bluuebunny/crossref_metadata_2025 huggingface dataset:
PF187 LEUKEMIA AND DEPLETED URANIUM IN KOSOVO
Authors: Latifi‐Pupovci H. , Selmonaj M. , Ahmetaj‐Shala B. , Dushi M. , Grajqevci V.
Published: June 2019

Background:

Prolonged exposure and overexposure to depleted uranium (DU) is leukemogenic and genotoxic due to its radiological (alpha particle) and chemical (metal) components. The use of DU in the 1999 Kosovo War raised concern about the increase of new cases of leukemia.

Aims:

The aim of this study was twofold: 1) to analyze the incidence rates of leukemia in Kosovo in the pre‐war (1995–1998) and two post‐ war periods (2000–2003 and 2012–2015); and 2) to examine if there is any association between the use of DU rounds and incidence rates of leukemia in different regions of Kosovo.

Methods:

Patients diagnosed with leukemia in the University Clinical Centre of Kosovo for the period 1995–2015 were subject of this study. Annual incidence crude rates per 100,000 persons/year were calculated for seven regions of Kosova in three periods (1995–1998, 2000–2003 and 2012–2015). The number of DU rounds by region was determined from accurate NATO records containing geographic coordinates. Regional distribution, difference in incidence between pre‐war period and first and last post‐war period were calculated. In addition, to examine possible links between the presence of DU ordnance and incidence rates of leukemia, we analyzed the correlation between rounds/km2 and average annual incidence rates in the 27 municipalities.

Results:

Difference of incidence rates between the pre‐war (1995–1998) and the first post‐war period (2000–2003) for the entire territory of Kosovo shows that leukemia increased by 12.63% whereas between pre‐war and last post war period by 68.95% (Table 1). Region of Gjakova and Peja, the first and third most exposed regions to DU ordnance (7.73 rounds/km2 and 4.78 rounds/km2 respectively) ranked first and second in difference in leukemia incidence whereas Prishtina, Gjilan and Ferizaj, regions with the least number of rounds/km2, were characterized by declining in incidence rates of leukemia. After 15 years, still the difference in leukemia between pre‐war period and the last post‐war period remains larger in Gjakova and Peja.

In the first post‐war period (2000–2003), significant moderate Spearman correlation was found between the DU rounds/km2 and cases of leukemia (Figure 1).

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Figure 1. Correlation between rounds/km2 and annual average incidence rates by municipalities for leukemia in the period 2000–2003. Data was analysed using the Spearman correlation test and significance accepted when p < 0.05.

Summary/Conclusion:

The rise in incidence of leukemia in Kosovo may be partially induced by the use of DU during the war, but further studies are needed to explore this.

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PF215 THE ROLE OF GROWTH FACTOR INDEPENDENCE 1 (GFI1) IN GENOME STABILITY, DNA REPAIR AND LEUKEMIA GENOMIC EVOLUTION
Authors: Frank D. , Al‐Matary Y. , Khandanpour C.
Published: June 2019

Background:

Growth factor independence 1 (GFI1) is a transcriptional repressor, which regulates the proliferation and differentiation of hematopoietic stem cells. We have previously shown that lower expression of GFI1 promotes the development of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) in patients and murine models of leukemiua. Additionally, a germline single nucleotide polymorphism variant of GFI1, called GFI1–36N (Ser36 replaced by Asn36) contributes to the development of MDS and AML. Both lower expression of GFI1 and presence of GFI1–36N leads to expression of a number key AML associated oncogenes and signaling cascades promoting AML development, as low level of GFI1 or GFI1–36N are not able to repress these patways. Aorund 30% of all AML patients have either low expression levels of GFI1 or are carrier of GFI1–36N. This patient cohort has a particular poor prognosis. However, we also have preliminary data that GFI1 might be involved in DNA repair.

Aims:

We analyzed whether GFI1 plays a role in DNA repair.

Methods:

We analyzed genome wide mutational analysis from AML patient cohorts and gene wide expression data.

Results:

We reanalyzed available genomic data of MDS/AML patients with expression of GFI1–36N or low expression of GFI1. These patients showed significantly more cytogenetic aberrations than patients with normal level of GFI1–36S. We have established two different mouse strains, which express either low level of GFI1 or express GFI1–36N. In murine models of human AML, low level of GFI1 or expression of GFI1–36N led to a significantly higher rate of genomic alterations such as mutations, deletions and insertions than GFI1 wildtype (wt) expressing murine leukemic cells. These findings indicate that low expression of GFI1 or expression of GFI1–36N is associated with genomic instability. To understand the molecular pathways GFI1 is involved with regad to DNA repair, we irradiated GFI1 wt, GFI1 low expressing and GFI1–36N expressing thymocytes. Using comet and γH2AX assay we showed that presence of Gfi1–36N or reduced level of GFI1 is associated with diminished DNA repair. Furthermore we found that presence of GFI136N or reduced level of GFI1 is associated with low level of MGMT. Other groups have shown that patients with low expression of MGMT respond well to treatment with Temozolomide (alkylating agent). Due to this fact we treated leukemic cells differently expressing GFI1 with Temozolomide. We found that the leukemic cells with low level of GFI1 or GFI1–36N are highly susceptible to Temozolomide compared to the leukemic control cells.

Summary/Conclusion:

In summary, low expression of GFI1 or expression of GFI1–36N leads to a clonal genetic evolution by impeding DNA repair. Therefore GFI1 could be a new target in leukemia therapy by using Temozolomide for these patients.
PF240 COMBINED INHIBITION OF SHP1 AND SHP2 WITH PHORBOL ESTERS AS A DIFFERENTIATION THERAPY AGAINST ACUTE MYELOID LEUKEMIA
Authors: Pérez‐Fernández A. , López‐Ruano G. , Prieto‐Bermejo R. , Ijurko C. , Díez‐Campelo M. , Sánchez‐Guijo F. , Hernández‐Hernández Á.
Published: June 2019

Background:

The differentiation‐based therapy for acute promyelocytic leukemia (APL) is an inspiring example for the search of novel strategies aimed at treatment of other subtypes of acute myeloid leukemia (AML). Thus, the discovery of new molecular players in cell differentiation becomes a paramount research area to achieve this goal.

