scholarly journals Monocytes from Patients with Polycythemia Vera Express Molecules Related to Stress Erythropoiesis and Have Increased Erythrocyte Phagocytosis

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1466-1466
Author(s):  
Marina Dorigatti Borges ◽  
Renata Sesti-Costa ◽  
Dulcinéia Martins de Albuquerque ◽  
Carolina Lanaro ◽  
Kleber Yotsumoto Fertrin ◽  
...  

Abstract Stress erythropoiesis (SE) is characterized by an increase in erythropoietic activity in the bone marrow and in extramedullary sites. The central macrophage present in the erythroblastic island (EBI) plays a key role in regulating SE through the expression of molecules mediating cell adhesion, iron metabolism, and those capable of identifying and engulfing damaged and senescent erythrocytes. Those receptors are also expressed in monocytes (MC), suggesting that their monocytic expression could be involved in erythropoiesis and erythrophagocytosis. CD14 +CD16 + intermediate MC (I-MC) express markers that are typically found in EBI macrophages and, together with CD14 +CD16 - classic MC (C-MC), are able to remove circulating iron. Polycythemia vera (PV) is characterized by autonomous overproduction of red blood cells (RBCs) with extramedullary hematopoiesis most often caused by an acquired JAK2 V617F mutation, resulting in a state of chronic SE. The depletion of macrophages from EBIs in animal model of PV reverses splenomegaly and erythrocytosis indicating that they are essential for the development of chronic SE. It is unknown if MC play the same role in humans or if they have different expressions of those key molecules, which could contribute to the severity of the disease. We aimed to investigate the role of MCs in SE present in PV by characterizing the expression of molecules relevant to RBC adhesion, anti-inflammation, erythrophagocytosis, and iron metabolism in MCs from PV patients and from healthy controls (HC). Peripheral blood MCs were isolated from HC (n=21) and PV patients (n=17) and phenotyped by flow cytometry (FC) for sialoadhesin (CD169), VCAM1 (CD106), the receptor for the hemoglobin-haptoglobin complex (CD163), mannose receptor (CD206), SIRPα (CD172), ferroportin (Fpn), and separated into subtypes according to expression of CD14 and CD16. We also evaluated MC erythrophagocytosis by determining positivity for intracellular glycophorin (CD235a) (nHC=13 and nPV=17). In PV, we observed significantly higher expression of CD169 and CD106, and lower expression of CD172 in C-MC (1,167±216.6 vs 1,834±241.9, p=0.009; 1,427±217.1 vs 2,849±182.3, p=0.0004; 104,707±9,546 vs 77,070±8,756, p=0.0428, respectively); higher CD169 and CD106 in I-MC (2,221±322.4 vs 3,150±321.8, p=0.0371; 2,186±201.7 vs 2,721±153.5, p=0.0238, respectively); and higher CD206, CD163, CD172, and CD106 in CD14 lowCD16 + non-classical MCs (NC-MC) (181.2±8.5 vs 268.6±13.4, p<0.0001; 312.3±15.1 vs 368.8±12.1, p=0.0174; 13,923±2256 vs 22,792±3211, p=0.0161; 1,234±96 vs 1,498±58.9 p=0.004, respectively). Fpn expression was not significantly different. A lower expression of CD172 in the C-MC suggests less inhibitory signaling for erythrophagocytosis in those cells. Although C-MC and I-MC have been previously linked to erythropoiesis, we saw a larger number of the investigated molecules being more expressed in NC-MC, supporting their possible involvement in regulating erythropoiesis. Our results suggest that MCs in PV could be more likely to attach erythroid cells and could therefore contribute to form EBIs if differentiated to macrophages. Higher molecule expression was associated to a higher percentage of MCs containing intracellular CD235a (0.35±0.07 vs 4.48±1.08, p<0.0001). This is evidence of circulating PV MCs performing erythrophagocytosis and supports a role for them in RBC clearance. Our findings reveal an increase in the expression of markers relevant to the adhesion of erythrocytes to MCs in all MC subsets from PV patients along with more frequent erythrocyte phagocytosis in circulating cells. Further studies should yield better understanding of the role of MCs in SE and in the formation of EBIs, providing future targets for the treatment of chronic SE in PV patients. Disclosures Fertrin: Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Costa: Novartis: Consultancy.

