G-CSF Mobilization Research Articles

Intermediate-dose cytarabine plus G-CSF as mobilization regimen for newly diagnosed multiple myeloma and heavily pre-treated patients with hematological and non-hematological malignancies

BackgroundIntermediate-dose cytarabine plus G-CSF has recently emerged as safe and effective mobilization regimen for heavily pre-treated patients with lymphoid malignancies. We prospectively tested this regimen in patients referred to our center in order to collect enough stem cells for hematopoietic rescue in autologous transplantation (auto-HSCT). Study design and methodscytarabine (1.6 g/m2) plus G-CSF (outpatient administration) was performed in 81 consecutive patients who underwent auto-HSCT. For analyses purposes patients were divided into Group A, consisted of 48 patients with newly diagnosed multiple myeloma (MM) and Group B with 33 heavily pre-treated patients (13 Hodgkin´s lymphoma, 7 non-Hodgkin´s lymphoma, 7 MM, 4 germ cell tumor, 2 non-promyelocytic acute myeloid leukemia). ResultsIn the Group A, circulating CD34+ cells/μL was significantly higher, 90% started stem cell harvest on day 14, 98% collected ≥5.0 × 106 CD34+cells/kg and a single apheresis was sufficient in 92% of the cases. In the Group B, 85% started leukapheresis on day 14, 88% collected ≥2.0 × 106 CD34+cells/kg which was achieved with a single apheresis in 82% of the cases; a higher proportion of the patients (63.6% versus 33.3%) required platelet transfusions. Both groups exhibited few adverse events and the time to neutrophil and platelet recovery was similar between groups. ConclusionIntermediate-dose cytarabine plus G-CSF mobilization is effective even for heavily pre-treated patients. The outpatient administration of G-CSF, the reliable prediction of the day to begin harvesting, the optimal CD34+ cell yield obtained with a single apheresis and the fewer occurrences of adverse events denoted the benefits of this regimen.

Genesis - a Phase III Randomized Double-Blind, Placebo-Controlled, Multi-Center Trial Evaluating the Safety and Efficacy of BL-8040 and G-CSF in Mobilization of Hematopoietic Stem Cells for Autologous Transplantation in Multiple Myeloma – Lead-in Period Results

Background CXCR4 mediates retention of hematopoietic stem cells (HSCs) in the bone marrow (BM) niche. BL-8040, a novel, high affinity CXCR4 antagonist is a potent mobilizer of HSCs to the peripheral blood with numerous potential clinical applications, including mobilization of CD34+ cells for autologous HSC transplantation (auto-HSCT) in Multiple Myeloma (MM). This study aims to evaluate the efficacy of single dose BL-8040 plus G-CSF in mobilization of ≥6.0 × 106 CD34+ cells/kg in up to 2 apheresis sessions for auto-HSCT in MM. Methods A Phase III study composed of an open-label, single-arm lead-in Part1 followed by a randomized, double-blinded, placebo-controlled Part2. Eligible MM patients age 18-78 will receive G-CSF (10 µg/kg; SC) daily for up to 8 days and one dose of BL-8040 (1.25 mg/kg; SC) or placebo on day 4 followed by up to 2 apheresis sessions; and if needed a second dose of BL-8040 or placebo on day 6 followed by up to 2 apheresis sessions. Part1 included up to 3 cohorts (∼10 patients/cohort), with Data Monitoring Committee (DMC) review after each cohort. Part2 will include 177 patients randomized 2:1. Results Part1 enrolled 11 patients, median age 61 (57-70). 9/11 patients (82%) reached the primary endpoint of ≥6 × 106 CD34+ cells/kg with one dose of BL-8040 and up to 2 apheresis sessions. 7/11 patients (64%) collected ≥6 × 106 CD34+ cells/kg in one apheresis session. Administration of BL-8040 resulted in a 7.86-fold average increase in circulating peripheral CD34+ cells (range 1.62-15.75, median 7.5, n=9). Additional CD34+ immunophenotyping/subset analyses are currently underway. BL-8040 plus G-CSF was found to be safe and well tolerated. Following these promising results, DMC recommended early continuation to Part2 of the Phase III trial. Conclusions The GENESIS lead-in results demonstrate BL-8040 is a potent mobilizer of HSCs, with potential to improve mobilization rates while minimizing mobilization-related healthcare costs.

Assessment of Safety and Efficacy of PBSC Mobilization with G-CSF and CD34+ Enrichment and Pbmnc (CD3+) Addback in Familial Haploidentical (FHI) Adult Donors with Sickle Cell Disease Trait (SCDT) Prior to Allogeneic HSCT of High-Risk SCD Patients

