Overview

CD BioGlyco has been focusing on glycosylation site-specific ADC development for many years. We provide three glycosylation site-specific conjugation strategies to bind payloads: 1) Glycan oxidation; 2) Glycan enzymatic modification; 3) Glycoengineering.

Due to the limited selectivity, systemic toxicity, and drug resistance of traditional small-molecule anticancer drugs against cancer cells, emerging targeted ADCs have received extensive attention from researchers. ADC is a humanized or human monoclonal antibody conjugated to a biologically active cytotoxic small molecule (payload) via a chemical linker. It targets cancer cells more effectively, thereby increasing the efficacy of the drug and reducing systemic toxicity. ADC is composed of three parts: antibody, cytotoxic drug, and the linker between them. During the development of ADCs, antibodies are the key to target specificity, and the payload drug is attached to different sites on the antibody through linker chemistry. Commonly used coupling methods include cysteine conjugation, glycoconjugation, unnatural or noncanonical amino acid incorporation, and peptide tags.

Action Mechanism of ADC

After the ADC enters the bloodstream, the antibody component of the ADC recognizes and binds to cell surface antigens that are highly expressed in target cells to form an ADC-antigen complex, resulting in the endocytosis of the complex. The internalized complex is processed within the lysosome and releases the cytotoxic payload inside the cell. The released payload binds to its targets such as deoxyribonucleic acid (DNA) strands or microtubules, or exerts topoisomerase or ribonucleic acid (RNA) polymerase inhibition, ultimately leading to cell death. Cytotoxic chemical agents that typically have high potency against cancer cells but have low off-target cytotoxicity are used as payloads.

Key Technologies

• Glycan Oxidation

Chemically oxidizes native antibody glycans to generate aldehyde groups for site-specific conjugation with payloads.

• Glycan Enzymatic Modification

Uses enzymatic strategies to modify glycans, including:

• Transfer of galactose and sialic acid
• Transfer of galactose and 9-azidosialic acid (enabling bioorthogonal conjugation)
• Enzymatic removal of terminal galactose
• Glycoengineering

Employs metabolic engineering to incorporate non-natural sugars (e.g., 6-thiofucose) into antibodies, followed by targeted conjugation (e.g., with maleimide linkers).

Targeting Glycans, Amplifying Cures: ADCs Perfected.

Immunoglobulin G (IgG) molecules have a conserved glycosylation site at each N297 residue in the CH2 domain, and this site is sufficiently distant from the variable region that regulates antigen interactions. Therefore, binding to linked glycans is unlikely to impair antigen-binding affinity and may serve as an excellent surrogate for site-specific ADC generation. At CD BioGlyco, we offer three glycosylation site-specific conjugation strategies to bind payloads: 1) Glycan oxidation; 2) Glycan enzymatic modification; 3) Glycoengineering.

Workflow

• Antibody Preparation

The process begins with the enzymatic remodeling of the client's monoclonal antibody. This step involves transferring galactose and sialic acid residues onto the native glycans, preparing the antibody for subsequent chemical modification. We ensure this process is meticulously controlled for consistency and high yield.

• Periodate Oxidation

The enzymatically modified antibody is then subjected to a mild oxidation using sodium periodate. This step is carefully optimized to selectively generate reactive aldehyde groups on the terminal sialic acids while minimizing any off-target oxidation that could compromise the antibody's integrity and function.

• Site-Specific Conjugation

The aldehyde-functionalized antibody is then reacted with a cytotoxic drug payload that has been synthesized with a corresponding aminooxy group. This reaction forms a highly stable oxime bond, creating an ADC with a precise and predictable DAR.

• Purification and Characterization

The final ADC product is purified to remove unconjugated drug-linker and other impurities. We perform extensive characterization using advanced analytical techniques such as hydrophobic interaction chromatography (HIC) and LC-MS to confirm homogeneity and the exact DAR, ensuring a final product of the highest quality.

Publication Data

Advantages

• Our mild, selective approach ensures the native function of the antibody is maintained. The binding affinity to the target antigen is preserved, and the conjugation process does not compromise the antibody's pharmacokinetics.
• Our approach is a modular platform that can be applied to any existing monoclonal antibody, significantly shortening development timelines.
• By targeting the native glycans at the Asn-297 site, our process produces a highly uniform ADC population with a defined DAR.

Application

• Oncology

The primary application for ADCs, our platform is optimized for the development of potent and selective anti-cancer agents.

• Autoimmune diseases

Targeted delivery of immunomodulatory or immunosuppressive agents can provide a more effective and less toxic treatment for autoimmune disorders.

• Infectious diseases

ADCs can be engineered to target and deliver antimicrobial agents to specific infected cells.

• Cell & gene therapy

The platform can be used to site-specifically label antibodies for diagnostic imaging or to deliver genetic material to target cells.

Frequently Asked Questions

Associated Services

Glycosylation site-specific ADC development platforms empower precision engineering of ADCs with optimized therapeutic indices—leveraging conserved glycosylation sites for homogeneous payload attachment. To validate the safety, purity, and efficacy of such advanced therapeutics and other critical pharmaceuticals, we provide Pharmaceutical Analysis Services that rigorously characterize drug composition, stability, and impurities:

CD BioGlyco is dedicated to offering glycosylation site-specific ADC development services to help our global clients in this field. If you have a related ADC development project in hand, please feel free to contact us for more information.