Efficacy of amorolfine nail lacquer for the prophylaxis of onychomycosis over 3 years

[[[ Background: ]]] Standard treatment for onychomycosis often results in less than half of subjects achieving disease-free nails. Onychomycosis is even more challenging to treat as relapses and re-infections are common. [[[ Objective: ]]] To determine if a prophylactic effect exists when a treatment with amorolfine nail lacquer (ANL), with half the frequency of the standard regimen, is instituted following successful treatment of dermatophytic toenail onychomycosis with matrix involvement. [[[ Methods: ]]] Efficacy and safety of a group treated with ANL (once every 2 weeks) were compared with that of an untreated group in a 36-month (3 years), single-centre, randomized, open-label, comparison study. Subjects to be included in the study were required to be cured of confirmed onychomycosis with matrix involvement after an initial treatment with either ANL + oral terbinafine or oral terbinafine alone in a previous study. Prophylaxis of onychomycosis was assessed by global recurrence rate, confirmed onychomycosis, clinical recurrence and mycological recurrence. [[[ Results: ]]] A total of 52 subjects were enrolled (26 in each group) in the study. Throughout the study, recurrences occurred more quickly in the untreated group compared with that in the ANL group. Statistically significant differences were observed at month 12 (ANL, 8.3%; untreated, 31.8%; P = 0.047). At endpoint, 70.8% of the subjects treated with ANL remained cured compared to 50% in the untreated group (P = 0.153). Recurrence was delayed by nearly 200 days for the ANL group compared with that of the untreated group. Amorolfine was safe and well tolerated during the study, with no treatment-related adverse events. [[[ Conclusion: ]]] These results suggest that amorolfine nail lacquer may be effective and is safe for use as a prophylactic treatment for the recurrence of onychomycosis.