bluuebunny/crossref_metadata_2025 huggingface dataset:
Superior Graft-Versus-Leukemia Effect in Haploidentical Transplantation Compared with HLA-Matched Sibling Transplantation for High-Risk Acute Myeloid Leukemia in First Complete Remission: A Prospective Multicentre Cohort Study
Authors: Yu Sijian , Liu Qifa
Published: November 2019

This study aimed to investigate graft-versus-leukemia (GVL) of haploidentical donor (HID) compared with HLA-matched sibling donor (MSD) for high-risk acute myeloid leukemia (H-AML) in first complete remission (CR1). One hundred and eighty-nine patients with H-AML in CR1 were enrolled in this multicentre prospective cohort study. Patients were assigned to groups transplanted with HID (n=83) or MSD (n=106) based on donor availability (biological randomization). The primary endpoint was the incidence of MRD positivity post-transplantation (post-MRD+). All post-MRD+ patients received preemptive interventions. The cumulative incidences of post-MRD+ were 18% and 42% in HID and MSD groups, respectively, (p<.001). Fifty-two patients received preemptive DLI, including 13 (16%) in HID and 39 cases (37%) in MSD groups (p=.001). Among HID and MSD groups, the 3-year cumulative incidence of relapse were 14% and 24% (p=0.101); the 3-year cumulative incidence of treatment-related mortality were 15% and 10% (p=0.368); the 3-year overall survival rates were 72% and 68% (p=0.687); the 3-year disease-free-survival were 71% and 66% (p=0.579); the 3-year graft-versus-host disease and relapse free survival were 63% and 43% (p=0.035), respectively. HID has a stronger GVL than MSD in H-AML patients. HID transplantation as post-remission therapy should be recommended as one of the optimal choices for H-AML in CR1.

Disclosures

No relevant conflicts of interest to declare.
A Rare Case of Kimura Disease in the Wrist
Authors: Tizro Parastou , Hashemi Zonouz Taraneh , Almutairi Fawaz , Karcher Donald
Published: November 2019

Kimura disease is a rare benign chronic inflammatory disorder of unknown etiology that typically involves lymph nodes and soft tissues. This disease is most common in middle-aged Asian men. Although the disorder most frequently involves the head and neck region, it has also been reported to involve the extremities. Lesions typically show follicular lymphocytic hyperplasia with prominent interfollicular venules and a mixed inflammatory infiltrate, including numerous eosinophils. We describe a case of Kimura disease in a 29-year-old female presenting with a slowly enlarging, painless soft tissue mass in her left wrist for five months. The lesion was non-tender, mobile, and compressible. Lab results were significant for peripheral blood eosinophilia and elevated IgE. Microscopically, the mass was circumscribed, with apparent fibrous capsule or pseudocapsule, prominent high-endothelial venules, and inflammatory cells consisting of lymphocytes and eosinophils. There were prominent secondary B-lymphocytic follicles with germinal centers containing many penetrating small blood vessels, and some follicles exhibiting follicle lysis and a small amount of eosinophilic extracellular material. Polykaryocytes were noted in many germinal centers. Angiolymphoid hyperplasia with eosinophilia, a main differential diagnosis of Kimura disease, was considered; however, the combined clinical and morphologic findings appeared to be more consistent with Kimura disease, particularly in the context of eosinophilia and elevated IgE level. Kimura disease may present as a rare cause of a soft tissue mass and a diagnostic challenge for clinicians and pathologists, especially in less common sites such as the wrist.

Disclosures

No relevant conflicts of interest to declare.
Phase Ib of Copanlisib in Combination with Ibrutinib in Recurrent/Refractory Primary CNS Lymphoma (PCNSL)
Authors: Grommes Christian , Gavrilovic Igor , Miller Alexandra M , Stone Jacqueline B , Kaley Thomas , Madzsar Juli T , Schumpp Alyssa , Butler Brittany T , Schaff Lauren , Mellinghoff Ingo K
Published: November 2019

BACKGROUND: PCNSL is an aggressive primary brain tumor with median progression free survival (PFS) after upfront methotrexate-based chemotherapy of 2-3 years. Outcome and treatment options are poor for recurrent/refractory (r/r) disease. This trial combines the pan-PI3K inhibitor copanlisib with Ibrutinib in patients with r/r PCNSL.

METHODS: Eligible patients had r/r PCNSL, age≥18, ECOG≤2, normal end-organ function, and an unrestricted number of CNS directed prior therapies. Ibrutinib was given orally daily; copanlisib intravenously on days 1, 8, and 15 of each 28-day cycle.

RESULTS: Six patients have been enrolled so far and received copanlisib at 60 mg and ibrutinib at 560 mg. Median age was 68 (range 50-77); 3 were women. Median ECOG was 1 (0: 2, 1: 3, 2: 1). All had recurrent parenchymal disease. Three had additional cerebrospinal fluid (CSF) involvement. Two had received prior single-agent ibrutinib. Initially, no prophylactic antimicrobial treatment was required. PCP prophylaxis was made mandatory after one patient developed PCP pneumonia leading to a grade 5 lung infection. Four patients are still on trial and one withdrew due to personal choice. Two grade 4 adverse events were observed in 2 patients (LFT elevation, lymphopenia); four grade 3 events in 3 patients (rash, lymphopenia, LFT elevation). The most common toxicities at any grade were transient, infusion-related hyperglycemia and hypertension. No Aspergillus infections have been observed. Enrollment into the next dose level (copanlisib 60 mg, ibrutinib 840 mg) is ongoing. After a median follow-up of 180 days (range 46-249), all patients were evaluated for response with an overall response rate of 67% with 1 CR, 3 PR, 1 SD and 1 PD as best response.

