FDA Gives Green Light to Kerydin (Tavaborole) for Treatment of Onychomycosis
First topical therapy for toenail involvement
The FDA has approved the new drug application for Kerydin (tavaborole) topical solution, 5% (Anacor Pharmaceuticals) — the first oxaborole antifungal approved for the topical treatment of onychomycosis of the toenails.
According to Podiatry Today, onychomycosis is a fungal infection of the nail and nail bed that affects approximately 35 million people in the U.S., but only 5 to 6 million have been diagnosed by a physician.
Kerydin (tavaborole) topical solution, 5%, is the first oxaborole antifungal agent developed for the topical treatment of onychomycosis of the toenails due to Trichophyton rubrum or T. mentagrophytes.
The product is a clear, colorless, alcohol-based solution applied with a dropper to the infected toenail once daily for 48 weeks. Debridement of the nail is not required during the treatment period. Because of its topical application, Kerydin has low systemic absorption and has not demonstrated systemic side effects.
The efficacy and safety of tavaborole were evaluated in two multicenter, double-blind, randomized, vehicle-controlled trials. Tavaborole or vehicle was applied once daily for 48 weeks in subjects with 20% to 60% clinical involvement of the target toenail without dermatophytomas or lunula (matrix) involvement. A total of 1,194 subjects (tavaborole, n = 795; vehicle, n = 399) 18 to 88 years of age participated in the two trials. Efficacy assessments were performed at 52 weeks after a 48-week treatment period.
The primary efficacy endpoint of both studies was a complete cure — defined as a completely clear nail (0% clinical involvement of the target toenail) plus a mycological cure (negative KOH wet mount and negative fungal culture) — at week 52. In the first trial, 6.5% of subjects treated with tavaborole reached the primary endpoint compared with 0.5% of subjects treated with vehicle. In the second trial, 9.1% of subjects treated with tavaborole reached the primary endpoint compared with 1.5% of the vehicle-treated group.
Secondary endpoints in the two pivotal trials included a complete or almost complete cure (i.e., less than or equal to 10% affected target toenail area involved plus a mycological cure) and a mycological cure. In the first and second trials, 15.3% and 17.9% of patients treated with tavaborole achieved a complete or almost complete cure compared with 1.5% and 3.9% of patients treated with vehicle, respectively. Moreover, 31.1% and 35.9% of patients treated with tavaborole achieved a mycological cure compared with 7.2% and 12.2% of patients treated with vehicle.
Common adverse reactions with tavaborole included application-site exfoliation, ingrown toenail, application-site erythema, and application-site dermatitis.