scholarly journals Safety of Emapalumab in Pediatric Patients with Primary Hemophagocytic Lymphohistiocytosis (HLH): Relationship to Treatment Exposure

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2061-2061
Author(s):  
Michael B Jordan ◽  
Franco Locatelli ◽  
Philippe Jacqmin ◽  
Christian Laveille ◽  
Eric Snoeck ◽  
...  

Abstract Introduction: Primary hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening, immune disorder characterized by a hyperinflammatory state in which interferon gamma (IFNγ) is considered a key cytokine. The treatment goal of primary HLH is to stabilize the disease by controlling the associated hyperinflammation to bring patients to allogeneic hematopoietic stem cell transplantation (HSCT), the only curative therapy so far. Current conventional therapy for HLH is based on immunochemotherapies, namely etoposide and glucocorticoids; this treatment, however, is associated with opportunistic infections and severe myelotoxicity. Emapalumab, a fully human, anti-IFNγ monoclonal antibody that neutralizes IFNγ, is the only FDA-approved treatment for primary HLH patients with refractory, recurrent or progressive disease, or intolerance to conventional HLH therapy. In patients with primary HLH, the pharmacokinetics (PK) of emapalumab is highly influenced by body weight, and also by IFNγ production due to target-mediated drug disposition. In the pivotal trial (Locatelli et al NEJM 2020;382:1811-22), treatment of primary HLH patients with emapalumab was associated with a favorable safety and tolerability profile, with no unexpected safety concerns. Objective: To describe prespecified exploratory exposure-safety analyses that were performed on data from patients with primary HLH receiving emapalumab in the pivotal trial. Methods: Data from a multicenter, open-label, pivotal phase 2/3 study (NCT01818492) and its long-term follow-up study (NCT02069899) were included in this analysis. The safety of emapalumab was assessed in 34 patients (27 treatment experienced; 7 treatment naïve) with active primary HLH. Emapalumab was initiated at a dose of 1 mg/kg administered intravenously every 3 days, on a background of dexamethasone 5-10 mg/kg/day. Subsequent doses could be increased to 3, 6 and 10 mg/kg, if required, based on predefined laboratory and clinical response parameters. Treatment duration was up to 8 weeks, with possible shortening to a minimum of 4 weeks, or extension up to time of transplantation if needed. Exploratory graphical analyses were performed to determine the incidence of adverse events (AEs) as a function of the exposure parameters at the time of the AE. The relationship between emapalumab exposure and the incidence of treatment-emergent AEs, serious AEs, severe AEs, and AEs related to infections and infusion-related reactions (IRRs) was explored by logistic regression analyses. Selected parameters of renal (creatine clearance [CRCL]) and liver (total bilirubin [TBIL] and alanine aminotransferase [ALT]) function were explored graphically. Exposure parameters were obtained from the population PK/pharmacodynamic (PD) data file that was used for the population PK and PK/PD analyses. Observed individual concentration-time data were used to derive the individual exposure parameters as a function of time. The analyses considered AEs that emerged after the start of the first infusion until last infusion and prior to initiation of HSCT conditioning. Results: Exploratory graphical exposure-safety analyses did not reveal any apparent relationship between the number of AEs and exposure to emapalumab. Logistic exposure-safety regression analyses using the observed exposure to emapalumab at the time of an AE for patients experiencing an event and the highest observed exposure to emapalumab for those patients experiencing no AE, indicated that the incidence of AEs did not increase as a function of increasing emapalumab concentration. In fact, a statistically significant decrease in the incidence of severe AEs and the incidence of AEs related to IRRs was observed. No multivariate effects were identified in the multivariate regression analyses. No clear trend was observed for TBIL, ALT or CRCL as a function of the duration of emapalumab treatment. The exposure of emapalumab did not appear to influence the levels of TBIL, ALT or CRCL in individual patients during treatment. Conclusion: In this study, the exposure-safety evaluation did not reveal any significant relationships between exposure to emapalumab and observed incidence rates of AEs, serious AEs, infections, or IRRs. These findings support the primary evidence of a favorable benefit-risk profile of emapalumab across the dose range used in this fragile patient population. Disclosures Jordan: Sobi: Consultancy. Locatelli: Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Miltenyi: Speakers Bureau; Medac: Speakers Bureau; Jazz Pharamceutical: Speakers Bureau; Takeda: Speakers Bureau. Jacqmin: Sobi: Consultancy. Laveille: Sobi: Consultancy. Snoeck: Sobi: Consultancy. de Min: Sobi: Consultancy, Ended employment in the past 24 months.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1226-1226
Author(s):  
Hassan Awada ◽  
Reda Z. Mahfouz ◽  
Jibran Durrani ◽  
Ashwin Kishtagari ◽  
Deepa Jagadeesh ◽  
...  

