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.

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.

Autologous peripheral blood stem cell transplantation in dialysis-dependent multiple myeloma patients-DAUTOS Study of the Polish Myeloma Study Group.

INTRODUCTION: Dialysis-dependent (DD) multiple myeloma patients (MM) have a poor prognosis and high tumour burden, thus may benefit from autologous peripheral blood stem cell transplantation (auto-PBSCT), however, these patients have an increased risk of toxicity. AIMS: To evaluate the outcomes (toxicity, PFS, OS) of high dose therapy followed by auto-PBSCT during an observational study and after propensity score matching. PATIENTS AND METHODS: Between 2004-2015, 24 DD patients, (aged 38-67 years), ISS 3, treated with auto-PBSCT, requiring dialysis at diagnosis and auto-PBSCT were evaluated, matched and compared to 55 normal renal function MM patients (NRF) with ISS 3 for outcomes of interest. RESULTS: In DD patients compared to NRF patients risk of mucositis (88% vs 55%), infection (79% vs 51%), parenteral nutrition (50% vs 24%), diarrhoea (71% vs 38%), prolonged duration of hospitalisation (medians: 30 vs 21 days), requirement for RBC transfusion (83% vs 36%) were significantly higher, while no significant differences were found in post-transplant response (ORR; 75% vs 87%), 5-year PFS (36% vs 20%) and OS (39% vs 50%). Subgroup analyses based on toxicity supported these results. CONCLUSIONS: Despite the increased risk of toxicity in DD patients these events do not significantly affect both the PFS and OS.

Stem cell mobilization in patients with dialysis-dependent multiple myeloma: Report of the Polish Myeloma Study Group.

INTRODUCTION: High-dose chemotherapy with autologous hematopoietic stem cell transplantation (auto-HSCT) improves the outcome of patients with multiple myeloma (MM). It seems that auto-HSCT is also a feasible therapeutic option in MM dialysis-dependent (MMDD) patients. However, to perform transplantation, a sufficient number of stem cells must be collected. MATERIALS AND METHODS: Given that data on mobilization of auto-HSC efficacy and safety in dialysis-dependent patients are limited, we report data from all Polish Centers belonging to the Polish Myeloma Study Group. Twenty-eight dialysis-dependent MM-patients were enrolled into this retrospective analysis. The study population comprised patients diagnosed between 2004 and 2015 in whom an attempt to collect auto-HSC was made (68%: women, median age: 56). Patients received granulocyte-colony stimulating factor (G-CSF) alone or in combination with chemotherapy and autologous peripheral blood stem cells (auto-PBSCs) were collected by leukapheresis. RESULTS AND CONCLUSIONS: The success rate in terms of obtaining sufficient number of CD34(+) cells/kg for an auto-HSCT (≥2 × 106 cells/kg body weight) during the first mobilization attempt was 92% (26/28 patients), and for 2 auto-HSCTs (≥4 × 106 cells/kg) - was 75% (21/28 patients). After the second mobilization attempt (undertaken in 8 patients), a sufficient number of CD34(+)/kg cells for an auto-HSCT was obtained for all patients and the number of CD34(+)/kg collected cells was sufficient for 2 auto-HSCT in 6 additional patients. Hematologic toxicity and infections were the most frequent complications. Higher doses of cytarabine (>1.6 g/m2 ) and cyclophosphamide (> 2 g/m2 ) should be avoided in MMDD patients due to toxicity. Further studies are needed to establish mobilization regimens, confirm their safety, and dosing in MMDD patients.

Bone marrow adipocytes in haematological malignancies.

Bone marrow adipocytes (BMAs) derived from mesenchymal stem cells (MSC) are an active and significant element of the bone marrow microenvironment. They are involved in metabolic functions, complex interactions with other stromal cells, and in the development and progression of tumours. Currently, there is little data regarding the role of BMAs in haematological malignancies. Due to this, we have attempted to characterise the BMAs in these malignancies in terms of quantity and morphology. Our study included 30 patients aged 22-76 with myelo- (n=17) and lymphoproliferative malignancies (n=13), both with and without bone marrow infiltration. Trepanobioptate was the evaluated material. The number and diameter of BMAs were measured, and the percentage of adipocytes (adipocyte fraction - AF), hematopoietic cells (hematopoietic fraction - HF) and trabecular bone (trabecular bone fraction - BF) was calculated. The obtained results were considered against the clinical parameters of age, sex, body weight, body surface area (BSA) and body mass index (BMI). We observed that as age increases, the number of BMA/mm2, the diameter of adipocytes and AF increase while BF and HF decrease. However, this relationship was not statistically significant. A significant correlation of BMA parameters was also not found in relation to weight, BMI and BSA, and the number and diameter of BMAs were comparable in both sexes. The trepanobioptate of infiltrated bone marrow showed a decreased number of BMA/mm2 compared to the trepanobioptate from bone marrow without infiltration (97.44±69.16 vs. 164.14±54.16; p=0.010) with a marked difference in men (69.75±65.26 vs. 180.33±60.40; p=0.007). These trepanobioptate also showed an increase in the number of BMA/mm2 with age (r=0.472; p=0.041), and with an increase of BMI, an increase in diameter of BMAs (r=0.625; p=0.007) and AF (r=0.546; p=0.023). The number and size of BMAs, as well as AF, BF and HF in patients with myeloproliferative malignancies did not differ significantly compared to patients with lymphoproliferative malignancies.