Emergence of Fc-Gamma-Riib-Dominance Contributes to Resistance to Therapeutic Antibodies in Patients with Chronic Lymphocytic Leukaemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 447-447
Author(s):  
Melinda Burgess ◽  
Sally Mapp ◽  
Roberta Mazzieri ◽  
Jonathan Ellis ◽  
Catherine Cheung ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Board Of Directors ◽  
Research Funding ◽  
Lymphocytic Leukaemia ◽  
Primary Cultures ◽  
Differential Sensitivity ◽  
Moderate Activity ◽  
Therapeutic Antibodies ◽  
Advisory Committees ◽  
Antibody Resistance

Abstract Aim: Chronic lymphocytic leukaemia (CLL) is the most common adult leukaemia. Whilst therapeutic antibodies show clinical activity in CLL patients, resistance develops. Thus, identifying mechanisms of antibody resistance and methods to reduce resistance would be valuable in managing CLL. Results: In this study we show that a therapeutic antibody against CD62L is able to induce antibody-dependent cell mediated cytotoxicity (ADCC) and phagocytosis (ADP) in primary cultures of CLL cells. Significantly, we observed that patients with stable disease retained sensitivity to CD62L-Ab whilst untreated patients, whose disease progressed, became progressively resistant to CD62L-Ab. Using strategies to enrich for monocytes we were able to show that the CD62L-Ab dependent killing was attributable to an FcγR-dependent mechanism within the monocyte derived cell (MDC) fraction of PBMCs. Transcriptomic profiling and marker analysis indicated that the MDCs acquired a macrophage phenotype. Both MDCs from antibody-sensitive or antibody-resistant patients were able to bind Ab-bound CLL cells equally. Moreover, resistance could not be attributed to reduced numbers of monocytes or macrophages or to distinct subtypes of monocytes or macrophages. Using pharmacological inhibitors of the activating pathway of FcγR signaling and the inhibitory FcγRIIB pathway we were able to show that the antibody resistance in MDCs, derived from patients with CLL, was due to the emerging dominance of the FcγRIIb pathway relative to the activating FcγR pathways. We examined whether the differential sensitivity to CD62L-Ab was also evident for anti-CD20 antibodies used clinically for CLL. Rituximab showed only moderate activity in vitro and no clear difference in cytotoxicity was observed between patients who were previously identified as being resistant or sensitive to the CD62L antibody. Obinutuzumab invoked similar differential cell killing in PBMCs from patients sensitive to, or resistant to, CD62L-Ab. Further comparison indicated that CD62L-Ab and obinutuzumab induced similar malignant B cell binding to MDCs and ADP in contrast to rituximab. Finally, similar to anti-CD62L, ADCC/ADP response to obinutuzumab was reduced following treatment of sensitive cultures with a syk or BTK inhibitor and increased in MDCs derived from resistant patients treated with a Ship1 inhibitor. Conclusions: These data establish, for the first time, that MDCs derived from CLL patients may switch from an antibody sensitive phenotype to an antibody-resistant phenotype as disease progresses. Significantly, we show that the resistance to MDC-mediated ADCC/ADP may be reversed by the inhibition of FcγRIIB with pharmacological modifiers. Disclosures Mollee: Onyx: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Gill:Sanofi Aventis: Research Funding; Roche: Honoraria; AbbVie: Honoraria; Roche: Research Funding.

scholarly journals Risk Factors Associated with the Development of Infusion-Related Reactions in Patients with Chronic Lymphocytic Leukaemia Treated with Anti-CD20 Monoclonal Antibodies: Analysis of the CLL11 Study Dataset

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3339-3339 ◽  
Author(s):  
Ciara Louise Freeman ◽  
Mark Dixon ◽  
Richard Houghton ◽  
Kathryn Humphrey ◽  
Gunter Fingerle-Rowson ◽  
...  
Keyword(s):  
Risk Factors ◽  
Monoclonal Antibodies ◽  
Board Of Directors ◽  
Research Funding ◽  
Lymphocytic Leukaemia ◽  
Signs And Symptoms ◽  
Leukemic Cells ◽  
Tumour Burden ◽  
Advisory Committees ◽  
Anti Cd20

Abstract Background: The administration of anti-CD20 monoclonal antibodies (mAb) in patients with B-cell lympho-proliferative disorders is frequently accompanied by a constellation of signs and symptoms that have been labelled as infusion-related reactions (IRR). The pathophysiology of IRR remains poorly understood as do predictors of risk, which may relate to the mechanism of action of the anti-CD20, disease-related factors such as tumour burden or host factors such as polymorphisms of Fc gamma receptor 3A (FcγRIIIA). In the CLL11 trial (NCT01010061), patients with previously untreated chronic lymphocytic leukaemia and comorbidities were randomised to receive either rituximab (type I anti-CD20 mAb) or obinutuzumab (type II and glycoengineered anti-CD20 mAb) in combination with chlorambucil for six cycles. Obinutuzumab led to faster depletion of B cells and achieved an improvement in outcome parameters such as response and progression-free survival compared with the rituximab arm, but was also associated with a higher rate and increased severity of IRR. To better understand the profile of risk for IRR in patients with CLL, we performed an exploratory analysis on data obtained from patients treated with either one of the two antibodies given in combination with chlorambucil. Methods: Patients from the prospective, randomized Phase III CLL11 study who received a first infusion of obinutuzumab (N=331) or rituximab (N=326) were included. Baseline pre-treatment risk factors thought to play a possible role in the development of IRR were identified a priori and included patient demographics, concurrent conditions and premedications, parameters of disease burden, prognostic factors, laboratory variables and FcγR genotype. Baseline values for mean fluorescence intensity (MFI) of CD20, gated on the circulating CLL clone, and MFI of CD16, gated on the natural killer (NK) cell population (CD56+16+) in peripheral blood were also available for N=510 patients. The primary outcome, development of an IRR with the first infusion, was defined as the occurrence of related signs and symptoms during or within 24 hours of administration of antibody. Due to the short-term nature of the initial IRR a multivariate logistical regression analysis was performed rather than a time to event analysis. Internal validation of this model, derived from a single dataset, was conducted using the established resampling technique of bootstrapping. This assessed the proportion of times each variable retained significance at α=0.10 when the model was fitted to bootstrapped samples of the dataset. Results: Patients that appeared to be at greater risk of developing any grade of IRR with the first infusion of rituximab or obinutuzumab were those treated with obinutuzumab, those with higher surface expression CD20 on CLL cells (MFI CD20) and greater FcγRIIIA (MFI CD16) on NK cells in peripheral blood, those with higher affinity FcγRIIIA genotype (VV), more pronounced neutropenia and splenomegaly at baseline (Table 1). Higher baseline absolute lymphocyte count and the presence of respiratory comorbidity also appeared to increase risk. All variables significant for inclusion in the model are shown in Table 1. Looking at those patients treated with obinutuzumab only, the most important determinant of risk was MFI CD20 (OR 3.6 95% CI 1.6-7.9). The impact of glucocorticoid premedication in reducing risk in obinutuzumab treated patients was not sufficient to reach significance, however, patients were not randomised to this intervention. Conclusion: This work identifies novel disease- and patient-specific biological variables that appear to play a role in the development of IRR in patients with CLL treated with anti-CD20 mAb, although the treatment received (obinutuzumab >rituximab) confers greatest risk. In addition to parameters of tumour burden, target antigen expression and gene polymorphisms of FcγR also appear to contribute to the risk of developing an IRR. Our results support the hypothesis that higher rates of IRR seen with the administration of obinutuzumab may result from stronger activation upon binding to CD20 on leukemic cells and subsequent enhanced cross-linking between CD20 expressing leukemic cells and FcγRIIIA bearing effector cells. Further studies involving obinutuzumab in this patient population will be needed to externally validate the results of this exploratory analysis. Disclosures Freeman: Roche Pharmaceuticals: clinical research fellowship supported by Roche Pharmaceuticals (secondment from Bart's) Other. Dixon:Roche Pharmaceuticals: Employment. Houghton:Roche Pharmaceuticals: Employment. Humphrey:Roche: Employment. Fingerle-Rowson:Roche Pharmaceuticals: Employment. Kreuzer:Roche Pharmaceuticals: Research Funding. Engelke:Roche: Travel grants Other. Hallek:Roche Pharmaceuticals: Consultancy, Research Funding, Speakers Bureau. Goede:Bristol Myers Squibb: Honoraria; Mundipharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Travel grants Other.

