Mobilization Failure Research Articles

A comparison of mobilization regimens used in Hodgkin lymphoma and factors that influence peripheral blood stem cell mobilization.

Various chemotherapy regimens have been used for chemo-mobilization of stem cells prior to autologous stem cell transplant in patients with Hodgkin lymphoma, and there is no clear standard of care. In this retrospective study, we analyzed mobilization outcomes and the factors affecting successful mobilization following different salvage chemotherapy regimens used in Hodgkin lymphoma. The primary objective was to compare success rates of different chemotherapy regimens. Successful mobilization was defined as the ability to harvest at least 2 × 106/kg of stem cells during one mobilization attempt. Secondary objectives were to find factors that influenced mobilization failures. This is a single-center, retrospective analysis of all Hodgkin lymphoma patients for whom peripheral blood stem cell (PBSC) mobilization was attempted at Tata Memorial Centre, Mumbai, India between December 1, 2007, and June 30, 2022. Salvage chemotherapy that was being used to treat relapsed/refractory lymphoma was generally preferred as a chemo-mobilization regimen. For patients who had already completed all salvage-chemotherapy cycles, GCSF ± plerixafor was used. Clinical parameters (age, sex, stage, lines of treatment, use of radiation therapy, disease status at time of harvest, platelet count at relapse) and stem cell collection parameters (day of chemotherapy, peripheral blood CD34 cell count on D1 of harvest, number of days of harvest, CD34 cells collected on D1 and total CD34 cells collected) were extracted from medical records and analyzed. A total of 174 PBSC mobilization attempts were made in 169 Hodgkin lymphoma patients during the study period. Chemo-mobilization with gemcitabine-dexamethasone-platinum (GDP)- and cytarabine-based regimens led to successful harvests in 95% and 100% patients, respectively. GDP-based mobilization was significantly better than other regimens and granulocyte colony-stimulating factor (G-CSF) (±plerixafor) mobilization (82%) (P = 0.000082). Patients who had previous radiation exposure to mediastinum, spine or pelvis and underwent mobilization following ifosfamide-based mobilization had a mobilization failure rate of 37%. GDP and cytarabine-based regimen have better mobilization success compared to ifosfamide-based regimen or G-CSF (±plerixafor) in lymphoma patients. It may be best to avoid ifosfamide-based regimens in patients who have received radiation to mediastinum, spine or pelvis due to high rates of mobilization failure.

Fault-tolerant mutual visibility without any axis agreement in presence of mobility failure

We aim to solve the mutual visibility problem using N autonomous, indistinguishable, homogeneous, oblivious and opaque point robots in the presence of mobility failure. The faulty robot cannot move when it becomes faulty, but the light remains working. Initially, from any arbitrary configuration, the problem of mutual visibility using robots aims to reach a configuration where any two robots can see each other. The challenge is to reach to such a configuration in the presence of faulty robots along with obstructed visibility under which two robots see each other only if the line segment joining them does not have any robots. Every robot operates in the conventional Look-Compute-Move cycles. Robots neither have any agreement in their coordinate system nor have the knowledge of N. The problem is not solvable for a specific symmetric initial configuration of the robots. We propose an algorithm that tolerates f(≤N) number of faulty robots and uses a constant number of colors in the FSYNC setting. To be specific, the algorithm requires 21 colors and runs in O(N2) synchronous rounds. We present another algorithm much simpler than the prior one but can tolerate a single faulty robot. This algorithm needs only 2 colors in the SSYNC and 5 colors in the ASYNC setting.

Analysis of Risk Factors and Development of a Nomogram Prediction Model for Stem Cell Mobilization Failure in Lymphoma Patients

Analysis of Risk Factors and Development of a Nomogram Prediction Model for Stem Cell Mobilization Failure in Lymphoma Patients

Predictors, Diagnoses, and Costs of Emergency Department Visits among Home Care Clients

ObjectivesTo examine factors, diagnoses, and costs associated with emergency department (ED) visits among home care clients. DesignA prospective 1-year follow-up study. Settings and ParticipantsMore information is needed regarding the reasons and costs associated with ED visits by home care clients. Participants were persons aged ≥65 years living in Eastern Finland and receiving regular home care services (n = 293). MethodsData collection included clients’ demographics, health status (Charlson Comorbidity Index), medication use, assessments of physical (Timed Up and Go) and cognitive functioning (Mini-Mental State Examination), Basic and Instrumental Activities of Daily Living, mood (Geriatric Depression Scale, GDS-15) and health-related quality of life [HRQoL, EuroQol (EQ-5D-3 L)]. Logistic regression and univariate analyses of variance were conducted. The costs (total and per person-year) of ED visits were calculated. ResultsThe number of ED visits was 775 during the follow-up (mean 350 days). The likelihood of ED visits was reduced by better HRQoL and increased by a higher GDS-15 score, longer TUG times, and a history of heart failure and decreased glomerular infiltration. The most common primary diagnoses for ED visits were heart failure (8.4%), atrial fibrillation (4.0%), respiratory infection (4.0%), and cystitis (3.5%). The total costs of all ED visits during the follow-up were 251,247 € and internal medicine and surgery accounted for 142,726 € and 89,212 € of the cost, respectively. The costs per person-year were 981 €. Conclusions and ImplicationsHRQoL, depressive symptoms, mobility, and heart and renal failure were associated with the number of ED visits. The most common reasons for ED visits were chronic heart conditions and infectious diseases and the highest costs were incurred by internal medicine treatment. With advanced care planning and active symptom screening and cooperation of home care nurses and physicians, some of the ED visits, for example due to heart failure, might be preventable.

