Econazole Nitrate Foam 1% Improves the Itch of Tinea Pedis

September 2016 | Volume 15 | Issue 9 | Original Article | 1111 | Copyright © September 2016

Alan B. Fleischer Jr. MDa and Isabelle Raymond PhDb

aDivision of Dermatology, Department of Surgery, University of Kentucky College of Medicine, Lexington, KY
bScientific & Professional Affairs, Exeltis USA, Inc., Florham Park, NJ

Abstract
Econazole nitrate topical foam, 1%, is indicated for the treatment of interdigital tinea pedis caused by Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum in patients 12 years of age and older. The symptom of itch or pruritus was evaluated in two randomized, double-blind, parallel-group, vehicle-controlled, multicenter Phase III studies in which econazole foam was compared with foam vehicle in subjects with interdigital tinea pedis. A thin, uniform layer of study treatment was applied once daily to all clinically affected interdigital regions of both feet for four weeks. At baseline, at least 69% of all subjects had moderate to severe itch. Throughout the duration of both studies, numerically econazole foam was numerically superior to vehicle in achieving absence of itch. After the cessation of treatment, from day 29, itching continues to improve until day 43 in the active treatment group, whereas there is no evident continued improvement within the vehicle foam groups. At day 43, in the active treatment groups, 83% in Study 1 and 71% in Study 2 achieved complete absence of itching. Using less stringent criteria, for the econazole nitrate foam arm, achieving no itch or mild itch (0 or 1), in Study 1, 95% and 86.8% in Study 2 achieved this outcome. Tolerability of the products was excellent with few treatment-related adverse events. In summary, econazole foam decreased the burden of itch as early as day 8 in patients with interdigital tinea pedis, and this improvement continued after cessation of treatment.

J Drugs Dermatol. 2016;15(9):1111-1114.

INTRODUCTION

Itch or pruritus remains one of the most bothersome clinical aspects of tinea pedis. Indeed, a PubMed search for tinea pedis and itch demonstrates over 1,300 published articles. Since itch may induce patients to seek care for management of their dermatophytosis, assessing the relief of this symptom is critical to understanding the success of treatment from the patient’s point of view.
Econazole nitrate is a broad-spectrum topical antifungal agent with known clinical or in vitro activity against a variety of dermatophytes and yeasts including Epidermophyton floccosum, Microsporum audouinii, M gypseum, M canis, Trichophyton rubrum, T mentagrophytes, T tonsurans, Candida albicans, Malassezia furfur, and certain gram-positive bacteria1-6. Econazole nitrate foam 1% (Ecoza®) was developed to improve ease of use and patient acceptability of treatment for tinea pedis. Results from multiple studies, including one of the author’s own studies (ABF), have shown that patients often prefer foam over cream preparations for topical treatment of dermatologic disease.7-10 Products with less messy vehicles have the potential to improve patient adherence and, in theory, improve the likelihood of success in clinical practice. Two Phase III clinical studies on interdigital tinea pedis show that econazole nitrate foam is effective in achieving complete cure of tinea pedis, with few adverse events associated with treatment.11
The purpose of the present study is to evaluate the improvement of itch in the Phase III clinical studies of econazole nitrate foam. Itch is an important outcome in clinical trials because this symptom negatively affects the quality of life of patients with skin disease.12-14 Furthermore, in some disease states, improving itch is associated with improved quality of life.15

METHODS

Study Design

Econazole nitrate foam 1% was evaluated in two randomized, double-blind, parallel-group, vehicle-controlled, multicenter studies in which it was compared with foam vehicle in subjects with interdigital tinea pedis. All subjects provided informed written consent prior to any study procedures.

Subjects

Eligible subjects were male or female ≥12 years of age, with a clinical diagnosis of interdigital tinea pedis involving ≥2 web spaces in total, which extended no more than approximately 1 inch proximal to the web spaces or metatarsophalangeal joints with at least moderate scaling and mild erythema at baseline. Subjects were also required to have microscopic evidence (positive KOH) of the presence of fungi and fungal culture positive for a dermatophyte in the skin scrapings.
Subjects who might be potentially pregnant, nursing, or planning a pregnancy during the study were excluded, as were those who had used topical antifungals or topical corticosteroids on the feet within 30 days prior to the start of the study or received systemic antifungal therapy within 12 weeks prior to the first dose of study