Efficacy and Safety of Naftifine HCl Gel 2% in the Treatment of Interdigital and Moccasin Type Tinea Pedis: Pooled Results from Two Multicenter, Randomized, Double-Blind, Vehicle-Controlled Trials

August 2013 | Volume 12 | Issue 8 | Original Article | 911 | Copyright © August 2013

Linda F. Stein Gold MD,a Lawrence Charles Parish, MD,b,c Tracey Vlahovic DPM,d Leon Kircik MD,e Stefan
Plaum MD,f Alan B. Fleischer Jr MD,f Amit Verma DrPH,f Babajide Olayinka MSc,f
and Bhushan Hardas MDf on behalf of the NAFT-600 Study Group*

aHenry Ford Health System, Detroit, MI
bDepartment of Dermatology and Cutaneous Biology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA
cPaddington Testing Company, Inc. Philadelphia, PA
dTemple University School of Podiatric Medicine, Philadelphia, PA
eMount Sinai Medical Center, New York, NY
fMerz Pharmaceuticals, LLC, Greensboro, NC
*See Appendix 1: List of Investigators from the NAFT-600 Study Group

BACKGROUND: Tinea pedis is the most common chronic fungal infection. Naftifine hydrochloride is a topical antifungal of the allylamine class, displaying fungicidal activity and clinically significant anti-bacterial and anti-inflammatory effects.
OBJECTIVE: To evaluate the efficacy and safety of two-weeks once daily application of naftifine gel 2% in the treatment of tinea pedis.
METHODS: At baseline, 1715 subjects were randomly assigned 2:1 to naftifine gel 2% (n=1144) and vehicle (n=571). Efficacy consisting of mycologic determination (KOH and dermatophyte cultures) and scoring of clinical symptom severity was evaluated at baseline and weeks 2, 4, and 6. Efficacy was analyzed in 1174 subjects (n=782, naftifine; n=392, vehicle) with a positive baseline dermatophyte culture and KOH for whom week 6 assessments were available. Safety was evaluated by adverse events (AE) and laboratory values in 1714 subjects (n=1143, naftifine; n=571, vehicle).
RESULTS: Subjects treated with naftifine gel 2% for interdigital-type tinea pedis demonstrated greater improvement from baseline for complete cure (P=0.001), mycological cure (P<0.0001), and treatment effectiveness (P<0.0001) as early as 2 weeks when compared to vehicle; however the highest response rates were seen 4-weeks post treatment (P<0.0001, for all endpoints). Statistically significant results for complete cure, mycological cure, and treatment effectiveness (P<0.0001, for all endpoints) were also seen at week 6 among subjects with moccasin-type tinea pedis. Treatment related adverse events were minimal.
CONCLUSIONS: Treatment with naftifine gel 2% applied once daily for two weeks is well-tolerated and is effective in treating both interdigital-type and moccasin-type tinea pedis. Continuous improvement is observed from the end of treatment to four-weeks after treatment cessation among key outcome measures (complete cure, mycological cure, and treatment effectiveness) as well as clinical signs and symptoms (erythema, scaling, and pruritus).

J Drugs Dermatol. 2013;12(8):911-918.


Tinea pedis (“athlete’s foot”) is the most common chronic, inflammatory fungal infection.1 It is estimated to be present at any one time in 15-20 percent of the US population, and is most common in men between the ages of 25 and 44.1,2 When categorizing the prevalence of skin diseases, Tinea pedis falls behind only acne in skin disease prevalence in the United States.3 The primary pathogens associated with tinea pedis are trichophyton rubrum and trichophyton mentagrophytes, with t. rubrum being responsible for about two-thirds of infections.3 Chronic tinea pedis infection presents as an interdigital-type, which is confined usually to the toe webs, and moccasin-type, which covers the sole, and lateral and plantar surfaces of the arch.2 Moccasin- type tinea pedis, in contrast to interdigital, generally presents with hyperkeratosis with fine or course scale and milder erythema. 2,4 Acute inflammatory episodes of vesiculation also occur and secondary bacterial infections may also be present.4
Naftifine was the first commercially available topical antifungal of the allylamine class. It displays potent fungicidal (and fungistatic) activity and clinically significant anti-inflammatory and anti-bacterial effects.5-8 Mycological and clinical cure rates for naftifine in tinea pedis are superior or equivalent to those of terbinafine, econazole, clotrimazole, miconazole, and tolnaftate. 6,7,9-17 Naftifine cream 2% formulation applied once daily for