A Phase I Dose-Escalation Study of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Polyethylene Glycol-Erythropoietin (PEG-EPO) in Healthy Subjects

PURPOSE:This first-in-human trial aimed to investigate the pharmacokinetics and pharmacodynamics characteristics and safety and tolerability of single ascending doses of subcutaneous polyethylene glycol-erythropoietin (PEG-EPO) in healthy subjects. METHODS:In this phase I, randomized, double-blind, placebo-controlled, dose-escalating trial, subjects were sequentially enrolled into 7 cohorts with 12 subjects in each cohort and randomized in a 5:1 ratio to receive a single dose of 0.2, 0.4, 0.8, 1.6, 2.4, 3.6, or 4.8 µg/kg PEG-EPO or matching placebo. Safety and tolerability including dose-limiting toxicities (DLTs) were assessed. Pharmacokinetics parameters, including Cmax, AUC0-inf, Tmax, and t1/2, and pharmacodynamics parameters, including reticulocyte count and hemoglobin content, were evaluated. FINDINGS:Eighty-four subjects (median age 30.4 years and 77.4% male) were enrolled. No subjects developed DLTs. Any grade treatment-related adverse events occurred in 66.7% of the subjects, but most (92.9%) were mild. No serious adverse events and no death occurred. Forty percent of the subjects receiving PEG-EPO had iron decreased, 27.1% reported ferritin decreased, 25.7% showed unsaturated iron binding capacity increased, and 17.1% had neutrophil count decreased. Cmax exhibited a dose-disproportionate rise from a geometric mean of 525 pg/mL with 0.2 µg/kg PEG-EPO to 23196 pg/mL with 4.8 µg/kg PEG-EPO. The mean t1/2 ranged between 82.4 ± 21.3 h with 0.4 µg/kg PEG-EPO and 160.6 ± 65.7 h with 1.6 µg/kg PEG-EPO. AUC0-inf displayed a largely dose-proportional rise from 226264.5 pg*h/mL with 0.2 µg/kg PEG-EPO to 5206434.0 pg*h/mL with 4.8 µg/kg PEG-EPO. The absolute reticulocyte count increased with escalating doses of PEG-EPO, with the mean maximal change from baseline between 3.2 ± 1.5*10^10/L (Q1,Q3 1.8-3.6*10^10/L) with PEG-EPO 0.2 µg/kg and 9.3 ± 4.0*10^10/L (Q1,Q3 6.2-13.5*10^10/L) with 3.6 µg/kg PEG-EPO. The mean maximal change from baseline in the mean hemoglobin content ranged between 5.9 ± 4.4 g/L (Q1,Q3 3.5,7.0) with 0.2 µg/kg PEG-EPO and 15.4 ± 8.7 g/L (Q1,Q3 10.5,20.0) with 2.4 µg/kg PEG-EPO. IMPLICATIONS:This trial demonstrated that PEG-EPO was safe and tolerable in healthy subjects. The subcutaneous route of administration allows outpatient treatment and the pharmacokinetics characteristics of PEG-EPO support less frequent dosing regimens and effective treatment for chronic kidney disease patients with anemia. TRIAL REGISTRATION:clinicaltrials.gov identifier: NCT03657238.