Fludarabine as a risk factor for poor stem cell harvest, treatment-related MDS and AML in follicular lymphoma patients after autologous hematopoietic cell transplantation

Impact of Clinical Parameters and Induction Regimens on Peripheral Blood Stem-Cell Mobilization and Collection in Multiple Myeloma Patients

Introduction

High-dose chemotherapy (HDCT) followed by autologous blood stem-cell transplantation (ABSCT) remains the standard consolidation therapy for newly diagnosed eligible multiple myeloma (MM) patients. As a prerequisite, peripheral blood stem cells (PBSCs) must be mobilized and collected by leukapheresis (LP). Many factors can hamper PBSC mobilization/collection. Here, we provide a comprehensive multiparametric assessment of PBSC mobilization/collection outcome parameters in a large cohort.

Methods

In total, 790 MM patients (471 [60%] male, 319 [40%] female) who underwent PBSC mobilization/collection during first-line treatment were included. Evaluated PBSC mobilization/collection outcome parameters included the prolongation of PBSC mobilization, plerixafor administration, number of LP sessions, and overall PBSC collection goal/result.

Results

741 (94%) patients received cyclophosphamide/adriamycin/dexamethasone (CAD) and granulocyte-colony-stimulating factor (G-CSF) mobilization. Plerixafor was administered in 80 (10%) patients. 489 (62%) patients started LP without delay. 530 (67%) patients reached the PBSC collection goal at the first LP session. The mean overall PBSC collection result was 10.3 (standard deviation [SD] 4.4) × 106 CD34+ cells/kg. In a multiparametric analysis, variables negatively associated with PBSC mobilization/collection outcomes were female gender, age >60 years, an advanced ISS stage, and local radiation pre-/during induction, but not remission status postinduction. Notably, the identified risk factors contributed differently to each PBSC mobilization/collection outcome parameter. In this context, compared to all other induction regimens, lenalidomide-based induction with/without antibodies negatively affected only the number of LP sessions required to reach the collection goal, but no other PBSC mobilization/collection outcome parameters. In contrast, the probability of reaching a high collection goal of ≥6 × 106 CD34+ cells/kg body weight was higher after lenalidomide-based induction compared to VCD/PAD or VAD - taking into account - that a higher G-SCF dosage was given in approximately one-third of patients receiving lenalidomide-based induction with/without antibodies.

Conclusion

Considering the identified risk factors in the clinical setting can contribute to optimized PBSC mobilization/collection. Moreover, our study demonstrates the necessity for a differentiated evaluation of PBSC mobilization/collection outcome parameters.

Local Radiation Therapy Before and During Induction Delays Stem Cell Mobilization and Collection in Multiple Myeloma Patients

In multiple myeloma, local radiation therapy (RT) of osseous lesions before peripheral blood stem cell (PBSC) mobilization is assumed to impair the PBSC mobilization and collection. However, the results of previously published studies are inconsistent and do not evaluate detailed metrics of RT and PBSC outcome parameters. In total, 352 patients undergoing PBSC mobilizations and RT in first-line treatment were evaluated. Patients were grouped into RT (n = 283) and no RT (n = 69) before PBSC mobilization. Except for the International Staging System score, both groups were homogeneous regarding the first diagnosis characteristics, first-line treatments, and response parameters. RT metrics (RT yes versus no, volume of irradiated hematopoietic bone marrow [BM], biologically equivalent doses in 2 Gy fractions [EQD2]) were analyzed for the following PBSC outcome parameters: achievement of the PBSC collection goal, CD34+ cell collection yield, duration of the mobilization phase, and number of leukapheresis (LP) sessions to reach the collection goal. No statistically significant differences in the percentage of collection failures to reach at least 3 sufficient PBSC transplants were identified comparing patients with (n = 32 [11%]) and without RT (n = 4 [6%]) before PBSC mobilization (P = .265). However, patients with RT before PBSC mobilization showed a significant prolongation of the PBSC mobilization (median 1 day, P =.026) and required a higher number of LP sessions to reach the collection goal (median 1 LP, P < .001) compared with patients who received RT after PBSC mobilization. Moreover, patients with RT before PBSC mobilization reached a significantly lower CD34+ cell collection result (mean 8.94 versus 9.81 × 10⁶/kg body weight [bw], P = .002). No correlation was identified between the overall CD34+ cell yield and the volume of irradiated hematopoietic BM or EQD2, respectively. In the RT before PBSC mobilization group, patients who required more than 1 LP session to reach the PBSC collection goal after RT had a significantly higher percentage of radiated hematopoietic BM compared to those who required only 1 LP session (mean 9.7% versus 7.2%, P = .002). Overall, our study indicates a negative impact of RT on PBSC mobilization and collection. Apart from emergency settings, it might be beneficial to postpone RT to a post-PBSC collection time point. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Low-dose peripheral blood stem cell graft after high-dose chemotherapy - an evaluation of hematopoietic reconstitution

