« USDA requests additional funding to battle avian flu | Main | (AFX UK Focus) 2005-11-01 08:33 GMT: New bird flu outbreak confirmed by Russian agriculture ministry (Interactive Investor)Yahoo! News - Search Results for agence france-presse »

November 02, 2005

Generex Pandemic Influenza Vaccine Program to Be Presented at Novel Vaccine Concepts Conference in Washington, D.C.Market Wire


TORONTO -- (MARKET WIRE) -- 11/02/05 -- Generex Biotechnology Corporation (NASDAQ: GNBT) announced today that Dr. Robert Humphreys, Chief Scientific Officer of Antigen Express, Inc., its wholly owned immunotherapeutics subsidiary, will make a presentation at a scientific symposium of a novel vaccination approach to protect against pandemic influenza.

Dr. Humphreys will present "Ii-Key/MHC class II Epitope Hybrid Peptide Vaccine For H5 Pandemic Flu" at the 3rd annual "Vaccines - All Things Considered" scientific symposium at the Sheraton Pentagon South conference center in Washington, D.C. Participants at this conference represent many academic groups and scientists from the Food and Drug Administration, the Center for Disease Control, and principal vaccine companies such as Baxter, Cel-Sci, Chiron, GlaxoSmithKline, Medimmune, Wyeth, and others.

The organizers of the conference said: "'Vaccines - All Things Considered' will explore new approaches and technologies to this imperative issue in society. This conference will cover many important aspects of vaccine discovery, development, acceptance and alternatives. Reports and successful stories of smallpox and polio, why concerns about an influenza outbreak remain fervent, and the progress of potential technologies, are just a few of the many topics to be discussed."

Dr. Humphreys explained that the primary means for controlling a potential pandemic of the influenza H5N1 virus is vaccination. Inactivated H5N1 viral and baculovirus-expressed H5 hemagglutinin (HA) protein vaccines have been evaluated in humans. The amount of vaccine needed to generate neutralizing antibody responses is reported to be 12-fold higher than the standard amount used in the seasonal flu vaccine, indicating that the H5 HA protein is poorly immunogenic in humans. The use of an adjuvant or other antigenic epitope-specific methods is needed to make best use of limited antigen supplies.

Antigen Express scientists have synthesized a series of hybrid vaccine peptides linking the immunoregulatory Ii-Key moiety to influenza H5 HA HLA class II epitopes in an effort to identify epitopes that potently stimulate T helper cells. These may be used to enhance immunogenicity of the current vaccines and as a stand-alone vaccine in people that do not have access to traditional vaccines. It is estimated that less than 5% of the US population and no one in the developing countries will have access to a traditional or cell-culture manufactured H5N1 influenza vaccine. For these people, H5 Ii-Key hybrid peptides will likely be the only vaccine available. This vaccine can also be readily produced for mass vaccinations in a short period of time.

In mouse studies, interferon-gamma responses to Ii-Key/hybrids are increased 8 to 10 times versus epitope-only peptide, when assayed by ELISPOT with immunopurified CD4+ cells. Antigen Express scientists chose influenza HA HLA class II epitopes predicted for presentation by a series of common HLA-DR alleles, toward making a selected set of 6-8 hybrid vaccine peptides cumulatively presented by HLA-DR alleles present in > 90% of humans. Upon infection, such activated T-helper cells will enhance the strength and duration of a virus neutralizing antibody response. Preliminary results indicate that H5 Ii-Key hybrid peptides enhance CD4+ T helper cell responses on their own and antibody responses following recombinant HA protein immunization (rHA).