T-cell large granular lymphocyte leukemia (T-LGLL) is a clonal proliferation of cytotoxic T lymphocytes (CTL). T-LGLL mainly manifest in elderly and is associated with autoimmune diseases including rheumatoid arthritis (RA), B cell dyscrasias, non-hematologic cancers and immunodeficiency (e.g., hypogammaglobulinemia). LGL manifestations often resemble reactive immune processes leading to the dilemmas that LGLs act like CTL expansion during viral infections (for example EBV associated infectious mononucleosis). While studying a cohort of 246 adult patients with T-LGLL seen at Cleveland Clinic over the past 10 years, we encountered 15 cases of overt T-LGLL following transplantation of solid organs (SOT; n=8) and hematopoietic stem cell transplantation (HSCT; n=7). Although early studies reported on the occurrence of LGL post-transplant, these studies focused on the analysis of oligoclonality skewed reactive CTL responses rather than frank T-LGLL. We aimed to characterize post-transplantation T-LGLL in SOT and HSCT simultaneously and compare them to a control group of 231 de novo T-LGLL (cases with no history of SOT or HSCT). To characterize an unambiguous "WHO-defined T-LGLL" we applied stringent and uniform criteria. All cases were diagnosed if 3 out of 4 criteria were fulfilled, including: 1) LGL count >500/µL in blood for more than 6 months; 2) abnormal CTLs expressing CD3, CD8 and CD57 by flow cytometry; 3) preferential usage of a TCR Vβ family by flow cytometry; 4) TCR gene rearrangement by PCR. In addition, targeted deep sequencing for STAT3 mutations was performed and charts of bone marrow biopsies were reviewed to exclude other possible conditions. Diagnosis was made 0.2-27 yrs post-transplantation (median: 4 yrs). At the time of T-LGLL diagnosis, relative lymphocytosis (15-91%), T lymphocytosis (49-99%) and elevated absolute LGL counts (>500 /µL; 93%) were also seen. Post-transplantation T-LGLL were significantly younger than de novo T-LGLL, (median age: 48 vs. 61 yr; P<.0001). Sixty% of post-transplantation T-LGLL patients were males. Fifteen% of patients had more cytogenetic abnormalities compared to de novo T-LGLL, had a lower absolute LGL count (median: 4.5 vs. 8.5 k/µL) and had less frequent neutropenia, thrombocytopenia and anemia (27 vs. 43%, 33 vs. 35% and 20% vs. 55%; P=.01). TCR Vb analysis identified clonal expansion of ≥1 of the Vb proteins in 60% (n=9) of the patients; the remaining 40% (n=6) of the cases had either a clonal process involving a Vb protein not tested in the panel (20%; n=3) or no clear expansion (20%; n=3). Signs of rejection were observed in 20% (n=3/15) and GvHD in 13% (n=2/15) of the patients. Post-transplantation, 27% of cases presented with neutropenia (absolute neutrophil count <1.5 x109/L; n=4), 33% with thrombocytopenia (platelet count <150 x109/L; n=5) and 25% with anemia (hemoglobin <10 g/dL; n=3). T-LGLL evolved in 10 patients (67%; 10/15) despite IST including cyclosporine (n=5), tacrolimus (n=4), mycophenolate mofetil (n=5), cyclophosphamide (n=1), anti-thymocyte globulin (n=1), and corticosteroids (n=6). Lymphadenopathy and splenomegaly were seen in 13% (n=2) and 33% (n=5) of the patients. Other conditions observed were MGUS (20%; n=3) and RA (7%; n=1). Conventional cytogenetic showed normal karyotype in 89% (n=11, tested individuals 13/15). Somatic STAT3 mutations were identified in 2 patients. Sixty% of cases (n=9) were seropositive for EBV when tested at different time points after transplant. Similarly, 53% (n=8) were seropositive for CMV, of which, 5 were positive post-transplantation and 3 pre-/post-transplantation. The complexity of T-LGLL expansion post-transplantation might be due to several mechanisms including active viral infections, latent oncogenic viral reactivation and graft allo-antigenic stimulation. However, in our cohort graft rejection or GvHD was encountered in a few patients (2 allo-HSCT recipients). Autoimmune conditions were present in 50% of SOT recipients (n=4/ 8, including RA, ulcerative colitis, systemic lupus erythematosus). Some of our patients also had low immunoglobulin levels. Overt EBV (post-transplant lymphoproliferative disorder) and CMV reactivation was diagnosed in only 27% (4/15) of the patients. In sum we report the long term follow up of a cohort of T-LGLL and emphasize the expansion of T-LGLL post-transplant highlighting the difficulty in assigning one unique origin of LGLL. Disclosures Hill: Genentech: Consultancy, Research Funding; Takeda: Research Funding; Celegene: Consultancy, Honoraria, Research Funding; Kite: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Honoraria; Amgen: Research Funding; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; TG therapeutics: Research Funding; AstraZeneca: Consultancy, Honoraria. Majhail:Atara Bio: Consultancy; Mallinckrodt: Honoraria; Nkarta: Consultancy; Anthem, Inc.: Consultancy; Incyte: Consultancy. Sekeres:Syros: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Maciejewski:Alexion: Consultancy; Novartis: Consultancy.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3562-3562
Author(s):  
Tae Min Kim ◽  
Dok Hyun Yoon ◽  
Ahmad H. Mattour ◽  
Jorge M. Chaves ◽  
Emily Curran ◽  
...  