Background

High-dose (HD) chemotherapy followed by autologous blood stem-cell transplantation (ASCT) is the standard treatment for multiple myeloma (MM) patients. However, the collection of sufficient peripheral blood stem cell (PBSC) grafts can be challenging, and the question arises whether reinfusion of low-dose grafts will lead to a hematopoietic recovery.

Methods

The hematopoietic recovery of 148 MM patients who underwent HD melphalan chemotherapy and received PBSC transplants with varying CD34+ cells doses (3–4 × 10⁶ [n = 86], 2–2.5 × 10⁶ [n = 53], < 2 × 10⁶ [n = 9] per kg body weight [bw]) was analyzed in this retrospective single-center study.

Results

All patients reached hematopoietic reconstitution, even those who received < 2 × 10⁶ CD34+ cells/kg bw. 62 (42%) patients received granulocyte-colony-stimulating factor (G-CSF). The median duration to leukocyte recovery ≥1.0 × 10⁹/L was 12 days in every group. The median duration to platelet recovery ≥20 × 10⁹/L was 11, 13 and 13 days, respectively. In the multivariate analysis, a low number of reinfused CD34+ cells was associated with prolonged time until leukocyte reconstitution (p = 0.010, HR 0.607) and platelet recovery (p < 0.001, HR 0.438). G-CSF support significantly accelerated leukocyte (p < 0.001, HR 16.742) but not platelet reconstitution.

Conclusion

In conclusion, reinfusion of low- and even very-low-dose PBSC grafts leads to sufficient hematopoietic reconstitution. No severe adverse events were observed during or after HD chemotherapy and ASCT in the analyzed cohort. While the impact of CD34+ cell dose is marginal, G-CSF significantly accelerates the leukocyte recovery.

Mobilization and Collection of Peripheral Blood Stem Cells in Adults: Focus on Timing and Benchmarking

Peripheral blood stem cells (PBSCs) are preferentially used as a hematopoietic stem cell source for autologous blood stem cell transplantation (ABSCT) upon high-dose chemotherapy (HDT) in a variety of hemato-oncologic diseases. As a prerequisite, hematopoietic stem cells have to be mobilized into the peripheral blood (PB) and collected by leukapheresis (LP). Despite continuous improvements, e.g., the introduction of plerixafor, current challenges are the further optimization regarding the leukapheresis procedure, preventing collection failures, as well as benchmarking and harmonization of mobilization approaches between institutions.This chapter summarizes the current PBSC mobilization and collection approaches and is focusing on timely orchestration of mobilization therapy, granulocyte colony-stimulating factor (G-CSF) application, and peripheral blood (PB) CD34⁺ cell assessment. Moreover, strategies for prediction and performance assessment of the PBSC collection yield are discussed.

Autologous Transplantation in Follicular Lymphoma with Early Therapy Failure: A National LymphoCare Study and Center for International Blood and Marrow Transplant Research Analysis

