Introduction
Patent expiration of first-generation biologics and the high cost of innovative biologics are 2 drivers for the
development of biosimilar products. However, recombinant monoclonal antibodies (mAbs), either native or recombinant,
are amenable to post-translational modifications (PTMs), including signal peptide processing, glycosylation,
phosphorylation, C-terminal lysine truncation. Additionally, chemical modifications (e.g., oxidation, deamidation,
isomerization, modification by reactive metabolites in cell culture), clipping and aggregation can arise during
expression, recovery, purification and storage in the final formulation. Besides PTMs, sequence variants can be
introduced during the translation step of the protein in the host system, as unintended amino acid substitution, and
can lead to increased product microheterogeneity. The degree of PTMs and variants for these mAbs may differ between
host cells, culture systems, downstream processes and formulations. As a result, the identification of sequence
variants between an originator and a biosimilar product is the basis for ensuring the efficacy of generic drugs.
Fig.1. Overview of monoclonal antibody
variants used in therapy. (Hoecke L V, et al., 2019)
Our Services
Creative Proteomics has developed an LC-MS-based antibody sequencing platform to provide customers
with accurate generic drug antibody sequencing services. Our software program for automated LC-MS data processing
and evaluation enables rapid characterization of protein identity, 100% full sequence coverage of these products,
and 100% guaranteed antibody sequence accuracy, boosting the development of customers' antibody generic
drugs. In addition, the mass spectrometry method we developed can be used to study PTM differences between candidate
biosimilars and innovator products, enabling the simultaneous identification and quantification of low-abundance
impurities, sequence variations and site-specific modifications. Which locates the mass difference between the
biosimilar and the innovator to a two amino acid residue variance in the heavy chain sequences.
Apart from primary sequence, it has been established that glycosylation can be critical for the biological function
of mAbs. Product-related substances or impurities such as deamidated, isomerized or oxidized forms, or protein
aggregates that may be introduced during cloning and production processes can affect both tertiary structure and
antigen binding properties of mAbs. Creative Proteomics also provieds biosimilar and glycan
analysis services to accelerate your drug development.
Our Technical Advantages
- 100% sequence coverage based on multiple digestions of different enzymes.
- Capable of detecting mutations at as low as 1%, some as low as 0.1% of the protein level.
- Comprehensive services for biosimilars, including PTM analysis, glycan analysis, etc.
At Creative Proteomics, our scientists not only provide professional sequence variation
identification between monoclonal antibodies and generic drugs, but also complete PTMs and glycan analysis services.
In addition, we can also provide customized services according to your specific requirements and describe them in a
detailed project report. Please contact us directly for details about our
services.
References
- Xie H, Chakraborty A, Ahn J, et al. (2010) Rapid comparison of a candidate biosimilar to an innovator
monoclonal antibody with advanced liquid chromatography and mass spectrometry technologies. MAbs.
2(4):379-94.
- Griaud F, Winter A, Denefeld B, et al. (2017) Identification of multiple serine to asparagine sequence
variation sites in an intended copy product of LUCENTIS® by mass spectrometry. MAbs. 9(8):1337-1348.
