<i>In Vitro</i> and <i>In Vivo</i> Evaluation of the Antifungal Activity of APX001A/APX001 against Candida auris

Abstract

<i>Candida auris</i> is an emerging multidrug-resistant yeast that has been responsible for invasive infections associated with high morbidity and mortality. <i>C. auris</i> strains often demonstrate high fluconazole and amphotericin B MIC values, and some strains are resistant to all three major antifungal classes. We evaluated the susceptibility of 16 <i>C. auris</i> clinical strains, isolated from a wide geographical area, to 10 antifungal agents, including APX001A, a novel agent that inhibits the fungal protein Gwt1 (glycosylphosphatidylinositol-anchored wall transfer protein 1). APX001A demonstrated significantly lower MIC₅₀ and MIC₉₀ values (0.004 and 0.031 μg/ml, respectively) than all other agents tested. The efficacy of the prodrug APX001 was evaluated in an immunocompromised murine model of disseminated <i>C. auris</i> infection. Significant efficacy (80 to 100% survival) was observed in all three APX001 treatment groups versus 50% survival for the anidulafungin treatment group. In addition, APX001 showed a significant log reduction in CFU counts in kidney, lung, and brain tissue (1.03 to 1.83) versus the vehicle control. Anidulafungin also showed a significant log reduction in CFU in the kidneys and lungs (1.5 and 1.62, respectively) but did not impact brain CFU. These data support further clinical evaluation of this new antifungal agent.