FDA Approves Amprenavir for HIV Infection

Date: April 16, 1999
Source: Food and Drug Administration (FDA)

The Food and Drug Administration has granted accelerated approval to amprenavir, a new protease inhibitor. Amprenavir is approved for use in children age four and older and in adults in combination with other antiretrovirals for HIV infection. The following may be used to answer questions:

FDA based its approval for amprenavir on 24-week data from two ongoing well-controlled clinical studies involving more than 700 patients. Results from these trials showed a decrease in viral load (or the amount of virus circulating in plasma), and an increase in CD4 cell counts (the measure of immune cells created by the body) in patients taking amprenavir. These results were shown in previously untreated patients and in patients who had previously received reverse transcriptase inhibitors.

Amprenavir was studied in 118 pediatric patients over the age of four years and is available as capsules or liquid. The two formulations of amprenavir are not interchangeable on a milligram per milligram basis.

For many patients, amprenavir is taken twice a day. For some children, however, the dosing regimen is three times daily. This drug is not approved to be used alone. It must be used in combination with other antiretroviral agents.

Amprenavir has shown antiviral activity in clinical trials, but there are no results from studies to show long-term suppression of HIV viral load, or HIV disease progression with this drug.

The most frequently reported adverse events among patients in the clinical trial were nausea, diarrhea, vomiting, and rash. Severe and life-threatening skin reactions, including Stevens-Johnson syndrome, have occurred in patients treated with amprenavir. Acute hemolytic anemia, diabetes melitus and hyperglycemia may also be associated with amprenavir. Amprenavir can be taken with or without food, but it should not be taken with a high-fat meal because the fat content may decrease the absorption of the drug.

Currently, there are five protease inhibitors approved by FDA for the treatment of HIV infection. These medications work at the final stage 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.

Amprenavir is manufactured by Glaxo Wellcome, Inc. under the trade name Agenerase.