Increased Efficacy of Stem Cell Chemomobilization with Intermediate-Dose Cytarabine Plus Granulocyte Colony-Stimulating Factor (G-CSF) Compared with G-CSF Alone in Patients with Multiple Myeloma: Results of a Randomized Trial

Evaluation of efficacy and safety in the use of cytarabine for mobilization of hematopoietic stem cells in a reference hospital in northeastern Brazil

Autologous hematopoietic stem cell transplantation (Auto-HSCT) is widely used in the treatment of patients with hematological neoplasms. Since these cells circulate in small quantities in the periphery, the use of regimens that promote their mobilization is essential. In this study, we retrospectively evaluated the efficacy and safety of using intermediate doses of cytarabine (1.6 g/m²) + filgrastim (10 mcg/kg/day) in the mobilization of stem cells in 157 patients treated by the Unified Health System at the Hematology and Bone Marrow Transplant Service of the Hospital Real Português de Beneficência, in Recife, Pernambuco. The sample included patients with multiple myeloma (MM) (58.6 %), lymphomas (29.9 %), and other neoplasms (11.5 %). The target of 2.0 × 10 6 CD34+ cells/kg was achieved by 148 (94.3 %) patients, in most cases (84.1 %) in a single apheresis and the median number of cells collected was 9.5 × 10 6 CD34+ cells/kg. No episode of febrile neutropenia was observed, however, 79 patients (50.3 %) required platelet transfusion (no cases attributed to bleeding). The median engraftment time was 11 days. Given these results, we suggest that the use of intermediate doses of cytarabine, combined with filgrastim, is safe and effective in mobilizing hematopoietic stem cells (HSCs).

Mobilization Strategies in Myeloma Patients Intended for Autologous Hematopoietic Cell Transplantation

Background

Multiple myeloma is currently the leading indication for autologous hematopoietic cell transplantation (AHCT). A prerequisite for AHCT is mobilization and collection of adequate blood graft to support high-dose therapy. Current mobilization strategies include granulocyte colony-stimulating factor (G-CSF) alone or in combination with chemotherapy most commonly cyclophosphamide (CY). More recently, plerixafor has become into agenda especially in patients who mobilize poorly. In the selection of a mobilization method, several factors should be considered.

Summary

Preplanned collection target is important as G-CSF plus plerixafor is more effective in the mobilization of CD34+ cells than G-CSF alone. On the other hand, CY plus G-CSF is superior to G-CSF only mobilization. Previous therapy and age of the patients are important considerations as G-CSF alone may not be effective enough in patients with risk factors for poor mobilization. These factors include extensive lenalidomide exposure, irradiation to bone marrow-bearing sites, higher age, or a previous mobilization failure. Also, local preferences and experiences as well as the number of apheresis needed are important issues as well as cost-effectiveness considerations. Mobilization method used may have implication for cellular composition of collected grafts, which might have an impact on posttransplant events such as hematologic and immune recovery in addition to also potential long-term outcomes.

Key Message

Currently, G-CSF alone and preemptive plerixafor if needed might be considered as a standard mobilization strategy in MM patients intended for AHCT.

Higher efficacy of Etoposide + Cytarabine Plus Pegfilgrastim in poorly mobilizing Multiple Myeloma and lymphoma Patients

BACKGROUND AIMS

An optimal strategy for mobilizing hematopoietic stem cells in poorly mobilizing patients with multiple myeloma (MM) and lymphoma has not yet been determined.

METHODS

We retrospectively analyzed the efficacy and safety of etoposide combined with cytarabine (etoposide 75 mg/m2, daily d1∼2; Ara-C 300 mg/m2, every 12 h d1∼2), plus pegfilgrastim (6 mg d6) in 32 patients with MM or lymphoma, among whom 53.1% were defined as "proven poor mobilizers."

