A randomized, double-blind, vehicle-controlled efficacy and safety study of naftifine 2% cream in the treatment of tinea pedis.

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.