Risk factors for a poor hematopoietic stem cell mobilization

Plerixafor and granulocyte colony stimulating factor for poor mobilizers in patients undergoing autologous peripheral hematopoietic stem cell transplantation: Single institution study

Background

Autologous hematopoietic stem cell transplantation (ASCT) has become the mainstay treatment for many hematological malignancies and solid tumors. An adequate number of stem cells must be collected for better ASCT outcomes, which is challenging in 5%-30% of patients. To improve mobilization, plerixafor is used along with granulocyte colony-stimulating factor (G-CSF).

Patients and methods

We conducted a retrospective single center study involving patients who received plerixafor pre-ASCTs between January 2013 and December 2020 at a tertiary care center in Lebanon. We identified a total of 84 consecutive adult patients. All patients identified were poor mobilizers and have eventually received plerixafor either as pre-emptive use before first apheresis in those with peripheral CD34 + of less than 20 cells/ul, or after failure of first apheresis in those with peripheral stem cells (PSC) >2.0 × 106 cells/Kg.

Results

The median age at ASCT was 52.7 years (22-74) with 61% male predominance. Multiple myeloma was the most prevalent disease 64% followed by Lymphoma 32%. The majority of patients were in complete remission 64% at the time of ASCT. Most patients received proteasome inhibitor-based induction therapy 67% and Melphalan-based conditioning therapy 68%. The median follow-up from ASCT was 9 months (1-59). It was noted that greater body mass index (BMI) is a significant factor for better PSC collection whether premobilization (P = 0.003), or post plerixafor mobilization (P = 0.024). Moreover, Multiple Myeloma patients showed better mobilization using Plerixafor (P = 0.049). Using Plerixafor along with G-CSF in poor mobilizers post G-CSF alone showed a statistically significant increase in the collected PSC mean from 0.67 × 106 cells/Kg to 4.90 × 106 cells/Kg (P < 0.001) with a failure rate only for 12 patients (15%). The infusion of PSC > 2.5 × 106 cells/Kg has shown 3 days decrease in time to platelet engraftment (P = 0.021) and a 36% decrease in progression/relapse rate (P = 0.025).

Conclusion

Plerixafor is effective in increasing the PSC yield in poor mobilizers. Low BMI and hematologic malignancies other than Multiple Myeloma are risk factors for poor mobilization. More studies should be performed to establish more risk factors, helping us to identify poor mobilizers more accurately and initiate plerixafor mobilization early on.

A concise review on factors influencing the hematopoietic stem cell transplantation main outcomes

BACKGROUND AND AIMS

As a curative procedure, hematopoietic stemcell transplantation (HSCT) is an approved treatment for many malignant orbenign hematologic and non-hematologic diseases. There are different outcomes of HSCT, as well as several parameters influencing these outcomes.

METHODS

We had searched scientific sources like Web ofScience and PubMed with a combination of keywords such as HSCT, engraftment,survival, outcomes, etc. Totally, 80 articles were included.

RESULTS

Here we have reviewed the effective factors onmain outcomes of HSCT including engraftment, survival, graft versus hostdisease, and Mobilization. Also, the prediction of hematological reconstitutionand some novel suggestions leading to better outcomes are reviewed.

CONCLUSION

The study will be applicable for improvedmanagement of autologous and allogeneic HSCT process to increase the procedureefficiency.

Risk factors for poor mobilization in solid tumors: How effectively can we mobilize patients with solid tumors?

BACKGROUND

In the literature, risk factors for poor mobilization were tried to identify. However, most of the studies consisted heterogeneous group of patients including both hematologic and oncologic malignancies. In this study, we aimed to identify the risk factors for poor mobilization in adults with solid tumors.

METHODS

We enrolled 49(47 men, 2 women) adult patients with solid tumor who were mobilized between September 2007 and February 2017. All the mobilization procedures were performed with G-CSF(10μg/kg/day) with chemotherapy. Mobilization insufficiency was defined as peripheral blood CD34+stem cell number less than 10/μl and/or total collected CD34+cells less than 2.5×10 ⁶/kg.

