ROP-ET: a prospective phase III trial investigating the efficacy and safety of ropeginterferon alfa-2b in essential thrombocythemia patients with limited treatment options

Interferon-based therapies, such as ropeginterferon alfa-2b have emerged as promising disease-modifying agents for myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET). Current ET treatments aim to normalize hematological parameters and reduce the thrombotic risk, but they do not modify the natural history of the disease and hence, have no impact on disease progression. Ropeginterferon alfa-2b (trade name BESREMi®), a novel, monopegylated interferon alfa-2b with an extended administration interval, has demonstrated a robust and sustained efficacy in polycythemia vera (PV) patients. Given the similarities in disease pathophysiology and treatment goals, ropeginterferon alfa-2b holds promise as a treatment option for ET. The ROP-ET trial is a prospective, multicenter, single-arm phase III study that includes patients with ET who are intolerant or resistant to, and/or are ineligible for current therapies, such as hydroxyurea (HU), anagrelide (ANA), busulfan (BUS) and pipobroman, leaving these patients with limited treatment options. The primary endpoint is a composite response of hematologic parameters and disease-related symptoms, according to modified European LeukemiaNet (ELN) criteria. Secondary endpoints include improvements in symptoms and quality of life, molecular response and the safety profile of ropeginterferon alfa-2b. Over a 3-year period the trial assesses longer term outcomes, particularly the effects on allele burden and clinical outcomes, such as disease-related symptoms, vascular events and disease progression. No prospective clinical trial data exist for ropeginterferon alfa-2b in the planned ET study population and this study will provide new findings that may contribute to advancing the treatment landscape for ET patients with limited alternatives. TRIAL REGISTRATION: EU Clinical Trials Register; EudraCT, 2023-505160-12-00; Registered on October 30, 2023.

Indication and management of allogeneic haematopoietic stem-cell transplantation in myelofibrosis: updated recommendations by the EBMT/ELN International Working Group

New options for medical therapy and risk scoring systems containing molecular data are leading to increased complexity in the management of patients with myelofibrosis. To inform patients' optimal care, we updated the 2015 guidelines on indications for and management of allogeneic haematopoietic stem-cell transplantation (HSCT) with the support of the European Society for Blood and Marrow Transplantation (EBMT) and European LeukemiaNet (ELN). New recommendations were produced using a consensus-building methodology after a comprehensive review of articles released from January, 2015 to December, 2022. Seven domains and 18 key questions were selected through a series of questionnaires using a Delphi process. Key recommendations in this update include: patients with primary myelofibrosis and an intermediate-2 or high-risk Dynamic International Prognostic Scoring System score, or a high-risk Mutation-Enhanced International Prognostic Score Systems (MIPSS70 or MIPSS70-plus) score, or a low-risk or intermediate-risk Myelofibrosis Transplant Scoring System score should be considered candidates for allogeneic HSCT. All patients who are candidates for allogeneic HSCT with splenomegaly greater than 5 cm below the left costal margin or splenomegaly-related symptoms should receive a spleen-directed treatment, ideally with a JAK-inhibitor; HLA-matched sibling donors remain the preferred donor source to date. Reduced intensity conditioning and myeloablative conditioning are both valid options for patients with myelofibrosis. Regular post-transplantation driver mutation monitoring is recommended to detect and treat early relapse with donor lymphocyte infusion. In a disease where evidence-based guidance is scarce, these recommendations might help clinicians and patients in shared decision making.

Arterial and Venous Thromboembolic Complications in 832 Patients with BCR-ABL-Negative Myeloproliferative Neoplasms