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Albert Jang ◽  
Hussein Hamad ◽  
Sarvari Venkata Yellapragada ◽  
Iberia R. Sosa ◽  
Gustavo A. Rivero

Background: Conventional risk factors for inferior outcomes in polycythemia vera (PV) include elevated hematocrit, white blood cell (WBC) count, age, and abnormal karyotype. Weight loss adversely impacts survival in cancer patients. JAK2 myeloproliferative neoplasms (MPN) upregulate tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-8 and induce decreased leptin levels leading to weight loss. The impact of weight loss in PV patients receiving best supportive care (i.e. frontline hydroxyurea [HU] therapy, phlebotomy) on overall survival (OS) is largely unknown. In this study, we seek to investigate: (1) differential effect on survival for weight loss, and (2) variables with predictive value for weight loss among JAK2 inhibitor-naïve PV patients. Methods: After IRB approval, 46 patients at the Michael E. DeBakey VA Medical Center diagnosed with PV between 2000 and 2016 were selected for analysis. Our outcome of interest was OS among PV patients exhibiting weight loss versus patients who maintained, gained weight or had minor weight loss. To objectively estimate weight changes overtime, the difference between baseline BMI [BMI-B] at the time of diagnosis and BMI at last follow-up (BMI-L) was obtained for each patient. Survival analysis was performed for PV patients exhibiting more than 10% weight loss (>10%) versus all other patients (less than 10% loss, stable and increased weight) (<10%) over time. Kaplan-Meier (KM) method was used to determine OS. Cox regression model was performed to assess independent role of different variables including age, blood cell counts and ferritin level Statistical analysis was performed using SAS software. Results: Median BMI loss was 10% (0.03-36.72%); 33/46 (71.7%) and 13/46 (28.2%) patients developed <10% and >10% BMI loss, respectively. Baseline characteristics are summarized in Table 1. Median BMI at last follow up was 21 for PV patients exhibiting >10% BMI loss and 27.7 for PV patients exhibiting <10% BMI loss (p<0.01). Median age was higher among patients exhibiting >10% BMI loss (68 vs 56 y, respectively, p=0.006). A non-significant clinical trend for higher WBC was observed among patients losing >10% BMI (10.9 vs 7.6 K/uL, p=0.08). Median Hemoglobin (Hb), hematocrit (Hct) and ferritin were intriguingly lower in the >10% loss group at 16 vs 18.3 g/dL (p=0.01), 49.3 vs 54.2% (p=0.04) and 29.8 vs 50.6 ng/mL (p=0.09) respectively, while median RDW was higher at 18 vs 15.1% (p=0.01). OS was 9125 days vs 5364 days, in patients with <10% and >10% BMI loss, respectively (p=0.02, HR=0.20; CI 95% 0.04-0.84) (Figure 1). On multivariate analysis, age (hazard ratio [HR], 1.34; p<0.02) and WBC count (HR, 1.57; p<0.01), were predictive of OS. Conclusions: A subgroup of PV patients exhibit progressive weight loss. Over 10% BMI reduction is associated with decreased survival, suggesting that "early weight loss" is an independent clinical variable that predicts high risk PV. While a larger study is needed to validate this observation, this small study highlights the role of leukocytosis, advanced age and weight loss in PV. Confirmation of the observations reported here could unveil an important role for pharmacologic and/or dietary interventions to improve survival among high-risk PV patients. Disclosures Rivero: agios: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 484-484 ◽  
Author(s):  
Jerry L. Spivak ◽  
Donna Marie Williams ◽  
Zhizhuang Joe Zhao ◽  
Ophelia Rogers ◽  
Amy S. Duffield ◽  
...  

Abstract Introduction: The MPN, polycythemia vera (PV), essential thrombocytosis (ET) and primary myelofibrosis (PMF) are clonal stem cell disorders, which share mutations constitutively activating the physiologic signal transduction pathways for hematopoiesis. Although the MPN have different natural histories, they share in common transformation to myelofibrosis and acute leukemia at differing frequencies and not explainable by a specific mutation. Impaired MPL expression, due to incomplete glycosylation is another common denominator amongst the MPN. Significantly, MPL is the only hematopoietic growth factor receptor expressed in MPN HSC, and we have demonstrated that the PV phenotype in a JAK2 V617F transgenic (V617tg) mouse could be abrogated by elimination of MPL or its ligand, TPO. Impaired MPL expression in the MPN cannot be completely explained by receptor-activated down regulation because not all MPN driver mutations directly activate MPL. However, we have discovered another common denominator in the MPN, variant MPL splicing, eliminating 7 amino acids in the MPL N-terminal domain, a common hotspot for both MPL driver and inactivating mutations, which impairs MPL glycosylation and expression. Methods: To determine the role of the MPL splice variant (MPL SV) in MPN pathophysiology, we cloned the full length MPLSV cDNA and created a transgenic mouse (MPLSV tg) using the same VAV promoter as the V617Ftg mouse to ensure hematopoietic cell-specific transcription. The MPLSV tg mice were produced by pronuclear injection of purified MPLSV cDNA into B6SJLF1 mice. Founders were crossed into a C57Bl/6 background, and then were crossed with V617Ftg mice in either an MPL knockout or wild type background. Mice were phenotyped by blood counts and necropsy with morphologic and immunophenotyping of bone marrow and tumor masses. Results: Amongst 19 founder B6SJLF1 mice, 6 expressed the MPLSV transgene with copy numbers ranging from one to 30; single copy number mice had no hematopoietic phenotype but all mice with higher MPLSV tg copy numbers had thrombocytopenia (median platelet count 500,000/µL; range 200- 600,000; wild type, 750,000/µL; 550-950,000). MPLSV tg mice from several different founders bred into a C57Bl/6 background for 6 generations maintained consistent copy numbers, Mendelian ratios and hematopoietic phenotypes with 100% penetrance and an inverse correlation between MPLSV copy number and the platelet count. The number of double transgenic (V617Ftg/MPLSV tg) offspring observed in the MPLSV tg to V617Ftg crosses were slightly lower than expected (20% vs 25%), indicating reduced embryo viability. Four week old V617Ftg/MPLSV tg mice displayed tumorous abnormalities of the head and hips as well as small size and failure to thrive (median weight 8.5 gms; range 8-9; wild type, 13 gms; 10-14), and enlarged spleens (median weight 0.29 gms; range 0.15-0.64; wild type 0.086 gms; 0.05-0.10). Histologically, the V617Ftg/MPLSV tg-associated head and hip abnormalities represented monomorphic myeloid sarcomas extending through the calvarium both extra and intracranially and from the femur into surrounding muscle. Both the marrow and spleen were diffusely infiltrated by large blasts with abundant basophilic cytoplasm, expressing CD34, CD61 and CD117 but lacking CD127, consistent with a myeloid origin. All V617Ftg/MPLSV tg mice either died or required humane sacrifice by 6 weeks. The extramedullary tumor was transplantable in secondary recipients, and flow cytometry-based phenotyping showed that the tumors (both primary and secondary) were CD34, CD117, CD61 and CD71- positive. Penetrance of the leukemia phenotype was 100% in V617Ftg/MPLSV tg from all founder lines with multiple copies of the MPLSV tg, whether in an MPL knockout or wild type background. The leukemia phenotype was never observed with the MPLSV tg alone or with V617Ftg alone despite observation of over 300 V617Ftg mice up to 50 weeks of age. Conclusion: We identified an MPL SV in human MPN that was functional in mice with a dominant-negative effect with respect to platelet production and at the same time synergized with JAK2 V617F to create a fulminant myeloid malignancy. We have recently shown that knockout of MPL or TPO alone abrogates the PV phenotype in the V617Ftg mouse, whereas the MPLSV uniquely drives a highly penetrant and fulminant leukemia, establishing MPL and TPO as targets for mitigation of malignant transformation in the MPN. Disclosures Spivak: Incyte: Membership on an entity's Board of Directors or advisory committees. Moliterno:incyte: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1602-1602
Author(s):  
Alberto Alvarez-Larrán ◽  
Paola Guglielmelli ◽  
Eduardo Arellano-Rodrigo ◽  
Martin Griesshammer ◽  
Chiara Paoli ◽  
...  

