A true magic bullet?
Monoclonal antibodies are being used to treat a host of different diseases
A crucial part of drug development is getting a therapeutic agent binding speciﬁcally to its target. But, as usual, nature is several steps ahead of us, and has already created highly targeted molecules: antibodies.
Monoclonal antibodies – in effect, cloned antibodies all recognising the same structure – are now entering the clinic in increasing numbers. Many monoclonal antibody therapies have been developed for cancers, as cancer cells have distinctive structures on their surfaces that can be speciﬁcally recognised by an antibody. If a toxin is attached to the antibody, it can be delivered directly to a tumour.
Other monoclonal antibodies are similar to small-chemical drugs, in that they target receptors or ligands, blocking biochemical signalling. Trastuzumab (Herceptin), for example, recognises a mutated receptor on breast cancer cells carrying a HER2 mutation. Inﬂiximab (Remicade) and adalimumab (Humira) block a molecule that promotes inﬂammation (tumour necrosis factor-α, or TNF-α) and have made a major impact on the treatment of rheumatoid arthritis.