A Randomized, Double-Blind, Vehicle-Controlled Efficacy and Safety Study of Naftifine 2% Cream in the Treatment of Tinea Pedis
November 2011 | Volume 10 | Issue 11 | Original Article | 1282 | Copyright © November 2011
Lawrence Charles Parish MD,a,b Jennifer L. Parish MD,a Hirak B. Routh MB BS,b Alan B. Fleischer Jr. MD,c Edward V. Avakian MA PhD,c Stefan Plaum MD,c Bhushan Hardas MD MBAc
aDepartment of Dermatology and Cutaneous Biology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA bPaddington Testing Company, Inc., Philadelphia, PA cMerz Pharmaceuticals, LLC, Greensboro, NC
Abstract
Objective: Naftifine HCl 2% cream (NAFT-2) is a topical allylamine antifungal agent under development in the United States. This randomized,
double-blind, vehicle-controlled, phase 3 trial evaluated the efficacy and safety of two weeks of NAFT-2 treatment in subjects
with tinea pedis. Naftifine 1% cream (NAFT-1) treatment for four weeks and vehicle were also evaluated as a positive control.
Methods: 709 subjects were randomly assigned 2:1:2:1 to one of four treatment groups: (i) NAFT-2 (n= 235), (ii) two-week vehicle
(n=118), (iii) NAFT-1 (n=237), or (iv) four-week vehicle (n=119). Efficacy was evaluated at baseline, week 2, week 4, and week 6 and
consisted of mycology determination (KOH and dermatophyte culture) and scoring of clinical symptom severity (erythema, scaling,
and pruritus). Efficacy was only analyzed in 425 subjects with positive baseline dermatophyte culture. Safety was evaluated by adverse
events (AE) and laboratory values in 707 subjects.
Results: At week 6, NAFT-2 subjects achieved 18 percent complete cure rate, 67 percent mycological cure rate, 57 percent treatment
effectiveness, 22 percent clinical cure rate, and 78 percent clinical success rate compared to respective vehicle rates of seven percent
(one-sided, P<0.01), 21 percent (P<0.001), 20 percent (P<0.001), 11 percent (P=0.04) and 49 percent (P<0.001). Week 6 efficacy responses
in NAFT-1-treated subjects were significantly higher than vehicle subjects and almost identical to NAFT-2 subjects. Mycological
cure and clinical response rates in both NAFT-2 and NAFT-1 increased from week 2 to week 6. Treatment-related AEs occurred in five
percent of NAFT-2 subjects, seven percent of vehicle subjects, four percent of NAFT-1 subjects and eight percent of vehicle subjects.
The most common AEs for all groups were application site pruritus and skin irritation.
Conclusion: Topical NAFT-2 for two weeks is safe and provides significantly superior antifungal treatment than vehicle in tinea pedis
subjects. NAFT-2 produces equivalent efficacy responses to four weeks of NAFT-1 treatment. The fungicidal activity of naftifine continues
to increase for at least one month after treatment is completed. (Clinical Trials Identification Numbe=NCT00750139).
J Drugs Dermatol. 2011;10(11):1282-1288.
INTRODUCTION
Tinea pedis, the proverbial "athlete's foot," is the most
common superficial fungal infection, estimated to be
present at any one time in 15-20 percent of the US and
European populations.1,2 For unknown reasons, tinea pedis is
most frequently seen in men between the ages of 25-44.1 Trichophyton
rubrum and Trichophyton mentagrophytes are the primary
pathogens in tinea pedis, with T. rubrum being responsible
for about two-thirds of infections.2 Clinical signs and symptoms
of tinea pedis include pruritus, scaling, flaky skin, erythema, and
sometimes, vesiculation.3
Tinea pedis is usually treated topically with an antifungal agent
that has broad-spectrum fungicidal properties, such as naftifine.4,5
Naftifine 1% cream was approved in 1988 as the first commercially
available topical allylamine antimycotic, and in 1990 a 1% topical
gel was introduced.5 The formulations are applied once (cream) or
twice (gel) daily for four weeks and are fungicidal against Trichophyton
rubrum, Trichophyton mentagrophytes, and other species.4-6
Naftifine also exerts clinically-significant anti-inflammatory effects
(local vasoconstriction and decreased erythema) equivalent to 1%
hydrocortisone,6-9 as well as antibacterial activity.6
The safety and efficacy of naftifine 1% cream and gel in the
treatment of tinea pedis and other superficial dermatophyte
infections are well documented.5-7,10-17 Mycological and clinical
cure rates for naftifine 1% cream in tinea pedis have been shown
to be equal or superior to those of other antifungal agents, including
terbinafine, econazole, clotrimazole, miconazole, and
