Predicting the successful peripheral blood stem cell harvesting

The effect of plerixafor on autologous stem cell mobilization, cell viability, and apheresis challenges

OBJECTIVE

The aim of this study was to determine the efficacy of plerixafor for hematopoietic stem cell (HSC) mobilization prior to autologous stem cell transplantation (aSCT) for patients with multiple myeloma (MM) and various lymphomas, using an oncologist-guided HSC collection goal and markers of cell viability.

METHODS

A retrospective chart review of all aSCT patients at Yale New Haven Hospital between 2017 and 2021 who met diagnostic criteria for MM, non-Hodgkin, or Hodgkin lymphoma (n = 382) was undertaken. Logistic regression evaluated plerixafor's effect on meeting the individual's HSC goal. The use of t-tests determined plerixafor's relationship to HSC yield and analysis of variance testing assessed its effect on cell viability.

RESULTS

Mobilization with granulocyte colony-stimulating factor (G-CSF) and plerixafor (odds ratio [OR] = 0.08; P < .05) relative to G-CSF alone was negatively associated with meeting the individual's HSC goal. Diffuse large B-cell lymphoma in patients mobilized with plerixafor yielded fewer HSCs than those without plerixafor (t = -2.78; P = .03). Mobilization regimen (P = .13) had no association with HSC viability. Mobilization failure with plerixafor was rare but occurred in patients with multiple risk factors, including exposure to several rounds of HSC-affecting chemotherapy.

CONCLUSION

Plerixafor is effective across multiple diagnoses using an oncologist-driven HSC collection endpoint. Its association with mobilization failure is likely attributable to its use in patients predicted to be poor mobilizers.

Gemcitabine, dexamethasone and cisplatin (GDP) is an effective and well-tolerated mobilization regimen for relapsed and refractory lymphoma: a single center experience

Background/aim

Gemcitabine, dexamethasone and cisplatin (GDP) is a well-established salvage regimen for relapsed and refractory lymphomas. In this study, we aimed to share our experience with the patients who received GDP/R-GDP (rituximab-gemcitabine, dexamethasone and cisplatin) for stem cell mobilization.

Materials and methods

Data of 69 relapsed and refractory Hodgkin lymphoma (HL) and Non-Hodgkin lymphoma (NHL) patients who received GDP/R-GDP as salvage chemotherapy in our center between July 2014 and January 2020 were retrospectively evaluated. After the evaluation of response, 52 patients had a chemosensitive disease and underwent mobilization with GDP/R-GDP plus G–CSF (granulocyte colony-stimulating factor). Collected CD34+ stem cells and related parameters were compared in terms of diagnosis of HL and NHL, early and late stage, patients who did not receive RT and those who received RT, and patients aged under 60 and over 60.

Results

On the 15th day on average (range 11–20), a median number of 8.7 × 106 /kg (4.1–41.5) CD34+ stem cells were collected in 51 (98%) of our 52 chemosensitive patients and 1 (2%) patients failed to mobilize. We observed acceptable hematological and nonhematological toxicity. The targeted amount of 2 × 106 /kg CD34+ stem cells was attained by 98% (n: 51) patients, and all of them underwent autologous stem cell transplantation. Moreover, low toxicity profiles provide outpatient utilization option clinics with close follow-up and adequate supportive care.

Conclusion

We suggest that GDP/R-GDP plus G-CSF can be used as an effective chemotherapy regimen for mobilizing CD34+ stem cells from peripheral blood in relapsed and refractory lymphoma patients due to low toxicity, effective tumor reduction, and successful stem cell mobilization. It can also be assumed that the GDP mobilization regimen may be more effective, especially in patients with early-stage disease and in HL patients.

Optimized peripheral blood progenitor cell mobilization for autologous hematopoietic cell transplantation in children with high-risk and refractory malignancies

BACKGROUND

Autologous hematopoietic stem cell transplantation (aHSCT) using hematopoietic progenitor cells (HPCs) has become an important therapeutic modality for patients with high-risk malignancies. Current literature on standardized method for HPC apheresis in children is sparse and failure rate reported as high as 30%.

PATIENTS/METHODS

A retrospective study of 125 pediatric patients with high-risk malignancies undergoing aHSCT in Western Australia between 1997 and 2016 was conducted.