CONCLUSION: Treatment with copanlisib and ibrutinib in patients with PCNSL has manageable adverse events after initiation of mandatory PCP prophylaxis. Clinical response was seen in 67% of patients.

Disclosures

Grommes: Squipps: Speakers Bureau; Kite: Consultancy; BTG: Consultancy.

OffLabel Disclosure:

The combination of the BTK inhibitor ibrutinib and the pan PI3K inhibitor copanlisib in recurrent PCNSL will be discussed
Combination of Dasatinib and Pediatric-Inspired Regimens in Newly Diagnosed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Single-Center Prospective Study
Authors: Guang ji Zhang , Wang Jianxiang , Wang Ying , Wei Hui , Mi Yingchang
Published: November 2019

Background: Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is a rare subtype of acute lymphoblastic leukemia with a poor long-term prognosis. Recent studies suggested that the addition of tyrosine kinase inhibitor (TKI) to the traditional chemotherapy treatment has significantly improved Ph+ ALL patients response rates, disease-free survival, and overall survival (OS). Dasatinib, a second-generation tyrosine kinase inhibitor, can pass the blood-brain barrier and possesses a stronger inhibitory effect on both SRC kinase and BCR-ABL. In theory, it might be beneficial in Ph+ ALL treatment. This prospective, single-arm study assesses the efficacy of a combination of dasatinib and pediatric-inspired regimens in Ph+ ALL patients.

Methods: 30 patients from the Institute of Hematology and Blood Diseases Hospital were enrolled in this study from January 2016 to April 2018. Eligible subjects were newly diagnosed Ph+ ALL adult patients. Chemotherapy regimens were initiated after the pediatric-inspired regimens, and standard induction chemotherapy was given for four weeks. Seven courses of consolidation or hematopoietic cell transplantation (HCT) were given to those who have achieved hematological complete remission (HCR). The primary objectives of this study were the HCR and molecular complete response (MCR), the major molecular response (MMR), the overall survival (OS), and the hematologic relapse-free survival (HRFS). The median follow-up time was 28 months. The trial registration number is NCT02523976.

Results : 30 subjects were enrolled in this study with a median age of 37.5 years (range 19-50 years). All patients achieved HCR after four weeks of induction therapy with a cumulative MCR rate of 87.5%(21/24). The median HRFS and median OS were 19.5 (range 2-40 months) and 21 (range 7-41 months), respectively. The molecular response, assessed through monitoring of BCR-ABL transcript expression, revealed that 61.3% of the patients reached MMR and MCR after three months of treatment. Additionally, the results indicated that patients who achieved MCR in the first three months had a better HRFS (p=0.038). Fifteen of the patients (50%) proceeded to stem cell transplantation (SCT) within the first HCR period (SCT in HCR1). Only 13.3% (2/15) of the SCT cohort relapsed, and 20% (3/15) died. It is worth mentioning that the SCT in HCR1 cohort had better HRFS (P=0.03). Most adverse events were reversible, and none of the subjects had pulmonary hypertension.

Conclusion: These findings indicate that an early MCR (3 months) has a positive impact on patients survival and that Dasatinib, combined with pediatric-inspired regimens, is effective and leads to a high MCR in patients with newly diagnosed Ph+ALL.

Disclosures

No relevant conflicts of interest to declare.
Chronic Myeloid Leukemia in Adolescents and Young Adults: A Single Institute Experience
Authors: Yassin Mohamed A , Abdulla Mohammad Abdul-Jaber , Chandra Prem , Aldapt Mahmood B , Hamad Yasser , Akiki Susanna Jane , Kassem Nancy , Nashwan Abdulqadir Jeprel , Nur Ula
Published: November 2019

Background and Objectives:

CML is a myeloproliferative neoplasm characterized by the dysregulated production and uncontrolled proliferation of mature and maturing granulocytes with fairly normal differentiation. It mainly affects adults, and is rarely seen in children. The average age at diagnosis of CML is around 64 years. There are few studies describing CML in adolescents and young adults. In Qatar we have one of the largest cohorts of adolescents and young adults with CML. This study aims to study this cohort and find out if there are any differences from older patients with CML.

Methods:

A retrospective analysis of 169 patients with CML treated at NCCCR over a 23-year period, 83 of them are younger than 40 years at diagnosis (adolescents and young adults) vs. 86 age 40 or older at diagnosis (controls). Comparison was done of all characteristics at diagnosis, including: gender, BMI, ethnicity, CBC parameters, spleen size, Sokal score, bone marrow findings, treatment modality, with response assessment using ELN guidelines.

Results:

Both groups were matched with regards to gender and ethnicity. Adolescents and young adults had higher WBC count and larger spleen on diagnosis compared to controls (174.1 vs. 142.2; and 18.0 vs. 15.6). 4 young patients presented in blast-phase vs. 1 in control group. 5 adolescents and young adults underwent allogeneic stem cell transplant vs. 1 patient in the control group. During a mean follow up of 70.7 months in adolescents and young adults vs. 72.7 months in the control group there were 2 deaths vs. 1 respectively. However, there were no other significant differences between the two groups, with regards to TKI used, or response at 1 year / latest assessment.

Conclusions:

Based on this data we may conclude that CML present more aggressively in adolescents and young adults as compared with older patients, however there is no difference in outcome. This might reflect different underlying etiology / better tolerance to treatment in the younger group.

