Risk of infections in patients with myeloproliferative neoplasms-a population-based cohort study of 8363 patients

Primary antifungal prophylaxis in hematological malignancies. Updated clinical practice guidelines by the European Conference on Infections in Leukemia (ECIL)

At the 10th European Conference on Infections in Leukaemia (ECIL), the guidelines for antifungal prophylaxis in pediatric and adult patients with hematological malignancies (HM) were updated and some changes introduced. Regarding acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) patients undergoing remission induction chemotherapy, a B-II grading has been assigned to isavuconazole, micafungin, and caspofungin, based on non-randomized studies that have shown efficacy in preventing invasive fungal diseases (IFD). Regarding high-risk MDS patients treated with azacytidine, prophylaxis with posaconazole during the first four cycles of treatment is supported in the literature. Prophylaxis is not indicated in patients treated for myeloproliferative neoplasms (NPM), acute lymphoid leukemia (ALL), and Hodgkin lymphoma (HL). For patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL), prophylaxis is not generally indicated. For patients with multiple myeloma (MM), prophylaxis is not indicated and the limited epidemiological data available do not support the use of prophylaxis in subjects treated with bispecific antibodies. For patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT), no substantial changes were made, apart from the addition of isavuconazole with grading B-II in the post-engraftment period. In patients undergoing auto-HSCT, antifungal prophylaxis is not indicated. Previous ECIL guidelines did not include CAR-T cells. The expert panel proposes to endorse the use of anti-mold prophylaxis in high-risk patients during pre-infusion and post-infusion, while in low-risk patients, anti-yeast prophylaxis can be recommended (B-II). For pediatric hematology patients, based on newly published data, caspofungin received a B-I grading as mold-active prophylaxis. Moreover, patients with ALL with insufficient treatment response during induction therapy, and children older than 12 y.o are now considered at high risk for IFD and are recommended to receive antifungal prophylaxis.

Proinflammatory and prothrombotic conditions in JAK2V617F-positive MPN: a case of Lemierre's syndrome in essential thrombocythemia

Lemierre's syndrome (LS) represents a rare yet potentially life-threatening systemic infection, characterized by thrombophlebitis of the internal jugular vein and abscess formation in distant organs. It typically follows episodes of tonsillitis or other infections of the oropharyngeal region. Pulmonary complications, including septic pulmonary emboli, are common. Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm (MPN) sometimes associated with the JAK2V617F mutation, which predisposes patients to thrombotic events. A 66-year-old male with JAK2V617F-positive ET presented with severe pulsatile pain radiating from the right temporal region to the occipital area following a recent dental infection. Although pain management was administered, the pain continued to persist. Computed tomography of the chest revealed multiple subpleural nodules, raising suspicion for septic pulmonary emboli. Further investigation with gadolinium-enhanced magnetic resonance imaging identified a thrombus extending from the right sigmoid sinus into the internal jugular vein, consistent with cerebral venous thrombosis. The patient was diagnosed with　LS, complicated by septic thrombosis. Blood cultures yielded alpha-hemolytic streptococcus. Empirical antimicrobial therapy combined with anticoagulation was initiated, resulting in a gradual improvement of symptoms, including the resolution of fever and pain. Follow-up imaging confirmed the resolution of both the infection and thrombosis. This is the first reported case of LS in a patient with JAK2V617F-positive ET. The coexistence of LS and JAK2V617F-positive MPN highlights the potential interplay between proinflammatory and prothrombotic conditions associated with the JAK2V617F mutation.

Intersecting Pathologies: Polycythemia Vera and Recurrent Infections in an Elderly Patient

This case report highlights the diagnostic and therapeutic challenges encountered in the management of a 95-year-old female patient with polycythemia vera (PV) complicated by recurrent infections. The patient presented with significant leukocytosis, thrombocytosis, and concurrent infections, including a urinary tract infection and influenza B. PV, a myeloproliferative neoplasm, is characterized by increased production of red blood cells and often involves heightened activation of myeloid and megakaryocytic lineages, resulting in leukocytosis and thrombocytosis. These hematological abnormalities, coupled with underlying immune dysregulation, predispose patients to recurrent and severe infections. The patient's condition was further complicated by resistance to initial antibiotic therapy, necessitating adjustments in treatment. Despite resolving the infections, persistent leukocytosis raised concerns about the interplay between inflammatory, infectious, and neoplastic processes. This case underscores the complexities of managing patients with PV who exhibit overlapping hematological abnormalities and recurrent infections. It emphasizes the need for a multidisciplinary approach involving hematologists and infectious disease specialists to optimize care. The report also discusses the importance of preventive strategies, such as vaccinations, in reducing the risk of infections in high-risk populations, particularly those with myeloproliferative disorders.

