The clinical trial (Study 934) compared a treatment regimen of Viread (tenofovir disoproxil fumarate), Emtriva (emtricitabine) and Sustiva (efavirenz) to a regimen of Combivir (lamivudine/zidovudine) with Sustiva in treatment-naive patients with HIV.
Data published in the New England Journal of Medicine show that a significantly greater percentage of patients taking a regimen containing Viread and Emtriva achieved and maintained HIV RNA less than 400 copies/mL, with fewer side effects that resulted in study discontinuation, and had a greater increase in CD4 cell counts compared to patients taking a Combivir-based regimen.
For the 48-week primary endpoint of the study, 84% of patients in the Viread/Emtriva arm compared to 73% of patients in the Combivir arm achieved and maintained HIV RNA less than 400 copies/mL through week 48 using the time to loss of virologic response algorithm (TLOVR).
Similarly, 80% of patients in the Viread/Emtriva arm compared to 70% of patients in the Combivir arm achieved and maintained HIV RNA less than 50 copies/mL through week 48 using the TLOVR algorithm.
The 48-week safety analysis, meanwhile, showed that a significantly greater percentage of patients in the Combivir group (9%) experienced adverse events that resulted in the discontinuation of study medications compared to the Viread/Emtriva arm (4%).
Viread and Emtriva are often prescribed together as a fixed-dose combination tablet called Truvada (emtricitabine and tenofovir disoproxil fumarate), which became commercially available after Study 934 began. Both Truvada and Combivir are widely used fixed-dose combination medicines from the nucleoside reverse transcriptase inhibitor (NRTI) class of antiretrovirals. NRTIs are commonly regarded as the ‘backbone’ of combination therapy for HIV.
“Data like these are important to help define ways for physicians to simplify effective HIV therapy for treatment-naive patients,” said Dr Joel Gallant, of the Johns Hopkins University School of Medicine, a lead investigator for the study and lead author of the paper. “Even with the remarkable advances made in the field of HIV medicine in the last 10 years, there is still a need for improved and simplified therapy.”