Bispecific Antibodies Could Be the Next Big Advance in Tumor Treatment Research

Monoclonal antibodies, tumor vaccines, immune checkpoint inhibitors, CAR-T cell immunotherapy, and bispecific antibodies are all effective cancer immunotherapy methods now available. CAR-T cells and bispecific antibodies, in particular, have gotten a lot of interest as potential anti-tumor immunotherapy techniques. Despite significant technical challenges in technology and industry, BsAb is seen as a promising medication for tumor and cancer treatment.

Bispecific antibodies (BsAb) are artificially engineered antibodies that can simultaneously bind two specific epitopes or proteins of interest. They have the ability to bind two different epitopes simultaneously and can play some special biological functions. BsAb mediates the killing of tumors by immune cells. Of the two antigen-binding arms, one binds to the target antigen and the other binds to the labeled antigen on the effector cells. The latter activates effector cells and targets them to kill tumor cells.

BsAb can simultaneously bind dual targets, block dual signaling pathways, play unique or overlapping functions, and effectively prevent drug resistance. What’s more, the two antigen binding arms bind different antigens, which effectively enhances the binding specificity and targeting of the antibody to cancer cells while reducing off-target toxicity. In addition, the use of BsAb can also effectively reduce the cost of treatment. Compared with monoclonal antibodies, it has stronger tissue penetration, tumor cell killing efficiency and clinical indications, and the dosage can be reduced to a minimum of 1/2000, which significantly reduces the cost of tumor treatment.

The preparation of BsAb mainly includes chemical coupling method, double hybridoma fusion method and genetic engineering. The chemical coupling method is the earliest preparation technique. Two complete IgG or antibody fragments are coupled into a BsAb through chemical coupling reagents. This technique is fast and simple, but it is easy to destroy the antigen binding site and is uncertain about safety and carcinogenicity. The double hybridoma fusion method is to synthesize two different hybridoma cells into two-hybridoma cell lines by cell fusion, and then obtain cloned cells through conventional hybridoma screening. The BsAb produced by this technology is random and low in efficiency, but has good biological activity and stable structure. Genetic engineering for bispecific antibody uses genetic engineering technology to transform antibodies to form various forms of bispecific antibodies. This technique is currently more commonly used to prepare BsAb.

"Bispecific antibody, as the latest concept in the field of antibody drugs, is regarded as the second-generation antibody therapy for the treatment of tumors." Said an expert at Creative Biolabs, a leading biotech company in BsAb field, "The ability to simultaneously detect several antigens or combine antigen binding sites with assay markers makes it an important target for further research in biomedicine, pharmacology and diagnostics."

Mismatches, purification, instability of downstream processes, instability of the two antibodies, and imbalance of their expression are only a few of the hurdles it encounters in commercialization as a forward-thinking technology. With the advancement of technology, it is expected that more and better approaches will be developed in the future to improve various BsAbs so that they have greater efficacy and fewer side effects, providing hope to cancer patients.