Selection of a mobilization regimen for multiple myeloma based on the response to induction therapy: granulocyte-colony stimulating factor (G-CSF) alone versus high-dose cyclophosphamide plus G-CSF

Prolonged infusion time of cyclophosphamide plus granulocyte colony-stimulating factor (G-CSF) as a mobilization regimen may improve mobilization efficiency in newly diagnosed multiple myeloma patients: a single center experience

OBJECTIVES

This study aimed to clarify the effectiveness and safety of two different infusion durations of cyclophosphamide (CTX) plus granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell mobilization in patients with newly diagnosed multiple myeloma (NDMM).

METHODS

One hundred and fifty-six consecutive NDMM patients receiving CTX plus G-CSF mobilization and autologous stem cell transplantation during the period of September 2008 to May 2020 were selected for retrospective analysis. According to differences in prolonged infusion time of CTX, they were divided into a 24-h group (24-h continuous infusion) and a control group (4-6 h of infusion). Mobilization and safety of infusion were analyzed. Flow cytometry was used to detect the peripheral blood CD34+ cell count. Multivariate analysis was performed to determine the factors influencing the number of CD34+ cells.

RESULTS

The mean CD34+ cell counts collected in 24-h and control groups were 6.78 (interquartile range [IQR] 3.59-11.69) and 4.48 (IQR 2.39-6.30) ×106/kg, respectively (p < 0.001). Meanwhile, the target number of CD34+ cells/kg (defined as ≥4 × 106/kg) was collected from 51 (75%) of cases in 24-h group vs. 45 (51%) in the control group (p = 0.002). Multivariate analysis identified the independence of CTX infusion time as a factor influencing the target number of CD34+ cells/kg [odds ratio OR, 4.045; 95% CI: 1.630-10.038, p = 0.003]. The post-transplantation time to neutrophil engraftment was 10 (IQR 9-11) in 24-h group and 11 (IQR 10-12) in control group (p < 0.001). Finally, no statistical differences were identified between groups in terms of hematologic and non-hematologic toxicities.

CONCLUSIONS

For patients with NDMM, 24-h continuous infusion of CTX plus G-CSF contributes to improved mobilization efficiency and equivalent toxicity as a stem cell mobilization regimen.

Prospective Comparative Study of Etoposide plus G-CSF versus G-CSF Alone, Followed by Risk-Adapted Plerixafor for Peripheral Blood Stem Cell Mobilization in Patients with Newly Diagnosed Multiple Myeloma: CAtholic REsearch Network for Multiple Myeloma Study (CAREMM-2001)

To explore the optimal mobilization for multiple myeloma (MM) patients, we conducted a prospective trial comparing single-dose etoposide (375 mg/m2 for one day) plus G-CSF versus G-CSF alone, followed by risk-adapted plerixafor. After randomization, 27 patients in the etoposide group and 29 patients in the G-CSF alone group received mobilizations. Six (22.2%) patients in the etoposide group and 15 (51.7%) patients in the G-CSF alone group received plerixafor based on a peripheral blood CD34+ cell count of < 15/mm3 (p = 0.045). The median count of CD34+ cells collected was significantly higher in the etoposide group (9.5 × 106/kg vs. 7.9 × 106/kg; p = 0.018), but the optimal collection rate (CD34+ cells ≥ 6 × 106/kg) was not significantly different between the two groups (96.3% vs. 82.8%; p = 0.195). The rate of CD34+ cells collected of ≥ 8.0 × 106/kg was significantly higher in the etoposide group (77.8% vs. 44.8%; p = 0.025). Although the rates of grade II-IV thrombocytopenia (63.0% vs. 31.0%; p = 0.031) and grade I-IV nausea (14.8% vs. 0%; p = 0.048) were significantly higher in the etoposide group, the rates of adverse events were low in both groups, with no neutropenic fever or septic shock. Thus, both single-dose etoposide plus G-CSF and G-CSF alone with risk-adapted plerixafor were effective and safe, but the former may be the better option for patients who are expected to receive two or more transplantations.

The Efficacy and Safety of Chemotherapy-Based Stem Cell Mobilization in Multiple Myeloma Patients Who Are Poor Responders to Induction: The Mayo Clinic Experience

We report the outcomes of 117 patients with newly diagnosed multiple myeloma who received novel agent induction, had a poor response to induction, and were mobilized using intravenous intermediate-dose cyclophosphamide (82%) or VD-PACE (18%) plus granulocyte colony-stimulating factor (G-CSF) and on-demand plerixafor. The median progression-free survival and overall survival of the chemo-mobilized cohort were 21 months (95% confidence interval [CI], 15-71) and 58 months (95% CI, 47-80), respectively. We compared our cohort to a 117-patient cohort matched by the level of response at pretransplant evaluation. The matched patients were mobilized with G-CSF and on-demand plerixafor without chemotherapy. Patients receiving chemo-mobilization had higher stem cell yields than the growth-factor-only cohort (median, 10.7 × 10⁶ cells/kg vs. 8.77 × 10⁶ cells/kg, respectively; P < .001). The safety profile of chemo-mobilization was favorable, and there was no difference between the two groups in length of hospitalization during autologous stem cell transplantation (P = .95), days to neutrophil engraftment (P = .22), days to platelet engraftment (P = .27), or risk of bacteremia (P = .52). Twenty-nine percent of the chemo-mobilized cohort and 65% of the matched cohort required plerixafor for adequate mobilization (P < .001). Chemo-mobilization enhances stem cell collection without adversely impacting the post-transplant clinical course.