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

Abstract 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.

Does immunohistochemical staining predict mobilization success in multiple myeloma patients?

BackgroundSo many risk factors for mobilization failure have been described so far. We aimed to identify the risk factors and search the possible effects of bone marrow fibrosis (BMF), CD56, c-myc, and cyclinD1 expression on mobilization. MethodsWe evaluated 189 patients with MM who were admitted for stem cell mobilization before autologous stem cell transplantation (ASCT) between 2015 and June 2021. Clinical, laboratory, treatment features, and survival outcomes were compared in patients who were successfully mobilized and who were not. ResultsMobilization failure rate was 11.1 % (21) in our study group. Male gender, mobilization with only G-CSF, history of previous ASCT, lenalidomide exposure, and 2 lines of chemotherapy before stem cell mobilization were observed more commonly in mobilization failure group. There is no relationship between mobilization failure and BMF, CD56, c-myc, and cyclin D1 expression status in patients who received either only G-CSF or G-CSF+ chemotherapy for mobilization. Overall survival (OS) was not different in groups of patients who were successfully mobilized and who were not. Neutrophil engraftment was faster in patients who were transfused > 5 × 106/kg stem cells (p = 0.015). ECOG performance status (p = 0.004), c-myc expression (p = 0.005), lenalidomide therapy before mobilization (p = 0.032), and mobilization with G-CSF+chemotherapy was found to be predictive factors for OS. ConclusionEven though we could not find any predictive value of CD56, c-myc, and cyclin D1 expression on mobilization, c-myc was found to be associated with low OS. Further studies with large and homogenous study population would be more informative.

Mutual visibility of luminous robots despite angular inaccuracy

We initiate the study of the Mutual Visibility problem using N opaque luminous point robots that have inaccurate movements. Each robot operates in Look-Compute-Move cycles and has a persistent light attached to it to have a weak form of communication between robots using a constant number of colors. The inaccuracy for a robot r is an angular deviation from its target point T to a point T′ such that the angle ∠TrT′<90∘. The problem becomes unsolvable if this angle is ≥90∘. From any initial configuration of the robots on the Euclidean plane, the problem aims to arrange the robots in a configuration such that any two robots are visible to each other. We assume that the robots agree on one coordinate axis. We present two collision-free algorithms, a 2 color algorithm (which is optimal in the number of colors used) for semi-synchronous setting and a 3 color algorithm for asynchronous setting, both of which run in O(N) epochs. We also study the problem in the presence of mobile faulty robots. A robot can exhibit both mobility failure and angular inaccuracies in its movement. We present a fault-tolerant algorithm that aims to bring the robots in a configuration where no three non-faulty robots are collinear, and no faulty robot lies between two non-faulty robots. This algorithm uses 10 colors and takes O(N) epochs under asynchronous settings.

A retrospective study on the efficacy of pegfilgrastim-filgrastim combination regimen in the mobilization for autologous stem cell transplantation in lymphoma patients

BackgroundThe high mobilization failure rate with the mobilization strategy of combining chemotherapy and filgrastim (rhG-CSF) in autologous hematopoietic stem cell transplantation (auto-HSCT) in lymphomas is one of the unresolved issues. Whether the combination of polyethylene glycol filgrastim [pegfilgrastim (PEG-FIL), PEG-rhG-CSF] and filgrastim (FIL) improves the mobilization success rate and the timing of combination therapy has not been studied. Methods107 lymphoma patients who received auto-HSCT were retrospectively enrolled and divided into groups of PEG+FIL and FIL. The group of PEG+FIL received pegfilgrastim (9 mg) on the third day of the chemotherapy, followed by filgrastim (10 μg/kg/day) based on the counts of peripheral blood stem cells (PBSC). The group of FIL received filgrastim 10 μg /kg/day depending on the number of PBSCs. ResultsThe incidence of neutropenic fever in the group of PEG+FIL was significantly lower than in the group of FIL. The mean recovery time of leukocytes at autologous stem cell transplantation was significantly shorter in the group of PEG+FIL than in the group of FIL. Compared to the groups of FIL, the group of PEG+FIL had lower hospitalization costs. We found that the combination therapy is more recommended for patients with a bone marrow hematopoietic area of less than 30 %. Filgrastim is best administered 5–6 days after pegfilgrastim administration. ConclusionsCompared to conventional filgrastim mobilization, the combination of pegfilgrastim and filgrastim schedule has high efficacy, non-inferior safety, and superior health economic benefits during auto-HSCT.