DEPTOR Is a Regulator of Response to mTOR Kinase Inhibitors in Multiple Myeloma

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2916-2916
Author(s):  
Diana Cirstea ◽  
Teru Hideshima ◽  
Loredana Santo ◽  
Homare Eda ◽  
Miriam Canavese ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Board Of Directors ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Mtor Inhibitors ◽  
Mtor Pathway ◽  
Differential Sensitivity ◽  
Advisory Committees ◽  
Mtor Kinase ◽  
Regulatory Cascade

Abstract Abstract 2916 Inhibition of the PI3K/mTOR pathway is a promising therapeutic strategy in targeting multiple myeloma (MM) cells in the bone marrow (BM) microenvironment, which abnormally activates PI3K/mTOR signaling cascade mediating proliferation, anti-apoptosis and drug resistance. Exploring the targeting of PI3K/mTOR pathway has led to the development of different therapeutic approaches; however, mTORC1 inhibitors (i.e., temsirolimus and everolimus) have demonstrated only modest activity as single agents. In this regard, several mechanisms underlying rapamycin resistance, including mTOR/S6K1-mediated feedback loops resulting in activation of PI3K/Akt and ERK signaling, have been proposed. Importantly, recent studies have identified mTOR kinase and the mTOR-DEPTOR counter-regulatory cascade as key mediators of mTORC1 and mTORC2 multi-protein complexes, with differential sensitivity to rapamycin. Indeed, targeting DEPTOR/mTORC1/mTORC2 signaling by inhibition of mTOR kinase proved an effective strategy to overcome some of the limitations of TORC1 inhibition in MM cells, evidenced in our studies of the novel dual mTORC1 and mTORC2 selective inhibitor AZD8055. Unlike rapamycin, AZD8055 induced apoptosis and inhibited MM cell growth even when co-cultured with cytokines (i.e., IL-6, IGF1) or BMSCs, presumably through simultaneous suppression of mTORC1 and mTORC2 signaling including the rapamycin-resistant 4E-BP1 (downstream of mTORC1) and Akt as well as NDRG1 (effectors of mTORC2). We examined mRNA and protein level of DEPTOR in MM cell lines treated with AZD8055 versus rapamycin and observed no significant changes. To examine the functional significance of DEPTOR in response to mTOR inhibitors, we utilized lentiviral shRNA to knockdown DEPTOR in OPM1 MM cells. DEPTOR-knockdown cells acquired resistance to AZD8055 treatment, suggesting that DEPTOR is a key modulator of mTORC1/2 signaling. Moreover, DEPTOR knockdown triggered decrease in Akt phosphorylation (Ser473), associated with suppression of Rictor phosphorylation (Thr1135). DEPTOR co-immunoprecipitation with Rictor was also abrogated by both AZD8055 and rapamycin treatment. Taken together, our results indicate the role of DEPTOR, either alone or as an mTOR/Rictor interacting molecule, in mediating the anti-MM activity induced by mTOR kinase inhibitors in MM cells. These data therefore both provide insights into the molecular profiles that may predict sensitivity/resistance to second generation of mTOR inhibitors in MM, and may be useful to select MM patients for mTOR inhibitor therapy. Disclosures: Hideshima: Acetylon: Consultancy. Anderson:Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Acetylon: Membership on an entity's Board of Directors or advisory committees. Guichard:AstraZeneca, UK: Employment, Shares from AstraZeneca, UK. Raje:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Acetylon: Research Funding.

scholarly journals Deep Igh Sequencing Identifies an Ongoing Somatic Hypermutation Process with Complex and Evolving Clonal Architecture in Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 21-21 ◽  
Author(s):  
Nikhil C. Munshi ◽  
Stephane Minvielle ◽  
Yu-Tzu Tai ◽  
Mariateresa Fulciniti ◽  
Mehmet K Samur ◽  
...  
Keyword(s):  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Somatic Hypermutation ◽  
Post Treatment ◽  
Differential Sensitivity ◽  
Advisory Committees ◽  
Maintenance Time ◽  
Equity Ownership ◽  
Time Point

