A nationwide survey of the use of plerixafor in patients with lymphoid malignancies who mobilize poorly demonstrates the predominant use of the "on-demand" scheme of administration at French autologous hematopoietic stem cell transplant programs.

BACKGROUND

High-dose chemotherapy supported with autologous stem cell transplantation is a standard therapeutic option for a subset of patients with lymphoid malignancies. Cell procurement is nowadays done almost exclusively through cytapheresis, after mobilization of hematopoietic stem and progenitor cells (HSPCs) from the marrow to peripheral blood (PB). The egress of HSPCs out of hematopoietic niches occurs in various physiologic or nonhomeostatic situations; pharmacologic approaches include the administration of acutely myelosuppressive agents or hematopoietic growth factors such as recombinant human granulocyte-colony-stimulating factor (rHuG-CSF). The introduction of plerixafor, a first-of-its-class molecule that reversibly inhibits the interaction between the chemokine CXCL-12 (also known as SDF-1) and its receptor CXCR-4, has offered new opportunities for the so-called "poor mobilizers" who achieve insufficient mobilization and/or collection with conventional approaches.

STUDY DESIGN AND METHODS

Because of the lack of consensus on a definition for poor mobilizers and the relatively high cost of plerixafor, French competent authorities have mandated a postmarketing survey on its use in routine practice.

RESULTS AND CONCLUSION

We report here the results of this nationwide survey that confirms the clinical efficacy of plerixafor, even in the subset of patients who barely increased PB CD34+ cell count in response to rHuG-CSF-containing mobilization regimen. Furthermore, analysis of this registry showed that despite heterogeneity in medical practices, the early-"on-demand" or "preemptive"-introduction of plerixafor was widely used and did not result in an excess of prescriptions, beyond its expected use at the time when marketing authorization was granted.