bluuebunny/crossref_metadata_2025 huggingface dataset:
Mir-135a Expression Is Associated with Relapse in Hodgkin Lymphoma.
Authors: Navarro Alfons , Gaya Anna , Pons Aina , Urbano-Ispizua Alvaro , Martinez Antonio , Gel Bernat , Balagué Olga , Granell Miquel , Artells Rosa , Abrisqueta Pau , Lopez-Guillermo Armando , Montserrat Emili , Monzo Mariano
Published: April 2020

MicroRNAs (miRNA) are small RNAs that act inhibiting the translation of mRNA to protein by complementary binding to his 3′UTR region. In a previous study we analyze the profile of miRNAs in classical Hodgkin lymphoma (HL) and found a 25 miRNAs signature that allows us to discriminate between HL and reactive lymph nodes. And some of them act inhibiting the translation of key genes in B lymphomagenesis. The aim of the study was to analyze if the expression of this miRNAs in the diagnostic samples predict clinical outcome in HL. Eighty nine adult patients (median age, 29 yrs; range, 13–89; males 47%) diagnosed with HL at a single institution between September 1995 and June 2005 have been studied. Seven patients (7.8%) were HIV+. Distribution according to histological subtypes was: nodular sclerosis (79%) and mixed cellularity (21%). Epstein-Barr Virus (EBV) was present in 28% of the samples. First-line treatment consisted of CMOPP/ABV or ABVD. Total RNA was extracted from formalin-fixed paraffin embedded lymph nodes using RecoverAll Total Nucleic Acid Isolation (Ambion). Mature miRNA expression was analyzed by stem loop RT-PCR and Real Time PCR (TaqMan MicroRNA Assay Protocol) in a 7500 Sequence Detection system(AB). Statistical analysis was performed with BRB Array Tools and SPSS 14.0. The characteristics considered were: age (<45 years vs. >45), ECOG, Hasenclever prognostic index (<1 vs 2–4 vs >5), HIV status, Ann Arbor (I–II vs. III–IV), WHO histological classification, bulky disease, EBV (LMP1+ vs LMP1−), ESR (EORTC criteria), and the expression of above-mentioned miRNAs. Clinical outcomes analyzed were relapse rate, disease-free survival (DFS) and overall survival (OS). Out of 89 patients, 75 (84.3%) achieved CR, 7 (7.8%) partial response, 7 (7.8%) were chemoresistant. After a median follow-up of 43 months (1–128), OS was 83% and DFS 74%. Of the 25 miRNAs, miR-135a appears underexpressed in HL samples versus reactive lymph nodes. Moreover, we found two groups of patients relative to miR-135a expression: patients with low expression (Ct<35.4) and patients without miR-135a expression(Ct=>35.4). In the Kaplan Meier analysis the patients without expression of miR-135a had a higher probability of relapse than the patients with miR-135a expression (Log Rank p=0.045). In the multivariate analysis the miRNA was the only prognostic factor for relapse (RR=6.533 p=0.021). In conclusion, miR-135a has as putative target HIF1A, a transcription factor related with hypoxia state that have been related in other tumors with tumoral growth and relapse when it’s overexpressed. Maybe through this target miR-135a play a role in relapse as prognostic value, but a higher number of patients and a functional analysis will be required to validate this new prognostic factor for HL.
AHOD0321: A COG Phase 2 Study of Weekly Gemcitabine and Vinorelbine for Children with Recurrent or Refractory Hodgkin Disease.
Authors: Cole Peter D. , Trippett Tanya M. , Drachtman Richard A. , de Alarcon Pedro , Chen Lu , Schwartz Cindy L.
Published: April 2020

Introduction: This COG Phase 2 study was conducted to assess the efficacy and toxicity of gemcitabine and vinorelbine (GV) in pediatric patients with heavily pre-treated relapsed/refractory Hodgkin disease. Both agents have significant single-agent response rates in this setting, and preclinical data suggest the combination will be at least additive.

Methods: GV was given on days 1 and 8 of each 21d treatment cycle: vinorelbine 25 mg/m2/dose IV push and gemcitabine 1000 mg/m2/dose IV over 100 minutes. Filgrastim 5 mg/kg/dose was started on Day 9 and continued for a minimum of 7 days, until the post-nadir absolute neutrophil count was greater than 1500/μL. Response was evaluated after every two cycles. Patients with measurable responses after two cycles were given the option of going off protocol therapy for stem cell transplantation (SCT). A minimum of two additional cycles was mandated for those with stable disease after two cycles. The statistical analysis of response used a two-stage minimax rule to test the null hypothesis that the response rate is ≤40% with 5% Type I error against an alternative hypothesis of a response rate >65%, with 80% power.

Results: Thirty-one eligible patients with a median age of 17.8 years (range 10.7 – 29) were enrolled. Fourteen were female (45%). All patients had received at least 2 prior chemotherapy regimens and 17 had prior autologous SCT. Toxicity and response data are currently available for 24 patients who completed at least two cycles and 16 who completed four cycles of GV. Among those who completed two cycles, hematologic toxicity was predominant, including grade 3–4 anemia (50%), leukopenia (71%), neutropenia (79%), and thrombocytopenia (83%). Nonhematologic grade 3–4 toxicity included elevated SGPT (38%) or SGOT (21%) and hyperbilirubinemia (4%). No patients developed non-cardiogenic pulmonary edema. There have been three documented infectious complications, including febrile neutropenia, sinusitis, and a urinary tract infection. One patient, with a history of prior mediastinal irradiation, developed pericardial and pleural effusions following cycles 4 and 5 of GV, consistent with gemcitabine-induced radiation recall. There were no toxic deaths. Response data are available for 24 patients of whom 18 (75%) have had measurable responses: 5 CRs, 10 VGPRs, and 3 PRs. All radiographic evaluations of treatment response are undergoing centralized review and full response data for all enrolled patients will be available for presentation.

