Optimal chemo-mobilization for the collection of peripheral blood stem cells in patients with multiple myeloma

Risk Factors and Outcomes of Stem Cell Mobilization Failure in Multiple Myeloma Patients

Introduction

Autologous hematopoietic stem cell transplantation (ASCT) is a well-established treatment for patients with multiple myeloma (MM), and adequate stem cell collection must be assured before ASCT. However, prediction of poor mobilizers (PMs) is still difficult despite several risk factors for mobilization failure having been identified.

Methods

We retrospectively analyzed MM patients at Taipei Veterans General Hospital in Taiwan who underwent stem cell collection between October 2006 and August 2020. A CD34⁺ cell collection of <1 × 10⁶ cells/kg was defined as a mobilization failure. The primary endpoint was mobilization failure. The secondary endpoint was overall survival (OS). Odds ratios (ORs) and 95% confidence intervals (CIs) for mobilization failure were calculated using a logistic regression model. The cumulative incidence of mortality was estimated using the Kaplan-Meier method.

Results

In the multivariate analysis, absolute monocyte count <500/µL (adjusted OR 10.75, 95% CI: 1.82-63.57, p = 0.009), platelet count <150,000/µL (adjusted OR 12.49, 95% CI: 2.65-58.89, p = 0.001) before mobilization, and time interval from diagnosis to stem cell harvest ≥180 days (adjusted OR 7.69, 95% CI: 1.61-36.87, p = 0.011) were risk factors for PMs. PM patients had poorer OS compared to patients with successful stem cell collection in the univariate analysis (log-rank test p = 0.027). The predicted probability of PMs was estimated by the multiple logistic regression model with a sensitivity of 84.6% and a specificity of 84.0%.

Conclusion

Absolute monocyte count <500/µL, platelet count <150,000/µL, and treatment duration more than 180 days before stem cell mobilization are risk factors for unsuccessful stem cell collection. Our prediction models have high sensitivity and specificity for mobilization failure prediction and allow for early interventions for possible PMs.

Predictors of Poor Haematopoietic Stem Cell Mobilisation In Patients With Haematological Malignancies at a South African Centre

BACKGROUND

Autologous stem cell transplant (ASCT) is an established consolidation strategy in the treatment of haematological malignancies, however poor mobilisation (PM) can contribute to patient morbidity and high resource utilisation. Identifying the incidence, risk factors for PM and engraftment outcomes are important goals in our resource limited setting.

METHODS

We retrospectively analyzed patients with haematological malignancies that consecutively underwent ASCT at Groote Schuur hospital, Cape Town, South Africa from January 2013 to January 2019.

RESULTS

146 patients - majority with multiple myeloma (MM)(41,8%), F:M= 1:2, underwent leukapheresis with median age of 32 years (range, 9 - 66 years). PM occurred in 25/146 (17%), mobilisation failure (MF) in 3/146 (2%) and super mobilisation (SMs) in 99/146 (68%), respectively. Risk factors for PM were: diagnosis of acute leukaemia (RR = 25, 95% CI 3.4 - 183, p = 0.002) and Hodgkin lymphoma (RR = 19, 95% CI 2.6 - 142, p = 0.004); low white cell count (WCC) at harvest (WCC < 9 × 10⁹/L (RR=4.3, 95% CI 2.3 - 8.3, p < 0.0001) and two vs one line of prior therapy (RR = 3.1, 95% CI 1.45 - 6.7, p = 0.0037). Median days to neutrophil and platelet engraftment were 14 days (95% CI 14-15 days) and 16 days (95% CI 15-16 days) respectively.

CONCLUSION

PM occurred in 17% of a contemporary South African ASCT cohort, albeit with a low MF rate (2%). There was surprisingly high rate (68%) of SMs, possibly reflective of superfluous mobilisation strategy in MM patients. We identified predictive factors for PM that will lead to enhanced cost-effective use of plerixafor.

Safety of outpatient stem cell mobilization with low- or intermediate-dose cyclophosphamide in newly diagnosed multiple myeloma patients

OBJECTIVES

Autologous stem cell transplantation is the gold standard for eligible newly diagnosed multiple myeloma patients. Patients are usually hospitalized for administration of mobilization chemotherapy. We aimed to assess safety and efficacy of mobilization therapy with low-dose (2 g/m² ) and intermediate-dose (3-4 g/m² ) cyclophosphamide administered as outpatient.

METHODS

A total of 176 consecutive newly diagnosed transplant-eligible myeloma patients receiving outpatient mobilization were retrospectively evaluated. Induction therapy was mainly performed with new drugs (91%).

RESULTS

Chemotherapy was very well tolerated with 16.6% of patients having all-grade adverse events (AEs) and only 1.2% having severe AEs. The most frequently reported AEs were nausea and vomiting grade 1-2 (6.8%). Only 5.7% of patients required hospitalization for AEs. Stem cell collection was successful in 93.1% of patients, with a median CD34⁺ harvest of 8.7 × 10⁶ /kg. Target for 2 autologous stem cell transplantation (at least 6 CD34⁺  × 10⁶ /kg) was reached by 76.3% of patients. Administration of plerixafor on demand was necessary in 12.1% of patients.

