PRINCETON, N.J.- Bristol-Myers Squibb Company today announced that the FDA has approved a labeling update for REYATAZ ® to include long-term data from the CASTLE Study. The CASTLE Study assessed a once-daily REYATAZ/ritonavir (REYATAZ/r)-based regimen versus a twice-daily lopinavir/ritonavir (LPV/r)-based regimen in previously untreated adult patients infected with HIV-1. Data from the study demonstrate enduring virologic response through 96 weeks of treatment with REYATAZ/r as part of combination therapy.
According to the most recent report from the Centers for Disease Control and Prevention, more than one million people are living with HIV and the annual incidence of new infections was 56,300 in the U.S. It is critical that effective and tolerable medicines are available to patients initiating antiretroviral therapy. Long-term data from the CASTLE Study demonstrate that treatment with REYATAZ/r can effectively suppress HIV viral load over 96 weeks in treatment-naïve patients.
In the CASTLE Study, a majority of patients on the REYATAZ/r regimen achieved undetectable viral load defined as HIV-1 RNA <50 copies/mL (REYATAZ/r 75% vs. LPV/r 68%) – confirming efficacy through 96 weeks. Low rates of drug resistance were observed at 96 weeks in patients who failed the REYATAZ/r regimen, with one patient developing genotypic/phenotypic resistance to REYATAZ and five patients developing genotypic/phenotypic resistance to emtricitabine. In a pre-specified analysis, efficacy in patients with high baseline viral load (?100,000 copies/mL) was demonstrated: 74% of 223 patients in the once-daily REYATAZ/r arm achieved undetectable viral load at 96 weeks vs. 67% of 222 patients in the twice-daily LPV/r arm.
In addition, the 96-week data confirmed the effect of REYATAZ on lipids. There were lower mean increases from baseline in total cholesterol, LDL cholesterol and triglycerides with REYATAZ/r compared to LPV/r; the REYATAZ/r arm was associated with the following mean increases from baseline: total cholesterol (13%), LDL cholesterol (14%), HDL cholesterol (21%), and triglycerides (13%). The LPV/r regimen was associated with the following mean increases in lipids: total cholesterol (25%), LDL cholesterol (17%), HDL cholesterol (29%), and triglycerides (50%).
Safety events at 96 weeks were consistent with the 48-week results in this study. Grade 2-4 treatment-related adverse events that occurred in 2% or greater of patients on the REYATAZ® (atazanavir sulfate)/r regimen, regardless of causality, included jaundice/scleral icterus (5% and 0%), nausea (4% and 8%), diarrhea (2% and 12%), and rash (3% and 2%) in the REYATAZ/r and LPV/r arms, respectively. Grade 3–4 increases in total bilirubin occured in 44% of patients in the REYATAZ/r arm and in less than 1% of patients on the LPV/r regimen.