SOURCE: DOR BioPharma, Inc.

August 07, 2008 07:00 ET

DOR BioPharma Announces Initiation of Second Human Clinical Trial for RiVax™, Its Ricin Toxin Vaccine

EWING, NJ--(Marketwire - August 7, 2008) - DOR BioPharma, Inc. (OTCBB: DORB) ("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.

About RiVax™

There are currently no vaccines available to prevent ricin poisoning or medical treatments to care for poisoning victims. RiVax™ was developed after the discovery that two key sites in the enzymatically active A chain of ricin toxin can be simultaneously altered to eliminate toxicity. After eliminating toxicity, the inactive ricin A chain induces antibodies in animals that recognize and neutralize the intact toxin. A vaccine is considered by many to be the best way to prospectively protect populations at risk of exposure against ricin toxin. RiVax™ is a subunit vaccine based on the purified and genetically inactivated A chain of ricin toxin. This vaccine would potentially be added to the Strategic National Stockpile and dispensed in the event of a terrorist attack.

The program is being funded by grants from NIAID, which have totaled over $11 million in direct funding to DOR. NIAID also awarded a $2.6 million grant to UT Southwestern for animal model development and the FDA Orphan Products Grants Program has funded ~$1 M for the conduct of the current clinical trial, supporting clinical supply and vaccine characterization.

About DOR BioPharma, Inc.

DOR BioPharma, Inc. (DOR) is a late-stage biopharmaceutical company developing products to treat life-threatening side effects of cancer treatments and serious gastrointestinal diseases, and vaccines for certain bioterrorism agents. DOR's lead product, orBec® (oral beclomethasone dipropionate or BDP), is a potent, locally acting corticosteroid being developed for the treatment of gastrointestinal Graft-versus-Host disease (GI GVHD), a common and potentially life-threatening complication of bone marrow transplantation. DOR filed a New Drug Application for orBec® with the FDA for the treatment of acute GI GVHD and received a not approvable letter in which the FDA has requested data from a confirmatory Phase 3 clinical trial to demonstrate the safety and efficacy of orBec®. orBec® is currently the subject of an NIH-supported, Phase 2, randomized, double-blind, placebo-controlled trial in the prevention of acute GVHD. Oral BDP may also have application in treating other gastrointestinal disorders characterized by severe inflammation. DOR has initiated a development program with its Lipid Polymer Micelle (LPM™) drug delivery technology for the oral delivery of leuprolide for the treatment of prostate cancer and endometriosis.

Through its Biodefense Division, DOR is developing biomedical countermeasures pursuant to the Project BioShield Act of 2004. DOR's biodefense products in development are recombinant subunit vaccines designed to protect against the lethal effects of exposure to ricin toxin, botulinum toxin and anthrax. DOR's ricin toxin vaccine, RiVax™, has been shown to be well tolerated and immunogenic in a Phase 1 clinical trial in normal volunteers.

For further information regarding DOR BioPharma, Inc., please visit the Company's website located at www.dorbiopharma.com.

This press release contains forward-looking statements, within the meaning of Section 21E of the Securities Exchange Act of 1934, that reflect DOR BioPharma, Inc.'s current expectations about its future results, performance, prospects and opportunities, including statements regarding the potential use of orBec® for the treatment of gastrointestinal GVHD and the prospects for regulatory filings for orBec®. Where possible, DOR has tried to identify these forward-looking statements by using words such as "anticipates," "believes," "intends," or similar expressions. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements. DOR cannot assure you that it will be able to successfully develop or commercialize products based on its technology, including orBec®, particularly in light of the significant uncertainty inherent in developing vaccines against bioterror threats, manufacturing and conducting preclinical and clinical trials of vaccines, and obtaining regulatory approvals, that its technologies will prove to be safe and effective, that its cash expenditures will not exceed projected levels, that it will be able to obtain future financing or funds when needed, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further grants and awards, maintain its existing grants which are subject to performance, enter into any biodefense procurement contracts with the US Government or other countries, enter into a definitive agreement with IDIS for a NPAP for orBec® for the treatment of GI GVHD, that the US Congress may not pass any legislation that would provide additional funding for the Project BioShield program, that it will be able to patent, register or protect its technology from challenge and products from competition or maintain or expand its license agreements with its current licensors, or that its business strategy will be successful. Important factors which may affect the future use of orBec® for gastrointestinal GVHD include the risks that: the FDA's requirement that DOR conduct additional clinical trials to demonstrate the safety and efficacy of orBec® will take a significant amount of time and money to complete and positive results leading to regulatory approval cannot be assumed; DOR is dependent on the expertise, effort, priorities and contractual obligations of third parties in the clinical trials, manufacturing, marketing, sales and distribution of its products; orBec® may not gain market acceptance if it is eventually approved by the FDA; and others may develop technologies or products superior to orBec®. These and other factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, DOR's most recent reports on Form 10-QSB and Form 10-KSB. DOR assumes no obligation to update or revise any forward-looking statements as a result of new information, future events, and changes in circumstances or for any other reason.

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