BioPharmaSpec provides a complete solution for Rituximab/ Rituxan comparability, biosimilarity and characterization studies.

Rituximab (trade names Rituxan/ MabThera) is a chimeric monoclonal antibody made up of murine variable regions and a human IgG1 conserved region. It is targeted against CD20, a protein found mainly on the surface of B cells and will therefore destroy these cells. For this reason, Rituximab is used to treat diseases with high or unusual B cell populations, such as lymphomas, leukemias, transplant rejection, and autoimmune disorders.

Biosimilar Characterization Considerations

The guidelines state that Rituximab/ Rituxan comparability and characterization studies should include determination of physicochemical and structural properties, purity, impurities and quantity in line with ICH Topic Q6B:

Structural Characterization

Physicochemical Characterization

Functional Testing by Custom Biologics

  • Antibody-Dependent Cell Cytotoxicity (ADCC) Reporter Bioassay
  • Complement-Dependent Cytotoxicity (CDC) Assay
  • Binding Assays – CD20, Fc-Receptors, C1q
    • ELISA
    • MSD
    • BLI

Product Specific Technical Considerations

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

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