Demographically, white, male subjects comprised the majority in the naftifine gel 2% and vehicle arms (Table 2). The mean age for the treatment group was 44.6 and the vehicle group was 47.7.
Results of the trial showed that the 2% gel was superior to vehicle
at week 6 (four weeks post-treatment) for complete cure of the subject who had both interdigital and moccasin-type presentations.
It was also shown to be significantly better than vehicle in achieving mycologic cure at week 6 in those same subjects. Overall, naftifine 2% gel was designed to provide a shorter and more convenient regimen while still maintaining the efficacy that practitioners have come to expect with the drug. Specifically for the moccasin group, the primary efficacy endpoint of complete cure at week 2 (end of treatment) was 1.7% (gel) vs 0.9% (vehicle) and week 6 (four weeks post-treatment)
was 19.2% (gel) vs 0.9% (vehicle). The secondary efficacy endpoints for the moccasin group are listed in Table 3. At week 6, complete cure, mycological cure, treatment effectiveness, clinical cure, and clinical success were statistically superior when compared to the matching vehicle group.
Naftifine gel 2% was well tolerated in the 14-day treatment period. Three subjects in the 2% gel group experienced treatment
emergent adverse events (TEAE) related to the study drug while no subjects in the vehicle group experienced TEAE related to the study treatment. TEAEs, which were rated by the investigator, included application site pruritus, rash, vesicles, and hypersensitivity.
As moccasin tinea pedis may present with plantar hyperkeratosis,
this focal hyperkeratosis presents a therapeutic challenge to both the patient and the physician both during
and after antifungal therapy. Hyperkeratotic tinea pedis accounts for 2-8% of tinea cases and presents as moccasin type tinea with hyperkeratosis confined to the weight bearing
areas.11 Hyperkeratosis in the presence of moccasin tinea pedis is typically bilateral and often only treated with a topical
antifungal. Often, after the tinea infection has resolved, the hyperkeratosis remains, which leads the patient to believe
the infection is still present. The addition of a keratolytic to reduce
stratum corneum thickening is warranted in these cases. There is no combination product targeting both the hyperkeratosis
and the tinea available at this time, but Kircik et al relates a pilot study of using naftifine 2% cream along with urea 39% cream on 18 subjects.12 Patients were evaluated for 8 weeks during which they used the naftifine 2% cream for two weeks in the morning and the urea 39% cream to the affected area nightly. Ultimately, the evaluable subjects had improvements in hyperkeratosis, the active tinea infection, and pruritus. This dual therapy ultimately proved efficacious and cosmetically pleasing for the patients to use.
Considering the chronic and refractory course of moccasin tinea pedis, naftifine gel 2% and naftifine cream 2% (in combination with urea 39% cream) have been shown to be useful agents in the management of this subtype; however both are still only approved for the interdigital type, not the moccasin type. The post-hoc data reported for naftifine HCl gel 2% is a first step in creating awareness and a possible protocol to determine the safety and efficacy for a topical antifungal in the presence of moccasin tinea pedis. A once daily dosing regimen for a shorter course of therapy (2 weeks vs the standard 4-week twice daily dosing) is advantageous in patients with this chronic superficial skin infection. And, in adding a urea product, a patient can also achieve a cosmetically and therapeutically pleasing result with their topical antifungal regimen. Overall, the naftifine gel 2%
