bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality Improvement Goals for Sickle Cell Disease Pain Management in an Urban Pediatric Emergency Department: We Can Do Better!.
Authors: Morris Claudia R. , Barreda Fernando , Leibovich Sara A. , Rutherford Mary , Saulys Augusta , Stewart Melinee , Lavrisha Lisa , Vichinsky Elliott , Bell Michael , Treadwell Marsha J
Published: October 2019

Abstract 2101

Background.

Vaso-occlusive painful episodes (VOE) are the leading cause of hospitalizations and emergency department (ED) visits in sickle cell disease (SCD), and are associated with increased mortality. Although disparities specific to pain management practices in the ED for children with SCD have not been identified, ethnic disparities in ED care have been reported, & adults with SCD experience longer delays in the initiation of analgesics compared to other patients with pain. However, initiation of treatment in the ED is often delayed as a result of random events that are beyond anyone's control, such as high patient volumes & acuity of other patients in the ED, even when policies are in place for immediate triage of patients with SCD & pain. In a recent study of children with SCD, median time from arrival to analgesia administration was 90 minutes, with high ED census as the biggest culprit for delays. Barriers to rapid care in the ED are common across the country, including overcrowding, nursing ratios, insufficient staff coverage, inadequate funding, & slow flow of patients from the ED to the wards in addition to patient acuity.

Methods.

As part of a quality improvement (QI) project to improve management of SCD pain in the ED at Children's Hospital & Research Center Oakland, we are reviewing quality indicators to determine areas that can be targeted for improvement. ED-based data was collected and analyzed from a sample of 47 patients initially evaluated in the ED and enrolled in a randomized, placebo-control trial of argininetherapy for children with SCD hospitalized for VOE between years 2000–2008, and compared to recent data in 2012 of 55 ED visits for VOE (66% admissions) to identify trends in practice in our ED.

Results.

See Table 1.

Conclusions.

To these authors' surprise, children with SCD commonly experienced delays in pain management in the ED. These trends have not changed dramatically over a decade, and are not likely to be unique to our facility. Areas to target for improvement include time of arrival to parenteral pioid administration, in particular, time from ED room placement to placement of intravenous catheter. Utilizing intranasal fentanyl in the ED for acute pain is one novel intervention that should significantly decrease time to initial pain management. These reported data will be used as baseline quality measures for comparison to determine the success of QI initiatives such as a refined pain management algorithm on ED-based clinical outcomes.

Disclosures:

No relevant conflicts of interest to declare.
Bimodal Induction of NK Cell Reactivity Against Acute Myeloid (AML) and Chronic Lymphoid Leukemia (CLL) by Fc-Engineered GITR-Fc Fusion Proteins.
Authors: Steinbacher Julia , Schmiedel Benjamin J , Werner Antje , Nuebling Tina , Buechele Corina , Grosse-Hovest Ludger , Kanz Lothar , Salih Helmut R
Published: October 2019

Abstract 2143

NK cells play an important role in anti-tumor immunity and largely contribute to the efficacy of therapeutic strategies like allogenic stem cell transplantation in AML and application of Rituximab that induces antibody-dependent cellular cytotoxicity (ADCC) in CLL. Recently, we demonstrated that the TNF family member GITR ligand (GITRL) is expressed on leukemia cells in a high proportion of AML and CLL patients and impairs direct and Rituximab-induced reactivity of NK cells which constitutively express its counterpart GITR (e.g., Buechele et al., Leukemia 2012). Here we developed a strategy to reinforce NK anti-leukemia reactivity by combining disruption of NK-inhibitory GITR-GITRL interaction with induction of ADCC against the GITRL-expressing leukemia cells using GITR-Ig fusion proteins with modified Fc moieties. Fc parts were engineered by amino acid exchange as previously described (Lazar et al., PNAS 2006; Armour et al., Eur. J. Immunol. 1999). Compared to wild type GITR-Ig (GITR-Fc-WT), our mutants (S239D/I332E and E233P/L234V/L235A/deltaG236/A327G/A330S) displayed highly enhanced (GITR-Fc-ADCC) and abrogated (GITR-Fc-KO) affinity to the Fc(gamma)RIIIa receptor (CD16) expressed on NK cells, respectively. In functional analyses of NK cells and primary leukemia cells, GITR-Fc-KO, which does not induce ADCC, already increased NK reactivity due to disruption of GITR-GITRL interaction. Treatment with GITR-Fc-WT further enhanced NK reactivity due to modest induction of ADCC, while GITR-Fc-ADCC induced highly increased NK-mediated target cell lysis, degranulation and cytokine production in a target-antigen dependent manner. With CLL cells, combined treatment with GITR-Fc-ADCC fusion protein and Rituximab caused additive effects, resulting in significantly enhanced NK cell ADCC. Notably, the effects of our fusion proteins were observed both in an allogenic setting and when employing NK cells of patients with autologous leukemia cells as targets. Our results demonstrate that Fc-engineered GITR-Fc-ADCC fusion protein may combine both neutralization of the NK-inhibitoryeffects of GITR-GITRL interaction and targeting GITRL-expressing malignant cells for NK anti-tumor reactivity and thus constitute an attractive immunotherapeutic means for the treatment of AML and CLL.

