scholarly journals RPS15 and TP53 Co-Mutation Drives B Cell Malignancy through Altered Translation and MYC Activation in a Murine Model

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 28-29
Author(s):  
Catherine Gutierrez ◽  
Tamara Ouspenskaia ◽  
Doris Fu ◽  
Peyton Waddicor ◽  
Anat Biran ◽  
...  
Keyword(s):  
B Cell ◽  
Rna Sequencing ◽  
Research Funding ◽  
Target Genes ◽  
Mrna Translation ◽  
Gene Set Enrichment Analysis ◽  
Mutant Mice ◽  
Enrichment Score ◽  
Publicly Traded ◽  
The Impact

Amongst the novel putative drivers identified by large-scale sequencing studies of chronic lymphocytic leukemia (CLL) is the ribosomal protein RPS15. Mutated in 5.3% of CLL, it co-occurs with heterozygous TP53 alterations in 36% of RPS15-mutated samples. Mutation of this mediator of ribosome maturation and translation is associated with poor disease prognosis and enriched in cohorts with del(17p) and relapsed CLL, suggesting a role in disease progression and therapeutic resistance. However, the impact of RPS15 mutation on B cell function and CLL development, in the presence or absence of TP53 mutation, has yet to be characterized. To this end, we developed overexpression HG3 CLL cell lines modeling four common RPS15 mutations (G134R, H137Y, S138F, and S139F) and a conditional knock-in mouse model of the S138F mutation with and without heterozygous Trp53 deletion (generated by crossing Rps15 and Trp53 mutant mice with Cd19-Cre mice). To characterize the impact of RPS15 mutation on transcription, we performed RNA-sequencing on splenic B cells from 3-month-old Rps15WT, Rps15Het and Rps15Hom mice (3 per cohort). We identified 255 and 670 upregulated and 596 and 777 downregulated genes in the Rps15MT vs Rps15WT mice (Rps15Het and Rps15Hom, respectively; log2FC>0.5, p<0.05). Gene set enrichment analysis (GSEA) revealed strong enrichment for MYC target genes that was also evident upon RNA-sequencing of the HG3 RPS15-S138F MT vs WT overexpression lines, and of 3 primary untreated CLLs with heterozygous RPS15 mutation (compared to 3 RPS15WT CLLs of similar genetic background). Pathway analysis of differentially expressed signatures across murine, cell line and primary CLL models revealed a common enrichment in translational machinery, such as mRNA splicing/processing, rRNA processing, and snRNP assembly (normalized enrichment score>1, nominal p-value<0.05). To evaluate whether RPS15 mutant proteins incorporate into ribosomes, we performed polysome profiling of the HG3 lines. All overexpressed RPS15-WT and MT proteins were observed to integrate into the small ribosomal subunit and mature ribosomes, potentially impacting translation. Next, ribosome profiling of HG3 RPS15-WT and S138F cells revealed 2,334 genes with differential translation efficiency (TE) between RPS15-S138F vs WT cells and 2,425 genes between RPS15-S138F vs WT in TP53 knock-out cells (log2FC>0.5, p<0.05). GSEA of differentially translated genes in RPS15 MT- vs WT cells revealed a strong enrichment for TP53-related genes, consistent with the activation of stress pathways by RPS15 mutant expression. RPS15 MT- vs WT cells with TP53-deletion, however, exhibited a strong increase in TE of MYC target genes and components of the ribosomal machinery. This finding suggests that loss of TP53 surveillance allows RPS15 MT cells to induce MYC-mediated changes in mRNA processing and translation - potentially setting the stage for oncogenesis. To determine whether Rps15 mutation can drive CLL-like disease, we engineered 6 novel mouse lines with B cell restricted expression of alterations through crossing with CD19-Cre mice: Rps15WT, Rps15Het, and Rps15Hom mutant mice alone or co-expressing Trp53 deletion. We detected circulating CLL-like (B220+CD5+) cells in 5 of 30 (17%) Rps15Het mice by 20 months of age, but not in 30 age-matched Rps15WT mice. We also detected CLL-like cells in 6 of 30 (20%) Trp53+/- mice by 17 months, indicating that Trp53 deletion alone can induce CLL-like disease. Interestingly, we found CLL-like cells in 2 of 30 Rps15Het/Trp53+/- mice as early as 15 months of age. The cohorts of Rps15Hom and Rps15Hom/Trp53+/- mice, however, have been monitored for 18 months of age with no disease occurrences, indicating that a double dosage of Rps15 mutation may be detrimental to disease formation. Altogether, Rps15 heterozygous mutation can drive CLL development in mice, and our early data hint that co-mutation with Trp53 may shorten the latency of CLL-like disease. Overall, RPS15 mutant protein can incorporate into the ribosome and induce changes in mRNA translation, resulting in MYC activation predominantly in the context of TP53 loss. Our mouse studies indicate that mut-Rps15 drives CLL development, with a more aggressive disease course when combined with Trp53 deletion. Our results collectively suggest that RPS15 and TP53 co-mutation drives CLL development through translational dysregulation and MYC-mediated signaling. Disclosures Neuberg: Pharmacyclics: Research Funding; Celgene: Research Funding; Madrigak Pharmaceuticals: Current equity holder in publicly-traded company. Getz:Broad Institute: Patents & Royalties: MuTect, ABSOLUTE, MutSig, MSMuTect, MSMutSig, POLYSOLVER and TensorQTL; Pharmacyclics: Research Funding; IBM: Research Funding; Scorpion Therapeutics: Consultancy, Current equity holder in publicly-traded company, Other: Founder. Wu:BionTech: Current equity holder in publicly-traded company; Pharmacyclics: Research Funding.

scholarly journals NOTCH1 Stabilization By PEST Mutations Enhances IgM-Mediated Activity in Chronic Lymphocytic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1832-1832
Author(s):  
Francesca Arruga ◽  
Valeria Bracciamà ◽  
Alison Yeomans ◽  
Annalisa D'Avola ◽  
Marta Coscia ◽  
...  
Keyword(s):  
Cell Growth ◽  
Chronic Lymphocytic Leukemia ◽  
Board Of Directors ◽  
Research Funding ◽  
Target Genes ◽  
Mrna Translation ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
Protein Levels ◽  
The Impact

