DOR BioPharma Announces Initiation of Second Human Clinical Trial for RiVax(TM), Its Ricin Toxin Vaccine
Thursday August 7, 7:00 am ET
EWING, NJ--(MARKET WIRE)--Aug 7, 2008 -- DOR BioPharma, Inc. (OTC BB:DORB.OB - News) ("DOR" or the "Company"), a late-stage biopharmaceutical company, announced today that one of its academic development partners has initiated a second human clinical trial of RiVax™ in healthy volunteers. RiVax™ is a recombinant subunit vaccine designed to induce protection against exposure to ricin toxin, a category B biothreat. This new trial is intended to evaluate the safety and immunogenicity of an improved formulation of the vaccine containing an adjuvant that is expected to result in long lasting and high levels of protective antibodies. The new trial is being conducted as part of a program funded by a grant from the Orphan Products Division of the FDA ("Food and Drug Administration"). Dr. Ellen Vitetta, Director of the University of Texas Southwestern Medical Center's Cancer Immunobiology Center, is the Principal Investigator of the study.
DOR is presently conducting manufacturing and characterization of the new RiVax™ formulation according to the FDA's current good manufacturing practices ("cGMPs"), anticipating that it will match requirements for stockpiled vaccines predicted from current stability results and pre-clinical efficacy results in animals. RiVax™ has already been evaluated in a Phase I clinical trial to test the safety and immunogenicity of the subunit lacking an adjuvant. Those results demonstrated that the adjuvant-free RiVax™ was well tolerated and induced antibodies in humans that neutralized ricin toxin in tissue culture and in mice. Serum antibodies that neutralize ricin are expected to function to reduce mortality and morbidity from exposure to ricin, even if exposure to ricin is through aerosolization. The new formulation employs an adjuvant that is very well characterized and used in many vaccines to induce protective, neutralizing antibodies in humans. The new trial employs an escalating dose strategy in which volunteers receive three intramuscular doses of vaccine at six-week intervals, matching many commonly employed vaccination regimens. The trial is designed to confirm that, in conjunction with the adjuvant, the vaccine is safe at doses that induce protective antibodies, and that an adjuvanted formulation results in sustained and higher titer antibodies. Safety and immunogenicity data is anticipated in the first half of 2009.
"From the vaccine dose levels being evaluated in this trial, we hope to establish a dose for Phase 2 human trials," said Dr. Vitetta.
"We have been encouraged by the safety and animal efficacy results to date, and combined with our accruing stability data, we are poised to carry out expanded Phase 2 human trials in the next six to nine months," said Dr. Robert N. Brey, Ph.D., Chief Scientific Officer of DOR. "This adjuvanted formulation will further guide us in determination of safety and efficacy. In conjunction with results from our ongoing non-human primate trial, it will aid in elucidating correlation between the antibody levels in humans and protection from aerosolized toxin in non-human primates."
About Ricin Toxin
Ricin toxin is a potent plant toxin that can be easily produced from abundantly available castor beans. Ricin enters cells and enzymatically inhibits protein synthesis leading to cell death and generation of an irreversible inflammatory response. General organ failure leading to death can occur within several days of exposure. Ricin is highly toxic to humans and other mammals because it has the ability to enter virtually any type of cell and affect any organ in the body. Exposure to small amounts, especially by inhalation, leads to lung damage, nausea, fever, and abdominal pain, and death within several days. Diagnosis of ricin poisoning is difficult since the symptoms resemble those of other illnesses. There are no known effective antidotes for ricin exposure. The potential use of ricin toxin as a biological weapon of mass destruction has been highlighted in a recent FBI Bioterror report released last November entitled Terrorism 2002-2005 which states that "Ricin and the bacterial agent anthrax are emerging as the most prevalent agents involved in WMD investigations" (http://www.fbi.gov/publications/terror/terrorism2002_2005.pdf). Ricin toxin is thought to be a bioterror threat because of its stability and high potency as well as the large worldwide reservoir created as a by-product of castor oil production. It is second only to botulinum toxin as the most lethal natural toxin. The need for protective countermeasures against ricin toxin has been emphasized by its recent and continued use as a biological weapon. The successful development of an effective vaccine against ricin toxin may act as a deterrent against the actual use of ricin as a biological weapon and could be used in rapid deployment scenarios in the event of a biological attack |
