FDA panel recommends new HIV drug Maraviroc

Apr 24 2007

Approval is expected to be granted in the United States for a new drug to treat HIV infections.

The drug Maraviroc which is produced by Pfizer targets the cells of HIV-infected patients and not the virus itself, and has been recommended by health advisers to the Food and Drug Administration (FDA).

Twelve advisers to the FDA unanimously voted their approval for Maraviroc, which Pfizer will to sell under the brand name Celsentri.

Celsentri represents the first so-called CCR5 receptor antagonist to be put on the market.

The drug which is produced as a pill to be taken twice a day is the first designed to keep the HIV virus from entering healthy immune cells; older AIDS medicines attack the virus itself.

The drug stops the virus entering and damaging the white blood cells, which are important in the immune system.

The FDA advisers have recommended that Pfizer does further studies into how Celsentri's interacts with other drugs as well as exploring its effects on women and minorities.

As a rule the FDA follows the advice of it's advisory panels.

The FDA and Pfizer cite studies which show that the addition of Celsentri to a traditional HIV treatment regimen is more effective in dropping the virus below detectable levels.

There are some concerns about this class of drugs such as there is the possibility of greater risk of infection, lymphoma or liver damage in HIV patients.

The drugs also have been linked to heart rhythm changes in animals.

The FDA panel say they saw no increase in lymphomas or infections among patients given Celsentri, but say there was a modest increase in liver problems.

Pfizer says the drug has been found to have no significant impact on the heart, and no there were no increased incidence of liver problems, cancer or infection compared with treatment involving other HIV drugs.

The biggest worry is that the drugs could accelerate a shift from one variant of HIV to another, a problem most often seen in the sickest AIDS patients.

This means patients on Celsentri would need to be monitored to determine whether the drug is causing such a shift.

An estimated 25,000 to 40,000 U.S. AIDS patients resist treatment with current drugs meant to keep the virus at bay; the new drug may benefit some patients who are running out of alternatives.