Background We and others have previously reported the safety of allogeneic stem cell transplantation in children with SCD without sibling HLA matched bone marrow donors who commonly have SCDT. The majority of the sibling donors donated bone marrow and received G-CSF mobilized PBSCs (Bhatia/Cairo et al, BMT 2014; Gluckman et al, Blood 2017). Furthermore, only 14-18% of siblings can serve as donors based on HLA match and presence of SCD (Mentzer, Am J Ped Hem/Onc 1994; Walters, BBMT 1996). Unrelated cord blood as a donor source for SCD patients was associated with unacceptable primary graft failure rates (Radhakrishnan/Cairo, BBMT 2013). MUD HSCT resulted in unacceptably high rates of CGVHD (Shenoy et al, Blood 2016). Parental FHI SCDT PBSCs represent an alternative donor source. However, little is known about G-CSF PBSC mobilization in older donors with SCDT. GCSF mobilization of PBSC in homozygous SCD patients in the past has been reported to be associated with major toxicity and death (Adler et al, Blood 2001). Objective To determine if FHI PBSC mobilization in older adult donors with SCDT is safe and effective. Methods Eighteen FHI donors with SCDT received 15mg/kg/d GCSF divided BID x4 days. PBSC leukapheresis on day 5, repeating qd until 10 × 106 CD34/kg and 2 × 105 CD3/kg (minimum) were cryopreserved. CD34+ enrichment utilized the CliniMACS® System (generously provided by Miltenyi), with 2 × 105 CD3/kg T-cell add-back before HSCT as we have previously described (Geyer/Cairo, BJH 2011). Donor chimerism assays for whole blood CD3, CD71, and CD56 were performed post-HSCT. Results Fifteen female/3 male FHI donors with SCDT were mobilized: mean age 41 yrs (30-55). The most common donor side effect was grade 1 bone pain (n = 11). Other side effects were grade 1 nausea/vomiting (n = 3), grade 1 headache (n = 2), grade 1 dizziness (n = 1), grade 1 fatigue (n = 2), grade 1 abdominal pain (n = 2), grade 3 bone pain (n = 1), and grade 3 thrombocytopenia (n = 1). The mean ± SEM cryopreserved CD34 count was 12.9 ± 0.8 × 106/kg recipient wt with the mean ± SEM yield 533.69 ± 48.9 × 106. Mean ± SD log T-cell (CD3) depletion was 4.84 ± 0.58 (Fig. 1). 100% of patients achieved neutrophil engraftment at a median of 9 days (range 6-13), and 92.1% of patients achieved platelet engraftment at a median of 19 days (range 8-90) (Fig 2A/2B, respectively). Mean ± SEM Blood and CD71+ (RBC) donor chimerism was 97 · 1 ± 1.4 and 96 · 4 ± 2.0%, respectively. Conclusion These data suggest that adult FHI stem cell donors with SCDT undergoing GCSF mobilization for PBSC collection is safe and well-tolerated with only minor temporary adverse events. PBSC collection and CD34 enrichment was effective and resulted in successful SCD recipient engraftment and long-term donor chimerism. Further studies are needed to evaluate the long-term outcome of high-risk SCD patients undergoing FHI AlloHSCT R01FD004090.

Optimizing Plerixafor Algorithm for Mobilization of Peripheral Blood Stem Cells in Patients with Multiple Myeloma Requiring Tandem Transplants

Background Plerixafor is used as an adjuvant to standard G-CSF mobilization to increases CD34+ cell mobilization and decreases the need for multiple days of collection. For patients with multiple myeloma (MM) and a collection goal of ≥5 × 10e6 CD34/kg our center follows an algorithm - if day 4 absolute CD34 is ≤20 cells/µl, patients are given a single dose of plerixafor in addition to G-CSF. For CD34 counts between 20 and 30/ µl, the administration of plerixafor was physician-dependent. Methods To assess the effectiveness of our algorithm we identified 119 consecutive MM patients who had GCSF only mobilization at our center and investigated the relationship between their day 4 absolute CD34, the administration of plerixafor and the number of days of apheresis. The patients were categorized into the following groups based upon day 4 CD34 count and administration of plerixafor (P): CD34 30 noP (n=26). Results In the 30noP group, 23/26 (88%) patients reached goal (range 4.01 × 106 – 9.14 × 106 CD34/kg) on day 1. Patients with Day 4 CD34 count between 20-30/ µl were significantly more likely to collect in one day if they have received Plerixafor (P=0.002). Conclusion This data justifies revision of the threshold for plerixafor administration to patients with a day 4, CD34 count from

Bortezomib in Combination with Cyclophosphamide and G-CSF for Hematopoietic Stem Cell Mobilization in Patients with Multiple Myeloma

Background: Proteasome inhibitors (PI) have become integral part of front-line treatment of multiple myeloma. Murine model experiments have shown mobilization of hematopoietic stem cells from bone marrow to peripheral blood after PI administration via down regulation of very late antigen 4 (VLA-4) which mediate adherence of hematopoietic stem cells to the bone marrow microenvironment via interaction with vascular cell adhesion molecule (VCAM-1). Human studies with bortezomib in combination with G-CSF for mobilization have yielded encouraging results with no additional toxicity and no malignant plasma cell mobilization was observed. Cyclophosphamide based chemo-mobilization offers advantage in term of higher stem cell yield and is able to overcome adverse impact of prior lenalidomide therapy on stem cell harvest. In the current study we added bortezomib to cyclophosphamide-GCSF (B-Cy-GCSF) chemo-mobilization regimen to study the effect of bortezomib on stem cell harvest and compared this with our earlier protocol of only cyclophosphamide-GCSF (Cy-GCSF) mobilization.Methods: Patients of multiple myeloma aged between 18 to 70 years were eligible for the study in the period between March 2016- June 2018. Patients after induction therapy achieving at least partial response and having no more than grade 1 peripheral neuropathy were enrolled. Patients received bortezomib at a dose of 1.3 mg/m2 on day 1, 4, 8 and 11 and cyclophosphamide (Cy) was administered at a dose of 1 g/m2 on day 8 and 9 followed by G-CSF 10µg/kg in two divided doses from day 11 onwards till target stem cell collection of at least 5 X 106/Kg. The peripheral blood CD34 (PB CD34) counts were monitored from day 14 and harvest was initiated when it reached above 20 cells/µL. The peak PB CD34 count achieved, the number of days of harvest required, the CD34 dose yield and the engraftment kinetics were recorded and compared with earlier patients who had undergone Cy-GCSF chemo-mobilization. These patients had received Cy 1 g/m2 on d1 and d2, G-CSF 10 mcg/kg from d4 onwards and PBCD34 monitored from d7 onwards.Result: A total of 37 patients were enrolled between March 2016 and June 2018. Median age of study cohort was 46 years (range 27-63) and 27 (73 %) were males. Median lines of therapy received were 1 (range 1 to 2) and 8 (21.6 %) had received lenalidomide prior to stem cell harvest. The median peak peripheral blood CD34 cell counts 71.3 cells /µL (range 27.5 -306). Median CD34 cells collected were 9.21 X 106 /Kg (range 4.95-17.1). Target CD34 cell collection was achieved after a median of one day harvest (range 1-2). Median time to neutrophil and platelet engraftment was 11.5 and 13.5 days respectively. These results were compared with 88 patients who had undergone Cy-GCSF chemo-mobilization earlier at our center from May 2008 till February 2016 as seen in Table1 . In Cy- G-CSF cohort, median number of harvest required for target CD34 was 2 (range 1-4) and median CD34 cell yield was 8.2 X 106/Kg (0.4-24.2).Target CD34 cells yield of 5 X 106/Kg was achieved with single apheresis in 58.6% of patients after B-Cy-GCSF mobilization as compared to 44.3% in Cy-G-CSF group, although this was not statistically significant (p=0.1). While 3(3.4 %) had failed chemo-mobilization after Cy-GCSF, none of patients in bortezomib group had mobilization failure.Conclusion: Patients undergoing B-Cy-GCSF mobilization have higher stem cell yield and required less days of harvest. This strategy should be explored in a larger cohort of patients. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Kinetics of Myeloid-Derived Suppressor Cells during Stem Cell Mobilization and Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma and Lymphoma Patients