Aims:

To assess the involvement of the protein tyrosine phosphatases SHP1 and SHP2 on leukemic cells differentiation along with the therapeutic possibilities of their targeting to enhance the differentiation induction effect of phorbol esters.

Methods:

The oxidation status and enzymatic activity of SHP1 and SHP2 during PMA‐induced differentiation of HEL cells was evaluated. Additionally, the effects of RNAi‐mediated downregulation of these phosphatases on cell differentiation was studied. Afterwards, the impact of chemical inhibition of SHP1 and SHP2 on differentiation both in the presence and absence of phorbol esters was tested. Finally, the anti‐leukemic potential of phorbol esters and chemical inhibitors of SHP1 and SHP2 was addressed in several AML model cell lines, a xenograft mouse model and AML primary cells in vitro.

Results:

An increase of oxidation with a concomitant decrease of activity was observed for both phosphatases at the onset of PMA‐induced differentiation. Consistently, silencing of these proteins favored the process, with an enhanced effect upon their simultaneous downregulation. Moreover, the proteins SRC and β‐catenin were identified as downstream targets of SHP1 and SHP2 in this context. In agreement with these findings, chemical inhibition of the phosphatases promoted cell differentiation itself and enhanced the effect of phorbol esters. Interestingly, treatment with the phorbol ester prostratin and the dual inhibitor of SHP1 and SHP2 NSC87877 synergistically hampered the proliferation of AML cell lines, prolonged the survival of xenografted mice and reduced the clonogenic potential of AML primary cells.

Summary/Conclusion:

SHP1 and SHP2 are relevant mediators of differentiation in AML cells and their inhibition either alone or in combination with prostratin seems a promising differentiation‐based therapeutic strategy against different subtypes of AML beyond APL.
PF243 AN MLL‐AF9 ZEBRAFISH LEUKEMIA MODEL
Authors: Saberi M. , Delfi O. , Browett P.J. , Kakadiya P.M. , Bohlander S.
Published: June 2019

Background:

Acute Leukaemia (AL) is a genetically heterogeneous disease caused by somatic mutations and chromosomal translocations. Translocations can lead to the formation of fusion genes such as the MLL‐AF9 fusion, which results from the t (9;11)(p22;q23). MLL‐AF9 is one of the most common fusions involving the MLL (KMT2A) gene. MLLAF9 leukemias have an intermediate to poor prognosis. The MLL‐AF9 fusion is frequently used to establish murine leukemia models. However, to date, no MLL‐AF9 leukemia model in zebrafish has been reported.

Aims:

Our aim was to establish a transgenic zebrafish leukemia model using the MLL/AF9

fusion gene.

Methods:

We cloned two transgenic constructs (pTol2‐Runx1+23_MLL‐AF9_IRES‐EGFP and pTol2‐Runx1+23_MLL‐AF9_IRES‐mCherry). The Runx1+23 murine promoter was used to target MLL‐AF9 expression to zebrafish hematopoietic stem cells, while EGFP or mCherry were used as fluorescent markers. The final transgenic constructs were co‐injected with Tol2 transposase mRNA into fertilized embryos at the one cell stage. The embryos were sorted 24 hours post fertilization based on the expression of the heart marker.

Results:

About 40% of the transgenic embryos died in the first week after injection but the remaining 60% reached adulthood. After 6 to 12 months, 30% (30 out of 100) fish showed signs of disease. They became less active, sat at the bottom of the tank and, in some cases, they had splayed eyes. When this happened, the fish were euthanized and dissected. The autopsies showed enlarged kidneys, splenomegaly and in some cases a pale spleen. Histological sections revealed increased cellularity of the kidney and liver with massive infiltration of hematopoietic cells in these organs. In flow cytometry, kidney marrow cells from the transgenic fish showed a different forward scatter (FSC) and side scatter (SSC) profile compared to that of the normal zebrafish kidney marrow cells. The FSC/SSC profile in the transgenic F0 zebrafish showed an expansion of the hematopoietic progenitor cell population. These findings strongly suggest that the fish had developed a leukemia‐like disease. We performed whole mount in situ hybridization (WISH) with early hematopoietic markers in 24 hpf embryos and detected reduced expression of gata1, myb and tal1as well as increased expression of lyz in transgenic embryos. Currently, transplantation experiments are being performed to determine whether the disease is transplantable which is a sign of leukemia.

Summary/Conclusion:

Although our flow cytometry, histology and WISH data strongly suggest that we have established an MLL/AF9‐driven leukemia model in zebrafish, additional experiments are needed to further characterize our model and confirm the malignant nature of the observed disease.

Our MLL/AF9 zebrafish leukemia model will be a helpful tool to study leukemia biology and test new therapeutic strategies.
PF246 PERSONALIZED FOLLOW‐UP OF ACUTE MYELOID LEUKEMIA THROUGH MULTIPARAMETER FLOW CYTOMETRY: A PROOF OF CONCEPT
Authors: Jacqmin H. , Louveaux Q. , Chatelain B. , Jacqmin P. , Chatelain C. , Dogné J.‐M. , Graux C. , Mullier F.
Published: June 2019

Background:

Standardization, machine learning techniques and comparison to normality are concepts that are changing the landscape of multiparameter flow cytometry data analysis in clinical hematology. We applied these concepts to the follow‐up of acute myeloid leukemia (AML), which remains challenging due to the heterogeneity of the disease.

Aims:

To evaluate a new flow cytometry data analysis approach for the follow‐up of measurable residual disease in AML.

