Effect of CD34(+) cell dose on resource utilization in patients after high-dose chemotherapy with peripheral-blood stem-cell support

An evidence-based and risk-adapted GSF versus GSF plus plerixafor mobilization strategy to obtain a sufficient CD34+ cell yield in the harvest for autologous stem cell transplants

BACKGROUND

Plerixafor is a bicyclam molecule with the ability to reversibly bind to receptor CXCR-4 thus leading to an increased release of stem cells (SC) into the circulation. This study aims to evaluate the efficacy of G-CSF plus plerixafor versus G-CSF alone mobilizing regimens on the basis of CD34+ cell yield and engraftment kinetics following hematopoietic SC transplants.

METHODS

The study incorporated 173 patients with plasma cell neoplasms (PCN), Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL), undergoing mobilization and following autologous SC-transplant. For patients with mobilization failure and those predicted to be at risk of harvesting inadequate CD34+ yields (poor-responders), plerixafor was administered. Data was collected and compared in relation to the harvesting protocols used, cell quantification, cell-engraftment potential and overall clinical outcome.

RESULTS

A total of 101 patients received plerixafor (58.4 %) and the median CD34+increase was 312 %. Chemotherapy-mobilized PCN-patients required less plerixafor administration (p = 0.01), no difference was observed in lymphoma groups (p = 0.46). The median CD34+cell yield was 7.8 × 106/kg bm. Patients requiring plerixafor achieved lower, but still comparable cell yields. Total cell dose infused was in correlation with engraftment kinetics. Patients requiring plerixafor had delayed platelet engraftment (p = 0.029).

CONCLUSIONS

Adequately selected plerixafor administration reduces "mobilization-related-failure" rate and assure a high-level cell dose for SC transplants, with superior "therapeutic-potential" and safety profile. The mobilization strategy that incorporates "just-in-time" plerixafor administration, also leads to a reduction of hospitalization days and healthcare resource utilization. For definitive conclusions, further controlled/larger clinical trials concerning correlation of CD34+ cell count/yield, with hematopoietic reconstitution are required.

Effect of Autograft CD34+ Dose on Outcome in Pediatric Patients Undergoing Autologous Hematopoietic Stem Cell Transplant for Central Nervous System Tumors

BACKGROUND

Consolidation with autologous hematopoietic stem cell transplantation (HSCT) has improved survival for patients with central nervous system tumors (CNSTs). The impact of the autologous graft CD34+ dose on patient outcomes is unknown.

OBJECTIVES

To analyze the relationship between CD34⁺ dose, total nucleated cell (TNC) dose, and clinical outcomes, including overall survival (OS), progression free survival (PFS), relapse, non-relapse mortality (NRM), endothelial-injury complications (EIC), and time to neutrophil engraftment in children undergoing autologous HSCT for CNSTs.

STUDY DESIGN

A retrospective analysis of the CIBMTR database was performed. Children aged <10 years who underwent autologous HSCT between 2008-2018 for an indication of CNST were included. An optimal cut point was identified for patient age, CD34⁺ cell dose, and TNC, using the maximum likelihood method and PFS as an endpoint. Univariable analysis for PFS, OS, and relapse was described using the Kaplan-Meier estimator. Cox models were fitted for PFS and OS outcomes. Cause-specific hazards models were fitted for relapse and NRM.

RESULTS

One hundred fifteen patients met the inclusion criteria. A statistically significant association was identified between autograft CD34+ content and clinical outcomes. Children receiving >3.6×10⁶/kg CD34⁺ cells experienced superior PFS (p=0.04) and OS (p=0.04) compared to children receiving ≤3.6×10⁶/kg. Relapse rates were lower in patients receiving >3.6×10⁶/kg CD34⁺ cells (p=0.05). Higher CD34⁺ doses were not associated with increased NRM (p=0.59). Stratification of CD34⁺ dose by quartile did not reveal any statistically significant differences between quartiles for 3-year PFS (p=0.66), OS (p=0.29), risk of relapse (p=0.57), or EIC (p=0.87). There were no significant differences in patient outcomes based on TNC, and those receiving a TNC >4.4×10⁸/kg did not experience superior PFS (p=0.26), superior OS (p=0.14), reduced risk of relapse (p=0.37), or reduced NRM (p=0.25). Children with medulloblastoma had superior PFS (p<0.001), OS (p=0.01), and relapse rates (p=0.001) compared to those with other CNS tumor types. Median time to neutrophil engraftment was 10 days vs 12 days in the highest and lowest infused CD34+ quartiles, respectively.

CONCLUSIONS

For children undergoing autologous HSCT for CNSTs, increasing CD34⁺ cell dose was associated with significantly improved OS and PFS, and lower relapse rates, without increased NRM or EICs.

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.

A Comprehensive Investigation to Reveal the Relationship Between Plasmacytoid Dendritic Cells and Breast Cancer by Multiomics Data Analysis

Plasmacytoid dendritic cells (pDC) are an essential immune microenvironment component. They have been reported for crucial roles in linking the adaptive and immune systems. However, the prognostic role of the pDC in breast cancer (BRCA) was controversial. In this work, we collected large sample cohorts and did a comprehensive investigation to reveal the relationship between pDC and BRCA by multiomics data analysis. Elevated pDC levels were correlated with prolonged survival outcomes in BRCA patients. The distinct mutation landscape and lower burden of somatic copy number alterations (SCNA) and lower intratumoral heterogeneity were observed in the high pDC abundance group. Additionally, a more sensitive immune response and chemotherapies response were observed in the high pDC group, which implicates that patients with high pDC abundance can be benefited from the combination of chemotherapy and immunotherapy. In conclusion, the correlation between pDC abundance and BRCA patients' overall survival (OS) was found to be positive. We identified the molecular profiles of BRCA patients with pDC abundance. Our findings may be beneficial in aiding in the development of immunotherapy and elucidating on the precision treatment for BRCA.

The Karolinska experience of autologous stem-cell transplantation for lymphoma: a population-based study of all 433 patients 1994-2016

Background

Autologous stem-cell transplantation (ASCT) is a common treatment for lymphoma but it has some mortality.

Methods

All 433 lymphoma patients who underwent ASCT for lymphoma at Karolinska Huddinge 1994–2016 were investigated, including CD34⁺ cell amounts, medications, infectious and other complications, intensive care, longitudinal laboratory values, and secondary myeloid neoplasia.

Results

The 100-day non-relapse and overall mortalities were 5.6% and 7.2%. Stem-cell harvests < 5 million CD34⁺ cells/kg correlated with inferior 100-day and long-term survival. Prior to conditioning (93% BEAM), elevated (both 3–9 and ≥ 10 mg/L) C-reactive protein (CRP) and creatinine, and low albumin (but not higher age) predicted inferior higher 100-day survival. Intravenous antibiotics were given to 97% (22% positive blood cultures) and parenteral nutrition to 89%. After 1 year, 86% had normalized hemoglobin. The 5-year risk for secondary myeloid neoplasia was 4.1%, associated with smaller harvests.

Conclusions

Before starting conditioning, patients should have preferably harvested ≥ 5 million CD34⁺ cells/kg and normal CRP, albumin, and creatinine. It appears safe to transplant patients ≥ 66 years.

Electronic supplementary material

The online version of this article (10.1186/s40164-019-0131-3) contains supplementary material, which is available to authorized users.

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.

