Reduced Intensity AlloSCT in(CML) With Persistent Disease
Status:
Terminated
Trial end date:
2010-06-01
Target enrollment:
Participant gender:
Summary
CML, a malignant disorder of stem cells, is characterized by increases in both immature and
mature myeloid, erythroid, and lymphoid cells, as well as platelets in the peripheral blood.
The cytogenetic hallmark of CML is the Philadelphia(Ph)chromosome found in the malignant
cells of 95% of patients. CML comprises 7-20% of all leukemias with an overall incidence in
the general population estimated at 1 to 2 per 100,000. The peak incidence occurs in the
fifth decade, however, all age groups, including children, are affected. The only reported
environmental risk factor is exposure to excessive ionizing radiation that is documented in
only a very small percentage of patients. Clinically, CML is characterized by an initial
chronic phase in which patients may report mild constitutional symptoms; however, 40-50% are
asymptomatic and are diagnosed based upon abnormal blood counts discovered during a routine
examination. The chronic phase typically lasts three to five years, and is followed by an
accelerated phase distinguished by progressive systemic symptoms, an increasing resistance to
conventional chemotherapy, and a rise in the peripheral blood and bone marrow blast count.
This evolves rapidly into a blastic crisis characterized by immature cells resembling the
blasts characteristic of acute leukemia. The presence of 30% or more blastic cells in the
blood or marrow is diagnostic of this final blastic phase which is typically fatal within 3
to 6 months.
The primary treatment options for CML have traditionally been monotherapy with either
busulfan or hydroxyurea. Both agents are able to control the clinical symptoms associated
with CML, as well as induce hematological remissions in 80% of chronic phase patients.
However, complete cytogenetic remissions with either agent are rare, and neither is able to
prevent eventual progression to the terminal blastic phase; therefore, these therapies can
only be considered palliative.
The primary purpose of this clinical research trial is to study the feasibility of a reduced
intensity allogenic transplant for CML. This study will also determine the side effects as
well as the response rate.