High-dose ara-C with autologous peripheral blood progenitor cell support induces a marked progenitor cell mobilization: an indication for patients at risk for low mobilization

Analysis of stem cell collections in adult patients with Ewing sarcoma

BACKGROUND

Ewing sarcoma is one of the most frequent soft-tissue tumors in pediatric patients. The current treatment protocols recommend stem cell apheresis (SCA) after completion of the second course of induction therapy with vincristine, ifosfamide, doxorubicine, and etoposide (VIDE). The feasibility of SCA and graft compositions in adult patients with Ewing sarcoma have not been previously analyzed.

METHODS AND MATERIALS

The authors analyzed 29 stem cell collections of 19 adult patients (9 male, 10 female) at a median age of 27 (range 19-53) years mobilized after VIDE (n = 17), cyclophosphamide/topotecan (n = 1) or vincristine, dactinomycin and ifosfamide (n = 1) chemotherapy. All patients were mobilized with filgrastim 5 μg/kg twice daily from day +7 of chemotherapy. The collections were performed if CD34+ cell count in peripheral blood was >10/μL. The target yields were ≥4×10⁶ CD34+ cells/kg body weight.

RESULTS

Median CD34+ cells/μL in peripheral blood before SCA were 45.8 (range 6.7-614.4)/μL. The median cumulative yields were 10.6 (range 1.5-38.8) CD34+ cells/kg body weight and ≥2×10⁶ in all but two patients (89%). CD34, CD3, and CD56 yields in collections after the third VIDE and after later courses did not differ. Four patients underwent high-dose therapy with autologous transplantation, and all were engrafted.

DISCUSSION

Stem cell mobilization is feasible in most Ewing sarcoma patients. Additionally, the present study's data suggest that it is safe to postpone stem cell collection to a later VIDE chemotherapy cycle if medically indicated.

Safety and Effectiveness of Plerixafor for Peripheral Blood Stem Cell Mobilization in Autologous Stem Cell Transplantation: Results of a Post-Marketing Surveillance Study

Background

Plerixafor was approved in Japan in 2016 for peripheral blood stem cell (PBSC) mobilization in autologous stem cell transplantation (A-SCT).

Objective

Our objective was to evaluate the safety and effectiveness of plerixafor in Japanese patients undergoing A-SCT for various indications in real-world practice.

Patients and Methods

This post-marketing surveillance study included Japanese patients initiating PBSC mobilization with plerixafor for A-SCT. Safety assessments included the incidence of adverse events (AEs) including serious AEs, adverse drug reactions (ADRs), and laboratory variables. Effectiveness assessments were the proportion of patients with the target CD34+ cell yield (≥2 × 10⁶ cells/kg) ≤4 days after plerixafor administration and the number of days required to reach the target CD34+ cell yield.

Results

In total, 785 patients were registered, and the safety and effectiveness analysis sets comprised 764 and 717 patients, respectively. ADRs occurred in 12.2% of patients, with gastrointestinal disorders (5.5%), laboratory investigations (4.5%), and blood and lymphatic system disorders (3.0%) being the most common. A total of 71.1% of patients had the target CD34+ cell yield within ≤4 days of treatment, with a mean (standard deviation) of 1.3 (0.7) days to reach the target CD34+ cell yield. Over 80% of patients with a baseline CD34+ cell count >2 cells/μL had a target CD34+ cell yield within ≤4 days of treatment.

Conclusions

This large post-marketing surveillance study provided real-world evidence detailing the safety and effectiveness of plerixafor for PBSC mobilization in Japanese patients undergoing A-SCT. Importantly, no new safety concerns were identified, and the safety profile of plerixafor was consistent with the established profile of this drug.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00276-1.

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.

Race/ethnicity and underlying disease influences hematopoietic stem/progenitor cell mobilization response: A single center experience

BACKGROUND

Whether race/ethnicity plays a role in hematopoietic stem/progenitor cells (HSPC) mobilization in autologous donors has not been studied. We hypothesize that donor characteristic including race/ethnicity, age, sex, body mass index, and diagnostic groups influences HSPC mobilization. Diagnostic groups include healthy allogeneic donors, autologous multiple myeloma (MM) and non-MM donors.

STUDY DESIGN AND METHODS

Here, we conducted a single-center retrospective study in 64 autologous patients and 48 allogeneic donors. Autologous donors were patients diagnosed with MM or non-MM. All donors were grouped as African American (AA), White (W), or "Other"(O).

RESULTS

Multivariate analysis demonstrated diagnostic group differences for CD34+ cell yields between race/ethnicity. Specifically, non-MM patients had the lowest CD34+ cell yields in AA and O, but not in W. For pre-apheresis peripheral blood (PB) CD34+ cell numbers, race/ethnicity had a significant effect both in bivariate and multivariate analyses. Non-MM patients had the lowest, and AA patients had the highest PB CD34+ cells. The results support the view that past therapies used in MM are likely more conducive of recovery of HSPC.

CONCLUSIONS

Our study shows that race/ethnicity and diagnostic group differences influenced CD34+ cell mobilization response across donor types. Interestingly, autologous MM donors with the aid of plerixafor displayed comparable CD34 yields to allogeneic donors. Even though both MM and non-MM donors received plerixafor, non-MM donors had significantly lower CD34 yields among AA and O donors but not in W donors. Larger studies would be required to validate the role of diagnostic groups and race/ethnicity interactions.

Plerixafor in poor mobilizers with non-Hodgkin's lymphoma: a multi-center time-motion analysis

High-dose chemotherapy alongside peripheral blood stem cell (PBSC) infusion has become the standard of care in different hematologic malignancies. The goal of PBSC mobilization is to allow collection of sufficient CD34+ cells to proceed to transplantation. The current mobilization regimen with granulocyte colony-stimulating factor (G-CSF), alone or in combination with chemotherapy, still fails in 10-25% of patients. Plerixafor is able to rescue most of these patients from mobilization failure. In this study, we investigated the impact of plerixafor on the cost and time spent on apheresis in patients who were considered poor mobilizers, with <20 × 10⁶/µl peripheral CD34+ cells after mobilization but prior to apheresis. Patient hospital records from ten centers in three European countries were reviewed and compared during two time periods, namely prior and after plerixafor introduction to the market. During the plerixafor period, patients spent less time on apheresis (350 vs. 461  min). Poor mobilizers given plerixafor collected more CD34+ cells during the first apheresis session, leading to a decrease in the average number of apheresis sessions needed. The total apheresis yield was unaffected. This analysis shows that the use of plerixafor lessens the time-effort associated with the management of poor mobilizers and reduces apheresis costs.

