Tenofovir-Associated Bone Adverse Outcomes among a US National Historical Cohort of HIV-Infected Veterans: Risk Modification by Concomitant Antiretrovirals

Joanne LaFleur; Adam P Bress; Joel Myers; Lisa Rosenblatt; Jacob Crook; Kristin Knippenberg; Roger Bedimo; Pablo Tebas; Heather Nyman; Stephen Esker

doi:10.1007/s40121-018-0194-1

Tenofovir-Associated Bone Adverse Outcomes among a US National Historical Cohort of HIV-Infected Veterans: Risk Modification by Concomitant Antiretrovirals

Infect Dis Ther. 2018 Jun;7(2):293-308. doi: 10.1007/s40121-018-0194-1. Epub 2018 Feb 28.

Authors

Joanne LaFleur^{1

2}, Adam P Bress^{3

4}, Joel Myers⁵, Lisa Rosenblatt⁵, Jacob Crook^{3

6}, Kristin Knippenberg^{7

3}, Roger Bedimo^{8

9}, Pablo Tebas¹⁰, Heather Nyman⁷, Stephen Esker⁵

Affiliations

¹ Department of Pharmacotherapy, University of Utah, Salt Lake City, UT, USA. Joanne.Lafleur@pharm.utah.edu.
² Salt Lake City VA Health Care System, Salt Lake City, UT, USA. Joanne.Lafleur@pharm.utah.edu.
³ Salt Lake City VA Health Care System, Salt Lake City, UT, USA.
⁴ Department of Population Health Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA.
⁵ Bristol-Myers Squibb, Lawrenceville, NJ, USA.
⁶ Division of Epidemiology, University of Utah, Salt Lake City, UT, USA.
⁷ Department of Pharmacotherapy, University of Utah, Salt Lake City, UT, USA.
⁸ VA North Texas Health Care System, Dallas, TX, USA.
⁹ University of Texas Southwestern Medical Center, Dallas, TX, USA.
¹⁰ Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Abstract

Introduction: Tenofovir disoproxil fumarate (TDF) has been associated with greater incidences of bone complications, which might be modified by some concomitantly administered antiretrovirals, possibly by their effect on tenofovir concentrations. We compared bone adverse outcomes among treatment-naïve HIV-infected US veterans initiating efavirenz (EFV)-containing TDF/emtricitabine (FTC) regimens versus those initiating non-EFV-containing TDF/FTC regimens.

Methods: Using national Veterans Health Administration clinical and administrative data sets, we identified a cohort of treatment-naïve HIV-infected veterans without bone disease who initiated therapy with TDF/FTC plus EFV, rilpivirine, elvitegravir/cobicistat, or ritonavir-boosted protease inhibitors in 2003-2015. The primary composite adverse bone outcome was the unadjusted incidence rate (IR) of osteoporosis, osteopenia, or fragility fracture (any hip, wrist, or spine fracture). To account for selection bias and confounding, we used inverse probability of treatment-weighted Cox proportional hazards regression models to calculate adjusted hazard ratios (HRs) for each outcome associated with EFV + TDF/FTC versus each non-EFV-containing TDF/FTC regimen.

Results: Of 33,048 HIV-positive veterans, 7161 initiated a TDF/FTC-containing regimen (mean age, 50 years; baseline CD4 < 200 cells/mm³, 33.3%; HIV-1 RNA > 100,000 copies/ml, 22.3%; mean follow-up, 13.0 months). Of these, 4137 initiated EFV- and 3024 non-EFV-containing regimens. Veterans initiating EFV- versus non-EFV-containing TDF/FTC regimens had a lower IR of the composite bone outcome (29.3 vs. 41.4 per 1000 patient-years), with significant risk reductions for this outcome [HR, 0.69; 95% confidence interval (CI), 0.58-0.83] and fragility fracture (HR, 0.59; 95% CI, 0.44-0.78).

Conclusion: EFV + TDF/FTC is associated with a lower risk of adverse bone outcomes compared with other TDF-containing regimens in the VHA.

Funding: Bristol-Myers Squibb.

Keywords: Efavirenz; Fracture; Osteoporosis; Tenofovir disoproxil fumarate; Veterans.