Minretumomab, also known as CC49, is a second-generation murine monoclonal antibody based on the antibody B72.3 that is directed against tumor-associated glycoprotein 72 (TAG-72). Minretumomab was designed for the treatment of breast, colon, lung, and pancreatic cancers. However, there are less clinical trials about it. Minretumomab is a murine antibody that cannot be used as a therapeutic antibody in human directly. Thus, the derivatives like chimeric and humanized minretumomab, a fusion protein of a minretumomab single-chain variable fragment and the enzyme beta-lactamase have been investigated in pharmaceutical research. In addition, dot-conjugated minretumomab also has been used in the in vitro gastric cancer cell imaging. Iodine-125-labeled minretumomab is also used to detect tumors in radioimmunoassay such as CA 72-4. Radiolabeled minretumomab has also been studied for tumor treatment, but has not shown any anti-tumor response.
Minretumomab is a protein optimized by monoclonal antibody (MAb) B72.3 antibody, which is produced in the membrane enrichment part of human breast cancer biopsy tissue. Minretumomab is designed to target TAG-72 to play a biological role. TAG-72 is a membrane-bound glycoprotein with mucin-like properties and highly expressed on the surface of a variety of tumor cells. It was found that TAG-72 was expressed in 80% of colorectal cancer tissues, but relatively less in normal mucosa. In addition, the expression rate of TAG-72 in ovarian cancer (26.0%) was significantly higher than that in normal ovarian tissue (0) (P < 0.05), and its expression was related to the clinical stage and differentiation of ovarian cancer. In prostate cancer, the expression of TAG-72 is also more active. In view of its high activity in tumor cells, TAG-72 is also considered to be a tumor marker. Researchers have developed some monoclonal analysis methods for TAG-72 to promote the diagnosis of cancer. The mechanism of the anti-tumor effect of minretumomab may be through the combination of TAG-72, but the specific mechanism remains to be further studied.
Fig.1 Mechanism of action of minretumomab