Abstract BACKGROUND. Mutations in NOTCH1 PEST domain (NOTCH1-M) are present in ~10% of Chronic Lymphocytic Leukemia (CLL) patients, result in accumulation of more stable NOTCH1 protein, and associate with poorer prognosis. NOTCH1-M are enriched in unmutated (U) immunoglobulin gene heavy-chain variable region (IGHV) CLL, which show high surface IgM (sIgM) expression and signaling capacity. mRNA translation is a prominent response to B cell receptor (BCR) engagement, increased in U-CLL, and for which therapeutic inhibitors are under active development. In CLL, c-MYC is an essential mediator of BCR-driven translation and direct target of NOTCH1, suggesting the impact of NOTCH1 on anti-IgM-mediated cell growth via MYC. AIMS AND METHODS. Our aim was to investigate the functional role of NOTCH1-M on anti-IgM-mediated signaling, compared to wild-type (WT) NOTCH1. The impact on global mRNA translation was studied using a flow cytometry-based O-propargyl-puromycin (OPP) incorporation assay and polysome fractionation assays. The effects of stabilized vs WT NOTCH1 were measured after 24-hour cultures of CLL cells, when data demonstrate differences in the expression of the two forms. Two cohorts of U-CLLs were compared: i) a subset of samples carrying NOTCH1-M [variant allele frequency (VAF) ≥30%, n=21] and ii) a cohort of samples with WT NOTCH1 (VAF<1%, n=23). In both subsets no additional cytogenetic lesions other than 13q deletion were present. RESULTS. sIgM levels and signaling capacity (measured by anti-IgM mediated iCa2+ mobilization) were higher in NOTCH1-M than in -WT samples, consistent with previous observations (1). Conceivably, anti-IgM-mediated phosphorylation of PLCg2 and ERK1/2 was stronger in M than in WT CLLs. In keeping with these results, expression of downstream targets as MYC and CCL3 was also induced at higher levels in M samples. Interestingly, inhibition of NOTCH1 with g-secretase inhibitor (DAPT) significantly decreased BCR target genes induction in M cells, reducing the differences with WT samples, and further enhanced the effects of ibrutinib when used in combination. In order to investigate the impact of NOTCH1 on IgM-mediated CLL cell growth, anti-IgM-induced global mRNA translation was compared in the two cohorts. Consistent with the higher MYC mRNA and protein levels, anti-IgM led to higher global mRNA translation in NOTCH1-M than in -WT cells. DAPT inhibited it in both CLL subsets, while ibrutinib led to complete inhibition of mRNA translation only in the -WT subset, suggesting a major contribution of NOTCH1 to the process. Consistently, the combination of DAPT+ibrutinib abrogated the difference between M and WT CLL cells. Importantly, MYC (but not translation initiation factors eIF4G, eIF4A or eIF3b) was already induced at 6 hours following anti-IgM stimulation and was maintained at high levels at 24 hours, while up-regulation of eIF4G, eIF4A and eIF3b was evident only at 24 hours, supporting the hypothesis of a direct MYC-dependent regulation of the translation machinery (2). NOTCH1 itself was post-transcriptionally regulated upon BCR ligation, as we observed increased NOTCH1 mRNA in polysome-enriched actively translated fractions and increased protein levels on the surface of anti-IgM stimulated cells, specifically inhibited by ibrutinib. Consequently, NOTCH1 pathway was significantly more activated upon anti-IgM stimulation in M than WT cells, as determined by qPCR of NOTCH1 target genes. Both Ibrutinib and DAPT significantly prevented NOTCH1 activation upon BCR triggering, with the drug combination being the most effective treatment. Moreover, in line with data showing NOTCH1-dependent regulation of a B cell gene signature, expression of BTK, LYN and BLNK was significantly increased in anti-IgM activated NOTCH1-M samples, an effect prevented by DAPT. CONCLUSIONS. These data indicate that NOTCH1 stabilization associates with stronger IgM signaling capacity and suggest an interplay between BCR and NOTCH1 pathway, with the former promoting NOTCH1 expression and activation. The evidence that NOTCH1 pathway inhibition reverts this difference suggests a direct effect of NOTCH1 on IgM signaling. In this scenario, stabilizing NOTCH1 mutations may enhance BCR signaling by boosting translation through MYC induction and by directly regulating expression of BCR cascade elements. NOTES. SD and FF share senior authorshipD'Avola, Blood 2016Ruggero, Cancer Res 2009 Disclosures Coscia: Abbvie, Gilead, Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen, Karyopharm: Research Funding. Gaidano:Janssen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Morphosys: Honoraria; Amgen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Allan:Genentech: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Sunesis: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy; Verastem: Membership on an entity's Board of Directors or advisory committees. Furman:Gilead: Consultancy; AbbVie: Consultancy; Verastem: Consultancy; Janssen: Consultancy; Genentech: Consultancy; Incyte: Consultancy, Other: DSMB; Loxo Oncology: Consultancy; TG Therapeutics: Consultancy; Sunesis: Consultancy; Acerta: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy. Packham:Aquinox: Research Funding. Deaglio:iTeos therapeutics: Research Funding; VelosBio inc: Research Funding; Verastem: Research Funding. Forconi:Abbvie: Consultancy; Janssen-Cilag: Consultancy.

scholarly journals Association between Sociodemographic, Clinical and Immunophenotypic Variables with Disease Relapse and Survival at 12 Months, in Patients with B-Cell Acute Lymphoblastic Leukemia Treated at a Colombian University Hospital

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4380-4380
Author(s):  
Luis Antonio Salazar ◽  
Sandra Vanesa Rios ◽  
Angela María Peña ◽  
Maria Luna-Gonzalez ◽  
Mario Andrés Arenas ◽  
...  
Keyword(s):  
Overall Survival ◽  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
Survival Function ◽  
Advisory Board ◽  
Overweight And Obesity ◽  
University Hospital ◽  
The Impact

Abstract INTRODUCTION Acute lymphoblastic leukemia (ALL) is a clonal hematopoietic disorder that originates from B or T lymphoid progenitors. It affects more frequently children, but prognosis is worse in adults. ALL has a high incidence in Hispanics (Swords R et al. Blood Cancer J. 2016) and is important to identify baseline clinical, sociodemographic, and cytogenetic characteristics in these patients that are relevant for relapse free and overall survival. Reports of Hispanic patients with ALL outsides of the U.S.A are scare but are important to further characterize the impact of this disease in minority populations. OBJETIVE To describe the association between sociodemographic, clinical and immunophenotypic variables with 12-month relapse free survival (RFS) and overall survival (OS) in patients diagnosed and treated for ALL in a Colombian university hospital (FOSCAL). MATERIALS AND METHODS This is a descriptive observational cohort study that included patients older than 18 years with a confirmed diagnosis of ALL treated in a tertiary university hospital between 2013-2020 and that had at least 12 months follow-up after starting treatment. Baseline sociodemographic, clinical, laboratory and immunophenotypic data were collected. Bivariate analyses of both relapse and mortality cumulative incidences at 12 months, with relative risks (RR) and their 95% Confidence intervals were performed, using either chi-square or Fischer exact test when needed. In a second term, bivariate survival analyses through Kaplan-Meier survival function and Hazard ratios were evaluated, using Cox proportional hazards as the main statistical test. RESULTS Among 128 of include patients, the median age at diagnosis was 34 years (range 0-89 years), 54% were men, 6.2% had type 2 Diabetes Mellitus (T2DM), most had an ECOG PS of 0 (72.7%), 31.8% had splenomegaly, 12% had hepatomegaly and 47% presented without organomegalies. The proportion of patients with overweight and obesity were 26.3% and 22.2% respectively. At diagnosis 80.5% and 8.8% of patients had high risk and standard risk ALL, respectively Forty-eight patients had a FAB classification with 58% being ALL-2 and most of the were unclassified. Most cases (81%) had B-cell immunophenotype, with 55% being pre-B-cell and 32% mature B-cell. Twelve percent of patients were Ph+ B-ALL. At 12 months, the proportion of mortality was 34.4%. Most of the patients (83%) did not have major co-morbidities, however patients with T2DM had a significantly inferior survival at 12 months, HR: 3.68 (95%CI 1.54-8.8 P=0.003), as patients older than 35 years (HR: 2.15, 95%CI: 1.14-4.0, P=0.017) (Table 1). CONCLUSIONS Colombian patients with B-cell ALL have similar clinical, immunophenotypic and cytogenetic (Ph+ prevalence) characteristics as seen in other international cohorts. In our cohort patients older than 35 years and subjects with T2DM had inferior survival at 1 year. Further analyses of socioeconomic factors, molecular features and response to specific regimens are needed to have a better understanding of Colombian B-ALL patients. Figure 1 Figure 1. Disclosures Salazar: Amgen: Research Funding. Peña: Amgen: Research Funding. Sandoval-Sus: BMS: Other: Advisory Board, Speakers Bureau; SeaGen, Janssen, MassiveBio, TG: Other: Advisory Board. Sossa: Amgen: Research Funding.

