Autologous Bone Marrow Transplantation - Blog Science Connections

7/2 Double Autografting in Acute Leukemia
The high-dose chemotherapeutic regimen for ablation used in all cases
was the UCH (University College Hospital) 1 protocol: cyclophosphamide 1.5
g/m 2 /dayi.v. on days -5, -4, and -3 (with mesna administration); doxorubicin,
50 mg/m 2 i.v. on day -5; l,3,bis-(2 chloroethyl)-l-nitrosourea, 300 mg/m 2 i.v.
on day -5; cytarabine, 100 mg/m 2 twice daily i.v.; and thioguanine, 100 mg/m 2
twice daily orally on days -5, -4, -3, and -2. The autologous bone marrow was
thawed and reinfused through a Hickman central venous catheter. The mean
number of nucleated cells frozen was 1.9 x 10 8
cells/kg of the recipient's
weight.
All patients in the study were considered eligible for two sequential
autografts, marrow for AF3MT II being harvested as soon as the patient's
hematologic system recovered. Only 26 of the 62 patients (42%) proceeded to
ABMTII. The reasons for the remaining patients not having a second ABMT are
outlined below for each patient group.
The rationale for two autografts was to increase the tumoricidal dosage of
drugs and to effect a form of "in vivo purging," as reported previously (2).
RESULTS
First-Remission AML
Of the 27 patients treated during first remission, 19 (70%) remain in
treatment-free remission at median follow-up of 26 months (range, 3-70
months). Eleven patients had two grafts and all remain in treatment-free
remission at median follow-up of 29 months (range, 4-70 months) after
transplantation. Sixteen patients received a single graft and 8 (50%) are in
treatment-free remission at a median follow-up of 15 months (range, 2-70
months) after ABMT. Of the 27 patients, 1 patient (3.7%) died of cerebral
hemorrhage during the thrombocytopenic phase posttransplant. No other
procedure-related mortality occurred in this group of patients. Seven patients
have relapsed following a single transplant at 4, 4, 5, 6, 8, 10, and 11 months
after ABMT. Of these patients, three had secondary leukemia and relapsed at 4,
4, and 5 months, respectively. The reasons for not progressing to ABMT 11 are
that five patients refused to proceed, three patients wish to proceed to ABMT II
but have not yet achieved sufficient hematologic recovery, three patients
relapsed before the second marrow harvest could be taken, one patient died
during ABMT I of the procedure, and four patients had delayed hematopoietic
recovery. Figure 1 shows the predicted disease-free survival of all patients
transplanted in first complete remission (CR) with AML. Figure 2 shows a
comparison of patients who received one ABMT with those who received two.
First-Remission ALL
Twelve patients with ALL received autografts during first CR, and only three
patients remain in remission after ABMT at 12,13, and 33 months, respectively.