Introduction:Myeloid-derived suppressor cells (MDSC) are immunosuppressive immature cells of the myeloid lineage that play a role in cancer induction, progression and immune evasion. Two major subtypes of MDSC can be distinguished: the polymorphonuclear (PMN-MDSC) and monocytic (M-MDSC).Immune reconstitution after autologous hematopoietic stem cell transplantation (ASCT) may play a role in the therapeutic effect of ASCT in multiple myeloma (MM) and lymphoma patients. Since MDSC are immunosuppressive cells, we postulate they might play a role in the immune reconstitution following ASCT. Here, we studied the effect of G-CSF mobilization on MDSC accumulation and the kinetics of MDSC during G-CSF mobilization and ASCT in MM and lymphoma patients.Methods:Flow cytometry was used to measure MDSC in the stem cell graft (SCG) and peripheral blood mononuclear cells (PBMC) of 9 MM and 4 aggressive lymphoma patients. PMN-MDSC were defined as CD11b+ CD33dim HLA-DR- CD15+ cells and M-MDSC as CD11b+ CD33+ HLA-DRlow/- CD14+ cells. MDSC were measured at G-CSF start, time of stem cell (SC) collection and following ASCT at predefined time points (day 0, day +14, day +28, day +100, day +360). Values are reported as mean percentage of MDSC of living cells. For SC mobilization, MM patients received high-dose cyclophosphamide and G-CSF, lymphoma patients received R-DHAP and G-CSF. 3/9 MM patients and 4/4 lymphoma patients had a complete response at the time of SC collection. As conditioning regimen MM patients received melphalan, lymphoma patients received BEAM.Results:In PBMC of both MM and lymphoma patients, G-CSF mobilization increased PMN-MDSC levels: 10.06% at start G-CSF vs 46.44% at SC collection in MM patients (p=0.0006); 19.65% at start G-CSF vs 50.74% at SC collection in lymphoma patients (p=0.1143). After ASCT, PMN-MDSC levels tended to decrease: 28.21% at day 0 vs 7.94% at day +180 in MM patients (p=0.1061); 40.35% at day 0 vs 2.32% at day +180 (p=0.2000) in lymphoma patients. This in contrast to M-MDSC levels, which were not influenced by the use of G-CSF: 5.77% at start G-CSF vs 3.67% at SC collection in MM patients (p=0.3704); 6.52% at start G-CSF vs 3.23% at SC collection in lymphoma patients (p=0.3429). M-MDSC levels remained rather stable during the transplant period, but tended to increase after ASCT: 3.80% at day 0 vs 8.81% at day +180 in MM patients (p=0.0417); 1.24% at day 0 vs 16.70% at day +180 in lymphoma patients (p=0.3333). When comparing MDSC levels in PBMC and the SCG, we observed a decrease in the PMN-MDSC/M-MDSC ratio in the SCG in MM patients (p=0.0078) and in lymphoma patients (p=0.1250). In the SCG, fewer PMN-MDSC and more M-MDSC were present as compared to PBMC. Interestingly, the expression of IL-4Rα on PMN-MDSC (p=0.0078) and M-MDSC (p=0.0078) in PBMC was increased after G-CSF, at time of SC collection.Conclusion:The kinetics of both MDSC subtypes were comparable between MM and lymphoma patients. G-CSF mobilization resulted in the accumulation of PMN-MDSC, but not of M-MDSC. In addition, the expression of IL-4Rα increased on both MDSC subtypes after G-CSF, indicating a potential higher immunosuppressive capacity of MDSC. In both MM and lymphoma patients, PMN-MDSC levels decreased after ASCT, whereas M-MDSC levels increased after ASCT. This might be due to the natural development of these cells. However, further research, including the effect of MDSC on immune reconstitution and the effect of G-CSF on the immunosuppressive capacity of MDSC, is warranted. DisclosuresNo relevant conflicts of interest to declare.

