Autologous Bone Marrow transplantation - Blog Science Connections

10 CBV and ABMT for AML in CR1
whereas other transplantation groups which have reported treatmentrelated
death rates of 19-22% (14-16). The incidence of severe nonhemopoietic
toxicity was low. The hemopoietic recovery was fast,
showing that prior exposure to high-dose ARA-C does not
compromise the regenerative potential of the bone marrow. We
optimized the bone marrow collection to obtain adequate numbers of
GM-CFCs, which predict rapidity of engraftment (9). It should also
be noted that we avoid the use of TBI (which can cause late
complications such as cataracts and pulmonary fibrosis), without
apparent decrease of therapeutic efficacy.
We can speculate that the following reasons may explain the high
percentage of long-term survivors achieved with our regimen:
a) The additive cytoreduction from high-dose ARA-C and CBV
over the initial leukemic cell kill from induction
chemotherapy.
b) The use of intensification with high-dose ARA-C prior to
bone marrow collection, effecting a better "in vivo purging"
than previous studies that used less intensive post-remission
chemotherapy regimens.
c) The combination of a) and b) should result in a very low load
of clonogenic leukemic cells after CBV-ABMT, which can be
more effectively controlled by the post-transplantation
chemotherapy and the body's immune surveillance
mechanisms.
d) No patients died as a result of the high-dose cytoreduction.
CONCLUSIONS
We have treated 18 adult AML patients with a program that
combines induction chemotherapy, early intensification with highdose
ARA-C, and late intensification with high-dose CBV and
ABMT. This doubly intensified regimen has resulted in a 56% longterm
disease-free survival in patients followed for a minimum time
of 32 months, with very tolerable toxicity and no treatment related
deaths. There is a trend for improved CR duration when these patients
are compared to controls treated with identical therapy except for the
use of CBV-ABMT. A multivariate logistic regression model may
better define the patient population that benefits from this regimen.
If these promising findings are confirmed with larger, randomized
studies, this treatment strategy may be incorporated to the
management of newly diagnosed patients with acute myelogenous
leukemia.