Reyataz comparable to lopinavir in both genders

Bristol-Myers Squibb says that data from the CASTLE study shows that once-daily ritonavir-boosted Reyataz (atazanavir sulfate) and twice-daily lopinavir 400mg plus ritonavir 100mg, showed similar results for undetectable viral load at 48 weeks regardless of gender in treatment-naive HIV-1-infected adults. The US drug major reported results from the pre-specified sub-analysis at the 2008 International AIDS Conference, held in Mexico City.

CASTLE is the first large-scale, open-label, randomized study designed to demonstrate the non-inferiority of Reyataz/r to lopinavir/r in previously-untreated HIV-1 infected patients. Overall, 78% of the 440 subjects in the Reyataz/r arm and 76% of the 443 patients in the lopinavir/r arm met the non-inferiority primary endpoint of achieving undetectable viral load (defined as HIV-1 RNA less than 50 copies/mL) at 48 weeks.

The gender sub-analysis data showed that 76% of the 138 female patients in the Reyataz/r arm and 73% of the 139 women in the lopinavir/r cohort achieved undetectable viral load at 48 weeks. In male subjects, this was 79% of 302 patients and 78% of the 304 patients, respectively. In the female participants, the mean increase in CD4+ cell count from baseline was 199 cells/mm3 in the Reyataz/r arm and 221 cells/mm3 in the lopinavir/r arm. In male patients, the mean increase in CD4+ cell count from baseline at 48 weeks was 205 cells/mm3 in the Reyataz/r arm and 219 cells/mm3 in the lopinavir/r arm.