Conclusion: GV is an effective and well-tolerated re-induction regimen for children with relapsed or refractory Hodgkin disease.
The Recurrent SET-NUP214 Fusion as a New HOXA Activation Mechanism in Pediatric T-Cell Acute Lymphoblastic Leukemia.
Authors: Van Vlierberghe Pieter , Tchinda Joelle , van Grotel Martine , Lee Charles , Beverloo H. Berna , van der Spek Peter , Stubbs Andrew , Cools Jan , Nagata Kyosuke , Fornerod Maarten , Buijs-Gladdines Jessica , Horstmann Martine , van Wering Elisabeth R. , Soulier Jean , Pieters Rob , Meijerink Jules P.P.
Published: April 2020

T-cell acute lymphoblastic leukemia (T-ALL) is mostly characterized by specific chromosomal abnormalities, some occurring in a mutually exclusive manner possibly delineating specific T-ALL subgroups. One subgroup, including MLL-rearranged, CALM-AF10 or inv(7)(p15q34) cases, is characterized by elevated expression of HOXA genes. Using a gene expression based clustering analysis of 67 T-ALL cases with recurrent molecular genetic abnormalities and 25 samples lacking apparent aberrations, we identified 5 new cases with elevated HOXA levels. Using array-CGH, a cryptic and recurrent deletion, del(9)(q34.11q34.13), was exclusively identified in 3 of these 5 cases. This deletion results in a conserved SET-NUP214 fusion product, that was also identified in the T-ALL cell line LOUCY. SET-NUP214 binds in the promoter regions of specific HOXA genes, where it interacts with CMR1 and DOT1L leading to the transcriptional activation of HOXA genes. Targeted inhibition of SET-NUP214 by siRNA abolished expression of HOXA genes, inhibited proliferation and induced differentiation in LOUCY but not in other T-ALL lines. We conclude that SET-NUP214 contributes to the pathogenesis of T-ALL by enforcing T-cell differentiation arrest.
Imatinib Mesylate Reduces Rituximab-Induced Tumor Growth Inhibition In Vivo on EBV-Associated Human B-Cell Lymphoma.
Authors: Némati Fariba , Mathiot Claire , Grandjean Isabelle , Lantz Olivier , Bordier Vincent , Dewulf Sébastien , Ekue Richard , Di Santo James P. , Poupon Marie-France , Decaudin Didier
Published: April 2020

We previously reported an increase of tumor growth inhibition following chemotherapy combined with concomitantly administration of imatinib mesylate [Decaudin D, et al. Int J Cancer2005;113:849–856; Decaudin D, et al. Anti-Cancer drugs2006;17:685–696; Decaudin D, et al. Impact of STI571 on the pharmacokinetics of etoposide and / or ifosfamide in mice. Cancer Res (AACR Annual Meeting) 2006;abstr:5154]. Inversely, combination of imatinib and rituximab was reported in very few cases of patients and remains controversial. In order to explore this particular combination of targeted therapies, we therefore investigated the in vivo impact of rituximab plus imatinib on a B-cell lymphoproliferation. Combination of the tyrosine kinase inhibitor imatinib mesylate (STI571) and the anti-CD20 monoclonal antibody rituximab was evaluated on an EBV-associated B-cell lymphoproliferative disorder xenografted into SCID or Rag2/gc −/− (B-, T-, and NK-) mice. Using SCID mice, we found that STI571 diminished the efficacy of rituximab to inhibit tumor growth in vivo (Figure 1A). Using alymphoid Rag2/gc −/− mice, we showed that the effect of STI571 was not dependent on the presence of NK cells (Figure 1B).

In contrast, serum complement administered after STI571 treatment reversed this inhibitory effect. Finally, using non immunodeficient mice, we observed an in vivo decrease of CD4-positive T-cells and mature B-cell lymphocytes after imatinib administration. We found that STI571 decreased the in vivo efficacy of rituximab via serum protein components that could influence complement-dependent cytotoxicity. In contrast, this effect was not dependent on the presence of NK cells.

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Tyrosine Kinase Inhibitors Only Partially Inhibit AKT-Dependent Signaling in Cells Expressing Oncogenic KIT, FLT3 or ABL Kinases. A Potential Model for Leukemia Cell Resistance to TKIs.
Authors: Schittenhelm Marcus M. , Kampa Kerstin M. , Shiraga Sharon , Kanz Lothar , Heinrich Michael C.
Published: April 2020

Activating mutations of the KIT, FLT3 and ABL tyrosine kinases (TKs) are found in association with hematologic malignancies including subsets of acute leukemias, systemic mastocytosis, and chronic myelogenous leukemia. TK inhibitors (TKIs) have proven clinical activity for treatment of these diseases, but responses are largely partial or incomplete. We and others have previously demonstrated that the small molecule TKIs imatinib (KIT, BCR/ABL), dasatinib (KIT, BCR/ABL), sunitinib (KIT, FLT3), and tandutinib (KIT, FLT3) are potent inhibitors of oncogenic kinases relevant to hematologic malignancies. We now report that inhibition of TK phosphorylation (a surrogate for kinase activation), potently silences STAT and MAPK1/2 signaling - but incompletely inhibits activation of the AKT pathway: Using mastocytosis, leukemia and hematopoietic cell lines with endogenous or exogenous mutant KIT (V560G, D816V), FLT3 (ITD, D835V) or BCR/ABL isoforms, oncogenic TK-dependent downstream pathways were evaluated by immunoblotting. In addition, we determined the effect of treatment with specific TKIs +/– rapamycin on cellular proliferation and the induction of apoptosis. (Auto)phosphorylation of KIT, FLT3 or BCR/ABL results in activation of downstream pathways important for cell viability and cell survival. This includes the MAP Kinase (MAPK), STAT and PI3K/AKT pathways. All tested TKIs were able to potently decrease phosphorylation of members of the MAPK1/2, STAT3 and AKT pathways in cells harboring a corresponding TKI-sensitive oncogenic kinase. Notably, TKI treatment abolished phosphorylation of AKT at the Ser-473 site, whereas the Thr-308 phospho-site remained constitutively phosphorylated. This partial inhibition of AKT activity was insufficient to completely inhibit downstream kinases, such as p70S6Kinase, a known substrate of mTOR (Target Of Rapamycin). The addition of low nanomolar doses of rapamycin completely abrogated p70S6K phosphorylation alone or in combination with TK-inhibition. To determine the biological effect of more completely inhibiting AKT-dependent signaling, we tested TKI in physiological concentrations in combination with low dosage rapamycin (5–20nM). While rapamycin had only weak anti-proliferative effects when administered as monotherapy, combining rapamycin with each TKI demonstrated a strong additive to synergistic inhibitory potency with an up to 4 fold increase of antiproliferative as well as enhanced pro-apoptotic effects when compared to TKI monotherapy. We conclude that TKI inhibition of mutant KIT, FLT3 or ABL signaling is insufficient to globally silence AKT-driven pathways that may contribute to therapy failure. The addition of inhibitors targeting the AKT pathway, such as rapamycin, may improve clinical efficacy of TKI.
Neither Serum Ferritin Nor Number of Red Blood Cell Transfusions Affect Overall Survival in Refractory Anemia with Ringed Sideroblasts.
Authors: Chee Cheng E. , Steensma David P. , Hanson Curtis A. , Tefferi Ayalew
Published: April 2020