A Phase II Study of Dasatinib and Dexamethasone As Primary Therapy Followed By Transplantation for Adults with Newly Diagnosed Ph/BCR-ABL1-Positive Acute Lymphoblastic Leukemia (Ph+ ALL): Final Results of Alliance/CALGB Study 10701

Dasatinib with corticosteroid yields high complete remission (CR) rates in Ph+ ALL with minimal induction death. Optimal post-remission therapy is not known. We report a prospective study evaluating dasatinib/dexamethasone induction then consolidation with reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT), autologous HCT (autoHCT), or chemotherapy alone (chemo), followed by dasatinib-based maintenance. Methods: We conducted a phase II, 3-arm, non-randomized trial (NCT01256398, Support: U10CA180821, U10CA180882, U10CA180861, U24CA196171) at 17 US centers with primary objectives to determine 3-year overall survival (OS) and disease-free survival (DFS) of adults ≥18 years (yrs) old with untreated Ph+ ALL treated with dasatinib/dexamethasone induction, CNS prophylaxis with systemic and intrathecal methotrexate, consolidation with alloHCT, autoHCT, or chemo, then dasatinib maintenance. Induction (Course I) used dasatinib 140 mg orally daily and dexamethasone 10 mg/m2/day orally or IV days 1-7. If ≤20% lymphoblasts in marrow at Day 15, Course II continued dasatinib with 7 days of dexamethasone. If >20% lymphoblasts, patients (pts) also received vincristine and daunorubicin. Pts not in CR/CRi received a second induction (Course III) with dasatinib, cyclophosphamide, vincristine, daunorubicin, and dexamethasone. CNS prophylaxis (Course IV) used dasatinib, IV vincristine and IV, oral, and intrathecal methotrexate. Course V consisted of HCT or chemo. Pts 18-70 yrs old underwent RIC alloHCT if they had a HLA-matched donor; otherwise they underwent autoHCT. AlloHCT conditioning used fludarabine 30 mg/m2/day IV day -7 through -3, alemtuzumab 20 mg/day IV day -7 through -3, and melphalan 140 mg/m2 IV once on day -2. GVHD prophylaxis with tacrolimus began day -2. Pts undergoing autoHCT received etoposide 10 mg/kg/day (age >65, 5 mg/kg/day) CIV for 4 days and cytarabine 2 g/m2 (age >65, 1 g/m2) IV every 12 hours for 8 doses then G-CSF for mobilization. AutoHCT conditioning was melphalan 100 mg/m2/day IV on days -2 and -1. Pts >70 yrs old or unable to undergo HCT received etoposide/cytarabine alone. Dasatinib maintenance (Course VI) began day 30 of Course V and continued for 12 months and until 2 consecutive negative BCR-ABL1 RT-PCR assays 3 months apart or relapse. BCR-ABL1 isoform and ABL1 kinase domain (KD) mutation determination were done locally. Results: From 12/15/2010 to 11/14/2014, 64 eligible pts enrolled. Median age was 60 yrs (22-87); median WBC 23.2 x 103/μl (0.3-454). The dominant BCR-ABL1 isoform was p190 in 59%, p210 in 17%, and not reported in 23%. The CR rate was 97% with no induction deaths. Fifty-five pts completed CNS prophylaxis (Course IV). Twenty pts underwent protocol-specified alloHCT, 7 autoHCT, and 9 chemo. Nine pts underwent off-study alloHCT and 5 skipped Course V. Dasatinib maintenance was tolerable with 72%, 80%, and 80% receiving >50% of planned maintenance doses in alloHCT, autoHCT, and chemo arms, respectively. With a median follow up of 48 months (37-78) for survivors, 3-yr OS and DFS were 55% (median OS 45 months) and 43% (median DFS 30 months), respectively. For pts undergoing consolidation with protocol-specified alloHCT, autoHCT, or chemo, 3-yr OS was 75%, 71%, and 55% respectively with median OS not reached (NR) for all groups. DFS at 3-yrs was 55%, 43%, and 46% respectively. Median DFS for alloHCT was 42 months vs 15 months for autoHCT and 34 months for chemo (Log-Rank P=0.4). Outcomes were similar with inclusion of off-study alloHCT and chemo patients skipping Course V. Relative to p190 BCR-ABL1 isoform, p210 was associated with shorter median OS (NR vs 16 months, P=0.04) and median DFS (35 months vs 10 months, P Conclusions: Dasatinib and dexamethasone followed by alloHCT, autoHCT, or chemo yield similar 3-yr survival comparable to approaches using intensive induction chemotherapy. Pts with the p210 BCR-ABL1 isoform had dismal outcomes and may benefit from alternate approaches. T315I mutation was the major cause of relapse and should be addressed in future studies. Disclosures Wieduwilt:Amgen: Research Funding; Reata Pharmaceuticals: Equity Ownership; Daiichi Sankyo: Membership on an entity9s Board of Directors or advisory committees; Leadiant: Research Funding; Shire: Research Funding; Merck: Research Funding. Uy:GlycoMimetics: Consultancy; Curis: Consultancy. Powell:Rafael Pharmaceuticals: Membership on an entity9s Board of Directors or advisory committees. Kolitz:Magellan Health: Consultancy, Honoraria. Liedtke:Caelum: Membership on an entity9s Board of Directors or advisory committees; Takeda: Membership on an entity9s Board of Directors or advisory committees, Research Funding; Amgen/Onyx: Consultancy, Honoraria, Research Funding; Gilead: Membership on an entity9s Board of Directors or advisory committees, Research Funding; celgene: Research Funding; Genentech/Roche: Research Funding; Pfizer: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding; Prothena: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding; BlueBirdBio: Research Funding. Stock:Jazz Pharmaceuticals: Consultancy. Devine:Kiadis Pharma: Consultancy. Larson:BristolMyers Squibb: Consultancy, Research Funding; Ariad/Takeda: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding.

