Bstrongximab-MMAE, a novel antibody-drug-conjugate for metastatic gastric and pancreatic cancers.

e15620 Background: As of today, there are no current beneficial clinical therapeutic cancer treatments for advance metastatic gastric or pancreatic cancers. A new approach to finding effective and meaningful drugs to treat these cancers is based an emerging hypothesis that cancer is a reprogramming disease and its origin and development is due to retrograde-like malignant cells with primitive and embryonic characteristics which are responsible for the dissemination of the disease and the almost universal clinical response of tumor resistance when treated with standard current therapies. Methods: A pluripotent human germ cell tumor cell line, TERA-1, was used to isolate and purify embryonic antigens which where used to immunized mice and, with standard B-cell hybridoma technology, to generate monoclonal antibodies. Antibodies were screened by ELISA and SDS-PAGE Western blotting to identify antibodies specific to gastric and pancreatic cancers but not to normal tissues. A second assay was used to screen the potential of the antibodies to function as antibody-drug-conjugate therapeutics against cancer. Results: A lead therapeutic antibody, Bstrongomab, was identified in the antibody screens: it is positive for gastric and pancreatic cancers but does not react with normal tissues. Bstrongomab is an IgG1 monoclonal antibody which has high affinity and specificity to the embryonic target TRA-1-60. TRA-1-60 is a carbohydrate molecule which is highly expressed in normal embryonic stem cells and not expressed in normal tissues but is re-expressed in gastric and pancreatic cancers. Immunohistochemical tissue staining studies show TRA-1-60 is expressed in gastric and pancreatic cancers. Recent published scientific reports confirm this finding. A human/mouse therapeutic version of Bstrongomab was developed - Bstrongximab - and used to generate a novel therapeutic antibody-drug-conjugate with Bstongximab and the toxic payload MMAE (Monomethyl auristatin E). Pre-clinical i n-vitro and in-vivo studies show Bstrongximab-MMAE is a potent drug for gastric and pancreatic cancers. Conclusions: Bstrongximab is a novel IgG1 human/mouse chimeric therapeutic antibody that targets TRA-1-60, a novel and yet to be tried cancer target that is highly expressed in gastric and pancreatic cancers but not in normal tissues. Bstrongximab-MMAE has the potential to be a first-in-class cancer therapeutic that provides real and meaningful benefits to patients with metastatic gastric and pancreatic cancers.