Final Results of the Fibromet Trial: An Open Label Phase II Study to Evaluate Metformin Effects on Bone Marrow Fibrosis and Disease Progression in Primary Myelofibrosis Patients

Abstract Background: Primary myelofibrosis (PMF) is a chronic myeloproliferative neoplasm characterized by myeloid expansion associated with elevation of cytokines involved in fibrosis, angiogenesis, and osteosclerosis, leading to progressive fibrous connective tissue deposition in the bone marrow (BM) and BM failure. Although JAK2, CALR and MPL mutations are frequently seen in PMF, patients' molecular heterogeneity and the lack of an expressive clinical and laboratory response following JAK1/2 inhibitors suggest that other factors, such as unknown protein interactions, additional mutations or epigenetic mechanisms may be involved in the progression of PMF. Metformin (MTF) is an anti-diabetic drug, which has been described to possess anti-cancerous properties through the modulation of the AMPK/TORC1 pathway, thereby causing apoptosis in neoplastic cells. Previous reports demonstrated that MTF significantly reduced Ba/F3 JAK2V617F tumor burden and splenomegaly in Jak2V617F knock-in-induced MPN mice. In this context, our goal was to evaluate the effects of MTF treatment in PMF patients. Aims: To report final results of an open label phase II trial (FIBROMET), which evaluated outcomes of PMF patients after 24mo on MTF treatment. Methods: PMF non-diabetic adults were eligible. Patients received MTF in increasing doses until a maximum of 2500mg PO daily, according to tolerance. Primary endpoint was BM fibrosis reversion. Secondary endpoints included reduction of inflammation and downregulation of the JAK-STAT pathway. Samples were collected at the time points: screening (0), 3mo, 6mo, 12mo, 18mo and 24mo. The extent of collagen deposits in BM biopsies was semi-quantitatively assessed with Masson's trichrome stainings, following the recommendations of the European Consensus on grading of BM fibrosis (grades 0, 1, 2 or 3). The levels of CXCL4, sIL-2Ra, IP-10, VEFG-A, MIG, MCP-1, MIP-1b, FGF-2, IL-1RA, IL-5, IL-6, IL-8, IL-15, IL-18, TNFa and TGFb1 were analyzed in BM samples using multiplex assay. Phosphorylation status of intracellular proteins STAT3 and STAT5 was analyzed by flow cytometry and the percentage of cells was recorded using FlowJo software. This trial was approved by the Institutional and National Review Board; written informed consent was obtained from all subjects. REBEC registry number: RBR-52ty66. Results: 11 patients (aged 40-84y) were included between Aug/2018- Feb/2019. Two subjects had early treatment discontinuation due to non-related causes. One patient had disease progression after 12mo of treatment and was submitted to BM transplantation. The median exposure to MTF was 21 mo (3-24) and the median dose was 2500mg/day (1500-2500mg). The most frequent adverse event was diarrhea. No life threatening event occurred. BM collagen deposits were independently evaluated by two hematopathologists with an overall agreement of 80.64% (grade 0: 100%, grade 1: 62.5%, grade 2: 60.0%, grade 3: 90.0%); discordant cases were submitted to joint review. BM collagen deposits did not change when different time points were compared. After 24mo of MTF treatment, a significant 35.4% reduction in IL-5 levels was observed (p=0.03); a 36% reduction in MCP-1 levels was also observed, however this finding was not statistically significant (p=0.06). Flow cytometry analysis demonstrated a STAT3 phosphorylation decrease when comparing screening samples versus 6, 12, 18 and 24 mo of MTF use (all p<0.05), as well as a STAT5 phosphorylation decrease when comparing screening samples versus 6 and 12 mo (all p<0.05). Mean fluorescence intensity for pSTAT3 was: screening 12.01±2.58, 3mo 7.24±1.19, 6mo 4.40±0.24, 12mo 6.31±0.47, 18 mo 6.89±1.01, 24mo 5.71±1.18; and for pSTAT5: screening 15.32±3.59, 3mo 11.50±3.74, 6mo 4.67±0.45, 12mo 6.25±0.58, 18mo 6.24±0.81, 24mo 4.98±0.72. Conclusions: Final results of the FIBROMET trial demonstrated that, in our study population, metformin was not capable of reversing established bone marrow fibrosis in PMF patients. However, a significant downregulation of the JAK-STAT pathway and reduction of cytokine secretion was observed. Finally, metformin showed to be a safe and well-tolerated drug. Phase III studies are required to confirm our results and to evaluate whether MTF treatment in early PMF phases could delay the progression of BM fibrosis through the downregulation of the JAK-STAT pathway. Disclosures Pagnano: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pintpharma: Other: Lecture; EMS: Other: Lecture; Jansenn: Other: Lecture. OffLabel Disclosure: Metformin for Primary Myelofibrosis treatment.

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Analysis of Metformin Effects on Bone Marrow Fibrosis and Disease Progression in Primary Myelofibrosis Patients: Preliminary Results of an Open Label Phase II Trial (FIBROMET)

Blood ◽

10.1182/blood-2019-130648 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 554-554 ◽

Cited By ~ 2

Author(s):

Paula De Melo Campos ◽

Katia B Pagnano ◽

Rubia Mancuso ◽

Francisco Breno S. Teófilo ◽

Juan L Coelho-Silva ◽

...

Keyword(s):

