Autologous Bone Marrow Transplantation - Blog Science Connections

128 Panel Discussion: Session IB
18 months. Actually, the disease-free survival was even slightly better but really
no different in the patients who had the shorter initial remission. We could not
predict, at least even show, any relationship between the patients surviving
long-term and the initial remission length.
DR. SPITZER: SO the plateau is not patients with long-term CRs?
DR. RAMSAY: NO it is not. 1 mean it is variable.
DR. D. BUCKNER: Dr. Ball, do you have long-term marrow culture data with
your antibody PM-81?
DR. BALL: NO, we don't have long-term marrow culture data for that
antibody because we don't get a decrease of colony-forming unit mix after
treating that antibody, so it was not particularly an issue. We have data for the
AML 199 antibody, which is somewhat premature, but it looks like there is
recovery of colony-forming units in liquid culture after an initial depletion.
DR. BUCKNER: This is in leukemic patients, not in hematologically normal
individuals.
DR. BALL:
question?
NO, this is in hematologically normal individuals. Is that your
DR. BUCKNER: Yes, I just wanted to know because we have an experience
with a similar antibody—Herb Bernstein's. The interesting thing is that cells
from hematologically normal individuals grow well after treatment but, in two
thirds of AMLs in remission, it definitely affects the long-term marrow cultures.
DR. C. READING: We have looked at the undifferentiated blast colony
assay after magnetic separation and didn't see any loss of those colonies that
were thought to be a very primitive cell, even though it hits maybe half of the
more mature granulocyte-macrophages.
DR. DICKE: Are there any questions for Dr. Herve? 1 think the point Dr.
Herve was making about the cryopreservation, the damage of cryopreservation
of the cells that are already treated in vitro is a very important one. Is there
anybody in the audience who has, as we do, difficulties with infusing these cells
after thawing, when they are being treated in vitro with 4-hydroperoxycyclophosphamide?
We have to wash the cells before infusion because of clumping. 1
would like to continue with Ton (Anton) Hagenbeek. I think you can conclude
from your data that the busulfan plus cyclophosphamide regimen is the best
one. Now what dose of cyclophosphamide are you using? Is that the
cyclophosphamide of the old Santos regimen or the new one, as advocated by
Tutschka?
DR. A. HAGENBEEK: The cyclophosphamide dose that we give in this
animal model is 100 mg/kg.
DR. DICKE: You can cure this rat model with Cytoxan, right?
DR. HAGENBEEK: That is right. If you go to very high dosages, at a different