VP-102 Tolerability Evaluated by Concomitant Analgesic Medication Usage in Two Phase 3 Trials for Molluscum Contagiosum

Background: Drug tolerability is the degree to which a patient can tolerate a drug's adverse effects. VP-102, a drug-device combination product containing cantharidin (0.7%), a vesicant, is approved for treatment of molluscum contagiosum (molluscum) in patients >2. Local skin reactions (LSRs) are expected, including pain. In Phase 3 trials, 97% of LSRs were mild to moderate. The discontinuation rate due to an adverse reaction was 2.3%:0.5% (drug:vehicle) treated subjects, respectively. This post-hoc analysis evaluated VP-102 tolerability based on analgesic usage over the study course. Methods: VP-102 or vehicle was applied to all baseline and new lesions once every 21 days until complete clearance, or up to a maximum of 4 applications. Acetaminophen or ibuprofen were permitted for application site pain and/or other Adverse Reactions. Results: Overall incidence of pain at any time for a VP-102 subject was 62.7% (195/311), with the majority [(60.5%),188/311] as mild to moderate. 18.6% (58/311) of VP-102 and 1.4% (3/216) of vehicle treated subjects received an analgesic, including 15.8% (49/311) for an LSR after the first VP-102 application. Median VP-102 analgesic use for LSR pain (range) was 2 (1-14) days for the entire study, and 2 (1-9) days after the first application. 29% of participants who reported analgesic usage took medication ≤1 day. Analgesic usage for AEs other than LSR pain (≥ 5% of participants) included 6% (19/311) for application site vesicles. There were no treatment-related SAEs reported. Conclusions: In this largely pediatric population, VP-102 was well-tolerated, with a short duration of elective analgesic use.