Monocytes generated by interleukin-6-treated human hematopoietic stem and progenitor cells secrete calprotectin that inhibits erythropoiesis

Elevated circulating levels of calprotectin (CAL), the S100A8/A9 heterodimer, are biomarkers of severe systemic inflammation. Here, we investigate the effects of CAL on early human hematopoiesis. CAL demonstrates limited impact on gene expression in stem and progenitor cells, in contrast with interleukin-6 (IL6), which promotes the expression of the S100A8 and S100A9 genes in hematopoietic progenitors and the generation of monocytes that release CAL. The main target of CAL is an erythroid-megakaryocyte progenitor (EMP) subset. CAL prevents both erythropoietin-driven differentiation of healthy progenitors and JAK2-V617F-driven erythropoiesis. In the context of JAK2-V617F, CAL also promotes the expression of S100A8 and S100A9 genes in monocytes. The signature of CAL effects is detected in the bone marrow progenitors of patients with myeloid malignancy or severe infection. These results position CAL as a mediator of IL6 effects on triggering anemia during inflammation, an effect that is amplified in the context of JAK2-V617F-driven hematopoiesis.

Cost-utility analysis of ropeginterferon alfa-2b to manage low-risk patients with polycythemia vera as compared to phlebotomy only in the Austrian healthcare system

Treatment of polycythemia vera (PV) aims to maintain hematocrit on target to reduce risk of thrombotic complications, while preventing disease progression to myelofibrosis (MF) and acute myeloid leukemia (AML). This analysis evaluated cost-effectiveness of adding ropeginterferon alfa-2b (ropegIFNα) to phlebotomy in patients with low-risk PV (those younger than 60 years without prior thrombosis), compared to phlebotomy alone. We combined a 12-month decision tree with a semi-Markov cohort model comparing ropegIFNα to the standard treatment from the Austrian healthcare system perspective over 30 years. Outcomes were quality adjusted life years (QALYs), costs, and incremental cost-utility ratio (ICUR). Model inputs were obtained from the phase 2 Low-PV study, additional published literature and from Austrian-specific cost databases. One-way and probabilistic sensitivity analyses (SA) assessed the robustness of findings. RopegIFNα led to 1,43 higher QALYs and 50.960 EUR overall higher costs compared to phlebotomy alone, with an ICUR of 35.525 EUR/QALY. Thrombosis, MF, and AML costs decreased for the ropegIFNα group by 12%, 30% and 16% respectively, due to the delayed complications onset and disease progression. In the one-way SA, ropegIFNα costs and discount rates had the greatest impact on results. The probabilistic SA showed a 100% probability of cost-effectiveness at willingness-to-pay threshold aligned to the Austrian GDP per capita. RopegIFNα is a cost-effective treatment option for patients with low-risk PV. These findings suggest that early treatment with ropegIFNα could ensure optimal resource allocation by preventing costly thrombotic events and progression to MF whilst increasing patient quality of life.

Washed microbiota transplantation stopped recurrent sepsis in a patient with myelofibrosis: a case report

BACKGROUND

Sepsis represents the most prevalent infectious complication and the primary cause of mortality in myeloproliferative neoplasms (MPN). The risk of sepsis and the difficulty of treatment are significantly increased in MPN patients due to the need for immunomodulators and antibiotics.

CASE PRESENTATION

On June 9, 2023, a 69-year-old male was admitted to the hospital. Following a battery of tests, the diagnosis of sepsis due to Escherichia coli was ultimately established. The patient was administered amoxicillin clavulanate potassium intravenously. In light of the patient's recurrent sepsis and the likelihood that the source of infection is the intestinal tract, we advised that the patient undergo washed microbiota transplantation (WMT) via a colonic transendoscopic enteral tube (TET).

CONCLUSIONS

WMT as the new method of fecal microbiota transplantation (FMT) successfully cured the recurrent sepsis in this case, indicating the novel option for challenging the refractory or serious infections.

Pacritinib and concurrent azole antifungal therapy is deliverable in patients with hematologic malignancies

OBJECTIVE

Pacritinib is a novel kinase inhibitor approved for the treatment of adults with intermediate or high-risk primary or secondary myelofibrosis. Strong and moderate CYP3A4 inhibitors, such as some azole antifungals, are contraindicated or recommended to be avoided in combination with pacritinib, respectively. We aim to report our experience in patients who received pacritinib with concurrent azole antifungal therapy.

DATA SOURCES

We queried for patients with hematologic malignancies in the electronic medical record who received concurrent pacritinib and azole antifungal therapy.

DATA SUMMARY

There were five cases of concurrent pacritinib and azole antifungal therapy in which none of the patients experienced grade 3 or higher non-hematologic toxicities. Some patients required dose modifications and/or interruptions in pacritinib therapy.

CONCLUSION

This is the first clinical experience describing concurrent pacritinib and azole antifungals. Our experience shows that in the setting where this interaction cannot be avoided, concurrent administration is feasible with close monitoring and possible empiric dose reductions in select patients.

Epidemiology and disease characteristics of myelofibrosis: a comparative analysis between Italy and global perspectives

Myelofibrosis (MF) is a clonal disorder of hematopoietic stem cells characterized by altered bone marrow function and fibrosis. The aim of this narrative review is to report on the most recent epidemiologic data and to discuss features of MF and current strategies for the management of this condition in clinical practice. MF features covered by our review will include: characteristics of patients with MF; myeloproliferative and myelodepletive phenotypes; MF-associated thrombosis and bleeding; risk of infections; prefibrotic and overt PMF; secondary MF. Finally, we will discuss a few aspects of MF management in clinical practice and suggest strategies for its optimization and standardization. The focus of our paper is on Italy, but relevant data from other countries will also be reviewed.

