In tests conducted on mice, the ricin toxin vaccine RiVax — developed by Soligenix, Inc. — provided at least a full year’s worth of protection against the deadly agent.
Ricin is a lethal plant-derived toxin feared for its potential use as a bioterrorism and chemical warfare agent. Highly stable and potent, it can be dispersed in power, mist, or pellet forms, and no effective treatments currently exist for those it has poisoned. The fact that RiVax has shown up to 100 percent protection in both mice and non-human primates exposed to lethal doses of the toxin is therefore huge.
“These results continue to reinforce the convenience and practicality of the RiVax vaccine,” Dr. Oreola Donini, Chief Scientific Officer of Soligenix, said. “This, and other ongoing work, has continued to corroborate the efficacy of RiVax and will facilitate its potential approval.”
The vaccine candidate was tested on mice on days 1 and 21 of a challenge study. Those mice were subsequently given 10 times the lethal dose of ricin. It had been previously tested for efficacy on mice and non-human primates. It also demonstrated the ability to be stored for at least a year at 104 degrees Fahrenheit during that testing. That makes it ideal for stockpiling and transport, being free of serious thermostability restrictions.
RiVax studies have been supported by $21.2 million from the National Institute of Allergy and Infectious Diseases. Soligenix intends the vaccine for soldiers and civilian first responders and will pursue approval for it under the U.S. Food and Drug Administration’s (FDA) Animal Rule since human efficacy trials would be unethical.
So far, RiVax has received Orphan Drug and Fast Track designations from the FDA, as well as Orphan Drug designation from the European Medicines Agency.