Onychomycosis is a common progressive fungal infection of the nail bed, matrix, or plate leading to destruction and deformity of the toenails and fingernails.1,2 It represents up to 50% of all nail disorders1,3 with a notable increasing prevalence in the United States.4-6
Latinos represent the largest ethnic minority group in the United States,7 which is growing rapidly through immigration, particularly in the southern United States. Prevalence data are limited. An incidence of 9.3% secondary to dermatophytes was recorded in a dermatology clinic setting (N=2000).8 Onychomycosis was reported in 31.9% of a group of Latino immigrants in North Carolina (N=518), with higher prevalence in poultry workers, possibly due to the work environment.9
Efinaconazole solution 10% was shown to be well tolerated and more effective than a vehicle in a phase 2 study in Mexico.10 Two identical phase 3 studies of 1655 participants assessed the safety and efficacy of efinaconazole solution 10% in the treatment of onychomycosis.11 This post hoc analysis compares the data for Latino versus non-Latino populations.
Methods
We evaluated the results of 2 multicenter, randomized, double-blind, vehicle-controlled studies that included a total of 1655 participants with mild to moderate toenail onychomycosis (20%–50% clinical involvement). Participants were randomized to efinaconazole solu-tion 10% or vehicle once daily (3:1) for 48 weeks with a 4-week posttreatment follow-up period.11
Our post hoc analysis included 270 Latino patients, defined as an individual of Cuban, Mexican, Puerto Rican, or South or Central American origin or other Latino culture, regardless of race. In addition, data were compared to the 1380 non-Latino patients in the 2 studies. Patients who were randomized in error and never received treatment were excluded from the intention-to-treat analysis.
Efficacy Evaluation
The primary efficacy end point was complete cure rate (0% clinical involvement of target toenail, and both negative potassium hydroxide examination and fungal culture) at week 52. Secondary end points included mycologic cure, complete/almost complete cure (≤5% clinical involvement of target toenail, mycologic cure), and treatment success (≤10% clinical involvement of target toenail) at week 52.
Safety Evaluation
Safety assessments included monitoring and recording of adverse events (AEs) at every postbaseline study visit through week 52. All AEs were classified using the Medical Dictionary for Regulatory Activities (version 12.1). Treatment-emergent AEs (ie, events that began after the first application of study drug) that occurred during the study were summarized for each treatment group by the number of patients reporting each event, as well as by system organ class, preferred term, severity, seriousness, and relationship to the study drug.
Results
A total of 270 Latino participants with toenail onychomycosis (efinaconazole solution 10%, n=193; vehicle, n=77) were included in our study. The mean age of participants at baseline was 45.9 years. They were predominantly male (69.6%) and white Latinos (91.1%). The mean area of target toenail involvement was 36.6%, and the mean number of affected nontarget toenails was 2.5. Latino participants tended to be younger than non-Latino participants (45.9 vs 52.6 years), with a higher proportion of females (30.4% vs 21.3%). Disease severity was similar in both populations. Diabetes was reported in 7.0% and 6.7% of Latino and non-Latino participants, respectively, and mean weight was 83.6 and 86.6 kg, respectively.
