Abbott Laboratories has submitted a supplemental New Drug Application to the US FDA and a Marketing Authorization variation to the European Medicines Agency (EMA), seeking approval of once-daily dosing for its protease inhibitor (PI) Kaletra.

The submission package includes data from a clinical study in which once-daily Kaletra had comparable efficacy to twice-daily Kaletra, both dosed in a regimen containing tenofovir and emtricitabine, in treatment-naïve patients. The current adult recommended dosage of Kaletra is 400/100 mg twice daily with food (three pills, twice daily vs. six pills, once daily), a release from Abbott said.

"Patients taking a once-daily Kaletra-based regimen demonstrated a comparable virologic response to the twice-daily regimen," said Joseph Gathe, lead investigator and clinical instructor at Baylor College of Medicine, and chief of Infectious Diseases at Park Plaza Hospital in Houston, Texas. "If approved, a once-daily dose would simplify a Kaletra-based treatment regimen while maintaining potency for HIV patients requiring initial therapy for whom alternative dosing options are appropriate," Joseph added.

Among patients who participated in the study submitted, Kaletra was generally well tolerated. In the 48-week study comparing a Kaletra once-daily vs. twice-daily based antiretroviral regimen, the most frequent drug-related adverse events of moderate or greater intensity reported were diarrhoea and nausea. Diarrhoea was reported more frequently in patients on once-daily therapy (16 per cent) versus patients on twice-daily therapy (5 per cent).

"As a part of our commitment to the HIV community, Abbott continues to explore additional options in HIV therapy that offer dosing flexibility to patients," said John Leonard, vice president of Global Pharmaceutical Development, Abbott Laboratories. He continued, "We aim to enhance patient choice and convenience without sacrificing efficacy. Kaletra remains an important treatment option in HIV therapy."

Under accelerated review, the FDA approved Kaletra for marketing on Sept. 15, 2000. Kaletra received full FDA approval on November 27, 2002. Abbott also obtained marketing approval for Kaletra in Canada, Japan, the European Union, throughout Latin America and in additional countries around the world.

According to the updated guidelines released by a panel convened by the US Department of Health and Human Services (DHHS) in March 2004, "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.