Compassionate-use rezafungin for proven deep-seated invasive candidiasis caused by Candidozyma auris: a clinical case report

Abstract

Candidozyma auris (Candida auris before 2024) is a fungus included in the list of priority fungal pathogens by the World Health Organization and characterized by high resistance to antifungal drugs. Proven deepseated invasive candidiasis caused by C. auris and meeting the EORTC/MSGERC 2020 and FUNDICU 2024 criteria is poorly characterized in the literature, and clinical data on rezafungin in this setting remain extremely scarce. Rezafungin is a next-generation echinocandin with a prolonged half-life, approved by the US FDA (March 2023) and the European Medicines Agency (December 2023) for the treatment of candidemia and invasive candidiasis in adults; the drug is not registered in the Russian Federation. We describe a 46-year-old patient with disseminated renal cell carcinoma who underwent multiple surgical interventions for tumour-related complications and subsequently developed candidemia and proven deepseated invasive candidiasis caused by C. auris with disseminated abdominal involvement (splenic-bed abscess, hepatic abscesses, peritonitis) and colonization of several non-sterile sites. Despite prolonged combination antifungal therapy with caspofungin, amphotericin B lipid complex, and anidulafungin together with staged surgical source control, the infection progressed with formation of new fluid collections and abscesses. Given disease progression and exhaustion of available antifungal options, rezafungin was administered on a compassionate-use basis after approval by the institutional medical commission and the local ethics committee. With rezafungin (400 mg intravenously on day 1, then 200 mg once weekly) the patient achieved clinical and laboratory stabilization and microbiological eradication of C. auris from monitored sites; the total rezafungin course lasted 12 weeks and was well tolerated. To the best of the authors’ knowledge, this is the first published clinical observation of rezafungin use for the treatment of invasive mycosis in the Russian Federation.