Abstract Introduction: Immunoglobulin (Ig) gene rearrangement is a hallmark of early B-cell development. Multiple myeloma (MM), a malignancy of plasma cells, typically have mutated Ig sequences but are thought to be stable throughout the course of the disease. We previously observed that multiple Ig sequences related by somatic hypermutation (SHM) may be present in some MM patients at diagnosis. Here we provide an expanded observation and investigate whether there is ongoing evolution in Ig sequences over the course of the disease. Methods: 550 MM patientsenrolled in IFM/DFCI study were included in this analysis. The next-generation sequencing (NGS)-based immunosequencing platform was used to detect evidence of oligoclonality at the Ig heavy chain loci. Using universal primer sets, we amplified IGH variable, diversity, and joining gene segments from DNA and/or RNA isolated from purified CD138+ MM cells collected at the time of diagnosis. Amplified products were sequenced and analyzed (Faham et al., Blood 2012). MM-specific clonotypes were identified for each patient based on their high frequency (5%) within the B-cell repertoire in the diagnostic (dx) sample. The highest frequency MM clonotype in a dx sample is termed the Òindex clonotype.Ó DNA and/or RNA isolated from dx AND post-treatment bone marrow samples were assessed for evidence of evolved MM clonotypes. A clonotype was considered ÒevolvedÓ based on CDR3 sequence homology to the dx Òindex clonotype.Ó Results: We identified Ig clones in 340 RNA samples and 311 DNA samples from the IFM/DFCI cohort.We first looked at V segment usage in these MM clones comparedto a database of ~30 million Ig VDJ sequences derived from normal B cells. The frequencies for 6 V segments were found to be significantly different from this dataset compared to the database.We then looked for cases with evidence that Myeloma cells have two unrelated origins. We found 9/550 (1.6%) cases which had evidence of unrelated clones as evident by having three IgH or two functional sequences. We then considered cases where we find two IgH sequences that are related to each other by SHM. 128/340 (37.6%) of RNA dx samples showed evidence of evolved clones via SHM, with 69/128 (53.9%) having 3 or more related clones, while 15/311 patients (4.8%) showed evidence of evolved clones related to the index clone via SHM in DNA samples from diagnosis. Of note, the majority of RNA evolved clones were found at low frequency (<10-3) which would have been impossible to observe in the limited cell input DNA samples available for testing. Out of the 15 patients with evidence of evolved clones related to the index clone, we tested RNA from 8 of them. In 4/8 cases, the index and the related clones were present at a similar ratio in the DNA and RNA, while in 3/8 cases the index clone was found in the RNA but not the related clone. 249 post-treatment samples from 164 patients were MRD positive and were assessed for the presence of clonal evolution. In 19/249 follow-up samples (7.6%), an evolved clone related to the index clone was observed. In 6/19 patients, a substantial change in the relative index and evolved clone frequencies was observed from the dx to post-treatment time points suggesting a differential sensitivity to treatment. For example, in one case, the evolved ÒnewÓ clonotype was not observed at diagnosis but appears in the post-maintenance sample only. In another case, the evolved clonotype either increased or decreased in the post-maintenance sample relative to the index clonotype (Fig 1). Conclusions: We observed multiple evolved clonotypes in a substantial percentage of dx MM samples (37.6%). The presence of multiple clonotypes related by SHM indicates that this mechanism remains active after myeloma development in at least a portion of the cells. We also found marked changes in the relative frequency of the MM clonotypes in post-treatment samples and emergence of new Ig clones which may not be due to selective advantage of the newly acquired mutations in the Ig gene, but rather some other ongoing genomic mutation process. Thus, these evolved myeloma clonotypes may be useful as surrogate markers for other oncogenic mutations providing resistance to therapy. Figure 1. Evolution of related clones in the post-maintenance time point. Below are the sequences of two related clones, with one base difference bolded and underlined. Figure 1. Evolution of related clones in the post-maintenance time point. Below are the sequences of two related clones, with one base difference bolded and underlined. Disclosures Richardson: Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gentium S.p.A.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium Takeda: Membership on an entity's Board of Directors or advisory committees. Attal:celgene: Membership on an entity's Board of Directors or advisory committees; jansen: Honoraria. Anderson:Celgene Corporation: Consultancy; Millennium: Consultancy; BMS: Consultancy; Gilead: Consultancy; acetylon pharmaceuticals: Equity Ownership; Oncocorp: Equity Ownership. Faham:Adaptive Biotechnologies Corp.: Employment, Other: Stockholder. Avet-Loiseau:BMS: Membership on an entity's Board of Directors or advisory committees; jansen: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; jansen: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees; onyx: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees; onyx: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees.

Differential Activity of Pazopanib and Imatinib Against PDGFRA-Related MPN and AML

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5153-5153
Author(s):  
Steffen Koschmieder ◽  
Mirle Schemionek ◽  
Christian Elling ◽  
Utz Krug ◽  
Torsten Kessler ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tyrosine Kinase Inhibitor ◽  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Kinase Inhibitor ◽  
Point Mutations ◽  
Differential Sensitivity ◽  
Advisory Committees

Abstract Abstract 5153 Introduction: Pazopanib is a tyrosine kinase inhibitor with proven activity against metastatic renal cancer. Due to its target spectrum of kinases (PDGFR, KIT, and VEGFR), we sought to investigate its activity against myeloid malignancies. Methods: 32D cells transduced with FIP1L1-PDGFRA or several activating PDGFRA point mutations as well as AML cell lines were analyzed for the effects of pazopanib vs. imatinib on cell growth, MTS activity, 7-AAD positivity, and clonogenic growth. Pazopanib and imatinib were purchased from LC Laboratories Woburn, MA, USA. Results: Pazopanib was found to decrease the growth of FIP1L1-PDGFRA transduced cell lines at low nanomolar concentrations (10 nM). 1000 nM doses were equally effective as 1000 nM of the PDGFR tyrosine kinase inhibitor imatinib. MTS assays confirmed that at 10 nM, pazopanib reduced cell proliferation to 28% of that of vehicle-treated control cells (DMSO 0.05%), while 100 nM of pazopanib completely abolished cell growth and suppressed MTS activity. Analysis of 7-AAD positivity using flow cytometry showed that reduction in cell growth and MTS activity was due to induction of apoptosis (17+/−0.6%, 63+/−0.5%, and 87+/−0.5%, 86+/−0.1% for 10, 100, and 1000 nM of pazopanib and 1000 nM of imatinib, respectively). Interestingly, while two PDGFRA activating point mutations (H650Q and R748G) recently identified in patients with idiopathic hypereosinophilic syndrome-type myeloproliferative neoplasms (MPN) were equally sensitive against pazopanib and imatinib, two other such point mutations showed differential sensitivity, with Y849S being more sensitive to imatinib and N659S being more sensitive to pazopanib. When evaluating the effect of pazopanib on acute myeloid leukemia cell lines, we found that imatinib inhibited the cell growth and reduced colony forming units of Kasumi-1 and BCR-ABL positive K562 but not MV4-11 or NB-4 cells, while Kasumi-1, MV4-11, and NB-4 cells were sensitive towards pazopanib treatment. Moreover, while the clonogenic growth of bone marrow-derived cells from two control patients (lymphoma or AML in remission) were only reduced to 75% of control with pazopanib treatment in vitro (100 nM), 100 nM pazopanib decreased colony growth to 18% in another patient with AML at diagnosis. Conclusion: Our data suggest that pazopanib may be active against a variety of myeloid neoplasms and that clinical studies assessing its efficacy are warranted. Also, cells may show differential sensitivity against the PDGFR and KIT inhibitors pazopanib and imatinib. Disclosures: Koschmieder: GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Off Label Use: Data on in vitro activity of pazopanib and imatinib in MPN and AML discussed. Krug:MedA Pharma: Honoraria; Novartis: Honoraria; Alexion: Honoraria; Boehringer Ingelheim: Research Funding; Sunesis: Honoraria. Müller-Tidow:Novartis: Research Funding.

