Stem Cell Collection In Patients Research Articles

Predictive model of the efficiency of hematopoietic stem cell collection in patients with multiple myeloma and lymphoma based on multiple peripheral blood markers.

Autologous hematopoietic stem cell transplantation (ASCT) has gained extensive application in the treatment of lymphoma and multiple myeloma (MM). Plenty of studies demonstrate that peripheral blood indicators could be considered potential predictive biomarkers for hematopoietic stem cells (HSCs) collection efficiency, including white blood cell count (WBC), monocyte count (Mono), platelet count (PLT), hematocrit, and hemoglobin levels. Currently, clinically practical predictive models based on these peripheral detection indicators to quickly, conveniently, and accurately predict collection efficiency are lacking. In total, 139 patients with MM and lymphoma undergoing mobilization and collection of ASCT were retrospectively studied. The study endpoint was successful collection of autologous HSCs. We analyzed the effects of clinical characteristics and peripheral blood markers on collection success, and screened variables to establish a prediction model. We determined the optimal cutoff value of peripheral blood markers for predicting successful stem cell collection and the clinical value of a multi-marker prediction approach. We also established a prediction model for collection efficacy. Univariate and multivariate logistic regression analyses showed that the mobilization regimen, Mono, PLT, mononuclear cell count (MNC), and peripheral blood CD34+ cell count (PB CD34+ counts) were significant predictors of successful collection of peripheral blood stem cells (PBSC). Two predictive models were constructed based on the results of multivariate logistic analyses. Model 1 included the mobilization regimen, Mono, PLT, and MNC, whereas Model 2 included the mobilization regimen, Mono, PLT, MNC, and PB CD34+ counts. Receiver operating characteristic (ROC) curve analysis showed that the PB CD34+ counts, Model 1, and Model 2 could predict successful HSCs collection, with cutoff values of 26.92 × 106/L, 0.548, and 0.355, respectively. Model 1 could predict successful HSCs collection with a sensitivity of 84.62%, specificity of 75.73%, and area under the curve (AUC) of 0.863. Model 2 could predict successful HSCs collection with a sensitivity of 83.52%, specificity of 94.17%, and AUC of 0.946; thus, it was superior to the PB CD34+ counts alone. Our findings suggest that the combination of the mobilization regimen, Mono, PLT, MNC, and PB CD34+ counts before collection has predictive value for the efficacy of autologous HSCs collection in patients with MM and lymphoma. Using models based on these predictive markers may help to avoid over-collection and improve patient outcomes.

Cost effective utilization of apheresis for stem cell transplantation in multiple myeloma.

e19528 Background: Salvage autologous stem cell transplantation (ASCT) is an effective and feasible treatment option for patients with relapsed multiple myeloma (MM). It is standard practice to collect stem cells adequate for two transplants for ASCT eligible patients with newly diagnosed MM (NDMM). Stem cell collection is an expensive procedure due to the cost of granulocyte-colony stimulating factor, plerixafor, apheresis, chemotherapy in select cases and finally cryopreservation. However, the rate of utilization of second ASCT is not known. Methods: We conducted a single institution, retrospective study of 511 consecutive patients with NDMM who underwent ASCT to identify the proportion of patients receiving second ASCT. Patients received ASCT as front-line therapy between 1/1/2015-2/13/2019. Demographic and disease characteristics were summarized using median and range for continuous variables, and frequency and percentages were calculated for categorical variables. The cumulative incidence of second ASCT was estimated using the Fine and Gray method, and competing risk regression models were used to estimate the hazard ratios for risk of second ASCT. All statistical tests were two-sided with a type 1 error of < 0.05 indicating statistical significance. All estimates were reported with 95% confidence intervals (95% CI). Results: At a median follow-up of 4.7 years, 25 out of 511 patients received a second ASCT. The cumulative incidence rate at 5 years was 2.6% (95% CI 1.4-4.4%).Age at diagnosis, age at first ASCT and Charlson comorbidity index (CMI) were significantly associated with the risk of second ASCT in univariable analysis (UVA). In multivariable analysis (MVA) age at first ASCT was the only factor that was predictive of a second ASCT. We devised a predictive score for utilization of second ASCT using hazard ratios for each of the three significant factors noted in the UVA. Scoring was done as follows: age < 65 years – 1 point, > 65 years – 7 points; 1 point for CMI 0-1, 2 points for CMI 2 or higher; serum creatinine ≤1.2 – 1 point, > 1.2 – 3 points. Based on the total score, patients are grouped into low ( < = 3), medium (4-6) and high (7+) likelihood categories, with cumulative incidence rates of receiving second ASCT at 4.0% (95% CI: 1.3-9.1%), 3.4% (95% CI 1.4-7.0%) and 0.6% (95% CI 0.1-3.1%) respectively. Patients older than 65 years were 87% less likely to receive a second ASCT compared with those younger than 65 years (HR = 0.13, 95% CI 0.02-0.98). Conclusions: Using this predictive score, goal of stem cell collection for patients with MM could be determined more efficiently. This could avoid extra days of apheresis, chemo mobilization, hospitalizations and need for cryopreservation at least for patients with a low likelihood of second ASCT, translating into cost effective utilization of resources. We plan to validate this score prospectively in a larger group of patients with NDMM undergoing ASCT in the future.

