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

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

Background

Autologous stem cell transplantation (ASCT) is a potentially curative strategy for relapse or refractory(r/r) aggressive lymphoma. However, a proportion of lymphoma patients who are at high risk of mobilization failure fail to mobilize stem cells and cannot proceed to ASCT. The aim of this study is to explore the efficacy and safety of Etoposide combined with Cytarabine (EA) plus G-CSF mobilization in poor mobilizers (PMs) with r/r aggressive lymphoma.

Methods

This retrospective study analyzed the outcomes of chemo-mobilization based on EA (Etoposide 0.1 g/m2, qd d1~3; AraC 0.5 g/m2, q12h d1~3) in 98 patients with r/r aggressive lymphoma. Of these, 39 patients met the criteria for predicted PMs as proposed by the Gruppo Italiano Trapianto di Midollo Osseo working group.

Results

Of the 39 PMs, 38(97.4%) patents harvested adequate mobilization (≥2×106 CD34+ cells/kg), while 31(79.5%) patients achieved optimal mobilization (≥5×106 CD34+ cells/kg). Overall, the mean number of CD34+ cells/kg collected was 17.99(range: 1.08~83.07) ×106 with an average of 1.4 apheresis sessions, and the number was 15.86(range: 0.37~83.07) ×106 for the first apheresis, respectively. A single apheresis procedure was sufficient to reach the target yield of adequate mobilization in 35(89.7%) PMs, while 76.9% of PMs achieved optimal collection within two apheresis sessions. We observed acceptable hematological toxicity and antibiotic usage exposure in 26 patients with a mean duration of 3.6 days. No grade 4 infection or mobilization-related mortality was recorded. Most patients underwent ASCT and achieved successful hematopoietic recovery with prompt engraftment duration, except for one NK/T-cell lymphoma patient who succumbed to severe septicemia after receiving conditioning chemotherapy.

Conclusion

Our findings indicate that EA plus G-CSF is an effective and tolerable CD34+ stem cell mobilization strategy for patients with r/r lymphoma, including those predicted to be PMs. This regimen could be an option for patients with r/r lymphoma, particularly those undergoing mobilization for salvage ASCT therapy.

Outcomes of patients after mobilization failure of hematopoietic stem cells for autologous stem cell transplantation

INTRODUCTION

Autologous hematopoietic stem cell transplantation (ASCT) is the long-term consolidation treatment for various hematological malignancies. The collection of hematopoietic stem cell yield is critical to successful ASCTs, but not always achieved due to hematopoietic stem cell mobilization failure (HSCMF). Details regarding the cell collection and outcomes of those who fail mobilization are still lacking. Therefore, this study aimed to yield data on clinical outcomes and cellular products after HSCMF.

METHODS

Retrospective, unicentric study assessing clinical outcomes and characteristics of collected progenitor cells. The data were collected from patient databases. The results were reported in median, rates and percentages and absolute values. Patients older than 18 years of age at the time of mobilization and HSCMF were included.

RESULTS

Five hundred ninety-nine patients underwent mobilization protocols. Thirty-five (5.8%) of them failed in the mobilization and fourteen (40%) died. Median time to death was eight months. Disease progression and infection were responsible for all deaths. Median relapse-free survival was 6.5 months (20 patients, 57%). Seven (20%) survivors were receiving salvage therapy and five (14%) were being followed clinically. Six (20.6%) participants underwent collection by apheresis, with insufficient cell collection. The median quantity of peripheral CD34+ cells in those patients was 10.5/mm3. The median CD34+ quantity collected was 0.86 × 106 CD34+ cells/kg.

CONCLUSIONS

The mobilization failure was associated with limited survival. Nonetheless, collected products offered perspectives for ex vivo expansion. Further studies should investigate the feasibility of expanding collected CD34+ cells to use as grafts for ASCT.

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.

