Abstract
We analyzed 67 patients with lymphoma who received alemtuzumab-based conditioning regimens for allogeneic stem cell transplant and no post-transplant DLI. The median age was 54 (24-70), 43% had unrelated donors, 34% had chemotherapy refractory disease, and 25% had an elevated LDH. With a median follow-up for survivors of 35 months, the estimated 3-year progression-free survival (PFS) and overall survival (OS) were 30% and 47%, respectively. Chemosensitivity by CT and pre-transplant LDH were independent prognostic factors for both overall survival and progression-free survival. Patient age, performance status, donor type, lymphoma subtype, disease sensitivity by PET, and conditioning regimen did not correlate with PFS and OS. Patients who relapsed greater than 6 months after allogeneic transplant were frequently able to re-enter a subsequent durable remission. Our experience confirms the curative potential of alemtuzumab-containing RIC regimens for allogeneic HCT in patients with relapsed lymphoma without prophylactic DLI. An elevated pre-transplant LDH and chemorefractory disease prior to transplant confer a worse prognosis, while PET scan findings do not have this same implication. Patients who relapse greater than 6 months after their transplant are likely to achieve a subsequent remission with any of a variety of interventions, suggesting that GVL effects can be operative even after recurrence. Our outcomes challenge the utility of the common practice of prophylactic DLI after T-depleted transplant for lymphoma.