FDA Approves First Integrase Inhibitor to Fight HIV
Last week, the US Food and Drug Administration (FDA) approved the new HIV drug raltegravir, which is being marketed under the name Isentress. Raltegravir is the first approved drug in a new class of HIV meds known as integrase inhibitors. Drugs in this class fight the virus in a different way from the other classes of HIV meds. When HIV makes copies of itself, it uses the chemical integrase to insert (integrate) its genetic material (DNA) into the cell’s control center, called the nucleus. Once HIV’s genetic material has been integrated into the cell’s own DNA, the cell can become a mini-factory for making new HIV. Integrase inhibitors disrupt this process by interfering with – inhibiting – the activity of integrase.
FDA’s recent action marks its second approval of a new HIV med in a new drug class during recent months. In August, FDA approved the drug maraviroc (marketed as Selzentry), which is in a drug class called CCR5 blockers. CCR5 blockers are designed to stop HIV from entering CD4 T-cells by preventing the virus from binding to a protein called CCR5 on the cell’s surface.
The availability of new drugs in new classes is an important advance in HIV treatment. Drugs in new classes are particularly valuable for people infected with a virus that is resistant to many of the existing HIV drugs – since they offer a fresh shot at controlling the virus. However, like other HIV meds, neither raltegravir nor maraviroc can completely control the virus on their own. To be fully effective, these drugs must be given with other HIV meds as part of a combination regimen.
