Mobilization with Plerixafor (Mozobil ®)Plus G-CSF Results in Superior Day 1 Collection of CD34+ Cells Compared to Placebo Plus G-CSF: Results From Two Randomized Placebo-Controlled Trials in Patients with Multiple Myeloma or Non-Hodgkin's Lymphoma.

Abstract Abstract 3224 Poster Board III-161 Background While most centers use 2 × 106 CD34+ cells/kg as the minimal cell dose for autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT), infusion of higher CD34+ cell dose is associated with better outcomes in patients with multiple myeloma (MM) or non-Hodgkin's lymphoma (NHL). Recent evidence suggests a correlation between CD34+ cell yield on Day 1 of collection and total CD34+ cell yield as well as post-transplant outcomes. This analysis was designed to: 1) compare Day 1 collection between patients with NHL or MM mobilized with plerixafor plus G-CSF or placebo plus G-CSF; and 2) determine whether Day 1 CD34+ cell yields correlated with the total mobilization yield and number of apheresis days. Methods Data were obtained from two prospective, randomized, double-blind, placebo-controlled, phase 3 clinical trials that compared the safety and efficacy of plerixafor (0.24 mg/kg/day SQ) plus G-CSF (10 μg/kg/day) with placebo plus G-CSF for mobilization of HSC for auto-HSCT in patients with NHL (3101 Study) or MM (3102 Study). Pearson correlation coefficient was used to evaluate the association of day 1 CD34+ cell collection with total CD34+ cell yield and the number of days of apheresis. Results In the NHL trial, 150 patients were mobilized with plerixafor plus G-CSF and 148 patients underwent mobilization with placebo plus G-CSF. More than half the patients (55.3%) in the plerixafor group collected ≥2 × 106 CD34+ cells/kg on Day 1 of apheresis (Figure 1A). In contrast, 19.6% patients in the placebo group collected ≥ 2 × 106 CD34+ cells/kg on Day 1 of apheresis (p< 0.001). In the MM study, 148 patients were mobilized with plerixafor plus G-CSF and 154 patients were mobilized with placebo plus G-CSF. More than half the patients (52.7%) in the plerixafor group collected ≥6 × 106 CD34+ cells/kg on the first day of collection compared to only 16.9% patients in the placebo group (p<0.001; Figure 1B). There was a strong positive correlation between day 1 collection and the total CD34+ cell yield in patients with NHL (r= 0.86, p-value= <0.0001) or MM (r= 0.87, p-value= <0.0001) in both the plerixafor and placebo groups. For NHL patients, the median Day 1 collection was higher in the plerixafor group compared to the placebo group: 2.66 × 106 vs. 0.77 × 106 CD34+ cells/kg (p<0.001) and this translated into higher total CD34+ cell yields in the two groups respectively: 5.69 × 106 vs. 1.98 × 106 CD34+ cells/kg (p<0.001). Similarly, for MM patients, the median CD34+ cells/kg collected on Day 1 was higher in the plerixafor group compared to the placebo group: 7.01 × 106 vs. 2.29 × 106 CD34+ cells/kg (p<0.001) and this translated into better overall collection in the plerixafor vs. placebo groups: 10.96 × 106 vs. 6.18 × 106 CD34+ cells/kg (p<0.001). A negative correlation was observed between CD34+ cells collected on Day 1 and the number of days of apheresis performed in patients with NHL (r= -0.67, p-value=<0.0001) or MM (r= -0.50, p-value= <0.0001) in both the plerixafor and placebo groups. Consequently, better Day 1 collection in plerixafor-treated NHL or MM patients translated into significantly fewer apheresis days to achieve the target collection compared to placebo treated patients. Conclusions These data support previous reports demonstrating a strong correlation between day 1 CD34+ cell collection and total CD34+ cell yield and apheresis days. These data also demonstrate that addition of plerixafor to G-CSF allows significantly more patients to achieve the target cell collection within 1 day of apheresis compared to G-CSF alone. These findings support the observation that mobilization with plerixafor plus G-CSF reduces the number of apheresis days required to achieve the minimal or optimal cell dose to proceed to transplantation. Disclosures Bolwell: Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Nademanee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stadtmauer:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Maziarz:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Gandhi:Genzyme Corporation: Employment, Equity Ownership. DiPersio:Genzyme: Honoraria.

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Plerixafor Plus G-CSF Is An Effective Regimen to Mobilize Hematopoietic Stem Cells in NHL Patients with Circulating Peripheral Blood CD34+ Cells/μl < 10.

Blood ◽

10.1182/blood.v114.22.33.33 ◽

2009 ◽

Vol 114 (22) ◽

pp. 33-33 ◽

Cited By ~ 1

Author(s):

Richard T. Maziarz ◽

Ivana N Micallef ◽

Patrick Stiff ◽

Brian J. Bolwell ◽

Sachin Marulkar ◽

...

Keyword(s):

Placebo Group ◽

Board Of Directors ◽

Research Funding ◽

Study Drug ◽

Minimal Cell ◽

Advisory Committees ◽

Hematopoietic Stem ◽

Cell Dose ◽

Cd34 Cells ◽

Equity Ownership

Abstract Abstract 33 Background: Circulating levels of peripheral blood (PB) CD34+ cells/μl are a strong predictor of hematopoietic stem cell (HSC) yields in patients with non-Hodgkin's lymphoma (NHL) undergoing autologous HSC transplantation (auto-HSCT), and are routinely monitored to optimize the timing and success of HSC collection after cytokine ± chemotherapy mobilization. The threshold PB CD34+ cell count to initiate apheresis varies from 5-20 cells/μl, depending on the institution. This analysis compared the efficacy of plerixafor + G-CSF to placebo + G-CSF for HSC mobilization in NHL patients with pre-apheresis PB CD34+ cells/μl <10. Methods: Data were obtained from a randomized, double-blind, phase 3 clinical trial comparing the safety and efficacy of plerixafor (0.24 mg/kg/day SC) + G-CSF (10 μg/kg/day) to placebo + G-CSF for mobilization and auto-HSCT in NHL patients. PB CD34+ cell count was measured on Day 4, before the first plerixafor/placebo dose, and on Day 5, 10-11 hours post study drug treatment. The proportion of patients collecting ≥2 × 106 (minimal) or ≥5 × 106 (optimal) CD34+ cells/kg, apheresis yields, and time to engraftment were compared between the plerixafor and placebo groups for patients with PB CD34+ cells/μl <10. Results: 77/150 (51%) patients and 73/148 (49%) patients in the plerixafor and placebo groups, respectively, had PB CD34+ cells/μl <10 on Day 4, prior to the first dose of study drug. Patient characteristics were similar between both groups. As shown in Table 1, addition of plerixafor to G-CSF resulted in a statistically significant increase in the absolute PB CD34+ cells/μl on Day 5 compared to G-CSF alone (p<0.001). The median fold increase in PB CD34+ cells from Day 4 to Day 5 was significantly higher in plerixafor-treated patients vs. placebo-treated patients: 6.0-fold vs. 1.6-fold (p<0.001). In these hard to mobilize patients, the median CD34+ cell yield after 2 days was significantly higher with plerixafor + G-CSF compared to placebo + G-CSF: 2.92 vs.0.94 × 106 cells/kg (p<0.001), respectively. The median CD34+ cell yield after 4 days was also significantly higher in the plerixafor vs. placebo groups: 3.96 vs.1.25 × 106 cells/kg (p<0.001). Plerixafor + G-CSF allowed a significantly greater proportion of patients with PB CD34+ cells/μl <10 to collect the minimal cell dose in 4 apheresis days: 77.9% vs. 34.2 % patients in the plerixafor and placebo group, respectively collected ≥2 × 106 CD34+ cells/kg in 4 days (p<0.001). The success rate of collecting the ≥5 × 106 CD34+ cells/kg in 4 days was 40.3% with plerixafor + G-CSF compared to only 9.6% with placebo + G-CSF (p<0.001). The proportion of patients collecting the optimal or minimal cell dose in 2 days was also significantly higher in the plerixafor vs. placebo group (p<0.001). The median time to platelet (19-21 days) and neutrophil (10-11 days) engraftment was similar in both groups. Similar, statistically significant increases in PB CD34+ cell collections were obtained when the efficacy of plerixafor + G-CSF was compared to placebo + G-CSF, in patients with a Day 4 PB CD34 cells/μl<20 (data not shown). Conclusions: Plerixafor + G-CSF allowed collection of the minimal transplantable cell dose in 78% patients with PB CD34+ cells/μl <10. These data show that adding plerixafor to G-CSF substantially reduces the risk of mobilization failure in patients with NHL predicted to be poor mobilizers based on low PB CD34+ cell counts. Thus, mobilization with plerixafor + G-CSF in patients with PB CD34+ cells/μl <10 increases stem cell collection efficiency allowing patients to pursue auto-HSCT with more optimal cell doses. Disclosures: Maziarz: Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corp.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Bolwell:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Calandra:Genzyme Corporation: Consultancy, Equity Ownership. DiPersio:Genzyme Corporation: Honoraria.

