Application of a topical immune response modifier, resiquimod gel, to modify the recurrence rate of recurrent genital herpes: A pilot study

Resiquimod (R-848), a topically active immune response modifier, induced pr oduction of interferon-alpha and interleukin-12 in cultured blood mononucle ar cells and decreased genital herpes recurrences in an animal model. In th is study, 52 patients with frequently recurrent genital herpes applied topi cal resiquimod gel 0.01% (twice or thrice weekly) or 0.05% (once or twice w eekly) or vehicle gel to herpes lesions for 3 weeks. During the 6-month obs ervation period after treatment, median days to first recurrence in the poo led resiquimod group was 169 days, compared with 57 days for the vehicle gr oup (P=.0058). In all, 32% of resiquimod-treated patients completed the obs ervation period without a recurrence, compared with 6% of vehicle-treated p atients (P=.039). Resiquimod 0.05% twice weekly produced dose-limiting infl ammation at the lesion sites, but the other regimens were well tolerated. A pplication of resiquimod to genital herpes lesions appeared to reduce the f requency of recurrences.