Abstract Background: BR101801 not only blocks the signaling responsible for cell growth caused by PI3K, but also efficiently induces cell cycle arrest and apoptosis through inhibition of DNA-PK activation and stimulates decreasing stability of the oncogenic protein, c-Myc(AACR2020 abstract #655). This phase I study evaluated safety, tolerability, pharmacokinetics and preliminary activity of the BR101801 (PI3Kγ/δ and DNA PK inhibitor) in patients with advanced hematologic malignancies. Method: This is a Phase I, multi-center, open-label, first-in-human study. The Phase Ia (dose escalation) part of the study was designed to determine the maximum tolerated dose (MTD)/recommended dose for expansion (RDE) of BR101801. BR101801 was administered orally once daily in 28-day cycles. The dose escalation part was initiated with a dose titration in the initial cohort, followed by a 3 + 3 design. Results: 11 patients were enrolled and have been treated at 4 dose levels: 50mg, 100mg, 200mg, 325mg and expanded 200mg through fifth cohort escalation. Pathological subtypes include 7 PTCL, 2 DLBCL, 1 MZBL and 1 composite CTCL/MF. 3 females and 8 males have been treated to date. Median age is 58 (range 30-71) and ECOG PS is in the range of 0-1. All patients had taken at least one prior chemotherapy. 10 of total patients have completed at least one cycle except 1 premature drop-out case due to disease progression. First interim analysis after completion of cycle 3 of the last patient of 200mg QD cohort had been conducted, which was to include 5 patients (1 DLBCL and 4 PTCLs). No DLT had been identified in Cohorts 1-3, and 2 patients discontinued the study treatment due to adverse event (G4 thrombocytopenia, not related to IP) and disease progression, respectively. The PK values from multiple dosing range of 50mg to 200mg cohort resulted in an approximate 2.92-fold and 4.97 fold increase in exposure based on Cmax and AUCtau, respectively. BR101801 PK profile showed that the exposure of concentration increased in a dose dependent manner and there was no accumulation observed in the dose range of 50mg to 200mg. 2 DLTs was observed at 325mg QD cohort. The dose was de-escalated to the previous lower dose level (200mg QD) and was expanded to 3 additional patients. The expansion cohort is ongoing at present. 2 of 11 patients had G3 skin reaction and 3 had G3 hepatotoxicites. All adverse effects were manageable and recovered to grade 0-1 upon BR1010801 discontinuation. Total 5 patients have been currently ongoing. For overall tumor response assessment, 4 SDs and 2 PRs have been obsereved. Summary/Conclusion: 200 mg QD of BR101801 was shown to provide target exposure for clinical efficacy with the tolerable and safe profiles. BR101801 was well tolerated and showed preliminary signs of activity in patients with relapsed or refractory hematologic malignancies. The phase Ib/II study of BR101801 is warranted in relapsed/refractory NHL. This study is registered at clinicaltrials.gov identifier NCT04018248. Disclosures Kim: AstraZeneca-KHIDI: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; GI CELL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Hanmi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Boryung: Consultancy, Membership on an entity's Board of Directors or advisory committees; BeyondBIO: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; AstraZeneca/MedImmune: Consultancy, Membership on an entity's Board of Directors or advisory committees. Curran: Servier pharmaceuticals and Amgen: Consultancy. Kim: Boryung pharmaceuticals: Current Employment.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3816-3816 ◽  
Author(s):  
Ryan J. Daley ◽  
Sridevi Rajeeve ◽  
Charlene C. Kabel ◽  
Jeremy J. Pappacena ◽  
Sarah E. Stump ◽  
...  

Introduction: Asparaginase (ASP) has demonstrated a survival benefit in pediatric patients (pts) with acute lymphoblastic leukemia (ALL) and is now part of standard-of-care frontline treatment. As a result, asparaginase preparations have been incorporated into the treatment of adult ALL to improve outcomes. Pegaspargase (PEG-ASP), a modified version of asparaginase with prolonged asparagine depletion, appears to be safe in adults up to age 40 (Stock, et al., Blood, 2019), but is associated with a unique spectrum of toxicities, the risks of which appear to increase with age. Therefore, the safety of PEG-ASP remains a significant concern in older adults w/ ALL. Methods: We conducted a single center retrospective chart review of pts age ≥40 years who received PEG-ASP as part of frontline induction/consolidation or reinduction, between March 2008 and June 2018 at Memorial Sloan Kettering Cancer Center. The primary objective was to evaluate the tolerability and toxicity of PEG-ASP based on the incidence and severity of ASP-related toxicities (hypersensitivity reactions, hypertriglyceridemia, hyperbilirubinemia, transaminitis, pancreatitis, hypofibrinogenemia, etc) according to the Common Terminology Criteria for Adverse Events, version 4.03. Laboratory values recorded were either the peak or the nadir, the more appropriate for toxicity assessment, within a 4-week period following PEG-ASP administration. Secondary objectives were to determine the total number of doses of PEG-ASP administered in comparison to the number of doses intended, and to characterize the rationale for PEG-ASP discontinuation when applicable. Fisher's exact test was used to compare the incidence of PEG-ASP toxicities with respect to pt and treatment characteristics (regimen, age, BMI, gender, Philadelphia chromosome positive (Ph+) vs. Ph-, presence of extramedullary disease, PEG-ASP dose). P values were not adjusted for multiple comparisons. Results: We identified 60 pts with ALL (40 B-ALL and 20 T-ALL) who received at least one dose of PEG-ASP. Nine pts were Ph+. The median pt age at initiation of the treatment was 53, (range, 40 to 80), and 19 pts had a BMI ≥30 kg/m2. Forty-four pts received treatment for newly diagnosed ALL, and 16 pts for relapsed disease. Table 1 lists pt baseline characteristics. Among the 44 pts with newly diagnosed ALL, 27 pts received PEG-ASP as part of pediatric or pediatric-inspired regimens at doses of 2000 - 2500 units/m2, and 1 pt received a modified dose of 1000 units/m2 due to age. The remaining 16 pts received PEG-ASP at doses of 1000 - 2000 units/m2 for consolidation, per established adult regimens (ALL-2 and L-20; Lamanna, et al., Cancer, 2013). Grade 3/4 ASP-related toxicities with a >10% incidence included: hyperbilirubinemia, transaminitis, hypoalbuminemia, hyperglycemia, hypofibrinogenemia, and hypertriglyceridemia. Frontline treatment regimens in which PEG-ASP was used in consolidation cycles only (ALL-2, L-20) were associated w/ a lower incidence of hyperbilirubinemia (p=0.009) and hypertriglyceridemia (p<0.001) compared to those regimens that