PS-targeting antibodies

“Based on these findings, PS-targeting antibodies such as bavituximab may represent a completely new class of drugs for the treatment of life-threatening viral infections.”

Dr. Philip Thorpe,
Nature Medicine study co-author and professor of pharmacology at University of Texas Southwestern Medical Center

PS-Targeting Infectious Disease Data PDF Print E-mail

A Novel Approach for the Treatment and Prevention of Infectious Diseases

Researchers have found that PS is exposed on the outer membrane of cells infected with HIV, influenza, herpes viruses, hemorrhagic fever viruses, respiratory syncytial virus, measles, and the smallpox and rabies virus families, as well as on cells infected with certain protozoan pathogens responsible for diseases including malaria and leishmaniasis. In preclinical studies, our lead PS-targeting antibody bavituximab has demonstrated the ability to bind to virus particles and virus-infected cells of five viruses that cause viral hemorrhagic fever (VHF), including the highly lethal Ebola virus.  In data presented at the November 2010 Chemical and Biological Defense Science & Technology Conference, preclinical efficacy studies also showed that bavituximab in combination with the antiviral drug ribavirin improved survival in animals compared to either drug used alone in several models of VHF (view poster).

The potential of bavituximab as a broad antiviral agent was highlighted in a research paper published in the December 2008 edition of Nature Medicine, describing preclinical studies in which PS-targeting antibodies cured animals infected with lethal amounts of CMV and Pichinde virus, a model for a hemorrhagic fever virus included on the U.S. biodefense Category A watch list. Findings include:

  • 100% of animals lethally infected with murine CMV and treated with a mouse equivalent of bavituximab survived as compared with 25% of the control treated animals.
  • Animals lethally infected with Pichinde virus and treated with bavituximab showed a 50% survival rate as compared to zero survivors in the control group. Survival was further enhanced when the bavituximab equivalent was administered with the standard antiviral drug ribavirin.

Poster Presentations

2012 Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting

  • Phosphatidylserine-Targeting Antibodies As A Potential New Therapy Against Choroidal Neovascularization: view poster
  • Efficacious Outcome of an Ophthalmic Formulation of Phosphatidylserine-binding Monoclonal Antibody in a Rabbit Model of Acute HSV-1 Keratitis: view poster

2011 Chemical & Biological Defense Science & Technology Conference

  • Phosphatidylserine as a Therapeutic Target for the treatment of Francisella tularensis and Yersinia pestis infections: view poster

2012 International Herpes Workshop

  • Ophthalmic Formulation of Phosphatidylserine Binding Monoclonal Antibody Is Effective in Reducing Rabbit HSV-1 Keratitis and Virus Shedding: view poster

    Bavituximab in Action

    In vitro experiments have shown that bavituximab targets exposed PS on virally infected cells.


    Blue: cell nuclei
    Red: cell skeleton
    Green: bavituximab