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Rapid and Robust Mobilization of CD34+ HSCs without G-CSF Following Administration of Mgta-145 Alone or in Combination with Plerixafor

Blood ◽

10.1182/blood-2019-127523 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1961-1961

Author(s):

John F. DiPersio ◽

Jonathan Hoggatt ◽

Steven Devine ◽

Lukasz Biernat ◽

Haley Howell ◽

...

Keyword(s):

Single Dose ◽

Adverse Events ◽

Board Of Directors ◽

Preliminary Data ◽

Research Funding ◽

Fold Change ◽

Employment Equity ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership

Background Granulocyte colony-stimulating factor (G-CSF) is the standard of care for mobilization of hematopoietic stem cells (HSCs). G-CSF requires 4-7 days of injections and often multiple aphereses to acquire sufficient CD34+ cells for transplant. The number of CD34+ HSCs mobilized can be variable and patients who fail to mobilize enough CD34+ cells are treated with the combination of G-CSF plus plerixafor. G-CSF use is associated with bone pain, nausea, headaches, fatigue, rare episodes of splenic rupture, and is contraindicated for patients with autoimmune and sickle cell disease. MGTA-145 (GroβT) is a CXCR2 agonist. MGTA-145, in combination with plerixafor, a CXCR4 inhibitor, has the potential to rapidly and reliably mobilize robust numbers of HSCs with a single dose and same-day apheresis for transplant that is free from G-CSF. MGTA-145 plus plerixafor work synergistically to rapidly mobilize HSCs in both mice and non-human primates (Hoggatt, Cell 2018; Goncalves, Blood 2018). Based on these data, Magenta initiated a Phase 1 dose-escalating study to evaluate the safety, PK and PD of MGTA-145 as a single agent and in combination with plerixafor. Methods This study consists of four parts. In Part A, healthy volunteers were dosed with MGTA-145 (0.0075 - 0.3 mg/kg) or placebo. In Part B, MGTA-145 dose levels from Part A were selected for use in combination with a clinically approved dose of plerixafor. In Part C, a single dose MGTA-145 plus plerixafor will be administered on day 1 and day 2. In Part D, MGTA-145 plus plerixafor will be administered followed by apheresis. Results MGTA-145 monotherapy was well tolerated in all subjects dosed (Table 1) with no significant adverse events. Some subjects experienced mild (Grade 1) transient lower back pain that dissipated within minutes. In the ongoing study, the combination of MGTA-145 with plerixafor was well tolerated, with some donors experiencing Grade 1 and 2 gastrointestinal adverse events commonly observed with plerixafor alone. Pharmacokinetic (PK) exposure and maximum plasma concentrations increased dose proportionally and were not affected by plerixafor (Fig 1A). Monotherapy of MGTA-145 resulted in an immediate increase in neutrophils (Fig 1B) and release of plasma MMP-9 (Fig 1C). Neutrophil mobilization plateaued within 1-hour post MGTA-145 at doses greater than 0.03 mg/kg. This plateau was followed by a rebound of neutrophil mobilization which correlated with re-expression of CXCR2 and presence of MGTA-145 at pharmacologically active levels. Markers of neutrophil activation were relatively unchanged (<2-fold vs baseline). A rapid and statistically significant increase in CD34+ cells occurred @ 0.03 and 0.075 mg/kg of MGTA-145 (p < 0.01) relative to placebo with peak mobilization (Fig 1D) 30 minutes post MGTA-145 (7-fold above baseline @ 0.03 mg/kg). To date, the combination of MGTA-145 plus plerixafor mobilized >20/µl CD34s in 92% (11/12) subjects compared to 50% (2/4) subjects receiving plerixafor alone. Preliminary data show that there was a significant increase in fold change relative to baseline in CD34+ cells (27x vs 13x) and phenotypic CD34+CD90+CD45RA- HSCs (38x vs 22x) mobilized by MGTA-145 with plerixafor. Mobilized CD34+ cells were detectable at 15 minutes with peak mobilization shifted 2 - 4 hours earlier for the combination vs plerixafor alone (4 - 6h vs 8 - 12h). Detailed results of single dose administration of MGTA-145 and plerixafor given on one day as well as also on two sequential days will be presented along with fully characterized graft analysis post apheresis from subjects given MGTA-145 and plerixafor. Conclusions MGTA-145 is safe and well tolerated, as a monotherapy and in combination with plerixafor and induced rapid and robust mobilization of significant numbers of HSCs with a single dose in all subjects to date. Kinetics of CD34+ cell mobilization for the combination was immediate (4x increase vs no change for plerixafor alone @ 15 min) suggesting the mechanism of action of MGTA-145 plus plerixafor is different from plerixafor alone. Preliminary data demonstrate that MGTA-145 when combined with plerixafor results in a significant increase in CD34+ fold change relative to plerixafor alone. Magenta Therapeutics intends to develop MGTA-145 as a first line mobilization product for blood cancers, autoimmune and genetic diseases and plans a Phase 2 study in multiple myeloma and non-Hodgkin lymphoma in 2020. Disclosures DiPersio: Magenta Therapeutics: Equity Ownership; NeoImmune Tech: Research Funding; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy; Incyte: Consultancy, Research Funding; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Macrogenics: Research Funding, Speakers Bureau; Bioline Rx: Research Funding, Speakers Bureau; Celgene: Consultancy; Amphivena Therapeutics: Consultancy, Research Funding. Hoggatt:Magenta Therapeutics: Consultancy, Equity Ownership, Research Funding. Devine:Kiadis Pharma: Other: Protocol development (via institution); Bristol Myers: Other: Grant for monitoring support & travel support; Magenta Therapeutics: Other: Travel support for advisory board; My employer (National Marrow Donor Program) has equity interest in Magenta. Biernat:Medpace, Inc.: Employment. Howell:Magenta Therapeutics: Employment, Equity Ownership. Schmelmer:Magenta Therapeutics: Employment, Equity Ownership. Neale:Magenta Therapeutics: Employment, Equity Ownership. Boitano:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Cooke:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Goncalves:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Raffel:Magenta Therapeutics: Employment, Equity Ownership. Falahee:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Morrow:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Davis:Magenta Therapeutics: Employment, Equity Ownership.

