Thursday, October 11, 2012
HIV VACCINE MOVES TO CLINICAL TRIALS
By Crystal MacKay
Chil-Yong Kang’s, PhD, modest office is tucked away at the back of a busy research lab on the edge of Western’s campus. There, he sits poring over data, with research papers and articles scattered across his cluttered desk, and only looks up to smile.
At first glance, you would never imagine by his humble demeanor that this man holds the key to unlocking one of the world’s most devastating diseases and the work being done in his lab is on the brink of saving millions of lives around the globe.
Schulich Medicine & Dentistry researcher Kang and his team have been working for the past three decades to find a solution to stop the spread of Human Immunodeficiency Virus (HIV), and were recently given the green light to start phase one human clinical trials on a vaccine developed in their lab. Since its discovery in 1981, the virus, which is part of the retrovirus family and leads to the development of Acquired Immunodeficiency Syndrome (AIDS), has led to approximately 30 million deaths worldwide and currently has a rate of infection of 2.5 million people per year.
In Canada alone, where infection rates are considered low compared to other countries, more than 65,000 people are living with the disease.
“An HIV vaccine would be an extremely powerful addition to the arsenal of prevention tools to put an end to the pandemic, both within Canada and worldwide,” says Monique Doolittle-Romas, Executive Director of the Canadian AIDS Society.
The first reported cases of HIV/AIDS in Canada came to light in the early 1980s, and at that time Kang and his team were working on similar viruses also part of the retrovirus family. “When we first saw HIV, my team didn’t begin studying it right away,” he says. “We thought someone else would solve the problem very quickly because of the knowledge we already had of retrovirology. It turns out, it wasn’t so easy.”
More than half a decade later, when no scientist had made any progress, Kang and his team turned their efforts toward investigating how and why the virus replicates in the body. They eventually used the knowledge gained in their lab to start working on a vaccine.
On December 16, 2011, after nearly three decades of work, Kang and his team received official approval from the U.S. Food and Drug Administration (FDA) to begin clinical trials in humans.
“That day was incredible,” Kang says. “We knew the FDA had the most stringent conditions to pass any human vaccine for clinical trials, and if we could pass their stringent conditions, then we could get approval anywhere else in the world.”
What made FDA approval so daunting is also what makes Kang’s approach different from anything that has been done before. The vaccine uses a genetically modified version of the inactivated HIV gene. Without the modifications, the virus is too dangerous to grow in amounts large enough to create a vaccine; and even with the modifications the virus still has to be killed using both chemical and radiation methods to be sure the virus is completely inactive. If there is even a single live virus in any dose of human vaccine, it is one too many.
Before giving the green light, the FDA needed Kang’s team to demonstrate that there were no residual infectious virus particles in any of the vaccine. Once they demonstrated that, the approval to start human trials came quickly.
Phase one of the clinical trial began in March of this year with a group of 32 HIV positive subjects. The trial uses a double-blind placebo control to evaluate the safety of the vaccine. Phase two will use a larger group of HIV-negative subjects in the high-risk population to evaluate the body’s response to the vaccine and phase three will be done world-wide on a large scale and will be the true test to show if the vaccine is in fact effective in protecting people against HIV infection. Those results are still at least another five years away.
“Five years seems very long,” says Kang. “But when you compare it to the three decades since the discovery of the disease, I think it will go by very fast.”
And Kang is already preparing for positive results. He has partnered with Sumagen Canada, the Canadian branch of Korean pharmaceutical venture company, Sumagen Co. Ltd. which has been producing the vaccine for clinical trials and holds the patent on the vaccine for mass production and distribution. Kang has also been working with the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) to discuss how the vaccine will be distributed to the world-wide population.
Kang personally met with the leaders of the WHO/UNAIDS HIV Vaccine Initiative at their annual meeting in Geneva to discuss how these world-wide organizations can assist with making sure that the most high-risk populations have access to the vaccine.
Dr. Paul De Lay, Deputy Executive Director, Programme, for UNAIDS says, “Overcoming cost constraints and production bottlenecks will be critical factors in achieving population level impact on the HIV epidemic, especially in high prevalence, low and middle income countries around the world.”
And here lies the conundrum; the highest prevalence of HIV/AIDS is in Sub-Saharan Africa where more than 22.9 million people are living with the disease; that’s nearly 25 per cent of the population in countries like Botswana and Swaziland. However, these countries have significant economic challenges and are unable to afford a vaccine if and when it proves successful.
That’s why Kang and his partners at Sumagen have made a commitment to UNAIDS that these populations will have access to the vaccine free-of-charge. “Professor Kang’s and Sumagen’s commitment to persevering with their distinctive strategy, and if successful, to donating the resulting vaccine for people in developing countries, is inspiring and admirable,” says De Lay.
Kang looks to the next five years with hope and optimism, and his team is already beginning work on a therapeutic vaccine that could help to reverse the infection in those who have already contracted the virus.
“If we can do that,” says Kang leaning back in his chair, an awe-inspired smile spreading across his face, “then we can have a real impact on controlling HIV infections and we can save millions of lives. That would be tremendous.”