DDI INFORMATION PUBLISHED

At a recent Washington, DC meeting of the American Federation for Clinical Research, Dr. Robert Yarchoan summarized results so far of the longest-running clinical trial of DDI (dideoxyinosine), being conducted by himself and others at the National Cancer Institute. DDI is a relative of AZT, but it may be considerably less toxic.

No written paper accompanied the talk, and the researchers are not giving interviews until their presentation at the V International Conference on AIDS in Montreal in early June. But the Los Angeles Times covered the Washington meeting in a page-one story published May 1; other newspapers reprinted parts of the Los Angeles Times report. That article may have the latest news available on DDI until June. (For background information, see AIDS TREATMENT NEWS #72, January 13, 1989, page 3, and the references cited there.)

The National Cancer Institute study, conducted in Bethesda, Maryland, should not be confused with a separate phase I trial conducted at New York University and the University of Rochester by the National Institute of Allergy and Infectious Diseases and Bristol-Meyers, which obtained an exclusive license to DDI from the National Institutes of Health.

According to the Los Angeles Times, Dr. Yarchoan reported that most of the patients improved, with "minimal toxicity" -- at least for the six months observed so far, even for those who cannot tolerate AZT. Two patients had seizures, which might or might not have been caused by the drug; two had low white counts; and some reported minor side effects such as headaches or insomnia. These problems, which can occur without drug treatment in persons with HIV, were fewer than would be expected in such a study.

DDI can be taken by mouth, if used with antacid, and it does cross the blood-brain barrier.

DDI has not been released for compassionate use, even for those who cannot tolerate AZT. We have heard that the phase I trials have been delayed by failure to find toxicity, since rules require that such trials continue until a maximum tolerated dose is found -- meaning that the safer the drug is, the longer the trial will take. Caution is understandable, as other drugs of the same class (AZT and DDC) have had serious toxicities which did not show up immediately. But the risk of some hypothetical side effect which appears only after months must be balanced against the risk of untreated AIDS for persons who cannot tolerate AZT and have no alternative. Persons with AIDS and their physicians should have some role in making this decision. Today they are shut out.

On March 30 of this year, the news service Reuters reported that the Japanese company Ajinomoto had set up mass production facilities to produce DDI from uridine, under contract with Bristol-Meyers for use as an AIDS treatment.