Bone Marrow ◽

Disease Progression ◽

Insulin Signaling ◽

Primary Myelofibrosis ◽

Pcr Array ◽

Open Label ◽

Time Points ◽

Tnf Α ◽

Open Label Phase ◽

Stat Pathway

Background: Primary Myelofibrosis (PMF) is a chronic myeloproliferative neoplasm (MPN) characterized by increased myeloid proliferation and associated with mutations that induce tyrosine-kinase activation mainly via JAK-STAT pathway, culminating in extensive bone marrow (BM) fibrosis in the course of disease progression. In contrast to the monoclonal origin of hematopoietic cells, fibroblasts proliferation is polyclonal, and mediators involved in fibrosis, neoangiogenesis and osteosclerosis seem to be involved in disease progression. Metformin (MTF) is a biguanide that exerts selective antineoplastic activity in a variety of malignancies, through its action on nutrients privation and hypoxia, leading to apoptosis. In JAK2-mutated cell lines, MTF reduced cell viability, proliferation and clonogenicity, while in Jak2V617F knock-in-induced mice, MTF reduced Ba/F3 JAK2V617F tumor burden and splenomegaly. These data suggest that MTF could have a therapeutic effect in PMF patients. Aims: To conduct an open label phase II study to evaluate MTF effects on BM fibrosis, inflammation mediators, JAK-STAT pathway activation and disease progression in PMF patients. Methods: PMF non-diabetic adults were eligible. Subjects with severe renal function impairment were not included. Patients received MTF (Glifage XR®) in rising doses until a maximum of 2500mg PO daily, according to tolerance. Primary endpoint was BM fibrosis reversion. Secondary endpoints included reduction of inflammation and downregulation of the JAK-STAT pathway. Clinical data was systematically compiled. Blood and BM samples were collected at the time points: pretreatment (0), 3 mo and 6 mo. Collagen was evaluated in BM biopsy specimens by Masson's trichrome stain: three representative areas from each slide were analyzed and the collagen/sample area was quantified using Image J software; the mean percentage of each slide was used for statistics. IL-6, IL-8 and TNF-α levels were analyzed in BM samples using multiplex assay. Phosphorylation status of intracellular proteins STAT3 and STAT5 was analyzed by flow cytometry and the percentage of cells was recorded using FlowJo software. In order to evaluate gene modulation following MTF exposure, samples at time points 0 and 6 mo were analyzed by PCR array for insulin signaling genes (PAHS-030Z, Qiagen). Genes with ±1.5 fold-change in both directions were selected for validation. For each experiment, statistical analysis was performed and a p value <0.05 was considered statistically significant. Results were expressed as medians (min-max). This trial was approved by the Institutional and National Review Board; written informed consent was obtained from all subjects. Results: 11 patients (aged 40-84y) were included. Two subjects had early treatment discontinuation due to non-related causes. The median exposure to MTF was 10 mo (5-11) and the median dose was 2000mg/day (1500-2500mg). The most frequent adverse event was diarrhea (n=3). No life threatening event occurred. A reduction in BM collagen area percentage was observed comparing pretreatment biopsies (26.9% (14.8-53.1%)) versus 3 months (3.8% (2.3-4.0%), p=0.062) and versus 6 months of MTF use (0.84% (0.12-17.1%), p=0.125), however, this result was not statistically significant probably due to the low number of patients analyzed (n=5). IL-6, IL-8 and TNF-α levels did not differ between time points. Flow cytometry analysis demonstrated a trend in STAT3 phosphorylation decrease when comparing pretreatment samples versus 6 months of MTF use, though this result was not statistically significant (p=0.06). Mean fluorescence intensity for pSTAT3 was: pretreatment 10.53 ± 5.75, 3 mo 7.34 ± 2.4, 6 mo 5.41 ± 1.14; and for pSTAT5: pretreatment 14.03 ± 7.41; 3 mo 10.71 ± 7.74; 6 mo 6.03 ± 1.41. PCR array for insulin signaling genes showed 21 genes downregulated after 6 months of MTF treatment, including genes previously associated with MPN phenotype: INS (0 and 6 mo treatment fold-decrease: 0.18), NOS2 (0.24), VEGFA (0.34), LEP (0.34), IGFBP1 (0.38) and IRS2 (0.62). Conclusions: In this study, metformin showed to be a safe and well-tolerated drug. Our preliminary results demonstrated a trend in BM collagen reduction in PMF patients following metformin treatment. Downregulation of important genes associated with MPN phenotype was also noted. The trial is ongoing and these results will be validated at other time points for all subjects. Disclosures Pagnano: Abbvie: Consultancy; Pint Pharma: Consultancy; Sandoz: Consultancy.

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Efficacy, Safety, and Confirmation of the Recommended Phase 2 Dose of Ruxolitinib Plus Panobinostat in Patients with Intermediate or High-Risk Myelofibrosis

Blood ◽

10.1182/blood.v124.21.711.711 ◽

2014 ◽

Vol 124 (21) ◽

pp. 711-711 ◽

Cited By ~ 6

Author(s):

Jean-Jacques Kiladjian ◽

Florian H Heidel ◽

Alessandro M. Vannucchi ◽

Vincent Ribrag ◽

Francesco Passamonti ◽

...

Keyword(s):

Bone Marrow ◽

High Risk ◽

Board Of Directors ◽

Research Funding ◽

Phase Iii ◽

Spleen Volume ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Expansion Phase ◽

