Chemical Payload

BOC Sciences develops a wide variety of payloads, each with its own characteristics. Early ADC drug research generally involved traditional small molecule chemotherapeutics, including doxorubicin. However, due to the limited availability of monoclonal antibody conjugated small molecule drugs as well as the limited amount of ADC enrichment in tumor tissues, the half-maximal inhibitory concentrations (IC50) of these small-molecule drugs remain in the micromolar range and achieve no significant therapeutic effects. Furthermore, when designing small molecule drugs, IC50 values of small molecule drugs are often required to be as low as the nanomolar or even picomolar range. These small molecule drugs mainly include two types, namely tubulin inhibitors and direct-acting DNA chemotherapy drugs.

Introduction to Chemical Payloads

Fig. 1. The structures of ADCs.

Payload is a critical factor in the successful development of ADC drugs. Because only a small part of the antibody injected into the body will accumulate in the solid tumor tissue; thus, toxic molecules with sub-nanomolar (IC50 value of 0.01-0.1nM) are suitable payloads. In addition, toxic molecules must contain cooperative coupling functional groups of strong cytotoxicity and hydrophobicity that are stable under physiological conditions. BOC Sciences' experienced project team is able to design and synthesize chemical payloads and related linkers based on customer needs, and our services are tailored to each project so to ensure all research goals are met or exceeded.

Custom Chemical Payloads Development Services

• Design chemical payloads of different action mechanisms
• Design of associated chemical-payload linkers
• Synthesis of personalized and highly potent cytotoxic payloads
• Synthesis of associated chemical-payload linkers
• Screening of payload-linker with various combinations
• Development and production of associated reagents
• Guidance and suggestions on chemical payloads selection

Our Chemical Payloads Products

Microtubule Inhibitors

Tubulin/Microtubule assembly and disassembly are among the chief processes during cell growth and division, which are also the targets of many commercially available and investigating cancer treatment drugs. Microtubule inhibitors can sufficiently interfere with cell mitosis and inhibit cell proliferation. Thus, drugs that perturb these processes are considered to be effective in inhibiting proliferative cancer cells.

DNA Inhibitors

DNA damage agents play an important role in cancer chemotherapy, and the primary cytotoxicity is manifested as inhibitory on vital cellular processes, such as transcription and replication. In fact, novel drug development targeting DNA damage response has become an active field of research for pharmaceutical companies, and various DNA damage agents have been used in ADC research and development.

RNA Polymerase Inhibitors

RNA polymerase synthesizes RNA using a DNA or RNA strand as the template and ribonucleoside triphosphate as a substrate, then polymerizes through a phosphate diester bond. Three RNA polymerases carry out eukaryotic gene transcription: RNA polymerase I, RNA polymerase II and RNA polymerase III. The potential therapeutic benefit of selectively inhibiting the RNA polymerase target to cancer cell survival prompted the need to identify small molecule drugs that selectively inhibit RNA synthesis.

Our Payload Development Workflow

Highlights of Our ADC Services

• Highly specific: drugs can be delivered precisely to target cells or tissues to reduce damage to normal cells.
• Long-acting: a longer drug half-life can improve the drug duration and therapeutic effect.
• Adjustability: flexible drug dosage and release rate adjustment capabilities ensure therapeutic effects and side effects.
• Safety: drug side effects and toxicity can be reduced to improve drug safety and tolerability.
• Diversity: different antibody and drug combination ratios can expand the scope of treatment and indications.

ADC Cytotoxins Development

Our ADC chemical payload services include the synthesis and purification of cytotoxic agents, and the development of linkers for conjugation to antibodies. We have a team of experienced chemists and biologists dedicated to the design and synthesis of these payloads, ensuring high quality and purity.

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