scholarly journals A Transgenic Murine Model Expressing Hyperactive STAT3 Recapitulates the Features of MDS/AML

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3308-3308
Author(s):  
Bianca L Rivera ◽  
Shanisha Gordon ◽  
Srinivas Aluri ◽  
Yang Shi ◽  
Samarpana Chakraborty ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transgenic Mice ◽  
Rna Sequencing ◽  
Murine Model ◽  
Research Funding ◽  
Publicly Traded ◽  
Gfp Expression ◽  
Hematopoietic Stem ◽  
Myeloid Malignancies ◽  
Stop Cassette

Abstract Myelodysplastic syndromes (MDS) are clonal, myeloid malignancies that emerge and progress due to the expansion of disease-initiating aberrant hematopoietic stem cells that can evolve into Acute Myeloid Leukemia (AML). FDA approved therapies such as the recently approved Bcl-2 inhibitor venetoclax, FLT3 inhibitors, among others, have moved the field forward in newly diagnosed MDS/AML. However, relapsed/refractory (R/R) disease, as well as leukemic transformation post-MDS continues to have a poor prognosis. A pool of hematopoietic stem and progenitor cells (HSPCs) escape chemotherapy, proliferate during disease remission, and causes relapse partly in effect due to signaling effector mutations. It is imperative, for future therapeutic agents, to target these HSPCs populations to achieve a durable remission for aggressive myeloid malignancies. There is an urgent need to develop mouse models that recapitulate human disease for the study of pathogenesis and drug development in these disorders. Signal transducer and activator of transcription 3 (STAT3) belongs to the STAT family of transcription factors that are inappropriately activated in several malignancies. Our preliminary data indicates that STAT3 is overexpressed in MDS and AML stem cells and is associated with an adverse prognosis in a large cohort of patients. (Shastri et al, JCI 2018). We have successfully demonstrated that a selective antisense oligonucleotide inhibitor of STAT3, Danvatirsen, is rapidly incorporated into MDS/AML HSPCs and induces selective apoptosis and downregulation of STAT3 in these cells in comparison with healthy control HSPCs. To determine the role of STAT3 in the initiation of myeloid malignancies, a murine model was generated by crossing R26STAT3C stopfl/fl mice with vavCre transgenic mice. In this model, a hyperactive version of STAT3, STAT3C, is knocked into the Rosa26 locus with an upstream floxed stop cassette (R26STAT3C stopfl). Excision of the stop cassette by Cre recombinase leads to expression of a flag-tagged STAT3C protein and concomitant expression of EGFP in hematopoietic cells. GFP expression allows tracking of cells in which the floxed stop/Neo cassette is deleted and STAT3C is expressed. STAT3C-vavCre double transgenic mice were validated by GFP expression in HSPCs and differentiated hematopoietic cells. The STAT3C-vavCre mice developed ruffled fur, a hunched phenotype and weight-loss by five months of age. CBC analysis of STAT3C-vavCre mice shows a proliferative phenotype reminiscent of high-risk MDS/AML with higher WBC & platelet counts and lower hemoglobin (Figure 1A). Review of the peripheral smear showed an increase in granulocytic precursors that are likely leukemic blasts (Fig 1E). In addition, STAT3C-vavCre mice developed massive splenomegaly (Figure 1B). HSC lineage analysis by FACS showed the presence of GFP positive cells (Figure 1C) with increased expansion of the MPP and HSC compartment compared to controls, suggesting a stem and progenitor phenotype (Figure 1D). Murine myeloid colony assays showed larger colonies in the STAT3C-vavCre mice compared to controls. At this time, single cell RNA sequencing, and bulk RNA sequencing are being performed and will be used to further characterize the phenotype of the STAT3C-vavCre transgenic mice in addition to bone marrow and splenic aspirates & biopsies. Through the generation of a STAT3C-vavCre mouse model, that recapitulates the features of MDS/AML, we aim to further our understanding of the molecular mechanisms and pathways that play an important role in MDS to AML transformation and will help us identify downstream mediators of this event that can be therapeutically targeted. We would also like to use this murine model as an ideal substrate for preclinical studies of STAT3 targeting therapies in hematologic malignancies such as previously reported antisense inhibitors of STAT3 and STAT3 degraders. Figure 1 Figure 1. Disclosures Frank: Roche Genentech: Research Funding; Kymera: Consultancy, Research Funding; Revitope: Consultancy; Vigeo: Consultancy. Verma: Throws Exception: Current equity holder in publicly-traded company; BMS: Research Funding; GSK: Research Funding; Acceleron: Consultancy; Incyte: Research Funding; Stelexis: Current equity holder in publicly-traded company; Medpacto: Research Funding; Curis: Research Funding; Eli Lilly: Research Funding; Celgene: Consultancy; Stelexis: Consultancy, Current equity holder in publicly-traded company; Novartis: Consultancy. Shastri: Kymera Therapeutics: Research Funding; GLC: Consultancy; Guidepoint: Consultancy; Onclive: Honoraria.

scholarly journals Ibrutinib-Resistant Mantle Cell Lymphoma Undergoes Metabolic Reprogramming Towards Oxphos

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 41-41
Author(s):  
Krystle Nomie ◽  
Liang Zhang ◽  
Yixin Yao ◽  
Yang Liu ◽  
Shaojun Zhang ◽  
...  
Keyword(s):  
B Cell ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Enrichment Analysis ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Gene Set Enrichment Analysis ◽  
Rna Seq ◽  
Advisory Committees ◽  
Oncogenic Pathways