included PEG-ASP during induction (pediatric/pediatric-inspired regimens) (Table 2). Younger age (40-59 vs. ≥60 years) was associated with a greater risk of hypertriglyceridemia (p<0.001) and higher PEG-ASP dose (≥2000 vs. <2000 units/m2) was associated with a greater risk of hypertriglyceridemia and hypofibrinogenemia (p=0.002 and p=0.025, respectively). Thirty-eight pts (63%) received all intended doses of PEG-ASP. Six pts stopped PEG-ASP to proceed to allogeneic hematopoietic stem cell transplantation (5 in CR1, 1 in CR2), and 7 pts stopped for hypersensitivity reactions. Hepatotoxicity was the only ASP-related toxicity that led to PEG-ASP discontinuation occurring in 5 pts (hyperbilirubinemia, N=4; transaminitis, N=1). The total number of intended doses of PEG-ASP based on regimens used was 186, and 112 were administered. Conclusion: PEG-ASP was incorporated into the treatment of 60 adult ALL pts age ≥40, with manageable toxicity. Seven pts discontinued PEG-ASP due to hypersensitivity reactions and 5 discontinued due to hepatotoxicity, but other reported toxicities did not lead to PEG-ASP discontinuation and the majority of the pts completed all intended doses of PEG-ASP. This study suggests that with careful monitoring, PEG-ASP can safely be administered in adults ≥40 years of age. Disclosures Rajeeve: ASH-HONORS Grant: Research Funding. Tallman:UpToDate: Patents & Royalties; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellerant: Research Funding; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Research Funding; Biosight: Research Funding; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees. Geyer:Dava Oncology: Honoraria; Amgen: Research Funding. Park:Takeda: Consultancy; Allogene: Consultancy; Amgen: Consultancy; AstraZeneca: Consultancy; Autolus: Consultancy; GSK: Consultancy; Incyte: Consultancy; Kite Pharma: Consultancy; Novartis: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1962-1962
Author(s):  
Sandhya R. Panch ◽  
Brent R. Logan ◽  
Jennifer A. Sees ◽  
Bipin N. Savani ◽  
Nirali N. Shah ◽  
...  

Introduction: Approximately 7% of unrelated hematopoietic stem cell (HSC) donors are asked to donate a subsequent time to the same or different recipient. In a recent large CIBMTR study of second time donors, Stroncek et al. incidentally found that second peripheral blood stem cell (PBSC) collections had lower total CD34+ cells, CD34+ cells per liter of whole blood processed, and CD34+ cells per kg donor weight. Based on smaller studies, the time between the two independent PBSC donations (inter-donation interval) as well as donor sex, race and baseline lymphocyte counts appear to influence CD34+ cell yields at subsequent donations. Our objective was to retrospectively evaluate factors contributory to CD34+ cell yields at subsequent PBSC donation amongst NMDP donors. Methods. The study population consisted of filgrastim (G-CSF) mobilized PBSC donors through the NMDP/CIBMTR between 2006 and 2017, with a subsequent donation of the same product. evaluated the impact of inter-donation interval, donor demographics (age, BMI, race, sex, G-CSF dose, year of procedure, need for central line) and changes in complete blood counts (CBC), on the CD34+ cell yields/liter (x106/L) of blood processed at second donation and pre-apheresis (Day 5) peripheral blood CD34+ cell counts/liter (x106/L) at second donation. Linear regression was used to model log cell yields as a function of donor and collection related variables, time between donations, and changes in baseline values from first to second donation. Stepwise model building, along with interactions among significant variables were assessed. The Pearson chi-square test or the Kruskal-Wallis test compared discrete variables or continuous variables, respectively. For multivariate analysis, a significance level of 0.01 was used due to the large number of variables considered. Results: Among 513 PBSC donors who subsequently donated a second PBSC product, clinically relevant decreases in values at the second donation were observed in pre-apheresis CD34+ cells (73.9 vs. 68.6; p=0.03), CD34+cells/L blood processed (32.2 vs. 30.1; p=0.06), and total final CD34+ cell count (x106) (608 vs. 556; p=0.02). Median time interval between first and second PBSC donations was 11.7 months (range: 0.3-128.1). Using the median pre-apheresis peripheral blood CD34+ cell counts from donation 1 as the cut-off for high versus low mobilizers, we found that individuals who were likely to be high or low mobilizers at first donation were also likely to be high or low mobilizers at second donation, respectively (Table 1). This was independent of the inter-donation interval. In multivariate analyses, those with an inter-donation interval of >12 months, demonstrated higher CD34+cells/L blood processed compared to donors donating within a year (mean ratio 1.15, p<0.0001). Change in donor BMI was also a predictor for PBSC yields. If donor BMI decreased at second donation, so did the CD34+cells/L blood processed (0.74, p <0.0001). An average G-CSF dose above 960mcg was also associated with an increase in CD34+cells/L blood processed compared to donors who received less than 960mcg (1.04, p=0.005). (Table 2A). Pre-apheresis peripheral blood CD34+ cells on Day 5 of second donation were also affected by the inter-donation interval, with higher cell counts associated with a longer time interval (>12 months) between donations (1.23, p<0.0001). Further, independent of the inter-donation interval, GCSF doses greater than 960mcg per day associated with higher pre-apheresis CD34+ cells at second donation (1.26, p<0.0001); as was a higher baseline WBC count (>6.9) (1.3, p<0.0001) (Table 2B). Conclusions: In this large retrospective study of second time unrelated PBSC donors, a longer inter-donation interval was confirmed to be associated with better PBSC mobilization and collection. Given hematopoietic stem cell cycling times of 9-12 months in humans, where possible, repeat donors may be chosen based on these intervals to optimize PBSC yields. Changes in BMI are also to be considered while recruiting repeat donors. Some of these parameters may be improved marginally by increasing G-CSF dose within permissible limits. In most instances, however, sub-optimal mobilizers at first donation appear to donate suboptimal numbers of HSC at their subsequent donation. Disclosures Pulsipher: CSL Behring: Membership on an entity's Board of Directors or advisory committees; Miltenyi: Research Funding; Bellicum: Consultancy; Amgen: Other: Lecture; Jazz: Other: Education for employees; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Medac: Honoraria. Shaw:Therakos: Other: Speaker Engagement.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3765-3765
Author(s):  
Cheuk-Him Man ◽  
David T. Scadden ◽  
Francois Mercier ◽  
Nian Liu ◽  
Wentao Dong ◽  
...  