Marrow Fibrosis

Abstract Background: Myelofibrosis (MF) is a clonal neoplastic disease resulting in bone marrow fibrosis, splenomegaly, and debilitating constitutional symptoms. The Janus kinase (JAK) pathway is often dysregulated in MF, and agents targeting this pathway have demonstrated efficacy in this disease. Ruxolitinib (RUX), a potent JAK1/JAK2 inhibitor, demonstrated superiority in spleen volume reduction, symptom improvement, and survival compared with the control arm in the phase III COMFORT-I and COMFORT-II studies. Panobinostat (PAN), a potent pan-deacetylase inhibitor (pan-DACi), inhibits JAK signaling through disruption of the interaction of JAK2 with the protein chaperone heat shock protein 90. In phase I/II studies, PAN has shown splenomegaly reduction and improvement of bone marrow fibrosis. The combination of RUX and PAN demonstrated synergistic anti-MF activity in preclinical studies. These preliminary results led to the initiation of a phase Ib study evaluating the combination of RUX and PAN in patients (pts) with MF. The updated results from the expansion phase of this trial are presented here. Methods: Eligible pts had intermediate-1, -2, or high-risk primary MF, post-polycythemia vera MF, or post-essential thrombocythemia MF by International Prognostic Scoring System criteria, with palpable splenomegaly (≥ 5 cm below the costal margin). The primary objective was determination of the maximum tolerated dose (MTD) and/or recommended phase II dose (RPIID). Secondary objectives included safety, efficacy, and pharmacokinetics. Exploratory endpoints included assessment of improvement in bone marrow fibrosis and reduction of JAK2 V617F allele burden. The treatment schedule was RUX (5-15 mg) twice daily (bid) every day and PAN (10-25 mg) once daily 3 times per week (tiw; days 2, 4, and 6) every other week (qow) in a 28-day cycle. Following dose escalation and identification of the potential RPIID, additional pts were enrolled into the expansion phase and treated at this dose. Results: As of March 14, 2014, a total of 61 pts were enrolled (38 escalation phase and 23 expansion phase). The median duration of exposure to PAN and to RUX was 24.6 weeks and 24.0 weeks, respectively, for pts treated in the expansion phase. Three DLTs were observed in the escalation phase (grade 4 thrombocytopenia [n = 2], grade 3 nausea [n = 1]). No MTD was reached. The RPIID was confirmed to be RUX 15 mg bid and PAN 25 mg tiw qow in May 2014. Among the 34 pts treated at the RPIID, grade 3/4 adverse events (AEs) regardless of causality included anemia (32%), thrombocytopenia (24%), diarrhea (12%), asthenia (9%), and fatigue (9%). AEs led to discontinuation in 6% of pts treated at the RPIID. Two pts treated at the RPIID died due to causes unrelated to study treatment (1 due to myocardial infarction and 1 due to progression of myelofibrosis). Among the pts treated at the RPIID, 79% showed a >50% decrease in palpable spleen length, with 100% decrease (non-palpable spleen) being observed in 53% of pts. Additionally, 48% of pts treated at the RPIID in the expansion phase achieved ≥35% reduction in spleen volume (Figure). These results are similar to those observed for spleen volume response at 24 weeks among pts who received single-agent RUX on the phase III COMFORT-I (41.9%) and COMFORT-II (32%) studies. Conclusions: The combination of the JAK1/JAK2 inhibitor RUX and the pan-DACi PAN was well tolerated and resulted in high rates of reductions in splenomegaly in pts with intermediate- and high-risk MF. Although a relatively larger proportion of patients experienced spleen volume reductions at week 24 as compared to the COMFORT studies, the smaller sample size, shorter follow up times and potential differences in the patient populations preclude definitive comparisons. Similar to COMFORT-I and II trials, hematological AEs, specifically anemia and thrombocytopenia, were the most common AEs observed in pts treated with the combination therapy. Pts continue to be treated in the expansion phase at the RPIID. Updated safety, efficacy, and exploratory analyses on bone marrow fibrosis, JAK V617F allele burden, and biomarkers, including cytokines, will be presented. Figure Change in Spleen Volume in Expansion Phase Figure. Change in Spleen Volume in Expansion Phase Disclosures Kiladjian: Novartis: Honoraria, Research Funding, Speakers Bureau; Shire: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Honoraria, Research Funding. Heidel:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Ribrag:Celgene: Consultancy; Pharmamar: Consultancy; Epizyme: Research Funding; Bayer: Consultancy, Research Funding; Servier: Consultancy, Honoraria, Research Funding. Conneally:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kindler:Novartis: Consultancy. Acharyya:Novartis: Employment. Gopalakrishna:Novartis: Employment. Ide:Novartis: Employment, Equity Ownership. Loechner:Novartis: Employment. Mu:Novartis: Employment. Harrison:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria; CTI: Consultancy, Honoraria; Gilead: Honoraria; SBio: Consultancy; Shire: Speakers Bureau.

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A Phase 2 Study to Evaluate the Efficacy and Safety of Simtuzumab in Adult Subjects with Primary, Post Polycythemia Vera (PV) or Post Essential Thrombocythemia (ET) Myelofibrosis

Blood ◽

10.1182/blood.v126.23.2810.2810 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2810-2810

Author(s):

Srdan Verstovsek ◽

Michael R. Savona ◽

Ruben A. Mesa ◽

Stephen Oh ◽

Hua Dong ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Phase 2 ◽

Fibrosis Score ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Equity Ownership ◽

Stage 1 ◽

Marrow Fibrosis

Abstract Background: Simtuzumab (SIM) is a humanized monoclonal antibody that inhibits lysyl oxidase-like molecule 2 (LOXL2), an extracellular matrix enzyme that catalyzes the covalent cross-linking of collagen and is widely expressed across many fibrotic diseases. In pre-clinical models, inhibition of LOXL2 blocks fibroblast activation, which plays an important role in the development of organ fibrosis. In Phase 1 studies, SIM was well-tolerated in patients (pts) with advanced solid tumors, liver fibrosis, and idiopathic pulmonary fibrosis (IPF). A Phase 2, open-label study to determine the efficacy of SIM alone (Stage 1) and combined with ruxolitinib (rux) (Stage 2) in pts with primary myelofibrosis (PMF) and post-ET/PV MF was initiated. Methods: Eligible pts had intermediate-1, intermediate-2, or high risk disease and Eastern Cooperative Oncology Group performance status of <2. The primary endpoint was rate of clinical response as defined by a reduction in bone marrow fibrosis score following 24 weeks of treatment with SIM. Patients were randomized in a 1:1 ratio to receive 200 mg or 700 mg SIM by intravenous infusion every 2 weeks as monotherapy (Stage 1, n=24) or combined with rux (Stage 2, n=30). Patients received SIM for up to 24 weeks. Bone marrow biopsies and aspirates were performed approximately every 3 months. Bone marrow fibrosis scoring was performed and quantified at local investigator sites using the European Consensus on Grading Bone Marrow Fibrosis. Myelofibrosis symptoms were evaluated using the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and changes in hematologic parameters and splenomegaly were assessed. Results: Between 7/14/11 and 9/22/14, 54 pts were randomized and treated (200 mg SIM [n=12], 700 mg SIM [n=12], 200 mg SIM/rux [n=15], and 700 mg SIM/rux [n=15]). In Stage 1, 0 subjects (0%) in the SIM 200 mg group and 2 subjects (16.7%; 90% CI 3.0%, 43.8%) in the SIM 700 mg group showed a reduction in bone marrow fibrosis score from Baseline to Week 24. In Stage 2, 1 subject (6.7%; 90% CI 0.3%, 27.9%) in the SIM 200 mg/rux group and 2 subjects (13.3%, 90% CI 2.4%, 36.3%) in the SIM 700 mg/rux group showed a reduction in bone marrow fibrosis score from Baseline to Week 24. In an exploratory analysis, similar numbers of subjects showed increases in bone marrow fibrosis scores. SIM treatment was not associated with meaningful improvements in hematologic parameters or reductions in MPN-SAF score or spleen size. The most frequent adverse events were those commonly associated with MF, including constitutional symptoms and reductions in hematological parameters. Conclusions: SIM treatment alone or in combination with rux is safe but does not reliably reduce bone marrow fibrosis in pts with MF. The reason for reduction of marrow fibrosis in some patients and increase in others is unclear and may be sampling variability. Clinical studies of SIM in IPF and liver fibrosis are ongoing. Disclosures Savona: Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Research Funding; Astex Pharmaceuticals, Inc: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Mesa:Incyte Corporation: Research Funding; CTI Biopharma: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Pfizer: Research Funding; Promedior: Research Funding; Genentech: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding. Oh:CTI Biopharma: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees. Dong:Gilead Sciences: Consultancy, Equity Ownership. Thai:Gilead Sciences: Employment, Equity Ownership. Gotlib:Allakos, Inc.: Consultancy.

