Charge Variant analysis of mAb Biosimilars by Nexera™ UHPLC with a Shim-pack™ Bio IEX Column

Introduction

Monoclonal antibodies (mAbs) are well-established biotherapeutics for a wide range of diagnostic and clinical applications. The newly emerging biosimilars are increasing in popularity in biopharmaceuticals because of the cost savings. However, biosimilars can undergo various post-translational modifications in manufacturing processes, including sialylation, deamidation, C-terminal lysine cleavage, glycosylation, succinimide formation, oxidation and so forth. These modifications can lead to variations of charge distribution that potentially affect the biological activity and stability of the products. Therefore, characterization and monitoring of charge variants of mAb biosimilars are critical quality requirements to ensure the stability and process consistency in drug development. Conventionally, ion exchange chromatography (IEX) with salt-gradient is the gold standard method for charge-sensitive antibody analysis. A key challenge of salt-gradient is that the method parameters often need to be optimized for each individual protein. In 2009, Genentech first reported the use of IEX with pH-gradient for mAb charge variant separations [1]. It was found that mAbs with isoelectric points in the range of pH 7-9 could be well separated. Moreover, the approach was more generic and could easily be used to separate different charge variants in a wide range of antibodies. In this study, we describe both salt-gradient and pH- gradient methods for separating the charge variants of bevacizumab biosimilar using Shimadzu Nexera UHPLC and a Shim-pack Bio IEX column (4.6 mm x 100 mm, 3 μm).

September 13, 2019 GMT