CONCLUSIONS

Outpatient mobilization with low- and intermediate-dose cyclophosphamide appears an efficient and safe procedure, with minimal and manageable AEs and low rate of hospitalization.

Alterations in microRNA Expression during Hematopoietic Stem Cell Mobilization

Simple Summary

Lymphoproliferative disorders comprise a heterogeneous group of hematological malignancies characterized by abnormal lymphocyte proliferation. Autologous hematopoietic stem cell transplantation plays a very important role in the treatment of lymphoproliferative diseases. The key element in this process is the effective mobilization of hematopoietic cells from the marrow niche to the peripheral blood. Mobilization of HSC is regulated by many factors, out of which miRNAs present in the hematopoietic niche via targeting cytokines, and signaling pathways may play an important regulatory role. This study investigated the expression of selected miRNAs in patients with multiple myeloma, Hodgkin’s lymphomas, and non-Hodgkin’s lymphomas undergoing mobilization procedures. The aim of the study was to evaluate the expression of hsa-miR-15a-5p, hsa-miR-16-5p, hsa-miR-34a-5p, hsa-miR-126-3p, hsa-miR-146a-5p, hsa-miR-155-5p, and hsa-miR-223-3p during the mobilization procedure, and to assess their role in mobilization efficacy. The level of miRNAs was tested at two time points before the initiation of mobilization and on the day of the first apheresis. Our results suggest that the investigated miRNAs, especially hsa-miR-146a-5p, may influence the efficacy of HSC mobilization.

Abstract

microRNAs play an important role in the regulation of gene expression, cell fate, hematopoiesis, and may influence the efficacy of CD34+ cell mobilization. The present study examines the role of hsa-miR-15a-5p, hsa-miR-16-5p, hsa-miR-34a-5p, hsa-miR-126-3p, hsa-miR-146a-5p, hsa-miR-155-5p, and hsa-miR-223-3p in the course of hematopoietic stem cell mobilization. The numbers of CD34+ cells collected in patients with hematological malignancies (39 multiple myelomas, 11 lymphomas) were determined during mobilization for an autologous hematopoietic stem cell transplantation. The miRNA level was evaluated by RT-PCR. Compared to baseline, a significant decline in hsa-miR-15a-5p, hsa-miR-16-5p, hsa-miR-126-3p, hsa-miR-146a-5p, and hsa-miR-155-5p was observed on the day of the first apheresis (day A). An increase was observed only in the expression of hsa-miR-34a-5p. On day A, a negative correlation was found between hsa-miR-15a-5p and hsa-miR-146a-5p levels and the number of CD34+ cells in peripheral blood. A negative correlation was observed between hsa-miR-146a-5p and the number of collected CD34+ cells after the first apheresis. Good mobilizers, defined according to GITMO criteria, demonstrated a lower hsa-miR-146a-5p level on day A than poor mobilizers. Patients from the hsa-miR-146a-5p “low expressors” collected more CD34+ cells than “high expressors”. Our results suggest that the investigated miRNAs, especially hsa-miR-146a-5p, may influence the efficacy of HSC mobilization.

Cyclophosphamide plus etoposide is a safe and effective mobilization regimen in patients with multiple myeloma

High-dose chemotherapy followed by autologous stem cell transplantation is a major component in the treatment of patients with multiple myeloma. As a prerequisite, the successful collection of a sufficient number of viable peripheral blood hematopoietic CD34+ cells is critical. A common standard protocol for mobilization is currently not defined and critically discussed especially in German-speaking Europe. In times of the Covid-19 pandemic, safe and effective strategies have to be chosen to minimize hospitalization times and severe courses. In this single-center retrospective analysis, safety and efficacy of cyclophosphamide plus etoposide (CE) and growth-factor support (n = 33) was compared to cyclophosphamide mono treatment and growth-factor support (n = 49) in 82 patients with multiple myeloma at first diagnosis. CE was superior to cyclophosphamide mono with a significantly higher number of collected CD34+ cells (15.46 × 10⁶ CD34⁺ cells/kg vs. 9.92 × 10⁶ CD34⁺ cells/kg), significantly faster engraftment of granulocytes after stem cell transplantation (day 10.5 vs. day 11.6), shorter duration of the inpatient stay (17.47 days vs. 19.16 days) and significantly less transfusions (8.82 % vs. 30.61 % patients receiving transfusions). The safety profile was comparable in both groups and in line with published data. We conclude that CE is a safe and highly effective mobilization protocol in patients with multiple myeloma at first diagnosis and appears to be superior to the commonly used cyclophosphamide mono regimen.

