Trying to stay one step ahead of the virus that causes AIDS, doctors and researchers are looking for ways to disable or disrupt the virus in as many stages of its life cycle as possible, particularly aiming at reproductive stages not being attacked by other drugs.Gaithersburg-based Panacos Pharmaceuticals is testing a drug called Bevirimat, which blocks the last step in the HIV life cycle ? retarding its maturation after a new virus exits an infected cell.
“Resistance to currently approved drugs is probably the leading cause of treatment failure,” Panacos Chief Operating Officer and President Graham Allaway, said.
According to the Centers for Disease Control and Prevention, 40,000 new HIV cases are diagnosed each year. As many as 80 percent of those in treatment for the disease have drug-resistant strains, and they appear in up to 25 percent of new cases.
In an infected person with no medical treatment, the disease produces as many as 10 billion copies of the virus each day, said Dr. Charles Davis, associate director of the Clinical Research Unit at the Institute of Human Virology. Simple reproductive mistakes can lead to mutations that thwart the mechanisms of drugs used to treat HIV.
He said the development of new drugs helps doctors and patients stay ahead of the virus.
Existing medications target the process by which HIV enters a human cell, creates copies of its own DNA and actually rewrites the cell?s DNA, he said.
Bevirimat is the first drug to target the maturation stage after new copies of the virus leave the cell and before they develop the ability to infect a new cell, Allaway said.
Various studies already performed by Panacos have shown positive results. In tests on mice, scientists witnessed a reduction of virus replication by 90 percent. Also, scientists suspect the compound should not cause reactions with other drugs.
The drug is broken down differently by the liver than other AIDS drugs, Allaway said.
Bevirimat recently entered Phase 2 B clinical trials in June to evaluate safety and efficacy of the drug.
The current trial, working with fewer than 50 patients around the nation, is not accepting new participants, though future trials could incorporate hundreds of participants.
Researcher Justin Snow contributed to this report.
