Anti-hCD20-Of-hIgG4 (S228P)

Anti-hCD20-Of-hIgG4 (S228P) features a human IgG4 constant region (Fc) with a S228P mutation, and the variable region of Ofatumumab with targets the human CD20 antigen found on the surface of normal and malignant B lymphocytes.
The S228P mutation allows stabilization of the disulfide bridges in the IgG4 core-hinge region. Therefore, this modification prevents the exchange of fragment antigen binding (Fab) regions between IgG4 antibodies, a process that potentially reduces their therapeutic efficacy.

Ofatumumab is a fully human type I (first generation) monoclonal antibody which mediates B cell destruction through complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Ofatumumab has been approved by the FDA for the treatment of chronic lymphocytic leukaemia (CLL) [1-3].

InvivoGen's Anti-hCD20-Of-hIgG4 (S228P) is generated by recombinant DNA technology, produced in CHO cells, and purified by affinity chromatography (protein G).
More isotypes of this antibody are available and can be used for comparison of biological activities such as ADCC (see below).
InvivoGen also provides type I anti-hCD20 mAbs featuring the variable regions of Rituximab or Obinutuzumab, with either native or engineered Fc region.

Read our review on Antibody Isotypes

References:

1. Baig NA. et al., 2014. Induced resistance to ofatumumab-mediated cell clearance mechanisms, including complement-dependent cytotoxicity, in chronic lymphocytic leukemia. J Immunol. 192(4):1620-9.
2. Lin TS., 2010. Ofatumumab: a novel monoclonal anti-CD20 antibody. Pharmgenomics Pers Med. 3:51-9.
3. Winiarska M. et al., 2011. Molecular mechanisms of the antitumor effects of anti-CD20 antibodies. Front Biosci (Landmark Ed). 16:277-306.