Abstract Young patients (age < 60 years) with essential thrombocythemia (ET) and no history of thrombosis are considered at low risk of thrombosis and therefore managed on a conservative approach with antiplatelet therapy or even without any treatment. JAK2 V617F and CALR exon 9 mutations are the most frequent molecular alterations observed in ET, with CALR-positive ET being considered a distinct clinical entity due to its higher platelet counts and lower incidence of thrombosis as compared with JAK2 V617F-positive ET. There is some evidence supporting a role for antiplatelet therapy in JAK2 V7617F-positive neoplasms. However, the role of antiplatelet therapy in CALR-positive ET has not been studied. The aim of the present study was to assess the effect of antiplatelet therapy in the primary prevention of thrombosis in patients with CALR-positive ET without indication of cytoreductive therapy. For such purpose, 240 patients (107 males, 133 females) diagnosed with ET at a median age of 42 years (range 13-59) were included in a multicenter retrospective study. Initial treatment consisted of antiplatelet therapy (n=109) or careful observation (n=108), whereas 23 patients received cytoreduction since diagnosis and were excluded. During a median follow up of 8 years, 137 patients were started on cytoreductive therapy because of the following indications: age > 60 years (n=10), thrombosis (n=10), bleeding (n=2), microvascular symptoms (n=18), extreme thrombocytosis (n=89), and others (n=8). Median time free of cytoreductive therapy was 3.2 years. Thrombosis-free survival restricted to the time of cytoreductive therapy abstention was calculated using the Kaplan-Meier method. Variables attaining a significant level at the univariate analysis were included in a Cox proportional hazard model. During the period of abstention of cytoreductive therapy, a total of 10 thrombotic events and 8 major bleeding episodes were registered. The probability of thrombosis at 3 years was 5% in patients managed with careful observation and 1% in those receiving antiplatelet therapy (p = 0.2). At multivariate analysis, antiplatelet therapy did not result in a lower risk of thrombosis after correction for age, sex and presence of cardiovascular risk factors. Interaction studies did not identify any subgroup of patients that benefited from antiplatelet therapy in thrombosis prevention. Regarding major bleeding, patients receiving antiplatelet therapy experienced a higher rate than those managed on observation (3-year probability of major bleeding, 5.5% and 0%, respectively, p=0.05). At multivariate analysis, antiplatelet therapy was associated with a tendency towards and increased risk of major bleeding (HR: 7.7, 95%CI: 0.9-66.2, p=0.06) independently of platelet count at diagnosis, age and gender. In conclusion, CALR-mutated low-risk ET patients under cytoreductive therapy abstention may not obtain a clear benefit from antiplatelet therapy since the increase in the rate of bleeding may offset the reduction in the rate of thrombosis Disclosures García-Gutierrez: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Harrison:CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Gilead: Honoraria; Sanofi: Honoraria, Speakers Bureau; Shire: Speakers Bureau. Cervantes:Sanofi-Aventis: Consultancy; Novartis: Consultancy, Speakers Bureau; CTI-Baxter: Consultancy, Speakers Bureau. Vannucchi:Shire: Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2947-2947
Author(s):  
Srdan Verstovsek ◽  
Jean-Jacques Kiladjian ◽  
Monika Wroclawska ◽  
Tuochuan Dong ◽  
Alessandro M. Vannucchi

Introduction: The RESPONSE trial (NCT01243944) compared ruxolitinib (Rux) and best available therapy (BAT) in pts with polycythemia vera (PV) who were intolerant of or resistant to hydroxyurea (HU) according to modified European LeukemiaNET criteria. In the primary analysis, at week (Wk) 32, 60% of (pts) randomized to Rux achieved HCT control (HCT <45%). The present analysis evaluated the effect of baseline characteristics on HCT response at Wk 32, and aimed to determine the long-term clinical efficacy of Rux in pts who did and did not achieve the protocol-defined HCT control (i.e., HCT control responders and non-responders at Wk 32) in RESPONSE at Wk 256. Methods: Adult pts with phlebotomy-dependent PV with splenomegaly, and resistant to or intolerant of HU were enrolled. Pts were randomized to receive Rux (at a starting dose of 10 mg BID) or single-agent BAT (1:1). HCT control was defined as lack of phlebotomy eligibility between Wks 8−32 with no more than 1 phlebotomy eligibility between randomization and Wk 8. Phlebotomy eligibility was based on protocol-defined HCT values (HCT > 45% and ≥ 3 percentage points higher than baseline or > 48%, whichever was lower; regardless of receipt of phlebotomy), and pts with missing data or assessments outside of protocol-defined time windows were considered non-responders. In this analysis, a logistic regression model was fitted to identify the significant baseline factors to predict HCT control response at Wk 32. Time to phlebotomy eligibility in the HCT control responders and time from the first phlebotomy eligibility to the second phlebotomy eligibility in the HCT control non-responders were plotted, and the changes in hematological parameters (HCT, WBC and platelet count), spleen volume and allele burden over time, up to Wk 256, were studied in HCT control responders and non-responders who were randomized to Rux treatment arm in RESPONSE. Results: A total of 222 pts were randomized to receive either Rux (n = 110) or BAT (n = 112). Baseline WBC (P=0.0198) and baseline JAK2 V617F allele burden (P=0.0159), were found to be predictors of the HCT response within Rux treated pt group (n = 110). In the HCT responder subgroup of the Rux arm, 23% (15/66) pts needed their first phlebotomy by Wk 256. In the HCT non-responder subgroup of the Rux arm, out of 28 patients who experienced their first phlebotomy between Wk 8 and