Examination of Noninferiority, Safety, and Tolerability of Lopinavir/ritonavir and Raltegravir Compared with Lopinavir/ritonavir and Tenofovir/Emtricitabine in Antiretroviral-Naive Subjects: The PROGRESS Study, 48-Week Results

Purpose: Current antiretroviral regimens recommended for treatment-naive patients include 2 nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs). The purpose of this study is to evaluate whether a new NRTI-sparing regimen may provide an alternative for persons for whom traditional regimens may not be the best option. Methods: PROGRESS is a 96-week, randomized, open-label, multicenter trial comparing the efficacy and safety of a boosted protease inhibitor (PI) and an integrase inhibitor (lopinavir/ritonavir [LPV/r] + raltegravir [RAL]) to a boosted PI and 2 NRTIs (LPV/r + tenofovir/emtricitabine [TDF/FTC]) in antiretroviral (ARV)-naive HIV-1 infected adults. Results: A total of 206 subjects were randomized to receive LPV/r + RAL (n=101) or LPV/r + TDF/FTC (n=105) and analyzed for ARV efficacy using the US Food and Drug Administration time to loss of virologic response (FDA-TLOVR) algorithm. The percentage of subjects with plasma HIV-1 RNA <40 copies/mL at week 48 was 83.2% in the LPV/r + RAL group and 84.8% in the LPV/r + TDF/FTC group (P = .850; difference -1.6%; exact 95% CI, -12.0% to 8.8%). As the lower limit of the exact 95% CI for the difference between regimens was at or above the protocol-defined threshold of -20% (as well as the more stringent threshold of -12%), LPV/r + RAL was noninferior to LPV/r + TDF/FTC. The occurrence of treatment-related, moderate/severe adverse events was similar between treatment groups through 48 weeks of treatment. Conclusions: The HIV treatment regimen of LPV/r + RAL resulted in noninferior efficacy and comparable safety and tolerability compared with a traditional NRTI-containing regimen through 48 weeks of treatment. These results support further evaluation of the LPV/r + RAL regimen.