RESULTS

This approach resulted in adequate mobilization (≥2.0 × 106 CD34+ cells/kg) in 93.8% of patients and optimal mobilization (≥5.0 × 106 CD34+ cells/kg) in 71.9% of patients. A total of 100% of patients with MM reached at least 5 × 106 CD34+ cells/kg collected, the amount required for double autologous stem cell transplant. In total, 88.2% of patients with lymphoma reached at least 2 × 106 CD34+ cells/kg collected, the amount required for a single autologous stem cell transplant. This was achieved with a single leukapheresis in 78.1% of cases. A median peak number of 42.0/μL circulating CD34+ cells and a median number of blood CD34+ cells counts in 6.7 × 106/L were collected among 30 successful mobilizers. Approximately 6.3% of patients required plerixafor rescue, which was successful. Nine (28.1%) of the 32 patients suffered grade 2∼3 infections, and 50% required platelet transfusions.

CONCLUSIONS

We conclude that chemo-mobilization with etoposide, Ara-C and pegfilgrastim in poorly mobilizing patients with MM or lymphoma is very effective and has acceptable toxicity.

Efficacy of hematopoietic stem cell mobilization regimens in patients with hematological malignancies: a systematic review and network meta-analysis of randomized controlled trials

Background

Efficient mobilization of hematopoietic stem cells (HSCs) from bone marrow niche into circulation is the key to successful collection and transplantation in patients with hematological malignancies. The efficacy of various HSCs mobilization regimens has been widely investigated, but the results are inconsistent.

Methods

We performed comprehensive databases searching for eligible randomized controlled trials (RCTs) that comparing the efficacy of HSCs mobilization regimens in patients with hematological malignancies. Bayesian network meta-analyses were performed with WinBUGS. Standard dose of granulocyte colony-stimulating factor (G-CSF SD) was chosen as the common comparator. Estimates of relative treatment effects for other regimens were reported as mean differences (MD) or odds ratio (OR) with associated 95% credibility interval (95% CrI). The surface under the cumulative ranking curve (SUCRA) were obtained to present rank probabilities of all included regimens.

Results

Databases searching and study selection identified 44 eligible RCTs, of which the mobilization results are summarized. Then we compared the efficacy of mobilization regimens separately for patients with multiple myeloma (MM) and non-Hodgkin lymphoma (NHL) by including 13 eligible trials for network meta-analysis, involving 638 patients with MM and 592 patients with NHL. For patients with MM, data are pooled from 8 trials for 6 regimens, including G-CSF in standard dose (SD) or reduced dose (RD) combined with cyclophosphamide (CY), intermediate-dose cytarabine (ID-AraC) or plerixafor. The results show that compared with G-CSF SD alone, 3 regimens including ID-AraC + G-CSF SD (MD 14.29, 95% CrI 9.99–18.53; SUCRA 1.00), G-CSF SD + Plerixafor SD (MD 4.15, 95% CrI 2.92–5.39; SUCRA 0.80), and CY + G-CSF RD (MD 1.18, 95% CrI 0.29–2.07; SUCRA 0.60) are associated with significantly increased total number of collected CD34⁺ cells (× 10⁶/kg), among which ID-AraC + G-CSF SD ranked first with a probability of being best regimen of 100%. Moreover, ID-AraC + G-CSF SD and G-CSF SD + Plerixafor SD are associated with significantly higher successful rate of achieving optimal target (collecting ≥ 4–6 × 10⁶ CD34⁺ cells/kg). For patients with NHL, data are pooled from 5 trials for 4 regimens, the results show that compared with G-CSF SD alone, G-CSF SD + Plerixafor SD (MD 3.62, 95% CrI 2.86–4.38; SUCRA 0.81) and G-CSF SD plus the new CXC chemokine receptor-4 (CXCR-4) antagonist YF-H-2015005 (MD 3.43, 95% CrI 2.51–4.35; SUCRA 0.69) are associated with significantly higher number of total CD34⁺ cells collected. These 2 regimens are also associated with significantly higher successful rate of achieving optimal target. There are no significant differences in rate of achieving optimal target between G-CSF SD + Plerixafor SD and G-CSF + YF-H-2015005.

