Efficacy and safety of rezafungin and caspofungin in candidaemia and invasive candidiasis: pooled data from two prospective randomised controlled trials

Background: Rezafungin, a new US Food and Drug Administration-approved, long-acting echinocandin to treat candidaemia and invasive candidiasis, was efficacious with a similar safety profile to caspofungin in clinical trials. We conducted pooled analyses of the phase 2 STRIVE and phase 3 ReSTORE rezafungin trials. Methods: ReSTORE was a multicentre, double-blind, double-dummy, randomised phase 3 trial conducted at 66 tertiary care centres in 15 countries. STRIVE was a multicentre, double-blind, double-dummy, randomised phase 2 trial conducted at 44 centres in 10 countries. Adults (≥18 years) with candidaemia or invasive candidiasis were treated with once-a-week intravenous rezafungin (400 mg and 200 mg) or once-a-day intravenous caspofungin (70 mg and 50 mg). Efficacy was evaluated in a pooled modified intent-to-treat (mITT) population. Primary efficacy endpoint was day 30 all-cause mortality (tested for non-inferiority with a pre-specified margin of 20%). Secondary efficacy endpoint was mycological response. Safety was also evaluated. The STRIVE and ReSTORE trials are registered with ClinicalTrials.gov, NCT02734862 and NCT03667690, and both studies are complete. Findings: ReSTORE was conducted from Oct 12, 2018, to Oct 11, 2021, and STRIVE from July 26, 2016, to April 18, 2019. The mITT population, pooling the data from the two trials, comprised 139 patients for rezafungin and 155 patients for caspofungin. Day 30 all-cause mortality rates were comparable between groups (19% [26 of 139] for the rezafungin group and 19% [30 of 155] for the caspofungin group) and the upper bound of the 95% CI for the weighted treatment difference was below 10% (−1·5% [95% CI −10·7 to 7·7]). Mycological eradication occurred by day 5 in 102 (73%) of 139 rezafungin patients and 100 (65%) of 155 caspofungin patients (weighted treatment difference 10·0% [95% CI −0·3 to 20·4]). Safety profiles were similar across groups. Interpretation: Rezafungin was non-inferior to caspofungin for all-cause mortality, with a potential early treatment benefit, possibly reflecting rezafungin's front-loaded dosing regimen. These findings are of clinical importance in fighting active and aggressive infections and reducing the morbidity and mortality caused by candidaemia and invasive candidiasis. Funding: Melinta Therapeutics and Cidara Therapeutics.