FDA Approves a Once Daily Protease Inhibitor for HIV Infection

The Food and Drug Administration (FDA) today announced the approval of Reyataz (atazanavir sulfate), a protease inhibitor to be used in combination with other anti-retroviral agents for the treatment of patients with HIV infection. As with other anti-retroviral agents, Reyataz does not cure and does not prevent transmission of HIV infection or AIDS.

Approval of this drug will now allow patients access to a protease inhibitor that only needs to be taken once daily with food and has a low "pill burden" (two pills each day).

FDA based its approval of Reyataz on data from two Phase 2 48-week trials and from 24-48 week data from Phase 3 studies. Results from these trials showed a decrease in viral load (the amount of HIV-1 virus circulating in plasma) and an increase in CD4 cell counts (a measure of immune cells created by the body) in patients taking Reyataz in combination with other anti-retroviral agents. These treatment benefits were observed both in patients who had not been previously treated and in patients who had previously received other anti-retroviral therapy.

A significant safety concern commonly observed with the use of protease inhibitors is hyperlipidemia (high cholesterol). Reyataz appears to have minimal impact on lipid parameters such as tryiglycerides and cholesterol.

The most common laboratory abnormality observed with the use of Reyataz is hyperbilirubinemia. This laboratory abnormality resulted in the clinical adverse event of jaundice (yellowing of the skin) or scleral icterus (yellowing of the eyes) in 15-24% of subjects taking Reyataz. This abnormality was shown to be reversible upon discontinuation of the drug. Hyperbilirubinemia with Reyataz did not appear to be associated with an increased risk of liver injury.

The most frequently reported adverse events among patients in the clinical trials were nausea, infection, headache, vomiting, diarrhea, abdominal pain, somnolence (drowsiness), insomnia, and fever.

Currently there are six other protease inhibitors approved by FDA for the treatment of HIV infection. These medications work at the final stages of viral replication and attempt to prevent HIV from making new copies of itself by interfering with the HIV protease enzyme. As a result, the new copies of HIV are not able to infect new cells.

Reyataz is manufactured by Bristol-Myers Squibb Company of Princeton, NJ.