Wk 32, 64% (18/28) of pts required subsequent phlebotomy by Wk 256, with a median duration of 28.4 Wks (12.7, NA). Pts receiving Rux demonstrated controlled hematologic parameters (HCT, WBC, and platelets) over the course of study, regardless of whether they were HCT control responders and HCT control non-responders at Wk 32. From Wk 48 to Wk 80, 97% HCT control responder pts and 84% HCT control non-responder pts of the Rux treatment arm required no phlebotomies. From Wk 80 to Wk 256, 91% and 68% of the evaluable pts in the Rux treatment arm remained phlebotomy-free for HCT control responders and non-responders, respectively. By Wk 256, spleen volume on an average was reduced from baseline by approximately 35% and 50% for HCT control responders and non-responders, respectively. In pts with available assessments, allele burden on an average was reduced approximately from 80% at baseline to 55% at Wk 256 in the HCT control responders, and approximately from 70% at baseline to 40% at Wk 256 in the HCT control non-responders. Conclusions: The results from present analysis demonstrated that the benefits of the Rux treatment were not limited to pts who achieved HCT control at Wk 32. Patients treated with Rux were able to maintain hematological parameters, spleen volume reduction, and JAK2 V617F allele burden reduction for a longer duration (up to 5 years), regardless of whether they were HCT control responders or non-responders at Wk 32. Disclosures Verstovsek: Constellation: Consultancy; Pragmatist: Consultancy; Incyte: Research Funding; Roche: Research Funding; NS Pharma: Research Funding; Celgene: Consultancy, Research Funding; Gilead: Research Funding; Promedior: Research Funding; CTI BioPharma Corp: Research Funding; Genetech: Research Funding; Blueprint Medicines Corp: Research Funding; Novartis: Consultancy, Research Funding; Sierra Oncology: Research Funding; Pharma Essentia: Research Funding; Astrazeneca: Research Funding; Ital Pharma: Research Funding; Protaganist Therapeutics: Research Funding. Kiladjian:Novartis: Honoraria, Research Funding; Celgene: Consultancy; AOP Orphan: Honoraria, Research Funding. Wroclawska:Novartis Pharma AG: Employment. Dong:Novartis: Employment. Vannucchi:Celgene: Membership on an entity's Board of Directors or advisory committees; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Italfarmaco: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2844-2844
Author(s):  
Giovanni Barosi ◽  
Mohan Agarwal ◽  
Sonja Zweegman ◽  
Wolfgang Willenbacher ◽  
Sima Pakstyte ◽  
...  

Abstract Abstract 2844 Background: Myeloproliferative neoplasms, including PMF, PET-MF, and PPV-MF, are a group of clonal stem cell–derived diseases characterized by bone marrow fibrosis, splenomegaly, and debilitating constitutional symptoms. Ruxolitinib (rux), a potent oral JAK1 & 2 inhibitor, demonstrated rapid and durable reductions in splenomegaly and improved MF-related symptoms and quality of life in 2 phase 3 studies (COMFORT-I and -II). Due to unmet medical need, rux has been made available through an individual patient supply program (IPSP) outside the US. Methods: Patients (pts) with PMF, PPV-MF, or PET-MF requiring treatment (as determined by their physician) and classified as high-, intermediate (int)-2–, or int-1–risk with an enlarged spleen were evaluated for eligibility on an individual basis by the sponsor, irrespective of JAK2 mutation status. The starting dose of rux was determined on the basis of baseline platelet count (15 or 20 mg twice daily for pts with platelet counts of 100–200 × 109/L and > 200 × 109/L, respectively) and can be adjusted for efficacy and safety. Dose changes during treatment, adverse events (AEs), and serious AEs (SAEs) are registered throughout the program. Results: To date, 1339 requests have been received from > 800 physicians in 48 countries, including locations in Europe, Latin America, the Middle East, and Asia. The baseline characteristics are shown in the Table for pts whose requests for access were approved (n = 1240). Drug resupply requests are received every ≈ 3 months. Follow-up information, based on the first resupply request, was available for 381/639 (60%) of the pts who were enrolled in the program prior to February 2012; 303 (80%) remain on rux therapy, 37 (10%) have discontinued, 11 (3%) died, and 30 (8%) did not initiate therapy. Spleen response was available for 247 pts (decreased, n = 201; unchanged, n = 39; increased, n = 7). Changes in constitutional symptoms were available for 203 pts (decreased, n = 151; unchanged, n = 49; increased, n = 3). In pts enrolled in the IPSP undergoing rux treatment, most pts who had a decrease in spleen length also had a decrease in symptoms. Dose-modification information was available for 259 pts, of whom 44 had dose increases and 89 had dose decreases. Reasons for dose modifications included efficacy (n = 28), safety (n = 69), and other reasons (n = 36). Safety information was available for 266 pts; 75 reported significant AEs or SAEs as determined by investigators. Enrolled pt characteristics are generally similar to those expected in the overall MF pt population. Thus far, the proportion of pts enrolled in the IPSP with the JAK2 V617F mutation (73%) is higher than that for the general MF population (50%-60%). This may reflect a misconception that JAK inhibition is primarily effective in pts who have the JAK2 V617F mutation, when in fact rux has demonstrated similar efficacy in both pt types in the phase 1/2 251 study and the two phase 3 COMFORT trials. This may also be reflected in the higher proportion of PPV-MF pts in the IPSP than in the general MF population (28% vs 10%-15%), of whom 95% are JAK2 V617 F–positive. Conclusions: Considerable requests for access to rux have been received through the IPSP, highlighting the need for an effective treatment in pts with a range of IPSS risk-assessment scores. The demographics of the IPSP pts are similar to those expected in the overall MF