Positive Phase III Results for Antifungal Agent Efinaconazole in Treatment of Nail Infections
Cure rates significantly higher versus vehicle at 1 year (Nov. 26)
The Journal of the American Academy of Dermatology has published the results from two pivotal, randomized, double-blind, vehicle-controlled studies that investigated the safety and efficacy of efinaconazole 10% topical solution (Valeant Pharmaceuticals) — the first triazole antifungal agent developed for distal lateral subungual onychomycosis (DLSO).
Onychomycosis is a common nail infection caused predominantly by dermatophyte fungi, resulting in nail destruction and deformity. The only approved topical treatments are lacquers with limited efficacy. Oral treatments, while more efficacious, are limited by drug interactions and numerous safety concerns, including the potential for acute liver injury.
The two phase III trials were conducted in subjects with DLSO affecting at least one great toenail. The toenail was required to have at least 20% to 50% clinical involvement. Study 1 enrolled 870 subjects, and Study 2 enrolled 785 subjects. The subjects were randomly assigned to treatment with efinaconazole topical solution 10% or vehicle. Treatment was applied once-daily for 48 weeks, with post-treatment follow-up at week 52. Debridement was not performed in either study.
The primary endpoint of both trials was the complete cure rate (defined as no clinical involvement and no evidence of fungus present by both KOH [potassium hydroxide] testing and a negative fungal culture in the target nail) at week 52. In Study 1, 17.8% of subjects treated with efinaconazole were completely cured, compared with 3.3% of subjects treated with vehicle, and in Study 2, 15.2% of subjects treated with efinaconazole were completely cured, compared with 5.5% of subjects treated with vehicle. Using the secondary endpoint of complete or almost complete cure (defined as ≤ 5% clinical involvement and 100% mycologic cure), cure rates for efinaconazole increased by 26.4% and 23.4%, respectively.
Both studies also found that mycologic cure rates were significantly (P < 0.001) greater with efinaconazole topical solution 10% versus vehicle. In Study 1, 55.2% of subjects treated with efinaconazole demonstrated a mycologic cure compared with 16.8% of subjects treated with vehicle. In Study 2, the corresponding mycologic cure rates were 53.4% and 16.9%. Because healthy toenails can require 78 weeks to grow completely, it was expected that the mycologic cure rates would be greater than the complete cure rates. In addition, more patients treated with efinaconazole achieved a complete or almost complete cure (defined as ≤ 5% clinical involvement and mycologic cure) compared with vehicle (26.4% vs. 7.0% in Study 1 and 23.4% vs. 7.5% in Study 2; both P < 0.001).
Adverse events were generally mild and transient and were similar between subjects treated with efinaconazole solution 10% and vehicle.
Source: Valeant Pharmaceuticals; November 26, 2012.