Impact of a Low CD34+ Cell Dose on Allogeneic Peripheral Blood Stem Cell Transplantation

Although the CD34⁺ cell dose in allogeneic peripheral blood stem cell transplantation (PBSCT) is considered to be associated with transplantation outcomes, a lower acceptable threshold has not been defined. We retrospectively analyzed 2919 adult patients with hematologic malignancies who underwent related PBSCT in Japan between 2001 and 2014. According to the number of CD34⁺ cells in the graft, we categorized 2494 patients in the standard group (2 to 5 × 10⁶ cells/kg), 377 patient in the low group (1 to 2 × 10⁶ cells/kg), and 48 patients in the very low group (<1 × 10⁶ cells/kg). Compared with the standard group, the low and very low groups showed delayed neutrophil recovery (93.8%, 89.5%, and 78.3%, respectively at day +28; P < .001) and platelet recovery (69.3%, 53.0%, and 45.5%, respectively at day +28; P < .001). The 2-year overall survival (OS) in the 3 groups was 45.5%, 45.3%, and 29.8%, respectively, with inferior survival in the very low group. However, a higher percentage of high-risk patients may account for the inferior survival in the very low group, and no significant difference in OS was found in a multivariate analysis. There were no differences in relapse, nonrelapse mortality, or the development of graft-versus-host disease among the 3 groups. In conclusion, allogeneic PBSCT with low CD34⁺ cell doses of 1 to 2 × 10⁶ cells/kg gives acceptable results, whereas further investigations are needed to evaluate the effects of lower doses of <1 × 10⁶ cells/kg owing to the smaller number and the higher percentage of patients with adverse prognostic factors in this cohort.

How do we mobilize and collect autologous peripheral blood stem cells?

Autologous stem cell transplantation (ASCT) with mobilized peripheral blood stem cells (PBSCs) has become a widely applied therapeutic approach for many hematologic and nonhematologic diseases. Adequate PBSC mobilization is critical to the success of ASCT. However, many factors can contribute to poor mobilization. Plerixafor is an effective yet costly adjunct agent that has been increasingly used to improve mobilization in a variety of diagnoses and clinical settings. However, to achieve both optimal cell collection yields and cost-effectiveness, the role of plerixafor in PBSC mobilization needs to be well defined in terms of triggers for initiating its use and criteria for monitoring response. As one of the largest hematopoietic transplant centers in the country, we have developed an approach to PBSC mobilization and collection that incorporates patient laboratory assessments, monitoring of the collection yields, and judicious use of plerixafor as well as various patient support and education programs. These measures have resulted in an increase in our collection success rate and a decrease in the mean number of collection days. In this article we describe our approach to autologous PBSC mobilization and collection. Pertinent reports in the literature are also reviewed and discussed.

Relapse risk after autologous stem cell transplantation in patients with lymphoma based on CD34+ cell dose

It is unclear whether higher CD34 + cell doses infused for ASCT have any influence on survival or relapse in patients with lymphoma. We analyzed the correlation of infused CD34 + cell dose with relapse, survival, and hematopoietic recovery in 146 consecutive patients undergoing ASCT for lymphoma. Higher doses (>5 × 10⁶/kg) were significantly correlated with earlier hematopoietic recovery, fewer infectious episodes, lower transfusion needs. No differences were observed in lymphoma outcomes (4-year relapse incidence of 38% [95%CI: 29%-48%] in the lower dose group versus 51% [95%CI: 30%-69%] in the higher dose group, 10-year OS probabilities of 58% [95%CI: 48%-68%] versus 75% [95%CI: 59%-91%], 10-year DFS probabilities of 47% [95%CI: 37%-57%] versus 42% [95%CI: 23%-61%], p = NS for all outcomes). In this series, a higher infused CD34 + cell dose did not correlate with survival or relapse but correlated with earlier hematopoietic recovery and lower resource consumption.

Optimizing mobilization strategies in difficult-to-mobilize patients: The role of plerixafor

Peripheral blood stem cell collection is currently the most widely used source for hematopoietic autologous transplantation. Several factors such as advanced age, previous chemotherapy, disease and marrow infiltration at the time of mobilization influence the efficacy of CD34(+) progenitor cell mobilization. Despite the safety and efficiency of the standard mobilization protocols (G-CSF ± chemotherapy), there is still a significant amount of mobilization failure rate (10-40%), which necessitate novel agents for effective mobilization. Plerixafor, is a novel agent, has been recently approved for mobilization of hematopoietic stem cells (HSCs). The combination of Plerixafor with G-CSF provides the collection of large numbers of stem cells in fewer apheresis sessions and can salvage those who fail with standard mobilization regimens. The development and optimization of practical algorithms for the use Plerixafor is crucial to make hematopoietic stem cell mobilization more efficient in a cost-effective way. This review is aimed at summarizing how to identify poor mobilizers, and define rational use of Plerixafor for planning mobilization in hard-to-mobilize patients.

A nationwide survey of the use of plerixafor in patients with lymphoid malignancies who mobilize poorly demonstrates the predominant use of the "on-demand" scheme of administration at French autologous hematopoietic stem cell transplant programs

BACKGROUND

High-dose chemotherapy supported with autologous stem cell transplantation is a standard therapeutic option for a subset of patients with lymphoid malignancies. Cell procurement is nowadays done almost exclusively through cytapheresis, after mobilization of hematopoietic stem and progenitor cells (HSPCs) from the marrow to peripheral blood (PB). The egress of HSPCs out of hematopoietic niches occurs in various physiologic or nonhomeostatic situations; pharmacologic approaches include the administration of acutely myelosuppressive agents or hematopoietic growth factors such as recombinant human granulocyte-colony-stimulating factor (rHuG-CSF). The introduction of plerixafor, a first-of-its-class molecule that reversibly inhibits the interaction between the chemokine CXCL-12 (also known as SDF-1) and its receptor CXCR-4, has offered new opportunities for the so-called "poor mobilizers" who achieve insufficient mobilization and/or collection with conventional approaches.

STUDY DESIGN AND METHODS

Because of the lack of consensus on a definition for poor mobilizers and the relatively high cost of plerixafor, French competent authorities have mandated a postmarketing survey on its use in routine practice.

RESULTS AND CONCLUSION

We report here the results of this nationwide survey that confirms the clinical efficacy of plerixafor, even in the subset of patients who barely increased PB CD34+ cell count in response to rHuG-CSF-containing mobilization regimen. Furthermore, analysis of this registry showed that despite heterogeneity in medical practices, the early-"on-demand" or "preemptive"-introduction of plerixafor was widely used and did not result in an excess of prescriptions, beyond its expected use at the time when marketing authorization was granted.

