ATLANTA, GA--(Marketwire - Sep 26, 2012) - GeoVax Labs, Inc. (
Paul A. Goepfert, MD, University of Alabama in Birmingham, Protocol Chair, reported safety and immunogenicity data for the HVTN 205 Phase 2a trial of the GeoVax vaccine candidates. HVTN 205 was undertaken in 300 participants to further compare full-dose regimens of DNA priming and modified vaccinia Ankara (MVA) boosting (DDMM regimen) with MVA priming and boosting (MMM regimen). Both vaccine regimens appeared safe and well-tolerated. Similar to Phase 1 testing, the GeoVax "DDMM regimen" induced higher rates of T cell responses whereas the "MMM regimen" induced higher rates of antibody responses. Antibody responses to Env were seen in more than 90 percent of both groups. The Phase 2a trial confirmed Phase 1 results, setting the stage for Phase 2b efficacy trials. The Phase 2b trial will test GeoVax's second-generation product that co-expresses HIV proteins and granulocyte-macrophage colony-stimulating factor in the DNA prime.
Nicole Frahm, Ph.D., Associate Laboratory Director, HVTN Laboratory in Seattle, compared immune responses elicited by vaccines developed by GeoVax to those by Therion Biologics Corp.and the South African AIDS Vaccine Initiative. All of these vaccines used DNA priming and poxvirus boosting or poxvirus priming and boosting. These studies compared DNA, MVA and fowlpox vectors. The results showed the GeoVax vaccines performed well in all categories of tested responses. The GeoVax MVA vaccine performed particularly well in the elicitation of neutralizing antibody for both Tier 1 (easy to neutralize) and Tier 2 (more difficult to neutralize) isolates of HIV.
Harriet L. Robinson, Ph.D., GeoVax's Chief Scientific Officer, presented data reviewing a long-term protection study (currently at four years) in which rhesus macaques vaccinated with simian homologs of the GeoVax second-generation vaccines were subjected to 43 independent rectal exposures to virus. At the 43rd challenge, the last two uninfected macaques in the study became infected. Combined with the consistency and quality of safety and immune responses for the first-generation vaccines in HVTN-sponsored clinical trials, the success of this long-term challenge study provides the rationale for proceeding with the second generation "GM-CSF co-expressing product" into Phase 2b human efficacy trials.
"We are very pleased with the ongoing progress and encouraging results resulting from both our clinical and preclinical studies," said David A. Dodd, GeoVax's Chairman. "The HVTN has very effectively proceeded with our GM-CSF co-expressing product into the clinic in HVTN 094. This Phase 1 study, which will provide safety and immunogenicity data for our 2nd generation product and support our progress into Phase 2b, is enrolling more rapidly than anticipated."
The AIDS Vaccine 2012 Conference Abstract Book can be found at the following link: http://vaccineenterprise.org/conference/2012/sites/default/files/AV12%20Abstract_WebFinal.pdf
Webcasts of the conference sessions can be found at the following link: http://aidsvac.capitalreach.com/
The unique GeoVax two-component vaccine regimen, a recombinant DNA and a recombinant modified vaccinia Ankara (MVA), is designed to stimulate both anti-HIV T cell and anti-HIV antibody immune responses. The GeoVax DNA and MVA vaccines are used in a prime/boost protocol in which priming is done with the DNA component and boosting with the MVA component. Both the DNA and MVA components express the three major proteins of the AIDS virus: Gag, Pol, and Env, and produce noninfectious virus-like-particles. Uniquely, the GeoVax vaccines express virus-like particles that display the trimeric membrane bound form of the HIV-1 envelope glycoprotein (Env). In GeoVax's second-generation vaccine regimen, the DNA prime co-expresses GM-CSF with the virus-like particles, delivering a normal human protein that stimulates immune responses to the site of vaccination. All preventive Phase 1 human clinical trials conducted to date have tested various combinations and doses of our DNA and MVA vaccines for their ability to raise anti-HIV humoral (antibody) and cellular (cytotoxic T cell) immune responses, as well as for the safety of the vaccines.
AIDS is an epidemic that can affect anyone, regardless of race, gender, age or sexual orientation. 33 million people are currently infected globally; it is estimated that there will be 2.5 million new infections this year. Since the beginning of the epidemic, more than a million people in the U.S. have contracted the virus. Every 9 1/2 minutes, someone in the U.S. is infected with AIDS. Globally, HIV is the top killer among women of reproductive age. HIV is a worldwide disease with different subtypes (or clades) of the virus predominating in different regions of the world. Clade B is the predominant subtype in North America. Globally, most infections involve subtypes AG, B and C. GeoVax vaccines are currently designed to function against clade B.
For more information, please visit www.geovax.com.
About the HVTN
The HVTN is the largest worldwide clinical trials network dedicated to the development and testing of preventive HIV/AIDS vaccines. The HVTN is an international collaboration that conducts all phases of clinical trials, from evaluating experimental vaccines for safety and the ability to stimulate immune responses, to testing vaccine efficacy. Support for the HVTN comes from the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health (NIH). The Network's HIV Vaccine Trial Units are located at leading research institutions in 27 cities on four continents. The Network's headquarters are at the Fred Hutchinson Cancer Research Center in Seattle, Washington.
Certain statements in this document are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act. These statements are based on management's current expectations and are subject to uncertainty and changes in circumstances. Actual results may differ materially from those included in these statements due to a variety of factors, including whether: HVTN will commence, complete enrollment, and generate data regarding GeoVax vaccine clinical trials as and when expected, GeoVax can develop and manufacture its vaccines with the desired characteristics in a timely manner, GeoVax's vaccines will be safe for human use, GeoVax's vaccines will effectively prevent AIDS in humans, vaccines will receive regulatory approvals necessary to be licensed and marketed, GeoVax raises required capital to complete vaccine development, there is development of competitive products that may be more effective, less costly, or easier to use than GeoVax's products, GeoVax will be able to enter into favorable manufacturing and distribution agreements, and other factors, over which GeoVax has no control. GeoVax assumes no obligation to update these forward-looking statements, and does not intend to do so. More information about these factors is contained in GeoVax's filings with the Securities and Exchange Commission including those set forth at "Risk Factors" in GeoVax's Form 10-K.