The biological sciences are in a period of rapid growth and discovery. In medicine, scientists are harnessing the power of the human body for healing by working alongside it, rather than trying to beat it into submission with aggressive treatments.
One of the biggest advances, which fits under the umbrella of precision medicine, is the use of monoclonal antibodies (mAbs), a type of treatment that uses the body’s own immune system to fight disease. These drugs fall into the category of immunotherapy, or biologics.
While producing monoclonal antibodies is complex and expensive, their use is transforming the way we treat many diseases by using the immune system itself in order to achieve the best possible outcomes, with the fewest possible side effects.
As the industry grows, scaling production remains the biggest challenge.Still, there is tremendous opportunity to develop new antibodies and new technologies that use them.
If you google “monoclonal antibody,” the top results will be clinical trials and existing studies from the NIH about how these treatments can be used in treating mild to moderate COVID-19. Monoclonal antibodies gained widespread fame when the US Food and Drug Administration (FDA) gave emergency use authorization to use specific monoclonal antibodies in COVID-19 treatment.
In the medical and scientific communities, monoclonal antibodies have been used for decades in transplant medicine, infectious diseases, cancer care, autoimmune conditions, and inflammatory conditions.
Monoclonal antibodies are produced to tag specific proteins produced by the immune system, which is why they are considered “immunotherapy”. Some of the most common are cell markers and signaling molecules, but there are many potential targets yet to be discovered. Because the targets are varied, the mechanisms of action of monoclonal antibodies are also varied and, in some cases, not wholly understood.
To understand how monoclonal antibodies are produced, it’s important to understand some basics about B-cells, a type of infection-fighting immune cell. All cells and cell fragments that make up blood - white blood cells, red blood cells, plasma cells, and platelets - are produced in the bone marrow. There are three types of white blood cells (immune cells): lymphocytes, granulocytes, and monocytes. The immune cells that we will be focusing on are lymphocytes. There are two types of lymphocytes, B-cells and T-cells, which protect us from and fight infection.
After developing in the bone marrow, T-cells move to the thymus (a secondary lymphoid organ) to mature. At the same time, B-cells start maturation in the bone marrow and then travel to the spleen to finish maturing. B-cells are then activated in the spleen or the secondary lymphoid organs like the lymph nodes.
There are two ways that B-cells can be activated. Either directly or through T-cell mediated activation, both of which require exposure to an antigen. For the purposes of this article, the important part of B-cell activation is what happens afterward:the activated B-cell differentiates into a plasma cell, which then secrete antibodies against the antigen it was exposed to. Antibodies can then activate other parts of the immune system in several different ways. The complexities of the immune system are endless.
If you’re interested in learning more, you can start with two articles provided by the NIH: immune cells and physiology, immune responses.
Monoclonal antibodies are named as such because they are all produced by a single B-cell and its clones. Once a useful antibody is discovered, a clonal cell population is grown using myeloma cells, which produce abnormally large quantities of plasma cells and, therefore, large quantities of antibodies.
Initially, B-cells from mice were used, which caused immune reactions and rapid removal from the bloodstream as these proteins were recognized as foreign. Scientists found a way around this by combining human and murine (mouse) protein sequences in the development of antibodies.
The initial production of monoclonal antibodies was through a hybridoma, a combination of splenic B-lymphocytes from an immunized mouse against an antigen of interest. This caused unwanted, sometimes dangerous immune reactions due to the antigenicity of the mouse protein.Still, scientists quickly learned that this could be mitigated.
Even using the hybridoma, chimeric and humanized antibodies can be created by fusing human and mouse proteins. The same can be done with transgenic mice. Most recently, fully human monoclonal antibodies have been made by infecting or vaccinating humans, harvesting the cells, and sorting them.
In all of these techniques, complicated screening and sorting tools are required, like ELISA and flow cytometry, to determine the antibodies with the highest affinity for their targets. They then undergo a process of maturation to maximize this affinity. Finally, the antibodies must be produced at a large scale, either in a live animal or in vitro tissue medium. Each of these techniques has its particular, resource-intensive challenges.
Monoclonal antibody therapy may have achieved notoriety during the coronavirus pandemic, but monoclonal antibody treatments have been used for decades and for applications far broader than infectious disease. This is because they interact with the immune system in many different ways - some of which are still unknown - through direct cell toxicity, modulation of various immune processes, and vascular interruption.
Each of these mechanisms is well-suited to a different disease or disease process. The first monoclonal antibody, muromonab, was developed in 1986 as an immunosuppressant to prevent transplant rejection, and the primary and most effective uses of monoclonal antibodies continue to be immunology, hematology, and oncology.
Because monoclonal antibodies target specific cells via their markers, or molecules involved in an immune response that needs to be interrupted, they have completely changed the toxicity profile of available treatment options.
For example, early cancer treatment was limited to chemotherapy, which indiscriminately interrupts processes of cell division, affecting many non-malignant cells. This is why cancer treatment can cause so many side effects that range from unpleasant, like hair loss and nausea, to life-threatening, like severe infections.
While chemotherapy continues to be an important part of cancer treatment, immunotherapy drugs like rituximab (which is used in a variety of B-cell malignancies, as well as autoimmune diseases like rheumatoid arthritis) have given healthcare providers many more options when it comes to cancer therapy. By using multiple treatment approaches, we can help patients with aggressive diseases go into remission faster and stay in remission longer.
In addition to their therapeutic applications, monoclonal antibodies have played a huge role in studying the biology of the diseases themselves. Scientists are able to observe how cancer cells behave by attaching monoclonal antibodies to malignant cells, which can be done in vitro or in tissue samples that can easily be viewed under a microscope.