Infections in patients with mantle cell lymphoma

Advancements in treatments have significantly improved the prognosis for mantle cell lymphoma (MCL), and there is a growing population of survivors with an increased susceptibility to infections. We assessed the incidence of infections by clinical characteristics and treatment both before and after MCL diagnosis in Sweden. Patients with a diagnosis of MCL ≥ 18 years between 2007 and 2019 were included, along with up to 10 matched comparators. Infectious disease diagnosis and anti-infective drug dispensation were identified by the National Patient and the Prescribed Drug Registers, respectively. Patients and comparators were followed from the diagnosis/matching date until death, emigration, or June 30, 2020. Overall, 1559 patients and 15,571 comparators were followed for a median duration of 2.9 and 5 years, respectively. The infection rate among patients was twofold higher, RRadj = 2.14 (2.01-2.27), contrasted to the comparator group. There was a notable rise in infection rates already 4 years before MCL diagnosis, which reached a fourfold increase in the first year after diagnosis and persisted significantly increased for an additional 8 years. Among patients, 69% (n = 1080) experienced at least one infection during the first year of follow-up. Influenza, pneumonia, other bacterial infections, urinary tract infections, and acute upper respiratory infections were the most frequent. Notably, MCL remained to be the primary leading cause of death among patients (57%, n = 467/817). Infections as the main cause of death were rare (2.6%, n = 21). Our study highlights the importance of thoroughly assessing infectious morbidity when appraising new treatments. Further investigations are warranted to explore strategies for reducing infectious disease burden.

Acute invasive fungal sinusitis with orbital tip syndrome in patients on long-term use of ruxolitinib: a case report

INTRODUCTION

A long-term ruxolitinib-treated patient with primary myelofibrosis, who was co-infected with aspergillosis infection during a short period, developed acute invasive fungal sinusitis with consequent orbit apex syndrome. This may be the first reported case in the world. This is a 75-year-old Chinese man; the patient was admitted with 2-month history of headache accompanied by numbness and 8-day history of vision loss. The preliminary clinical diagnoses were suspected acute invasive fungal sinusitis or adenoid cystic carcinoma. We performed endoscopic debridement and antifungal therapy. About 90 days after surgery, magnetic resonance imaging revealed no recurrence of pathological tissue.

CONCLUSION

One of the bases for the occurrence of invasive fungal sinusitis may be the patient's long-term use of ruxolitinib for essential thrombocythemia. Some patients with invasive fungal sinuses have atypical nasal symptoms and are referred to the corresponding departments with eye and headache as the first symptoms. It is suggested that enhanced magnetic resonance imaging should be performed at an early stage. Surgical treatment in combination with antifungal and enhanced immunotherapy can effectively prevent the spread of infection and reduce the risk of death.

Disseminated Histoplasmosis in a Patient with Myelofibrosis on Ruxolitinib: A Case Report and Review of the Literature on Ruxolitinib-Associated Invasive Fungal Infections

Ruxolitinib, a selective inhibitor of Janus kinases, is a standard treatment for intermediate/high-risk myelofibrosis (MF) but is associated with a predisposition to opportunistic infections, especially herpes zoster. However, the incidence and characteristics of invasive fungal infections (IFIs) in these patients remain uncertain. In this report, we present the case of a 59-year-old woman with MF who developed disseminated histoplasmosis after seven months of ruxolitinib use. The patient clinically improved after ten weeks of combined amphotericin B and azole therapy, and ruxolitinib was discontinued. Later, the patient received fedratinib, a relatively JAK2-selective inhibitor, without relapse of histoplasmosis. We also reviewed the literature on published cases of proven IFIs in patients with MF who received ruxolitinib. Including ours, we identified 28 such cases, most commonly due to Cryptococcus species (46%). IFIs were most commonly disseminated (39%), followed by localized lung (21%) infections. Although uncommon, a high index of suspicion for opportunistic IFIs is needed in patients receiving JAK inhibitors. Furthermore, the paucity of data regarding the optimal management of IFIs in patients treated with JAK inhibitors underscore the need for well-designed studies to evaluate the epidemiology, pathobiology, early diagnosis, and multimodal therapy of IFIs in patients with hematological malignancies receiving targeted therapies.

Myeloproliferative Neoplasms: Contemporary Review and Molecular Landscape

Myelofibrosis (MF), Myeloproliferative neoplasms (MPNs), and MDS/MPN overlap syndromes have a broad range of clinical presentations and molecular abnormalities, making their diagnosis and classification complex. This paper reviews molecular aberration, epigenetic modifications, chromosomal anomalies, and their interactions with cellular and other immune mechanisms in the manifestations of these disease spectra, clinical features, classification, and treatment modalities. The advent of new-generation sequencing has broadened the understanding of the genetic factors involved. However, while great strides have been made in the pharmacological treatment of these diseases, treatment of advanced disease remains hematopoietic stem cell transplant.

