Immunotherapy, as its name suggests, heavily relies on the immune system in order to effectively deal with tumors in the body. As a result, people with a weakened immune system have a more difficult time fighting off any disease, let alone cancer, and the method of activating one’s immune system to fight disease is, in turn, less effective. So how do you treat a cancer patient with a weakened immune system with immunotherapy despite these limitations?
Enter monoclonal antibodies. As explained by the FDA, monoclonal antibodies (mAbs) are “laboratory-made proteins that mimic the immune system’s ability to fight off harmful pathogens such as viruses.” In layman’s terms, they’re man made defense mechanisms that are injected into people’s bodies to help fight off infection.
The origins of this technology date back to the 1970’s and were not tied to cancer research at all. Scientists at the time were trying to figure out a way to replicate or clone B cells. B cells are a part of the immune system responsible for producing antibodies, which fight off pathogens in the body. While previous cloning attempts had a slew of problems, German biologist Georges Köhler and Danish immunologist Niels Kaj Jerne developed the first successful monoclonal antibodies by combining a mouse’s spleen cells with tumor cells from a cancer known as myeloma. The science is very tricky and messy, but ultimately, Köhler and Jerne, alongside Argentine biochemist César Milstein, won a Nobel Prize for their work in developing these proteins in 1984.
These man made proteins work like the antibodies produced by our bodies and as a result share the same limitations, since both can only destroy specific cells based on the antigen, or marker, presented outside of the cell. Because of this, monoclonal antibodies are frequently engineered to account for types of antigens that could be presented on a tumor cell, and thus are able to treat different cancers. Fortunately, mAbs also share the positive attributes of natural antibodies, most importantly their ability to target specific cells. This makes them less harmful than chemotherapy, which can damage healthy cells in addition to cancer cells. Monoclonal antibodies therefore offer a safer and more effective alternative to chemotherapeutic drugs, assisting the immune system by helping it destroy cancer cells.
Despite being under 50 years old, monoclonal antibodies have already proven to be extremely beneficial in cancer research and to patients with compromised immune systems across a variety of cancers. Over 79 mAbs have been approved by the FDA, with 30 being used for cancer, including breast cancer, leukemia, liver cancer, and more. While the search for a cure is never ending, these medical miracles have assisted one of the most effective cancer therapies, immunotherapy, in the war against cancer.