Rezafungin

Rezzayo

Rezafungin is a next-generation echinocandin antifungal, approved in 2023 and the first new drug in its class in more than a decade. Like the earlier echinocandins, it kills fungi by inhibiting β-(1,3)-D-glucan synthase, the enzyme that builds a polymer essential to the fungal cell wall — a target absent from human cells, which underlies the class's good tolerability. What sets rezafungin apart is its pharmacokinetics: it was structurally derived from anidulafungin with a modification that greatly increases stability and extends its half-life, so it can be dosed once weekly rather than daily. Rezafungin is given by intravenous infusion for the treatment of candidemia and invasive candidiasis in adults with limited or no alternative treatment options. The once-weekly schedule, enabled by a high loading dose followed by weekly maintenance and a front-loaded high exposure, can simplify treatment, reduce the need for daily infusions and indwelling lines, and potentially support earlier discharge from hospital. It is fungicidal against many Candida species and has been studied against a broad range of Candida, including some resistant species. As a member of the echinocandin class, rezafungin shares the practical limits of intravenous-only administration and limited penetration into the central nervous system and urine. It is a prescription hospital medicine used under specialist (infectious-disease) guidance for serious invasive fungal infection, not a treatment for superficial fungal conditions. Its long duration is an advantage for adherence and logistics but also means its exposure persists, which is factored into how it is used.