Stem Cell Mobilization in Multiple Myeloma: Comparing Safety and Efficacy of Cyclophosphamide +/- Plerixafor versus Granulocyte Colony-Stimulating Factor +/- Plerixafor in the Lenalidomide Era

Growth factor and chemotherapy-based stem cell mobilization strategies are commonly used to treat patients with multiple myeloma. We retrospectively compared 398 patients mobilized between 2017 and 2020 using either cyclophosphamide (4 g/m²) plus granulocyte colony-stimulating factor (G-CSF) or G-CSF alone, with on demand plerixafor (PXF) in both groups. Although total CD34⁺ yield was higher after chemomobilization compared with G-CSF +/- PXF (median, 13.6 × 10⁶/kg versus 4.4 × 10⁶/kg; P < .01), achievement of ≥2 × 10⁶ CD34⁺ cells (95% versus 93.7%; P = .61) and rates of mobilization failure (5% versus 6.3%; P = .61) were similar. Fewer patients required PXF with chemomobilization (12.3% versus 49.5%; P < .01), and apheresis sessions were fewer (median, 1 [range, 1 to 4] versus 2 [range, 1 to 5]). The rate of complications, including neutropenic fever, emergency department visits, and hospitalizations, was higher after chemomobilization (30% versus 7.4%; P < .01). Previous use of ≤6 cycles of lenalidomide did not impair cell yield in either group. The median cost of mobilization was 17.4% lower in the G-CSF +/- PXF group (P = .01). Between group differences in time to engraftment were not clinically significant. Given similar rates of successful mobilization, similar engraftment time, and less toxicity and lower costs compared with chemomobilization, G-CSF with on-demand PXF may be preferable in myeloma patients with adequate disease control and limited lenalidomide exposure.

Circulatory miR-155 correlation with platelet and neutrophil recovery after autologous hematopoietic stem cell transplantation, a multivariate analysis

The involvement of microRNAs in the regulation of hematopoietic stem cells paves the way for their use in the management of autologous HSC transplantation (AHSCT). We aimed to evaluate the predictive value of circulatory microRNAs in extracellular vesicles (EVs) and plasma in platelet and neutrophil engraftment. Circulatory miR-125b, mir-126, miR-150, and miR-155 expression was assessed in isolated EVs and plasma in samples collected from AHSCT candidates. Multivariate analysis, COX models, and ROC assessment were performed to evaluate the predictive values of these microRNAs in platelet and neutrophil engraftment. miR-155 expression following conditioning with other clinical factors such as chemotherapy courses after diagnosis was the most significant predictors of platelet/neutrophil engraftment. A CD34⁺ cell count ≥ 3.5 × 10⁶/kg combined with miR-155 could be used as an engraftment predictor; however, in cases where the CD34⁺ cell count was < 3.5 × 10⁶/kg, this parameter lost its predictive value for engraftment and could be replaced by miR-155. The correlation between miR-155 and platelet/neutrophil engraftment even with lower numbers of CD34⁺ cells suggests the importance of this microRNA in the prediction of AHSCT outcome. Moreover, miR-155 could be utilized in therapeutic approaches to provide a better outcome for patients undergoing AHSCT.

Engraftment after autologous hematopoietic stem cell transplantation in patients mobilized with Plerixafor: A retrospective, multicenter study of a large series of patients

Plerixafor (PLX) appears to effectively enhance hematopoietic stem-cell mobilization prior to autologous hematopoietic stem cell transplantation (auto-HCT). However, the quality of engraftment following auto-HCT has been little explored. Here, engraftment following auto-HCT was assessed in patients mobilized with PLX through a retrospective, multicenter study of 285 consecutive patients. Information on early and 100-day post-transplant engraftment was gathered from the 245 patients that underwent auto-HCT. The median number of PLX days to reach the stem cell collection goal (≥2 × 10⁶ CD34⁺ cells/kg) was 1 (range 1-4) and the median PLX administration time before apheresis was 11 h (range 1-18). The median number of apheresis sessions to achieve the collection goal was 2 (range 1-5) and the mean number of CD34⁺ cells collected was 2.95 × 10⁶/kg (range 0-30.5). PLX administration was safe, with only 2 mild and transient gastrointestinal adverse events reported. The median time to achieve an absolute neutrophil count (ANC) >500/μL was 11 days (range 3-31) and the median time to platelet recovery >20 × 10³/μL was 13 days (range 5-69). At 100 days after auto-HCT, the platelet count was 137 × 10⁹/L (range 7-340), the ANC was 2.3 × 10⁹/L (range 0.1-13.0), and the hemoglobin concentration was 123 g/L (range 79-165). PLX use allowed auto-HCT to be performed in a high percentage of poorly mobilized patients, resulting in optimal medium-term engraftment in the majority of patients in whom mobilization failed, in this case mainly due to suboptimal peripheral blood CD34⁺ cell concentration on day +4 or low CD34⁺ cell yield on apheresis.