There are two major issues with monoclonal antibodies. Hypersensitivity or allergic reactions are the most common and, potentially, the most life-threatening. This occurs primarily when the monoclonal antibody administered is not a fully human antibody, because it still contains some mouse protein that the human body recognizes as foreign.
The more humanized the antibody is, the less likely a reaction will occur. Patients can experience fever, chills, rigors, flushing, hives, low blood pressure, and anaphylaxis. Fortunately, most reactions end as soon as the infusion is stopped and rescue medications are administered. Rarely do patients who have infusion reactions require emergency attention.
When the medication is re-challenged, the patient usually tolerates the drug without a reaction. However, these reactions are resource-intensive for infusion centers, as they require extra personnel, time, and rescue medications.
The main challenge of developing and producing monoclonal antibodies is that the processes are very resource-intensive. They require a significant amount of time to identify and produce, and also require complex equipment, like antibody analyzers, single cell analyzers and dispensers, live cell analysis systems, and more.
As mentioned before, antibodies have to be grown in a culture medium, sorted into useful antibodies, isolated, analyzed for immunogenicity, and produced at scale. These steps necessitate expensive lab equipment, dedicated personnel, and extreme diligence. Until recently, growing mAbs in mice was the most reliable method.
However, thanks to the phage-display technique, it is becoming much easier and cheaper to grow antibodies in vitro. Another major challenge has been the administration of monoclonal antibodies, which requires prolonged infusion and monitoring times when delivered intravenously.
New and existing antibodies are being made into subcutaneous formulations, which are considerably cheaper and faster to administer and have shorter monitoring times, which will make them more widely available in a variety of outpatient healthcare settings.
There is tremendous potential to continue developing new antibodies and combination therapies that use antibodies. As described earlier in this article, the major pain points in using monoclonal antibodies are production, reactions, and medication administration. One arm of mAb-related research is focused primarily on improving the production and delivery of these medications.
Another equally important arm is developing medications that attach monoclonal antibodies to other molecules (other drugs or antibodies themselves) to deliver cytotoxic drugs only to specific cells. Antibody-drug conjugates are already being used, but there are endless possibilities to expand this category of treatment. As described above, the antibody targets a specific cell, and the drug acts only on that cell. Once again, this mitigates the many potential problems of traditional chemotherapy.
The latest generation of monoclonal antibodies are called bispecific antibodies, which have two antigen-binding domains instead of one, meaning they can have two different targets. Most of these are designed to recruit cytotoxic T-cells to kill the target malignant cells. Unfortunately, these therapies are only available to patients who have failed standard of care treatments. Because of complicated regulation and approval processes, standard of care is considered first-line treatment as its efficacy has been proven and safety profile established through the final clinical trial stage. While the data in these studies is promising, we have yet to see major studies published with head-to-head comparisons against standard of care.
However, the promise of this new generation of monoclonal antibody therapy to treat cancer might make riskier therapies, like stem-cell transplants, a thing of the past.
Currently, the market is dominated by a few pharmaceutical giants, so it’s unlikely that a new company would be able to take a substantial share of the market, but there are certainly significant opportunities to be involved in this exciting industry. Developing monoclonal antibodies requires scalable production, which most small companies do not have. However, the potential for creating new antibodies and new ways to use them is vast.
Life sciences startups doing groundbreaking research can partner with larger companies to finalize their R&D and even start production. Additionally, there are many steps in antibody production and development that small companies may be able to tap into and build deep expertise and credibility. This would enable a company to invest less capital in lab equipment and get significant ROI from the equipment they do have.
Furthermore, computational approaches to antibody development, including deep learning and artificial intelligence, are becoming increasingly important as we continue to study antibodies and their molecular structures. Next generation sequencing (NGS) has rapidly increased our understanding of B-cell receptors, and has allowed us to collect a huge amount of data as a result.
Artificial intelligence has made it possible to sort through libraries of antibodies to identify which ones may be useful, and deep learning has made it possible to model protein structures to figure out which might have the most binding affinity, which helps in the antibody maturation process.
The most cutting-edge uses of deep learning in antibody production involve producing de novo antibodies, meaning that they don’t involve using existing cells for production. Computational antibody design is poised to dramatically decrease both the time and cost associated with antibody development and allow for the creation of products that are much less resource-intensive to distribute and administer.
There is no limit to the use of monoclonal antibodies. Unlike most therapies for some of the illnesses that have long stumped the medical research field, they are effective and have minimal side effects. However, much more research must be done to continue improving the use of monoclonal antibodies and making them accessible to more patients.
Small biotech startups should not be deterred by the fact that large pharmaceutical companies already dominate the industry. Whether it’s in hands-on discovery, protein modeling, or selection and maturation of antibodies, there are incredible opportunities to become involved in this rapidly expanding area of science.
By investing in mAb development, diseases like cancer could become a thing of the past. If drug production and delivery becomes more efficient and cheaper, lifesaving treatments will become widely available to patients around the world. Now, more than ever, improving global health outcomes should be a priority for everyone.
Monoclonal antibody R&D is a substantial investment that requires heaps of time and money. This often means investing in expensive lab equipment, hiring additional scientists, and building or contracting out computational services.
And because these technologies change so rapidly, purchasing your equipment is not always cost-effective, especially for small companies who are working to stay on the cutting edge of science. Leasing with Excedr makes it possible to quickly pivot to new areas of R&D as your business grows and you find your niche.
Get in touch with us to learn more about our leasing program and get the equipment you need in your lab faster, for less up front.
