Efficacy and Safety of Topical Efinaconazole 10% for Onychomycosis: Pooled Phase 3 Trials by Race

Background Clinical efficacy and safety data for toenail onychomycosis treatments in patients with skin of color are limited. Topical efinaconazole 10% solution has demonstrated efficacy and safety in two phase 3 studies and post hoc analyses of age and sex. This post hoc analysis was conducted to evaluate efficacy and safety of efinaconazole in participants with onychomycosis categorized by race. Methods Data were pooled from 2 multicenter, double-blind, phase 3 trials (NCT01007708, NCT01008033). Participants aged 18-70 years with mild to moderate distal lateral subungual onychomycosis in ≥1 great toenail (n=1655) were randomized (3:1) to once-daily efinaconazole 10% or vehicle for 48 weeks. Efficacy endpoints at week 52 included rates of mycologic cure (negative potassium hydroxide [KOH] examination + negative fungal culture), complete cure (0% clinical involvement + mycologic cure), complete/almost complete cure (≤5% clinical involvement + mycologic cure), and clinical efficacy (<10% clinical involvement only). Adverse events (AEs) were assessed. Participants were categorized by self-reported race: White (n=1251), Asian (n=269), or Black/African American (n=98). Results At week 52, more participants treated with efinaconazole versus vehicle achieved complete cure (White, 14.7% vs 2.0%; Asian, 27.5% vs 13.0%; Black, 12.9% vs 7.1%), complete/almost complete cure (22.8% vs 4.6%; 35.5% vs 18.8%; 25.7% vs 7.1%, respectively), and clinical efficacy (31.2% vs 8.6%; 46.0% vs 23.2%; 31.4% vs 21.4%). Over half of White (53.4%), Asian (56.5%), and Black (61.4%) efinaconazole-treated participants achieved mycologic cure versus only 10.7%-30.4% with vehicle. Most treatment-emergent AEs with efinaconazole were mild to moderate, with low discontinuation rates due to AEs in all subgroups (<6%). Conclusions Topical efinaconazole 10% showed good efficacy/safety in White, Asian, and Black participants with mild to moderate onychomycosis, although generalizability of the smaller Black population results may be limited. These results were generally consistent with the overall phase 3 populations and demonstrated that efinaconazole is an efficacious treatment for patients with skin of color.