Monoclonal antibodies are a type of immunotherapy, which are made in a laboratory and are several copies of a single antibody.

Monoclonal antibodies are a type of immunotherapy that is created in a laboratory and consists of several copies of a single antibody. The US Food and Drug Administration has approved several monoclonal antibodies for the treatment of inflammatory, cancer, and other illnesses (FDA). There are four varieties of monoclonal antibodies, depending on the source: murine, chimeric, humanised, and human. Murine antibodies are wholly produced from a murine source, whereas chimeric antibodies have fluctuating murine origin regions and consistent human origin regions. Humanized antibodies are derived from a human source with a small part of a mouse or rat monoclonal antibody and human antibodies are entirely derived from a human source. Monoclonal antibodies are majorly used in cancer treatment along with certain inflammatory, infectious, and other diseases. Depending upon the functions of monoclonal antibodies (for cancer), they are further classified into subtypes such as radiolabeled antibodies, chemo labeled antibodies, and bispecific monoclonal antibodies. Commercially available monoclonal antibodies include Iplimumab, Nivolumab, Rituximab, Blinatumomab, Proleukin, Gardasil, and Kymriah.

Because of the complicated processes involved and the overall size of the molecules, monoclonal antibodies are more expensive to make than tiny molecules, in addition to the substantial research and development costs needed in bringing a new chemical entity to patients. They are priced to allow producers to recuperate their normally high investment costs, and in countries with no price regulations, such as the United States, prices can be higher if they represent excellent value. Seven University of Pittsburgh researchers concluded that "the annual price of mAb therapy in cancer and haematology is around $100,000 greater than in other disease states," when comparing them on a per patient basis to those for other diseases. Seven University of Pittsburgh researchers concluded, "The annual price of mAb therapies is about $100,000 higher in oncology and hematology than in other disease states," comparing them on a per patient basis, to those for cardiovascular or metabolic disorders, immunology, infectious diseases, allergy, and ophthalmology.

Monoclonal antibodies have been employed in the diagnosis and treatment of a wide range of human ailments, including cancer and infectious diseases, as well as for immune response modulation. However, effective therapy with unmodified monoclonal antibodies has remained difficult.Recently, monoclonal antibody-mediated therapy has been revolutionized by advances such as the definition of cell-surface structures on abnormal cells as targets for effective monoclonal antibody action, genetic engineering to create less immunogenic and more effective monoclonal antibodies, and the arming of such antibodies with toxins or radionuclides to enhance their effector function.