Abstract
We investigated the safety and efficacy of administering rituximab in combination with a standard myeloablative conditioning regimen of cyclophosphamide (Cy, 60 mg/kg daily x 2 doses) and total body irradiation (TBI, 12 Gy in four daily fractions) with allogeneic SCT in adult patients (pts) with ALL. Pts were eligible if their disease expressed CD20 in >20% blasts by flow cytometry. Rituximab was administered at 375 mg/m2 on days 6, −1, +7 and +14 following stem cell infusion. 24 pts were entered on study. The results were retrospectively compared with those of a historical control group of 31 pts receiving the same preparative regimen without rituximab. The two treatment groups had similar numbers of matched sibling and unrelated donor grafts. Pt and donor characteristics are detailed in Table 1. GVHD prophylaxis consisted of tacrolimus and methotrexate for nearly all pts in both study and control groups; 4 pts in the control group and 1 pt in the study group received pentostatin in addition to tacrolimus and methotrexate. Preliminary data suggests that pentostatin reduces the incidence of acute GVHD (
Patient, Donor Characteristics, and Outcomes
. | Cy/TBI/rituximab No. pts . | Cy/TBI No. pts . | P-value . |
---|---|---|---|
1. Donor age missing for 1 pt in each treatment group. | |||
Total Pts | 24 | 31 | |
Median Recipient Age, yrs (range | 30 (18–54) | 35 (18–53) | |
Median Pt Age, yrs (range)1 | 38 (15–53) | 36 (14–54) | |
Donor Type (%) | |||
Matched related | 15 (62) | 21 (68) | |
Matched unrelated | 9 (38) | 10 (32) | 0.7 |
Stem Cell Source (%) | |||
BM | 9 (38) | 17 (55) | |
PB | 15 (62) | 14 (45) | 0.2 |
Sex donor/pt mismatch (%) | 8 (33) | 12 (40) | 0.7 |
CMV donor/pt mismatch (%) | 10 (43) | 12 (40) | 0.8 |
ABO donor/pt mismatch (%) | 14 (58) | 10 (33) | 0.05 |
Graft Composition, median (range) | |||
Total nucleated cells (x108/kg) | 4 (1–14) | 4 (1–9) | 0.6 |
CD34+(x106/kg) | 5 (1–9) | 5 (2–8) | 0.9 |
CD3+ (x106/kg) | 110 (8–370) | 37 (5–286) | 0.2 |
Disease Status at SCT (%) | |||
CR1 | 6 (25) | 17 (54) | |
Remission, beyond CR1 | 13 (54) | 7 (23) | |
Not in Remission | 5 (21) | 7 (23) | 0.03 |
Acute GVHD II–IV | 17% | 39% | 0.07 |
Chronic Extensive GVHD | 37% | 34% | 0.7 |
OS, 2 yrs | 45% | 37% | 0.5 |
PFS, 2 yrs | 31% | 38% | 0.8 |
. | Cy/TBI/rituximab No. pts . | Cy/TBI No. pts . | P-value . |
---|---|---|---|
1. Donor age missing for 1 pt in each treatment group. | |||
Total Pts | 24 | 31 | |
Median Recipient Age, yrs (range | 30 (18–54) | 35 (18–53) | |
Median Pt Age, yrs (range)1 | 38 (15–53) | 36 (14–54) | |
Donor Type (%) | |||
Matched related | 15 (62) | 21 (68) | |
Matched unrelated | 9 (38) | 10 (32) | 0.7 |
Stem Cell Source (%) | |||
BM | 9 (38) | 17 (55) | |
PB | 15 (62) | 14 (45) | 0.2 |
Sex donor/pt mismatch (%) | 8 (33) | 12 (40) | 0.7 |
CMV donor/pt mismatch (%) | 10 (43) | 12 (40) | 0.8 |
ABO donor/pt mismatch (%) | 14 (58) | 10 (33) | 0.05 |
Graft Composition, median (range) | |||
Total nucleated cells (x108/kg) | 4 (1–14) | 4 (1–9) | 0.6 |
CD34+(x106/kg) | 5 (1–9) | 5 (2–8) | 0.9 |
CD3+ (x106/kg) | 110 (8–370) | 37 (5–286) | 0.2 |
Disease Status at SCT (%) | |||
CR1 | 6 (25) | 17 (54) | |
Remission, beyond CR1 | 13 (54) | 7 (23) | |
Not in Remission | 5 (21) | 7 (23) | 0.03 |
Acute GVHD II–IV | 17% | 39% | 0.07 |
Chronic Extensive GVHD | 37% | 34% | 0.7 |
OS, 2 yrs | 45% | 37% | 0.5 |
PFS, 2 yrs | 31% | 38% | 0.8 |
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