Overview on novel strategies and current guidelines for hematopoietic stem cell mobilisation and collection

The success of the autologous stem cell transplantation is strictly related to an adequate hematopoietic stem cell mobilization and collection. The minimum threshold for a successful mobilization is currently defined as 2 × 106/kg CD34+ cells. However, the optimal stem cell mobilization strategy is still controversial. The availability of plerixafor, a selective and reversible CXCR4 inhibitor, has been associated with an higher use of chemo-free protocols by many centres. In the near future, it is conceivable that artificial intelligence may became more accurate and comprehensive, possibly guiding clinicians in choosing the optimal mobilisation treatment for the various patients undergoing hematopoietic stem cell transplantation. Machine learning-based scoring models may be the basis for the development of "intelligent" mobilisation algorithms.

Mobilization and Hematopoietic Stem Cell Collection in Poor Mobilizing Patients with Lymphoma: Final Results of the German OPTIMOB Study

Introduction

Successful mobilization and collection of peripheral hematopoietic stem cells (HSCs) are necessary for lymphoma patients eligible for myeloablative chemotherapy with subsequent autologous stem cell transplantation (ASCT). Albeit G-CSF alone or combined with chemotherapy is well-established methods for HSC mobilization, up to 40% of the patients fail to mobilize (poor mobilizer, PM). Plerixafor (PLX) is commonly used in PM patients resulting in increased migration of HSCs into peripheral blood and thus improves the collection outcome.

Methods

The prospective, multicenter, open-label, non-interventional OPTIMOB study assessed mobilization and collection parameter of patients with lymphoma or multiple myeloma to get deep insights in the treatment of those patients in clinical routine focusing on PM patients. PM was defined as follows: (1) no achievement of ≥20 CD34+ progenitor cells/µL before first apheresis, (2) PLX administration at any time point during the observational period, (3) reduction of the initially planned CD34+ progenitor cell yield as necessity due to failed mobilization or HSC collection, and (4) no performance of apheresis due to low CD34+ progenitor level. Primary objective of the study was to assess mobilization success by the proportion of PM patients achieving >2 × 106 CD34+ progenitor cells/kg body weight on the first day of apheresis. Here, the data of the lymphoma cohort are presented.

Results

Out of 238 patients with lymphoma documented in the study, 32% were classified as PM. 87% of them received PLX. Demographic data revealed no obvious differences between PM and good mobilizing (GM) patients. All patients were treated highly individualized prior to mobilization. Majority of all PM patients were able to undergo apheresis (95%) and reached their individual requested CD34+ progenitor cell target (72%). 57% of the PM patients achieved >2.0 × 106 CD34+ progenitor cells/kg body weight on day 1 of apheresis and nearby 70% of them underwent ASCT. Median time to engraftment was similar in PM and GM patients of the lymphoma cohort.

Conclusions

Majority of PM patients with lymphoma were successfully mobilized and underwent ASCT. Most of them received PLX during the study.

Poor Mobilizers in Lymphoma but Not Myeloma Patients Had Significantly Poorer Progression-Free Survival after Autologous Stem Cell Transplantation: Results of a Large Retrospective, Single-Center Observational Study

In our single-center study, 357 myeloma and lymphoma patients between 2009 and 2019 were mobilized with granulocyte colony-stimulating factor (G-CSF 7.5 µg/kg bid for four days) plus a fixed dose of 24 mg Plerixafor when indicated (Plerixafor Group, n = 187) or G-CSF alone (G-CSF Group, n = 170). The target CD34 cell yields were ≥2.0 × 10⁶ CD34+ cells/kg in lymphoma and ≥4.0 × 10⁶ CD34+ cells/kg in myeloma patients to enable putative second transplants in the latter. There were no significant differences in engraftment kinetics or transfusion requirements between the Plerixafor Group and the control group in the myeloma cohort, with lymphoma patients not requiring Plerixafor showing significantly faster neutrophil recovery, a trend to faster platelet recovery, and a significantly lower need for platelet transfusions, probably due to the significantly lower number of CD34-positive cells re-transfused. While in myeloma patients the outcome (overall survival, progression-free survival) following autologous stem cell transplantation (ASCT) was similar between the Plerixafor Group and the control group, hard to mobilize lymphoma patients had significantly poorer progression-free survival (47% vs. 74% at 36 months after ASCT, p = 0.003) with a trend also to poorer overall survival (71% vs. 84%). In conclusion, while there seem to be no differences in stemness capacity and long-term engraftment efficiency between the Plerixafor and the G-CSF Group in lymphoma as well as myeloma patients, poor mobilizing lymphoma patients per se constitute a high-risk population with a poorer outcome after ASCT. Whether disease characteristics and/or a more intense or stem cell-toxic pre-mobilization chemo-/radiotherapy burden in this cohort are responsible for this observation remains to be shown in future studies.