Table

Disclosures

No relevant conflicts of interest to declare.
Dose-Adjusted Granulocyte Colony-Stimulating Factor Plus Dexamethasone Achieves More CD34+ Cell Mobilization and Earlier Engraftment in Haploidentical Hematopoietic Stem Cell Transplantation
Authors: Li Chenglong , Yang Xi , Dai Jingying , Tang Ningning , Zheng Hong , Wang Chunsen , Huang Xiaobing
Published: November 2019

Introduction: Previous studies have showed that higher doses of CD34+ cell were associated with more rapid neutrophil and platelet engraftment, lower probabilities of graft rejection, as well as reduced transplant-related mortality. The aim of this study was to investigate the effects of G-CSF (Filgrastim) plus dexamethasone in CD34+ cell mobilization and engraftment in T-cell replete haploidentical hematopoietic stem cell transplantation(HHSCT) which was based on G-CSF-primed bone marrow and peripheral blood graft.

Methods: A total of 79 healthy donors, who underwent bone marrow (BM) harvest and peripheral blood Stem Cells (PBSCs) collection between January 2015 and June 2019, were investigated. In G-CSF group, G-CSF was administered subcutaneously at a dose of 5μg/kg once a day from 1st to 5th day, while BM and PBSC were harvested on the 4th day and 5th day, respectively. In Dose-Adjusted G-CSF+Dex group, G-CSF was administered subcutaneously at a dose of 5μg/kg once a day on the 1st and 2nd day, then twice a day from the 3rd to 5th day; 5mg dexamethasone was injected intravenously before BM collection on the 4th day and before PBSC apheresis on the 5th day, respectively. All 79 recipients with hematological malignancies underwent HHSCT based on modification of BU/CY (busulfan/cyclophosphamide) and Anti-human T Lymphocyte Rabbit Immunoglobulin (ATG-F). All recipients received cyclosporine A, mycophenolate mofetil, and short-term cyclophosphamide as GVHD prophylaxis.

Results: There were no significantly statistical differences between these two groups on characteristics of both recipients and donors. In Dose-Adjusted-G-CSF+Dex group, more mono nuclear cells (MNCs) were collected from BM and PB in comparison to the cells collected in the G-CSF group (p<0.001). There was a significant difference between the two groups on CD34+ cell counts from PB (p=0.002), which led to a significant difference on CD34+ cells in mixture allografts (p=0.04). In DA-G-CSF + Dex group, more CD34+ cells achieved earlier neutrophil (p=0.001) and platelet (p<0.001) engraftment compared with G-CSF group.

Conclusion: Compared to G-CSF alone, dose-adjusted G-CSF plus dexamethasone on healthy donors can lead to more collection of MNCs and CD34+ cells in mixture allografts, which achieves earlier neutrophil and platelet engraftment.

Disclosures

Zheng: Pfizer: Research Funding.
Downregulation of Transcription Factor LRF/ZBTB7A Increases Fetal Hemoglobin Expression in β-Thalassemia/Hemoglobin E Erythroid Cells
Authors: Chumchuen Sukanya , Pornsukjantra Tanapat , Khamphikham Pinyaphat , Anurathapan Usanarat , Sripichai Orapan , Songdej Duantida , Hongeng Suradej
Published: November 2019

LRF/ZBTB7A is a transcription factor that has been recently identified as a new key regulator of fetal hemoglobin (HbF; α2γ2) production in erythroid cells. Reduction of LRF/ZBTB7A expression led to increases in levels of HbF in human CD34+ hematopoietic stem and progenitor cell (HSPC)-derived erythroblast and in human immortalized erythroid line (HUDEP-2). Since reactivation of γ-globin gene is associated with the improvement of clinical manifestations of β-hemoglobinopathy patients, decrement in LRF/ZBTB7A expression might be a substantial interest as a novel target for gene therapy in β-thalassemia. In this study, we investigated the effects of LRF/ZBTB7A downregulation in erythroid cells derived from β-thalassemia/HbE patients in order to evaluate its therapeutic potential. The hematopoietic CD34+ progenitor cells were collected from 3 patients and 3 healthy normal individuals' peripheral blood and subjected for in vitro erythroblast culture. The cells were transduced with lentivirus carrying LRF/ZBTB7A specific shRNA, and used untransduced cells and non-targeted control shRNA (shNTC) as experimental controls. The LRF/ZBTB7A shRNA reduced LRF/ZBTB7A transcript and protein to nearly undetectable levels. Interestingly, downregulation of LRF/ZBTB7A increased expression of γ-globin, ε-globin and ζ-globin in both adult normal and β-thalassemia/HbE derived cells, whereas α-globin, β-globin and δ-globin expression were decreased. As previously reported, we found that the LRF/ZBTB7A knockdown produced a robust increase in HbF levels in both normal (43.3±9.0% vs. 5.9±2.1% in shNTC) and β-thalassemia/HbE erythroblasts (78.1±3.5% vs. 26.3±3.9% in shNTC). Noteworthy, the delay of erythroid differentiation was observed in the LRF/ZBTB7A knockdown cells of both derived from β-thalassemia/HbE patients and normal control, suggesting an additional role of LRF/ZBTB7A in regulating erythroid maturation. These data support the manipulation of LRF/ZBTB7A as one of the most interesting gene therapy candidates for treating the β-thalassemia, but the effect on erythroid cell maturation is needed to be concerned and required further investigation.

Disclosures

No relevant conflicts of interest to declare.
Ruxolitinib, a JAK1/JAK2 Selective Inhibitor, Ameliorates Gastrointestinal and Cutaneous Pathogenesis in MHC-Mismatched Preclinical Models of Acute and Chronic Graft-Versus-Host Disease
Authors: Huarte Eduardo , Parker Melissa , Juvekar Ashish , Oliver Julian , Yao Wenqing , Smith Paul
Published: November 2019

Background: Allogeneic hematopoietic cell transplantation (alloHCT) is potentially curative for a variety of hematologic malignancies. However, rather than targeting tumor cells, alloreactive donor T cells may attack healthy recipient tissue triggering graft-versus-host disease (GVHD) resulting in morbidity and mortality. Acute GVHD (aGVHD) clinically presents with gastrointestinal (GI) pathology and is primarily T cell mediated. In contrast, chronic GVHD commonly demonstrates skin inflammation and fibrosis with an autoimmune-like phenotype. Pharmacological inhibition of JAK/STAT signaling has the potential to regulate aberrant immune cell functions involved in the pathogenesis of acute and chronic GVHD.