Predictive Score for Utilization of Second Autologous Stem Cell Transplantation in Patients with Multiple Myeloma

Introduction: Salvage autologous stem cell transplantation (ASCT) is an effective and feasible treatment option for patients with relapsed multiple myeloma (MM). It is standard practice to collect stem cells adequate for two transplants for ASCT eligible patients with newly diagnosed multiple myeloma (NDMM). Apheresis is an expensive procedure with the added risk of complications from central venous access such as bleeding, infection and, granulocyte colony stimulating factor administration. However, the rate of utilization of second ASCT is not known. Methods: We conducted a single institution, retrospective study of 511 consecutive patients with NDMM who underwent ASCT to identify factors predictive of receiving second ASCT. Patients received ASCT as front-line therapy between 1/1/2015-2/13/2019. Demographic and disease characteristics were summarized using median and range for continuous variables, and frequency and percentages were calculated for categorical variables. The cumulative incidence of second ASCT was estimated using the Fine and Gray method, and competing risk regression models were used to estimate the hazard ratios for risk of second ASCT. Analyses were performed using Stata version 18 (StataCorp, College Station, TX), and all statistical tests were two-sided with a type 1 error of <0.05 indicating statistical significance. All estimates were reported with 95% confidence intervals (95% CI). Results: At a median follow-up was 4.7 years, 25 out of 511 patients received a second ASCT. The cumulative incidence rate at 5 years was 2.6% (95% CI 1.4-4.4%) (Figure 1).Age at diagnosis, age at first ASCT and Charlson comorbidity index (CMI) were significantly associated with the risk of second ASCT in univariable analysis (UVA). In multivariable analysis (MVA) age at first ASCT was the only factor that was statistically significantly associated with the likelihood of a second ASCT. We devised a predictive score for utilization of second ASCT using hazard ratios for each of the three significant factors noted in the UVA. Scoring was done as follows: age <65 years - 1 point, >65 years - 7 points; 1 point for CMI 0-1, 2 points for CMI 2 or higher; serum creatinine </=1.2 - 1 point, >1.2 - 3 points. Based on the total score, patients are grouped into low (<=3), medium (4-6) and high (7+) likelihood categories, with cumulative incidence rates of receiving second ASCT at 4.0% (95% CI: 1.3-9.1%), 3.4% (95% CI 1.4-7.0%) and 0.6% (95% CI 0.1-3.1%) respectively. Patients older than 65 years were 87% less likely to receive a second ASCT compared with those younger than 65 years (HR=0.13, 95% CI 0.02-0.98). Conclusion: Using this predictive score, goal of stem cell collection for patients with MM could be determined more efficiently. This could avoid extra days of apheresis, chemo mobilization, hospitalizations and need for stem cell storage at least for patients with a low likelihood of second ASCT, translating into cost effective utilization of resources. We plan to validate this score prospectively in a larger group of patients with NDMM undergoing ASCT in the future.

Comparison of different plerixafor-based strategies for adequate hematopoietic stem cell collection in poor mobilizers

Objectives: The main objective of the present study was to evaluate whether the use of plerixafor in combination with granulocyte colony-stimulating factor (G-CSF) or subsequent use of isolated G-CSF and then plerixafor following disease-specific chemotherapy, and whether it would allow for adequate peripheral stem cell collection in patients. Methods: The retrospective study evaluated 54 patients with previous mobilization failure who were administered plerixafor in 2 centers. In patients without any side effects, CD 34+ cell counts, the percentage of patients who were found eligible for autologous transplantation, the engraftment kinetics of the patients who underwent transplantation, and their overall survival results were compared between the two groups where G-CSF was used with plerixafor, or where plerixafor was used after isolated G-CSF following chemotherapy. Results: The median age of the patients was 49 years (range: 17-70), and 64.8% (n = 35) were males. It was identified that 31 (57.4%) patients underwent mobilization treatment with isolated G-CSF and plerixafor, and 23 (42.6%) patients underwent mobilization treatment with chemotherapy plus G-CSF and plerixafor. In all patients, mean hemoglobin level (11.3 ± 1.5 g/dL vs. 9.3 ± 1.3 g/dL; p < 0.001) and median platelet level (129.2 ×103/µL vs. 58.4 ×103/µL) were found to be higher, while febrile neutropenia rate (3.3% vs. 60.9%), the percentage of replacement patients (6.7% vs. 65.2%), and median days of G-CSF (6 vs. 9) were found to be lower on the day of plerixafor administration in the isolated G-CSF and plerixafor group compared to the chemotherapy and G-CSF and plerixafor group. Conclusions: In conclusion, our study demonstrated that administration of plerixafor is generally safe and well-tolerated. Regardless of the underlying disease, it offers an effective alternative for patients with previous failed mobilization attempts using conventional regimens, and allows stem cell collection with fewer apheresis sessions.

Steady-state versus chemotherapy-based hematopoietic cell mobilization after anti-CD38-based induction therapy in newly diagnosed multiple myeloma.

The incorporation of anti-CD38 monoclonal antibodies (mAb) in induction regimens of newly diagnosed transplant-eligible multiple myeloma (MM) patients has been established as a new standard. However, the optimal strategy of stem cell mobilization in this context is not yet clear. From May 2020 till September 2022, we retrospectively reviewed patients receiving anti-CD38 mAb-based induction therapy followed by stem cell mobilization either in a steady-state protocol (SSM) using 10 μg/kg granulocyte colony-stimulating factor (G-CSF) for 5 days or in a chemotherapy-based protocol (CM) using 1-4 g/m2 cyclophosphamide and G-CSF. Overall, 85 patients (median age 61 years) were included in the analysis. In total, 90 mobilization attempts were performed, 42 with SSM and 48 with CM. There was no significant difference in the median concentration of CD34+ cells in peripheral blood (PB) prior to apheresis between SSM and CM (61/μL vs. 55.4/μL; p = .60). Cumulative CD34+ yields did not differ between the groups with median of 6.68 and 6.75 × 106 /kg body weight, respectively (p = .35). The target yield (≥4 × 106 CD34+ cells/kg body weight) was reached in 88% (CM) and 86% (SSM), with a high proportion even after a single apheresis session (76% vs. 75%). Plerixafor was found to be more frequently used in SSM (52%) than in CM (23%; p < .01). A total of 83 patients underwent autologous transplantation and all were engrafted. Stem cell collection in patients undergoing anti-CD38-based induction therapy is feasible with either CM or SSM, although SSM more frequently requires plerixafor.