Antifouling nanoplatform for controlled attachment of E. coli

Biofouling is the most common cause of bacterial contamination in implanted materials/devices resulting in severe inflammation, implant mobilization, and eventual failure. Since bacterial attachment represents the initial step toward biofouling, developing synthetic surfaces that prevent bacterial adhesion is of keen interest in biomaterials research. In this study, we develop antifouling nanoplatforms that effectively impede bacterial adhesion and the consequent biofilm formation. We synthesize the antifouling nanoplatform by introducing silicon (Si)/silica nanoassemblies to the surface through ultrafast ionization of Si substrates. We assess the effectiveness of these nanoplatforms in inhibiting Escherichia coli (E. coli) adhesion. The findings reveal a significant reduction in bacterial attachment on the nanoplatform compared to untreated silicon, with bacteria forming smaller colonies. By manipulating physicochemical characteristics such as nanoassembly size/concentration and nanovoid size, we further control bacterial attachment. These findings suggest the potential of our synthesized nanoplatform in developing biomedical implants/devices with improved antifouling properties.

Predictive factors for peripheral blood stem cell mobilization in multiple myeloma in the era of novel therapies: A single‐center experience

AbstractObjectiveMultiple myeloma (MM) is the leading indication of autologous hematopoietic stem cell transplantation. The aim of this study was to determine the incidence of mobilization failure and characterize the risk factors associated with poor mobilization (PM) of MM patients in novel therapies era.MethodsWe conducted a retrospective study of 211 MM patients who received their first peripheral blood stem cells (PBSC) mobilization at our single center. The following data were collected: age, gender, clinical stage, disease status, complete blood cell count, induction regimen, CD34+ cell count in peripheral blood (PB), and PBSC collections.ResultsIn addition to conventional drugs, 22 (10.4%) patients received daratumumab containing induction, and 33 (15.6%) patients used plerixafor for poor mobilization (pre‐apheresis PB CD34+ cells &lt;20/μL). Failure of collection occurred in 24 (11.4%) patients and was correlated with low white blood cell (WBC), ≥3 cycles of lenalidomide treatment before mobilization, steady‐state mobilization and nouse of plerixafor are associated with mobilization failure. Daratumumab‐based induction treatment ≥2 courses, albumin &gt;41 g/L before mobilization, and steady‐state mobilization were risk factors for PM in subgroups of patients treated with lenalidomide for &lt;3 courses. In addition, Hepatitis B virus infection at baseline, thalassemia and measurable residual disease positivity were recognized as predictive factors for PM in subset of chemo‐mobilization patients.ConclusionIn addition to some well‐recognized risk factors, baseline WBC count and daratumumab exposure ≥2 courses before mobilization were revealed as the predictive factors of mobilization failure, providing consultation for preemptive use of plerixafor.

Is an earlier strategy for harvesting peripheral blood stem cells in healthy allogeneic donors feasible?

IntroductionPeripheral blood stem cells (PBSC) mobilization with granulocyte colony stimulating factor (G-CSF) for healthy donors is generally performed at 5th day. However, earlier collection is sometimes feasible, raising the question of whether to initiate apheresis early to limit further G-CSF exposure, while considering the risk of mobilization failure. In the current study, we examined the factors predicting successful 4th day collection and developed a model that can be used practically. Patients and methodsThe study was carried out by obtaining the data of PBSC mobilizations performed between January 2009 and September 2022 in our transplantation center. ResultsA total of 141 healthy donors with a median donor age of 32 (18–64) were included. Adequate mobilization was achieved in 115 (81.6 %) patients. Median peripheral CD34 + cell count was 69.4/μL in the adequate mobilization group and 46/μL in the mobilization failure group (p < 0001). Multivariate analysis revealed that donor/recipient weight ratio and the 4th day peripheral CD34 + cell count≥ 50/μL were independent markers for 4th day collection success. A predictive model of our center including these parameters was available with 0.765 sensitivity and 0.968 specificity [(AUC):0.948 (95 % CI, 0.90–0.99), p < 0.001]. ConclusionThe result of the current study shows that peripheral 4th day collection can be performed in selected donors, taking into account peripheral CD34+ cell count and donor/recipient weight ratio. In addition, using these indicators, new predictive models can be created that may assist clinicians in daily practice.

