AntoXa is working with Defence Research & Development Canada (DRDC) to develop and produce a plant-made antibody, PhD9, to protect against ricin exposure, a program that has received more than $400,000 (CDN) from the Government of Canada since 2014.
Ricin is a naturally occurring protein from Ricinus communis. It is extremely toxic to humans when inhaled or injected and is considered a high bioterrorism risk for the public. Ricin is listed as a Category B threat agent by the U.S. Centers for Disease Control and Prevention due to its ease of production, worldwide availability, relative stability and extreme lethality.
There is currently no antidote against ricin poisoning. It acts very quickly and leaves a short window for administering therapeutic antibodies.
The PhD9 antibody drug candidate developed by DRDC and produced using AntoXa’s vivoXPRESS® system prevents ricin from penetrating cells. DRDC conducted in vitro and in vivo studies that found the plant-made version of the antibody showed therapeutic efficacy against ricin intoxication that was comparable to hD9 produced using mammalian cell technology. The findings were presented at the Antibody Engineering and Therapeutics Conference in December 2015.
“We’re very encouraged by the initial study results for the plant-produced anti-ricin antibody,” said Dr. Don Stewart, AntoXa President and CEO. “We believe that plants hold the key to cost-effective, large-scale production of antidotes for ricin and other potential bioterrorism threats.”