Disease severity impacts plerixafor-mobilized stem cell collection in patients with sickle cell disease

Recent studies suggest that plerixafor mobilization and apheresis in patients with sickle cell disease (SCD) is safe and can allow collection of sufficient CD34+ hematopoietic stem cell (HSC) collection for clinical gene therapy applications. However, the quantities of plerixafor-mobilized CD34+ cells vary between different SCD patients for unknown reasons. Twenty-three participants with SCD underwent plerixafor mobilization followed by apheresis, processing, and HSC enrichment under a phase 1 safety and efficacy study conducted at 2 institutions. Linear regression or Spearman's correlation test was used to assess the relationships between various hematologic and clinical parameters with total CD34+ cells/kg collected. Median CD34+ cells/kg after 2 or fewer mobilization and apheresis cycles was 4.0 × 106 (range, 1.5-12.0). Similar to what is observed generally, CD34+ yield correlated negatively with age (P < .001) and positively with baseline (P = .003) and preapheresis blood CD34+ cells/µL (P < .001), and baseline white blood cell (P = .01) and platelet counts (P = .03). Uniquely for SCD, CD34+ cell yields correlated positively with the number of days hydroxyurea was held (for up to 5 weeks, P = .01) and negatively with markers of disease severity, including hospitalization frequency within the preceding year (P = .01) and the number of medications taken for chronic pain (P = .002). Unique SCD-specific technical challenges in apheresis were also associated with reduced CD34+ cell collection efficiency and purification. Here, we describe factors that impact plerixafor mobilization success in patients with SCD, confirming known factors as described in other populations in addition to reporting previously unknown disease specific factors in patients with SCD. This trial was registered at www.clinicaltrials.gov as #NCT03226691.

A new protocol for improving efficiency of autologous peripheral blood stem cell collection in patients with high white blood cell counts.

Collection efficiency (CE) of peripheral blood stem cell (PBSC) collections is negatively affected by increasing white blood cell (WBC) counts of the patient. This study compared a new optimized mononuclear cell (MNC) collection protocol (OPP) to the standard MNC collection protocol recommended by the manufacturer (STP) for PBSC collection in patients with WBC counts >35 000/μL. Single-center, retrospective, and observational study of 81 autologous PBSC collections on Fenwal Amicus cell separators in 70 adult patients. Median peripheral WBC count (×103 /μL; 44.2 in OPP group vs 46.5 in STP group) and median CD34+ count (105/μL in OPP group vs 40/μL in STP group) at the beginning of PBSC collection did not differ significantly. Median CE2 (45% vs 31%; P < .001) as well as CD34+ yield of the apheresis product both with regards to median absolute CD34+ content (×106 ; 793 vs 188; P = .001) as well as median CD34+ content (×106 )/kg body weight (8.93 vs 2.51; P = .002) were significantly higher for the OPP. Overall, 18/21 (86%) patients with the OPP obtained their target CD34+ amount with a single apheresis session, compared to 25/50 (50%) with the STP (P = .005). PBSC collections using OPP lasted significantly longer (median 377 minutes vs 260 minutes; P < .001) than with the STP. The OPP significantly improves CE2 for PBSC collections on Fenwal Amicus cell separators in patients with pre-apheresis WBC counts >35 000/μL and significantly reduces the necessity for multiple apheresis sessions. The OPP is therefore suited to reduce both patient burden and cost in autologous PBSC collection.

Impact of Plerixafor Use at Different Peripheral Blood CD34+ Thresholds on Autologous Stem Cell Collection in Patients with Multiple Myeloma.

Patients with multiple myeloma (MM) scheduled for autologous stem cell transplantation must undergo autologous stem cell mobilization; unfortunately, however, many do not obtain an adequate collection yield. Despite the availability of plerixafor, its widespread and uniform use is limited by its cost, and consequently, many institutions have adopted various risk-adapted algorithms. We report our mobilization experience as we have modified our plerixafor algorithm to a more liberal one, with the expectation of greater collection efficiency and mobilization success with higher plerixafor use. A total of 344 mobilization attempts were analyzed over 3 time periods and using 3 different peripheral blood CD34+ cell counts to guide plerixafor use: <15/µL (n=66), <20/µL (n=130), and <40/µL (n=148). The primary endpoints were evaluation of changes in mean plerixafor utilization and apheresis days and assessment of the impact on overall mobilization costs. Secondary endpoints were a description of the impact of lenalidomide use on mobilization and evaluation of the rate of mobilization failure. We found that mean plerixafor use increased from 1.32 to 1.65 to 1.74 doses per mobilization (P=.026) and the mean days of apheresis decreased from 2.15 to 2.17 to 1.89 days per mobilization for the <15/µL, <20/µL, and <40/µL cohorts, respectively (P=.011). The combined cost of plerixafor and apheresis procedures at a threshold of 40/µL is close to that at a threshold of 15/µL, while saving 26 apheresis days per 100 patients. In general, there were low rates of mobilization failure across all thresholds. Patients who received more than 6 cycles of lenalidomide demonstrated impaired mobilization and required more apheresis sessions (P < .013) and greater plerixafor use (P < .001) to achieve target stem cell yields. Overall, using plerixafor in patients with MM, with a day 4 pCD34 count of <40/µL is a reasonable and cost-effective strategy to optimize apheresis utilization.

Safe and Efficient Peripheral Blood Stem Cell Collection in Patients with Sickle Cell Disease Using Plerixafor