Plerixafor plus pegfilgrastim is a safe, effective mobilization regimen for poor or adequate mobilizers of hematopoietic stem and progenitor cells: a phase I clinical trial

The safety, kinetics and efficacy of plerixafor+pegfilgrastim for hematopoietic stem and progenitor cell (HSPC) mobilization are poorly understood. We treated 12 study patients (SP; lymphoma n=10 or myeloma n=2) with pegfilgrastim (6 mg SC stat D1) and plerixafor (0.24 mg/kg SC nocte from D3). Six SP were 'predicted poor-mobilizers' and six were 'predicted adequate-mobilizers'. Peripheral blood (PB) CD34(+) monitoring commenced on D3. Apheresis commenced on D4. Comparison was with 22 historical controls (HC; lymphoma n=18, myeloma n=4; poor mobilizers n=4), mobilized with pegfilgrastim alone. Eight (67%) SP had PB CD34(+) count ⩽5 × 10(6)/L D3 post pegfilgrastim; all SP surpassed this threshold the morning after plerixafor. In SP, PBCD34(+) counts peaked D4 6/12 (50%), remaining ⩾5 × 10(6)/L for 4 days in 8/12 (67%). All SP successfully yielded target cell numbers (⩾2 × 10(6)/kg) within four aphereses. After maximum four aphereses, median total CD34+ yield was higher in SP than HC; 8.0 (range 2.4-12.9) vs 4.8 (0.4-14.0) × 10(6)/kg (P=0.04). Seven of twelve (58%) SP achieved target yield after one apheresis. Flow cytometry revealed no tumor cells in PB or apheresis product of SP. Plerixafor+pegfilgrastim was well tolerated with bone pain (n=2), diarrhoea (n=2) and facial paraesthesiae (n=3). Plerixafor+pegfilgrastim is a simple, safe and effective HSPC mobilization regimen in myeloma and lymphoma, in both poor and good mobilizers, and is superior to pegfilgrastim alone.

Hematopoietic stem and progenitor cell mobilization in mice

Hematopoietic stem cell transplantation (HSCT) can be performed with hematopoietic stem and progenitor cells (HSPC) acquired directly from bone marrow, from umbilical cord blood or placental tissue, or from the peripheral blood after treatment of the donor with agents that enhance egress of HSPC into the circulation, a process known as "mobilization." Mobilized peripheral blood stem cells (PBSC) have become the predominate hematopoietic graft for HSCT, particularly for autologous transplants. Despite the success of PBSC transplant, many patients and donors do not achieve optimal levels of mobilization. Thus, accurate animal models and basic laboratory investigations are needed to further investigate the mechanisms that lead to PBSC mobilization and define improved or new mobilizing agents and/or strategies to enhance PBSC mobilization and transplant. This chapter outlines assays and techniques for exploration of hematopoietic mobilization using mice as a model organism.

Stem cell mobilization in HIV seropositive patients with lymphoma

High-dose chemotherapy with autologous peripheral blood stem cell rescue has been reported as feasible and effective in HIV-associated lymphoma. Although a sufficient number of stem cells seems achievable in most patients, there are cases of stem cell harvest failure. The aim of this study was to describe the mobilization policies used in HIV-associated lymphoma, evaluate the failure rate and identify factors influencing mobilization results. We analyzed 155 patients who underwent attempted stem cell mobilization at 10 European centers from 2000-2012. One hundred and twenty patients had non-Hodgkin lymphoma and 35 Hodgkin lymphoma; 31% had complete remission, 57% chemosensitive disease, 10% refractory disease, 2% untested relapse. Patients were mobilized with chemotherapy + G-CSF (86%) or G-CSF alone (14%); 73% of patients collected >2 and 48% >5 × 10(6) CD34(+) cells/kg. Low CD4+ count and refractory disease were associated with mobilization failure. Low CD4(+) count, low platelet count and mobilization with G-CSF correlated with lower probability to achieve >5 × 10(6) CD34(+) cells/kg, whereas cyclophosphamide ≥ 3 g/m(2) + G-CSF predicted higher collections. Circulating CD34(+) cells and CD34/WBC ratio were strongly associated with collection result. HIV infection alone should not preclude an attempt to obtain stem cells in candidates for autologous transplant as the results are comparable to the HIV-negative population.

CD34+ stem cell therapy in nonischemic dilated cardiomyopathy patients

Recent trends indicate that patients with nonischemic dilated cardiomyopathy represent the largest subpopulation of heart failure patients with a significant need for alternative treatment modalities. Similar to patients with ischemic cardiomyopathy, patients with nonischemic dilated cardiomyopathy have been found to have myocardial regions with flow abnormalities, which may represent targets for neoangiogenic therapies. CD34(+) stem cells might contribute to the formation of new blood vessels from existing vascular structures in ischemic tissues by the direct incorporation of injected cells into the newly developing vasculature or by the production and secretion of angiogenic cytokines. This review summarizes the long-term clinical effects and potential underlying mechanisms of CD34(+) cell therapy in patients with nonischemic dilated cardiomyopathy.

Cost effectiveness of pegfilgrastim versus filgrastim after high-dose chemotherapy and autologous stem cell transplantation in patients with lymphoma and myeloma: an economic evaluation of the PALM Trial

BACKGROUND

Use of the recombinant human granulocyte colony-stimulating factor (rhG-CSF) filgrastim accelerates neutrophil recovery following myelosuppressive chemotherapy. Since filgrastim requires multiple daily administrations, forms of rhG-CSF with a longer half life, including pegfilgrastim, have been developed. Pegfilgrastim is safe and effective in supporting neutrophil recovery and reducing febrile neutropenia after conventional chemotherapy. Pegfilgrastim has also been successfully used to support patients undergoing peripheral blood stem cell (PBSC) transplantation for haematological malignancies. To our knowledge, no cost-effectiveness analysis (CEA) of pegfilgrastim in this setting has been published yet.

OBJECTIVE

We undertook a CEA to compare a single injection of pegfilgrastim versus repeated administrations of filgrastim in patients who had undergone PBSC transplantation for lymphoma or myeloma. The CEA was set in France and covered a period of 100 ± 10 days from transplant.

METHODS

The CEA was designed as part of an open-label, multicentre, randomized phase II trial. Costs were assessed from the hospital's point of view and are expressed in 2009 euros. Costs computation focused on inpatient, outpatient, and home care. Costs in the two arms of the study were compared using the Mann-Whitney test. When differences were statistically significant, multiple regression analyses were performed in order to identify cost drivers. Incremental cost-effectiveness ratios (ICER) were calculated for the major endpoints of the trial; i.e., duration of febrile neutropenia (absolute neutrophil count [ANC] <0.5 × 10(9)/L and temperature ≥38 °C), duration of neutropenia (ANC <1.0 × 10(9)/L and ANC <0.5 × 10(9)/L), duration of thrombopenia (platelets <50 × 10(9)/L and <20 × 10(9)/L), and days with a temperature ≥38 °C). Uncertainty around the ICER was captured by a probabilistic analysis using a non-parametric bootstrap method.

RESULTS

151 patients were enrolled at ten French centres from October 2008 to September 2009. The mean total cost in the pegfilgrastim arm of the study (n = 74) was <euro>25,024 (SD 9,945). That in the filgrastim arm (n = 76) was <euro>28,700 (SD 20,597). Pegfilgrastim strictly dominated filgrastim for days of febrile neutropenia avoided, days of neutropenia (ANC <1.0 × 10(9)/L) avoided, days of thrombopenia (platelets <20 × 10(9)/L) avoided, and days with temperature ≥38 °C) avoided. Pegfilgrastim was less costly and less effective than filgrastim for the number of days with ANC <0.5 × 10(9)/L avoided and the number of days with platelets <50.0 × 10(9)/L avoided. Taking uncertainty into account, the probabilities that pegfilgrastim strictly dominated filgrastim were 67 % for febrile neutropenia, 86 % for neutropenia (ANC <1.0 × 10(9)/L), 59 % for thrombopenia (platelets <20 × 10(9)/L), 86 % for temperature ≥38 °C, 32 % for neutropenia (ANC <0.5 × 10(9)/L), and 43 % for thrombopenia (platelets <50 × 10(9)/L). Conversely, the probability that filgrastim strictly dominated pegfilgrastim for neutropenia (ANC <0.5 × 10(9)/L) is 5 %.

