First vaccine for deadly ricin toxin moves closer
could be the world's first vaccine for the deadly ricin toxin.
The urgency for protective countermeasures against ricin has been heightened by its recent and continued use as a biological weapon in both the United States and Europe.
Ricin, which is extracted from castor beans, has a highly lethal toxicity in small doses, causing fever, nausea abdominal pain or lung damage, followed by death within a few days of exposure.
Because castor beans are readily available, ricin is easily manufactured and it is also easily aerosolised - making it all the more dangerous - however currently there is no prevention or cure for the deadly substance.
Dor and its manufacturing partner, Cambrex BioSciences, developed a robust and reproducible manufacturing process for the large-scale production of its developmental RiVax vaccine and has now reached a crucial manufacturing milestone under a $6.4m (€5m) grant awarded in 2004 to make the vaccine by the National Institutes of Health (NIH).
"We now have a means to manufacture RiVax at the scale necessary for potential future immunisation programs of civilian or military personnel," said Michael Sember, president and CEO of DOR BioPharma.
The safety and immunogenicity of RiVax was previously confirmed in a Phase I clinical trial earlier this year and the results were published in the Proceedings of the National Academy of Sciences.
Moving forward, the company will now test the vaccine in further clinical trials to examine the influence of an immunological adjuvant formulation and vaccination regimen on the human immune response and gather the evidence it needs to gain US Food & Drug Administration (FDA) approval of the vaccine.
Dor will also carry out additional animal testing to provide correlation of antibody levels in human serum with protection against ricin exposure in animal models.
This is because the ricin vaccine cannot ethically be tested in humans so the product will be approved under the FDA's "two animal rule," which permits approval of a drug based on results from animal trials in exceptional circumstances.
Dor, through its BioDefense Division is active in developing biomedical countermeasures as part of the US government's "Project BioShield," enacted in 2004 to encourage the development of effective drugs and vaccines to protect against attack by biological and chemical weapons or other dangerous pathogens.
The firm has already developed a vaccine against the deadly botulinum toxin and is in the process of developing a treatment for botulism exposure in conjunction with contract manufacturer, Dowpharma.
