Tibotec Therapeutics, a division of Centocor Ortho Biotech Products, LP, announced that the US Food and Drug Administration (FDA) has approved a revision to the dosing recommendation to include once-daily dosing of Prezista (darunavir) tablets in combination with ritonavir for the treatment of Human Immunodeficiency Virus (HIV-1) in treatment-experienced adult patients with no Darunavir Resistance-Associated Mutations (DRV RAMs).

The revised dosing recommendation extends the same dosing already approved for treatment-naive patients – Prezista, co-administered with ritonavir (in combination with other antiretroviral agents and with food, once-daily (800/100 mg) – to treatment-experienced patients with no DRV RAMs. The previously approved dosing recommendation for Prezista/ritonavir in treatment-experienced patients (patients who have taken HIV medications in the past) was Prezista/ritonavir 600/100 mg twice daily.

For antiretroviral treatment-experienced patients, genotypic testing is recommended. However, when genotypic testing is not feasible, Prezista/ritonavir 600/100 mg twice daily dosing is recommended.

The approval of this revision is based on 48-week data from the ODIN (Once-daily Darunavir In treatment-experieNced patients) study. ODIN evaluated the efficacy and safety of Prezista/ritonavir once daily vs. Prezista/ritonavir twice daily for the treatment of HIV-1 in treatment-experienced adult patients with no DRV RAMs (i.e., V11I, V32I, L33F, I47V, I50V, I54M, I54L, T74P, L76V, I84V, or L89V).

“With this once-daily dosing recommendation, boosted Prezista is now a viable option for more treatment-experienced patients,” said Glenn Mattes, president, Tibotec Therapeutics. “This approval reflects Tibotec's ongoing commitment to optimizing dosing strategies for HIV patients.”

Data from the Phase 3b ODIN study were presented earlier this year at CROI 2010, the 17th Conference on Retroviruses and Opportunistic Infections, in San Francisco. The study achieved its primary objective of demonstrating non-inferiority of Prezista/ritonavir once daily compared with twice daily.

Prezista, co-administered with ritonavir and with other antiretroviral agents, is indicated for the treatment of HIV-1 infection.

This indication is based on analyses of plasma HIV-1 RNA levels and CD4+ cell counts from two controlled, phase III trials of 48 weeks duration in antiretroviral treatment-naïve and treatment-experienced patients, and two controlled, phase II trials of 96 weeks duration in clinically advanced, treatment-experienced adult patients.

In treatment-experienced adult patients, the following points should be considered when initiating therapy with Prezista/ritonavir: Treatment history and, when available, genotypic or phenotypic test