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. 2018 Mar 27;32(6):761-765.
doi: 10.1097/QAD.0000000000001744.

Plasma and intracellular pharmacokinetics of tenofovir in patients switched from tenofovir disoproxil fumarate to tenofovir alafenamide

Affiliations

Plasma and intracellular pharmacokinetics of tenofovir in patients switched from tenofovir disoproxil fumarate to tenofovir alafenamide

Anthony T Podany et al. AIDS. .

Abstract

Objectives: The aim of the study was to compare the intraindividual plasma and intracellular peripheral blood mononuclear cell (PBMC) pharmacokinetics of tenofovir (TFV) and its intracellular metabolite, TFV-diphosphate (TFV-DP) in patients switched from a fixed-dose combination (FDC) tablet of TFV disoproxil fumarate (TDF)/emtricitabine (FTC)/elvitegravir (EVG)/cobicistat (COBI) to a FDC containing TFV alafenamide (TAF)/FTC/EVG/COBI.

Design: A single-arm, prospective, nonrandomized, cross-over, pharmacokinetic study in patients receiving a TDF-containing regimen (TDF 300 mg/FTC 200 mg/EVG 150 mg/COBI 150 mg) switched to a TAF-containing FDC regimen (TAF 10 mg/FTC 200 mg/EVG 150 mg/COBI 150 mg).

Methods: Single, sparse plasma and PBMC samples were collected during TDF therapy and 4-8 weeks post-switch to the TAF-containing regimen. Plasma TFV and cell associated TFV-DP concentrations were determined with validated liquid chromatography tandem mass spectrometry methods. PBMC cell enumeration was performed by quantification of RNaseP (RPP30) gene copy numbers using a highly sensitive droplet digital PCR assay. Plasma and PBMC pharmacokinetics were summarized as geometric mean and compared as a geometric mean ratio with a Wilcoxon signed-rank test.

Results: In 30 participants with evaluable data, TFV plasma concentrations decreased 90% [TDF: 99.98 (2.24) ng/ml vs. TAF: 10.2 (1.6) ng/ml, P < 0.001] after the switch while cell-associated TFV-DP increased 2.41-fold [TAF: 834.7 (2.49) vs. TDF: 346.85 (3.75) fmol/10 cells, P = 0.004].

Conclusion: Intraindividually, plasma TFV concentrations significantly decreased while cell associated TFV-DP concentrations significantly increased after switching from a TDF to a TAF-containing antiretroviral therapy regimen.

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Conflict of interest statement

Conflicts of Interest

The remaining authors have no conflicts of interest to declare.

Figures

Figure 1
Figure 1
Whisker plot of plasma tenofovir and PBMC tenofovir diphosphate concentrations during TDF and TAF based dosing. Data presented as 25th, 50th and 75th percentiles.

Comment in

References

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