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Transcriptional Landscape of the Microenvironment in Bone Marrow Fibrosis at Single Cell Level

Blood ◽

10.1182/blood-2019-126897 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1675-1675

Author(s):

Nils B. Leimkühler ◽

Ronghui Li ◽

Helene Gleitz ◽

Inge Snoeren ◽

Stijn Fuchs ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Cell Level ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Molecular Alterations ◽

Ecm Proteins ◽

Travel Grant ◽

Marrow Fibrosis

Although the molecular alterations in hematopoietic cells which drive the development of myeloproliferative neoplasms (MPN) have been largely defined, reactive cellular alterations in the non-hematopoietic compartment remain rather obscure and have not been studied at single cell level. We therefore profiled enriched non-hematopoietic bone marrow cells by scRNAseq in bone marrow (BM) fibrosis compared to healthy marrow. BM fibrosis was induced by transplantation of hematopoietic stem and progenitor cells (HSPCs) with overexpression of Thrombopoietin (ThPO) into lethally irradiated mice. As ThPO-overexpression robustly leads to reticulin fibrosis in all mice (100%), we were able to study 1) pre-fibrosis (5 weeks after transplantation; reticulin fibrosis grade 0) and 2) manifest bone marrow fibrosis (10 weeks after transplantation, reticulin grade 2-3). The analysis revealed a total of 8 distinct clusters: 1-4) subpopulations of mesenchymal stromal cells (MSC-1: adipogenic, MSC-2: osteogenic, MSC-3: transition, MSC-4: interferonhigh), 5) osteoblastic lineage cells (OLCs), 6) arterial endothelial cells (ECs) and 7-8) Schwann cell precursors (SCP-1: non-myelinating SCPs; SCP-2: myelinating SCPs). Exposure to ThPO overexpressing HSPCs resulted in an overrepresentation of adipogenic MSCs at the expense of all other MSC subclusters. Differential gene expression analysis revealed a functional reprogramming of the "adipogenic" expanding MSCs with down-regulation of hematopoiesis-support and induction of a secretory phenotype including upregulation of various extracellular matrix (ECM) proteins driving fibrosis. Interestingly, only two MSC subclusters gained significant ECM expression indicating myofibroblast differentiation. Expansion of OLCs in BM fibrosis suggested a differentiation of the underrepresented MSC subpopulations into osteolineage cells which was confirmed by pseudotime analysis. Myelinating SCPs, highly expressing interleukin-33 (IL-33), showed the largest expansion in fibrosis. IL-33 is described to play a significant role in solid organ fibrosis by having both pro- and anti-fibrotic effects. Nerve injury triggers the expansion of myelinating and non-myelinating Schwann cells to promote repair, suggesting that mSCPs increase as compensatory and regenerative mechanism for the previously described MPN-induced sympathetic neuropathy. Dissection of cellular and molecular alterations in pre-fibrosis and manifest fibrosis demonstrated that only one MSC subpopulation was already significantly expanded in the pre-fibrotic phase, but only showed minor transcriptional changes. The upregulation of ECM proteins, osteogenesis as well as proinflammatory genes were hallmark features of manifest fibrosis. Interestingly, the overrepresentation of IL-33 expressing mSCPs was more pronounced in the pre-fibrotic phase, indicating that the expansion is a regenerative phenomenon failing in the stages of manifest fibrosis. Our findings were validated in the clinically relevant JAK2(V617F)-induced model of myelofibrosis. In conclusion, we here identified two distinct MSC subsets that are pro-fibrotic and contribute to osteosclerosis in PMF. The functional reprogramming of these MSCs in the bone marrow niche was accompanied by expansion of mSCPs with regenerative capacities, most likely caused by neural damage and Schwann cell death triggered by mutant HSCs. Disclosures Crysandt: Amgem: Other: travel grant; Pfizer: Other: travel grant; Gilead: Other: travel grant; Incyte: Membership on an entity's Board of Directors or advisory committees; celgene: Other: travel grant. Koschmieder:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers-Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Ariad: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AOP Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; CTI: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis Foundation: Research Funding.

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Thrombopoietic Agents in the Treatment of Childhood Immune Thrombocytopenia (ITP): Clinical Treatment At 2 Centers

Blood ◽

10.1182/blood.v118.21.2230.2230 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2230-2230

Author(s):

Kavitha Ramaswamy ◽

Loan Hsieh ◽

Hatice Melda Ürekli ◽

Diane J. Nugent ◽

James B Bussel

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Rescue Therapy ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Equity Ownership ◽