Background: Most experts agree that iron chelation therapy is unlikely to benefit myelodysplastic syndrome (MDS) patients with a bone marrow (BM) blast percentage of ≥ 5% because of the associated short life expectancy. In contrast, using a serum ferritin of 1,000 ng/mL as a surrogate for iron overload, a recent study suggested a negative impact of iron overload on overall survival in MDS patients with < 5% BM blasts including those with refractory anemia with ringed sideroblasts (RARS) (Malcovati et al. JCO2005:23:7594). In the current retrospective study, we examined the validity of this observation in a large group of RARS patients seen at a single institution.

Methods: The diagnosis of RARS was based on the French-American-British cooperative group criteria. Serum ferritin levels obtained both at diagnosis and during follow-up as well as total number of packed red blood cells transfused were recorded. Standard statistical methods were used for survival and other analyses.

Results: A total of 126 RARS patients (median age 73 years, range 44-90; 67% males) were seen at our institution over the last several years. At diagnosis, median (range) values were 9.4 g/dL (5.7-13.4) for hemoglobin (Hgb), 2.8 × 109/L (0.3-13.7) for absolute neutrophil count (ANC) and 214× 109/L (22-819) for platelet count; 38% of the patients had received red blood cell (RBC) transfusions at the time of initial diagnosis. International Prognostic Scoring System (IPSS) risk distributions in evaluable patients were 66% for low, 28% for intermediate-1 and 6% for intermediate-2 risk. Median follow-up was 36 months and during this time 83 patients (66%) had died and leukemic transformation was documented antemortem in 8 patients (6%). As expected, IPSS was highly predictive of survival outcome (p<0.0001). In addition, history of RBC transfusions at diagnosis (p=0.001) but not the total number of RBC transfusions received during the entire disease course (p=0.17) carried an independent prognostic value for inferior survival. There were no significant correlations between overall survival and serum ferritin level at either diagnosis (median 567 ng/mL, range 16-3,475; p=0.24) or the maximum value during follow-up (median 1,108 ng/mL; range 238-43,500; p=0.72). Similarly, Kaplan-Meier plots of 77 evaluable patients stratified by serum ferritin levels of < or ≥1000 ng/mL at diagnosis or 107 evaluable patients stratified by maximal serum ferritin levels of < 1000, 1000-5000, or > 5000 ng/mL during follow-up revealed similar curves (Figure).

Conclusions: The current study suggests no significant association between transfusional hemosiderosis and survival even in good risk patients with MDS. The study also undermines the utility of serum ferritin as a surrogate for assessing the value of therapeutic iron chelation.

Figure Figure Figure Figure
Monoclonal Gammopathy of Undetermined Significance: Estimated Incidence and Duration Prior to Recognition.
Authors: Kyle Robert A. , Therneau Terry M. , Melton Lee J. , Dispenzieri Angela , Larson Dirk R. , Benson Joanne T. , Katzmann Jerry A. , Rajkumar S. Vincent
Published: April 2020

Background: Monoclonal gammopathy of undetermined significance (MGUS) is defined by a monoclonal protein concentration in serum of 3 g/dL or less and a proportion of plasma cells in the bone marrow of 10% or less, absence of lytic bone lesions, anemia, hypercalcemia, and renal insufficiency related to the proliferation of the monoclonal plasma cells. Two major questions remain unanswered:

What proportion of patients with MGUS in the population is unrecognized clinically? What is the likely duration of MGUS at the time of its discovery?

Methods: We examined the serum of 21,463 (77%) of the 28,038 enumerated residents of Olmsted County, Minnesota, in a population-based screening study and found that MGUS was present in 1.3% of persons 50 years of age and 3.8% of those 70 years of age. The risk of progression of MGUS to multiple myeloma (MM), primary amyloidosis (AL), Waldenstrom’s macroglobulinemia (WM), or related plasma cell disorders was 1% per year.

Results: By age 70, only 21% of Olmsted County residents with MGUS, as determined by the prevalence study, had been recognized by routine clinical practice (Fig. 1). This is probably higher in Olmsted County than elsewhere because serum protein electrophoresis is frequently ordered on Mayo Clinic patients. The incidence of MGUS, estimated from the prevalence data, indicates onset of the condition long before clinical recognition. The duration of MGUS prior to detection at age 70 is shown in Fig. 2. Thus, 30% of patients recognized to have MGUS at age 70 probably had MGUS onset before age 50 and 55% had a prior (unrecognized) MGUS already by age 60. The median duration of MGUS prior to its recognition on the basis of clinical practice is 11 years (median). Linear extrapolation of the incidence curve implies a first appearance of MGUS around 30 years of age.

