Peripheral Blood Stem Cell Mobilization and Engraftment after Autologous Stem Cell Transplantation with Biosimilar rhG-CSF

INTRODUCTION: Biosimilar versions of filgrastim [recombinant human granulocyte colony-stimulating factor (rhG-CSF)] are now widely available. To date, biosimilar rhG-CSF has demonstrated a comparable quality, safety and efficacy profile to the originator product (filgrastim [Neupogen((R))], Amgen Inc., CA, USA) in the prevention and management of neutropenia. Biosimilar rhG-CSFs have also been used to induce peripheral blood stem cell (PBSC) mobilization in patients undergoing autologous stem cell transplantation (AHSCT). The authors have examined the effectiveness of a biosimilar rhG-CSF (Zarzio((R)), Sandoz Biopharmaceuticals, Holzkirchen, Germany) in two retrospective studies across two medical centers in Hungary. METHODS: In Study 1, 70 patients with hematological malignancies scheduled to undergo AHSCT received chemotherapy followed by biosimilar rhG-CSF (2 x 5 mug) for facilitating neutrophil, leukocyte, and platelet engraftment. In study 2, 40 additional patients with lymphoid malignancies and planned AHSCT received chemotherapy followed by biosimilar rhG-CSF for PBSC mobilization. The effectiveness of treatment was assessed by the average yield of cluster of differentiation (CD) 34+ cells and the number of leukaphereses required. RESULTS: In Study 1 (patients undergoing AHSCT), the median age was 56 years and most patients were male (60%). The conditioning regimens were mainly high-dose melphalan (n = 41) and carmustine (BiCNU((R)), Bristol-Myers Squibb, NJ, USA), etoposide, cytarabine and melphalan BEAM (n = 21). Median times to absolute neutrophil and leukocyte engraftment were 9 (range 8-11 days) and 10 (8-12) days, respectively. Median time to platelet engraftment was 10.5 days (7-19 days). In Study 2, the patients' median age was 54 years and the majority (57.5%) were female. The median time interval between day 1 of mobilizing chemotherapy and first leukapheresis was 12 (9-27) days. In the autologous PBSC grafts, the median number of CD34+ cells harvested was 5.2 x 10(6)/kg (2.22-57.07 x 10(6)/kg). The median yield of CD34+ cells per leukapheresis product was 2.47 x 10(6)/kg. In total, 58 leukaphereses were performed in 40 successfully harvested patients. CONCLUSIONS: In line with previous studies with originator rhG-CSF, the findings of this study indicate that biosimilar rhG-CSF following AHSCT is effective and generally well tolerated in the engraftment setting. In addition, biosimilar rhG-CSF is comparable to the originator rhG-CSF in terms of kinetics of PBSC mobilization and yield of CD34+ cells. In conclusion, the authors have demonstrated that the use of biosimilar rhG-CSF is effective and safe in autologous PBSC mobilization and engraftment after AHSCT

Parallel testing of liquid biopsy (ctDNA) and tissue biopsy samples reveals a higher frequency of EZH2 mutations in follicular lymphoma

Background Recent genomic studies revealed enhancer of zeste homolog 2 (EZH2) gain-of-function mutations, representing novel therapeutic targets in follicular lymphoma (FL) in around one quarter of patients. However, these analyses relied on single-site tissue biopsies and did not investigate the spatial heterogeneity and temporal dynamics of these alterations. Objectives We aimed to perform a systematic analysis of EZH2 mutations using paired tissue (tumor biopsies [TB]) and liquid biopsies (LB) collected prior to treatment within the framework of a nationwide multicentric study. Methods Pretreatment LB and TB samples were collected from 123 patients. Among these, 114 had paired TB and LB, with 39 patients characterized with paired diagnostic and relapse samples available. The EZH2 mutation status and allele burden were assessed using an in-house-designed, highly sensitive multiplex droplet digital PCR assay. Results EZH2 mutation frequency was found to be 41.5% in the entire cohort. In patients with paired TB and LB samples, EZH2 mutations were identified in 37.8% of the patients with mutations exclusively found in 5.3% and 7.9% of TB and LB samples, respectively. EZH2 mutation status switch was documented in 35.9% of the patients with paired diagnostic and relapse samples. We also found that EZH2 wild-type clones may infiltrate the bone marrow more frequently compared to the EZH2 mutant ones. Conclusion The in-depth spatio-temporal analysis identified EZH2 mutations in a considerably higher proportion of patients than previously reported. This expands the subset of FL patients who most likely would benefit from EZH2 inhibitor therapy

