Bispecific antibodies are engineered antibody molecules designed to simultaneously recognize two distinct antigens or epitopes, enabling unique mechanisms of action compared with conventional monoclonal antibodies. By combining dual-targeting capability, bispecific antibodies can enhance immune cell recruitment, block multiple signaling pathways, or improve tumor cell targeting, offering significant potential in cancer immunotherapy and other therapeutic applications.

Early bispecific antibody generation mainly relied on chemical conjugation or cell fusion approaches, which were limited by low efficiency and difficulties in controlling antibody pairing. Advances in antibody engineering have led to the development of innovative platforms, including knob-into-hole (KiH), CrossMab, and DVD-Ig technologies, which improve chain pairing accuracy, antibody homogeneity, and production yield. These advances have accelerated the development of bispecific antibodies as promising candidates for clinical and translational research.

Bispecific antibodies can be generated through various approaches, including chemical conjugation, hybridoma-based methods, and advanced genetic engineering platforms. Chemical conjugation directly links two antibodies or antibody fragments to form bispecific molecules; however, limitations such as reduced antigen-binding activity and potential heterogeneity restrict its broader application.

Genetic engineering has become the most widely adopted strategy for bispecific antibody development due to its flexibility in antibody design and optimization. By recombining antibody fragments or variable regions from different monoclonal antibodies, engineered bispecific antibodies with defined structures and functions can be generated. Advanced antibody engineering platforms, including knob-into-hole (KiH), CrossMab, and other molecular formats, further improve chain pairing accuracy, stability, and production efficiency. During bispecific antibody design, careful optimization of molecular structure and specificity is essential to minimize off-target interactions and enhance therapeutic potential.

Efficient purification is critical for obtaining high-purity and biologically active bispecific antibodies. The purification process typically begins with affinity chromatography for initial antibody capture, followed by advanced purification steps to remove impurities and improve product quality.

For IgG-like bispecific antibodies, Protein A affinity chromatography is commonly used, while alternative affinity strategies may be applied for non-IgG formats. Additional purification approaches, including ion exchange chromatography, ultrafiltration, and nanofiltration, help eliminate host cell proteins, aggregates, and other impurities. The final product is concentrated and formulated in an optimized buffer system to maintain antibody stability and support downstream applications.