VIRxSYS Corporation was issued US patent 6,627,442 from the United States Patent and Trademark Office entitled, "Methods for stable transduction of cells with viral vectors" by Humeau et al. This patent broadly covers the method for achieving greater than 90% stable transduction of primary hematopoietic (blood-related) cells by HIV-based lentiviral vectors. More specific claims cover methods for highly efficient stable gene delivery to lymphocytes, dendritic cells and hematopoietic stem cells.

The patent adds to VIRxSYS' extensive lentiviral vector portfolio that includes eight other issued US patents (5,888,806; 5,888,767; 6,114,141; 6,168,953; 6,207,426; 6,232,120; 6,410,257 & 6,498,033), encompassing over 250 claims. VIRxSYS' lentiviral vector is the first and only lentiviral vector that is being used in human clinical trials. VRX496, the company's lead candidate vector designed for the treatment of HIV/AIDS, is currently being evaluated in phase I clinical trials at the University of Pennsylvania in Philadelphia.

Boro Dropulic, the company's Founder and Chief Scientific Officer, stated, "Efficient and stable gene delivery of genetic payloads into primary human cells will be essential for effective genetic therapies. The technology covered by this patent will enable such delivery into a variety of blood cell types. Importantly, the method is scalable and does not compromise stable gene delivery at the clinical scale. We are excited at the prospect of using this technology for the treatment of many blood-based diseases such as HIV/AIDS."