VI Autologous Bone Marrow Transplantation.pdf - Blog Science ...

R. Harousseau reviewed the results of a prospective study organized by the
GOELAM Group. 318 patients with newly diagnosed AML were registered and
78 percent achieved CR. 56 underwent allo-BMT, 54 were randomized to intensive
consolidation and 52 to the ABMT arm. At a median follow-up of 34
months DFS appears similar between the chemotherapy and ABMT groups
(48.7 vs 47.6 percent, respectively).
Finally, J. Reiffers outlined results of a prospective trial on behalf of the
French BGMT Group. After one consolidation, patients were randomized to
ABMT or to maintenance chemotherapy. 204 patients were entered, 162
achieved CR (80 percent) and 77 were randomized to maintenance (38) or
ABMT (39). Actuarial DFS at 3 years was not significantly different: 48.3+8.5 percent
for ABMT and 38.9+8.4 percent for the maintenance arm.
A review of these trials indicates that several points deserve emphasis. First,
the proportion of subjects registering at induction who were randomized to an
ABMT arm is quite small and relatively consistent from trial to trial: from 12 to
19 percent. This confirms the need to enter very large numbers of patients at the
outset in order to address questions related to DFS after transplant. Second, although
data are preliminary, there are no striking differences between conventional
therapy or transplant, whether autologous or allogeneic. Longer followup
will be required and may disclose the superiority of one type of treatment. In
two of the 3 studies, the trend was in favor of ABMT over conventional intensive
consolidation therapy. Unfortunately, one difficulty in conducting prospective
trials over extended periods (4 to 5 years) is that previously unrecognized prognostic
factors may be identified and found not to be controlled for in the study.
Moreover, big improvements (>15 percent) in chemotherapy or ABMT in the
interim, although unlikely to occur, could make the studies obsolete. One possibility
here is that marrow purging will be shown to be of clinical benefit possibly
from gene marking studies or analysis of marrow transplant registry data. Of
relevance, C. Gorin provided an update on the EBMTG experience and indicated
no benefit of marrow purging from an overall evaluation of 1483 transplants.
However, a retrospective analysis identified a subgroup with AML CR-1
that underwent marrow purging and had a reduced relapse rate and improved
DFS. None of the prospective studies reviewed at the Symposium employed
ABMT with purged autografts.
Despite these potential limitations, the investigators who designed and conducted
these trials should be complimented since the data generated are likely
to lead to conclusions of greater validity than can be derived from single arm
studies with small numbers of subjects. It will be very interesting to hear the final
reports on these trials.
248 SIXTH INTERNATIONAL SYMPOSIUM ON AUTOLOGOUS BONE MARROW TRANSPLANTATION