New AIDS drugs bests Kaletra

SYDNEY, July 25 (UPI) -- In a head-to-head clinical trial, Johnson & Johnson's Prezista (darunavir) outperformed Abbott's Kaletra (lopinavir) in controlling the AIDS virus.

The drugs, both boosted with doses of ritonavir, were used to treat patients who had previously been using other drugs to control infection with the human immunodeficiency virus, the virus that causes AIDS.

"This is the first time that any drug has been shown to be superior to lopinavir," Jose Valdez-Madruga, director of clinical trials for the Sao Paulo AIDS Program in Brazil, told United Press International Tuesday. "Patients with experienced HIV infection now have an option for treatment."

In a presentation at the 4th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Sydney, Valdez-Madruga demonstrated that after 48 weeks of treatment, 71 percent of HIV-infected participants who were taking darunavir had undetectable viral loads. In comparison, 60 percent of patients on lopinavir achieved the undetectable level on that assay.

That difference reached statistical significance. The trial aimed to show there were no differences in outcomes, but, in fact, Valdez-Madruga said he found superiority with darunavir, developed by J&J's Belgium-based Tibotec.

The patients were assigned to either drug and also took other background antiretrovirals optimized for each patient.

"We also found that darunavir appears to protect the other drugs classes better than lopinavir," Valdez-Madruga said. He explained that fewer resistance mutations in the nucleoside reverse transcriptase class and in the protease inhibitor class appeared while patients were being treated with darunavir.

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Ed Susman, UPI Correspondent