The Mean ◽

Marrow Fibrosis

Abstract Abstract 2230 Introduction: Thrombopoietic agents (TPO-A) are widely used in adults for difficult ITP. However only 1 study has been published describing the use of a TPO mimetic (Nplate) in 22 children with ITP. This study is a post hoc analysis of 32 children (<21yr) who received clinical treatment (off study) with either Nplate or Promacta. Methods: All children described are from 2 centers:,Weill Cornell in New York (n=22, 9 on Nplate, 13 on Promacta) and Childrens Hospital Orange County (10, all on Nplate). All patients in this abstract were treated off study although some had previously participated in the AMGEN195 (Pediatric) followed by AMGEN 213 (long term maintenance) studies. Responses (taken from the published study) were defined as platelet count (plt ct) > 50k on 2 consecutive weeks, plt increase ≥ 20k on 2 consecutive weeks, and the percent of weeks at ≤ 50k independent of rescue therapy. Rescue therapy e.g. IVIG, steroids, plt transfusion, resulted in counts being considered “non-responder” for 2 full weeks after initiation of treatment. Bone marrows were evaluated for reticulin fibrosis (RF) using consensus grades 0–3. Several patients had more than one marrow during treatment; in these cases, the most recent on-therapy marrow was used. Results: The median age of patients on Nplate was 10 years of age (2–19) while for those on Promacta it was 16 years (5–19). Of the 32 patients treated with TPO-A, 24 responded with a plt ct ≥ 50k twice; 19/32 received Nplate and 15/19 responded; 13/32 received Promacta and 9/13 responded. Plt increases ≥ 20k were seen in 23 of 32 patients. The number of patients whose platelet count was ≥ 50k for at least 50 percent of visits was 20/32. The mean number of previous treatments for responders to Nplate was 3.2 while for Nplate non-responders it was 2.25. For Promacta, the mean for responders was 2.9 treatments and for non-responders 3 treatments. Younger patients did not seem to respond as well to treatment with either TPO-A (see table). Nplate patients received treatment for a mean of 19.2 weeks; for patients treated with Promacta it was 13.7 weeks. Baseline bone marrows were available in 17 patients of whom 6 had grade 1 reticulin fibrosis (RF). There were 10 children with marrows performed after the start of TPO-A: 2 with RF score=0, 7 with score=1+, and 1 with score=2+ Adverse events (AEs) other than bone marrow fibrosis and bleeding (lack of efficacy) were all 1–2+ and not related to TPO-A. In particular, no thrombosis or development of malignancy was seen. In conclusion, TPO-A were an effective treatment of chronic ITP in the 32 consecutive children retrospectively analyzed here from 2 centers. Younger children in this study seemed not to respond as well as older children, in contrast to small numbers of young children in published data who responded very well. No major changes were seen in the bone marrows but a formal baseline and on therapy study in children is needed to assess this issue. AEs were infrequent and tolerable. Additional studies with both Nplate and Promacta, either planned or in progress, are needed to clarify the response rates, AEs eg bone marrow fibrosis, and effects in subgroups of children. Disclosures: Bussel: Portola: Consultancy; Eisai: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlaxoSmithKline: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Cangene: Research Funding; Genzyme: Research Funding; Immunomedics: Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sysmex: Research Funding.

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Bone Marrow Fibrosis In Immune Thrombocytopenia (ITP) Patients Treated With Thrombopoietin Receptor Agonists (TRA) – a Single Center Long-Term Follow-Up

Blood ◽

10.1182/blood.v122.21.3527.3527 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3527-3527

Author(s):

Waleed Ghanima ◽

Julia Turbiner Geyer ◽

Christina Soo Lee ◽

Attilio Orazi ◽

Leonardo Boiocchi ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Single Center ◽

Duration Of Treatment ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Equity Ownership ◽

Marrow Fibrosis

Abstract Introduction TRAs increase platelet counts by stimulating the TPO-receptor. A known effect of TRA treatment is increased bone marrow fibrosis (MF). This study explored extent of MF, its clinical relevance, and incidence of phenotypic or karyotypic abnormalities in TRA-treated ITP patients. Methods This single-center study was carried out at the Platelet Disorders Center of Weill Cornell Medical College (WCMC), NY, USA. Eligibility criteria were: diagnosis of ITP; treatment with a TRA (romiplostim, eltrombopag, AKR 501 (Eisai) or Shionogi agent), ≥ 1 bone marrow biopsy (BMB) performed during TRA treatment. BMBs were performed every 1–2 years as standard f/u procedure for our ITP patients on TRA. MF grade was assessed from MF-0 to MF-3 according to the European Consensus Grading System in 141 BMBs acquired prior to (n=15), during (n=117) and after (n=9) TRA-treatment from 66 patients. Fifty disease-free staging BMBs served as controls. BMBs were separately reviewed by 3 pathologists to assess the grade of MF and then reviewed concurrently as needed to reach consensus. The study was approved by the IRB of WCMC; informed written consent was obtained from patients. Results Median (Q1-Q3) age at the time of 1st BMB was 38 years (18-63); 34 males 32 females. 32 patients had > 2 on-treatment BMBs. The distribution of MF-grades is shown in the figure. The proportion of MF-0 decreased from 67% in pretreatment biopsies (BM0) to 21% in the first set of BMBs (BM1); in the 15 patients with pre- and on-treatment BMBs there was a significantly higher number of MF-0 in BM0 as compared to BM1 (10/15 vs. 3/15;p=0.016) suggesting that TRAs induce fibrosis in treated patients. In patients with multiple on-treatment BMBs (n=32), first on-treatment BMB was graded as MF-1 in 24. In the last set of biopsies (BM-Last) 8 had progressed to MF-2/3, 12 remained MF-1, and 4 became MF-0 illustrating the unpredictability of the future course of MF from the first on-treatment marrow. Nonetheless, a higher number of MF-2/3 BMB was found in BM-Last as compared to BM1 [10 (31%) vs. 3 (9%) of 32; p=0.039]. In 5 patients with MF-2/3 BMB, TRA were discontinued: on f/u 2 had less fibrosis, 1 remained the same, and 2 are awaiting f/u BMB. BMB was graded MF-0 in 54% and MF-1 in 46% of control BMB; no difference was found in the proportion of MF-0/1 and 2/3 in BM0 compared to controls, but increased MF-2/3 was seen in BM-last compared to controls (p<0.001). At BM-last in patients dichotomized by MF-0/1 vs. MF-2/3, differences in hemoglobin levels (13.6 vs. 12.4 g/dl, respectively), absolute neutrophil counts (4.8 vs. 7 x109/L), platelet counts (92 vs. 123 x109/L), and LDH levels (212 vs. 219 U/L) were not significantly different. Of the following 6 clinical factors: age, duration of disease, duration of treatment, splenectomy status, type and dose of agent; only age was significantly higher in patients with MF-2/3 as opposed to MF0/1 at time of BM-last [57 vs. 38 years; p=0.01]. There was a tendency toward longer duration of treatment in patients with MF-2/3 as compared to MF-0/1 (3.6 y vs. 2.7y; p=0.16). Flow cytometric immunophenotyping of BMB in 89 examinations did not reveal emergence of clonal abnormalities. Cytogenetic analysis in 72 BMBs did not show any clonal karyotypic abnormalities. Conclusions This large single center experience indicates that TRAs induce some degree of MF as supported by: 1) decreasing fraction of MF-0 after initiation of TRA, 2) decreasing fraction of MF-0/1 (normal grades of MF) in subsequent on-treatment BMBs, 3) increasing fraction of MF-2/3 (pathological grades) in patients with multiple on-treatment BMBs. Only older age was associated with higher grades of fibrosis. However, MF remained stable in most patients within the range found in normal individuals. Higher grades of MF (MF-2/3) observed in some patients were not clinically significant based on peripheral blood counts. Overall, since a number of patients developed MF-2 and even MF-3, this suggests a risk of progressive fibrosis in approximately 20% of patients. No neoplastic immunophenotypic or karyotypic abnormalities emerged during treatment with TRAs. Annual or bi-annual follow-up with BMB should be carefully considered in TRA-treated patients. Discontinuation of TRA should be encouraged in those who develop/progress to MF-3 and possibly even MF-2 to avoid potential further progression of MF Disclosures: Bussel: Amgen: Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Research Funding; GlaxoSmithKline: Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Cangene: Research Funding; Genzyme: Research Funding; IgG of America: Research Funding; Immunomedics: Research Funding; Ligand: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Eisai: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Shionogi: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Sysmex: Research Funding; Symphogen: Membership on an entity’s Board of Directors or advisory committees.

