Intra-anal use of imiquimod: what is the clinical evidence?

Abstract

Imiquimod has been demonstrated to be rather effective in patients with anal as well as perianal high-grade squamous intraepithelial lesions (HSILs). Nevertheless, until now the intra-anal use of imiquimod has been considered off-label. The aim of this study is to review the clinical evidence related to the intra-anal use of imiquimod in the treatment of human papillomavirus-related anal lesions. A systematic search in PubMed and Scopus was performed. In total, 422 patients were included. The most common referred comorbidity was HIV infection (281 patients, 66.6%). The principal clinical entities, which were treated with intra-anal imiquimod, were HSILs. The most frequent formulation was self-applied imiquimod cream. In the HSIL group, there was complete healing in 74 patients (35%) and partial in 44 patients (20.9%), while in the wart group, there was complete healing in 128 patients (67%). Recurrence of HSIL was present in 19 patients (15%), while in cases with warts recurrence was present in 38 patients (19.8%). The most common adverse events were pain, itching, and burning sensation. In conclusion, the adverse effects associated with the intra-anal use of imiquimod seem to be minor. The present clinical evidence suggests that imiquimod may be proposed as effective, safe, and relatively well tolerated treatment.

Perianal squamous cell carcinoma in a Quarter Horse colt

“…Imiquimod acts as an agonist of Toll-like receptor-7. It Research, Society and Development, v. 11, n. 2, e31511225710, 2022 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org /10.33448/rsd-v11i2.25710 activates nuclear factor kappa-B, stimulating the dermal dendritic cells to express cytokines, such as tumor necrosis factor-a, interferon-a (IFN-a), and interleukins 1, 6, 8, and 12 at the site of application (Gkegkes et al, 2019). Consequently, imiquimod stimulates the immune system to release several cytokines, which are essential in the elimination of viruses and destruction of neoplastic cells (Knottenbelt et al, 2015).…”

“…Tumor-specific T-cells are multiplied and infiltrate the affected area. At the same time, B cells start producing antibodies that subsequently increase antigen presentation (Gkegkes et al, 2019).…”

A phase I study of intra-anal artesunate (suppositories) to treat anal high-grade squamous intraepithelial lesions

“…However, a recent small, single center, longitudinal cohort study of MSM living with HIV and diagnosed with HSIL found excellent response rates and tolerability of imiquimod with less recurrence compared to surgical treatment [4]. In a systematic review of 14 studies of intraanal imiquimod, complete response in 211 patients with HSIL was observed in 35%, partial response 20.9% and recurrence in 15% [16]. Differences in the response rates may be related to patient factors such as extent of disease, degree of immunosuppression or other risk factors such as smoking but also to the dose of imiquimod or the formulation (cream vs suppository versus tampon) [16].…”

Infecciones transmisibles sexualmente que afectan colon, recto y ano.

“…Cuando se utiliza en mucosas puede desencadenar un síndrome similar al gripal. 93 Los efectos adversos locales están íntimamente asociados al modo de acción y pueden ser manejados adecuando la frecuencia de aplicación.…”

“…Las tasas de recurrencia fueron 15% para HSIL y 20% para condilomas. 93 En un ensayo controlado y aleatorizado, 64 pacientes HSH con HIV con HSIL endoanal recibieron imiquimod al 5% o placebo, ambos aplicados en el conducto anal tres veces por semana durante cuatro meses. De 28 pacientes que completaron el tratamiento, cuatro tuvieron resolución completa y ocho disminuyeron su grado a LSIL.…”