Disclosures:

No relevant conflicts of interest to declare.
The Role of IL-4 Signaling in CD8+ Innate-Like Lymphocyte Development.
Authors: Carty Shannon A. , Koretzky Gary A , Jordan Martha S
Published: October 2019

Abstract 2161

The innate and adaptive arms of the immune system collaborate to protect the host against invading pathogens and perform immune surveillance against malignant transformation. As key effectors of the adaptive immune system, conventional T cells develop in the thymus and exit to the periphery as naïve cells, requiring antigenic stimulation and subsequent differentiation to gain effector functions, such as cytokine secretion or cytolytic activity. In contrast to conventional T cells, non-conventional T lymphocytes possess characteristics of innate immune cells, such as expression of surface markers associated with activation/memory and acquisition of effector function during thymic development, and thus are termed innate-like lymphocytes (ILLs). Recently, an expanded population of CD8+ ILLs was identified in mice with a mutation in the T cell receptor signaling protein SLP-76 (SLP-76 Y145F mice). These CD8+ ILLs are characterized by expression of activation/memory markers CD44 and CD122, the expression of the T-box transcription factor Eomesodermin (Eomes) and rapid production of IFN-γ after ex vivo stimulation. The development of these CD8+ ILLs occurs in a cell-extrinsic manner and requires IL-4. We demonstrate that IL-4 is sufficient to upregulate Eomes expression in wild-type CD8 single-positive (SP) thymocytes in short-term in vitro culture and potentiate CD8+ ILL development in fetal thymic organ culture. Using phospho-flow cytometry, we find that CD8+ ILLs from SLP-76 Y145F mice have increased STAT6 and Akt activation vs. CD8+ non-ILLs. In CD8SP thymocytes deficient in STAT6, Eomes expression is not upregulated in response to IL-4. In addition, we demonstrate that pharmacologic inhibition of Akt in SLP-76 Y145F fetal thymic organ culture blocks CD8+ ILL development and also prevents IL-4 induced Eomes upregulation in WT CD8SP thymocytes. Importantly, we have identified CD8+ ILLs in human fetal thymocytes and umbilical cord blood and found that IL-4 is sufficient to up-regulate Eomes expression in these cells. Taken together, our data suggest that IL-4 signaling via STAT6 and Akt pathways is required for IL-4 induction of Eomes expression and CD8+ ILL development. Understanding signal transduction pathways required for CD8+ ILL development will provide insight into the development of this unique lymphocyte subset that sits at the interface between innate and adaptive immunity and has been identified in human umbilical cord blood.

Disclosures:

No relevant conflicts of interest to declare.
PAK and Akt Interactions Regulate PAR-Mediated Akt Translocation to Membrane in Platelets: A Novel PIP3-Independent Mechanism.
Authors: Badolia Rachit
Published: October 2019

Abstract 2166

Akt has been shown to be an important signaling molecule regulating platelet aggregation. It was proposed that Akt translocates to the membrane for its activation where it is phosphorylated on Thr308 by PDK1 and Ser473 by mTORC2. However, the specific signaling events that regulate the Akt phosphorylation and its mechanism of translocation to the membrane are not clearly defined. It has been shown that Akt phosphorylation by many agonists requires signaling events downstream of Gi activation, involving PI3-kinaseb. In addition, it was proposed that Akt translocates to the plasma membrane by binding to PIP3 (Phosphatidylinositol-3,4,5-trisphosphate) generated by PI3-kinase. Our previous studies have revealed that Gq and G12/13 pathways enhance Akt phosphorylation in platelets, suggesting a role for these pathways independently of PIP3. Hence we investigated the mechanisms of Akt translocation in platelets. Stimulation of platelets with the PAR4 activation peptide (AYPGKF) caused translocation of Akt to the membrane rapidly (as early as 20 seconds) whereas, the phosphorylation of Akt occurred at the later time points (Figure 1). Pan-phoshatidylinositide 3-kinase (PI3-Kinase) inhibitors, LY-294002 (Figure 2) and Wortmannin inhibited Ser473 phosphorylation but failed to affect translocation of Akt to the membrane indicating that Akt translocation can occur independent of PI3-kinase activity. However, translocation of Akt was dramatically inhibited in the presence of a Gq-selective inhibitor, YM254890, indicating that Akt translocation is regulated downstream of Gqsignaling pathways (Figure 3).

The p21-activated kinases (PAKs) are a family of serine/threonine kinases and are key regulators of actin polymerization and cell migration. PAK functions as a scaffolding protein and is reported to interact with numerous proteins including Akt. Here, we evaluated whether PAK activated by the Gqpathways plays a significant role in the translocation of Akt to the membrane. The co-immunoprecipitation studies revealed that Akt associates with PAK upon stimulation with AYPGKF (Figure 4). This association was abolished when platelets were pre-treated with YM254890 (Figure 5).

These results suggest that PAK1/2 activation downstream of Gq pathway mediates Akt translocation to the membrane when stimulated by PAR agonist in platelets and that this translocation is PIP3- independent.

Disclosures:

No relevant conflicts of interest to declare.
Deficient ADAMTS13 Activity in Ticlopidine-Associated Thrombotic Thrombocytopenic Purpura (TTP) in Populations From Japan in 2012: Validation of Findings Initially Reported in the United States in 1998 and 2000.
Authors: Bennett Charles , Matsumoto Masanori , Georgantopoulos Peter , Jacob Sony , Dunn Brianne L , Qureshi Zaina Parvez , Bandarenko Nicholas , Kwaan Hau C. , Winters Jeffrey , Sarode Ravindra , Kiss Joseph E , Danielson Constance , Ortel Thomas L. , Raife Thomas , Clark William F , Rock Gail , Zheng X. Long , Raisch Dennis , Fujimura Yoshihiro
Published: October 2019

Abstract 2203

Background:

Thrombotic thrombocytopenic purpura (TTP) is frequently characterized by severe ADAMTS13 deficiency, the cause of which is unknown. An important exception is ticlopidine-associated TTP (tc-TTP), the most common drug-induced TTP syndrome. In 1998, a possible association of TTP with ticlopidine was reported. In 1999, two additional series reported this association. In 2000, a fourth study reported severe A DAMTS13 deficiency among six of seven tc-TTP persons- suggesting a causal pathway. All of these reports were from the United States. Recently, we reported characteristics of 186 acquired idiopathic (ai)- TTP patients in Japan with severe ADAMTS13 deficiency, noting that clinical and laboratory findings for ai-TTP patients in Japan differed from those for cohorts of ai-TTP patients in Europe and North America- raising concern that TTP findings vary by region of the world. (PLOS One 2011) We now on report clinical and laboratory characteristics of a cohort of TTP patients from Japan with tc-TTP, and compare these findings to three cohorts of tc-TTP in the United States and one cohort of ai-TTP patients from Japan.

