Investigation of the Efficacy and Safety of TO-208 in Patients 2 Years of Age or Older With Molluscum Contagiosum in Japan: A Randomized, Double-Blind, Placebo-Controlled, Phase 3 Study (208-3-1) and Its Open-Label Extension
In brief
Cantharidin cleared molluscum lesions in half of treated Japanese patients
In a Japanese phase 3 trial, 50% of patients aged 2 years or older receiving topical cantharidin had complete lesion clearance by day 85, compared with 23% receiving placebo. Up to four applications commonly caused mild or moderate skin reactions, including blistering and pain; whether clearance lasts beyond day 85 remains unclear.
- Journal
- The Journal of dermatology (Q1)
- Published
- 28 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Takafumi Kadono, Tsuyoshi Mitsuishi, Akira Shimizu, Yasushi Suga, Daisuke Watanabe, Shinya Kaneko, et al.
- PMID
- 42806629
- DOI
- 10.1111/1346-8138.70517
Why clinicians should know about it
- Picked for Dermatology (paper of the day, 30 September 2026): Phase 3 RCT of TO‑208 cantharidin for molluscum contagiosum
Abstract
Molluscum contagiosum (MC) is a common viral skin infection in children. In the two Phase 3 Cantharidin Application in Molluscum Patients [CAMP-1 and CAMP-2] studies, cantharidin, a drug-device combination containing cantharidin (0.7%), a topical vesicant, was significantly superior to placebo in achieving complete clearance of MC lesions at the end of the study. The aim of this study was to evaluate the efficacy and safety of TO-208, a drug-device combination containing 0.7% w/v cantharidin, compared with a placebo in patients with MC in Japan. In this Phase 3, double-blind study, patients aged ≥ 2 years with ≥ 5 MC lesions at baseline were randomly assigned (1:1 ratio) to the TO-208 group or placebo group, with up to 4 applications every 21 days. The primary efficacy endpoint was the proportion of subjects with complete MC lesion clearance (baseline and new) at Day 85. The full analysis set was conducted for the efficacy population. The secondary efficacy outcome was the percentage change from baseline in the total number of MC lesions, including both baseline and newly developed lesions. The safety endpoints were adverse events and local skin reactions. In total, 148 subjects received TO-208 and 155 received placebo. The proportion of subjects achieving complete clearance at Day 85 was significantly higher with TO-208 compared to placebo 50.0% versus 23.2% (p < 0.001). The percentage change in MC lesions from baseline to Day 85 was -88.35% versus -44.57% (p < 0.001). Commonly reported adverse events with TO-208 were mild or moderate blistering, pruritus, pain, and erythema at the application site. Overall, TO-208 was significantly superior to the placebo in achieving complete clearance of MC lesions at the end of the study visit and was generally well tolerated, with adverse events that were predominantly mild to moderate in severity and limited to application sites. Trial Registration: Japan Registry of Clinical Trials: jRCT2041220039.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.