scholarly journals A Novel Evolutionary Pattern Revealed Using Deep Sequencing of Immunoglobulin Loci at Diagnosis and over the Course of Treatment in Multiple Myeloma Patients

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 238-238 ◽  
Author(s):  
Nikhil C. Munshi ◽  
Joaquin Martinez-Lopez ◽  
Victoria Carlton ◽  
Stephanie Minvielle ◽  
Yu-Tzu Tai ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Post Treatment ◽  
Large Cohort ◽  
Differential Sensitivity ◽  
Advisory Committees ◽  
Myeloma Cells ◽  
Equity Ownership

Abstract Introduction: Immunoglobulin (Ig) gene rearrangement is a hallmark of early B-cell development. As multiple myeloma is considered a clonal disease originating from the transformation of a single plasma cell, myeloma cells are traditionally thought to have one clonal Ig gene sequence that remains stable throughout the course of the disease. We previously observed that multiple Ig sequences related by somatic hypermutation (SHM) may be present in some MM patients at diagnosis. Here we provide an expanded observation in a very large cohort of the patients, and perform mutational analysis of the oligoclonal myeloma clonotypes observed at diagnosis and post-treatment, revealing changes in the relative frequency of the MM clonotypes and emergence of new Ig clones. Methods : 620 MM patientsenrolled in IFM/DFCI and Hospital 12 de Octubre trials were included in this analysis. The next-generation sequencing (NGS)-based immunosequencing platform was used to detect evidence of oligoclonality at the Ig heavy chain loci. Using universal primer sets, we amplified IGH variable, diversity, and joining gene segments from DNA and/or RNA isolated from purified CD138+ MM cells collected at the time of diagnosis. MM-specific clonotypes were identified for each patient based on their high frequency (5%) within the B-cell repertoire in the diagnostic (dx) sample. The highest frequency MM clonotype in a dx sample is termed the "index clonotype." DNA and/or RNA isolated from dx AND post-treatment bone marrow samples were assessed for evidence of evolved MM clonotypes. Results: We identified Ig clones in 367 RNA samples and 430 DNA samples from the cohort. We first looked for cases with evidence that myeloma cells have two unrelated origins. We found 11/620 (1.8%) cases at diagnosis, which had evidence of unrelated clones as evident by having three IgH or two functional sequences. In 8 of the 11 cases (72.6%), we had multiple samples to analyze, including two samples at diagnosis or diagnosis/post-treatment pairs. In 4 of the 8 samples, we saw dramatically different relative frequencies of unrelated clones in these samples suggesting that these unrelated clones are likely to be present in two distinct cells. We then considered cases where we found two IgH sequences that are related to each other by SHM at diagnosis. Overall 79 (12.7%) of 620 samples had more than one evolved clone; of these 63/367 (17.2%) of RNA dx samples showed evidence of evolved clones via SHM, while 22/430 patients (5.1%) showed evidence of evolved clones related to the index clone via SHM in DNA samples from diagnosis. Mutant clonotypes had an average of 3.9 to 4.5 mutations in the CDR3 region. We also noted mixed isotypes in 13 clones from 13 patients at diagnosis. The majority of related clones observed in the RNA samples are present at very low frequencies (<10-4), as the greater sequencing depth in RNA allows for identification of low frequency clones. 304 post-treatment samples from 206 patients were MRD positive and were assessed for the presence of clonal evolution. In 27/304 follow-up samples (8.8%) and 7/206 patients (3.4%), an evolved clone related to the index clone was observed even though the period between diagnosis and post-treatment samples was only 6 months. In 6 patients, a substantial change in the relative index and unrelated clone frequencies was observed from the dx to post-treatment time points suggesting a differential sensitivity to treatment. Conclusions: We confirm presence of multiple evolved clonotypes in a substantial percentage of diagnostic MM samples in a large cohort of patients. The evolution of multiple clones related by SHM indicates that SHM remains active after myeloma development and may also impact other non-Ig sites. These findings shed light on the biology and pathogenesis of MM and may provide prognostic information. The very high depth of our sequencing also indicates that the emergence of new IgH clones may be newly acquired mutations in the Ig gene, driven by some ongoing genomic mutation process. Thus, these evolved myeloma clonotypes may be useful as surrogate markers for other oncogenic mutations providing resistance to therapy. Disclosures Munshi: Takeda: Consultancy; Pfizer: Consultancy; Merck: Consultancy; Celgene Corporation: Consultancy; Oncopep: Consultancy, Equity Ownership. Carlton:Adaptive Biotechnologies: Employment, Equity Ownership. Richardson:Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees. Attal:amgen: Consultancy, Research Funding; celgene: Consultancy, Research Funding; janssen: Consultancy, Research Funding; sanofi: Consultancy. Moreau:Takeda: Honoraria; Celgene: Honoraria; Janssen: Honoraria, Speakers Bureau; Novartis: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria. Anderson:Celgene: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sonofi Aventis: Membership on an entity's Board of Directors or advisory committees; Acetylon: Other: Scientific Founder; Oncopep: Other: Scientific Founder. Faham:Adaptive Biotechnologies Corp: Employment. Avet-Loiseau:janssen: Consultancy; sanofi: Consultancy; celgene: Consultancy; amgen: Consultancy.

