Immunotherapy for acute myelogenous leukaemia: a controlled clinical study 2 1/2 years after entry of the last patient.

One hundred and thirty-nine untreated patients with acute myelogenous leukaemia (AML) were admitted between August 1970 and December 1973 and allocated into two remission treatment regimens: one to receive chemotherapy alone and the other chemotherapy with immunotherapy. Of the patients who attained remission. 22 were in the chemotherapy group and in September 1975 2 remained alive, the median survival time being 270 days and after relapse 75 days. Twenty-eight patients received immunotherapy during remission, and 5 remained alive; the median survival time of the group being 510 days and after relapse 165 days. Ongoing acturial analysis precisely predicted early in the study the median survival of the two groups, but it took a 2-year follow-up after entry of the last patient before it became clear that there were very few long-term survivors. The increase in survival time produced by the immunotherapy is apparently made up of two components: prolongation of the first remission and length of survival after the first relapse. It must be notted that the chemotherapy for this study was devised 6 years ago and the results of the control arm (chemotherapy alone) may be poorer than those obtained in contemporary studies.