title: Determination of soluble vascular endothelial growth factor receptor 3 (sVEGFR-3) in plasma as pharmacodynamic biomarker.
abstract: Soluble VEGFR-3 (sVEGFR-3) is a potential biomarker for the anti-angiogenic activity of tyrosine kinase inhibitors. The aim of this investigation was the validation of an enzyme-linked immunosorbent assay (ELISA) to measure sVEGFR-3 in human plasma and the investigation of its applicability in clinical trials as first step of the biomarker validation process. General validation criteria were assessed based on current guidelines and recommendations for immunoassays. The ELISA was applied in two clinical trials including healthy volunteers and metastatic colorectal cancer (mCRC) patients receiving 50 or 37.5mg sunitinib per day, respectively. SVEGFR-3 was measured at predefined time points. Undiluted, inactivated fetal calf serum was identified as surrogate matrix to substitute for human plasma. Dilutional linearity and parallelism could be successfully confirmed. The analyte was measured in the study matrix with intra- and inter-run precision and accuracy ≤20%. Stability was proven over a period of at least 15 months as well as upon three freeze-thaw cycles. SVEGFR-3 concentrations decreased in response to sunitinib to 57% (IQR 50-88%) and 58% (IQR 47-80%) of the respective baseline concentrations in healthy volunteers and mCRC patients, respectively, with subsequent increase after stop of treatment. The ELISA for the quantification of sVEGFR-3 in human plasma was successfully validated. The applicability of the assay was demonstrated in two clinical trials.
authors: Institute of Pharmacy, Clinical Pharmacy, University of Bonn, Germany.
authors: Friederike
authors: F
authors: Kanefendt
authors: Andreas
authors: A
authors: Lindauer
authors: Klaus
authors: K
authors: Mross
authors: Uwe
authors: U
authors: Fuhr
authors: Ulrich
authors: U
authors: Jaehde
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000097:blood*; D002138:Calibration; D015179:Colorectal Neoplasms / Q000097:blood* / Q000098:blood supply / Q000188:drug therapy / Q000556:secondary; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005858:Germany; D006801:Humans; D007211:Indoles / Q000008:administration & dosage; D011237:Predictive Value of Tests; D011446:Prospective Studies; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage; D055550:Protein Stability; D011758:Pyrroles / Q000008:administration & dosage; D012015:Reference Standards; D015203:Reproducibility of Results; D000077210:Sunitinib; D016896:Treatment Outcome; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000097:blood*
chemical_list: D020533:Angiogenesis Inhibitors; D014408:Biomarkers, Tumor; D007211:Indoles; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D040321:Vascular Endothelial Growth Factor Receptor-3; D000077210:Sunitinib