New experimental and clinical data on leukaemia immunotherapy.

The present results of our treatment of acute lymphoid leukaemia patients are summarized: 7 out of 20 randomized patients given active immunotherapy after chemoradiotherapy are still in complete remission after periods varying from seven to ten years (compared to none in the control group). The actuarial results on 100 patients show remission and survival curves presenting a plateau between three and five years for a certain percentage, suggesting a possible cure. Several parameters studied in 200 patients indicate that the factors affecting this percentage are age, cytological type, volume of the tumour, and the localization of leukaemic cells in certain areas. Experiments with L1210 leukaemia show that immunotherapy enhances the effect of chemotherapy when administered after chemotherapy but decreases it when administered before, which is in favour of the use of the sequence chemotherapy-immunotherapy clinically.