population. Responses and safety patterns observed in the IPSP appear to be comparable to those from the COMFORT trials. Disclosures: Off Label Use: Jakafi™ (ruxolitinib) is indicated in the United States for the treatment of patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post–polycythemia vera myelofibrosis and post–essential thrombocythemia myelofibrosis. In Canada, JAKAVI ® is indicated for the treatment of splenomegaly and/or its associated symptoms in adult patients with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post-polycythemia vera myelofibrosis or post-essential thrombocythemia myelofibrosis. This abstract reports on a clinical study conducted outside the US including patients of all risk categories. All patients have provided written informed consent. Zweegman:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Willenbacher:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Raymakers:Novartis: Consultancy. Cantoni:CSL Behring Switzerland: Research Funding; Robapharm/Pierre Fabre Oncology Switzerland: Research Funding; Janssen-Cilag Switzerland: Consultancy; Novartis Oncology Switzerland: Consultancy, Research Funding. Modi:Novartis Pharmaceuticals Corporation: Employment. Khan:Novartis: Employment. Perez:Novartis Pharmaceuticals Corporation: Employment, Equity Ownership. Gisslinger:AOP Orphan Pharmaceuticals AG: Consultancy, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau. Lavie:Novartis: Membership on an entity's Board of Directors or advisory committees. Harrison:Sanofi Aventis: Honoraria; YM Bioscience: Consultancy, Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau; Shire: Honoraria, Research Funding.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5563-5563
Author(s):  
Archrob Khuhapinant ◽  
Kamoltip Lertchaisataporn ◽  
Ployploen Phikulsod ◽  
Noppadol Siritanaratkul

Abstract Background: Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are members of myeloproliferative neoplasm group. They shared common features such as JAK2 V617F+ mutation, thrombosisor hemorrhage, progression to marrow fibrosis or acute leukemia. Objective: To study incidence and clinical characteristics of PV, ET and PMF with complications and treatment modalities in Thailand. Study Designs: Retrospective chart review Methods: All JAK2 V617F+ and V617F- mutation patients during 2008-2012 were reviewed for demographic data, diagnosis of PV, ET and PMF according to WHO 2008 criteria, complications and treatment. Results: 363 of 735 patients were 140 PV, 172 ET, 47 PMF and 4 MPN-U. 372 patients were excluded due to routine thrombotic workup (98), secondary erythrocytosis (97), reactive thrombocytosis (55), CML (26), HES/eosinophilia (24), MPN/MDS (3), others (69). In PV, JAK2 V617F+ and JAK2 exon 12 mutation patients were 106 and 2. PV showed male:female ratio of 85:55, mean age 57.7 year (11-86), mean hemoglobin 17.6 g/dl (6.7-24.6), and received aspirin (125), hydroxyurea (116), phlebotomy (84), clopidogrel (10), warfarin (7), anagrelide (6), busulfan (5) and each for interferon, oxymethalone, corticosteroid, and JAK inhibitor. Thrombosis:hemorrhage was 34:16. Myelofibrosis and AML transformation were 7 and 2. In ET, JAK2 V617F+ patients were 121. ET showed male:female ratio of 83:89, mean age 59.45 year (14-91), mean platelet count 924,168/mm3 (283,000-2,235,000), and received aspirin (140), hydroxyurea (139), anagrelide (47), warfarin (11), clopidogrel (7), erythropoietin (6), oxymethalone (3), busulfan (3), corticosteroid (2), interferon (1) and splenectomy (1). Thrombosis:hemorrhage was 52:16. Myelofibrosis and AML transformation were 4 and 1. In PMF, JAK2 V617F+ patients were 32. PMF showed male:female ratio of 21:26, mean age 62.2 year (23-81), mean hemoglobin 8.6 g/dl (3.7-15.5), mean subcostal splenic size 10 cm (1-26) and received hydroxyurea (26), erythropoietin (16), corticosteroid (10), oxymethalone (8), JAK inhibitor (7), transfusion dependency (6), aspirin (3), warfarin (2) and each for anagrelide, thalidomide, splenectomy and allogeneic transplantation. Thrombosis:hemorrhage was 4:5. AML transformation was 4. In multivariate analysis, previous thrombosis, clopidogrel use, splenomegaly, alcohol use and JAK2 V617F+ were independent risk factors for thrombosis. Conclusion: PV, ET and PMF carry high risk for vascular events. Disclosures Khuhapinant: Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: 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; Celgene: Honoraria. Phikulsod:Novartis: Honoraria. Siritanaratkul:Novartis: Research Funding; Roche: Research Funding; Janssen: Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2827-2827
Author(s):  
Susan C Rhodes ◽  
Rafaella Gavriilidou ◽  
Mark W. Drummond ◽  
Mhairi Copland ◽  
Helen Wheadon

Abstract Polycythemia vera (PV) is characterized by the presence of the Janus kinase 2 (JAK2) V617F mutation in 97% of patients. This results in constitutive activation of the JAK/signal transduction and activators of transcription (STAT) pathway. JAK2 can also enter the nucleus directly following SUMOylation to effect alterations in histone function. Patients with PV display elevated peripheral blood counts, chronic inflammation and cytokine driven symptoms leading to morbidity and reduced quality of life. An important target of inflammation via JAK-mediated interferon (IFN) signalling is promyelocytic leukemia protein (PML), necessary for nuclear body (NB) formation. NBs act as a hub for transcriptional regulation and histone modification, bringing together multiple proteins to elicit diverse cellular functions including apoptosis, cellular senescence, DNA repair and inflammatory responses. Multiplex analysis of a 29 cytokine/chemokine panel in normal donor (n=8) and PV patient (n=10) serum, indicated significant upregulation of inflammatory cytokines through both JAK2-dependent and independent signalling, including IFNγ, interleukin (IL)-5, IL-12 (p< 0.05; JAK2 dependent), and CXCL10, MIP-1α and TNF-α (p< 0.001; JAK2 