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Dynamic Stromal Changes in Myelofibrosis Patients Pre/Post JAK Inhibition Is Revealed in Clinically Archived Bone Marrow Biopsies By Smooth Muscle Actin (SMA)-CD34 Dual Immunohistochemistry

Blood ◽

10.1182/blood-2021-151458 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3286-3286

Author(s):

Katelyn Wang ◽

Iran Rashedi ◽

James T. England ◽

Rashmi S. Goswami ◽

Larissa Liontos ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Smooth Muscle Actin ◽

Muscle Actin ◽

Analysis Pipeline ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Bone Marrow Biopsies ◽

Marrow Fibrosis

Abstract The natural history of BCR-ABL1 negative myeloproliferative neoplasms (MPNs) is progression towards an overt myelofibrotic (MF) phase with variable risk to develop secondary acute myeloid leukemia. Current treatments include Janus kinase inhibitors (JAKi) which can temporarily alleviate MF-related symptoms but are non-curative and most patients eventually progress to a more advanced stage. Given the negative prognostic impact of bone marrow fibrosis in MPNs and generally poor outcome post JAKi failure, it would be important to identify in situ biomarkers that address the initiation, perpetuation and early reversal of the fibrotic reaction. The current clinical standard for bone marrow fibrosis assessment involves reticulin/trichrome stains that detect relatively static extracellular matrix products rather than the fibrosis driving cells directly. To address this, we have developed a smooth muscle actin stromal-vascular (SMA-CD34) dual immunohistochemical (IHC) technique amenable to morphologic scoring and complemented with a CellProfiler image analysis pipeline. SMA was prioritized over other validated stromal IHC markers given work by others in experimental models demonstrating SMA+ myofibroblasts to be the differentiated output of critical fibrosis inducing Gli1+ 'driver' mesenchymal stem/progenitor cells in MPN. Herein, we demonstrate the feasibility of our translational approach using a clinically annotated cohort of MF patients from the Princess Margaret Cancer Centre MPN Registry. After selecting for high quality (>1.0 cm) paired pre and post JAKi biopsies amenable to image and transcriptome-based analysis, the pilot cohort was comprised of 13 cases with 38% high-risk, 54% intermediate-2 and 8% intermediate-1 risk by DIPSS. Driver mutations were JAK2 V617F (77%), CALR (15%) and other (8%). JAKi therapies included ruxolitinib (31%) + pelabresib (23%), momelotinib (15%), itacitinib (15%) and pacritinib (8%). The SMA-CD34 stromal assessment at baseline revealed distinct interstitial myofibroblast patterns and vascular perturbations not captured by conventional clinical hematopathology assessment (e.g. SMA+ dilated sinusoids). A SMA-CD34 scoring system was developed using a 4-point scale representing normal (0 pts), increased vascularity (1 pt), focal interstitial SMA (2 pts), multifocal interstitial SMA (3 pts) and diffuse SMA (4 pts). Scoring was then performed by blinded hematopathologists. A trend towards JAK2 mutated MF cases demonstrating higher SMA grade at baseline was noted. Interestingly, variable trajectories in SMA scores emerged following treatment with JAKi. Specifically, SMA signals had increased in 15%, decreased in 46% and were stable in 38% post-JAKi when using a morphologic SMA grading scheme. When compared to reticulin fibrosis, the severity of SMA signals had diverged in 1/3 of the cases (e.g. SMA grade decreased, reticulin grade stable). To further complement the SMA-CD34 morphologic grading, a CellProfiler image analysis pipeline was developed yielding a non-vessel associated normalized SMA area metric as a supervised correlate of the clinical SMA scoring system (R 2 = 0.68). Additional supervised and unsupervised bioinformatic approaches for clustering of relevant SMA-CD34 features including an algorithm that informs SMA spatial patterns with respect to niche elements such as arterioles (CD34+SMA+), sinusoids (CD34+) and adipocytes is in development. Lastly, Nanostring Fibrosis V2 panel was employed on a subset that met RNA concentration and quality metrics. Exploratory interpretation showed significant differentially expressed genes in pre vs. post JAKi specimens related to lipid metabolism such as ADIPOR1, SCD, ELOVL6 as well as the chemokine CXCL16. This may suggest a link between fatty acid metabolism and inflammatory differentiation along the SMA-vascular axis in the bone marrow modulated by JAKi treatment. SMA-CD34 IHC stratifies MF bone marrow biopsies differentially from standard WHO reticulin/trichome grading providing a practical formalin-fixed paraffin embedded (FFPE) tissue-based biomarker for assessing fibrosis related bone marrow niche elements from archived clinical samples. While our pilot numbers precluded statistical evaluation by JAKi-type, clinical response and NGS mutational profile at this time, further studies are underway to validate the SMA-CD34 signature on a larger MF cohort. Figure 1 Figure 1. Disclosures Gupta: Sierra Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS-Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Incyte: Honoraria, Research Funding; Constellation Pharma: Consultancy, Honoraria; Pfizer: Consultancy.