Post-ASCT Outcomes in Multiple Myeloma Patients Who Underwent ASCT with G-CSF+Plerixafor Versus G-CSF Mobilized Graft

BACKGROUND: Impact of Plerixafor (P) mobilized stem cells on immune reconstitution of autologous stem cell transplant (ASCT) patients has not been established. Early lymphocyte recovery (Absolute lymphocyte count of > 1 K/uL at day 30 after transplant) has been established to predict outcomes in multiple myeloma (MM) patients. The purpose of this study was to evaluate lymphocyte recovery in MM patients who underwent ASCT with stem cells mobilized with G-CSF vs G-CSF+P. Secondary objective was to evaluate the survival outcomes.METHODS: This is a retrospective analysis of MM patients who underwent first ASCT between 2008 and 2016 with either G-CSF or G-CSF+P mobilization at Karmanos Cancer Institute in Detroit, Michigan. Plerixafor was used per institutional guidelines when the peripheral CD-34+ve cell-count was < 20/ uL on day 5 of G-CSF mobilization. 610 total patients were identified. Mobilization agents used were G-CSF alone (n= 469) or G-CSF+P (n= 141). All patients underwent transplant after Melphalan (M) conditioning and dose of M was at treating physician's discretion (140 vs 200 mg/m2). The primary endpoint was the Absolute Lymphocyte Count at day 30 (ALC30). Secondary endpoints were PFS and OS Univariable and multivariable Cox proportional hazards regression models were fit to assess associations between ten pre chosen predictors( age, race, stage at diagnosis, doublet vs. triplet therapy, lines of treatment, disease status, mobilization agents, melphalan dose, ALC at day 30, post- transplant maintenance) and survival benefit (PFS and OS).RESULTS: Median age of patients was older in G-CSF+P group (62 vs 60 years, p=. 006) and they were more likely to receive triplet therapy (82 vs 72%, p=. 015) for induction compared to G-CSF group (Table 1). Patients in G-CSF group were more likely to receive greater than one line of treatment before transplant (p=. 006). Disease status at transplant was similar between the two groups. G-CSF patients received higher dose of M (at 200mg/ m2) more frequently (69 vs. 58%, p = 0.010) and median cell dose infused was higher in G-CSF group (3.19 vs 2.88 x106 CD 34+ve-cells/Kg, p= 0.001).Primary endpoint, ALC30, was 1.3 K/uL(.1-4.5) and 1.2 K/uL(.1-5.1) for G-CSF and G-CSF+P, respectively (p=. 608). Median day to neutrophil recovery were similar in both groups (ANC of 500 at Day 12). Post-transplant maintenance use was similar between the two groups. The median PFS was 2.46 years (95% CI, 2.14 to 3.15) and 2.77 years (95% CI, 1.99 to 3.27) for G-CSF and G-CSF+P, respectively (HR: 1.128; 95% CI, (.843-1.509); p=. 417) (Figure 1). The median OS was 6.09 years (95% CI, 4.55 to NR) and 3.73 years (95% CI, 3.20 to NR) for G-CSF and G-CSF+P, respectively (HR: 1.638; 95% CI, (1.118-2.399); p=. 011) (Figure 2) .In MVA, higher stage at diagnosis, less than PR before ASCT, and no post-transplant maintenance therapy were associated with worse PFS and OS. More lines of treatment adversely impacted PFS. Use of G-CSF+P for mobilization and Melphalan dose ≤ 200-mg/ m2 adversely impacted OS. ALC30 did not impact PFS or OS in MVA. There were no significant differences in causes of death among the 2 groups.CONCLUSIONS: In this large, retrospective analysis of MM patients mobilized with G-CSF vs G-CSF + P, there was no significant difference in lymphocyte recovery. Higher Melphalan dose resulted in improved OS in the MVA. There was an overall survival difference favoring the G-CSF group, however, differences in baseline characteristics not accounted for in the MVA may be responsible for this observation. A Prospective study comparing these mobilization regimens including patients with similar baseline characteristics is necessary to confirm this finding. [Display omitted] DisclosuresDeol:Kite Pharmaceuticals: Consultancy; Novartis: Consultancy.

Intrabone Delivery of CD34+ Cells Using an Optimized Delivery System Does Not Enhance Engraftment in a Rhesus Macaque Model of Hematopoietic Stem Cell Transplantation

Introduction: Umbilical cord blood (UCB) grafts are the only option for a significant minority of patients who require hematopoietic stem cell transplantation (HSCT) but lack a suitable related or unrelated donor. While UCB can serve as a suitable ‘off the shelf’ graft for many patients, units with the best HLA match often contain low and sometimes insufficient numbers of CD34+ cells for use in transplantation, particularly for adult patients. Furthermore, UCB grafts contain lower CD34+ cells number compared to BM or PBSC grafts, which leads to longer engraftment times and a higher risk of graft failure. BM and PBSC grafts are usually injected intravenously, homing to the bone marrow after several hours in the circulation. During this time, CD34+ cells are lost in the lungs, liver and spleen with typically < 20% making it to the bone marrow.1 Investigators have sought to overcome the limitation of low cell dose in UCB grafts and loss of CD34+ cells in the circulation by injecting CD34+ cells directly into the bone marrow space. However, we have recently shown that conventional intrabone delivery methods used in investigational trials to transplant UCB, result in low-level retention of hematopoietic progenitor cells in the intrabone space. Recently, we developed an optimized intrabone (OIB) transplant method using computer controlled low pressure and low volume injection (controlled infusion rate <0.2ml/min, total volume <5ml) under CT guidance. Utilizing porcine and rhesus macaque models, we have shown that OIB delivery of CD34+ cells improves intrabone retention, preventing circulation of CD34+ cells through the lungs, which is observed with conventional non-optimized intrabone methods.2 Here we conducted experiments using an autologous myeloablative transplant model in rhesus macaques comparing engraftment of gene-marked CD34+ cells transplanted intravenously, with cells transplanted using OIB delivery.Methods: Rhesus macaques received GCSF and plerixafor mobilization prior to apheresis. Products were CD34+ selected using Miltenyi beads. CD34+ cells were split equally for transduction with lentiviral vectors encoding the reporters GFP and YFP. After myeloablative conditioning with 10Gy total body irradiation, half the graft was injected directly intra-bone using the OIB method, with the other half of the autograft simultaneously being injected intravenously via slow iv push. Peripheral blood samples were measured daily by flow cytometry to assess the proportion of engrafting cells deriving from each source. To address whether OIB transplantation could allow engraftment of low CD34+ cell numbers, as found in UCB units, the cell doses transplanted in one rhesus macaque recipient were reduced to only 0.5 x 106CD34+ cells/kg.Results: CD34+ cells injected intrabone utilizing the OIB method engrafted in all 3 animals. However, flow cytometric analysis gating on GFP vs YFP positive neutrophils showed CD34+ cells injected utilizing OIB delivery did not engraft quicker than IV transplanted cells. Sequential monitoring of neutrophils over 30 days showed the contribution to hematopoiesis of OIB delivered cells was significantly lower than the cells injected IV (Table 1.)Conclusions: We developed a novel intrabone delivery system that optimizes the retention of CD34+ cells into the bone marrow space. Although autologous CD34+ cells injected using this OIB transplant method were capable of engrafting in rhesus macaques that had undergone myeloablative conditioning, they did not engraft faster and contributed less to hematopoiesis than CD34+ cells simultaneously transplanted using conventional IV infusion. These data raise questions over whether intrabone delivery, even when using techniques to optimize intrabone retention, has utility in improving CD34+ cell engraftment.