Prospective noninterventional study on peripheral blood stem cell mobilization in patients with relapsed lymphomas

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) to rescue hematopoiesis is considered standard care for patients with a relapsed chemosensitive lymphoma, but diagnosis of lymphoma has been a risk factor for poor mobilization in several studies. The aim of this prospective noninterventional clinical audit was to review the mobilization strategies used by EBMT centers in relapsed lymphoma and to evaluate their efficacy. Between 2010 and 2014, 275 patients with relapsed lymphoma from 30 EBMT centers were prospectively registered. Almost all patients were mobilized with chemotherapy plus G-CSF (96%), but there was a large variation in chemotherapy schedules. Thirty (11%) of them were poor mobilizers (<2 × 10⁶ CD 34+ cells/kg body weight) at the first mobilization. Poor mobilization was not associated with gender, age, bone marrow involvement at diagnosis, primary diagnosis, number of previous chemotherapy lines, previous radiotherapy or mobilization with G-CSF alone. The use of high dose cyclophosphamide alone was associated with mobilization failure (P = 0.0006), whereas the use of a platinum-containing regimen was associated with a good mobilization outcome (P = 0.013). Because failure rate is low, we can conclude from this study that PBSC mobilization failure in relapsed lymphomas is not an important problem in the EBMT centers.

PBSC mobilization in lymphoma patients: analysis of risk factors for collection failure and development of a predictive score based on the kinetics of circulating CD34+ cells and WBC after chemotherapy and G-CSF mobilization

Autologous stem cell transplantation (ASCT) is a potentially curative treatment of lymphoma, but peripheral blood stem cell (PBSC) mobilization fails in some patients. PBSC mobilizing agents have recently been proved to improve the PBSC yield after a prior mobilization failure. Predictive parameters of mobilization failure allowing for a preemptive, more cost-effective use of such agents during the first mobilization attempt are still poorly defined, particularly during mobilization with chemotherapy + granulocyte colony-stimulating factor (G-CSF). We performed a retrospective analysis of a series of lymphoma patients who were candidates for ASCT, to identify factors influencing PBSC mobilization outcome. Premobilization parameters-age, histology, disease status, mobilizing protocol, and previous treatments-as well as white blood cell (WBC) and PBSC kinetics, markers potentially able to predict failure during the ongoing mobilization attempt, were analyzed in 415 consecutive mobilization procedures in 388 patients. We used chemotherapy + G-CSF in 411 (99%) of mobilization attempts and PBSC collection failed (<2 × 10(6) CD34+ PBSC/kg) in 13%. Multivariable analysis showed that only a low CD34+ PBSC count and CD34+ PBSC/WBC ratio, together with the use of nonplatinum-containing chemotherapy, independently predicted mobilization failure. Using these three parameters, we established a scoring system to predict risk of failure during mobilization ranging from 2 to 90%, thus allowing a selective use of a preemptive mobilization policy.

Peripheral blood CD34+ cell monitoring after cyclophosphamide and granulocyte-colony-stimulating factor: an algorithm for the pre-emptive use of plerixafor

Plerixafor "on demand" after chemotherapy plus granulocyte-colony-stimulating factor (G-CSF) is efficient in peripheral stem cell mobilization, but the timing of administration and criteria for patient selection are under investigation. To devise an algorithm for the "on demand" use of plerixafor at the first mobilization attempt, we analyzed the kinetics of hematopoietic recovery and peripheral blood CD34+ cells in 107 patients treated with high-dose cyclophosphamide plus G-CSF. Fifty-one patients with myeloma were treated with cyclophosphamide 3-4 g/m(2) on day 0 followed by G-CSF 10 μg/kg from day + 6, and 56 patients with lymphoma received cyclophosphamide 6-7 g/m(2) followed by G-CSF 5 μg/kg from day + 1. Peripheral blood CD34+ cell monitoring was started on day + 8 in patients with myeloma and day + 10 in patients with lymphoma. The outcome of interest was a collection of ≤ 2 × 10(6) CD34+/kg. By a multivariate logistic regression model, CD34+ cell count < 10/μL at leukocyte recovery (> 1000/μL) or leukocyte count < 1000/μL after day + 12 in myeloma and day + 14 in lymphoma predicted the failure of mobilization by 2.7 and 2.8 times (p = 0.001 and p = 0.02) with a sensitivity of 89% and specificity of 88%, respectively. Plerixafor "on demand" may be considered in patients with myeloma and lymphoma with delayed hematopoietic recovery and < 10/μL CD34+ cells, as a first-line mobilization strategy.

Which regimen is better for stem cell mobilization of lymphoma patients?

Although chemotherapy combined with G-CSF is an effective method for hematopoietic stem cell mobilization, standard chemotherapy protocol leading to best stem cell yield is not defined. In our study, we aimed to assess the impact of chemotherapy choice on mobilization outcome in lymphoma patients. Patients were mobilized with cyclophosphamide (n:15), ASHAP (n:11) or VGEPP (n:12) protocols. Groups were similar according to collected CD34+ cell count, total nucleated cell count and median apheresis days. Five out of fifteen (33%) patients could not be mobilized in Cy group but there was only one failed mobilization attempt in both salvage groups (9% with ASHAP vs 8% with VGEPP). In conclusion, we showed that VGEPP and ASHAP are safe protocols in terms of stem cell mobilization and have similar mobilization capacity as cyclophosphamide alone.

