by Carolyn Chu, MD, MSc, AAHIVS, AAHIVM Chief Medical Officer
December 3, 2024
Featured Literature:
Andreatta K, Sax PE, Wohl D, et al. Efficacy of bictegravir/emtricitabine/tenofovir alafenamide versus dolutegravir-based three-drug regimens in people with HIV with varying adherence to antiretroviral therapy. J Antimicrob Chemother. 2024 Nov 18:dkae407. doi: 10.1093/jac/dkae407.
Pooled adherence and virologic outcome data from five Phase 3 randomized studies comparing BIC/F/TAF to dolutegravir plus 2 NRTIs were used to determine how varying adherence levels affected viral suppression and emergent resistance. 2622 participants had evaluable data for analyses through week 48 (1306 on BIC/F/TAF and 1316 on DTG+2NRTI); at screening, 57% were treatment naïve and 43% were virologically suppressed. Through 48 weeks, 78% had high (≥95%) adherence, 17% intermediate (≥85% to <95%) adherence, and 4% low (<85%) adherence, with similar distributions between the BIC/F/TAF and DTG+2NRTI groups. Virologic suppression was similarly high in all adherence categories of the BIC/F/TAF group: 96% of participants with low adherence had viral load <50 copies/mL at last study visit compared with 98% in the intermediate and 99% in the high adherence group. In the DTG+2NRTI group, virologic suppression was significantly lower for participants with low adherence (90%) compared with the intermediate (98%) and high (99%) adherence groups. Among 68 participants with VL ≥50 copies/mL at last visit, 39 underwent resistance analyses (through week 144); no participants in either the BIC/F/TAF or DTG+2NRTI group had treatment-emergent resistance. Two participants receiving DTG/ABC/3TC with intermediate adherence had emergent M184V detected after week 144, and subsequently resuppressed on BIC/F/TAF.
Author’s Commentary:
Results of this analysis further support the observation that BIC/F/TAF appears to have a high level of “forgiveness”, maintaining virologic suppression even in the setting of missed doses. Investigators posit this feature may be related to bictegravir’s longer dissociation half-life and in vitro synergy observed between the various components of BIC/F/TAF. Among participants with low adherence in this study, median adherence through week 48 was 78% for individuals in the BIC/F/TAF group, and no emergent resistance mutations were observed up to 144 weeks. Such findings help reinforce its utility in clinical practice and continued role as a favored option for initial ART in several major guidelines, including recently updated recommendations from the International Antiviral Society-USA.
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