Efficiency and Safety of Pegylated Filgrastim Combined with Plerixafor in Multiple Myeloma Autologous Hematopoietic Stem Cells Mobilization
Authors: Liu Chenfei , Song Yuanbin , Liang Yang , Lu Lu , Wang Weida , Wu Bingyi 
Published: December 2024

Background
Autologous Hematopoietic Stem Cell Transplantation (Auto-HSCT) is an important treatment for Multiple Myeloma (MM). Effective stem cell mobilization is essential for the success of Auto-HSCT.
Method
We conducted a single-center retrospective analysis to investigate the most effective and safe mobilization regimen by analyzing data from 123 MM patients who underwent mobilization at Sun Yat-sen University Cancer Center from January 1, 2021 to June 30, 2024. We collected age, gender, previous recurrence, monoclonal immunoglobulin type, express Kappa or Lambda light chain, previous radiotherapy, body weight at the time of collection, volume of collection, number of CD34+ cells collected on the first day, the proportion of CD34+ cells number mobilized at first apheresis day&gt;2*10^6/k and &gt;5*10^6/kg, total number of CD34+ collected, and adverse events.Patient satisfaction survey and social economy benefit analysis was also conducted.
1) Filgrastim group
Day 1-4: Filgrastim 10mcg/kg/day, subcutaneous injection
Day5: Apheresis
2) Pegylated Filgrastim group
Day 1: Pegylated Filgrastim 6mcg/day, subcutaneous injection
Day5: Apheresis
3) Filgrastim + Plerixafor group
Day 1-4: Filgrastim 10mcg/kg/day, subcutaneous injection
Day 4 at night: Plerixafor 240 mcg/kg/day
Day5 Apheresis
4) Pegylated Filgrastim + Plerixafor group
Day 1: Pegylated Filgrastim 6mcg/day, subcutaneous injection
Day 4 at night: Plerixafor 240 mcg/kg/day
Day5 Apheresis
Results
123 mobilized MM patients were included in this study, and 38.2% (47/123) of patients were female, with a mean age of 53.5 years and a mean weight of 63.2kg. As for monoclonal immunoglobulin type, IgG (60/123,48.8%), Light Chain Myeloma (24/123,19.5%) , IgA (18/123,14.6%) are the top three, and 51.2% patients express Kappa light chain and 34.1% patients express Lambda light chain. Most patients received VRD treatment (89/123,72.4%), followed by PAD treatment (16/123,13.0%). 5.69% (7/123) of patients were in the relapse status and 2.44% (3/123) of patients previously received radiotherapy.During mobilization, a mean volume of 265 ml apheresis were collected, and mean white blood cell (WBC) count was 277 * 10^9/L, mean CD34+cell proportion in PBMC was 0.38%, mean CD34+cell number at first apheresis was 4.26*10^6/kg, mean CD34+cell number total collected was 4.80*10^6/kg and 75.6% (93/123) of patients achieved CD34+cell number at first apheresis&gt;2*10^6/kg, 31.7% (39/123) of patients achieved CD34+cell number at first apheresis&gt;5*10^6/kg.
Compared to Filgrastim + Plerixafor group, Pegylated Filgrastim + Plerixafor group had better mobilization performance at CD34+ cell proportion in Aphresis (0.39 versus 0.20, p=0.022), CD34+ cell number at first apheresis (10^6/kg) (4.64 versus 1.62, p&lt;0.001), CD34+ cell number at first apheresis&gt;2*10^6/kg (82.4% versus 20.0%, p=0.006), CD34+cell number total collected(10^6/kg) (5.14 versus 2.43, p&lt;0.001).
Used Bonferroni method to adjust p value，Pegylated Filgrastim + Plerixafor group still had a higher CD34+cell number at first apheresis (10^6/kg) (p.adjust = 0.0244) and a higher CD34+cell number total collected(10^6/kg) (p.adjust = 0.0379) .
Interestingly, Pegylated Filgrastim group had higher volume of collection than Filgrastim group (243 versus 126, p=0.002). There was also a higher tendency in Pegylated Filgrastim + Plerixafor group compared to Filgrastim + Plerixafor group (280 versus 216, p=0.123), which suggested Pegylated Filgrastim might increase the volume of collection (Supplement 3). Moreover, we collate the WBC count and CD34+ cell proportion in blood after G-CSF usage, and there is higher WBC count in blood after Pegylated Filgrastim usage (40.7 vs 22.1, p=0.002) and no statistically significant difference in CD34+ cell proportion.
Adverse events of mobilizing agent were mild and controllable, mainly occured in patients with Plerixafor.
Patient satisfaction survey showed MM patients(84.7%) preferred Pegylated Filgrastim mobilization regimen, and social economy benefit analysis showed Pegylated Filgrastim + Plerixafor mobilization regimen was more economic.
Conclusion
Compared with Filgrastim + Plerixafor, Pegylated Filgrastim + Plerixafor is more efficient, economic and patient-friendly in mobilization.
Key words
Multiple Myeloma，Autologous Hematopoietic Stem Cell Transplantation，mobilization，G-CSF，CXCR4 antagonist.