Ten years of treatment with ruxolitinib for myelofibrosis: a review of safety

Myelofibrosis (MF) is a chronic myeloproliferative neoplasm characterized by bone marrow fibrosis, anemia, extramedullary hematopoiesis, and splenomegaly. Patients with MF are at risk for reduced survival versus the general population and often experience burdensome signs and symptoms that reduce quality of life. The oral Janus kinase (JAK) 1/JAK2 inhibitor ruxolitinib was initially approved by the US Food and Drug Administration in 2011 for the treatment of patients with intermediate or high-risk MF, including primary MF, post-polycythemia vera MF, and post-essential thrombocythemia MF, based on efficacy and safety findings from the randomized, controlled, phase 3 COMFORT trials. Over a decade later, ruxolitinib continues to be the standard of care in higher-risk MF, and dose optimization and management remain crucial for safely maximizing clinical benefits of ruxolitinib. This review summarizes the safety profile of ruxolitinib in patients with MF in the COMFORT trials leading up to approval and in the subsequent JUMP, ROBUST, EXPAND, and REALISE trials; in pooled analyses; and in postmarketing analyses in the 10 years following approval. There is a focus on the occurrence of common hematologic and nonhematologic adverse events, with guidance provided on the management of patients with anemia or thrombocytopenia, including dosing strategies based on findings from the REALISE and EXPAND trials. Finally, to ensure a greater understanding of the safety profile of ruxolitinib, practical considerations are discussed.

Myelofibrosis

The clinical phenotype of primary and post-polycythemia vera and postessential thrombocythemia myelofibrosis (MF) is dominated by splenomegaly, symptomatology, a variety of blood cell alterations, and a tendency to develop vascular complications and blast phase. Diagnosis requires assessing complete cell blood counts, bone marrow morphology, deep genetic evaluations, and disease history. Driver molecular events consist of JAK2V617F, CALR, and MPL mutations, whereas about 8% to 10% of MF are "triple-negative." Additional myeloid-gene variants are described in roughly 80% of patients. Currently available clinical-based and integrated clinical/molecular-based scoring systems predict the survival of patients with MF and are applied for conventional treatment decision-making, indication to stem cell transplant (SCT) and allocation in clinical trials. Standard treatment consists of anemia-oriented therapies, hydroxyurea, and JAK inhibitors such as ruxolitinib, fedratinib, and pacritinib. Overall, spleen volume reduction of 35% or greater at week 24 can be achieved by 42% of ruxolitinib-, 47% of fedratinib-, 19% of pacritinib-, and 27% of momelotinib-treated patients. Now, it is time to move towards new paradigms for evaluating efficacy like disease modification, that we intend as a robust and unequivocal effect on disease biology and/or on patient survival. The growing number of clinical trials potentially pave the way for new strategies in patients with MF. Translational studies of some molecules showed an early effect on bone marrow fibrosis and on variant allele frequencies of myeloid genes. SCT is still the only curative option, however, it is associated with relevant challenges. This review focuses on the diagnosis, prognostication, and treatment of MF.

Sepsis-Related Outcomes of Patients with Philadelphia-Negative Myeloproliferative Neoplasms

We analyzed the National Inpatient Sample (NIS) database to study the sepsis-related outcomes in patients with Philadelphia negative myeloproliferative neoplasms (MPN). A total of 82,087 patients were included, most had essential thrombocytosis (83.7%), followed by polycythemia vera (13.7%), and primary myelofibrosis (2.6%). Sepsis was diagnosed in 15,789 (19.2%) patients and their mortality rate was higher than nonseptic patients (7.5% vs 1.8%; p < .001). Sepsis was the most significant risk factor of mortality (aOR, 3.84; 95% CI, 3.51-4.21), others included liver disease (aOR, 2.42; 95% CI, 2.11-2.78), pulmonary embolism (aOR, 2.26; 95% CI, 1.83-2.80), cerebrovascular disease (aOR, 2.05; 95% CI, 1.81-2.33), and myocardial infarction (aOR, 1.73; 95% CI, 1.52-1.96).

Sepsis-related outcomes of patients with Philadelphia-negative myeloproliferative neoplasms

We analyzed the National Inpatient Sample (NIS) database to study the sepsis-related outcomes in patients with Philadelphia negative myeloproliferative neoplasms (MPN). A total of 82,087 patients were included, most had essential thrombocytosis (83.7%), followed by polycythemia vera (13.7%), and primary myelofibrosis (2.6%). Sepsis was diagnosed in 15,789 (19.2%) patients and their mortality rate was higher than non-septic patients (7.5% vs 1.8%; P<.001). Sepsis was the most significant risk factor of mortality (aOR, 3.84; 95% CI, 3.51-4.21), others included liver disease (aOR, 2.42; 95% CI, 2.11-2.78), pulmonary embolism (aOR, 2.26; 95% CI, 1.83-2.80), cerebrovascular disease (aOR, 2.05; 95% CI, 1.81-2.33), and myocardial infarction (aOR, 1.73; 95% CI, 1.52-1.96).