Background: Hematopoietic stem cell (HSC) gene therapy is potentially curative for sickle cell disease (SCD) provided that a sufficient quantity of long-term engrafting CD34+ HSCs can be safely collected and infused. In patients with SCD, peripheral blood (PB) mobilization with granulocyte colony stimulating factor is contraindicated, and steady-state bone marrow (BM) harvesting is associated with suboptimal HSC quality and yield. Hence, agents that promote safe and effective peripheral HSC mobilization in SCD are required. Methods: This phase I multicenter study investigated the safety and efficacy of plerixafor mobilization (240 µg/kg) followed by apheresis, processing, and HSC enrichment in 15 adult subjects with SCD (NCT03226691). Hydroxyurea treatment was stopped at least two weeks prior to mobilization and all participants who were not receiving long-term transfusion therapy received prophylactic red blood cell exchange prior to plerixafor administration to achieve a target sickle Hb (HbS) &lt;30%. The primary endpoint was efficient collection of PB HSCs (target 2.0x106 CD34+ cells/kg, minimum 1.5x106) after plerixafor mobilization without serious adverse events (SAEs). Collection products were assessed for total WBC, CD34+, CD3+, and CD19+ composition by flow cytometry. Spearman's correlation test was used to assess the relationship between baseline CD34/µL, total CD34+ cells/kg collected, and total blood volume processed. Findings: Fifteen participants with SCD (HbSS n=13, HbSC n=1, HbSβ+ n=1) who met inclusion criteria were enrolled at St. Jude Research Children's Hospital (n=3) or NIH (n=12) between July 2017 and February 2019. All participants except one successfully met the minimum target CD34+ cells/kg yield with 2 or fewer mobilization and apheresis procedures, with almost half the participants (n=7) achieving ≥5.0x106 CD34+ cells/kg. The total WBC count increased by an average of 3.2-fold over baseline (range 1.7-5.0) to an average peak WBC count of 26.5x103/µL (range 14.1-47.4), with counts returning to baseline within 1-2 days. Median total WBC, CD34+, CD19+, and CD3+ cells/kg in the final apheresis product after one (n=12) or two (n=3) collection procedures were 0.9 x109 WBC/kg (range 0.4-1.7), 4.5x106 CD34+ cells/kg (range 0.9-12.0), 3.4x108 CD19+ cells/kg (range 0.5-4.9), and 3.6x108 CD3+ cells/kg (range 1.7-7.3), respectively. There was a strong positive correlation between baseline CD34/µL and total CD34+ cells/kg (rs = 0.7776, 95% CI 0.446-0.9215, p = 0.001). Participants with the lowest pre-apheresis CD34 cell count generally underwent higher blood volume processing (rs = - 0.1443, 95% CI -0.6075 to 0.3921, p = 0.59) in an effort to achieve target yields. However, higher blood volume processing did not translate to higher total CD34+ cells/kg collection yields (rs = - 0.2104, 95% CI -0.6488 to 0.3328, p = 0.43). A median of 97% of positively selected CD34+ cells were CD34high (range 73.6-99.4%) compared to 1.3% CD34low (range 0.09-24.4%) phenotype suggesting enrichment for long-term engrafting HSCs. Seven grade III AEs (two non-pain and five pain related) and one grade IV AE (non-pain - hemolysis) occurred and each resolved with symptomatic treatment. Plerixafor mobilization was overall safe and in most cases generated CD34+ cell yields that were sufficient for both genetic modification and back-up allogeneic transplantation (median cell yield 4.2x106 CD34+ cells/kg). Interpretation: This first multi-institutional phase I study suggests the efficiency and safety of plerixafor mobilization and apheresis collection in 15 adult subjects with SCD. The primary endpoint to obtain a target of 2.0x106 CD34+ cells/kg from the PB was exceeded without SAEs. Importantly, immunophenotyping data suggest that for individuals with SCD, the plerixafor mobilized cell product is more enriched for long-term engrafting HSCs compared to CD34+ cells isolated from BM. Given the risks of general anesthesia and the low quality and yield of CD34+ cells harvested from the BM of individuals with SCD, plerixafor mobilization represents a safe and potentially superior alternative for HSC isolation. Disclosures Hankins: Novartis: Research Funding; ASPHO: Honoraria; NHLBI: Research Funding; LYNKS Foundation: Research Funding; NHLBI: Honoraria; National Committee for Quality Assurance: Consultancy; Global Blood Therapeutics: Research Funding; Bluebird Bio: Consultancy. Sharma:Vertex Pharmaceuticals: Other: Study PI; Doris Duke Foundation: Research Funding. Weiss:GlaxoSmithKline: Consultancy; Rubius INC: Consultancy; Esperian: Consultancy; Beam Therapeutics: Consultancy; Cellarity INC: Consultancy.

Safe and Efficient Peripheral Blood Stem Cell Collection in Patients with Sickle Cell Disease Using Plerixafor

Safe and Efficient Peripheral Blood Stem Cell Collection in Patients with Sickle Cell Disease Using Plerixafor

192 - Impact of Plerixafor Use at Different Peripheral Blood CD34+ Cell Thresholds on Autologous Stem Cell Collection in Patients with Multiple Myeloma

Background: Since the introduction of plerixafor, uniform application in mobilization protocols has not been realized. Widespread use of plerixafor is limited by its price. Some institutions have adopted a conservative approach, reserving plerixafor for second mobilization attempts or predicted difficult mobilizations. Our institutional procedure has shifted from using a relatively stringent peripheral blood CD34 threshold to a more generous threshold for plerixafor administration. We report our experience with a risk-adapted strategy for plerixafor use at different pCD34 thresholds. Methods: We retrospectively evaluated patients with multiple myeloma and amyloidosis undergoing autologous stem cell collection with G-CSF mobilization from 1/2012-12/2016. Our algorithm for triggering plerixafor administration has evolved from a pCD34 count of <15/µL to <20/µL to <40/µL. Patients received G-CSF 10 mcg/kg daily for 4 days. On day 4, patients received plerixafor if the pCD34 was below the threshold and was continued until collection was completed. Plerixafor use, days of collection, collection yield, mobilization failure rates, and mobilization costs were calculated. Target collection yield is >4 × 106 CD34+ cells/kg, and an optimal mobilization would allow for two transplants. Results: We identified 348 mobilization attempts. Median age was 59.9 years (range, 28-74) and 60% were male patients. Most patients were in CR (n = 94), VGPR (n = 107), or PR (n = 98). On average, patients received 1.9 prior lines of systemic therapy. Plerixafor use increased from 80% in the <15/µL group to 91% in the <40/µL group, while average number of doses increased from 1.32 to 1.74 per mobilization. The average apheresis days decreased from 2.15 days for the <15/µL group to 1.89 days for the <40/µL group. For patients in the <15/µL and <20/µL groups, 23% completed collection in 1 day, and 65-70% completed within 2 days. For patients in the <40/µL group, 39% completed collection in 1 day and 77% completed within 2 days. A collection yield > 4 × 106 CD34+ cells/kg was reached in 91% of cases in the <15/µL group and 94% in the <40/µL group. More patients (51% vs 41%) collected >8 × 106CD34+ cells/kg in the <40/µL group than <15/µL group and reached that goal within 2 days (49% vs 32%). Mobilization failure rates were <5% across all thresholds. Mobilization costs were comparable. Conclusion: We demonstrate that a liberal strategy for plerixafor administration correlates with fewer apheresis days while having similar mobilization costs. There were 26 fewer days of collection per 100 mobilization attempts with a pCD34 threshold of 40/µL compared to 15/µL at our institution. More patients completed collection in one day, and more reached an optimal collection yield.

Results of a Prospective Randomized, Open-Label, Noninferiority Study of Tbo-Filgrastim (Granix) versus Filgrastim (Neupogen) in Combination with Plerixafor for Autologous Stem Cell Mobilization in Patients with Multiple Myeloma and Non-Hodgkin Lymphoma

Autologous hematopoietic stem cell transplantation (auto-HSCT) improves survival in patients with multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). Traditionally, filgrastim (Neupogen; recombinant G-CSF) has been used in as a single agent or in combination with plerixafor for stem cell mobilization for auto-HSCT. In Europe, a biosimilar recombinant G-CSF (Tevagrastim) has been approved for various indications similar to those of reference filgrastim, including stem cell mobilization for auto-HSCT; however, in the United States, tbo-filgrastim (Granix) is registered under the original biological application and is not approved for stem cell mobilization. In retrospective studies, stem cell mobilization with tbo-filgrastim has shown similar efficacy and toxicity as filgrastim, but no prospective studies have been published to date. We have conducted the first prospective randomized trial comparing the safety and efficacy of tbo-filgrastim in combination with plerixafor with that of filgrastim in combination with plerixafor for stem cell mobilization in patients with MM and NHL. This is a phase 2 prospective randomized (1:1) open-label single-institution noninferiority study of tbo-filgrastim and filgrastim with plerixafor in patients with MM or NHL undergoing auto-HSCT. Here 10 µg/kg/day of tbo-filgrastim/filgrastim was administered s.c. for 5 days (days 1 to 5). On day 4 at approximately 1800 hours, 0.24 mg/kg of plerixafor was administered s.c. Apheresis was performed on day 5 with a target cumulative collection goal of at least 5.0 × 106 CD34+ cells/kg. The primary objective was to compare day 5 CD34+ cells/kg collected. Secondary objectives included other mobilization endpoints, safety, engraftment outcomes, and hospital readmission rate. A total of 97 evaluable patients were enrolled (tbo-filgrastim, n = 46; filgrastim, n = 51). Tbo-filgrastim was not inferior to filgrastim in terms of day 5 CD34+ cell collection (mean, 11.6 ± 6.7 CD34+ cells/kg versus 10.0 ± 6.8 CD34+ cells/kg. Multivariate analysis revealed a trend toward increased mobilization in the tbo-filgrastim arm, but this was not statistically significant. The tbo-filgrastim and filgrastim arms were similar in all secondary endpoints. Tbo-filgrastim is not inferior in efficacy and has similar safety compared to reference filgrastim when used for stem cell mobilization in patients with MM and NHL. Granix can be safely used instead of Neupogen for stem cell collection in patients undergoing auto-HSCT for MM or NHL.The study is registered at https://clinicaltrials.gov/ct2/show/NCT02098109.

Phase I/II Study of Intravenous Plerixafor Added to a Mobilization Regimen of Granulocyte Colony–Stimulating Factor in Lymphoma Patients Undergoing Autologous Stem Cell Collection

Plerixafor, given subcutaneously with granulocyte colony–stimulating factor (G-CSF), improves autologous stem cell collection in patients with lymphoma and multiple myeloma. Intravenous (i.v.) administration of plerixafor allows administration of plerixafor on the same day as pheresis and it may improve stem cell collection. The primary objectives of this phase I/II study were to determine the maximum tolerated dose of i.v. plerixafor and the efficacy of i.v. plerixafor + G-CSF to mobilize ≥ 2 × 106 CD34+ cells/kg from patients with lymphoma. In phase I, 25 patients were treated with G-CSF + i.v. plerixafor at escalating doses; in phase II, 36 patients were treated with G-CSF + plerixafor .40 mg/kg. The treatment was well tolerated. Fifty-nine of 61 patients (98%) met the collection goal and 47 of 61 patients (77%) collected ≥ 5.0 × 106 CD34+ cells/kg in a median of 2 pheresis days. Analysis of CD34+ hematopoietic stem and progenitor cells (HSPCs) revealed that G-CSF–mobilized grafts were enriched with CD34+CD45RA-CD123+/- primitive HSPCs whereas plerixafor preferentially mobilized CD34+CD45RA+CD123++ plasmacytoid dendritic cell precursors. In conclusion, i.v. plerixafor is well tolerated and effective when added to G-CSF for the mobilization of stem cells from patients with lymphoma, with mobilization kinetics and stem cell collections that compare favorably with subcutaneous dosing.

Impact of Melphalan-Based Chemotherapy on Stem Cell Collection in Patients with Light Chain Amyloidosis

