Rezafungin
A once-weekly echinocandin antifungal for candidaemia
Rezafungin is an echinocandin, a cyclic lipopeptide antifungal, engineered to be stable enough to last about six days in the blood. Approved as Rezzayo in 2023, it is given once a week, where older echinocandins are given daily, for candidaemia and invasive candidiasis when other options are limited.
What is it?
Rezafungin shares the echinocandin mechanism of blocking the fungal cell-wall enzyme beta-(1,3)-D-glucan synthase. Its structure resists breakdown, giving a terminal half-life of about 152 hours in patients, so a 400 mg loading dose followed by 200 mg once a week maintains exposure. The label says it is not a clinically relevant substrate of CYP450 enzymes.
In the phase 3 ReSTORE trial, 199 patients with candidaemia or invasive candidiasis received weekly rezafungin or daily caspofungin. Day-30 death or unknown survival was 24% against 21%, and global cure at day 14 was 59% against 61%, meeting noninferiority. Pooled with the phase 2 STRIVE trial, day-30 mortality was 19% in both groups.
FDA approved it as Rezzayo on March 22, 2023, for patients with limited or no alternative options, noting approval rests on limited clinical data; safety beyond four weekly doses has not been established. The label warns of hypersensitivity, infusion reactions, photosensitivity and liver reactions.
At a Glance
Every value in this table is printed from the Grey Peptides dataset, the same record the compound explorer and comparison tool read, so the three can never disagree.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Half-Life: How Much Remains
The dataset records a half-life of terminal half-life 152 ± 29 hours in patients for Rezafungin. After each half-life, half of what was in the circulation is gone, so about 3% remains after five. Real clearance varies with the person, the dose, the route and kidney or liver function; this is arithmetic on a published figure, not a dosing tool.
Published Research
The studies behind rezafungin, from their PubMed abstracts.
ReSTORE: phase 3 against caspofungin
In 199 patients, global cure at day 14 was 59% on weekly rezafungin and 61% on daily caspofungin, and death or unknown survival at day 30 was 24% against 21%, meeting the EMA and FDA noninferiority endpoints.
Pooled ReSTORE and STRIVE
Across 294 patients, day-30 all-cause mortality was 19% in both groups; mycological eradication by day 5 occurred in 73% on rezafungin and 65% on caspofungin, with similar safety.
STRIVE: phase 2
In 207 patients, overall cure was 76.1% on the 400/200 mg rezafungin regimen against 67.2% on caspofungin, with 30-day all-cause mortality of 4.4% against 13.1%; candidaemia cleared in about 20 hours in both groups.
Patients in intensive care
Among 113 ICU patients pooled from STRIVE and ReSTORE, day-30 all-cause mortality was 34.8% on rezafungin against 25.4% on caspofungin, while mycological eradication at day 5 was higher (78.3% against 59.7%) and blood cultures cleared faster (median 18 against 38 hours).
Side Effects & Contraindications
Reported Side Effects
From the studies above.
Contraindications & Cautions
Warnings from the Rezzayo label (DailyMed, effective July 1, 2026).
Legal Status
Rezafungin is an approved prescription drug in the US.
Frequently Asked Questions
?What is Rezzayo?
Rezzayo is rezafungin, an echinocandin antifungal given by intravenous infusion once a week for candidaemia and invasive candidiasis in patients with limited or no other options.
?How does rezafungin differ from caspofungin?
Both block the same fungal cell-wall enzyme, but rezafungin's half-life of about six days allows once-weekly dosing, while caspofungin is given daily. In the ReSTORE trial the two had similar cure and survival rates.
?Why is it approved only when options are limited?
FDA's approval is based on limited clinical safety and efficacy data, and safety beyond four weekly doses has not been established, so the indication is restricted.
References
- [fda] US FDA, Drugs@FDA (openFDA): REZZAYO, NDA 217417 (March 22, 2023). Read October 3, 2026.
- [fda-pi] FDA. Rezzayo (rezafungin) US prescribing information (DailyMed set 90073508-6dca-4d27-aa5a-ed837737c35b, effective July 1, 2026). Read October 3, 2026.
- [clinical-trial] Thompson GR 3rd, et al. "Rezafungin versus caspofungin for treatment of candidaemia and invasive candidiasis (ReSTORE): a multicentre, double-blind, double-dummy, randomised phase 3 trial." Lancet, 2023;401(10370):49-59. PMID: 36442484.
- [pubmed] Thompson GR 3rd, et al. "Efficacy and safety of rezafungin and caspofungin in candidaemia and invasive candidiasis: pooled data from two prospective randomised controlled trials." Lancet Infect Dis, 2024;24(3):319-328. PMID: 38008099.
- [clinical-trial] Thompson GR, et al. "Rezafungin Versus Caspofungin in a Phase 2, Randomized, Double-blind Study for the Treatment of Candidemia and Invasive Candidiasis: The STRIVE Trial." Clin Infect Dis, 2021;73(11):e3647-e3655. PMID: 32955088.
- [pubmed] Honoré PM, et al. "Rezafungin versus caspofungin for patients with candidaemia or invasive candidiasis in the intensive care unit: pooled analyses of the ReSTORE and STRIVE randomised trials." Crit Care, 2024;28(1):348. PMID: 39468640.
Sources & Citations
Studies were read from their PubMed records; regulatory sources are listed below, read October 3, 2026.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Consult a licensed healthcare provider before making health decisions.