DOR BioPharma Reports Initiation of Dosing of Ricin Vaccine - RiVax - in Phase I Clinical Trial; First Human Clinical Trials of a Ricin Toxin Vaccine.

MIAMI -- DOR BioPharma, Inc. ("DOR" or the "Company") (AMEX:DOR) announced today that DOR and its academic partner began human testing of RiVax(TM), a recombinant vaccine designed to protect against ricin toxin. After having successfully passed prerequisite animal safety and efficacy evaluations, RiVax(TM) (recombinant ricin toxin vaccine) is the first ricin vaccine to be tested in humans.

The Phase I trial is a dose escalating trial in which volunteers will receive three monthly intramuscular doses of vaccine. Three cohorts of five volunteers each will receive low, medium, or high doses of RiVax(TM). The five volunteers receiving the lowest dose of vaccine (10 micrograms) will be monitored for adverse side effects before receiving the next injection. The safety outcomes in each of the volunteers will be evaluated one month following the first injection before proceeding to the next dose level. The last cohort of volunteers will receive 100 micrograms of RiVax(TM). Blood from the volunteers will be tested for ricin neutralizing antibodies prior to each injection and regularly for six months, with the final measure of immunogenicity/effectiveness one year after the first injection. The trial is designed to confirm that the vaccine is safe at doses that induce ricin neutralizing antibodies. The Company expects that preliminary interim safety and immunogenicity data will be available as early as the second quarter 2005.

DOR is developing RiVax(TM) pursuant to the FDA's "animal rule" adopted in May 2002, which provides an expedited path to regulatory approval for biodefense products based upon sufficient demonstration of safety in humans with hypothetical efficacy demonstrated in animals. As part of the Phase I clinical trial, if sufficient immunogenicity is achieved in humans, DOR intends to isolate ricin specific antibodies from the human volunteers and transfer them to animal models to test the human antibodies' effectiveness in protecting the animals from ricin toxin exposure.

Given its FDA-approved Investigational New Drug Application (IND) and initial human dosing, DOR has made substantial progress in preparing for a potential procurement contract from the U.S. Government for the manufacture and delivery of investigational vaccines to the U.S. Strategic National Stockpile. The recently enacted BioShield Act of 2004 permits the U.S. Government to procure and purchase biodefense countermeasures, such as RiVax(TM), while still investigational and prior to FDA regulatory approval.

Michael Sember, President and CEO of DOR BioPharma commented, "This Phase I clinical trial represents an important milestone for DOR and our collaborators as we move assertively to develop vaccines against known bioterrorism threats. This achievement is indicative of the effort being expended to ensure that our biodefense vaccines are developed as quickly as possible so they will be available to protect people from potential bioterrorism."

Obtained from castor beans, ricin is a protein toxin that enters cells and enzymatically inhibits protein synthesis leading to cell death soon after exposure. Ricin 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.

RiVax(TM) 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. The presence of these antibodies protect against exposure to ricin toxin. During the past year, DOR and its collaborators have cGMP produced and tested the highly purified RiVax(TM) that is being used in this trial.

In 2004, the National Institute of Allergy and Infectious Diseases (NIAID), a division of the National Institutes of Health (NIH), awarded a $5.2 million grant to DOR for process development, scale up and cGMP manufacturing of RiVax(TM). DOR is planning to conduct additional clinical studies to optimize dose and regimen, pending the results of this current trial. In August 2003, NIAID also awarded a $2.6 million grant to DOR's academic partner for the further development and testing of RiVax(TM).

About DOR BioPharma, Inc.

DOR BioPharma, Inc. is a biopharmaceutical company focused on the development of biodefense vaccines and therapeutics for areas of unmet medical needs. Through its BioDefense Division, DOR is developing bioengineered vaccines designed to protect against the deadly effects of ricin toxin and botulinum toxin for potential U.S. Government procurement. DOR's lead therapeutic product, orBec(R) (an oral formulation of beclomethasone dipropionate), is a potent, locally-acting corticosteroid being developed for the treatment of intestinal Graft-versus-Host Disease (iGVHD), a severe, life-threatening form of gastrointestinal inflammation. DOR recently announced top line results of its pivotal Phase III clinical trial of orBec(R) in iGVHD in which orBec(R) demonstrated a highly statistically significant reduction in mortality during the prospectively defined Day 200 post-transplant period and positive trends on its primary endpoint. DOR will meet with the FDA in the coming months to determine appropriate next steps for the development of orBec(R).

For further information regarding DOR BioPharma, please visit the Company's website located at http://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's current expectations about its future results, performance, prospects and opportunities, including statements regarding the potential use of orBec(R) for the treatment of iGVHD and the prospects for regulatory filings for orBec(R). Where possible, DOR BioPharma 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 BioPharma cannot assure you that it will be able to successfully develop or commercialize products based on its technology, including orBec(R), 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 (including that the results of its Phase I clinical trial of RiVax(TM) will demonstrate acceptable safety and immunogenicity/efficacy), 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 U.S. Government or other countries, 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, that it will be able to maintain its listing on the American Stock Exchange, or that its business strategy will be successful. Important factors which may affect the future use of orBec(R) for iGVHD include the risks that: because orBec(R) did not achieve statistical significance in its primary endpoint in this study (i.e. a p-value of less than or equal to 0.05), the FDA may not consider orBec(R) approvable based upon existing studies, orBec(R) may not show therapeutic effect or an acceptable safety profile in future clinical trials, if required, or could take a significantly longer time to gain regulatory approval than DOR BioPharma expects or may never gain approval; Dor BioPharma 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; or orBec(R) may not gain market acceptance; and others may develop technologies or products superior to orBec(R). These and other factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, DOR BioPharma's most recent reports on Form 10-QSB and Form 10-KSB. DOR BioPharma 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.