CONCLUSION

This study found no evidence that the use of pegfilgrastim is associated with greater cost in lymphoma and myeloma patients after high-dose chemotherapy and PBSC transplantation.

Advances in stem cell mobilization

The use of mobilized peripheral blood stem cells (PBSCs) has largely replaced the use of bone marrow as a source of stem cells for both allogeneic and autologous stem cell transplantation. G-CSF with or without chemotherapy is the most commonly used regimen for stem cell mobilization. Some donors or patients, especially the heavily pretreated patients, fail to mobilize the targeted number of stem cells with this regimen. A better understanding of the mechanisms involved in hematopoietic stem cell (HSC) trafficking could lead to the development of newer mobilizing agents and therapeutic approaches. This review will cover the current methods for stem cell mobilization and recent developments in the understanding of the biology of stem cells and the bone marrow microenvironment.

Growth factor plus preemptive ('just-in-time') plerixafor successfully mobilizes hematopoietic stem cells in multiple myeloma patients despite prior lenalidomide exposure

Lenalidomide is associated with suboptimal autologous hematopoietic stem cell (AHSC) mobilization. We hypothesized that growth factor plus preemptive plerixafor is an effective strategy for AHSC mobilization in multiple myeloma (MM) despite prior exposure to lenalidomide. We retrospectively reviewed patient characteristics and mobilization outcomes of 89 consecutive MM patients undergoing first mobilization with filgrastim or pegfilgrastim +/- preemptive plerixafor using a previously validated algorithm based on day 4 peripheral blood CD34+ cell count (PB-CD34+) and mobilization target. Outcomes were analyzed according to the extent of prior exposure to lenalidomide: no prior exposure (group A, n=40), 1- 4 cycles (group B, n=30) and >4 cycles (group C, n=19). Multivariate analysis yielded only age and number of cycles of lenalidomide as negatively associated, and mobilization with pegfilgrastim as positively associated with higher PB-CD34+. Only 45% of patients in group A required plerixafor vs 63% in groups B and 84% in C, P=0.01. A higher proportion of patients in group A (100%) met the mobilization target than in groups B (90%) or C (79%), P=0.008. All patients yielded at least 2 × 10(6) CD34+/kg. Growth factor mobilization with preemptive plerixafor is an adequate upfront mobilization strategy for MM patients regardless of prior exposure to lenalidomide.

Mobilisation strategies for normal and malignant cells

This review evaluates the latest information on the mobilisation of haemopoietic stem cells for transplantation, with the focus on what is the current best practice and how new understanding of the bone marrow stem cell niche provides new insights into optimising mobilisation regimens. The review then looks at the mobilisation of mesenchymal stromal cells, immune cells as well as malignant cells and what clinical implications there are.

How I treat patients who mobilize hematopoietic stem cells poorly

Transplantation with 2-5 × 106 mobilized CD34+cells/kg body weight lowers transplantation costs and mortality. Mobilization is most commonly performed with recombinant human G-CSF with or without chemotherapy, but a proportion of patients/donors fail to mobilize sufficient cells. BM disease, prior treatment, and age are factors influencing mobilization, but genetics also contributes. Mobilization may fail because of the changes affecting the HSC/progenitor cell/BM niche integrity and chemotaxis. Poor mobilization affects patient outcome and increases resource use. Until recently increasing G-CSF dose and adding SCF have been used in poor mobilizers with limited success. However, plerixafor through its rapid direct blockage of the CXCR4/CXCL12 chemotaxis pathway and synergy with G-CSF and chemotherapy has become a new and important agent for mobilization. Its efficacy in upfront and failed mobilizers is well established. To maximize HSC harvest in poor mobilizers the clinician needs to optimize current mobilization protocols and to integrate novel agents such as plerixafor. These include when to mobilize in relation to chemotherapy, how to schedule and perform apheresis, how to identify poor mobilizers, and what are the criteria for preemptive and immediate salvage use of plerixafor.

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.

The effect of CD34 count and clonogenic potential of hematopoietic stem cells on engraftment

In this study we have determined that the number of the CD34 (+) cells in the grafts that were infused to 48 patients who underwent autologous and allogeneic hematopoietic cell transplantation and evaluated the number of colony forming units in vitro. Our aim was to determine whether there is a relation between these cell counts and post transplantation engraftment kinetics. A negative correlation was detected (p<0.05) between the CD34 (+) cell count and all colony forming units. A correlation between the CD34 (+) cell count and the kinetics of engraftment could not be demonstrated. In the autologous group, only a weak negative correlation between the CFU-GEMM and neutrophil engraftment was detected. In the allogeneic group, colony forming units did not determine the engraftment.

Semi-mechanistic model for neutropenia after high dose of chemotherapy in breast cancer patients

PURPOSE

To describe the absolute neutrophil counts (ANC) profile in breast cancer patients receiving high-dose of chemotherapy and peripheral blood stem-cells (PBSC) transplantation.

METHODS

Data from 41 subjects receiving cyclophosphamide, thiotepa and carboplatin were used to develop the ANC model consisting of a drug-sensitive progenitor cell compartment, linked to the peripheral blood compartment, through three transition compartments. PBSC were incorporated into the first transit compartment following a zero-order process, k(in), and the rebound effect was explained by a feedback mechanism. A 'kinetics of drug action' model was used to quantify the HDC effect on the progenitor cells according to a linear function, with a slope (alpha).

RESULTS

The typical of the ANC at baseline (Circ(0)), mean transit time (MTT), feedback parameter (gamma), k(in) and alpha were estimated to be 5,610 x 10(6)/L, 3.25 days, 0.145, 0.954 cell/kg/day and 2.50 h/U, respectively. rHuG-CSF shortens the MTT by 92% and increases the mitotic activity by 120%. Bootstrap analysis, visual predictive check and numerical predictive checks evidenced accurate prediction of the ANC nadir, time to ANC nadir and time to grade 4 neutropenia recovery.

CONCLUSION

The time course of neutropenia following high-dose of chemotherapy and PBSC transplantation was accurately predicted. Higher amount of CD34+ cells in the PBSC transplantation and earlier administration rHuG-CSF were associated with faster haematological recovery.

Paclitaxel and filgrastim for hematopoietic progenitor cell mobilization in patients with hematologic malignancies after failure of a prior mobilization regimen

Paclitaxel and G-CSF have been evaluated for HPC mobilization in breast cancer and found to have tolerable toxicity with a predictable time to initiate leukapheresis. However, this approach has not been reported in patients with hematologic malignancies failing prior mobilization. We report a case-series of 26 adults given paclitaxel and G-CSF for HPC mobilization after failure of an initial mobilization. Patients received paclitaxel 250 mg/m(2) followed by G-CSF 10-16 mcg/kg/day. Compared to the initial regimen, paclitaxel mobilization produced greater CD34+ cell yields (median 1.53 x 10(6) CD34+ cells/kg vs. 0.79 x 10(6) CD34+ cells/kg, p = 0.004). Seventy-six percent of patients initiated leukapheresis on day 8, the remainder on day 9 or 10. Three patients developed febrile neutropenia resulting in one death prior to leukapheresis. Overall, 73% of patients proceeded with autologous HPC transplant. This case-series suggests paclitaxel may be an option for HPC mobilization in patients failing prior regimens.