Risk-adjusted safety analysis of the oral JAK2/IRAK1 inhibitor pacritinib in patients with myelofibrosis

The safety profile of the novel oral JAK2/IRAK1 inhibitor pacritinib in patients with cytopenic myelofibrosis was described in the Phase 2 PAC203 and Phase 3 PERSIST-2 studies. To account for longer treatment durations on the pacritinib arms compared to best available therapy (BAT), we present a risk-adjusted safety analysis of event rates accounting for different time on treatment. While the rate of overall events was higher on pacritinib compared to BAT, the rate of fatal events was lower, and there was no excess in bleeding, cardiac events, secondary malignancy, or thrombosis on pacritinib, including in patients with severe thrombocytopenia.

Fedratinib: a pharmacotherapeutic option for JAK-inhibitor naïve and exposed patients with myelofibrosis

INTRODUCTION

Ruxolitinib is the most commonly used JAK-inhibitor (JAKi) for the management of symptoms related to splenomegaly and cytokine-mediated inflammation in patients with myelofibrosis (MF), but is limited by variable durability of response with most patients experiencing failure after 2-3 years. Long-term data on other approved JAKi, fedratinib and pacritinib, are not available due to the clinical hold put on pivotal trials for toxicity concerns.

AREAS COVERED

Following the initial hold for concern of Wernicke's encephalopathy, fedratinib was approved by the Food and Drug Administration (FDA) in 2019 for MF. We review the data available from early, and late phase critical trials, outline a role for fedratinib in the current treatment landscape of MF, and highlight the knowledge gaps in optimizing use of fedratinib.

EXPERT OPINION

The JAKARTA and JAKARTA2 trials established efficacy in spleen volume response (SVR) and symptom reduction in JAKi-naïve and ruxolitinib-exposed MF patients, respectively. Further trials, FREEDOM and FREEDOM2, are in progress to understand long-term effects of fedratinib; and include strategies to mitigate gastrointestinal toxicity, monitor thiamine levels and surveil for encephalopathy. We use fedratinib for symptomatic MF following ruxolitinib failure in patients without significant cytopenias; with practical strategies for monitoring and managing potential toxicity.

Interferon-alpha2 treatment of patients with polycythemia vera and related neoplasms favorably impacts deregulation of oxidative stress genes and antioxidative defense mechanisms

Chronic inflammation is considered a major driving force for clonal expansion and evolution in the Philadelphia-negative myeloproliferative neoplasms, which include essential thrombocythemia, polycythemia vera and primary myelofibrosis (MPNs). One of the key mutation drivers is the JAK2V617F mutation, which has been shown to induce the generation of reactive oxygen species (ROS). Using whole blood gene expression profiling, deregulation of several oxidative stress and anti-oxidative defense genes has been identified in MPNs, including significant downregulation of TP53, the NFE2L2 or NRF2 genes. These genes have a major role for maintaining genomic stability, regulation of the oxidative stress response and in modulating migration or retention of hematopoietic stem cells. Therefore, their deregulation might give rise to increasing genomic instability, increased chronic inflammation and disease progression with egress of hematopoietic stem cells from the bone marrow to seed in the spleen, liver and elsewhere. Interferon-alpha2 (rIFNα) is increasingly being recognized as the drug of choice for the treatment of patients with MPNs. Herein, we report the first gene expression profiling study on the impact of rIFNα upon oxidative stress and antioxidative defense genes in patients with MPNs (n = 33), showing that rIFNα downregulates several upregulated oxidative stress genes and upregulates downregulated antioxidative defense genes. Treatment with rIFNα induced upregulation of 19 genes in ET and 29 genes in PV including CXCR4 and TP53. In conclusion, this rIFNα- mediated dampening of genotoxic damage to hematopoietic cells may ultimately diminish the risk of additional mutations and accordingly clonal evolution and disease progression towards myelofibrotic and leukemic transformation.

The immune landscape in BCR-ABL negative myeloproliferative neoplasms: inflammation, infections and opportunities for immunotherapy

Breakpoint cluster region-Abelson (BCR-ABL) negative myeloproliferative neoplasms (MPNs) are chronic myeloid neoplasms initiated by the acquisition of gene mutation(s) in a haematopoietic stem cell, leading to clonal expansion and over-production of blood cells and their progenitors. MPNs encompass a spectrum of disorders with overlapping but distinct molecular, laboratory and clinical features. This includes polycythaemia vera, essential thrombocythaemia and myelofibrosis. Dysregulation of the immune system is key to the pathology of MPNs, supporting clonal evolution, mediating symptoms and resulting in varying degrees of immunocompromise. Targeting immune dysfunction is an important treatment strategy. In the present review, we focus on the immune landscape in patients with MPNs - the role of inflammation in disease pathogenesis, susceptibility to infection and emerging strategies for therapeutic immune modulation. Further detailed work is required to delineate immune perturbation more precisely in MPNs to determine how and why vulnerability to infection differs between clinical subtypes and to better understand how inflammation results in a competitive advantage for the MPN clone. These studies may help shed light on new designs for disease-modifying therapies.

