Conference Coverage

New cantharidin formulation alleviates molluscum contagiosum in pivotal trials



A novel, standardized preparation of topical cantharidin effectively cleared lesions in patients with molluscum contagiosum, compared with placebo, according to the results of two trials presented at the annual meeting of the American Academy of Dermatology.

VP-102, a drug-device combination, was well tolerated and was not associated with serious adverse events.

No Food and Drug Administration–approved treatment is available for treating molluscum contagiosum, which is routinely treated with cantharidin, a naturally occurring vesicant.

VP-102 is a novel formulation of 0.7% cantharidin solution, provided in a single-use applicator, to provide consistent delivery and long-term drug stability.

To test the efficacy and safety of VP-102, Lawrence Eichenfield, MD, chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego, and his associates conducted the CAMP-1 (Cantharidin Application in Molluscum Patients) and CAMP-2 phase 3 studies, which had similar designs. The studies enrolled patients with molluscum contagiosum aged 2 years and older who had not received any treatment in the 2 weeks before enrollment. Patients were randomized to VP-102 or vehicle for 12 weeks. Treatment was administered topically to each lesion every 3 weeks for a maximum of four applications, and washed off with soap and warm water 24 hours after application.

The trials’ primary endpoint was the percentage of patients with complete clearance of their lesions. Secondary endpoints were the percentage of patients with complete clearance at 3, 6, and 9 weeks, and decrease in lesions over time. The researchers also assessed safety and tolerability.

In the two studies, 528 patients aged 2-60 years (mean age, approximately 7 years) were randomized to treatment or vehicle. About 30% of participants had prior treatment. The baseline lesion count ranged from 1 to 184.

At day 84, the proportion of patients in the VP-102 arm who achieved complete clearance of lesions was 46% in CAMP-1 and 54% in CAMP-2, compared with 18% and 13%, respectively, among controls (P less than .0001). By day 84, among treated patients, the lesion count had decreased by a mean of 69% in CAMP-1 and 83% in CAMP-2, compared with 20% and 19%, respectively, among controls. Results among controls were “probably consistent with natural history,” Dr. Eichenfield observed.

The researchers observed a high incidence of treatment-emergent adverse events among patients receiving VP-102. “Any crust or vesiculation was considered to be a treatment-emergent adverse event,” Dr. Eichenfield said. Most adverse events were mild, although five patients discontinued the studies because of treatment-emergent adverse events. Vesiculation was a common adverse event in the VP-102 group; pruritus and application-site pain were reported as well.

Verrica Pharmaceuticals developed VP-102 and funded the study. Dr. Eichenfield reported receiving no funding from the company; several other investigators are employees of Verrica, which plans to submit for FDA approval in the second half of 2019.

SOURCE: Eichenfield L et al. AAD 19, Abstract 11251.

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