Aim: Characterize the effectiveness of ruxolitinib to modulate in vitro and in vivo immunological mechanisms that are described to be critical in acute and chronic GVHD pathogenesis.

Materials and Methods: MHC-mismatch aGVHD was induced in recipient BALB/c mice receiving C57BL/6 donor transplant. Sclerodermatous cGVHD was induced in C57BL/6 mice using LP/J strain donor splenocytes and bone marrow cells. Ruxolitinib or vehicle was orally administered twice daily. Efficacy was assessed by GVHD symptom scores, cachexia, and histological analysis of end organ damage.

Mixed lymphocyte reactions (MLR) were cultured for five days in the presence of ruxolitinib for changes in activation markers and cytokine release.

Results: Ruxolitinib treatment ameliorated daily aGVHD severity scores with concomitant reduction of GI tract infiltration and tissue damage. Overall aGVHD mice survival was significantly improved with JAK1/2 inhibition. Therapeutic ruxolitinib treatment initiated after cGVHD symptom onset significantly inhibited the chronic-progressive symptom phenotype and reduced tissue markers of inflammation and fibrosis. Ruxolitinib demonstrated concentration-dependent inhibition of activated T cells and reduced JAK-STAT signaling cytokines considered relevant in GVHD inflammation.

Conclusion: Ruxolitinib, a potent and selective JAK1/2 inhibitor, significantly ameliorated pro-inflammatory pathways in vitro and in vivo which are thought to be highly relevant for acute and chronic GVHD pathogenesis. On May 24, 2019, the FDA approved ruxolitinib for steroid-refractory acute graft-versus-host disease (aGVHD) in adult and pediatric patients 12 years and older. Ruxolitinib is currently being evaluated in clinical trial (REACH3: NCT03112603) for patients with steroid-refractory cGVHD.

Disclosures

Huarte: Incyte corporation: Employment, Equity Ownership. Parker:Incyte corporation: Employment, Equity Ownership. Juvekar:Incyte corporation: Employment, Equity Ownership. Oliver:Incyte corporation: Employment, Equity Ownership. Yao:Incyte corporation: Employment, Equity Ownership. Smith:Incyte corporation: Employment, Equity Ownership.
Identification of a Novel Indel Mutation in GATA-1 Gene In Vivo and Verified Its Defective Function in Vitro
Authors: Huang Junbin , Huang Lifeng , Lu Yingsi , Zhu Chengming , Chen Chun
Published: November 2019

GATA-1 is a zinc finger TF encoded by the GATA-1 gene located on the short-arm of the X-chromosome. Most of GATA-1 mutations were located in exon2 or 3. We describe a male infant presented with dyserythropoietic anemia, who is harbored a novel GG deletion of exon6 in GATA-1 gene and varified its disrupted function in vitro. We confirmed that: (1) by using an unique GATA-1 antibody, which corresponded to amino acids 394-413 of human GATA1, the mutation of the proband led to GATA-1 protein and mRNA defective expressions in both peripheral blood and bone marrow; (2) demonstrated the expression of the GATA-1 mutated form is restricted to erythroblasts and red blood cells, consisted with the proband's abnormal erythropoiesis; (3) temporary transfection of GATA-1-wt(wild type) and GATA-1-indel in Hela cell line, which has no expression of GATA-1 originally, resulted in normal and defective expression both in protein and mRNA leve, respectively; (4) in a manipulated K562 cell line, that its GATA-1 had been knocked down by shRNA, stable transfection GATA-1-indel can not rescue K562 from GATA-1 deficiency.. Our reseach provide new insights into the clinically relevant in vivo function of the C-terminal domain of GATA-1 in human hematopoiesis and the results were validated in two seprerated cell line.

Disclosures

No relevant conflicts of interest to declare.
Review of Therapeutic Erythrocytapheresis in Patients with Thalassemia Major
Authors: Wall Erika , Bolster Lauren
Published: November 2019

Introduction

Therapeutic erythrocytapheresis, or red cell exchange (RCE) is a non-invasive procedure in which a patient's erythrocytes are removed from the bloodstream while being replaced with erythrocytes from blood donors. RCE is commonly used as a transfusion technique in patients with sickle cell disease (SCD) to help treat and prevent complications associated with sickling of erythrocytes and iron overload. In the rare blood disorders (RBD) clinic at the University of Alberta in Edmonton, Canada, RCE has been utilized as a therapeutic adjunct to traditional chelation therapies for patients with thalassemia major with uncontrolled iron overload. The aim of this study is to describe and review the rate of observed complications or benefits associated with RCE in patients with thalassemia major.

Methods

Patients with a documented diagnosis of thalassemia major who were enrolled in the RCE program via the RBD clinic were identified. Charts were retrospectively reviewed from time of initiation of RCE to the time of most recent RCE or clinic follow up. Complications were documented and analyzed, then compared to standard rates of complications of iron overload in patients with thalassemia major.

