Management of serious fungal infections caused by Candida continues to be an important area of study. Within the healthcare environment, candidemia and invasive candidiasis have become issues of strong concern due to the rate of morbidity and mortality associated with the conditions. Therefore, the demand for improved, effective treatment options is growing. Thanks to a new approval, the next generation of the latest therapy is poised to become available in summer 2023.

Conservative estimates of cases of candidemia in the US stand at approximately 25,000. Mortality rates among candidemia patients can be as high as nearly 50%. The opportunistic pathogens are troublesome and often life-threatening for some at-risk patients. The Candida that lives on and in the body does not cause health issues for most individuals. Certain circumstances and comorbidities may predispose some people to bloodstream infections such as candidemia or even deeper-seated occurrences like invasive candidiasis that can arise in the heart, bones, or other internal organs. Patients with immunosuppression or recent surgery are susceptible to fungal infection, especially where skin or mucosal barriers are disrupted. Of particular risk are those who require central venous catheters. All these circumstances create vulnerabilities in patients, and invasive infections that can occur with Candida can become significantly more difficult to treat and even result in death.

After a patient is diagnosed with candidemia or invasive candidiasis, typically by taking a blood culture, treatment will begin as soon as possible. In most cases, the recommended antifungal treatment will be one of the newest antifungals, a class known as echinocandins. Until now, three echinocandins have been available, caspofungin, micafungin, and anidulafungin. As a class, they have been preferred for fungicidal use due to their unique mechanism of action. They inhibit β-D-glucan synthase, which is necessary within cell wall synthesis. Since mammalian cells do not have cell walls, there are minimal toxic adverse effects when these agents are used in humans. Coupled with high efficiency in invasive infection, the benefits of the class make it a promising area to research and develop.

In 2018, the newest echinocandin, rezafungin, received a fast-track and qualified infectious disease product designations from the FDA. The differentiation of rezafungin compared to the other echinocandins that preceded it is that it demonstrated a higher level of stability while in solution and has been modified for improved pharmacokinetics. Thus, the stage was set for continued study to determine the clinical significance of rezafungin. After completing its clinical trials, the drug was reviewed by the FDA’s Antimicrobial Drugs Advisory Committee, and ultimately the agency decided that its benefit-risk profile was, in fact, favorable. In March 2023, Rezzayo (rezafungin) became the first new treatment option approved for patients with candidemia and invasive candidiasis in over a decade. Its once-weekly dosing is one of its most notable traits, as the previously approved drugs in its class require daily dosing. Simplified dosing can greatly help patients and caregivers when fighting challenging infections. The official indication for Rezzayo states that it is for use in patients aged 18 years or older who have limited or no alternative options for the treatment of candidemia and invasive candidiasis. Approval of this indication is based on limited clinical safety and efficacy data for Rezzayo. Its label includes a limitation of use statement explaining that it has not been studied in patients with endocarditis, osteomyelitis, and meningitis due to Candida.

As treatment-resistant pathogens continue to emerge, the clinical tools and therapies to fight them must continue to be developed with precision and effectiveness at the forefront. New approvals like Rezzayo help healthcare providers keep pace with the complexities of infection in patients and serve to close gaps with current therapies. Stay informed about emergent drug information, including treatment options for serious fungal infections, by updating or registering your profile to receive email alerts and other critical drug information updates from PDR. You can also stay current by using the official PDR app, mobilePDR, available for free from your favorite app stores.