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Interim Results from a Phase 1/2 Clinical Study of Lentiglobin Gene Therapy for Severe Sickle Cell Disease

Blood ◽

10.1182/blood.v128.22.1176.1176 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1176-1176 ◽

Cited By ~ 19

Author(s):

Julie Kanter ◽

Mark C. Walters ◽

Matthew M. Hsieh ◽

Lakshmanan Krishnamurti ◽

Janet Kwiatkowski ◽

...

Keyword(s):

Gene Therapy ◽

Board Of Directors ◽

Research Funding ◽

Phase 1 ◽

Globin Gene ◽

Advisory Committees ◽

Cell Dose ◽

Cd34 Cells ◽

Equity Ownership

Abstract β-globin gene transfer into hematopoietic stem cells (HSCs) has the potential to reduce or eliminate the symptoms and long-term complications of severe sickle cell disease (SCD). LentiGlobin Drug Product (DP) is a gene therapy product containing autologous CD34+ cells transduced with the BB305 lentiviral vector. BB305 encodes a human β-globin gene containing a single point mutation (AT87Q) designed to confer anti-sickling properties similar to those observed in fetal hemoglobin (γ-globin). In two ongoing studies, subjects with transfusion-dependent β-thalassemia (Studies HGB-204 and HGB-205) or SCD (Study HGB-205) receiving LentiGlobin DP have demonstrated sustained expression of 3-9 g/dL therapeutic hemoglobin (HbAT87Q) and have shown marked improvements in clinical symptoms 1 year post-treatment. Study HGB-206 is a multi-center, Phase 1/2 safety and efficacy study of LentiGlobin DP in adults with severe SCD. We previously (ASH 2015) presented results from 2 subjects, who had 3 and 6 months of follow-up after LentiGlobin treatment. We now present data from 7 treated subjects, 4 of whom have ≥6 months of follow-up data. Subjects (≥18 years of age) with severe SCD (history of recurrent vaso-occlusive crisis [VOC], acute chest syndrome, stroke, or tricuspid regurgitant jet velocity of >2.5 m/s) were screened for eligibility. Following bone marrow harvest (BMH), CD34+ cells were transduced with the BB305 vector. Subjects underwent myeloablative conditioning with busulfan prior to infusion of the transduced cells. Safety assessments include adverse events (AEs), integration site analysis (ISA) and surveillance for replication competent lentivirus (RCL). After infusion, subjects are monitored for hematologic engraftment, vector copy number (VCN), HbAT87Q expression, and other laboratory and clinical parameters. As of July 2016, 7 subjects with severe SCD (median age: 26 years, range 18-42 years) have received LentiGlobin DP in this study. All subjects successfully underwent BMH, with a median of 2 harvests required (range 1-4). Fifteen Grade 3 AEs in 5 subjects were attributed to BMH: pain (n=10), anemia (n=3) and VOC (n=2); all resolved with standard measures. Table 1 summarizes cell harvest, DP characteristics, and lab results. The median LentiGlobin DP cell dose was 2.1x10e6 CD34+ cells/kg (range 1.6-5.1) and DP VCN was 0.6 (0.3-1.3) copies/diploid genome. Median post-infusion follow-up as of July 2016 is 7.1 months (3.7-12.7 months). All subjects successfully engrafted after receiving LentiGlobin DP, with a median time to neutrophil engraftment of 22 days (17-29 days). The toxicity profile observed from start of conditioning to latest follow-up was consistent with myeloablative conditioning with single-agent busulfan. To date, there have been no DP-related ≥Grade 3 AEs or serious AEs, and no evidence of clonal dominance or RCL. The BB305 vector remains detectable at low levels in the peripheral blood of all subjects infused, with median VCN 0.08 (0.05-0.13, n=7) at last measurement. All subjects express HbAT87Q, with a median of 0.4g/dL (0.1-1.0 g/dL, n=7) at 3 months; most subjects demonstrated modest increases over time, and the 2 subjects with the longest follow-up expressed 0.31 and 1.2 g/dL HbAT87Q at 9 months. All 4 subjects with ≥6 months of follow-up experienced multiple VOCs in the 2 years prior to study entry (2-27.5 VOCs annually). Since LentiGlobin DP infusion, 3 of these 4 subjects have had fewer VOCs, although this trend may be confounded by the short follow-up, the effects of transplant conditioning, and/or post-transplant RBC transfusions. The decrease in VCN between DP and peripheral cells contrasts with previous reports of successful LentiGlobin gene therapy in ongoing studies HGB-204 and HGB-205. The relatively low in vivo VCN in this study appears to result in the lower HbAT87Q expression seen to date. We are exploring multiple hypotheses as to the etiology of the VCN drop between DP and peripheral blood, including the adverse impact of sickle marrow pathology on HSCs, the adequacy of myeloablation, and the magnitude of the transduced cell dose. We will provide an update on study data and ongoing efforts to increase in vivo VCN in patients with SCD, such as increasing the transduced cell dose through alternate HSC procurement methods or enhancing the DP VCN through manufacturing improvements. Disclosures Kanter: Novartis: Consultancy. Walters:Bayer HealthCare: Honoraria; AllCells, Inc./LeukoLab: Other: Medical Director ; ViaCord Processing Laboratory: Other: Medical Director ; Leerink Partners, LLC: Consultancy; Kiadis Pharma: Honoraria; bluebirdBio, Inc: Honoraria. Kwiatkowski:Ionis pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Shire Pharmaceuticals: Consultancy; Sideris Pharmaceuticals: Consultancy; Apopharma: Research Funding; Luitpold Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. von Kalle:bluebird bio: Consultancy; GeneWerk: Equity Ownership. Kuypers:Children's Hospital Oakland Research Institute: Employment; bluebird bio: Consultancy. Leboulch:bluebird bio: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding. Joseney-Antoine:bluebird bio: Employment, Equity Ownership. Asmal:bluebird bio: Employment, Equity Ownership. Thompson:bluebird bio: Consultancy, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Amgen: Research Funding; Baxalta (now part of Shire): Research Funding; ApoPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Mast: Research Funding; Eli Lily: Research Funding.