Methods:

Based on retrospective flow cytometry data, we developed a strategy for personalized monitoring of AML. This strategy is an evolution of the “leukemia associated immunophenotype” or “LAIP”‐approach that has been used the last decades in specialized flow cytometry laboratories. It relies on new concepts, comparing simultaneously the patient's follow‐up and diagnosis results to control group samples. We named these concepts the “leukemic cloud” and the “abnormality ratio”. To evaluate this approach, flow cytometry data of 6 AML patients and 20 control patients was used. All samples were analyzed with the same 10‐parameter (FSC‐A, SSC‐A, CD45, CD34, CD117, CD13, CD33, CD19, CD3, HLA‐DR) FACS Canto II flow cytometry assay. The “abnormality ratio” results over time were compared with morphology and molecular biology results.

Results:

The “Abnormality Ratio” results over time were in line with the clinical evolution of the patients (see example on image below) and were overall more sensitive for detecting residual disease than morphology and molecular biology, excepted for NPM1‐mutated AML. The “Abnormality Ratio” did not consider phenotypic switches of the malignant cell population identified at diagnosis. However, the discrepancy between the “abnormality ratio” results and morphology or molecular biology results could be used to objectify these phenotypic switches.

Summary/Conclusion:

We developed a quasi‐fully automatable flow cytometry data analysis algorithm. It could be used as a basis for the development of “next generation” flow cytometry assays for monitoring of hematological malignancies such as AML. Prospective studies are needed to confirm the applicability and limitations of our concepts.

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PF278 DECITABINE COMBINED WITH HAAG AS INDUCTION CHEMOTHERAPY FOR NEWLY DIAGNOSED ACUTE MYELOID LEUKEMIA
Authors: Zhu J. , Cui W. , Zhang Q. , Jin Z. , Sun A. , Zhu X. , Qiu H. , Wu D. , Tang X.
Published: June 2019

Background:

Treatment of newly diagnosed acute myeloid leukemia (AML) remains challenging. Several patients and disease‐related factors contribute to poor outcome in elderly patients or high risk patients with AML, including medical comorbidities, physical frailty, and poor‐risk biologic features. It is confirmed that Decitabine(DAC) has the synergistic reaction with daunomycin or cytarabine. Therefore, we investigated whether DAC combined with HAAG regimen might also be effective for the newly diagnosed of AML patients.

Aims:

To evaluate the efficacy and toxicity of DAC combined with HAAG regimen as an induction therapy for newly diagnosed AML patients as well as compared with standard IA(IDA 12 mg/m2/d∗3d) regimen.

Methods:

237 patients with AML who were newly diagnosed in our center between February 2014 and July 2018 were enrolled in this retrospective study. Among them,50 cases received DAC+HAAG regimen(DAC 20 mg/m2/d∗5d combined with low dose of homoharringtonine 1 mg/ m2/ d∗7–14d, cytarabine subcutaneously 10 mg/m2/q12h∗7–14d, aclarubicin 10 mg/d∗4–8d and G‐CSF priming). The other 187 patients received standard IA regimen (idarubicin 12 mg/m2/d∗3d and cytarabine 100 mg/m2/d∗7d).The outcomes of all the patients after one cycle of chemotherapy were evaluated.

Results:

1.The complete remission(CR) rate of DAC+HAAG group was significantly superior than that of IA group(96.0% vs 75.9%, P = 0.000). And the overall response rate (ORR) of DAC+HAAG group was also superior than that of IA group(100.0% vs 90.7%, P = 0.0.013).2.One‐year OS of DAC+HAAG and IA group were 75.3% and 74.8%.And two‐year OS were 69.0% and 66.1%,respectively. The median OS of the poor‐risk patients receiving DAC+HAAG and IA were 26 months and 32 months, respectively (P = 0.9625). Although the OS of two groups were similar, but the age of patients in DAC+HAAG group were statistically older than the IA group(P = 0.00).Furthermore,there were more patients with PS ECOG>2 in DAC+HAAG group(P = 0.000).3. Treatment related mortality (TRM), duration of neutropenia and thrombopenia were similar in both groups. Patients in DAC+HAAG group had significantly less infection grade 3–4 compared to the patients in IA group(16.0 vs 34.8%,p = 0.011). While the incidence of adverse events including bleeding, cadiotoxicity,liver damage and mucositis were similar(P = 0.424,0.296,0.259,0.060).

Summary/Conclusion:

DAC+HAAG regimen is a promising induction chemotherapy for newly diagnosed AML patients with mild toxicity, especially for patients who are not suit for standard induction chemotherapy.
PF281 CLI24–001: FIRST IN HUMAN STUDY OF SEL24/MEN1703, AN ORAL DUAL PIM/FLT3 KINASE INHIBITOR, IN PATIENTS WITH ACUTE MYELOID LEUKEMIA
Authors: Ravandi F. , Strickland S. , Solomon S. , Nazha A. , Walter R. , Valimberti I. , Tagliavini A. , Fiesoli C. , Binaschi M. , Brzozka K. , Baldini S. , Heeger S. , Pellacani A.
Published: June 2019

Background:

PIM kinases are oncogenic FLT3 targets expressed in acute myeloid leukemia (AML) cells. Increased PIM expression is found in samples of relapsed AML patients exposed to FLT3 inhibitors (FLT3i). There is preclinical evidence that PIM inhibition restores cell sensitivity to FLT3i, and that dual FLT3/PIM inhibition eradicates FLT3‐ITD+ primary AML cells. SEL24/MEN1703, a potent PIM/FLT3 dual inhibitor, showed a significantly broader spectrum of activity in AML cell lines and primary AML blasts, irrespective of FLT3 status compared to FLT3 or PIM inhibitors alone

Aims:

To determine the recommended phase 2 dose (RP2D), the PK profile and the single agent activity of SEL24/MEN1703 in relapsed/refractory or newly diagnosed AML patients (excluding APL) unsuitable to chemotherapy