Prediction of engraftment after autologous peripheral blood progenitor cell transplantation: CD34, colony-forming unit?granulocyte-macrophage, or both?

BACKGROUND

The rate of hematologic recovery after peripheral blood progenitor cell (PBPC) transplantation is influenced by the dose of progenitor cells. Enumeration of cells that express CD34+ on their surface is the most frequently used method to determine progenitor cell dose. In vitro growth of myeloid progenitor cells (colony-forming unit-granulocyte-macrophage [CFU-GM]) requires more time and resources, but may add predictive information.

STUDY DESIGN AND METHODS

A series of 323 patients, who underwent autologous PBPC transplantation for multiple myeloma, malignant lymphoma, or locally advanced breast cancer, were studied for the effect of CD34+ dose and CFU-GM dose on hematologic recovery. Measures for engraftment were days to absolute granulocyte and platelet (PLT) counts to greater than 500 per muL and than 20 x 10(9) per L, respectively, and number of PLT transfusions and red cell units required.

RESULTS

The CD34+ dose had a median of 8.4 x 10(6) per kg, and the CFU-GM dose a median of 84.9 x 10(4) per kg. The CD34+ and CFU-GM doses showed significant correlation (R = 0.63; p < 0.0001) but a wide variation in the ratio of CD34+ and CFU-GM. Both CD34+ and CFU-GM doses had significant correlation with the measures of engraftment, but for all measures the relationship of CD34+ was stronger. Multivariate analysis and subgroup analysis of patients receiving CD34+ doses of less than 5 x 10(6) per kg also did not reveal an independent predictive value for CFU-GM.

CONCLUSION

For prediction of hematologic recovery after autologous PBPC transplantation, determination of CFU-GM dose does not add to the predictive value of the CD34+ dose.

Low doses of GM-CSF (molgramostim) and G-CSF (filgrastim) after cyclophosphamide (4 g/m2) enhance the peripheral blood progenitor cell harvest: results of two randomized studies including 120 patients

The use of a combination of G-CSF and GM-CSF versus G-CSF alone, after cyclophosphamide (4 g/m2) was compared in two randomized phase III studies, including 120 patients. In study A, 60 patients received 5 x 2 microg/kg/day of G-CSF and GM-CSF compared to 5 mug/kg/day of G-CSF. In study B, 60 patients received 2.5 x 2 microg/kg/day G-CSF and GM-CSF compared to G-CSF alone (5 microg/kg/day). With the aim to collect at least 5 x 10(6)/kg CD34 cells in a maximum of three large volume leukapherises (LK), 123 LK were performed in study A, showing a significantly higher number of patients reaching 10 x 10(6)/kg CD34 cells (21/29 in G+GM-CSF arm vs 11/27 in G-CSF arm, P=0.00006). In study B, 109 LK were performed, with similar results (10/27 vs 15/26, P=0.003). In both the study, the total harvest of CD34 cells/kg was twofold higher in G-CSF plus GM-CSF group (18.3 x 10(6) in study A and 15.85 x 10(6) in study B) than in G-CSF group (9 x 10(6) in study A and 8.1 x 10(6) in study B), a significant difference only seen in multiple myeloma, with no significant difference in terms of mobilized myeloma cells between G-CSF and GM-CSF groups.

Implementation of peripheral blood CD34 analyses to initiate leukapheresis: marked reduction in resource utilization

BACKGROUND

Analysis of the peripheral blood (PB) C34 value may determine the optimal time to initiate leukapheresis.

STUDY DESIGN AND METHODS

After selecting a threshold PB CD34 value of five CD34 + cells per microL to initiate leukapheresis procedure, a prospective analysis of 50 consecutive patients was initiated to identify the optimal time to initiate leukapheresis and its impact on costs and resource utilization. Clinical decisions were made to commence or to postpone leukapheresis with this PB CD34 threshold number. Based on PB CD34 values for each patient, the number of leukapheresis procedures, postponed or canceled, the number of CD34+ cells per kg, and the total number of cells collected were identified. Costs of mobilization were obtained from the hospital cost accounting system.

RESULTS

In 13 months, 50 patients with a hematologic disorder underwent mobilization. There were 34 cancellations or postponements of collections due to a low PB CD34 value in 13 patients. By use of our identified costs per initial collection, this resulted in a savings of 67,660 US dollars.

CONCLUSIONS

This prospective study defines how the implementation of the PB CD34 value results in costs savings. A low PB CD34 value canceled or postponed a significant number of leukapheresis procedures, resulting in a substantial cost savings. Use of the PB CD34 value should be the standard of care during mobilization and peripheral blood progenitor cell collection.

Role of CXCR4 chemokine receptor blockade using AMD3100 for mobilization of autologous hematopoietic progenitor cells

G-CSF mobilization of hematopoietic progenitor cells (HPCs) is mediated through enzyme release from maturing myeloid cells, leading to digestion of adhesion molecules, trophic chemokines and their receptors, and the extracellular matrix. HPCs traffic to and are retained in the marrow through the trophic effects of the chemokine SDF-1alpha/CXCL12 binding to its receptor, CXCR4. AMD3100 reversibly inhibits SDF-1alpha/CXCR4 binding, and AMD3100 administration mobilizes CD34+ cells into the circulation. AMD3100 has been tested in several clinical trials which demonstrate that it improves the number of CD34+ cells mobilized including patients failing to mobilize with G-CSF alone. Engraftment of AMD3100-mobilized cells is prompt and durable. Toxicities are mild and infrequent. Lymphoma and myeloma cells do not appear to be mobilized. AMD3100 appears to be a promising agent for HPC mobilization.

Cost of autologous peripheral blood stem cell transplantation: the Norwegian experience from a multicenter cost study

High-dose therapy with autologous blood progenitor cell support is now routinely used for patients with certain malignant lymphomas and multiple myeloma. We performed a prospective cost analysis of the mobilization, harvesting and cryopreservation phases and the high-dose therapy with stem cell reinfusion and hospitalization phases. In total, 40 consecutive patients were studied at four different university hospitals between 1999 and 2001. Data on direct costs were obtained on a daily basis. Data on indirect costs were allocated to the specific patient based on estimates of relevant department costs (ie the service department's costs), and by means of predefined allocation keys. All cost data were calculated at 2001 prices. The mean total costs for the two phases were US$ 32,160 (range US$ 19,092-50,550). The mean total length of hospital stay for two phases was 31 days (range 27-37). A large part of the actual cost in the harvest phase was attributed to stem cell mobilization, including growth factors, harvesting and cryopreservation. In the high-dose chemotherapy phase, the most significant part of the costs was nursing staff. Average total costs were considerably higher than actual DRG-based reimbursement from the government, indicating that the treatment of these patients was heavily subsidized by the basic hospital grants.

Economic assessment in the management of non-Hodgkin’s lymphoma

An increasing need for economic evaluations of non-Hodgkin's lymphoma (NHL) treatments exists. We performed a literature review on the currently available NHL economic evaluations, using PubMed and the Cochrane database. English and Dutch language papers on treatment in adults were selected. A total of 88 publications were found, 44 of which were included. Of these, 6 economic evaluation-specific methodological items are evaluated (study perspective, overhead costs, data sources, charges or prices, sensitivity analysis, presentations of resource use and unit costs), enabling readers to judge the value of these studies. The 11 subjects covered by the economic evaluations are discussed. Many NHL treatments remain to be studied in economic evaluations. Future publications should report on the six methodological items in more detail, and preferably tackle them in the recommended way.