Poor mobilizer: a retrospective study on proven and predicted incidence according to GITMO criteria

The Italian Group for Bone Marrow Transplantation (Gruppo Italiano Trapianto di Midollo Osseo, GITMO) recently formalized criteria for a shared definition of poor mobilizer in order to facilitate randomized clinical trials and study comparison focusing on the efficacy of current mobilizing regimens. The availability of a standardized tool for poor mobilizer definition suggested us to retrospectively test GITMO criteria feasibility and applicability. Therefore we analyzed medical and laboratory records of adult patients affected by myeloma (MM) or lymphoma undergoing mobilization for autologous peripheral blood HSC collection from January 2010 to June 2011, at Servizio di Emotrasfusione, Istituto di Ematologia, Università Cattolica Del Sacro Cuore, Roma, UOC SIMT AO S. Camillo Forlanini Roma and SIMT Fondazione Policlinico Tor Vergata Roma. We collected data about 227 patients (134 male, 93 female) affected by MM (31.3%) NHL (58.6%) e HD (10.1%). Thirty-nine patients, 21 male and 18 female met proven poor mobilizer criteria definition resulting in a incidence of 17.2% (12.7% in MM, 21.8% in NHL and 4.3% in HD). Eleven patients, seven affected by lymphoma and four affected by myeloma, were defined predicted PM according to major criteria. Eight patients, seven affected by lymphoma and one affected by myeloma, were define predicted PM according to minor criteria. Sixteen out of 39 patients defined as poor mobilizer either according to major or minor criteria underwent collection procedures and eight (20.5%) achieved a cell dose ⩾2×10(6)/kg CD34(+) cells. GITMO criteria application was easy and resulted in poor mobilizer incidence comparable to current literature. Definitions of proven poor mobilizer and predicted poor mobilizer according to major criteria were very effective while minor criteria were less predictive. These results came from a retrospective analysis and therefore should be validated in future prospective trial. On the other hand these data could be an early overall view of the foreseeable future of peripheral blood stem cell collection. In conclusion we believe that these criteria will be able to better characterize poor mobilizer phenomenon and, consequently, to identify patients taking advantage from new mobilizing agents.

Who should be really considered as a poor mobilizer in the plerixafor era?

Patients with a number of peripheral CD34+ cells ≥20/μL have recently been defined in the literature as "poor mobilizers". We retrospectively reviewed medical records from a total of 248 patients affected by hematological malignancies or solid tumors undergoing peripheral blood stem cell collection following chemotherapy plus G-CSF. On the basis of the CD34+ cell peak in peripheral blood following mobilization therapy, patients were defined as good mobilizers (group A, CD34+ cells ≥20/μL), relative poor mobilizers (group B, CD34+ cells <20 and ≥8/μL) and absolute poor mobilizers (group C, CD34+ cells <8/μL). One hundred and seventy-seven (71%) patients resulted good mobilizers, 35 (14%) patients relative poor mobilizers and 36 (15%) patients absolute poor mobilizers. Target of stem cell collection was ≥2.0×10(6) CD34+cells/kg for each transplantation procedure. All patients in group A, 20 patients in group B (57%) and 1 patient in group C (2.7%) were able to collect ≥2.0×10(6) CD34+cells/kg. The multivariate analysis confirmed that more than three lines of previous chemotherapy and a previous autologous PBSC transplantation negatively affect mobilization of CD34+ cells in peripheral blood. Our data suggest that a number of CD34+ cells ≥20/μL does not always result in a failed stem cell collection and in fact in our patient series more than 70% of the patients defined as poor mobilizers have indeed collected the minimum number of 2.0×10(6) CD34+cells/kg required for a successful transplantation. The use of new agent such as CXCR4 antagonist plerixafor might further improve mobilization efficacy in such patients.

Proposed definition of 'poor mobilizer' in lymphoma and multiple myeloma: an analytic hierarchy process by ad hoc working group Gruppo ItalianoTrapianto di Midollo Osseo

Many lymphoma and myeloma patients fail to undergo ASCT owing to poor mobilization. Identification of poor mobilizers (PMs) would provide a tool for early intervention with new mobilization agents. The Gruppo italianoTrapianto di Midollo Osseo working group proposed a definition of PMs applicable to clinical trials and clinical practice. The analytic hierarchy process, a method for group decision making, was used in setting prioritized criteria. Lymphoma or myeloma patients were defined as ‘proven PM' when: (1) after adequate mobilization (G-CSF 10 μg/kg if used alone or ⩾5 μg/kg after chemotherapy) circulating CD34⁺ cell peak is <20/μL up to 6 days after mobilization with G-CSF or up to 20 days after chemotherapy and G-CSF or (2) they yielded <2.0 × 10⁶ CD34⁺ cells per kg in ⩽3 apheresis. Patients were defined as predicted PMs if: (1) they failed a previous collection attempt (not otherwise specified); (2) they previously received extensive radiotherapy or full courses of therapy affecting SC mobilization; and (3) they met two of the following criteria: advanced disease (⩾2 lines of chemotherapy), refractory disease, extensive BM involvement or cellularity <30% at the time of mobilization; age ⩾65 years. This definition of proven and predicted PMs should be validated in clinical trials and common clinical practice.

In and out of the niche: perspectives in mobilization of hematopoietic stem cells

Several stem cell mobilization strategies have been employed in the past 2 decades, including chemotherapy, hematopoietic growth factors, and chemotherapy plus growth factors. Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage CSF are standard agents approved for peripheral blood stem cell mobilization since the early 1990s. Between 5% and 20% of patients, however, fail to mobilize a sufficient numbers of peripheral blood stem cells in response to G-CSF with or without chemotherapy. Recent advances in defining the basic mechanisms regulating the interactions between hematopoietic stem cells and their marrow niche had led to the discovery that CXCR4 and stromal-cell-derived factor 1α axis play a significant role. Plerixafor, an antagonist of the CXCR4-stromal-cell-derived factor 1α axis has been shown to result in a significant mobilization of hematopoietic stem cells. Numerous clinical trials have demonstrated that the combination of G-CSF and AMD3100 (G+A) resulted in a significant increase in CD34(+) cell yield as compared to the administration of G-CSF alone. In particular, the progenitors mobilized have been shown to comprise a significantly higher proportion of primitive and possibly more potent CD34(+)/CD38(-) subpopulation. Transplantation of PBSC mobilized by G+A administration have led to a rapid and sustained neutrophil and platelet engraftment. Another prospective role of this new class of agents might lie in the mobilization of dormant leukemia stem cells that are well protected by the niche. The future role of CXCR4 antagonists in treatment of hematologic malignancies includes mobilization of hematopoietic stem cells for transplantation and mobilization of leukemia-initiating cells for long-term cure.