Arterial (ATE) and venous (VTE) thromboembolic complications are common causes of morbidity and mortality in BCR-ABL-negative myeloproliferative neoplasms (MPNs). However, there are few studies that include all MPN subtypes and focus on both MPN-associated ATE and VTE. In our single-center retrospective study of 832 MPN patients, a total of 180 first thromboembolic events occurred during a median follow-up of 6.6 years (range: 0-37.6 years), of which 105 were VTE and 75 were ATE. The probability of a vascular event at the end of the follow-up period was 36.2%, and the incidence rate for all first ATE/VTE was 2.43% patient/year. The most frequent VTE localizations were deep vein thrombosis with or without pulmonary embolism (incidence rate: 0.59% patient/year), while strokes were the most frequent ATE with an incidence rate of 0.32% patient/year. When comparing the group of patients with ATE/VTE (n = 180) and the group without such an event (n = 652) using multivariate Cox regression analyses, patients with polycythemia vera (hazard ratio [HR]: 1.660; [95% confidence interval [CI] 1.206, 2.286]) had a significantly higher risk of a thromboembolic event than the other MPN subtypes. In contrast, patients with a CALR mutation had a significantly lower risk of thromboembolism compared with JAK2-mutated MPN patients (HR: 0.346; [95% CI: 0.172, 0.699]). In summary, a high incidence of MPN-associated VTE and ATE was observed in our retrospective study. While PV patients or generally JAK2-mutated MPN patients had a significantly increased risk of such vascular events, this risk was reduced in CALR-mutated MPN patients.

Differenzialdiagnose der Erythrozytose – Ursachen und klinische Bedeutung

Aufgrund ihres seltenen Auftretens stellt die Erythrozytose häufig eine Herausforderung für die behandelnden Ärzte dar. Die Erythropoese (= Produktion von Erythrozyten) ist im Knochenmark angesiedelt, und das Hormon Erythropoetin (EPO) übernimmt die Kontrolle über ihre Regulation. Daher ist die Messung von EPO im Serum einer der wichtigsten diagnostischen Schritte. Bei der Erythrozytose muss zwischen angeborenen und erworbenen Ursachen unterschieden werden. Darüber hinaus gibt es primäre und sekundäre Formen. Angeborene Ursachen von Erythrozytosen treten sehr selten auf, werden meist in jungen Jahren diagnostiziert und sollten in spezialisierten Zentren behandelt werden. Die Polycythaemia vera (PV), eine klonale Störung und eine der wichtigsten myeloproliferativen Neoplasien (neben der essenziellen Thrombozythämie und der primären Myelofibrose), stellt die häufigste primär erworbene Ursache für Erythrozytosen dar. Klinisch treten eine erhöhte Thrombophilie und mikrovaskuläre Störungen auf. Die Initialtherapie bei Patienten mit PV umfasst die Verabreichung von Aspirin und Aderlass-Therapie. Sekundär erworbene Formen der Erythrozytose treten vor allem aufgrund einer durch Nikotinabusus oder chronische Herz- und Lungenerkrankungen ausgelösten Hypoxie auf. Als weitere Differenzialdiagnosen müssen eine tumorbedingte EPO-Produktion, Nierenerkrankungen oder eine exogene Zufuhr von EPO (= EPO-Doping) in Betracht gezogen werden.

Subtyping non-small cell lung cancer by histology-guided spatial metabolomics

Purpose

Most cancer-related deaths worldwide are associated with lung cancer. Subtyping of non-small cell lung cancer (NSCLC) into adenocarcinoma (AC) and squamous cell carcinoma (SqCC) is of importance, as therapy regimes differ. However, conventional staining and immunohistochemistry have their limitations. Therefore, a spatial metabolomics approach was aimed to detect differences between subtypes and to discriminate tumor and stroma regions in tissues.

Methods

Fresh-frozen NSCLC tissues (n = 35) were analyzed by matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) of small molecules (< m/z 1000). Measured samples were subsequently stained and histopathologically examined. A differentiation of subtypes and a discrimination of tumor and stroma regions was performed by receiver operating characteristic analysis and machine learning algorithms.

Results

Histology-guided spatial metabolomics revealed differences between AC and SqCC and between NSCLC tumor and tumor microenvironment. A diagnostic ability of 0.95 was achieved for the discrimination of AC and SqCC. Metabolomic contrast to the tumor microenvironment was revealed with an area under the curve of 0.96 due to differences in phospholipid profile. Furthermore, the detection of NSCLC with rarely arising mutations of the isocitrate dehydrogenase (IDH) gene was demonstrated through 45 times enhanced oncometabolite levels.

Conclusion

MALDI-MSI of small molecules can contribute to NSCLC subtyping. Measurements can be performed intraoperatively on a single tissue section to support currently available approaches. Moreover, the technique can be beneficial in screening of IDH-mutants for the characterization of these seldom cases promoting the development of treatment strategies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03834-w.