Distinct Gene Expression Signatures in Patients with Richter's Syndrome and Chronic Lymphocytic Leukemia with Prior Exposure to Ibrutinib

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 30-31
Author(s):  
Hanyin Wang ◽  
Shulan Tian ◽  
Qing Zhao ◽  
Wendy Blumenschein ◽  
Jennifer H. Yearley ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Activation ◽  
Expression Profiles ◽  
Lymphocytic Leukemia ◽  
B Cell Activation ◽  
Advisory Committees ◽  
Upregulated Genes

Introduction: Richter's syndrome (RS) represents transformation of chronic lymphocytic leukemia (CLL) into a highly aggressive lymphoma with dismal prognosis. Transcriptomic alterations have been described in CLL but most studies focused on peripheral blood samples with minimal data on RS-involved tissue. Moreover, transcriptomic features of RS have not been well defined in the era of CLL novel therapies. In this study we investigated transcriptomic profiles of CLL/RS-involved nodal tissue using samples from a clinical trial cohort of refractory CLL and RS patients treated with Pembrolizumab (NCT02332980). Methods: Nodal samples from 9 RS and 4 CLL patients in MC1485 trial cohort were reviewed and classified as previously published (Ding et al, Blood 2017). All samples were collected prior to Pembrolizumab treatment. Targeted gene expression profiling of 789 immune-related genes were performed on FFPE nodal samples using Nanostring nCounter® Analysis System (NanoString Technologies, Seattle, WA). Differential expression analysis was performed using NanoStringDiff. Genes with 2 fold-change in expression with a false-discovery rate less than 5% were considered differentially expressed. Results: The details for the therapy history of this cohort were illustrated in Figure 1a. All patients exposed to prior ibrutinib before the tissue biopsy had developed clinical progression while receiving ibrutinib. Unsupervised hierarchical clustering using the 300 most variable genes in expression revealed two clusters: C1 and C2 (Figure 1b). C1 included 4 RS and 3 CLL treated with prior chemotherapy without prior ibrutinib, and 1 RS treated with prior ibrutinib. C2 included 1 CLL and 3 RS received prior ibrutinib, and 1 RS treated with chemotherapy. The segregation of gene expression profiles in samples was largely driven by recent exposure to ibrutinib. In C1 cluster (majority had no prior ibrutinb), RS and CLL samples were clearly separated into two subgroups (Figure 1b). In C2 cluster, CLL 8 treated with ibrutinib showed more similarity in gene expression to RS, than to other CLL samples treated with chemotherapy. In comparison of C2 to C1, we identified 71 differentially expressed genes, of which 34 genes were downregulated and 37 were upregulated in C2. Among the upregulated genes in C2 (majority had prior ibrutinib) are known immune modulating genes including LILRA6, FCGR3A, IL-10, CD163, CD14, IL-2RB (figure 1c). Downregulated genes in C2 are involved in B cell activation including CD40LG, CD22, CD79A, MS4A1 (CD20), and LTB, reflecting the expected biological effect of ibrutinib in reducing B cell activation. Among the 9 RS samples, we compared gene profiles between the two groups of RS with or without prior ibrutinib therapy. 38 downregulated genes and 10 upregulated genes were found in the 4 RS treated with ibrutinib in comparison with 5 RS treated with chemotherapy. The top upregulated genes in the ibrutinib-exposed group included PTHLH, S100A8, IGSF3, TERT, and PRKCB, while the downregulated genes in these samples included MS4A1, LTB and CD38 (figure 1d). In order to delineate the differences of RS vs CLL, we compared gene expression profiles between 5 RS samples and 3 CLL samples that were treated with only chemotherapy. RS samples showed significant upregulation of 129 genes and downregulation of 7 genes. Among the most significantly upregulated genes are multiple genes involved in monocyte and myeloid lineage regulation including TNFSF13, S100A9, FCN1, LGALS2, CD14, FCGR2A, SERPINA1, and LILRB3. Conclusion: Our study indicates that ibrutinib-resistant, RS-involved tissues are characterized by downregulation of genes in B cell activation, but with PRKCB and TERT upregulation. Furthermore, RS-involved nodal tissues display the increased expression of genes involved in myeloid/monocytic regulation in comparison with CLL-involved nodal tissues. These findings implicate that differential therapies for RS and CLL patients need to be adopted based on their prior therapy and gene expression signatures. Studies using large sample size will be needed to verify this hypothesis. Figure Disclosures Zhao: Merck: Current Employment. Blumenschein:Merck: Current Employment. Yearley:Merck: Current Employment. Wang:Novartis: Research Funding; Incyte: Research Funding; Innocare: Research Funding. Parikh:Verastem Oncology: Honoraria; GlaxoSmithKline: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Ascentage Pharma: Research Funding; Genentech: Honoraria; AbbVie: Honoraria, Research Funding; Merck: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Kenderian:Sunesis: Research Funding; MorphoSys: Research Funding; Humanigen: Consultancy, Patents & Royalties, Research Funding; Gilead: Research Funding; BMS: Research Funding; Tolero: Research Funding; Lentigen: Research Funding; Juno: Research Funding; Mettaforge: Patents & Royalties; Torque: Consultancy; Kite: Research Funding; Novartis: Patents & Royalties, Research Funding. Kay:Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; Juno Theraputics: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Sunesis: Research Funding; MEI Pharma: Research Funding; Agios Pharma: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Cytomx: Membership on an entity's Board of Directors or advisory committees. Braggio:DASA: Consultancy; Bayer: Other: Stock Owner; Acerta Pharma: Research Funding. Ding:DTRM: Research Funding; Astra Zeneca: Research Funding; Abbvie: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Membership on an entity's Board of Directors or advisory committees; alexion: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Identifying Factors That Predict for Unplanned Readmissions for Acute Myeloid Leukemia Patients Receiving Consolidation Cytarabine Based Therapies

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3433-3433
Author(s):  
Caitlin Siebenaller ◽  
Madeline Waldron ◽  
Kelly Gaffney ◽  
Brian P. Hobbs ◽  
Ran Zhao ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Smoking Status ◽  
Consolidation Therapy ◽  
Peripheral Vascular ◽  
Consolidation Chemotherapy ◽  
Advisory Committees ◽  
History Of ◽  
Acute Myeloid