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Carfilzomib Thalidomide and Dexamethasone Is Safe and Effective in the Treatment of Relapsed/Refractory Multiple Myeloma: Preliminary Outcome from the Open Label Phase II ALLGMM018/AMN003 Study

Blood ◽

10.1182/blood-2018-99-111434 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1955-1955

Author(s):

Hang Quach ◽

Simon J. Harrison ◽

Slavisa Ninkovic ◽

Jane Estell ◽

Noemi Horvath ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

T Cells ◽

Board Of Directors ◽

Peripheral Blood ◽

Research Funding ◽

Open Label ◽

Advisory Committees ◽

Open Label Phase ◽

Grade 3

Abstract Background: Carfilzomib lenalidomide and dexamethasone (KRd) is FDA-approved for the treatment relapsed/refractory multiple myeloma (RRMM) based on data from the ASPIRE study (Stewart K et al. NEJM 2015). Thalidomide, a first generation immunomodulatory drug (IMiD) is less costly than lenalidomide and is synergistic in combination with proteasome inhibitors in the treatment of MM. ALLG MM018/ AMN003 is an open label phase II study of carfilzomib thalidomide and dexamethasone (KTd) for patients with RRMM. The primary end point is progression free survival (PFS). Secondary endpoints include overall response rate (ORR), duration of response (DOR), safety and health related quality of life. Method: Eligible patients were those with RRMM who have had 1-3 prior lines of treatment. The KTd regimen consisted of carfilzomib [20mg/m2 IV C1D1 and 2, 56mg/m2 (36mg/m2 for patients age ≥75 years) from C1D8 onwards], thalidomide (100mg po nocte) and dexamethasone [40mg (20mg for patients age ≥75 years) po weekly], in a 28-day cycle. After 12 cycles, thalidomide was omitted and Kd [carfilzomib 56mg/m2 (36/m2 for patients age ≥75 years) on days 1,2,15,16 and dexamethasone 40mg (20mg for patients age ≥75 years) on days 1,15 every 28 days]was continued for a further 6 cycles. Peripheral blood and bone marrow aspirate and trephine for correlative studies were collected from the first 30 patients, at baseline, after cycle 6 and at confirmed disease progression. The aim of the correlative study was to assess for immunological correlates to clinical outcome. Immunological parameters that will be assessed include NK and T cells subsets on peripheral blood via mass cytometry (CyTOF). On the bone marrow trephine, NK cells, T cells, GRP78 expression within CD38 positive plasma cells, PD1 and PDL1 expression will be assessed at the myeloma site and the surrounding microenvironment using OPAL multiplex immunohistochemistry technology. Results: Between March 2017 to June 2018, 56 patients (median age 66 years, range 56-79; 77% Caucasian and 23% Asian) out of the planned 100 were enrolled, with a median follow up of 4.9 (range, 1.0-13.7) months. Response rates in 39 evaluable patients were ≥MR (97%), ≥PR (89%) and ≥VGPR (66%). Median PFS is not reached, and no patients with ≥MR have relapsed. Grade ≥3/4 AEs occurred in 56% of patients, the most common of which were peripheral sensory neuropathy (13%), dyspnoea (13%) and infections (7%). All grade cardiovascular AEs included dyspnoea (27%), cardiac complications (5%), systemic-hypertension (9%) and pulmonary-hypertension (1.9%), however very few were grade ≥3. Three patients have died on study from disease complications, haemorrhage, and primary cardiac ischaemic event. Thus far, we have not found a significant difference in rates or profile of adverse events between the Caucasian versus Asian subgroups of patients. Conclusion: This preliminary analysis demonstrates that the KTd combination is a tolerable regimen for patients with RRMM with a safety profile in line with previous reports for each of carfilzomib and thalidomide. Initial response rates appear very promising and durable with responses up to 13.7 months thus far in some patients. Patient accrual is ongoing. Disclosures Quach: Janssen Cilag: Consultancy; Sanofi Genzyme: Research Funding; Celgene: Consultancy, Research Funding; Amgen: Consultancy, Research Funding. Harrison:Janssen-Cilag: Other: Scientific advisory board. Mollee:Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Durie:Takeda: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Amgen: Consultancy. Chng:ASLAN Pharmaceuticals: Research Funding.

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A Phase 2 Study of Cpi-0610, a Bromodomain and Extraterminal (BET) Inhibitor, in Patients with Myelofibrosis (MF)

Blood ◽

10.1182/blood-2018-99-119157 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 5481-5481 ◽

Cited By ~ 4

Author(s):

Marina Kremyanskaya ◽

Ronald Hoffman ◽

John Mascarenhas ◽

Srdan Verstovsek ◽

Jennifer Mertz ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Inadequate Response ◽

Phase 2 ◽

Spleen Volume ◽

Bone Marrow Fibrosis ◽

Advisory Committees ◽

Phase 2 Study ◽

Marrow Fibrosis

Abstract MF is a myeloproliferative neoplasm characterized by abnormal megakaryocytes and elevated proinflammatory cytokines which results in bone marrow fibrosis, progressive hepatosplenomegaly due to extramedullary hematopoiesis, and debilitating constitutional symptoms. Current treatments, including ruxolitinib (the only approved drug for MF), provide symptomatic relief but have limited effects on the underlying disease. Effective therapies with potential MF disease course modification and second line therapies are urgently needed. CPI-0610 has been evaluated in 3 Phase 1 studies in > 140 patients with lymphoma, multiple myeloma and acute leukemias/myelodysplastic syndrome/MF. Although CPI-0610 was tested at doses as high as 400 mg PO QD, the maximum tolerated dose was 225 mg PO QD for 2 weeks on, 1 week off. Clear anti-tumor activity was observed in patients with lymphomas, particularly ABC-DLBCL (Blum et al. TAT conference 2018). Preclinical data on CPI-0610 demonstrated downregulation of pro-inflammatory cytokines through its effects on NF-κB pathway as well as inhibition of megakaryocyte differentiation. Both of these features are thought to be important in the pathogenesis of MF. In addition, a recent preclinical publication using a mouse model of MF, suggests that BET inhibition reduces inflammatory cytokine production, platelet counts, spleen volume and bone marrow fibrosis, the effects of which were further magnified when combined with ruxolitinib (Kleppe et al. 2018). Taken together, these data suggest that BET inhibitors such as CPI-0610, administered with and without ruxolitinib, have the potential to affect the underlying MF disease and supports further clinical evaluation of CPI-0610 in patients with MF. Therefore, we have embarked on a Phase 2 trial of CPI-0610 as monotherapy or in combination with ruxolitinib. This Phase 2 study aims to evaluate CPI-0610 as a monotherapy and in combination with ruxolitinib in patients with MF who are not eligible to receive a JAK inhibitor or have had an inadequate response to ruxolitinib. The primary objectives are to evaluate spleen volume response by imaging after 24 weeks of therapy and to evaluate the effect on transfusion independence rate. Other key secondary objectives are to evaluate the change in patient reported outcomes and the duration of splenic response. Exploratory objectives include characterizing the effects of treatment on the bone marrow and blood biomarkers. The Phase 2 study has a 2-stage design to enroll up to 35 patients in each arm (monotherapy and combination therapy) if ≥2 responses are observed during stage 1. The study is registered at ClinicalTrials.gov NCT02158858. Disclosures Kremyanskaya: Incyte: Research Funding. Hoffman:Formation Biologics: Research Funding; Summer Road: Research Funding; Incyte: Research Funding; Merus: Research Funding; Janssen: Research Funding. Mascarenhas:CTI Biopharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Promedior: Research Funding; Merck: Research Funding; Janssen: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Verstovsek:Italfarmaco: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees. Mertz:Constellation Pharma: Employment. Garner:Constellation Pharma: Employment. Senderowicz:Constellation Pharma: Employment.