Bleeding complications in bcr-abl-negative myeloproliferative neoplasms (MPN): A retrospective single-center study of 829 MPN patients

In patients with bcr-abl-negative myeloproliferative neoplasms (MPN), concerns are often raised about the use of anticoagulants because of an increased bleeding risk. However, there are few MPN studies focusing on bleeding. To investigate bleeding complications in MPN, we report our retrospective, single-center study of 829 patients with a median follow-up of 5.5 years (range: 0.1-35.6). A first bleeding event occurred in 143 of 829 patients (17.2%), corresponding to an incidence rate of 2.29% per patient/year. During the follow-up period, one out of 829 patients (0.1%) died due to bleeding. Regarding anticoagulation, most bleeding occurred in patients on antiplatelet therapies (60.1%), followed by patients on anticoagulation therapies (20.3%) and patients not on anticoagulation (19.6%). In multivariate analysis, administration of antiplatelet (HR 2.31 [1.43, 3.71]) and anticoagulation therapies (HR 4.06 [2.32, 7.09]), but not age, gender or mutation status, was associated with an increased bleeding risk. Comparing the "probability of bleeding-free survival" between the MPN subtypes, no significant difference was observed (p = 0.91, log-rank test). Our retrospective study shows that antiplatelet and anticoagulation therapies significantly increase the risk of bleeding in MPN patients without affecting mortality. However, there is no reason to refrain from guideline-conform primary or secondary anticoagulation in MPN patients.

Unmet clinical needs in the management of CALR-mutated essential thrombocythaemia: a consensus-based proposal from the European LeukemiaNet

Recommendations regarding management of essential thrombocythaemia rely on studies done before the discovery of the CALR mutation. On May 20, 2020, the European LeukemiaNet annual meeting was held with the goal to identify unmet clinical needs in myeloproliferative neoplasms. Because patients with a CALR mutation have specific clinical characteristics, treatment of CALR-mutated essential thrombocythaemia was considered an unmet clinical need by the European LeukemiaNet. The elaboration of a consensus document with recommendations according to current evidence was proposed as a solution for resolving uncertainties in the treatment of CALR-mutated essential thrombocythaemia. A steering committee comprising four European LeukemiaNet members was then formed and a panel of ten experts in the field was recruited. The experts proposed 51 potential unmet clinical needs in the management of CALR-mutated essential thrombocythaemia and were asked to score the relevance of each topic. Those topics that obtained the highest scores as relevant unmet clinical needs were identified, including antiplatelet therapy in patients at low risk, definition of extreme thrombocytosis and its management in patients at low risk, indications of cytoreduction and targets of therapy, first-line treatment of choice in young patients (<60 years), and management of pregnancy. After the steering committee revised the available evidence for each topic, a consensus on management and proposal for improving knowledge was achieved by use of an email-based, two round, Delphi approach. Consensus was achieved when 90% of the panellists agreed with a statement and included 14 recommendations and six solution proposals. Key recommendations included careful observation for asymptomatic patients with classical, low-risk, CALR-mutated essential thrombocythaemia without cardiovascular risk factors; caution in the use of antiplatelet therapy for symptomatic patients at low risk with platelet counts of 1000-1500 × 109 platelets per L, in such cases cytoreduction is an adequate option, especially if adquired Von Willebrand disease is present; cytoreduction is recommended for extreme thrombocytosis (platelet count >1500 × 109 platelets per L) with pegylated interferon alfa being the preferred option for younger patients; both hydroxycarbamide and anagrelide might be given to patients ineligible for pegylated interferon alfa; and treatment algorithms for patients with high-risk pregnancies should not be changed according to genotype. The European LeukemiaNet proposes to use these recommendations in the routine management of patients with CALR-mutated essential thrombocythaemia, and designing new clinical studies in this field might be useful.

