Today at the 17th International AIDS Conference in Mexico City, Martin Markowitz of New York City, and Mario Santoscoy of Mexico City presented data on the use of new antiretroviral agents as components in combination antiretroviral therapy (ART) for treatment-naïve patients. These studies raise the possibility of new, more tolerable agents as first options to treatment-naïve patients.
Martin Markowitz presented 96-week data on a Phase-II study evaluating the efficacy and safety of the integrase inhibitor raltegravir versus efavirenz in combination with tenofovir/lamivudine in ART-naive patients. This study was a multicenter, double-blind, randomized study that evaluated raltegravir at different doses (100, 200, 400, or 600mg bid) versus efavrirenz (600mg qd) both with tenofovir/lamivudine (TDF/3TC) for 48 weeks, after which participants received raltegravir (400mg bid) plus TDF/3TC.
Enrolled patients had baseline HIV-1 RNA greater than or equal to 5000 copies/mL and CD4+ T-cells greater than or equal to 100/uL. At week 96, both arms of the study demonstrated comparable results with 83% and 84%, respectively, attaining HIV-1 RNA less than 50 copies/mL in the raltegravir and efavirenz groups.
In addition, both groups showed similar immunologic responses to the agents. Fewer drug-related clinical adverse experiences (AEs) were reported in the raltegravir group than in the efavirenz group (51% versus 74%, respectively). Neuropsychiatric adverse events were more frequent among patients receiving efavirenz (32% versus 16%, respectively).
Mario Santoscoy presented data on the safety and efficacy of a new NNRTI, rilpivirine (TMC-278), in treatment-naïve patients. This Phase-IIb study evaluated three doses of rilpivirine (25, 75 and 150mg once daily) versus efavirenz (600mg daily), with NRTI backbone of either AZT/3TC or TDF/FTC.
The study demonstrated similar immunologic and virologic outcomes for all three doses of rilpivirine compared with efavirenz. Serious grade-3 or -4 AEs and laboratory abnormalities were similar in the groups; however, the rates of all rash (9.7% versus 22.5%, respectively) and psychiatric adverse experiences (16.1% versus 21.3%, respectively) were higher in those receiving efavirenz. A Phase-III study is currently underway.
08/06/08
New Antiretroviral Agents used in Treatment-Naïve Patients
Source: Reporting from Mexico City for PRN News: Anita Radix MD, MPH and Rona Vail MD