RESULTS

The patients were divided into two groups, patients with successful mobilization at the first attempt(group 1, 36 patients,73.5%) and poor mobilizers (group 2, 13 patients 26.5%). Second and third mobilization attempt was needed in 11 and 2 patients, respectively. The median number of CD34+cells collected was 7,08×10⁶/kg(0,6-19) with a median 4(1-6) apheresis. There was no statistical difference between two groups in terms of patient's and mobilization characteristics. Only number of CD 34+stem cells collected was statistically different (median 9,07×10⁶/kg CD34+cells in group 1 versus 2,14×10⁶/kg in group 2, p<0.05). The only possible risk factor that we could define was presence of organ metastasis.

CONCLUSIONS

Since several methods and new drugs are available for peripheral stem cell collecting, risk factors should be identified clearly in adult population with solid tumors. So multicenter studies should be constructed for resolving this problem.

Mobilization of hematopoietic progenitor cells for autologous transportation: consensus recommendations

Selected patients with certain hematological malignancies and solid tumors have the potential to achieve long-term survival with autologous hematopoietic progenitor cell transplant. The collection of these cells in peripheral blood avoids multiple bone marrow aspirations, results in faster engraftment and allows treatment of patients with infection, fibrosis, or bone marrow hypocellularity. However, for the procedure to be successful, it is essential to mobilize a sufficient number of progenitor cells from the bone marrow into the blood circulation. Therefore, a group of Brazilian experts met in order to develop recommendations for mobilization strategies adapted to the reality of the Brazilian national health system, which could help minimize the risk of failure, reduce toxicity and improve the allocation of financial resources.

Circulating hematopoietic progenitors and CD34(+) cells predicted successful hematopoietic stem cell harvest in myeloma and lymphoma patients: experiences from a single institution

Background

Previous studies have shown that the numbers of both circulating hematopoietic progenitor cell (HPC) and CD34⁺ cell are positively correlated with CD34⁺ cell harvest yield. However, the minimal numbers of both circulating HPCs and CD34⁺ cells required for performing an efficient hematopoietic stem cell (HSC) harvest in lymphoma and myeloma patients have not been defined in our institution.

Patients and methods

Medical records of 50 lymphoma and myeloma patients undergoing peripheral blood HSC harvest in our institution were retrospectively reviewed. The minimal and optimal HSC harvest yield required for the treatment was considered to be ≥2×10⁶ CD34⁺ cells/kg and ≥5×10⁶ CD34⁺ cells/kg, respectively.

Results

The minimally required or optimal HSC yield obtained was not influenced by age (≥60 years), sex, underlying malignancies, disease status, multiple rounds of chemotherapy, or history of radiotherapy. The numbers of both circulating HPC and CD34⁺ cell were higher in patients with minimally required HSC yields (P=0.000 for HPC and P=0.000 for CD34⁺ cell) and also in patients with optimal HSC yields (P=0.011 for HPC and P=0.006 for CD34⁺ cell). The cell count cutoff for obtaining minimally required HSC harvest was determined to be 20/mm³ for HPCs and 10/mm³ for CD34⁺ cells. Furthermore, the cell count cutoff for obtaining optimal HSC harvest was determined to be 60/mm³ for HPCs and 35/mm³ for CD34⁺ cells.

Conclusion

A total of 60/mm³ of HPCs and 35/mm³ of CD34⁺ cells in peripheral blood predicted optimal HSC harvest in lymphoma and myeloma patients.

[A retrospective analysis of autologous peripheral blood hematopoietic stem cell mobilizations and collections in 149 multiple myeloma patients]

OBJECTIVE

To analyze the results and influential factors of mobilization and harvesting of autologous peripheral blood stem cell in patients with multiple myeloma (MM).

METHODS

Retrospective analysis of peripheral blood stem cell collection data [CD34⁺ cells collected, successful mobilization rate (CD34⁺ cells≥2×10⁶/kg body weight), good mobilization rate (CD34⁺ cells≥5×10⁶/kg body weight)] of 149 multiple myeloma patients who were treated with cyclophosphamide (CTX) or E-CHOP (etoposide+ CTX+epirubicin+vindesine+prednisone) chemotherapy combined with G-CSF mobilization from January 1998 to March 2014. The relevance between gender, age, subtype, DS staging, ISS staging, treatment before mobilization, disease status at mobilization, regiment of mobilizationand the collection results was analyzed.