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Successful Plerixafor-Mediated Mobilization, Apheresis, and Lentiviral Vector Transduction of Hematopoietic Stem Cells in Patients with Severe Sickle Cell Disease

Blood ◽

10.1182/blood.v130.suppl_1.990.990 ◽

2017 ◽

Vol 130 (Suppl_1) ◽

pp. 990-990

Author(s):

John F Tisdale ◽

Francis J. Pierciey ◽

Rammurti Kamble ◽

Julie Kanter ◽

Lakshmanan Krishnamurti ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Ex Vivo ◽

Cell Disease ◽

Employment Equity ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership

Abstract Background Patients with severe sickle cell disease (SCD) may benefit from β-globin gene transfer into autologous hematopoietic stem cells (HSC). Successful HBB gene transfer requires vector-mediated transduction of primitive HSCs. Steady-state bone marrow (BM) is the default HSC source in patients with SCD. Normal human BM contains up to 30% CD34+CD19+ pro-B cells and other lineage-committed cell types (CD34dim) that will not contribute to improved long-term erythropoiesis via gene therapy; these cells mobilize at low rates. CD34+ cell yields from BM harvest (BMH) are typically lower than those after mobilization and peripheral blood (PB) apheresis; multiple rounds of BMH may be required to obtain adequate cell doses for autologous gene therapy (GT) protocols. As G-CSF can cause life-threatening SCD complications and is contraindicated, plerixafor, a CXCR4 receptor antagonist, may accomplish HSC mobilization without the neutrophil or endothelial activation that elicit vaso-occlusion. We modified the protocol for the HGB-206 phase 1 study of LentiGlobin GT in severe SCD (NCT02140554) to assess HSC mobilization with plerixafor alone, followed by apheresis and transduction of mobilized cells. We also characterized BM-derived and plerixafor-mobilized HSC populations from patients with SCD. Methods HGB-206 is a phase 1 study of LentiGlobin Drug Product (DP), which contains autologous HSCs transduced ex vivo with the betibeglogene darolentivec (BB305) lentiviral vector, in patients with severe SCD (defined as a history of recurrent vaso-occlusive crisis [VOC], acute chest syndrome, stroke, or tricuspid regurgitant jet velocity of >2.5 m/s). Patients in group B receive 240 µg/kg plerixafor followed 4-6 hours later by apheresis, processing ~3 total blood volumes to collect backup HSCs. If < 1.5 x 106 CD34+ cells are collected, patients undergo a second day of apheresis. Cells collected in excess of those required for backup in case of graft failure are transduced with BB305 lentiviral vector for exploratory analyses. Group B patients then proceed to BMH to obtain cells for clinical DP manufacture. Group C will receive DP manufactured from mobilized PB. Mass cytometry (CyTOF) was used to analyze ex vivo cultured CD34+ cells with over 35 cell surface markers. Results To date, 3 patients have undergone plerixafor mobilization. Patients had a transient 1.5- to 3-fold increase in peak white blood cell and absolute neutrophil levels after plerixafor. Peak absolute CD34+ cell counts in PB were 170, 58, and 160 x 106 CD34+ cells/liter. A total of 15.3, 5.6, and 9.0 x 106 CD34+ cells/kg were collected in a single day of apheresis, and no subsequent apheresis or mobilization was required. In the same study, a mean of 5.0 (range 0.3-10.8) x 106 CD34+ cells/kg were collected per BMH (N=21). The mobilization and apheresis procedures had an acceptable toxicity profile. No dose-limiting toxicities were observed after plerixafor dosing. One patient had a single VOC approximately 48 hours after receiving plerixafor; this patient also experienced VOCs of similar severity after BMH. In contrast, after 21 BMHs in 9 patients, 18 ≥ grade 3 AEs were reported in 6 patients, primarily pain. Ex vivo cultured CD34+ cells isolated from BMH consisted of an average of 41.0% (17.3%-50.7%) CD34dim cells, with 16%-50% of the CD34dim cells expressing lymphoid markers. In contrast, ex vivo cultured CD34+ cells isolated from plerixafor mobilized PB contained an average of 8.2% (1.5-19.5%) CD34dim cells. Similar drug product vector copy numbers were obtained after research-scale transduction of CD34+ cells from marrow and PB from the same patient. Conclusion Initial results suggest that obtaining adequate doses of CD34+ cells from plerixafor-mobilized PB of patients with SCD may be safe and feasible, without the life-threatening complications associated with G-CSF, and with fewer, less invasive procedures compared with BMH. PB-derived CD34+ cells may contain lower proportions of lineage-committed CD34+ cells than BM-derived cells from patients with SCD. Cells collected by BMH and PB mobilization/apheresis appear to have an equivalent transduction efficiency. Together these results indicate that it may be possible to use plerixafor-only mobilization in clinical studies of autologous HSC GT in SCD. Results of mobilization, apheresis, and DP manufacturing at clinical scale for additional patients will be available for presentation. Disclosures Pierciey: bluebird bio: Employment. Kanter: American Society of Hematology (Sickle Cell Disease Guideline Panel): Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; MUSC: Other: The site PI for sponsored research conducted at MUSC who receives funds from: Novartis, bluebird bio, GBT, Sancillo, Apopharma, Pfizer; NHLBI (sickle cell disease research advisory committee): Membership on an entity's Board of Directors or advisory committees, Research Funding; Sancillo: Research Funding; Apopharma: Research Funding; Pfizer: Research Funding; GBT: Research Funding; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kwiatkowski: Novartis: Research Funding; Bluebird Bio: Research Funding; Apopharma: Research Funding; Agios: Consultancy, Honoraria; Ionis: Consultancy, Honoraria. Thompson: Novartis: Consultancy, Research Funding; bluebird bio: Consultancy, Research Funding; Baxalta: Research Funding; Celgene: Consultancy, Research Funding. Shestopalov: bluebird bio: Employment, Equity Ownership. Bonner: bluebird bio: Employment, Equity Ownership. Joseney-Antoine: bluebird bio: Employment, Equity Ownership. Asmal: bluebird bio: Employment, Equity Ownership. Walters: bluebird bio: Research Funding; ViaCord Processing Lab: Other: Medical Director; Sangamo Therapeutics: Consultancy; AllCells, Inc: Other: Medical Director.

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

Blood ◽

10.1182/blood-2018-99-112667 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1025-1025 ◽

Cited By ~ 6

Author(s):

Franco Locatelli ◽

Mark C. Walters ◽

Janet L. Kwiatkowski ◽

John Porter ◽

Martin G. Sauer ◽

...

Keyword(s):

