Cel-Sci, a Maryland and Virginia-based biotechnology company, says it hopes to launch large-scale human trials within two years on an AIDS vaccine it is developing as a result of promising early test results that were announced yesterday at the 11th Annual Conference on AIDS in Vancouver, British Columbia.
At the conference, Dr. James Kahn, a University of California professor of medicine who oversaw a study of the vaccine, told scientists that 78 percent of laboratory mice given white blood cells from people vaccinated with Cel-Sci's drug showed protective immune responses against the human immunodeficiency virus that causes AIDS.
Cel-Sci's vaccine is one of about 25 experimental AIDS vaccines being investigated, according to experts.
The company's vaccine is based on a synthetic copy of a protein found in the core of the virus. Many other AIDS vaccine candidates are based on the outer surface of HIV. Other approaches include chemically inactivated HIV and live altered HIV.
The market for a reliable AIDS vaccine, even one that could be used to slow the progression of the disease in those already infected, is potentially huge -- in the billions, say industry analysts.
Geert Kersten, president and chief executive officer of Cel-Sci, said the company believes that its vaccine holds greater promise than competitors' candidates because the studies show it may provide protection against many different strains of the virus, not just the strain it is based on.
If that property is seen in large-scale clinical trials, the vaccine could prove particularly marketable in developing countries, where new, mutating strains of the virus are being seen, said Kersten.
"We think what we found is a ray of hope," Kersten said. "We've opened a door no one else has been able to open."
Kersten said the company, which has its executive offices in Alexandria, Va., and its research headquarters in Baltimore, would focus first on developing a therapeutic vaccine to block progression of the disease in infected individuals. From there, the company hopes to gather enough scientific data to further develop its vaccine, called HGP-30, into a general vaccine that would protect the body from infection in the first place.
A therapeutic vaccine, said Kersten, could be highly marketable in developing countries like Thailand, where the disease is exploding, but where the average resident does not have the financial means to afford aggressive new therapies, which can cost $12,000 to $18,000 for one year.
Meanwhile, Kersten said the company is testing the safety of its HGP-30 vaccine in 22 HIV infected people in California.
Cel-Sci, he said, will likely seek a well-heeled partner to help pay for the expensive, large-scale human trials needed to prove the vaccine is effective.
Dr. James E. Talmadge, a professor of pathology and immunology at the University of Nebraska, who conducted studies on the mice injected with the California volunteers' white blood cells and then HIV, said the results were significant.
"It's the first time we've had a vaccine that appears to provide a degree of protection against a viral challenge," said Talmadge. "It's just the tip of the iceberg.
"There is a long way to go before anyone can say how effective HGP-30 will be. But this is a very encouraging observation."
Research on the Cel-Sci vaccine showed the vaccine triggered antibodies that are associated with controlling many different kinds of viral diseases. That's a sign the vaccine may be effective against several strains of HIV, the company said.
Other biotechnology companies at the conference have announced promising test results with their AIDS vaccine candidates, including Genenvax, a spin-off of Genentech Inc., and Pasteur Merieux of France, a unit of Rhone-Poulenc Rorer Inc.
Genenvax has said it hopes to launch large-scale human trials next year on a vaccine called gp120, based on a genetically engineered piece of the outer surface of HIV.
Pasteur Merieux is working on a vaccine based on the canarypox virus. The company hopes it will be ready for large-scale human tests in 1998.
Many experts believe the introduction of any AIDS vaccine to the market is at least five years away. The largest likely market for an AIDS vaccine would be in third-world countries.
That is where 90 percent of the world's 21.8 million people infected with HIV live.
Kahn's presentation at the AIDS conference occurred after the stock market closed yesterday. Cel-Sci's shares closed yesterday at $9.625, down 75 cents.
Pub Date: 7/12/96