Minimum cascade repair method for mobile network nodes failure under time–frequency feature fusion

Minimum cascade repair method for mobile network nodes failure under time–frequency feature fusion

High Dose Chemotherapy With Autologous Stem Cell Transplant for Patients With Advanced Germ Cell Tumors: Real-World Evidence From a Tertiary Cancer Center in Brazil

BackgroundHigh-dose chemotherapy followed by stem cell transplant (HDCT) is potentially curative for patients with refractory germ cell tumors (rGCT). There is scarce real-world data supporting its implementation in low- and middle-income countries. We described the experience of our tertiary cancer center in Sao Paulo, Brazil. MethodsWe identified male patients ≥18 years-old with rGCT referred to HDCT after board discussion. Clinical data, including delays in HDCT protocol, were extracted from medical records, and survival outcomes were estimated using the Kaplan-Meier method. The log-rank test and Cox proportional hazard were used to determine effects on overall survival (OS). ResultsFrom January 2013 to January 2023, 34 patients were referred and considered eligible to receive 2 cycles of HDCT. Most patients had primary testicular tumors (82%), nonseminomatous histology (88%), and poor International Germ Cell Collaborative Group (IGCCCG) (79%). Twenty-three patients received HDCT (1 cycle, n = 8; 2 cycles, n = 15). Main reasons for not receiving any HDCT were death due to progressive disease (n = 1), performance deterioration (n = 7), and failure of stem cell mobilization (n = 3). OS at 2 years was 36.7% for the eligible population, 56.1% for patients who underwent at least 1 HDCT, and 77.1% for those who had ≥2 cycles. The 2-year OS rate for patients not given HDCT was 0%. All patients had delays in protocol, and poor-risk patients had longer intervals from referral to protocol initiation (0.7 vs. 1.8 month, P < .01). ConclusionOutcomes of patients who received ≥1 HDCT were encouraging; however, only 15 from 34 eligible patients were able to receive the planned 2 cycles of HDCT. Further strategies to minimize treatment delays in low- and middle-income countries are needed.

Efficacy and safety of stem cell mobilization with etoposide +cytarabine plus G-CSF in poor mobilizers with relapsed or refractory lymphoma.

Autologous stem cell transplantation (ASCT) is a potentially curative strategy for relapse or refractory(r/r) aggressive lymphoma. However, a proportion of lymphoma patients who are at high risk of mobilization failure fail to mobilize stem cells and cannot proceed to ASCT. The aim of this study is to explore the efficacy and safety of Etoposide combined with Cytarabine (EA) plus G-CSF mobilization in poor mobilizers (PMs) with r/r aggressive lymphoma. This retrospective study analyzed the outcomes of chemo-mobilization based on EA (Etoposide 0.1 g/m2, qd d1~3; AraC 0.5 g/m2, q12h d1~3) in 98 patients with r/r aggressive lymphoma. Of these, 39 patients met the criteria for predicted PMs as proposed by the Gruppo Italiano Trapianto di Midollo Osseo working group. Of the 39 PMs, 38(97.4%) patents harvested adequate mobilization (≥2×106 CD34+ cells/kg), while 31(79.5%) patients achieved optimal mobilization (≥5×106 CD34+ cells/kg). Overall, the mean number of CD34+ cells/kg collected was 17.99(range: 1.08~83.07) ×106 with an average of 1.4 apheresis sessions, and the number was 15.86(range: 0.37~83.07) ×106 for the first apheresis, respectively. A single apheresis procedure was sufficient to reach the target yield of adequate mobilization in 35(89.7%) PMs, while 76.9% of PMs achieved optimal collection within two apheresis sessions. We observed acceptable hematological toxicity and antibiotic usage exposure in 26 patients with a mean duration of 3.6 days. No grade 4 infection or mobilization-related mortality was recorded. Most patients underwent ASCT and achieved successful hematopoietic recovery with prompt engraftment duration, except for one NK/T-cell lymphoma patient who succumbed to severe septicemia after receiving conditioning chemotherapy. Our findings indicate that EA plus G-CSF is an effective and tolerable CD34+ stem cell mobilization strategy for patients with r/r lymphoma, including those predicted to be PMs. This regimen could be an option for patients with r/r lymphoma, particularly those undergoing mobilization for salvage ASCT therapy.

