MANCHESTER, United Kingdom & OSAKA, Japan, June 18, 2026
F2G Ltd and Shionogi & Co., Ltd. announced positive topline results from the global Phase 3 OASIS (NCT05101187) clinical trial evaluating the investigational oral antifungal olorofim versus AmBisome® (liposomal amphotericin B) followed by standard of care in adults with invasive aspergillosis whose infections were refractory to or unsuitable for azole therapy. The study successfully achieved its primary endpoint of non-inferiority, with Day 42 all-cause mortality rates of 23.8% for olorofim and 24.3% for the AmBisome-based treatment arm. The findings represent a significant clinical milestone in the development of a first-in-class oral antifungal that could become the first novel mechanism treatment for invasive aspergillosis in more than 20 years, addressing a major unmet need for patients with life-threatening fungal infections.
Clinical Results Demonstrate Comparable Survival with Improved Safety Profile
The randomized global Phase 3 study demonstrated that olorofim delivered survival outcomes comparable to the current standard treatment while showing a more favorable tolerability profile. The difference in Day 42 all-cause mortality was -0.5%, confirming non-inferiority within the predefined statistical margin. Importantly, no new safety signals were identified during the trial. Drug-related treatment-emergent adverse events (TEAEs) occurred in 35.8% of patients receiving olorofim, compared with 63.9% of patients treated with AmBisome followed by standard of care. The higher adverse event rate in the comparator arm was primarily associated with renal toxicity, a well-recognized limitation of amphotericin B-based therapy. These results strengthen earlier Phase 2b clinical findings that supported the U.S. FDA’s Breakthrough Therapy Designations for olorofim and reinforce its potential to provide a safer treatment option for patients who have limited or no effective antifungal alternatives.
Regulatory Plans Advance Following Positive Pivotal Study
Following the successful completion of the OASIS trial, F2G and Shionogi confirmed plans to present the full clinical dataset at a future international medical congress before submitting the results to regulatory authorities. F2G will lead regulatory submissions in the United States, while Shionogi will oversee filings across Europe and Asia under the companies’ commercialization partnership. Olorofim, the lead candidate from F2G’s proprietary orotomide antifungal class, selectively inhibits dihydroorotate dehydrogenase, introducing a completely new mechanism of antifungal action distinct from currently available therapies. The investigational medicine has already received FDA Orphan Drug Designation, Qualified Infectious Disease Product (QIDP) designation, multiple Breakthrough Therapy Designations, and European Medicines Agency Orphan Drug Designation, reflecting its potential to address severe invasive fungal diseases with few existing treatment options.
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New Oral Antifungal Could Transform Treatment for Invasive Aspergillosis
Invasive aspergillosis remains one of the deadliest fungal infections among immunocompromised patients, including individuals undergoing cancer treatment, stem cell transplantation, or receiving immunosuppressive therapies. Increasing azole resistance, limited therapeutic options, and treatment-related toxicities continue to complicate patient management worldwide. If approved, olorofim would become the first antifungal with a novel mechanism of action introduced for invasive aspergillosis in over two decades, offering clinicians an important new oral therapy with the potential to improve treatment outcomes while reducing toxicity concerns. The positive Phase 3 OASIS results further reinforce the growing importance of innovation in infectious disease research and position F2G and Shionogi to significantly expand the therapeutic landscape for patients facing difficult-to-treat invasive fungal infections.
Source: F2G press release
