[Combination therapy of chronic myelogenous leukemia with busulfan and bestatin]

We demonstrated the clinical effectiveness of combination therapy with Busulfan and Bestatin in 13 patients with Philadelphia chromosome positive chronic myelogenous leukemia, including 9 in chronic phase and 4 in acute phase. Sequential cytogenetic studies and molecular analysis of the breakpoint cluster regions were performed every 2 months. Complete hematologic remissions were observed in all 13 patients. Five minor cytogenetic responses, 2 partial cytogenetic remissions and 2 complete cytogenetic remissions were observed. All of the 4 patients in early chronic phase achieved cytogenetic remission and in 3 of them there was a complete disappearance of rearranged restrictive fragments of the bcr gene. In contrast, 4 of the 5 patients in late chronic phase failed to achieve cytogenetic remission and only 1 achieved minor cytogenetic response, suggesting excellent effects, particularly in patients with early disease. It is clear from this pilot study that combining Bestatin with Busulfan is an effective way to reduce or eliminate Ph1 positive clone and to maintain this status.