Figure 1 Figure 1 Figure 2 Figure 2
MicroRNA Expression Analysis in Multiple Myeloma Plasma Cells and Cell Lines by a Quantitative Real-Time PCR Approach.
Authors: Bakkus Marleen , Dujardin Sylvie , Van Riet Ivan , De Waele Marc
Published: April 2020

MicroRNAs (miRNAs) are small RNA molecules that negatively regulate gene expression at the post transcriptional level. Over the past few years, these miRNAs have been shown to be widely involved in diverse biological processes, like apoptosis, cell metabolism and cancer. The aim of this study was to compare the miRNA expression in multiple myeloma plasma cells to that in their normal counterparts. A subset of ten miRNAs was chosen based upon evidence in the literature for their role in tumorigenesis with special emphasis on B cell malignancies. The expression of mature miRNAs was examined with quantitative real-time reverse transcription based polymerase chain reaction (TaqMan®MicroRNA assay) in 7 human multiple myeloma (MM) cell lines, in purified bone marrow derived plasma cells from 4 MM patients, one MGUS patient and 3 healthy adults. The plasma cells from patients and controls were positively selected using CD138-coated microbeads. Our results showed that miR-15a and miR-21 were equally expressed in cell lines, patients and healthy controls. Therefore, these 2 miRNAs were used for normalization. All data were compared with the data derived from normal plasma cells. Higher expression was seen for let-7a, miR-16 and 2 members of the miR-17 cluster (miR-17-5p and miR-19b) both in MM patients and cell lines. Expression of miR-16 was much higher in the MM plasma cells than in the MGUS plasma cells (only one sample). The miR-181a showed a heterogeneous expression in cell lines but was normally expressed in patients. The miR-372 expression was below the level of accurate quantification in all samples. There was a dramatic difference between the stroma dependent (MM5.1) and the stroma independent cell line (MM5.2) in miR-155 expression. The miR-143 was less abundant in all cell lines and in one MM sample that contained more than 90% plasma cells. Interestingly, the MM5.2 cell line, which is stroma independent, reflecting a more aggressive MM stage, showed also a much lower expression for miR-143 than the stroma dependent counterpart (MM5.1). In summary, the results of this study show that there is a difference in miRNA expression between MM plasma cells and their healthy counterparts and also between more and less aggressive MM plasma cells, suggesting that miRNAs could play a role in disease onset and progression.
Dexamethasone Induced Apoptotic Mechanisms in Myeloma Cells by Analysis of Mutant Glucocorticoid Receptors.
Authors: Sharma Sanjai , Lichtenstein Alan
Published: April 2020

Although glucocorticoids (GC) like dexamethasone (dex) are very effective in Multiple myeloma (MM), it is still unknown how they induce MM cell apoptosis. To investigate this issue, we studied the MM1S and MM1R cell lines. The MM1S cells are sensitive to dex-mediated apoptosis, while the MM1R cells are resistant due to lack of expression of the glucocorticoid receptor (GR). The latter resistant cells were exploited by the stable lentiviral-mediated expression of wild type (wt) or mutant GRs. Initial experiments demonstrated that infection of the MM1R cells with wt GR lentiviral vector resulted in stable expression of the wt GR and GC-induced reporter expression through the GR response element (GRE). These infected cells were now sensitive to GC-mediated apoptosis, although slightly less than MM1S cells. Nevertheless, this indicated that GR expressing MM1R cells could be used as a model to study the effectors of dex mediated apoptosis. MM1R cells were also similarly infected with lentiviral vectors expressing four different mutant GRs, that are either deficient in mediating GC-induced transactivation through the GRE or deficient in the ability to transrepress NF-KB activity. A GR mutant that transactivated through the GRE but was deficient in NF-KB transrepression did not induce apoptosis indicating that GRE transactivation was not sufficient for apoptosis. Further support for this notion was found when MM1S cells were treated with a concentration of cycloheximide which prevented GRE reporter expression but did not induce apoptosis by itself. This concentration did not affect GC-induced apoptosis supporting the finding that GC-induced transactivation is not required for apoptosis. In contrast, there was a correlation between the ability of mutant GRs to transrepress NF-KB and induce apoptosis. To test if GC-induced transactivation could participate in apoptosis in the setting of NF-KB transrepression, MM1R cells expressing a mutant GR which activates through GRE but does not transrepress NF-KB and is deficient in GC-induced apoptosis was infected with an adenoviral vector expressing the IKB super repressor to inhibit NF-KB. With abrogation of NF-KB, these cells underwent apoptosis at a higher level as compared to infection with a control adenoviral vector. Also, the addition of dex to these cells expressing IKB super repressor significantly enhanced apoptosis suggesting that transactivation through GRE can participate in apoptosis if the NF-KB survival factor is paralyzed.
IL-6-Induced C-MYC Down-Regulates the Expression of CD33 in CD33(+) Myeloma Cell Lines.
Authors: Shamsasenjan Karim , Otsuyama Ken-ichiro , Iqbal Mohd S. , Abroun Saeid , Amin Jakia , Islam Abul , Kawano Michio M.
Published: April 2020

Since human myeloma cells specifically lose the expression of PAX-5 gene, the master gene of B cell lineage, we frequently detect the ectopic expressions of non-B cell lineage markers such as CD56 and CD33. As for the expression of CD33, we confirmed that CD33 expression was found in primary myeloma cells from about 12% of 120 cases with overt myeloma and also in 2 myeloma cell lines (ILKM8 and Liu01 (a subclone of U266)) in the protein and mRNA levels. In primary myeloma cells as well as CD33(–) myeloma cell lines, DMSO treatment could induce the expression of CD33 in the in vitro culture. In these CD33(+) myeloma cell lines and DMSO-induced myeloma cells, we found that expressions of C/EBPα and PU.1 were markedly increased by gene expression profiling. On the other hand, IL-6 down-regulated the expression of CD33 in CD33(+) myeloma cell lines accompanying with down-regulation of C/EBPα and PU.1 expressions. Also, we found that IL-6 up-regulated the expression of C-MYC and the increased C-MYC bound to the promoter region of C/EBPα gene followed by the down-regulation of C/EBPα expression. It was confirmed that introduction of sh-RNA for C-MYC to two CD33(+) myeloma cell lines blocked the IL-6-induced down-regulation of CD33 and C/EBPα expression. Therefore, these results indicate that IL-6 can reverse the ectopic expression of non-B cell lineage markers by up-regulating C-MYC followed by its down-regulation of C/EBPα expression and also suggest that constitutive activation of STAT3 by IL-6 may keep PAX-5(–) myeloma cells being uncommitted cells to any lineage; myeloma cells could be one of stem cell-like cancer cells.
Phase 1/2 Study of AMG 531 in Thrombocytopenic Patients (pts) with Low-Risk Myelodysplastic Syndrome (MDS): Update Including Extended Treatment.
Authors: Kantarjian Hagop , Fenaux Pierre , Sekeres Mikkael A. , Becker Pamela , Boruchov Adam , Bowen David , Larson Richard , Lyons Roger , Muus Petra , Shammo Jamile , Ehrman Michael , Hu Kuolung , Nichol Janet
Published: April 2020