Immune Dysregulation and Infectious Complications in MPN Patients Treated With JAK Inhibitors

BCR-ABL1-negative myeloproliferative neoplasms are burdened by a reduced life expectancy mostly due to an increased risk of thrombo-hemorrhagic events, fibrotic progression/leukemic evolution, and infectious complications. In these clonal myeloid malignancies, JAK2V617F is the main driver mutation, leading to an aberrant activation of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway. Therefore, its inhibition represents an attractive therapeutic strategy for these disorders. Several JAK inhibitors have entered clinical trials, including ruxolitinib, the first JAK1/2 inhibitor to become commercially available for the treatment of myelofibrosis and polycythemia vera. Due to interference with the JAK-STAT pathway, JAK inhibitors affect several components of the innate and adaptive immune systems such as dendritic cells, natural killer cells, T helper cells, and regulatory T cells. Therefore, even though the clinical use of these drugs in MPN patients has led to a dramatic improvement of symptoms control, organ involvement, and quality of life, JAK inhibitors–related loss of function in JAK-STAT signaling pathway can be a cause of different adverse events, including those related to a condition of immune suppression or deficiency. This review article will provide a comprehensive overview of the current knowledge on JAK inhibitors’ effects on immune cells as well as their clinical consequences, particularly with regards to infectious complications.

Paroxysmal Nocturnal Hemoglobinuria in the Context of a Myeloproliferative Neoplasm: A Case Report and Review of the Literature

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by intravascular hemolytic anemia and thrombosis and is notoriously associated with aplastic anemia and myelodysplastic syndromes. Rarer associations include myeloproliferative neoplasms (MPNs), which are also burdened by increased thrombotic tendency. The therapeutic management of this rare combination has not been defined so far. Here, we describe a 62-year-old man who developed a highly hemolytic PNH more than 10 years after the diagnosis of MPN. The patient started eculizumab, obtaining good control of intravascular hemolysis but without amelioration of transfusion-dependent anemia. Moreover, we performed a review of the literature regarding the clinical and pathogenetic significance of the association of PNH and MPN. The prevalence of PNH clones in MPN patients is about 10%, mostly in association with JAK2V617F-positive myelofibrosis. Thrombotic events were a common clinical presentation (35% of subjects), sometimes refractory to combined treatment with cytoreductive agents, anticoagulants, and complement inhibitors. The latter showed only partial effectiveness in controlling hemolytic anemia and, due to the paucity of data, should be taken in consideration after a careful risk/benefit evaluation in this peculiar setting.

Cytoreductive treatment in real life: a chart review analysis on 1440 patients with polycythemia vera

Purpose

Patients with polycythemia vera (PV) show an elevated incidence of thromboembolic complications and decreased survival when compared to age-matched healthy individuals. Hypercellularity as indicated by elevated hematocrit, pathophysiological changes induced by the JAK2 driver mutation and cardiovascular risk factors contribute to the increased incidence of thromboembolic events. Higher age and a history of thromboembolic events define a high-risk population of PV patients. Depending on the individual risk profile, phlebotomy or pharmacologic cytoreduction is recommended in combination with low-dose acetylsalicylic acid. Stringent cytoreduction is required for effective risk reduction. However, in recent reports, the rate of thromboembolic complications in PV patients under cytoreductive therapy appears still elevated compared to healthy individuals. This study reports on a chart review to assess for cytoreductive therapy of 1440 PV patients in real life.

Methods

Forty-two eligible hematologists/oncologists in private practice treating patients with MPN were recruited to participate in a paper–pencil-based survey conducted between January 2019 and March 2020 in Germany. Physicians were asked to report primary documented data obtained from patient charts. Descriptive analyses were conducted to assess for patient characteristics, treatment modalities, risk factors and thromboembolic complications.

Results

Data were collected from the patient charts of 1440 individuals diagnosed with PV. The patient population was older than those reported in multicenter trials with a median age of 72.2 years at the time of reporting and 63.5 years at diagnosis. Age was the main factor accounting for high-risk status with 84.7% of patients being above the age of 60 followed by thromboembolic complications reported in 21.3% of patients. The use of pharmacologic cytoreduction was highly variable between participating centers with an average of 60.7% and a range of 10.1–100%. Hydroxyurea was the most frequently used drug followed by ruxolitinib, while interferons were reported for a minority of patients. For 35.4% of patients a persistent need for phlebotomy in addition to cytoreductive treatment was reported. Although presence of high-risk criteria and insufficient disease control were reported as main triggers to initiate pharmacologic cytoreduction, 28.1% had elevated hematocrit values (> 45%) and 38.6% showed persistence of elevated leukocyte count (> 10^9/l) while on cytoreductive treatment. In contrast, physician-reported symptom burden was lower than published in clinical trials and patient-reported outcomes. The rate of patients experiencing thromboembolic complications was 32.2% at any time and 14.3% after diagnosis with most patients receiving acetylsalicylic acid and 10.8% remaining on oral anticoagulants or heparin.

