Evaluation of Hematopoietic Stem Cell Mobilization Rates with Early Plerixafor Administration for Adult Stem Cell Transplantation

Abstract

The addition of plerixafor to high-dose colony-stimulating growth factor has been shown to improve stem cell mobilization rates in autologous transplant patients with multiple myeloma and non-Hodgkin lymphoma. This study evaluates the change in administration time of plerixafor to determine if cell mobilization rates are similar between the US Food and Drug Administration-approved administration time of 11 hours before apheresis and an earlier administration time of 16 hours before apheresis. Medical records of patients age ≥ 18 years undergoing autologous stem cell transplantation requiring the use of plerixafor after at least 4 days of granulocyte colony-stimulating factor therapy to complete stem cell mobilization from January 1, 2010 through September 30, 2014 were retrospectively reviewed. The primary outcome was CD34 cell mobilization success rates when plerixafor was administered 11 ± 2 hours (standard administration group) compared with 16 ± 2 hours before cell apheresis (early administration group), as defined as collection of ≥2 × 10 CD34 cells/kg. Secondary outcomes included the number of plerixafor therapy days required to collect a total of ≥2 × 10 CD34 cells/kg, the number of apheresis cycles required to achieve ≥2 × 10 CD34 cells/kg, the median CD34 cells/kg collected in each apheresis session, and the rates of reported adverse events that occurred in the standard administration time group compared with the early administration time group. Of the 197 patients included, 114 patients received plerixafor 11 ± 2 hours before apheresis and 83 patients received plerixafor 16 hours ± 2 hours before apheresis. Ninety-four percent of patients in the early administration group achieved successful stem cell mobilization compared with 81.6% in the standard administration group (P = .0111). The median number of plerixafor days to reach the collection goal of ≥2 × 10 CD34 cells/kg was 1 day for each group (P = .323), and the median number of apheresis days to reach the collection goal was 2 days for the standard administration group compared with 1 day for the early administration group (P = .0156). Most adverse events were similar between the 2 groups except for fever, which occurred in 4.8% of the patients in the early administration group and none of the patients in the standard administration group. This study demonstrates plerixafor effectively mobilizes peripheral blood stem cells when given at an early administration time of 16 hours before apheresis compared with standard administration of 11 hours before apheresis. However, further prospective studies could strengthen these results.

Impact of Plerixafor Use at Different Peripheral Blood CD34+ Thresholds on Autologous Stem Cell Collection in Patients with Multiple Myeloma

“…Our practice is to administer plerixafor at the end of the clinic day, approximately 14 to 16 hours before apheresis. Whether this practice leads to suboptimal harvests is unclear; however, retrospective [47,48] and prospective studies [49] have demonstrated adequate collection of minimum and target yields in myeloma and lymphoma patients when plerixafor is given 16 to 18 hours before leukocytapheresis. In our analysis, the longer time between plerixafor administration and apheresis does not appear to diminish stem cell collection.…”

A Novel Hematopoietic Progenitor Cell Mobilization Regimen Comprising Bortezomib, G-CSF, and Preemptive Plerixafor for Multiple Myeloma

“…With G-CSF plerixafor therapy, the proportion of patients from whom 2 10 6 CD34-positive cells kg were collected in 4 or fewer apheresis sessions was 88.3% 14 . Similarly, two other studies reported that for adequate cell collection, the median number of aphereses was 2 range 1-4 3,4 . Moreover, in a comparative cohort of Japanese patients, Yogo et al reported that 17% of 63.8% patients who received lenalidomide did not yield more than 2.0 10 6 CD34 cells kg with a single apheresis session 17 .…”

“…Musto et al reported predictors for unsuccessful or sub-optimal HPC mobilization, which include advanced age, lenalidomide treatment, and severe toxicity in response to high-dose cyclophosphamide 2 . The use of plerixafor in combination with G-CSF improves mobilization compared with G-CSF alone or in combination with cyclophosphamide, and the plerixafor combination is recommended for a standard collection method [3][4][5] . However, even after using plerixafor, some patients still show poor mobilization.…”

Evaluation of mobilization efficacy with an extended interval following plerixafor administration

“…2 Â 10 6 CD34þ cell/kg compared to 82% of patients receiving plerixafor 11 AE 2 h prior to apheresis. 22 Most recently, El Rahi et al used a CD34þ cell concentration of < 10-20 cells/mL as their threshold for plerixafor and similarly found that collection yield was not compromised with the use of an extended plerixafor dosing window. In their evaluation, 91% of patients receiving plerixafor at 4:00 p.m. achieved a minimum collection goal of !…”

“…2 Â 10 6 CD34þ cells/kg was achieved in 95% of patients in our evaluation, similar to the overall mobilization success rate reported in other studies. 14,22 The current study represents other unique strategies in addition to a risk-based algorithm for administration of plerixafor. It included the use of plerixafor as a rescue approach for low yield apheresis sessions.…”