Efficacy and Safety of Tenofovir Alafenamide vs Tenofovir Disoproxil Fumarate in HIV-infected, Virologically Suppressed Black and Non-Blacks Adults Through Week 48: Subgroup Analysis of a Randomized Switch Study

Background: Black adults are disproportionately affected by HIV.

Methods: We conducted a 48-week subgroup analysis by race (Black vs. non-Black) for efficacy (pre-specified) and safety (post-hoc) from a randomized, double blind, active-controlled study in virologically suppressed HIV-infected individuals who switched to emtricitabine/tenofovir alafenamide (FTC/TAF) from FTC/tenofovir disoproxil fumarate (FTC/TDF) vs continuing FTC/TDF while remaining on the same third agent.

Results: Of the 663 treated, 136 (20.5%) self-identified as Black (FTC /TAF n=69, FTC /TDF n=67). Baseline viral load, CD4 counts, renal laboratory parameters, and bone mineral density (BMD) were similar between the two arms within Blacks and non-Blacks. For Blacks, virologic success by FDA snapshot algorithm at Week 48 was FTC /TAF 94.2% vs. FTC /TDF 89.6%; for non-Blacks, it was 94.3% vs 93.9%. Few participants discontinued study drug due to adverse events in either subgroups (Black, FTC /TAF 0 vs. FTC /TDF 1.5%; non-Black, 2.7% vs. 0.8%). In assessment of renal and bone safety using estimated glomerular filtration rate (eGFR), renal biomarkers, and BMD, there were differences between two arms that generally favored FTC/TAF over FTC/TDF (Table 1). No cases of Fanconi syndrome or proximal renal tubulopathy were reported in the overall population.

Conclusion: In virologically suppressed Black adults, FTC/TAF demonstrated improvements in renal and bone safety over FTC/TDF with similar high-level efficacy at Week 48. These results support switching to FTC/TAF from FTC/TDF for the treatment of HIV-1 infection in Black adults.