Filgrastim alone versus cyclophosphamide and filgrastim for mobilization in multiple myeloma patients

BACKGROUND AND OBJECTIVE

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is standard treatment approach in most multiple myeloma (MM) patients. Before ASCT, chemomobilization or only granulocyte-colony stimulating factor (G-CSF) mobilization can be preferred in stem cell mobilization. The primary aim of the study is to compare the effect of the two mobilization regimens on hematopoietic engraftment times, CD34+cell counts and number of apheresis required to harvest stem cells.

MATERIALS AND METHODS

The records of MM patients who applied to our hospital between 2010 and 2020 were analysed retrospectively. Patients were divided into two groups (Group A: Cyclophosphamide plus filgrastim, Group B: Filgrastim alone) according to the mobilization regimen.

RESULTS

A total of 223 MM patients were included in this study (Group A:153, Group B:70 patients). When the patients in Group A and Group B were compared, the number of collected CD34+ cells were higher in Group A (p < 0.001). However, there was no significant difference between the two groups in terms of median times to neutrophil and platelet engraftment, and number of apheresis required to harvest stem cells (p > 0.05). The rate of infection development during mobilization in the patients in group A and the duration of hospitalization of these patients were higher than the patients in group B (p < 0.001). Patients receiving >6 cycles of chemotherapy and immunomodulatory treatment had lower collected CD34+ cells than other patients (p = 0.012 and p = 0.054).

CONCLUSION

Based on our findings, filgrastim alone seems to provide a sufficient amount of stem cells in MM patients.

Comparison of the efficiency, safety, and survival outcomes in two stem cell mobilization regimens with cyclophosphamide plus G-CSF or G-CSF alone in multiple myeloma: a meta-analysis

Autologous stem cell transplantation as a frontline treatment for patients with multiple myeloma (MM) requires an adequate peripheral blood stem cell (PBSC) collection before processing. Granulocyte-colony stimulating factor (G-CSF) with or without cyclophosphamide (CTX) is a common regimen for PBSC mobilization; their benefits and risks are controversial. To compare the efficiency, safety, and survival outcomes between the two regimens, we conducted a meta-analysis including 18 studies with 4 prospective and 14 retrospective studies; a total of 2770 patients with MM were analyzed. The CTX plus G-CSF regimen had higher yields of total CD34⁺ cells (SMD = 0.39, 95% CI (0.30, 0.49)), and higher mobilization rates of the target ⩾ 2 × 10⁶/kg (OR = 3.34, 95% CI (1.82, 6.11)) and 4 × 10⁶/kg (OR = 2.16, 95% CI (1.69, 2.76)) cells. A favorable event-free survival (EFS) (HR = 0.73, 95% CI (0.58, 0.93), p = 0.01) and better 3-year EFS rate (OR = 1.65, 95% CI (1.1, 2.47), p = 0.02) were also reached in the patients with CTX plus G-CSF mobilization, although the risks of admission (OR = 26.49, 95% CI (7.31, 95.97)) and fever (OR = 13.66, 95% CI (6.21, 30.03)) during mobilization were increased, the treatment-related mortality was consistent (p = 0.26). The CTX plus G-CSF regimen was superior to the G-CSF-alone regimen for PBSC mobilization in patients with MM.

Improved progression-free and event-free survival in myeloma patients undergoing PBSCH receiving a cyclophosphamide + G-CSF regimen than G-CSF alone

Two regimens are commonly used for peripheral blood hematopoietic stem cell harvesting (PBSCH) in multiple myeloma: high-dose cyclophosphamide (HD-CY) + granulocyte-colony stimulating factor (G-CSF), and G-CSF alone. The objective of the present study was to evaluate the anti-myeloma effect of the PBSCH regimen including HD-CY. We retrospectively assessed harvesting efficiency, complications, and anti-myeloma effects in 115 patients receiving HD-CY + G-CSF (HD-CY group) and 32 patients receiving G-CSF alone (G-alone group). We collected > 2 × 10⁶ CD34-positive cells/kg from 93 and 75% of patients in the HD-CY and G-alone groups, respectively (P = 0.0079). The mean HSC count was also higher in the HD-CY group. No severe complications were observed in the G-alone group, whereas 66% of patients in the HD-CY group were treated with intravenous antibiotics. The median progression-free and event-free survival (PFS and EFS) were longer in the HD-CY group than in the G-alone group (28 vs. 18 months and 25 vs. 13 months, respectively; P = 0.0127 and 0.0139), with no difference in median overall survival. HD-CY showed anti-myeloma effect, as verified by prolonged EFS and PFS, when a vincristine, doxorubicin, and dexamethasone regimen was administered as induction before PBSCH.