A new antibody, called MEDI8852, has promise as a potential treatment for influenza A - the source of seasonal and pandemic flu outbreaks - new research suggests. The findings, from lab-based and animal studies, also have implications for the design of a universal influenza vaccine.
Flu remains a serious threat to global health. Annual epidemics result in an estimated 3-5 million cases of severe disease and 250,000-500,000 deaths globally, and higher mortality rates are possible during pandemics. Influenza A is the type of flu virus responsible for most hospitalizations and is the only type to cause pandemics.
Given the emergence of drug-resistance, the short treatment window of existing antiviral drugs and the lack of universal or broadly cross-protective vaccines, there is a significant unmet medical need for new therapeutic agents.
The research was a joint effort by researchers at MedImmune, the; Humabs BioMed; the Institute for Research in Biomedicine (Università della Svizzera italiana) and the Francis Crick Institute.
JoAnn Suzich, Vice President of R&D at MedImmune, the global biologics research and development arm of AstraZeneca, said: "The results of this study confirm how MEDI8852's unique molecular features have the potential to differentiate it from current treatment options for influenza, with the potential to become an important anti-influenza candidate during pandemic periods."
The researchers discovered that MEDI8852 exhibits multiple mechanisms of action, including blocking essential steps of the viral lifecycle, and that it also engages the immune system to eliminate virus-infected cells.
"We compared the binding activity of MEDI8852 with other antibodies, as well as its precursor, and found it has the highest activity and the widest breadth of coverage," said Davide Corti, Chief Scientific Officer, Humabs BioMed. "This antibody targets a unique epitope in the stem of the influenza HA [a glycoprotein on the surface of the virus] and can attack the virus' entry and exit by blocking multiple mechanisms."
John Skehel of the Crick said: "This new antibody binds to numerous different influenza viruses to block their infectivity. Our studies show how this is achieved and highlight differences between this and other antibodies to explain its potential as an anti-influenza therapeutic."
The paper, Structure and function analysis of a therapeutic monoclonal antibody that recognizes all subtypes of influenza A, is published in Cell.