Abstract Introduction Mantle cell lymphoma (MCL) is an incurable B-cell lymphoma subtype and constitutive activation of the B-cell receptor pathway is a hallmark of B-cell lymphomas. Bruton's tyrosine kinase (BTK) is a critical component of the B-cell receptor pathway, and ibrutinib, a first-in-class, once-daily, and oral covalent inhibitor of BTK, was developed to reduce/silence B-cell receptor pathway activity, leading to clinically remarkable anti-tumor activity. In our prior multiple-center Phase II clinical trial, the overall response rate in relapsed/refractory MCL patients was 68% (Wang et al., NEJM, 2013), surpassing the effectiveness of other therapies. Although ibrutinib is extremely efficacious in patients with relapsed/refractory MCL, the one-year overall survival rate of ibrutinib-exposed patients who relapse is only 22%. Methods Patient primary cells were isolated from MCL patients treated with ibrutinib either prior to treatment or at treatment discontinuation. Whole exome sequencing (WES) was performed to determine the mutational landscape of ibrutinib resistance. RNA-seq was employed to compare the gene expression profiles between ibrutinib-sensitive and -resistant patient samples. Gene set enrichment analysis was utilized to identify dysregulated molecular pathways associated with the resistant phenotype. The RNA-seq data were then validated with reverse phase protein array (RPPA) analysis of ibrutinib-sensitive and -resistant MCL cell lines. Metabolic assays including the measurement of mitochondria respiration rates with the Seahorse analyzer and reactive oxygen species (ROS) levels, targeted metabolomics, and ATP analysis. Functional studies targeting this molecular pathway were conducted, including in vitro cell viability and apoptosis assays, as well as in vivo efficacy studies in an ibrutinib-resistant MCL patient-derived xenograft mouse model. Results WES data analysis identified frequent inactivating somatic alterations in ATM, KMT2D, and TP53 in both the ibrutinib-sensitive and -resistant tumors. CDKN2A (5/7, 71%) was frequently deleted, and the deletion was only observed in the ibrutinib-resistant tumors (p = 0.010). The RNA-seq analysis identified a total of 63 protein-coding genes as the most differentially expressed genes (DEGs) between the ibrutinib-resistant and -sensitive groups, with a fold change of ≥ 2 or ≤ -2 and the false discovery rate (FDR q-value) ≤ 0.01. Among the DEGs, 26 genes were upregulated in ibrutinib-resistant tumors. In addition, gene set enrichment analysis (GSEA) revealed the marked upregulation of oncogenic pathways including c-MYC, mTOR (mTORC1), Wnt, and NF-ĸb signaling, followed by cell cycle, apoptosis, BCR signaling and DNA repair in the ibrutinib-resistant tumors. Notably, in addition to these oncogenic pathways, the metabolic pathways, including oxidative phosphorylation (OXPHOS), were significantly enriched in the ibrutinib-resistant tumors (normalized enrichment score > 3 and FDR q-value < 1e-5). In further support of this finding, metabolomics analysis and the measurement of ATP production and mitochondrial respiration indicated that the OXPHOS pathway is the predominant metabolic pathway employed by ibrutinib-resistant MCL cells. To determine the effects of targeting these pathways, OXPHOS was inhibited with a novel electron transport complex I inhibitor (IACS-010759, developed by MD Anderson Cancer Center) in both MCL cell lines and ibrutinib-resistant MCL patient-derived xenograft (PDX) models. Single agent IACS-010759 treatment at 10 mg/kg oral gavage for 5 consecutive days/week completely prevented tumor growth compared with the vehicle control as shown by measuring tumor volume (n = 5, p < 0.0001) and human β2M levels (n = 5; p < 0.0001) throughout treatment. No apparent toxicities were observed in the IACS-010759-treated MCL PDX mice. Conclusion This current study warrants the exploitation of active cancer metabolic pathways, especially OXPHOS, to improve the clinical outcomes of MCL and additional lymphoma, which is actively being investigated in a Phase I lymphoma clinical trial (NCT03291938). Disclosures Wang: AstraZeneca: Consultancy, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno: Research Funding; Novartis: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; MoreHealth: Consultancy; Acerta Pharma: Honoraria, Research Funding; Kite Pharma: Research Funding; Pharmacyclics: Honoraria, Research Funding; Dava Oncology: Honoraria.

scholarly journals Single-Cell Multi-Omics Defines the Cell-Type Specific Impact of SF3B1 Splicing Factor Mutations on Hematopoietic Differentiation in Human Clonal Hematopoiesis and Myelodysplastic Syndromes

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 145-145
Author(s):  
Federico Gaiti ◽  
Allegra Hawkins ◽  
Paulina Chamely ◽  
Ariel Swett ◽  
Xiaoguang Dai ◽  
...  
Keyword(s):  
Single Cell ◽  
Research Funding ◽  
Mrna Translation ◽  
Splicing Factor ◽  
Cell Type ◽  
Advisory Committees ◽  
Oxford Nanopore ◽  
Cell Type Specific ◽  
The Impact ◽  
Oxford Nanopore Technologies

Abstract Splicing factor mutations are recurrent genetic alterations in blood disorders, highlighting the importance of alternative splicing regulation in hematopoiesis. Specifically, mutations in splicing factor 3B subunit 1 (SF3B1) are implicated in the pathogenesis of myelodysplastic syndromes (MDS) and linked to a high-risk of leukemic transformation in clonal hematopoiesis (CH). SF3B1 mutations are associated with aberrant RNA splicing, leading to increased cryptic 3' splice site (ss) usage and MDS with ring sideroblasts phenotype. The study of mutant SF3B1-driven splicing aberrations in humans has been hampered by the inability to distinguish mutant and wildtype single cells in patient samples and the inadequate coverage of short-read sequencing over splice junctions. To overcome these limitations, we developed GoT-Splice by integrating Genotyping of Transcriptomes (GoT; Nam et al. 2019) with Nanopore long-read single-cell transcriptome profiling and CITE-seq (Fig. A). This allowed for the simultaneous single-cell profiling of protein and gene expression, somatic mutation status, and alternative splicing. Our method selectively enriched full-length sequencing reads with the accurate structure, enabling the capture of higher number of junctions per cell and greater coverage uniformity vs. short-read sequencing (10x Genomics; Fig. B, C). We applied GoT-Splice to CD34+ bone marrow progenitor cells from MDS (n = 15,436 cells across 3 patients; VAF: [0.38-0.4]) to study how SF3B1 mutations corrupt human hematopoiesis (Fig. D). High-resolution mapping of SF3B1 mutvs. SF3B1 wt hematopoietic progenitors revealed an increasing fitness advantage of SF3B1 mut cells towards the megakaryocytic-erythroid lineage, resulting in an expansion of SF3B1 muterythroid progenitor (EP) cells (Fig. E, F). Accordingly, SF3B1 mutEP cells displayed higher protein expression of erythroid lineage markers, CD71 and CD36, vs. SF3B1 wt cells (Fig. G). In these SF3B1 mutEP cells, we identified up-regulation of genes involved in regulation of cell cycle and checkpoint controls (e.g., CCNE1, TP53), and mRNA translation (eIFs gene family; Fig. H). Next, while SF3B1 mut cells showed the expected increase of cryptic 3' splicing vs. SF3B1 wt cells (Fig. I), they exhibited distinct cryptic 3' ss usage as a function of hematopoietic progenitor cell identity, displaying stage-specific aberrant splicing during erythroid maturation (Fig. J). In less differentiated EP cells, we observed mis-splicing of genes involved in iron homeostasis, such as the hypoxia-inducible factor HIF1A, and key regulators of erythroid cell growth, such as SEPT2. At later stages, we observed mis-splicing of BAX, a pro-apoptotic member of the Bcl-2 gene family and transcriptional target of p53, and erythroid-specific genes (e.g., PPOX). We further predicted 54% of the aberrantly spliced mRNAs to introduce premature stop codons, promoting RNA degradation through nonsense-mediated decay (NMD). In line with this notion, we observed a significant decrease in expression of NMD-inducing genes in SF3B1 mut vs . SF3B1 wtEP cells (Fig. K). Lastly, splicing factor mutations observed in CH subjects provide an opportunity to interrogate the downstream impact of SF3B1 mutations prior to development of disease. Like MDS, by applying GoT-splice to CD34+ progenitor cells from SF3B1 mut CH subjects (n = 9,007 cells across 2 subjects; VAF: [0.15-0.22]; Fig. L), we revealed increased mutant cell frequency in EP cells (Fig. M) with concomitant increased expression of genes involved in mRNA translation (Fig. N), consistent with SF3B1 mutation causing mis-splicing injury to translational machinery and ineffective erythropoiesis. Notably, CH patients already exhibited cell-type specific cryptic 3' ss usage in SF3B1 mut cells (Fig. O). In summary, we developed a novel multi-omics single-cell toolkit to examine the impact of splicing factor mutations on cellular fitness directly in human samples. With this approach, we showed that, while SF3B1 mutations arise in uncommitted HSCs, their effect on fitness increases with differentiation into committed EPs, in line with the mutant SF3B1-driven dyserythropoiesis phenotype. We revealed that SF3B1 mutations exert cell-type specific mis-splicing that leads to abnormal erythropoiesis. Finally, we demonstrated that the impact of SF3B1 mutations on EP cells begins before disease onset, as observed in CH subjects. Figure 1 Figure 1. Disclosures Dai: Oxford Nanopore Technologies: Current Employment. Beaulaurier: Oxford Nanopore Technologies: Current Employment. Drong: Oxford Nanopore Technologies: Current Employment. Hickey: Oxford Nanopore Technologies: Current Employment. Juul: Oxford Nanopore Technologies: Current Employment. Wiseman: Astex: Research Funding; Novartis: Consultancy; Bristol Myers Squibb: Consultancy; Takeda: Consultancy; StemLine: Consultancy. Harrington: Oxford Nanopore Technologies: Current Employment. Ghobrial: AbbVie, Adaptive, Aptitude Health, BMS, Cellectar, Curio Science, Genetch, Janssen, Janssen Central American and Caribbean, Karyopharm, Medscape, Oncopeptides, Sanofi, Takeda, The Binding Site, GNS, GSK: Consultancy. Abdel-Wahab: H3B Biomedicine: Consultancy, Research Funding; Foundation Medicine Inc: Consultancy; Merck: Consultancy; Prelude Therapeutics: Consultancy; LOXO Oncology: Consultancy, Research Funding; Lilly: Consultancy; AIChemy: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Envisagenics Inc.: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Improvement in the Clinical Global Impression of Change with Voxelotor in Patients with Sickle Cell Disease in the Phase 3 HOPE Trial

