A Double-Blind, Randomized, Vehicle-Controlled Study Evaluating the Efficacy and Safety of Naftifine 2% Cream in Tinea cruris

October 2011 | Volume 10 | Issue 10 | Original Article | 1142 | Copyright © October 2011


Abstract
Objective: Naftifine HCl 2% cream (NAFT-2%) is a topical allylamine antifungal preparation under development in the U.S. The objective of this randomized, double-blind, vehicle-controlled study was to evaluate the efficacy and safety of a two-week course of once-daily NAFT-2% vs. vehicle in the treatment of Tinea cruris ("jock itch"). Methods: A total of 334 subjects with T. cruris were enrolled and randomly assigned to NAFT-2% (n=166) or vehicle (n=168), which was applied once daily for 14 days. Efficacy and safety were evaluated at week 2 (end of treatment) and week 4. Efficacy measures included complete cure, treatment effectiveness, mycological cure, clinical cure, and clinical success and were analyzed only in subjects with a positive potassium hydroxide (KOH) and dermatophyte culture at baseline (n=75, naftifine; n=71, vehicle). Safety was assessed by adverse events and changes from baseline in clinical status and laboratory studies. Results: At week 4, 25 percent of naftifine-treated subjects achieved complete cure vs. three percent of vehicle subjects and 72 percent achieved mycological cure vs. 16 percent of vehicle treated subjects (one-sided, P<0.001). Treatment effectiveness was achieved in 60 percent of NAFT-2% subjects vs. 10 percent of vehicle subjects (one-sided, P<0.001). Clinical cure rate and clinical success rate were 33 percent and 84 percent in NAFT-2% subjects, respectively vs. 10 percent and 46 percent in vehicle subjects (both P<0.001, 2-sided). Week 2 efficacy response rates in NAFT-2% subjects were all lower than at week 4 but were significantly higher than week 2 vehicle-treated counterparts (P<0.025). Treatment-related AE occurred in 11 subjects (7 NAFT-2%, 4 vehicle) during the study. The most common AE in both groups were contact dermatitis (2 NAFT-2%), pruritus (2 vehicle), and application site reaction (1 per group). Conclusion: NAFT-2% applied once daily for two weeks (one-half the treatment duration for naftifine 1% cream) is efficacious and safe for the treatment of T. cruris. J Drugs Dermatol. 2011;10(10):1142-1147.

INTRODUCTION

Tinea cruris (“jock itch”) is a dermatophyte infection most often caused by Trichophyton rubrum.1 It is the second most common clinical presentation for superficial fungal infections.2 While the epidemiology is not always clear, excessive perspiration (i.e., warm, moist environment) and constrictive clothing in the area are the most often encountered predisposing factors.
T. cruris is usually treated with daily application(s) of a topical fungicidal agent such as naftifine for four weeks or longer.3 Naftifine 1% cream or gel is a broad-spectrum, allylamine antifungal which readily penetrates the epidermis and is fungicidal for T. rubrum and Trichophyton mentagrophytes.4, 5, 6 Naftifine also exerts clinically significant anti-inflammatory activity equivalent to hydrocortisone,5, 7, 10 as well as antibacterial activity.5 Naftifine 1% cream was first marketed in 1988 as the first commercially available allylamine class antifungal agent.4 It is applied once daily for four weeks, and the gel formulation is applied twice daily for four weeks. Naftifine 1% cream and gel have been shown to be effective and safe in the treatment of T. cruris, Tinea pedis, and Tinea corporis.5, 7, 11-15 Mycological and clinical cure rates from naftifine 1% formulations are equal to or superior to those of other antifungal agents including clotrimazole, miconazole, bifonazole, terbinafine, and tolnaftate, alone or in combination with a corticosteroid. 5, 7, 11-19
A naftifine HCl 2% cream is currently under development for the treatment of T. cruris,T.corporis , and T. pedis. This randomized, double-blind, vehicle-controlled, parallel-group trial evaluated the efficacy and safety of a two-week, once-daily treatment with naftifine HCl 2% cream in the treatment of T. cruris.