Methods:

We queried a database of thrombotic microangiopathy patients identified from a national TTP referral laboratory in Japan of cases identified between 1998 and 2008.

Severe ADAMTS13 deficiency was characterized by activity levels < 5%. All tc-TTP patients and 186 of 911 ai-TTP patients in the database had severe ADAMTS13 deficiency and first onset of TTP. Comparisons were made to tc-TTP patients reported previously from the United States.

Results:

Characteristics of ai- TTP with severe ADAMTS13 deficiency in Japan and tc-TTP in Japan and US

Conclusions:

These data from Japan validate insights about tc-TTP initially proposed in 1998, 1999, and 2000 in the United States. Ticlopidine is a likely cause of TTP, the mechanism is via a cross-reactive antibody to ADAMTS13:AC resulting in formation of an ADAMTS13:INH, and therapeutic plasma exchange is necessary for treatment.

Disclosures:

Ortel: Eisai: Research Funding; Glaxo SmithKline: Research Funding; Pfizer: Research Funding; Instrumentation Laboratory, Inc: Consultancy, Research Funding; Boehringer Ingelheim: Consultancy. Fujimura:Baxter BioScience: Membership on an entity's Board of Directors or advisory committees; Alexion Pharma: Membership on an entity's Board of Directors or advisory committees.
A Coagulation Mechanism for the Mild Bleeding Tendency in a Patient with Severe Hemophilia A Possessing an Arg1781His Mutation.
Authors: Yada Koji , Nogami Keiji , Ogiwara Kenichi , Wakabayashi Hironao , Fay Philip J. , Shima Midori
Published: October 2019

Abstract 2213

The severity and frequency of bleeding appears to be different in hemophilia A (HA) with similar factor (F)VIII activity, as a mild bleeding phenotype has been reported in 10–15% of individuals with severe HA. This heterogeneity in the clinical expression is presently not fully resolved, however. Severe HA patients with the point mutation Arg1781 to His (R1781H) in FVIII also represent a severe to mild/moderate clinical phenotype. We had a patient with mild phenotype (FVIII:C 0.9 IU/dl), presenting with this mutation. In this study, we investigated this mechanism using several global coagulation assays and purified assays with a recombinant FVIII mutant. The levels of all plasma coagulation, anti-coagulation, and fibrinolysis factors were within normal range, except for FVIII. Rotational thromboelastometry using patient whole blood revealed that the clot time and clot firmness time were significantly shortened compared to the control with similar level of FVIII:C, and were comparable to those observed at FVIII:C 5∼10 IU/dl. Thrombin and FXa generation tests using plasmas also demonstrated that the levels of peak thrombin in the former and the initial rate in the latter were comparable to those observed at FVIII:C 5∼10 IU/dl, respectively, supportive of significantly greater hemostatic potential, and potential effects upon formation of the tenase complex consisting of FVIIIa, FIXa, and FX on the phospholipid surface. The addition of excess amounts of FX to control plasma (FVIII:C 0.9 IU/dl) showed a similar waveform pattern in the R1781H patient sample, whilst the addition of FIXa did not show, might suggesting a significant alteration in the interaction of the R1781H patient FVIII(a) and FX. To clarify this mechanism, we prepared and stably expressed a recombinant, B-domainless FVIII mutant, R1781H. Thrombin generation tests using the control plasma with FVIII wild type revealed that the hemostatic function observed with R1781H FVIII (∼0.9 IU/dl) was comparable to that observed at FVIII:C ∼5 IU/dl, indicating the contribution of R1781H on the greater hemostatic potential of patients' plasma. Furthermore, a purified FXa generation assays showed that R1781H possessed an ∼1.9-fold decrease in Km for FX compared to wild type (32.5±3.8 and 58.5±6.1 nM, respectively). This mutant did not affect the FVIIIa binding to either FIXa or phospholipid, however. These results demonstrated that the enhancement of binding affinity of FVIII R1781H for FX appeared to reflect the severity of the HA phenotype. This finding of the higher coagulant potential of the R1781H mutation may suggest utility as a new replacement therapy for HA patients. The addition of this mutant could yield a sufficient hemostatic effect at lower dose, and thus require less protein than a similar dose of native FVIII, as a ‘super-FVIII product’.

Disclosures:

No relevant conflicts of interest to declare.
Hepatitis B Virus Reactivation in Chronic Myeloid Leukemia Treated with Various Tyrosine Kinase Inhibitors: Multicenter, Retrospective Study
Authors: Kim Sung-Hyun , Kim Hyeoung Joon , Kwak Jae-Yong , Kim Jin Seok , Mun Yeung-Chul , Park Joon Seong , Sohn Sang Kyun , Kim Dong-Wook
Published: October 2019

Abstract 3738

Background

BCR/ABL tyrosine kinase inhibitors (TKI) is now a standard initial treatment for chronic myeloid leukemia (CML). Several cases reported that hepatitis B virus (HBV) reactivation were related to imatinib therapy. However, it is still unclear whether imatinib or other TKIs induce HBV reactivation in hepatitis B surface antigen (HBsAg)-positive patients. The aim of this study is to investigate the incidence of HBV reactivation and analyze risk factors associated with HBV reactivation in CML patients who are treated with various TKIs.

