Ciclosporin

Ciclosporin, also spelled cyclosporine and cyclosporin, and known as ciclosporin A,cyclosporine A, or cyclosporin A (often shortened to CsA) is an immunosuppressant drug widely used in organ transplantation to prevent rejection. It reduces the activity of the immune system by interfering with the activity and growth of T cells.

It was initially isolated from the fungus Tolypocladium inflatum (Beauveria nivea), found in a soil sample obtained in 1969 from Hardangervidda, Norway, by Hans Peter Frey, a Sandoz biologist. Most peptides are synthesized by ribosomes, but ciclosporin is a cyclic nonribosomal peptide of 11 amino acids and contains a single D-amino acid, which is rarely encountered in nature.

It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system.

Medical uses

Ciclosporin is approved by the FDA to prevent and treat graft-versus-host disease in bone-marrow transplantation and to prevent rejection of kidney, heart, and liver transplants. It is also approved in the US for the treatment of rheumatoid arthritis and psoriasis, as an ophthalmic emulsion for the treatment of dry eyes and as a treatment for persistent nummular keratitis following adenoviral keratoconjunctivitis.