VP-102 Demonstrates More Rapid Complete Clearance of Molluscum Contagiosum Regardless of Disease Duration: A Pooled Analysis of Two Phase 3 Trials

Background Molluscum contagiosum (MC) is a viral skin infection that evades the host immune response and, without treatment, may persist for up to 5 years.¹ Two Phase 3, multicenter, randomized, vehicle-controlled trials previously demonstrated the safety and efficacy of VP-102, a proprietary drug-device combination product containing cantharidin 0.7% (w/v), for the treatment of MC.² However, the impact of disease duration on treatment response and the time to complete clearance have not been well characterized. This post hoc pooled analysis evaluated complete clearance and change in lesion count according to time since MC diagnosis and also compared the time to first complete clearance with VP-102 versus vehicle. Methods Subjects aged ≥2 years with MC were randomized 3:2 to VP-102 (n=310) or vehicle (n=218). Study drug was applied topically to all baseline and new treatable lesions every 21 days until complete clearance or for a maximum of 4 treatments (Days 1, 21, 42, and 63), with final evaluation on Day 84. Median time since MC diagnosis at baseline was 25 days (range, 1–1,247) in the VP-102 group and 31.5 days (range, 1–1,302) in the vehicle group. Complete clearance and change in lesion count at Day 84 were evaluated by disease duration (≤12 months or >12 months). Time to first complete clearance was evaluated using Cox proportional hazards regression, with additional sensitivity analyses performed across analysis populations and statistical approaches. Results Among subjects diagnosed with MC for ≤12 months, complete clearance at Day 84 was achieved by 48.9% of VP-102-treated subjects compared with 16.7% of vehicle-treated subjects (P<0.0001). Among subjects with MC for >12 months, complete clearance was achieved by 58.8% with VP-102 compared with 5.0% with vehicle (P<0.0001). Median lesion count reduction was 100% with VP-102 in both disease-duration groups compared with 47.9% and 50.9%, respectively, with vehicle (P<0.0001 for both comparisons). In the pooled Per Protocol population (N=423), Cox proportional hazards regression demonstrated a hazard ratio (HR) for complete clearance of 4.16 (95% CI, 2.88–6.19; P<0.0001), indicating an approximately 4-fold higher rate of achieving complete clearance with VP-102 compared with vehicle. Results were consistent across sensitivity analyses, including a Cox model stratified by study (HR= 4.19), the pooled intention-to-treat population (ITT HR=4.06), and a discrete-time proportional hazards analysis (HR, 4.05). In the pooled ITT population, Kaplan-Meier estimates of cumulative complete clearance reached 60.1% with VP-102 versus 19.9% with vehicle by Day 84. Median time to complete clearance was reached by Day 84 with VP-102 but was not reached with vehicle. Conclusion VP-102 demonstrated clinically and statistically significant complete clearance and lesion count reduction of MC regardless of disease duration and resulted in significantly more rapid clinical clearance compared with vehicle. Subjects treated with VP-102 achieved complete clearance at an approximately 4-fold higher rate versus vehicle over the study period, with a consistent treatment effect across multiple statistical approaches. These findings demonstrate that molluscum lesions clear faster when treated with VP-102 than when allowed to resolve on their own across a broad range of disease durations compared with vehicle.