Acute myeloid leukemia (AML) cells exhibit metabolic alterations that may provide therapeutic targets not necessarily evident in the cancer cell genome. Among the metabolic features we noted in AML compared with normal hematopoietic stem and progenitors (HSPC) was a strikingly consistent alkaline intracellular pH (pHi). Among candidate proton regulators, monocarboxylate transporter 4 (MCT4) mRNA and protein were differentially increased in multiple human and mouse AML cell lines and primary AML cells. MCT4 is a plasma membrane H+and lactate co-transporter whose activity necessarily shifts protons extracellularly as intracellular lactate is extruded. MCT4 activity is increased when overexpressed or with increased intracellular lactate generated by glycolysis in the setting of nutrient abundance. With increased MCT4 activity, extracellular lactate and protons will increase causing extracellular acidification while alkalinizing the intracellular compartment. MCT4-knockout (MCT4-KO) of mouse and human AMLdid not induce compensatory MCT1 expression, reduced pHi, suppressed proliferation and improved animal survival. Growth reduction was experimentally defined to be due to intracellular acidification rather than lactate accumulation by independent modulation of those parameters. MCT4-KOmetabolic profiling demonstrated decreased ATP/ADP and increased NADP+/NADPH suggesting suppression of glycolysis and the pentose phosphate pathway (PPP) that was confirmed by stable isotopic carbon flux analyses. Notably,the enzymatic activity of purified gatekeeper enzymes, hexokinase 1 (HK1), pyruvate kinase M2 isoform (PKM2) and glucose-6-phosphate dehydrogenase (G6PDH) was sensitive to pH with increased activity at the leukemic pHi (pH 7.6) compared to normal pHi (pH 7.3). Evaluating MCT4 transcriptional regulation, we defined that activating histonemarks, H3K27ac and H3K4me3, were enriched at the MCT4 promoter region as were transcriptional regulators MLL1 and Brd4 by ChIP in AML compared with normal cells. Pharmacologic inhibition of Brd4 suppressed Brd4 and H3K27ac enrichment and MCT4 expression in AML and reduced leukemic cell growth. To determine whether MCT4 based pHi changes were sufficient to increase cell proliferation, we overexpressed MCT4 in normal HSPC and demonstrated in vivo increases in growth in conjunction with pHi alkalization. Some other cell types also were increased in their growth kinetics by MCT4 overexpression and pHi increase. Therefore, proton shifting may be a means by which cells respond to nutrient abundance, co-transporting lactate and protons out of the cell, increasing the activity of enzymes that enhance PPP and glycolysis for biomass generation. Epigenetic changes in AML appear to exploit that process by increasing MCT4 expression to enforce proton exclusion thereby gaining a growth advantage without dependence on signaling pathways. Inhibiting MCT4 and intracellular alkalization may diminish the ability of AML to outcompete normal hematopoiesis. Figure Disclosures Scadden: Clear Creek Bio: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Sponsored research; Editas Medicine: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bone Therapeutics: Consultancy; Fog Pharma: Consultancy; Red Oak Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; LifeVaultBio: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Magenta Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics: Consultancy, Equity Ownership.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3199-3199
Author(s):  
Ji Zha ◽  
Lori Kunselman ◽  
Hongbo Michael Xie ◽  
Brian Ennis ◽  
Jian-Meng Fan ◽  
...  