Conclusions

In conclusion, ID-AraC plus G-CSF is associated with the highest probability of being best mobilization regimen in patients with MM. For patients with NHL, G-CSF in combination with plerixafor or YF-H-2015005 showed similar improvements in HSCs mobilization efficacy. The relative effects of other chemotherapy-based mobilization regimens still require to be determined with further investigations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02802-6.

High Efficacy of Stem Cell Mobilization With Etoposide+Cytarabine Plus G-CSF in Patients With Multiple Myeloma

Background

Efficient mobilization of CD34+ hematopoietic stem cells plays a vital role in successful autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM), especially in cases with high-risk cytogenetic recommended for tandem ASCT. However, the optimal mobilization strategy remains a matter of debate in the era of lenalidomide. The combination of etoposide with Cytarabine plus G-CSF as a novel mobilization regimen in MM has not been reported previously.

Methods

This research retrospectively studied mobilization efficacy and safety using etoposide combined with Cytarabine (etoposide 50–100 mg/m², qd d1–3; AraC 0.5 g/m², q12h d1~3) plus G-CSF (5 µg/kg/day, from d5 until the day of apheresis) in 128 patients with MM. 70(54.7%) patients received lenalidomide-based induction regimens treatment

Results

A median of 27.75×10⁶ CD34+ cells/kg was collected in the first apheresis, and 28.23×10⁶ CD34+ cells/kg were collected overall. Of the 128 patients, all achieved adequate collection (≥2×10⁶ CD34+ cells/kg), 121(94.5%) achieved optimal collection for single ASCT (≥5×10⁶ CD34+ cells/kg), and 114(89.1%) harvested optimal collection for tandem ASCT (≥10×10⁶ CD34+ cells/kg). In particular, the target yield of optimal collection for tandem ASCT was reached in 82.8% (106/128) by a single apheresis procedure. 14 patients obtained deeper response post mobilization. In multivariate analysis, cycles of prior chemotherapy independently affected the optimal achievement of CD34+ cells (p=0.004, OR 0.695, 95% CI 0.544~0.888). Previous lenalidomide exposure did not significantly impair CD34+ cells collection. Although 68% episodes of antibiotic usage were observed, no severe infection or treatment-related mortality occurred.

Conclusion

Stem cell mobilization with Etoposide + Cytarabine plus G-CSF was highly efficient and safe in patients with MM, which could be considered in high-risk MM patients who were referred for tandem ASCT.

The association of mobilising regimen on immune reconstitution and survival in myeloma patients treated with bortezomib, cyclophosphamide and dexamethasone induction followed by a melphalan autograft

G-CSF only mobilisation has been shown to enhance immune reconstitution early post-transplant, but its impact on survival remains uncertain. We undertook a retrospective review of 12 transplant centres to examine overall survival (OS) and time to next treatment (TTNT) following melphalan autograft according to mobilisation method (G-CSF only vs. G-CSF and cyclophosphamide [CY]) in myeloma patients uniformly treated with bortezomib, cyclophosphamide and dexamethasone induction. Six centres had a policy to use G-CSF alone and six to use G-CSF + CY. Patients failing G-CSF only mobilisation were excluded. 601 patients were included: 328: G-CSF + CY, 273: G-CSF only. Mobilisation arms were comparable in terms of age, Revised International Staging System (R-ISS) groups and post-transplant maintenance therapy. G-CSF + CY mobilisation generated higher median CD34 + yields (8.6 vs. 5.5 × 10⁶/kg, p < 0.001). G-CSF only mobilisation was associated with a significantly higher lymphocyte count at day 15 post-infusion (p < 0.001). G-CSF only mobilisation was associated with significantly improved OS (aHR = 0.60, 95%CI 0.39-0.92, p = 0.018) and TTNT (aHR = 0.77, 95%CI 0.60-0.97, p = 0.027), when adjusting for R-ISS, disease-response pre-transplant, age and post-transplant maintenance therapy. This survival benefit may reflect selection bias in excluding patients with unsuccessful G-CSF only mobilisation or may be due to enhanced autograft immune cell content and improved early immune reconstitution.

