United Kingdom (UK)
Recombinant monoclonal antibody to CEA. Manufactured using AbAb’s Recombinant Platform with variable regions (i.e. specificity) from the phage display antibody CH1A1A (2F1, CH1A1A-2F1).
UniProt Accession Number of Target Protein: P06731
Alternative Name(s) of Target: CD66e; CEACAM5; Carcinoembryonic antigen; Carcinoembryonic antigen-related cell adhesion molecule 5; Meconium antigen 100 ; PR1A3; PR1.A3
Immunogen: The original murine antibody PR.1A3 was generated by immunizing BALB/c mice with mucosal scrapings and cell membrane preparations from normal large intestine. Booster dose was given with same antigen or in one case boosting was also performed with HT29 colon carcinoma cells. CH1A1A was later one generated for affinity maturation and stability enhancement by phage display.
Specificity: This antibody is capable of recognizing a membrane-proximal epitope in the B3 domain of CEA (CEACAM5, Cd66e), whereas it does not recognize shed CEA or soluble CEA as found in the circulation (PMID: 19904275; 7514303; 11517330).
Application Notes: CH1A1A is a humanized, affinity matured, and stability-engineered version derived from the murine parental PR1A3 antibody, first disclosed in PMID: 2434440. This antibody is also basis of CEA TCB (RG7802), a CEA-CD3 T cell bispecific antibody currently in Phase 1/1b clinical trials (PMID: 27622073; 27117182; 26861458). This antibody was also used in the generation of cergutuzumab amunaleukin (CEA-IL2v, RG7813), a monomeric CEA-targeted immunocytokine, that comprises a single IL-2 variant (IL2v) moiety with abolished CD25 binding, fused to the C-terminus of a high affinity, bivalent carcinoembryonic antigen (CEA)-specific antibody devoid of Fc mediated effector functions. The binding affinity of this antibody for CEA was tested using ELISA. This antibody can also be used in the immunohistochemical analysis of CEA expression by various tumors (PMID: 28405498). This antibody was also used to study the surface expression heterogeneity of CEA in cells extracted from patient derived colorectal cancer organoids (PDOs) using flow cytometry (PMID: 30982469).
Antibody first published in: Richman et al. Monoclonal antibodies to human colorectal epithelium: markers for differentiation and tumour characterization. Int J Cancer. 1987 Mar 15;39(3):317-28. PMID:2434440