DEXTRAN SULFATE SHOWS MINIMAL BIOAVAILABILITY WHEN TAKEN ORALLY

Executive Summary

DEXTRAN SULFATE SHOWS MINIMAL BIOAVAILABILITY WHEN TAKEN ORALLY, a Feb. 23 FDA "Talk Paper" maintains. Preliminary findings from a bioavailability study, conducted by FDA in conjunction with the National Institute of Allergy and Infectious Diseases (NIAID) and Johns Hopkins University Medical Center, indicate that "when the drug is taken by mouth, very little of of it is absorbed, thereby reducing the chance it could have an effect on AIDS," the agency paper explains. A spokesperson from NIAID, however, noted that only a single dose of the drug was administered to the patients in which minimal absorption was detected. The institute remarked that the bioavailability results are preliminary, and that the drug has not been tested in a multi-dose format. FDA's Center for Drug Evaluation and Research initiated the cooperative bioavailability project last summer in response to difficulties researchers were having developing suitable assays to determine the drug's level of absorption. The group devised "methods for both direct measurements of dextran sulfate blood levels and for indirect measurement of dextran sulfate levels through its effects on blood clotting," the agency noted. The drug is currently in Phase I/II clinical trials in the U.S. through a joint effort between the drug's Japanese developer, Ueno Fine Chemicals, and NIAID. The dose-ranging trial, which began in August, has enrolled 60 patients with AIDS, ARC. or asymptomatic HIV-infection. The protocols provide that the patients be administered the drug for a 28-week period. Nine NIAID AIDS Clinical Trials Units are participating in the study. The institute reported that no preliminary results are available. Dextran sulfate has been marketed as a blood cholesterol-lowering drug in Japan for many years. In the U.S., some people infected with the AIDS virus have been importing the drug in small quantiities for personal use. The agency currently permits this practice "when such a product is not commercialized and not hazardous," the notice points out.