Current status of stem cell mobilization

New advances in effective mobilization of peripheral blood stem cells have permitted a greater proportion of patients to benefit from autologous stem cell transplantation. In this review, the relative merits of peripheral blood and mobilized bone marrow are discussed. All available agents are reviewed. A critical assessment of the appropriate dosing and frequency of available growth factors is undertaken, and the most commonly used chemotherapy plus growth factor combinations are covered. Specific recommendations for patients who are poor mobilizers are dealt with including the role of plerixafor.

Mobilization of hematopoietic stem cells for use in autologous transplantation

Autologous hematopoietic stem cell transplantation (HSCT) is a potentially curative therapeutic approach for various malignant hematologic and lymphoid diseases. Hematopoietic stem cells (HSCs) may be collected from the blood or the bone marrow. HSCs are capable of self-renewal and give rise to progenitor cells, multipotent cells that differentiate and proliferate into the mature cells of the blood and immune system. HSCs and progenitor cells are released from the bone marrow into the peripheral blood through a process called mobilization. HSCs then are collected from the blood in a process called apheresis and cryopreserved for administration following the high-dose preparative regimen. This article reviews stem cell biology, current mobilization strategies, use of novel mobilization agents, and nursing care of patients during the mobilization phase of autologous HSCT. Understanding the biology and process of HSC mobilization is critical for transplantation nurses to deliver and coordinate care during this complex phase of autologous HSCT.

The addition of plerixafor is safe and allows adequate PBSC collection in multiple myeloma and lymphoma patients poor mobilizers after chemotherapy and G-CSF

We report 13 multiple myeloma (MM) or lymphoma patients who were failing PBSC mobilization after disease-specific chemotherapy and granulocyte-CSF (G-CSF), and received plerixafor to successfully collect PBSCs. Patients were considered poor mobilizers when the concentration of PB CD34(+) cells was always lower than 10 cells/μL, during the recovery phase after chemotherapy and/or were predicted to have inadequate PBSC collection to proceed to autologous transplantation. Plerixafor (0.24 mg/kg) was administered subcutaneously for up to three consecutive days, while continuing G-CSF, 10-11 h before the planned leukapheresis. Plerixafor administration was safe and no significant adverse events were recorded. We observed a 4.7 median fold-increase in the number of circulating CD34(+) cells after plerixafor as compared with baseline CD34(+) cell concentration (from a median of 6.2 (range 1-12) to 21.5 (range 9-88) cells/μL). All patients collected >2 × 10(6) CD34(+) cells/kg in 1-3 leukaphereses. In all, 5/13 patients have already undergone autograft with plerixafor-mobilized PBSCs, showing a rapid and durable hematological recovery. Our results suggest that the pre-emptive addition of plerixafor to G-CSF after chemotherapy is safe and may allow the rescue of lymphoma and MM patients, who need autologous transplantation but are failing PBSC mobilization.

Plerixafor plus granulocyte CSF can mobilize hematopoietic stem cells from multiple myeloma and lymphoma patients failing previous mobilization attempts: EU compassionate use data

Plerixafor was recently approved by the US Food and Drug Administration (FDA) and the European Medicines Evaluation Agency (EMEA) to enhance stem cell mobilization for autologous transplant in patients with lymphoma and multiple myeloma. In this study, we present the first European compassionate use experience in mobilization failures, patients who are hardest to remobilize but were not included in registration trials. A total of 56 consecutive patients from 15 centers in Spain and the United Kingdom were included: age 60 (33-69) years; 29 men (32 with myeloma and 24 with lymphoma); 2 lines of previous chemotherapy (1-10); 73 previously failed mobilization attempts with G-CSF (28), chemotherapy plus G-CSF (43) or G-CSF plus SCF(2). Overall, 71% of patients reached ≥ 10 CD34+ cells per μL with plerixafor on day 5 after a 7.6-fold expansion from day 4. A total of 42 patients (75%) collected ≥ 2 × 10⁶, average 3.0 ± 1.7 (0.4-10.6) CD34+ cells per kg with plerixafor plus G-CSF. There were no severe drug-related adverse events. In all, 35 patients (63%) underwent transplant, receiving an average of 3.1±1.2 (1.9-7.7) × 10⁶ CD34+ cells per kg. All patients engrafted neutrophils (day 12; 13.4 ± 0.8; 8-30) and platelets (day 15; 18.5 ± 2.4; 8-33). In our experience, plerixafor offers an effective alternative to collect sufficient CD34+ cells for autologous SCT from patients who fail conventional mobilization methods, with good tolerance and a high success rate.

Comparative assessment of telomere length before and after hematopoietic SCT: role of grafted cells in determining post-transplant telomere status

Our objective was to characterize the role of grafted cells in determining telomere length (TL) after hematopoietic SCT (HSCT). A total of 20 patients undergoing autografts had PBSC collected after two sequential mobilization courses: TL in the first collection was significantly longer than in the second. For their autografts, 10 patients used PBSC from the first collection and 10 from the second. TL was also investigated before and after HSCT and on the graft in 10 allogeneic HSCT. After autografting, patients receiving PBSC from the first collection had BM TL reflecting that of grafted cells (median bp: 7730 on PBSC vs 7610 on post-HSCT BM, P=NS) and significantly longer than TL of the second collection; analogously, patients autografted with PBSC from the second collection had BM TL reflecting that of grafted cells (7360 on PBSC vs 7120 on post-HSCT BM, P=NS) and significantly shorter compared with the first collection. In the allograft setting, eight patients had their pre-transplant TL significantly shorter than donor PBSC (5960 vs 7110; P=0.0005); following HSCT, BM TL (median 7380 bp) was identical to that of the graft (P=NS). We conclude that grafted cells have a major role in determining TL after HSCT.