independent). PV patients also had significant deregulation of JAK2 dependent and IFN response genes (n=84 genes) especially upregulation of GBP1 (p< 0.05), MGST3 and SUMO3 (p< 0.001) and downregulation of PML (p< 0.01) and NFκB (p< 0.001). Using Duolink® in situ proximity ligation assays in both JAK2 V617F cell lines (UKE1 and SET2) and PV patient/normal donor monocytes, we demonstrate that JAK2 is SUMOylated and actively co-localises with PML in the cell nucleus. Importantly, there was a significant increase in the degree of interaction between JAK2 and PML in PV monocytes compared to normal donors (n=3, p< 0.001). Treatment of UKE1 and SET2 cell lines with the JAK1/2 inhibitor ruxolitinib led to a decrease in JAK2 dependent and IFN response genes as well as the degree of JAK2/PML co-localisation indicating active JAK2 mediates these responses. To determine whether the deregulation of these cellular processes is manifested by a functional alteration in the myeloid lineages of patients with PV, we analysed their monocyte profiles and the ability of monocytes to form M1 and M2 macrophages as well as neutrophil function. Monocytes exist in different subsets defined by the expression of CD14 and CD16. In PV, the proinflammatory intermediate subset was significantly increased (16.4% ±2.04 vs 6.5% ±1.08, p< 0.05, n=5) at the expense of the classical subset of monocytes (79% ±2.04 vs 88.9% ±1.07, p< 0.05, n=5). The non-classical, IL-1RA producing subset remains unchanged (3.6% ±0.38 vs 4.6% ±0.48 p= 0.1). Macrophages generated from these monocytes were polarized for M1 or M2 differentiation using GM-CSF and M-CSF respectively. They were then cultured in the presence of normal or PV patient serum with or without stimulation; IFNγ and lipopolysaccharide (LPS) for M1 macrophages and IL-4 for M2 macrophages. Culture supernatant was then assessed for the same 29 cytokine/chemokine panel as above and showed significant alterations including an increase in IL-6 and CXCL10 in PV derived M1 macrophages (p< 0.001), while M2 macrophages had a decrease in CXCL1 and increase in IL-1RA (p< 0.01). Neutrophils were cultured for 24 hours in the presence of normal or PV patient serum with or without stimulation with LPS and showed significant alteration in the production of several proinflammatory cytokines/chemokines compared to neutrophils cultured in Promocell Base Media DXF alone including IFNγ, VEGF, and CXCL10 (p< 0.001), indicating that serum from PV patients can elicit neutrophil activation. In conclusion, we have shown that inflammation is a major pathophysiological process in PV patients resulting in increased PML/JAK2 co-localisation, increased transcription of direct JAK2 target and IFN response genes, high circulating proinflammatory cytokine/chemokine levels, altered proinflammatory monocyte profiles, and significant change in the secretory production of mature granulocytes following stimulation. Treatment of JAK2 V617F positive cell lines with ruxolitinib significantly alters the inflammasome supporting its efficacy in the treatment of PV patients to alleviate the symptoms and complications of chronic inflammation. Disclosures Drummond: Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees. Copland:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4087-4087
Author(s):  
Paola Guglielmelli ◽  
Annalisa Pacilli ◽  
Giada Rotunno ◽  
Alessandro Pancrazzi ◽  
Tiziana Fanelli ◽  
...  

Abstract Background. The JAK1/2 inhibitor ruxolitinib (RUX) demonstrated clinical benefit compared with best available therapy (BAT) in patients (pts) with polycythemia vera (PV) in a phase 3 study (RESPONSE TRIAL) (NEJM 2015; 372:426). A reduction of JAK2 V617F allele burden of 12.1% from baseline at week (w)32 was observed in pts receiving ruxolitinib compared to BAT (1.2%). Conversely, no information was available about other mutations that may occur in some PV pts. Aim. To analyze the molecular landscape of PV pts enrolled in the RESPONSE trial specifically as regarded subclonal mutations. Methods: In the RESPONSE study, PV pts with intolerance or refractoriness to hydroxyurea, showing an enlarged spleen volume (SV) >450 ml and phlebotomy requirement, were randomized (1:1) to receive RUX (n = 110) or BAT (n = 112). After institutional approval and informed written consent, samples for genotyping were available in 150 cases (67.5% of total, 75 each RUX and BAT). Mutations in 22 genes (JAK1, JAK2, JAK3, EZH2, ASXL1, TET2, IDH1, IDH2, CBL, SRSF2, DNMT3A, NFE2, SOCS1, SOCS2, SOCS3, SH2B3, STAT1, STAT3, STAT5A, STAT5B, SF3B1, U2AF1) were analyzed in blood DNA at baseline and at the latest available sample by deep sequencing with Ion Torrent-PGM. CALR mutations were analyzed by capillary electrophoresis. JAK2 V617F allele burden was confirmed by RT-qPCR assays. Results. 149/150 patients had informative sequencing results (RUX, n = 74 and BAT, n = 75). Mutation frequency at baseline in RUX pts was: JAK2 V617F 97.3% (mean allele burden=83.7±20.0%); JAK2Exon12 1.3%; other mutations in JAK2 5.4%; JAK3 1.3%; ASXL1 4.0%; TET2 20.3%; EZH2 4.0%; CBL 1.3%; SH2B3 2.0%; SOCS1 2.7%; NFE2 2.7%; STAT5A 1.3%. No somatic variants were detected in CALR, JAK1, SRSF2, IDH1, IDH2, SOCS2, SOCS3, DNMT3, STAT1, STAT5B, SF3B1, U2AF1. These frequencies were comparable in BAT arm. One patient was un-mutated in all assessed genes. 