Pharmacokinetic evaluations
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BLOOD
Blood samples for determination of fruquintinib plasma concentrations were collected at pre-dose and 1, 2, 4, 8, and 24 h after dosing on Days 1, 14, and 21 of C1. The 24-h samples were collected prior to the next dose. PK samples were analyzed by LabCorp Bioanalytical (Shanghai, China) using a validated, specific, and sensitive liquid chromatography with tandem mass spectrometry assay method with an analytical range of 1.00 ng/mL (lower limit of quantitation) to 750 ng/mL (upper limit of quantitation). Inter-run variability was ≤ 5.2%. Quality control (QC) samples at 5 concentrations (3, 30, 45, 300, and 600 ng/mL) were assayed along with study samples, and the calculated QC sample concentrations deviated by ± 3.3% from the nominal concentrations.PK parameters were determined by noncompartmental analysis using Phoenix® WinNonlin® v8.2. Systemic exposure to fruquintinib was evaluated based on PK parameters including maximum observed concentration (C