Methods:

First in Human, open label, non‐randomized, multi‐center, dose‐escalation (DE) and cohort expansion (CE) study of oral SEL24/MEN1703. SEL24/MEN1703 is given orally, QD, FOR 14 days in a 21‐day cycle with cycles repeated until disease progression or unacceptable toxicity. Dose escalation follows a 3+3 design to identify the RP2D; CE at RP2D is planned to confirm the safety profile and assess single agent activity. Patients are eligible for the study regardless of mutations and/or prior FLT3i treatment; prior PIM inhibitors are not allowed. White blood count (WBC) of ≤30 x 109/L is required at baseline. Key secondary objectives include PK profile and single agent anti‐leukemic activity; exploratory objectives include assessment of clinical activity in relevant AML subsets of patients (eg FLT3 mutated)

Results:

As of January 8th, 2019 (data cutoff), n = 17 patients were treated and the study is enrolling. In the RP2D expansion phase, the study (currently running in 5 US sites) will be expanded to approximately 40 sites in the US and EU

Summary/Conclusion:

SEL24/MEN1703, a first in class, oral dual PIM/FLT3‐ITD inhibitor, is completing the DE part of a two‐part FIH study in patients with relapsed/refractory or unfit newly diagnosed AML unsuitable to chemotherapy. The RP2D expansion phase is planned to involve either US and EU investigational sites. This is the first clinical trial testing a dual PIM/FLT3‐ITD inhibitor, potentially active in AML regardless of FLT3 status and able to overcome FLT3i resistance
PF283 A RETROSPECTIVE STUDY OF MYELOID LEUKAEMIA IN CHILDREN WITH DOWN SYNDROME IN IRELAND
Authors: Dowling G.P. , Piccin A. , O’Marcaigh A. , Gavin K.T. , Malone A. , Betts D. , Cotter M. , Smith O.P.
Published: June 2019

Background:

Children with trisomy 21 have several clinical complications such as a variety of dysmorphic features, congenital malformations and endocrine abnormalities for example. An important complication of Down Syndrome (DS) is that they may also develop leukaemia. Acute myeloid leukaemia (AML) is the type of haematological malignancy most commonly reported in this population. A subtype of AML called M7 leukaemia (as classified by FAB system) has an incidence nearly 200 times greater compared to children without DS. This is a type of leukaemia otherwise very rare in both adults and children. M7 leukaemia is often preceded by a transient neonatal pre‐leukaemic syndrome, called Transient Abnormal Myelopoiesis (TAM). TAM is unique as it has the ability to resolve spontaneously. However, 20–30% of these patients may develop M7 leukaemia over time. This is most likely to occur within the first 4 years of life.

Aims:

A retrospective national audit of all documented cases of childhood TAM and M7 leukaemia referred from 1990–2018 to the National Paediatric Hematology/Oncology Centre at Our Lady's Children's Hospital Crumlin (OLCHC) Ireland. We also aimed to compare our demographic and outcome findings with the recent medical literature and make recommendations for future research.

Methods:

All consecutive charts of the children with a diagnosis of M7 leukaemia treated at (OLCHC) between the years 1990 – 2019 were sourced from medical records. The hospital database and charts were reviewed and information including date and age of diagnosis of AML, comorbidities, previous history of TAM, treatment regime and outcome was noted. Cytogenetic information was obtained by accessing a dedicated database. Kaplan‐Meier survival curves were constructed.

Results:

Twenty‐seven patients with M7 leukaemia were treated in OLCHC. A prior neonatal diagnosis of TAM was described in 10 patients (37%). Patients had a low platelet count (<50 × 109 /L) at presentation. Nineteen patients (70%) are alive and well, in complete remission, at a median follow up of 11.4 years. Overall survival (OS) of this cohort has risen from 54% from those treated between the years 1990 – 2004 (n = 13) to 93% for those treated between the years 2005 – 2019 (n = 14).

Summary/Conclusion:

Overall an excellent outcome is observed in M7 leukaemia when treated with current poly‐chemotherapy protocols. In general children with DS have a much better response to the cytotoxic‐chemotherapy than constitutionally normal children. Our finding of a low platelet count at diagnosis is in accordance with the current knowledge that M7 leukaemia is a condition affecting platelet precursors. GATA‐1 is mutated universally in M7 leukaemia and therefore appears to be an interesting molecular target.
PF285 ZELLA‐101: PHASE 1 STUDY OF ALVOCIDIB FOLLOWED BY 7+3 INDUCTION IN NEWLY DIAGNOSED AML PATIENTS
Authors: Lee D. , Smith B. , Frattini M. , Anthony S. , Bearss D. , Zeidner J.
Published: June 2019

Background:

Alvocidib, a potent cyclin‐dependent kinase‐9 (CDK‐9) inhibitor, has been studied extensively in newly diagnosed and relapsed/refractory AML in a timed sequential combination with cytarabine and mitoxantrone (ACM) with promising activity. Inhibition of CDK‐9 leads to downregulation of BCL‐2 family member, MCL‐1, which in turn inhibits tumor growth. We hypothesized that alvocidib followed by 7+3 induction therapy would be safe and effective in newly diagnosed non‐favorable risk AML.

Aims:

To evaluate the safety and clinical activity of alvocidib, in combination with cytarabine and daunorubicin (7+3), in previously untreated AML

Methods:

We are conducting a multicenter, open‐label, dose‐escalation, safety and biomarker prediction study (Zella 101) of alvocidib given as timed sequential therapy prior to cytarabine and daunorubicin for adults with previously untreated AML. The key eligibility criteria are: ages 18–65 years; previously untreated AML; ECOG PS 0–2; and no major organ dysfunction. Treatment consisted of increasing dose levels of alvocidib starting at 20 mg/m2as a 30‐minute IV bolus followed by 30 mg/m2over 4 hours on days 1–3, cytarabine 100 mg/m2/day by continuous IV infusion on days 5–11, and daunorubicin 60 mg/m2IV on days 5–7. Dose escalation was assessed by standard 3+3 design. Reinduction therapy with alvocidib (same dose as induction) days 1–3, followed by cytarabine 100 mg/m2/day continuous IV days 5–9 and daunorubicin 45 mg/m2IV days 5–6 was recommended in patients with >10% and >5% cellularity and blasts, respectively.