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 5-6
Author(s):  
Wally R Smith ◽  
Jane S. Hankins ◽  
Miguel R Abboud ◽  
Ze Cong ◽  
Jonathan Sorof ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Board Of Directors ◽  
Clinical Global Impression ◽  
Research Funding ◽  
Cell Disease ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Global Impression Of Change ◽  
Study Participants ◽  
The Impact

Background: Patients with sickle cell disease (SCD) experience varied salient symptoms that impact their health-related quality of life, which incorporates illness severity, their level of distress and other aspects of impairment, and the impact of the illness on functional status. SCD symptoms may begin at an early age, and their severity varies over time and between patients. Although detection of changes in patients' self-assessed symptoms may be obfuscated by their lifelong symptoms, treating physicians with SCD expertise may be able to detect changes in a patient's status given their experience in treating the diverse symptoms across multiple patients. We evaluated the longitudinal impact of voxelotor (Oxbryta®) in the HOPE study using the single-item Clinical Global Impression of Change (CGI-C), a validated clinician-reported outcome analogous to the commonly used Patient Global Impression of Change (PGI-C), which provides expert clinical impressions that transcend symptom checklists. Methods: In the randomized, placebo-controlled, double-blinded HOPE study, participants with SCD aged 12 to 65 years were randomized to receive voxelotor (1500 mg or 900 mg dose administered orally, once daily) or placebo. Study participants had a hemoglobin (Hb) level 5.5 to 10.5 g/dL at enrollment and 1 to 10 vaso-occlusive crises in the past 12 months at screening. Clinicians were blinded to treatment assignment and to all central laboratory measures (eg, hematological parameters) throughout the 72-week study period. Clinicians rated the CGI-C at 24 and 72 weeks from baseline. CGI-C ratings used a 7-point scale ("very much improved," "moderately improved," "minimally improved," "no change," "minimally worse," "moderately worse," and "very much worse"). CGI-C outcomes were stratified by baseline Hb levels and baseline markers of hemolysis to identify measures predictive of assessment outcomes. Results: Trends of improvement from baseline in overall clinical status with voxelotor 1500 mg, as assessed by CGI-C scores, were observed as early as week 24. At week 72, patients receiving voxelotor 1500 mg were more often rated by the clinician as "very much improved" or "moderately improved" (74%; 39 of 53) compared with those who received placebo (47%; 24 of 51) (P&lt;0.01, Figure 1). CGI-C score improvement was consistently greater in participants treated with voxelotor compared with placebo regardless of baseline Hb. Greater proportions of participants were rated "very much improved" or "moderately improved" with voxelotor 1500 mg than placebo regardless of baseline hemolysis markers (indirect bilirubin, percentage reticulocytes, absolute reticulocyte count). Conclusions: Treatment with voxelotor 1500 mg resulted in improved clinician-reported patient outcomes, as assessed using the CGI-C. Greater proportions of participants were rated "very much improved" or "moderately improved" regardless of baseline Hb levels and baseline markers of hemolysis. The CGI provides an overall clinician-determined summary measure that takes all available information into account, including the patient's history, psychosocial circumstances, symptoms, and behavior, as well as the impact of symptoms on the patient's ability to function. Therefore, a tool that provides a holistic assessment of a patient's well-being may be complementary in capturing changes in a patient's status, considering the substantial interpatient and intrapatient variability in SCD symptomatology. CGI-C assessments are being included in ongoing studies of voxelotor. Disclosures Smith: Emmaeus Pharmaceuticals, Inc.: Consultancy; Novartis, Inc.: Consultancy, Other: Investigator, Research Funding; Global Blood Therapeutics, Inc.: Consultancy, Research Funding; Shire, Inc.: Other: Investigator, Research Funding; NHLBI: Research Funding; Patient-Centered Outcomes Research Institute: Other: Investigator, Research Funding; Health Resources and Services Administration: Other: Investigator, Research Funding; Incyte: Other: Investigator; Pfizer: Consultancy; Ironwood: Consultancy; Novo Nordisk: Consultancy; Imara: Research Funding; Shire: Research Funding; GlycoMimetics, Inc.: Consultancy. Hankins:American Society of Pediatric Hematology/Oncology: Honoraria; UptoDate: Consultancy; Novartis: Research Funding; MJH Life Sciences: Consultancy, Patents & Royalties; LINKS Incorporate Foundation: Research Funding; National Heart, Lung, and Blood Institute: Honoraria, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding. Abboud:Novartis: Consultancy, Honoraria, Research Funding; Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Crispr Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Other: Travel support; Eli Lilly: Research Funding; Modus Pharmaceuticals: Research Funding. Cong:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Sorof:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Gray:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Hoppe:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Telfer:Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Terumo: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Honoraria, Research Funding; ApoPharma: Membership on an entity's Board of Directors or advisory committees.

scholarly journals An Insight into the Impact of Hemophilia a on Daily Life According to Disease Severity: A Preliminary Analysis of the CHESS II Study

