Optimization of Alemtuzumab Dose for Graft-Versus-Host Disease Prophylaxis for Reduced Intensity Transplantation from Unrelated Donors for Patients with Hematologic Malignancies

Tabled 1Table 1: Hematopoietic recovery, engraftment, acute and chronic GVHD in patients undergoing unrelated transplantation using alemtuzumab based GVHD prophylaxisCharacteristicsWhole study patients (n=36)Cohort 1 - alemtuzumab 60mg(n=17)Cohort 2 - alemtuzumab 30 mg (n=19)P value(cohort 1 vs. cohort 2)Median days to neutrophil recovery (range)19 (12-29)20 (15-29)16 (12-22)0.001Median days to platelet recovery(range)13 (9-33)14 (10-33)11 (9-24)0.10Median % donor cells on day 30 (range)98 (52-100)98 (52-100)99 (76-100)0.89Median % donor cells on day 60 (range)98 (8-100)99 (8-100)98 (87-100)0.14Median % donor cells on day 120 (range)98 (5-100)96 (5-100)98 (73-100)0.39Graft failure (Primary/ Late)2/21/11/11.00Median days to onset of acute GVHD (range)40 (9-168)46 (9-89)38 (15-168)1.00Cumulative incidence of ≥ grade 2 acute GVHD (95% CI) @ 200 days58% (44-77)59% (39-90)58 (39-87)0.98Median days to onset of chronic GVHD (range)153 (101-541)144 (101-369)174 (102-541)0.67Cumulative incidence of chronic GVHD (95% CI) @ 1-year42% (28-64)38% (19-72)47% (28-80)0.56 Open table in a new tab Of note, no cases of grade 4 acute GVHD, steroid refractory acute GVHD or severe chronic GVHD (using NIH consensus criteria on global severity of chronic GVHD) in any of the cohorts. Our data suggest that a low dose of alemtuzumab (30 mg) with CsA is an effective GVHD prophylaxis for the prevention of severe acute and chronic GVHD with acceptable risk of relapse in the setting of RIC for MUD transplantation and warrants further studies. Of note, no cases of grade 4 acute GVHD, steroid refractory acute GVHD or severe chronic GVHD (using NIH consensus criteria on global severity of chronic GVHD) in any of the cohorts. Our data suggest that a low dose of alemtuzumab (30 mg) with CsA is an effective GVHD prophylaxis for the prevention of severe acute and chronic GVHD with acceptable risk of relapse in the setting of RIC for MUD transplantation and warrants further studies.