Outcomes associated with treatment change from tenofovir disoproxil fumarate to tenofovir alafenamide in HIV-1-infected patients: a real-world study in Japan

Objectives To investigate the impact of switching from tenofovir disoproxil fumarate (TDF)- to tenofovir alafenamide (TAF)-containing regimens on bone, kidney, serum lipids and body weight among Asian patients. Methods A prospective, multicentre, observational cohort study was conducted at three centres for HIV infection in Japan during 2017-2019. HIV-infected adults previously treated with TDF-containing regimens and scheduled to switch to TAF-containing regimens were included. Bone mineral density (BMD), renal markers, lipids and weight were measured consecutively from 12 months before to 12 months after the switch. Results Among 118 patients evaluated, the mean percentage change to spine BMD during 1 year of TAF treatment was higher than that during 1 year of TDF treatment (mean difference = 1.9%; 95% confidence interval (CI): 0.8-3.1). Urine protein and beta(2)-microglobulin levels decreased significantly after the switch, while low-density lipoprotein cholesterol and triglycerides increased. During the TDF and TAF periods, the mean weight gains were 0.2 and 1.9 kg, respectively (mean difference = 1.6 kg; 95% CI: 0.9-2.3). Subgroup analysis revealed a significant difference between the mean body weight change associated with an integrase inhibitor (INSTI) (+2.8 kg) and that associated with a non-INSTI (+1.2 kg) third agent treatment only during the TAF period. Conclusions Among predominantly Japanese HIV-infected patients, BMD and renal tubular markers improved, while lipid profiles worsened significantly after the switch. Weight gain during the TAF period was larger than that during the TDF period. Concurrent use of INSTI with TAF may act synergistically to gain body weight.