Steady-state versus chemotherapy-based hematopoietic cell mobilization after anti-CD38-based induction therapy in newly diagnosed multiple myeloma.

BACKGROUND: The incorporation of anti-CD38 monoclonal antibodies (mAb) in induction regimens of newly diagnosed transplant-eligible multiple myeloma (MM) patients has been established as a new standard. However, the optimal strategy of stem cell mobilization in this context is not yet clear. STUDY DESIGN AND METHODS: From May 2020 till September 2022, we retrospectively reviewed patients receiving anti-CD38 mAb-based induction therapy followed by stem cell mobilization either in a steady-state protocol (SSM) using 10 µg/kg granulocyte colony-stimulating factor (G-CSF) for 5 days or in a chemotherapy-based protocol (CM) using 1-4 g/m2 cyclophosphamide and G-CSF. RESULTS: Overall, 85 patients (median age 61 years) were included in the analysis. In total, 90 mobilization attempts were performed, 42 with SSM and 48 with CM. There was no significant difference in the median concentration of CD34+ cells in peripheral blood (PB) prior to apheresis between SSM and CM (61/µL vs. 55.4/µL; p = .60). Cumulative CD34+ yields did not differ between the groups with median of 6.68 and 6.75 × 106 /kg body weight, respectively (p = .35). The target yield (≥4 × 106 CD34+ cells/kg body weight) was reached in 88% (CM) and 86% (SSM), with a high proportion even after a single apheresis session (76% vs. 75%). Plerixafor was found to be more frequently used in SSM (52%) than in CM (23%; p < .01). A total of 83 patients underwent autologous transplantation and all were engrafted. CONCLUSIONS: Stem cell collection in patients undergoing anti-CD38-based induction therapy is feasible with either CM or SSM, although SSM more frequently requires plerixafor.

Salvage treatment with plerixafor in poor mobilizing allogeneic stem cell donors: results of a prospective phase II-trial.

We conducted a prospective clinical trial to investigate the safety and efficacy of plerixafor (P) in allogeneic peripheral blood stem cells (PBSC) donors with poor mobilization response to standard-dose granulocyte colony-stimulating factor (G-CSF), defined by <2 × 106 CD34 + cells/kg recipient body-weight (CD34+/kg RBW) after 1st apheresis. A single dose of 240 µg/kg P was injected subcutaneously at 10 p.m. on the day of the 1st apheresis. Thirty-seven allogeneic PBSC donors underwent study treatment. The median CD34+ count in peripheral blood was 15/µl on Day 1 after G-CSF alone, versus 44/µl on Day 2 after G-CSF plus P (p < 0.001). The median yield of CD34+ cells was 1.1 × 108 on Day 1 and 2.8 × 108 on Day 2. In contrast to a median yield of only 1.31 × 106 CD CD34+/kg RBW on Day 1, triggering study inclusion, a median of 3.74 × 106 CD CD34+/kg RBW were collected with G-CSF plus P on Day 2. Of 37 donors, 21 reached the target cell count of >4.5 × 106 CD34+/kg RBW (57%, 95%CI 40-73%). No donor experienced a severe adverse event requiring treatment. In conclusion, P might be considered on a case-by-case basis for healthy allogeneic donors with very poor stem cell mobilization success after G-CSF.

Peripheral blood stem cell collection in allogeneic donors: impact of venous access.

BACKGROUND: Peripheral blood stem cell (PBSC) collection is accepted as a routine procedure in related and unrelated healthy donors worldwide. Venous access can be accomplished by peripheral veins or a central venous catheter (CVC). STUDY DESING AND METHODS: We compared efficacy and tolerability of 40 PBSC collections via CVC with 6267 PBSC collections via peripheral veins in healthy allogeneic donors. Results of the leukapheresis procedures and side effects in the donors were evaluated. RESULTS: The median CD34+ cell counts on Day 5 and the results of the stem cell collection were not significantly different between the two groups of allogeneic donors. Pain or problems at the site of puncture or catheter insertion occurred in 58.6% of the donors with a CVC versus 37.8% of the donors with peripheral venous access (p = 0.03). The incidence and severity of paresthesia during the leukapheresis was not significantly different in both groups of donors (p = 0.09). During follow-up no major adverse events related to CVC were reported. CONCLUSION: Central femoral lines proved to be safe and tolerable in healthy allogeneic donors but peripheral venous access should be preferred, whenever possible.

Single-dose pegfilgrastim for the mobilization of allogeneic CD34+ peripheral blood progenitor cells in healthy family and unrelated donors.

BACKGROUND AND OBJECTIVES: Short-term treatment with granulocyte colony-stimulating factor (G-CSF) has been established as the standard regimen for mobilizing allogeneic peripheral blood progenitor cells (PBPC) from healthy donors. The pegylated form of filgrastim (pegfilgrastim) has a longer elimination half-life because of decreased serum clearance and might be a convenient alternative for stem cell mobilization. DESIGN AND METHODS: Twenty-five family (n=15) or unrelated (n=10) healthy donors received a single-dose of 12 mg pegfilgrastim for mobilization of allogeneic PBPC. Donors with inadequate mobilization (blood CD34+ cells

Second donation of granulocyte-colony-stimulating factor-mobilized peripheral blood progenitor cells: risk factors associated with a low yield of CD34+ cells.

BACKGROUND: There are still limited data on the efficacy and safety of repeated donations of granulocyte-colony-stimulating factor (G-CSF)-mobilized peripheral blood progenitor cells (PBPCs) for allogeneic transplantation. STUDY DESIGN AND METHODS: Sixty-seven healthy donors undergoing two consecutive mobilizations of PBPCs within a median interval of 5 months (range, 0.1-47 months) were investigated. For both first mobilization (FM) and second mobilization (SM), G-CSF (lenograstim) at 7.5 microg per kg per day was administered. RESULTS: The nonhematologic side effects were comparable between both mobilizations. A significantly lower yield of CD34+ cells x 10(6) per kg of donor weight was obtained on Day 5 of SM in female (n = 31; FM, 5.0; SM, 3.23; p = 0.008) but not in male (n = 36; FM, 5.96; SM, 5.36; p = 0.24) donors. Multivariate analysis identified a lower CD34+ blood concentration on Day 5 of FM (p < 0.001) as well as female sex (p = 0.015) as independent risk factors for a lower yield of progenitor cells, whereas donor age and body mass index, interval between donations, and schedule of G-CSF application showed no significant impact. CONCLUSION: The identified risk factors allow the estimation of the efficacy of a SM in an individual donor before G-CSF administration, thus avoiding distress to both the donor and the recipient.