Switching from TDF- to TAF-Containing Antiretroviral Therapy: Impact on Bone Mineral Density in Older Patients Living With HIV
Maggiolo F, Rizzardini G, Raffi F, et al. Bone mineral density in virologically suppressed people aged 60 years or older with HIV-1 switching from a regimen containing tenofovir disoproxil fumarate to an elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide single-tablet regimen: a multicentre, open-label, phase 3b, randomised trial. Lancet HIV. 2019;6(10):e655-e666.
Applications for Clinical Practice
This study shows that making the switch from TDF- to TAF-containing ART can lead to improved bone mineral density. We can extrapolate that switching may lead to a decreased risk of osteoporosis and osteoporosis-related complications, such as bone fracture, but this needs to be investigated in more detail. As demonstrated in this study, switching from a TDF- to a TAF-containing regimen can also lead to improved renal function while maintaining HIV viral suppression and CD4 counts.
Unfortunately, the regimen selected with TAF in this study (elvitegravir, cobicistat, and emtricitabine) includes cobicistat, which is no longer recommended as initial therapy due to its risk of drug-drug interactions, and elvitegravir, which has a lower barrier to resistance than other integrase strand inhibitors.10,11 The United States Department of Health and Human Services guidelines and the International Antiviral Society-USA Panel suggest using several other TAF-containing regimens for beginning or even switching therapy in older patients.10,11
When choosing between either a TAF- or a TDF-containing regimen to treat HIV infection in older patients, increasing evidence shows that using a TAF-containing ART regimen may be more beneficial for people living and aging with virologically suppressed HIV infection.
–Sean P. Bliven, and Norman L. Beatty, MD, University of Florida College of Medicine, Division of Infectious Diseases and Global Medicine, Gainesville, FL
