Comparison of weight gain after antiretroviral switch to integrase strand transfer inhibitor or tenofovir alafenamide-based therapy

PURPOSE: Several studies have reported weight gain after switching to integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART). Debate persists if weight gain also occurs when switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF)-based ART. METHODS: We performed a retrospective chart review of virally suppressed HIV-infected patients who were switched from non INSTI- to INSTI-based ART (INSTI switch group) as well as patients switched from TDF- to TAF-based ART (TAF switch group), and compared the mean weight change in these groups to the mean change in weight in patients maintained on NNRTI-based regimens (control group). RESULTS: 329 patients were identified. 256 patients in the INSTI switch group gained a mean 2.4 kg over 17 months compared to 0.5 kg in 54 patients in the control group over the same period (p = 0.008). 161 patients in the TAF switch group gained a mean 2.8 kg over 17 months compared to 0.5 kg in the control group (p = 0.003). There was no statistical difference in weight gain between the INSTI and TAF switch groups. Although the highest mean weight gain of 3.2 kg was seen in those 90 patients switched from both TDF- to TAF-based and non INSTI- to INSTI-based ART (TAF/INSTI switch group), this weight gain was not statistically different compared with the INSTI switch or TAF switch groups. CONCLUSION: Our study suggests that weight gain is associated with both switching HIV regimens from non INSTI- to INSTI-based ART and TDF- to TAF-based ART