Background: AMG 531 is a novel thrombopoiesis-stimulating peptibody that is being studied for its ability to increase platelet production by stimulating the thrombopoietin receptor. This report updates outcomes in Part A of the study as of May 2007 on pts who continued into the extension phase of this ongoing phase 1/2, open-label, sequential-cohort, dose-escalation study to evaluate the safety and efficacy of AMG 531 in low risk MDS pts with severe thrombocytopenia (Kantarjian et al., ASCO, 2007).

Methods: Pts with low- risk MDS (IPSS Low or Intermediate-1, excluding CMML), a mean baseline platelet count ≤50×109/L, and only receiving supportive care were eligible to enter this study. Pts were enrolled into sequential cohorts of 300, 700, 1000, and 1500μg, receiving 3 weekly subcutaneous injections of AMG 531. After evaluation of platelet response at week 4, pts could continue AMG 531 in an optional treatment extension at their assigned dose or dose adjust to achieve or maintain a response.

Results: The mean duration of exposure to AMG 531 was 23±15.5 (SD) weeks. Of 44 pts enrolled, 40 continued into the extension phase; 16 pts remain on treatment. Eighteen pts (41%) achieved a durable platelet response (per IWG 2006 criteria for at least 8 consecutive weeks). Evaluation of durable responses based on baseline platelet count showed that responses occurred in 12/29 (41%) pts with a baseline count of ≥20×109/L, and in 6/15 (40%) pts with a baseline count of <20×109/L. The mean duration of the platelet response was 22.8±13.3 (SD) weeks. A total of 104 platelet transfusions were given to 17/44 (39%) pts during this study; of these transfusions, 7 were given in 3/18 (17%) pts who achieved a durable response. Treatment-related AEs were reported in 17 pts. There were 3 deaths unrelated to treatment. Two confirmed cases of transformation to AML were reported. These two pts received maximum doses of 300 and 1000μg. Six pts were confirmed to have temporary blast cell increases, three of whom had increases above 20%. Of the 6, 4 were receiving 1500μg and 2 were receiving 1000μg. In all 6 pts, blast cell counts were observed to have fallen upon follow-up assessments within 7 weeks after treatment discontinuation. In one case, treatment was reinitiated at 700μg.

Conclusions: In this study, AMG 531 appeared to be well-tolerated in severely thrombocytopenic low-risk MDS pts, and resulted in increased and sustained platelet counts in the responding pts. AMG 531 may have a role in the treatment of low-risk MDS pts who are thrombocytopenic or have a history of bleeding. These data suggest that further exploration is merited in this pt population. Pt recruitment is ongoing until reaching the planned 84 pts.
HuLuc63 in Combination Regimens with Conventional and Targeted Therapies Has Additive and Synergistic Anti-Tumor Activity in Pre-Clinical Models of Myeloma.
Authors: Rice Audie G. , Dillon Myles B.C. , Van Abbema Anne M. , Afar Daniel E.H.
Published: April 2020

Introduction: HuLuc63 is a humanized monoclonal antibody that targets CS1 (CD2 subset 1, CRACC, SLAMF7, CD319), a cell surface glycoprotein that is highly and universally expressed on myeloma cells. In preclinical studies, we have shown that HuLuc63 treatment of mice with multiple myeloma (MM) xenograft tumors resulted in significant in vivo anti-tumor activity that is mediated at least in part by an antibody-dependent cellular cytotoxicity (ADCC) mechanism of action. The purpose of this study was to examine whether using HuLuc63 in combination with a panel of drugs having distinct modes of action (dexamethasone, thalidomide, bevacizumab (Avastin®), bortezomib (Velcade®)) could result in additional therapeutic benefit and provide a rationale for the design of future clinical trials.

Methods: HuLuc63 in combination with other agents was tested in vivo for anti-tumor activity using the human L363 and OPM2 xenograft models. SCID mice were implanted subcutaneously with myeloma cells and randomized into different groups (10–15 mice per treatment group) when the average tumor volume reached ∼100 mm3. HuLuc63 was administered via intra-peritoneal injection twice per week at doses of 1–10 mg/kg. Dosing for dexamethasone was 10 mg/kg twice weekly, thalidomide 50 mg/kg daily, bevacizumab twice weekly at 0.5 mg/kg, and bortezomib 1 mg/kg for two dosing cycles, each cycle consisting of twice weekly dosing for 2 weeks followed by a week of rest.

Results: The combination of dexamethasone with HuLuc63 showed a statistically significant increase in anti-tumor activity over either agent alone (p < 0.04). Combination with thalidomide only showed a slight enhancement of tumor inhibition when dosed in combination with HuLuc63 but its anti-tumor activity did not reach a statistically significant increase in over that of HuLuc63 alone. Co-treatment of the anti-VEGF anti-angiogenic monoclonal antibody bevacizumab with HuLuc63 resulted in a significant increase in tumor inhibition (p < 0.05) over that observed with either antibody when used as a single agent. The strongest anti-myeloma activity was observed when HuLuc63 was combined with bortezomib, which appeared to result in a synergistic inhibition of tumor cell growth. None of the agents tested changed the CS1 expression level on the myeloma cells or diminished the anti-myeloma activity of HuLuc63.