Peripheral Blood Stem Cell Mobilization and Engraftment after Autologous Stem Cell Transplantation with Biosimilar rhG-CSF

INTRODUCTION: Biosimilar versions of filgrastim [recombinant human granulocyte colony-stimulating factor (rhG-CSF)] are now widely available. To date, biosimilar rhG-CSF has demonstrated a comparable quality, safety and efficacy profile to the originator product (filgrastim [Neupogen((R))], Amgen Inc., CA, USA) in the prevention and management of neutropenia. Biosimilar rhG-CSFs have also been used to induce peripheral blood stem cell (PBSC) mobilization in patients undergoing autologous stem cell transplantation (AHSCT). The authors have examined the effectiveness of a biosimilar rhG-CSF (Zarzio((R)), Sandoz Biopharmaceuticals, Holzkirchen, Germany) in two retrospective studies across two medical centers in Hungary. METHODS: In Study 1, 70 patients with hematological malignancies scheduled to undergo AHSCT received chemotherapy followed by biosimilar rhG-CSF (2 x 5 mug) for facilitating neutrophil, leukocyte, and platelet engraftment. In study 2, 40 additional patients with lymphoid malignancies and planned AHSCT received chemotherapy followed by biosimilar rhG-CSF for PBSC mobilization. The effectiveness of treatment was assessed by the average yield of cluster of differentiation (CD) 34+ cells and the number of leukaphereses required. RESULTS: In Study 1 (patients undergoing AHSCT), the median age was 56 years and most patients were male (60%). The conditioning regimens were mainly high-dose melphalan (n = 41) and carmustine (BiCNU((R)), Bristol-Myers Squibb, NJ, USA), etoposide, cytarabine and melphalan BEAM (n = 21). Median times to absolute neutrophil and leukocyte engraftment were 9 (range 8-11 days) and 10 (8-12) days, respectively. Median time to platelet engraftment was 10.5 days (7-19 days). In Study 2, the patients' median age was 54 years and the majority (57.5%) were female. The median time interval between day 1 of mobilizing chemotherapy and first leukapheresis was 12 (9-27) days. In the autologous PBSC grafts, the median number of CD34+ cells harvested was 5.2 x 10(6)/kg (2.22-57.07 x 10(6)/kg). The median yield of CD34+ cells per leukapheresis product was 2.47 x 10(6)/kg. In total, 58 leukaphereses were performed in 40 successfully harvested patients. CONCLUSIONS: In line with previous studies with originator rhG-CSF, the findings of this study indicate that biosimilar rhG-CSF following AHSCT is effective and generally well tolerated in the engraftment setting. In addition, biosimilar rhG-CSF is comparable to the originator rhG-CSF in terms of kinetics of PBSC mobilization and yield of CD34+ cells. In conclusion, the authors have demonstrated that the use of biosimilar rhG-CSF is effective and safe in autologous PBSC mobilization and engraftment after AHSCT

Low‐burden TP53 mutations represent frequent genetic events in CLL with an increased risk for treatment initiation

Abstract TP53 aberrations predict chemoresistance and represent a contraindication for the use of standard chemoimmunotherapy in chronic lymphocytic leukaemia (CLL). Recent next‐generation sequencing (NGS)‐based studies have identified frequent low‐burden TP53 mutations with variant allele frequencies below 10%, but the clinical impact of these low‐burden TP53 mutations is still a matter of debate. In this study, we aimed to scrutinise the subclonal architecture and clinical impact of TP53 mutations using a sensitive, NGS‐based mutation analysis in a ‘real‐world’ cohort of 901 patients with CLL. In total, 225 TP53 mutations were identified in 17.5% (158/901) of the patients; 48% of these alterations represented high‐burden mutations, while 52% were low‐burden TP53 mutations. Low‐burden mutations as sole alterations were identified in 39% (62/158) of all mutated cases with 82% (51/62) of these being represented by a single low‐burden TP53 mutation. Patients harbouring low‐burden TP53 mutations had significantly lower time to first treatment compared to patients with wild‐type TP53. Our study has expanded the knowledge on the frequency, clonal architecture, and clinical impact of low‐burden TP53 mutations. By demonstrating that patients with sole low‐burden TP53 variants represent more than one‐third of patients with TP53 mutations and have an increased risk for treatment initiation, our findings strengthen the need to redefine the threshold of TP53 variant reporting to below 10% in the routine diagnostic setting