Methods

We retrospectively reviewed the medical records from 8 centers in South Korea. HBsAg-positive CML patients under imatinib or other TKIs treatment were analyzed.

Results

702 patients were diagnosed CML from participating centers. HBsAg-positive rate was 6.1% (43/702) at diagnosis. In the 43 HBsAg-positive patients, nine patients received prophylactic therapy and HBV reactivation rate was 34.9% (15/43) (95% CI: 21.0–50.9%). Patients who received prophylaxis did not develop HBV reactivation. The median age and the male to female ratio of the HBV reactivated patients were 47.0 years (range; 22–63) and 4:1, respectively. HBV reactivation according to each TKI treatments were: 12 cases under imatinib, 2 cases under dasatinib, and 1 case under nilotinib. Median time to HBV reactivation was 9.3 months (range; 2.3–68.8 months) (95% CI: 5.9 – 28.5 months). None of the patients died due to HBV reactivation, but one patient received liver transplantation due to hepatic failure. Prophylactic therapy and HBV DNA level at diagnosis were the factors associated with HBV reactivation (P=0.011 and P=0.036, respectively).

Conclusion

This is first report that has analyzed HBV reactivation in HBsAg-positive CML patients during TKIs treatment. Prophylaxis should be considered to prevent HBV reactivation during TKI treatment. Also, we recommend that HBsAg-positive patients with CML receiving TKI treatment be closely monitored.

Disclosures:

No relevant conflicts of interest to declare.
Comparison of IPSS and IPSS-R Scoring in a Population Based Myelodysplastic Syndromes (MDS) Study
Authors: Warlick Erica D. , Hirsch Betsy A. , Nguyen Phuong L. , Cioc Adina , Roesler Michelle A. , Fonstad Rachel , Miller Jeffrey S. , Weisdorf Daniel J. , Ross Julie A.
Published: October 2019

Abstract 3841

Introduction:

The International Prognostic Scoring System (IPSS) has recently been revised (IPSS-R) to capture more inclusive cytogenetic characterization, more stringent blast description, and more detailed cytopenia assignments. To validate the IPSS-R in a prospective cohort of patients, we compared IPSS and IPSS-R categorization within a group of newly diagnosed MDS patients in a prospective population-based epidemiologic study in Minnesota.

Methods:

We identified all newly diagnosed MDS cases in Minnesota between the ages of 20 and 85 years from April 1, 2010 to April 2012. Our process includes rapid case identification by the Minnesota Cancer Surveillance System (MCSS), patient contact and enrollment, central medical review including: 1) independent review by two hematopathologists to confirm diagnosis and WHO subclassification; 2) independent cytogeneticist's review for classification as defined by IPSS and IPSS-R; and 3) medical chart review with prospective calculation of IPSS, IPSS-R, and WPSS by a an oncologist.

Results:

Classification of the 128 patients by IPSS versus IPSS-R is shown (Table)

Kendall's Tau = 0.77

In this comparative classification, IPSS-R scoring refined the MDS prognostic risk groups. Low IPSS remained low risk in the IPSS-R spanning the Very Low and Low groups, while all high risk IPSS remained in the Very High risk group in the IPSS-R. However, those in the INT-1 and INT-2 IPSS categories were inconsistently reclassified in the IPSS-R. INT-1 IPSS spanned from Very Low to High and INT-2 IPSS spanned from Intermediate to Very High in the IPSS-R. While reclassification of this prospective cohort resembles results in the IPSS-R reports, ongoing follow-up will be needed to determine if the survival and AML progression measures are reproducible.

Conclusion:

Until molecular data are available to refine future prognostic scoring systems, the IPSS-R enhances our prognostic risk stratification abilities and is applicable to the general MDS population. As treatment decisions are based on this initial prognostic risk assessment, the more diverse differentiation of risk within the IPSS-R will directly refine prognosis and impact decisions on therapy.

Disclosures:

Miller: Celgene: Membership on an entity's Board of Directors or advisory committees; Coronado Bioscience: Membership on an entity's Board of Directors or advisory committees.
Novel Tyrosine Kinase Inhibitors Trigger Drug Sensitivity of Primary CLL Cells by Controlling Glucosylation of Ceramides
Authors: Schwamb Janine , Feldhaus Valeska , Baumann Michael , Patz Michaela , Brodesser Susanne , Brinker Reinhild , Claasen Julia , Pallasch Christian P. , Hallek Michael , Wendtner Clemens-Martin , Frenzel Lukas P.
Published: October 2019

Abstract 3905

Background:

Apoptosis resistance of chronic lymphocytic leukemia (CLL) cells is mediated by several pro-survival stimuli. In particular, engagement of the B-cell receptor (BCR), CD40-CD40 ligand (CD40L) interaction or stimulation by interleukin-(IL)-4 were identified as major factors to regulate chemoresistance. Sphingolipids are known to be involved in several metabolic pathways involved in chemoresitance. Therefore, we focused on ceramide as pro-apoptotic molecule and its counterpart glucosylceramide, which rather contributes to proliferation and survival.

