Pharmacokinetic and pharmacodynamic assessments
PD
BLOOD, CLOT
Blood samples were collected on Day −1 at 8 AM, 12 PM, and 8 PM to characterize each patient’s baseline iron status, pre-dose on Day 0, and then at 1, 2, 6, 12, 24, 48, and 72 h post-dose. Whole blood samples were collected in 5 mL evacuated red-top blood collection tubes (no anticoagulant) and were allowed to clot while standing at room temperatures and then centrifuged at 2000g. Serum samples (minimum volume 800 µL) were then transferred to cryovials, frozen at –20 °C and shipped on dry ice for analysis (Butterworth Laboratories Limited, Teddington, Middlesex, UK). Serum samples were analyzed for iron content using inductively coupled plasma-mass spectrometry. The assay was validated over the range of 1–1000 µg/mL and does not distinguish between endogenous serum iron and that derived from the FCM infusion.PK parameters were determined for each patient. The primary PK parameters for iron were maximum serum concentration (Secondary PK parameters for iron were mean residence time, apparent serum clearance (CL), and apparent volume of distribution (PK analyses were conducted by ICON plc (Reading, UK) using Phoenix WinNonlin v6.3 (Certara Corp, St Louis, MO). PK parameters for baseline-corrected total serum iron were calculated using noncompartmental analysis (WinNonlin Model 200–202 for IV dosing). Actual elapsed time from the start of the infusion and actual dose amounts were used in calculations. Concentrations determined to be below the limit of quantitation were assigned a value of zero before achievement of PD assessments included serum ferritin, serum transferrin, serum hemoglobin, reticulocyte count, and TSAT. Blood samples for all PD assessments were collected at screening (up to 14 days before treatment Day 0), at 72 h post-dose, and on Days 14, 28, and 35. The change from baseline in ferritin, hemoglobin, and TSAT at each scheduled visit; and the change from baseline to the highest post-dose value in serum ferritin, transferrin, hemoglobin, reticulocyte count, and TSAT were summarized.