Omalizumab (trade name Xolair) is an IgG1 monoclonal antibody that binds to free immunoglobulin E (IgE) in blood and interstitial fluid and to membrane-bound IgE on the surface of IgE-expressing B lymphocytes. Due to the role IgE plays in allergic diseases, Xolair is used to treat cases of severe asthma where there is no response to high doses of corticosteroids. The patents on Xolair will expire in the US in June 2017 and in Europe in August 2017.

Biosimilar Characterization Considerations

The guidelines state that characterization of Omalizumab 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: