BACKGROUND AND PURPOSE:

• Surgical excision is the gold standard treatment for high-grade squamous intraepithelial lesions (HSIL) of the cervix
• Imiquimod, an imidazoquinoline amine, inhibits viral replication and stimulates natural killer cells
  • FDA approved for treatment of external genital and perianal warts, small superficial basal cell carcinomas, and clinically typical actinic keratoses | Also used off-label for VIN and VAIN
• Fonseca et al. (Obstetrics & Gynecology, 2021) evaluated the histologic response rate of HSIL after topical application of 5% imiquimod cream

METHODS:

• Phase II randomized controlled trial
• Participants
  • Cervical HSIL (CIN 2 or CIN3)
• Interventions
  • 250 mg of 5% imiquimod cream applied to the cervix weekly for 12 weeks followed by LEEP
  • LEEP without preceding treatment
• Study design
  • Outcomes stratified by human papillomavirus type and lesion grade
  • Analyses for both per protocol (PP) and Intention-to-treat (ITT)
• Primary outcome
  • Rate of histologic regression (≤CIN 1) in LEEP specimens
• Secondary outcomes
  • Surgical margin status
  • Adverse events

RESULTS:

• Imiquimod: 49 women | LEEP only: 41 women
• In the PP population, histologic regression was observed in more women vs imiquimod
  • Imiquimod + LEEP: 61%
  • LEEP only: 23%
  • P=0.001
• More women in the imiquimod group had surgical margins that were negative for HSIL
  • Imiquimod + LEEP: 95%
  • LEEP only: 70%
  • P=0.004
• Rates of adverse events for the imiquimod treatment group were similar in both the PP and ITT populations
  • PP: 74%
  • ITT: 78%
• Adverse events were generally mild
  • Abdominal pain was the most common
• Three patients in the imiquimod group had grade 2 adverse events, including
  • Vaginal ulcer
  • Vaginal pruritus with local edema
  • Moderate pelvic pain

CONCLUSION:

• The weekly use of topical imiquimod promoted histologic regression of cervical HSIL
• The authors state

Weekly topical treatment with imiquimod for 12 weeks is effective in promoting regression of cervical HSIL

One clinical application of these findings is the potential to use in larger lesions to achieve a higher rate of free surgical margins

We observed histologic regression (to CIN 1 or less) in more than half of patients, which suggests this might be an alternative treatment strategy to a cervical excision procedure

Learn More – Primary Sources:

Topical Imiquimod for the Treatment of High-Grade Squamous Intraepithelial Lesions of the Cervix

Related ObG Topics:

What Are the Risk Factors for Recurrence after Large Loop Excision for CIN 2/3?

Natural History of CIN2 Lesions: Informing Practice Decisions

Treatment for Women with HIV and High-Grade Cervical Lesions: Cryotherapy or LEEP?