Management of poor peripheral blood stem cell mobilization: incidence, predictive factors, alternative strategies and outcome. A retrospective analysis on 2177 patients from three major Italian institutions

CD34+ peripheral blood hematopoietic stem cells (HSC) are usually collected following mobilization therapy accomplished by using growth factors (GF) such as rHuG-CSF or rHuGM-CSF with or without chemotherapy. A target dose of yielded CD34+ is usually prescribed by the attending physician depending on different protocols, which may include single or double transplantation. HSC collection usually is performed when at least 20 CD34+ HSC/microL are detected by means of flow cytometry. A cumulative dose of at least 2 x 10(6)/Kg/bw CD34+ HSC has been considered as the threshold to allow a prompt and persistent hematopoietic recovery. Unfortunately, this goal is not achieved by the totality of patients undergoing mobilization regimen. In fact, 5-46% of patients who underwent mobilization therapy fail HSC collection due to very low peripheral blood HSC CD34+ count. Patients' characteristics, including age, sex, stage of the underlying disease (complete or partial remission), diagnosis, previously administered radio/chemotherapy regimens, time-lapse from last chemotherapy before mobilization and mobilization schedule (including dose of GF) were considered as possibly predictive of poor or failed mobilization. We performed a retrospective analysis in 2177 patients from three large Italian academic institutions to assess the incidence of poor mobilizers within our patients' series. Therefore, a patient who fails a first mobilization (and when an HLA-compatible related on unrelated donor is not available) could undergo a second attempt either with different mobilization schedule or by using different GF, such as stem cell factor, growth hormone (GH), or more recently newly introduced drugs such as AMD3100, alone or in combination with rHuG- or -rHuGM-CSF. Thus, we investigated the fate of those who failed a first mobilization and subsequently underwent a second attempt or alternative therapeutic approaches.

Poor hematopoietic stem cell mobilizers: a single institution study of incidence and risk factors in patients with recurrent or relapsed lymphoma

The purpose of this retrospective study was to determine the incidence and predictive factors if any, of mobilization failure in lymphoma patients referred for autologous stem cell transplantation. A total of 588 lymphoma patients were referred for transplant consultation from January 2003 to December 2004. Predictors of mobilization failure were evaluated using logistic regression analysis including diagnosis, mobilization regimen, age, sex, type and number of prior chemotherapies, bone marrow cellularity, platelet count, white count, prior bone marrow involvement with malignancy, and prior radiation therapy. Two hundred and six patients were eligible for transplantation and underwent stem cell mobilization. Twenty-nine (14%) patients failed to mobilize adequate stem cells after the first attempt. For the entire group age (>or=60 versus <60 years), diagnosis (Hodgkin's versus non-Hodgkin's lymphoma), use of cytokines alone, platelet count <150 x 10(9)/L, and bone marrow cellularity <30% were significant predictors for mobilization failure on univariate analysis. In view of small number of patients multivariate analysis was not possible. However, a low platelet count (150 x 10(9)/L) was the only significant predictor when the analysis was restricted to non-Hodgkin's lymphoma patients who were mobilized with chemotherapy. Mobilization failure rates are higher in patients with non-Hodgkin's lymphoma compared with those with Hodgkin's lymphoma. In the subset of patients who undergo chemomobilization for non-Hodgkin's lymphoma platelet count at the time of mobilization is a predictor of mobilization failure.

Impact of mobilization and remobilization strategies on achieving sufficient stem cell yields for autologous transplantation

The purpose of this article was to examine historic institutional autologous stem cell mobilization practices and evaluate factors influencing mobilization failure and kinetics. In this retrospective study we analyzed clinical records of 1834 patients who underwent stem cell mobilization for autologous transplantation from November 1995 to October 2006 at the Washington University in St. Louis. Successful mobilization was defined as collection of > or =2 x 10(6) CD34(+) cells/kg. From 1834 consecutive patients, 1040 met our inclusion criteria (502 non-Hodgkin's lymphoma [NHL], 137 Hodgkin's lymphoma, and 401 multiple myeloma [MM]). A total of 976 patients received granulocyte colony-stimulating factor (G-CSF) and 64 received G-CSF plus chemotherapy (G/C) for the initial mobilization. Although the median CD34(+) cell yield was higher in G/C group than in G-CSF alone group, the failure rates were similar: 18.8% and 18.6%, respectively. Overall, 53% of patients collected > or =2 x 10(6) CD34(+) cells/kg during the first apheresis with either mobilization regimen. Regardless of mobilization regimen used, MM patients had the highest total CD34(+) cell yield and required less aphereses to collect > or =2 x 10(6) CD34(+) cells/kg. Mobilized, preapheresis, peripheral blood CD34(+) count correlated with first day apheresis yield (r = .877, P < .001) and 20 cells/microL was the minimum threshold needed for a successful day 1 collection. For the remobilization analysis we included patients from the whole database. A total of 269 of 1834 patients underwent remobilization using G/C, G-CSF, and/or GM-CSF, and G-CSF plus plerixafor. Only 23% of remobilized patients achieved > or =2 x 10(6) CD34(+) cells/kg and 29.7% failed to pool sufficient number of stem cells from both collections. Patients receiving G-CSF plus plerixafor had lowest failure rates, P = .03. NHL patients remobilized with G-CSF who waited > or =25 days before remobilization had lower CD34(+) cell yield than those who waited < or =16 days, P = .023. Current mobilization regimens are associated with a substantial failure rate irrespective of underlying disease. Patients who fail initial mobilization are more likely to fail remobilization. These findings suggest that there is a need for more effective first-line mobilization agents.

High-Dose Yttrium-90–Ibritumomab Tiuxetan With Tandem Stem-Cell Reinfusion: An Outpatient Preparative Regimen for Autologous Hematopoietic Cell Transplantation

Purpose

To develop high-dose myeloablative therapy for CD20+ non-Hodgkin's lymphoma (NHL) as a safe and widely applicable regimen.