Board Of Directors ◽

Peripheral Blood ◽

Research Funding ◽

Additional Data ◽

Employment Equity ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership ◽

La Jolla

Abstract Background Transfusion-dependent β-thalassemia (TDT) is a severe genetic disease caused by impaired β-globin production, leading to severe anemia, lifelong transfusion dependence with iron overload and serious comorbidities. Gene therapy (GT) offers a potentially transformative option for these patients. LentiGlobin GT contains autologous CD34+ hematopoietic stem cells (HSCs) transduced ex vivo with the BB305 lentiviral vector (LVV) encoding β-globin with a T87Q substitution. The safety and efficacy of LentiGlobin in patients with TDT was assessed in the phase 1/2 Northstar study in which 8/10 patients with non-β0/β0 genotypes and 3/8 patients with a β0/β0 genotype stopped transfusions. A refined manufacturing process to improve drug product (DP) characteristics is being evaluated in the studies presented here. Methods Northstar-2 (HGB-207; NCT02906202) and Northstar-3 (HGB-212; NCT03207009) are ongoing, international, single-arm, phase 3 studies in patients with TDT (≥ 100 mL/kg/yr of red blood cells [RBCs] or ≥ 8 RBC transfusions/yr) and non-β0/β0 genotypes or a β0/β0 genotype, respectively. HSCs were collected by apheresis after G-CSF and plerixafor mobilization. CD34+ HSCs were transduced with the BB305 LVV using a refined manufacturing process. Patients received single-agent, myeloablative busulfan conditioning and transduced cells were infused. The primary endpoint in Northstar-2 is the proportion of patients achieving transfusion independence (TI, weighted average hemoglobin [Hb] ≥ 9g/dL without RBC transfusions for ≥ 12 months continuously) and in Northstar-3 is the proportion of patients achieving transfusion reduction (≥ 60% reduction in transfused RBC volume post-DP infusion compared to pre-DP infusion). Patients were evaluated for engraftment, DP and peripheral blood vector copy number (VCN), GT-derived Hb (HbAT87Q), adverse events (AEs), vector integration, and evidence of replication competent lentivirus (RCL). Patients are followed for 2 years and offered participation in a long-term follow-up study. Results Eleven patients (median age 20 [min - max: 12 - 24] years) with TDT and non-β0/β0 genotypes (5 β+/β0, 4 βE/β0, 2 β+/β+) have been treated in Northstar-2 as of May 15, 2018 with a median follow-up of 8.5 (min - max: 0.3 - 16.2) months. DPs had a median cell dose of 7.4 x 106 (min - max: 5.0 - 19.4 x 106) CD34+ cells/kg, median VCN of 3.4 (min - max: 2.4 - 5.6) copies/diploid genome (c/dg) and a median of 82% (min - max: 53 - 90%) CD34+ cells were transduced. Median time to neutrophil and platelet engraftment was 21.5 (min - max: 16 - 28) and 44.5 (min - max: 34 - 84) days, respectively, in 10 patients; 1 patient was not yet evaluable. Serious AEs after DP infusion included 2 events of grade 4 liver veno-occlusive disease treated with defibrotide and 1 event each of hypotension, hypoxia, sepsis, and transfusion reaction, all resolved. Only 1 AE (grade 1 abdominal pain) was related to LentiGlobin. There were no deaths or graft failure and no evidence of vector-mediated RCL or clonal dominance. Of 8 patients with ≥ 6 months follow-up, 7 have stopped RBC transfusions. At last study visit, peripheral blood VCN was 1.1 - 5.0 c/dg and total Hb was 11.1 - 13.3 g/dL of which 7.6 - 10.2 g/dL (68 - 92%) was contributed by HbAT87Q. Median Hb at month 6 was 11.9 (min - max: 11.2 - 13.3) g/dL. The first treated patient achieved TI. The additional patient with ≥ 6 months follow-up had no transfusions for 11 months, however had a peripheral blood VCN of 0.2 c/dg and resumed transfusions due to symptomatic anemia. Bone marrow assessment of dyserythropoesis and data with longer follow-up will be presented. Two patients, 26- and 7- years old, have been treated in Northstar-3. Both had 2 DP lots manufactured with DP VCNs of 2.9/3.3 and 3.4/3.9 c/dg and 82%/85% and 78%/78% CD34+ cells were transduced, respectively. Both successfully engrafted. Additional data for these patients will be presented. Summary Seven of 8 patients with TDT and non-β0/β0 genotypes produced sufficient HbAT87Q to stop chronic transfusions following LentiGlobin GT in Northstar-2. The safety profile appears consistent with busulfan myeloablative conditioning with no grade ≥ 3 DP-related AEs. Initial results show DP characteristics in Northstar-3 are consistent with those in Northstar-2. Additional data from Northstar-3 will determine the impact of HbAT87Q production on transfusion reduction in patients without endogenous β-globin production. Disclosures Locatelli: bluebird bio: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Miltenyi: Honoraria; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Walters:AllCells Inc.: Other: Medical Director; ViaCord Processing Lab: Other: Medical Director; bluebird bio: Research Funding; Sangamo Therapeutics: Consultancy. Kwiatkowski:Terumo: Research Funding; Apopharma: Research Funding; Novartis: Research Funding; Agios Pharmaceuticals: Consultancy, Research Funding; bluebird bio: Consultancy, Honoraria, Research Funding. Porter:Agios: Honoraria; Cerus: Honoraria; Novartis: Consultancy. Thuret:Addmedica: Research Funding; bluebird bio: Research Funding; Novartis: Research Funding. Kulozik:bluebird bio: Consultancy, Honoraria. Lal:Terumo Corporation: Research Funding; Celgene Corporation: Research Funding; Insight Magnetics: Research Funding; Bluebird Bio: Research Funding; La Jolla Pharmaceutical Company: Consultancy, Research Funding; Novartis: Research Funding. Thrasher:Orchard Therapeutics: Consultancy, Equity Ownership; Generation Bio: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Rocket Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. Elliot:bluebird bio: Employment, Equity Ownership. Tao:bluebird bio: Employment, Equity Ownership. Asmal:bluebird bio: Employment, Equity Ownership. Thompson:Amgen: Research Funding; Baxalta/Shire: Research Funding; La Jolla Pharmaceutical: Research Funding; Novartis: Research Funding; bluebird bio: Consultancy, Research Funding; Celgene: Research Funding; Biomarin: Research Funding.

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Incidence of Vaso-Occlusive Crisis Does Not Increase with Achieving Higher Hemoglobin Levels on Voxelotor Treatment or after Discontinuation: Analyses of the HOPE Study

Blood ◽

10.1182/blood-2019-129026 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 2313-2313

Author(s):

Elliott P. Vichinsky ◽

Paul Telfer ◽

Adlette Inati ◽

Margaret Tonda ◽

Barbara Tong ◽

...

Keyword(s):