Trends in hematopoietic stem cell utilization and cost of cryopreservation

Abstract Autologous stem cell transplantation (ASCT) is the standard of care treatment for multiple myeloma. Standard ASCT procedures collect hematopoietic stem cells (HPSC) in excess for multiple transplants due to reports of high mobilization failure and unsuccessful ASCT collections following myeloablative treatments. Cost analysis studies estimate that one year of cryopreservation and one day of HPSC collection would each cost $5000 per patient. Limited data is available on the usage of the second transplant and the storage costs of non-transplanted products. This study evaluates the utilization of cryopreserved HPSC products and calculates the cost of cryopreservation. A retrospective chart review study of a cohort of 240 deceased MM patients, who received ASCT between January 2010 to December 2015. Demographic and clinical data were obtained from the laboratory and electronic medical record. The cohort was categorized into two groups, with 130 patients in Group 1 (≤60 years) and 110 patients in Group 2 (&amp;gt;60 years). Cumulative incidence of a second transplant was computed from the life table using the Kaplan Meier method. The cost of cryopreservation was calculated based on the time HPSC products remained in the freezers before disposal. PBSC was mobilized using Granulocyte Colony Stimulating Factor (GCSF), or GCSF and Mozobil. The average age of patients at first collection is 61 (IQR: 54-66) years and the average age of death is 64 (IQR: 58 -70) years. The average life span of patients after receiving the first transplant is 3 (IQR: 2-5) years. The average number of collection days is 2 (IQR: 1-3). 65 patients had 1-day collections, 105 had 2-day collections and 70 had ≥3-day collections. 175 patients (73%) had &amp;gt;1 day collection. Only 22 patients (9%) received a second transplant and 18 of them (82%) were in Group 1 (≤60). The cumulative incidence of a second transplant by 5 years is 23% for Group 1 and 4% for Group 2. Two-transplant collections required 492 days of apheresis with an overall cost of $2,500,000; however, one-transplant collections would cost $1,400,000 for 279 apheresis days. The median cost of cryopreservation for each patient who did not receive the second transplant is $15,000 (IQR: $8000 - $25,000). Therefore, the estimated cost for all patients in the study is $3,600,000 until the disposal of HPSC products. The incidence of a second transplant is low across all patients and significantly lower in patients greater than 60 years of age. Cryopreserved stem cell products remain under-utilized, leading to substantial financial burden. The duration of HPSC collection and cryopreservation must be re-evaluated for future treatment plans. Institutional policies should be revised based on the utilization trend to lower the operational cost of storage.

Incidence, Clinical Characteristics and Risk Factors for Poor Mobilization of Hematopoietic Stem Cells in a Colombian Bone Marrow Transplantation Unit: A Retrospective Cohort Study

Background: mobilized peripheral hematopoietic stem cells (PHSC) are the main cell source for autologous bone marrow transplantation. Failure to mobilize an appropriate number of PHSC can jeopardize autologous bone marrow transplantation procedure. Objective: our aim was to describe the clinical and demographics characteristics, the incidence of mobilization failure and the prevalence of risks factors for poor mobilization in patients in whom PHSC mobilization were attempted for autologous bone marrow transplantation between January 1st 2017 and 31 December 2022. A univariate and multivariate analysis (binary logistic regression) were done to determinate the association between risk factors and mobilization failure. Results: 129 patients were included , the patients median age was 54 years. Indications for autologous bone marrow transplantation were multiple myeloma in 50,4 %, lymphoma in 46,5 % and systemic sclerosis in 2,3 % of patients respectively. Mobilization was attempted with Filgrastim in 71,1 %, Filgrastim plus Plerixafor in 26,6 % and chemotherapy (Cyclophosphamide) plus Filgrastim in 2,3 % of patients respectively. Mobilization failure occurred in 9,3 % of patients (12 patients) occurring in 11 % of patients who received Filgrastim, in 5,6 % who received Filgrastim plus Plerixafor and in none of patients who received chemotherapy plus Filgrastim. No difference in mobilization failure was found between patients who received Filgrastim monotherapy versus those who received Filgrastim plus Plerixafor ( χ 2 p=0,388, relative risk: 1,8, confidence interval 95% 0,43 - 8,1). Patients who received Filgrastim plus Plerixafor had been treated more frequently (four of more cycles of Lenalidomide) compared with patients who received Filgrastim alone (63,3 % versus 18,7 %, χ 2 p &amp;lt; 0,001, RR=4,01, CI 95 %; 2,32-6,87).The median age of patients was superior in patients who received Filgrastim plus Plerixafor compared with those who received Filgrastim (58 vs 51 years, U Mann Whitney p = 0,02). The median number of treatment lines tended to be superior in patients receiving Filgrastim plus Plerixafor compared to those receiving Filgrastim (2 lines versus 1 line of therapy, U Mann Withney p= 0,054). Patients who had been treated with intensive chemotherapy regimens like DHAP, ESHAP or Hyper CVAD (p=0,004, RR: 4,3, CI 1,5-12,3)) and patients older than 60 years (p=0,018, RR: 3,4 (1,2-9,85)) were significant more prone to mobilization failure in bivariate and multivariate analysis. Conclusion: mobilization failure occurred in 9,3 % of patients , Filgrastim monotherapy was more frequently used, no difference in mobilization failure was found between those who received Filgrastim versus Filgrastim plus Plerixafor, history of treatment with more than 4 cycles of lenalidomide and older age were more frequently in patients who received Filgrastim plus Plerixafor. History of a treatment intensive chemotherapy regimen and being older than 60 years were consistently associated with mobilization failure in univariate and multivariate analysis.