Plerixafor use in autologous hematopoietic stem cell mobilization: Experience from a single center in Southern India

BACKGROUND

Plerixafor is used for patients at risk of Stem cell mobilization failure based on clinical factors or low peripheral blood CD34 count. It is also added upfront to any mobilization irrespective of risk factor, but the cost-effectiveness of the approach is an issue. Data on plerixafor in different settings of autologous hematopoietic stem cell (HSC) collection from India are scant. We are hereby reporting the experience of failure/success of mobilization rate and few important significant variables (CD34+ dosage, failed collection) between plerixafor and granulocyte colony-stimulating factor alone groups among autologous hematopoietic stem cell transplantation (aHSCT) at our institute.

METHODS

This was a record-based single-center study on patients who underwent aHSCT from January 2013 to June 2019 at a tertiary care hospital. Descriptive statistics were used for baseline characteristics, transplant-related factors, and peritransplant outcomes. All statistical analyses were performed at the 5% significance level.

RESULTS

During the study duration, a total of 96 patients had undergone autologous hematopoietic stem cell collection (aHSCC), all by peripheral blood stem cell harvest, requiring 131 apheretic collections. Of the total 131 collections in 96 patients, plerixafor was used in 63 apheresis collections (48% of total pheresis) in 40 patients. Among the 40 patients who were administered plerixafor to augment the collection, 34 patients had upfront use of plerixafor. We did not observe any significant adverse event related to plerixafor use.

CONCLUSION

A rational utilization of plerixafor can facilitate the process and logistics of aHSCC outcome.

Use of Plerixafor for Stem Cell Mobilization in the Setting of Autologous and Allogeneic Stem Cell Transplantations: An Update

Mobilization failure is an important issue in stem cell transplantations. Stem cells are yielded from the peripheral blood via apheresis. Granulocyte colony-stimulating factor (G-CSF) is the most commonly used mobilization agent among patients and donors. G-CSF is administered subcutaneously for multiple days. However, patients with mobilization failure cannot receive autologous stem cell transplantation and, therefore, cannot be treated adequately. The incidence rate of mobilization failure among patients is about 6–23%. Plerixafor is a molecule that inhibits the binding of chemokine receptor-4 with stromal-cell-derived factor-1, thereby resulting in the release of CD34+ cells in the peripheral blood. Currently, plerixafor is used in patients with mobilization failure with G-CSF and is administered subcutaneously. Several studies conducted on different clinical settings have shown that plerixafor is effective and well tolerated by patients. However, more studies should be conducted to explore the optimal approach for plerixafor in patients with mobilization failure. The incidence of mobilization failure among donors is lower. However, plerixafor is not approved among donors with mobilization failure. Moreover, several clinical studies in donors have shown a beneficial effect of plerixafor. In addition, the adverse events of plerixafor are mild and transient, which can overcome the adverse events due to G-CSF. This review assessed the current role and effects of plerixafor in stem cell mobilization for autologous and allogeneic stem cell transplantations.

