Bestatin treatment of myelodysplastic syndromes and chronic myelogenous leukemia

A high remission rate (56%) was achieved in a preliminary study using Bestatin in patients with myelodysplastic syndromes. In particular, 9 out of 13 patients (69%) in the high blast group achieved hematologic remission. After Bestatin treatment, intrinsic hematopoietic stem cell abnormalities as well as hematologic findings were markedly improved. The success of Bestatin therapy in MDS led us to investigate the clinical activity of Bestatin in CML. In the current study the busulfan and Bestatin combination therapy resulted in complete hematologic remission in all of the patients. The most exciting result was the suppression of the Philadelphia chromosomes among the responding patients. Complete cytogenetic response was obtained in 3 patients (21%), partial cytogenetic response in 1 (7%), and minor cytogenetic response in 5 (36%). In particular, the majority of early chronic phase CML patients achieved significant cytogenetic response with sustained Ph1 negativity. The results are very encouraging and warrant further studies.