Results

Seven (7) patients with were identified for analysis. The average age of patients enrolled was 30 years. One hundred percent (100%) of patients had confirmed diagnosis of thalassemia major by hemoglobin electrophoresis. 85.7% of patients were of male sex. Six (85.7%) patients were on chelation therapy (3 patients on Jadenu plus Ferriprox; 3 patients on Jadenu alone). On average RCE was performed every 3.85 weeks. Of the patients analyzed during RCE, 85.7% had hepatic iron overload and 42.9% had cardiac dysfunction. 71.4% had evidence of extramedullary hematopoiesis. Two patients had syncopal events while on RCE. Two patients developed red cell antibodies during RCE. Improvements in iron overload correlated with initiation of dual chelation therapy in the three patients who were on maximal dual chelation.

Conclusions

Although RCE is a useful transfusion strategy in patients with SCD with less iron loading than simple transfusion, it does not appear to have the same benefits in patients with thalassemia major. Improvements in myocardial and hepatic T2* scores correlated with being on dual chelation therapy rather than with the frequency or duration of RCE. There was evidence of significant extramedullary hematopoiesis in 5 of the 7 patients on RCE possibly due to poor hemoglobin increment. Given the observed increase in extramedullary hematopoiesis, syncope, and antibody formation associated with RCE, and lack of benefit in reducing iron overload, we do not recommend its use as a treatment in patients with thalassemia major.

Disclosures

No relevant conflicts of interest to declare.
An Autosomal Dominant SCID Form Due to a Gain of Function Mutation in the RAC2 Gene
Authors: Lagresle-Peyrou Chantal , Olichon Aurélien , Sadek Hanem , Roche Philippe , Tardy Claudine , Da Silva Cindy , Garrigue Alexandrine , Fischer Alain , Moshous Despina , Collette Yves , Picard Capucine , Casanova Jean-Laurent , André Isabelle , Cavazzana Marina
Published: November 2019

Severe combined immunodeficiencies (SCIDs) form a heterogeneous group of life-threatening genetic disorders defined by the absence of autologous T cells and an intrinsic or extrinsic defect in the B-cell compartment. In our cohort, three newborn patients with bone-marrow hypoplasia associated with clinical and biological features of SCID received allogenic hematopoietic stem cell transplantation in the first weeks of life. To identify the molecular defect involved in this life threatening SCID form, we performed whole-genome sequencing on patient's fibroblasts. The same heterozygous, dominant missense mutation was found in the RAC2gene encoding for the RAC2 GTPase (p.G12R). By biochemical analyses we demonstrated that arginine substitution at position 12 leads to sustained activation of the RAC2 signalling pathway; the G12R mutation is therefore a gain of function mutation. In cord blood hematopoietic cells, we observed that the mutation disrupts mitochondrial activity and blocks hematopoietic stem/progenitor cells (HSPCs) differentiation toward the myeloid and lymphoid lineages. Altogether, our data emphasize the involvement of the RAC2 signalling pathway during hematopoeisis and might thus explain the severity of the patients' clinical and immunological phenotype.

The present study is the first to report an autosomal dominant form of SCID and suggest that RAC2 gene sequencing should be considered for patients with SCID clinical presentation.

Disclosures

Cavazzana: Smartimmune: Other: Founder of Smartimmune.
Safety and Anti-Tumor Activity Study of Loncastuximab Tesirine and Ibrutinib in Diffuse Large B-Cell or Mantle Cell Lymphoma
Authors: Depaus Julien , Bryan Locke J. , Ungar David , Dautaj Ilva , Wagner-Johnston Nina D.
Published: November 2019

Introduction:

Loncastuximab tesirine (Lonca) is an antibody-drug conjugate (ADC) comprising a humanized anti-CD19 antibody conjugated to a pyrrolobenzodiazepine dimer toxin. In a Phase 1, first-in-human study (ADCT-402-101), Lonca demonstrated single agent anti-tumor activity with manageable toxicity in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL). Ibrutinib is a small-molecule inhibitor of Bruton's tyrosine kinase (BTK), a mediator of the B-cell-receptor signaling pathway implicated in the pathogenesis of B-cell cancers. BTK plays a crucial role in B-cell-receptor signaling, resulting in activation of pathways necessary for B-cell trafficking, chemotaxis, and adhesion. In vitro data show synergy between the two compounds, providing the rationale for studying them in combination.

Study Design and Methods:

This is a Phase 1b (ADCT-402-103; NCT03684694), open-label, dose escalation (Part 1) and expansion (Part 2) trial of Lonca combined with ibrutinib in patients with R/R DLBCL or MCL. The key inclusion and exclusion criteria for this study are reported in Table 1. This trial will evaluate the safety and tolerability, preliminary anti-tumor activity, pharmacokinetics, pharmacodynamics, and immunogenicity of this combination. Patients will receive Lonca once every 3 weeks for a total of 2 doses, and ibrutinib daily for up to 1 year. Patients with a partial response or stable disease at the second disease evaluation may receive 2 additional doses of lonca. During Part 1, the dose of Lonca will be escalated using a classic 3+3 design. The dose of ibrutinib will be fixed. Part 2 will consist of up to 2 expansion cohorts, one for each of the DLBCL and MCL populations. All patients in Part 2 will receive the dose of Lonca determined in Part 1, with a fixed dose of ibrutinib. The trial opened in February 2019 and recruitment is ongoing.

Study sponsored by ADC Therapeutics SA, with the support of Pharmacyclics LLC, an AbbVie company, which supplies ibrutinib (http://clinicaltrials.gov/show/NCT03684694).

Disclosures

Ungar: ADC Therapeutics: Employment, Other: Stock options;equity interest. Dautaj:ADC Therapeutics: Employment, Other: Stock options. Wagner-Johnston:Jannsen: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees.
Deletions of 5q Promote Genome Instability in TP53-Mutant MDS/AML
Authors: Reilly Andreea , Busch Stephanie , Abkowitz Janis L. , Becker Pamela S. , Doulatov Sergei
Published: November 2019

Purpose

TP53 mutations in myeloid neoplasms (MDS/AML) are associated with high-risk disease, poor outcome, and complex karyotype. The molecular mechanisms which lead to global chromosomal instability remain poorly understood. Loss of 5q [del(5q)] is the most frequent cytogenetic abnormality associated with TP53 mutations suggesting that haploinsufficiency of genes on 5q contributes to chromosomal instability.

