Biopharmaceutical Comparability Studies

Comparability studies are of major importance in the development of biopharmaceuticals. For new products, such studies may be needed to qualify sources of clinical trial materials following process development, optimization, and scale up as progress through the clinical development phases is made. The demonstration of equivalence to materials used in toxicology and early phase clinical trials is necessary to avoid bridging toxicology or clinical trials which would clearly add significantly to drug development timescales and cost. Comparability studies are also key to the development of biogenerics/biosimilars.

Intertek is highly experienced in the biophysical characterization of a diverse range of biopharmaceuticals and has undertaken detailed comparability studies. There is a regulatory expectation that “orthogonal” approaches will be applied such that conclusions for key quality attributes are based on multiple technologies. Recent projects have included comparing the study materials using the following approaches:

Primary Structure:

• Molecular weight by MALDI-MS, electrospray MS and LCMS

• Amino acid composition

• Peptide mappng by protease digestion followed by LCMS, LCMSMS and MALDI-MS (this typically also provides the N– and C– terminal sequence information)

Post Translational Modifications:

• Disulphide bridge mapping using protease digest and chemical modification experiments followed by MALDI-MS

• Free thiol determination

• Glycosylation detection/fingerprinting using acid hydrolysis followed by anion exchange chromatography with electrochemical detection

• Characterisation of other PTMs i.e.deamidation, acetylation, phosphorylation

Chromatographic Profiles:

• Profiles generated using LCMS, reducing and non-reducing gel electrophoresis, horizontal and vertical gel isoelectric focusing and capillary isoelectric focusing

Secondary / Tertiary Structure:

• Determination of secondary structural attributes (α-helix, β-sheet, β-turns) using FTIR and circular dichroism (CD)*

• NMR studies using 500 MHz instrument to compare the behaviour of samples when stressed by heating, resulting in loss of secondary/tertiary structure and precipitation

Quarternary Structure / Aggregation State:

• SEC-MALLS and Analytical Ultra Centrifugation (AUC*) studies

• Imaging of aggregates using electron microscopy following immuno-gold labelling

• Fluorescence studies of behaviour under denaturing conditions e.g. heat or urea

• Further aggregation techniques

*CD and AUC data is generated in partner laboratories following QA audit and can be included in formal regulatory studies and in conclusions drawn across multiple techniques

Biopharmaceutical Services include:

• Structural Characterisation and Confirmation

• Method Development and Validation

• Higher Order Structural Characterisation

• Aggregation State Characterisation

• Isolation and Characterisation of Product Related Impurities

• Process Impurity Method Development, Validation and QC

• Comparability Studies

• Specialist Services for Antibody Therapeutics

• Stability Studies