Impact of preexisting nucleos(t)ide reverse transcriptase inhibitor resistance on the effectiveness of bictegravir/emtricitabine/tenofovir alafenamide in treatment experience patients

Introduction: Few clinical trials and cohort studies have evaluated the efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in people with HIV (PWH) with preexisting M184V/I or other nucleos(t)ide reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs). Real-world data are also scarce. Methods: Retrospective review of treatment-experienced patients who started B/F/TAF in a cohort of PWH. HIV-RNA less than 50 copies/ml was analyzed at 48 weeks in an intention-to-treat (ITT) analysis (missing=failure) and per protocol analysis (patients with missing data or changes for reasons other than virological failure were excluded). Results were compared in patients with and without previous NRTI-RAMs. Results: Five hundred and six PWH were included (16.2% women). Median age and time with HIV infection were 52.3 and 18.9 years, respectively. At baseline, viral load was less than 50 copies/ml in 440 patients (86.6%). Overall, 69 (13.6%) participants had documented preexisting NRTI-RAMs: 57 (11.2%) M184V/I and 30 (5.9%) tenofovir RAMs. In the ITT analysis, 83% (420/506) had HIV-RNA less than 50 copies/ml [82.2% (359/437) and 88.4% (61/69) in persons without and with NRTI-RAMs, respectively (P = 0.2)]. In the per protocol analysis 94.2% (420/445) had HIV-RNA less than 50 copies/ml [94.4% (359/380) vs. 93.8% (61/65); P = 0.2]. A total of 61 participants were excluded from the per protocol analysis (23 missing data, 19 discontinued B/F/TAF because of toxicity, 13 for other reasons, and 6 died). Conclusion: Switching to B/F/TAF is well tolerated and effective in the real-world setting, even in patients with preexisting NRTI RAMs, such as M184V and RAMs conferring resistance to tenofovir. These results confirm the robustness of this combination.

Automated summary

This study retrospectively evaluated the efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in HIV patients with preexisting NRTI resistance-associated mutations. The results demonstrated that switching to B/F/TAF is well tolerated and effective, even in patients with previous NRTI RAMs such as M184V and tenofovir resistance.