Kidney Dysfunction Is Associated with Thrombosis and Disease Severity in Myeloproliferative Neoplasms: Implications from the German Study Group for MPN Bioregistry

Simple Summary

In patients with myeloproliferative neoplasms (MPN) and in patients with kidney dysfunction, a higher rate of thrombosis has been reported compared with the general population. Furthermore, MPN patients are more prone to develop kidney dysfunction. In our study, we assessed the importance of specific risk factors for kidney dysfunction and thrombosis in MPN patients. We found that the rate of thrombosis is correlated with the degree of kidney dysfunction, especially in myelofibrosis. Significant associations for kidney dysfunction included arterial hypertension, MPN treatment, and increased inflammation, and those for thrombosis comprised arterial hypertension, non-excessive platelet counts, and antithrombotic therapy. The identified risk factor associations varied between MPN subtypes. Our data suggest that kidney dysfunction in MPN patients is associated with an increased risk of thrombosis, mandating closer monitoring, and, possibly, early thromboprophylaxis.

Abstract

Inflammation-induced thrombosis represents a severe complication in patients with myeloproliferative neoplasms (MPN) and in those with kidney dysfunction. Overlapping disease-specific attributes suggest common mechanisms involved in MPN pathogenesis, kidney dysfunction, and thrombosis. Data from 1420 patients with essential thrombocythemia (ET, 33.7%), polycythemia vera (PV, 38.5%), and myelofibrosis (MF, 27.9%) were extracted from the bioregistry of the German Study Group for MPN. The total cohort was subdivided according to the calculated estimated glomerular filtration rate (eGFR, (mL/min/1.73 m²)) into eGFR1 (≥90, 21%), eGFR2 (60–89, 56%), and eGFR3 (<60, 22%). A total of 29% of the patients had a history of thrombosis. A higher rate of thrombosis and longer MPN duration was observed in eGFR3 than in eGFR2 and eGFR1. Kidney dysfunction occurred earlier in ET than in PV or MF. Multiple logistic regression analysis identified arterial hypertension, MPN treatment, increased uric acid, and lactate dehydrogenase levels as risk factors for kidney dysfunction in MPN patients. Risk factors for thrombosis included arterial hypertension, non-excessive platelet counts, and antithrombotic therapy. The risk factors for kidney dysfunction and thrombosis varied between MPN subtypes. Physicians should be aware of the increased risk for kidney disease in MPN patients, which warrants closer monitoring and, possibly, early thromboprophylaxis.

Direct oral anticoagulants (DOAC) for prevention of recurrent arterial or venous thromboembolic events (ATE/VTE) in myeloproliferative neoplasms

In patients with BCR-ABL-negative myeloproliferative neoplasms (MPN), arterial or venous thromboembolic events (ATE/VTE) are a major burden. In order to control these complications, vitamin K antagonists (VKA) are widely used. There is no robust evidence supporting the use of direct oral anticoagulants (DOAC) in MPN patients. We therefore compared the efficacy and safety of both anticoagulants in 71 cases from a cohort of 782 MPN patients. Seventy-one of 782 MPN patients (9.1%) had ATE/VTE with nine ATE (12.7%) and 62 VTE (87.3%). Forty-five of 71 ATE/VTE (63.4%) were treated with VKA and 26 (36.6%) with DOAC. The duration of anticoagulation therapy (p = 0.984), the number of patients receiving additional aspirin (p = 1.0), and the proportion of patients receiving cytoreductive therapy (p = 0.807) did not differ significantly between the VKA and DOAC groups. During anticoagulation therapy, significantly more relapses occurred under VKA (n = 16) compared to DOAC treatment (n = 0, p = 0.0003). However, during the entire observation period of median 3.2 years (0.1-20.4), ATE/VTE relapse-free survival (p = 0.2) did not differ significantly between the two anticoagulants. For all bleeding events (p = 0.516) or major bleeding (p = 1.0), no significant differences were observed between VKA and DOAC. In our experience, the use of DOAC was as effective and safe as VKA, possibly even potentially beneficial with a lower number of recurrences and no increased risk for bleedings. However, further and larger studies are required before DOAC can be routinely used in MPN patients.