Aggressive non-Hodgkin's lymphoma: economics of high-dose therapy

High-intermediate grade non-Hodgkin's lymphoma (NHL) is an aggressive form of the disease, which can respond well to combination chemotherapy, with long-term survival seen in 40-50% of patients. When NHL relapses following standard treatment, high-dose chemotherapy with peripheral blood stem cell or bone marrow support may still cure a significant proportion of patients. Despite a significant rise in the incidence of NHL over recent years, there remains only limited published economic study concerning the overall lifetime cost of treatment, the cost effectiveness of specific treatments or the overall societal cost burden of the disease. The majority of studies identified for the purposes of this review considered the cost of alternative forms of chemotherapy and bone marrow support strategies for patients with advanced disease. Data from these studies suggest that there is a definite trend towards reduced costs for high-dose therapy, possibly reflecting increasing technical experience and improved bone marrow recovery through the use of stem cell transplantation and growth factors. The limited number of cost-effectiveness evaluations suggest that high-dose therapy, following a chemosensitive relapse, is likely to be considered favourable against commonly quoted cost-effectiveness thresholds. Cost effectiveness is becoming an increasingly important factor to consider in the formal assessment of new interventions conducted by groups such as the UK National Institute for Clinical Excellence. In light of the increasing incidence of NHL and the extended use of high-dose treatments in other subgroups of patients, there is a need for increased research into the economics of new interventions for NHL.

Using point-of-care CD34 enumeration to optimize PBSC collection conditions

BACKGROUND

A PBSC graft containing 4-5 x 10(6) CD34(+) cells/kg is considered optimal in terms of durable engraftment. Tracking CD34 kinetics via point-of-care testing during PBSC mobilization could determine which (and when) patients will yield an optimal product. We evaluated whether microvolume fluorimetry (MVF) would be useful in optimizing PBSC mobilization/harvest and if it will shorten our standard 6 h collection.

METHODS

Absolute CD34 values were obtained using the IMAGN 2000 and STELLer CD34 assay (50 microL sample volume). Peripheral blood (PB) CD34 values from 30 patients undergoing PBSC mobilization were used to generate a PB CD34-based algorithm that would predict collection day/duration of apheresis. The algorithm was then used prospectively to collect PBSC products on 50 hematologic malignancy (HM) patients.

RESULTS

Using the algorithm, patients were assigned to either a 6 (11-20 CD34/microL), 4 (21-49 CD34/microL) or 2 (> or = 50 CD34/microL) h collection. Patients with a CD34 value < or = 10/microL were re-tested. All patients (n = 43) predicted to mobilize reached the optimal CD34 (4-5 x 10(6)/kg) value with 1.0 apheresis procedure; seven patients had < or = 10/microL (nonmobilizers). The majority (75%) had apheresis charges decreased by 33-66%; 47% only required a 2 h procedure and 28% required 4 h. All patients demonstrated rapid trilineage engraftment.

DISCUSSION

Absolute PB CD34 measurement using MVF offers a rapid and reliable approach to obtaining optimal PBSC products with minimal technical expertise. Although not a replacement for conventional flow cytometry, it meets the requirements for a point-of-care procedure.

Phase III randomized study comparing 5 or 10 microg per kg per day of filgrastim for mobilization of peripheral blood progenitor cells with chemotherapy, followed by intensification and autologous transplantation in patients with nonmyeloid malignancies

BACKGROUND

It is not known whether increasing the dose of filgrastim after mobilizing chemotherapy improves collection of peripheral blood progenitor cells (PBPC) and leads to faster hematopoietic engraftment after autologous transplantation.

STUDY DESIGN AND METHODS

A randomized, open-label, multicenter trial was carried out in patients with breast cancer, multiple myeloma, and lymphoma, in which patients were randomized to receive 5 or 10 microg per kg per day of filgrastim after standard chemotherapy to mobilize PBPCs. After high-dose chemotherapy, the components from the first two leukapheresis procedures were returned, and all patients received 5 microg per kg day of filgrastim after transplantation.

RESULTS

A total of 131 patients were randomized, of whom 128 were mobilized (Group A, 5 microg/kg, n = 66; Group B, 10 microg/kg, n = 62) and 112 were transplanted. Only six patients were not transplanted because of insufficient CD34+ cell numbers. The median number of CD34+ cells collected in the first two leukapheresis procedures tended to be higher in Group B than in Group A (12.0 vs. 7.2 x 10(6)/kg, NS), but after transplantation there was no significant difference in median times to platelet (9 days in both groups) or neutrophil (8 days in both groups) engraftment or the number of platelet transfusions (three in both groups). A subsequent subgroup analysis separating patients transplanted after first- or second-line chemotherapy also showed no measurable impact of filgrastim dose on the median CD34+ cell yield or on platelet engraftment in either subgroup.

CONCLUSION

PBPC mobilization with chemotherapy and 5 microg per kg of filgrastim is very efficient, and 10 microg per kg of filgrastim does not provide additional clinical benefit.

High percentage of CD34-positive cells in autologous AML peripheral blood stem cell products reflects inadequate in vivo purging and low chemotherapeutic toxicity in a subgroup of patients with poor clinical outcome

In this study, a high CD34% in autologous peripheral blood stem cell (PBSC) products from 71 AML patients was associated directly with a high relapse rate (P = 0.006) and inversely with disease-free survival (P = 0.003), irrespective whether patients were transplanted or not. The relapse rate at 12 months was 67% in a group with >0.8% CD34+ cells and 34% in a group with < or = 0.8% CD34+ cells. Although the percentage of malignant CD34+ cells in the CD34+ compartment in the relapses of the first group was not high (median 8%), the total number of malignant cells as a percentage of WBC was about 13 times higher than for the patients remaining >12 months in remission. When all patients evaluable were taken together, this frequency of malignant cells correlated strongly with disease-free survival (P < 0.001). Both this massive mobilization of normal CD34+ cells and high frequency of malignant cells in the subgroup of patients with CD34 >0.8% and relapse within 12 months indicate an insufficient in vivo purging, as well as low chemotherapeutic bone marrow toxicity. This was confirmed by an inverse correlation between hypoplasia period after the induction therapy and CD34% in PBSC products (P < 0.002). It is concluded that a subgroup of patients has been identified that might benefit from a more intensive chemotherapeutic treatment.

Optimising parameters for peripheral blood leukapheresis after r-metHuG-CSF (filgrastim) and r-metHuSCF (ancestim) in patients with multiple myeloma: a temporal analysis of CD34(+) absolute counts and subsets

Patients (n = 69) with multiple myeloma undergoing peripheral blood stem cell collection (PBSC) were treated with cyclophosphamide and a combination of recombinant methionyl human granulocyte colony-stimulating factor (r-metHuG-CSF, filgrastim) and recombinant methionyl human stem cell factor (r-metHuSCF, ancestim). The objectives of this study were to determine: (1) The proportion of patients reaching a target yield of >or=5 x 10(6) CD34(+) cells/kg in one or two successive large-volume (20 liter) leukapheresis procedures; (2) the optimal collection time for leukapheresis; (3) mobilization kinetics of CD34(+) subsets in response to G-CSF/SCF. All patients were mobilized with cyclophosphamide (2.5 g/m(2)) on day 0 followed by filgrastim (10 microg/kg ) plus ancestim (20 microg/kg) commencing day 1 and continuing to day 11 or 12. Of the 65 evaluable patients, 57 were considered not heavily pretreated and 96.5% obtained a target of >or=5 x 10(6)/kg in one collection. The median CD34(+) cells/kg was 39.5 x 10(6) (range: 5.2-221.2 x 10(6)). Subset analysis demonstrated the number of CD38(-), CD33(-), and CD133(+) peaked at day 11; and CD34(+), CD90(+) cells peaked at day 10. The optimum day for leukapheresis was determined to be day 11. The median absolute peripheral blood CD34(+) cell numbers on day 11 was 665 x 10(6)/l (range: 76-1481 x 10(6)/l). Eight of the 10 heavily pretreated patients were evaluable: three achieved the target dose in one leukapheresis (37.5%) and three (37.5%) achieved the target dose with two leukaphereses. Use of this mobilization strategy allowed the collection of high numbers of CD34(+) cells and early progenitors and the ability to predictably schedule leukapheresis.