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 1-3
Author(s):  
Declan Noone ◽  
Francis Nissen ◽  
Tao Xu ◽  
Tom Burke ◽  
Sohaib Asghar ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Disease Severity ◽  
Research Funding ◽  
Hemophilia A ◽  
Daily Life ◽  
Social Activity ◽  
Publicly Traded ◽  
Advisory Committees ◽  
On Demand ◽  
The Impact

Introduction: Hemophilia A (HA) is a congenital bleeding disorder caused by a deficiency in clotting factor VIII (FVIII). There are currently limited data on the impact of HA on daily life. Here we examine the impact of HA on the daily life of adult persons with HA (PwHA) without current FVIII inhibitors according to disease severity. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey II (CHESS II) is a retrospective, burden-of-illness study in adults with mild, moderate, and severe HA or hemophilia B (defined by endogenous FVIII/IX [IU/dL] relative to normal; mild, 5-&lt;40%; moderate, 1-5%; severe, &lt;1%); this analysis includes only PwHA. Male participants (aged ≥18 years) diagnosed with HA (without FVIII inhibitors) at least 12 months prior to clinical consultation were enrolled from Denmark, France, Germany, Italy, the Netherlands, Romania, Spain, and the UK. Data on clinical outcomes and healthcare resource utilization were captured via electronic case report forms disseminated to hemophilia specialists. PwHA completed a paper-based questionnaire utilizing 5-point Likert scales to assess the disease burden on their daily life. Overall, 12 months' retrospective data were examined. Informed consent was obtained and the study was approved by the University of Chester ethical committee. Results: Of 258 PwHA completing questionnaires, 15.9% (n=41), 27.9% (n=72), and 56.2% (n=145) had mild, moderate, and severe HA, respectively. Of those with severe HA, 60.0% were currently receiving FVIII prophylaxis (standard of care for severe HA); in comparison, 4.9% and 6.9% of those with mild and moderate HA were receiving prophylaxis (Table 1). Treatment adaptation in anticipation of physical or social activity was reported by 19.5%, 23.6%, and 38.6% of those with mild, moderate, and severe HA, respectively. Over a third of participants with mild (36.6%) and moderate (44.4%) HA, and 64.8% of those with severe HA (58.6% with severe HA receiving on-demand treatment and 69.0% receiving prophylaxis) agreed or strongly agreed that HA had reduced their physical activity (Figure 1). Overall, 38.9% of those with moderate HA and 58.6% of those with severe HA (63.8% with severe HA receiving on-demand treatment and 55.2% receiving prophylaxis) agreed or strongly agreed that their HA had reduced their social activity; this was less pronounced in mild HA (9.8%). Additionally, 31.7%, 36.1%, and 64.1% of those with mild, moderate, and severe HA (62.1% with severe HA receiving on-demand treatment and 65.5% receiving prophylaxis) agreed or strongly agreed that their HA had caused them to miss opportunities. Correspondingly, frustration due to HA was felt by 19.5%, 34.7% and 57.9% (56.9% with severe HA receiving on-demand treatment and 58.6% receiving prophylaxis) of people, respectively. When asked whether they believed their daily life was compromised due to their hemophilia, 24.4%, 37.5%, and 63.4% of those with mild, moderate, and severe HA, respectively, agreed. Pain, as reported by the physician, was noted in 36.6% of people with mild HA (100% was reported as 'mild'); in people with moderate HA, pain was reported as 'mild', 'moderate', and 'severe' in 44.4%, 20.8%, and 1.4% of PwHA, respectively. In people with severe HA, pain was reported as 'mild', 'moderate', and 'severe' in 39.7%, 27.6%, and 8.6% for those receiving on-demand treatment, and 37.9%, 32.2%, and 8.0% for those receiving prophylaxis, respectively. Conclusions: In all disease severity groups, there was a notable group of PwHA that felt that they have had to reduce their physical and social activity, have had fewer opportunities and are frustrated due to their disease. While the impact on daily life is most pronounced in people with severe HA (including those receiving on-demand treatment and those receiving prophylaxis), it is also apparent in mild and moderate HA, indicating that there may be an unmet medical need in these groups. Disclosures Noone: Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; Research Investigator PROBE: Research Funding; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees. Nissen:F. Hoffmann-La Roche Ltd: Current Employment; Actelion: Consultancy; Novartis: Research Funding; GSK: Research Funding. Xu:F. Hoffmann-La Roche Ltd: Current Employment, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Burke:University of Chester: Current Employment; HCD Economics: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Asghar:HCD Economics: Current Employment. Dhillon:F. Hoffmann-La Roche Ltd: Other: All authors received editorial support for this abstract, furnished by Scott Battle, funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland. ; HCD Economics: Current Employment. Aizenas:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara:HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Khair:Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Haemnet: Membership on an entity's Board of Directors or advisory committees.

scholarly journals FLT3 and LSD1 Inhibitor Combinations Synergistically Repress Growth of FLT3-Mutant Acute Myeloid Leukemia Via Blockage of MYC Function

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 31-32
Author(s):  
Daniel J. Coleman ◽  
Brittany M. Smith ◽  
Cody Coblentz ◽  
Rowan L. Callahan ◽  
Jake VanCampen ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Board Of Directors ◽  
Transcriptional Activation ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Target Genes ◽  
Publicly Traded ◽  
Private Company ◽  
Advisory Committees ◽  
Flt3 Inhibitor