Stem cell mobilization in multiple myeloma patients relapsing after previous autologous hematopoietic stem cell transplantation: A multicenter report by the Polish Myeloma Study Group

BACKGROUND

Salvage autologous hematopoietic stem cell transplantation (autoHSCT) may be used to treat relapse of multiple myeloma occurring after previous autoHSCT. When insufficient number of hematopoietic stem cells was stored from the initial harvest, remobilization of stem cells is necessary.

PURPOSE

The analysis of stem cell remobilization after previous autoHSCT.

PATIENTS AND METHODS

Fifty-eight patients, 60% males, median 59 years, were included. Median time interval between autoHSCT and remobilization was 42 months. The first remobilization was performed mostly after chemotherapy: cyclophosphamide (33%), cytarabine (43%), and etoposide (19%).

RESULTS

The first remobilization was successful in 67% patients. About 19% patients required plerixafor rescue, among whom it allowed for successful harvesting in 14%. Use of cyclophosphamide, cytarabine, and etoposide allowed for successful remobilization in 53%, 84%, and 55% patients, respectively. Patients treated with cytarabine had the highest yield of CD34+ cells (median 7.5 × 10⁶ /kg vs 5.8 and 2.4 for etoposide and cyclophosphamide, P = .001). Higher percentage of patients was able to collect ≥2 × 10⁶ CD34+ cells/kg during one leukapheresis after cytarabine (76% vs 21% for cyclophosphamide vs 36% for etoposide, P = .001). Cytarabine use was associated with lower risk of remobilization failure OR = 0.217, P = .02. Toxicity comprised mostly hematological toxicity (thrombocytopenia and neutropenia). One patient succumbed to septic shock.

CONCLUSION

Remobilization after previous autoHSCT is feasible only in a proportion of patients. Cytarabine is associated with the highest rate of successful mobilization and the highest yield of mobilized CD34+ cells. The toxicity requires careful surveillance of these patients.

Tandem autologous hematopoietic cell transplantation with sequential use of total marrow irradiation and high-dose melphalan in multiple myeloma

The goal of this phase II trial was to evaluate safety and efficacy of a tandem autologous hematopoietic cell transplantation (auto-HCT) using sequentially total marrow irradiation (TMI) at the dose of 12 Gy (4 Gy on days -3, -2, and -1) and melphalan 200 mg/m² for patients with multiple myeloma (MM). TMI was performed using helical tomotherapy. Additional "boosts" (total 24 Gy) were applied for patients with active lesions as revealed by PET-FDG. Fifty patients with median age 58 years (41-64 years) were included and received tandem auto-HCT. TMI resulted in absolute neutropenia in all patients. Grade 3 infections were reported in 30% patients. Other toxicities were rare. Proportion of patients who achieved at least very good partial response increased from 46% before the first auto-HCT to 82% after tandem transplantation. Complete remission rates changed from 10% to 42%, respectively. The probabilities of overall and progression-free survival at 5 years were 74% and 55%, respectively. No patient died without progression. We conclude that conditioning with TMI ± PET-guided "boosts" represents personalized treatment approach in MM and is characterized by very good toxicity profile. Tandem auto-HCT using TMI in sequence with high-dose melphalan appears safe with encouraging early efficacy.

