A prospective study of alpha-interferon and autologous bone marrow transplantation in chronic myeloid leukemia. The Italian Co-operative Study Group on Chronic Myeloid Leukemia

Abstract

BACKGROUND AND OBJECTIVE: Alpha-interferon (alphaIFN) can induce cytogenetic remissions in chronic myeloid leukemia (CML). Hemopoietic progenitors can be collected from the marrow in remission and utilized for autologous repopulation after high dose chemotherapy. This study was designed with the purpose of evaluating the feasibility of a combined treatment policy of alphaIFN followed by autologous bone marrow transplantation (autoBMT). DESIGN AND METHODS: A prospective study of alphaIFN and autoBMT was begun in 1989. Two hundred and seventy-two consecutive previously untreated non-blastic Ph positive chronic myeloid leukemia (CML) patients, who were less than 56 years old, were enrolled over a 3-year period (1989-1991) and were assigned to receive human recombinant alphaIFN 2a (Roferon-A) at a dose of 9 MIU daily for at least one year. If they achieved a cytogenetic response consisting in a percentage of Ph neg metaphases of more than 25%, they were eligible for marrow harvesting and subsequent autografting after high dose busulfan (16 mg/kg) and melphalan (60 mg/m(2)). RESULTS: Seventy-six patients (28%) were eligible for a marrow harvest but the marrow was harvested in only 37 cases (14%), and only twenty-three patients (8%) were actually autografted. One patient died of infection nine days after autoBMT. The other patients recovered and did not suffer any late adverse events. Five patients progressed to blastic phase, six are alive in complete hematologic remission and eleven are alive in complete hematologic and cytogenetic remission. AlphaIFN treatment was reinstituted after autoBMT in 18 of 22 cases, but four patients who are in continuous complete cytogenetic remission were not given alphaIFN anymore. The progression-free survival of the autografted patients is 65% 8 years after registration. INTERPRETATION AND CONCLUSIONS: This study shows that bone marrow hemopoietic progenitors (Ph neg and Ph pos) can be collected from patients who respond to alphaIFN and can be used to rescue hemopoietic activity after high dose chemotherapy. Though some complete and durable cytogenetic remissions were obtained, the treatment could be applied only to a small group of good risk patients, highlighting that selection is very important and results cannot be extrapolated to the average patient.