Despite being nearly broke, DOR is up about 46% on two news events: (a) General Alexander Haig has been elected Chairman of its Board of Directors [http://biz.yahoo.com/bw/030107/72062_1.html] and (b) <<it has executed an exclusive option with the University of Texas Southwestern Medical Center (UT Southwestern) in Dallas to license patent applications pending in the United States and elsewhere pertaining to the use of novel recombinant ricin A chain mutants as vaccines to protect against aerosolized ricin. The exclusive option covers the development of intranasal, oral and inhalable vaccines that can be developed using the proprietary non-toxic mutants of ricin.
Ricin is the second most potent toxin known to man. It could be deployed as a weapon by aerosolization, and there is no effective antidote or vaccine approved for human use. Ricin is described by the Centers for Disease Control and Prevention (CDC) as a category B biological agent that could be used as bioterrorist weapons. Lung damage caused by inhalation of ricin toxin is quick and irreversible. Even relatively small-scale use of ricin by terrorists has the capacity to cause widespread disruption and huge expenditures of resources to diagnose and treat ricin exposure and to clean up contamination.
DOR stated, "We envision the development of ricin vaccines using a totally non-toxic portion of ricin as the safest and best choice to combat the potential use of ricin toxin in terrorist attacks or its use on the battlefield, since there are no effective antidotes or vaccines currently available. Other experimental ricin vaccines have been based on derivatives of ricin that are likely to be too toxic for use in humans. The ricin vaccine will be the first in a series of biodefense products developed by DOR." The developed vaccine can be stockpiled for biodefense and used to protect soldiers on the battlefield or to protect first responders, health care workers and other civilian populations, in the event of an attack in which ricin may be used.
This novel ricin vaccine has been developed in the laboratory of Dr. Ellen Vitetta, Director of the Cancer Immunobiology Center at UT Southwestern. Dr Vitetta stated, "We are very excited about the prospects of developing a safe and effective ricin vaccine and the potential for delivering it to mucosal sites where it would stimulate systemic and pulmonary immunity. There is an urgent need to develop effective vaccines against aerosolized toxins which represent potential biothreats to both the military and civilian populations of many countries." Dr. Vitetta's group recently reported their vaccine work in the journal Vaccine, demonstrating that the non-toxic ricin A chain elicits antibodies in animals that protect them against very large doses of ricin. (Smallshaw et al. 2002. Vaccine volume 20: p. 3422-77). The vaccine candidate consists of only one of the two subunits of the ricin toxin which has been genetically engineered to eliminate both its enzymatic activity and its ability to induce vascular leak syndrome (VLS). Complete elimination of both types of toxicity is likely to render this vaccine very safe at effective doses.
Further development will be aimed towards optimizing an effective formulation. This will then be delivered mucosally, e.g. by the oral or intranasal routes, using DOR's proprietary Microvax(TM) polymer microspheres that encapsulate antigens and usher them into lymphoid tissue (immune cells that produce antibodies) in the intestine or in the nasopharynx. DOR's Microvax(TM), synthetic (non-live) mucosally administered vaccine technology is protected by worldwide issued patents. In recent results obtained by investigators at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) in Fort Detrick, Maryland, also published in the journal Vaccine, showed that an experimental orally delivered encapsulated ricin toxoid was capable of protecting 100% of animals against lethal challenge to ricin toxin by subsequent inhalation (Kende, et al. 2002. Vaccine, volume 20: p. 1681-91). >> |
