BOC Sciences provides an integrated biological platform with antibody-drug conjugates (ADCs) payloads development and manufacturing capabilities from preclinical to commercial stages. ADCs connect biologically active small molecule drugs with monoclonal antibodies through chemical bonds. Meanwhile, antibodies served as carriers for small molecule drugs for cancer cell targeting.
Fig. 1. Mechanism of ADC activity (Pharmacology & Therapeutics. 2018; 181: 126-142).
Ideal payloads are highly pharmacological and non-immunogenic, and these properties are significant, especially in cancer treatment. However, cytotoxic drugs used in the body often interfere with cellular regulatory mechanisms and lead to side effects such as impaired immune defense function, hair loss, and nausea. Therefore, the best treatment method is directly introducing the loaded toxic drug into tumor cells prior to its cytotoxicity manifestation. Toxins that were used as payloads should be soluble, easy to bind, suitable for conjugation, and stable. In order to trigger cytotoxic effects, payloads should have the following characteristics: (i) high cytotoxicity, (ii) target the inside of tumor cell, (iii) small molecular structure to reduce the risk of immunogenicity. According to action mechanisms, biological payloads commonly used in clinical trials can be divided into two categories: protein toxin and enzyme toxin.
Small molecule (natural product) toxins are the main category of ADCs that have been approved for treatment or in clinical trials, accounting for 70% of the market. A successful biopharmaceutical of fusion protein should contain protein toxin conjugated to an anti-tumor antibody. The various types of protein toxin development BOC Sciences can provide include: pseudomonas exotoxin, Shiga toxin, Shiga-like toxin, diphtheria toxin, and phytotoxins.
BOC Sciences provides antibody-directed enzyme prodrug therapy (ADEPT), which uses antibody-enzyme conjugates to induce and achieve selective tumor cell death. ADEPT can generate highly localized concentrations of cytotoxic agents in the tumor, thereby reducing the collateral toxicity associated with normal tissue exposure. ADEPT is a two-component approach. First, a non-toxic antibody-enzyme fusion protein is localized to the tumor matrix by binding a specific antigen expressed only on the surface of cancer cells. Once the fusion protein is attached, an inert small-molecule prodrug is administered, the substrate for the enzyme bound to the tumor surface. When the prodrug comes into contact with the bound enzyme, an active cytotoxic agent is generated. BOC Sciences has developed a series of different methods to facilitate your ADEPT research.
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