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Evidence summaries

Imiquimod for Genital Warts

Imiquimod is effective for clearance of genital warts compared with placebo, but appears to be less effective than electrotherpay or carbon dioxide laser. Level of evidence: "A"

A systematic review 3 evaluated the clinical effectiveness and cost-effectiveness of interventions for the treatment of anogenital warts. 60 randomised controlled trials (RCTs) evaluating 19 interventions were included. Analysis by mixed-treatment comparison (MTC) indicated that ablative techniques were typically more effective than topical interventions at completely clearing warts at the end of treatment. Podophyllotoxin 0.5% solution was found to be the most effective topical treatment evaluated. Networks for other outcomes included fewer treatments, which restrict conclusions on the comparative effectiveness of interventions. Podophyllotoxin 0.5% solution first line followed by carbon dioxide (CO2) laser therapy second line if warts did not clear was most likely to be considered a cost-effective use of resources at a willingness to pay of £20,000-30,000 per additional quality-adjusted life-year gained. Probability (percentage) of complete clearance at another time point by treatment (sensitivity analysis): Placebo/no treatment 7.9, imiquimod 5% cream 44.7, cryotherapy 52.4, cryotherapy plus podophyllotoxin 0.15% cream 57.5, electrotherapy 65.5.

A Cochrane review [Abstract] 2 included 10 studies with a total of 1734 subjects. 6 trials were funded by industry. Six trials (1294 participants) compared the use of imiquimod vs placebo. There was very low quality evidence that imiquimod was superior to placebo in achieving complete and partial regression (RR 4.03, 95% CI 2.03 to 7.99; RR 2.56, 95% CI 2.05 to 3.20, respectively). However, one better quality multicenter RCT (RR 2.30, 95% CI 1.41 to 3.74; n=534) favoured imiquimod over placebo. When compared with placebo, the effects of imiquimod on recurrence (RR 2.76, 95% CI 0.70 to 10.91), appearance of new warts (RR 0.76, 95% CI 0.58 to 1.00) and frequency of systemic adverse reactions (RR 0.91, 95% CI 0.63 to 1.32) were imprecise.Two trials (105 participants) compared the use of imiquimod versus any other patient-applied treatment (podophyllotoxin and podophyllin). The estimated effects of imiquimod on complete regression (RR 1.09, 95% CI 0.80 to 1.48), partial regression (RR 0.77, 95% CI 0.40 to 1.47), recurrence (RR 0.49, 95% CI 0.21 to 1.11) or the presence of local adverse reactions (RR 1.24, 95% CI 1.00 to 1.54) were imprecise (very low quality evidence).

A topic in Clinical Evidence 1 summarizes the results of one systematic review (search date 2000, 5 RCTs, 588 people with genital warts without HIV infection and 1 RCT (100 people) with HIV infection) and one subsequent RCT. The review found that, in people without HIV, imiquimod cream (1-5%) increased clearance rates compared with placebo (AR for clearance with imiquimod 51% vs 6% with placebo, RR 8.3, 95% CI 5.2 to 13.0, NNT 3). The subsequent RCT found similar results. The RCT on people with HIV found no difference between imiquimod and placebo.

    References

    • Buck H. What are the effects of treatments for external genital warts? Genital warts. Clinical Evidence 2005;13:2005-2015.
    • Grillo-Ardila CF, Angel-Müller E, Salazar-Díaz LC et al. Imiquimod for anogenital warts in non-immunocompromised adults. Cochrane Database Syst Rev 2014;(11):CD010389.[PubMed]
    • Thurgar E, Barton S, Karner C et al. Clinical effectiveness and cost-effectiveness of interventions for the treatment of anogenital warts: systematic review and economic evaluation. Health Technol Assess 2016;20(24):v-vi, 1-486. [PubMed]

Primary/Secondary Keywords