September 12, 2012
Engineered Human Antibodies Lead To Flu Cure
Michael Harper for redOrbit.com — Your Universe Online
One drug maker took to the stage on Monday in San Francisco to announce some very encouraging and positive results at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).
VIS410 works by targeting hemagglutinin (HA) which is present across all subtypes of the Influenza A virus. Although this HA is resistant to the development of mutations, VIS410 is still able to neutralize these strains of Influenza A in vitro.
Testing the drug even further, Visterra injected mice with a lethal dose of Influenza virus before later injecting them with VIS410. Then, the researchers injected another group of mice with VIS410 before giving them the same lethal dose of the flu virus. These tests proved to be incredibly encouraging for the drug, as 100% of those mice who had first been injected with VIS410 survived the subsequent injection of the Influenza A virus. Likewise, 100% of those mice who had first been injected with the deadly virus were then able to recover from the injection within 72 hours after it had been administered.
“This data with VIS410 shows several ways that this drug candidate has promise for fighting influenza, including possible pandemic strains,” explained Chief Medical Officer of Visterra, Dr. Donna Ambrosino in a press statement.
“With VIS410, we have designed an antibody that targets the viral hemagglutinin protein (HA) to enable to healthy person or patient to prevent or treat an established infection. Secondly, we have designed VIS410 as an antibody that neutralizes both groups of viral strains for influenza A, Group 1 and Group 2 viruses, opening the potential for a single monoclonal antibody to provide protection from all influenza A strains.”
Visterra gave an oral presentation explaining these results entitled “Design of a Broadly Neutralizing Antibody Targeting Influenza A” Monday at the ICAAC conference in San Francisco. By using their own, proprietary platform, Visterra was able to not only identify the common HA in Influenza A, but also target it in an accurate and yet potent way.
Using this platform, the drug company designed more than 50 human antibodies which can be used to bind and neutralize these viruses. In the mice tests, doses as small as 2.5 mg to 10 mg were sufficient enough to provide protection from deadly flu outbreaks. Furthermore, when the same amount is administered after an infection, VIS410 can completely treat the outbreak with a 100% survival rate, based on Visterra´s testing.
Visterra, Inc´s CEO was understandably very proud, saying, “We are highly encouraged by these VIS410 results, which suggest that an antibody approach such as Visterra´s may be a turning point in the development of a new universal approach for both seasonal and pandemic influenza.”
“This study confirms proof of concept for our proprietary platform to identify unique targets that guide the engineering of novel drugs that are designed to be highly effective in the prevention or treatment of infectious disease.”