New Hope for Transplant Patients: Mundipharma's Once-Weekly Antifungal Succeeds

CAMBRIDGE, England – April 27, 2026 – Mundipharma today announced a significant breakthrough in the protection of highly vulnerable patients, unveiling positive results from a pivotal Phase III trial for its next-generation antifungal agent, REZZAYO® (rezafungin). The global study confirmed that a once-weekly infusion of rezafungin is as effective as the current, often daily, standard of care in preventing life-threatening invasive fungal diseases (IFDs) in adults undergoing allogeneic haematopoietic stem cell transplantation (HSCT).

The findings from the ReSPECT trial represent a potential paradigm shift in prophylactic care for this immunocompromised population, promising to reduce treatment burden, improve safety, and potentially change the standard of care for thousands of patients annually.

A New Shield for Vulnerable Patients

Patients undergoing allogeneic HSCT, a procedure used to treat aggressive blood cancers and other disorders, receive intensive chemotherapy or radiation that decimates their immune systems. This leaves them profoundly susceptible to opportunistic infections, with invasive fungal diseases caused by pathogens like Candida, Aspergillus, and Pneumocystis posing a constant and deadly threat. The mortality rate for some of these infections can be as high as 40%.

To combat this risk, patients are placed on extended prophylactic antifungal regimens. However, the current standard treatments, typically involving daily oral azole medications, come with a significant cost. Patients often struggle with complex medication schedules, burdensome side effects, and dangerous drug-drug interactions (DDIs), a critical concern for individuals already taking numerous other essential medications.

Rezafungin, a next-generation echinocandin, was designed to address these challenges directly. Its unique pharmacokinetic profile allows for a prolonged half-life, enabling a simple, once-weekly intravenous dosing schedule. The positive results of the ReSPECT trial suggest that this convenience does not come at the cost of efficacy. For patients and clinicians, this could mean fewer pills, a lower risk of adverse events, simplified medication management, and potentially shorter hospital stays, dramatically improving the quality of life during a gruelling recovery period.

According to infectious disease specialists, a well-tolerated, effective, once-weekly option would be a monumental advance. The ability to provide robust protection with a reduced interaction profile is a key unmet need that rezafungin appears poised to fill.

Unpacking the ReSPECT Trial Results

The ReSPECT study was one of the largest and most robust trials of its kind, enrolling patients across more than 50 centers in seven countries. The randomized, double-blind design compared once-weekly rezafungin to a standard antifungal regimen (SAR) for the prevention of IFDs.

The trial successfully met its primary endpoint for both U.S. and European regulatory standards. At Day 90, the rate of fungal-free survival was 60.7% in the rezafungin arm compared to 59.0% in the SAR arm. This result established non-inferiority, confirming that rezafungin provides comparable protection to the existing standard of care.

Beyond the primary goal, the data revealed several key advantages for rezafungin. The study showed comparable mortality rates and equivalent efficacy against the most common and dangerous fungal pathogens. Crucially, rezafungin demonstrated a superior profile on multiple secondary endpoints related to safety and tolerability. Patients receiving rezafungin experienced fewer treatment-emergent adverse events that led to dose reductions, interruptions, or complete discontinuation of the study drug. This favorable safety profile is a critical differentiator in a patient population where toxicity can lead to treatment failure and poor outcomes.

“We are very excited by the study results, which met all its endpoints, and reflect the contribution of patients enrolled across more than 50 centres in seven countries,” said Dr. Yuri Martina, Chief Development & Medical Officer at Mundipharma. “These findings represent a meaningful step forward in advancing care for this vulnerable population. Rezafungin holds the potential to change the standard of care for these patients.”

Reshaping a Multi-Billion Dollar Market

The clinical success of rezafungin in the ReSPECT trial positions it to disrupt a significant and growing market. CorMedix, Mundipharma’s U.S. licensee for REZZAYO®, estimates the potential U.S. market opportunity for fungal prophylaxis in HSCT patients to exceed $2 billion. This new indication would build upon rezafungin's existing approval for the treatment of candidaemia and invasive candidiasis, expanding its role from active therapy to preventative care.

The path to market is now becoming clear. Mundipharma and CorMedix intend to target a supplemental New Drug Application (sNDA) submission to the U.S. Food and Drug Administration (FDA) in the second half of 2026. A corresponding submission to the European Medicines Agency (EMA) is expected in the third quarter of 2026. Given the drug's existing approvals and strong data, the outlook for this expanded indication is optimistic.

For CorMedix, which distributes the drug in the U.S. through its subsidiary Melinta Therapeutics, a successful launch in the prophylaxis setting could be transformative. The drug already benefits from considerable market protection, with Orphan Drug Exclusivity in the U.S. extending through 2035 and patent coverage lasting until 2038. This provides a long commercial runway to establish rezafungin as a cornerstone of antifungal care.

The Path Forward: From Trial to Treatment

With the successful completion of the ReSPECT trial, the focus now shifts to regulatory review and eventual clinical adoption. Hematologists and infectious disease specialists who manage HSCT patients have long sought prophylactic options that balance potent efficacy with improved safety and patient convenience. The data from ReSPECT suggests rezafungin is precisely that option.

Its once-weekly administration simplifies care, its favorable DDI profile reduces complications, and its proven non-inferiority provides the confidence needed for widespread adoption. As Mundipharma and CorMedix prepare their regulatory submissions, the medical community is watching with anticipation. If approved, REZZAYO® is poised to become not just another tool, but a new standard in the critical effort to shield the most vulnerable transplant patients from deadly fungal infections.