Regarding Ricin: New Vaccine Candidate Study Results

DOR BioPharma, Inc. is developing a non-injectable ricin toxin vaccine candidate using a genetically detoxified mutant of ricin A chain as the vaccine antigen and is preparing to enter into GMP manufacturing of clinical batches of vaccine. Intranasal or oral administration is contemplated.

Inhaled ricin causes rapid lung damage that is irreversible and leads to death. There is no antidote to ricin following exposure, and no vaccine has been developed or licensed. Vaccine candidates based on inactivated ricin toxin have been tested experimentally, and recently researchers at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) successfully tested a prototype in DOR BioPharma's MicroVax system that showed protection in animals after intranasal or oral vaccination (Kende et al. 2002. Vaccine. 20:1681-91).

The company is currently collaborating with the University of Texas Southwestern Medical Center to develop the MicroVax technology with a safe, completely detoxified version of ricin A chain which is considered the best option for further development. The vaccine antigen candidate has been recently described in the journal Vaccine (Smallshaw et al. 2002. Vaccine. 20:3422-27). This study and two related papers are available for review and downloading at

DOR BioPharma, Inc. is a specialty pharmaceutical company specializing in the oral delivery of approved chemical entities and synthetic (non-live) mucosally-administered vaccines that may conveniently and rapidly confer mucosal immunity (such as in the lungs) against, potentially, the entire spectrum of identified bioterrorism threats while completely avoiding the risks associated with vaccines that contain live replication competent pathogens or genetic material. The company's lead product, orBec (oral beclomethasone dipropionate), is currently in a pivotal Phase III clinical trial for the treatment of intestinal graft vs. host disease, and the company is currently testing orBec's usefulness in treating a large percentage of persons diagnosed with irritable bowel syndrome (IBS), a disease that affects approximately 35 million persons in the U.S. alone.

Source: DOR BioPharma, Inc.