Engraftment after autologous hematopoietic stem cell transplantation in patients mobilized with Plerixafor: A retrospective, multicenter study of a large series of patients

Plerixafor (PLX) appears to effectively enhance hematopoietic stem-cell mobilization prior to autologous hematopoietic stem cell transplantation (auto-HCT). However, the quality of engraftment following auto-HCT has been little explored. Here, engraftment following auto-HCT was assessed in patients mobilized with PLX through a retrospective, multicenter study of 285 consecutive patients. Information on early and 100-day post-transplant engraftment was gathered from the 245 patients that underwent auto-HCT. The median number of PLX days to reach the stem cell collection goal (≥2 × 10⁶ CD34⁺ cells/kg) was 1 (range 1-4) and the median PLX administration time before apheresis was 11 h (range 1-18). The median number of apheresis sessions to achieve the collection goal was 2 (range 1-5) and the mean number of CD34⁺ cells collected was 2.95 × 10⁶/kg (range 0-30.5). PLX administration was safe, with only 2 mild and transient gastrointestinal adverse events reported. The median time to achieve an absolute neutrophil count (ANC) >500/μL was 11 days (range 3-31) and the median time to platelet recovery >20 × 10³/μL was 13 days (range 5-69). At 100 days after auto-HCT, the platelet count was 137 × 10⁹/L (range 7-340), the ANC was 2.3 × 10⁹/L (range 0.1-13.0), and the hemoglobin concentration was 123 g/L (range 79-165). PLX use allowed auto-HCT to be performed in a high percentage of poorly mobilized patients, resulting in optimal medium-term engraftment in the majority of patients in whom mobilization failed, in this case mainly due to suboptimal peripheral blood CD34⁺ cell concentration on day +4 or low CD34⁺ cell yield on apheresis.

Bortezomib and cyclophosphamide based chemo-mobilization in multiple myeloma

Hematopoietic stem and progenitor cell (HSPC) mobilization regimens in multiple myeloma typically use filgrastim (GCSF) alone or combination of GCSF with plerixafor or high-dose cyclophosphamide. Murine model and human studies have shown HSPC mobilization potential of bortezomib. A total of 37 patients underwent mobilization using bortezomib 1.3 mg/m² on day 1, 4, 8 and 11, cyclophosphamide 1 g/m² on day 8 and 9, and GCSF 10 μg/kg from day 10 (B-Cy-GCSF). This regimen was compared with our earlier cohort of patients where cyclophosphamide was given at dose of 1 g/m² on day 1 and day 2 followed by GCSF 10 μg/kg from day 4 (Cy-GCSF). In B-Cy-GCSF group, median CD34 cells collected were 9.21 × 10⁶/kg (range 4.95-17.1) while in the Cy-GCSF cohort, the median CD34 cell yield was 8.2 × 10⁶/kg (0.4-24.2). Target CD34 cells yield of 5 × 10⁶/kg was achieved with single apheresis in 58.6% of patients after B-Cy-GCSF mobilization as compared to 44.3% in Cy-GCSF group (p = 0.07). Three patients failed mobilization after Cy-GCSF, while no patients failed mobilization in bortezomib group. Addition of bortezomib to Cy-GCSF mobilization showed a trend towards increased CD34 collection and reduced need for apheresis sessions.

Mobilization of Hematopoietic Stem Cells into Peripheral Blood for Autologous Transplantation Seems Less Efficacious in Poor Mobilizers with the Use of a Biosimilar of Filgrastim and Plerixafor: A Retrospective Comparative Analysis

Introduction

Biosimilars of granulocyte colony-stimulating factors (G-CSF) have shown similar efficacy to originator filgrastim (Neupogen® [NEU]; Amgen Inc.) as prophylaxis in neutropenia and in the mobilization of stem cells in patients receiving combination chemotherapy with G-CSF.

Methods

This was a retrospective study in which the characteristics of stem cell mobilization treated with a G-CSF alone were compared in 216 patients and 56 donors. The two G-CSF compared were NEU and the biosimilar filgrastim Zarzio® (Sandoz GmbH) (referred to hereafter as BIO). Primary objectives were mobilization rate (minimum of 10 × 10³/ml CD34+ on day 4 of treatment [day +4]) and use of the immunostimulant plerixafor (PLEX) in each group.

Results

The general characteristics of the patients receiving NEU (n = 138) and those receiving BIO (n = 78) did not differ significantly. PLEX was used in 24% of BIO patients and in 25.7% of NEU patients. The median CD34+ cell count on day +4 was significantly lower in BIO patients who needed PLEX than in those who did not (2.4 vs. 4.8 × 10³/ml; p = 0.002), as was the final CD34+ cell count (2.5 vs. 3.3 × 10⁶/kg; p 0.03). Mobilization failure rate was higher in the BIO group than in the NEU group (20 vs. 0%; p = 0.01). With respect to donors, more than one apheresis was needed in three BIO donors, one of them with PLEX. The use of BIO was the only risk factor for mobilization failure in patients who needed PLEX (hazard ratio 10.3; 95% confidence interval 1.3–77.8).

Conclusion

The study revealed that BIO had a lower efficacy for stem cell mobilization when the only treatment was G-CSF, especially in poor mobilizers needing PLEX.

Efficacy and safety of stem cell mobilization following gemcitabine, dexamethasone, cisplatin (GDP) salvage chemotherapy in patients with relapsed or refractory lymphoma

High-dose chemotherapy and autologous stem cell transplant (ASCT) remains a cornerstone of treatment in relapsed/refractory (R/R) aggressive-histology lymphomas. This retrospective study examined efficacy and safety of peripheral blood stem cell (PBSC) mobilization using cyclophosphamide/etoposide and GCSF (CE + GCSF, n = 129) versus gemcitabine, dexamethasone and cisplatin and GCSF (GDP + GCSF, n = 210). All patients received first salvage with GDP. Patients mobilized with CE + GCSF required fewer days of leukapheresis (median 1 vs 2 day; p = .001) and achieved higher total CD34+ yield than GDP + GCSF patients (8.5 vs 7.1 × 10⁶ CD34+ cells/kg, p = .001). Rates of febrile neutropenia and CD34+ collection ≥5 × 10⁶ CD34+ cells/kg were similar (OR 1.19, 95% CI: 0.54-2.6, p = .66). In multivariable analysis, days to engraftment and admission duration were not statistically different between the two mobilization strategies. While CE + GCSF appeared more efficacious for mobilization after GDP salvage, this did not translate to significant differences in clinical outcomes.

Cost and efficacy of peripheral stem cell mobilization strategies in multiple myeloma

Mobilization of peripheral blood stem cells (PBSC) can be performed using plerixafor, which is expensive, or high-dose cyclophosphamide (HDCy). We hypothesized that the overall cost of mobilization with plerixafor might not be greater if the cost of complication management was considered. We performed a cost analysis of these two strategies. This multicentric observational study recruited patients with myeloma who underwent a first PBSC mobilization. We considered direct medical costs, including hospitalization, mobilization agents, apheresis, and supportive treatments. We included 111 patients, 54 and 57 in the HDCy and plerixafor groups, respectively. Cost of mobilization with HDCy was 5097 ± 2982€ vs. 10958 ± 1789€ for plerixafor (p < 0.0001). Cost of agents used was 1287 ± 779€ vs. 6552 ± 509€, respectively (p = 0.0009). The mean number of days of hospitalization was 2 and 2.1 days, respectively (p = 0.035). All patients achieved the minimum PBSC collection target (p = 1.0); however, ASCT was performed with HDCy in 67% patients and with plerixafor in 86% (p = 0.02). Plerixafor mobilization incurred a greater cost, mostly due to the greater cost of the drug. Hospitalization length in the two groups was similar in our series. Interestingly, plerixafor appeared to be a very effective and safe mobilizing approach translating into a greater ASCT success.