Lentiglobin Gene Therapy for Patients with Transfusion-Dependent β-Thalassemia (TDT): Results from the Phase 3 Northstar-2 and Northstar-3 Studies

Lentiglobin Gene Therapy for Patients with Transfusion-Dependent β-Thalassemia (TDT): Results from the Phase 3 Northstar-2 and Northstar-3 Studies

Clinical Outcomes of Lentiglobin Gene Therapy for Transfusion-Dependent β-Thalassemia Following Completion of the Northstar HGB-204 Study

Clinical Outcomes of Lentiglobin Gene Therapy for Transfusion-Dependent β-Thalassemia Following Completion of the Northstar HGB-204 Study

Effects of CD34(+) selected stem cells for the treatment of poor graft function after allogeneic stem cell transplantation

目的观察输注纯化供者CD34+细胞治疗单倍型造血干细胞移植后移植物功能不良的疗效和安全性。方法对2014年1月至2018年3月期间接受供者纯化CD34+细胞治疗的12例单倍型造血干细胞移植后移植物功能不良患者进行回顾性分析。结果12例患者中男9例、女3例，中位年龄26（14~54）岁；急性淋巴细胞白血病4例，急性髓系白血病5例，慢性髓性白血病2例，慢性粒-单核细胞白血病1例。分选产物CD34+细胞纯度为92.0%（44.0%~97.0%），回收率为55.0%（45.0%~96.7%），回输CD34+细胞的中位数为1.9（0.9~4.4）×106/kg，CD3+细胞中位数为0.6（0.3~2.0）×104/kg。中性粒细胞恢复中位时间为18（14~39）d，血小板恢复中位时间为29（16~153）d，红细胞恢复中位时间为60（9~124）d。12例患者输注过程中未发生严重不良反应，10例获得完全缓解，1例患者获得部分缓解，1例患者无效，未发生重症感染和重度GVHD。结论回输供者纯化CD34+细胞是单倍型造血干细胞移植后植入功能不良的一种安全、有效治疗方法。

Efficiency of DA-EPOCH and MA chemotherapy in the mobilization of autologous peripheral blood stem cells in non-Hodgkin's lymphoma

Objective: To study the effect and safety of the DA-EPOCH chemotherapy combined with G-CSF and the MA chemotherapy combined with G-CSF on mobilizing and collecting the peripheral blood stem cells and the later hematopoietic recovery. Methods: A total of 40 patients accepted mobilization and collection of peripheral blood stem cells(PBSC) after being treated by DA-EPOCH+ G-CSF and MA+ G-CSF therapy respectively, and performed auto-transfusion. The effect of mobilization, the adverse effects and the hematopoietic recovery after autologous transplantation were analyzed retrospectively. Results: Two cases in DA-EPOCH group and 1 case in MA group did not achieve the collection goal and required a G-CSF mobilization therapy again. During the DA-EPOCH mobilization therapy, the lowest median WBC was[0.7(0.5, 0.9)]×10(9)/L and the median lowest platelet (PLT) count was[75.0 (53.0, 107.0)]×10(9)/L.Low-grade fever occurred in 7 cases (37.5-38.3 ℃) and platelet transfusion was required in 2 cases. The collection of MNC number was (5.8±1.8)×10(8)/kg, and the median CD34(+) cell number was[3.7(2.8, 6.7)]×10(6)/kg; for the MA therapy groups, the numbers were[0.4 (0.2, 0.9)]×10(9)/L and[12.0 (6.0, 16.0)]×10(9)/L, respectively. High fever occurred in 8 cases (above 39 ℃). PLT transfusion was required in 15 cases and red blood cell(RBC) transfusion in 4 cases. The collected number of MNC was (6.0±2.9)×10(8)/kg, and CD34(+) median cell number was[8.5(2.6, 11.2)]×10(6)/kg. There are significant differences between the lowest PLT counts and CD34(+) cell numbers in the two groups of patients(P<0.05). A peripheral blood leukocyte increase in 10(9, 11) days and platelet implantation in 12(11, 16) days were observed after ASCT by DA-EPOCH therapy. In MA group, the number were 10(9, 11) and 12(11, 15) days. The hematopoietic recovery in both groups were successful, without any statistically difference(P>0.05). No death occurred during the process of transplantation. Conclusions: DA-EPOCH and MA chemotherapy could effectively mobilize the peripheral blood stem cells in suitable NHL patients.DA-EPOCH chemotherapy was higher in safety and lower in price, and required less transfusion compared with MA therapy.

