autologous blood and marrow transplantation - Blog Science ...

Stein et al.
early after the transplant regimen. Nevertheless, no patient had graft failure as a
consequence of this, and all have achieved hematopoietic recovery. Most patients
undergoing autologous stem cell transplant in centers around the world received a
regimen of busulfan and cyclophosphamide. 1
Whether there are benefits to a
radiation-based regimen compared with one using only chemotherapy cannot be
assessed from this study.
One of the major questions addressed in this pilot study was whether it would
be possible to administer doses of IL-2 that have been reported to induce natural
killer cell activity early after transplant at a time when the disease burden was at a
minimum. The use of IL-2 is designed to treat not only the residual body burden of
tumor not addressed by the preparative regimen but also the leukemia cells that
may have been reinfused with the stem cell graft. This study shows that with proper
use of supportive care, it is possible to administer IL-2 in these doses early after
recovery from transplantation with minimal toxicity to the patient. As described
above, no patient required admission to the ICU and none suffered respiratory
failure as a consequence, despite fever and fluid accumulation, well-recognized
side effects of IL-2.
This study was also designed to assess the incidence of relapse before
autologous transplant, the number of patients unable to undergo adequate
collection of peripheral blood stem cells, and toxicities during consolidation that
precluded proceeding to autologous transplant. In this trial, 85% of patients who
were entered on protocol were able to proceed to transplant, with the most common
cause of failure being failure to collect adequate numbers of stem cells. Some
studies suggest that combined cytokine therapy could facilitate stem cell
collection. 20
Trials are now being initiated in the Southwest Oncology Group to
determine whether the addition of thrombopoietin to G-CSF will increase the
quality and rate of stem cell procurement after high dose Ara-C consolidation and
thereby reduce the numbers of patients who are unable to proceed to autologous
transplantation because of inadequate stem cell collections.
In summary, this pilot study indicates that it is feasible to use high-dose IL-2
following a radiation-based autologous transplant program and that a program of
intensive consolidation, stem cell collection, transplant, and DL-2 may improve
disease-free survival for patients with AML in first remission undergoing transplantation.
Further studies with larger numbers of patients will help determine the
efficacy of this transplant approach and the role of IL-2 in curing patients with AML.
ACKNOWLEDGMENTS
This study was supported in part by U.S. Public Service Grants NCI PPG CA
30206 and NCI CA 33572. The authors would like to acknowledge the dedication
of nurses at the City of Hope for the care of patients on this study, the staff of
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