Plerixafor combined with standard regimens for hematopoietic stem cell mobilization in pediatric patients with solid tumors eligible for autologous transplants: two-arm phase I/II study (MOZAIC)

This study (NCT01288573) investigated plerixafor's safety and efficacy in children with cancer. Stage 1 investigated the dosage, pharmacokinetics (PK), pharmacodynamics (PD), and safety of plerixafor + standard mobilization (G-CSF ± chemotherapy). The stage 2 primary endpoint was successful mobilization (doubling of peripheral blood CD34+ cell count in the 24 h prior to first apheresis) in patients treated with plerixafor + standard mobilization vs. standard mobilization alone. In stage 1, three patients per age group (2-<6, 6-<12, and 12-<18 years) were treated at each dose level (160, 240, and 320 µg/kg). Based on PK and PD data, the dose proposed for stage 2 was 240 µg/kg (patients 1-<18 years), in which 45 patients were enrolled (30 plerixafor arm, 15 standard arm). Patient demographics and characteristics were well balanced across treatment arms. More patients in the plerixafor arm (24/30, 80%) met the primary endpoint of successful mobilization than in the standard arm (4/14, 28.6%, p = 0.0019). Adverse events reported as related to study treatment were mild, and no new safety concerns were identified. Plerixafor + standard G-CSF ± chemotherapy mobilization was generally well tolerated and efficacious when used to mobilize CD34+ cells in pediatric cancer patients.

Efficacy and safety of plerixafor for hematopoietic stem cell mobilization for autologous transplantation in patients with non-Hodgkin lymphoma and multiple myeloma: A systematic review and meta-analysis

Plerixafor in combination granulocyte-colony stimulating factor (G-CSF) has been used for the mobilization of hematopoietic stem cells (HSCs) to the peripheral blood for collection and subsequent autologous transplantation in patients with non-Hodgkin lymphoma (NHL) and multiple myeloma (MM). The aim of this study was to systematically search the published literature and analyze evidence on the efficacy of additional plerixafor for successful HSC mobilization in patients with NHL and MM, and to evaluate the safety of the drug. The PubMed, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL) and Google scholar databases were searched electronically for studies published in the English language up to March, 2019. Five studies (3 on NHL and 2 on MM) were included in this review article. The meta-analysis of data of 364 patients in the treatment group and 368 patients in the control group, indicated that the mobilization of ≥5/6×10⁶ CD34⁺ cells/kg in 4 or less apheresis days was superior with plerixafor + G-CSF than with G-CSF alone (RR=2.59, 95% CI: 1.40 to 4.81; P<0.0001). Similarly, a greater proportion of patients in the treatment group exhibited the mobilization of ≥2×10⁶ CD34⁺ cells/kg in 4 or less apheresis days (RR=1.46, 95% CI: 1.01 to 2.12; P=0.04). The addition of plerixafor significantly increased the total collection of CD34⁺ cells (random: MD=4.21; 95% CI: 2.85 to 5.57; P<0.00001). Meta-analysis indicated no significant increase in adverse events with the addition of plerixafor for HSC mobilization (RR=1.03, 95% CI: 0.99 to 1.06; P=0.16). On the whole, the findings of this study indicate that the addition of plerixafor to G-CSF leads to an increased HSC collection in a shorter period of time with no concomitant increase in adverse events. Further randomized controlled trials with a larger sample size evaluating short term efficacy, as well as long term survival would help to further strengthen the evidence on this subject.

Comparison of filgrastim, pegfilgrastim, and lipegfilgrastim added to chemotherapy for mobilization of CD34+ cells in non-Hodgkin lymphoma patients

BACKGROUND

Data are limited on the long-acting granulocyte-colony stimulating factors (G-CSFs) pegfilgrastim (PEG) and lipegfilgrastim (LIPEG) compared with filgrastim (FIL) regarding the mobilization efficiency of CD34⁺ cells, graft cellular composition, and engraftment.

