Comparability studies for protein therapeutics and biologics according to ICH Q5E including physiochemical properties, structure, conformation and potency characterization

Comparability studies are key to ensuring that a manufacturing process change will not have an adverse impact on the quality, safety (e.g. immunogenicity) or efficacy of a biologic or biopharmaceutical product.  

Under the principals of the ICH Q5E Comparability of Biotechnological/Biological Products guideline, comparability studies should provide analytical confirmation that your drug substance or drug product has highly similar quality attributes before and after manufacturing process changes. Changes to manufacturing processes of products can be necessary during development and after approval, perhaps due to driving improvements in scale, product quality or product stability. Changes to processes can also be necessary to respond to changes in regulatory requirements.

Our comparability studies team design bespoke analytical programmes that ensure that the relevant quality attributes for your drug substance or drug product are evaluated to support your manufacturing process changes. We select protein analytics referenced by the ICH Q6B Guideline to carefully examine the product from all aspects including biologic structural features including primary, secondary and higher order structure and assessment of post-translational modifications (PTM), glycosylation, physicochemical properties, biological activity /potency and immunogenicity in order to demonstrate that modifications did not occur which may adversely impact the safety and efficacy of the drug. We also assess purity/impurity profiles and can conduct comparability to Good Laboratory Practice (GLP) or Good Manufacturing Practice (cGMP) standards.

Our laboratories are equipped with a broad technology base and our strengths in mass spectrometry (Orbitrap and QToF) analysis, in particular, allow the ability to provide high-resolution, accurate-mass (HRAM) data. Based on many years of experience, our strategic approach to comparability programs means that we select from many different analytical techniques to deliver highly relevant comparability study programmes for proteins, antibodies, antibody drug conjugates, biosimilars, oligonucleotides and other biologic products.

Biosimilarity Programs  

Our teams provide analytical programs to demonstrating biosimilarity to a reference product which allows highly relevant early-stage characterisation and later-stage comparative data. These programs evaluate and compare all pertinent features of the biosimilar product and are based on the criteria outlined in ICH Q6B. 

Your Comparability Study Services Partner

As your comparability outsourcing service provider, we apply our knowledge of detailed analytics to evaluate the key quality attributes of your drug substance or drug product to help you ensure that manufacturing process changes do not impact product quality, efficacy or safety. Across your product’s lifecycle, from early-stage through to later-phase development, CMC requirements and ongoing production, we apply our Total Quality Assurance expertise to meet your comparability study needs in line with the latest regulatory requirements. 


We conduct physicochemical characterization programs to determine the physical properties such as the molecular weight by high-resolution mass spectrometry (QToF or Orbitrap ), isoform patterns, Extinction coefficient determination and validation, electrophoretic patterns, liquid chromatographic patters, spectroscopic profiles and protein quantity.

We apply high-resolution accurate-mass spectrometry (Orbitrap, QToF) coupled with U(H)PLC technology and Amino Acid Analysis methods to determine the amino acid sequence. Enzyme digestion of proteins or peptides produce suitable peptide fragments for LC-MS/MS. The mass of the peptides and the fragmentation data is used to determine the Amino Acid sequence. These studies are often accompanied by Amino Acid Analysis for the quantitative distribution of the amino acids present in the protein.

Intertek conduct selective fragmentation of the selected protein into discrete peptides by enzyme or chemical digestion followed by high-resolution mass spectrometry (Orbitrap, QToF) analysis. Peptide map methods can then be validated as UPLC-UV (MS) and used routinely for batch release or stability studies.

Confirmation of the amino-terminal  (N-terminal) and carboxy-terminal (C-terminal) amino acids is performed by MALDI-MS and high resolution mass spectrometry (Orbitrap, QToF) for product identification and to establish homogeneity, where understanding the type and extent of modifications at either termini, is a fundamental aspect of product quality control.

Where cysteine residues are present in the molecule, our scientists perform a qualitative / semi-quantitative assessment of the position and extent of expected and mismatched disulphide bridges by high resolution mass spectrometry (Orbitrap, QToF) and colorimetric tests for free sulfhydryl groups.


Project and molecule specific glycosylation studies typically include determination of the levels of neutral and amino monosaccharides as well as sialic acids, assessment of glycoform distribution and glycan structure elucidation. Multiple technologies are applied to these studies including selective enzymatic cleavage and MALDI-TOF mass spectrometry, HPAEC-PAD, HILIC-FLD or CE-LIF, to provide the level of structural information required.

Our post-translational modification analysis experts apply a strategic approach to PTM analysis during early development phases to help you to establish product acceptance criteria and as part of structural characterization studies and comparability programs, stability studies or quality control testing.

Our biologics characterisation group provides higher-order structure analysis via a suite of orthogonal techniques iusing far and near-UV circular dichroism (CD), nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR), intrinsic fluorescence studies or ultraviolet-visible (UV-vis, second derivative) spectroscopy. Our biophysical characterisation suite of technologies also includes protein aggregation studies through dynamic light scattering (DLS), SEC with multi-angle laser light scattering (MALS), sedimentation velocity analytical ultracentrifugation (SV-AUC) and differential scanning calorimetry (DSC).
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