Evaluation of in vitro activity of manogepix against multidrug-resistant and pan-resistant Candida auris from the New York Outbreak

Abstract

An ongoing Candida auris outbreak in the New York metropolitan area is the largest recorded to date in North America. Laboratory surveillance revealed NY C. auris isolates are resistant to fluconazole, with variable resistance to other currently used broad-spectrum antifungal drugs, and that several isolates are pan-resistant. Thus, there is an urgent need for new drugs with a novel mechanism of action to combat the resistance challenge. Manogepix (MGX) is a first-in-class agent that targets the fungal Gwt1 enzyme. The prodrug, fosmanogepix, is currently in Phase 2 clinical development for the treatment of fungal infections. We evaluated the susceptibility of 200 New York C. auris isolates to MGX and 10 comparator drugs using CLSI methodology. MGX demonstrated lower MICs than comparators (MIC50 and MIC90 0.03 mg/L; range 0.004-0.06 mg/L). The MGX epidemiological cutoff value (ECV, 99% cutoff) for the tested C. auris isolates was 0.06 mg/L. MGX was 8-32-fold more active than the echinocandins, 16-64-fold more active than the azoles, and 64-fold more active than amphotericin B. No differences were found in the MGX or comparators MIC50, MIC90, or GEOMEAN values when subsets of clinical, surveillance, and environmental isolates were evaluated. The range of MGX MIC values for six C. auris pan-resistant isolates was 0.008-0.015 mg/L, and the median and mode MIC values were 0.015 mg/L, demonstrating that MGX retains activity against these isolates. These data support further clinical evaluation of fosmanogepix for the treatment of C. auris infections, including highly resistant isolates.