Primary myelofibrosis: 2017 update on diagnosis, risk-stratification, and management

Safety and efficacy of fedratinib in patients with myelofibrosis previously treated with ruxolitinib: primary analysis of FREEDOM trial

The phase 3b FREEDOM trial (ClinicalTrials.gov: NCT03755518) evaluates efficacy/safety of fedratinib in intermediate- or high-risk myelofibrosis patients with platelet count ≥50 × 109/L, previously treated with ruxolitinib. The trial design included protocol specified strategies to mitigate the risk for gastrointestinal (GI) adverse events (AEs), thiamine supplementation, and encephalopathy surveillance. Due to COVID-19, accrual was cut short with 38 patients enrolled. In the efficacy evaluable population (n = 35), nine (25.7%; 95% confidence interval 12.5-43.3) patients achieved primary endpoint of ≥35% spleen volume reduction (SVR) at end of cycle (EOC) 6; and 22 (62.9%) patients showed best overall response of ≥35% SVR up to end of treatment. Sixteen (44.4%) patients showed ≥50% reduction in total symptom score at EOC6 (n = 36). Compared to previously reported JAKARTA-2 trial, rates of GI AEs were lower, and no patient developed encephalopathy. Overall, FREEDOM study showed clinically relevant spleen and symptom responses with fedratinib, and effective mitigation of GI AEs.

Cardiac tamponade associated with primary myelofibrosis: a case report

Background

Cardiac tamponade is a life-threatening condition that occurs when an abnormal amount of fluid accumulates in the pericardial sac and impedes the cardiac filling process. Although extremely rare, haematological diseases have the potential to trigger an extramedullary haematopoiesis (EMH) process within the pericardium, resulting in a substantial build-up of pericardial effusion.

Case summary

We present the case of a 29-year-old male previously diagnosed with primary myelofibrosis (PMF), who presented to the emergency unit with cardiac tamponade. An emergent pericardiocentesis procedure was performed, successfully evacuating 850 mL of haemorrhagic fluid. Over the course of 3 days, a total of 1.5 L of haemorrhagic effusion were drained from the pericardial space. Analysis of the pericardial fluid revealed evidence of haematopoietic activity, suggesting a potential association with the EMH process occurring within the pericardium. Following a 7-day hospitalization, the patient was discharged in stable condition but later experienced the development of constrictive pericarditis.

Discussion

Haemorrhagic pericardial effusion is a rare occurrence. The majority of cases stems from complications of medical procedures (iatrogenic), malignancies, or side effects of antiplatelet/anticoagulant medications. In patients with PMF, the impaired haematopoietic ability caused by the fibrotic process in the bone marrow compels the body to produce blood components elsewhere, a phenomenon known as EMH. On very rare occasions, EMH can develop in the pericardial space, potentially leading to life-threatening cardiac tamponade. Our patient was successfully managed through pericardial fluid evacuation and drainage but later developed constrictive pericarditis.

Application of Fourier Transform InfraRed spectroscopy of machine learning with Support Vector Machine and principal components analysis to detect biochemical changes in dried serum of patients with primary myelofibrosis

Primary myelofibrosis (PM) is a myeloproliferative neoplasm characterized by stem cell-derived clonal neoplasms. Several factors are involved in diagnosing PM, including physical examination, peripheral blood findings, bone marrow morphology, cytogenetics, and molecular markers. Commonly gene mutations are used. Also, these gene mutations exist in other diseases, such as polycythemia vera and essential thrombocythemia. Hence, understanding the molecular mechanism and finding disease-related biomarker characteristics only for PM is crucial for the treatment and survival rate. For this purpose, blood samples of PM (n = 85) vs. healthy controls (n = 45) were collected for biochemical analysis, and, for the first time, Fourier Transform InfraRed (FTIR) spectroscopy measurement of dried PM and healthy patients' blood serum was analyzed. A Support Vector Machine (SVM) model with optimized hyperparameters was constructed using the grid search (GS) method. Then, the FTIR spectra of the biomolecular components of blood serum from PM patients were compared to those from healthy individuals using Principal Components Analysis (PCA). Also, an analysis of the rate of change of FTIR spectra absorption was studied. The results showed that PM patients have higher amounts of phospholipids and proteins and a lower amount of H-O=H vibrations which was visible. The PCA results indicated that it is possible to differentiate between dried blood serum samples collected from PM patients and healthy individuals. The Grid Search Support Vector Machine (GS-SVM) model showed that the prediction accuracy ranged from 0.923 to 1.00 depending on the FTIR range analyzed. Furthermore, it was shown that the ratio between α-helix and β-sheet structures in proteins is 1.5 times higher in PM than in control people. The vibrations associated with the CO bond and the amide III region of proteins showed the highest probability value, indicating that these spectral features were significantly altered in PM patients compared to healthy ones' spectra. The results indicate that the FTIR spectroscope may be used as a technique helpful in PM diagnostics. The study also presents preliminary results from the first prospective clinical validation study.

Advances in management of primary myelofibrosis and polycythaemia vera: Implications in clinical practice

Primary myelofibrosis (PMF) and polycythaemia vera (PV) are rare BCR-ABL1-negative myeloproliferative neoplasms, associated with an increased risk of thrombosis, haemorrhagic complications and progression to fibrosis or leukaemia or fibrosis for PV. Both diseases are characterised by biological and clinical heterogeneity, leading to great variability in their management in routine clinical practice. In this review, we present an updated overview of the diagnosis, prognosis and treatment of PMF and PV, and we discuss how our multidisciplinary expert group based across France translates this evidence-based knowledge into routine clinical practice.

Trends in overall mortality among US veterans with primary myelofibrosis

BACKGROUND

Primary myelofibrosis [PMF] is a myeloproliferative neoplasm associated with reduced overall survival (OS). Management strategies for PMF have evolved over the last two decades, including approval of ruxolitinib as the first Janus kinase 1 (JAK1)/JAK2 inhibitor for patients with intermediate or high-risk myelofibrosis. This study assessed changes in mortality before and after ruxolitinib approval, independent of ruxolitinib treatment.

METHODS

This retrospective study investigated mortality trends among US veterans with PMF in 2 time periods, pre-ruxolitinib approval (01/01/2007-12/31/2010) and post-ruxolitinib approval (01/01/2015-09/30/2018). Deidentified patient-level data were extracted from US Veterans Health Administration (VHA) databases using PMF diagnosis codes; index was the first PMF diagnosis date. The analysis included adults with ≥2 PMF claims during the analysis periods who were continuously enrolled in the VHA plan 1 calendar year prior to and 6 months post-index and had ≥1 available International Prognostic Scoring System (IPSS) risk factor (available factors were age > 65, hemoglobin < 10 g/dL, and white blood cell count > 25 × 10⁹/L; each counted as one point). Patients with ≥1 MF diagnosis for 12 months before the index period were excluded. Ruxolitinib treatment was not a requirement to be included in the post-ruxolitinib approval cohort. Mortality rates and OS were estimated using the Kaplan-Meier approach; all-cause mortality hazard ratio was estimated using univariate Cox regression.

RESULTS

The pre- and post-ruxolitinib approval cohorts included 193 and 974 patients, respectively, of which 80 and 197 had ≥2 IPSS risk factors. Ruxolitinib use in the post-ruxolitinib cohort was 8.5% (83/974). At end of follow-up, median (95% CI) OS was significantly shorter in the pre-ruxolitinib cohort (1.7 [1.2-2.6] years vs not reached [3.4-not reached]; P < 0.001). Overall mortality rates for the pre- versus post-ruxolitinib approval cohorts were 79.8% versus 47.3%, respectively, and overall risk of death was 53% lower in the post-ruxolitinib period (hazard ratio, 0.47; 95% CI, 0.37-0.58; P < 0.001). Mortality rates were lower among patients with < 2 vs ≥2 IPSS risk factors.

CONCLUSIONS

Although veterans with PMF have high overall mortality rates, and results in this population might not be generalizable to the overall population, there was a significant lowering of mortality rate in the post-ruxolitinib period.

Anxieties, age and motivation influence physical activity in patients with myeloproliferative neoplasms - a multicenter survey from the East German study group for hematology and oncology (OSHO #97)

Background

Physical activity (PA) is a non-pharmacological approach to alleviate symptom burden and improve health-related quality of life (HrQoL) in cancer patients (pts). Whether pts with myeloproliferative neoplasms (MPN) PA behavior changes due to symptom burden and/or knowledge of the putative beneficial effects of PA has not yet been investigated.

