Background: The single-tablet regimen B/F/TAF is a guideline-recommended treatment for HIV-1. We evaluated whether people receiving dolutegravir (DTG) plus F/TAF or F/TDF can safely and effectively switch to B/F/TAF.
Methods: In this phase 3, double-blinded study, virologically suppressed adults taking DTG plus either F/TAF or F/TDF were randomized (1:1) to switch to B/F/TAF or DTG+F/TAF, once daily with matching placebo. Documented or suspected prior resistance to NRTIs (i.e., M184V, K65R and thymidine analogue mutations [TAMs]), NNRTIs and/or PIs was permitted; INSTI-resistance was exclusionary. Primary endpoint was the proportion with HIV-1 RNA ≥50 c/mL at Week (W) 48 (FDA snapshot). Noninferiority was assessed through 95% confidence intervals (CI) using a margin of 4%. Secondary endpoints were the proportion with HIV-1 RNA < 50 c/mL and change from baseline in CD4 counts at W48. Safety was assessed by adverse events [AEs] and laboratory results.
Results: 565 participants were randomized/treated (B/F/TAF n=284, DTG+F/TAF n=281): 14% women, 23% Black, median age 51 years (range 20-79), 24% had resistance to NRTIs including 5% with K65R or ≥3TAMs, and 14% with M184V/I with or without other mutations. At W48, 0.4% on B/F/TAF and 1.1% on DTG+F/TAF had HIV-1 RNA ≥50 c/mL demonstrating noninferiority. There was no treatment emergent resistance. No participant with NRTI-resistance had HIV-1 RNA ≥50 c/mL at W48. Overall, 93% on B/F/TAF and 91% on DTG+F/TAF had HIV-1 RNA ≤50 c/mL. Change in CD4 was similar between groups (p=0.23). The most common AEs were nasopharyngitis, diarrhea, and upper respiratory tract infection. Six (2%) in each group discontinued study drug due to AEs.
Conclusions: At W48, switching to B/F/TAF was noninferior to DTG+F/TAF, with high rates of virologic suppression in both groups. The single-tablet regimen B/F/TAF is an effective option for people virologically suppressed on DTG+F/TDF or F/TAF, with or without NRTI resistance mutations including M184V, K65R and TAMs.