Clinical validation of an RIA for natural and recombinant erythropoietin in serun and plasma

Molecular and electrical heterogeneity of circulating human erythropoietin measured by sensitive enzyme immunoassay

“…The minimum detectable quantity was 0·15 mIU mL ¹1 in the assay. The sensitivity was much greater than 5 mIU mL ¹1 in commercially available radioimmunoassay kit [2], and equal to or higher than sensitive immunoassay of EPO previously reported [13][14][15][16][17][18][19][20][21][22][23]. The sample volume of 20 mL is sufficient enough for measurement of plasma EPO concentration, which was only one-tenth smaller in volume than those in previous reports.…”

Oral Hypoxia‐Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat (FG‐4592) for Treatment of Anemia in Chronic Kidney Disease: A Placebo‐Controlled Study of Pharmacokinetic and Pharmacodynamic Profiles in Hemodialysis Patients

“…Mechanistically, a robust transient endogenous EPO response to roxadustat was observed, with peak endogenous EPO levels (C max ) resembling physiologic responses to hypoxia. [27][28][29] In this study, 1-and 2mg/kg doses of roxadustat resulted in median peak plasma endogenous EPO concentrations of approximately 96 mIU/mL and 268 mIU/mL, respectively. These exposures are approximately within the range of physiologic effects seen in healthy patients adjusting to high altitude (200-300 mIU/mL) 30,31 or to phlebotomy, hemorrhage, or hypoxemia (50-1250 mIU/mL) [27][28][29] and are substantially lower (4-to 20-fold) than those resulting from an intravenous epoetin-alfa dose typically used in standard-of-care dialysis.…”

“…The plasma samples were collected before dosing, and PK analysis was performed for each roxadustat dose with samples taken immediately prior to dosing and at multiple time points after dosing on days 1 and 8. Day 1 postdose sampling time points were 0.5, 1.0, 2.0, 3.0, 4.0, 8.0, 12.0, 22.0, 48.0, 48.5, 49.5, 50.5, 51.5, 52, 71, and 95 hours after dosing; day 8 time points were 0.5, 1, 2, 2.5, 3.5, 4.5, 5,11,15,27,53, and 77 hours after dosing.…”