The structural comparison of the originator rhEPO alfa and two of its biosimilars was assessed using already recognized techniques such as reversed-phase high-performance liquid chromatography (RP-HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF–MS) for qualitative and quantitative analysis of the protein content and a two-dimensional gel electrophoresis (2D-PAGE) technique for detection of the isoforms.

The biological activity of the originator rhEPO alfa and two of its biosimilars was studied at the preclinical level using two different approaches: an in vitro study on the human TF-1 cell line and an in vivo study using the innovative experimental animal model represented by zebrafish embryos.

These studies confirmed the effective structural and functional similarity between the originator rhEPO alfa and the biosimilars analyzed.