“Although the GeoVax vaccines are currently being studied for HIV prevention, this is the first study using the same products for treatment of persons who already have HIV infection. ARCA is the only site for this trial.”
The GeoVax vaccine boosts the body’s immune system by increasing T-Cell counts and anti-HIV antibody response. Dr. Harriet Robinson began her research in the 1990s and has been moving the vaccine through the clinical trial process.
Data from Robinson’s primate trials show that the vaccine was effective in preventing simian HIV from spreading, and controlling HIV in positive primates. The animal studies were conducted at the Yerkes National Primate Research Center, an affiliate of Atlanta’s Emory University. The preventative portion of the vaccine is currently in a Phase II human trial.
“We were very impressed with the animal data that GeoVax has for this vaccine… Monkeys aren’t people, but it’s very impressive data and we wanted to work with them to design a study to see if this would be applicable to humans,” ARCA principal investigator Dr. Melanie Thompson said.
Thompson helped found ARCA 21 years ago to perform HIV clinical trials and has helped to investigate 27 HIV drugs now licensed by the federal Food & Drug Administration. For the GeoVax trial, the non-profit organization needs a very narrow group of people.
“They are people with very special characteristics, and so we know it is not going to be easy to find these people,” Thompson said. “Based on study in monkeys it appears that people who are earlier in their infection are most likely to benefit from the vaccine, so what we are looking for is people who know roughly when they were infected, and have that documented with a negative test and then followed that up with a positive test.”
Specifically, ARCA is looking for volunteers who tested negative for HIV six months or less before a positive HIV test. Volunteers must have gone on medication within six months of the initial test and that medication must have successfully suppressed their viral loads. Because of the amount of testing required volunteers must live in the Atlanta metro area or be willing to relocate to the city.
GeoVax CEO Dr. Bob McNally is confident that the vaccine will reproduce its effects in humans the way it did in the primate tests.
“One of the objectives of a trial like this is to ultimately wean people off their meds and let their immune system fight the virus on their own,” he said. “It’s the meds that have the huge cost and over time some of them stop working, and so it’s really not a long-term solution.”
The study consists of four vaccinations given about eight weeks apart. After the vaccination stage there would be an interruption of medication so that researchers can monitor if the vaccine suppresses the viral load and a T-Cell count to gauge how the immune system handles the HIV virus.
After this information is gathered, volunteers will go back on their medications.“We have gone through of effort to make sure that people are very well observed during the interruption phase,” Thompson said. “We have built-in safeguards to make sure that if they get into a situation where they could be in trouble they will be returned to their medication, but based on the data we saw in primates we don’t expect that to happen.”
Top photo: ARCA principal investigator Dr. Melanie Thompson is seeking a narrow group of HIV-positive people for a new HIV vaccine trial. (by Dyana Bagby)