Abstract
The subchronic toxicity of Hematide™, a synthetic PEGylated peptidic erythropoiesis-stimulating agent (ESA), was evaluated in CD-1 mice at intravenous doses of 0, 1, 5, 25, and 125 mg/kg administered once every 3 weeks for 3 months. Hematide displayed sustained plasma levels with reduced clearance and prolonged half-lives up to 59.4 hours that translated into sustained, pronounced polycythemia, bone marrow hyperplasia, and splenic and liver extramedullary hematopoiesis. Toxicological findings were considered to be secondary to exaggerated pharmacology, rather than a direct drug effect, and included mortality at ≥25 mg/kg/dose. The no-observed-adverse-effect-level was determined to be 5 mg/kg.
Acknowledgements
Declaration of interest: Three of the authors (KWW, QF, PJS) are employed by Affymax whose potential product was studied in the present work.