Background: Younger patients (pts) with acute myeloid leukemia (AML) who enter a remission after intensive induction chemotherapy routinely receive at least one cycle of consolidation therapy with high dose cytarabine (HiDAC). This is commonly administered over a five-day inpatient stay, after which pts are discharged home as their blood counts nadir. It is thus a natural consequence of therapy that readmission for febrile neutropenia (FN) occurs, which can impact measures of quality and value in this population. Precise descriptions of incidence, type, and severity of infection, if identified, are lacking, and thus it is unknown to what standard cancer centers should be held for anticipated readmission. We measured these rates, and attempted to identify predictive factors for readmission. Methods: Adult AML pts ≥ 18 years of age who received at least one cycle of HiDAC consolidation (1000-3000 mg/m2 for six doses) in 2009-2019 were included. Our primary aim was to identify predictive factors for readmission after the first cycle of consolidation chemotherapy. The following pt characteristics and co-morbid conditions were analyzed: age, gender, body mass index (BMI), smoking status, AML cytogenetic risk status, history of diabetes, peripheral vascular disease, cardiovascular disease, chronic pulmonary disease, hepatic impairment, and other cancers. Secondary aims included: estimating rates of all-cause readmissions among all HiDAC cycles, defining the rate of FN readmissions, estimating rates of intensive care unit (ICU) admissions, clinical (e.g., probable pneumonia per imaging) and microbiologically-documented infections, prophylactic (ppx) medications used, and mortality. Statistical analyses interrogated potential risk factors for evidence of association with hospital readmission after the first cycle of consolidation chemotherapy. Results: We identified 182 AML pts who fit inclusion criteria. The median age was 50 years (range 19-73); 55% were female and 45% were male. Statistical analyses revealed no association with readmission after cycle 1 for cytogenetic risk (p=0.85), history of heart failure (p= 0.67), chronic pulmonary disease (p=1), connective tissue disease (p=0.53), cerebrovascular accident (p=0.63), diabetes (p=0.63), gender (p=0.07), history of lymphoma (p=0.53), other solid tumors (p=0.53), liver disease (p=1), myocardial infarction (p=0.71), peripheral vascular disease (p=1), or smoking status (p= 0.52). For 480 HiDAC cycles analyzed (88% at 3000 mg/m2), the overall readmission rate was 50% (242/480), of which 85% (205/242) were for FN. Those readmissions which were not FN were for cardiac complications (chest pain, EKG changes), non-neutropenic fevers or infections, neurotoxicity, bleeding or clotting events, or other symptoms associated with chemotherapy (nausea/vomiting, pain, etc.). Median time to FN hospital admission was 18 days (range 6-27) from the start of HiDAC. Of the 205 FN readmissions, 57% had documented infections. Of these infections, 41% were bacteremia, 23% fungal, 16% sepsis, 12% other bacterial, and 8% viral. Of 480 HiDAC cycles, ppx medications prescribed included: 92% fluoroquinolone (442/480), 81% anti-viral (389/480), 30 % anti-fungal (142/480), and 3% colony stimulating factor (14/480). Only 7% (14/205) of FN readmissions resulted in an ICU admission, and 1% (3/205) resulted in death. Conclusions: Approximately half of patients treated with consolidation therapy following intensive induction therapy can be expected to be readmitted to the hospital. The majority of FN readmissions were associated with clinical or microbiologically documented infections and are not avoidable, however ICU admission and death associated with these complications are rare. Readmission of AML pts following HiDAC is expected, and therefore, should be excluded from measures of value and quality. Disclosures Waldron: Amgen: Consultancy. Hobbs:Amgen: Research Funding; SimulStat Inc.: Consultancy. Advani:Macrogenics: Research Funding; Abbvie: Research Funding; Kite Pharmaceuticals: Consultancy; Pfizer: Honoraria, Research Funding; Amgen: Research Funding; Glycomimetics: Consultancy, Research Funding. Nazha:Incyte: Speakers Bureau; Abbvie: Consultancy; Daiichi Sankyo: Consultancy; Jazz Pharmacutical: Research Funding; Novartis: Speakers Bureau; MEI: Other: Data monitoring Committee; Tolero, Karyopharma: Honoraria. Gerds:Imago Biosciences: Research Funding; Roche: Research Funding; Celgene Corporation: Consultancy, Research Funding; Pfizer: Consultancy; CTI Biopharma: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Sierra Oncology: Research Funding. Sekeres:Syros: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees. Mukherjee:Partnership for Health Analytic Research, LLC (PHAR, LLC): Consultancy; McGraw Hill Hematology Oncology Board Review: Other: Editor; Projects in Knowledge: Honoraria; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Comparable Outcomes between Unrelated Donor (8/8 or 7/8 matched) and Haploidentical Donor for Allogeneic Stem Cell Transplantation in Adult Patients with Severe Aplastic Anemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4619-4619
Author(s):  
Jee Yon Shin ◽  
Sung-Soo Park ◽  
Gi June Min ◽  
Silvia Park ◽  
Sung-Eun Lee ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Acute Gvhd ◽  
Chronic Gvhd ◽  
Advisory Committees ◽  
Sibling Donor ◽  
Alternative Donor ◽  
Matched Sibling ◽  
Grade Ii

Background Either allogeneic hematopoietic stem cell transplantation (SCT) from HLA-matched sibling donor or immunosuppressive therapy (IST) has been recommended as one of the standard treatments for severe aplastic anemia (SAA). Regarding only 30% of chance finding HLA‐matched sibling donor, SCT from an alternative donor including unrelated (URD) or haplo-identical related donor (HAPLO) is considered to be a treatment option after failure to IST in patients who lack of a HLA-matched sibling donor. The aim of this study was to compare the outcomes of URD SCT and HAPLO SCT for SAA patients. Method Consecutive 152 adult patients with SAA who received first SCT between March 2002 and May 2018 were included: 73 of HLA-well-matched (8/8) URD (WM-URD), 34 of HLA-mismatched URD (MM-URD), and 45 of HAPLO. With the intention to have a follow-up period at least 1 year, data were analyzed at May 2019. A conditioning regimen with total body irradiation (TBI) and cyclophosphamide was used for URD-SCT, whereas that with TBI and fludarabine was administered for HAPLO-SCT (Lee et al, BBMT 2011;17:101, Park et al, BBMT 2017;23:1498, Lee et al, Am J Hematol 2018;93:1368). The combination of tacrolimus and methotrexate were used as graft-versus-host disease (GVHD) prophylaxis. Results The median follow-up was 53.4 (range, 0.2-174.1) months. The median age of URD and HAPLO cohort was 30 (range 18-59) and 34 (range 18-59) years, respectively. Except for one and three patients who failed respective a neutrophil and platelet engraftment, other patients achieved neutrophil and platelet engraftments with median 11 and 15 days for WM-URD, 13 and 16.5 days for MM-URD, and 12 and 14 days for HAPLO, respectively. The five-years overall survival (OS), failure-free survival (FFS), and cumulative incidences (CIs) of graft-failure and transplant-related mortality were similar among three groups: 88.3%, 85.5%, 2.7%, and 11.7% for WM-URD; 81.7%, 81.7%, 0%, and 18.3% for MM-URD, and 86.3%, 84.1%, 6.7%, and 9.2% for HAPLO. The 180-days CI of grade II-IV acute GVHD in WM-URD, MM-URD and HAPLO were 35.6%, 52.9%, and 28.9%, respectively; and moderate to severe chronic GVHD were 28.7%, 38.7% and 11.8% in respective cohort. The CI of grade II-IV acute GVHD and moderate to severe chronic GVHD were significantly higher in MM-URD than those in HAPLO (both, p=0.026). ATG is the only factor affecting both grade II-IV acute GVHD (Hazard ratio 0.511, p=0.01) and moderate to severe chronic GVHD (Hazard ratio 0.378, p=0.003) in multivariate analysis. Other complications including CMV DNAemia, hemorrhagic cystitis, invasive fungal disease, secondary malignancy, and sinusoidal obstruction syndrome were similar among three groups. Survival outcomes of a subgroup of ≥ 2 allele MM-URD (n=16) extracted form MM-URD were inferior that of other donor types (n=136): 75.0% vs. 86.9% (p=0.163) for 5-year OS and 75.0% vs. 84.7% (p=0.272) for 5-year FFS. Conclusion This study shows that there were no significant differences between alternative donor sources in the absence of suitable matched sibling donor. Host/donor features and urgency of transplant should drive physician towards the best choice among alternative donor sources for SAA patients treated with SCT. However, selection of ≥ 2 allele MM-URD should not be recommended due to high incidence of GVHD and inferior outcomes. Figure Disclosures Kim: Celgene: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Hanmi: Consultancy, Honoraria; AGP: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; SL VaxiGen: Consultancy, Honoraria; Novartis: Consultancy; Amgen: Honoraria; Chugai: Honoraria; Yuhan: Honoraria; Sanofi-Genzyme: Honoraria, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Handok: Honoraria; Janssen: Honoraria; Daiichi Sankyo: Honoraria, Membership on an entity's Board of Directors or advisory committees; BL & H: Research Funding; Otsuka: Honoraria. Lee:Alexion: Consultancy, Honoraria, Research Funding; Achillion: Research Funding.