Patients with follicular lymphoma (FL) experiencing early therapy failure (ETF) within 2 years of frontline chemoimmunotherapy have poor overall survival (OS). We analyzed data from the Center for International Blood and Marrow Transplant Research (CIBMTR) and the National LymphoCare Study (NLCS) to determine whether autologous hematopoietic cell transplant (autoHCT) can improve outcomes in this high-risk FL subgroup. ETF was defined as failure to achieve at least partial response after frontline chemoimmunotherapy or lymphoma progression within 2 years of frontline chemoimmunotherapy. We identified 2 groups: the non-autoHCT cohort (patients from the NLCS with ETF not undergoing autoHCT) and the autoHCT cohort (CIBMTR patients with ETF undergoing autoHCT). All patients received rituximab-based chemotherapy as frontline treatment; 174 non-autoHCT patients and 175 autoHCT patients were identified and analyzed. There was no difference in 5-year OS between the 2 groups (60% versus 67%, respectively; P = .16). A planned subgroup analysis showed that patients with ETF receiving autoHCT soon after treatment failure (≤1 year of ETF; n = 123) had higher 5-year OS than those without autoHCT (73% versus 60%, P = .05). On multivariate analysis, early use of autoHCT was associated with significantly reduced mortality (hazard ratio, .63; 95% confidence interval, .42 to .94; P = .02). Patients with FL experiencing ETF after frontline chemoimmunotherapy lack optimal therapy. We demonstrate improved OS when receiving autoHCT within 1 year of treatment failure. Results from this unique collaboration between the NLCS and CIBMTR support consideration of early consolidation with autoHCT in select FL patients experiencing ETF.

Long-Term Results of the FOLL05 Trial Comparing R-CVP Versus R-CHOP Versus R-FM for the Initial Treatment of Patients With Advanced-Stage Symptomatic Follicular Lymphoma

Purpose The FOLL05 trial compared R-CVP (rituximab plus cyclophosphamide, vincristine, and prednisone) with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) and R-FM (rituximab plus fludarabine and mitoxantrone) regimens without rituximab maintenance as initial therapy for patients with advanced-stage follicular lymphoma (FL). A previous analysis with a median follow-up of 34 months showed a superior 3-year time to treatment failure, the primary study end point, with R-CHOP and R-FM versus R-CVP and showed R-CHOP to have a better risk-benefit ratio in terms of toxicity than R-FM. We report a post hoc analysis of this trial after a median follow-up of 7 years. Patients and Methods Of the 534 enrolled patients, 504 were evaluable. At the time of analysis, the median follow-up was 84 months (range, 1 to 119 months). Results The 8-year time to treatment failure and progression-free survival rates were 44% (95% CI, 39% to 49%) and 48% (95% CI, 43% to 53%), respectively. The hazard ratio for progression-free survival adjusted by FL International Prognostic Index 2 versus R-CVP was 0.73 for R-CHOP (95% CI, 0.54 to 0.98; P = .037) and 0.67 for R-FM (95% CI, 0.50 to 0.91; P = .009). The 8-year overall survival (OS) rate was 83% (95% CI, 79% to 87%), with no significant differences among study arms. Overall, we observed a higher risk of dying as a result of causes unrelated to lymphoma progression with R-FM versus R-CVP. Conclusion With an 83% 8-year OS rate, long-term follow-up of the FOLL05 trial confirms the favorable outcome of patients with advanced-stage FL treated with immunochemotherapy. The three study arms had similar OS but different activity and toxicity profiles. Patients initially treated with R-CVP had a higher risk of lymphoma progression compared with those receiving R-CHOP, as well as a higher risk of requiring additional therapy.

Peripheral blood stem cell mobilization in multiple myeloma: Growth factors or chemotherapy?

High-dose therapy followed by autologous hematopoietic stem cell (HSC) transplant is considered standard of care for eligible patients with multiple myeloma. The optimal collection strategy should be effective in procuring sufficient HSC while maintaining a low toxicity profile. Currently available mobilization strategies include growth factors alone, growth factors in combination with chemotherapy, or growth factors in combination with chemokine receptor antagonists; however, the optimal strategy has yet to be elucidated. Herein, we review the risks and benefits of each approach.

Therapy-related myeloid neoplasms: when genetics and environment collide

Therapy-related myeloid neoplasms (t-MN) arise as a late effect of chemotherapy and/or radiation administered for a primary condition, typically a malignant disease, solid organ transplant or autoimmune disease. Survival is measured in months, not years, making t-MN one of the most aggressive and lethal cancers. In this Review, we discuss recent developments that reframe our understanding of the genetic and environmental aetiology of t-MN. Emerging data are illuminating who is at highest risk of developing t-MN, why t-MN are chemoresistant and how we may use this information to treat and ultimately prevent this lethal disease.

