Advertisement Covers IAS 2015


A Study About Switching From TDF to TAF

October/November 2015

 < Prev  |  1  |  2 

Focus on Lipids (Cholesterol and Triglycerides)

In general, when researchers assessed blood samples that were taken when participants had been fasting, they found that, over time, there were modest elevations in lipid levels among TAF users compared to TDF users. The lipids assessed included the following:

  • total cholesterol
  • bad cholesterol (LDL-C)
  • good cholesterol (HDL-C)
  • triglycerides

However, the ratio of total cholesterol to HDL-C was similar in TAF and TDF users, suggesting that their future risk for cardiovascular disease was more or less the same in people who received TAF or TDF.

The distribution of participants who initiated lipid-lowering therapy during the study was as follows:

  • TAF users -- 8%
  • TDF users -- 6%


Comparing Changes in Bone Density

Overall, a statistically significant increase in bone density (2%) occurred among TAF users. In contrast, participants who remained on TDF had their bone density decrease slightly.

Changes in Osteoporosis Status

Bone thinness can be grouped into two categories -- osteopenia, a mild form of decreased bone density, and osteoporosis, a severe form of bone density loss.

Looking at the Spine

At the start of the study, osteopenia and osteoporosis were distributed among participants as follows:

TAF-based regimen

  • 36% had osteopenia in the spine
  • 6% had osteoporosis of the spine

TDF-based regimen

  • 35% had osteopenia in the spine
  • 7% had osteoporosis of the spine

After 48 weeks, the distribution of these conditions in the spine was as follows:

TAF-based regimen

  • 32% had osteopenia
  • 5% had osteoporosis

TDF-based regimen

  • 37% had osteopenia
  • 8% had osteoporosis

Looking at the Hips

When researchers assessed bone density in the hips, the distribution of osteopenia and osteoporosis at the start of the study was as follows:

TAF-based regimen

  • 31% had osteopenia in the hips
  • 0.7% had osteoporosis of the hips

TDF-based regimen

  • 32% had osteopenia in the hips
  • 1.3% had osteoporosis of the hips

After 48 weeks, the distribution of osteoporosis and osteopenia in the hips was as follows:

TAF-based regimen

  • 26% had osteopenia
  • 0.7% had osteoporosis

TDF-based regimen

  • 32% had osteopenia
  • 2.1% had osteoporosis

Kidney Injury

Research has found that the original formulation of tenofovir (TDF) can, in some users, cause varying degrees of kidney injury. Therefore, in clinical trials of TDF (and its successor compound, TAF) it is important to conduct detailed and complex assessments of kidney health.

In the present study, in general, participants taking TDF-based regimens were more likely to develop signals of kidney injury than participants on TAF-based regimens.

Researchers assessed certain proteins in the urine as follows:

  • protein to creatinine ratio
  • albumin to creatinine ratio
  • retinol-binding protein to creatinine ratio
  • beta2-microglobulin to creatinine ratio

Note: Some of the tests above, particularly concerning retinol-binding protein and beta2-microglobulin, are usually only done as part of research, not routine care in the clinic.

While participants were on a TAF-based regimen, levels of the four proteins in the urine fell, suggesting improved kidney health in participants. Another measure of kidney health, eGFR (estimated glomerular filtration rate), improved very modestly in TAF users. In contrast, changes to the urinary proteins among participants on a TDF-based regimen were unfavourable.

Key Points

Switching from a TDF-based regimen to a TAF-based regimen appears to be safer for kidney and bones.

TAF appears to be equivalent to TDF when used as part of combination anti-HIV therapy.


Mils A, Andrade-Villanueva J, DiPerri G, et al. Switching from a tenofovir disoproxil fumarate (TDF)-based regimen to a tenofovir alafenamide (TAF)-based regimen: data in virologically suppressed adults through week 48 of treatment. In: Program and abstracts of the 8th IAS Conference on HIV Pathogenesis, Treatment and Prevention, 19-22 July 2015, Vancouver, Canada. Abstract TUAB0102.

 < Prev  |  1  |  2 

Related Stories

The Most Important HIV Study at IDWeek 2015
Tenofovir Alafenamide (TAF) Still Noninferior to Current Tenofovir -- With Better Bone/Kidney Signals

This article was provided by Canadian AIDS Treatment Information Exchange. It is a part of the publication TreatmentUpdate. Visit CATIE's Web site to find out more about their activities, publications and services.

No comments have been made.

Add Your Comment:
(Please note: Your name and comment will be public, and may even show up in
Internet search results. Be careful when providing personal information! Before
adding your comment, please read's Comment Policy.)

Your Name:

Your Location:

(ex: San Francisco, CA)

Your Comment:

Characters remaining:

Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.


The content on this page is free of advertiser influence and was produced by our editorial team. See our content and advertising policies.