Conclusions: These results suggest that HuLuc63 may be combined with different classes of drugs to enhance its anti-myeloma effects. In particular, agents that may induce apoptosis of myeloma cells (dexamethasone and bortezomib) and anti-angiogenics (bevacizumab) may be of particular interest for future clinical testing. Further preclinical studies using HuLuc63 in combination with other agents are in progress. HuLuc63 is currently being evaluated in a phase I clinical study as monotherapy for the treatment of relapsed/refractory multiple myeloma.
Allogeneic Stem Cell Transplantation for Therapy-Related Myelodysplastic Syndrome (t-MDS) and Acute Myeloid Leukemia. A Report from the MDS Subcommittee of the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT).
Authors: Kroeger Nicolaus , Brand Ronald , van Biezen Anja , Niederwieser Dietger , de Witte Theo
Published: April 2020

Background: With the prolonged survival and increasing cure rate for some malignancies there appears to be an increasing incidence of therapy related MDS or AML.

Methods: Between 1981 and 2006, 486 patients (pts) with t-MDS or t-AML underwent allogeneic stem cell transplantation (SCT) and were reported to the EBMT registry. The median age of the pts was 40 years (r., 3–69) and primary disease were solid tumor (n=167), malignant lymphoma (n=141), myeloproliferative syndrome (n=12), acute leukaemia (n=32), aplastic anemia (n=16) and autoimmune disease (n=1). The median time from primary diagnosis to t-MDS/t-AML was 54 months (r., 1–416). Diagnosis were: RA/RARS (n=28), RAEB (n=49), RAEB-T (n=44) and t-AML (n=308). At time of transplantation, 268 pts were in complete and 186 pts not in complete remission (CR). Cytogenetic abnormalities were found in 262 pts.

Results: For the entire study population the cumulative incidence of non-relapse mortality (NRM) and relapse at 3 years was 37% and 34%. In a multivariate analysis significant factors for higher incidence of relapse were “non CR” at SCT (HR:2.20; 95% CI: 1.44–3.36, p<0.001) and abnormal cytogenetic (HR: 1.78; 95% CI: 1.03–3.07; p=0.04), while higher NRM was noted for higher pts age: 40–50 years (HR: 2.25; 95%CI: 1.46–3.46, p<0.001) and older than 50 years (HR: 2.67; 95% CI: 1.68–4.25, p<0.001). Furthermore, there was a marked reduction in NRM per calendar year during the study period (HR: 0.93; 95% CI: 0.90–0.96, p<0.001). The 3 year event-free (EFS) and overall survival (OS) was 31% and 34%. In a multivariate analysis EFS was negatively influenced by higher age: 40–50 years (HR: 1.91; 95% CI: 1.39–2.61, p<0.001) and age > 50 years (HR: 1.95; 95% CI: 1.36–2.78, p<0.001), abnormal cytogenetic (HR: 1.41; 95% CI: 1.01–1.99; p=0.05), “non CR” at SCT (HR: 1.78; 95% CI 1.34–2.36; p<0.001) and disease status RAEB-T (HR:2.23; 95% CI: 1.20–4.13; p=0.01) and t-AML (HR: 2.00; 95% CI; 1.13–3.52, p=0.02). A significant higher EFS and OS was seen per calendar year (HR: 0.96:; 95% CI: 0.94–0.98, p=0.004) and (HR: 0.95:; 95% CI: 0.93–0.98, p=0.001). OS was further influenced by higher age: 40–50 years (HR: 1.93; 95%CI: 1.61–2.68, p<0.001) and age > 50 years (HR: 2.13; 95% CI: 1.47–3.08, p<0.001), “non CR” at SCT (HR: 1.57; 95% CI 1.18–2.09; p<0.001) and disease status RAEB-T (HR:2.44; 95% CI: 1.27–4.66; p=0.007) and t-AML (HR: 2.26; 95% CI; 1.19–3.92, p=0.02).

Conclusion: Allogeneic SCT can cure pts with therapy related MDS or AML. During study period a better EFS and OS could be seen per calendar year due to a marked reduction in non-relapse mortality. Advanced disease-status, abnormal cytogenetics and higher age of the pts are the most significant factors for survival.
Inhibition of Hsp90 Targets Multiple Myeloma Cell Growth, Angiogenesis, and Osteoclastogenesis in the BM Microenvironment.
Authors: Okawa Yutaka , Hideshima Teru , Ikeda Hiroshi , Vallet Sonia , Kiziltepe Tanyel , Raje Noopur , Yasui Hiroshi , Enatsu Sotaro , Pozzi Samantha , Breitkreutz Iris , Podar Klaus , Richardson Paul G. , Anderson Kenneth C.
Published: April 2020