Comparison of Various Stem Cell Mobilization Regimens for Multiple Myeloma - a 15-Year Retrospective Institutional Analysis from India

Introduction For multiple myeloma (MM), Cyclophosphamide (Cy) based chemo-mobilization offers advantage in term of higher stem cell yield and can overcome adverse impact of prior lenalidomide therapy on stem cell harvest. However, considering need for hospital stay and risk of febrile neutropenia, steady state mobilization with G-CSF and pre-emptive plerixafor (PEF) is becoming increasingly popular. Until few years back, cost of PEF was prohibitive thereby limiting its use and prompting a search for alternative cheaper drugs. Mouse models have shown that Proteasome Inhibitors aid in hematopoietic stem-cell (HSC) mobilization by down-regulating very-late antigen-4 (VLA-4) on bone marrow stromal cells which interacts with vascular cell adhesion molecule (VCAM-1) on HSC. We previously reported that bortezomib (Bort) in combination with Cy-G-CSF showed a trend towards higher CD34 yield and reduced need for apheresis sessions, without additional toxicity. There is limited data comparing mobilization regimens, especially from low-middle income countries where HSC collection may not be done after 4-6 cycles of first-line therapy. We hereby report our 15-year experience of various mobilization regimens for MM. Methods All patients with MM who underwent HSC mobilization from September 2007 - December 2022 were included in this analysis. Various mobilization regimens [Group 1 - G-CSF + Bort (August 2018 - December 2022); Group 2 - G-CSF + plerixafor (August 2018 - December 2022); Group 3 - Bort-Cy-GCSF (April 2016 - July 2018); Group 4 - Cy + G-CSF (September 2007 - March 2016)] were used as per respective time-periods (Table 1). Our aim was to collect CD34 cell dose of 5million/kg to suffice for 2 transplants. G-CSF (5 mcg/kg subcutaneously BD) was given on days 1-5 (Groups 1 and 2). Bort (1.3mg/m 2 iv / sc) (Group 1) or PEF (Group 2) were given on day 4 twelve hours prior to planned apheresis on day 5. Apheresis was done on day 5, and additionally on day 6, if first harvest was inadequate for 2 transplants. In group 3, Bort (1.3mg/m 2 iv) was given on days-1,4,8,11, with Cy (1gm/m 2 iv) on days 8 and 9, followed by G-CSF from day 11 onwards. Cy (1gm/m 2 iv) was given on day 1 and 2 (Group 4), followed by G-CSF from day 4 onwards. Stem cell harvest was done in groups 3 and 4 once peripheral blood CD34 (PB CD34) was &amp;gt;20/µL. In groups 3 and 4, if PB CD34 was &amp;lt;20/µL for 2 subsequent days, PEF was used according to physician's discretion, if available. Similarly in Group 1, if PB CD34 was between 10-20/µl on day 4, PEF was used according to physician's discretion. PEF was used in any group after the first harvest if the cell dose was deemed inadequate, at physician's discretion. Primary objective was to determine proportion of patients with CD34 + dose ≥5x10 6/kg in first apheresis in various groups. Secondary objectives were to determine total median CD34 + dose (x10 6/kg) collected, median CD34 + (x10 6/kg) in first apheresis, and frequency of mobilization failure. Mobilization failure was defined as total collected CD34 + dose of &amp;lt;2x10 6/kg or abandoned harvest attempt anticipating a poor collection.Analysis was done as per planned regimen (intention to treat analysis). Results Total 205 patients were analyzed. Median age was 48 years (27-65 years) and 143 (70%) were males (Table 1). Median day of first collection in groups 3 and 4 was day10 from the first dose of cyclophosphamide. Percentage of patients who collected ≥5x10 6 CD34 + cells/kg in first apheresis were 26%, 53%, 69% and 63%, respectively in Groups 1-4 (p=0.0001) (Table 1). CD34+ cell-dose in first apheresis and total dose collected are shown in Table 1. In comparison to groups 1 and 2, both chemo-mobilization groups (group 3 and 4) had a significantly higher total cell dose (Figure 1). In comparison to group 1, both Cy chemo-mobilization groups had a significantly higher cell dose in first harvest, but there was no significant difference between group 2 and group 4 (p=0.23) (Figure 1). PEF was required additionally in 47%, 22%, and 7% of patients in groups 1, 3 and 4 respectively (P&amp;lt;0.00001). Amongst transplanted patients, there was no difference in neutrophil or platelet engraftment and the frequency of engraftment syndrome in various groups. Conclusion Cy-based chemo-mobilization regimens have advantage of higher total stem cell yield, while they are equivalent to G-CSF + Plerixafor for harvest in single apheresis. Addition of Bortezomib to Cyclophosphamide may help to increase stem cell yield.

