Trastuzumab (trade name Herceptin) is a standard IgG1 monoclonal antibody that binds to the HER2/ neu receptor. Due to this receptor being over-expressed in around 20% of breast cancers, Trastuzumab’s main use is to treat certain breast cancers.

Biosimilar Characterization Considerations

The guidelines state that characterization of Trastuzumab products should include determination of physicochemical and structural properties, purity, impurities and quantity in line with ICH Topic Q6B:

Structural Characterization

Physicochemical Characterization

Product Specific Technical Considerations

Particular attention should be paid to the Post Translational Modifications (PTMs) including:

  1. Levels of Pyroglutamination of the heavy chain
  2. Disulfide bridges
  3. Heavy chain C-terminal Lysine
  4. Glycosylation (in particular galctosylation and fucosylation levels)
  5. Deamidation
  6. Oxidation