Methods

We reprogrammed MDS/AML patient samples to establish genetically accurate iPSC lines from preleukemic subclones. We generated iPSCs with TP53 mutations and del(5q), differentiated them to hematopoietic progenitors (HPCs), and determined the contribution of del(5q) to genome instability.

Results

By reprogramming MDS/AML complex karyotype patient samples, we identified iPSCs with heterozygous TP53 mutations (TP53-only), as well as iPSCs with TP53 mutations and del5(q22-q31) (TP53;del5q), and an otherwise normal karyotype. HPCs derived from TP53;del5q iPSCs had decreased multilineage differentiation potential compared to the TP53-only HPCs. Gene expression analysis of TP53;del5q HPCs revealed downregulation of genes involved in chromosome segregation and DNA damage repair. Following irradiation TP53;del5q cells had significantly delayed DNA damage repair kinetics. In order to evaluate the effects of TP53 and del(5q) on chromosomal segregation during stress, we arrested the cells in mitosis by disrupting the mitotic spindle and quantified the induction of micronuclei, a marker of chromosomal instability that occurs due to lagging chromosomes. TP53;del5q cells had an increased frequency of micronuclei formation compared to TP53-only cells. We also detected micronuclei in primary AML patient samples. Micronuclei in iPSC-HPCs and primary patient cells had disrupted nuclear envelope and DNA damage marked by y-H2AX.

Conclusions

Our reprogramming approach revealed that TP53 mutations are disease-initiating and frequently followed by 5q loss. We propose that del(5q) cooperates with mutant TP53 to promote genome instability via two distinct mechanisms: classical double-stranded break repair and micronuclei formation. The latter is associated with global chromosomal instability, aneuploidy, and chromothripsis. We propose that loss of 5q accelerates genome instability in TP53-mutant cells which over time impedes normal hematopoietic differentiation and leads to complex karyotype.

Disclosures

Becker: The France Foundation: Honoraria; Accordant Health Services/Caremark: Consultancy; AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding.
ADAMTS13 Immunohistochemical Expression in Normal and Diseased Equine Tissues
Authors: Flax Sherri
Published: November 2019

ADAMTS13 is a metallopeptidase primarily synthesized in the liver. Its main function is to cleave von Willebrand factor (VWF) on the endothelial surface, and thus regulate platelet adhesion at the sites of vascular injury; VWF acts as a scaffold at the site of injury for platelet activation, platelet binding, and clot formation. Platelet activation also results in the release of platelet-dense granule components (such as cytokines, pro- and anti-inflammatory factors and other bioactive molecules) that are essential regulators of coagulation, but are also associated with inflammation.

Reduced activity of ADAMTS13 is found in human patients with acquired thrombotic thrombocytopenic purpura (TPP), sepsis, and DIC. Both human TTP and equine colic are histologically characterized by the presence of microthrombi. Cleavage of VWF is dependent upon allosteric activation of ADAMTS13, which is broadly conserved in many animals, including horses. Human TTP and equine idiopathic colic share several interesting clinical similarities. Both have seasonal variations, typically in summer, can be associated with viral and bacterial infections, may be hereditary, have autoimmune associations, and recur. Both TTP and equine colic are clinically characterized by fever, abdominal pain renal failure, and neurologic symptoms. Microangiopathy is the predominant pathology in both TTP and equine colic.

Using tissues obtained from thirteen horses euthanized for non-thrombotic conditions, immunohistochemical stains indicate the presence of ADAMTS13 in equine liver and colon. Furthermore, in one horse with colic, immunohistochemical staining of the resected colon indicates the presence of ADAMTS13 in the aboral margin (Figure 1) and the absence ADAMTS13 staining in the diseased tissue.

These findings suggest that equine colic may be an animal model of thrombotic microangiopathy, very similar to TTP. Future studies will investigate immunohistochemical detection of ADAMTS13 in human tissues.

Figure 1

Disclosures

No relevant conflicts of interest to declare.
Study of the Role of Hydroxychloroquine in Immunomodulation and Control of Hypercoagulability in Patients Diagnosed with Primary Antiphospholipid Syndrome
Authors: Mangolin Sabrina , Mazetto Bruna M , Annichino- Bizzacchi Joyce Maria , Orsi Fernanda Andrade
Published: November 2019

Aim: Hydroxychloroquine (HCQ) could form an alternative treatment for thrombotic primary antiphospholipid syndrome (t-PAPS) if HCQ is proven to reduce the risk of thrombosis. We investigated whether HCQ affects immune response and lipid metabolism in t-PAPS.

Methods: HCQ at 400mg/day was given to anticoagulated t-PAPS patients for 6 months. After HCQ withdrawal and a wash-out period of 6 months, the same patients were followed for further 6 months. Blood samples taken at baseline and at the end of each 6-months follow-up period were analyzed employing flow cytometry and biochemical assays.