Introduction: Melphalan based chemotherapy is commonly used for treatment of light chain amyloidosis (AL). Patients with AL often receive chemotherapy before autologous stem cell transplantation (ASCT) if they have high plasma cell burden or while awaiting ASCT. Melphalan is an alkylator and can affect bone marrow stem cells. Limited data is available on the effect of melphalan on stem cell mobilization in patients with amyloidosis. This study aims to identify the impact of melphalan therapy on collection of stem cells and ASCT in amyloidosis.Methods: All patients with AL seen at our institution within 90 days of diagnosis over a 10-year period (2006 to 2015) who underwent stem cell harvest were identified from an institutional database. Data pertaining to demographics, diagnosis, treatment, stem cell harvest and ASCT was extracted from the electronic medical records. Analysis was carried out by chi-square and Fisher's exact test for categorical variables and Kruskal-Wallis and Wilcoxon rank sum test for ordinal and continuous variables.Results: Three hundred and seventy two patients with AL who met the inclusion criteria were identified, of whom 10% (n=38) received melphalan based chemotherapy prior to harvesting, 28.5% (n=106) received non-melphalan based chemotherapy and 61.3% (n=228) received no chemotherapy prior to stem cell collection. Bortezomib based regimens were the most common (78%, n=83) non-melphalan based chemotherapy.All three groups were similar in terms of median age at diagnosis (59.1 years), median age at collection (59.4 years), gender distribution (59% males, n=221) and type of involved free light chain (FLC), with lambda being more common (72.2%, n=268). Patients who received melphalan-based chemotherapy had more cardiac (73.8% vs. 45.2% vs. 46.4%, p=0.005) and renal (84.2% vs. 50.9% vs. 68%, p=0.0002) involvement compared to other chemotherapy and no chemotherapy groups, respectively. In contrast, patients who received non-melphalan based chemotherapy had higher plasma cell burden (15% vs. 6% vs. 10%, p< 0.0001) and greater difference between involved and uninvolved FLC (44.2 mg/dL vs. 13.3 mg/dL vs. 13.2 mg/dL, p< 0.0001) compared to melphalan and no chemotherapy, respectively.Median duration of melphalan based chemotherapy was shorter at 54 days (34.5 to 79.5) or estimated 2 cycles compared to 101 days (60 to 135.5) or estimated 4 cycles (p=0.0019). Despite shorter duration of chemotherapy, total stem cell yield (million CD34/kg) was lower in patients who received melphalan based chemotherapy (5.54) compared to non-melphalan based chemotherapy (8.14) or no prior chemotherapy (7.94); p<0.0001. Similarly, day one stem cell yield (million CD34/kg) was the lowest in the melphalan group (2.71), followed by other chemotherapy group (3.63) and highest in no chemotherapy group (4.84); p<0.0001. This trend persisted for average stem cell yield per collection as illustrated in table 1.Filgrastrim (GCSF) alone was the most common mobilizing agent. However, patients with any chemotherapy prior to harvesting had higher utilization of plerixafor; 26.3% (n=10) in the melphalan group and 39.6% (n=42) in the non-melphalan group compared to 11.6% (n=27) if no prior chemotherapy (p<0.0001). However, no statistically significant difference was seen for melphalan vs. non-melphalan chemotherapy groups (p=0.44).In patients who underwent ASCT (85%, n=315), median stem cell dose (million CD34/kg) was different in the melphalan (3.66), non-melphalan (4.2) and no chemotherapy groups (4.44) (p=0.047), though the difference was not statistically significant amongst the 2 chemotherapy groups (p=0.34). There was also no difference in time to engraftment (table 1).Conclusions: Melphalan based chemotherapy, even if used for a short duration of time, significantly decreases both total stem cell yield and the yield on day one. It therefore has the potential to add to resource utilization with more collections needed. As much as possible, limited cycles of melphalan based chemotherapy or non-melphalan based treatment should be utilized in patients who are transplant eligible. [Display omitted] DisclosuresDispenzieri:GSK: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; Celgene: Research Funding; pfizer: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Kumar:Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Research Funding; Glycomimetics: Consultancy; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Kesios: Consultancy.

Chemotherapy Combined with Granulocyte Colony Stimulating Factor (G-CSF) for Mobilization of CD34+ Cells in Lymphoma and Multiple Myeloma Patients

Objective: To investigate and analyze factors which effect autologous stem cell collection in patients with lymphoma and multiple myeloma (MM) during chemotherapy combined with G-CSF mobilization, for improving quality and effectiveness of autologous stem cell transplantation.Methods: A retrospective analysis was performed from April 1, 2006 to October 31, 2013 in our hospital and 128 lymphoma and MM patients whose autologous peripheral blood stem cells (PBSCs) were collected including 75 patients with malignant lymphoma,7 cases of Hodgkin's lymphoma and 68 non-Hodgkin's lymphoma (NHL) cases as well as 53 MM patients were enrolled. The stem cells of all patients were mobilized by chemotherapy combined with G-CSF and collected via a continuous flow cell separation instrument (COBE Spectra, Lakewood, CO). Mobilize failure was defined when the amount of CD34 + cells was less than 2.0 x 106 / kg, whereas ≥2.0 * 106 / kg was defined as successful mobilization. More than 5.0x 106 cells / kg or more was considrered as ideal mobilization. Univariate and multivariate regression analyses of factors for mobilization failure, successful mobilization and ideal mobilization acquisition were performed.Results: There were more CD34+ cells in MM patients than in lymphoma patients (P = 0.064). The collection rates of CD34 + cells in MM patients were ≥ 2.0 x106 / kg in 64.8% (83 cases) and ≥ 5.0 x 106 / kg in 35.2% (45 cases). MM patients with a success collection ratio was 73.6 % (39/53) and the ideal collection rate was 43.4% (23/53), which was higher than in the NHL group with a success rate and ideal rate of 58.7% (44/75) and 30.7% (23/75). A total of 35.2 % (45 cases, including 31MM cases and 14 lymphoma cases) a mobilization was not successful.Conclusion: In different chemotherapy regimens in patients with lymphoma, remission, ever use MTX and/or Ara-c treatment and collecting the outer peripheral hematocrit could significantly affect the success rate of stem cell collection; In MM patients, who received lenalidomide treatment and multiple courses of treatment, still not got CR, which these reasons were the factors of non- successful mobilization.Although Plerixafor and peripheral blood CD34-positive cell counts could help to improve the success collection rate and predict collection rate, but there is still a need for further improvement of the current mobilization protocols, recognizing the ideal stem cell collection dynamics, efficiency and cost in order to select the appropriate mobilization protocols. DisclosuresNo relevant conflicts of interest to declare.

Predicting poor peripheral blood stem cell collection in patients with multiple myeloma receiving pre-transplant induction therapy with novel agents and mobilized with cyclophosphamide plus granulocyte-colony stimulating factor: results from a Gruppo Italiano Malattie EMatologiche dell'Adulto Multiple Myeloma Working Party study.

