The Food and Drug Administration has given nod to the first of a new class of HIV drugs, which hits the virus differently.

Isentress, made by Merck & Co., is specifically designed for patients who have developed resistance to existing cures.

The company said that the drug has been sanctioned for grownups who already have been undergoing treatment, but additional examination is essential before it is okayed for new HIV patients or kids.

Isentress belongs to a drugs class known as ‘integrase inhibitors,’ which work to stop the virus from entering its DNA into human DNA, thus stunting its capability to replicate and contaminate new cells.

Isentress is the initial drug in the new class to get FDA authorization.

Dr. Anthony Fauci, a noted HIV expert and director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, said, “The FDA’s approval will be most welcome in the community of physicians taking care of HIV-infected patients.”

“Its mechanism of action is particularly important in that it blocks the ability of the virus to integrate itself into the genes of cells. This property of the virus to integrate is important in establishing the reservoir of virus in the body that has made it extremely difficult to eradicate HIV, even with prolonged treatment,” Dr. Fauci said.

Two previous forms of anti-HIV drugs including protease and reverse transcriptase inhibitors also work by blocking up special enzymes that replicates HIV infection.

The recent decision by FDA will give physicians a fresh technique to assist patients who have who have shown resistance to existing cures or who are infected with HIV’s drug-resistant strains.

Similar to protease and reverse transcriptase inhibitors, Isentress will also be approved for patients together with other drugs in order to maximize the number of modes the HIV virus is being attacked.

Merck said that the cost for the recommended daily schedule of Isentress (400 mg tablet taken twice a day) will be $27,