Treatment of the blastic transformation of chronic granulocytic leukemia using high dose BCNU chemotherapy and cryopreserved autologous peripheral blood stem cells

Seven nonsplenectomized patients with blastic CGL have received high dose BCNU chemotherapy followed by cryopreserved peripheral blood stem cells (PBSC). The PBSC obtained at diagnosis were stored in the vapor phase of liquid nitrogen in 10% dimethyl sulfoxide for 11–46 months prior to use. Patients received 2.9 × 10⁸ (1.9–7.8) thawed washed mononuclear cells/kg over 30 minutes with minimal morbidity. One patient was not rendered pancytopenic and died with blastic leukemia at 4 months. One patient, previously treated with daily busulfan, died of progressive hepatic failure 2 months after high dose BCNU. Restoration of the chronic phase of CGL was observed in the remaining five patients. Peripheral blood counts returned to normal ranges after a median of 19 days. Median survival for all patients is 11 months. Cytogenetic studies revealed elimination of acquired aneuploid cell lines in four of seven patients with persistence of Ph¹. We conclude that: 1) frozen PBSC retain their viability for up to 4 years after cryopreservation and 2) the use of autologous PBSC following ablative chemotherapy may be associated with both symptomatic and karyotypic improvement in patients with blastic CGL.