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A multicentre, randomised, double-blind, placebo controlled study of cryotherapy versus cryotherapy and podophyllotoxin cream as treatment for external anogenital warts
  1. R J C Gilson1,
  2. J Ross2,
  3. R Maw3,
  4. D Rowen4,
  5. C Sonnex5,
  6. C J N Lacey6
  1. 1
    Centre for Sexual Health and HIV Research, UCL and The Mortimer Market Centre, Camden Primary Care Trust, London, UK
  2. 2
    Whittall Street Clinic, Birmingham, UK
  3. 3
    Royal Victoria Hospital, Belfast, UK
  4. 4
    Royal South Hampshire Hospital, Southampton, UK
  5. 5
    Addenbrooke’s Hospital, Cambridge, UK
  6. 6
    Hull York Medical School, University of York, York, UK
  1. Correspondence to Dr R J C Gilson, Centre for Sexual Health and HIV Research, UCL Medical School, The Mortimer Market Centre, Mortimer Market, London WC1E 6JB, UK; rgilson{at}


Objectives: To compare the efficacy and safety of combination therapy with cryotherapy and podophyllotoxin 0.15% cream versus cryotherapy alone in the treatment of anogenital warts.

Methods: A randomised, double-blind, multicentre controlled trial. Patients received podophyllotoxin cream or placebo twice daily for 3 days/week for up to 4 weeks, with weekly cryotherapy continued to week 12 if required. Further treatment from week 12 to 24 was discretionary. Patients were stratified by sex and history of warts. HIV positivity, warts treated in the past 4 months, or warts with a combined area of less than 10 mm2 were exclusion criteria. Primary endpoints were clearance at weeks 4 and 12.

Results: 70 patients per group were randomly assigned and started treatment; 101 first-episode warts, 91 male. No treatment-related serious adverse events were reported. Follow-up at week 12 was 85%. By intention-to-treat analysis, clearances at 4 and 12 weeks were higher in the combination group (60.0% and 60.0%, respectively) than with cryotherapy alone (45.7%, 45.7%) although not statistically significant (RR 1.31, 95% CI 0.95to 1.81). By week 24 there was no difference between the groups (68.6% and 64.3%, respectively; RR 1.07, CI 0.84 to 1.35). At week 4, wart clearance was higher in men (p = 0.001) and those with a past history of warts (p = 0.009), but these differences were not detected at week 12. There was some evidence for a higher relapse rate in the group receiving cryotherapy alone.

Conclusions: Initial combination therapy with podophyllotoxin/cryotherapy was well tolerated and may have resulted in earlier clearance in some patients, compared with cryotherapy alone; however, overall differences in clearance rates were not statistically significant.

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  • Funding This was an investigator-led study funded by Stiefel International R&D.

  • Competing interests None.

  • Ethics approval The study was reviewed by the London Multicentre Research Ethics Committee.

  • Patient consent Obtained.

  • Contributors: RJCG and CJNL led the design of the study in consultation with the sponsors; RJCG was principal investigator at one centre, and drafted the manuscript. JR, RM, DR and CS were site investigators, commented on the design of the study and the report. Study sites: Department of Genitourinary Medicine, Camden Primary Care Trust, The Mortimer Market Centre, London; Camden PCT; Whittall Street Clinic, Birmingham; Royal Victoria Hospital, Belfast; Royal South Hampshire Hospital, Southampton; Addenbrooke’s Hospital, Cambridge.

  • Provenance and Peer review Not commissioned; externally peer reviewed.

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