German Team Works on Anti-SARS Drug
German scientists have identified two chemicals that could be used to create a drug against the SARS virus, according to a paper published online Tuesday by the journal Science. One of the drugs is in clinical trials for treating the common cold.
However, the development of a specific anti-SARS drug could take years, the authors cautioned.
The team of German researchers, led by Rolf Hilgenfeld of the University of Luebeck, had been studying a human coronavirus that causes mild cases of the cold and another virus that causes a fatal disease in pigs.
In the course of their research, they had determined the crystal structure of an important virus protein, known as a protease. The protein is essential for the virus to replicate itself and spread through the body.
The researchers designed a chemical that binds to the protease, thus preventing the virus from replicating.
When the genetic sequence of the SARS virus genome was released last month, the scientists immediately noticed that the SARS virus’ protease was very similar to that of the two they had been studying, Hilgenfeld said.
The team realized that the protease inhibitor they had already developed would be a good starting point for the development of a chemical inhibitor to block the SARS protease, the authors said.
Through chemical modeling studies, the scientists also concluded that a drug known as AG7088 that is in clinical trials for the treatment of some forms of the common cold, could also be modified to create a SARS protease inhibitor. The drug is being developed by Pfizer Inc.
In both cases, modification and testing of the drugs could take years, the authors said.
Hilgenfeld said he and his co-workers have made their information available in the hope that companies will start developing SARS drugs.
Other scientists are pursuing a variety of approaches to combat the SARS virus, which has infected more than 7,500 people and killed 573, primarily in China and Hong Kong.
The development of therapies has become all the more crucial after a report last week that the fatality rate for the infection is significantly higher than it had first appeared. The World Health Organization now estimates the overall death rate for severe acute respiratory syndrome at about 15%.
Scientists at the U.S. Army Medical Research Institute of Infectious Diseases at Ft. Detrick, Md., are testing large numbers of existing drugs against SARS.
Researchers are working on several strategies to create a vaccine. Some, for example, are experimenting with vaccines created from inactivated SARS virus particles. Another approach involves inserting key SARS proteins into the genome of harmless viruses so they can trigger an immune response against SARS.
“We have to do things in a way that we cover all our bases,” said Dr. Gary Nabel, director of the vaccine research center at the National Institute of Allergy and Infectious Diseases in Bethesda, Md. “This is not something we can just sit back and wait on.”
