A-TAP (Antibody-Targeted Anti-vasculogenic Payload) is a fully biological payload platform . It involves the linking of highly potent anti-angiogenic properties of a variant of endostatin, Endostatin-P125A, with the proven selectivity and anti-tumor activities of tumor-targeting monoclonal antibodies. The genetic combination of endostatin variant to an antibody, or an antibody fragment generates a fusion molecule that provides excellent inhibition of both angiogenesis and vasculogenic mimicry. A-TAP can be applied to antibodies to increase their potency, diversify their functions or generate innovative multifunctional product candidates.
The A-TAP fusion is essentially a “bi-targeted” and poly-functional molecule. The antibody part of the fusion provides targeted delivery of the endostatin payload to the therapeutic locale to inhibit angiogenesis and vasculogenic mimicry leading to both inhibition of tumor growth and metastasis. Additionally, the antibody also provides anti-tumor signal through the interaction with its own receptors, and also could elicit ADCC or CDC functions thereby synergistically augmenting the anti-tumor effects of antibody-TAP.
Even though A-TAP is an antibody-linked payload system, however unlike ADCs (Antbody Drug Conjugates) which involves covalent conjugation of chemical drugs to antibodies, A-TAP is a fully biological payload that genetically fuses endostatin-P125A to antibodies. Additionally,
A-TAP fusion can be produced recombinantly in commercial cell lines and thus is less complex as well as less expensive relative to the in vitro chemical conjugation and follow up purification to generate ADCs.
A-TAP serves as a building block for creating next generation polyfunctional therapeutic antibodies specifically for targeting purposes to generate more efficient anti-cancer drugs.
A-TAP is a next generation biological payload technology, outside of cytokines (which have significant toxicity issues) that could generate both “biobetter” and first-in-line products.
A-TAP also provides several benefits that are not possible by ADCs including its ability to utilize both internalizable as well as non-internalizable targets, as compared to ADC’s utility in internalizable targets only.