Changes in Glomerular Filtration Rate after Switching from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide Fumarate for HIV Pre-exposure Prophylaxis

Abstract

Abstract Background Tenofovir alafenamide fumarate (TAF) was promoted as a safer alternative to tenofovir disoproxil fumarate (TDF) for HIV oral pre-exposure prophylaxis (PrEP). It is unknown if switching from TDF to TAF translates to improved renal function. We used electronic health records (EHR) data to assess changes in creatinine-estimated glomerular filtration rate (eGFR) after switching from TDF to TAF. Methods We conducted a retrospective cohort study using EHR data from Kaiser Permanente Southern California. We identified individuals who switched from TDF to TAF between October 2019-May 2022 and used time-varying propensity score matching to identified controls who were on TDF (“non-switchers”). We then used Bayesian longitudinal modeling to compare differences in eGFR between switching and non-switching scenarios. Results Among 5,246 eligible individuals, we included 118 TDF-to-TAF switchers and 114 non-switchers. Compared to non-switchers, switchers had older age of starting TDF but similar weights at index date. A higher proportion of switchers were White, on Medicare or Medicaid. and had dyslipidemia at index date. Switching to TAF was associated with a higher eGFR compared to staying on TDF in 3-15 months post-switch, but the differences were not statistically significant. (e.g., month 9 difference: 1.27, 95% Credible interval: -1.35 to 3.89). While most of estimated changes showed eGFR increase associated with switching, most were less <2 eGFR units. Sensitivity analyses to address missingness or non-adherence showed similar results. Conclusion Switching from TDF to TAF for PrEP was associated with a non-significant increase in eGFR. Findings need to be confirmed using larger cohorts.