People who switched to tenofovir alafenamide (TAF) from the previous version of tenofovir (tenofovir disoproxil fumarate – TDF) experienced rapid weight gain regardless of whether they were taking an integrase inhibitor or a drug from another class alongside TAF, Aidsmap reports analysis of a large US cohort shows. The findings are presented as part of the virtual 23rd International AIDS Conference (AIDS 2020: Virtual) by Professor Patrick Mallon of St Vincent’s University Hospital, Dublin.
The investigators reported on results for an 'average' or referent patient in this population, who was a 45-year-old non-black man, with a baseline BMI of 27, a baseline CD4 cell count of 700, no endocrine disorders and not taking any other medication previously associated with weight loss or gain. The investigators did not model the weight gain patterns for groups of patients at higher risk, such as women or black people.
The average patient in this cohort gained 0.42kg a year on the old formulation of tenofovir (TDF) prior to switching (95% CI 0.26, 0.59). In the nine months after switching to TAF, the model showed a sharp increase in weight (+2.64kg [2.26, 3.01]) after which weight gain diminished to a level of +0.29kg a year (0.08, 0.51).
These findings “suggest an independent effect of a switch from TDF to TAF on weight gain”, said Mallon. The patterns of weight change were consistent across regimens, indicating that people who switched to TAF experienced an early and rapid weight gain in the nine months after switching, followed by a slowing or plateauing of weight gain.
Abstract (not available online)
Mallon, P et al: Weight gain before and after switch from TDF to TAF. 23rd International AIDS Conference, abstract 3283, 2020.
[link url="https://www.aidsmap.com/news/jul-2020/rapid-weight-gain-after-switching-taf-regardless-other-hiv-drugs-taken"]Full Aidsmap report[/link]