Long-Term Safety and Efficacy of TAF vs. TDF in Blacks and Non-Blacks
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SAN DIEGO—Among HIV-infected, virologically suppressed black adults, emtricitabine/tenofovir alafenamide (FTC/TAF) showed improvements in renal and bone safety compared to emtricitabine/tenofovir disoproxil fumarate (FTC/TDF), according to Jason A. Flamm, MD, from Kaiser Permanente, Sacramento, CA, and coauthors.
At Week 96, FTC/TAF "demonstrated high rates of virologic suppression, improved bone and renal safety, and small increases in lipids, with no treatment differences in total cholesterol:HDL ratio," reported Dr. Flamm and colleagues. "Efficacy and safety of FTC/TAF in black patients were similar to those in nonblack patients."
"Given the safety advantage of TAF vs. TDF from a renal standpoint, FTC/TAF is an important backbone for black patients living with HIV," the authors concluded.
The research team performed a 96-week subgroup analysis by race for pre-specified efficacy and post-hoc safety outcomes, using data from a randomized, double-blind, active-controlled study (n=663) in virologically suppressed adults with HIV infection who switched to FTC/TAF from FTC/TDF (n=333) vs. continuing FTC/TDF while taking the same third agent (n=330).
Twenty percent of patients identified themselves as black. Baseline viral load, CD4 cell counts, renal laboratory parameters, and bone mineral density (BMD) were similar between the 2 treatment arms for blacks and non-blacks.
At Week 96, virologic success among black patients was 87% for FTC/TAF vs. 88% for FTC/TDF and 89% vs. 90% for non-blacks.
Adverse events leading to study drug discontinuation occurred in 1 (2%) black patient in the FTC/TDF group and 4% of non-black patients (8 patients [3%] in the FTC/TAF group and 3 [1%] in the FTC/TDF group). Adverse events leading to discontinuation included (1 patient each): insomnia/mood alteration, dysphagia, atrial fibrillation, diarrhea, peripheral edema, overdose, lymphoma, increased serum creatinine, rectal tenesmus, feeling abnormal/headache, renal tubular disorder, and acquired lipodystrophy/affective disorder.
The renal tubular disorder case involved a non-black patient in the FTC/TDF group.
Renal biomarkers at Week 96 demonstrated a difference in the median change in eGFR of 10.1 for FTC/TAF group-patients vs. 4.0mL/min in the TDF/TAF group (P=0.06) among black patients. That difference in median change in eGFR was similar to the 10.0 vs. 3.9mL/min changes reported for non-blacks.
Among black patients, median percent-change in urine protein:Cr and urine β2M:Cr were significantly different between those in the FTC/TAF group and the FTC/TDF group (-21.5% vs. 6.3% and -16.6% vs. 26.8%, respectively; P=0.01 and P<0.001).
In general, FTC/TAF showed improvements in renal and bone safety vs. FTC/TDF along with sustained efficacy at Week 96. "These results support switching to FTC/TAF from FTC/TDF for the treatment of HIV-1 infection in Black adults," concluded Dr. Flamm.
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Flamm, JA. Efficacy and Safety of Tenofovir Alafenamide vs Tenofovir Disoproxil Fumarate in HIV-infected, Virologically Suppressed Black and Non-Blacks Adults Through Week 96: Subgroup Analysis of a Randomized Switch Study. Poster presented at IDWeek; October 4–8, 2017; San Diego, CA. http://www.idweek.org