Methods

We performed a large questionnaire study in MPN pts. Self-reported PA behavior and potential influencing factors of 634 MPN pts were analyzed. Questionnaires were used to assess demographics, anxiety, severity of symptoms, HrQoL, current level of everyday and sports activities, and the level of information regarding the importance/possibilities of PA. According to their PA, the pts were assigned to the three groups: "inactive", "non-targeted active", and "sporty active" and compared with each other.

Results

Key findings are that in 73% of the pts, the disease had an impact on PA, with 30% of pts reducing their PA. The prevalence of anxieties (e.g., occurrence of thrombosis and bleeding) regarding PA was 45%. Sporty active pts had a lower symptom burden and better HrQoL (p ≤ 0.001) compared to the other groups. Inactive pts were significantly older and had a higher body mass index than sporty active pts. Inactive and non-targeted active pts felt less informed about the importance/possibilities of PA (p = 0.002).

Conclusion

Our results suggest that especially older and non-sporty MPN pts could benefit from motivational as well as disease-specific PA information. This study was registered at the German Registry of Clinical Trials, DRKS00023698.

The third dose of mRNA SARS-CoV-2 vaccines enhances the spike-specific antibody and memory B cell response in myelofibrosis patients

Vaccination against SARS-CoV-2 using mRNA-based vaccines has been highly recommended for fragile subjects, including myelofibrosis patients (MF). Available data on the immune responsiveness of MF patients to mRNA SARS-CoV-2 vaccination, and the impact of the therapy with the JAK inhibitor ruxolitinib, are still fragmented. Here, we profile the spike-specific IgG and memory B-cell response in MF patients, treated or not with ruxolitinib, after the second and the third dose of SARS-CoV-2 BNT162b2 (BioNTech) and mRNA-1273 (Moderna) vaccines. Plasma and peripheral blood mononuclear cells samples were collected before vaccination, post the second and the third doses and tested for spike-specific antibodies, ACE2/RBD antibody inhibition binding activity and spike-specific B cells. The third vaccine dose significantly increased the spike-specific IgG titers in both ruxolitinib-treated and untreated patients, and strongly enhanced the percentage of subjects with antibodies capable of in vitro blocking ACE2/RBD interaction, from 50% up to 80%. While a very low frequency of spike-specific B cells was measured in blood 7 days after the second vaccination dose, a strong and significant increase was elicited by the third dose administration, generating a B cell response similar to the one detected in healthy controls. Despite the overall positive impact of the third dose in MF patients, two patients that were under active concomitant immunosuppressive treatment at the time of vaccination, and a patient that received lymphodepleting therapies in the past, remained low responders. The third mRNA vaccine dose strongly increases the SARS-CoV-2 specific humoral and B cell responses in MF patients, promoting a reactivation of the immune response similar to the one observed in healthy controls.

Evaluation of different diagnostic tools for detection of acquired von Willebrand syndrome in patients with polycythemia vera or essential thrombocythemia

INTRODUCTION

Patients with myeloproliferative neoplasms (MPNs) are at increased risk of both thromboembolic and hemorrhagic complications. Among the risk factors for bleeding is the development of an acquired qualitative von Willebrand factor defect with loss of larger VWF plasma multimers, resulting in acquired von Willebrand syndrome (aVWS). The diagnosis of aVWS is challenging, because no single automated test is sufficient to prove or exclude aVWS. We aimed to compare different diagnostic tools used for the detection of MPN-associated aVWS in daily practice.

METHODS

Patients with polycythemia vera (PV) or essential thrombocythemia (ET), who had been routinely assessed for quantitative and qualitative abnormalities of plasma VWF, were retrospectively studied.

RESULTS

Sixty-four patients (37 with PV and 27 with ET) were analyzed. Using multimer analysis of plasma VWF, aVWS with a loss of VWF high-molecular-weight multimers was detected in 51.4 % and 55.6 % of PV and ET patients, respectively.

A VWF

GPIbM/Ag threshold of <0.8 was defined as useful screening tool for aVWS, with acceptable sensitivity (88.2 %) and specificity (76.7 %) and good agreement with VWF multimer analysis (κ = 0.653). VWF:GPIbM/Ag showed better performance than VWF:CB/Ag. Regarding hematological parameters, there was no difference in hematocrit between patients with and without aVWS. However, leukocyte and platelet counts were significantly increased in the aVWS cohort.

CONCLUSION

For the first time, we identified a VWF:GPIbM/Ag ratio of <0.8 as simple screening tool for aVWS in patients with PV or ET. This observation, however, should be confirmed in a larger patient cohort.

Beyond Pathogenic RUNX1 Germline Variants: The Spectrum of Somatic Alterations in RUNX1-Familial Platelet Disorder with Predisposition to Hematologic Malignancies

Simple Summary

Pathogenic germline variants affecting RUNX1 are associated with qualitative and/or quantitative platelet defects, and predispose to hematologic malignancies. The latter manifests in approximately 44% of carriers and can occur from early childhood to late adulthood. In addition to the predisposing RUNX1 germline variant, the acquisition of somatic genetic alterations is presumed to drive leukemic transformation in an inflammatory bone marrow niche. The spectrum of somatic mutations occurs heterogeneously between individuals, even within families, and there is no clear genotype–phenotype correlation. In this review, we summarize previously published patients harboring (likely) pathogenic RUNX1 germline alterations in whom somatic alterations were additionally analyzed. We provide an overview of their phenotypes and the most frequent somatic genetic alterations.

Abstract

Pathogenic loss-of-function RUNX1 germline variants cause autosomal dominantly-inherited familial platelet disorder with predisposition to hematologic malignancies (RUNX1-FPD). RUNX1-FPD is characterized by incomplete penetrance and a broad spectrum of clinical phenotypes, even within affected families. Heterozygous RUNX1 germline variants set the basis for leukemogenesis, but, on their own, they are not transformation-sufficient. Somatically acquired secondary events targeting RUNX1 and/or other hematologic malignancy-associated genes finally lead to MDS, AML, and rarely other hematologic malignancies including lymphoid diseases. The acquisition of different somatic variants is a possible explanation for the variable penetrance and clinical heterogeneity seen in RUNX1-FPD. However, individual effects of secondary variants are not yet fully understood. Here, we review 91 cases of RUNX1-FPD patients who predominantly harbor somatic variants in genes such as RUNX1, TET2, ASXL1, BCOR, PHF6, SRSF2, NRAS, and DNMT3A. These cases illustrate the importance of secondary events in the development and progression of RUNX1-FPD-associated hematologic malignancies. The leukemia-driving interplay of predisposing germline variants and acquired variants remain to be elucidated to better understand clonal evolution and malignant transformation and finally allow risk-adapted surveillance and targeted therapeutic measures to prevent leukemia.

Tet2 deficiency drives liver microbiome dysbiosis triggering Tc1 cell autoimmune hepatitis

The triggers that drive interferon-γ (IFNγ)-producing CD8 T cell (Tc1 cell)-mediated autoimmune hepatitis (AIH) remain obscure. Here, we show that lack of hematopoietic Tet methylcytosine dioxygenase 2 (Tet2), an epigenetic regulator associated with autoimmunity, results in the development of microbiota-dependent AIH-like pathology, accompanied by hepatic enrichment of aryl hydrocarbon receptor (AhR) ligand-producing pathobionts and rampant Tc1 cell immunity. We report that AIH-like disease development is dependent on both IFNγ and AhR signaling, as blocking either reverts ongoing AIH-like pathology. Illustrating the critical role of AhR-ligand-producing pathobionts in this condition, hepatic translocation of the AhR ligand indole-3-aldehyde (I3A)-releasing Lactobacillus reuteri is sufficient to trigger AIH-like pathology. Finally, we demonstrate that I3A is required for L. reuteri-induced Tc1 cell differentiation in vitro and AIH-like pathology in vivo, both of which are restrained by Tet2 within CD8 T cells. This AIH-disease model may contribute to the development of therapeutics to alleviate AIH.

Fedratinib, the first selective JAK2 inhibitor approved for treatment of myelofibrosis - an option beyond ruxolitinib

Introduction: Myelofibrosis, a life shortening clonal disorder, presents with a constellation of features: bone marrow fibrosis, abnormal blood counts, extramedullary hematopoiesis, splenomegaly, thrombohemorrhagic complications and constitutional symptoms. Until recently Ruxolitinib, a JAK1 and 2 inhibitor, has been the only targeted therapy available for transplant-ineligible patients requiring treatment for splenomegaly and disease related symptoms. However, most patients discontinue Ruxolitinib after 3-5 years, mostly due to loss of response. There has been an unmet need for this patient group. In August 2019 Fedratinib (INREBIC® capsules, Impact Biomedicines, Inc., a wholly owned subsidiary of Bristol Meyer Squibb), a JAK2 inhibitor, was approved by US FDA for treatment of myelofibrosis in both JAK inhibitor naïve and pre-treated patients for the management of symptoms and splenomegaly.Areas covered: Here, we discuss the development, evidence base to date for Fedratinib. Including early and late phase, and ongoing trials, safety issues, potential role and current position of Fedratinib in the treatment of myelofibrosis, as well as future direction of targeted therapy in myelofibrosis.Expert opinion: Fedratinib presents a much needed option of treatment, particularly, for patients failing Ruxolitinib, with response rates that are quite similar. Nonetheless, there remain important questions including sequencing and options for combining therapy.