Methods and Results:

Applying liquid chromatography electrospray ionization tandem mass spectrometry, we revealed a significant decrease of pro-apoptotic ceramide in BCR/IL-4/CD40L-stimulated primary CLL cells compared to untreated controls (p=0.0258, p=0.0478, p=0.0114). Anti-apoptotic glucosylceramide levels were significantly increased after BCR cross-linking (p=0.0435) while other stimuli caused no relevant change in glucosylceramide expression. We identified BCR engagement to catalyze the crucial modification of ceramide to glucosylceramide via the enzyme UDP-glucose ceramide glucosyltransferase (UGCG) (p=0.0001). Besides specific UGCG inhibitors, we could show for the first time that IgM-mediated UGCG expression was significantly inhibited by the novel and highly effective PI3Kδ and BTK inhibitors CAL-101 and PCI-32765, which were able to revert IgM-induced apoptosis resistance of CLL cells. Recently published data revealed sphingolipids to be essential for mediation of apoptosis via mitochondria. Therefore, we chose ABT-737 – a well-known and also mitochondria-targeting drug – as candidate partner for PI3Kδ and BTK inhibition. When combining each tyrosine kinase inhibitor with ABT-737, a synergistic apoptotic effect could be documented, even under protection by BCR stimulation.

Conclusion:

In summary, we could demonstrate that sphingolipids are critically involved in CLL pathogenesis. UGCG could be identified as drugable target by the novel kinase inhibitors CAL-101 and PCI-32765 resulting in even synergistic apoptosis following additional application of ABT-737. Sphingolipids seem to offer further targets providing novel treatment options in CLL.

C.M.W. and L.P.F. contributed equally to this work.

Disclosures:

No relevant conflicts of interest to declare.
Gene Expression Profiling (GEP) of Whole Bone Marrow Biopsies (BMB) in Multiple Myeloma (MM) – Relationship to Plasma-Cell (PC)-Based GEP-Defined Risk and Molecular Subgroups
Authors: Johann Donald , Qu Pingping , Sexton Rachael , Hoering Antje , Epstein Joshua , Yaccoby Shmuel , van Rhee Frits , Usmani Saad Z , Crowley John , Barlogie Bart
Published: October 2019

Abstract 3953

PC-GEP provides great insight into MM heterogeneity as defined by 7 distinct molecular subgroups, along with clinical correlates and prognosis, as identified by the GEP-70 model. As is now increasingly appreciated in MM, a close interaction exists between PC and the bone marrow micro-environment (ME), which results not only in MM bone disease but also contributes to MM progression and drug resistance. We postulated that such interaction could be revealed by performing GEP both on PC and the bone marrow biopsy (BMB) proper. In addition to having demonstrated that BMB-GEP can attain a normal (NL)-like status in comparison with NL donors with favorable prognostic implications, we are now reporting on paired comparisons of BMB-GEP and PC-GEP toward elucidating whether different molecular subgroups (MOLS) (namely, CD-1, CD-2, MAF, MAF-B, MS, HY, PR) and GEP-70-defined prognostic risk groups (RISK) engage the ME differentially. Toward this end, a recently defined BMB-GEP model of 65 genes, distinguishing NL, MGUS/AMM, MM and MM-CR, was applied to determine whether linkage existed to MOLS and RISK. Indeed, based on mean-based statistics, BMB-65 scores varied among MOLS and RISK (both p=0.013). A negative correlation (R=-0.204) existed between BMB-65 and PC-70 scores (p=0.0014). Further analysis within MOLS revealed significant negative correlations within MF (R=-0.57, p=0.0087) and MS subtypes (R=-0.33, p=0.037). None of the other MOLS showed any significant correlations. This is the first demonstration in patient MM samples that MOLS may engage the ME differentially. The more pronounced inverse correlations of MF and MS subtypes reveal a counter-relationship between RISK and BMB-65 score. This implies that with greater aggressiveness of PC, the BMB appears less NL-like, and is thus more modified to support the malignant PC processes. More detailed analyses will be presented in the context of other GEP and clinical parameters, specifically concerning the prognostic implications of BMB scores at baseline.

Correlation between GEP70 score and BMBX 65-gene score within each molecular subgroup Molecular Subgroup N Correlation of GEP70 risk and BMBX 65-gene score P value for testing no correlation CD-1 15 −0.39 0.1494 CD-2 39 −0.22 0.1747 HY 71 −0.15 0.1931 LB 33 0.12 0.4927 MF 20 −0.57 0.0087 MS 40 −0.33 0.0368 PR 25 −0.13 0.55 Overall 243 −0.204 0.001373

Disclosures:

No relevant conflicts of interest to declare.
Once Weekly Subcutanous Bortezomib with Cyclophosphamide and Dexamethasone Is Well Tolerated and Effective As Initial Treatment in Symptomatic Multiple Myeloma
Authors: Simpson David , Liang James , Henderson Ross , Hanna Merit , Merriman Eileen
Published: October 2019

Abstract 4049

Background

Bortezomib became funded for frontline therapy of symptomatic multiple myeloma (SMM) in New Zealand on 1 May 2011. From this date all new patients requiring treatment at our institution, both transplant eligible (TE) and ineligible (TIn), were initially treated with CyBorD consisting of weekly Cyclophosphamide 300mg/m2 PO, Bortezomib 1.6mg/m2 SC(2.5mg/ml) and Dexamethasone 40mg PO. One cycle was arbitrarily defined as 28 days, TE patients received 4–6 cycles CyBorD before ABMT (using 200mg/m2 melphalan), then 3 cycles of VTD (Bortezomib 1.6mg/m2 weekly, Thalidomide 100mg daily, Dexamethasone 40mg weekly) as post transplant consolidation. TIn patients received 4 cycles of CyBorD then 4 cycles of VTD. In June 2011 we changed all patients to subcutaneous bortezomib due to ease of administration and reduced toxicity.

Methods

The records of all untreated SMM patients initiating treatment with Bortezomib at our institution from 1 May 2011 were analyzed for response.