STUDY DESIGN AND METHODS

In this prospective nonrandomized study, 36 patients with non-Hodgkin lymphoma received FIL, 67 received PEG, and 16 patients received LIPEG as a cytokine after chemotherapy. We analyzed the mobilization and collection of CD34⁺ cells, cellular composition of blood grafts, and hematologic recovery after auto-SCT according to the type of G-CSF used.

RESULTS

Patients in the LIPEG group had fewer apheresis sessions (1 vs. 2, p = 0.021 for FIL and p = 0.111 for PEG) as well as higher median blood CD34⁺ cell counts at the start of the first apheresis (LIPEG 74 × 10⁶ /L vs. FIL 31 × 10⁶ /L, p = 0.084 or PEG 27 × 10⁶ /L, p = 0.021) and CD34⁺ yields of the first apheresis (FIL 5.1 × 10⁶ /kg vs. FIL 2.3 × 10⁶ /kg, p = 0.105 or PEG 1.8 × 10⁶ /kg, p = 0.012). Also, the costs associated with G-CSF mobilization and apheresis were lower in the LIPEG group. The graft composition was comparable except for the higher infused CD34⁺ cell counts in the LIPEG group. The engraftment kinetics were significantly slower in the FIL group.

CONCLUSION

LIPEG appears to be more efficient compared with PEG after chemotherapy to mobilize CD34⁺ cells for auto-SCT demonstrated as fewer sessions of aphereses needed as well as 2.8-fold CD34⁺ cell yields on the first apheresis day. Early hematologic recovery was more rapid in the LIPEG group. Thus further studies on LIPEG in the mobilization setting are warranted.

Poor mobilizer and its countermeasures

Mobilization failure is a major concern in patients undergoing hematopoietic cell transplantation, especially in an autologous setting, as almost all donor harvests can be accomplished with granulocyte-colony stimulating factor (G-CSF) alone. Poor mobilizers, defined as those with a peripheral blood CD34⁺ cell count ≤20 cells/μl after mobilization preceding apheresis is a significant risk factor for mobilization failure. We recommend preemptive plerixafor plus G-CSF (filgrastim, 10 μg/kg daily) as a first mobilization strategy, which yields sufficient peripheral blood progenitor cells (PBPCs) in almost all patients and avoids otherwise unnecessary remobilization. Preemptive plerixafor is administered in patients with a day-4 peripheral blood CD34⁺ count <15, depending on the disease and the target PBPC amount. Cyclophosphamide is reserved for patients who fail the first PBPC collection. We recommend second mobilization for patients who could not achieve a sufficient PBPC amount with the first mobilization. In these patients, a second attempt with plerixafor plus G-CSF or mobilization with plerixafor in combination with cyclophosphamide and G-CSF is recommended. Increased dose and/or twice daily administration of G-CSF can be considered.

Plerixafor in non-Hodgkin's lymphoma patients: a German analysis of time, effort and costs

Mobilization and collection of peripheral blood stem cells is part of the standard treatment procedure for non-Hodgkin’s lymphoma patients eligible for high-dose chemotherapy with autologous stem cell transplantation. Mobilization is usually achieved with chemotherapy and/or cytokines, but plerixafor might be added in case of poor mobilization. Due to the high cost several institutions have developed their own management pathway to optimize use of plerixafor. Such models are however rarely generalizable; in a multi-center, European, non-interventional study, evaluating the impact of plerixafor in poor mobilizers, country specific differences in patient treatment and cost structure were obvious. For German centers, there was a non-significant reduction in the number of apheresis sessions carried out and in apheresis costs. In contrast to other European countries the majority of German Plerixafor patients were very poor mobilizing patients with initial CD34+ cell count ≤ 10/µl (40/51). In this group the number of apheresis sessions decreased from 2.1 to 1.6 sessions per patient (p = 0.01) and costs decreased from €6246 to €4758 (p = 0.01). Our results show that preemptive plerixafor use has a strong effect in poor mobilizers with an initial CD34+ cell count ≤ 10 cells/µl.