IntroductionA still not well defined proportion of patients with multiple myeloma (MM) and eligible for autologous stem cell transplantation (AuSCT) fails to mobilize CD34+ peripheral blood stem cells (PBSC) at all or to collect an adequate number for a safe procedure or sufficient for multiple transplants. These so-called “poor-mobilizers” are difficult to be predicted, due to marked difference across previous heterogeneous studies.MethodsWe aimed to develop a method based on simple clinical parameters for predicting unsuccessful (<2 × 106/kg) or sub-optimal (<5 × 106/kg) collections of CD34+ PBSC in newly diagnosed MM patients eligible for AuSCT, treated with novel agents and receiving an homogeneous mobilizing therapy with cyclophosphamide and granulocyte-colony stimulating factor (G-CSF). To this purpose, 1,348 patients enrolled in five consecutive Italian clinical trials were retrospectively analysed. Age, baseline low peripheral blood cell counts, use of lenalidomide, and haematological toxicity developed during induction were taken into account as possible factors associated with poor mobilization.ResultsOverall, 280 patients (20.8%) showed either sub-optimal (167 patients, 12.4%) or unsuccessful (113 patients, 8.4%) collections. All analysed parameters negatively influenced the procedure, but only age and haematological toxicity during induction maintained their significance at multivariate analysis. Based on ordinal logistic regression model, we constructed a risk heat-map where the four parameters were pooled and weighted according to their relevance as single or combined variables. This model was predictive for different probabilities of failure, suboptimal or optimal outcomes.ConclusionsWe found that about one fifth of newly diagnosed MM fails to collect an adequate number of PBSC. Our model, based on a large group of patients treated frontline with novel agents and receiving the most popular mobilizing approach currently employed in Europe, is applicable in individual subjects and may contribute to the early identification of “poor mobilizer” phenotypes.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-015-0033-1) contains supplementary material, which is available to authorized users.

Evaluation of Dutch guideline for just-in-time addition of plerixafor to stem cell mobilization in patients who fail with granulocyte-colony-stimulating factor.

Plerixafor in combination with granulocyte-colony-stimulating factor (G-CSF) is approved for the use of stem cell collection in patients who fail to mobilize on G-CSF. In 2009 the Stem Cell Working Party of the Dutch-Belgian Cooperative Trial group for Hematology Oncology (HOVON) composed a guideline for the use of plerixafor. According to this guideline it is recommended to add plerixafor to G-CSF in patients with circulating CD34+ cell counts of fewer than 20 × 10(6) /L on 2 consecutive days accompanied by increasing white blood cells. In this analysis we evaluated retrospectively the outcome of the use of this guideline in the Netherlands. In total 111 patients received plerixafor with a median one administration (range, one to four administrations). Of these patients 55.8% had non-Hodgkin lymphoma, 31.5% multiple myeloma, 8.1% Hodgkin lymphoma, and 4.5% nonhematologic malignancies. In 63.9% patients sufficient numbers of CD34+ cells were collected. In patients with multiple myeloma more successful mobilizations with plerixafor were observed compared to patients with non-Hodgkin lymphoma (71.4% vs. 61.3%). In patients with circulating CD34+ cell counts of at least 2.0 × 10(6) /L before administration of plerixafor a successful mobilization was achieved in 76.5%, and in the patients with very low (0-1 × 10(6) /L) circulating CD34+ cell counts the success rate was 44.2%. Application of the HOVON guideline on the just-in-time administration of plerixafor is effective for mobilization of hematopoietic stem cells in the majority of patients. Stem cell yield in patients with non-Hodgkin lymphoma was lower compared to patients with multiple myeloma. Also patients with very low circulating CD34+ cells before addition of plerixafor might benefit from this approach.

Analysis of VDT-PACE Utilization in Multiple Myeloma Patients Treated at MSKCC for Relapsed Disease or Cytoreduction and Stem Cell Mobilization after Initial Induction Therapy

Background: The total therapy 3 protocol for multiple myeloma (MM) introduced the use of intensive induction with VDT-PACE, a combination of bortezomib, dexamethasone, thalidomide, cisplatin, adriamycin, cyclophosphamide, and etoposide for newly diagnosed MM patients. This regimen, which demonstrated rapid responses in the first-line setting, has also been used in relapsed disease, to rescue induction failures or for stem cell mobilization. We evaluated the efficacy and toxicity of using VDT-PACE in these clinical settings.Patients and Methods: We identified 84 patients through pharmacy profile review who received at least one cycle of VDT-PACE for the treatment of MM between 1/2007 and 8/2013 at our institution. Patients were grouped into a stem cell collection cohort (C) if stem cell pheresis was performed following VDT-PACE. Remaining patients were analyzed in the relapsed cohort (RR). The primary objective of this study was to determine the overall response rate with combination VDT-PACE. Secondary Objectives include progression-free survival (PFS), overall survival (OS), stem cell collection in patients that underwent chemomobilization, and the extent of toxicity.Results: In the RR group, 45 patients received VDT-PACE after a median of 4 prior therapies (range 1-8) including autologous stem cell transplantation (ASCT) in 79%. The median time between diagnosis and first cycle of VDT-PACE treatment was 35.4 months (range 1.3-163.4). 47% of patients had adverse cytogenetics defined as presence of complex karyotype or FISH with del 17p, t4;14, or t14;16. Patients received a median of 2 cycles of VDT-PACE (range 1-4) with a response rate after all cycles of 51% (2% CR, 22% VGPR, 27% PR). Additional therapy was administered in 82% within 6 months (18% allogeneic SCT, 35% ASCT, 29% chemotherapy regimens). 18% of patients died without additional therapy (13% from disease progression, 5% from toxicity), all within 5 months of their last VDT-PACE cycle. PFS and OS for the RR group was 8.8 months (95% CI 4.6, 13.1) and 10.3 months (95% CI 8.8, 17.4), respectively. Patients that received subsequent lines of therapy following VDT-PACE achieved a median PFS and OS of 9.5 months (95% CI 5.6, 13.3) and 9.5 months (95% CI 7.5, 32.1), respectively, measured from the time of next therapy.In the C group, 39 patients received a median of 2 prior regimens (range 1-4) before starting VDT-PACE and 31% of patients had adverse cytogenetics. Reasons for using VDT-PACE for mobilization included residual or progressive disease (64%), provider discretion (33%), and failure of a prior attempt at collection (3%). The median time between diagnosis and first cycle of VDT-PACE treatment was 7 months (range 2.3-122.7). Patients received a median of 2 cycles (range 1-4) of VDT-PACE. The median number of cells collected was 12.3x106CD34 cells/kg (range 0.21-43.74) and the median number of collection session required was 2 (range 1-6), with 21% of patients requiring plexirafor. Two patients (5%) from this group failed collection. The response rate after all cycles of VDT-PACE was 59% (3% CR, 13% VGPR, 44% PR). 35 out of the 39 patients went to transplant following VDT-PACE (34 ASCT, 1 allogeneic SCT). Of the 4 patients who did not receive transplant, 2 were for toxicity attributed to VDT-PACE, 1 for failure to mobilize, and 1 for personal reasons. The post-transplant response rate was 91% (17% CR, 34% VGPR, 40% PR) with 1 patient (3%) experiencing disease progression immediately after transplant. Median PFS and OS for the C group patients was 34.5 months (95% CI 20.2, n.r.) and 64.8 months (95% CI 26.0, n.r.), respectively.Reported toxicities following treatment included infection (20%), fatigue (19%), nausea (17%), renal complications (6%), thrombosis (4%), and edema (4%), which were seen in 67% and 62% of the RR and C groups, respectively. Hospital readmission for management of side effects occurred in 30% of patients.Conclusions: VDT-PACE is an effective therapy for RR patients and for stem cell mobilization in patients with residual or progressive disease following initial therapy. Importantly, it is also associated with significant morbidity and requires careful monitoring. VDT-PACE does not appear to adversely affect stem cell collection or SCT outcomes. At our institution, this regimen is commonly used for stem cell collection in patients with unfavorable outcomes following initial therapy. DisclosuresNo relevant conflicts of interest to declare.

