Rates and predictors of switching to tenofovir alafenamide-containing ART in a nationwide cohort. BMC Infectious Diseases
Surial et al. aimed to determine the proportion of patients with and without risk factors for tenofovir disoproxil fumarate (TDF-) related toxicity who had been switched from TDF to tenofovir alafenamide fumarate (TAF) and explored individual predictors for being switched.
The authors included all participants of the Swiss HIV Cohort Study on TDF-containing antiretroviral therapy with follow-up visits after January 2016. They determined the proportion of switches from TDF to TAF overall, and among patients with risk factors for TDF toxicity, including osteoporosis, impaired renal function or marked proteinuria.
Overall, the study included 5′012 patients, of whom 652 (13.0%) had risk factors for TDF toxicity. A switch from TDF to TAF was undertaken in 2′796 (55.8%) individuals overall, and in 465 (71.3%) with risk factors. Predictors of switching to TAF were male sex (adjusted odds ratio 1.27, 95% confidence interval 1.07–1.50), age>50years (1.43, 1.23–1.66) and the presence of risk factors for TDF toxicity (2.21, 1.77–2.75). In contrast, patients with a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based single-pill regimen (0.11, 0.09–0.13), those treated in non-tertiary care centers (0.56, 0.46–0.70), as well as those with CD4 cell counts below 500/μL (0.77, 0.66–0.90) and with chronic hepatitis C infection (0.66, 0.54–0.80) were most likely to stay on TDF.
In conclusion, the majority of patients at risk for TDF-toxicity were switched from TDF to TAF within two years after its introduction in Switzerland. Among 30% of patients at risk of TDF-toxicity who did not switch during this time-period, being on a NNRTI-based single-pill regimen seemed to be an important reason for remaining on TDF. However, large differences across clinics were observed and related reasons should be further explored. Since current recommendations on switching to TAF are based on limited data from selected groups of patients in randomized controlled trials, further data on clinical outcomes after the introduction of TAF in cohorts such as the SHCS remain essential to inform optimal patient management.