Conclusions

Cytoreductive treatment of high-risk PV in real life is highly variable regarding indication for cytoreduction and definition of therapy resistance. This study highlights the need for (i) improved risk stratification for thromboembolic events, (ii) consequent indication of pharmacologic cytoreduction in high-risk PV and (iii) attention to signs of therapy resistance that can trigger an earlier and stringent switch to second line agents.

The Slower Antibody Response in Myelofibrosis Patients after Two Doses of mRNA SARS-CoV-2 Vaccine Calls for a Third Dose

Immunization with mRNA SARS-CoV-2 vaccines has been highly recommended and prioritized in fragile subjects, including patients with myelofibrosis (MF). Available data on the vaccine immune response developed by MF patients and the impact of ruxolitinib treatment are still too fragmented to support an informed decision on a third dose for this category of subjects. Here, we show that 76% of MF patients develop spike-specific IgG after the second mRNA SARS-CoV-2 vaccine dose, but the response has a slower kinetics compared to healthy subjects, suggesting a reduced capability of their immune system to promptly react to vaccination. A reduced ACE2/RBD binding inhibition activity of spike-specific antibodies was also observed, especially in ruxolitinib-treated patients. Our results, showing slow kinetics of antibody responses in MF patients following vaccination with mRNA SARS-CoV-2 vaccines, support the need for a third vaccine dose.

Philadelphia-Negative Myeloproliferative Neoplasms Around the COVID-19 Pandemic

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) is associated with a high rate of respiratory failure, thromboembolism, bleeding, and death. Patients with myeloproliferative neoplasms (MPNs) are prone to both thrombosis and bleeding, calling for special care during COVID-19. We reviewed the clinical features of MPN patients with COVID-19, suggesting guidance for treatment.

RECENT FINDINGS

One study by the European LeukemiaNet collected 175 MPN patients with COVID-19 during the first wave of the pandemic, from February to May 2020. Patients with primary myelofibrosis (PMF) were at higher risk of mortality (48%) in comparison with essential thrombocythemia (ET) (25%) and polycythemia vera (19%); the risk of death was higher in those patients who abruptly discontinued ruxolitinib. In patients followed at home, in regular wards, or in ICU, the thrombosis rate was 1.0%, 2.8%, and 18.4%, respectively. Independent risk factors for thrombosis were ET phenotype, transfer to ICU, and neutrophil/lymphocyte ratio; major bleeding occurred in 4.3% of patients, particularly those with PMF. MPN patients with non-severe COVID-19 treated at home should continue their primary or secondary antithrombotic prophylaxis with aspirin or oral anticoagulants. In the case of hospitalization, patients assuming aspirin should add low molecular weight heparin (LMWH) at standard doses. In contrast, LMWH at intermediate/therapeutic doses should replace oral anticoagulants prescribed for atrial fibrillation or previous venous thromboembolism. Intermediate/high doses of LMWH can also be considered in ICU patients with ET, particularly in the case of a rapid decline in the number of platelets and progressive respiratory failure.

Classical Philadelphia-negative myeloproliferative neoplasms (MPNs): A continuum of different disease entities

Classical Philadelphia-negative myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell-derived disorders characterized by uncontrolled proliferation of differentiated myeloid cells and close pathobiologic and clinical features. According to the 2016 World Health Organization (WHO) classification, MPNs include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The 2016 revision aimed in particular at strengthening the distinction between masked PV and JAK2-mutated ET, and between prefibrotic/early (pre-PMF) and overt PMF. Clinical manifestations in MPNs include constitutional symptoms, microvascular disorders, thrombosis and bleeding, splenomegaly secondary to extramedullary hematopoiesis, cytopenia-related symptoms, and progression to overt MF and acute leukemia. A dysregulation of the JAK/STAT pathway is the unifying mechanistic hallmark of MPNs, and is guided by somatic mutations in driver genes including JAK2, CALR and MPL. Additional mutations in myeloid neoplasm-associated genes have been also identified, with established prognostic relevance, particularly in PMF. Prognostication of MPN patients relies on disease-specific clinical models. The increasing knowledge of MPN biology led to the development of integrated clinical and molecular prognostic scores that allow a more refined stratification. Recently, the therapeutic landscape of MPNs has been revolutionized by the introduction of potent, selective JAK inhibitors (ruxolitinib, fedratinib), that proved effective in controlling disease-related symptoms and splenomegaly, yet leaving unmet critical needs, owing the lack of disease-modifying activity. In this review, we will deal with molecular, clinical, and therapeutic aspects of the three classical MPNs aiming at highlighting either shared characteristics, that overall define a continuum within a single disease family, and uniqueness, at the same time.