Combination of Propranolol and a Novel CXCR4 Antagonist Burixafor (GPC-100) for Enhanced Hematopoietic Cell Mobilization

Burixafor (GPC-100), a novel CXCR4 antagonist, has shown safe and effective mobilization of hematopoietic stem and progenitor cells (HSPC) in a phase I clinical study. In multiple myeloma patients, GPC-100 combined with granulocyte-colony stimulating factor (G-CSF) elicited a significant increase in circulating HSPCs that was comparable with the historical results from G-CSF plus the CXCR4 antagonist plerixafor. GPC-100 is currently being investigated for HSPC mobilization in combination with the FDA-approved ß-adrenergic receptor (ß-AR) blocker propranolol in a phase II clinical trial for autologous stem cell transplant (ASCT) in multiple myeloma. Here, we present preclinical findings indicating that the addition of propranolol to GPC-100 alone or GPC-100 and G-CSF combination can address the unmet needs of patients undergoing mobilization. Additionally, we show an enhanced and unique pattern of lymphoid cell mobilization that may have applications in adoptive cell therapies. Compared to chemotherapy, ASCT significantly improves survival in multiple myeloma patients. Because HSPCs constitute a very small fraction (~ 0.1%) of circulating mononuclear cells, it is critical to mobilize a sufficient number of HSPC into peripheral blood during the ASCT process. Current therapies for HSPC mobilization include G-CSF as a monotherapy or combined with plerixafor. However, mobilization failure is experienced by 15-50% patients, leading to potential loss of ASCT as a treatment option and significant toxicity from repeated mobilization attempts. Moreover, G-CSF is contraindicated in sickle cell disease and may exacerbate autoimmune diseases. Therefore, our goal is to identify novel strategies that will not only address the mobilization failure, but also explore non-G-CSF options for adequate mobilization. G protein-coupled receptors like CXCR4 can form heteromers with other receptors and result in altered signaling pathways. Using Proximity Ligation Assay in Namalwa (lymphoma) cells, we show that endogenously expressed CXCR4 and ß 2AR form heteromers, which are absent in CXCR4 knockout cells. In cell-based assays, co-activation of both receptors with their respective ligands, CXCL12 and epinephrine, leads to a synergistic increase in calcium flux (Figure 1) as well as ß-arrestin recruitment, indicating functional consequences of the heteromerization. Complete blockade of this enhanced signaling is only achieved with co-inhibition by both antagonists. Like CXCR4, ß 2AR is also expressed by HSPCs, and in lymph nodes was shown to heteromerize with CXCR4 to increase lymphocyte retention. In multiple myeloma patients, propranolol upregulated stem-cell like gene signature. Therefore, we sought to understand the effects of propranolol on HSPC mobilization by GPC-100. In mice, single injection of GPC-100 effectively mobilized hematopoietic stem cells characterized as Lin negSca1 +cKit +(LSK) cells as well as mature Lin negCD34 + progenitor cells by 2-4-fold, respectively. Seven-day pretreatment with propranolol enhanced LSK cell mobilization by GPC-100 resulting in a 4-fold increase in circulating HSPCs (Figure 2). Addition of propranolol to G-CSF and GPC-100 led to 8-17-fold increases in mobilization of long-term repopulating HSCs (CD34 negLSK and CD150 +LSK), which were greater than the 4-7-fold increases elicited by G-CSF and G-CSF with plerixafor. Additionally, propranolol enhanced GPC-100 induced mobilization of white blood cells, neutrophils, and lymphocytes (Figure 2). Immune cell subset analyses revealed that GPC-100 induced a 3-fold increase in circulating CD8 +T cells, which was increased to 7-fold when combined with propranolol (Figure 2). For comparison, plerixafor increased CD8 + T cell mobilization by only 2-fold. GPC-100 induced mobilization of NK and B cells was also improved by propranolol. These pre-clinical data support our phase II clinical trial currently in progress (NCT05561751). In the first arm of this two-arm trial, GPC-100 is combined with orally administered propranolol, and in the second arm, G-CSF is added to this combination. We anticipate that our clinical studies can fill the gap in the current standard of care without adding a significant financial burden or co-morbidities. Furthermore, enhanced mobilization of CD8+ T cells can provide extended opportunities for improved adoptive cell therapies.

The Combination of Pegfilgrastim and Filgrastim Improves the Outcomes of Mobilization and Engraftment after Transplantation of Autologous Hematopoietic Stem Cells for the Treatment of Lymphoma