Results:

A total of 13 patients have been enrolled to date with the median age of 59 years (Range: 31–65 years) (See Table 1). The maximum dose of alvocidib administered was 30 mg/m2as a 30‐minute IV bolus followed by 60 mg/m2over 4 hours on days 1–3 as previously given in prior studies. Overall, alvocidib was well tolerated. The most common NCI CTCAE ≥Grade 3 treatment emergent nonhematologic AEs noted in ≥3 patients in the safety population were device related infection (30.8%), diarrhea (30.8%) and lung infection (23.1%). Cytogenetics were reported on 7 patients, 5 were intermediate to high risk. Ten patients were evaluable with post baseline response assessments, two patients were too early for disease assessment, and one patient died prior to disease assessment due to septic shock. Nine of the 10 evaluable patients achieved CR (9/10, 90%).

Summary/Conclusion:

Alvocidib given as timed sequential therapy prior to cytarabine and daunorubicin (7+3) induction in newly diagnosed AML demonstrated an acceptable safety profile with an MTD (30 mg/m2IV bolus followed by 60 mg/m2infusion over 4 hours) similar to previously investigated timed sequential regimens of alvocidib. Future directions include a randomized phase 2 expansion comparing cytarabine and daunorubicin with or without preceding timed sequential alvocidib, and prospective BH3 profiling of AML patients.

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PF324 RITUXIMAB DOSE ASSOCIATED WITH OVERALL SURVIVAL IN DIFFUSE LARGE B CELL LYMPHOMA
Authors: Kong J.H. , Kim H.S. , Lee J.Y. , Hyun S.Y.
Published: June 2019

Background:

The outcome of diffuse large B cell lymphoma (DLBCL) improved significantly, due to the addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy. However, significant range of patients showed relapse or refractory to R‐CHOP, and the role of body surface area (BSA) or body mass index (BMI) to overall survival (OS) was not known or still controversial.

Aims:

We evaluated effects of rituximab dose, BSA or BMI on OS using National Health Information Database.

Methods:

This study included patients 5,332 patients who were diagnosed with DLBDL and received R‐CHOP as a frontline therapy between 2006 and 2014. The exclusion criteria were as follows;1) age <20 years 2) R‐CHOP was given less than 4 times or over 8 times 3) R‐CHOP 2 months after diagnosis 4) Interval between two consecutive R‐CHOP injection was over 60 days. We extracted age, sex, prescribed medication list, and date of death from NHID. Weight and height of patients who had national general health examination before 1st cycle of R‐CHOP was collected.

Results:

Median age was 58(20–92) years, and 57%(n = 3021) of them were male. Thirty‐eight % of patients (n = 2019) received R‐CHOP 4–5 times, and 62% (n = 3303), 6–8 times. Median dose of injected rituximab was total 7200(1,600–16,800) mg, and median mean dose of rituximab per each cycle was 600(400–1,000) mg. A total 2,523 patients (47.4%) were treated at medical institution in capital (Seoul) area. About 72% of patients (n = 3813) had national health examination before chemotherapy. Their median weight and height were 63(31–121) kg and 163(131–196) cm, respectively. Median BSA and BMI were 1.69m2 and 23.9 kg/m2.

With median 66(24–144) months of follow up, estimated 5‐year and 10‐year overall survival was 37.1% and 25.6% respectively. Log‐rank test for 10‐year OS, age≤60 (vs age>60), female (vs male), 6–8 times of R‐CHOP injection (vs 4–5 times of R‐CHOP), total R dose≥7200 mg (vs <7200), mean R dose≥600 mg, and medical institution in Seoul (vs others) were associated OS, significantly (p < 0.05). However, total R dose did not affect OS in multivariate analysis (p = 0.152).

Among 3813 patients who had national health examination before R‐CHOP, patients whose BSA <1.69m2 had worse OS than BSA≥1.69m2. But BMI did not differentiate OS.

Summary/Conclusion:

With 66 (24–144) months of median follow up, estimated OS at 5‐year and 10‐year of DLBCL patients were 37.1% and 26.5%, respectively. Mean rituximab dose ≥600 mg showed better OS than <600 mg. High BSA showed favorable OS, but BMI did not affected OS significantly.

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PF328 PREDICTORS OF TREATMENT RESPONSE TO IMMUNOSUPPRESSANTS IN ACQUIRED HEMOPHILIA A
Authors: Lau W.N. G. , Leung M.K. G. , Yip P.L. P. , Cheung K.M. C. , Lau S.M. J. , Lee K.K. H. , Mak W.M. V. , Ho S.K. S. , Kwok C.H. K.
Published: June 2019

Background:

Acquired hemophilia A (AHA) is a rare bleeding disorder, caused by inhibitors against factor VIII, which may result in life‐threatening bleeding. Management of AHA is two pronged ‐ to arrest bleeding with hemostatic agent and to eradicate FVIII inhibitors by immunosuppressants. However, immunosuppressants are associated with frequent adverse events, with infection being the leading cause of morbidity and mortality. Identifying predictors of treatment response may help tailor treatment strategies and reduce treatment associated adverse events.

Aims:

The aims of the study were to evaluate the presenting features, treatment, and outcomes of patients with AHA in our local population, to identify the predictors of normalization of aPTT after immunosuppressive therapy and overall survival; and to investigate the patient characteristics that predict normalization of aPTT by steroid alone within 6 weeks.

