WASHINGTON - The refusal of the FDA's Antiviral Drugs Advisory Committee to endorse Unimed Inc.'s NDA for Cryptaz nitazoxanide last week may indicate that the bar for approval of AIDS therapies has been raised from the early, desperate days of the epidemic when the panel was satisfied with a slight suggestion of efficacy.

UMED's experience, in which a panel voted 9 to 1 against approval of Cryptaz to treat cryptosporidiosis-induced diarrhea in AIDS patients, also reflects the increasing difficulty in running clinical trials in AIDS-related conditions.