Incorporating Reduced-Dose Plerixafor to a Preemptive Mobilization Algorithm Increases Access to Autologous Transplantation in a Limited-Resource Setting

Background Patients with lymphoma and myeloma undergoing autologous transplantation (ASCT) are at risk for mobilization failure. This limitation can be surpassed by combining multiple apheresis, cryopreservation and adding plerixafor to filgrastim. However, these strategies increase costs and are unaffordable for patients in low and middle-income countries (LMIC). We developed a mobilization strategy using peripheral CD34+ cell analysis and reduced-dose plerixafor (RD-plerixafor) to be used in a setting with limited resources. Objective To evaluate the efficacy of a mobilization algorithm defined by our ability to harvest ≥2 × 106Kg CD34+ cells in one apheresis session. Methods We performed a single-arm prospective study including adults with lymphoma or myeloma undergoing ASCT. Patients received filgrastim 5 μg/kg BID for 4 days followed by peripheral blood CD34+ cell analysis. We designed a mobilization algorithm hypothesizing that if the day 4 CD34+ pre-count was 5-10 cells/μL, a single RD-plerixafor dose at 0.12 mg/kg (11 hours prior to apheresis) would be sufficient to achieve a successful harvest (≥2 × 106/kg CD34+) in one large-volume session based on a prior study. Patients with Results Twenty-nine adults were included with a median day 4 CD34+cell pre-count of 15 cells/μL (1.4-88.7). N=19 received filgrastim (65.5%), N=6 received RD-plerixafor (20.7%) and N=4 full-dose plerixafor (13.8%). Median day 5 peripheral blood CD34+ increased to 34.3 cells/μL (10.8-107) (p Conclusion Incorporating RD-plerixafor into a mobilization algorithm is a safe and effective strategy that increases access to transplantation in patients with lymphoma and myeloma.