Clinical Trial ◽

Placebo Group ◽

Board Of Directors ◽

Incidence Rate ◽

Research Funding ◽

Post Treatment ◽

Drug Discontinuation ◽

Employment Equity ◽

Advisory Committees ◽

Equity Ownership

Background: Sickle cell disease (SCD) is an inherited disorder in which pathology is driven by hemoglobin (Hb) polymerization and red blood cell sickling, leading to chronic anemia and hemolysis as well as episodic vaso-occlusive crises (VOC). These manifestations of SCD contribute to the cumulative organ damage that leads to disability, reduced quality of life, and accelerated mortality. In particular, VOCs and their associated episodic pain are a hallmark symptom of SCD and frequently require emergency medical attention. Voxelotor is a first-in-class sickle hemoglobin-polymerization inhibitor in development for the treatment of SCD. It has demonstrated robust, rapid, and sustained improvements in patient Hb levels with numerically fewer VOCs compared with placebo, which suggests that viscosity was not increased with voxelotor treatment. The objective of this study was to further explore this observation by examining the association between absolute Hb achieved by voxelotor treatment and VOC incidence rate. In addition, to inform on the potential for symptom exacerbation after drug discontinuation, rates of VOCs after voxelotor discontinuation were analyzed. Methods: The HOPE trial is a phase 3, randomized, placebo-controlled, double-blind, multicenter study comparing the efficacy and safety of voxelotor (1500 mg and 900 mg daily) versus placebo for ≥24 weeks in patients with SCD aged 12 to 65 years. The primary endpoint is the percentage of patients with a Hb response at week 24, defined as a >1.0 g/dL increase in Hb. Secondary endpoints included the annualized incidence rate of VOC. This abstract reports a post hoc analysis of VOC incidence in the per-protocol population stratified by Hb level at 24 weeks of treatment. In addition, VOCs in patients who discontinued voxelotor and completed a 28-day follow-up are reported here (data cutoff October 31, 2018). Results: The proportion of patients with ≥1 VOC was 67.0% (59/88) in the voxelotor 1500 mg group, 66.3% (61/92) in the voxelotor 900 mg group, and 69.2% (63/91) in the placebo group. Overall, the annualized adjusted incidence rate of VOCs (the number of crises per person-year) was 2.77 in the voxelotor 1500 mg group, 2.76 in the voxelotor 900 mg group, and 3.19 in the placebo group. When stratified by Hb level after 24 weeks of treatment, the incidence of VOCs was generally lower in patients who achieved higher absolute Hb levels on voxelotor treatment compared with placebo (Figure 1). Patients who discontinued voxelotor were also observed for 28 days post-treatment. At the time of data cutoff, 55 patients (n=21, voxelotor 1500 mg; n=17, voxelotor 900 mg; n=17, placebo) had discontinued treatment and had post-treatment follow-up. During the 28-day period after treatment discontinuation, 5 patients in the voxelotor 1500 mg group reported 6 VOCs; 3 patients in the voxelotor 900 mg group reported 3 VOCs; and 5 patients in the placebo group reported 8 VOCs. The estimated incidence rates of post-treatment VOCs were 4.63, 4.30, and 7.01 in the voxelotor 1500 mg, voxelotor 900 mg, and placebo groups, respectively. Conclusions: Patients who achieved the greatest absolute Hb level after 24 weeks of treatment with voxelotor had numerically fewer VOCs, suggesting that increasing Hb levels resulting from voxelotor treatment did not lead to a viscosity-related increase in risk of vaso-occlusion. Following drug discontinuation, there was a numerically lower incidence of VOCs in the voxelotor arms compared with placebo. Altogether, these results suggest that voxelotor treatment safely raises Hb without causing a viscosity-related increased risk of VOC and that treatment discontinuation did not increase risk for VOC. Disclosures Vichinsky: GBT: Consultancy, Research Funding; bluebird bio: Consultancy, Research Funding; Agios: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Telfer:ApoPharma: Membership on an entity's Board of Directors or advisory committees, Other: Speaker activities, clinical trial activities; Terumo: Honoraria, Other: Speaker activity; Pfizer: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: clinical trial activity; Kyowa Kirin Limited: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: clinical trial activities; Napp Pharma: Other: clinical trial involvement; Celgene: Other: clinical trial involvement; Bluebird Bio: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Inati:Global Blood Therapeutics: Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novonordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Tonda:Global Blood Therapeutics: Employment, Equity Ownership. Tong:Global Blood Therapeutics: Employment, Equity Ownership. Agodoa:Global Blood Therapeutics: Employment, Equity Ownership. Lehrer-Graiwer:Global Blood Therapeutics: Employment, Equity Ownership. Ataga:Modus Therapeutics: Honoraria; Emmaus Life Sciences: Honoraria, Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Bioverativ: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

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Current Results of Lentiglobin Gene Therapy in Patients with Severe Sickle Cell Disease Treated Under a Refined Protocol in the Phase 1 Hgb-206 Study

Blood ◽

10.1182/blood-2018-99-113480 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1026-1026 ◽

Cited By ~ 11

Author(s):

John F. Tisdale ◽

Julie Kanter ◽

Markus Y. Mapara ◽

Janet L. Kwiatkowski ◽

Lakshmanan Krishnamurti ◽

...

Keyword(s):

Gene Therapy ◽

Board Of Directors ◽

Research Funding ◽

Phase 1 ◽

Employment Equity ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership ◽

Grade 3

Abstract Background β-globin gene transfer has the potential for substantial clinical benefit in patients with sickle cell disease (SCD). LentiGlobin Drug Product (DP) contains autologous CD34+ hematopoietic stem cells (HSCs) transduced with the BB305 lentiviral vector (LVV), encoding β-globin with an anti-sickling substitution (T87Q). The safety and efficacy of LentiGlobin gene therapy is being evaluated in the ongoing Phase 1 HGB-206 study (NCT02140554). Results in the initial 7 patients treated with LentiGlobin DP from steady state bone marrow harvested (BMH) HSCs using original DP manufacturing process (Group A) demonstrated stable HbAT87Q production in all patients, but at levels below the anticipated target. The protocol was thus amended to include pre-harvest RBC transfusions, optimize myeloablation by targeting higher busulfan levels, and use a refined DP manufacturing process (Group B); additionally, HSC collection by plerixafor mobilization/apheresis was instituted (Group C). Data from patients in Group C, treated under the modified protocol with DPs manufactured from plerixafor-mobilized HSCs using the refined process, are reported here. Results in patients in Groups A and B are reported separately. Methods Patients with severe SCD (history of recurrent vaso-occlusive crisis, acute chest syndrome, stroke, or tricuspid regurgitant jet velocity of >2.5 m/s) were enrolled. Patients in Group C received ≥2 months of transfusions to reach Hb of 10 - 12 g/dL and <30% HbS before HSC collection. Patients received 240 μg/kg of plerixafor 4 - 6 hours before HSCs were collected by apheresis and CD34+ cells were transduced with the BB305 LVV at a central facility. Following myeloablative conditioning with busulfan, the DP was infused, and patients were monitored for adverse events (AEs), engraftment, peripheral blood (PB) vector copy number (VCN), HbAT87Q expression, and HbS levels. Summary statistics are presented as median (min - max). Results As of 15 May 2018, 11 Group C patients (age 25 [18 - 35] years) had undergone mobilization/apheresis, 9 patients had DP manufactured (median 1 cycle of mobilization [1 - 3]) and 6 patients had been treated. Cell dose, DP VCN and % transduced cells in the 6 treated patients were: 7.1 (3 - 8) x 106 CD34+ cells/kg, 4.0 (2.8 - 5.6) copies/diploid genome (c/dg) and 81 (78 - 88) % transduced cells. The median follow-up was 3.0 (1.2 - 6.0) months. Patients achieved neutrophil engraftment at a median of 19 (18 - 20) days. Platelet engraftment was achieved at a median of 28 (12 - 64) days in 4 patients; platelet engraftment was pending in 2 patients. Two of 11 patients experienced 4 grade ≥3 AEs associated with plerixafor mobilization/HSC collection: 1 had vaso-occlusive pain and hypomagnesaemia, and the other had vaso-occlusive pain and non-cardiac chest pain. The toxicity profile from DP infusion to last follow-up in the 6 treated patients was consistent with myeloablative conditioning. Febrile neutropenia (n=5) and stomatitis (n=4) were the most common non-hematologic grade ≥3 AEs. Serious AEs were reported in 3 patients post-DP infusion: splenic hematoma, non-cardiac chest pain and mucosal inflammation. To date, there have been no DP-related AEs, graft failure, vector-mediated replication competent lentivirus, or clonal dominance. In the 6 treated patients, PB VCN at last visit ranged from 1.4 - 2.9 c/dg. In the 3 patients with 3 months follow-up, total Hb levels were 11.7 g/dL, 9.8 g/dL and 9.2 g/dL, and HbAT87Q levels were 4.7 g/dL, 3.2 g/dL and 3.5 g/dL. One additional patient with 6 months follow-up was off transfusions and had total Hb of 14.2 g/dL, of which 62% (8.8 g/dL) was vector-derived HbAT87Q and 36% (5.1 g/dL) was HbS. All 4 patients had HbAT87Q (median 39%) levels higher than or equal to HbS (median 31%) at the 3-month visit. Summary HGB-206 protocol changes and refined DP manufacturing have improved the LentiGlobin DP characteristics resulting in significantly improved outcomes. In addition, the HbAT87Q expression is comparable to, or exceeds, HbS levels as early as 3 months post DP infusion. These data support the feasibility of plerixafor-mediated CD34+ cell collection in patients with severe SCD and the efficacy of gene therapy. The safety profile of LentiGlobin gene therapy remains consistent with single-agent busulfan conditioning. Additional data and longer follow-up will determine the clinical effect of increased HbAT87Q/HbS ratios. Disclosures Kanter: Global Blood Therapeutics: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; bluebird bio: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Sancilio: Research Funding; NHLBI: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Apopharma: Research Funding; ASH: Membership on an entity's Board of Directors or advisory committees. Mapara:Incyte: Consultancy. Kwiatkowski:Novartis: Research Funding; bluebird bio: Consultancy, Honoraria, Research Funding; Apopharma: Research Funding; Terumo: Research Funding; Agios Pharmaceuticals: Consultancy, Research Funding. Schmidt:GeneWerk GmbH: Employment; German Cancer Research Center: Employment; bluebird bio: Consultancy. Miller:bluebird bio: Employment, Equity Ownership. Pierciey:bluebird bio: Employment, Equity Ownership. Shi:bluebird bio: Employment, Equity Ownership. Ribeil:bluebird bio: Employment, Equity Ownership. Asmal:bluebird bio: Employment, Equity Ownership. Thompson:Amgen: Research Funding; Celgene: Research Funding; Baxalta/Shire: Research Funding; bluebird bio: Consultancy, Research Funding; Novartis: Research Funding; Biomarin: Research Funding; La Jolla Pharmaceutical: Research Funding. Walters:Sangamo Therapeutics: Consultancy; bluebird bio: Research Funding; ViaCord Processing Lab: Other: Medical Director; AllCells Inc.: Other: Medical Director.

