Real-world outcomes of CD34⁺ mobilization and early autologous hematopoietic stem cell transplantation recovery after daratumumab-based induction

INTRODUCTION: Daratumumab, an Anti-CD38 monoclonal antibody, is now widely used in frontline induction for transplant-eligible multiple myeloma. Although highly effective, concerns remain regarding its potential impact on CD34⁺ stem cell mobilization and early outcomes after autologous hematopoietic stem cell transplantation, particularly when combined with lenalidomide. This study aims to evaluate whether prior daratumumab exposure affects CD34⁺ mobilization, stem cell collection, engraftment, or early post-autologous hematopoietic stem cell transplantation complications. METHODS: a retrospective, single-center cohort study was conducted in 100 adults who underwent autologous hematopoietic stem cell transplantation. Data on mobilization, CD34⁺ counts, plerixafor use, collection yield, engraftment, infectious complications, engraftment syndrome, intensive care unit admission, and hospitalization were extracted from medical records. RESULTS: Of the 100 patients, 46% had received daratumumab therapy. Baseline characteristics were similar except for more frequent prior lenalidomide use in controls (78% versus 35%; p < 0.001). No mobilization failures occurred. Peripheral CD34⁺ levels during mobilization (15 versus 19 cells/µL; p = 0.220) were comparable. Plerixafor use (26% versus 24%; p = 1.0), final CD34⁺ yield (3.80 versus 4.07×10⁶ cells/kg; p = 0.358), and time to neutrophil engraftment (10 versus 10.5 days; p = 0.539) were statistically equivalent. Rates of engraftment syndrome (25%), febrile neutropenia (89%), bacteremia (23%), intensive care unit admission (12%), and hospitalization metrics did not differ significantly. One death occurred in the control group. CONCLUSION: In this real-world cohort, no significant differences in CD34⁺ mobilization, apheresis outcomes, engraftment, or early post-autologous hematopoietic stem cell transplantation complications were observed based on prior daratumumab exposure. These findings support the safety and feasibility of autologous hematopoietic stem cell transplantation following anti-CD38-based induction regimens, including those incorporating lenalidomide.