Result: Twenty-seven patients were included, mean age was 44 years, 78% were female, 44% had hypertension, 44% dyslipidemia, 7% diabetes, 77% had venous thrombosis, 30% arterial thrombosis and 33% recurrent thrombosis. Triple aPL positivity was detected in 37%. Lymphocyte counts decreased during HCQ use (mean change -318/mm3; 95%CI -438 to -198) and were not changed during non-HCQ use period. CD8+ and CD4+ cells decreased during HCQ treatment and remained unchanged during non-treatment period. In contrast, TREG (FoxP3+) cells increased during HCQ treatment (mean change 0.2U; 95%CI 0 to 0.4) and decreased in the period of non-HCQ treatment (mean change -0.6U; 95%CI -0.9 to -0.1). Serum glucose, total cholesterol and low density lipoprotein cholesterol decreased during HCQ use (7%, 9% and 12% respectively) and did not change substantially during non-HCQ period.

Conclusion: HCQ reduces cytotoxic T lymphocytes, increases regulatory T lymphocytes and decreases LDL cholesterol and serum glucose levels in t-PAPS. These HCQ may contribute to reduce the risk of thrombosis.

Disclosures

No relevant conflicts of interest to declare.
Iron Overload Impairs Bone Marrow Mesenchymal Stromal Cells from MDS Patients and Promotes Leukemia Transformation
Authors: Fu Rong , Zhaoyun Liu , Huang Lei , Liu Hui , Shao Zonghong , Ding Kai
Published: November 2019

Bone marrow microenvironment plays an important role in the development of myelodysplastic syndrome (MDS). Iron overload (IO) may be related to the prognosis of the MDS patients. The effects of IO damaging mesenchymal stromal cells (MSCs) from MDS patients and promoting leukemia transformation were investigated. In our study, the IO group showed the decreased quantity and weakened abilities on proliferation and differentiation of MSCs. The gene expressions of VEGFA, CXCL12 and TGF-β1 in MSCs regulating hematopoiesis were significantly downregulated in IO group. The levels of reactive oxygen species (ROS) and apoptosis in IO group were significantly higher than those in non-iron overload (NIO) group, with highly expressed caspase3 and β-catenin. Meanwhile, the damages of MSCs caused by IO could be partially reversed by antioxidant or iron chelator. Due to the higher gene mutation frequency in IO group, the effects of IO promoting leukemia transformation were investigated. The IO MDS/AML group had a lower quantity of MSCs compared with IO MDS group, with significantly decreased expression of p-AKT. However, there was no significant differences in apoptosis, gene expressions of VEGF, CXCL12 supporting hematopoiesis, and β-catenin involving leukemia transformation in MSCs between them. In conclusion, IO damages MSCs of MDS patients by inducing ROS related apoptosis and activating caspase3 signals, which could be partially reversed by antioxidant or iron chelator. The increased genetic mutations and activated β-catenin signals in MSCs of MDS patients caused by IO may involve in promoting leukemia transformation.

Disclosures

No relevant conflicts of interest to declare.
Tandem CAR T Cells Targeting CD19 and CD22 Is a Safe and Highly Efficacious Treatment for Relapse/ Refractory ALL Patients
Authors: Tang Xiaowen , Kang Liqing , Qi Wei , Cui Wei , Dai Haiping , Li Zheng , Yin Jia , Qu Changju , Xu Ting , Zhu Xiaming , Yu Lei , Wu Depei
Published: November 2019

Background: CAR-T immunotherapy has shown remarkable promising results for relapsed/ refractory (R/R) acute lymphoblastic leukemia (ALL). However, CD19-targeted CAR T cell therapy for R/R ALL has a relapse rate of approximately 50% at 1 year after CART therapy, and the most common mechanism of relapse is due to CD19 antigen loss or decreased target expression on the surfaces of the lymphoblastic leukemia cells. Potential approaches to overcome this challenge include engineering CAR T cells to achieve multispecificity and to respond to lower expression levels of target antigens by dual target CAR T strategies.

Objective: In order to evaluate the efficacy and safety of CD19/CD22 dual target CAR T cells for R/R ALL patients to determine if targeting multiple antigens can prevent treatment failure and improve response rates and durability of response.

Method: A novel CAR T cells with tandem targeting CD19 and CD22 antigens and a third generation CAR construct of CD28 and OX40 co-stimulatory domains were administered to 23 patients with R/R ALL with a median age of 24(6-56)years. High-risk patients were enrolled in this cohort, including 10 with BCR-ABL+ALL (6 of 10 with T 315I mutation), 4 with TP53 mutation, 2 with Ph-like ALL and 3 with relapsed ALL post allo-HSCT. The patients received a single infusion of CAR T cells with dose escalation schedule:10%--30%--60%. The median infusion dose of CAR T cells was 1 (0.5- 2.5) ×107cells/kg.

Results: The median follow-up was 9 (3.5-20) months. The day 28 CR/CRi rate was 100% with21/22 (95.5%) molecular remission. Six-month OS was 94.4% and RFS was 76.9%. One-year OS was 57.2% and RFS was 67.3%. One-year OS of high tumor burden (BM blast> 30%)(15/22) and low tumor burden(BM blast≤30%)(7/22) was 47.5% and 75% respectively (p>0.05). The 1-year OS of the CAR T- to- allo-HSCT group(14/22) was better than that of the non-transplant group(8/22) (OS 72.9% vs. 26.7%, p = 0.116). The cumulative relapse rate of 6 months and 1 year were 23.1% and 32.7% respectively. The overall incidence of CRS were 91% included 22.7%grade III CRS ,4.5% grade IV CRS and 0% severe CRES. Only one patient presented MAH syndrome and was cured with low dose dexamethasone. There was no CAR T-related death.

Conclusions: The tandem CD19/CD22 dual target CAR T cells therapy is a safe and high efficacy treatment for R/R ALL patients. It is possible that multi-targeted CAR-T cell therapy may overcome this resistance mechanism and improve clinical outcomes.

