Abstract

Background: Raltegravir 1200mg (2x600mg tablets) once daily (QD) demonstrated noninferior efficacy and similar safety to raltegravir 400mg twice daily (BID) at week 48 of the ONCEMRK trial. Here, we report the week 96 results from this study. Methods: ONCEMRK is a phase 3, multicenter, double-blind, noninferiority trial comparing raltegravir 1200mg QD with raltegravir 400mg BID in treatment-naive HIV-1-infected adults. Participants were assigned (2:1) to raltegravir 2x600mg QD or 400mg BID, both with emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) for 96 weeks. Randomization was stratified by screening HIV-1 RNA and hepatitis B/C status. Efficacy was assessed as the proportion of participants with HIV-1 RNA 40 copies per milliliter (Food and Drug Administration Snapshot approach); the noninferiority margin was 10 percentage points. Results: Of the 797 participants who received study therapy (84.6% were men, 59.3% were white, and mean age was 35.9 years), 694 completed 96 weeks of treatment (87.6% QD; 84.4% BID), with few discontinuations because of lack of efficacy (1.1% for both groups) or adverse events (1.3% QD; 2.3% BID). At week 96, 81.5% (433/ 531) of QD recipients and 80.1% (213/266) of BID recipients achieved HIV-1 RNA 40 copies per milliliter (difference 1.4%, 95% confidence interval: -4.4 to 7.3). CD4 + T-cell counts increased >260 cells/mm(3) from baseline in both groups. Resistance to raltegravir was infrequent, occurring in 0.8% of each treatment group through week 96. Adverse event rates were similar for the 2 regimens. Conclusions: In HIV-1-infected treatment-naive adults receiving FTC/TDF, raltegravir 1200mg QD demonstrated noninferior efficacy to raltegravir 400mg BID that was durable to week 96, with a safety profile similar to raltegravir 400mg BID.