Methods:

This was a retrospective multi‐center study which recruited 108 patients diagnosed with AHA between 1st January 2002 and 31st December 2016. AHA is defined by the presence of a neutralizing FVIII inhibitor ≥ 0.6 Bethesda units (BU)/ml and a FVIII activity <50%. Patients with congenital hemophilia A with inhibitors were excluded.

Prognostic factors for normalization of aPTT and overall survival were analyzed using Cox proportional hazards regression analysis.

Results:

Normalization of aPTT was an independent predictor of overall survival (OR 0.14, 95% CI 0.07–0.27, P < 0.001). Patients with ECOG performance status ≤2 were more likely to attain normal aPTT (HR 2.09, 95% CI 1.28–3.42, P 0.003) while patients with underlying autoimmune diseases were less likely to achieve normal aPTT (HR 0.46, 95% CI 0.23–0.91, P 0.027).

Female (OR 3.73, CI 1.15–12.2, P 0.028) and an inhibitor titer ≤20 BU/ml (OR 4.3, CI 1.36–13.63, P 0.013) predicted a higher chance of normalization of aPTT with steroid alone within 6 weeks.

Summary/Conclusion:

Identification of patients who are more likely to respond to steroid alone within 6 weeks may avoid unnecessary immunosuppressants and thus reduce treatment‐related adverse events. This finding may help individualize treatment strategies.

Normalization of aPTT was an independent prognostic factor of survival. This finding echoed other studies and reiterated the importance of achieving remission. To date, the optimal immunosuppressive strategy remains elusive. Further high‐quality evidence is needed to guide the choice and intensity of treatment.
PF331 COST‐EFFECTIVENESS OF EMICIZUMAB VERSUS BY‐PASSING AGENTS IN PATIENTS WITH HAEMOPHILIA A AND FVIII INHIBITORS IN FRANCE
Authors: Polack B. , Trossaert M. , Godard C. , Cousin M. , Baffert S. , Pruvot A. , Pinguet J.‐M.
Published: June 2019

Background:

The development of an anti‐FVIII inhibitor is the most serious complication of haemophilia A. On February 23, 2018, Emicizumab obtained a European Marketing Authorization for the prevention of bleeding episodes in patients with haemophilia A who developed an anti‐FVIII inhibitor. In France, emicizumab is reimbursed by National Insurance since February 7th2019. As part of its inscription on the list of products reimbursed by French National Health Insurance, emicizumab has been evaluated by health authorities (HAS): The Transparency Committee granted a major added medical benefit (ASMR II), and a medico‐economic analysis was evaluated by the Health Economic and Public Health Committee.

Aims:

The purpose of this analysis is to evaluate the Incremental Cost‐Effectiveness Ratio (ICER) of emicizumab compared to the current management by Bypassing Agents (BPA) taking into account the final price that has just being published.

Methods:

The analysis is based on a Markov model with two health states (alive, dead) over a 5‐year time horizon. Emicizumab is compared with current BPA management (aPCC and rFVIIa) in prophylaxis or on‐demand, according to their real‐life use in the FranceCoag Network cohort (RFC). The ICER is expressed in euros per QALY (Quality‐Adjusted Life Year). Bleeding rates are derived from the HAVEN 1 clinical trial for emicizumab and BPA on‐demand, and an indirect comparison for BPA prophylaxis. Quality of life data are derived from the HAVEN 1 trial. The costs of treatment acquisition, adverse events and hospitalizations were taken into account. Deterministic and probabilistic sensitivity analyzes were performed to evaluate the uncertainty around the result.

Results:

Emicizumab prophylaxis is a dominant strategy, in children and adult patients: it is more effective and less costly than the current BPA strategy. Over 5 years, the mean total cost per patient was 2,3 M€ in patients treated with emicizumab, versus 2,7 M€ with BPA, associated to 3,3 and 2,4 QALYs respectively. Thus, emicizumab brings 0,9 additional QALYs per patients for a saving of almost 426 000€. Exploration of uncertainty does not alter these results.

Summary/Conclusion:

The health economic analysis shows the cost‐effectiveness of emicizumab versus BPA in France. The methodology used was accepted by the CEESP in its Opinion of October 9, 2018. The limitations of this analysis are mainly based on the lack of data to model the consequences of the reduction of bleeding on the long‐term evolution of arthropathy and disability.
PF336 EVALUATION OF THROMBOPOIETIN‐RECEPTOR AGONISTS (TPO‐RAS) «STOP‐THERAPY» IN IDIOPATHIC THROMBOCYTOPENIC PURPURA (ITP)
Authors: Vinogradova O. , Pankrashkina M. , Tkachenko N. , Chernikov M. , Mukha L. , Perova V. , Kobzev Y. , Shikhbabaeva D. , Ptushkin V.
Published: June 2019

Background:

For a number of years, it has been shown that TPO‐RAs are a highly effective therapy of ITP. Still, there are few published guidelines/recommendations addressing the management of ITP patients (pts) on TPO‐RAs after they achieve continuous remission.

Aims:

To evaluate the TPO‐RAs «stop‐therapy» in ITP pts with complete response (CR) to TPO‐RAs.

Methods:

We analyzed data of TPO‐RA «stop‐therapy» in patients with CR. Primary endpoints of the study were the duration and type of response (CR, partial – PR, minor – MR, and loss of response) after TPO‐RAs had been stopped. Secondary endpoints included types of response (CR, PR, MR) after TPO‐RAs had been resumed in those pts who relapsed.

Results:

194 ITP pts treated at Moscow City Hematology Center (Botkin Hospital) in 2014–2018 were administered TPO‐ARs: (romiplostim (R): n = 123; eltrombopag (E): n = 71). 106 pts (55%) achieved CR (platelets >100х109/l)(R: n = 79 (64%); E: n = 27 (38%).