Chronic myeloid leukemia: a type of MPN

This review article classifies chronic myeloid leukemia (CML) based on cytogenetic analyses and different mutations detected in CML patients. The use of advanced technologies, such as karyotyping, fluorescent in situ hybridization, and comparative genomic hybridization, has allowed us to study CML in detail and observe the different biochemical changes that occur in different CML types. This review also highlights the different types of receptor and signaling pathway mutations that occur in CML.

Impact of Individual Comorbidities on Survival of Patients with Myelofibrosis

The comorbidity burden is an important risk factor for overall survival (OS) in several hematological malignancies. This observational prospective study was conducted to evaluate the impact of individual comorbidities on survival in a multicenter series of 668 patients with primary myelofibrosis (PMF) or MF secondary to polycythemia vera (PPV-MF) or essential thrombocythemia (PET-MF). Hypertension (hazard ratio (HR) = 4.96, p < 0.001), smoking (HR = 5.08, p < 0.001), dyslipidemia (HR = 4.65, p < 0.001) and hepatitis C virus (HCV) (HR = 4.26, p = 0.015) were most adversely associated with OS. Diabetes (HR = 3.01, p < 0.001), pulmonary disease (HR = 3.13, p < 0.001) and renal dysfunction (HR = 1.82, p = 0.037) were also associated with an increased risk of death. Multivariate analysis showed that pulmonary disease (HR = 2.69, p = 0.001), smoking (HR = 3.34, p < 0.001), renal dysfunction (HR = 2.08, p = 0.043) and HCV (HR = 11.49, p = 0.001) had a negative impact on OS. When ruxolitinib exposure was included in the model, the effect of each comorbidity on survival was modified. Therefore, individual comorbidities should be taken into account in determining the survival prognosis for patients with MF.

Pediatric immune myelofibrosis (PedIMF) as a novel and distinct clinical pathological entity

Myelofibrosis is a rare myeloproliferative disorder. The detailed descriptions of myelofibrosis in children and adolescents is limited to a few case series and case reports describing fewer than 100 patients, thus suggesting the extreme rarity of this condition prior to adulthood. Though pediatric patients rarely present the typical features and outcomes usually observed in older people, pediatric myelofibrosis is not considered an independent entity. Here we aim to describe patients with pediatric myelofibrosis, showing different clinical and pathological features when compared to the World Health Organization 2016 Primary Myelofibrosis classification. We retrospectively collected and analyzed 14 consecutive pediatric myelofibrosis diagnosed in our Pediatric hematology outpatient clinic over a six-year period. According to clinical data and bone marrow biopsy findings, patients were classified into three subgroups: adult-like myelofibrosis, pediatric immune myelofibrosis, idiopathic myelofibrosis. Pediatric Immune Myelofibrosis was the predominant subgroup in our cohort (7/14). Pediatric Immune Myelofibrosis is characterized by peculiar bone marrow features (i.e., T lymphocyte infiltration) and a milder course compared to the other patients Pediatric Immune Myelofibrosis is a novel and distinct pathological entity. We suggest to carefully consider Pediatric Immune Myelofibrosis in case of bone marrow biopsies showing myelofibrosis that do not fulfill WHO criteria.

Combined Drug Targeting of p53-dependent and -independent Pathways Depletes Myelofibrosis Hematopoietic Stem/Progenitor Cells

Current therapy for myelofibrosis (MF) results in a limited prolongation of patient survival. In order to improve treatment outcomes, we developed a strategy to effectively deplete MF hematopoietic stem/progenitor cells (HSPCs). In the present study, an imipridone, ONC201, was combined with RG7112, an antagonist of MDM2, a p53 negative regulator, to activate downstream events of the p53 and TNF-related apoptosis-inducing ligand (TRAIL)/death receptor (DR) pathways. As compared to treatment with the individual drugs, the combination of ONC201 and RG7112 promoted greater degrees of apoptosis of MF CD34⁺ cells through activation of both p53-dependent and -independent pathways. Importantly, treatment with ONC201-RG7112 not only decreased the number of JAK2V617F⁺ and calreticulin mutated colonies assayed from MF CD34⁺ cells, but allowed for the persistence or appearance of JAK2 wild type colonies. Treatment with ONC201 combined with RG7112 could be a potentially effective strategy for treating MF patients.

Value and pitfalls of assessing bone marrow morphologic findings to predict response in patients with myelofibrosis who undergo hematopoietic stem cell transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative option for patients with myelofibrosis (MF). Bone marrow (BM) morphologic evaluation of myelofibrosis following allo-HSCT is known to be challenging in this context because resolution of morphologic changes is a gradual process.

PATIENTS AND METHODS

We compared BM samples of patients with myelofibrosis who underwent first allo-HSCT and achieved molecular remission by day 100 with BM samples of patients who continued to have persistent molecular evidence of disease following allo-HSCT.

RESULTS

The study group included 29 patients: 17 primary MF, 7 post-polycythemia vera (PV) MF, and 5 post-essential thrombocythemia (ET) MF. In this cohort there were 18 JAK2 p.V617F, 8 CALR; 1 MPL, and 2 patients had concurrent JAK2 p.V617F and MPL mutations. The control group included 5 patients with primary MF, one with post-PV MF, one with post-ET MF (5 JAK2 p.V617F; 2 CALR). Following allo-HSCT, both groups showed reduction in BM cellularity and number of megakaryocytes. The study cohort also less commonly had dense megakaryocyte clusters and endosteal located megakaryocytes and showed less fibrosis. There was no statistical difference in BM cellularity, presence of erythroid islands, degree of osteosclerosis, or megakaryocyte number, size, nuclear lobation, presence of clusters or intrasinusoidal location.

CONCLUSIONS

Following allo-HSCT at 100 days, morphologic evaluation of BM in patients with MF cannot reliably predict persistence versus clearance of molecular evidence of MF. Disappearance of BM MF, dense megakaryocyte clusters, and endosteal localization of megakaryocytes are suggestive of disease response.

Transcriptome research identifies four hub genes related to primary myelofibrosis: a holistic research by weighted gene co-expression network analysis

Objectives: This study aimed to identify specific diagnostic as well as predictive targets of primary myelofibrosis (PMF).

Methods: The gene expression profiles of GSE26049 were obtained from Gene Expression Omnibus (GEO) dataset, WGCNA was constructed to identify the most related module of PMF. Subsequently, Gene Ontology (GO), Kyoto Encyclopedia Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA) and Protein-Protein interaction (PPI) network were conducted to fully understand the detailed information of the interested green module. Machine learning, Principal component analysis (PCA), and expression pattern analysis including immunohistochemistry and immunofluorescence of genes and proteins were performed to validate the reliability of these hub genes.

Results: Green module was strongly correlated with PMF disease after WGCNA analysis. 20 genes in green module were identified as hub genes responsible for the progression of PMF. GO, KEGG revealed that these hub genes were primarily enriched in erythrocyte differentiation, transcription factor binding, hemoglobin complex, transcription factor complex and cell cycle, etc. Among them, EPB42, CALR, SLC4A1 and MPL had the most correlations with PMF. Machine learning, Principal component analysis (PCA), and expression pattern analysis proved the results in this study.

Conclusions: EPB42, CALR, SLC4A1 and MPL were significantly highly expressed in PMF samples. These four genes may be considered as candidate prognostic biomarkers and potential therapeutic targets for early stage of PMF. The effects are worth expected whether in the diagnosis at early stage or as therapeutic target.

Increased Plasma Levels of lncRNAs LINC01268, GAS5 and MALAT1 Correlate with Negative Prognostic Factors in Myelofibrosis

Simple Summary

Myelofibrosis (MF) displays the worst prognosis among Philadelphia-negative chronic myeloproliferative neoplasms. There is no curative therapy for MF, except for bone marrow transplantation, which however has a consistent percentage of failure. There is thus an urgent need of novel biomarkers to complement current stratification models and to enable better management of patients. To address this issue, we herein measured the plasma levels of several long noncoding RNAs (lncRNAs). Circulating lncRNAs has been already largely described as potential non-invasive biomarkers in cancers. In our study we unveiled that LINC01268, MALAT1 (both p < 0.0001) and GAS5 (p = 0.0003) plasma levels are significantly higher in MF patients if compared with healthy donors, and their increased plasma levels correlate with several detrimental features in MF. Among them, LINC01268 is an independent variable for both OS (p = 0.0297) and LFS (p = 0.0479), thus representing a putative new biomarker suitable for integrate contemporary prognostic models.

