Bispecific antibody development: Effective solutions explored

Bispecific antibody development refers to the process of creating a type of engineered antibody designed to bind to two different antigens or epitopes simultaneously.

Developing a bispecific antibody (bsAb) presents a series of challenges, ranging from optimizing binding affinity and ensuring correct assembly to managing immunogenicity and achieving efficient manufacturing. Despite these difficulties, bispecific antibodies have the potential to revolutionize therapeutic approaches in oncology, immunotherapy, hematologic disorders and more, due to their unique simultaneous engagement of two different antigens.

At evitria, we combine expert guidance with advanced technologies, such as Lonza’s bYlok® bispecific pairing technology, to deliver high-quality bispecific antibodies with rapid turnaround times, supporting you through every phase of development from target selection to production.^​1​ This article explores the development of bsAbs, highlighting the main challenges encountered, and innovative solutions used to address them.

Development of bispecific antibodies

The development process begins with the selection of appropriate target antigens. Identifying two distinct yet therapeutically-relevant antigens is essential for creating effective bsAbs. These targets must be carefully chosen to ensure they complement each other and provide a synergistic therapeutic effect.

Following target selection, the design of the bsAb format is crucial. Researchers must decide on the appropriate structure, balancing factors such as molecular weight, valency, and the spatial arrangement of binding sites. Possible valencies include “1+1” (one binding site for each target), “2+2” (two binding sites for each target), and more complex designs like “2+1” (two binding sites for one target and one for the other). 

The engineering of the bsAb requires sophisticated techniques to ensure correct assembly and functionality. This involves optimizing the variable regions to maintain high binding affinity and specificity for both targets. Additionally, the constant regions must be engineered to avoid unwanted interactions and immunogenicity.

Finally, the production process must ensure high yield, purity, and consistency, which is often complicated by the complex nature of bsAbs. Ensuring the correct pairing of heavy and light chains is a critical factor. Techniques such as the Duobody system^​2​ and the “knobs-into-holes” approach^​3​ have been developed to address these issues, facilitating the production of bsAbs with high precision and efficiency.

Challenges in bispecific antibody development

Developing bispecific antibodies presents a unique set of challenges that span across multiple phases of research, design, and production. Understanding these challenges can significantly influence the strategies employed and the eventual success of the project.

1. Target selection and validation

One of the primary challenges in bispecific antibody development is the selection of appropriate target antigens. The chosen targets must be therapeutically relevant and should ideally complement each other to maximize the therapeutic effect. Additionally, thorough validation of these targets is essential to ensure they can effectively interact with the bsAb without causing unintended side effects.

2. Format design

Designing the optimal format for a bsAb is a complex task. Researchers must balance various factors, such as the molecular weight, valency, and spatial arrangement of binding sites. The choice of format affects the antibody’s binding efficiency, stability, and ease of manufacturing.

3. Manufacturing

The production of bispecific antibodies is more complicated than traditional monoclonal antibodies. Ensuring high yield, purity, and consistency is challenging due to the complex nature of bsAbs. Correct pairing of heavy and light chains is critical to ensure the antibody functions correctly. Technologies such as the Duobody system and the “knobs-into-holes” approach have been developed to address these issues, but manufacturing still requires precise optimization and control.

4. Stability and aggregation

BsAbs often face stability issues, which can lead to aggregation. Aggregated antibodies can lose their efficacy and increase the risk of immunogenic reactions.^​4​ Ensuring the stability of the bsAb throughout its lifecycle—from production to storage and delivery—is crucial. This involves rigorous testing and the use of stabilizing agents or modifications to the antibody structure.

5. Immunogenicity

Like other antibodies, bsAbs may generate an immune response that can render them ineffective or cause adverse side effects. Engineering efforts must focus on reducing this risk while maintaining the antibody’s therapeutic function.

6. Regulatory Compliance

BsAbs must meet stringent regulatory requirements to ensure their safety and efficacy. This involves comprehensive preclinical and clinical testing, detailed documentation, and adherence to Good Manufacturing Practices (GMP).

7. Cost and Scalability

The complexity of bsAbs production often leads to higher costs compared to traditional monoclonal antibodies. Scaling up production while maintaining quality and consistency can be economically challenging. Efficient production methods and cost-effective technologies are essential to overcome these barriers.

Effective solutions in bispecific antibody development

Developing bispecific antibodies presents numerous challenges, but innovative solutions exist to address these obstacles effectively. Here are key strategies for overcoming the most significant hurdles:

Advanced target selection techniques

Employing high-throughput screening methods and bioinformatics tools facilitates the identification of promising target pairs based on biological relevance and therapeutic potential. This approach streamlines target validation processes and enhances the likelihood of success in bispecific antibody development.

Optimized bispecific antibody formats

Leveraging advanced technologies such as Genmab’s Duobody system and Lonza’s bYlok® bispecific pairing technology^​1​ is instrumental in overcoming key challenges and ensuring success. Lonza’s bYlok® bispecific pairing technology offers an elegant and confident approach to antibody design engineering, delivering >95% correct pairing of heavy and light chains and minimizing the formation of misassembled species and impurities.

This technology provides a close-to-nature solution for developing IgG-like bsAbs, enhancing their therapeutic potential and reducing the risk of unwanted immunogenicity.

Efficient manufacturing 

Efficient manufacturing is essential for translating bsAb development into tangible therapeutic solutions. With extensive expertise and experience in recombinant antibody production, evitria offers rapid and efficient bsAb expression services using a state-of-the-art CHO cell expression platform. 

This approach ensures the highest quality results and allows us to initiate production from antibody sequences and complete the process in just 4 weeks. By leveraging advanced manufacturing technologies and streamlined processes, evitria accelerates the transition from research to clinical application, enabling faster access to innovative bsAb therapeutics.

Minimizing immunogenicity

Employing humanization techniques and epitope modification approaches reduces the immunogenicity of bsAbs^​5​, enhancing their compatibility with the human immune system. These strategies minimize the risk of immune responses, improving the safety and tolerability profile of bsAb therapies.

Bispecific antibody development with evitria

At evitria, we specialize in guiding you through the complex process of selecting and developing the ideal bispecific antibody format for your therapeutic objectives. Our extensive experience and advanced technologies, such as Lonza’s bYlok® bispecific pairing technology, ensure that we can provide high-quality bispecific antibodies with rapid turnaround times. We support you from target selection and format optimization to antibody production, ensuring that your bispecific antibody projects progress smoothly and successfully.

With evitria, you can rely on expert guidance, robust production capabilities, and cutting-edge technologies to navigate the challenges of bispecific antibody development and achieve clinical success. Our collaborative approach ensures that you are well-equipped to make informed decisions and advance your therapeutic innovations with confidence.

Read more about Bispecific Antibodies from Desmond Schofield

• Bispecific antibody production – A comprehensive overview
• Bispecific Antibody Expression Service
• Bispecific antibodies – a comprehensive overview
• Understanding the side effects of bispecific antibodies
• How to choose a bispecific antibody format?
• Types of bispecific antibodies: exploring the diverse formats in therapeutic development
• What companies are developing bispecifc antibodies?
• FDA approved bispecifc antibodies