BACKGROUND : Hematopoietic stem cell transplantation (HSCT) is broadly utilized for the treatment of lymphoma. Autologous peripheral blood stem cell (PBSC) transplantation (ASCT) requires mobilization of hematopoietic stem cell/ hematopoietic progenitor cell (HSC/HPC) in peripheral blood (PB) to collect HSCs. The high mobilization failure rate with the mobilization strategy of combining chemotherapy and filgrastim (rhG-CSF, recombinant human granulocyte colony-stimulating factor) in ASCT is one of the unresolved issues. Whether the combination of polyethylene glycol filgrastim [pegfilgrastim (PEG-FIL), PEG-rhG-CSF] and filgrastim (FIL) improves the mobilization success rate and the timing of combination therapy has not been studied. METHODS: To test the hypothesis that the combination of pegfilgrastim and filgrastim schedule has superiority, we retrospectively investigated a cohort of 107 lymphoma patients who received auto-HSCT and collection in the First Hospital of Jilin University from Jan 1st 2015 to Dec 1st 2022. These patients were categorized into PEG+FIL group and FIL group. The group of PEG+FIL received pegfilgrastim (9 mg) on the third day of the chemotherapy, followed by filgrastim (10 μg/kg/day) based on the counts of peripheral blood stem cells (PBSC). The group of FIL received filgrastim 10 μg /kg/day depending on the number PBSCs. Demographic information, laboratory results, and treatment plans were collected for these two groups of patients. RESULTS：We compared their mobilization efficacy (mononuclear cell [MNC] and CD34 + cell counts) and transplantation efficacy (days to leukocyte and platelet recovery post-transplantation). Successful ASCT mobilization was achieved in 93 patients (86.9%), with the PEG+FIL group exhibiting a higher success rate compared to the FIL group (89.2% [58/65] vs. 83.3% [35/42], p = 0.032). The PEG+FIL group also demonstrated significantly higher CD34+ cell counts [MNC: 8.9 (6.9, 11.2) vs. 7.8 (6.2, 9.8) × 10 8 cells/kg, p = 0.024; CD34 + cell count: 7.5 (5.6, 13.0) vs. 4.9 (3.2, 9.2) × 10 6 cells/kg, p = 0.008] and a lower incidence of neutropenic fever compared to the FIL group (11.8% vs. 24.3%, p = 0.038). The PEG+FIL group also demonstrated a shorter mean leukocyte recovery time in autologous stem cell transplantation than the FIL group (10.02 ± 0.73 vs. 10.9 ± 1.1 days, p &amp;lt; 0.001). To delve deeper into the safety considerations of both groups, we evaluated the advantages of each regimen and the methodologies for selecting time windows. A bone marrow aspiration and biopsy were performed on all patients before stem cell collection. Among 18 patients who had a hematopoietic area less than 30% and a fat area greater than 40%, 10 were in the PEG+FIL group and 8 in the FIL group. For patients who required only one collection, the durability was 80% in the PEG+FIL group compared to 0% in the FIL group (p &amp;lt; 0.01), indicating a superior recommendation for patients with a bone marrow hematopoietic area of less than 30%. In the PEG+FIL group, monitoring was carried out for PB CD34 + percentage and WBC count following pegfilgrastim administration, with subsequent computation of CD34 + cells in PB. Filgrastim administration was found to be optimal 5-6 days post-pegfilgrastim administration. CONCLUSIONS: In conclusion, relative to conventional filgrastim mobilization, the conjunctive use of pegfilgrastim and filgrastim demonstrates superior efficacy, non-inferior safety during ASCT. The schedule enhanced the the outcomes of mobilization in the patients of less hematopoietic area. KEY WORDS: Pegylated recombinant human granulocyte-stimulating factor (pegfilgrastim, PEG-rhG-CSF), recombinant human granulocyte-colony stimulating factor (filgrastim, rhG-CSF), lymphoma, hematopoietic stem cell transplantation (HSCT) autologous hematopoietic stem cell mobilization.

A prospective, multicenter study on hematopoietic stemcell mobilization with cyclophosphamide plus granulocyte colony-stimulating factor and 'on-demand' plerixafor in multiple myeloma patients treated with novel agents.

High-dose melphalan plus autologous stem cell transplantation (ASCT) is a standard of care for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM), and adequate hematopoietic stem cell (HSC) collection is crucial to ensure hematologic recovery after ASCT. In this prospective, observational study we evaluated HSC mobilization with granulocyte colony-stimulating factor (G-CSF), cyclophosphamide, and 'on-demand' plerixafor (in patients with <20×106 CD34+ cells/L after at least 4 days of G-CSF or failing to collect ≥1×106 CD34+ cells/kg after the first apheresis) in NDMM patients treated with novel agent-based induction therapy. The primary endpoint was the rate of poor mobilizers (patients collecting <2×106 CD34+ cells/kg or requiring plerixafor rescue to reach an adequate HSC harvest). Secondary endpoints included the rate of patients collecting ≥2×106 CD34+ cells/kg after plerixafor administration and the identification of factors predicting mobilization failure or plerixafor need. Overall, 301 patients (median age 60 years) were enrolled. Two hundred and eighty-seven of 301 (95%) and 274 of 301 (93%) patients collected ≥2×106 and ≥4×106 CD34+ cells/kg, respectively, with a median of 9.9×106 CD34+ cells/kg collected. Poor mobilizers were 48 of 301 (16%): 34 of 301 (11%) required plerixafor rescue, and 14 of 301 (5%) failed HSC collection regardless of plerixafor. Thirty-four of 38 (90%) patients receiving plerixafor collected ≥2×106 CD34+ cells/kg. Bone marrow plasmacytosis at diagnosis >60% (odds ratio [OR]=4.14), lenalidomide use (OR=4.45), and grade 3-4 hematologic toxicities during induction (OR=3.53) were independently associated with a higher risk of mobilization failure or plerixafor need. Cyclophosphamide plus G-CSF and 'on-demand' plerixafor is an effective strategy in NDMM patients treated with novel agents, resulting in a high rate of HSC collection and high HSC yield (clinicaltrials gov. identifier: NCT03406091).