Abstract

Long non-coding RNAs (lncRNAs) have been recently described as key mediators in the development of hematological malignancies. In the last years, circulating lncRNAs have been proposed as a new class of non-invasive biomarkers for cancer diagnosis and prognosis and to predict treatment response. The present study is aimed to investigate the potential of circulating lncRNAs as non-invasive prognostic biomarkers in myelofibrosis (MF), the most severe among Philadelphia-negative myeloproliferative neoplasms. We detected increased levels of seven circulating lncRNAs in plasma samples of MF patients (n = 143), compared to healthy controls (n = 65). Among these, high levels of LINC01268, MALAT1 or GAS5 correlate with detrimental clinical variables, such as high count of leukocytes and CD34+ cells, severe grade of bone marrow fibrosis and presence of splenomegaly. Strikingly, high plasma levels of LINC01268 (p = 0.0018), GAS5 (p = 0.0008) or MALAT1 (p = 0.0348) are also associated with a poor overall-survival while high levels of LINC01268 correlate with a shorter leukemia-free-survival. Finally, multivariate analysis demonstrated that the plasma level of LINC01268 is an independent prognostic variable, suggesting that, if confirmed in future in an independent patients’ cohort, it could be used for further studies to design an updated classification model for MF patients.

Insufficiency of non-canonical PRC1 synergizes with JAK2V617F in the development of myelofibrosis

Insufficiency of polycomb repressive complex 2 (PRC2), which trimethylates histone H3 at lysine 27, is frequently found in primary myelofibrosis and promotes the development of JAK2V617F-induced myelofibrosis in mice by enhancing the production of dysplastic megakaryocytes. Polycomb group ring finger protein 1 (Pcgf1) is a component of PRC1.1, a non-canonical PRC1 that monoubiquitylates H2A at lysine 119 (H2AK119ub1). We herein investigated the impact of PRC1.1 insufficiency on myelofibrosis. The deletion of Pcgf1 in JAK2V617F mice strongly promoted the development of lethal myelofibrosis accompanied by a block in erythroid differentiation. Transcriptome and chromatin immunoprecipitation sequence analyses showed the de-repression of PRC1.1 target genes in Pcgf1-deficient JAK2V617F hematopoietic progenitors and revealed Hoxa cluster genes as direct targets. The deletion of Pcgf1 in JAK2V617F hematopoietic stem and progenitor cells (HSPCs), as well as the overexpression of Hoxa9, restored the attenuated proliferation of JAK2V617F progenitors. The overexpression of Hoxa9 also enhanced JAK2V617F-mediated myelofibrosis. The expression of PRC2 target genes identified in PRC2-insufficient JAK2V617F HSPCs was not largely altered in Pcgf1-deleted JAK2V617F HSPCs. The present results revealed a tumor suppressor function for PRC1.1 in myelofibrosis and suggest that PRC1.1 insufficiency has a different impact from that of PRC2 insufficiency on the pathogenesis of myelofibrosis.

The Role of Navitoclax in Myelofibrosis

Primary myelofibrosis (PMF) is the most aggressive type of chronic myeloproliferative neoplasm, characterized by a disarray of hematopoietic stem cells and bone marrow fibrosis. The estimated incidence is 1.5 per 100,000 individuals per year with a median survival of less than six years. This statistic can vary by risk category, primarily based on clinical and cytogenetic features. Death can result from many causes, including leukemic transformation, cachexia, vascular events, and infection. Currently, allogeneic hematopoietic cell transplant is the only curative method for those at high risk. Unfortunately, only about 10% are eligible for this therapy. JAK2 kinase inhibitors are commonly used for high-risk patients with symptomatic splenomegaly or systemic symptoms from PMF. In clinical trials, the major endpoint is a reduction of spleen size by 35%. Secondary endpoints have included amelioration of symptomatic PMF and overall survival, which can be difficult to determine because of frequent co-morbid conditions. Current Food and Drug Administration (FDA)-approved JAK2 inhibitors have not shown increased survival or reduced risk of leukemic transformation. In relapsed or refractory disease, there is currently no standard of care. In this paper, we discuss the role of a new anti-apoptotic B cell leukemia 2 (Bcl-2) inhibitor, Navitoclax, for the treatment of myelofibrosis. The clinical data thus far for Navitoclax, especially in synergistic combination with traditional JAK2 inhibitors, have been promising for those with a refractory or relapsing disease on prior therapies. Following the encouraging results of phase II trials, ongoing phase III trials will primarily evaluate splenic size reduction versus the standard of care and evaluate secondary endpoints such as symptom reduction and overall survival. These studies may establish a new standard of care for refractory or relapsed myelofibrosis.

Efficacy and safety of ruxolitinib in patients with myelofibrosis: a retrospective and multicenter experience in Turkey

Background/aim

The aim of this study is to assess the efficacy and safety of ruxolitinib in patients with myelofibrosis.

Materials and methods

From 15 centers, 176 patients (53.4% male, 46.6% female) were retrospectively evaluated.

Results

The median age at ruxolitinib initiation was 62 (28–87) and 100 (56.8%) of all were diagnosed as PMF. Constitutional symptoms were observed in 84.7%. The median initiation dose of ruxolitinib was 30 mg (10–40). Dose change was made in 69 (39.2%) patients. Forty seven (35.6%) and 20 (15.2%) of 132 patients had hematological and nonhematological adverse events, respectively. The mean spleen sizes before and after ruxolitinib treatment were 219.67 ± 46.79 mm versus 199.49 ± 40.95 mm, respectively (p < 0.001). There was no correlation between baseline features and subsequent spleen response. Overall survival at 1-year was 89.5% and the median follow up was 10 (1–55) months. We could not show any relationship between survival and reduction in spleen size (p = 0.73).

Conclusion

We found ruxolitinib to be safe, well tolerated, and effective in real-life clinical practice in Turkey. Ruxolitinib dose titration can provide better responses in terms of not only clinical benefit but also for long term of ruxolitinib treatment.

Gene expression profile correlates with molecular and clinical features in patients with myelofibrosis

Myelofibrosis (MF) belongs to the family of classic Philadelphia-negative myeloproliferative neoplasms (MPNs). It can be primary myelofibrosis (PMF) or secondary myelofibrosis (SMF) evolving from polycythemia vera (PV) or essential thrombocythemia (ET). Despite the differences, PMF and SMF patients are currently managed in the same way, and prediction of survival is based on the same clinical and genetic features. In the last few years, interest has grown concerning the ability of gene expression profiles (GEPs) to provide valuable prognostic information. Here, we studied the GEPs of granulocytes from 114 patients with MF, using a microarray platform to identify correlations with patient characteristics and outcomes. Cox regression analysis led to the identification of 201 survival-related transcripts characterizing patients who are at high risk for death. High-risk patients identified by this gene signature displayed an inferior overall survival and leukemia-free survival, together with clinical and molecular detrimental features included in contemporary prognostic models, such as the presence of high molecular risk mutations. The high-risk group was enriched in post-PV and post-ET MF and JAK2V617F homozygous patients, whereas pre-PMF was more frequent in the low-risk group. These results demonstrate that GEPs in MF patients correlate with their molecular and clinical features, particularly their survival, and represent the proof of concept that GEPs might provide complementary prognostic information to be applied in clinical decision making.

[The basophil: From control of immunity to control of leukemias]

The basophils, first described by Paul Ehlrich in 1879, are rare circulating cells, representing approximately 0.01 to 0.3% of the blood leukocytes. Until recently, these cells have been neglected because of their minority status among immune cells and because they show some similarities to mast cells residing in tissues. However, basophils and mast cells are now recognized as distinct cell lines and it appears that basophils have important and non-redundant functions, distinct from those of mast cells. On the one hand, basophils have beneficial contribution to protective immunity, in particular against parasitic infections. On the other hand, basophils are involved in the development of various benign and malignant pathologies, ranging from allergy to certain leukemias. Basophils interact with other immune cells or neoplastic cells through direct contacts or soluble mediators, such as cytokines and proteases, thus contributing to the regulation of the immune system but also to allergic responses, and probably to the process of neoplastic transformation. In this review, we will develop recent knowledge on the involvement of basophils in the modulation of innate and adaptive immunity. We will then describe the benign or malignant circumstances in which an elevation of circulating basophils can be observed. Finally, we will discuss the role played by these cells in the pathophysiology of certain leukemias, particularly during chronic myeloid leukemia.