Hematopoietic stem cell (HSC) transplantation (HSCT) is required for curative therapy for patients with high-risk hematologic malignancies, and a number of non-malignant disorders including inherited bone marrow failure syndromes (iBMFS). Strategies to enhance bone marrow (BM) niche capacity to engraft donor HSC have the potential to improve HSCT outcome by decreasing graft failure rates and enabling reduction in conditioning intensity and regimen-associated complications. Several studies in animal models of iBMFS have demonstrated that BM niche dysfunction contributes to both the pathogenesis of iBMFS, as well as impaired graft function after HSCT. We hypothesize that such iBMFS mouse models are useful tools for discovering targetable niche elements critical for donor engraftment after HSCT. Here, we report the development of a novel mouse model of Shwachman-Diamond Syndrome (SDS) driven by conditional Sbds deletion, which demonstrates profound impairment of healthy donor hematopoietic engraftment after HSCT due to pathway-specific dysfunctional signaling within SBDS-deficient recipient niches. We first attempted to delete Sbds specifically in mature osteoblasts by crossing Sbdsfl/flmice with Col1a1Cre+mice. However, the Col1a1CreSbdsExc progenies are embryonic lethal at E12-E15 stage due to developmental musculoskeletal abnormalities. Alternatively, we generated an inducible SDS mouse model by crossing Sbdsfl/flmice with Mx1Cre+ mice, and inducing Sbds deletion in Mx1-inducible BM hematopoietic and osteolineage niche cells by polyinosinic-polycytidilic acid (pIpC) administration. Compared with Sbdsfl/flcontrols, Mx1CreSbdsExc mice develop significantly decreased platelet counts, an inverted peripheral blood myeloid/lymphoid cell ratio, and reduced long-term HSC within BM, consistent with stress hematopoiesis seen in BMF and myelodysplastic syndromes. To assess whether inducible SBDS deficiency impacts niche function to engraft donor HSC, we transplanted GFP+ wildtype donor BM into pIpC-treated Mx1CreSbdsExc mice and Sbdsfl/flcontrols after 1100 cGy of total body irradiation (TBI). Following transplantation, Mx1CreSbdsExc recipient mice exhibit significantly higher mortality than controls (Figure 1). The decreased survival was related to primary graft failure, as Mx1CreSbdsExc mice exhibit persistent BM aplasia after HSCT and decreased GFP+ reconstitution in competitive secondary transplantation assays. We next sought to identify the molecular and cellular defects within BM niche cells that contribute to the engraftment deficits in SBDS-deficient mice. We performed RNA-seq analysis on the BM stromal cells from irradiated Mx1CreSbdsExc mice versus controls, and the results revealed that SBDS deficiency in BM niche cells caused disrupted gene expression within osteoclast differentiation, FcγR-mediated phagocytosis, and VEGF signaling pathways. Multiplex ELISA assays showed that the BM niche of irradiated Mx1CreSbdsExc mice expresses lower levels of CXCL12, P-selectin and IGF-1, along with higher levels of G-CSF, CCL3, osteopontin and CCL9 than controls. Together, these results suggest that poor donor HSC engraftment in SBDS-deficient mice is likely caused by alterations in niche-mediated donor HSC homing/retention, bone metabolism, host monocyte survival, signaling within IGF-1 and VEGF pathways, and an increased inflammatory state within BM niches. Moreover, flow cytometry analysis showed that compared to controls, the BM niche of irradiated Mx1CreSbdsExc mice contained far fewer megakaryocytes, a hematopoietic cell component of BM niches that we previously demonstrated to be critical in promoting osteoblastic niche expansion and donor HSC engraftment. Taken together, our data demonstrated that SBDS deficiency in BM niches results in reduced capacity to engraft donor HSC. We have identified multiple molecular and cellular defects in the SBDS-deficient niche contributing to this phenotype. Such niche signaling pathway-specific deficits implicate these pathways as critical for donor engraftment during HSCT, and suggest their potential role as targets of therapeutic approaches to enhance donor engraftment and improve HSCT outcome in any condition for which HSCT is required for cure. Disclosures Olson: Merck: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Miltenyi: Honoraria.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 37-38
Author(s):  
Caroline Wilson ◽  
Wei-i Lee ◽  
Matthew Cook ◽  
Lillian Smyth ◽  
Dipti Talaulikar

Introduction Hemophagocytic lymphohistiocytosis (HLH) is a rare condition resulting from a dysregulated inflammatory response. It can prove difficult to diagnose and portends a poor prognosis. Bone marrow (BM) biopsy is an easily accessible test that is often used to identify the presence of hemophagocytosis and assess for underlying malignancy. Currently there are no evidence-based guidelines on the reporting of hemophagocytosis on BM biopsy and no reports of a correlation between hemophagocytosis with the clinical diagnostic criteria for HLH. We therefore aimed to assess if the amount of hemophagocytosis identified in the BM biopsy correlates with HLH-2004 criteria. Secondary aims were to evaluate inter-observer variability in reporting hemophagocytosis, and to formulate recommendations for screening in BM specimens. Method A retrospective review of bone marrow biopsies from adult patients under investigation for HLH was undertaken independently by 2 hematopathologists who were blinded to the original biopsy report. Relevant clinical and laboratory data was extracted from medical records. The average number of actively hemophagocytic cells in each slide prepared from BM aspirates were quantified into 0, 1, 2-4 and ≥5. On trephine samples, hemophagocytosis was reported as either 'present' or 'absent', with the assistance of the CD68 immunohistochemical stain. Cases with discordance pertaining to the degree of hemophagocytosis were reviewed by both assessors to reach a consensus. Results Sixty-two specimens from 59 patients were available for assessment. An underlying hematological condition was identified in 34 cases (58%). The most common underlying hematological condition was lymphoma, found in 15 cases (25%). There was a significant association between the amount of hemophagocytosis identified on the aspirate samples and the number of HLH-2004 criteria met (p&lt;0.05). In patients where hemophagocytosis was present (n=31), there was a significant correlation between the amount of hemophagocytosis and ferritin levels (p&lt;0.05). Interobserver variability was present in 63% of cases. Based on our review, we make the following recommendations for reporting of hemophagocytosis in the BM samples:&gt; 1. Count only macrophages ingesting intact hemopoietic cells. W2. Quantify the average number of active histiocytes per aspirate slide. W3. Count histiocytes away from particles where the cellular outline is clear. W4. Avoid counting conglomerates of histiocytes where the cellular margins are indistinct W5. On the aspirate specimen, assess for hemophagocytosis on both the trail and squash preparations. W6. Delineating hemophagocytosis on trephine samples is difficult without the use of a CD68 immunohistochemical stain. Interestingly, a study by Ho et al found no association between the BM histologic findings and the probability of hemophagocytosis (Ho et al, American Journal of Clinical Pathology, 2014). This difference highlights the need for standardised reporting of BM specimens. Conclusion Our findings indicate that the amount of hemophagocytosis present on BM samples correlates with the number of HLH-2004 criteria met. We found marked interobserver variability which we anticipate can be rectified with our recommendations on the reporting of hemophagocytosis. Disclosures Talaulikar: Takeda: Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3229-3229 ◽  
Author(s):  
Ivana N Micallef ◽  
Eric Jacobsen ◽  
Paul Shaughnessy ◽  
Sachin Marulkar ◽  
Purvi Mody ◽  
...  