Heat-shock protein 90 (hsp90) is a important molecular chaperone required for protein folding, assembly, and maintenance of conformational integrity of several client proteins regulating cell survival, proliferation, and apoptosis. In this study, we investigate whether targeting hsp90 induces cytotoxicity of multiple myeloma (MM) cells in the bone marrow (BM) microenvironment using the small molecule hsp90 inhibitor SNX-2112. SNX-2112 induces growth inhibition in both MM cell lines and patient MM cells resistant to conventional therapeutic agents, with IC50 of 0.019-7.339 uM. Interestingly, SNX-2112 is more potent against all MM cell lines than 17-allylamino-17-demethoxy-geldanamycin (17-AAG) and orally bioavailable. These data suggest its potential utility to overcome conventional drug resistance in MM. MM cell apoptosis triggered by SNX-2112 is mediated via caspase-8,-9,-3 and PARP cleavage. In addition, SNX-2112 significantly inhibits Akt and extracellular signal-related kinase (ERK) signaling pathways induced by interleukin-6 (IL-6) and insulin-like growth factor 1 (IGF-1), which mediate cell proliferation and survival in MM cells, both known client proteins of hsp90. Moreover, SNX-2112 overcomes the survival and growth advantages conferred by IL-6, IGF-1 and bone marrow stromal cells (BMSC). Importantly, SNX-2112 inhibits in vitro capillary-like tube formation by human umbilical vein endothelial cells (HUVEC) via abrogation of endothelial nitric oxide (eNOS)/Akt pathway which is essential cascade in angiogenesis. It also markedly inhibits osteoclast formation associated with downregulation of ERK/c-fos, p38MAPK, and PU.1 pathways, which mediate osteoclastogenesis. Furthermore SNX-5422, a prodrug of SNX-2112, significantly inhibits MM tumor growth and prolongs survival in vivo in a xenograft murine model. We also confirm that SNX-5422 triggers MM cell apoptosis in vivo by TUNEL assay, associated with an inhibitory effect on microvessel density (MVD), evidenced by immunohistochemical analysis for CD34 expression. Therefore, targeting hsp90 by novel small molecule inhibitor SNX-2112 not only inhibits MM cell growth, but also acts in the BM microenvironment to block angiogenesis and osteoclast formation associated with downregulation of Akt and ERK signaling. Taken together, our data provide the preclinical rationale for clinical evaluation of SNX-2112 to improve patient outcome in MM.
In Vitro Characterization of Wnt/β-Catenin Pathway Inhibition in Multiple Myeloma Cell Lines Using a Novel Class of Small Molecules.
Authors: Strovel Jeffrey W. , Lawrence Tammy , Natarajan Pachai , Glanowski Stephen , Lonskaya Irina , Weaver Zoe , Padia Janka , Watthey Jeffrey W. , Cholody Wieslaw M. , Hamilton J. Michael , Bol David K. , Horrigan Stephen K.
Published: April 2020

Multiple Myeloma (MM) is a fatal form of hematologic cancer characterized by the clonal expansion of plasma cells in the bone marrow. Recent finding by several research laboratories have shown that Wnt/β-Catenin signaling pathway is activated in MM leading to the translocation of β-Catenin to the nucleus where it binds to T cell factor (TCF) and drives transcription of genes involved in the progression of cancer (Derksen et. Al., PNAS 2004). The mechanism by which Wnt/β-Catenin signaling is activated in MM is not well understood, however, β-Catenin is expressed in the majority of MM cell lines and inhibition of the pathway with a dominant negative form of TCF4 or the small molecule PKF115-584 have shown anti-proliferative effects in in vitro and in vivo cell line and xenograft models making inhibition of Wnt/β-Catenin signaling a promising modality for the treatment of MM (Sukhdeo et al., PNAS 2007). To this end, Avalon Pharmaceuticals has developed a series of small molecule compounds, lead candidate series-363 (LC-363), with potent inhibitory effects on Wnt/β-Catenin signaling and anti-proliferative effects in colon cancer cell lines and in vivo models (EORTC, 2007). LC-363 compounds down regulate expression of the noted β-Catenin/TCF transcriptional targets c-jun, fra-1, and PPARδ as well as increase expression of the Dickkopf family of secreted proteins 1 and 3 which inhibit Wnt signaling. In this study, we report on the in vitro characteristics of LC-363 in MM cell line models. We show that LC-363 compounds have broad and potent growth inhibitory and cytotoxic effects on MM cell lines. Additionally, these effects are mediated through a G1 phase cell cycle block, apoptosis, and decrease in cytoplasmic levels of β-Catenin. Importantly, we show the relationship between expression level of β-Catenin protein and sensitivity to LC-363 compounds in terms of growth inhibition and apoptosis. Lastly, we describe the gene expression signatures induced by LC-363 in MM cell models across multiple time and dose studies to detail their dynamic effects on expression of genes within the Wnt/β-Catenin signaling pathway. In conclusion, we believe that inhibition of Wnt/β-Catenin signaling is a viable therapeutic alternative for treatment of MM patients with activated Wnt/β-Catenin signaling and to that end; LC-363 compounds are promising candidates currently in pre-clinical development for treatment of cancers with activated Wnt/β-Catenin signaling including MM.
Prospective Identification of Resistance Mutants to the JAK2 Inhibitor TG101348.
Authors: Hood John D. , Alomia Marcela , Cao Jon , Chow Chun , Ehab Hanna , Dan Lohse , Ching Mak Chi , Andy McPherson , Glenn Noronha , Betty Tam , Hong Zhu , Soll Richard
Published: April 2020

Introduction: Clinical resistance to kinase inhibitors is an emerging theme in targeted, oncology therapies. For example, Gleevec resistance results due to a host of mutations in bcr-abl, the kinase associated with chronic myelogenous leukemia (CML), and have necessitated the development of 2nd generation inhibitors dasatinib and notilinib. More recently, mutations in JAK2 kinase have recently been identified as the key molecular drivers for the majority of patients with the chronic MPDs polycythemia vera, essential thrombocythemia and myelofibrosis with myeloid metaplasia. TG101348 is a selective inhibitor of JAK2 kinase and represents a novel therapy for these MPDs.

Methods: In order to better understand what mutations may occur in clinic as a result of TG101348 treatment, we used N-ethyl-N-nitrosourea (ENU)-exposed human erythroleukemia (HEL) cells to evaluate resistance mutations to TG101348. In brief, ENU pretreated HEL cells were exposed to 3 uM TG101348, a dose that is 10X the cellular IC50, for 28 days followed by genotyping to determine the incidence and location of kinase domain mutants that arose in resistant cells.

Results: Eleven different mutations were identified, with the most prevalent mutations in associated with the ATP binding pocket. In cells bearing these mutations TG101348 did not inhibit STAT5 phosphorylation, cellular proliferation or induced apoptosis at concentrations up to 3 uM, whereas in wildtype HEL cells it did. Consistent with the mutations arising specific for TG101348, JAK2 inhibitors which are derived from chemically distinct series were equally potent on wildtype or TG101348 resistant HEL cells.