Disclosures

No relevant conflicts of interest to declare.
Histopathology of Chronic Kidney Disease after Allogeneic Hematopoietic Cell Transplantation: A Multi-Center Observational Study of Kidney Biopsies
Authors: Chen Feng , Wu Depei , Wang Ran , Huang Xianghua , Li Xiaozhong , Huang Chaoxing
Published: November 2019

Background Renal dysfunction is a common complication of allogeneic hematopoietic cell transplantation (Allo-HCT) with proven negative impact on early and long-term mortality. The cumulative incidence of chronic kidney disease(CKD) after Allo- HCT varies from 13~60% in adult studies to as high as 62% in children. So far, most knowledge on chronic renal impairment in the context of Allo-HCT is based on clinical and laboratory findings. Causes of CKD are diverse, usually overlapping, and poorly understood. Kidney biopsies are performed in less than 5% patients with CKD, the pathophysiology of idiopathic CKD remains obscure. We conducted a multi-center clinicopathologic study of Allo-HCT patients with CKD to described the histopathologic spectrum of renal manifestations.

Methods and Results Between 2005 and 2018, 24 recipients(17 males and 7 females) of Allo-HCT underwent kidney biopsy for either proteinuria or deterioration of kidney function at four centers. The median age was 43.8 (7.2~54.3) years, and the median time from Allo-HCT to kidney biopsy was 17.2(2.0~74.6)months. Evidence for GVHD was found in 20 (83.3%) patients. Among the 24 patients, 10 patients had a large amount of proteinuria (24-hour urine protein > 3.5 g/L), and 12 patients had elevated serum creatinine (Scr >110μmol/l). The most common pathological findings of kidney biopsy were GVHD (n=8), membranous nephropathy (MN, n=5), thrombotic microangiopathy (TMA, n=4), BK virus nephropathy (n=2), and we also found ischemic nephropathy, chronic interstitial nephritis, minimal change disease (MCD), GVHD with TMA, MN with focal segmental glomerular sclerosis (FSGS), MCD with acute tubular injury, BK virus nephropathy combined with calcineurin inhibitor nephrotoxicity in one case. The follow-up data showed 3 died of recurrent malignancy, 6 loss to follow-up , the median follow-up time was 18.3(12.3~120.2)months. Of the 18 patients, 8 (44.4%) had an estimated glomerular filtration rate (eGFR) of less than 60 ml/(min1.73m2), 5 (27.8%) still had moderate proteinuria.

Conclusions A wide spectrum of renal pathologic findings can be observed in Allo-HCT patients. Either severe proteinuria or elevated serum creatinine were common presentations in this unique setting, which can be due to GVHD , MN, TMA, BK virus nephropathy , MCD, FSGS, and overlapping lesions. Kidney biopsies are necessary to establish the underlying cause of CKD in Allo-HCT patients.

Disclosures

No relevant conflicts of interest to declare.
Using Circ-ANAPC7 As a Novel Type of Biomarker in the Monitoring of Acute Myeloid Leukemia
Authors: Shen Ying , Jia Yachun , Zhang Ru , Chen Hongli , Feng Yuandong , Wang Fang-Xia , Zhao Wanhong , Wang Jianli , He Aili , Yang Yun , Xu Yan
Published: November 2019

Introduction: Acute myeloid leukemia (AML) is a heterogeneous disease characterized by the clonal proliferation of immature myeloid progenitor cells in the bone marrow, compressing normal blood cell production and leading to bone marrow failure ultimately. Overwhelming evidence has established that non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) have great role in AML pathogenesis. Circular RNAs (circRNAs) that occupy gene expression at the transcriptional or post-transcriptional level have great potential to be biomarker for types of cancers. We have screened one altered circRNA named circ-ANAPC7 in AML before. In this study, we aimed to validate its expression by enlarging sample size and illuminating the diagnostic and monitoring value of circ-ANAPC7 in AML.

Methods: Real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was supposed to confirm the expression of circ-ANAPC7 of AML patients. The sequences of circ-ANAPC7 primers were as follows: 5′- GGGAGCAGCACTTAGGAACAT -3′ (sense) and 5′-AAAGCTGGTACTTCTGAGGTGG-3′ (antisense). Receiver operating characteristic (ROC) curve was carried out to evaluate the diagnostic value. Overall survival rate and event-free survival rate were estimated by the Kplan-Meier analysis and compared using the log-rank test. All tests were two-sided, and P < 0.05 was defined as a significant difference.

Results: The expression level of circ-ANAPC7 in newly diagnosed AML was significantly higher than CR patients and iron deficiency anemia (IDA) control group (P < 0.001) (Figure 1A). Furthermore, we chose 24 AML patients who undergo the condition of newly diagnosed AML, CR and relapse to dynamical monitor the expression of circ-ANAPC7. We discovered that circ-ANAPC7 expression level changed accompanied with the disease condition transformation. It was high expressed in newly diagnosed and relapsed AML patients. When patients got CR, the expression level of circ-ANAPC7 decreased (P < 0.05). In the continuous CR patients, it remained in a minimal level (Figure 1C). ROC curve analysis revealed that circ-ANAPC7 has significant value of AML diagnosis (AUC = 0.915, P < 0.001) (Figure 1B). Moreover, we conducted survival analysis to explore long-term effect of circ-ANAPC7 expression in AML patients. The result revealed that circ-ANAPC7 expression was not related to overall survival (OS) and disease-free survival (DFS) of AML patients (P > 0.05) (Figure 1D).

Conclusions: We validated that circ-ANAPC7 was upregulated in AML patients. The clinical analysis revealed that circ-ANAPC7 may be a predictive index for diagnosing and supervising early recurrence of AML. What's more, additional molecular mechanisms and biological functions of circ-ANAPC7 merit deeper investigation.

Figure 1

Disclosures

No relevant conflicts of interest to declare.