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Complete Clinical, Histopathologic and Molecular Remission of Primary Myelofibrosis with Long-Term Treatment with the JAK1/2 Inhibitor Ruxolitinib

Blood ◽

10.1182/blood.v124.21.1836.1836 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1836-1836 ◽

Cited By ~ 4

Author(s):

Haifa Kathrin Al-Ali ◽

Karolin Hubert ◽

Thoralf Lange ◽

Udo Siebolts ◽

Claudia Wichenhauser ◽

...

Keyword(s):

Bone Marrow ◽

Board Of Directors ◽

Jak2 V617f ◽

Primary Myelofibrosis ◽

Spleen Volume ◽

Advisory Committees ◽

Allele Burden ◽

Night Sweats ◽

Marrow Fibrosis

Abstract The JAK1/2 inhibitor ruxolitinib (RUX) is effective in decreasing symptomatic splenomegaly, and constitutional symptoms in patients with myelofibrosis (MF). Long-term data suggest that treatment with RUX is associated with a survival benefit, and may delay/reverse bone marrow fibrosis. Further, a ≥ 20% reduction in JAK2 V617F allele burden with RUX has been described (Vannucchi et al. Blood. 2012). Yet, many uncertainties surrounding the full clinical potential of RUX persist. The conceivable disease-modifying impact including the achievement of a JAK2 V617F molecular remission under sustained JAK1/JAK2 inhibition in a patient with primary myelofibrosis (PMF) is presented. Patient and Methods: the diagnosis of JAK2 V617F-positive PMF according to the 2008 WHO criteria was made in a 50-years old caucasian male in February 2009. On the first consultation in November, 2009, he complained of fatigue and night sweats. Spleen was 12 cm below costal margin by palpation. Laboratory results were: Hb 153 g/L, WBC 18.9 x109/L, platelets 268 x109/L, peripheral blasts 2%, a leucoerythroblastic blood picture, LDH 10.6 µkat/L [2.8x upper limit of normal]. With an IPSS of 2 points (night sweats and peripheral blasts > 1%) the IPSS risk category for survival was intermediate-II. After signing informed consent, the patient was included in the phase 3, multicenter COMFORT-II trial and randomized to treatment with RUX at a dose of 20mg bid based on platelets count. By week (w) 4, the dose was increased to 25mg bid per protocol (< 40% reduction is palpable spleen length). For efficacy and safety evaluations, serial clinical, spleen volume [by magnetic resonance imaging (MRI)], blood picture, blood chemistry, bone marrow trephine biopsy, and JAK2 V617F allele burden from both peripheral blood samples as well as bone marrow assessments were conducted. The histology of the biopsies was evaluated according to the WHO criteria by experienced pathologists (Table). The JAK2 V617F allele burden was measured from blood samples using allele-specific oligonucleotide quantitative real-time polymerase chain reaction (qPCR) with a dynamic detection range from 0.1 to100% mutated allele (Lange et al. Haematologica 2013) and from bone marrow samples via qPCR followed by pyrosequencing for determining the allelic burden with a sensitivity of 5% of mutated DNA. If necessary, blocking of the non-mutated allele for sensitivity enhancement from 5% up to 0,001% of mutated DNA was done (Siebolts et al. J Clin Pathol 2010). Results: After a follow-up of 240 weeks, treatment with 25mg bid is ongoing. No dose modification/interruption because of adverse events was required. Clinical response was rapid with a 52% reduction in baseline spleen volume from 3.77 L to 1.8 L and improvement in constitutional symptoms at w 12. This was followed by a further decline in spleen volume. By w 216, spleen volume was 0.5 L which corresponded to 85.5% reduction from baseline (Figure). WBC and LDH normalized by w 24 and w 84 respectively. Histologic improvement in marrow cellularity, megakaryocytic, and granulocytic lineages was first evident at w 126 with further reversal of MF-related abnormalities including marrow fibrosis by w 216 (Table). JAK2 V617F allele burden of < 10% in a peripheral blood sample and < 1% in the bone marrow were first documented at w 108 and w 132 respectively. As of w 216, an allele burden <1% was sustained in both blood and marrow samples (Figure). Conclusions: The rapid symptomatic improvement with ruxolitinib could be followed by a considerable MF-modifying response with the potential to alter the course of disease and prognosis. Unlike targeted therapy for chronic myeloid leukemia, ruxolitinib-delivered molecular and histologic remissions could be gradual, and progressive. Whether such deep long-term responses are dose-dependent is not yet known. Thus, the full potential of a sustained JAK1/JAK2 inhibition needs to be elucidated by carefully analyzing the possible correlation between dose, short-term spleen responses and long-term molecular and histologic responses; both in retro- and prospective studies. Changes in marrow histology and spleen volume under ruxolitinib Table 1. Marrow Cellularity % Megakaryocyte Granulocytic ProliferationG:E Marrow Fibrosis (EUMNET) Spleen volume (L)ProliferationAtypiaBaseline100%+++++++++8:1PMF13.8Week 4880%+++++++5:1PMF21.2Week 12630%+++-1:3PMF10.6Week 21640%-+-3:1PMF00.5 Figure 1 Figure 1. Disclosures Al-Ali: Novartis: Honoraria, Research Funding. Lange:Novartis: Consultancy, Honoraria, Research Funding. Prashanth:Novartis: Employment. Niederwieser:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gentium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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