719. Susceptibility Testing of Oteseconazole (VT-1161) Against Clinical Isolates from Phase 3 Clinical Studies in Subjects with Recurrent Vulvovaginal Candidiasis

Abstract

Abstract Background Oteseconazole (VT-1161) is a novel, investigational oral therapy that is currently under FDA review for the treatment of recurrent vulvovaginal candidiasis (RVVC). Susceptibility testing was performed on all viable clinical isolates collected from three Phase 3 studies to determine the susceptibility of causative pathogens to oteseconazole versus the current treatment standard of care, fluconazole. Methods Vaginal cultures were obtained at screening and at all subsequent study visits throughout the duration of the studies (approx. 48 Weeks) and submitted to a central mycology laboratory for fungal species identification and storage. Susceptibility testing was conducted in accordance with the CLSI Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeast M27-Ed4. Results Candida albicans was identified as the primary causative pathogen in 87% of women with RVVC presenting with an acute infection, followed by C. glabrata (8%). Other non-albicans species including; C. parapsilosis, C. tropicalis, C. krusei, C. dubliniensis, C. kefyr and Saccharomyces cerevisiae were responsible for < 1% of infections. A total of 1910 isolates were collected. The MIC range, MIC50 and MIC90 values against all isolates for oteseconazole were ≤ 0.0005 to > 0.25, 0.002 and 0.06 µg/mL, respectively. In comparison, the MIC range, MIC50 and MIC90 values for fluconazole were, ≤ 0.06 to > 32, 0.25 and 8 µg/mL respectively. The MIC range, MIC50 and MIC90 values against all C.glabrata isolates for oteseconazole were 0.002 to > 0.25, 0.03 and 0.125 µg/mL, respectively. In comparison, the MIC range, MIC50 and MIC90 values for fluconazole were, ≤ 0.06 to 32, 2 and 8 µg/mL respectively. Conclusion Oteseconazole demonstrated very low MIC values against most Candida strains, including fluconazole resistant isolates, aligning with clinical study outcomes. Oteseconazole MICs against C. glabrata strains were approximately 6-fold lower than fluconazole. Disclosures Mahmoud Ghannoum, PhD, Mycovia Pharmaceuticals (Grant/Research Support, Research Grant or Support) Thorsten Degenhardt, Ph.D, Mycovia Pharmaceuticals (Employee, Shareholder) Karen Person, M.S., Mycovia Pharmaceuticals, Inc. (Employee)Mycovia Pharmaceuticals, Inc. (Employee) Stephen Brand, Ph.D, Mycovia Pharmaceuticals (Employee)