B-MS' Reyataz/r non-inferior to lopinavir/r

US drug major Bristol-Myers Squibb says that results from the CASTLE study, in which 300mg of once-daily Reyataz (atazanavir sulfate) plus 100mg ritonavir (Reyataz/r), showed similar antiviral efficacy to twice-daily lopinavir 400mg boosted with ritonavir 100mg (lopinavir/r) in previously untreated adult HIV-1 infected patients at 48 weeks.

In this study, data from which were presented at the Conference on Retroviruses and Opportunistic Infections, held in Boston, USA, show that 78% of the 440 patients in the Reyataz/r arm met the primary endpoint of achieving undetectable viral load (defined as HIV-1 RNA less than 50 copies/mL) at 48 weeks, compared with 76% of the 443 patients in the lopinavir/r arm.

The CASTLE trial is the first large-scale, open-label, randomized study designed to demonstrate the non-inferiority of Reyataz to lopinavir/r in previously-untreated HIV-1 infected adult patients. The data could help expand its indication as, throughout the European Union, the agent is currently only indicated for treatment-experienced HIV patients, and not for use those who are treatment naive.