Effects of different doses of granulocyte colony-stimulating factor mobilization therapy on ischemic cardiomyopathy

G-CSF mobilization might be beneficial to ICM, but the relationship between effect/safety and the dosage of G-CSF remains unclear. In this study, 24 pigs were used to build ICM models and were randomized into four groups. Four weeks later, different dosages of G-CSF were given daily by subcutaneous injection for 5 days. Another 4 weeks later, all the animals were sacrificed. Electrocardiography, coronary arteriography, left ventriculography, transthoracic echocardiography, cardiac MRI, and SPECT, histopathologic analysis, and immunohistochemistry techniques were used to evaluate left ventricular function and myocardial infarct size. Four weeks after G-CSF treatment, pigs in middle-dose G-CSF group exhibited obvious improvements of left ventricular remodeling and function. Moderate G-CSF mobilization ameliorated the regional contractility of ICM, preserved myocardial viability, and reduced myocardial infarct size. More neovascularization and fewer apoptotic myocardial cells were observed in the ischemic region of the heart in middle-dose group. Expression of vWF, VEGF and MCP-1 were up-regulated, and Akt1 was activated in high- and middle-dose groups. Moreover, CRP, TNF-α and S-100 were elevated after high-dose G-CSF mobilization. Middle-dose G-CSF mobilization therapy is an effective and safe treatment for ICM, and probably acts via a mechanism involving promoting neovascularization, inhibiting cardiac fibrosis and anti-apoptosis.

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.

DA-EPOCH Chemotherapy Combined with G-CSF Effectively Mobilizes Autologous PBHSC in NHL Patients

To study the effect of the DA-EPOCH chemotherapy combined with G-CSF and the CTX therapy with G-CSF on mobilizing and collecting the peripheral blood hematopoietic stem cells and the later hematopoietic recovery. Forty patients accepted mobilization and collection of peripheral blood stem cells(PBSC) after treated by CTX+G-CSF and DA-EPOCH+G-CSF therapy respectively, and were treated by auto-transfusion after BEAM pre-regimen. The mobilization efficacy, adverse effects and hematopoietic recovery after autologous transplantation were analyzed retrospectively. During the CTX+G-CSF mobilization, only one patient achieved the white blood cell(WBC) at 0.8×109/L, while the others were with the lowest WBC level above 2.0×109/L. The platelet counts were all normal with the exception of 3 cases at 80×109/L. The median percentage of CD34+ cells in one period of collection was 0.99(0.35-1.30)%. The median MNC was (3.80±2.05)×1010. The cumulative total of mononuclear cell was (5.84±2.48)×108/kg, and the median CD34+ cell count was 3.84(3.91-6.5)×106/kg. During the DA-EPOCH+G-CSF mobilization, the peripheral WBC count of patients were decreased to the lowest level at (0.2-1.4)×109/L. The platelet counts were all above 40×109/L except for 1 case in which the platelet count was reduced to 8×109/L. The median percentage of CD34+ cells in one period of collection was 0.85(0.34-1.2)%. The median MNC was (3.68±1.56)×1010. The cumulative total of mononuclear cells was (6.01±2.26)×108/kg, and the median CD34+ cell count was 4.44(2.7-7.10)×106/kg. There were no statistical differences between the 2 groups in the median percentage of CD34+ cells, the median MNC, the cumulative total of mononuclear cells and the median CD34+ cell counts (P>0.05). The average acquired time for granulocyte engraftment was 10.00(9.00-11.00) days, and for platelet engraftment was 12.50(11.00-17.25) days, with no statistical difference(P>0.05). No death occurred during the process of transplantation. DA-EPOCH therapy combined with G-CSF can effectively mobilize the peripheral blood hematopoietic stem cells in NHL patients with higher safety and lower price, and proves to be worth recommending in clinical use.

UK consensus statement on the use of plerixafor to facilitate autologous peripheral blood stem cell collection to support high-dose chemoradiotherapy for patients with malignancy.

Plerixafor is a CXC chemokine receptor (CXCR4) antagonist that mobilizes stem cells in the peripheral blood. It is indicated (in combination with granulocyte-colony stimulating factor [G-CSF]) to enhance the harvest of adequate quantities of cluster differentiation (CD) 34+ cells for autologous transplantation in patients with lymphoma or multiple myeloma whose cells mobilize poorly. Strategies for use include delayed re-mobilization after a failed mobilization attempt with G-CSF, and rescue or pre-emptive mobilization in patients in whom mobilization with G-CSF is likely to fail. Pre-emptive use has the advantage that it avoids the need to re-schedule the transplant procedure, with its attendant inconvenience, quality-of-life issues for the patient and cost of additional admissions to the transplant unit. UK experience from 2 major centers suggests that pre-emptive plerixafor is associated with an incremental drug cost of less than £2000 when averaged over all patients undergoing peripheral blood stem cell (PBSC) transplant. A CD34+ cell count of <15 µl-1 at the time of recovery after chemomobilization or after four days of G-CSF treatment, or an apheresis yield of <1 × 106 CD34+ cells/kg on the first day of apheresis, could be used to predict the need for pre-emptive plerixafor.

G-CSF inhibits LFA-1-mediated CD4+ T cell functions by inhibiting Lck and ZAP-70.

In this study, we showed that G-CSF mobilization increased the frequency of T cells, specifically CD3+CD4+ T cells. G-CSF mobilization decreased the secretion of inflammatory cytokines of CD4+ T cells through the LFA-1/ICAM-1 signaling pathway, whereas it did not alter the TH1/TH2 ratio. We found that G-CSF mobilization inhibited LFA-1-mediated CD4+ T cell polarization and motility. In vitro, G-CSF stimulation also attenuated the polarization and adhesiveness of CD4+ T cells through the LFA-1/ICAM-1 interaction. Further investigation revealed that G-CSF mobilization suppressed LFA-1 signaling by down-regulating Lck and ZAP-70 expression in CD4+ T cells, similar results was also confirmed by in-vitro studies. These findings suggested that G-CSF directly suppressed LFA-1-mediated CD4+ T cell functions through the down-regulation of Lck and ZAP-70. The immunosuppressive effect of G-CSF mobilization deepened our understanding about peripheral blood hematopoietic stem cell transplantation. LFA-1/ICMA-1 pathway may become a potential target for graft-versus-host disease prophylaxis.