Single Dose Preemptive Plerixafor for Stem Cell Mobilization for ASCT After Lenalidomide Based Therapy in Multiple Myeloma: Impact in Resource Limited Setting

Peripheral blood stem cell mobilization with cytokines for autologous stem cell transplant in multiple myeloma is adversely affected by initial induction therapy consisting of either Lenalidomide or cytotoxic drugs, with failure rates of up to 45%. The use of Plerixafor with G-CSF for PBSC mobilisation significantly improves the chances of a successful mobilization. Plerixafor is a costly therapy and increases the overall costs of ASCT which can affect the number of patients being taken up for ASCT in resource limited settings. We prospectively studied the impact of single dose preemptive Plerixafor for PBSC mobilization in patients with prior Lenalidomide exposure. 26 patients who had received Lenalidomide based induction protocol underwent PBSC mobilisation during the study period with G-CSF 10 μg/kg/day SC for 4 days and single dose preemptive Plerixafor 240 μg/kg SC stat 11 h before the scheduled PB stem cell harvest on D5, based on a D4 PB CD34+ counts of <20/μL. A median of 07 cycles of Lenalidomide based combination therapy was used for induction therapy prior to ASCT. 84% patients underwent successful mobilization with one sitting of stem cell harvest post a single dose of Inj Plerixafor. 7.6% patients failed to mobilise the predefined minimum cell dose of CD34 and could not be taken up for ASCT. The median CD34% of the harvest bag sample was 0.33% (0.1-0.97%). Injection site erythema (34%), paresthesia's (34%) and nausea (30%) were the commonest adverse events reported post Inj Plerixafor. We did a real-world cost analysis for a resource limited setting for PBSC mobilization and found significant cost savings for the preemptive Plerixafor group.

Patient age and number of apheresis days may predict development of secondary myelodysplastic syndrome and acute myelogenous leukemia after high-dose chemotherapy and autologous stem cell transplantation for lymphoma

BACKGROUND

The goal of our study was to find predictors for the development of secondary myelodysplastic syndrome or acute myelogenous leukemia (s-MDS/AML) in patients with relapsed or refractory lymphoma who received high-dose chemotherapy and autologous stem cell transplantation (ASCT).

STUDY DESIGN AND METHODS

We conducted a retrospective review of 295 patients with relapsed or refractory lymphoma who had undergone their first stem cell collection and ASCT. Patient, disease, and treatment characteristics were collected. The primary goal of this study was to analyze the association between the number of apheresis days needed to collect the requisite stem cell dose in addition to the previously described factors such as age, sex, number and type of prior chemotherapeutic regimens, disease type and status, and the risk of developing s-MDS/AML.

RESULTS

Twenty-two patients of 295 were diagnosed with s-MDS/AML after a median follow-up of 62 months. Multivariate analysis using a classification and regression tree showed that the incidence of s-MDS/AML was lowest in patients who were not more than 55 years old at transplantation and in whom the target cell dose was collected in fewer than two apheresis sessions (5-year cumulative incidence, 1%), whereas incidence was highest in patients who were more than 55 years old at transplantation and who received a transplant more than 21 months after their initial lymphoma diagnosis (5-year cumulative incidence, 20%).

CONCLUSION

Our study defines a subset of relapsed or refractory lymphoma patients who should be closely monitored for development of s-MDS/AML after high-dose chemotherapy and ASCT.

Autologous Stem Cell Mobilization in the Age of Plerixafor

BACKGROUND

Autologous stem cell transplantation remains important in the treatment of myeloma and relapsed lymphoma. Plerixafor has been shown to significantly enhance stem cell mobilization but is very expensive.

PATIENTS AND METHODS

We evaluated plerixafor use in the 3-year period after its approval in December 2008.