Impact of Radiation Therapy on Stem Cell Harvest in Multiple Myeloma

Background:Bone disease is a hallmark of multiple myeloma (MM) and destructive osteolytic bone lesions affect more than 80 % of patients resulting in pain, spinal cord compression and a reduced quality of life. Local radiation therapy (RT) is generally used to achieve rapid improvement of bone pain, control of local tumor growth and recalcification of osseous lesions. However, patients with a high tumor burden, eligible for high dose therapy and autologous stem cell transplantation (ASCT) require systemic treatment with three to four cycles of induction therapy followed by stem cell harvest and high dose therapy. So far, it remains uncertain, if RT prior to mobilization influences stem cell harvest in newly diagnosed patients with MM.Methods:We retrospectively analyzed the impact of RT on stem cell harvest and outcome in 168 transplant-eligible patients with newly diagnosed symptomatic MM (median age 57 years, range 28-73 years). All patients received RT to symptomatic lytic bone lesions before (n=114) or after (n=54) stem cell harvest and high dose therapy. A median of three cycles induction therapy was applied followed by mobilization therapy before stem cell harvest and high dose therapy. We analyzed, whether RT before stem cell collection influenced the number of leukaphereses needed to achieve stem cell yield, the number of stem cells collected per leukapheresis and the total number of collected stem cells. Additionally, we investigated if timing of RT influenced progression-free (PFS) and overall survival (OS) after high-dose therapy and ASCT.Results:Patients receiving RT before stem cell harvest needed more than one leukapheresis to collect the planned number of stem cells (before: 68.8%; after: 44.2%; p=0.09). The median number of stem cells collected per leukapheresis was significantly lower in patients treated with RT before harvest (before: 2.6 x 106 CD34+ cells per kg / bodyweight, after: 3.8 x 106 CD34+ cells per kg / bodyweight; p<0.001). Also the total median number of collected stem cells was significantly lower in the group treated with RT before stem cell harvest (before: 9.0 x 106 CD34+ cells per kg/bodyweight, after: 10.3 x 106CD34+ cells per kg/bodyweight; p<0.02). Patients treated with RT after stem cell harvest showed a longer PFS (48.9 months) compared to the group receiving RT before harvest (36.3 months; p=0.09). No effect on OS was observed.Conclusion:We demonstrate that RT before stem cell harvest negatively influences stem cell collection in patients with symptomatic MM. Furthermore, we observed a negative trend towards shorter PFS in the group treated with RT before stem cell collection. Therefore, we suggest applying RT after stem cell mobilization in transplant-eligible patients with MM if clinically possible. DisclosuresWuchter:Sanofi: Honoraria; ETICHO: Consultancy, Honoraria. Goldschmidt:Janssen-Cilag: Honoraria, Research Funding, Speakers Bureau; Polyphor: Research Funding; Celgene: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Chugai: Research Funding, Speakers Bureau; Onyx: Consultancy, Speakers Bureau; Millenium: Consultancy, Speakers Bureau.

Advanced lytic lesion is a poor mobilization factor in peripheral blood stem cell collection in patients with multiple myeloma.

This study examined the incidence and predictors of peripheral blood stem cell (PBSC) mobilization failure in patients with multiple myeloma (MM). Retrospective data for 104 patients who received granulocyte colony-stimulating factor (G-CSF) alone or with cyclophosphamide as mobilization regimens were analyzed. The rates of mobilization failure using two definitions of failure (< 2 × 10(6) and < 4 × 10(6) CD34(+) cells/kg) following the first collection attempt were 16.3 and 33.7%, respectively. Predictors of mobilization failure were evaluated using logistic regression analysis which included age, advanced osteolytic lesions, bone marrow cellularity before mobilization, platelet count, body mass index before mobilization, and mobilization method. Lytic bone lesions were assessed using a conventional skeletal survey, and advanced osteolytic lesions were defined as lytic lesions in more than three skeletal sites regardless of the number of lytic lesions. On multivariate analysis, advanced osteolytic lesions [hazard ratio (HR) = 10.95, P = 0.001] and age ≥60 years (HR = 5.45, P = 0.016) were associated with a PBSC yield < 2 × 10(6) CD34(+) cells/kg, and advanced osteolytic lesions (HR = 5.08, P = 0.006), white blood cell count ≤4,000/µL before mobilization (HR = 4.72, P = 0.005), and G-CSF only mobilization (HR 10.52, P < 0.001) were associated with PBSC yield < 4 × 10(6) CD34(+) cells/kg. The data suggest that an advanced osteolytic lesion is a significant predictor of mobilization failure in MM patients.