Abstract Abstract 3229 Poster Board III-166 Introduction Low platelet count prior to mobilization is a significant predictive factor for mobilization failure in patients with non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD) undergoing autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT; Hosing C, et al, Am J Hematol. 2009). The purpose of this study is to assess the efficacy of HSC mobilization with plerixafor plus G-CSF in patients with concomitant thrombocytopenia undergoing auto-HSCT. Methods Patients who had failed successful HSC collection with any mobilization regimen were remobilized with plerixafor plus G-CSF as part of a compassionate use program (CUP). Mobilization failure was defined as the inability to collect 2 ×106 CD34+ cells/kg or inability to achieve a peripheral blood count of ≥10 CD34+ cells/μl without having undergone apheresis. As part of the CUP, G-CSF (10μg/kg) was administered subcutaneously (SC) every morning for 4 days. Plerixafor (0.24 mg/kg SC) was administered in the evening on Day 4, approximately 11 hours prior to the initiation of apheresis the following day. On Day 5, G-CSF was administered and apheresis was initiated. Plerixafor, G-CSF and apheresis were repeated daily until patients collected the minimum of 2 × 106 CD34+ cells/kg for auto-HSCT. Patients in the CUP with available data on pre-mobilization platelet counts were included in this analysis. While patients with a platelet count <85 × 109/L were excluded from the CUP, some patients received waivers and were included in this analysis. Efficacy of remobilization with plerixafor + G-CSF was evaluated in patients with platelet counts ≤ 100 × 109/L or ≤ 150 × 109/L. Results Of the 833 patients in the plerixafor CUP database, pre-mobilization platelet counts were available for 219 patients (NHL=115, MM=66, HD=20 and other=18.). Of these, 92 patients (NHL=49, MM=25, HD=8 and other=10) had pre-mobilization platelet counts ≤ 150 × 109/L; the median platelet count was 115 × 109/L (range, 50-150). The median age was 60 years (range 20-76) and 60.4% of the patients were male. Fifty-nine patients (64.1%) collected ≥2 × 109 CD34+ cells/kg and 13 patients (14.1%) achieved ≥5 × 106 CD34+ cells/kg. The median CD34+ cell yield was 2.56 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 68.5%. The median time to neutrophil and platelet engraftment was 12 days and 22 days, respectively. Similar results were obtained when efficacy of plerixafor + G-CSF was evaluated in 29 patients with platelet counts ≤ 100 × 109/L (NHL=12, MM=10, HD=3 and other=4). The median platelet count in these patients was 83 × 109/L (range, 50-100). The median age was 59 years (range 23-73) and 60.4% of the patients were male. The minimal and optimal cell dose was achieved in 19(65.5%) and 3(10.3%) patients, respectively. The median CD34+ cell yield was 2.92 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 62.1%. The median time to neutrophil and platelet engraftment was 12 days and 23 days, respectively. Conclusions For patients mobilized with G-CSF alone or chemotherapy ±G-CSF, a low platelet count prior to mobilization is a significant predictor of mobilization failure. These data demonstrate that in patients with thrombocytopenia who have failed prior mobilization attempts, remobilization with plerixafor plus G-CSF allows ∼65% of the patients to collect the minimal cell dose to proceed to transplantation. Thus, in patients predicted or proven to be poor mobilizers, addition of plerixafor may increase stem cell yields. Future studies should investigate the efficacy of plerixafor + G-CSF in front line mobilization in patients with low platelet counts prior to mobilization. Disclosures Micallef: Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Jacobsen:Genzyme Corporation: Research Funding. Shaughnessy:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Mody:Genzyme Corporation: Employment, Equity Ownership. van Rhee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1210-1210
Author(s):  
Elisabeth Bolton ◽  
Linda Kamp ◽  
Hardik Modi ◽  
Ravi Bhatia ◽  
Steffen Koschmieder ◽  
...  

