There is no known resistance to the individual components of the HIV medication bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF). The effectiveness of B/F/TAF has been demonstrated in several studies in patients with nucleoside reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs), primarily identified by proviral DNA testing; however, data on the effectiveness of B/F/TAF in patients with NRTI RAMs identified in viraemic plasma is scarce. Patients receiving B/F/TAF were located through an electronic health records search, and eligibility was verified through a manual assessment of each patient’s medical data. Patients were included if they were less than 18 years old, had at least 1 HIV viral load (VL) before commencing B/F/TAF, and had major RAMs impacting NRTIs as defined by the 2019 International Antiviral Society-USA (IAS-USA) identified in viraemic plasma. In all, 50 patients met the study criteria: mean age of 54 years, mean proximal CD4 count of 609 cells/μL, 64% male.  A total of 46 were virologically suppressed (< 200 copies/mL) when B/F/TAF was initiated,   had undetectable viral loads (VL) at the time B/F/TAF was started, 2 were medication-naive, 1 had discontinued prior ART, and 1 had a VL of 961 HIV-1 RNA copies/mL while on treatment. There were 29 with a single NRTI RAM (24 of which were M184V/I), 9 with 2 NRTI RAMs, 3 with 3, 4 with 4, 2 with 5, 1 with 6, 1 with 7, and 1 with 8 NRTI RAMs. At the last VL on B/F/TAF, a mean of 18.6 months after starting B/F/TAF, 49 out of 50 had VL less than 100 copies/mL, and 1 had a VL of 208 copies/mL at 11 months but only filled 5 months of B/F/TAF. Patients with known NRTI RAMs who did not have integrase resistance benefited greatly from B/F/ability TAF’s to keep HIV VL at undetectable levels.

Source: onlinelibrary.wiley.com/doi/10.1111/hiv.13376