RESULTS

A total of 277 patients with myeloma and lymphoma had stem cell mobilization; 97.5% were successfully mobilized, including 41.5% who received plerixafor. Plerixafor was generally used for rescue after suboptimal granulocyte-colony stimulating factor (G-CSF) mobilization ("just in time") or for remobilization after an unsuccessful attempt with chemotherapy plus G-CSF. In addition, 10% of patients received planned G-CSF plus plerixafor because of high risk factors for inadequate collection. Rescue plerixafor was more effective in patients with myeloma than lymphoma as after 1 dose of plerixafor; 85% versus 55% collected a minimum number of stem cells (2 × 10E6 CD34 cells/kg) for 1 transplant and 51% versus 15% collected > 5 × 10E6 CD34 cells/kg. After transplantation, there were no significant differences in engraftment as a consequence of plerixafor use. Among all patients, there were less platelet transfusions in patients provided ≥ 3.5 × 10E6 CD34(+) cells/kg.

CONCLUSION

With the judicious use of plerixafor, nearly all patients can collect enough stem cells to proceed to transplantation. Further studies, including hematologic tolerance to posttransplantation therapy, are required to determine the cost-effectiveness of using plerixafor to convert adequate to more optimal mobilizers.

A phase II study of bendamustine in combination with rituximab as initial treatment for patients with indolent non-follicular non-Hodgkin lymphoma

The purpose of this phase 2 study was to determine the activity and safety of six cycles of bendamustine and eight rituximab (RB) as first-line treatment of adult patients with advanced stage non-follicular indolent non-Hodgkin lymphomas (INFL). The primary end-point was the complete response rate (CRR) with expected CRR of 75%. Sixty-nine patients were enrolled; median age was 65 years (45-75), 65% were male, 93% of patients had stage IV disease. Complete and overall response rates were 48% (95% CI = 35.6-60.2) and 86% (CI = 75.0-92.8). The most common grade 3/4 adverse events were neutropenia (43%), thrombocytopenia (7%) and anemia (4%); whereas the rate of febrile neutropenia was very low (3%). At a median follow-up of 22 months (1-43 months), 2-year progression-free survival was 89% (CI = 79-95) and 2-year overall survival was 96% (CI = 87-99). RB combination is active and well tolerated in patients with advanced stage previously untreated INFL.

Prognostic factors for re-mobilization using plerixafor and granulocyte colony-stimulating factor (G-CSF) in patients with malignant lymphoma or multiple myeloma previously failing mobilization with G-CSF with or without chemotherapy: the Korean multicenter retrospective study

Plerixafor in combination with granulocyte colony-stimulating factor (G-CSF) has been shown to improve the rates of successful peripheral blood stem cell (PBSC) mobilization in patients with malignant lymphoma or multiple myeloma (MM) who experienced prior failure of PBSC mobilization. We evaluated the mobilization results of re-mobilization using plerixafor and G-CSF in insufficiently mobilizing patients. Forty-four patients with lymphoma (n = 29) or MM (n = 15) were included in the study. The median age was 50 (range, 24-64) years. Previous mobilization regimens were chemotherapy with G-CSF (n = 28), including cyclophosphamide with G-CSF (n = 15), and G-CSF only (n = 16). All patients with lymphoma achieved at least partial response (PR) before the mobilization, including 13 complete responses (CRs). Eleven patients with MM achieved at least PR and four patients with MM were in stable disease before mobilization. The median number of apheresis was 3 (range, 1-6). The median yield of PBSC collections was 3.41 (0.13-38.11) × 10(6) CD34(+) cells/kg. Thirty-four (77.3 %) patients had successful collections defined as at least 2 × 10(6) CD34(+) cells/kg. The rate of successful collections was not different between the two underlying diseases (79.3 % in lymphoma and 73.3 % in MM). Of the entire cohort, 38 (86.4 %) of patients went on to receive an autologous transplant. Previous long-term use of high-risk drugs (>4 cycles use of alkylating agents, platinum-containing agents, or thalidomide) (HR 10.8, 95 % CI 1.1-110.0, P = 0.043) and low platelet count (<100 × 10(9)/L) 1 day before the first apheresis (HR 27.9, 95 % CI 2.9-273.7, P = 0.004) were independent prognostic factors for predicting failure of PBSC re-mobilization using plerixafor and G-CSF. In conclusion, re-mobilization using plerixafor and G-CSF showed a success rate of 77.3 % in patients with lymphoma or MM who experienced prior failure of PBSC mobilization, and the majority of them underwent autologous transplant. Therefore, plerixafor-based re-mobilization was an effective method in poor mobilizers.

