PS Targeting Antibody Inventor Philip Thorpe, Ph.D., discusses the broad potential of Peregrine's PS targeting drug bavituximab to address both cancer and viral disease.		Phosphatidylserine: A Novel and Emerging Target in Cancer Therapy A growing body of independent research publications implicate the involvement of exposed PS in the growth and spread of cancer. This document reviews recent publications investigating the role of PS in immune suppression and tumor growth, as well as the potential of targeting PS as broad anti-tumor therapy.

To take advantage of this effect, Peregrine has developed a monoclonal antibody called bavituximab that preferentially binds to aminophospholipids when they are exposed on the surfaces of virally infected or malignant cells. The drug’s binding to the phospholipids alerts the body’s immune system to attack the tumor and its blood supply, or to attack the virally infected cells while potentially minimizing unwanted side effects in healthy tissues.  Bavituximab is Peregrine’s lead Anti-Phospholipid Therapy agent. 

	Phospholipids are normal molecular structures that are present in all cells of the human body. (Here they are represented by the green line within the cell.)
	Scientists working with Peregrine discovered that certain phospholipids normally found on the inside of cell membranes become exposed on the surface of cells infected by a broad class of viruses known as enveloped viruses.  When these viruses reproduce and exit the host cell, they carry along the host cell’s membrane to make their own envelope or coat. This outer shell of the virus is known as the viral envelope.
	This exposes the target phospholipid on both the surface of the host cell and the virus cells. These phospholipids are similarly exposed on the surface of tumor blood vessels.
	To take advantage of this effect, Peregrine has developed a monoclonal antibody called bavituximab that preferentially binds to these target phospholipids, but can reach them only when they are exposed on the surfaces of virally infected or malignant cells.
	The drug’s binding to the phospholipids alerts the body’s immune system to attack the virally infected cells, while non-targeted healthy cells are left intact. Because bavituximab binds to a phospholipid from the infected human cell rather than from the virus, it should not be affected by virus mutations, a problem that frequently leads to viral drug resistance.

The findings were generated in the laboratory of Philip Thorpe, Ph.D., professor of pharmacology at the University of Texas Southwestern Medical Center at Dallas and a member of Peregrine's Scientific Resource Board.