Patients and Methods

Patients with relapsed/refractory (n = 25) or de novo high-risk (n = 5) NHL received one myeloablative dose of yttrium-90 (90Y)–ibritumomab tiuxetan after five chemotherapy courses, including three cycles of anthracycline- or platinum-containing regimens, one cycle of cyclophosphamide (4 to 7 g/m2), and one cycle of cytarabine (12 to 24 g/m2). The only exclusion criteria were CNS lymphoma and Eastern Cooperative Oncology Group performance status of more than 3. Primary end points were overall survival (OS) and event-free survival (EFS). Secondary end points included safety and applicability of high-dose 90Y-ibritumomab tiuxetan. To minimize hematologic toxicity, stem cells were reinfused at days 7 and 14 after 90Y-ibritumomab tiuxetan.

Results

Thirteen patients received 90Y-ibritumomab tiuxetan 0.8 mCi/kg, and 17 patients received 1.2 mCi/kg. At 1.2 mCi/kg, the radiation absorbed by critical nonhematologic organs approached the protocol-defined upper safety limit, defining this as the recommended dose for subsequent studies. Hematologic toxicity was mild to moderate and of short duration. Infections occurred in 27% of patients (none had a severity grade greater than 3). After a median observation time of 30 months (range, 22 to 48 months), no myeloid secondary malignancy or chromosomal abnormality was observed, the OS rate was 87%, and the EFS rate was 69%.

Conclusion

High-dose 90Y-ibritumomab tiuxetan seems to be an innovative myeloablative regimen with unprecedented short-term toxicity and wide applicability. Further studies are required to assess its long-term safety and role in the management of CD20+ NHL.

Prolonged survival in poor-risk diffuse large B-cell lymphoma following front-line treatment with rituximab-supplemented, early-intensified chemotherapy with multiple autologous hematopoietic stem cell support: a multicenter study by GITIL (Gruppo Italiano Terapie Innovative nei Linfomi)

A prospective multicenter program was performed to evaluate the combination of rituximab and high-dose (hd) sequential chemotherapy delivered with multiple autologous peripheral blood progenitor cell (PBPC) support (R-HDS-maps regimen) in previously untreated patients with diffuse large B-cell lymphoma (DLB-CL) and age-adjusted International Prognostic Score (aaIPI) score 2-3. R-HDS-maps includes: (i) three APO courses; (ii) sequential administration of hd-cyclophosphamide (CY), hd-Ara-C, both supplemented with rituximab, hd-etoposide/cisplatin, PBPC harvests, following hd-CY and hd-Ara-C; (iii) hd-mitoxantrone (hd-Mito)/L-Pam + 2 further rituximab doses; (iv) involved-field radiotherapy. PBPC rescue was scheduled following Ara-C, etoposide/cisplatin and Mito/L-Pam. Between 1999 and 2004, 112 consecutive patients aged <65 years (74 score 2, 38 score 3) entered the study protocol. There were five early and two late toxic deaths. Overall 90 patients (80%) reached clinical remission (CR); at a median 48 months follow-up, 87 (78%) patients are alive, 82 (73%) in continuous CR, with 4 year overall survival (OS) and event-free survival (EFS) projections of 76% (CI 68-85%) and 73% (CI 64-81%), respectively. There were no significant differences in OS and EFS between subgroups with Germinal-Center and Activated B-cell phenotype. Thus, life expectancy of younger patients with aaIPI 2-3 DLB-CL is improved with the early administration of rituximab-supplemented intensive chemotherapy compared with the poor outcome following conventional chemotherapy.

Placental Growth Factor-1 Potentiates Hematopoietic Progenitor Cell Mobilization Induced by Granulocyte Colony-Stimulating Factor in Mice and Nonhuman Primates

The complex hematopoietic effects of placental growth factor (PlGF) prompted us to test in mice and nonhuman primates the mobilization of peripheral blood progenitor cells (PBPCs) elicited by recombinant mouse PlGF-2 (rmPlGF-2) and recombinant human PlGF-1 (rhPlGF-1). PBPC mobilization was evaluated by assaying colony-forming cells (CFCs), high-proliferative potential-CFCs (HPP-CFCs), and long-term culture-initiating cells (LTC-ICs). In mice, both rmPlGF-2 and rhPlGF-1 used as single agents failed to mobilize PBPCs, whereas the combination of rhPlGF-1 and granulocyte colony-stimulating factor (rhG-CSF) increased CFCs and LTC-ICs per milliliter of blood by four- and eightfold, respectively, as compared with rhG-CSF alone. rhPlGF-1 plus rhG-CSF significantly increased matrix metalloproteinase-9 plasma levels over rhG-CSF alone, suggesting a mechanistic explanation for rhPlGF-1/rhG-CSF synergism. In rhesus monkeys, rhPlGF-1 alone had no mobilization effect, whereas rhPlGF-1 (260 microg/kg per day) plus rhG-CSF (100 microg/kg per day) increased rhG-CSF-elicited mobilization of CFCs, HPP-CFCs, and LTC-ICs per milliliter of blood by 5-, 7-, and 15-fold, respectively. No specific toxicity was associated with the administration of rhPlGF-1 alone or in combination. In conclusion, our data demonstrate that rhPlGF-1 significantly increases rhG-CSF-elicited hematopoietic mobilization and provide a preclinical rationale for evaluating rhPlGF-1 in the clinical setting.

Long-term follow-up of patients with peripheral T-cell lymphomas treated up-front with high-dose chemotherapy followed by autologous stem cell transplantation

We report the results of two prospective phase II studies investigating the role of high-dose sequential chemotherapy, followed by autologous stem cell transplantation (ASCT) in 62 patients with advanced stage peripheral T-cell lymphomas (PTCLs) at diagnosis. Conditioning regimen consisted of mitoxantrone (60 mg/m2) and melphalan (180 mg/m2) or carmustine, etoposide, Ara-C and melphalan followed by peripheral blood stem cell autografting. In an intent-to-treat analysis, 46 out of 62 patients (74%) completed the whole programme, whereas 16 patients did not undergo ASCT, mainly because of disease progression. At a median follow-up of 76 months, the estimated 12-year overall (OS), disease-free and event-free survival (EFS) were 34, 55 and 30%, respectively. OS and EFS were significantly better in patients with anaplastic lymphoma-kinase (ALK)-positive anaplastic large-cell lymphoma (ALCL), as compared with the remaining PTCL. Multivariate analysis showed that patients attaining complete remission (CR) before ASCT had a statistically significant benefit in terms of OS and EFS (P<0.0001). Overall treatment-related mortality rate was 4.8%. In conclusion, our findings indicate (1) up-front high-dose therapy and ASCT are feasible, but could induce a high rate of long-term CR only in patients with ALK-positive ALCL and (2) the achievement of CR before autografting is a strong predictor of better survival.

