Cindy Kramer

Growth factor plus preemptive ('just-in-time') plerixafor successfully mobilizes hematopoietic stem cells in multiple myeloma patients despite prior lenalidomide exposure

Lenalidomide is associated with suboptimal autologous hematopoietic stem cell (AHSC) mobilization. We hypothesized that growth factor plus preemptive plerixafor is an effective strategy for AHSC mobilization in multiple myeloma (MM) despite prior exposure to lenalidomide. We retrospectively reviewed patient characteristics and mobilization outcomes of 89 consecutive MM patients undergoing first mobilization with filgrastim or pegfilgrastim +/− preemptive plerixafor using a previously validated algorithm based on day 4 peripheral blood CD34+ cell count (PB-CD34+) and mobilization target. Outcomes were analyzed according to the extent of prior exposure to lenalidomide: no prior exposure (group A, n=40), 1– 4 cycles (group B, n=30) and >4 cycles (group C, n=19). Multivariate analysis yielded only age and number of cycles of lenalidomide as negatively associated, and mobilization with pegfilgrastim as positively associated with higher PB-CD34+. Only 45% of patients in group A required plerixafor vs 63% in groups B and 84% in C, P=0.01. A higher proportion of patients in group A (100%) met the mobilization target than in groups B (90%) or C (79%), P=0.008. All patients yielded at least 2 × 106 CD34+/kg. Growth factor mobilization with preemptive plerixafor is an adequate upfront mobilization strategy for MM patients regardless of prior exposure to lenalidomide.

Beyond CD34+ cell dose: impact of method of peripheral blood hematopoietic stem cell mobilization (granulocyte-colony-stimulating factor [G-CSF], G-CSF plus plerixafor, or cyclophosphamide G-CSF/granulocyte-macrophage [GM]-CSF) on number of colony-forming unit-GM, engraftment, and Day +100 hematopoietic graft function.

BACKGROUND: The dose of CD34+ cells/kg in the mobilized peripheral blood product is the main determinant of neutrophil and platelet (PLT) engraftment after autologous hematopoietic stem cell transplantation (AHSCT). Whether the method of mobilization, namely, granulocyte–colony‐stimulating factor (G‐CSF) alone (G), G‐CSF plus plerixafor (G+P), or cyclophosphamide + G/granulocyte‐macrophage (GM)‐CSF (Cy+G/GM), independently affects number of colony‐forming unit (CFU)‐GM, engraftment, and hematopoietic graft function is unknown.

Pegfilgrastim- versus filgrastim-based autologous hematopoietic stem cell mobilization in the setting of preemptive use of plerixafor: efficacy and cost analysis.

BACKGROUND: Plerixafor enhances the ability of filgrastim (FIL) to mobilize CD34+ cells but adds cost to the mobilization. We hypothesized that replacing weight‐based FIL with flat‐dose pegfilgrastim (PEG) in a validated cost‐based mobilization algorithm for patient‐adapted use of plerixafor would add convenience without increased cost.

Similar dynamics of intraapheresis autologous CD34+ recruitment and collection efficiency in patients undergoing mobilization with or without plerixafor

Compared with growth factor (G) alone, the combination of G with plerixafor (G + P) increases peripheral blood CD34+ count (PB‐CD34+) and improves CD34+ collection yield (yCD34+) in multiple myeloma and lymphoma patients undergoing autologous hematopoietic progenitor cell (AHPC) mobilization. It is unknown whether the improved yCD34+ with G + P results entirely from expansion of PB‐CD34+ or also from increased intraapheresis CD34+ recruitment and collection efficiency.

The effect of bone marrow graft composition on pediatric bone marrow transplantation outcomes

Hematopoietic stem cell graft cellular composition has been generally accepted to impact outcomes. Recent studies question this hypothesis. We conducted a single‐center retrospective study of sixty‐one pediatric BMT recipients for malignant (68%) and nonmalignant diseases (32%) examining effects of graft composition on engraftment, acute GVHD, chronic GVHD, and survival at day 100 and 1 year. Grafts contained a median of 3.63 x 08 TNC/kg (range: 0.031‐10.31 x 108 TNC/kg) and 4.09 x 106 CD34+/kg (range: 0.76‐24.15 x 106 CD34+/kg) with median neutrophil and platelet engraftment times of 17 and 29 days, respectively. A univariate analysis showed a trend for increasing TNC and increasing time to neutrophil engraftment HR: 0.875; CI: 0.075‐1.001). Increasing CD34+ counts shortened time to platelet engraftment (HR: 1.085; CI: 1.015‐1.161). No significant relationship was found between TNC, CD34+, or CD3+ and acute or chronic GVHD. TNC or CD34+ did not affect day 100, 1‐year survival, or 2‐year survival. Increasing CD3+ counts demonstrated a negative trend on day 100 survival (HR: 1.108; CI: 1.001‐1.036) but not 1‐year survival or 2‐year survival. These results add additional data questioning the effect of graft composition on outcomes in pediatric BMT patients with important ramifications for the management of donors.