High CD34 cell doses do not worsen regimen-related toxicity or early mortality after autologous blood stem cell transplantation for breast cancer

BACKGROUND

Some transplant-related complications, such as the engraftment syndrome, are thought to be mediated by cytokines released during expansion of hematopoietic progenitors at the time of neutrophil recovery. Since there is an inverse correlation between CD34(+) cell dose and time to neutrophil recovery, we sought to determine if peritransplant toxicity and early mortality were adversely affected by high CD34(+) cell doses.

METHODS

The study group included 186 women with breast cancer who received high-dose cyclophosphamide, carmustine, thiotepa and an autologous PBSC transplant. The median CD34(+) cell dose was 5.9 x 10(6)/kg (1.0-154.7 x 10(6)/kg). Patients were categorized by CD34(+) cell dose (1.0-3.5, 3.6-5.9, 6.0-19.9, and 20.0-154.7 x 10(6)/kg) for assessment of outcomes.

RESULTS

Grades 2-4 mucositis occurred in 49%, cardiac toxicity in 7%, pulmonary toxicity in 5%, cystitis in 4%, diarrhea in 3%, renal toxicity in 1%, and central nervous system toxicity in 1%. A Grade 2-4 regimen-related toxicity occurred in 109 patients (59%) and Grade 3-4 in eight patients (4%). Overall survival was 100% at Day 30, 96% at Day 90, and 89% at 1 year. Treatment-related mortality was 3.8%. In multivariate analyses that included prior chemotherapy, disease status, visceral metastases, prior chest radiation and age, CD34(+) cell dose group was not an independent risk factor for Grade 2-4 mucositis, Grade 2-4 maximum toxicity, Grade > or =3 cumulative toxicity, 90 day survival or 1 year survival.

DISCUSSION

We conclude that CD34(+) cell doses >20 x 10(6)/kg do not affect transplant outcome in a negative or positive fashion.

Impact of mobilized blood progenitor cell quality determined by the CFU-GM/CD34+ ratio on rapid engraftment after blood stem cell transplantation

To find a parameter to predict the quality of collected mobilized CD34+ blood as hemopoietic reconstituting cells, the ratio of CFU-GM to CD34+ cells was examined. One hundred six consecutive patients who underwent blood stem cell transplantation at the University of Rochester from 01/01/99 to 12/31/99 were examined retrospectively for the number of days to reach an absolute neutrophil count of 500 or 1000 cells/microl and an absolute platelet count of 20,000 or 50,000 cells/microl without transfusion support as measures of engraftment. Linear regression analyses were conducted to determine factors influencing engraftment. The number of CD34+ cells/kg and CFU-GM/kg correlated highly with the number of nucleated blood cells/kg. In this population, in which 90% of patients received >2 x 10(6) CD34+ cells/kg, neither the number of CD34+ cells/kg nor the number of CFU-GM/kg correlated with the time to engraftment as judged by neutrophil or platelet levels. In contrast, the lower the ratio of CFU-GM to CD34+ cells, the more rapid the reconstitution of platelets to 20,000/microl (P = 0.03) and 50,000/microl (P = 0.02). Thus, a lower ratio of the CFU-GM/CD34+ appended to reflect a greater number of hematopoietic reconstituting cells in the blood cell collection. The CFU-GM/CD34+ ratio is an apparent predictor of earlier platelet engraftment, suggesting that the ratio reflects the engraftment potential of mobilized donor progenitor cells.

Association of CD34 cell dose with hematopoietic recovery, infections, and other outcomes after HLA-identical sibling bone marrow transplantation

Although CD34 cell dose is known to influence outcome of peripheral stem cell- and/or T-cell-depleted transplantation, such data on unmanipulated marrow transplantation are scarce. To study the influence of CD34(+) cell dose on hematopoietic reconstitution and incidence of infections after bone marrow transplantation, we retrospectively analyzed 212 patients from January 1994 to August 1999 who received a transplant of an unmanipulated graft from an HLA-identical sibling donor. Median age was 31 years; 176 patients had hematologic malignancies. Acute graft-versus-host disease prophylaxis consisted mainly in cyclosporin associated with methotrexate (n = 174). Median number of bone marrow nucleated cells and CD34(+) cells infused were 2.4 x 10(8)/kg and 3.7 x 10(6)/kg, respectively. A CD34(+) cell dose of 3 x 10(6)/kg or more significantly influenced neutrophil (hazard ratio [HR] = 1.37, P =.04), monocyte (HR = 1.47, P =.02), lymphocyte (HR = 1.70, P =.003), erythrocyte (HR = 1.77, P =.0002), and platelet (HR = 1.98, P =.00008) recoveries. CD34(+) cell dose also influenced the incidence of secondary neutropenia (HR = 0.60, P =.05). Bacterial and viral infections were not influenced by CD34 cell dose, whereas it influenced the incidence of fungal infections (HR = 0.41, P =.008). Estimated 180-day transplantation-related mortality (TRM) and 5-year survival were 25% and 56%, respectively, and both were highly affected by CD34(+) cell dose (HR = 0.55, P =.006 and HR = 0.54, P =.03, respectively). Five-year survival and 180-day TRM were, respectively, 64% and 19% for patients receiving a CD34(+) cell dose of 3 x 10(6)/kg or more and 40% and 37% for the remainders. In conclusion a CD34(+) cell dose of 3 x 10(6)/kg or more improved all hematopoietic recoveries, decreased the incidence of fungal infections and TRM, and improved overall survival.

Mobilization of peripheral blood stem cells with paclitaxel and rhG-CSF in high-risk breast cancer patients

Preclinical studies have demonstrated the rapid and efficient mobilization of hematopoietic peripheral blood stem cells (PBSC) in a mouse model using the combination of paclitaxel with recombinant human granulocyte colony-stimulating factor (rhG-CSF). On the basis of these results, a clinical trial was initiated using rhG-CSF with paclitaxel for PBSC mobilization in high-risk breast cancer patients. The mobilized PBSC were evaluated for CD34(+) cell number, mononuclear cell content, and clonogenic potential. One-hundred and seventeen breast cancer patients received paclitaxel (300 mg/m(2)) administered as a 24-h continuous intravenous infusion. Forty-eight hours after completing paclitaxel, rhG-CSF (5 microg/kg) was initiated and continued until completion of PBSC collection. Leukapheresis was initiated once the white blood cell count reached 1.0 x 10(9)/L. Each collection was evaluated for the numbers of mononuclear cells (MNC) and CD34(+) cells. Clonogenic potential was enumerated using colony-forming units-granulocyte-macrophage (CFU-GM) and burst-forming units-erythroid (BFU-E). Patients receiving paclitaxel with rhG-CSF mobilized a large number of mononuclear cells/apheresis (mean, 3.7 x 10(8); range, 3.3-4.1) and CD34(+) cells/apheresis (mean, 7.2 x 10(6); range, 6.1-8.4). The average number of leukophereses needed was 1.8 (mean, range 1.6-2.0). Colony growth was normal with 178.9 x 10(5) and 214.8 x 10(5) colonies counted in CFU-GM and BFU-E assays, respectively. Patients engrafted platelets and neutrophils on day 10 following transplantation. In conclusion, PBSC mobilization with paclitaxel and rhG-CSF results in a large number of mononuclear cells and CD34(+) cells with normal clonogenic potential. The cells engraft normally following high-dose chemotherapy and autologous stem cell transplantation in high-risk breast cancer patients. These results demonstrate that paclitaxel with rhG-CSF is an efficient mobilizing agent in high-risk breast cancer patients.

