Plerixafor for Autologous Peripheral Blood Stem Cell Mobilization in Patients Previously Treated with Fludarabine or Lenalidomide
Authors: Malard Florent , Kröger Nicolaus , Gabriel Ian H , Hübel Kai , Apperley Jane F. , Basak Grzegorz , Douglas Kenneth W , Geraldes Catarina , Jaksic Ozren , Koristek Zdenek , Lanza Francesco , Lemoli Roberto M. , Mikala Gabor , Selleslag Dominik , Worel Nina , Duarte Rafael F. , Mohty Mohamad 
Published: October 2019

Abstract
Abstract 1932
High dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT) is an effective treatment for patients with non-Hodgkin lymphoma (NHL) and multiple myeloma (MM). At present, G-CSF-mobilized peripheral blood stem cells (PBSCs) are the preferred stem cell source for autologous HSCT. Fludarabine and lenalidomide are essential drugs in the front line treatment of NHL and MM respectively. Data suggests that fludarabine and lenalidomide therapy may have a deleterious effect on stem cell mobilization. Prior to the drug approval in Europe, a plerixafor compassionate use program (CUP) was available from July 2008 to August 2010 to provide access to the drug for patients with MM or lymphoma who had previously failed a mobilization attempt, and who were not eligible for another specific plerixafor trial.
In the European CUP, 48 patients (median age 57 years; range, 36–69), previously treated with fludarabine (median 5 cycles; range, 1–7 cycles) were given plerixafor plus G-CSF for remobilization following a primary mobilisation attempt. All 48 patients had a diagnosis of NHL. The overall median number of CD34+ cells collected was 2.3×106 /Kg (range, 0.3–13.4). The minimum required number of CD34+ cells (≥2.0×106 per kg) was collected from 58% of patients, while only 3 patients (6%) collected ≥5.0×106 CD34+ cells. The collection target of 2.0×106/Kg was reached in a median of 2 apheresis sessions (range, 1–3). Thirty-five patients (median age 57 years; range, 34–66), previously treated with lenalidomide (median 5 cycles; range, 1–10 cycles) were given plerixafor plus G-CSF for remobilization. All patients the 35 patients had MM. The overall median number of CD34+ cells collected was 3.4×106/Kg (range, 1.1–14.8). The minimum required number of CD34+ cells (≥2.0×106 per kg) was collected from 69% of patients, including 12 patients (34%) who were able to collect ≥5.0×106 cells/Kg. In the Len group, 7 patients (20%) had received a prior autologous HSCT before salvage mobilization with plerixafor. Both targets were reached with a median of 2 apheresis sessions (range, 1–4).
In conclusion, salvage mobilization with plerixafor plus G-CSF is successful in the majority of patients with MM previously treated with lenalidomide. In fludarabine-exposed patients, only 58% of patients will achieve successful salvage mobilization with plerixafor plus G-CSF, suggesting the need for large prospective studies evaluating the efficacy of plerixafor for frontline mobilization in this subgroup of patients.Table 1.Study population characteristicsCharacteristic (%)Fludarabine (N=48)Lenalidomide (N=35)Patient age, median (range)57 (36–69)57 (34–66)Patient gender    Male26 (54)18 (51)    Female22 (46)17 (42)Fludarabine or Lenalidomide cycles, median (range)5 (1–7)5 (1–10)Diagnosis and disease statusIndolent NHL48 (100)0 (0)Multiple myeloma0 (0)35 (100)Previous chemotherapy: number of lines, median (range)3 (1–6)4 (1–9)Previous autograft    Yes07 (20)    No43 (90)20 (57)    Data missing5 (10)8 (23)Radiotherapy    Yes5 (10)3 (9)    No36 (75)24 (68)    Data missing7 (15)8 (23)Mobilization strategy with plerixafor    Steady-state GCSF mobilization38 (79)27 (77)    Chemotherapy+GCSF mobilization10 (21)8 (23)No. of patients collected44 (92)34 (97)CD34+ cells collected per Kg, median (range)2.3 (0.3–13.4)3.4 (1.1–14.8)No. of patients who reached ≥ 2.106 CD34+28 (58)24 (69)No. of apheresis days to reach ≥ 2.106 CD34+2 (1–3)2 (1–4)No. of patients who reached ≥ 5.106 CD34+3 (6)12 (34)No. of apheresis days to reach ≥ 5.106 CD34+2 (1–3)2 (1–3)NHL, non-Hodgkin lymphoma

Disclosures:
Mohty: Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees.