Quality of original and biosimilar epoetin products.

PURPOSE: To compare the quality of therapeutic erythropoietin (EPO) products, including two biosimilars, with respect to content, aggregation, isoform profile and potency. METHODS: Two original products, Eprex (epoetin alpha) and Dynepo (epoetin delta), and two biosimilar products, Binocrit (epoetin alpha) and Retacrit (epoetin zeta), were compared using (1) high performance size exclusion chromatography, (2) ELISA, (3) SDS-PAGE, (4) capillary zone electrophoresis and (5) in-vivo potency. RESULTS: Tested EPO products differed in content, isoform composition, and potency. CONCLUSION: Of the tested products, the biosimilars have the same or even better quality as the originals. Especially, the potency of originals may significantly differ from the value on the label.