Comparing the safety and efficacy of ruxolitinib in patients with Dynamic International Prognostic Scoring System low-, intermediate-1-, intermediate-2-, and high-risk myelofibrosis in JUMP, a Phase 3b, expanded-access study

Ruxolitinib, a potent Janus kinase 1/2 inhibitor, has demonstrated durable improvements in patients with myelofibrosis. In this analysis of the Phase 3b JUMP study, which included patients aged ≥18 years with a diagnosis of primary or secondary myelofibrosis, we assessed the safety and efficacy of ruxolitinib in patients stratified by Dynamic International Prognostic Scoring System (DIPSS) risk categories. Baseline characteristic data were available to assess DIPSS status for 1844 of the 2233 enrolled patients; 60, 835, 755, and 194 in the low‐, intermediate (Int)‐1‐, Int‐2‐, and high‐risk groups, respectively. Ruxolitinib was generally well tolerated across all risk groups, with an adverse‐event (AE) profile consistent with previous reports. The most common hematologic AEs were thrombocytopenia and anemia, with highest rates of Grade ≥3 events in high‐risk patients. Approximately, 73% of patients experienced ≥50% reductions in palpable spleen length at any point in the ≤24‐month treatment period, with highest rates in lower‐risk categories (low, 82.1%; Int‐1, 79.3%; Int‐2, 67.1%; high risk, 61.6%). Median time to spleen length reduction was 5.1 weeks and was shortest in lower‐risk patients. Across measures, 40%–57% of patients showed clinically meaningful symptom improvements, which were observed from 4 weeks after treatment initiation and maintained throughout the study. Overall survival (OS) was 92% at Week 72 and 75% at Week 240 (4.6 years). Median OS was longer for Int‐2‐risk than high‐risk patients (253.6 vs. 147.3 weeks), but not evaluable in low‐/Int‐1‐risk patients. By Week 240, progression‐free survival (PFS) and leukemia‐free survival (LFS) rates were higher in lower‐risk patients (PFS: low, 90%; Int‐1, 82%; Int‐2, 46%; high risk, 15%; LFS: low, 92%; Int‐1, 86%; Int‐2, 58%; high risk, 19%). Clinical benefit was seen across risk groups, with more rapid improvements in lower risk patients. Overall, this analysis indicates that ruxolitinib benefits lower‐risk DIPSS patients in addition to higher risk.

A review of hydroxyurea-related cutaneous adverse events

Introduction: Hydroxyurea (HU) is an S-phase specific oral chemotherapeutic agent that inhibits ribonucleotide diphosphate reductase. It is the most common used cytoreductive drug in patients (pts) with BCR-ABL1 negative myeloproliferative neoplasms (MPN) and sickle cell disease (SCD). The World Health Organization lists HU as an "essential drug". Although most patients tolerate HU well, cutaneous adverse events (CAE) are frequent side effects and may limit its long-term use. This has become increasingly evident in recent years, especially in MPN patients, where CAE were previously underestimated and underdiagnosed.Areas covered: In this review, we present the available literature on HU-related CAE in MPN patients. In particular, data from a recently published and so far, only prospective non-interventional study investigating CAE in 172 MPN patients will be discussed in detail and compared with previously available data. Finally, we give an overview of the management of HU-related CAE in MPN patients and provide recommendations on the practical clinical approach.Expert opinion: In clinical practice, HU associated CAE are common and have important diagnostic and therapeutic consequences. Therefore, they should be considered in all MPN patients treated with HU in the future.

Primary Thromboprophylaxis in Patients with Malignancies: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO), the Society of Thrombosis and Hemostasis Research (GTH), and the Austrian Society of Hematology and Oncology (ÖGHO)

Patients with cancer, both hematologic and solid malignancies, are at increased risk for thrombosis and thromboembolism. In addition to general risk factors such as immobility and major surgery, shared by non-cancer patients, cancer patients are exposed to specific thrombotic risk factors. These include, among other factors, cancer-induced hypercoagulation, and chemotherapy-mediated endothelial dysfunction as well as tumor-cell-derived microparticles. After an episode of thrombosis in a cancer patient, secondary thromboprophylaxis to prevent recurrent thromboembolism has long been established and is typically continued as long as the cancer is active or actively treated. On the other hand, primary prophylaxis, even though firmly established in hospitalized cancer patients, has only recently been studied in ambulatory patients. This recent change is mostly due to the emergence of direct oral anticoagulants (DOACs). DOACs have a shorter half-life than vitamin K antagonists (VKA), and they overcome the need for parenteral application, the latter of which is associated with low-molecular-weight heparins (LMWH) and can be difficult for the patient to endure in the long term. Here, first, we discuss the clinical trials of primary thromboprophylaxis in the population of cancer patients in general, including the use of VKA, LMWH, and DOACs, and the potential drug interactions with pre-existing medications that need to be taken into account. Second, we focus on special situations in cancer patients where primary prophylactic anticoagulation should be considered, including myeloma, major surgery, indwelling catheters, or immobilization, concomitant diseases such as renal insufficiency, liver disease, or thrombophilia, as well as situations with a high bleeding risk, particularly thrombocytopenia, and specific drugs that may require primary thromboprophylaxis. We provide a novel algorithm intended to aid specialists but also family practitioners and nurses who care for cancer patients in the decision process of primary thromboprophylaxis in the individual patient.

