Switching Tenofovir HIV Regimens Can Cause Weight Gain

Swapping out tenofovir disoproxil fumarate (TDF) for a newer version, tenofovir alafenamide (TAF), in HIV patients was more often associated with weight gain than when TAF was substituted for abacavir, researchers reported at the virtual IDWeek 2020 conference.

In this exclusive MedPage Today video, Monica Gandhi, MD, of UCSF/San Francisco General Hospital, discusses the study findings.

Following is a transcript of her remarks:

I do want to stress that this study was supported by Gilead Sciences, and it was on a very concerning question that we're having these days for us in the HIV community: what is happening with weight change in people who switched from tenofovir disoproxil fumarate to tenofovir alafenamide? And essentially this is now over the last two years, we've been seeing a study from the longitudinal OPERA cohort, we have seen studies in the advanced study. We have seen this in multiple other settings that TAF is associated with weight gain, especially when it is in tandem with integrase inhibitors.

And so this specific study was asking the question, well, does it make a difference if you're switching from abacavir to TAF, or if you were switching from TDF to TAF with your INSTI in this particular study population in terms of weight gain. And the reason that this question would even be asked is that TDF has been associated with weight loss. So the question was going from abacavir to TAF, do you still see the same weight gain or was it that when you go from TDF to TAF, you lose that weight loss that can occur with TDF, and then you see the kind of return to health over time.

Now, this was done over 10 HIV treatment centers, 42,000 patients. And essentially just the bottom line of this study is that there was more participants in the observational study that showed weight gain of more than 3% if you were switching from TDF to TAF, than if you were switching from abacavir to TAF. And it was a little confusing because they didn't show all the weight parameters, they just use this kind of major metric of gaining more than 3% weight.

So I do have to say that there wasn't as many people switching from abacavir to TAF, most people -- 85% -- were switching from TDF to TAF. It was a pharmaceutical company sponsored study as opposed to just providing educational grants. And so, I think we all have to just sort of look at this more carefully, ask a little bit more about the data before we make major conclusions on this. I still think that TAF is associated with weight gain. This is shown in this study and many others, and most people are switching from TDF. So not sure if it adds that much to our knowledge base, but it could be that the switch from abacavir is not as great in terms of the weight gain with TAF. Thank you.

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