The FDA has granted accelerated approval to Kaletra (Abbott Laboratories, North Chicago, Ill), a coformulation of lopinavir and ritonavir, a previously approved protease inhibitor, in combination with other antiretroviral agents for treatment of HIV infection in adults and children older than 6 months. Lopinavir is an inhibitor of HIV protease, and ritonavir inhibits the metabolism of lopinavir, thereby increasing its level in plasma.
The approval is based on analyses of the proportion of patients with RNA viral load below detection level (<400 copies/mL) and increases in CD4 cell counts. The primary study, an ongoing, controlled trial of 24 weeks' duration, compared treatment with Kaletra plus stavudine and lamivudine vs nelfinavir plus stavudine and lamivudine in 653 patients without prior antiretroviral therapy. The proportion of patients with undetectable viral load at 24 weeks was greater for the Kaletra group than for the nelfinavir group, 79% vs 71%, respectively (P = .015). The mean increase from baseline in CD4 cell counts, comparable for both treatments, was approximately 150 cells/mm3.
Henney JE. New Drug for HIV Infection. JAMA. 2000;284(17):2178. doi:10.1001/jama.284.17.2178-JFD00009-2-1