RESULTS

A total of 177 stem cell mobilizations were performed in 149 MM patients, the median CD34⁺ cells harvested were 3.20 (0.13-22.34)×10⁶/kg body weight (BW), successful mobilization rate and good mobilization rate were 74.5% and 27.5%, respectively. The single logistic regression analysis showed that gender, age （>60 ys vs ≤60 ys）, subtype, DS staging (III vs II+I), ISS staging (III vs II+I) and regiment of mobilization (E-CHOP+G-CSF vs ID-CTX+G-CSF) were not correlated with the cell collection or successful mobilization rate (P>0.05). However, successful collection rate of single harvest in old patients (age>60 ys) was lower (P<0.05), andthe good mobilization rate in patients at ISS stage III was lower (P<0.05). The collection results of patients with fewer cycles of treatment (treatment before mobilization ≤6 cycles) and optimal disease status (disease status at mobilization ≥partial remission) were much better. Analysis of logistic factors revealed that treatment efficacy before mobilization affected success rate of collection (P=0.006). Risk of collection failure in patients who received more than 6 cycles of treatment before mobilization was high (OR 3.57, 95% CI 1.45-8.78).

CONCLUSION

Gender, age, subtype, DS staging, ISS staging and mobilization regimen did not influence MM patients peripheral blood stem cell collection; but old patients may need twice mobilizations to collect sufficiently. Few cycles of treatment and stable disease status before mobilization is favorable to the mobilization and collection of peripheral blood stem cells.

Optimizing mobilization strategies in difficult-to-mobilize patients: The role of plerixafor

Peripheral blood stem cell collection is currently the most widely used source for hematopoietic autologous transplantation. Several factors such as advanced age, previous chemotherapy, disease and marrow infiltration at the time of mobilization influence the efficacy of CD34(+) progenitor cell mobilization. Despite the safety and efficiency of the standard mobilization protocols (G-CSF ± chemotherapy), there is still a significant amount of mobilization failure rate (10-40%), which necessitate novel agents for effective mobilization. Plerixafor, is a novel agent, has been recently approved for mobilization of hematopoietic stem cells (HSCs). The combination of Plerixafor with G-CSF provides the collection of large numbers of stem cells in fewer apheresis sessions and can salvage those who fail with standard mobilization regimens. The development and optimization of practical algorithms for the use Plerixafor is crucial to make hematopoietic stem cell mobilization more efficient in a cost-effective way. This review is aimed at summarizing how to identify poor mobilizers, and define rational use of Plerixafor for planning mobilization in hard-to-mobilize patients.

Predicting poor peripheral blood stem cell collection in patients with multiple myeloma receiving pre-transplant induction therapy with novel agents and mobilized with cyclophosphamide plus granulocyte-colony stimulating factor: results from a Gruppo Italiano Malattie EMatologiche dell'Adulto Multiple Myeloma Working Party study

INTRODUCTION

A still not well defined proportion of patients with multiple myeloma (MM) and eligible for autologous stem cell transplantation (AuSCT) fails to mobilize CD34+ peripheral blood stem cells (PBSC) at all or to collect an adequate number for a safe procedure or sufficient for multiple transplants. These so-called "poor-mobilizers" are difficult to be predicted, due to marked difference across previous heterogeneous studies.

METHODS

We aimed to develop a method based on simple clinical parameters for predicting unsuccessful (<2×10(6)/kg) or sub-optimal (<5×10(6)/kg) collections of CD34+ PBSC in newly diagnosed MM patients eligible for AuSCT, treated with novel agents and receiving an homogeneous mobilizing therapy with cyclophosphamide and granulocyte-colony stimulating factor (G-CSF). To this purpose, 1,348 patients enrolled in five consecutive Italian clinical trials were retrospectively analysed. Age, baseline low peripheral blood cell counts, use of lenalidomide, and haematological toxicity developed during induction were taken into account as possible factors associated with poor mobilization.

RESULTS

Overall, 280 patients (20.8%) showed either sub-optimal (167 patients, 12.4%) or unsuccessful (113 patients, 8.4%) collections. All analysed parameters negatively influenced the procedure, but only age and haematological toxicity during induction maintained their significance at multivariate analysis. Based on ordinal logistic regression model, we constructed a risk heat-map where the four parameters were pooled and weighted according to their relevance as single or combined variables. This model was predictive for different probabilities of failure, suboptimal or optimal outcomes.

CONCLUSIONS

We found that about one fifth of newly diagnosed MM fails to collect an adequate number of PBSC. Our model, based on a large group of patients treated frontline with novel agents and receiving the most popular mobilizing approach currently employed in Europe, is applicable in individual subjects and may contribute to the early identification of "poor mobilizer" phenotypes.