SKIN 
 

December 2018     Volume 2 Supplemental Issue  
 

Copyright 2018 The National Society for Cutaneous Medicine 103 

RISING DERM STARS 
 

 
Topical Cantharidin Revisited: A Phase 2 Study Investigating a Commercially-
Viable Formulation of Cantharidin (VP-102) for the Treatment of Molluscum 
Contagiosum 
 
Anthony K Guzman MD1, Jessica L Garelik DO1, Steven R Cohen, MD, MPH1 
 

1Department of Internal Medicine, Division of Dermatology, Albert Einstein College of 
Medicine, Bronx, NY. 
 

 
 
Background: Molluscum contagiosum (MC) 
is a common cutaneous infection caused by 
a DNA poxvirus, predominantly affecting 
children. There is a paucity of high quality 
evidence on which to make clinical decisions 
in treating MC. (1) Cantharidin, a topical 
vesicant historically derived from a blister 
beetle, is a commonly-used treatment for this 
condition. However, despite the prevalence 
of its use, cantharidin is not FDA-approved, 
is not standardized in formulation or 
treatment regimen and is not always 
manufactured in accordance with Good 
Manufacturing Practices (GMP), leading to a 
lack of commercial availability. (2,3) 
 
Objective: To determine the efficacy and 
safety of VP-102, a novel, standardized, 
commercially-viable cantharidin formulation 
produced under GMP for the treatment of 
MC. 
 
Methods: We conducted a 12-week, open-
label pilot trial at a single outpatient 
dermatology clinic. Subjects 2-17 years (n = 
30) with a clinical diagnosis of MC and < 50 
lesions were included. Subjects were treated 
with a single-use vial containing a 
standardized 0.7% w/v 

cantharidin solution, produced under GMP 
(VP-102), applied with the wooden end of a 
cotton swab approximately every 21 days, for 
up to 4 treatments or until complete lesion 
clearance. Subjects were instructed to wash 
treatment off all lesions at either 6 hours 
(Cohort 1: 14/30, 46.7%) or 24 hours (Cohort 
2: 16/30, 53.3%), or earlier if significant 
blistering occurred. Lesion counts and 
adverse events (AEs), including local skin 
reactions, were documented at each visit. 
Quality of life was also measured using the 
Children’s Dermatology Quality of Life Index 
(CDLQI) at baseline and at the end of study 
(EOS). The primary endpoint was the 
percentage of subjects achieving total 
clearance by EOS on Day 84. 
 
Results: The mean patient age was 5.8 
(range= 2-12 yrs). A total of 26 subjects 
(86.7%) experienced at least one expected 
local skin reaction such as blistering or 
erythema. No serious or unexpected 
treatment-related AEs were encountered. A 
total of 25 subjects pooled from both cohorts 
completed the study. Eleven subjects 
(44.0%) achieved total lesion clearance by 
EOS. 
The mean ± SD lesion count was significantly 
reduced from 23.0 ± 15.6 at baseline to 6.8 ± 



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December 2018     Volume 2 Supplemental Issue  
 

Copyright 2018 The National Society for Cutaneous Medicine 104 

11.7 at EOS (p < 0.0001). The mean CDLQI 
score was markedly improved from 3.9 ± 5.6 
at baseline to 0.38 ± 1.3 at EOS (p = 0.01). 
 
Conclusions: VP-102 was well-tolerated 
with either a 6 or 24-hour exposure and was 
associated with a significantly reduced lesion 
count, improved quality of life and complete 
clearance of MC lesions in nearly half of the 
patients. 
 
Figure 1: Lesion clearance after VP-102. 

 
 
 

References: 
References: 
1. van der Wouden JC, van der Sande R, 
Kruithof EJ, Sollie A, van Suijlekom-Smit 
LW, Koning S. Interventions for cutaneous 
molluscum contagiosum. The Cochrane 
database of systematic reviews 
2017;5:CD004767. 
2. Coloe J, Morrell DS. Cantharidin use 
among pediatric dermatologists in the 
treatment 
of molluscum contagiosum. Pediatric 
dermatology 2009;26:405-408. 
3. Pompei DT, Rezzadeh KS, Viola KV, Lee 
DH, Schairer DO, Chismar LA, et al. 
Cantharidin therapy: practice patterns and 
attitudes of health care providers. Journal 
of the American Academy of Dermatology 
2013;68:1045-1046