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Transient Inhibition of Transforming Growth Factor-β1 in Human Blood-Derived CD34+ Cells Enhances Survival and Proliferation in Vitro and Vascular Reparative functions In Vivo.

Blood ◽

10.1182/blood.v114.22.3546.3546 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3546-3546

Author(s):

Stephen Bartelmez ◽

Ashay Bhatwadekar ◽

Patrick Iversen ◽

Francis W Ruscetti ◽

Maria Grant

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Ex Vivo ◽

Cxcr4 Expression ◽

Employment Equity ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership ◽

Tgf Β1

Abstract Abstract 3546 Poster Board III-483 CD34+ cells from diabetic patients demonstrate reduced vascular reparative function due to decreased proliferation as well as diminished migration prowess which is largely due to lower levels of bioavailable nitric oxide (NO). We asked whether a transient TGF-β1 blockade in CD34+ cells from diabetics would improve their reparative ability given that TGF-β is a key factor modulating stem cell quiescence. Peripheral blood lin-CD34+ cells or lin-CD34+CD38+/− cells were treated ex vivo with antisense phosphorodiamidate morpholino oligomers (TGF-β1 -PMO), demonstrated to inhibit TGF-β1 protein expression in stem cells. Cells were then analyzed for cell surface TGF-β Receptor 2 (TGF-β R2) and CXCR4 expression, their ability to generate NO, their ability to migrate toward SDF-1, their ability to survive in the absence of added growth factors, and tested in vivo for their vascular reparative ability. After TGF-β1-PMO treatment, healthy and diabetic CD34+CD38+ and - cells downregulated TGF-βR2, upregulated CXCR4 expression, survived in the absence of added growth factors ex vivo and migrated more efficiently to SDF-1 compared to controls. TGF-β1-PMO treated diabetic CD34+ cells restored NO production to non-diabetic levels. In contrast, TGF-β1-PMO did not enhance NO generation in CD34+ cells from healthy subjects. Using an in vivo retinal ischemia reperfusion model, we observed that TGF-β1-PMO treatment increased the ability of both healthy and diabetic CD34+ cells to home to injured capillaries compared to control PMO treated cells. As also observed in our current study, a reduction of TGF-β1 levels in murine hematopoietic stem cells correlates with a reduction in TGF-βR2 expression which may induce proliferation in vivo. We also show that both diabetic and healthy lin-CD34+CD38+ cells express TGF-βR2 by FACS. In contrast, only healthy lin-CD34+CD38- cells expressTGF-βR2 while diabetic lin-CD34+CD38 - cells express essentially no cell surface TGF-βR2 (<5 % of cells are TGF-βR2+). Our results suggest that a transient blockade of TGF-β1 may represent a promising therapeutic strategy in restoring vascular reparative function in diabetic CD34+ cells. Disclosures: Bartelmez: BetaStem Therapeutics: Employment, Equity Ownership, Head, SRB, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Iversen:AVI-Biopharma: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

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Plerixafor (Mozobi ®)Plus G-CSF Is More Effective Than Placebo Plus G-CSF in Mobilizing CD34+ Hematopoietic Stem Cells in Patients with Multiple Myeloma Who Have Low (<20 cells/μl) Peripheral Blood CD34+ Cell Count.

Blood ◽

10.1182/blood.v114.22.3230.3230 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3230-3230 ◽

Cited By ~ 1

Author(s):

Auayporn P. Nademanee ◽

Edward Stadtmauer ◽

Ivana N Micallef ◽

Patrick Stiff ◽

Sachin Marulkar ◽

...

Keyword(s):