Philadelphia-Negative Chronic Myeloproliferative Neoplasms during the COVID-19 Pandemic: Challenges and Future Scenarios

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) started in December 2019 in China and then become pandemic in February 2020. Several publications investigated the possible increased rate of COVID-19 infection in hematological malignancies. Based on the published data, strategies for the management of chronic Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are provided. The risk of severe COVID-19 seems high in MPN, particularly in patients with essential thrombocythemia, but not negligible in myelofibrosis. MPN patients are at high risk of both thrombotic and hemorrhagic complications and this must be accounted in the case of COVID-19 deciding on a case-by-case basis. There are currently no data to suggest that hydroxyurea or interferon may influence the risk or severity of COVID-19 infection. Conversely, while the immunosuppressive activity of ruxolitinib might pose increased risk of infection, its abrupt discontinuation during COVID-19 syndrome is associated with worse outcome. All MPN patients should receive vaccine against COVID-19; reassuring data are available on efficacy of mRNA vaccines in MPNs.

The Binary Classification of Protein Kinases

In an earlier publication a binary model for chronic diseases classification has been proposed. According to the model, chronic diseases were classified as “high Treg” or “low Treg” diseases, depending on whether the immune response is anti- or pro-inflammatory and assuming that regulatory T cells are major determinants of the response. It turned out that most cancers are “high Treg” diseases, while autoimmune diseases are “low Treg”. This paper proposes a molecular cause for this binary response. The mechanism proposed depends on the effect of protein kinases on the immune system. Thus, protein kinases are classified as anti- or pro-inflammatory kinases depending on whether they drive “high Treg” or “low Treg” diseases. Observations reported in the earlier publication can be described in terms of anti-inflammatory kinase (AIK) or pro-inflammatory kinase (PIK) activity. Analysis of literature data reveals that the two classes of kinases display distinctive properties relating to their interactions with pathogens and environmental factors. Pathogens that promote Treg activity (“high Treg” pathogens) activate AIKs, while pathogens that suppress Treg activity (“low Treg” pathogens) activate PIKs. Diseases driven by AIKs are associated with “high Treg” pathogens while those diseases driven by PIKs are associated with “low Treg” pathogens. By promoting the activity of AIKs, alcohol consumption increases the risk of “high Treg” cancers but decreases the risk of some “low Treg” autoimmune diseases. JAK1 gain-of-function mutations are observed at high frequencies in autoimmune diseases while JAK1 loss-of-function mutations are observed at high frequencies in cancers with high tumor-infiltrating Tregs. It should also be noted that the corresponding two classes of protein kinase inhibitors are mutually exclusive in terms of their approved therapeutic indications. There is no protein kinase inhibitor that is approved for the treatment of both autoimmune diseases and “high Treg” cancers. Although there are exceptions to the conclusions presented above, these conclusions are supported by the great bulk of published data. It therefore seems that the binary division of protein kinases is a useful tool for elucidating (at the molecular level) many distinctive properties of cancers and autoimmune diseases.

Ruxolitinib-Associated Infections in Polycythemia Vera: Review of the Literature, Clinical Significance, and Recommendations

Simple Summary

Polycythemia vera (PV) is a chronic blood disease characterized by elevated red blood cells and splenomegaly. About 98% of all PV patients harbor the JAK2 mutation. Ruxolitinib (RUX), a JAK1/JAK2 inhibitor, received approval as a second-line indication in PV patients who are resistant or intolerant to standard therapy hydroxyurea in both the United States (2014) and Europe (2015). In the studies relevant to approval, RUX achieved excellent PV control. Due to its mechanism of action, RUX also has immunosuppressive effects. As expected, an increased rate of infection was observed in clinical studies and in practical application. In this overview, we have compiled all previous literature references on RUX and infections in PV. However, apart from a few individual cases with special infections and an increased rate of zoster infections, there are no exceptional high infection problems. Recommendations are given on how infections in RUX treated PV patients can be avoided.

Abstract

Ruxolitinib (RUX), a JAK1/JAK2 inhibitor, is approved for second-line therapy in patients with polycythemia vera (PV) who are resistant or intolerant to hydroxyurea. Due to the immunomodulatory and immunosuppressive effect of RUX, there is an increased susceptibility to infections. However, an increased risk of infection is inherent to even untreated myeloproliferative neoplasms (MPN). To obtain more information on the clinical significance of RUX-associated infections in PV, we reviewed the available literature. There is no evidence-based approach to managing infection risks. Most data on RUX-associated infections are available for MF. In all studies, the infection rates in the RUX and control groups were fairly similar, with the exception of infections with the varicella zoster virus (VZV). However, individual cases of bilateral toxoplasmosis retinitis, disseminated molluscum contagiosum, or a mycobacterium tuberculosis infection or a hepatitis B reactivation are reported. A careful assessment of the risk of infection for PV patients is required at the initial presentation and before the start of RUX. Screening for hepatitis B is recommended in all patients. The risk of RUX-associated infections is lower with PV than with MF, but compared to a normal population there is an increased risk of VZV infection. However, primary VZV prophylaxis for PV patients is not recommended, while secondary prophylaxis can be considered individually. As early treatment is most effective for VZV, patients should be properly informed and trained to seek medical advice immediately if cutaneous signs of VZV develop. Vaccination against influenza, herpes zoster, and pneumococci should be considered in all PV patients at risk of infection, especially if RUX treatment is planned. Current recommendations do not support adjusting or discontinuing JAK inhibition in MPN patients to reduce the risk of COVID-19.