Mundipharma has announced additional results from the Phase 3 ReSPECT clinical trial evaluating Rezzayo (rezafungin acetate) for preventing invasive fungal diseases (IFDs) in adults undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT). The findings were presented as a late-breaking oral presentation at IDWeek 2026.
The trial met its primary endpoint, demonstrating that once-weekly intravenous rezafungin was non-inferior to a standard antimicrobial prophylaxis regimen for fungal-free survival at Day 90 following transplantation. The additional analyses were consistent with the previously announced topline results.
Key Highlights
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Phase 3 trial: ReSPECT randomised 602 adults undergoing allo-HSCT.
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Primary endpoint achieved: Rezafungin demonstrated non-inferiority to the standard antimicrobial regimen for fungal-free survival at Day 90.
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Fungal-free survival: 60.7% with rezafungin versus 59.0% with standard prophylaxis.
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Fungal infection outcomes: Proven or probable invasive fungal disease contributing to endpoint failure occurred in 3.5% versus 4.5%, respectively.
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Safety: No new safety signals were identified in allo-HSCT recipients.
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Regulatory status: Data have been submitted to the US Food and Drug Administration (FDA) and European Medicines Agency (EMA). The prophylaxis indication remains investigational.
ReSPECT Trial Demonstrates Non-Inferiority
The global, multicentre, randomised, double-blind Phase 3 ReSPECT study compared once-weekly intravenous rezafungin with a standard daily antimicrobial prophylaxis regimen in adults undergoing allo-HSCT.
A total of 602 patients were randomised: 402 received rezafungin and 200 received the standard antimicrobial regimen.
At Day 90, fungal-free survival (FFS) was:
| Outcome | Rezafungin | Standard regimen |
|---|---|---|
| Fungal-free survival at Day 90 | 60.7% | 59.0% |
| Proven or probable invasive fungal disease contributing to FFS failure | 3.5% | 4.5% |
| Death contributing to FFS failure | 4.5% | 5.5% |
| Use of non-study systemic antifungal therapy for more than 10 cumulative days | 27.4% | 32.5% |
The estimated treatment difference in fungal-free survival was 1.6 percentage points (95% confidence interval: −6.2 to 9.3), with a reported p-value of 0.0002 for non-inferiority.
The primary endpoint combined survival, absence of proven or probable invasive fungal disease, and no use of non-study systemic antifungal therapy for more than 10 cumulative days. Six pre-specified sensitivity analyses supported the primary endpoint findings.
Safety Findings
Treatment-emergent adverse events were reported in 99.7% of patients receiving rezafungin and 100% of those receiving the standard regimen. Serious adverse events occurred in 66.0% and 67.5%, respectively.
Adverse events leading to study discontinuation occurred in 9.3% of the rezafungin group compared with 14.7% of the standard-regimen group. No new safety signals were identified in the study population.
Why Fungal Infection Prevention Matters After Transplantation
Patients undergoing allo-HSCT are particularly vulnerable to invasive fungal diseases because of their compromised immune systems. These infections can be life-threatening, making antifungal prophylaxis an important part of post-transplant care.
Existing approaches can present challenges, including drug toxicities, drug–drug interactions, therapeutic drug monitoring, antifungal resistance and adherence to daily oral regimens. Rezafungin’s once-weekly intravenous dosing is being investigated as an alternative approach in this setting.
Rezafungin’s Dosing Regimen
In the ReSPECT study, rezafungin was administered as a 400 mg intravenous loading dose on Day 1, followed by 200 mg once weekly. The comparator regimen consisted of daily oral fluconazole or posaconazole, alongside trimethoprim/sulfamethoxazole following engraftment.
These regimens were evaluated specifically for prevention of invasive fungal disease following allo-HSCT. This investigational use is distinct from Rezzayo’s currently approved treatment indications.
Regulatory Status and Next Steps
Mundipharma stated that ReSPECT data have been submitted to the FDA and EMA for regulatory review. In the United States, the FDA has granted Priority Review, with a Prescription Drug User Fee Act (PDUFA) target action date in the first quarter of 2027.
Rezafungin prophylaxis following allo-HSCT is not currently an approved indication in the United States or European Union. Rezzayo has separate approved indications for treating invasive candidiasis, subject to jurisdiction-specific prescribing information.
Mundipharma plans to share further research updates at international scientific meetings and through peer-reviewed medical publications.
What This Means for Antifungal Research
The ReSPECT findings add Phase 3 evidence on once-weekly rezafungin for preventing invasive fungal disease in adults undergoing allo-HSCT. The non-inferiority result supports continued regulatory evaluation, while approval for this prophylactic use remains pending.
SEO Title: Mundipharma Reports Phase 3 Rezafungin Results in ReSPECT Trial
Meta Description: Mundipharma reports Phase 3 ReSPECT results showing rezafungin was non-inferior to standard prophylaxis for fungal-free survival after stem cell transplantation.
URL Slug: mundipharma-rezafungin-respect-phase-3-results
Keywords: Mundipharma, Rezzayo, rezafungin, ReSPECT trial, Phase 3 clinical trial, invasive fungal disease, antifungal prophylaxis, allo-HSCT, IDWeek 2026
