ROME—Best outcomes from donor lymphocyte infusion in chronic myelogenous leukemia (CML) occur when the first dose does not exceed 0.2 × 108 mononuclear cells/kg, Cesare Guglielmi, MD, reported in a presentation at the 43rd Annual Meeting of the American Society of Clinical Oncology.
Dr. Guglielmi, who is in the Department of Cellular Biotechnology and Hematology at La Sapienza University in Rome, reported data from a retrospective study of 344 CML patients treated in 51 transplant centers affiliated with the European Group for Blood and Marrow Transplantation (EBMT). He said that lower starting doses decrease both morbidity and mortality, with a beneficial effect on overall and failure-free survival.
"Donor lymphocyte infusion can produce durable remissions in patients with CML who relapse after an allogeneic stem cell transplantation. However, the best modality to administer the infusions is unclear. The objective of this study was to evaluate how the outcome of CML relapse was affected by the cell dose of the first donor lymphocyte infusion," Dr. Guglielmi said.
Methods and Design
The initial cell dose (number of mononuclear cells × 108/kg received in the first infusion) was available for 298 patients. This ranged from 0.002 to 24.4 × 108/kg, with a median initial dose of 1 × 108/kg. For purposes of this analysis the investigators stratified patients into three groups according to the initial dose they had received. Group A (n = 98) was the low-dose group, ranging from 0.002 to 0.20 × 108/kg, with a median dose of 0.1 × 108/kg. Group B (n = 107) was the intermediate-dose group, ranging from 0.21 to 2.0 × 108/kg, with a median dose of 1 × 108/kg. Group C (n = 95) was the high-dose group, ranging from 2.1 to 24.4 × 108/kg, with a median dose of 3.5 × 108/kg. Dr. Guglielmi said that more than one infusion was given to 62%, 20%, and 5% of patients in the low-, intermediate-, and high-dose groups, respectively, and that the number, dose, and frequency of additional infusions did not correlate with the initial dose.
Outcome Analysis
Responses were seen with single or multiple infusions, irrespective of the initial cell dose. The outcomes analyzed were graft-vs-host disease after donor lymphocyte infusion (acute grade 2-4 and/or chronic graft-vs-host disease), myelosuppression (neutropenia and/or thrombocytopenia), response (cytogenetic and/or molecular complete remission), overall survival (OS), failure-free survival (FFS), and donor lymphocyte infusion-related mortality.