scholarly journals Rapid and Robust Mobilization of CD34+ HSCs without G-CSF Following Administration of Mgta-145 Alone or in Combination with Plerixafor

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1961-1961
Author(s):  
John F. DiPersio ◽  
Jonathan Hoggatt ◽  
Steven Devine ◽  
Lukasz Biernat ◽  
Haley Howell ◽  
...  
Keyword(s):  
Single Dose ◽  
Adverse Events ◽  
Board Of Directors ◽  
Preliminary Data ◽  
Research Funding ◽  
Fold Change ◽  
Employment Equity ◽  
Advisory Committees ◽  
Cd34 Cells ◽  
Equity Ownership

Background Granulocyte colony-stimulating factor (G-CSF) is the standard of care for mobilization of hematopoietic stem cells (HSCs). G-CSF requires 4-7 days of injections and often multiple aphereses to acquire sufficient CD34+ cells for transplant. The number of CD34+ HSCs mobilized can be variable and patients who fail to mobilize enough CD34+ cells are treated with the combination of G-CSF plus plerixafor. G-CSF use is associated with bone pain, nausea, headaches, fatigue, rare episodes of splenic rupture, and is contraindicated for patients with autoimmune and sickle cell disease. MGTA-145 (GroβT) is a CXCR2 agonist. MGTA-145, in combination with plerixafor, a CXCR4 inhibitor, has the potential to rapidly and reliably mobilize robust numbers of HSCs with a single dose and same-day apheresis for transplant that is free from G-CSF. MGTA-145 plus plerixafor work synergistically to rapidly mobilize HSCs in both mice and non-human primates (Hoggatt, Cell 2018; Goncalves, Blood 2018). Based on these data, Magenta initiated a Phase 1 dose-escalating study to evaluate the safety, PK and PD of MGTA-145 as a single agent and in combination with plerixafor. Methods This study consists of four parts. In Part A, healthy volunteers were dosed with MGTA-145 (0.0075 - 0.3 mg/kg) or placebo. In Part B, MGTA-145 dose levels from Part A were selected for use in combination with a clinically approved dose of plerixafor. In Part C, a single dose MGTA-145 plus plerixafor will be administered on day 1 and day 2. In Part D, MGTA-145 plus plerixafor will be administered followed by apheresis. Results MGTA-145 monotherapy was well tolerated in all subjects dosed (Table 1) with no significant adverse events. Some subjects experienced mild (Grade 1) transient lower back pain that dissipated within minutes. In the ongoing study, the combination of MGTA-145 with plerixafor was well tolerated, with some donors experiencing Grade 1 and 2 gastrointestinal adverse events commonly observed with plerixafor alone. Pharmacokinetic (PK) exposure and maximum plasma concentrations increased dose proportionally and were not affected by plerixafor (Fig 1A). Monotherapy of MGTA-145 resulted in an immediate increase in neutrophils (Fig 1B) and release of plasma MMP-9 (Fig 1C). Neutrophil mobilization plateaued within 1-hour post MGTA-145 at doses greater than 0.03 mg/kg. This plateau was followed by a rebound of neutrophil mobilization which correlated with re-expression of CXCR2 and presence of MGTA-145 at pharmacologically active levels. Markers of neutrophil activation were relatively unchanged (<2-fold vs baseline). A rapid and statistically significant increase in CD34+ cells occurred @ 0.03 and 0.075 mg/kg of MGTA-145 (p < 0.01) relative to placebo with peak mobilization (Fig 1D) 30 minutes post MGTA-145 (7-fold above baseline @ 0.03 mg/kg). To date, the combination of MGTA-145 plus plerixafor mobilized >20/µl CD34s in 92% (11/12) subjects compared to 50% (2/4) subjects receiving plerixafor alone. Preliminary data show that there was a significant increase in fold change relative to baseline in CD34+ cells (27x vs 13x) and phenotypic CD34+CD90+CD45RA- HSCs (38x vs 22x) mobilized by MGTA-145 with plerixafor. Mobilized CD34+ cells were detectable at 15 minutes with peak mobilization shifted 2 - 4 hours earlier for the combination vs plerixafor alone (4 - 6h vs 8 - 12h). Detailed results of single dose administration of MGTA-145 and plerixafor given on one day as well as also on two sequential days will be presented along with fully characterized graft analysis post apheresis from subjects given MGTA-145 and plerixafor. Conclusions MGTA-145 is safe and well tolerated, as a monotherapy and in combination with plerixafor and induced rapid and robust mobilization of significant numbers of HSCs with a single dose in all subjects to date. Kinetics of CD34+ cell mobilization for the combination was immediate (4x increase vs no change for plerixafor alone @ 15 min) suggesting the mechanism of action of MGTA-145 plus plerixafor is different from plerixafor alone. Preliminary data demonstrate that MGTA-145 when combined with plerixafor results in a significant increase in CD34+ fold change relative to plerixafor alone. Magenta Therapeutics intends to develop MGTA-145 as a first line mobilization product for blood cancers, autoimmune and genetic diseases and plans a Phase 2 study in multiple myeloma and non-Hodgkin lymphoma in 2020. Disclosures DiPersio: Magenta Therapeutics: Equity Ownership; NeoImmune Tech: Research Funding; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy; Incyte: Consultancy, Research Funding; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Macrogenics: Research Funding, Speakers Bureau; Bioline Rx: Research Funding, Speakers Bureau; Celgene: Consultancy; Amphivena Therapeutics: Consultancy, Research Funding. Hoggatt:Magenta Therapeutics: Consultancy, Equity Ownership, Research Funding. Devine:Kiadis Pharma: Other: Protocol development (via institution); Bristol Myers: Other: Grant for monitoring support & travel support; Magenta Therapeutics: Other: Travel support for advisory board; My employer (National Marrow Donor Program) has equity interest in Magenta. Biernat:Medpace, Inc.: Employment. Howell:Magenta Therapeutics: Employment, Equity Ownership. Schmelmer:Magenta Therapeutics: Employment, Equity Ownership. Neale:Magenta Therapeutics: Employment, Equity Ownership. Boitano:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Cooke:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Goncalves:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Raffel:Magenta Therapeutics: Employment, Equity Ownership. Falahee:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Morrow:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Davis:Magenta Therapeutics: Employment, Equity Ownership.

