The Food and Drug Administration today, June 23, 2006, granted accelerated approval for Prezista (darunavir -- formerly known as TMC-114), a new drug for treatment experienced adults whose infection with the human immunodeficiency virus (HIV) is not responding to treatment with other antiretroviral drugs. Prezista, a protease inhibitor, is indicated to be co-administered with a low-dose of ritonavir, in combination with other active anti-HIV agents. Ritonavir, which is also a protease inhibitor, slows the metabolism of Prezista, resulting in increased plasma concentrations. The recommended oral dose of Prezista tablets is 600 mg (two 300 mg tablets) twice daily taken with ritonavir 100 mg twice daily and with food. The type of food does not affect exposure to darunavir.
The accelerated approval is based on evidence from two randomized, controlled studies comparing the safety and effectiveness of a Prezista-ritonavir combination with other ritonavir-boosted protease inhibitor combinations. Patients in both arms of these trials also used other anti-HIV agents (nucleoside reverse transcriptase inhibitors) with or without enfuvirtide, a fusion inhibitor that inhibits the virus from entering the cell. In these studies, patients on a Prezista-ritonavir combination experienced higher rates of reduction of their HIV viral load than patients on other ritonavir-boosted protease inhibitor combinations. Seventy percent of treatment-experienced patients achieved a virologic response with PREZISTA/ritonavir in combination therapy compared to 21 percent in control group at week 24.
The most common side effects reported by patients on the Prezista-ritonavir regimen included diarrhea, nausea, and headache. About seven percent of patients on this combination therapy experienced skin rashes ranging from mild to serious.
The risks and benefits of Prezista have not been established for adults who have not been previously treated for HIV, or for children.
As a condition of the accelerated approval, the manufacturer is required to conduct post-marketing trials to verify and describe the clinical benefits of Prezista. In addition, the manufacturer has committed to conducting other postmarketing studies that include studies in pediatric populations, studies to better define certain drug-drug interactions, and to evaluate the drug in patients with varying degrees of liver impairment to identify appropriate dosing for this patient population.
Prezista is manufactured for Tibotec, Inc., Division of Ortho Biotech Products, L.P., Raritan, N.J., by JOLL, Gurabo, Puerto Rico.
To see a PDF version of the approved labeling, click here.