Efficacy and Safety of Efinaconazole 10% Topical Solution for Treatment of Onychomycosis in Older Adults: A Post Hoc Analysis of Two Phase 3 Randomised Trials.

Background: Onychomycosis is common in older adults and can be difficult to treat owing to slower nail growth, increased nail thickness, comorbidities, and concomitant medications. Oral treatments can be complicated by contraindications, drug-drug interactions, and adverse effects. Topical treatments such as efinaconazole 10% solution may be beneficial for treating older adults.

Objectives: To evaluate the efficacy/safety of efinaconazole 10% solution in adults aged ≥ 65 years with toenail onychomycosis.

Patients/methods: In two multicenter, double-blind, phase 3 studies (NCT01008033; NCT01007708), patients with mild to moderate toenail onychomycosis were randomised (3:1) to once-daily efinaconazole or vehicle for 48 weeks, with a 4-week follow-up. Pooled data for participants aged ≥ 65 years were analysed post hoc (n = 162 efinaconazole, n = 56 vehicle). The primary endpoint was complete cure (0% involvement of target toenail plus mycologic cure [negative KOH and fungal culture]) at week 52. Treatment-emergent adverse events (TEAEs) were assessed throughout.

Results: At week 52, a significantly greater proportion of older adults (aged 65-71 years) achieved complete cure with efinaconazole than vehicle (13.6% vs. 3.6%; p < 0.05). Complete/almost complete cure rate was also significantly greater (≤ 5% involvement and mycologic cure; 19.1% vs. 5.4%; p = 0.01), and over half (59.2%) of participants achieved mycologic cure with efinaconazole versus 12.5% with vehicle (p < 0.001). Treatment-related TEAE rates with efinaconazole were low (6.0%) and similar to the overall study population.

Conclusions: Efinaconazole 10% solution showed similar efficacy/safety in participants aged ≥ 65 years to the overall phase 3 population, despite potential age-related nail changes. These results demonstrate the benefits of efinaconazole in older patients with onychomycosis.