125 - Impact of G-CSF mobilization on T-cell functionality: New aspects for adoptive immunotherapy

125 - Impact of G-CSF mobilization on T-cell functionality: New aspects for adoptive immunotherapy

A Phase II Study of Dasatinib and Dexamethasone As Primary Therapy Followed By Hematopoietic Cell Transplantation for Adults with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: CALGB Study 10701 (Alliance)

Background:Potent inhibitors of BCR-ABL1have improved remission results and altered post-remission therapy for Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Dasatinib plus dexamethasone followed by hematopoietic cell transplantation (HCT) promises high response rates, reduced toxicity, and durable remissions.Methods:We conducted a Phase II trial at 17 U.S. centers with the primary objective being to estimate the 3-year overall survival and disease-free survival of patients with Ph+ ALL treated with dasatinib and dexamethasone for remission induction and intensification, central nervous system (CNS) prophylaxis, consolidation with reduced-intensity conditioning (RIC) allogeneic HCT, autologous HCT, or etoposide and cytarabine, and dasatinib-based maintenance. Eligible patients had untreated Ph+ ALL, were ≥18 years old, and had normal cardiac function. Induction (Course I) used dasatinib 140 mg oral daily and dexamethasone 10 mg/m2/day oral or intravenous (IV) days 1-7. For patients with ≤20% blasts in the Course I, Day 15 bone marrow biopsy, intensification (course II) continued daily dasatinib with another 7 days of dexamethasone. Those with >20% lymphoblasts also received vincristine (VCR) and daunorubicin (DNR). Patients (n=3) not in CR/CRi after Course II received a second induction (Course III) with dasatinib, cyclophosphamide, VCR, DNR, and dexamethasone. After Course II or III, CNS prophylaxis (Course IV) consisted of IV VCR and IV, oral, and intrathecal methotrexate (MTX). Dasatinib was restarted at serum [MTX] <0.05 microM. Course V consisted of HCT or chemotherapy. Patients aged 18-70 years with an HLA-matched donor underwent RIC allogeneic HCT; otherwise they underwent autologous HCT. Allogeneic HCT conditioning used fludarabine 30 mg/m2/day IV day -7 through -3, alemtuzumab 20 mg/day IV day -7 through -3, and melphalan 140 mg/m2 once on day -2. GVHD prophylaxis with tacrolimus began day -2. Patients undergoing autologous HCT received etoposide 10 mg/kg/day (age >65 years, 5 mg/kg/day) continuous IV for 4 days and cytarabine 2 g/m2 (age >65 years, 1 g/m2) IV every 12 hours for 8 doses (EA) then G-CSF for mobilization. Autologous HCT conditioning used melphalan 100 mg/m2/day on days -2 and -1. Patients >70 years or unable to undergo HCT received EA alone. Dasatinib maintenance (Course VI) began on day 30 of Course V and continued for 12 months and until 2 consecutively negative bone marrow BCR-ABL1RT-PCR assays 3 months apart or until relapse. Dasatinib levels were measured on day 15 of induction.Results:Sixty-six patients enrolled from 12/15/2010 to 11/14/2014; 65 received dasatinib and are evaluable. Median age was 60 years (22-87); 49% were male. Median presenting WBC count was 23.1 x 103/ul (0.3-453.6). No deaths occurred during induction or intensification. CR or CRi occurred 31 patients (48%) by Day 15 of induction and in 62 patients overall (95%; CR 86%). Median dasatinib levels in serum and CSF on Day 15 of induction were 30.3 ng/mL (<3-308) and 0.29 ng/mL (<0.2-1.37), respectively suggesting approximately 1% of plasma dasatinib penetrates into the CSF, less than the unbound fraction (6%). Fifty-four patients started Course IV, 38 Course V, and 37 Course VI. Fourteen patients continue on protocol therapy. Of 38 patients receiving Course V, 22 had allogeneic HCT, 6 had autologous HCT, and 10 had EA chemotherapy. Median age of allogeneic HCT recipients was 61 years (31-69). Robust autologous stem cell mobilization was observed [median CD34+ cell count, 90 x 106/kg (31-166, n=6)]. Dasatinib maintenance was feasible after allogeneic HCT, autologous HCT, and chemotherapy alone with no missed doses in 59%, 83%, and 63% of cycles, respectively. Ten patients have relapsed with one isolated CNS relapse. No relapses have occurred after allogeneic HCT with 3 relapses after autologous HCT and one after Course V EA alone. Median follow up for survivors is 22.8 months (longest, 51 months). There have been 23 deaths: 5 treatment-related (4 after allogeneic HCT, 1 after course V EA), 16 disease-related and 2 unrelated.Conclusions:Dasatinib with dexamethasone yields CR rates comparable to those reported with tyrosine kinase inhibitors combined with conventional chemotherapy. Post-remission therapy with reduced-intensity allogeneic HCT, autologous HCT, or chemotherapy followed by dasatinib maintenance is feasible. Survival follow up is maturing. DisclosuresStock:Sigma-Tau: Honoraria, Research Funding; Royalties for a chapter in Up to Date: Patents & Royalties; ADC Therapeutics: Honoraria; Amgen: Honoraria; Gilead Sciences: Honoraria. Beumer:Bristol-Myers Squibb: Research Funding. Stone:Abbvie: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Pfizer: Consultancy; Juno Therapeutics: Consultancy; Karyopharm: Consultancy; Sunesis Pharmaceuticals: Consultancy; Agios: Consultancy; Amgen: Consultancy; Celator: Consultancy; Celgene: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Novartis: Consultancy; Jansen: Consultancy; Merck: Consultancy; ONO: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Xenetic Biosciences: Consultancy. Larson:Bristol-Myers Squibb: Consultancy; Astellas: Consultancy, Research Funding.