FDA Approves Antifungal Rezzayo for Patients With Limited Treatment Options

The Food and Drug Administration (FDA) has approved Rezzayo^™ (rezafungin for injection) for the treatment of candidemia and invasive candidiasis in adults with limited or no alternative treatment options. Approval of this indication was based on limited clinical safety and efficacy data for Rezzayo.

Rezafungin is a once-weekly echinocandin antifungal. The approval was based on data from the randomized, double-blind phase 3 ReSTORE study (ClinicalTrials.gov Identifier: NCT03667690), which included 187 adults diagnosed with candidemia and/or invasive candidiasis.

Treatment with rezafungin was found to be noninferior to caspofungin for the primary endpoint of all-cause mortality at day 30, using a 20% noninferiority margin. The trial provided evidence for efficacy to support an indication with a limited use statement, given the wider noninferiority margin. All-cause mortality at day 30 was reported to be 23.7% for the rezafungin group and 21.3% for the caspofungin group (treatment difference, 2.4% [95% CI, -9.7, 14.4]).

The approval was also supported by safety and efficacy data from the double-blind, randomized, phase 2 STRIVE study (ClinicalTrials.gov Identifier: NCT02734862). The primary objectives of this study were to evaluate safety and tolerability of rezafungin and overall success (mycological eradication and resolution of systemic signs attributable to candidemia and/or invasive candidiasis) at day 14.

The most common adverse reactions reported with rezafungin were hypokalemia, pyrexia, diarrhea, anemia, vomiting, nausea, hypomagnesemia, abdominal pain, constipation, and hypophosphatemia.

Rezzayo is supplied as a solid (cake or powder) in a single-dose vial containing 200mg of rezafungin. Treatment is administered once weekly by intravenous infusion after reconstitution.

“The FDA approval of Rezzayo is tremendous news for those of us who have been hoping for a new option to treat our patients with these deadly fungal infections,” said George Thompson, MD, principal investigator in the ReSTORE trial and professor of clinical medicine at the University of California, Davis, School of Medicine. “Based on the totality of clinical data generated, Rezzayo has the potential to simplify the management of invasive candidiasis and enhance the continuity of echinocandin care.”

The product is expected to be available in the summer of 2023.