FDA Approves Anacor Pharmaceuticals' Kerydin to Treat Onychomycosis

The FDA approved Anacor Pharmaceuticals' New Drug Application for Kerydin (tavaborole) topical solution, 5%, the first oxaborole antifungal approved for the topical treatment of onychomycosis of the toenails due to Trichophyton rubrum or Trichophyton mentagrophytes.

"I am very excited about the release of this therapy for an infection that is very difficult to treat," said Boni Elewski, MD, Vice Chair of Clinical Affairs and Professor of Dermatology at the University of Alabama at Birmingham. "Kerydin will offer patients a new, safe and effective treatment option for onychomycosis."

Kerydin 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. Due to its topical application, Kerydin has low systemic absorption and has not demonstrated systemic side effects.

Kerydin'a efficacy and safety was evaluated in two multicenter, double-blind, randomized, vehicle-controlled trials. Kerydin 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 1194 subjects (795 Kerydin, 399 Vehicle) 18 to 88 years of age, participated in these two trials. Efficacy assessments were made at 52 weeks following a 48-week treatment period.

The primary efficacy endpoint was "Complete Cure" at Week 52. "Complete Cure" is defined as "Completely Clear Nail" (0 percent clinical involvement of the target toenail) plus "Mycological Cure" (negative KOH wet mount and negative fungal culture). In the first trial, 6.5 percent of subjects treated with Kerydin reached the primary endpoint, compared to 0.5 percent of subjects treated with vehicle. In the second trial, 9.1 percent of subjects treated with Kerydin reached the primary endpoint, compared to 1.5 percent of subjects treated with vehicle.

Secondary endpoints in the pivotal trials included "Complete or Almost Complete Cure" (less than or equal to 10 percent affected target toenail area involved plus "Mycological Cure") and "Mycological Cure." 15.3 percent and 17.9 percent of patients treated with Kerydin achieved "Complete or Almost Complete Cure" compared to 1.5 percent and 3.9 percent of patients treated with vehicle in the first and second trials, respectively. 31.1 percent and 35.9 percent of patients treated with Kerydin achieved "Mycological Cure" compared to 7.2 percent and 12.2 percent of patients treated with vehicle in the first and second trials, respectively.

Common adverse reactions occurring in at least 1 percent of subjects treated with Kerydin included application site exfoliation, ingrown toenail, application site erythema, and application site dermatitis.

"Kerydin was designed to be convenient for patients to use and has demonstrated efficacy in the treatment of the fungal infection, thus allowing growth of new uninfected nail," said Vince Ippolito, Chief Commercial Officer of Anacor Pharmaceuticals. "In market research conducted by Anacor, Kerydin's product profile was received with great enthusiasm by the participating physicians and we believe this response demonstrates the need for a safe topical treatment for onychomycosis of the toenails."