Quantification of JAK2V617F mutation load by droplet digital PCR can aid in diagnosis of myeloproliferative neoplasms

INTRODUCTION

This study developed a method for quantifying the JAK2V617F mutation load in patients with myeloproliferative neoplasm (MPN) using droplet digital PCR (ddPCR), which provides a new laboratory method for diagnosing polycythemia vera (PV), essential thrombocythemia (ET), and pre-primary myelofibrosis (pre-PMF).

METHODS

Patients with MPN who had JAK2V617F mutations from March 2013 to August 2019 were enrolled in this study. JAK2V617F mutation loads were quantified using ddPCR technology.

RESULTS

The study examined 225 patients, including 135 with ET, 58 with PV, and 32 with PMF. JAK2V617F mutation loads significantly differed (P < .001) between the ET and PV groups and between the ET and PMF groups. Bone marrow biopsies were reclassified in accordance with the 2016 World Health Organization diagnostic criteria, which revealed 132 patients with MPN: 62 with ET, 35 with PV, 17 with pre-PMF, and 18 with overt-PMF. JAK2V617F mutation loads significantly differed (P < .001) between the ET and PV groups and between the ET and pre-PMF groups. The cutoff value between the ET and pre-PMF groups was 49.9.

CONCLUSION

JAK2V617F mutation loads provide an additional basis for diagnosis of ET, PV, and PMF, particularly regarding differentiation between ET and pre-PMF.

Patient-reported Effects of Fedratinib, an Oral, Selective Inhibitor of Janus Kinase 2, on Myelofibrosis-related Symptoms and Health-related Quality of Life in the Randomized, Placebo-controlled, Phase III JAKARTA Trial

Patients with myelofibrosis (MF) experience an array of symptoms that impair health-related quality of life (HRQoL). Fedratinib, an oral, selective Janus-kinase 2 (JAK2) inhibitor, was investigated in the randomized, placebo-controlled, phase III JAKARTA study in adult patients with intermediate- or high-risk JAK-inhibitor-naïve MF. The effect of fedratinib 400 mg/d on patient-reported MF symptoms and HRQoL in JAKARTA was assessed. Participants completed the modified Myelofibrosis Symptom Assessment Form (MFSAF v2.0), which evaluates 6 key MF symptoms (night sweats, early satiety, pruritus, pain under ribs on the left side, abdominal discomfort, bone/muscle pain). The modified MFSAF v2.0 was completed during the first 6 treatment cycles and at end of cycle 6 (EOC6). Symptom response was a ≥50% improvement from baseline in total symptom score (TSS). Overall HRQoL was assessed by EQ-5D-3L health utility index (HUI) score. The MFSAF-evaluable population comprised 91/96 patients randomized to fedratinib 400 mg and 85/96 patients randomized to placebo. Mean baseline TSS was 17.6 and 14.7 for fedratinib and placebo, respectively, and mean EQ-5D-3L HUI was 0.70 and 0.72. Fedratinib elicited statistically significant and clinically meaningful improvements in TSS from baseline versus placebo at all postbaseline visits. Symptom response rates at EOC6 were 40.4% with fedratinib and 8.6% with placebo (OR 7.0 [95% CI, 2.9-16.9]; P < 0.001), and a significantly higher proportion of fedratinib-treated patients achieved clinically meaningful improvement from baseline on the EQ-5D-3L HUI at EOC6 (23.2% versus 6.5%; P = 0.002). Fedratinib provided clinically meaningful improvements in MF symptoms and overall HRQoL versus placebo in patients with JAK-inhibitor-naïve MF.

Fedratinib Improves Myelofibrosis-related Symptoms and Health-related Quality of Life in Patients with Myelofibrosis Previously Treated with Ruxolitinib: Patient-reported Outcomes from the Phase II JAKARTA2 Trial

Myelofibrosis symptoms compromise health-related quality of life (HRQoL). Ruxolitinib can reduce myelofibrosis symptom severity, but many patients discontinue ruxolitinib due to loss of response or unacceptable toxicity. Fedratinib is an oral, selective JAK2 inhibitor approved in the United States for treatment of patients with intermediate-2 or high-risk myelofibrosis. The single-arm, phase II JAKARTA2 trial assessed fedratinib 400 mg/d (starting dose) in patients with myelofibrosis previously treated with ruxolitinib. Patient-reported changes in myelofibrosis symptom severity using the modified Myelofibrosis Symptom Assessment Form (MFSAF), and overall HRQoL and functional status using the EORTC QLQ-C30, were evaluated at each cycle. Clinically meaningful changes from baseline HRQoL scores were based on effect sizes. Ninety patients were MFSAF-evaluable. Myelofibrosis symptoms were mild-to-moderate at baseline. Patients showed statistically significant and clinically meaningful improvements in total symptom scores from baseline on the MFSAF at all post baseline visits through the end of cycle 6 (EOC6). Baseline global health status/QoL and functional domain scores on the EORTC QLQ-C30 were meaningfully worse than in the general population. At EOC6, 44% of patients reported clinically meaningful improvements in global health status/QoL, and 30%–53% of patients experienced clinically meaningful improvement in QLQ-C30 functional domains across post baseline timepoints. Over 80% of ongoing patients perceived fedratinib as beneficial on the Patient’s Global Impression of Change questionnaire. Fedratinib effects were consistent among prognostically relevant patient subgroups. Patients with myelofibrosis previously treated with ruxolitinib experienced clinically meaningful improvements in myelofibrosis symptom burden, overall HRQoL, and functional status in the first 6 months of fedratinib treatment.

The Epidemiology of Myeloproliferative Neoplasms in New Zealand between 2010 and 2017: Insights from the New Zealand Cancer Registry

BACKGROUND

There is a paucity of data on ethnic disparities in patients with the classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs): polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF).

METHODS

This study analysed the demographic data for PV, ET and PMF collected by the New Zealand Cancer Registry (NZCR) between 2010 and 2017.

RESULTS

We found that the NZCR capture rates were lower than average international incidence rates for PV and ET, but higher for PMF (0.76, 0.99 and 0.82 per 100,000, respectively). PV patients were older and had worse outcomes than expected, which suggests these patients were reported to the registry at an advanced stage of their disease. Polynesian patients with all MPN subtypes, PV, ET and PMF, were younger than their European counterparts both at the time of diagnosis and death (p < 0.001). Male gender was an independent risk factor for mortality from PV and PMF (hazard ratios (HR) of 1.43 and 1.81, respectively; p < 0.05), and Māori ethnicity was an independent risk factor for mortality from PMF (HR: 2.94; p = 0.006).

CONCLUSIONS

New Zealand Polynesian patients may have increased genetic predisposition to MPN, thus we advocate for modern genetic testing in this ethnic group to identify the cause. Further work is also required to identify modifiable risk factors for mortality in MPN, in particular those associated with male gender and Māori ethnicity; the results may benefit all patients with MPN.

Transcriptome profiling reveals target in primary myelofibrosis together with structural biology study on novel natural inhibitors regarding JAK2

This study aimed to identify effective targets for carcinogenesis of primary myelofibrosis (PMF), as well as to screen ideal lead compounds with potential inhibition effect on Janus kinase 2 to contribute to the medication design and development. Gene expression profiles of GSE26049, GSE53482, GSE61629 were obtained from the Gene Expression Omnibus database. The differentially expressed genes were identified, and functional enrichment analyses such as Gene Ontology, protein-protein interaction network etc., were performed step by step. Subsequently, highly-precise computational techniques were conducted to identify potential inhibitors of JAK2. A series of structural biology methods including virtual screening, ADMET (absorption, distribution, metabolism, excretion, and toxicity) prediction, molecule docking, molecular dynamics simulation etc., were implemented to discover novel natural compounds. Results elucidated that PMF patients had abnormal LCN2, JAK2, MMP8, CAMP, DEFA4, LTF, MPO, HBD, STAT4, EBF1 mRNA expression compared to normal patients. Functional enrichment analysis revealed that these genes were mainly enriched in erythrocyte differentiation, neutrophil degranulation and killing cells of other organisms. Two novel natural compounds, ZINC000013513540 and ZINC000004099068 were found binding to JAK2 with favorable interaction energy together with high binding affinity. They were predicted with non-Ames mutagenicity, low-rodent carcinogenicity, less developmental toxicity potential as well as non-toxicity with liver. Molecular dynamics simulation demonstrated that these two complexes: ZINC000013513540-JAK2 and ZINC000004099068-JAK2 could exist stably under natural circumstances. In conclusion, this study revealed hub genes in the carcinogenesis of PMF. ZINC000013513540 and ZINC000004099068 were promising drugs in dealing with PMF. This study may also accelerate exploration of new drugs.

