637. Outcomes by Body Mass Index (BMI) in the STRIVE Phase 2 Trial of Once-Weekly Rezafungin for Treatment of Candidemia and Invasive Candidiasis Compared with Caspofungin

BACKGROUND: There is increasing evidence of antifungal underdosing in the treatment of invasive disease, particularly in special populations such as the obese. Body size is often an important variable affecting drug exposure, and pharmacokinetic (PK) models of antifungal dosing have suggested size-based dose adjustments to achieve target drug exposure. Rezafungin (RZF) is a novel echinocandin in Phase 3 development for treatment of candidemia and invasive candidiasis (IC) and for prevention of invasive fungal disease caused by Candida, Aspergillus, and Pneumocystis in blood and marrow transplant recipients. Distinctive PK properties of RZF (e.g., long half-life, extensive tissue distribution, and front-loaded drug exposure) lend themselves to RZF once-weekly (QWk) dosing and antifungal efficacy. In this sub-analysis of the Phase 2 STRIVE trial of RZF in the treatment of candidemia and/or IC, outcomes based on patient BMI were evaluated. METHODS: The STRIVE trial (NCT02734862) compared the safety and efficacy of RZF QWk compared with once-daily caspofungin (Fig. 1). For this subanalysis, data were stratified by BMI categories of < 30 kg/m(2) and ≥ 30 kg/m(2). Efficacy (overall response [resolution of clinical signs of infection + mycological eradication], mycological response, and investigator assessment of clinical response) and safety (treatment-emergent adverse events [TEAEs]) endpoints by treatment group were evaluated, as well as PK data (area under the curve [AUC]) from RZF-treated patients. Figure 1. [Image: see text] RESULTS: Mean BMI values were similar across treatment arms (26.9 kg/m(2) in RZF Group 1 and 26.8 kg/m(2) in RZF Group 2 and CAS arms). Efficacy outcomes at Day 14 were similar between BMI categories (Table 1). Rates of TEAEs were generally similar between BMI categories as well (Table 2), with no concerning safety trends. Following one dose of RZF 400 mg (Week 1), the ranges of AUCs by BMI category overlapped and there was a minor mean difference of ~20% (lower for those with BMI ≥ 30 kg/m(2)) (Fig. 2). Table 1 [Image: see text] Table 2 [Image: see text] Figure 2. [Image: see text] CONCLUSION: The safety, efficacy, and PK of RZF in the Phase 2 STRIVE trial was consistent across BMI categories. These results suggest that dose adjustments in obese patients are not necessary. These findings contribute to the evaluation of RZF in a range of patient populations and its ongoing development. DISCLOSURES: Shawn Flanagan, PhD, Cidara Therapeutics, Inc. (Employee, Shareholder) Peter Pappas, MD, SCYNEXIS, Inc. (Consultant, Advisor or Review Panel member, Research Grant or Support) Taylor Sandison, MD, MPH, Cidara Therapeutics, Inc. (Employee, Shareholder) Patrick M. Honore, MD, PhD, FCCM, Cidara Therapeutics, Inc. (Scientific Research Study Investigator)