Reduced-dose plerixafor as a mobilization strategy in autologous hematopoietic cell transplantation: a proof of concept study

Background Autologous stem cell transplantation (ASCT) is an effective treatment for patients with relapsing myeloma or lymphoma, diseases associated with unsuccessful peripheral blood stem cell (PBSC) collection. Plerixafor is a potent mobilizing agent, allowing more CD34+ cells to be obtained; however, the main obstacle for its use is its high cost. Our aim was to demonstrate that of the use of reduced doses of plerixafor (RD-plerixafor) can be sufficient to collect at least 2 × 106 /Kg CD34+ PBSC in patients with multiple myeloma (MM) or lymphoma undergoing ASCT. Study design and methods Twenty patients were mobilized with filgrastim (10 μg/kg/4 days) plus a single dose of plerixafor 0.12 mg/kg in Day 4. Apheresis collection was performed on Day 5. One vial of plerixafor was used for two patients. Clinicaltrials.gov NCT03244930. Results Cell mobilization and collection was successful in 85% of patients (≥2 × 106 CD34+ cells per kilogram). The median collected CD34+ cell count was 4.62 × 106 /kg (range, 1.27-24.5). A 4.1-fold-increase in the median CD34+ PBSC pre-count was observed (from 10.4/μl to 42.4/μl) after RD-plerixafor administration. Seven patients had mild to moderate adverse events. Conclusion RD-plerixafor is an effective, safe, and affordable strategy to ensure adequate PBSC mobilization in patients with MM or lymphoma who undergo ASCT.