RedHill Biopharma Advances Opaganib for Bundibugyo Ebola Outbreak as Cases Surpass 3,200
核心洞察
The Bundibugyo ebolavirus (搜索) outbreak has escalated to 3,221 confirmed cases and 1,407 deaths, with no approved medications or vaccines available for this rare subtype.
RedHill Biopharma is in active partnership discussions with the African Medicines Agency, Ugandan Ministry of Health, and MUST to clinically evaluate oral host-directed antiviral opaganib.
Phase 3 COVID-19 data showed a 70.2% mortality reduction when opaganib was added to remdesivir plus corticosteroids (6.98% vs. 23.4%, p=0.034) with improved viral RNA clearance.
RedHill Biopharma Ltd. (NASDAQ: RDHL) is actively advancing its investigational oral drug opaganib as a potential treatment for the rapidly escalating Bundibugyo ebolavirus (搜索) (BDBV) outbreak, which has now reached 3,221 confirmed cases and 1,407 deaths. The company is engaged in finalizing development next steps and partnership discussions with the Emergency Task Force expert group of the African Medicines Agency, the Ugandan Ministry of Health, Mbarara University of Science and Technology (MUST), and the Scientific Advisory Committee of the Democratic Republic of Congo (DRC).
The Bundibugyo ebolavirus (搜索) subtype currently has no approved medications or vaccines, creating an urgent unmet medical need. Ebola virus disease (搜索) can be fatal in approximately half of all cases, according to the World Health Organization.
Clinical Evidence Supporting Opaganib's Antiviral Activity
Opaganib's clinical rationale draws on Phase 3 data from a severe COVID-19 trial, which the company presents as analogous to an Ebola treatment pathway. In that study, opaganib given as add-on therapy to best available standard of care — remdesivir plus corticosteroids — demonstrated a 70.2% mortality reduction: 6.98% (n=3/43) in the opaganib plus standard-of-care arm versus 23.4% (n=11/47) in the placebo plus standard-of-care arm (nominal p=0.034), with no additional safety signals.
The study also showed improved median time to viral RNA clearance by at least four days in opaganib-treated patients, with a median of 10 days versus not reached by Day 14 in the placebo group (HR 1.34, p=0.043). Opaganib has demonstrated its safety and tolerability profile in more than 470 clinical trial participants across multiple studies.
Preclinical Ebola-Specific Data
Preclinical studies funded by the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) showed opaganib inhibited Ebola virus disease (搜索) in human macrophages. In animal models, increased survival was observed in the opaganib-treated group in one of two studies, though the company noted mixed results across the two animal models, underscoring model variability. Notably, a synergistic effect was demonstrated when opaganib was combined with Gilead Sciences' remdesivir (Veklury).
Dual Mechanism of Action
Opaganib is a first-in-class, orally administered sphingosine kinase-2 (SPHK2 (搜索)) selective inhibitor. Published literature in ACS Infectious Diseases explicitly validates sphingosine kinases as targets for filovirus inhibition. Opaganib's potential dual mechanism of action against Ebola virus disease (搜索) involves disrupting host-cell components essential for filovirus entry and replication that are conserved across Filoviridae, inhibiting the PI3K/Akt pathway required for filovirus entry and membrane trafficking, and suppressing NLRP3 inflammasome, IL-6/TNFα secretion, and S1P-mediated vascular permeability — thereby addressing immune dysregulation and vascular leak characteristic of viral hemorrhagic fever.
"The current Bundibugyo ebolavirus (搜索) (BDBV) outbreak continues to pose a significant public health challenge, despite the extraordinary efforts of healthcare workers and public health authorities," said Professor Pauline Byakika-Kibwika, Vice Chancellor of Mbarara University of Science and Technology. "The absence of proven therapies for Bundibugyo ebolavirus disease underscores the urgent need to evaluate promising treatment options. Opaganib is a host-directed antiviral with an oral formulation, an established human safety profile, and encouraging preclinical and clinical evidence."
Strategic Positioning for Outbreak Response
Opaganib's oral administration, ease of storage and distribution, and lack of cold-chain requirements position it as a practical candidate for outbreak settings where healthcare infrastructure may be suboptimal. The U.S. government's Biomedical Advanced Research and Development Authority (BARDA) previously selected opaganib for joint development and funding as a medical countermeasure to treat Ebola virus disease (搜索).
Gilead Raday, Chief Operating Officer and Head of R&D at RedHill, stated: "Opaganib's potential role in the ongoing Ebola outbreak as an add-on therapy to remdesivir is supported by both clinical and non-clinical data. We will work to ensure that any required supplies of opaganib are rapidly made available to potential partners seeking to fight the deadly effects of Ebola."
Currently, only two FDA-approved treatments exist for Ebola virus disease (搜索) — Inmazeb (Regeneron Pharmaceuticals), a combination of three monoclonal antibodies, and Ebanga (Ridgeback Biotherapeutics), a single monoclonal antibody — both of which are intravenously administered direct-acting antivirals. There remains an urgent need for host-directed small molecule therapies effective against multiple ebolavirus strains, less susceptible to viral mutation, and easy to store, distribute, and administer.
Opaganib is an investigational new drug and has not been approved by any regulatory authority. The company has proactively provided supply readiness information and all available clinical and preclinical safety and efficacy data to relevant government, industry, and other organizations to aid rapid clinical and regulatory discussions.