HIV-1 Resistance Analysis of Participants With HIV-1 and Hepatitis B Initiating Therapy With Bictegravir/Emtricitabine/Tenofovir Alafenamide or Dolutegravir Plus Emtricitabine/Tenofovir Disoproxil Fumarate: A Subanalysis of ALLIANCE Data

Background: In the Phase 3 ALLIANCE study, both bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) and dolutegravir plus emtricitabine/tenofovir disoproxil fumarate (DTG + F/TDF) achieved high rates of HIV-1 RNA suppression through Week 96 in adults with HIV-1 and hepatitis B virus (HBV) initiating treatment (NCT03547908). Here, we quantify preexisting HIV-1 resistance, evaluate its effect on HIV-1 virologic suppression, and describe postbaseline HIV-1 resistance through Week 96. Methods: Preexisting HIV-1 resistance was assessed by historical and/or screening genotyping. HIV-1 RNA suppression to <50 copies (c)/mL at Week 96 was assessed by preexisting resistance category. Postbaseline resistance was assessed in participants with HIV-1 RNA ≥200 c/mL through Week 96. Results: Primary nucleoside/nucleotide reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor, and protease inhibitor resistance substitutions were present at baseline in 4 (1.7%), 19 (7.9%), and 5 (2.1%) of 241 participants, respectively. Virologic suppression rates were high, irrespective of preexisting primary resistance substitutions, including M184I. Six participants (3 per group) had confirmed HIV-1 RNA ≥200 c/mL and did not resuppress to <50 c/mL while on study drugs; none of the 5 with postbaseline resistance data had treatment-emergent primary resistance substitutions. One participant on DTG + F/TDF with multiple virologic failures and documented nonadherence by pill count had treatment-emergent K70E and M184V/I, and subsequently resuppressed. Conclusion: In people with HIV-1 and HBV treated with first-line B/F/TAF or DTG + F/TDF, preexisting HIV-1 resistance was uncommon and did not affect virologic suppression. No treatment-emergent HIV-1 resistance occurred with B/F/TAF, further supporting the high barrier to resistance of this regimen.