Results in children of acute lymphoid leukaemia protocol ICIG-ALL 9 consisting of chemotherapy for only nine months followed by active immunotherapy

Summary Protocol ICIG-ALL 9 with only nine months' remission chemotherapy followed by active immunotherapy has given a proportion of about 50% of the patients on the plateau of the first remission curve, while 60% of the children are on the plateau of survival curve.These results do not differ from those of another protocol (ICIG-ALL 10) conducted on an identical population of patients and comprising a 25 month remission chemotherapy before immunotherapy.This observation, confirmed by a randomized trial of the EORTC Haemopathy Working Party, suggests that between the 9th and the 25th month, active immunotherapy is as efficient as maintenance chemotherapy.The overall results of this protocol with short chemotherapy followed by active immunotherapy have been compared with those of another prolonged maintenance chemotherapy before immunotherapy protocol (ICIG-ALL 11), and with published protocols comprising only long maintenance chemotherapy: protocol 9 is, as far as the first remission plateau and the survival plateau are concerned, superior to most of these protocols (if not all their branches).Lethal toxicity of active immunotherapy is nil, in contrast to the proportion of deaths (4–28%) occurring during remission in the patients submitted to maintenance chemotherapy.However, not all patients with so-called acute lymphoid leukaemias should be treated identically: our early prognosis parameters (WHO cytological types and volume of the tumour, in this study) allow us to distinguish a good prognosis group in which protocol 9 gave an 80% cure expectancy.The patients with a poor prognosis should be the object of further research for a more efficient therapy. Even if this should be more intensive, the risk is justified in this group, while it is not so for the good prognosis group.