952. Efficacy and Safety of Tenofovir Alafenamide vs Tenofovir Disoproxil Fumarate in HIV-infected, Virologically Suppressed Older Adults: Subgroup Analysis of a Randomized, Double-blind Switch Study
Session: Oral Abstract Session: HIV Clinical Management
Friday, October 28, 2016: 11:30 AM
Room: 275-277

Background: As the HIV-infected population ages and has increasing prevalence of co-morbidities, efficacy and safety of antiretrovirals in older participants is of heightened importance. Tenofovir alafenamide (TAF) has a potential to benefit older individuals, as it has previously demonstrated an improved renal and bone safety profile compared to tenofovir disoproxil fumarate (TDF).

Methods: We conducted a 48-week subgroup analysis in those ≥ 50 years old for efficacy (pre-specified) and safety (post-hoc) from a randomized, double blind, active-controlled study in virologically suppressed HIV-infected participants who switched to emtricitabine/TAF (FTC/TAF) from FTC/TDF vs continuing FTC/TDF while remaining on their original third agent.

Results: Of 663 treated, 294 were ≥ 50 years (FTC/TAF n=150, FTC/TDF n=144). Baseline viral load, CD4 counts, renal laboratory parameters, and bone mineral density (BMD) were similar between the two arms within those ≥ and < 50 years. For participants ≥ 50 years, virologic success by FDA snapshot algorithm at Week 48 was FTC/TAF 96.0% vs. FTC/TDF 94.4%; for those < 50 years, it was 92.9% vs 91.9%. Few participants discontinued study drug due to adverse events in either subgroups (≥ 50 years, FTC/TAF 3.3% vs. FTC/TDF 1.4%; < 50 years, 1.1% vs. 0.5%). The assessment of renal and bone safety using estimated glomerular filtration rate (eGFR), renal biomarkers, and BMD had significant differences between the two arms that consistently favored FTC/TAF over FTC/TDF (Table 1). No cases of Fanconi syndrome or proximal renal tubulopathy were reported in the overall population.

Conclusion: Participants ≥ 50 years receiving 48 weeks of FTC/TAF had comparable efficacy and improved bone and renal safety compared to those remaining on FTC/TDF. These findings demonstrate improved safety with TAF relative to TDF in older individuals. This is of particular importance as the population living with HIV ages and experiences more renal and bone-related comorbidities.

Eric S. Daar, MD, Los Angeles Biomedical Research Institute At Harbor-UCLA Medical Center, Torrance, CA, Joel Gallant, MD, MPH, FIDSA, Southwest CARE Center, Santa Fe, NM, Gordon Crofoot, MD, The Crofoot Research Center, Houston, TX, Kenneth Lichtenstein, MD, National Jewish Health, Denver, CO, Anthony Lamarca, MD, FACP, Therafirst Medical Center, Fort Lauderdale, FL, Peter Shalit, MD, PhD, Tribal Med, Seattle, WA, Christopher Lucasti, DO, FACOI, South Jersey Infectious Diseases, Somers Point, NJ, Daniel Coulston, MD, FCCM, AAHIVS, Premier Clinical Research, Spokane, WA, Craig Dietz, DO, MPH, FACOI, AAHIVS, Kansas City CARE Clinic, Kansas City, MO, Mingjin Yan, PhD, Biostatistics, Gilead Sciences, Inc., Foster City, CA, Sandra Friborg, BS, Clinical Operations, Gilead Sciences, Foster City, CA and Martin Rhee, MD, Gilead Sciences, Foster City, CA

Disclosures:

E. S. Daar, Bristol Myers Squib: Consultant , Consulting fee
Teva: Consultant , Consulting fee
Janssen: Consultant , Consulting fee
Gilead: Consultant and Research Contractor , Consulting fee and Research support
Merck: Consultant and Research Contractor , Consulting fee and Research support
ViiV: Consultant and Research Contractor , Consulting fee and Research support

J. Gallant, AbbVie: Investigator , Research support
Bristol-Myers Squibb: Investigator and Scientific Advisor , Consulting fee and Research support
Gilead Sciences: Investigator and Scientific Advisor , Consulting fee and Research support
Janssen Therapeutics: Investigator and Scientific Advisor , Consulting fee and Research support
Merck & Co.,: Investigator and Scientific Advisor , Consulting fee and Research support
Sangamo Biosciences: Investigator , Research support
ViiV Healthcare/GlaxoSmithKline: Investigator and Scientific Advisor , Consulting fee and Research support

G. Crofoot, Gilead: Investigator , Research support

K. Lichtenstein, Gilead Sciences: Consultant and Investigator , Consulting fee

A. Lamarca, Gilead: Investigator , Research support

P. Shalit, Gilead: Investigator and Speaker's Bureau , Research support and Speaker honorarium

C. Lucasti, Gilead: Investigator and Speaker's Bureau , Research grant and Speaker honorarium

D. Coulston, Gileax: Investigator , Research support

C. Dietz, Gilead: Investigator , Consulting fee , Research support and Speaker honorarium
Merck: Investigator , Consulting fee and Research support
Janssen: Investigator , Research support

M. Yan, Gilead: Employee , own stock and Salary

S. Friborg, Gilead: Employee , own stock and Salary

M. Rhee, Gilead: Employee , Owns stocks/options and Salary

Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.