28.4% and 8.1% of RUX and 32.0% and 8.0% in BAT pts had 1 and >2 subclonal mutations, respectively. The proportion of PV pts harboring at least 1 mutation in either ASXL1, EZH2, SRSF2, IDH1/2, was significantly lower (8.1% in RUX and 10.6% in BAT) compared to reference series of primary myelofibrosis pts (31%) as it was for those having >2 HMR mutations (0.0 in RESPONSE vs 7.4% in PMF) (Leukemia 2014;28:1804) The median duration of treatment corresponding to the latest available sample for analysis was 82.8w; at that time, 43 pts (58.1%) randomized to RUX achieved a JAK2 V617F allele burden reduction ≥10%, of which 15 (20.3%) had >50% reduction. Among the latter pts, the median allele burden was 83.7% at baseline, 84.9%, 55.1% and 44.3% at 1, 2, and 3 years. Three patients attained an allele burden below 5% (from 65.1%, 17.3% and 83.7% at baseline to 3.2%, 0.5% and 1.4%, respectively, at latest follow up). Of the 27 pts harboring subclonal mutations at baseline, 12 (44.4%) presented a reduction of mutational allele burden ≥10%: 4 in JAK2 (other than JAK2 V617F/exon 12 mutations), 4 in TET2, 3 in ASXL1 and 1 each in JAK3, EZH2 and SH2B3. In 10 of the 12 pts, comparable decreases in JAK2 V617F allele burden were observed, suggesting reduction of a single clone expressing both mutations. Conversely, in 5 pts (18.5%) the allele burden of a baseline TET2 clone at increased by ≥10% (range: 10-37%); of these, one had concurrent reduction of JAK2 V617F burden from 17.3 to 0.5, thereby suggesting two independent clones. Eight pts (29.6%) acquired new mutations: 3 in TET2, 3 in U2AF1, 1 in DNMT3A and 1 in IDH1. Among these, 4 pts had achieved a reduction ≥10% of JAK2 V617F allele burden (18.4%, 25.4%, 30.5% and 39.4%, respectively). Three pts (4.0%) progressed during treatment (2 myelofibrosis,1 acute leukemia); no novel acquired mutation in the 22 genes was observed in these pts. All 3 pts were homozygous for V617F (92.3%, 72.7% and 59.0%) and did not show appreciable changes of allele burden during treatment. Conclusions. The current study identifies mutations and mutational combinations at baseline and during follow up in a representative cohort of pts enrolled in RESPONSE trial and treated with Ruxolitinib. We observed progressive reduction of JAK2 V617F allele burden that in some cases was associated with concurrent reduction of subclonal mutations. Conversely, emergency of novel clones as observed in some pts, whose significance might be clarified by ongoing analysis of hydroxyurea and phlebotomy treated patients that will be presented at the meeting. Disclosures Mahtab: Novartis Pharma AG: Employment. Rodriguez:Novartis Pharma: Employment. Vannucchi:Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Shire: Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 886-886
Author(s):  
Partow Kebriaei ◽  
Matthias Stelljes ◽  
Daniel J. DeAngelo ◽  
Nicola Goekbuget ◽  
Hagop M. Kantarjian ◽  
...  

Abstract Introduction: Attaining complete remission (CR) prior to HSCT is associated with better outcomes post-HSCT. Inotuzumab ozogamicin (INO), an anti-CD22 antibody conjugated to calicheamicin, has shown significantly higher remission rates (CR/CRi and MRD negativity) compared with standard chemotherapy (SC) in patients (pts) with R/R ALL (Kantarjian et al. N Engl J Med. 2016). Pts treated with INO were more likely to proceed to HSCT than SC, which allowed for a higher 2-yr probability of overall survival (OS) than patients receiving SC (39% vs 29%). We investigated the role of prior transplant and proceeding directly to HSCT after attaining remission from INO administration as potential factors in determining post-HSCT survival to inform when best to use INO in R/R ALL patients. Methods: The analysis population consisted of R/R ALL pts who were enrolled and treated with INO and proceeded to allogeneic HSCT as part of two clinical trials: Study 1010 is a Phase 1/2 trial (NCT01363297), while Study 1022 is the pivotal randomized Phase 3 (NCT01564784) trial. Full details of methods for both studies have been previously published (DeAngelo et al. Blood Adv. 2017). All reference to OS pertains to post-HSCT survival defined as time from HSCT to death from any cause. Results: As of March 2016, out of 236 pts administered INO in the two studies (Study 1010, n=72; Study 1022, n=164), 101 (43%) proceeded to allogeneic HSCT and were included in this analysis. Median age was 37 y (range 20-71) with 55% males. The majority of pts received INO as first salvage treatment (62%) and 85% had no prior SCT. Most pts received matched HSCTs (related = 25%; unrelated = 45%) with peripheral blood as the predominant cell source (62%). The conditioning regimens were mainly myeloablative regimens (60%) and predominantly TBI-based (62%). Dual alkylators were used in 13% of pts, while thiotepa was used in 8%. The Figure shows post-transplant survival in the different INO populations: The median OS post-HSCT for all pts (n=101) who received INO and proceeded to HSCT was 9.2 mos with a 2-yr survival probability of 41% (95% confidence interval [CI] 31-51%). In patients with first HSCT (n=86) the median OS post-HSCT was 11.8 mos with a 2-yr survival probability of 46% (95% CI 35-56%). Of note, some patients lost CR while waiting for HSCT and had to receive additional treatments before proceeding to HSCT (n=28). Those pts who went directly to first HSCT after attaining remission with no intervening additional treatment (n=73) fared best, with median OS post-HSCT not reached with a 2-yr survival probability of 51% (95% CI 39-62%). In the latter group, 59/73 (80%) attained MRD negativity, and 49/73 (67%) were in first salvage therapy. Of note, the post-HSCT 100-day survival probability was similar among the 3 groups, as shown in the Table. Multivariate analyses using Cox regression modelling confirmed that MRD negativity during INO treatment and no prior HSCT were associated with lower risk of mortality post-HSCT. Other prognostic factors associated with worse OS included older age, higher baseline LDH, higher last bilirubin measurement prior to HSCT, and use of thiotepa. Veno-occlusive disease post-transplant was noted in 19 of the 101 pts who received INO. Conclusion: Administration of INO in R/R ALL pts followed with allogeneic HSCT provided the best long-term survival benefit among those who went directly to HSCT after attaining remission and had no prior HSCT. Disclosures DeAngelo: Glycomimetics: Research Funding; Incyte: Consultancy, Honoraria; Blueprint Medicines: Honoraria, Research Funding; Takeda Pharmaceuticals U.S.A., Inc.: Honoraria; Shire: Honoraria; Pfizer Inc.: Consultancy, Honoraria, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Research Funding; BMS: Consultancy; ARIAD: Consultancy, Research Funding; Immunogen: Honoraria, Research Funding; Celgene: Research Funding; Amgen: Consultancy, Research Funding. Kantarjian: Novartis: Research Funding; Amgen: Research Funding; Delta-Fly Pharma: Research Funding; Bristol-Meyers Squibb: Research Funding; Pfizer: Research Funding; ARIAD: Research Funding. Advani: Takeda/ Millenium: Research Funding; Pfizer: Consultancy. Merchant: Pfizer: Consultancy, Research Funding. Stock: Amgen: Consultancy; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Wang: Pfizer: Employment, Equity Ownership. Zhang: Pfizer: Employment, Equity Ownership. Loberiza: Pfizer: Employment, Equity Ownership. Vandendries: Pfizer: Employment, Equity Ownership. Marks: Pfizer: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 41-42
Author(s):  
Cristina Panaroni ◽  
Keertik Fulzele ◽  
Tomoaki Mori ◽  
Chukwuamaka Onyewadume ◽  
Noopur S. Raje

Multiple myeloma (MM) originates in the bone marrow where adipocytes occupy 65% of the cellular volume in a typical myeloma patient. Cancer associated adipocytes support the initiation, progression, and survival of solid tumors via mechanisms including adipokine secretion, modulation of the tumor microenvironment, and metabolic reprogramming of cancer cells. Although MM cells are surrounded by abundant bone marrow adipocytes (BMAd), the nature of their interaction remains unclear. Recent studies have elucidated the role of BMAds in supporting the survival of MM cells, in part, through secreted adiponectin. Increased fatty acid (FA) metabolism may result in metabolic reprogramming of cancer cells impacting their growth and survival. Here, we hypothesize that MM cells extract FA from adipocytes for their growth. We first characterized mesenchymal stem cells (MSCs) from MGUS, smoldering MM (SMM), and newly diagnosed MM (NDMM) patients by flow cytometry analysis. MSCs showed significant increase in Pref1, leptin receptor and perilipin A, suggesting increased adipogenic commitment. MSCs from healthy donors (HD), MGUS, SMM, and NDMM patients were induced to differentiate into adipocytes and then co-cultured with human MM MM.1S cells. After 72 hr of co-culture, CyQUANT assay demonstrated significant increase in proliferation of MM.1S cells in the presence of BMAd from HD; this was further increased in the presence of BMAd from MGUS/SMM and NDMM. These data suggest that the BMAd support the growth of MM cells and this effect is more pronounced in patient derived BMAd. A PCR-array targeting lipid metabolism on BM fat aspirates showed significant deregulation of genes involved in FA synthesis and lipolysis. Taken together, our data suggest that BMAd in MM patients are altered to further support the aggressive expansion of MM cells. The proliferative-supportive role of adipocytes was further validated in co-culture of OP9 murine BM stromal preadipocytes with 5TGM1 murine MM cells. To study the bidirectional interaction of MM/ BMAd, mature OP9 adipocytes were co-cultured with 5TGM1 or human OPM2 MM cells for 24 hr. Intracellular lipid droplets were labelled with Deep Red LipidTox stain. The lipid droplet sizes were significantly decreased in the presence of both 5TGM1 and OPM2 cells compared to OP9 alone. The decrease in lipid size suggested that MM cells may induce lipolysis in adipocytes. Indeed, 24hr co-culture of 5TGM1 cells with OP9 mature adipocytes significantly increased lipolysis 3-fold as measured by glycerol secretion in conditioned media. Co-culture of OP9 adipocytes with other MM cell lines of human origin, MM.1S, INA6, KMS-12 PE, and OPM2 also significantly increased the glycerol production as much as 4-fold. Taken together these data indicate that MM cells induce lipolysis in adipocytes. In contrast, treatment of 5TGM1 cells with synthetic catecholamine isoproterenol did not induce lipolysis, or glycerol production, indicating lack of triglyceride storage. Next, we hypothesized that the free FAs released from adipocytes are taken up by MM cells for various biological processes. To test this, 5TGM1, MM.1S and OPM2 cells were incubated with BODIPY-C12 and BODIPY-C16, the BODIPY-fluorophore labelled 12-carbon and 16-carbon long chain FA. All MM cells showed saturated uptake of the FA within 10 minutes suggesting that MM cells have efficient FA transporters. To confirm this uptake, unstained 5TGM1, OPM2 and KMS12 PE cells were co-cultured with the LipidTox-labelled OP9 mature adipocytes. After 24 hours, flow cytometric analysis showed LipidTox signal in MM cells. These data demonstrate that FAs released by MM induced adipocyte lipolysis are taken up by MM cells. Long-chain FAs such as BODIPY-C12 and BODIPY-C16 are transported into cells through FA transporter protein (FATP) family of lipid transporters. We therefore analyzed patient samples which showed that CD138+ plasmacells and myeloma cells expressed high levels of FATP1 and FATP4 whereas, their expression was absent in lineage-sibling T-cells. Moreover, pretreatment with Lipofermata, a FATP inhibitor, was able to decrease the uptake of BODIPY-C12 and -C16 in 5TGM1 cells. Taken together, our data show that myeloma cells induce lipolysis in adipocytes and the released free FAs are then uptaken by myeloma cells through FATPs. Inhibiting myeloma cell induced lipolysis or uptake of FA through FATPs may be a potential anti-tumor strategy. Disclosures Fulzele: FORMA Therapeutics, Inc: Current Employment, Other: Shareholder of Forma Therapeutics. Raje:Amgen: Consultancy; bluebird bio: Consultancy, Research Funding; Caribou: Consultancy, Membership on an entity's Board of Directors or advisory committees; Immuneel: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy; Celgene: Consultancy; Immuneel: Consultancy; Janssen: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy.


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