Getting blood out of a stone: Identification and management of patients with poor hematopoietic cell mobilization

Hematopoietic cell transplantation (HCT) has become a primary treatment for many cancers. Nowadays, the primary source of hematopoietic cells is by leukapheresis collection of these cells from peripheral blood, after a forced egress of hematopoietic cells from marrow into blood circulation, a process known as "mobilization". In this process, mobilizing agents disrupt binding interactions between hematopoietic cells and marrow microenvironment to facilitate collection. As the first essential step of HCT, poor mobilization, i.e. failure to obtain a desired or required number of hematopoietic cell, is one of the major factors affecting engraftment or even precluding transplantation. This review summarizes the available mobilization regimens using granulocyte-colony stimulating factor (G-CSF) and plerixafor, as well as the current understanding of the factors that are associated with poor mobilization. Strategies to mobilize patients or healthy donors who failed previous mobilization are discussed. Multiple novel agents are under investigation and some of them have shown the potential to enhance the mobilization response to G-CSF and/or plerixafor. Further investigation of the risk factors including genetic factors will offer an opportunity to better understand the molecular mechanism of mobilization and help develop new therapeutic strategies for successful mobilizations.

Autologous stem cell transplantation in multiple myeloma

The treatment of patients with multiple myeloma has changed in the last decades, with an improved median survival of 8-10 years. The current treatment for newly diagnosed multiple myeloma patients eligible for autologous transplantation consists of 4 phases: pretransplant, induction, transplant, post-transplant consolidation and maintenance. Even today, a long-term disease control is the goal of multiple myeloma treatment in current clinical practice. In this review we discuss the role of autologous stem cell transplantation in multiple myeloma, the eligibility of patients for transplantation and the usefulness of an upfront tandem transplantation. The assessment of frailty and significant comorbidities plays an important role in determining transplant eligibility. Careful patient selection based on overall health status is crucial to ensure a balance between risks and benefits. In the era of induction regimens with new agents, upfront autologous transplantation remains the standard of care for young patients with newly diagnosed multiple myeloma due to the longer progression-free survival showed in randomized clinical studies. With the currently available data, the tandem transplantation in multiple myeloma may be considered in patients with high-risk cytogenetics, in particular, those who did not receive a new triplet combination or those with a lower response than very good partial response following their first transplantation.

Higher efficacy of intermediate dose cytarabine + G-CSF compared to cyclophosphamide + G-CSF in hematopoietic stem cell mobilization in patients with multiple myeloma

BACKGROUND

There are several regimens used in hematopoietic stem cell (HSC) mobilization in multiple myeloma (MM). Cyclophosphamide (Cy) is one of the most commonly used agents, although it does not always result in collecting adequate number of CD34+ cells. Recently, cytarabine (Ara-C) has been proposed as potentially efficient and safe option.

AIMS

Since the data regarding Ara-C in HSC mobilization is limited, the aim of our study was to compare retrospectively the efficiency and toxicity of G-CSF combined with either Ara-C or Cy in MM patients.

MATERIALS & METHODS

Of a total of 89 patients, 43 received low or intermediate doses of Cy, and 46 were treated with 800 mg/m² /day of Ara-C administered for two days.

RESULTS

The mean peak of CD34+ cells/ul in peripheral blood was 132 (range, 84-202) in Ara-C and 51 (range, 29-69) in Cy cohort (p < 0.001). The median number of collected CD34+ cells (×106/kg) was 10.3 (range, 4.2-17.9) vs 4.5 (range, 2.7-8.9), respectively (p < 0.001). Mobilization failure was observed in one patient in Ara-C cohort (2%) and in 8 patients treated with Cy (19%) (p = 0.013). In the Ara-C group 98% of patients obtained more than 4×106 CD34+ cells/kg required for tandem transplantation. Moreover, we observed a trend toward increased paraprotein levels measured at transplant compared to before HSC mobilization in Ara-C cohort and significantly higher transfusion rates in that group.

CONCLUSION

Our findings confirm higher HSC mobilization efficacy of Ara-C compared to Cy in MM patients. However, lower transfusions rate and better disease control of Cy may justify its use in some cases.

Stem-cell transplantation in multiple myeloma: how far have we come?

