The Food and Drug Administration approved Prezista (darunavir), a new drug developed by Tibotec Pharmaceuticals Ltd. 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 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, thereby 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 with meals.

The accelerated approval is based on evidence from two randomized, controlled studies comparing the safety and efficacy of a Prezista-ritonavir combination with other ritonavir-boosted protease inhibitor combinations. Patients in both arms of these trials used other anti-HIV agents 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 lessening of their HIV viral load than patients on other ritonavir-boosted protease inhibitor combinations. 70% of treatment-experienced patients achieved a virologic response with Prezista/ritonavir in combination therapy compared to 21% in control group at week 24.

The most common side effects reported by patients on the Prezista-ritonavir regimen included nausea, diarrhea, and headache. About 70% of patients on this combination therapy experienced skin rashes ranging from mild to serious.

Prezista is manufactured for Tibotec Incorporation, Division of Ortho Biotech Products, LP, Raritan, NJ, by JOLL, Gurabo, Puerto Rico.