Topical imiquimod treatment of residual or recurrent cervical intraepithelial neoplasia lesions (TOPIC-2): A randomised controlled trial.

Objective: To investigate the efficacy of imiquimod in women with residual or recurrent cervical intraepithelial neoplasia (rrCIN), compared with large loop excision of the transformation zone (LLETZ).

Design: Randomised controlled non-inferiority trial.

Setting: One academic and one regional hospital in the Netherlands.

Population: Thirty-five women with rrCIN were included in the study between May 2016 and May 2021.

Methods: Women were randomised to receive treatment with 5% imiquimod cream (12.5 mg) intravaginally (three times a week for a duration of 16 weeks) or a LLETZ procedure (standard treatment).

Main Outcome Measures: The primary outcome was reduction to normal cytology at 6 months after starting treatment. Secondary outcomes were clearance of high-risk human papilloma virus (hr-HPV) in both groups and reduction to ≤CIN1 in the imiquimod group. Side effects were monitored.

Results: Treatment success was 33% (6/18) in the imiquimod group versus 100% (16/16) in the LLETZ group (P < 0.001), whereas HPV clearance was 22% (4/18) in the imiquimod group versus 88% (14/16) in the LLETZ group (P < 0.001). After the randomisation of 35 women, the futility of treatment with imiquimod was proven and the trial was prematurely finished. In the follow-up period, three patients remained without additional treatment, whereas all other patients underwent LLETZ, conisation or hysterectomy. In the LLETZ group none of the patients received additional treatment during 2 years of follow-up.

Conclusions: This is the first randomised controlled trial to show that topical imiquimod has a significantly lower success rate in terms of reduction to normal cytology and hr-HPV clearance, compared with LLETZ, in women with rrCIN. Additionally, imiquimod has numerous side effects and after using imiquimod most women with rrCIN still required additional surgical treatment.