High-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) has historically been an essential part of multiple myeloma (MM) management since early studies demonstrated its efficacy in relapsed disease, and subsequent phase III trials demonstrated better responses and improved survival with this modality compared with standard chemotherapy. With further advances in the MM treatment landscape, including the development of potent novel agents, there has been an increasing debate around various aspects of ASCT, including the optimal timing, role of single versus tandem ASCT, and the practice of consolidation and maintenance therapy post-ASCT. Routine incorporation of the novel agents at each of the treatment phases, induction, consolidation when used, and maintenance has led to better responses as reflected by increasing rates of minimal residual disease (MRD) negativity, longer progression-free survival (PFS) with improvement in overall survival (OS) and in some of the trials. The phase III trials over the last decade have provided significant clarity on the current approach, and have raised important questions regarding the applicability of this modality in all patients. This review aims to summarize the latest literature in the field and discusses how these findings impact the practice of ASCT today.

The comparison of effectiveness and safety between different biosimilars of G-CSF in the mobilization of peripheral blood stem cells (PBSCs) for autologous transplantation (autologous peripheral blood stem cell transplantation, auto-PBSCT)

BACKGROUND

Autologous peripheral blood marrow stem cell transplantation (auto-PBSCT) preceded by high-dose chemotherapy is a well-known method of treatment for patients with hematological cancers. Performing the procedure entails obtaining from the patient their own stem cells from peripheral blood using G-CSF. Currently, various filgrastim biosimilars are widely used.

AIM OF THE STUDY

The purpose of this study is to compare the efficacy and safety of three different biosimilars of filgrastim in PBSC mobilization in patients with hematological malignancies.

MATERIALS AND METHODS

This is a retrospective analysis of 282 patients (118 women and 164 men) who underwent stem cells mobilization for auto-PBSCT in the Department of Hematology in Wroclaw in 2012-2014. Three filgrastim biosimilars were used: Tevagrastim (95), Nivestim (92), and Zarzio (95). Ninety patients (32%) were diagnosed with multiple myeloma, 55 (19%) with Hodgkin's lymphoma, 90 (32%) with NHLs, 20 (7%) with acute myeloid leukemia, and 27 (10%) with another hematological cancer.

RESULTS

The mean number of CD34+ cells collected during the first leukapheresis was 5.95 × 10⁶ /kg for Tevagrastim, 7.08 × 10⁶ /kg for Nivestim, and 6.8 × 10⁶ /kg for Zarzio (P > .05). The necessary number of leukapheresis for patients receiving Zarzio, Nivestim, and Tevagrastim was 1.32, 1.37, and 1.66, respectively (P > .05). The percentage of effective mobilizations was 88.2% for Zarzio, 86.2% for Nivestim, and 84.9% for Tevagrastim. The side effects included bone pain and headache.

CONCLUSION

All tested biosimilars demonstrated similar effectiveness and safety profiles in patients with hematological tumors undergoing PBSC mobilization; therefore, they can be used interchangeably.

Current status of autologous stem cell transplantation for multiple myeloma

More than 30 years after its introduction, autologous stem cell transplantation (ASCT) remains the standard of care for young patients with newly diagnosed multiple myeloma. Not only did the arrival of novel agents such as immunomodulatory drugs (IMiDs), proteasome inhibitors (PI) and monoclonal antibodies not replace ASCT, instead they solidified its central role as standard of care. Novel agent use is now inarguably essential in induction, maintenance, and possibly consolidation. In light of these new advancements, new challenges arise in deciding on optimal practice. Who is most suited to undergo ASCT? Is there an age threshold that should not be surpassed? Should transplantation be embarked on early or is it reasonable to delay it? What are the optimal induction, consolidation, and maintenance therapies? What is the role of tandem transplantation in the era of novel agents and where do patient-specific cytogenetics come into the equation when deciding on treatment? These are some of the questions addressed in this review which we will attempt to answer with the latest currently available data.