DOR BioPharma Announces Publication Describing Results of Its Multivalent Botulinum Toxin Vaccine BT-VACC(TM)
- Category: Vaccines
- Published on Tuesday, 03 July 2007 04:00
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MIAMI, FL, USA | July 2, 2007 | DOR BioPharma, Inc. (OTCBB: DORB) ("DOR" or the "Company") announced today that the first results from testing of a multivalent form of its botulinum toxin vaccine, BT-VACC™, have been published in the journal Infection and Immunity (Ravichandran et al., 2007, Infection and Immunity, v. 75, p. 3043 ). These results are the first that describe the protective immunity elicited by a multivalent vaccine that is active by the mucosal route. The vaccine consists of a combination of three non-toxic subunits of botulinum toxin that induced protection against the corresponding versions of the natural toxins.
The results published in Infection and Immunity show that non-toxic subunits (protein components of the natural toxin) of three of the serotypes of botulinum toxin that cause almost all instances of human disease, namely serotypes A, B, and E, can be combined and delivered via nasal administration. The combination vaccine induced antibodies in the serum of mice and protected against subsequent exposure to high doses of a combination of the natural A, B, and E serotype neurotoxins. Further, the combination vaccine can induce protection when given mucosally as a booster to animals that have been given a primary vaccine injection.
BT-VACC™ is composed of a component of what is known as the heavy chain of each of the A, B, and E serotypes. These components lack the region of the toxin that are responsible for blocking neurotransmitter functions. The subunits can bind avidly to receptors on the surface of mucosal cells and traverse lung and gastrointestinal tissue to stimulate immunity. Because the binding subunits lack the toxic part of the molecule, the vaccine is safe and stimulates antibodies in not only the blood but those antibodies that coat mucosal surfaces. It is thought that antibodies that are present in lung and gastrointestinal secretions will block the uptake of the toxin before entering the bloodstream and reaching peripheral nerves. BT-VACC™ originated from the work of Lance Simpson, PhD, and has been exclusively licensed from Jefferson Medical College.
"These results are a major step forward and represent the first demonstration of a multivalent vaccine that is active by the mucosal route," said Christopher J. Schaber, PhD, President and CEO of DOR. "We think that these results in animals demonstrate the potential of developing subunit vaccines that can be given by a mucosal route, avoiding the use of needles and injections, with greater ease of administration and convenience for the provider and the patient. Such vaccines would further have the advantage to stimulate antibodies that block absorption of toxin into the body. We expect that the successful development of a multivalent oral botulinum toxin vaccine that can be applied to rapidly deployable mass immunization programs will be a major step forward in Biodefense countermeasures."
"These results are valuable for two reasons," added Lance L. Simpson, PhD, Professor of Medicine and Director of the Center for Research on Bioterrorism and Biodefense at Jefferson Medical College. "First, they are a clear demonstration that it is feasible to create an inhalation or intranasal vaccine against the three botulinum serotypes that are of greatest concern to human health. Second, and looking toward the future, the results are a promising indicator that it should be possible to create an oral vaccine. There is a consensus among immunologists and public health officials that oral vaccination is one of the most desirable ways to protect vulnerable populations against toxic substances."
Because the toxin naturally enters lung and intestinal tissues very efficiently, it is specifically possible to engineer a botulinum vaccine that can be administered orally or via nasal administration. Unpublished results have also shown that oral administration of one of the serotype to rats results in significant levels of circulating antibodies as well as protection against toxin exposure.
About Botulinum Toxin
Botulinum toxin is an extremely potent neurotoxin of bacterial origin that inhibits peripheral nerve function, causing severe and often fatal descending flaccid paralysis. Natural botulism resulting from ingestion of toxin from contaminated food is very rare, but artificially, botulism also can result from bioterrorism and biowarfare. Because extremely small amounts can cause neurological effects, it is classified as a category A Biothreat by the CDC. The toxin can enter the body very efficiently through lung tissue and through the gastrointestinal tract, making the threat of purposeful food contamination a real possibility for use of the toxin as a biological weapon. Because the toxin rapidly enters target neural cells, exposure is difficult to treat with any available therapeutic regimen other than supportive care. In extremely minute quantities, botulinum toxin can be used therapeutically, as for the cosmetic use of Botox®, a commercial preparation of serotype A botulinum toxin, but the effects of the neurotoxin are extremely long lasting and paralytic at higher than therapeutic doses.
About Botulinum Toxin Vaccines
Vaccination is considered the best option to prevent neurological effects of toxin exposure. Because of the rarity of the natural disease, a vaccine would not be used in mass population immunization programs unless they were actually used or a significant threat. In that event, the vaccine would have to be made available for widespread dissemination for rapid and convenient vaccination of a large population. The only vaccine available is an experimental vaccine based on inactivation of a mixture of serotypes of the natural toxins that is given by injection, is not licensed by the FDA and cannot be used for widespread immunization. New multivalent vaccines based on non-toxic subunits are being developed, including BT-VACC™.
About DOR BioPharma, Inc.
DOR BioPharma, Inc. is a biopharmaceutical company developing products to treat life-threatening side effects of cancer treatments and serious gastrointestinal ("GI") diseases, and vaccines for certain bioterrorism agents. DOR's lead product, orBec® (oral beclomethasone dipropionate), is a potent, locally acting corticosteroid being developed for the treatment of GI graft-versus-host disease ("GVHD"), a common and potentially life-threatening complication of bone marrow transplantation. DOR has filed an NDA with the FDA for the treatment of GI GVHD, and has received a PDUFA date of July 21, 2007. An MAA with the EMEA for orBec® has also been filed and validated. orBec® may also have application in treating other gastrointestinal disorders characterized by severe inflammation. DOR has also recently initiated a clinical development program with its Lipid Polymer Micelle ("LPMTM") oral 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 recently enacted 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 and botulinum toxin. DOR's ricin toxin vaccine, RiVax™, has been shown to be safely tolerated and immunogenic in a Phase 1 clinical trial in normal volunteers.
For further information regarding DOR BioPharma, 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 U.S. Government or other countries, that the U.S. 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: because orBec® did not achieve statistical significance in its primary endpoint in the pivotal Phase 3 clinical study (i.e. a p-value of less than or equal to 0.05), the Oncologic Drug Advisory Committee ("ODAC") appointed by the FDA voted that the data supporting orBec® did not show substantial evidence of efficacy by a margin of 7 to 2 for the treatment of GI GVHD, although the FDA is not bound by ODAC's decision, the FDA may not consider orBec® approvable based upon existing studies, orBec® 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 expects or may never gain approval; 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; or orBec® may not gain market acceptance; 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.
SOURCE: DOR BioPharma, Inc.