Abstract Abstract 1210 Background: BCR-ABL1 transforms hematopoietic stem cells to induce chronic myeloid leukemia in chronic phase (CML-CP). Although CML is stem cell-derived, it is a progenitor cell-driven disease. In CML-CP, leukemia stem cells (LSCs) are characterized by elevated BCR-ABL1 expression in comparison to leukemia progenitor cells (LPCs). Increased expression of BCR-ABL1 kinase is also associated with progression from CML-CP to CML-blast phase. Previously we showed that BCR-ABL1 kinase stimulates reactive oxygen species (ROS)-dependent DNA damage resulting in genomic instability in vitro, which was responsible for acquired imatinib-resistance and accumulation of chromosomal aberrations (Nowicki et al., Blood, 2005; Koptyra et al., Blood, 2006; Koptyra et al., Leukemia, 2008). Result: To examine the effects of BCR-ABL1 expression on genomic instability during in vivo leukemogenesis we employed an inducible transgenic mouse model of CML-CP with targeted expression of p210BCR-ABL1 in hematopoietic stem and progenitor cells (Koschmieder et al., Blood, 2005). Mice exhibiting CML-CP-like disease resulting from BCR-ABL1 induction demonstrated splenomegaly, leukocytosis, and Gr1+/CD11b+ myeloid expansion in bone marrow, spleen and peripheral blood, as detected by FACS analysis. BCR-ABL1 mRNA expression was higher in Lin-c-Kit+Sca1+ stem-enriched cells than in Lin-c-Kit+Sca1- progenitor-enriched cells, thus reminiscent of CML-CP (LSCs>LPCs). BCR-ABL1 increased levels of ROS (hydrogen peroxide, hydroxyl radical) and oxidative DNA lesions (8-oxoG) in LSC-enriched Lin-c-Kit+Sca1+ cells. Preliminary data also suggested that quiescent (CFSEmax) Lin-c-Kit+Sca1+ cells from BCR-ABL1-induced mice exhibited greater ROS (superoxide) production than non-induced counter parts. Moreover, higher levels of ROS were detected in BCR-ABL1-positive Lin-c-Kit+Sca1+ stem-enriched population in comparison to BCR-ABL1-positive Lin-c-Kit+Sca1- progenitor population, suggesting a dosage-dependent effect of BCR-ABL1. To confirm that BCR-ABL1 exerts a dosage-dependent effect on ROS-induced oxidative DNA damage, we showed that the levels of ROS, 8-oxoG and DNA double-strand breaks were proportional to BCR-ABL1 kinase expression in murine 32Dc13 and human CD34+ cells. Conclusion: In summary, this mouse model recapitulates the BCR-ABL1 expression profile attributed to stem and progenitor populations in human CML-CP. It also shows that the BCR-ABL1-positive, stem cell-enriched Lin-c-Kit+Sca1+ population displays elevated levels of ROS and oxidative DNA damage in comparison to normal counterparts, which makes it suitable to study the mechanisms of genomic instability in LSCs. Single nucleotide polymorphism (SNP) arrays will shed more light on the genomic instability of this BCR-ABL1-induced transgenic model of CML-CP. Disclosures: Koschmieder: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1244-1244
Author(s):  
Géraldine Salmeron ◽  
Raphaël Porcher ◽  
Anne Bergeron ◽  
Marie Robin ◽  
Regis Peffault de Latour ◽  
...  

Abstract Abstract 1244 Background. Voriconazole (V) treatment has been shown to improve the 12 week (W) survival rate of hematological patients (pts) with invasive aspergillosis (IA), including recipients of allogeneic hematopoietic stem cell transplants (HSCT). We investigated whether this early survival advantage could translate into a significant increase in overall survival. Methods. We retrospectively reviewed all consecutive pts who received a transplant between Sept. 1997 and Dec. 2008 at Saint-Louis Hospital and were diagnosed as having IA. The temporal origin of the study was the date of IA diagnosis for each patient. Factors associated with survival were analyzed using Cox proportional hazard models. Separate models were estimated for survival up to 12 W and for survival between 12 W and 24 months (M) in pts surviving longer than 12 W. The deaths of pts with and without IA were analyzed with a competing risk framework. Cumulative incidence curves were compared using Gray's tests. Results. Our study examined 89 IA pts. The median follow-up was 70 M (range, 11–130 M). Two pts did not receive any antifungal treatment and were excluded from subsequent analyses. Of the 87 pts, 42 received first-line V and 45 primarily received a lipid formulation of amphotericin B (n=25), amphotericin B deoxycholate (n=10), caspofungin (n=8) or itraconazole (n=2). The primary characteristics of pts with IA and their causes of death, separated by V as first-line treatment, are shown in the table below. The median survival was 2.6 M, and the overall survival at 24 M was 19% (95% CI 12–30 M) (see figure). Overall, the survival rates of the two groups were significantly different (P= 0.010). However, the differences in survival were quite dramatic prior to 10 M, whereas both survival curves became very close after one year. At 18 M, the numbers of surviving pts were almost identical in the two groups [19% (95% CI: 11–34%) in pts who did not receive V as first-line treatment vs. 21% (95% CI 11–38%) in pts who did]. Pts who did not receive V as a first-line treatment displayed a higher probability of dying from IA than those who did (P=0.004), whereas opposite results were found for mortality in pts without IA (P=0.006). The 24-M cumulative incidence of death from IA was 47% (95% CI 31–61%) in the no V group and 19% (95% CI 9–33%) in the group treated with V. The 24-M cumulative incidence of death in pts without IA was 4% (95% CI 7–14%) in the no V group and 27% (95% CI 14–42%) in pts treated with V. The probability of death from another cause, with IA, was similar in both groups (29% vs. 36% at 24 M; P=0.46). After adjusting for donor type, conditioning regimen, progressive GVHD at diagnosis of IA and cumulated steroid dose (mg/kg) in the W preceding IA diagnosis, administration of V as first-line treatment was found to decrease the risk of death during the first 12 W by approximately 70% [HR=0.31 (95% CI 0.16–0.60); P=0.0005]. Conversely, analysis of mortality between 12 W and 24 M failed to identify any significant predictor of risk of death; however, only 24 pts died during this period. Conclusions. The finding that first-line treatment with V, which is associated with a tremendous improvement in IA outcome, does not translate into an increase in overall survival (even in the context of early diagnosis) is striking. Diagnosis of IA following HSCT, whatever the outcome, appears to be a strong marker for poor long-term prognosis. Disclosures: Bergeron: Pfizer: Speakers Bureau, none; Merck: Speakers Bureau, none; Schering: Speakers Bureau, none. Sulahian:Pfizer: Research Funding, non; Merck: Research Funding, none. Ribaud:Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau, none; Schering: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau, none; Gilead: Speakers Bureau, none.


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