Adhesion to fibronectin via α5β1 integrin supports expansion of the megakaryocyte lineage in primary myelofibrosis

Excessive accumulation of extracellular matrix (ECM) is a hallmark of bone marrow (BM) milieu in primary myelofibrosis (PMF). Because cells have the ability to adhere to the surrounding ECM through integrin receptors, we examined the hypothesis that an abnormal ECM-integrin receptor axis contributes to BM megakaryocytosis in JAK2V617F+ PMF. Secretion of ECM protein fibronectin (FN) by BM stromal cells from PMF patients correlates with fibrosis and disease severity. Here, we show that Vav1-hJAK2V617F transgenic mice (JAK2V617F+) have high BM FN content associated with megakaryocytosis and fibrosis. Further, megakaryocytes from JAK2V617F+ mice have increased cell surface expression of the α5 subunit of the α5β1 integrin, the major FN receptor in megakaryocytes, and augmented adhesion to FN compared with wild-type controls. Reducing adhesion to FN by an inhibitory antibody to the α5 subunit effectively reduces the percentage of CD41+ JAK2V617F+ megakaryocytes in vitro and in vivo. Corroborating our findings in mice, JAK2V617F+ megakaryocytes from patients showed elevated expression of α5 subunit, and a neutralizing antibody to α5 subunit reduced adhesion to FN and megakaryocyte number derived from CD34+ cells. Our findings reveal a previously unappreciated contribution of FN-α5β1 integrin to megakaryocytosis in JAK2V617F+ PMF.

Thrombocytopenia: Perioperative Considerations for Patients Undergoing Cardiac Surgery

The etiologies of thrombocytopenia in patients presenting for cardiac surgery are extensive, but clinically relevant conditions generally can be categorized by those related to decreased platelet production or increased platelet destruction. Many causes require mere acknowledgment and availability of allogeneic platelet transfusion; others have unique considerations for which providers should be familiar. The purpose of this review is to provide an overview of the common causes of thrombocytopenia, summarize the literature, and discuss perioperative considerations for patients undergoing cardiac surgery.

A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose, Multiple Ascending Dose and Food Effect Study to Evaluate the Tolerance, Pharmacokinetics of Jaktinib, a New Selective Janus Kinase Inhibitor in Healthy Chinese Volunteers

Background: Jaktinib is a novel selective janus kinase 1/2 inhibitor. The phase I first-in-human study evaluated the tolerance and pharmacokinetics of jaktinib in healthy Chinese subjects. Methods: A randomized, double-blind, placebo-controlled study were designed. A total of 126 healthy subjects were enrolled into the single ascending dose, multiple ascending dose and food effect study. Safety endpoints included adverse events, abnormal vital signs, 12-lead ECGs, abdominal ultrasound, chest x-ray, physical examination and clinical laboratory tests. Blood, urine and feces samples were collected at predetermined time points for pharmacokinetic analysis of jaktinib, the metabolites ZG0244 and ZG0245, which are formed by oxidation or hydrolysis metabolic pathway, respectively. Results: Jaktinib was absorbed with a median time to peak plasma concentration of 1.25-3.5 h and was eliminated with a half-life of 2.952-9.040 h. Linear pharmacokinetic characteristic was presented over the dose range from 25 to 400 mg. No obvious accumulation was observed after multiple doses for 10 days. Administration after a high-fat breakfast significantly increased the absorption of jaktinib. The accumulated fraction of jaktinib and the determined metabolites excreted in urine and feces was 19.478%. Jaktinib was well tolerated in all single dose cohorts. In multiple dose cohorts, 200 mg q24 h method was evaluated as maximally tolerated dose. Neutropenia, diarrhea, dizziness and headache were the most frequently reported treatment related adverse events. No deaths, serious or Grade ≥4 adverse events was developed. Conclusion: Jaktinib was well tolerated when single dose ranging from 25 to 400 mg and multiple dose up to 200 mg q24 h. The safety and pharmacokinetic characteristics support the next trial in myelofibrosis patients.

Somatically acquired mutations in primary myelofibrosis: A case report and meta-analysis

Familial myeloproliferative disease (MPD) cases account for 7.6% of the global MPD cases. The present study reported 2 cases of primary myelofibrosis (PMF). The patients were two sisters; the older sister succumbed to the disease at the age of 37, whereas the younger sister maintained a stable disease status and gave birth to a son through in vitro fertilization. Genetic analysis of bone marrow DNA samples showed that both sisters carried a Janus kinase 2 (JAK2) V617F mutation, and the older sister also had a trisomy 8 chromosomal abnormality (47, XX, +8). A systematic literature search was also performed using PubMed, CNKI and Wanfang databases, to determine the association between JAK2 and PMF. Following comprehensive screening of the published literature, 19 studies were found to be eligible for the current meta-analysis. The results showed that JAK2 V617F was a risk factor of PMF, and no sex dimorphism was observed in JAK2 V617F mutation prevalence amongst all PMF cases. In addition, there was a lack of association between the JAK2 V617F mutation and PMF-related mortality.

Clinical impacts of the mutational spectrum in Japanese patients with primary myelofibrosis

Patients with primary myelofibrosis (PMF) have a poorer prognosis than those with other subtypes of myeloproliferative neoplasms (MPNs). To investigate the relationship between gene mutations and the prognosis of Japanese PMF patients, we analyzed mutations in 72 regions located in 14 MPN-relevant genes (CSF3R, MPL, JAK2, CALR, DNMT3A, TET2, EZH2, ASXL1, IDH1/2, SRSF2, SF3B1, U2AF1, and TP53) utilizing a target resequencing platform. In our cohort, ASXL1 mutations were more frequently detected in both overt and prefibrotic PMF patients than other mutations. The frequency of ASXL1 mutations was slightly higher among overt PMF patients than among prefibrotic PMF patients (44.6% vs 25.0%, FDR = 0.472). Decision tree classification algorithms revealed that ASXL1, EZH2, and SRSF2 mutations were associated with a poor prognosis for overt PMF. Overall survival was significantly shorter in patients harboring ASXL1, EZH2, or SRSF2 mutations than in those without these mutations (p = 0.03). These results suggest that, as reported in Western countries, MIPSS70 is applicable to Japanese PMF patients and ASXL1, EZH2, and SRSF2 mutations may be utilized as surrogate markers of a poor prognosis.

Shared and Distinctive Ultrastructural Abnormalities Expressed by Megakaryocytes in Bone Marrow and Spleen From Patients With Myelofibrosis

Numerous studies have documented ultrastructural abnormalities in malignant megakaryocytes from bone marrow (BM) of myelofibrosis patients but the morphology of these cells in spleen, an important extramedullary site in this disease, was not investigated as yet. By transmission-electron microscopy, we compared the ultrastructural features of megakaryocytes from BM and spleen of myelofibrosis patients and healthy controls. The number of megakaryocytes was markedly increased in both BM and spleen. However, while most of BM megakaryocytes are immature, those from spleen appear mature with well-developed demarcation membrane systems (DMS) and platelet territories and are surrounded by platelets. In BM megakaryocytes, paucity of DMS is associated with plasma (thick with protrusions) and nuclear (dilated with large pores) membrane abnormalities and presence of numerous glycosomes, suggesting a skewed metabolism toward insoluble polyglucosan accumulation. By contrast, the membranes of the megakaryocytes from the spleen were normal but these cells show mitochondria with reduced crests, suggesting deficient aerobic energy-metabolism. These distinctive morphological features suggest that malignant megakaryocytes from BM and spleen express distinctive metabolic impairments that may play different roles in the pathogenesis of myelofibrosis.

The SIMM study: Survey of integrative medicine in myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) are characterized by significant symptom burden. Integrative medicine (IM) offers unique symptom management strategies. This study describes IM interventions utilized by MPN patients and the association with symptom burden, quality of life, depression, and fatigue adjusted for lifestyle confounders. MPN patients were surveyed online for IM utilization, MPN symptom burden (MPN‐Symptom Assessment Form Total Symptom Score), depression (Patient Health Questionnaire), fatigue (Brief Fatigue Inventory), and a single question on overall quality of life. Measures were compared by IM participation and adjusted for alcohol and tobacco use, BMI, diet, and MPN type using multiple linear and logistic regression. A total of 858 participants were included in the analysis. Aerobic activity (p =< 0.001) and strength training (p = 0.01) were associated with lower mean symptom burden while massage (p =< 0.001) and support groups (p =< 0.001) were associated with higher levels of symptom burden. Higher quality of life was reported in massage (p = 0.04) and support groups (p = 0.002) while lower quality of life was noted in aerobic activity (p =< 0.001) and strength training (p = 0.001). A lower depression screening score was noted in those participating in aerobic activity (p = 0.006), yoga (p = 0.03), and strength training (p = 0.02). Lower fatigue was noted in those participating in aerobic activity (p =< 0.001) and strength training (p = 0.03) while higher fatigue was noted in those participating in massage (p =< 0.001) and breathing techniques (p = 0.02). Data available on request from the authors. This international survey of MPN patients on IM usage, has shown that patients who participated in a form of IM had a pattern of decreased levels of symptom burden, fatigue, depression, and higher QoL, as adjusted for health lifestyle practices overall.