scholarly journals Pre-Clinical Efficacy of Co-Treatment with KDM1A (LSD1) Inhibitor and Ruxolitinib or BET Inhibitor Against Post-MPN-sAML Blast Progenitor Cells

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1274-1274
Author(s):  
Warren Fiskus ◽  
Christopher Peter Mill ◽  
Vrajesh Karkhanis ◽  
Bernardo H Lara ◽  
Prithviraj Bose ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Progenitor Cells ◽  
Board Of Directors ◽  
Research Funding ◽  
Amine Oxidase ◽  
Genetic Alterations ◽  
Advisory Committees ◽  
Bet Inhibitor ◽  
Oncology Research ◽  
Differentiation Block

LSD1 (KDM1A) is an FAD-dependent amine-oxidase that demethylates mono and dimethyl histone H3 lysine 4 (H3K4Me1 and H3K4Me2), which regulates active enhancers and transcription in AML stem/progenitor cells (LSCs). LSD1 is part of the repressor complexes involving HDACs, CoREST or GFI1, mediating transcriptional repression and differentiation block in LSCs that persist in the minimal residual disease (MRD) following attainment of clinical complete remission, leading to relapse and poor outcome in AML. In AML LSCs, genetic alterations and epigenetic dysregulation of enhancers affect levels of myeloid transcriptional regulators, including c-Myc, PU.1, GATA 2 and CEBPα, and their target genes, which are involved in differentiation block in LSCs. Our present studies demonstrate that CRISPR/Cas9-mediated knockout of LSD1 in the AML OCI-AML5 cells significantly increased the permissive H3K4Me2/3-marked chromatin, reduced H3K27Ac occupancy at super-enhancers and enhancers (SEs/Es) (by ChIP-Seq), especially of c-Myc and CDK6, as well as repressed CoREST, c-Myc, CDK6, and c-KIT, while inducing p21, CD11b, and CD86 levels (log2 -fold change by RNA-Seq, and protein expression by Western analyses). This led to significant growth inhibition, differentiation and loss of viability of OCI-AML5 and patient-derived AML blasts (p < 0.01). Similar effects were observed following exposure of OCI-AML5 (96 hours) to tet-inducible shRNA to LSD1. Knock-down of GFI1 by shRNA (by 90%) also inhibited growth and induced differentiation, associated with upregulation of PU.1, p21 and CD11b levels. Treatment with irreversible (INCB059872, 0.25 to 1.0 µM) or reversible (SP2577, 1.0 to 2.0 µM) LSD1 inhibitor (LSD1i) inhibited binding of LSD1 to CoREST, and significantly induced growth inhibition, differentiation and loss of viability (over 96 hours) of the OCI-AML5, post-myeloproliferative neoplasm (post-MPN) sAML SET2 and HEL92.1.7 cells, as well as patient-derived AML and post-MPN sAML blasts (p < 0.01). Co-treatment with INCB059872 and ruxolitinib synergistically induced apoptosis of the post-MPN sAML SET2 and HEL92.1.7 cells and patient-derived CD34+ post-MPN sAML blasts (combination indices < 1.0). Notably, pre-treatment with the LSD1i for 48 hours significantly re-sensitized ruxolitinib-persister/resistant SET2 and HEL92.1.7 cells to ruxolitinib (p < 0.001). We previously reported that treatment with the BET inhibitor (BETi) JQ1 or OTX015 represses SE/E-driven AML-relevant oncogenes including MYC, RUNX1, CDK6, PIM1, and Bcl-xL, while inducing p21 and p27 levels in post-MPN sAML blasts (Leukemia 2017;31:678-687). This was associated with inhibition of colony growth and loss of viability of AML and post-MPN sAML blasts (p < 0.01). Here, we determined that INCB059872 treatment induced similar levels of lethality in BETi-sensitive or BETi-persister/resistant AML and post-MPN sAML cells. Since BETi treatment also depleted LSD1 protein levels, co-treatment with the BETi OTX015 and LSD1i INCB059872 or SP2577 induced synergistic lethality in AML and post-MPN sAML blasts (combination indices < 1.0). Co-treatment with INCB059872 (1.5 mg/kg) and OTX015 (50 mg/kg) both orally for 21 days, compared to each agent alone or vehicle control, significantly reduced the sAML burden and improved survival of immune-depleted mice engrafted with HEL92.1.7 or HEL92.1.7/OTX015-resistant-GFP/Luc sAML xenografts (p < 0.01). Collectively, these findings strongly support further in vivo testing and pre-clinical development of LSD1i-based combinations with ruxolitinib against post-MPN sAML and with BETi against AML or post-MPN sAML cells. Disclosures Bose: CTI BioPharma: Research Funding; Astellas: Research Funding; NS Pharma: Research Funding; Promedior: Research Funding; Constellation: Research Funding; Incyte Corporation: Consultancy, Research Funding, Speakers Bureau; Celgene Corporation: Consultancy, Research Funding; Blueprint Medicine Corporation: Consultancy, Research Funding; Kartos: Consultancy, Research Funding; Pfizer: Research Funding. Kadia:Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Research Funding; Bioline RX: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees. Bhalla:Beta Cat Pharmaceuticals: Consultancy. Khoury:Stemline Therapeutics: Research Funding; Angle: Research Funding; Kiromic: Research Funding. Verstovsek:Ital Pharma: Research Funding; Pharma Essentia: Research Funding; Astrazeneca: Research Funding; Incyte: Research Funding; CTI BioPharma Corp: Research Funding; Promedior: Research Funding; Gilead: Research Funding; Celgene: Consultancy, Research Funding; NS Pharma: Research Funding; Protaganist Therapeutics: Research Funding; Constellation: Consultancy; Pragmatist: Consultancy; Sierra Oncology: Research Funding; Genetech: Research Funding; Blueprint Medicines Corp: Research Funding; Novartis: Consultancy, Research Funding; Roche: Research Funding.

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