Exploring Early Antifungal Activity of Rezafungin as a Stepping-Stone for Shorter Treatment Duration for Candidemia: Pooled Analysis of Two Randomized Trials

Background Guidelines recommend ≥2 weeks of antifungal therapy after candidemia clearance and for invasive candidiasis (IC). This post-hoc analysis evaluates day-7 pooled data from the phase 2 STRIVE and phase 3 ReSTORE trials to explore early antifungal activity. Methods Adults with candidemia and/or IC received weekly rezafungin 400/200 mg or daily caspofungin 70/50 mg for ≤4 weeks. Efficacy was evaluated in the modified intent-to-treat population via all-cause mortality (ACM; primary endpoint; 20% noninferiority margin), mycological eradication, and time to negative blood culture (TTNBC) at days 7, 14, and 30 (TTNBC assessed only in patients with candidemia). Day-7 safety was evaluated in the safety population. Results Rezafungin was noninferior to caspofungin at each timepoint. Day-7 ACM rates were 7.9% (11/139) for rezafungin and 5.2% (8/155) for caspofungin (weighted difference [95% CI]: 3.0% [−3.7, 9.7]). Mycological eradication was similar between groups at all timepoints. Day-7 rates were 71.2% (99/139) and 65.2% (101/155), respectively (weighted difference [95% CI]: 6.6% [−4.0, 17.1]). Median (interquartile range) TTNBC was numerically shorter for rezafungin (22.3 [14.3–47.0] hours; caspofungin 26.3 [17.8–112.6] hours). Subgroup analyses suggested potential day-7 benefits for rezafungin in patients with candidemia or C. albicans. Day-7 safety for rezafungin was consistent with previous reports. Conclusions Rezafungin was noninferior to caspofungin in candidemia and/or IC from day 7, with shorter TTNBC in patients with candidemia. Subgroup analysis suggested a potential early benefit with rezafungin in some patients. Trials exploring shorter treatment durations for some patients are warranted. Clinical trials registrations: NCT02734862 (STRIVE); NCT03667690 (ReSTORE)