Virend (SP-303), a new topical antiviral agent with activity against herpesvirus, was evaluated in a multicenter, double-blind, placebo-controlled Phase II study for safety and effectiveness against recurrent genital herpes lesions in patients with AIDS. The primary endpoints of this study were complete healing of lesions and time to healing. Patients had a history of recurrent genital or anogenital herpes with at least one lesion and positive HSV culture at enrollment. Participants received Virend (15% ointment; 24 patients) or matching placebo (21 patients) three times a day for 21 days. Excluding two patients in the Virend group who received an initial treatment but were lost to follow-up, 9 of 22 (41%) patients treated with Virend experienced complete healing of their lesions compared with three (14%) patients in the placebo group (P = 0.053). Viral culture revealed that 50% of Virend-treated patients and 19% of placebo-treated patients became culture-negative during treatment (P = 0.06). Based on these preliminary clinical findings, further evaluation of Virend for topical treatment of genital herpes in patients with AIDS is planned.