Poor mobilization is an independent prognostic factor in patients with malignant lymphomas treated by peripheral blood stem cell transplantation

Haemopoietic stem cell therapy is an increasingly adopted procedure in the treatment of patients with malignant lymphoma. In this retrospective analysis, we evaluated 262 patients, 57 (22%) with Hodgkin's and 205 (78%) with non-Hodgkin's lymphomas (NHL), and 665 harvesting procedures in order to assess the impact of poor mobilization on survival and to determine the factors that may be predictive of CD34(+) poor mobilization. The mobilization chemotherapy regimens consisted of high-dose cyclophosphamide in 92 patients (35.1%) and a high-dose cytarabine-containing regimen (DHAP in 87 patients -(33.2%), MAD in 83 (31.7%)). The incidence of poor mobilizers (<2 x 10(6) CD34(+) cells/kg) was 17.9% overall, with a 10% of very poor mobilizers (< or = 1 x 10(6)/kg). Refractory disease status and chemotherapeutic load (>3 regimens) before mobilization played a negative role and were associated with poor mobilization. Survival analysis of all harvested patients showed an overall survival at 3 years of 71% in good mobilizers vs 33% in poor mobilizers (P=0.002). The event-free survival at 3 years was 23% in poor mobilizers and 58% in good mobilizers (P=0.04). We conclude that in NHL patients, poor mobilization status is predictive of survival.

Impact of different strategies of second-line stem cell harvest on the outcome of autologous transplantation in poor peripheral blood stem cell mobilizers

The optimal approach to obtain an adequate graft for transplantation in patients with poor peripheral blood stem cell (PBSC) mobilization remains unclear. We retrospectively assessed the impact of different strategies of second-line stem cell harvest on the transplantation outcome of patients who failed PBSC mobilization in our institution. Such patients were distributed into three groups: those who proceeded to steady-state bone marrow (BM) collection (group A, n = 34); those who underwent second PBSC mobilization (group B, n = 41); those in whom no further harvesting was carried out (group C, n = 30). PBSC harvest yielded significantly more CD34+ cells than BM collection. Autologous transplantation was performed in 30, 23 and 11 patients from groups A, B and C, respectively. Engraftment data and transplantation outcome did not differ significantly between groups A and C. By contrast, group B patients had a faster neutrophil recovery, required less platelet transfusions and experienced less transplant-related morbidity, as reflected by lower antibiotics needs and shorter hospital stays. In conclusion, remobilization of PBSC constitutes an effective approach to ensure a rapid hematopoietic engraftment and a safe transplantation procedure for poor mobilizers, whereas unprimed BM harvest does not provide any clinical benefit in this setting.

Marked telomere shortening in mobilized peripheral blood progenitor cells (PBPC) following two tightly spaced high-dose chemotherapy courses with G-CSF

The purpose of the study was to compare telomere length (TL) in peripheral blood progenitor cells (PBPC) collected after two tightly spaced high-dose (hd) chemotherapy courses. We assessed 37 previously untreated lymphoma patients undergoing a hd-chemotherapy program with autografting. They sequentially received hd-cyclophosphamide (CY) and hd-Ara-C, both followed by PBPC harvesting. Both post-CY and post-Ara-C harvests were assessed for TL by Southern blot analysis. In 12 patients, the assay was also performed on purified CD34+ cells. All patients displayed high PBPC mobilization following both hd-CY and hd-Ara-C. In all but one patient, TL was shorter in PBPC collected after Ara-C compared to CY: 7226bp (range: 4135-9852) vs 8282 bp (range 4895-14860) (P < 0.0001). This result was confirmed on CD34+ cells. Platelet recovery in patients receiving post-Ara-C PBPC was significantly slower compared to those receiving post-CY PBPC. In conclusion, (i) administration of tightly spaced hd-chemotherapy courses induces marked telomere shortening on harvested PBPC; (ii) engraftment kinetics seem slower, with delayed platelet recovery, in patients autografted with PBPC suffering marked TL erosion; (iii) long-term follow-up is required to verify whether PBPC with shortened telomeres display defective engraftment stability and/or risk of secondary leukemia; (iv) TL evaluation is advisable whenever new mobilization procedures are developed.

The role of diagnosis in patients failing peripheral blood progenitor cell mobilization

BACKGROUND

Failure to mobilize PBPCs for auto-logous transplantation has mostly been attributed to previous therapy and poses therapeutic problems.

STUDY DESIGN AND METHODS

The role of underlying disease was analyzed in 17 of 73 (23%) patients with PBPC mobilization failure, and secondary mobilization with high-dose filgrastim was attempted.

RESULTS

Of 16 patients with acute leukemia, 13 (81%) mobilized poorly. In contrast, of 57 patients with non-Hodgkin's lymphoma, Hodgkin's lymphoma, multiple myeloma, and solid tumor, 53 (93%, p < 0.001) showed good PBPC mobilization. Relapsed disease did not predispose to poor mobilization. As secondary mobilization attempt, 7 patients received 25 micro g per kg per day filgrastim without chemotherapy leading to a 3.7 +/- 2.8-fold (SD) increase in the maximum number of circulating CD34+ cells (p = 0.104). PBPC apheresis yielded 3.3 (+/-0.5) x 10(6) CD34+ cells per kg of body weight in 5 patients. Four poor mobilizers received 50 micro g per kg per day filgrastim as second or third mobilization attempt. Circulating CD34+ cells in these patients increased by 1.5 (+/-0.7) compared with the primary G-CSF application.