Results

We have treated 25 patients with SMM, 14 TE and 11 TIn. The median age was 68 yrs (range 45 to 88 yrs). The treatments were well tolerated. There was one Bortezomib dose reduction due to toxicity (burning feet on VTD). Injection site skin redness was common, but local reactions were not severe, one patient changed to IV Bortezomib because of this. There were no dose delays due to thrombocytopenia, and no patient had a pre-dose thrombocytopenia of <75 × 109/l. So far 6 patients have completed transplant, no patients have failed to proceed to transplant. There have been no deaths. Responses have improved with each cycle of treatment, after the first cycle the overall response (OR) was 54% (≥VGPR 25%), after 5 cycles the OR rate was 92% (≥VGPR 58%). confirmed CR rates are low, in part as patients are awaiting final bone marrow biopsy.

Response after each cycle

Conclusions

Weekly subcutaneous Bortezomib is well tolerated, and has high patient acceptance. Dose limiting neuropathy is rare, and responses are high when used in combination with CyBorD or VTD.

Disclosures:

No relevant conflicts of interest to declare.
CXCR4 Invalidation Limits the MLL-ENL Induced Leucemogenesis in Vivo
Authors: Zhang Yanyan , Abdelouahab Hadjer , Betems Aline , Wittner Monika , Vainchenker William , Louache Fawzia
Published: October 2019

Abstract 4089

The receptor CXCR4 and its ligand SDF-1 play major physiological roles especially on hematopoietic stem cells homing and retention. Many studies have implicated CXCR4 in the invasion by tumor cells of organs that produce SDF-1. In acute myeloid leukemia, the physiological role of CXCR4 is not fully understood. We used retrovirus to express MLL-ENL oncogene in CXCR4+/+ and CXCR4−/− hematopoietic primitive cells (Lin- isolated from fetal liver) and showed that CXCR4 is dispensable for generation of immortalized colonies in vitro. To determine CXCR4 function in vivo, CXCR4+/+ and CXCR4−/− transformed cells were transplanted into lethally irradiated mice. Whatever their phenotype, the recipient developed a myelo-monocytique leukemia characterized by their expression of Gr-1 and Mac-1. As expected, all recipients of MLL-ENL transduced CXCR4+/+ cells were moribund within 35 to 80 days post transplant (median survival time: 50 days). Strikingly, recipients of MLL-ENL transduced CXCR4−/− cells showed significantly increased lifespan, with a median survival time of 90 days. The cellularity of the peripheral blood of recipients of MLL-ENL transduced cells displayed considerable increases over time although this increase was much lower in CXCR4−/− than in CXCR4+/+ chimera. Bone marrow of MLL-ENL transduced CXCR4−/− chimera had moderately decreased numbers of mononuclear cells. There were important numbers of leukemic CD45.2+/Gr1+/Mac1+/c-kit+ cells in spleen from MLL-ENL CXCR4+/+ chimera which suggested that CXCR4 is important for leukemic progenitors cells retention in the bone marrow and especially in the spleen. The homing capacity of transduced CXCR4+/+ cells is comparable to the CXCR4−/− cells. Finally, more DNA damages were found in the BM cells of MLL-ENL CXCR4−/− chimera. All these results were confirmed by treating of MLL-ENL CXCR4+/+ chimera with CXCR4 inhibitor (TN140).

These results demonstrated that in absence of CXCR4, the cells transduced by oncogene MLL-ENL are capable of generating leukemia in the recipients. However, mice transplanted with MLL-ENL transduced CXCR4−/− FL cells developed acute myeloid leukemia with reduced aggressiveness and organ infiltration, which is associated with induced differentiation and DNA instability. These results indicated that the MLL-ENL progenitors are dependent on CXCR4 for their maintenance in the BM and spleen suggesting that CXCR4 inhibitors might have potential therapeutic applications.

Disclosures:

No relevant conflicts of interest to declare.
Low Dose Azacitidine Maintenance Therapy Following Allogeneic Stem Cell Transplantation for MDS/AML Does Not Interact with Tacrolimus Dosing or Serum Levels
Authors: Lee Hans C. , Howell Joshua , Milton Denái , Giralt Sergio A , Chen Julianne J , Rondon Gabriela , Champlin Richard E. , Parmar Simrit , De Lima Marcos
Published: October 2019

Abstract 4209

Background:

Recurrence of disease remains a significant cause of morbidity and mortality in patients who undergo allogeneic SCT for AML and MDS. Low-dose azacitidine is currently under investigation in the post-transplant setting with the goal of prolonging disease-free survival and decreasing relapse rates. It is unclear if there is potential pharmacologic interaction between azacitidine and dose-adjusted tacrolimus used to prevent post-transplant graft-versus-host disease (GVHD), a clinically relevant question since any resultant tacrolimus under- or over-dosing may lead to increased risk of GVHD or drug toxicity, respectively. We hypothesized that azacitidine does not significantly interact with tacrolimus levels and performed a retrospective analysis to test this hypothesis.

Patients and Methods:

We reviewed tacrolimus daily doses and serum drug levels of 62 AML and MDS patients who received azacitidine maintenance therapy (n=30) or no maintenance therapy (n=32) following allogeneic stem cell transplantation at MD Anderson Cancer Center between 2008–2012. Patient characteristics are summarized in the Table. Patients in the maintenance cohort received subcutaneous azacitidine at 32 mg/m2 on days 1–5 repeated every 28 days starting at a median time of post-transplant day +65 (range 43–100). Tacrolimus doses and serum levels were averaged for 28 days for each patient before and after initiation of azacitidine maintenance and at day +66 in the non-maintenance cohort. Differences between the two cohorts in their mean change of tacrolimus doses and serum drug levels were assessed using a Student's t-test.

