CD22 is a common cell surface glycoprotein expressed in B-cells and present in B-cell lymphomas; e.g., hairy cell leukemia (HCL), non-Hodgkins lymphoma (NHL), chronic lymphoblastic leukemia (CLL), and other cancers. It is therefore a target for cancer immunotherapy. Conjugation of anti-CD22 monoclonal antibodies with toxins or drugs has shown promise in clinical trials. However, all monoclonal anti-CD22 antibodies used in clinical trials are of murine origin. This is problematic because they have the potential of causing immunogenic reactions when used repeatedly in patients to achieve higher efficacy.
NCI scientists isolated two human monoclonal anti-CD22 Fab antibodies; m972 and m971 with 2nM and 20nM affinities respectively. These two human anti-CD22 monoclonal antibodies are better alternatives for cancer immunotherapy over current humanized murine antibodies as they overcome the problem of immune reactivity. They also developed a murine anti-CD22 monoclonal antibody M973 with better affinity and solubility than its parent antibody HA22 and could have improved efficacy in cancer immunotherapy than the murine monoclonal anti-CD22 antibodies currently in use. The m971 binder has also been incorporated into chimeric antigen receptors (CARs) with positive results which are covered under NIH Reference Number E-291-2012 and other related filings.
Researchers at the NCI seek research and co-development partners and/or licensing for the development of human monoclonal antibodies and antibody-based therapeutics against CD22.
- Fully human monoclonal antibodies overcome the problem of immune reactivity to murine antibodies
- Improved monoclonal antibodies have better affinity and solubility than current antibodies
- Monoclonal antibody therapeutic against B-cell lymphomas and other CD22-positive cancers
- Diagnostic tool for detection of CD22-positive cancers
- Delivery of drugs, toxins and liposomes to CD22-positive cancers