Respiratory syncytial virus or RSV for most people can seem like a lingering chest cold, but for people with compromised immune systems or infants and the elderly, RSV can send them to the hospital and even to the grave.

 

The virus is responsible for 1 million hospitalizations worldwide each year and more than ten times as deadly than the flu for infants. Efforts to develop a drug to stop RSV, though, have been evasive. Trellis Bioscience thinks it’s onto a solution.

 

The South San Francisco, California based-biotech company has discovered an antibody that targets a protein on the surface of RSV known as the G protein. Researchers at the Centers for Disease Control and Prevention had figured out the mechanism of how that protein fools the immune system by displacing a key modulator of the immune system that triggers a response to invaders.

 

Because of the way RSV works and the ability of the G protein to mutate, people are generally unable to effectively fight the virus with their own immune system after they have been previously exposed to it. Year after year, seasonal exposure to the virus will still get people sick. But they do produce antibodies to the virus in very small quantities.

 

Trellis, using its technology called CellSpot, was able rapidly hunt through 10 million antibody producing b-cells from blood samples of dozens of healthcare workers and others with exposure to RSV to find the rare antibody with desired characteristics to fight the virus.

 

“CellSpot makes possible for the first time very large screening libraries in such a way that we are able to gain an order of magnitude more information than was previously available,” said Brian Cunningham. “That ability makes it practical to screen, for instance, human blood.”

 

Trellis has identified a lead antibody and plans on advancing it into the clinic in the second half of 2009. Though AstraZeneca markets its antibody Synagis as a prophylactic against the virus in premature babies, there is currently no treatment for RSV. But the greater promise of Trellis lies in CellSpot.

 

“You can pick a needle out of a haystack here,” said Jim Broderick, a partner with Morgenthaler Ventures, an investor in Trellis. “These guys can identify and quantify millions of protein secreting cells simultaneously and through their screening technology pick out the one out of ten million with the attributes you want.”