Results:

Mean (SD) oral tacrolimus doses pre- and post-maintenance therapy were 2.61 (2.13) mg daily and 2.44 (2.15) mg daily in the azacitidine group and 2.54 (1.86) mg and 2.23 (1.39) mg daily in the non-azacitidine cohort. This resulted in a mean change in tacrolimus dosing of -0.17 (1.16) mg daily in the azacitidine patients and -0.31 (1.10) mg daily in the non-maintenance group (p=0.62). Mean (SD) serum tacrolimus levels pre- and post-maintenance therapy were 8.07 (1.16) ng/mL and 7.58 (2.32) ng/mL in the azacitidine group and 8.23 (1.49) ng/mL and 7.10 (1.69) ng/mL in patients on no maintenance therapy. This resulted in a mean change in serum tacrolimus levels of -0.49 (2.75) ng/mL in the azacitidine cohort and -1.13 (2.04) ng/mL in the non-maintenance group (p=0.30).

Conclusion:

Maintenance azacitidine therapy following allo-SCT for AML and MDS does not appear to affect concurrent tacrolimus dosing or serum drug levels.

Disclosures:

Off Label Use: azacitidine: off-label use as maintenance therapy following allogeneic stem cell transplant for MDS/AML. Champlin:Otsuka: Research Funding. De Lima:Celgene: Research Funding.
Early Development of Immunity to CMV Following Hematopoietic-Stem Cell Transplantation Is Associated with Graft-Versus Leukaemia Effect
Authors: Khourouj Valérie Guérin-El , Porcher Raphaël , Leveille Sandrine , Le Goff Jérôme , Pédron Béatrice , Baruchel Andre , Dalle Jean-Hugues , Sterkers Ghislaine
Published: October 2019

Abstract 4214

Relapse of disease remains the most common cause of failure in children undergoing hematopoietic-stem cell transplantation (HSCT) for acute leukaemia. A favourable impact, on graft-versus leukaemia effect (GVL), from recipient CMV-seropositivity before HSCT and from CMV-reactivations in the recipient after HSCT has been suggested. The potential role, in this process, for the immune response triggered by CMV has not been directly addressed so far.

108 children (median age 8 years) were included at HSCT following myeloablative conditioning for primary acute leukaemia (lymphoblastic 54%, myeloblastic 42%, biphenotypic 4%). HSCT were from HLA-matched related (41%) or unrelated (44%) donors. 15% patients received cord blood units. CMV- DNAemia was programmed weekly for at least 3 months post-HSCT. When PCR showed ≥1000 copies/ml, patients received ganciclovir as pre-emptive therapy. Immunity to CMV was evaluated sequentially since the first month post-HSCT using 3H-Thymidine incorporation assay (T-cell proliferation) and intracytoplasmic cytokine accumulation assay (IFNg secretion).

Median follow-up from transplant was 40 months. 57% of patients were CMV-seropositive before HSCT. Cumulative incidence of recipients with CMV-DNAemia at day 120 was 31% (median time to onset: 26 days). Cumulative incidence of recipients with immunity to CMV (T-cell proliferation and/or IFNγ secretion assays) at 1 year was 38% (median time to onset: 2 months). As expected, recipient CMV seropositivity represented a major factor contributing to DNAemia (p<0.0001) and to immunity (p<0.001) occurrence as well. The 2 years cumulative incidence of relapse was 26% Among the 89 recipients free of relapse at day +120 and evaluated for immunity before that time, the 2 years cumulative incidence of relapse was 15%. Multivariable analysis revealed a different risk of leukemic relapse according to immunity to CMV and CMV-reactivation (p=0.039), with the lowest risk in recipients with early (before day 120) immunity to CMV but no CMV-reactivation and the highest risk in recipients with early (before day 120) CMV-reactivation but no immunity to CMV (HR: 0.06, 95%CI 0.01–0.69, p=0.024).

In conclusion, early development of immunity to CMV rather than early viremia had a favourable impact on GVL in this pediatric series.

Disclosures:

No relevant conflicts of interest to declare.
Confirmation of A Strong Relationship Between Race and Probability of Transplant Among Patients Referred for Hematopoietic Cell Transplantation (HCT) for Hematological Maliganancies – A 17 Year Experience
Authors: Sharma Manish , Klumpp Thomas R , Ulicny John A , Fasan Omotayo O. , Kropf Patricia , Martin Mary Ellen , Mangan Kenneth F.
Published: October 2019

Abstract 4266

Background

Hematopoietic cell transplantation (HCT) is considered standard of care in patients with numerous types of hematological malignancies. A limited number of large, database derived, retrospective studies have observed the existence of racial disparities between Caucasian and African American patients who are candidates for a transplant for multiple myeloma and other hematological malignancies. We have recently demonstrated that there was no such disparity once a patient with a diagnosis of myeloma was referred to our transplant center. We expanded this analysis to include all patients referred for a transplant with a diagnosis of a hematological malignancy.

Methods

We utilized the existing data in our federally-mandated quality management database to retrospectively analyze the potential associations between race and the following parameters: Age, sex, cancer subtype, stage, best response prior to transplant, best response following transplant, treatment related mortality, overall survival, median interval between date of diagnosis and date of referral, median interval between date of initial visit and date of transplant, probability of actually receiving a transplant following formal evaluation by a transplant physician by race, type of transplant recommended and reasons for not receiving a transplant. We reviewed patients referred to consider a transplant within the time period of July 1st 1993 to December 31st2011.

Results

Total number of patients evaluated was 2009. The pertinent patient characteristics are described in Table 1 for this heterogeneous group of patients. Table 2 describes the univariate analysis of the impact of age, race and sex on obtaining a transplant. Both race and age were statistically significant variables for the probability of making it to transplant. The Kaplan-Meier curve for the probability of undergoing a transplant as per race is shown in Figure 1 and is statistically significant with a p-value of 0.0088. We also determined that patient diagnosis is significant in influencing the probability of making it to transplant, p-value of 0.0001. The era of when a patient was referred for transplant (from July/1993 to June/1998 versus July/1998 to December/2011) was also a significant factor for the probability of receiving a transplant, p-value of 0.0001.

