Cobicistat (Gilead Sciences) success in Study 114 as "booster" in AIDS treatment

Study 114 of Cobicistat from Gilead Sciences reported a primary endpoint analysis that indicated that after 48 weeks of treatment, 85 percent of patients taking a regimen of cobicistat-boosted atazanavir (a protease inhibitor) plus Truvada(R) (emtricitabine and tenofovir disoproxil fumarate) achieved HIV RNA (viral load) of less than 50 copies/mL, compared to 87 percent of patients taking ritonavir-boosted atazanavir plus Truvada (95 percent CI for the difference: -7.4 percent to 3.0 percent). The predefined criterion for non-inferiority was a lower bound of a two-sided 95 percent CI of -12 percent. Discontinuation rates due to adverse events were 7.3 percent and 7.2 percent in the cobicistat and ritonavir arms of the study, respectively. Gilead plans to submit these data for presentation to a scientific conference in 2012. Cobicistat is Gilead's proprietary potent mechanism-based inhibitor of cytochrome P450 3A (CYP3A), an enzyme that metabolizes drugs in the body.