No evidence for cell activation or brain vaso-occlusion with plerixafor mobilization in sickle cell mice

Gene therapy for sickle cell disease is currently in active trials. Collecting hematopoietic progenitor cells safely and effectively is challenging, however, because granulocyte colony stimulating factor, the drug used most commonly for mobilization, can cause life-threatening vaso-occlusion in patients with sickle cell disease, and bone marrow harvest requires general anesthesia and multiple hip bone punctures. Plerixafor is an inhibitor of the CXCR4 chemokine receptor on hematopoietic progenitor cells, blocking its binding to SDF-1 (CXCL12) on bone marrow stroma. In support of a clinical trial in patients with sickle cell disease of plerixafor mobilization (NCT02193191), we administered plerixafor to sickle cell mice and found that it mobilizes hematopoietic progenitor cells without evidence of concomitant cell activation or brain vaso-occlusion.