Early measurement of CD34+ cells in peripheral blood after cyclophosphamide and granulocyte colony-stimulating factor treatment predicts later CD34+ mobilisation failure and is a possible criterion for guiding "on demand" use of plerixafor

Prediction of Stem Cell Mobilization Failure in Patients with Hodgkin and Non-Hodgkin Lymphoma

Objective:

Autologous stem cell transplantation (ASCT) is a significant and potentially curative treatment modality for patients with relapsed/refractory lymphoma. Insufficient mobilization and harvest of peripheral stem cells can be a major obstacle for performing ASCT. The aim of this study was to evaluate the factors that might influence mobilization failure in patients with lymphoma.

Materials and Methods:

Eighty-seven patients diagnosed with non-Hodgkin and Hodgkin lymphoma who underwent stem cell mobilization afterwards at the Hacettepe University Medical School Bone Marrow Transplantation Center, Turkey, between the years of 2000 and 2018 were evaluated.

Results:

A total of 87 patients were included in this study. In 66 of 87 patients (75.9%), the first mobilization trial was successful. Adequate (≥2x106/kg) CD34+ cells were collected in the first apheresis for 66 patients (9.5±8.1). For 21 of 87 (24.1%), the first mobilization trial was unsuccessful. Therefore, a second mobilization trial was performed for these patients with plerixafor (5.5±3.3). The number of CD34+ cells was significantly higher in patients who were successful in the first mobilization (p=0.002).

Conclusion:

The success rate of the first mobilization trial was found to be higher in patients with high platelet counts before mobilization and patients who received chemotherapy-based mobilization protocols. In the patients who had mobilization failure in the first trial, plerixafor was used in a later mobilization, and those patients had an adequate amount of stem cells for ASCT. Parameters predicting mobilization failure would allow for preemptive, more cost-effective use of such agents during the first mobilization attempt; however, risk factors for mobilization failure are still not clear.

Plerixafor on-demand in association with low-dose cyclophosphamide and G-CSF in the mobilization of patients with multiple myeloma: High effectiveness, low toxicity, and affordable cost

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In CD34 mobilization of Multiple Myeloma patients, Cyclophosphamide at the dose of 4 gr/m2 is usually administered. A lower dose of Cyclophosphamide (1.5–2.0 gr/m2) has a lower mobilizing effect and, for this reason, this dose is not widely used in CD34+ cells mobilization.

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The use of Plerixafor on demand, however, could have changed these conclusions. We hypothesized that when used in conjunction with on-demand Plerixafor, low lose CTX is more advantageous than the higher dose.

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The results of this prospective trial support, indeed, the view that low dose Cyclophosphamide in association to on-demand PLX allows the reaching efficacy and low toxicity.

In CD34+ cells mobilization of patients with multiple myeloma (MM), the use of Cyclophosphamide (CTX) at a dose of 2 g/m² has low efficacy although also lower toxicity. The suboptimal mobilizing effect of low-dose CTX, however, may be overcome by plerixafor (PLX) on demand.

We conducted a prospective multicenter study in 138 patients with MM to evaluate CTX 2 g/m² in association with granulocyte-colony stimulating factor (G-CSF) and on-demand PLX. We compared results with a historical group of MM patients (n = 138) mobilized using CTX at a dose of 4 g/m².

CD34+ cells greater than 2 × 10⁶/kg in max three aphereses were harvested in 98.6% of patients in the on-demand PLX study group while in 84.0% in the historical group, (p = 0.0001). In the on-demand-PLX study group, a successful harvest greater than 5 × 10⁶/kg in max three aphereses was observed in 85.5% of patients versus 62.3% of patients in the historical control group, (p=0.0001). In the on-demand-PLX study group, 4.3% (6/138) of patients had febrile complications. Salvage mobilization in the on-demand PLX study group was 1.4%.

In conclusions, on-demand PLX + CTX 2 g/m2 + G-CSF 10 μg/kg has higher efficacy and lower toxicity compared with CTX 4 g/m2 + G-CSF. An analysis of costs is presented.

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.

Angiopoietins in haematopoietic stem cell mobilisation in patients with haematological malignancies

BACKGROUND

The bone marrow niche contains different types of cells including osteoblasts and endothelial progenitors, all of which interact and take part in the process of mobilisation. The aim of our study was to evaluate the levels of cytokines (osteopontin and angiopoietins 1 and 2) active in the bone marrow niche during the mobilisation of haematopoietic stem cells for autologous transplantation.

MATERIALS AND METHODS

Forty-eight patients (24 females, 24 males), median age 56.5 years, entered the study. The group consisted of patients with multiple myeloma (n=34), lymphoma (n=13) and acute myeloid leukaemia (n=1). Blood samples were collected before chemotherapy and on the day of the first apheresis. Cytokines were evaluated by enzyme-linked immunosorbent assays. Additionally, circulating endothelial cells were assessed by flow cytometry.

RESULTS

The median concentration of angiopoietin 1 at the time of apheresis was lower than that at baseline (2.7 vs 7.8 ng/mL, p<0.001). In contrast, the median level of angiopoietin 2 increased during the mobilisation procedure (3.6 vs 2.8 ng/mL, p=0.001). The patients were divided according to the number of days of granulocyte colony-stimulating factor treatment before the first apheresis into "early" (<median=11 days) and "late" (>median) mobilisers. The group of "early mobilisers" had higher baseline angiopoietin 1 levels (median=11.6 ng/mL) than those of the "late mobilisers" (median=6.0 ng/mL, p=0.05). An adverse correlation was observed between duration of granulocyte colony-stimulating factor treatment and baseline angiopoietin 1 level. Baseline angiopoietin 1 levels correlated with numbers of circulating endothelial cells. Low angiopoietin 2 level increased the chance of poor mobilisation.

CONCLUSIONS

The angiogenic processes can influence the timing of mobilisation. Angiopoietins 1 and 2 need further evaluation in the context of mobilisation.