Wednesday, 23 February 2011

Phase 1 clinical trial testing of HIV/AIDS vaccine products

GeoVax Labs Inc announced today the publication of the results of Phase 1 clinical trial testing of its HIV/AIDS vaccine products. The article, titled “Phase 1 Safety and Immunogenicity Testing of DNA and Recombinant Modified Vaccinia Ankara Vaccines Expressing HIV-1 Virus-like Particles,” will appear in the March 1 issue of The Journal of Infectious Diseases. A PDF of the article is available at the following URL: .

GeoVax is developing two vaccine components: a recombinant DNA-vectored vaccine; and a recombinant MVA-vectored vaccine. Both produce non-infectious virus-like particles in the body of a vaccine recipient. These non-infectious particles are designed to 'train' the immune system of the vaccinated person to recognize HIV should the vaccinated person be exposed to the real virus. Both the DNA and MVA vaccines induce humoral (antibody) and cellular (T cell) responses. Antibodies have the potential to block virus before it infects cells. The T cells have the potential to recognize and kill cells that become infected by virus that gets past the antibody.

The publication reports the results of three different trial regimens: (1) priming with two doses of the pGA2/JS7 recombinant DNA vaccine and boosting with two doses of MVA/HIV62B recombinant MVA vaccine (DDMM regimen); (2) priming with one dose of the recombinant DNA and boosting with two doses of the recombinant MVA (DMM regimen); and (3) priming and boosting with a total of three doses of the recombinant MVA vaccine (MMM regimen). The Phase 1 trial, initiated in 2006 and completed in 2009, included 120 participants, was sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health, and was conducted by the NIAID-funded HIV Vaccine Trials Network (HVTN). Support for the development of both DNA and MVA vaccines was also received from NIAID.

The vaccines showed excellent safety characteristics in each of the three regimens. All of the regimens induced both antibody and T cell responses. Antibody-induced immune response rates were highest in the MMM group, whereas T cell response rates were highest in the DDMM group. The DMM group had intermediate response rates. “We are encouraged with the results seen in this trial, as the vaccine is safe and is able to induce a wide variety of immune responses directed against HIV,” notes Dr Paul A Goepfert, the study’s lead investigator.

On the basis of the excellent safety and immune response rates, HVTN has moved both the DDMM and MMM regimens forward into Phase 2a testing, which is currently ongoing in the trial designated HVTN 205. HVTN 205 has 300 participants in both North and South America and is designed to increase the base of information on safety and immunogenicity.

The HIV Vaccine Trials Network (HVTN) is the largest worldwide clinical trials network dedicated to the development and testing of 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.

GeoVax Labs Inc