CTAT: Further proof-of-concept data presented at PEGS Boston 2014

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EUCODIS presented latest developments of CTATTM,  its proprietary ADC linker technology at the10th Annual Protein Engineering Summit (PEGS) in Boston, May 5th – 9th.
CTATTM is a novel, enzyme-based technology for the directed c-terminal conjugation of antibodies with a broad spectrum of different payload molecules. In contrast to existing first generation chemical linker technologies or second generation site-specific linker technologies, the CTATTM technology combines the benefits of efficient c-terminal, site-directed conjugation without affecting the specificity and stability of the antibody.

CTATTM is a novel, enzyme-based technology for the directed c-terminal conjugation of antibodies with a broad spectrum of different payload molecules. In contrast to existing first generation chemical linker technologies or second generation site-specific linker technologies, the CTATTM technology combines the benefits of efficient c-terminal, site-directed conjugation without affecting the specificity and stability of the antibody.


At the conference new insights into the CTATTM technology were presented including proof-of-concept data using an anti-Her2 full length antibody and a Fab fragment, both conjugated to CTATTM-enabled drug molecules and dyes. Full biochemical characterization with regard to drug to antibody ratio will be shown as well as efficacy data generated with different Her2-positive cancer cell lines.


As the current proof of concept (PoC) data show, the short, 3-4 amino acid peptide linker combines the high stability of a covalent peptide bond and controllable DAR with all benefits of conventional ADCs. In addition, the short peptide linker offers lowest immunogenic potential and cleavability after cellular internalization of the ADC. In vitro experiments with cancer cell lines prove the applicability and versatility of CTATTM for the generation of antibody conjugates.


The CTATTM enzyme recognizes a defined, three-amino acid sequence added to the c-terminus of the antibody, cleaves this sequence and attaches the payload by forming a new peptide bond in a nucleophilic addition reaction (transamidation). This allows to carefully control the antibody drug ratio (ADR) in contrast to chemical conjugation methods, which produce a heterogeneous mixture of antibodies with variable drug load of 0-8 drug molecules per antibody.

For download of the poster click here.

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