Cyclosporine--a model for the testing of bio-immunological reaction modifiers in man

Cyclosporine is a member of a new family of drugs which interfere and modify the biological regulation of the immune system without being cytotoxic and has now been tested extensively in man. Observation of its toxicity in a homogeneous group of 72 patients with acute myeloblastic leukaemia receiving bone marrow transplants serves to illustrate some of the new and unexpected problems that may be seen when BIRM agents start to be tested in the clinic.