Salvage Therapy Using Azacitidine for Relapsed Primary Myelofibrosis after Cord Blood Transplantation

We present the case of a 53-year-old woman with prefibrotic stage primary myelofibrosis (PMF) who underwent cord blood transplantation. Nine years after transplantation, she relapsed, which was confirmed by a bone marrow examination. We decided to treat her using azacitidine. After three courses of azacitidine, a partial cytogenetic response was confirmed. Azacitidine maintenance therapy successfully maintained a low level of recipient-origin peripheral blood cells with a stable hematological condition. Azacitidine may therefore be a promising therapeutic option for PMF patients who relapse after allogeneic stem cell transplantation.

Autoimmune myelofibrosis associated with systemic lupus erythematosus: a case report

A 66-year-old woman presented with severe anaemia, thrombocytopenia and lymphopenia. The bone marrow biopsy demonstrated hypocellular marrow with myelofibrosis (MF); there was no evidence of malignancy, but infiltration of peripheral T and B cells were noticed. Magnetic resonance imaging (MRI) revealed that bone marrow of the spine exhibited low signal intensity (SI) with spotty high SI in T1- and T2-weighted images. Because there was evidence of autoimmune abnormality, she had fulfilled the classification criteria for systemic lupus erythematosus (SLE). She was diagnosed with autoimmune myelofibrosis (AIMF) associated with SLE and was treated with corticosteroid. Cytopenia improved after 1 month of corticosteroid therapy. A repeated bone marrow biopsy demonstrated that cellularity had increased and that the amount of reticulin fibre had reduced after treatment. Compared with primary MF, AIMF has generally a favourable prognosis and is often associated with autoimmune diseases, especially SLE. Bone marrow biopsy, but not aspiration, was useful for diagnosing bone marrow fibrosis. Although the association between SLE and MF has been rarely reported, we should pay attention to MF as a possible cause of pancytopenia.

Heterogeneity of the bone marrow niche in patients with myeloproliferative neoplasms: ActivinA secretion by mesenchymal stromal cells correlates with the degree of marrow fibrosis

Mesenchymal stromal cells (MSCs) represent an essential component of the bone marrow (BM) niche and display disease-specific alterations in several myeloid malignancies. The aim of this work was to study possible MSC abnormalities in Philadelphia-negative myeloproliferative neoplasms (MPNs) in relationship to the degree of BM fibrosis. MSCs were isolated from BM of 6 healthy donors (HD) and of 23 MPN patients, classified in 3 groups according to the diagnosis and the grade of BM fibrosis: polycythemia vera and essential thrombocythemia (PV/ET), low fibrosis myelofibrosis (LF-MF), and high fibrosis MF (HF-MF). MSC cultures were established from 21 of 23 MPN patients. MPN-derived MSCs did not exhibit any functional impairment in their adipogenic/osteogenic/chondrogenic differentiation potential and displayed a phenotype similar to HD-derived MSCs but with a decreased expression of CD146. All MPN-MSC lines were negative for the patient-specific hematopoietic clone mutations (JAK2, MPL, CALR). MSCs derived from HF-MF patients displayed a reduced clonogenic potential and a lower growth kinetic compared to MSCs from HD, LF-MF, and PV/ET patients. mRNA levels of hematopoiesis regulatory molecules were unaffected in MSCs from HF-MF compared to HD. Finally, in vitro ActivinA secretion by MSCs was increased in HF-MF compared to LF-MF patients, in association with a lower hemoglobin value. Increased ActivinA immunolabeling on stromal cells and erythroid precursors was also observed in HF-MF BM biopsies. In conclusion, higher grade of BM fibrosis is associated with functional impairment of MSCs and the increased secretion of ActivinA may represent a suitable target for anemia treatment in MF patients.

HLA-mismatched donor and high ferritin level showed poor clinical outcomes after allogeneic hematopoietic cell transplantation in patients with advanced myelofibrosis

Background:

Preconditioning intensity, donor choice and graft-versus-host disease (GVHD) prophylaxis of allogeneic hematopoietic cell transplantation (allo-HCT) for advanced myelofibrosis (MF) have not been fully elucidated.

Methods:

Thirty-five patients with advanced MF were treated with reduced-intensity conditioning (RIC) allo-HCT. We searched for matched sibling donors first, followed by matched or mismatched unrelated donors and familial mismatched donors. Preconditioning regimen consisted of fludarabine (total 150 mg/m²) and busulfan (total 6.4 mg/kg) with total body irradiation ⩽400cGy.

Results:

All showed engraftments, but four showed either leukemic relapse or delayed graft failure. Two-year overall survival (OS) and non-relapse mortality (NRM) was 60.0% and 29.9%, respectively. Acute GVHD was observed in 19 patients, and grade III–IV acute GVHD (eight grade III and four grade IV) was higher in human leukocyte antigen (HLA)-mismatched donor HCT compared with HLA-matched HCT (70% versus 20%). Chronic GVHD was observed in 16 patients, and a cumulative incidence of severe chronic GVHD was 33% in HLA-mismatched donor HCT and 7.7% in HLA-matched HCT. Significant hepatic GVHD was observed in nine patients (five acute, four chronic) and six of them died. Multivariate analysis revealed inferior OS in HLA-mismatched donor HCT (hazard ratio (HR) = 6.40, 95% confidence interval (CI) 1.6–25.7, p = 0.009) and in patients with high ferritin level at the time of pre-conditioning period (HR = 7.22, 95% CI 1.9–27.5, p = 0.004), which were related to higher incidence of hepatic GVHD with high NRM rate.

Conclusion:

RIC allo-HCT can be a valid choice providing graft-versus-fibrosis effect for advanced MF patients. However, HLA-mismatched donor and high pre-HCT ferritin level related to fatal hepatic GVHD should be regarded as poor-risk parameters.

Cryostorage to What End? - Autologous Stem Cell Products in Burkitt Lymphoma, Acute Lymphoblastic Leukemia, Acute Myeloid Leukemia, and Myeloproliferative Neoplasm Patients

Introduction

Recently, we identified a huge discrepancy between the collection practice and the actual utilization of cryopreserved peripheral blood stem cells (PBSCs) for high-dose chemotherapy (HDCT) and autologous blood stem cell transplantation (ABSCT). Specifically, patients with Burkitt lymphoma, acute leukemia, and myeloproliferative neoplasms (MPN) were frequently not referred for ABSCT after successful PBSC collection.

Objective

The aim of this study was to identify variables that are associated with the non-utilization of PBSC grafts.

Methods

We retrospectively analyzed the collection, storage, and disposal of PBSC grafts in Burkitt lymphoma (n = 18), acute lymphoblastic leukemia (ALL, n = 22), MPN (n = 18), and acute myeloid leukemia (AML, n = 71) patients. Patients who underwent autologous PBSC collection at 2 collection and transplantation centers between 2001 and 2012 were included and followed up until 2016.

Results

None of the Burkitt lymphoma patients were referred for ABSCT. Only in 1 (6%) patient, the graft was discarded after the patient's death. In all other patients (n = 17, 94%), the grafts were stored independently of the patient's status (death, n = 4, 22%; no follow-up, n = 6, 33%; no indication for ABSCT given, n = 7, 39%). In ALL patients, 4 (18%) patients underwent ABSCT after a median follow-up of 74 (1-182) months. In the remaining patients, PBSC grafts were either discarded (8 patients, 36%) or stored until the reference date (10 patients, 45%). Seven of 18 MPN patients (39%) underwent ABSCT. ABSCT was performed in 24 (34%) AML patients. In 20 (28%) patients who were not referred to ABSCT, an allogeneic transplantation (TPL) was performed. Fifteen (21%) patients received palliative care or deceased, and their grafts were discarded in all but 1 patient. Additional grafts were discarded in 21 (31%) patients and stored in 9 (13%) patients who underwent ABSCT or allogeneic TPL (n = 44).

Conclusions

As the role and efficacy of autologous HDCT/ABSCT are not established in the analyzed entities, the indication for PBSC collection should be reanalyzed in regular intervals. Moreover, PBSC grafts from patients who have deceased, have insufficient grafts, or have already undergone an allogeneic TPL should be considered for disposal or (if applicable) for research use, to economize storage costs on a rational basis.