Conclusions

We have demonstrated that race, age, disease type and era of patient referral were significant factors in patients receiving a transplant at our institution. Further study is needed to identify the reasons for these barriers in obtaining a transplant.

Disclosures:

No relevant conflicts of interest to declare.
The Effect of Hyperglycemia On the Outcome of Patients with Acute Myelogenous Leukemia
Authors: Schmidt Shannon Leah , Blust Linda , Knudson Paul , Richter Emily , Fenske Timothy S. , Palmer Jeanne , Zhang Mei-Jie , Eastwood Dan , Atallah Ehab
Published: October 2019

Abstract 4323

Introduction:

Hyperglycemia (HyG) has been shown to be detrimental in acute leukemia. In patients with acute myelogenous leukemia, hyG was associated with increased hospital mortality (Ali, et. al. Cancer 2007) while in patients with acute lymphocytic leukemia, hyG was associated with a shorter duration of complete response (CR) (Weiser et. al. Cancer 2004.) Our aim is to evaluate the effects of hyperglycemia on achievement of CR, disease free survival (DFS) and overall survival (OS) in patients with AML in our institution.

Patients and Methods:

We retrospectively reviewed all patients diagnosed with AML from 1/1/2005 to 1/1/2012 who underwent initial induction chemotherapy with 7+3 at our institution. Responses were defined according to the 2003 International Working Group criteria as CR within 6 weeks or no response. HyG was defined as 2 or more serum blood glucose levels ≥ 200 in the 30 days following induction chemotherapy. OS was determined using the Kaplan Meier method and compared using the log rank test.

Results:

Of the 91 patients identified, 43 (47%) were female. The median age at diagnosis was 53 years old. The cytogenetic categories were good (15 patients, 17%), intermediate (44 patients, 50%), and poor (29 patients, 33%). The median OS for all patients was 321 days. Median OS in the good, intermediate and poor cytogentics group was 423 days, 314 days and 314 days respectively. HyG, as previously defined, was seen in 39 (43%) of patients. CR was achieved in 40 (44%) of patients within 6 weeks of induction. Of the 40 patients achieving CR within 6 weeks, 19 (48%) were HyG and 21 (52%) were normoglycemic (p=0.67). Median OS was 375 days in the normoglycemic group and 210 days in the HyG group (p=0.74). Of the patients achieving CR in 6 weeks, median DFS was 290 days in the normoglycemic group and 243 days in the HyG group (p=0.54).

Conclusions:

Hyperglycemia in the post-induction period does not appear to have an impact on achievement of CR, DFS, or OS in the AML population.

Disclosures:

No relevant conflicts of interest to declare.
GMP-Grade Generation of B-Lymphocytes for Adoptive Immunotherapy in Patients After Allogeneic Stem Cell Transplantation
Authors: Winkler Julia , Mach Michael , Zingsem Juergen , Weisbach Volker , Mackensen Andreas , Winkler Thomas H.
Published: October 2019

Abstract 4352

Background and objectives:

We have recently shown that memory B-lymphocytes from murine CMV immune donor animals adoptively transferred into immunodeficient mice were highly effective in protecting from a viral infection indicating a therapeutic potential of virus specific memory B-cells. These preclinical data provided evidence that a cell-based strategy supporting the humoral immune response might be effective in a clinical setting of post-HSCT immunodeficiency (Klenovsek et al., 2007, Blood 110: 3472–9). As adoptive transfer of B-cells has not been used before in a clinical setting, it is necessary to establish a technology for the generation of GMP-grade B-cell products.

Methods:

Starting from the leukapheresis of healthy donors, B-cells were purified by two different separation strategies using GMP-grade microbeads and the CliniMACS∧TM device. A one-step protocol was used for positive enrichment of B-lymphocytes with anti-CD19 microbeads. In a two-step enrichment protocol, first T-lymphocytes were depleted by anti-CD3 microbeads and the remaining fraction was positively selected by anti-CD19 microbeads.

Results:

The leukapheresis contained a mean of 9.0×10∧8 CD19-positive B-cells (4.5–12.4 ×10∧8). After the one-step positive purification strategy a mean purity of CD20∧+ B-lymphocytes of 78.1% with a recovery of 32–41% was obtained. With the two-step T-cell depletion/B-cell enrichment protocol we achieved a mean purity of 96.4 % (93.4–97.8%) with a slightly lower recovery of 14–37%. The absolute B-cell numbers obtained in the product were 1.3 to 4.0 ×10∧8 and 1.7 to 2.6 ×10∧8 for the one-step positive enrichment and the two-step protocol, respectively. Importantly, the absolute number of T-cells was lower in cell products after the two-step protocol (0.1 to 0.9 ×10∧6 T-cells) as compared to the one-step positive CD19-enrichment (1.6 to 3.4 ×10∧6 T-cells). Assuming a patient with 70 kg body weight, the B-cell products obtained after the combined CD3-depletion and CD19-enrichment contained less then 4×10∧4 T-lymphocytes/kg bodyweight, which is a critical threshold number of T-cells in haploidentical HSCT. The B-cell products showed antibody production after in vitro stimulation in a limiting dilution assay and showed excellent viability after cryopreservation.

Conclusions:

A GMP-grade B-cell product can be obtained with high purity and very low T-cell contamination using the two-step enrichment protocol based on CliniMACS∧TM technology. (Supported by BayImmuNet)

Disclosures:

No relevant conflicts of interest to declare.