Internal Tandem Duplication mutations of Fms Related Receptor Tyrosine Kinase 3 (FLT3), known as FLT3-ITD mutations, are associated with poor prognosis in Acute Myeloid Leukemia (AML). The clinical efficacy of inhibiting FLT3 in AML is limited by the rapid development of drug resistance and relapse, underscoring a need for more potent and durable treatment strategies. The early persistence of leukemic blasts during FLT3 inhibition is a key driver of resistance. We find that in combination, inhibitors of Lysine Specific Demethylase 1 (LSD1) potentiate the activity of FLT3 inhibitors, driving synergistic cell death. This novel therapeutic approach has the potential to drive deeper therapeutic responses in FLT3-Mutant AML, delaying or preventing the development of resistance. LSD1 is a dynamic DNA-associated protein that functions as a chromatin modifier and transcription factor. LSD1 removes methylation on both lysine 4 of histone H3 (H3K4), associated with transcriptional activation, and lysine 9 (H3K9), associated with transcriptional repression. Additionally, LSD1 has been reported to function as a transcription factor independent of its catalytic demethylase function. LSD1 inhibition reduces cell proliferation in several cancer types. In AML specifically, inhibition of LSD1 has been reported to activate enhancers associated with genes that promote differentiation. We hypothesized that combining LSD1 inhibition with FLT3 inhibition in FLT3-ITD AML would result in synergistic effects on cell viability through reactivating differentiation pathways and more strongly blocking proliferation. In this study, we aimed to examine the efficacy, transcriptional effects, and changes in chromatin dynamics when combining LSD1 inhibition with FLT3 inhibition in a FLT3-ITD mutant cell line and patient samples. We used matrix combination screening to determine that combining the FLT3 inhibitor Quizartinib with LSD1 inhibitors (GSK-2879552 or ORY-1001) synergistically represses cell viability in the FLT3-ITD mutant MOLM-13 cell line and in multiple primary AML samples. RNA-seq followed by Gene Set Enrichment Analysis revealed that combining LSD1 and FLT3 inhibition synergistically represses target genes of the oncogenic transcription factor MYC. This finding was corroborated through high-throughput genome-wide profiling of histone marks, using the recently developed technique Cleavage Under Targets and Tagmentation (CUT&Tag). Specifically, we discovered several promoter regions in which acetylation of lysine 27 of Histone H3 (H3K27Ac), associated with transcriptional activation, was repressed by combining LSD1 and FLT3 inhibition. The genes associated with these regions were strongly enriched for known MYC target genes. Through additional genomic profiling methods including ChIP-seq and ATAC-seq, we have established potential roles for several DNA-binding transcription factors including CEBPA, RUNX1, STAT5, and LSD1 itself, that may mediate repression of MYC function resulting from combining LSD1 and FLT3 inhibition. Together, our work establishes LSD1 and FLT3 inhibitor combinations as a promising treatment strategy in FLT3-ITD AML. Importantly, this study identifies combined FLT3 and LSD1 inhibition as an effective strategy to indirectly target MYC function, as MYC is often referred to as an "undruggable" target. Furthermore, it has the potential to drive deeper molecular responses in FLT3-mutant AML, decreasing the likelihood of treatment resistance. Disclosures Druker: Bristol-Myers Squibb: Research Funding; Blueprint Medicines: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; VB Therapeutics: Membership on an entity's Board of Directors or advisory committees; Millipore (formerly Upstate Biotechnology): Patents & Royalties; Pfizer: Research Funding; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Patient True Talks: Consultancy; Oregon Health & Science University: Patents & Royalties; Novartis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; MolecularMD (acquired by ICON): Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Henry Stewart Talks: Patents & Royalties; Iterion Therapeutics (formerly Beta Cat Pharmaceuticals): Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics Inc. (formerly Lorus): Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Merck & Co: Patents & Royalties; GRAIL: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Aileron Therapeutics: Membership on an entity's Board of Directors or advisory committees; McGraw Hill: Patents & Royalties; Leukemia & Lymphoma Society: Research Funding; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Dana-Farber Cancer Institute: Patents & Royalties; EnLiven: Consultancy, Research Funding. Maxson:Gilead Sciences: Research Funding; Ionis Pharmaceuticals: Other: Joint oversight committee for a collaboration between OHSU and Ionis Pharmaceuticals.

scholarly journals Inotuzumab Ozogamicin (Ino) May Overcome the Impact of Philadelphia Chromosome (Ph)-like Phenotype in Adult Patients (pts) with Relapsed/Refractory (R/R) Acute Lymphoblastic Leukemia (ALL)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1641-1641 ◽  
Author(s):  
Elias Jabbour ◽  
Kathryn G. Roberts ◽  
Koji Sasaki ◽  
Yaqi Zhao ◽  
Chunxu Qu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Overall Survival ◽  
Stem Cell ◽  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
Advisory Committees ◽  
The Impact

Background: Ino showed significant activity in phase II trials in pts with R/R ALL, that was subsequently confirmed in Phase III trial where Ino demonstrated higher response rates and superior overall survival vs standard of care chemotherapy (SOC) in adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R ALL).Ph-like or BCR-ABL1-like ALL possesses a gene expression profile similar to that of BCR-ABL1 ALL but lacks the BCR-ABL1 fusion protein. It is characterized by increased expression of hematopoietic stem-cell genes, deletion of B-cell lineage genes and kinase-activating alterations. Ph-like ALL is associated with refractoriness to standard induction/consolidation chemotherapy and poor prognosis. Aim: To evaluate the outcomes of pts with R/R Ph-like ALL treated in phase II trial with Ino monotherapy. Methods: We performed an integrated analysis of whole genome sequencing (to identify sequence mutations, structural variations and DNA copy number alterations), and transcriptome sequencing (RNAseq; to quantify gene expression, determine Ph-like gene expression profile and identify fusions) on 53 patients' samples treated with Ino between June 2010 and September 2012. Results: Fifty-three evaluable pts with R/R ALL with stored baseline samples were analyzed. Pts characteristics are summarized in Table 1. Median age was 50 years. Ino was given as Salvage 1, Salvage 2, and Salvage 3 and beyond in 20 (38%), 18 (34%), and 15 (28%) pts, respectively. Figure 1 reflects the different genomic subgroups identified among 53 evaluable pts. Ph-like gene signature was found in 12 pts (22.6%). Among these 12 pts, 6 had IGH-CRLF2, 2 IGH-EPOR, 1 SNX2-ABL1, and 3 had no fusions identified. The overall response rates (ORR) were 54% [complete remission (CR) 20%, CR with partial hematologic recovery (CRh) 32%, and marrow CR (CRi) 2%]. Among pts with morphologic remission, 46% and 82% achieved minimal residual disease (MRD) negativity at CR and at any time, respectively. The ORR for pts with Ph-like ALL, Ph-positive ALL, ALL with KMT2A, and others were 58% (CR=25%; CRh=33%), 42% (CR=8%; CRh=33%), 57% (CR=14%; CRh=29%; CRi=14%), and 56% (CR=26%; CRh=30%), respectively. The respective overall MRD negativity rates were 71%, 100%, 75%, and 83% (Table 1). The median follow-up was 60 months. The median event-free (EFS) and overall survival (OS) were 3.3 and 5.4 months, respectively. There was no difference in EFS and OS between the subgroups analyzed (P=0.464; P=0.824). The median EFS and OS were 4.5 and 4.5 months for pts with Ph-like, 3.1 and 7.2 months for those with Ph-positive ALL, 2.8 and 4.4 months for those with KMT2A, and 2.2 and 4.6 months for others (Table 1). 21 (40%) pts had subsequent allogeneic stem cell transplant; 6 (50%), 3 (25%), 4 (57%), and 8 (36%) in each subgroup, respectively. The rate of VOD was 3 (6%) with no difference among different subgroups. Conclusion: The current analysis suggest that Ino therapy may overcome the impact of Ph-like phenotype in pts with ALL. Confirmation of these findings in a larger cohort and in frontline ALL patients is needed. Disclosures Jabbour: Takeda: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Cyclacel LTD: Research Funding. Sasaki:Pfizer: Consultancy; Otsuka: Honoraria. Jain:Precision Biosciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics, an AbbVie company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cellectis: Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Ravandi:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Xencor: Consultancy, Research Funding; Macrogenix: Consultancy, Research Funding; Menarini Ricerche: Research Funding; Selvita: Research Funding; Cyclacel LTD: Research Funding. Short:AstraZeneca: Consultancy; Takeda Oncology: Consultancy, Research Funding; Amgen: Honoraria. Garcia-Manero:Amphivena: Consultancy, Research Funding; Helsinn: Research Funding; Novartis: Research Funding; AbbVie: Research Funding; Celgene: Consultancy, Research Funding; Astex: Consultancy, Research Funding; Onconova: Research Funding; H3 Biomedicine: Research Funding; Merck: Research Funding. Konopleva:Cellectis: Research Funding; Agios: Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Ascentage: Research Funding; Eli Lilly: Research Funding; Calithera: Research Funding; Stemline Therapeutics: Consultancy, Honoraria, Research Funding; Forty-Seven: Consultancy, Honoraria; Reata Pharmaceuticals: Equity Ownership, Patents & Royalties; Kisoji: Consultancy, Honoraria; Ablynx: Research Funding; Genentech: Honoraria, Research Funding; Amgen: Consultancy, Honoraria; F. Hoffman La-Roche: Consultancy, Honoraria, Research Funding; Astra Zeneca: Research Funding. Mullighan:Illumina: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: sponsored travel; Pfizer: Honoraria, Other: speaker, sponsored travel, Research Funding; AbbVie: Research Funding; Loxo Oncology: Research Funding; Amgen: Honoraria, Other: speaker, sponsored travel. Kantarjian:Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Honoraria, Research Funding; Ariad: Research Funding; Novartis: Research Funding; Amgen: Honoraria, Research Funding; Immunogen: Research Funding; AbbVie: Honoraria, Research Funding; Astex: Research Funding; BMS: Research Funding; Cyclacel: Research Funding; Daiichi-Sankyo: Research Funding; Pfizer: Honoraria, Research Funding; Jazz Pharma: Research Funding; Takeda: Honoraria.

