Plerixafor (Mozobil): A Stem Cell-Mobilizing Agent for Transplantation in Lymphoma Patients Predicted to Be Poor Mobilizers - A Pilot Study

Autologous hematopoietic stem cell transplantation is the standard therapy for refractory/relapsed aggressive lymphoma. The initial step of the procedure involves mobilization and collection of hematopoietic stem cells. G-CSF fails to achieve mobilization in 15-25% of lymphoma patients. Plerixafor is a novel CXCR4 antagonist that can promote mobilization. It has been used successfully in patients after the failure of G-CSF. It is reasonable to test whether plerixafor should become the mobilizing agent of choice in patients expected to exhibit difficulties in mobilization. We initiated a study to assess the use of plerixafor as a first-line stem cell mobilizer in 20 elderly or heavily pretreated patients with non-Hodgkin or Hodgkin lymphoma. The minimum defined CD34+ cell dose of ≥2 × 10⁶ cells/kg was achieved by 90% of the patients, and for 83% of them with one apheresis procedure. The target CD34+ dose of ≥5 × 10⁶ cells/kg was achieved by 70% of the patients. The median number of circulating CD34+ cells before and after plerixafor was 14.4 and 42.8 cells/μl, respectively. The post-plerixafor adverse events were mild. All patients promptly engrafted after high-dose chemotherapy treatment. We conclude that plerixafor administration is safe and efficient for upfront mobilization in lymphoma patients predicted to be poor mobilizers.