Soligenix receives patent for ricin vaccine

Soligenix, Inc., the late-stage biopharmaceutical company, has been granted United States patent number 7,829,668, for RiVax, its ricin vaccine.

Created through a collaborative partnership with Soligenix and Ellen Vitetta, the director of the Cancer Immunobiology Center, and her colleagues at the University of Texas Southwest Medical Center in Dallas, RiVax is a recombinant subunit of the A chain of ricin toxin, which functions as a vaccine by inducing ricin neutralizing antibodies in humans and animals.

Ricin is a plant toxin that has two molecular chains - the A chain can deactivate cellular machinery and induce toxicity, while the B chain allows it to bind to cells with high affinity. The alterations in the A chain of the ricin toxin, which are detailed in the patent, will affect the vascular leak of the cell, which is one of the deadly toxicities of the toxin.

“This patent issuance is another milestone towards obtaining broad patent coverage for RiVax™,” Robert N. Brey, chief scientific officer of Soligenix, said. “We continue to be enthusiastic about the prospects of developing a ricin vaccine to anticipate civilian and military biodefense requirements. We believe the technology that Dr. Vitetta and her colleagues at UT Southwestern have developed for RiVax is the most advanced in this area.”

Ricin is believed to be a potential bioterror threat because of its high potency, its stability and the large reservoir worldwide created as a by-product of the production of castor. If ricin is inhaled, it may cause nausea, fever, lung damage, abdominal pain and death within a few days. General exposure can cause organ failure and death. There is currently no effective means against ricin intoxication.