CONCLUSION

Selective PBPC mobilization failure was seen in patients with acute leukemia whereas remarkably good mobilization was seen in other malignancies. Increasing the filgrastim dose to 25 micro g per kg per day may allow PBPC collection in patients failing PBPC mobilization.

Use of recombinant human growth hormone (rhGH) plus recombinant human granulocyte colony-stimulating factor (rhG-CSF) for the mobilization and collection of CD34+ cells in poor mobilizers

The activity of recombinant human growth hormone (rhGH) in enhancing CD34+ cell mobilization elicited by chemotherapy plus recombinant human granulocyte colony-stimulating factor (rhG-CSF) was evaluated in 16 hard-to-mobilize patients, that is, those achieving a peak of circulating CD34+ cells 10/μL or less, or a collection of CD34+ cells equal to or less than 2 × 106/kg. Patients who had failed a first mobilization attempt with chemotherapy plus rhG-CSF (5 μg/kg/d) were remobilized with chemotherapy plus rhG-CSF and rhGH (100 μg/kg/d). As compared with rhG-CSF, the combined rhGH/rhG-CSF treatment induced significantly higher (P ≤ .05) median peak values for CD34+ cells/μL (7 versus 29), colony-forming cells (CFCs)/mL (2154 versus 28 510), and long-term culture-initiating cells (LTC-ICs)/mL (25 versus 511). Following rhG-CSF and rhGH/rhG-CSF, the median yields of CD34+ cells per leukapheresis were 1.1 × 106/kg and 2.3 × 106/kg (P ≤ .008), respectively; the median total collections of CD34+ cells were 1.1 × 106/kg and 6 × 106/kg (P ≤ .008), respectively. No specific side effect could be ascribed to rhGH, except a transient hyperglycemia occurring in 2 patients. Reinfusion of rhGH/rhG-CSF-mobilized cells following myeloablative therapy resulted in prompt hematopoietic recovery. In conclusion, our data demonstrate that in poor mobilizers addition of rhGH to rhG-CSF allows the patients to efficiently mobilize and collect CD34+ cells with maintained functional properties. (Blood. 2004;103: 3287-3295)

Chemotherapy plus G-CSF mobilized peripheral blood stem cell harvests from acute myeloid leukaemia patients contain large amounts of polyclonal myeloid linneg CD11cpos dendritic precursor cells

Dendritic cells (DC) are potent antigen-presenting cells that can induce effective tumour-specific T-cell responses. This study investigated leucapheresis products as source of DC precursors in 48 patients undergoing autologous peripheral blood stem cell (PBSC) transplantation for haematological malignancies. Strikingly, high-dose cytarabine and etoposide plus granulocyte colony stimulating factor (G-CSF) mobilized PBSC harvests from acute myeloid leukaemia (AML) patients containing the highest number of myeloid lin(neg)CD11c(pos) DC (mean: 7.04 x 106/kg, range: 1.46-19.67) which was 18.1-fold higher than in non-AML patients mobilized using chemotherapy (CT) regimens plus G-CSF. Clonality of purified lin(neg)CD11c(pos) DC from CT plus G-CSF mobilized AML patients (n = 8 ) was assessed using the human androgen-receptor locus methylation, disclosing a polyclonal pattern in five female patients. These cells displayed morphological and phenotypic features of myeloid DC precursors with expression of HLA-DR, HLA-ABC, CD86, CCR5 and CD54 molecules but lacking CD80, CD83, CD1a and CD40 antigens. Short-term culture with autologous leukaemic cell lysates plus tumour necrosis factor-alpha yielded maturated myeloid DC capable of triggering interleukin-2 and interferon-gamma production by autologous T-lymphocytes. These findings suggest that the use of post-remission CT and G-CSF as mobilizing regimen in AML patients generates PBSC containing high doses of polyclonal myeloid lin(neg)CD11c(pos) DC precursors, which could be used to design feasible immunotherapy protocols.

Patients with high-risk aggressive lymphoma treated with frontline intensive chemotherapy and autografting: evidence of marked differences in outcome between patients with age-adjusted International Prognostic Index scores 2 and 3

BACKGROUND

The goal of the current study was to evaluate the impact of presentation with an age-adjusted International Prognostic Index (aaIPI) score of 2 or 3 on patients with high-risk aggressive lymphoma who are treated with frontline intensive chemotherapy and autografting.

METHODS

Sixty-nine consecutive patients (median age, 40 years) with either B-cell (n = 60) or non-B-cell (n = 9) aggressive lymphoma were treated with high-dose sequential (HDS) chemotherapy and peripheral blood progenitor cell (PBPC) autografting. The patients who were examined had poor prognoses, with aaIPI scores of 2 (n = 37) or 3 (n = 32). The original treatment regimen, sequential delivery of cyclophosphamide, methotrexate, and etoposide, followed by PBPC autografting (o-HDS), was used in the first 32 patients; the program was intensified by the addition of a course of high-dose cytosine arabinoside (C-HDS) in the next 37 patients.

RESULTS

There were 4 toxicity-related deaths-2 in each aaIPI subgroup (treatment-related mortality, 5.8%). The complete remission rate was significantly higher among patients with an aaIPI score of 2 (n = 32 [86%]) compared with those with an aaIPI score of 3 (n = 13 [41%]; P < 0.001). Patients with an aaIPI score of 2 had significantly better outcomes than did patients with an aaIPI score of 3 in terms of both overall survival (78% vs. 34% at 8 years; P < 0.001) and event-free survival (72% vs. 28% at 8 years; P < 0.001). Similar results were observed when the analysis was limited to the 60 patients with B-cell-derived lymphoma. No significant differences in outcome between patients receiving o-HDS and patients receiving C-HDS were observed. Multivariate analysis demonstrated that an aaIPI score of 3 was the only parameter that was significantly associated with poor overall and event-free survival.

CONCLUSIONS

Age-adjusted International Prognostic Index score is applicable to patients with aggressive lymphoma who are treated with frontline intensive chemotherapy and autografting. In addition, upfront use of HDS chemotherapy appears to be beneficial to patients with an aaIPI score of 2 but not to those with an aaIPI score of 3.