Clinical and mycological outcomes of candidaemia and/or invasive candidiasis by Candida spp. and antifungal susceptibility: pooled analyses of two randomized trials of rezafungin versus caspofungin

Objectives: A post hoc analysis used pooled STRIVE/ReSTORE trial data to determine outcomes with rezafungin versus caspofungin by Candida species and antifungal susceptibility.

Methods: The efficacy and safety of once weekly rezafungin 400/200 mg versus once daily caspofungin 70/50 mg was demonstrated in the randomized, double-blind phase 2 STRIVE (NCT02734862) and phase 3 ReSTORE (NCT03667690) trials involving adults with candidaemia and/or invasive candidiasis. In this analysis, data were pooled for patients with a documented Candida infection within 96 hours of randomization who also received ≥1 dose of study drug. Treatment outcomes were evaluated by Candida species and baseline MICs. Susceptibility was determined using European Committee on Antimicrobial Susceptibility Testing E.Def 7.4 broth microdilution methodology, with Tween 20-supplemented medium for rezafungin.

Results: A total of 294 patients were included (rezafungin: N = 139, caspofungin: N = 155). Susceptibility testing at baseline identified three rezafungin non-susceptible isolates. Day 14 global cure rates were numerically similar between groups for C. albicans (rezafungin: 61.0% [36/59], caspofungin: 65.2% [45/69]) and C. tropicalis (rezafungin: 70.4% [19/27], caspofungin: 63.6% [14/22]), but higher with rezafungin than caspofungin for C. glabrata (rezafungin: 71.1% [27/38], caspofungin: 60.0% [21/35]) and C. parapsilosis (rezafungin: 78.6% [11/44], caspofungin: 55.6% [15/27]). Day 30 all-cause mortality rates were numerically similar between groups for C. albicans (rezafungin: 22.0% [13/59], caspofungin: 18.8% [13/69]) and C. glabrata (rezafungin: 15.8% [6/38], caspofungin: 11.4% [4/35]), but higher with caspofungin than rezafungin for C. tropicalis (rezafungin: 18.5% [5/27], caspofungin: 31.8% [2/22]) and C. parapsilosis (rezafungin: 7.1% [1/14], caspofungin: 29.6% [8/27]). Day 5/14 mycological eradication rates were numerically similar between treatments for C. albicans and C. parapsilosis, but higher with rezafungin for C. glabrata and C. tropicalis. Outcomes by Candida species were not associated with treatment-specific MICs.

Discussion: Rezafungin appears to be an effective treatment for candidaemia/invasive candidiasis irrespective of baseline Candida species.