scholarly journals A Phase 1 Study to Evaluate the Safety, Pharmacokinetics (PK) and Pharmacodynamics (PD) of Lisaftoclax (APG-2575), a Novel BCL-2 Inhibitor (BCL-2i), in Patients (pts) with Certain Relapsed or Refractory (R/R) Hematologic Malignancies (HMs)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3730-3730
Author(s):  
Mingyuan Sun ◽  
Junyuan Qi ◽  
Zi Chen ◽  
Hongli Zhang ◽  
Yongping Song ◽  
...  
Keyword(s):  
B Cell ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Phase 1 ◽  
Single Agent ◽  
Objective Response ◽  
Tumor Lysis Syndrome ◽  
B Cell Lymphoma ◽  
Severe Neutropenia ◽  
Publicly Traded

Abstract Background: Many B-cell malignancies evade apoptosis by overexpressing BCL-2 proteins. Studies of the BCL-2i venetoclax have demonstrated activity in certain HMs but show that venetoclax requires a slow dose ramp-up over several weeks to reduce the risk of tumor lysis syndrome (TLS), which may warrant frequent or intensive laboratory monitoring. Cases of severe neutropenia with venetoclax treatment have also been reported. Lisaftoclax is a novel, potent, selective BCL-2i that is active against HMs and offers a potential advantage of a daily clinical ramp-up (rather than weekly) to the target dose over a few days. Methods: This Chinese, multicenter, open-label, single-agent, phase 1 trial is evaluating the safety (including dose-limiting toxicity [DLT] and maximum tolerated dose [MTD]), efficacy, PK, and PD of lisaftoclax in adults with histologically confirmed diagnoses of R/R chronic lymphocytic leukemia (CLL) or non-Hodgkin's lymphoma. Eligibility criteria include an ECOG performance score of 0-1 (in dose escalation) or 0-2 (in dose expansion); life expectancy ≥ 3 months; and adequate bone marrow, renal, and liver function. Lisaftoclax was orally administered once daily in 4-week cycles across multiple dose cohorts. Results: As July 27, 2021, 31 pts had been enrolled and treated with lisaftoclax at doses ranging from 20 to 800 mg. Pts had a median (range) of 4 (1-14) prior lines of treatment and diagnoses of CLL/SLL (n = 9), mantle cell lymphoma (MCL; n = 6), marginal zone lymphoma (MZL; n = 3), follicular lymphoma (n = 8), diffuse large B-cell lymphoma (n = 2), lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia (n = 1), angioimmunoblastic T-cell lymphoma (n = 1) or mycosis fungoides (MF; n = 1). DLT, MTD, and laboratory/clinical TLS have not been observed at doses up to 800 mg. The recommended phase 2 dose (RP2D) is 600 mg. Lisaftoclax was generally well tolerated. Treatment-related adverse events (TRAEs) were reported in 28 pts (87.5%), most of which were grade 1 to 2. Any grade TRAEs in &gt; 10% of pts include thrombocytopenia (34.4%), neutropenia (21.9%), leukopenia (21.9%), anemia (28.1%), hyperuricemia (15.6%), hyperphosphatemia (12.5%), hypertriglyceridemia (12.5%), and diarrhea (15.6%). Grade 3-4 TRAEs were reported in 7 pts (21.9%), including thrombocytopenia (18.8%), neutropenia (12.5%), leukopenia (9.4%), and anemia (6.3%). Serious TRAEs occurred in 1 pt and included anemia and thrombocytopenia (in 3.1% each). With a median (range) treatment of 4 (1-14) cycles, 9 of 25 evaluable pts achieved an objective response (CR or PR), for an ORR of 39% with a median (range) time to response of 2 (2-4) cycles. The highest response rates were seen in pts with CLL/SLL (ORR 66.7% [6/9]). At doses ≥ 200 mg, an ORR of 100% (6/6 including 1 CR and 5 PR) was observed. Responses were also observed in MZL, with a PR in 2 of 3 pts (ORR, 66.7%), and MCL, with a PR in 1 of 4 pts (ORR, 25%). In 1 pt with MF, skin tumor shrinkage was observed after 1 lisaftoclax treatment cycle. Favorable absolute lymphocyte count (ALC) profiles included reductions at lisaftoclax doses as low as 100 mg/day. The preliminary PK profile showed that exposures increased with lisaftoclax doses from 20 to 800 mg, with an average half-life of 4 to 6 hours. On BH3 profiling, lisaftoclax rapidly triggered changes in BCL-2 complex in CLL/SLL pt samples, which were consistent with rapid clinical reductions in ALCs. Conclusions: Lisaftoclax was well tolerated up to 800 mg/day. No TLS was observed, even with the daily ramp-up schedule. There were no significantly new or unmanageable safety findings. Lisaftoclax showed single-agent antitumor activity in CLL/SLL, MZL, and MCL. The BCL-2i lisaftoclax offers a treatment alternative for pts with R/R HMs, with a daily ramp-up schedule that may be more pt friendly with a favorable preliminary safety profile. Internal study identifier APG-2575-CN-001; ClinicalTrials.gov identifier: NCT03913949. Figure 1 Figure 1. Disclosures Chen: Ascentage Pharma (Suzhou) Co., Ltd: Current Employment, Current equity holder in publicly-traded company. Zhang: Ascentage Pharma (Suzhou) Co., Ltd.: Current Employment, Current equity holder in publicly-traded company. Lu: Ascentage Pharma Group Inc.: Current Employment, Current equity holder in publicly-traded company. Ahmad: Ascentage Pharma Group Inc.: Current Employment, Current equity holder in publicly-traded company. Men: Ascentage Pharma (Suzhou) Co., Ltd.: Current Employment, Current equity holder in publicly-traded company. Cen: Ascentage Pharma (Suzhou) Co., Ltd.: Current Employment, Current equity holder in publicly-traded company. Yang: Ascentage Pharma (Suzhou) Co., Ltd.: Current Employment, Current equity holder in publicly-traded company, Other: Leadership and other ownership interests, Patents & Royalties, Research Funding. Wang: Astellas Pharma, Inc.: Research Funding; AbbVie: Consultancy. Zhai: Ascentage Pharma Group Inc.: Current Employment, Current equity holder in publicly-traded company, Other: Leadership and other ownership interests, Patents & Royalties, Research Funding.

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