High-dose CD34+ cells are not clinically relevant in reducing cytopenia and blood component consumption following myeloablative therapy and peripheral blood progenitor cell transplantation as compared with standard dose

BACKGROUND

No agreement exists about the number of autologous peripheral blood progenitor cells (PBPCs) to transfuse for optimal hematologic recovery after high-dose chemotherapy.

STUDY DESIGN AND METHODS

To determine CD34+ cell dosage following high-dose chemotherapy (in terms of hematologic recovery and blood component consumption), the effects of two schedules of CD34+ cell transfusions in a cohort of patients with myeloma or non-Hodgkin's lymphoma were examined. Forty patients (Group 1) received between 2.5 and 5 x 106 CD34+ cells per kg, with a median of 3.4 x 106 per kg following high-dose chemotherapy, and 40 patients (Group 2), selected to match Group 1 for age, diagnosis, prior therapies, and procedure for PBPC mobilization, received a dose of CD34+ cells >5 x 106 per kg, with a median of 8.4 x 106 per kg (5-33).

RESULTS

The median number of days to achieve a neutrophil count of >0.5 x 109 per L and unsupported platelets of >20 x 109 per L was identical for the two groups, but the time required to reach 1.5 x 109 neutrophils per L and 50 x 109 platelets per L was greatly delayed in Group 1. No significant difference was observed for the median number of RBC and platelet transfusions, or for the proportion of patients in each group that did not require either platelet or RBC transfusions.

CONCLUSION

Our data confirm a dose-response relationship between CD34+ cell dose transfused and time to hematologic recovery after high-dose chemotherapy. However, the minimal Hb and platelet counts for transfusion independence in the two groups are similar when the CD34+ cell dose is greater than 5 x 106 CD34+ cells per kg. Therefore, our data suggest that it is not necessary to go on with apheresis procedures after 5 x 106 CD34+ cells per kg are harvested to sustain one high-dose chemotherapy.

Long-term engraftment stability of peripheral blood stem cells cryopreserved using the dump-freezing method in a -80 degrees C mechanical freezer with 10% dimethyl sulfoxide

In this study, we summarize our long-term follow-up data of 24 patients who underwent autologous peripheral blood stem cell transplantation (PBSCT) using the dump-freezing method in a -80 degrees C freezer. Collected peripheral blood mononuclear cells were mixed with a cryoprotectant solution consisting of autologous plasma and 20% dimethyl sulfoxide, then placed in a -80 degrees C freezer. The recovery rate of mononuclear cells (MNCs), colony-forming unit-granulocyte/macrophage (CFU-GM) colonies, and CD34+ cells were calculated. Engraftment time (with neutrophil count > 0.5 x 10(9)/L, platelet count > 50 x 10(9)/L) and normal hemopoiesis (neutrophil count > 2 x 10(9)/L, platelet count > 100 x 10(9)/L) were evaluated. Median duration of cryopreservation was 76 days. The mean recovery rates of MNCs, CFU-GM colonies, and CD34+ cells were 93.4%, 78.4%, and 95.3%, respectively. The median engraftment times of neutrophils and platelets were 8 and 27 days, respectively. The median normal hemopoiesis times of neutrophil and platelet were 31 and 45 days, respectively. Nine patients are alive and in complete remission (CR). Seven patients in first CR sustained normal hemopoiesis with a median duration of 35 months. Two patients, who achieved second CR after salvage chemotherapy due to a leukemia relapse after PBSCT, maintained engraftment status for 24 and 28 months, and 1 reached normal hemopoiesis. These results demonstrate that PBSCT using the dump-freezing method in a -80 degrees C freezer leads to acceptable long-term engraftment stability.

Mobilization of peripheral blood stem cells following myelosuppressive chemotherapy: a randomized comparison of filgrastim, sargramostim, or sequential sargramostim and filgrastim

Myelosuppressive chemotherapy is frequently used for mobilization of autologous CD34(+) progenitor cells into the peripheral blood for subsequent collection and support of high-dose chemotherapy. The administration of myelosuppressive chemotherapy is typically followed by a myeloid growth factor and is associated with variable CD34 cell yields and morbidity. The two most commonly used myeloid growth factors for facilitation of CD34 cell harvests are granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF). We performed a randomized phase III clinical trial comparing G-CSF, GM-CSF, and sequential administration of GM-CSF and G-CSF following administration of myelosuppressive chemotherapy. We evaluated CD34 yields, morbidity, and cost-effectiveness of the three cytokine schedules. One hundred and fifty-six patients with multiple myeloma, breast cancer, or lymphoma received cyclophosphamide with either paclitaxel or etoposide and were randomized to receive G-CSF 6 microg/kg/day s.c., GM-CSF 250 microg/m(2)/day s.c., or GM-CSF for 6 days followed by G-CSF until completion of the stem cell harvest. Compared with patients who received GM-CSF, patients who received G-CSF had faster recovery of absolute neutrophil count to 0.5 x 10(9) per liter (median of 11 vs14 days, P = 0.0001) with fewer patients requiring red blood cell transfusions (P= 0.008); fewer patients with fever (18% vs 52%, P = 0.001); fewer hospital admissions (20% vs 42%, P = 0.13); and less intravenous antibiotic therapy (24% vs 59%, P = 0.001). Patients who received G-CSF also yielded more CD34 cells (median 7.1 vs 2.0 x 10(6) kg per apheresis, P = 0.0001) and a higher percentage achieved 2.5 x 10(6) CD34 cells per kilogram (94% vs 78%, P = 0.21) and 5 x 10(6) CD34 cells per kilogram (88% vs 53%, P = 0.01) or more CD34 cells per kilogram with fewer aphereses (median 2 vs 3, P = 0.002) and fewer days of growth factor treatment (median 12 vs 14, P = 0.0001). There were no significant differences in outcomes between groups receiving G-CSF alone and the sequential regimen. After high-dose chemotherapy, patients who had peripheral blood stem cells mobilized with G-CSF or the sequential regimen received higher numbers of CD34 cells and had faster platelet recovery with fewer patients requiring platelet transfusions than patients receiving peripheral blood stem cells mobilized by GM-CSF. In summary, G-CSF alone is superior to GM-CSF alone for the mobilization of CD34(+) cells and reduction of toxicities following myelosuppressive chemotherapy. An economic analysis evaluating the cost-effectiveness of these three effective schedules is ongoing at the time of this writing.