Cyclic chemotherapy in childhood acute leukaemia.

During the phase of complete remission children with acute leukaemia are in apparently full health and can take part in all normal childhood activities. Until a form of therapy is devised which can achieve cure in a significant proportion of these children, the most desirable clinical objective appears to be the prolongation of these remissions with the mini- mum of hospitalization and the minimum of toxic side-effects. We have been evaluating the cyclic use of oral mercaptopurine, methotrexate, and cyclophosphamide for this purpose since late 1964.