GeoVax Labs has received the latest $3.6 million tranche of a (to date) $19.6 million Integrated Preclinical/Clinical AIDS Vaccine Development (IPCAVD) grant awarded by the National Institute of Allergy and Infectious Diseases, to support the firm’s HIV/AIDS vaccine program. The latest annual award is GeoVax’ fifth (the grant was first approved in 2007), and will be used for production of a GM-CSF adjuvanted vaccine for human clinical trials that are projected to start in the next six months.
GeoVax’ HIV vaccines are designed to express virus-like particles that display the trimeric membrane-bound form of the HIV-1 envelope glycoprotein. Phase I clinical trials have been completed with various combinations and doses of nonadjuvanted DNA and modified vaccinia Ankara (MVA) vaccines, including their ability to raise anti-HIV humoral and cellular immune responses, as well as safety. A Phase II preventive study was initiated in January 2009 and will involve 300 participants at sites in the U.S. and South America. GeoVax recently began enrolling patients in a Phase I therapeutic trial for individuals already infected with HIV. The clinical program is being carried out in collaboration with the NIAID and the HIV Vaccine Trials Network (HVTN).
In April the firm announced expanding its preventive HIV/AIDS vaccine program to test an additional vaccine product that expresses human GM-CSF in combination with noninfectious HIV virus-like particles. The vaccination protocol using this GM-CSF candidate will involve a priming vaccination using the DNA vaccine, followed by a booster vaccination comprising a recombinant MVA vectored vaccine. The MVA expresses the HIV virus-like-particles but doesn’t express GM-CSF, GeoVax explains. The regimen builds on the GeoVax DNA/MVA vaccine that is currently in Phase IIa clinical testing through the HVTN.
“This award will allow us to maintain momentum on the successful development of our GM-CSF adjuvanted vaccine,” comments Harriet Robinson, Ph.D., CSO at GeoVax and program director for the NIAID award. “The exciting thing about using the GM-CSF adjuvant is that it significantly increases prevention of infection. Without the adjuvant, our vaccine has been demonstrated to successfully control infection, but prevention of infection is the ultimate goal.”
In December 2010 GeoVax reported early data from the ongoing Phase IIa study, which is evaluating two recombinant DNA-vectored vaccine inoculations: the first administered at week 0 and the second at week eight, followed by two recombinant MVA-vectored vaccine inoculations at weeks 16 and 24. Data from 180 patients highlighted no safety concerns, and data on vaccine-induced T cell responses from 128 patients showed similar to those observed in the Phase I trial. At the time these early results were reported, GeoVax said additional testing was ongoing to measure antibody responses and to further characterize cellular immune responses.