Conclusions: A series of JAK2 point mutations were identified which generate resistance to the JAK2 inhibitor TG101348 in JAK2V617F-bearing cells. None of these mutations corresponded to any mutations that have been previously reported for MPD patients and therefore the clinical relevance of these mutations is not yet known. While these ENU induced mutations do not yet have clinical correlates, monitoring for their presence in any patients who do not respond to TG101348 in clinical trials may shed light on mechanisms of resistance as they occur.
Active Immunotherapy with Mitumprotimut-T (FavId®, Id-KLH) Following Rituximab Induction in Patients (pts) with Follicular B-Cell Lymphoma (FL): Progression Free Survival (PFS) at 4-Year Follow Up.
Authors: Koc Omer , Redfern Charles , Wiernik Peter , Rosenfelt Fred , Winter Jane , Guthrie Troy , Kaplan Lawrence , Holman Peter , Densmore John , Hainsworth John , Lin Thomas S. , Castillo Rene , Janakiraman Nalini , Bender John
Published: April 2020

Background: We report here PFS with a 4-year follow-up of previously reported results from a Ph 2 trial in which both treatment-naïve (TN) and relapsed/refractory (R/R) pts with FL with stable disease (SD) or a clinical response (PR or CR/CRu) following 4 weekly doses of rituximab received mitumprotimut-T active immunotherapy (Koc et al, Blood, 2006; 108: #691).

Treatment: Pts received rituximab (375 mg/m2 i.v. weekly × 4) and those with stable or responding disease assessed at Week 11 received mitumprotimut-T (1 mg sq monthly × 6) starting on Week 12 along with Leukine® (sargramostim, GM-CSF, 250 mcg, sq) on days 1-4. Pts continued to receive booster injections on a reduced schedule (every 2 months (mos) × 6, then quarterly) until disease progression. Radiological scans were performed every 3 mos for the first 2 years on study, then every 6 mos thereafter and reviewed centrally. Objective response and disease progression were assessed using modified IWG criteria.

Results: 89 pts had ≥SD following rituximab and received mitumprotimut-T + Leukine, 54 R/R and 35 TN. There were 2 CRs and 40 PRs following rituximab for a pre mitumprotimut-T objective response rate (ORR) of 47%. The overall response for the combined treatment was 63% (18 CR, 38 PR). During the mitumprotimut-T treatment phase, 16 pts (9 TN, 7 RR) converted to CR/CRu. The following table presents PFS for all pts and patient subsets.

Conclusion: These data show that 43% of all rituximab responders and 51% of TN rituximab responders remain in remission with 42 mos follow up. These results appear favorable when compared to published results of single-agent rituximab studies in pts with TN FL, where the reported 3-yr PFS are ∼20%, and suggest a clinical benefit to adding mitumprotimut-T to rituximab therapy. This hypothesis is being tested in an ongoing Ph 3 study of rituximab single agent vs. rituximab followed by mitumprotimut-T + GM-CSF. A total of 349 pts have been randomized and 78% are TN. An interim blinded analysis of response in the first 226 randomized pts showed an ORR of 70% with 47% of pts in CR/CRu (Freedman et al, Blood2006; 108:#2756).

Subjects Progression-Free at: Group n 12 mos 24 mos 36 mos 42 mos All Efficacy-Evaluable Subjects 89 61% 38% 31% 29% Relapsed/Refractory Subjects 54 57% 31% 22% 19% Treatment-Naive Subjects 35 67% 48% 44% 44% All rituximab Responders 43 70% 50% 43% 43% Relapsed/Refractory Responders 19 63% 41% 33% 33% Treatment-Naive Responders 24 75% 57% 51% 51%
B Cell Lymphomas Escape Bone Morphogenetic Protein (BMP) Induced Growth Inhibition: Downregulation of BMP Receptors and Upregulation of Inhibitory Smads.
Authors: Huse Kanutte , Bakkebo Maren , Oksvold Morten , Smeland Erlend B. , Myklebust June H.
Published: April 2020

Bone morphogenetic proteins (BMPs) belong to the TGF-β superfamily and mediate their effects mainly through the Smad signaling pathway. TGF-β is one of the most potent negative regulators in hematopoietic cells, and many cancers develop reduced sensitivity towards TGF-β induced growth inhibition by several mechanisms, including functional loss of TGF-β receptors and Smad proteins. We have previously shown that BMP-6 inhibits the growth of normal peripheral blood B cells. As high BMP-6 mRNA expression is associated with poor outcome in diffuse large B cell lymphoma (DLBCL; Rosenwald et al, N Engl J Med 2002), we hypothesized that reduced sensitivity towards BMP-induced growth inhibition might contribute to lymphomagenesis. In the current study, 10 B lymphoma cell lines (representing Burkitt, DLBCL and FL) and tumor material from lymphoma patients were investigated to unravel the role of BMPs in lymphomas. We found that 5 – 7 out of 10 lymphoma cell lines were resistant towards BMP-2, -4, -6 and -7 induced growth inhibition. In comparison, only 3 of the cell lines were resistant towards TGF-β. Analysis of BMP receptor expression by FACS analysis showed that all lymphoma cell lines and the malignant B cells from primary lymphoma biopsies expressed the BMPR type I Alk-2, whereas the expression of Alk-3 and Alk-6 was variable. Interestingly, the expression of BMPRII was low or undetectable in BMP-6 resistant cell lines, whereas it was highly expressed in 3 out of 4 sensitive cell lines. Also, malignant B cells from lymphoma biopsies showed reduced levels of BMPRII, suggesting that downregulation of BMPRII is a mechanism for evading BMP induced growth inhibition. Interestingly, upregulation of Smad6 or Smad7 was seen in 3 of the BMP-6 resistant cell lines and might represent another way of escaping the inhibitory effects of BMP. The lymphoma cell lines were investigated for endogenous production of BMPs by real-time RT-PCR, and 2 out of 10 cell lines had detectable BMP-6 mRNA, whereas 7 cell lines expressed BMP-7 mRNA. Analysis of purified malignant B cells or normal tumor infiltrating T cells from patient biopsies, confirmed the expression of BMP-6 and BMP-7 in the malignant B cells. Altogether, the data suggest that escape from BMP induced growth inhibition might contribute to increased tumor growth in B cell lymphomas.