Merck says FDA approves new AIDS treatment

By Kim Dixon

WASHINGTON (Reuters) - A new AIDS treatment made by Merck & Co, 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 drug will be available in about two weeks, Merck said.

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

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," said Dr. Homayoon Khanlou, the AIDS Healthcare Foundation's Chief of Medicine, who was involved in the clinical testing.

Cowen & Co analysts have forecast that the drug could reap up to a $1 billion in sales by 2012. The drug could compete with a similar therapy being tested by Gilead Sciences.

Isentress was approved based on testing for 24 weeks in combination with a current therapy in about 700 patients who have become highly resistant to several marketed medicines for HIV, the virus that causes AIDS. The disease is often treated with a mixture of several medicines.

The company promised to study the drug for at least five years to monitor any side effects that might not have shown up in its initial clinical trials.