Based on CD4 cell count data obtained in early trials, as well as an interim evaluation of CD4 cell count data from a controlled trial, this early approval was given in order to make the drug available for treatment of HIV-infected individuals for whom there are no alternative therapies. A two-year controlled clinical trial, sponsored by the manufacturer and the National Institutes of Health, has compared patients who had received prior AZT treatment and were switched to one of two doses of ddI, with patients who continued AZT treatment. Page 2, T92-44, DDI therapy was 13.7 months. These new data were submitted to FDA in response to the agency's request for a followup to its original approval of the drug. The study provided no information on the optimal time at which patients should be switched from AZT to ddI. The new FDA-approved physician package insert for ddI describes the study's participants and results.
Physicians can then interpret the information in the context of the individual patient.
The lower dose was demonstrated clearly to be no less effective than the higher dose studied. Other studies comparing several doses of ddI, as well as a study of ddI versus AZT in patients who have not received prior antiretroviral therapy, are ongoing.