Co-formulated bictegravir, emtricitabine, and tenofovir alafenamide versus dolutegravir with emtricitabine and tenofovir alafenamide for initial treatment of HIV-1 infection: week 96 results from a randomised, double-blind, multicentre, phase 3, non-inferiority trial.

BACKGROUND

The single-tablet regimen consisting of bictegravir, emtricitabine, and tenofovir alafenamide is recommended for treatment of HIV-1 infection on the basis of data from 48 weeks of treatment. Here, we examine the longer-term efficacy, safety, and tolerability of bictegravir, emtricitabine, and tenofovir alafenamide compared with dolutegravir plus co-formulated emtricitabine and tenofovir alafenamide at week 96.

METHODS

This ongoing, randomised, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial was done at 126 outpatient centres in ten countries. We enrolled treatment-naive adults (aged ≥18 years) with HIV-1 infection who had an estimated glomerular filtration rate of at least 30 mL/min and sensitivity to emtricitabine and tenofovir. People with chronic hepatitis B or C infection, or both, and those who had used antivirals previously for prophylaxis were allowed. We randomly assigned participants (1:1) to receive treatment with either co-formulated bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg (the bictegravir group) or dolutegravir 50 mg with co-formulated emtricitabine 200 mg and tenofovir alafenamide 25 mg (the dolutegravir group), each with matching placebo, once daily for 144 weeks. Treatment allocation was masked to all participants and investigators. All participants who received at least one dose of study drug were included in primary efficacy and safety analyses. We previously reported the primary endpoint. Here, we report the week 96 secondary outcome of proportion of participants with plasma HIV-1 RNA less than 50 copies per mL at week 96 by US Food and Drug Administration snapshot algorithm, with a prespecified non-inferiority margin of -12%. This study was registered with ClinicalTrials.gov, number NCT02607956.

FINDINGS

Between Nov 13, 2015, and July 14, 2016, we screened 742 individuals, of whom 657 were enrolled. 327 participants were assigned to the bictegravir group and 330 to the dolutegravir group. Of these, 320 in the bictegravir group and 325 in the dolutegravir group received at least one dose of study drug. At week 96, HIV-1 RNA less than 50 copies per mL was achieved by 269 (84%) of 320 participants in the bictegravir group and 281 (86%) of 325 in the dolutegravir group (difference -2·3%, 95% CI -7·9 to 3·2), demonstrating non-inferiority of the bictegravir regimen compared with the dolutegravir regimen. Both treatments continued to be well tolerated through 96 weeks; 283 (88%) of 320 participants in the bictegravir group and 288 (89%) of 325 in the dolutegravir group had any adverse event and 55 (17%), and 33 (10%) had any serious adverse event. The most common adverse events were diarrhoea (57 [18%] of 320 in the bictegravir group vs 51 [16%] of 325 in the dolutegravir group) and headache (51 [16%] of 320 vs 48 [15%] of 325). Deaths were reported for three (1%) individuals in each group (one cardiac arrest, one gastric adenocarcinoma, and one hypertensive heart disease and congestive cardiac failure in the bictegravir group and one unknown causes, one pulmonary embolism, and one lymphoma in the dolutegravir group); none were considered to be treatment related. Adverse events led to discontinuation in six (2%) participants in the bictegravir group and five (2%) in the dolutegravir group; one of these events in the bictegravir group versus four in the dolutegravir group occurred between weeks 48 and 96. Study drug-related adverse events were reported for 64 (20%) participants in the bictegravir group and 92 (28%) in the dolutegravir group.

INTERPRETATION

These week 96 data support bictegravir, emtricitabine, and tenofovir alafenamide as a safe, well tolerated, and durable treatment for people living with chronic HIV.

FUNDING

Gilead Sciences, Inc.