Denosumab and gct
Denosumab and the magic bullet
Giant cell tumours: are rich in Osteoclast cells and contain mononuclear cells that produce rank ligand (RANKL). RANKL seems to play a big part in the formation and activation of the osteoclast (giant cells) which are responsible for the bone destruction seen in giant cell tumours.
Denosumab: A fully human monoclonal antibody that specifically targets a ligand known as RANKL. Given almost any substance, it is possible to create monoclonal antibodies that specifically bind to that substance; they can then detect or kill that substance.
Magic bullet: The idea of a magic bullet was first introduced by Paul Ehrlich at the beginning of the 20th century. He proposed that, if a drug could be made that attacked tumour producing cells, then a toxin for these cells could be delivered along with the agent of attacking these cells and not others.
Rachael has been a participant in Amgen’s Phase II clinical trial of Denosumab since May 2010.
Although this drug has been released for the use in the treatment of severe osteoporosis, it has not yet been approved for the treatment of Giant Cell Tumours.
At the time of writing, Rachael has had 8 injections of Denosumab, each of 120mg. After her fifth injection she was scanned to check the effectiveness of the drug. The scan revealed that her tumour had shrunk by 1.4cm and was showing signs of death. This was quite amazing, considering that two operations, radiotherapy and bisphosphonate infusions had done nothing to halt this tumour from growing.
Rachael has her injection monthly in her stomach. The injection is subcutaneous, under the skin. She also takes calcium and vitaminD daily this is also part of the trial along with the drug. The only side effects she has had is an upset stomach, which she tolerates well. The trial team seem to think it is the calcium and vitaminD that causes this and not the drug.