Placebo Group ◽

Cell Count ◽

Board Of Directors ◽

Research Funding ◽

Fold Increase ◽

Advisory Committees ◽

Hematopoietic Stem ◽

Cell Counts ◽

Cd34 Cells ◽

Equity Ownership

Abstract Abstract 3230 Poster Board III-167 Background Pre-apheresis peripheral blood (PB) CD34+ cells of < 20 cells/μl is a significant risk factor for poor hematopoietic stem cell (HSC) mobilization and collection in patients with multiple myeloma (MM) undergoing autologous HSC transplantation (auto-HSCT). PB CD34+ cells are routinely monitored to optimize the timing and success of HSC collection after mobilization with cytokines ± chemotherapy. This analysis was designed to compare the efficacy of plerixafor + G-CSF to placebo + G-CSF for mobilization in patients with MM who had pre-apheresis PB CD34+ cell counts < 20 cells/μl. We hypothesized that the addition of plerixafor to G-CSF would improve the stem cell yield in these patients with baseline CD34+ cells < 20 cells/μl. Methods Data were obtained from a prospective, randomized, double-blind, placebo-controlled, phase 3 clinical trial that compared the safety and efficacy of plerixafor (0.24 mg/kg/day SC) + G-CSF (10 μg/kg/day) to placebo + G-CSF for mobilization and auto-HSCT in patients with MM. PB CD34+ cell count was measured on Day 4, prior to first plerixafor/placebo dose, and on Day 5, 10-11 hours post study treatment. The proportion of patients achieving the minimal (≥2 × 106 CD34+ cells/kg) or optimal (≥6 × 106 CD34+ cells/kg) cell doses in 2 apheresis days, apheresis yields, and time to engraftment were compared between the plerixafor and placebo groups for PB CD34+ cell count <10 cells/μl (PB<10) and <20 cells/μl (PB<20). Results In the plerixafor group (n=148), 27 (18%) and 56 (38%) patients had Day 4 PB CD34+ cells/μl <10 and <20 which was as expected identical to the 30 (19%) and 60 (39%) patients in the placebo group, respectively (n=154). Patient characteristics were similar in both groups. Plerixafor + G-CSF resulted in a statistically significant increase in the absolute PB CD34+ cells/ml on Day 5 compared to placebo + G-CSF (p<0.001; Table 1). For patients with PB <10, the median fold increase in PB CD34+ cells in the plerixafor (n = 27) vs. placebo (n = 30) groups was 9.6 vs. 2 (p<0.001). Similarly, for patients with PB <20 the median fold increase in PB CD34+ cells in the plerixafor (n = 56) vs. placebo (n = 60) groups was 6.6 vs. 2 (p<0.001).The median CD34+ cell yield after 2 aphereses was significantly higher in the plerixafor vs. placebo group: 5.44 vs.1.68 × 106 cells/kg (p<0.001; PB<10) and 7.06 vs. 3.27 × 106 cells/kg (p<0.001; PB <20). The proportion of patients achieving ≥2 × 106 CD34+ cells/kg in 2 aphereses was significantly higher in the plerixafor group compared to the placebo group: 92.6% vs. 43.3 % in patients with PB<10 (p<0.001), and 94.6% vs. 66.7% in patients with PB<20 (p<0.001). Similarly, the proportion of patients achieving ≥6 × 106 CD34+ cells/kg in 2 apheresis days was significantly higher in the plerixafor vs. placebo group: 40.7% vs. 3.3 % in patients with PB<10 (p<0.001), and 55.4% vs. 15% in patients with PB<20 (p<0.001). The median time to platelet (19-20 days) and neutrophil (11 days) engraftment was similar in both groups. Conclusions These data demonstrate that in patients with MM who are predicted to fail mobilization based on low PB CD34+ cell count, the addition of plerixafor to G-CSF allows for 2-day collection of the minimal and optimal cell dose in a greater proportion of patients compared to G-CSF alone. Thus, addition of plerixafor to G-CSF can decrease the risk of poor mobilization in patients with MM who have PB CD34+ cell counts < 20 or even < 10 cells/μl. Disclosures Nademanee: Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Stadtmauer:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Micallef:Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stiff:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Calandra:Genzyme Corporation: Consultancy, Equity Ownership. DiPersio:Genzyme: Honoraria.

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Inecalcitol, a Novel Adjuvant Therapy Inhibiting Chronic Myeloid Leukemia (CML) Stem Cells, Activates a Macrophage Differentiation Pathway in Leukemic Progenitors

Blood ◽

10.1182/blood.v126.23.4020.4020 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4020-4020

Author(s):

Christophe Desterke ◽

Hyacinthe Johnson-Ansa ◽

Patricia Hugues ◽

Jean Francois Dufour-Lamartinie ◽

Remi Delansorne ◽

...

Keyword(s):

Stem Cells ◽

Chronic Myeloid Leukemia ◽

Board Of Directors ◽

Myeloid Leukemia ◽

P Value ◽

Employment Equity ◽

Macrophage Differentiation ◽

Advisory Committees ◽

Cd34 Cells ◽

Equity Ownership

Abstract Despite the major success obtained with their use in chronic myeloid leukemia (CML), recent data obtained from treatment discontinuation trials suggest that tyrosine kinase inhibitors (TKI) alone are not sufficient to eradicate the most primitive CML stem cells in the majority of the patients. The mechanisms of this inefficiency might involve cell autonomous (activation of alternate signaling, reduced BCR-ABL expression) or non-cell autonomous (niche-related) pathways. Several strategies of targeting the primitive stem cell compartment, in association with TKI, are currently being studied. Inecalcitol (ICC) is a vitamin D3 analog exerting antiproliferative effects in several types of cancer cells. ICC was tested in CD34+ cells isolated from CML patients at diagnosis (n=18) in clonogenic assays as well as in the more primitive LTC-IC-derived progenitors. ICC alone inhibits the clonogenic growth in the majority of the CML patients at diagnosis (15/18 patients). The combination of ICC with either, Imatinib (IM), Dasatinib (DA) or Nilotinib (NIL) in clonogenic assays showed a synergistic effect for the inhibition of CFC growth (10-25% CFC survival) with no toxicity on normal progenitors. Synergistic effects of ICC and TKI was also demonstrated in LTC-IC-derived progenitors with IM, NIL and DA. To determine possible mechanism of action of ICC in CML stem cells, we have performed a gene profiling analysis of CD34+ cells obtained at diagnosis from 4 CML patients. CD34+ cells were cultured for 7 days in the presence of growth factors with or without ICC. In phenotypic analyses, CD34+ cells treated in the presence of ICC showed an increase of monocyte/macrophage differentiation features with increased expression of CD13/CD14 as well as CD11b expression. Day 0 and Day7 RNA with or without ICC treatment were then studied by transcriptome hybridation on human-v2 (8*60k) Agilent technologies microarrays. Data were treated with Feature Extraction 11.5.11, Genespring GX12, Mev 4.9, R software and GSEA 2.2.20. Gene set enrichment analysis performed at day 7 of culture between ICC condition and control untreated cells showed an increase of cell differentiation markers under ICC (Normalized enrichment score = +1.94, p-value < 0.001) One way ANNOVA with False Discovery Rate (FDR) correction allowed to discover 7176 modulated probes between the 3 experimental conditions (Day 0, Day7 without ICC, Day 7 with ICC). CYP24A1 was the gene with the greatest induction by the treatment (Fold Change = +150). CYP24A1 is responsible of the degradation of 1.25(OH)2D3 by the monocyte/macrophage cells. Unsupervised classification with 372 macrophage connected genes (ANOVA p<0.01, FDR with 1000 permutations) allowed to separate samples by their experimental classes. This macrophage expression profile allows to discriminate samples from Day7 control to those of treated cells at the same time on hierarchical classification. This was confirmed by first factorial map of principal component analysis which explained 72% (PCA1 axis) hematopoietic differentiation during 7 days and 10% (PCA2 axis) effect of the treatment at the end of the differentiation. 23 macrophagic genes were indeed found to be specifically induced by the treatment with a fold change greater than 2 as compared to the untreated control: 11 of them participate to integrin-interleukins-chemokines signalizations pathways (p-value adjust FDR = 4.04e-10). Some macrophagic ligands and receptors are over-expressed in CML cells treated with ICC, including CSF2, OSM, TNFSF11, CXCL12 as well as FAS and CXCR2. In summary, these results suggest that one of the major mechanisms of action of ICC in the leukemic progenitors involve differentiation and activation of macrophagic expression profile. This profile could be used to design further therapeutic actions and to predict response to ICC, which is now tested in combination with IM in a clinical trial in France. Disclosures Dufour-Lamartinie: Hybrigenics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Delansorne:Hybrigenics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Turhan:Bristol Myers Squibb: Consultancy; Novartis: Research Funding.

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