[Immunotherapy of acute myelogenous leukemia (AML) in adults with the Nocardia rubra cell wall skeleton].

The effect of immunotherapy with Nocardia rubra cell-wall skeleton (N-CWS) on the remission duration and survival of adults with acute myelogenous leukemia (AML) was studied in a prospective randomized controlled study. After having been induced into complete remission and consolidated, 73 patients were randomized either to maintenance chemotherapy or maintenance chemotherapy plus immunotherapy with N-CWS and irradiated allogeneic AML cells. Thirty-four patients in the chemotherapy group and 32 in the chemoimmunotherapy group were evaluable. Six months after the closure of the study, the immunotherapy showed a borderline beneficial effect on remission duration (p = 0.080) and on survival length (p = 0.098). When the data were analyzed at 42 months after entry, there was a borderline significant difference in remission duration (p = 0.066) between the two groups, prolonging the 50% remission period by 120 days, but no significant differences in survival length (p = 0.306), although the 50% survival was 168 days longer in the chemoimmunotherapy group. Thus, immunotherapy with N-CWS and irradiated allogeneic AML cells seems to be active in the treatment of adult AML when used for maintenance therapy in combination with chemotherapy.