TORONTO -- Canadian researchers have been given the green light for human testing of an experimental HIV vaccine, but the initial trial will determine only its safety, not whether it prevents infection.
The U.S. Food and Drug Administration granted approval for researchers at the University of Western Ontario to test the vaccine, which is based on a genetically modified killed whole virus.
The SAV001 vaccine, developed by Dr. Chil-Yong Kang's lab with financial support from Sumagen Canada, has been shown to stimulate a strong immune response in preliminary toxicology tests.
"FDA approval for human clinical trials is an extremely significant milestone for our vaccine, which has the potential to save the lives of millions of people around the world by preventing HIV infection," said Kang, whose lab has spent 10 years developing the vaccine.
To make the vaccine, the researchers start by altering the genetic makeup of the human immunodeficiency virus to make it non-pathogenic -- incapable of causing disease -- then further inactivate it with chemicals and radiation.
"We have to make sure the virus is completely safe," Kang said Tuesday from London, Ont.
In Phase I testing, set to begin in January, 40 HIV-positive volunteers will be injected with the vaccine to see if they suffer any dangerous side-effects.
If the SAV001 vaccine is found to be safe, it would require two more clinical trials that prove it works before it could be brought to market.
"So as long as it doesn't show adverse effects, then we can go on for Phase II human clinical trials, that is to look at the immune responses and see whether they make antibodies against the virus," said Kang, explaining testing would be performed in about 600 HIV-negative people whose lifestyles put them at high risk of becoming infected.
Phase III would test the effectiveness of the vaccine in a larger group of similarly at-risk individuals. Researchers hope to recruit about 6,000 high-risk volunteers. Half would be vaccinated and half left unvaccinated.
The SAV001 is not the first experimental HIV vaccine to show promise in pre-clinical testing. A few others have reached this stage and gone beyond, only to fall short in the final analysis.
-- The Canadian Press