Peripheral blood stem cell mobilization failure

Autologous hematopoietic stem cell transplantation (HSCT) is an important and often life saving treatment for many hematological malignancies and selected solid tumors. To rescue hematopoiesis after high-dose chemotherapy in autologous HSCT depends on maintaining sufficient stem cells. Hematopoietic stem cells and progenitor cells expressing CD34 in the BM are mobilized into the circulation with granulocyte-colony stimulating factor ± chemotherapy prior to autologous HSCT. One of the most important factors for success of autologous HSCT is hematopoietic stem cell (HSC) count. Minimum threshold for the engraftment of hematopoietic cells is accepted as 2 × 10(6) CD34 + cells/kg especially for platelet engraftment. Below this level it is defined as stem cell mobilization failure. There are several factors affecting stem cell mobilization: prior chemotherapy (such as fludarabine, melphalan, lenalidomide) and radiotherapy, age, type of disease, bone marrow cellularity. We tried to summarize the reasons of peripheral stem cell mobilization failure.

Hematopoietic stem and progenitor cell harvesting: technical advances and clinical utility

Hematopoietic stem and progenitor cell (HSPC) transplantations require prior harvesting of allogeneic or autologous HSPCs. HSPCs are usually present in bone marrow (BM) during the entire life, in cord blood (CB) at birth, or in peripheral blood (PB) under particular circumstances. HSPCs were first harvested in BM and later in CB and PB, as studies showed interesting features of such grafts. All harvesting methods were in use throughout the years, except BM harvesting for HSPC autologous transplantation, which was replaced by PB harvesting. BM, CB, and PB harvesting methods have been developed, and materials and devices technically improved to increase the number of HSPCs harvested. In parallel, knowing the features of the donors or patients associated with successful numbers of HSPCs allows the adaptation of appropriate harvesting methods. Moreover, it is important to ensure the safety of donors or patients while harvesting. This review describes the methods used for harvesting based on recent studies or developments around these methods, and more particularly, the means developed to increase the numbers of HSPCs harvested in each method. It also explains briefly the influence of technical improvements in HSPC harvesting on potential changes in HSPC graft composition.

Current therapeutic strategies and new treatment paradigms for follicular lymphoma

Follicular lymphoma (FL) is an indolent non-Hodgkin's lymphoma that remains an incurable disease for most patients. It is responsive to a variety of different treatments, however it follows a pattern of relapsing and remitting disease. Traditional therapeutic options for patients with untreated FL include expectant observation for asymptomatic and low tumor burden and multiagent cytotoxic chemotherapy for symptomatic and/or high tumor burden. Biologics have become an integral part of therapy with agents that target B lymphocytes, including monoclonal anti-CD20 antibodies and radiolabeled anti-CD20 antibodies. Treatment response to cytotoxic and biologic therapy is high initially; however, with subsequent treatments, response rate and remission duration typically decline and cumulative toxicities increase. The identification of novel targeted agents, use of stem cell transplantation, and new treatment combinations provide the opportunity to enhance patient outcomes. In this review, we critically examine standard treatment strategies for patients with newly diagnosed and relapsed or refractory FL and discuss established and emerging novel therapeutic approaches.

Autologous haematopoietic stem cell mobilisation in multiple myeloma and lymphoma patients: a position statement from the European Group for Blood and Marrow Transplantation

Autologous haematopoietic SCT with PBSCs is regularly used to restore BM function in patients with multiple myeloma or lymphoma after myeloablative chemotherapy. Twenty-eight experts from the European Group for Blood and Marrow Transplantation developed a position statement on the best approaches to mobilising PBSCs and on possibilities of optimising graft yields in patients who mobilise poorly. Choosing the appropriate mobilisation regimen, based on patients' disease stage and condition, and optimising the apheresis protocol can improve mobilisation outcomes. Several factors may influence mobilisation outcomes, including older age, a more advanced disease stage, the type of prior chemotherapy (e.g., fludarabine or melphalan), prior irradiation or a higher number of prior treatment lines. The most robust predictive factor for poor PBSC collection is the CD34(+) cell count in PB before apheresis. Determination of the CD34(+) cell count in PB before apheresis helps to identify patients at risk of poor PBSC collection and allows pre-emptive intervention to rescue mobilisation in these patients. Such a proactive approach might help to overcome deficiencies in stem cell mobilisation and offers a rationale for the use of novel mobilisation agents.

