Cyclosporine is a drug derived from a species of fungus present in the soil in Norway. The name of this fungus is Tolypocladium inflatum. When an organ is transplanted, the body’s immune system tends to reject the new organ, treating it as a foreign body. Cyclosporine suppresses this action by the immune system but allows the immune system to function as usual in fighting other regular infections.
The initial research for the development of cyclosporine was carried out from 1969 but it was only in 1976 that the importance of this drug was realized by two scientists David White and Sir Roy Calne. Over the years, the drug received some setbacks as it was proved to cause tumors and kidney damage. It was later discovered that these problems could be circumvented by using the drug in combination with steroids. Cyclosporine was finally approved by the FDA in 1983.