Abbott received US FDA approval to market a once-daily dosing regimen for Kaletra (lopinavir/ritonavir), a protease inhibitor used in combination with other anti-HIV medications, for the initial treatment of HIV.

Approval for the new regimen is based on data from a clinical study conducted in 190 patients new to HIV therapy which evaluated the effectiveness of the once-daily and twice-daily Kaletra doses, both administered in combination with once-daily tenofovir and emtricitabine, over a period of 48 weeks. Results demonstrated comparable virologic responses (HIV RNA less than 50 copies per millilitre) between the once- and twice-daily dosing groups. Kaletra once-daily was generally well tolerated.

"We are pleased to be able to provide patients with a once-daily, Kaletra-based regimen, as an alternative that provides comparable efficacy to the twice-daily dosing option in initial treatment of HIV," said Scott Brun, divisional vice president, Infectious Disease Development, Abbott.

According to the updated guidelines released by a panel convened by the US Department of Health and Human Services (DHHS) in April 2005, "Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents," Kaletra, in combination with zidovudine or stavudine plus lamivudine, are recommended as the preferred PI-based regimens for the treatment of patients new to HIV therapy, the release said.