Brief Report: HIV-1 Resistance Analysis of Participants With HIV-1 and Hepatitis B Receiving Bictegravir/Emtricitabine/Tenofovir Alafenamide or Dolutegravir Plus Emtricitabine/Tenofovir Disoproxil Fumarate Through the Open-Label Extension of the ALLIANCE Study.

BACKGROUND

ALLIANCE is a phase 3 randomized study of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) versus dolutegravir + emtricitabine/tenofovir disoproxil fumarate (DTG+F/TDF) in treatment-naïve people with HIV-1/hepatitis B virus (HBV) coinfection.

METHODS

After the 96-week randomized phase of ALLIANCE, participants could enter a 48-week open-label B/F/TAF-only phase. This subanalysis reports HIV-1 resistance results to the end of masked treatment (DTG+F/TDF, n = 122) and to study end (B/F/TAF, n = 119; DTG+F/TDF to B/F/TAF, n = 89). Baseline resistance was determined using historical and screening genotypes of protease (PR), reverse transcriptase (RT), and integrase (IN), if available. Participants with virologic failure had postbaseline resistance testing of PR/RT/IN; those subsequently not achieving virologic suppression (VS; HIV-1 RNA <50 copies/mL) were included in final resistance analysis population (RAP).

RESULTS

Baseline resistance mutations were uncommon and did not affect VS rates. Criteria for final RAP inclusion were met by 7, 6, and 1 participant in the DTG+F/TDF, B/F/TAF, and DTG+F/TDF to B/F/TAF groups, respectively. For participants with genotyping data, no treatment-emergent primary resistance mutations to study drugs developed. From 8 participants who had resistance testing but did not qualify for inclusion in final RAP, 1 participant on DTG+F/TDF with documented nonadherence had emergent resistance mutations to tenofovir and emtricitabine and subsequently achieved VS.

CONCLUSIONS

In people with HIV-1 and HBV receiving B/F/TAF for ≥144 weeks continuously, or for 48 weeks postswitch, VS rates were unaffected by the presence of pre-existing HIV-1 resistance. No participants in final RAP developed resistance to study drugs, demonstrating the high barrier to resistance of this regimen.

TRIAL REGISTRATION: NCT03547908.