The phase I clinical trial of RiVax represents the first ricin toxin vaccine ever to be clinically tested in humans. In the dose-escalating, open-label trial, three cohorts of five normal volunteers each have been dosed three times with 10, 33 and 100 micrograms of the drug. These interim data are from the first two lower dose cohorts of volunteers.
Early results demonstrate that the vaccine is safe and immunogenic after immunization with three monthly injections of vaccine, with volunteers developing antibodies. This is the first indication that a ricin toxin vaccine elicits immune responses and predicts that humans can be protected against ricin exposure. Antibody data from all three cohorts is expected in the next several months.
RiVax is a form of ricin that consists of a fragment of the toxin that has been proven in pre-clinical studies to be non-toxic but retains the capacity to elicit protective immunity. Ricin toxin is relatively easy to produce and exposure to small amounts, especially by inhalation, can lead to lung damage, nausea, fever, abdominal pain, and death within several days.
The research is being conducted by DOR’s academic partner, the University of Texas Southwestern Medical Center at Dallas, led by Dr Ellen Vitetta. The work is supported by a number of grants awarded by National Institute of Allergy and Infectious Diseases (NIAID) to the University and DOR BioPharma to support both the development and manufacturing of the product.