title: Dried Blood Spot Methodology in Combination With Liquid Chromatography/Tandem Mass Spectrometry Facilitates the Monitoring of Teriflunomide.
abstract: Teriflunomide, a once-daily oral immunomodulator approved for treatment of relapsing-remitting multiple sclerosis, is eliminated slowly from plasma. If necessary to rapidly lower plasma concentrations of teriflunomide, an accelerated elimination procedure using cholestyramine or activated charcoal may be used. The current bioanalytical assay for determination of plasma teriflunomide concentration requires laboratory facilities for blood centrifugation and plasma storage. An alternative method, with potential for greater convenience, is dried blood spot (DBS) methodology. Analytical and clinical validations are required to switch from plasma to DBS (finger-prick sampling) methodology.
  
  
  
  Using blood samples from healthy subjects, an LC-MS/MS assay method for quantification of teriflunomide in DBS over a range of 0.01-10 mcg/mL was developed and validated for specificity, selectivity, accuracy, precision, reproducibility, and stability. Results were compared with those from the current plasma assay for determination of plasma teriflunomide concentration.
  
  
  
  Method was specific and selective relative to endogenous compounds, with process efficiency ∼88%, and no matrix effect. Inaccuracy and imprecision for intraday and interday analyses were <15% at all concentrations tested. Quantification of teriflunomide in DBS assay was not affected by blood deposit volume and punch position within spot, and hematocrit level had a limited but acceptable effect on measurement accuracy. Teriflunomide was stable for at least 4 months at room temperature, and for at least 24 hours at 37°C with and without 95% relative humidity, to cover sampling, drying, and shipment conditions in the field. The correlation between DBS and plasma concentrations (R = 0.97), with an average blood to plasma ratio of 0.59, was concentration independent and constant over time.
  
  
  
  DBS sampling is a simple and practical method for monitoring teriflunomide concentrations.
authors.affiliation: *Sanofi R&D, Alfortville, France; †Sanofi R&D, Chilly-Mazarin, France; ‡Sanofi R&D, Bridgewater, NJ; and §Sanofi Genzyme, Cambridge, MA.
authors.forename: Aziz
authors.initials: A
authors.lastname: Filali-Ansary
authors.forename: Catherine
authors.initials: C
authors.lastname: Lunven
authors.forename: Sandrine
authors.initials: S
authors.lastname: Turpault
authors.forename: Yann-Joel
authors.initials: YJ
authors.lastname: Beyer
authors.forename: Amy
authors.initials: A
authors.lastname: OʼBrien
authors.forename: Astrid
authors.initials: A
authors.lastname: Delfolie
authors.forename: Neli
authors.initials: N
authors.lastname: Boyanova
authors.forename: Ger-Jan
authors.initials: GJ
authors.lastname: Sanderink
authors.forename: Francesca
authors.initials: F
authors.lastname: Baldinetti
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D003437:Crotonates / Q000097:blood*; D059788:Dried Blood Spot Testing / Q000379:methods; D004355:Drug Stability; D006400:Hematocrit / Q000379:methods; D006801:Humans; D006885:Hydroxybutyrates; D009570:Nitriles; D010949:Plasma / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods; D014052:Toluidines / Q000097:blood*
chemical_list: D003437:Crotonates; D006885:Hydroxybutyrates; D009570:Nitriles; D014052:Toluidines; C527525:teriflunomide