Feasibility of 5-fluorouracil and imiquimod for the topical treatment of cervical intraepithelial neoplasias (CIN) 2/3.

Objectives: To determine the feasibility (as measured by tolerability and safety) and efficacy of topical 5-fluorouracil (5-FU) and imiquimod for the treatment of cervical intraepithelial neoplasia (CIN) 2/3.

Methods: This pilot prospective study was conducted in women aged 18-45 years with p16+ CIN 2/3. Participants underwent an 8-week alternating regimen of self-applied 5% 5-FU on weeks 1, 3, 5, and 7 and physician-applied imiquimod on weeks 2, 4, 6, and 8. Adverse events (AEs) were collected by symptom diary and clinical exam. Feasibility was measured by tolerability and safety (AEs) of the study intervention. Tolerability was assessed as the number of participants able to apply 50% or more of the treatment doses. The safety outcome was calculated as the number of participants who experienced "specified AEs" defined as possibly, probably, or definitely related grade 2 or worse AE or grade 1 genital AEs (blisters, ulcerations, or pustules) lasting more than 5 days. The efficacy of the intervention was determined by histology and high-risk human papillomavirus (hrHPV) testing was done after treatment.

Results: The median age of the 13 participants was 27 ± 2.9 years. Eleven (84.61%) participants applied 50% or more of the treatment. All participants reported grade 1 AEs; 6 (46.15%) reported grade 2 AEs; and 0 reported grade 3/4 AEs. Three (23.08%) participants had specified AEs. Histologic regression to normal or CIN 1 among those completing 50% or more of the treatment doses was observed in 10 (90.91%) participants, and 7 (63.63%) tested negative for hr-HPV at the end of the study.

Conclusions: Topical treatment for CIN 2/3 with 5-FU/imiquimod is feasible, with preliminary evidence of efficacy. Topical therapies need further investigation as adjuncts or alternatives to surgical therapy for CIN 2/3.