28 pts in continuous CR (≥3 months (mo) had TPO‐RA stopped: (R: n = 19; E: n = 9). Group R (GR) comprised of 4 males and 15 females, with median age (Mе) age at the time of diagnosis of 51 (range 1 ‐ 69) years, and Me follow‐up time from the time of diagnosis was 108 (9 ‐ 483) mo. Group E (GE) included 1 male and 8 females with Me age of 54 (range 12 ‐ 75) years and Me follow‐up time from the time of diagnosis of 74 (27 ‐ 228) mo.

Me stop‐therapy length was 69 (range 20 ‐ 276) weeks in GR, and 38 (range 13 ‐ 131) weeks in GE.

At the time of analysis, CR was maintained in 5 (26%) GR pts, and in 1 (11%) GE pt. PR was seen in 7 (37%) GR pts and in 2 (23%) GE pts; and MR in 5 (26%) GR pts and in 1 (11%) GE pt. 2 (11%) GR pts and 5 (55%) GE pts did not respond to TPO‐RAs.

TPO‐RAs were resumed in 2 GR and 2 GE pts who relapsed (7 pts have relapsed altogether), and 1 PR and 1 MR in each group were achieved.

Summary/Conclusion:

Our data adds to the growing body of evidence that ITP pts maintain remission after TPO‐RAs are stopped. This may possibly represent a change in therapeutic approach to these patients who usually require continuous maintenance therapy. Longer follow‐up and larger number of pts enrolled in the study are required to fully assess benefits of such approach.
PF398 KNOCKDOWN OF LASP1 IN CXCR4 EXPRESSING CML CELLS PROMOTES CELL PERSISTENCE, PROLIFERATION AND TKI RESISTANCE
Authors: Herrmann A.B. , Müller M.‐L. , Orth M.F. , Müller J.P. , Zernecke A. , Hochhaus A. , Ernst T. , Butt E. , Frietsch J.J.
Published: June 2019

Background:

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by a fusion protein, the constitutively active BCR–ABL tyrosine kinase, leading to expansion of differentiated granulocytes. Although tyrosine kinase inhibitors (TKI) have significantly improved patient care, minimal residual disease (MRD) remains a clinical challenge. Recently, the LIM and SH3 domain protein 1 (LASP1) has been identified as a novel BCR–ABL substrate, which is hyperphosphorylated at Y171 in CML cells. LASP1 is associated with proliferation, migration, tumorigenesis and chemoresistance. Furthermore, the protein can bind to the chemokine receptor 4 (CXCR4), known to be involved in homing of leukemic stem cells and relapse of CML patients.

Aims:

These two LASP1‐influenced disease promoting effects prompted us to investigate the effect of LASP1 and CXCR4 on processes involved in initiation, progression and maintenance of CML in order to identify and exploit BCR‐ABL‐independent pathways and other extrinsic factors, which may help to eradicate MRD.

Methods:

Using a CRISPR/Cas9‐based LASP1 knockout system and a lentivirus‐mediated CXCR4 overexpression in the CML cell line K562, the biological influence of CXCR4 and LASP1 was characterized in apoptosis, viability, cell cycle, migration and adhesion assays in the presence of nilotinib. Furthermore, comprehensive transcriptomic microarray data from a public database, immunofluorescence imaging and biochemical analysis were employed to elucidate the roles of LASP1 in CML.

Results:

Microarray analysis revealed that LASP1 is significantly lower expressed in samples of CML patients not responding to imatinib therapy. The in vitro data indicate that not only the overexpression of CXCR4, but also knockdown of LASP1 contributed to proliferation, reduced apoptosis and impaired cell migration. Additionally, we show that LASP1 depletion leads to decreased cytokine release and reduced natural killer (NK)‐cell mediated cytotoxicity. Finally, we describe a phosphorylation‐dependent loss of direct binding between pLASP1‐Y171 and CXCR4 in CML, which most likely results in receptor destabilization.

Summary/Conclusion:

Taken together, our results indicate that in CML, reduced levels of LASP1 alone and especially in combination with high CXCR4 expression contribute to TKI resistance and stem cell persistence.
PF427 FOSTAMATINIB, A SPLEEN TYROSINE KINASE INHIBITOR, FOR THE TREATMENT OF WARM ANTIBODY AUTOIMMUNE HEMOLYTIC ANEMIA: INITIAL RESULTS OF THE OPEN‐LABEL EXTENSION PERIOD OF THE SOAR PHASE 2 STUDY
Authors: Kuter D. , Richy A. , Boxer M. , Broome C. , Arnold D. , Field J. , Murakhovskaya I. , Rogers K. , Lowe A. , Numerof R. , Zayed H. , Tong S. , Duliege A.‐M.
Published: June 2019

Background:

Warm antibody autoimmune hemolytic anemia (wAIHA) is a rare and often serious disease resulting from antibody‐mediated destruction of red blood cells (RBCs). The SYK inhibitor, fostamatinib, markedly improved Hgb levels in patients with wAIHA during a phase 2, open‐label, multicenter study, in which 9 of 21 (43%) met the primary endpoint (Hgb >10 g/dL with an increase of ≥2 g/dL from baseline by Week 24 without rescue therapy or RBC transfusion).

Aims:

We report the results of the ongoing extension period of the study.

Methods:

Adults with primary or secondary wAIHA had to have failed ≥1 prior treatment for wAIHA, have hemoglobin (Hgb) <10 g/dL, an IgG‐positive direct antiglobulin test, haptoglobin <10 mg/dL, and lactate dehydrogenase (LDH) >ULN. Fostamatinib 150 mg BID was taken orally with no food restriction (dose reduction permitted based on tolerability). To enter the extension, patients had to meet the primary endpoint OR show a marked improvement in Hgb and had to have tolerated study drug.

Results:

Nine patients who completed the initial treatment phase entered the extension: 7 patients met the primary endpoint, 1 was a late responder, and 1 had a beneficial trend during the initial treatment phase. For baseline characteristics, see table. Median Hgb levels increased over the study. Five of 9 patients have an ongoing response to fostamatinib as of July 2018, and none have had rescue therapy or an RBC transfusion. Six of 9 patients are still on the study, and 3 discontinued due to lack of response plus AE (1), consent withdrawn (1), and unknown (1).

