Imiquimod treatment of anal Intraepithelial neoplasia in HIV-positive men

Objective: To evaluate the treatment of anal intraepithelial neoplasia (AIN) with the local immune response modifier imiquimod in human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). Design: Prospective, nonrandomized, open-label pilot study, with a mean follow-up time of 9 1/2 months. Setting: Dermatology department of a university hospital. Patients: Twenty-eight consecutive HIV-positive MSM with histologically confirmed perianal (n = 23) or intra-anal (n=5) AIN. Intervention: Overnight treatment with self-applied imiquimod cream (perianal AIN) or suppositories (intra-anal AIN) 3 times a week for 16 weeks. Main Outcome Measures: Response to treatment was documented using clinical, cytologic, and histologic criteria. Human papillomavirus (HPV) typing and HPV DNA load determination for the high-risk HPV types 16, 18, 31, and 33 were performed. Results: Seventeen (61%) of all 28 patients included in the study and 17 (77%) of the 22 patients with AIN, who applied imiquimod as instructed, showed clinical and histologic clearance at the end of therapy. Four patients had residual AIN and 1 patient did not improve. Clinical response was accompanied by a sharp decline in HPV DNA loads and by a reduction in the number of HPV types, but long-term HPV clearance was rarely achieved. In the follow-up period, AIN cleared in 3 patients with residual AIN. Fourteen (78%) of 18 imiquimod responders with at least 5 five months of follow-up had a normal cytologic and clinical picture at the end of the follow-up period. Three primary responders developed a recurrence. In 6 noncompliant patients, there was no clinical or morphological improvement and the HPV DNA loads remained high. Conclusions: Imiquimod appears to be a safe and effective treatment option for AIN in HIV-positive MSM. Clinical response is accompanied by a significant decrease in high-risk HPV DNA load. These results should encourage controlled randomized studies of imiquimod treatment of AIN.