ATLANTA, GA--(Marketwired - Jan 13, 2014) - GeoVax Labs, Inc. (OTCQB: GOVX) announced today preliminary top-line results from GV-TH-01, a Phase 1 clinical trial investigating the ability of the Company's GOVX-B11 vaccine to control HIV infections in patients who initiated antiretroviral drug treatment within 18 months of seroconversion. The Company expects to release additional results from this trial as final analyses are completed, and in conjunction with scientific presentations and publications.
GV-TH-01 is an open label Phase 1 treatment interruption trial investigating the safety and immunogenicity of the Company's novel DNA/MVA vaccine in 9 HIV-infected patients who had initiated drug treatment within 18 months of seroconversion and had stably controlled virus for at least 6 months. Patients were vaccinated with two DNA inoculations followed by two MVA inoculations at intervals of two months. Eight weeks following the last inoculation, patients suspended drug therapy for a 12 week period. Vaccinated patients' ability to control the time and temporal height of re-emergent virus in the absence of drugs was then observed. Drug treatment was re-instituted after 12 weeks, and trial participants were observed for an additional 6 months.
During the vaccination phase of the trial, enhanced CD8+ T cells were elicited in 8 of 9 patients and enhanced CD4+ T cell and antibody responses in 4 of 9 participants. Preliminary analyses in the first 7 patients who completed the treatment interruption phase of the trial demonstrated expanded antiviral T cell and antibody responses associated with re-emergent virus. There was a trend toward enhanced viral control in individuals with the best CD4+ and CD8+ T cell responses. Excellent safety was observed throughout the trial, with none of the participants needing to reinstate antiretroviral drugs during the treatment interruption phase of the trial. Final results will be presented when all patients have completed the study.
"We are very pleased with the safety of the vaccine and its ability to enhance immune responses in infected and drug-treated patients" said Harriet Robinson, Chief Scientific Officer of GeoVax. "The MVA component of our vaccine has always been noted for its outstanding ability to boost immune responses and this has held true in drug-treated and vaccinated patients. In particular we are pleased with the extent of the elicited anti-Gag CD8+ T cell response, which is associated with viral control in HIV-infected individuals."
GOVX-B11 consists of a recombinant DNA to prime the immune response and a recombinant poxvirus vector (modified vaccinia Ankara, or "MVA") to boost the primed response. Both the DNA and MVA express the three major proteins of HIV: Gag, Pol and Env, to elicit anti-HIV T cells and anti-HIV antibodies. Elicited CD8+ T cells have the potential to recognize and kill virus infected cells whereas elicited Ab can block spreading infections as well as identify infected cells for destruction by innate immune responses such as complement and natural killer cells. Elicited CD4+ T cells are "helper" cells that support the generation of CD8+ T cells and antibody-producing B cells. Infected patients who control infections in the absence of drugs typically exhibit robust anti-Gag CD8+ and CD4+ T cell responses.
"Twenty years ago, we did not anticipate the levels of viral control that could be achieved with multi-drug therapy," said Dr. Robinson. "The opportunity for our vaccine now lies in its ability to complement drug therapies, which can control virus spread but not recognize and kill infected cells, with a vaccine response capable of recognizing and eradicating infected cells. Our next step in the development of our therapeutic vaccine, will be to initiate a placebo-controlled trial."
About GeoVax's Technology
GeoVax's unique, two component vaccine, a recombinant DNA and a recombinant modified vaccinia Ankara (MVA), is designed to stimulate both anti-HIV antibody and anti-HIV T cell immune responses. GeoVax's DNA and MVA vaccines are used in a prime/boost protocol in which priming is done with the DNA and boosting with the MVA. GeoVax has two vaccines undergoing development: GOVX-B11 and GOVX-B21. Both are for the clade B virus that is prevalent in the developed world. In both, the DNA and MVA express the three major proteins of the AIDS virus: Gag, Pol, and Env, and produce non-infectious virus-like-particles. GOVX-B21 differs from GOVX-B11 in co-expressing the genetic adjuvant granulocyte-macrophage colony-stimulating factor (GM-CSF) with VLPs in the DNA prime. GeoVax's vaccines are currently being tested in human clinical trials, for both preventive and therapeutic applications. Clinical trials for GeoVax's preventive HIV vaccines have been conducted by the US National Institutes of Health-supported HIV Vaccine Trials Network (HVTN) with funding from the National Institute of Allergy and Infectious Disease (NIAID). GOVX-B11 has been tested in various doses and combinations in over 400 humans and is the company's lead product for a preventive vaccine. GOVX-B21 has been tested in 40 people in a phase 1 dose escalation and regimen trial.
HIV can infect anyone, regardless of race, gender, age or sexual orientation. 33 million people are currently infected globally and it is estimated that there will be over 2 million new infections this year. Since the beginning of the epidemic, over a million people in the U.S. have contracted the virus. Every 10 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 the Americas, Europe, and Australia. Globally, most infections involve Clades AG, B, and C. GeoVax most advanced vaccines under development are designed to function against Clade B.
For more information, please visit www.geovax.com.
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: 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 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.