AIDS drug passes preliminaries.

AIDS drug passes preliminaries

The two most recent tests of the experimental AIDS drug dideoxyinosine (DDI) have provided a more revealing peek at a potentially powerful weapon against AIDS.

The studies, detailed in the May 10 NEW ENGLAND JOURNAL OF MEDICINE, involved a combined total of 71 AIDS patients and were conducted to determine safe DDI doses. Although the higher doses brought serious side effects, including inflammation of the pancreas and painful aching in the legs and feet, smaller doses nonetheless combated the disease. Within two weeks, levels of the p24 antigen -- a gauge of AIDS virus replication -- dropped significantly in patients receiving high or low doses of the drug, while CD4 lymphocytes -- infection-fighting white blood cells usually ravaged by the AIDS virus -- increased significantly. After six weeks, many of the patients had gained weight and said they felt more energetic.

Pancreatitis, DDI's most dangerous side effect, diminished with lower doses. Since last October, 34 AIDS patients receiving DDI have died from pancreatitis, says Susan Yarin, public relations officer for DDI manufacturer Bristol-Meyers Co. of New York City. Only two of these victims, however, had been enrolled in a clinical study; the rest had obtained the drug through an expanded-access program available to patients who are already too sick to qualify for clinical research programs.

Unlike zidovudine (AZT) -- the only AIDS drug so far approved by the FDA -- DDI did not cause anemia. Hastened by these preliminary successes, large-scale clinical studies involving more than 900 patients are now underway to compare DDI's long-term effectiveness with that of AZT.