Journal of Fungi
In Vitro Terbinafine Susceptibility of Dermatophytes and Mycological Cure Outcomes from a Multicenter Phase III Onychomycosis Trial
By Mahmoud Ghannoum, Erin Marie D. San Valentin and Amir Tavakkol.
Abstract
Background
Dermatophyte infections, including onychomycosis, affect millions worldwide. Terbinafine, an allylamine antifungal, remains a foundational method of treatment.
Objective
We aim to evaluate the in vitro antifungal susceptibility of terbinafine against dermatophyte isolates obtained from patients participating in a Phase III onychomycosis clinical trial.
Methods
A total of 506 viable dermatophyte baseline isolates were tested using the Clinical and Laboratory Standard Institute (CLSI) M38-A3 broth microdilution method. The minimum inhibitory concentration (MIC) distributions in baseline isolates were compared between isolates from patients who were randomized and treated (group 1: terbinafine, n = 218 and vehicle, n = 108) and isolates from patients who screen-failed and therefore were not treated (group 2, n = 180). In addition, baseline MICs from group 1 were linked to their end-of-study mycological cure (negative KOH microscopy and negative fungal culture) to determine the relationship between MICs and mycological cure in study patients.