Tibotec's Prezista cleared for HIV in EU

Irish drugmaker Tibotec Pharmaceuticals' Prezista (darunavir) has been approved in the European Union for the treatment of HIV. The firm, which is a unit of US health care major Johnson & Johnson, explained that the proposed multidrug therapy of Prezista boosted with 100mg of ritonavir is intended for highly pre-treated HIV-1 patients who have failed one or more protease inhibitor-based therapeutic regimens.

The approval of the novel protease inhibitor was based on 24-week safety and efficacy data from POWER 1 and POWER 2, two ongoing, randomized, controlled trials involving 255 treatment-experienced adults. In a pooled analysis of these studies, 70% of the 131 patients in the Prezista arm had at least a 90% viral load decrease from baseline compared to 21% of 124 patients in the control group. 45% of those in the Prezista arm achieved an undetectable viral load (HIV RNA of less than 50 copies/mL) versus 12% of those in the investigator-selected PI arm.

PI boosting employs a co-administered dose of the antiretroviral PI ritonavir to pharmacologically enhance exposure. Ritonavir also inhibits the liver enzyme cytochrome P450, which is responsible for metabolizing drugs, and thus increases drug levels to improve efficacy, lower pill burden, add dosing flexibility and remove fasting restrictions.