ATLANTA — Rezafungin was safe and effective at two separate dosings when compared with standard of care for the treatment of candidemia and invasive candidiasis, according to research presented at ASM Microbe in Atlanta.
Researchers presented data from STRIVE, a phase 2 study evaluating the safety and efficacy of Cidara Therapeutics’ novel echinocandin rezafungin (RZF). Formerly known as CD101, the agent’s pharmacokinetics allow for once-weekly dosing and front-loaded plasma drug exposure, they said.
In the study, patients aged at least 18 years were randomly assigned to receive an IV dose of RZF once weekly for up to 4 weeks at either 400 mg (group 1; n = 35) or 400 mg on week 1 and 200 mg thereafter (group 2; n = 36), or daily caspofungin with optional oral stepdown after day 4, which is considered the standard of care (group 3; n = 36).
Clinical cure plus mycological eradication — or overall success — at day 14 was the primary endpoint. All-cause mortality at day 30 was a secondary endpoint.
Overall success, which excluded indeterminate responses due to missing data points, was reported for 73.1% of patients in group 1, 78.6% of patients in group 2 and 69.2% of patients in group 3.
Mortality rates at day 30 were 15.2% in group 1, 3.2% in group 2 and 10.7% in group 3.
In all cohorts, treatment-emergent adverse events were observed in most patients, including 88.6% in group 1, 94.4% in group 2 and 81.8% in group 3. Rates of severe adverse events were lower overall, with 37.1% in group 1, 27.8% in group 2 and 39.4% in group 3.
Group 1 had the highest percentage of adverse events leading to drug discontinuation (11.4%), followed by 3% in group 3 and 2.8% in group 2.
The standard-of-care group was most likely to have severe adverse events leading to death, the researchers said.
The researchers determined that a dosing regimen of 400 mg in week 1 followed by 200 mg once weekly would be used going forward in the phase 3 trial.
“The investigators and sites did a great job of collaborating and conducting this study in a timely fashion, and now these results allow us to proceed with phase 3 studies in the treatment of candidemia and invasive candidiasis and in the prevention of invasive fungal infections in patients undergoing allogeneic hematopoietic stem cell transplantation,” Taylor Sandison, MD, MPH, chief medical officer of Cidara Therapeutics, told Infectious Disease News. – by Bruce Thiel
Thompson GR, et al. Abstract AAR LB21. Presented at: ASM Microbe; June 7-11, 2018; Atlanta.
Sandison is chief medical officer of Cidara Therapeutics, which funded the study.