Platelet Dysfunction and Thrombosis in JAK2V617F-Mutated Primary Myelofibrotic Mice

OBJECTIVE

The risk of thrombosis in myeloproliferative neoplasms, such as primary myelofibrosis varies depending on the type of key driving mutation (JAK2 [janus kinase 2], CALR [calreticulin], and MPL [myeloproliferative leukemia protein or thrombopoietin receptor]) and the accompanying mutations in other genes. In the current study, we sought to examine the propensity for thrombosis, as well as platelet activation properties in a mouse model of primary myelofibrosis induced by JAK2^V617F (janus kinase 2 with valine to phenylalanine substitution on codon 617) mutation. Approach and Results: Vav1-hJAK2^V617F transgenic mice show hallmarks of primary myelofibrosis, including significant megakaryocytosis and bone marrow fibrosis, with a moderate increase in red blood cells and platelet number. This mouse model was used to study responses to 2 models of vascular injury and to investigate platelet properties. Platelets derived from the mutated mice have reduced aggregation in response to collagen, reduced thrombus formation and thrombus size, as demonstrated using laser-induced or FeCl₃-induced vascular injury models, and increased bleeding time. Strikingly, the mutated platelets had a significantly reduced number of dense granules, which could explain impaired ADP secretion upon platelet activation, and a diminished second wave of activation.

CONCLUSIONS

Together, our study highlights for the first time the influence of a hyperactive JAK2 on platelet activation-induced ADP secretion and dense granule homeostasis, with consequent effects on platelet activation properties.

Body Mass Index and Total Symptom Burden in Myeloproliferative Neoplasms Discovery of a U-shaped Association

Elevated body mass index (BMI) is a global health problem, leading to enhanced mortality and the increased risk of several cancers including essential thrombocythemia (ET), a subtype of the Philadelphia-chromosome negative myeloproliferative neoplasms (MPN). Furthermore, evidence states that BMI is associated with the severity of symptom burden among cancer patients. MPN patients often suffer from severe symptom burden. The purpose of this study was to examine whether deviations from a normal BMI in an MPN population are associated with higher symptom burden and reduced quality of life (QoL). A combined analysis of two large cross-sectional surveys, the Danish Population-based Study, MPNhealthSurvey (n = 2044), and the international Fatigue Study (n = 1070), was performed. Symptoms and QoL were assessed using the validated Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF). Analysis of covariance was used to estimate the effects of different BMI categories on symptom scores while adjusting for age, sex, and MPN subtype. A U-shaped association between BMI and Total Symptom Burden was observed in both datasets with significantly higher mean scores for underweight and obese patients relative to normal weight (mean difference: underweight 5.51 (25.8%), p = 0.006; obese 5.70 (26.6%) p < 0.001). This is an important finding, as BMI is a potentially modifiable factor in the care of MPN patients.

Excretion balance and pharmacokinetics following a single oral dose of [14C]-fedratinib in healthy subjects

PURPOSE

Fedratinib is an oral and selective kinase inhibitor with activity against wild type and mutationally activated Janus kinase 2 and FMS-like tyrosine kinase 3, for the treatment of adult patients with intermediate-2 or high-risk primary or secondary myelofibrosis. This open-label mass balance study in healthy subjects investigated the excretion balance and systemic exposure of radioactivity after oral administration of [¹⁴C]-fedratinib; and the pharmacokinetics of fedratinib and its contribution to overall exposure of radioactivity.

METHODS

Six healthy males received a single oral dose of 200 mg [¹⁴C]-fedratinib base (2.775 MBq, 75 μCi) as a solution. Blood, urine and feces samples were collected for up to 35 day postdose. Urine and feces samples were collected until the 24-h excretion of radioactivity fell below 0.5% of administered dose (at least 14 day postdose). Expired air was collected up to 8-h postdose. Total radioactivity (blood, plasma, urine, feces, and expired air) and fedratinib concentrations (plasma) were measured.

RESULTS

Approximately 77% (23% unchanged) of fedratinib derived radioactivity was excreted in feces and 5% (3% unchanged) was excreted in urine. Excretion via expired air was negligible. The time to maximum concentration for both total radioactivity and parent drug was similar, with unchanged drug representing the majority of the circulating radioactivity. The ratio of blood to plasma concentration of radioactivity ranged from 0.615 to 0.753 indicating limited distribution of fedratinib and/or its metabolites into red blood cells.

CONCLUSIONS

Fedratinib derived radioactivity was primarily excreted in feces following a single oral dose of radiolabeled fedratinib to healthy subjects.

Fedratinib, a newly approved treatment for patients with myeloproliferative neoplasm-associated myelofibrosis

Myeloproliferative neoplasm (MPN)-associated myelofibrosis (MF) is characterized by cytopenias, marrow fibrosis, constitutional symptoms, extramedullary hematopoiesis, splenomegaly, and shortened survival. Constitutive activation of the janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway in MF leads to cell proliferation, inhibition of cell death, and clonal expansion of myeloproliferative malignant cells. Fedratinib is a selective oral JAK2 inhibitor recently approved in the United States for treatment of adult patients with intermediate-2 or high-risk MF. In mouse models of JAK2V617F-driven myeloproliferative disease, fedratinib blocked phosphorylation of STAT5, increased survival, and improved MF-associated disease features, including reduction of white blood cell counts, hematocrit, splenomegaly, and fibrosis. Fedratinib exerts off-target inhibitory activity against bromodomain-containing protein 4 (BRD4); combination JAK/STAT and BRD4 inhibition was shown to synergistically block NF-kB hyperactivation and inflammatory cytokine production, attenuating disease burden and reversing bone marrow fibrosis in animal models of MPNs. In patients, fedratinib is rapidly absorbed and dosed once daily (effective half-life 41 h). Fedratinib showed robust clinical activity in JAK-inhibitor-naïve patients and in patients with MF who were relapsed, refractory, or intolerant to prior ruxolitinib therapy. Fedratinib is effective regardless of JAK2 mutation status. Onset of spleen and symptom responses are typically seen within the first 1–2 months of treatment. The most common adverse events (AEs) with fedratinib are grades 1–2 gastrointestinal events, which are most frequent during early treatment and decrease over time. Treatment discontinuation due to hematologic AEs in clinical trials was uncommon (~3%). Suspected cases of Wernicke’s encephalopathy were reported during fedratinib trials in ~1% of patients; thiamine levels should be monitored before and during fedratinib treatment as medically indicated. Phase III trials are ongoing to assess fedratinib effects on long-term safety, efficacy, and overall survival. The recent approval of fedratinib provides a much-needed addition to the limited therapeutic options available for patients with MF.

Assessment of effects of repeated oral doses of fedratinib on inhibition of cytochrome P450 activities in patients with solid tumors using a cocktail approach

PURPOSE

Fedratinib, an oral selective kinase inhibitor with activity against both wild type and mutationally activated Janus kinase 2, has been approved for the treatment of adult patients with intermediate-2 or high-risk myelofibrosis by the US Food and Drug Administration. In vitro studies indicated that fedratinib was an inhibitor of several cytochrome P450 (CYP) enzymes. The primary objective of this study was to evaluate the effects of repeated doses of fedratinib on the activity of CYP2D6, CYP2C19, and CYP3A4 in patients with solid tumors using a CYP probe cocktail.

METHODS

An open-label, one-sequence, two-period, two-treatment crossover study was conducted. Patients were administered a single oral dose cocktail of metoprolol (100 mg), omeprazole (20 mg), and midazolam (2 mg) used as probe substrates for CYP2D6, CYP2C19, and CYP3A4 enzyme activities, respectively, without fedratinib on Day -1 or with fedratinib on Day 15.

RESULTS

Coadministration of 500 mg once-daily doses of fedratinib for 15 days increased the mean area under the plasma concentration-time curve from time zero to infinity following a single-dose cocktail containing metoprolol (CYP2D6 substrate), omeprazole (CYP2C19 substrate), and midazolam (CYP3A4 substrate) by 1.77-fold (90% confidence interval [CI] 1.27-2.47) for metoprolol, 2.82-fold (90% CI 2.26-3.53) for omeprazole, and 3.84-fold (90% CI 2.62-5.63) for midazolam, respectively. The mean plasma Day 14/Day 1 ratio of 4β-hydroxycholesterol, an endogenous biomarker of CYP3A4 activity, was 0.59 (90% CI 0.54-0.66), suggesting a net inhibition of CYP3A4 by fedratinib.

CONCLUSION

Fedratinib is a weak inhibitor of CYP2D6, and a moderate inhibitor of CYP2C19 and CYP3A4. These results serve as the basis for dose modifications of these CYP substrate drugs when co-administered with fedratinib.