The management, outcome, and postpartum disease course of 41 pregnancies in 20 women with polycythemia vera

OBJECTIVES

Pregnancies in women with polycythemia vera (PV) are associated with an increased risk of PV-related maternal complications and often result in miscarriage. Recommendations for the management of PV pregnancies are mainly based on studies with a small number of patients. A correlation between pregnancy outcome and postpartum course has been reported for essential thrombocythemia, but corresponding data for PV are lacking so far.

METHODS

In 41 PV pregnancies, the pregnancy outcome, the use of PV-specific therapies (ie, acetylsalicylic acid, low-molecular weight heparin and/or interferon-alpha), and the postpartum PV course were investigated.

RESULTS

A live birth rate of 51.2% (21/41 pregnancies) was observed. 43.9% of pregnancies ended in spontaneous abortion and 4.9% in stillbirth. A significantly increased live birth rate occurred in pregnancies with PV-specific therapies compared to standard antenatal care (69.0% vs. 8.3%; P < .0019). The use of PV-specific therapy significantly increased the number of maternal hemorrhages (P = .021) without increasing the risk of fetal complications. During the median postpartum follow-up period of 1.2 years (range 0.1-13.7), complicated postpartum PV occurred significantly more often after miscarriages (P = .035).

CONCLUSIONS

According to our analysis, PV-specific therapy improved the live birth rate. Significantly more complicated postpartum PV courses were observed after miscarriages.

Interferon alpha for essential thrombocythemia during 34 high-risk pregnancies: outcome and safety

PURPOSE

Pregnancies in women with essential thrombocythemia (ET) are at a higher risk for obstetrical complications. Acetylsalicylic acid (ASA) and low-molecular weight heparin (LMWH) are common options to prevent miscarriages and maternal complications, whereas interferon alpha (IFN) seems to be the cytoreductive therapy of choice. This retrospective study analyzes the largest number of IFN pregnancies to date in terms of outcome and safety.

METHODS

Data of 34 high-risk pregnancies in 23 women presenting at the University hospitals of Minden and Jena from 01-Jun-2007 to 01-Jun-2020 were collected. Reasons defining high-risk ET pregnancy in all 23 patients were: Thrombosis (n = 9) or severe hemorrhage (n = 2) in history, platelet count ≥ 1500 × 10³/µl (n = 8) or severe microcirculatory disturbances not completely responding to ASA (n = 4).

RESULTS

Without the use of IFN, live birth rate was 60% (6/10), however, after the use of IFN live birth rate increased to 73.5% (25/34 pregnancies). Nine pregnancies ended in miscarriages (9/34; 26.5%); all of them spontaneous abortions. Live birth rate significantly improved with ASA (90% versus 50%, p = 0.0168), however, if ASA and LMWH was added (n = 14), live birth rate was 100%. IFN compound (PEGylated versus standard IFN) and JAK2-driver mutation had no impact on pregnancy outcome. One major maternal complication occurred as a major peripartal bleeding after abortion curettage.

CONCLUSION

IFN was associated with an encouraging live birth rate of 73.5% with no fatal maternal events and manageable side effects.

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.