Nine patients had ≥1 AE, 6 with treatment‐related AEs. AEs were mostly mild to moderate, and the most common AEs were diarrhea and upper respiratory tract infection. Three Grade 3 AEs were reported in 2 patients. AEs resulted in dose reduction in 2 patients, dose interruption in 2, and study drug withdrawn in 1.

Summary/Conclusion:

Fostamatinib markedly improved Hgb levels in 9 of 21 (43%) patients with wAIHA during a phase 2, open‐label, multicenter study. Adverse events (AE) were manageable and consistent with those previously reported for fostamatinib in other conditions. A randomized, placebo‐controlled, Phase 3 trial is underway.

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PF442 TREATMENT WITH 5‐AZACYTIDINE RESULTS IN EXPRESSION OF LONG TERMINAL REPEAT (LTR) ELEMENTS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH MDS AND AML: FIRST PILOT STUDY
Authors: Daskalakis M. , Haubitz M. , Steiner D. , Helf M. , Goyal A. , Brocks D. , Pleyer L. , Greil R. , Plass C. , Baerlocher G.M. , Oppliger Leibundgut E.
Published: June 2019

Background:

Epigenetic drugs are used for the treatment of several hematologic malignancies, but their pharmacological mechanism remains poorly understood. By genome wide analysis of transcription start sites (TSS), methylation status and chromatin dynamics, we showed for DNA methyltransferase and histone deacetylase inhibitors (DNMTi and HDACi) global reactivation of long terminal repeat elements (LTRs) in vitro (cell line models) and in vivo (neuroblastoma mouse xenograft model). The LTR reactivation is resulting in numerous fusion transcripts that encode novel protein isoforms which have the potential to influence cell proliferation, seem to be an explanation for the priming effect of epigenetic therapy and might be used as a potential marker for epigenetic treatment response.

Aims:

To investigate the reactivation of LTRs in sequential peripheral blood samples of AML and MDS patients upon epigenetic drug treatment with 5‐Azacytidine (DNMT‐inhibitor) by qRT‐PCR and ddPCR and to correlate the expression results with treatment response.

Methods:

Sequential RNA samples from peripheral blood mononuclear cells (PBMCs) of three AML and four MDS patients treated with 5‐Azacytidine were analyzed. Consensus primers covering the transcript variants of LTR12C as well as particular primers for specific LTR elements were used. Expression of LTRs was analyzed by qRT‐PCR technique with SYBRGreen as well as ddPCR technique with EvaGreen. Expression results were associated with treatment response.

Results:

In AML and MDS patients, we could detect LTR expression in sequential samples from PBMCs over time with 5‐Azacytidine treatment. LTR12C expression values measured by qRT‐PCR were confirmed by ddPCR and allowed to assess specific LTR elements. Patients with response to 5‐Azacytidine showed increased LTR12C expression whereas patients without treatment response had no increase in LTR12C expression. In contrast to the results from our previous NSCLC cell line model, specific LTR elements were only partially expressed in sequential PBMC samples from AML patients treated with 5‐Azacytidine.

Summary/Conclusion:

In this first in‐vivo pilot study, we detected LTR expression in sequential PBMC samples of AML and MDS patients treated with 5‐Azacytidine. In this group of patients, treatment response correlated with LTR expression over several treatment cycles with 5‐Azacytidine. These are the first results in AML and MDS patients showing expression of LTRs upon epigenetic drug treatment. Larger patient cohorts are necessary to confirm these results by either PCR‐ or genome wide‐analysis of transcription start sites (TSS) (Cap analysis of gene expression (CAGE) sequencing) as well as to evaluate the association of LTR expression and treatment response.
PF443 ADOPTIVE IMMUNOTHERAPY OF INVASIVE ASPERGILLOSIS BY T CELLS VACCINES AGAINST ASPERGILLOSIS IN MOUSE MODEL
Authors: Xing H. , Chen D. , Wang M. , Tian W. , Sun H. , Jiang Z.
Published: June 2019

Background:

Invasive aspergillosis is a common cause of life‐threatening infection in immunocompromised patients, especially those who require aggressive immunosuppressive treatment, as Aspergillus fumigatus is the most common pathogen. Despite advances in early diagnosis and new antifungal agents, the majority of cases still associated with high morbidity and unacceptable mortality. The reconstitution of specific immunity against A. fumigatus during periods of severe immunosuppression has the potential to impact enormously on the health and well being of patients.

Aims:

To screened the amino acid sequences of A. fumigatus recombinant protein ASP f16 by bioinformation software and determine the potential CTL epitopes processed and presented by mature DCs to prime specific CTL cells.

Methods:

We confirmed the killing ability of Asp f16 peptides specific CTLs against A. fumigatus by conidiacidal and hyphae killing assays, which indicated that CTLs culture supernatant contains substances that killed fresh A. fumigatus conidia and CTLs have killing activity directly against the hyphae in vitro. In our study, we also accessed the evaluation of the protection against A. fumigatus in vivo by adoptive transfer peptides specific CTLs to an invasive aspergillosis model of HLA A0201 transgenic mouse.

Results:

The results demonstrated the adoptive transfer of ASP f16 peptides specific CTLs significantly altered the course of the Aspergillus infection, as indicated by statistical significantly extended survival hours after the infection and reduced fungal burden in the lung tissue, as opposed to mice not receiving T cells or receiving nonrelated peptides (NPM1) specific T cells, which all died faster with extensive fungal growth.

Summary/Conclusion:

Generate Asp f16 specific CTL clones in vitro and adoptive transfer to the recipients when they’re susceptive to or involved in IA, will be a promising potential option to protect the recipients against the fatal fungal infection.