acting urgently enough to educate people about the use of condoms and other means of reducing their risk of infection.

Dr. Jonathan Mann, the head of the World Health Organization's global AIDS program, estimated that about 35 million teen-agers become sexually active each year. But many of them do not take precautions.

Indeed, a study from medical researchers at the University of California at San Francisco showed that many young women who should be aware of the dangers ignore the precautions. The study found that many women who have had sexually transmitted diseases or unwanted pregnancies still do not insist that their partners use condoms.

Another study from the University of California at San Francisco found that physicians do not routinely counsel patients about AIDS prevention, although patients say they are willing to discuss AIDS and sexual behavior. Several Years to a Vaccine

On the vaccine front, the scientists agreed that an effective version is still years away. Ivan L. Head, who was chairman of the six-day conference, calculated that more than a million babies were born in the world during the meeting. And the scientists noted that many if not most of these babies are likely to become sexually active before a vaccine is licensed.

Dr. Dani P. Bolognesi, an AIDS vaccine researcher at Duke University, said scientists took 18 years to develop the vaccine against hepatitis B, even with advances in molecular biology techniques.

While scientists boast of having learned more about the AIDS virus in the six years since it was discovered than they have ever learned about any other virus, the virus still holds many secrets.

For instance, doctors still do not know why some people become infected after a single encounter with one partner while others have escaped infection after hundreds of encounters with many partners, said Dr. Peter Piot, an AIDS expert at the Institute of Tropical Medicine in Antwerp, Belgium.

Dr. Robert Gallo, a discoverer of the AIDS virus, said that if some strains of the virus are less virulent than others, some infected people may never get AIDS.

Another mystery is whether some microbe, drug or other factor enhances the virus's ability to cause AIDS. Dr. Gallo reported briefly on research suggesting that two viruses, HHV-6 and HTLV-1, might be such co-factors. But he said that scientists are still a long way from fully understanding the phenomenom.

Dr. Osborn of Michigan said that scientists still had much to learn about the medical problems caused by the AIDS virus and that "we do not yet know how to predict for an individual the likely duration of symptom-free infection." Infected People Participate

The meeting here was the fifth annual gathering of scientists in various North American and European cities to summarize the state of knowledge about AIDS. The meeting, the largest ever, was extraordinary because it included infected people as participants for the first time.

In many respects it resembled a convention more than an interdisciplinary scientific meeting. Rooms were so jammed that when one scientist finished a presentation, participants often were unable to move on to hear another paper elsewhere. Red-coated security agents often broke up hallway discussions in an effort to keep traffic flowing.

Only a few hundred among the participants had AIDS, but they and the advocates representing their cause punctuated the meeting with heckles and protests. Their prime complaint was that not enough money is being spent on AIDS research. Many advocates also demanded more public accountability from scientists who use tax dollars. When researchers said they had learned more in a short time about the AIDS virus than they have about any other virus, some protesters called them arrogant and misleading.

Many researchers, upset by the interruptions and lack of the decorum, called for separating the scientific and political portions of future meetings.

But Dr. Luc Montagnier of the Pasteur Institute in Paris said he welcomed "the solidarity shown between researchers and patients." There are already enough other scientific meetings on AIDS, he said, adding that he was challenged by points made by the "many patients who are as well informed about AIDS as their doctors." Dr. Montagnier is a discoverer of the AIDS virus. A Willingness to Share

Dr. Mann, the World Health Organization official, said that periodically "we need to refresh our sense of unity, speak to each other and renew our willingness to share across all boundaries of race, religion, culture, language, profession, sexual preference, HIV-infection status and national origin."

Indeed, the meeting offered evidence that at least some boundaries are falling. Consider, for example, the turnabout by one official. In 1985, the press secretary to President Kenneth D. Kaunda of Zambia, denied a request for an interview about AIDS and scolded a reporter for going to Africa to report on what the press secretary said was an American disease. President Kaunda, the press secretary said, had more important things to do.

A year later, President Kaunda lost a son to AIDS.

In an address here, the president spoke about his family's loss and said that "a cure for AIDS must be found at any price." If scientists fail in this quest, he said, the AIDS epidemic will become "a soft nuclear bomb on human life."

President Kaunda urged world leaders "to divert our massive resource of dollars and rubles wasted on self-destruction through nuclear weapons to the more worthwhile destruction of AIDS."