Antibody drugs

In the spotlight! Monoclonal antibodies

Monoclonal antibodies are the most commonly used antibody drugs today. As the name implies, monoclonal antibodies are produced from a single B cell (mono) and do not contain any genes (clonal), so they can only bind to one type of antigen. By taking advantage of this ability to act only on specific antigens, it is possible to develop drugs with fewer side effects and higher therapeutic efficiency.

How to make monoclonal antibodies?

How are monoclonal antibodies produced? To explain briefly, monoclonal antibodies are produced through the following process.

• ①　 Mice are injected with cancer antigens to produce cancer antibodies.
• ②　B cells, which produce antibodies, are taken out of the mice and fused with cells that continue to increase indefinitely.
• ③　From the fused cells, cells that are effective against cancer are selected and propagated.
• ④　 Monoclonal antibodies are produced.

Types of monoclonal antibodies

Monoclonal antibodies in the medical field can be divided into four types: mouse antibodies, chimeric antibodies, humanized antibodies, and fully human antibodies. The difference between these four types lies in the percentage of human antibodies used. Conventional drugs that use mouse antibodies are easy to manufacture, but there is a risk that our immune system will recognize them as foreign and cause an allergic reaction. This is why chimeric antibodies, in which only the variable region of the antibody is left from the mouse, and humanized antibodies have been developed to increase safety. Recently, research into fully human antibodies that do not use mouse antibodies is also underway.

• "Monoclonal antibodies" that bind only to specific antigens
• There are four types of Monoclonal antibodies!