Myeloablative I-131-tositumomab with escalating doses of fludarabine and autologous hematopoietic transplantation for adults age ≥ 60 years with B cell lymphoma

Myeloablative therapy and autologous stem cell transplantation (ASCT) are underutilized in older patients with B cell non-Hodgkin (B-NHL) lymphoma. We hypothesized that myeloablative doses of (131)I-tositumomab could be augmented by concurrent fludarabine, based on preclinical data indicating synergy. Patients were ≥ 60 years of age and had high-risk, relapsed, or refractory B-NHL. Therapeutic infusions of (131)I-tositumomab were derived from individualized organ-specific absorbed dose estimates delivering ≤ 27 Gy to critical organs. Fludarabine was initiated 72 hours later followed by ASCT to define the maximally tolerated dose. Thirty-six patients with a median age of 65 years (range, 60 to 76), 2 (range, 1 to 9) prior regimens, and 33% with chemoresistant disease were treated on this trial. Dose-limiting organs included lung (30), kidney (4), and liver (2) with a median administered (131)I activity of 471 mCi (range, 260 to 1620). Fludarabine was safely escalated to 30 mg/m(2) × 7 days. Engraftment was prompt, there were no early treatment-related deaths, and 2 patients had ≥ grade 4 nonhematologic toxicities. The estimated 3-year overall survival, progression-free survival, and nonrelapse mortality were 54%, 53%, and 7%, respectively (median follow up of 3.9 years). Fludarabine up to 210 mg/m(2) can be safely delivered with myeloablative (131)I-tositumomab and ASCT in older adults with B-NHL.

Therapy-related myeloid neoplasms after autologous hematopoietic stem cell transplantation in lymphoma patients

Lymphoma patients treated with autologous transplantation (ASCT) live an increasingly long life with the recent advancement in therapeutic modalities. This has resulted in an increase in the incidence of therapy-related myeloid neoplasms (t-MN), which is one of the leading causes of non-relapse mortality. Several observational studies have linked the development of t-MN after ASCT with the intensity and frequency of chemotherapy, particularly alkylating agents, use of total body irradiation (TBI), and peripheral blood progenitor cells. In addition, role of genetic factors is increasingly being identified. It is postulated that the use of chemotherapy prior to ASCT results in DNA damage of progenitor cells, mitochondrial dysfunction, and altered gene expression related to DNA repair, metabolism as well as hematopoietic regulation. Cytogenetic studies have shown the presence of abnormalities in the peripheral blood progenitor cells prior to ASCT. It is, therefore, likely that the reinfusion of peripheral blood progenitor cells, proliferative stress on infused progenitor cells during hematopoietic regeneration and associated telomere shortening ultimately result in clonal hematopoiesis and blastic transformation. Cytopenias, myelodysplasia, or cytogenetic abnormalities are common and can be transient after ASCT; therefore, only when present together, they do confirm the diagnosis of t-MN. Attempts to reduce the occurrence of t-MN should be directed toward minimizing the exposure to the identified risk factors. Although the median survival is few months to less than a year, studies have shown the promising role of allogeneic transplantation in select young t-MN patients without high-risk cytogenetics. In this review we will explain the recent findings in the field of t-MN in lymphoma patients that have implications for identifying the molecular and genetic mechanisms of leukemogenesis and discuss potential strategies to reduce the risk of t-MN in this patient population.

Optimizing autologous stem cell mobilization strategies to improve patient outcomes: consensus guidelines and recommendations

Autologous hematopoietic stem cell transplantation (aHSCT) is a well-established treatment for malignancies such as multiple myeloma (MM) and lymphomas. Various changes in the field over the past decade, including the frequent use of tandem aHSCT in MM, the advent of novel therapies for the treatment of MM and lymphoma, and the addition of new stem cell mobilization techniques, have led to the need to reassess current stem cell mobilization strategies. Mobilization failures with traditional strategies are common and result in delays in treatment and increased cost and resource utilization. Recently, plerixafor-containing strategies have been shown to significantly reduce mobilization failure rates, but the ideal method to maximize stem cell yields and minimize costs associated with collection has not yet been determined. A panel of experts convened to discuss the currently available data on autologous hematopoietic stem cell mobilization and transplantation and to devise guidelines to optimize mobilization strategies. Herein is a summary of their discussion and consensus.

