The U.S. Food and Drug Administration (FDA) has approved raltegravir tablets for treatment of Human Immunodeficiency Virus (HIV)-1 infection in combination with other antiretroviral agents in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents.
Raltegravir is the first agent of the pharmacological class known as HIV integrase strand transfer inhibitors, designed to interfere with the enzyme that HIV-1 needs to multiply. Raltegravir, sold under the trade name Isentress, received a priority review by the FDA.
“This is an important new product for many HIV-infected patients whose infections are not being controlled by currently available medications,” said Janet Woodcock, M.D., FDA’s deputy commissioner for scientific and medical programs, chief medical officer and acting director, Center for Drug Evaluation and Research.
When used with other anti-HIV medicines, raltegravir may reduce the amount of HIV in the blood and may increase white blood cells, called CD4+ (T) cells, that help fight off other infections.
FDA’s approval of raltegravir is based on data from two double-blind, placebo-controlled studies in 699 HIV-1 infected adult patients with histories of extensive antiretroviral use. A greater proportion of the patients who received raltegravir in combination with other anti-HIV drugs experienced reductions in the amount of HIV in the blood, compared with patients who received placebo in combination with other anti-HIV drugs.
The most common adverse events reported with raltegravir were diarrhea, nausea, and headache. Blood tests also showed abnormal elevated levels of a muscle enzyme in some patients receiving raltegravir. Caution is advised when using raltegravir in patients at increased risk for certain types of muscle problems, including those who use other medications that can cause muscle problems.
Patients taking raltegravir may still develop infections, including opportunistic infections or other conditions that may develop in patients living with HIV-1 infection. The long-term effects of raltegravir are not known, and its safety and effectiveness in children less than 16 years of age has not been studied.
Raltegravir also has not been studied in pregnant women. Women who are taking HIV medications when they get pregnant are advised to talk with their physician or other health care professional about use of this drug during pregnancy, and about registering with the Antiviral Pregnancy Registry if they use raltegravir.
Raltegravir is distributed by New Jersey-based Merck & Co., Inc.