RESULTS

Mobilization was achieved by means of chemotherapy and granulocyte colony-stimulating factor (G-CSF). Patients underwent apheresis the day after CD34⁺ counts reached ≥20/µL and an additional dose of G-CSF. Peripheral arterial and intravenous lines were inserted in pediatric intensive care unit under local anesthetic and/or sedation, omitting the need for general anesthesia as well as facilitating an uninterrupted apheresis flow. Larger apheresis total blood volumes were processed in patients weighing ≤20 kg. The minimal dose of ≥2 × 10⁶ CD34⁺ cells/kg was successfully collected in 98.4% of all patients. The optimal dose of 3-5 × 10⁶ CD34⁺ cells/kg was collected in 96% of patients scheduled for a single aHSCT, 87.5% for tandem, and 100% for triple aHSCT. All HPC collections were completed in one apheresis session. Mobilization after ≤3 chemotherapy cycles and cycles including cyclophosphamide resulted in a significantly higher yield of CD34⁺ cells.

CONCLUSION

Our approach to HPC mobilization by means of chemotherapy and single myeloid growth factor combined with optimal collection timing facilitated by continuous apheresis flow resulted in highly effective HPC harvest in children and adolescents with high-risk cancers.

Stem cell mobilization kinetics in elderly patients with multiple myeloma

In this study, we aimed to investigate whether the procedure and product kinetics differ according to age groups in advanced-age MM patients who underwent autologous HSCT. 59 patients who underwent autologous HSCT were retrospectively analyzed. Then, the patients were divided into two groups as 60-65 years and ≥65 years. It was significantly lower in ≥65 years group (p = 0.008) and proportionally, the procedure duration was also significantly shortened in this group (p = 0.013). Total number of collected CD34 positive stem cells was 6.20 × 106 (±3.83) in 60-65 years group while it was 5.51 × 106 (±2.48) in ≥65 years group with no statistically significant difference (p = 0.825). In conclusion, there was no significant difference in terms of the number of collected CD34-positive stem cells in this study that investigates the mobilization data, procedure and product kinetics, we think that successful stem cell mobilization can be performed in appropriately selected patients regardless of age.

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.

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.

The current status in hematopoietic stem cell mobilization

Hemotopoietic stem cell mobilization with cytokines alone, has still been widely accepted as the initial attempt for stem cell mobilization. Chemotherapy based mobilization can be preferred as first choice in high risk patients or for remobilization. But mobilization failure still remains to be a problem in one third of patients. Salvage mobilization strategies have been composed to give one more chance to 'poor mobilizers'. Synergistic effect of a reversible inhibitor of CXCR4, plerixafor, with G-CSF has opened a new era for these patients. Preemptive approach in predicted poor mobilizers, immediate salvage approach for patients with suboptimal mobilization or remobilization approach of plerixafor in failed mobilizers have all been demonstrated convincing results in various studies. Alternative CXCR4 inhibitors, VLA4 inhibitors, bortezomib, parathormone have also been emerged as novel agents for mobilization failure.

Limited effects of intravenous paracetamol on patent ductus arteriosus in very low birth weight infants with contraindications for ibuprofen or after ibuprofen failure

Finding the optimal pharmacological treatment of a patent ductus arteriosus (PDA) in preterm neonates remains challenging. There is a growing interest in paracetamol as a new drug for PDA closure. In this prospective observational cohort study, we evaluated the effectiveness of intravenous paracetamol in closing a PDA in very low birth weight infants with a hemodynamically significant PDA who either did not respond to ibuprofen or had a contraindication for ibuprofen. They received high-dose paracetamol therapy (15 mg/kg/6 h intravenous) for 3-7 days. Cardiac ultrasounds were performed before and 3 and 7 days after treatment. Thirty-three patients were included with a median gestational age of 25(1/7) weeks (IQR 1.66), a median birth weight of 750 g (IQR 327), and a median postnatal age of 14 days (IQR 12). Paracetamol was ineffective in 27/33 patients (82 %). Even more, after previous exposure to ibuprofen, this was even 100 %.

CONCLUSION

In this study, paracetamol after ibuprofen treatment failure was not effective for PDA closure in VLBW infants. From the findings of this study, paracetamol treatment for PDA closure cannot be recommended for infants with a postnatal age >2 weeks. Earlier treatment with paracetamol for PDA might be more effective.