[Results of follow-up studies on prognosis after immunotherapy with bestatin in acute nonlymphocytic leukemia].

We have recently performed a prognostic investigation of a randomized controlled trial with bestatin for acute non-lymphocytic leukemia in adults. Out of 115 patients registered in this study, 101 patients (48 in a bestatin group and 53 in a control group) were evaluated as eligible. The 50% remission duration was 20.4 months for the bestatin group compared with 11.3 months for the control group. Long-term remission rate at 4 years was 36.5% for the bestatin group compared with 24.1% for the control group, and their respective 50% survival time were 33.0 and 18.1 months, while the long-term survival rate at 4 years was 46.0% for the bestatin group compared with 25.5% for the control group. The bestatin group had a longer remission duration and survival time than the control group. The remission duration and survival time in patients under 49 years of age were not different between the groups. However, in patients over 50 years of age, the bestatin group had a significantly longer remission duration and survival time than the control group. Side effects of bestatin were mild and transient. These data suggest the usefulness of bestatin for the treatment of adult acute nonlymphocytic leukemia.