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.