Bictegravir/emtricitabine/tenofovir alafenamide in viremic people with HIV harbouring nucleos(t)ide reverse transcriptase inhibitor resistance‐associated mutations

INTRODUCTION: Accumulating evidence supports switching virologically suppressed people with HIV (PWH) harbouring nucleoside reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs) to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF). However, real-world data on initiating B/F/TAF in individuals with NRTI RAMs and ongoing viremia remain limited. METHODS: We retrospectively included adult PWH treated at the Second Hospital of Nanjing between June 2020 and November 2024 who had at least one NRTI RAM and an HIV-1 RNA ≥200 copies/mL at B/F/TAF initiation. The primary outcome was virological suppression at 12 months (HIV-1 RNA <50 copies/mL). Laboratory adverse events were assessed. RESULTS: A total of 45 participants were included (97.8% male). At baseline, the median HIV-1 RNA was 36 800 copies/mL (interquartile range [IQR]: 5130-243 000), and the median CD4 cell count was 53 cells/μL (IQR: 18-307). AIDS-defining illnesses were documented in 13 participants (28.9%). M184V/I was present in 71.1% and K65R/N in 8.9%. At 12 months, 41/45 (91.1%) participants achieved HIV-1 RNA <50 copies/mL, and 44/45 (97.8%) achieved <200 copies/mL, with high suppression rates across resistance subgroups, including those with K65R/N or thymidine analogue mutations. All participants without suppression at 12 months achieved virological suppression with extended follow-up. Grade 3-4 laboratory adverse events occurred in 10/45 (22.2%) participants, most commonly severe bone marrow suppression. These events were frequently attributable to comorbidities and concomitant medications, with no discontinuations of B/F/TAF. CONCLUSIONS: B/F/TAF demonstrated high virological suppression and acceptable laboratory safety in viremic PWH with pre-existing NRTI RAMs, supporting its use in this challenging clinical setting.