Merck Wins FDA Approval for AIDS Drug


A new AIDS treatment made by Merck, the first in a new class of drugs aimed at preventing replication of the virus, has been approved by U.S. regulators, Merck said on Friday.

The U.S. Food and Drug Administration cleared Isentress, a pill given twice a day and known generically as raltegravir. An FDA advisory panel had recommended approval of the drug in September.

Shares of Merck rose 47 cents, or 0.89 percent, to $53.51 Friday.

It is the first in a new class of HIV treatments called integrase inhibitors that seek to block insertion of HIV genetic material into human DNA to prevent the creation of copies of the virus.

"It seems very safe, compared to other agents. It is very potent in terms of HIV viral suppression," Dr. Homayoon Khanlou, the AIDS Healthcare Foundation's Chief of Medicine who was involved in the clinical testing, said.

The drug was tested in patients who have become highly resistant to several marketed medicines for HIV, the virus that causes AIDS. Resistance is a major problem as the human immunodeficiency virus (HIV) that causes AIDS can mutate, especially in patients who fail to rigorously follow the often complicated drug regimes.

The drug-resistant patient population has the highest unmet medical need, according to Merck, which is also studying the drug in previously untreated patients.

Because of treatment advances, more people are living longer with HIV or AIDS. In the United States alone in 2006, more than 1 million people were living with HIV or AIDS. An estimated 40,000 new cases are expected this year, according to the U.S. Centers for Disease Control and Prevention.