The Antigen Express team is developing a vaccine for pandemic Asian bird flu (H5N1 strain) based on H5 MHC class II epitopes, which have been selected for likelihood of being both potent and presented by many HLA-DR alleles. Ii-Key/MHC class II epitope hybrid peptides contain an immunoregulatory segment of the Ii protein (the Ii-Key moiety), loosening the epitope-binding groove of MHC class II molecules and permitting insertion of a polymethylene-linked MHC class II epitope. Doing so increases the potency of epitope presentation up to 200 times in vitro, as measured in a T-cell hybridoma response assay. In addition, Ii-Key hybrids with MHC class II epitopes of principal cancer and infectious disease antigens increase the T-helper cell response 4-8 times in vaccinated mice, as measured using purified CD4+ T cell IFN-gamma ELISPOT assays. Presently, Antigen Express has an ongoing phase I clinical trial with Ii-Key/Her-2/neu hybrids in breast cancer patients. Data from these trials are relevant to establishing the safety and effect of this novel type of vaccine, for later use in validating an influenza vaccine.

Ongoing experiments lead by Drs. Douglas Powell and John Zinckgraf of Antigen Express with such Ii-Key/influenza H5 antigenic epitope hybrid peptides are aimed at determining: 1) Which Ii-Key/H5 MHC class II epitope hybrids best stimulate T helper cells in BALB/c and DR4 transgenic mice; 2) The optimal immunization scheme and hybrids to prime for rH5-elicited, neutralizing antibodies; 3) The lowest dose/least frequency of rH5 immunizations after optimal priming with a selected set of Ii-Key/H5 MHC II epitope hybrids that produce protective titers of neutralizing antibodies; and 4) The duration and potency of T cell memory induced by a heterologous Ii-Key hybrid/rHA immunization regimen. The focus of these studies is to identify a potent vaccine against pandemic H5N1 influenza for clinical testing.

Anna Gluskin, President & Chief Executive Officer of Generex, said, "I am pleased with the progress of the Antigen Express team to advance this novel vaccine technology toward the clinic. The initial experiments in mice are very promising. It is important to recognize that the vaccine peptides being studied in mice were designed to be the ones actually used in any final commercial product for humans. Being able to test these vaccine peptides in mice is very fortunate, especially in terms of rapidly developing the best prime-boost vaccination protocols."

About Generex

Generex is engaged in the research and development of drug delivery systems and technologies. Generex has developed a proprietary platform technology for the delivery of drugs into the human body through the oral cavity (with no deposit in the lungs). The Company's proprietary liquid formulations allow drugs typically administered by injection to be absorbed into the body by the lining of the inner mouth using the Company's proprietary RapidMist(TM) device. The Company's flagship product, oral insulin (Oral-lyn(TM)), which has been approved for commercial sale in Ecuador for the treatment of patients with Type-1 and Type-2 diabetes, is in various stages of clinical trials around the world. Antigen Express is a wholly owned subsidiary of Generex. The core platform technologies of Antigen Express comprise immunotherapeutics for the treatment of malignant, infectious, allergic, and autoimmune diseases.

For more information, visit the Generex Web site at www.generex.com.

Safe Harbor Statement: This release and oral statements made from time to time by Generex representatives concerning the same subject matter may contain "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. These statements can be identified by introductory words such as "expects," "plans," "intends," "believes," "will," "estimates," "forecasts," "projects" or words of similar meaning, and by the fact that they do not relate strictly to historical or current facts. Forward-looking statements frequently are used in discussing potential product applications, potential collaborations, product development activities, clinical studies, regulatory submissions and approvals, and similar operating matters. Many factors may cause actual results to differ from forward-looking statements, including inaccurate assumptions and a broad variety of risks and uncertainties, some of which are known and others of which are not. Known risks and uncertainties include those identified from time to time in the reports filed by Generex with the Securities and Exchange Commission, which should be considered together with any forward-looking statement. No forward-looking statement is a guarantee of future results or events, and one should avoid placing undue reliance on such statements. Generex claims the protection of the safe harbor for forward-looking statements that is contained in the Private Securities Litigation Reform Act.

Shayne Gilliatt
Generex Biotechnology Corporation

Ed Lewis
CEOcast, Inc.
Email Contact
for Generex Biotechnology Corporation

Content copyright Marketwire LLC. All rights reserved. This content may not be redistributed or retransmitted.

Posted by dymaxion at November 2, 2005 10:50 AM

Trackback Pings

TrackBack URL for this entry:


Post a comment

Remember Me?