High-grade squamous intraepithelial lesions of the skin near the anus are caused by the human papillomavirus (HPV). Antiviral drugs,, such as cidofovir, act against viruses and may stop these lesions from becoming cancer.

This phase II trial is studying the side effects and how well topical cidofovir works in treating HIV-infected patients with high-grade squamous intraepithelial lesions of the skin near the anus.