Pharmacoeconomics of hematopoietic stem cell mobilization: an overview of current evidence and gaps in the literature

Adequate hematopoietic stem cell (HSC) mobilization and collection is required prior to proceeding with high dose chemotherapy and autologous hematopoietic stem cell transplant. Cytokines such as G-CSF, GM-CSF, and peg-filgrastim, alone or in combination with plerixafor, and after chemotherapy have been used to mobilize HSCs. Studies have shown that the efficiency of HSC mobilization and collection may vary when different methods of mobilization are used. No studies have shown that survival is significantly affected by the method of mobilization, but some studies have suggested that cost and resource utilization may be different between different mobilization techniques. After the FDA approval of plerixafor with G-CSF to mobilize HSCs many transplant centers became concerned about the cost of HSC mobilization. A panel of experts was convened ant this paper reviews the current literature on the pharmacoeconomics of HSC mobilization.

Potential for a pluripotent adult stem cell treatment for acute radiation sickness

Accidental radiation exposure and the threat of deliberate radiation exposure have been in the news and are a public health concern. Experience with acute radiation sickness has been gathered from atomic blast survivors of Hiroshima and Nagasaki and from civilian nuclear accidents as well as experience gained during the development of radiation therapy for cancer. This paper reviews the medical treatment reports relevant to acute radiation sickness among the survivors of atomic weapons at Hiroshima and Nagasaki, among the victims of Chernobyl, and the two cases described so far from the Fukushima Dai-Ichi disaster. The data supporting the use of hematopoietic stem cell transplantation and the new efforts to expand stem cell populations ex vivo for infusion to treat bone marrow failure are reviewed. Hematopoietic stem cells derived from bone marrow or blood have a broad ability to repair and replace radiation induced damaged blood and immune cell production and may promote blood vessel formation and tissue repair. Additionally, a constituent of bone marrow-derived, adult pluripotent stem cells, very small embryonic like stem cells, are highly resistant to ionizing radiation and appear capable of regenerating radiation damaged tissue including skin, gut and lung.

Predictive factors for poor peripheral blood stem cell mobilization and peak CD34(+) cell count to guide pre-emptive or immediate rescue mobilization

BACKGROUND AIMS

Failure in mobilization of peripheral blood (PB) stem cells is a frequent reason for not performing hematopoietic stem cell transplantation (HSCT). Early identification of poor mobilizers could avoid repeated attempts at mobilization, with the administration of pre-emptive rescue mobilization.

METHODS

Data from the first mobilization schedule of 397 patients referred consecutively for autologous HSCT between 2000 and 2010 were collected. Poor mobilization was defined as the collection of < 2 × 10(6) CD34(+)cells/kg body weight (BW).

RESULTS

The median age was 53 years (range 4-70) and 228 (57%) were males. Diagnoses were multiple myeloma in 133 cases, non-Hodgkin's lymphoma in 114, acute myeloid leukemia or myelodysplastic syndrome in 81, Hodgkin's lymphoma in 42, solid tumors in 17 and acute lymphoblastic leukemia in 10. The mobilization regimen consisted of recombinant human granulocyte-colony-stimulating factor (G-CSF) in 346 patients (87%) and chemotherapy followed by G-CSF (C + G-CSF) in 51 (13%). Poor mobilization occurred in 105 patients (29%), without differences according to mobilization schedule. Diagnosis, previous therapy with purine analogs and three or more previous chemotherapy lines were predictive factors for poor mobilization. A CD34(+)cell count in PB > 13.8/μL was enough to ensure ≥ 2 × 10(6) CD34(+)cells/kg, with high sensitivity (90%) and specificity (91%).

CONCLUSIONS

The prevalence of poor mobilization was high, being associated with disease type, therapy with purine analogs and multiple chemotherapy regimens. The threshold of CD34(+) cell count in PB identified poor mobilizers, in whom the administration of immediate or pre-emptive plerixafor could be useful to avoid a second mobilization.