Second cancers in MPN: Survival analysis from an international study

One out of ten patients with Philadelphia-negative myeloproliferative neoplasms (MPN) develop a second cancer (SC): in such patients we aimed at assessing the survival impact of SC itself and of MPN-specific therapies. Data were therefore extracted from an international nested case-control study, recruiting 798 patients with SC diagnosed concurrently or after the MPN. Overall, 2995 person-years (PYs) were accumulated and mortality rate (MR) since SC diagnosis was 5.9 (5.1-6.9) deaths for every 100 PYs. A "poor prognosis" SC (stomach, esophagus, liver, pancreas, lung, ovary, head-and-neck or nervous system, osteosarcomas, multiple myeloma, aggressive lymphoma, acute leukemia) was reported in 26.3% of the patients and was the cause of death in 65% of them (MR 11.0/100 PYs). In contrast, patients with a "non-poor prognosis" SC (NPPSC) incurred a MR of 4.6/100 PYs: 31% of the deaths were attributed to SC and 15% to MPN evolution. At multivariable analysis, death after SC diagnosis was independently predicted (HR and 95% CI) by patient age greater than 70 years (2.68; 1.88-3.81), the SC prognostic group (2.57; 1.86-3.55), SC relapse (1.53; 10.6-2.21), MPN evolution (2.72; 1.84-4.02), anemia at SC diagnosis (2.32; 1.49-3.59), exposure to hydroxyurea (1.89; 1.26-2.85) and to ruxolitinib (3.63; 1.97-6.71). Aspirin was protective for patients with a NPPSC (0.60; 0.38-0.95). In conclusion, SC is a relevant cause of death competing with MPN evolution. Prospective data are awaited to confirm the role of cytoreductive and anti-platelet drugs in modulating patient survival after the occurrence of a SC.

Primary analysis of JUMP, a phase 3b, expanded-access study evaluating the safety and efficacy of ruxolitinib in patients with myelofibrosis, including those with low platelet counts

Ruxolitinib is a potent Janus kinase (JAK) 1/JAK2 inhibitor approved for the treatment of myelofibrosis (MF). Ruxolitinib was assessed in JUMP, a large (N = 2233), phase 3b, expanded-access study in MF in countries without access to ruxolitinib outside a clinical trial, which included patients with low platelet counts (<100 × 10⁹ /l) and patients without splenomegaly - populations that have not been extensively studied. The most common adverse events (AEs) were anaemia and thrombocytopenia, but they rarely led to discontinuation (overall, 5·4%; low-platelet cohort, 12·3%). As expected, rates of worsening thrombocytopenia were higher in the low-platelet cohort (all grades, 73·2% vs. 53·5% overall); rates of anaemia were similar (all grades, 52·9% vs. 59·5%). Non-haematologic AEs, including infections, were mainly grade 1/2. Overall, ruxolitinib led to meaningful reductions in spleen length and symptoms, including in patients with low platelet counts, and symptom improvements in patients without splenomegaly. In this trial, the largest study of ruxolitinib in patients with MF to date, the safety profile was consistent with previous reports, with no new safety concerns identified. This study confirms findings from the COMFORT studies and supports the use of ruxolitinib in patients with platelet counts of 50-100 × 10⁹ /l. (ClinicalTrials.gov identifier NCT01493414).

Long-term efficacy and safety of ruxolitinib versus best available therapy in polycythaemia vera (RESPONSE): 5-year follow up of a phase 3 study

BACKGROUND

Polycythaemia vera is a myeloproliferative neoplasm characterised by excessive proliferation of erythroid, myeloid, and megakaryocytic components in the bone marrow due to mutations in the Janus kinase 2 (JAK2) gene. Ruxolitinib, a JAK 1 and JAK 2 inhibitor, showed superiority over best available therapy in a phase 2 study in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea. We aimed to compare the long-term safety and efficacy of ruxolitinib with best available therapy in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea.

METHODS

We report the 5-year results for a randomised, open-label, phase 3 study (RESPONSE) that enrolled patients at 109 sites across North America, South America, Europe, and the Asia-Pacific region. Patients (18 years or older) with polycythaemia vera who were resistant to or intolerant of hydroxyurea were randomly assigned 1:1 to receive either ruxolitinib or best available therapy. Patients randomly assigned to the ruxolitinib group received the drug orally at a starting dose of 10 mg twice a day. Single-agent best available therapy comprised hydroxyurea, interferon or pegylated interferon, pipobroman, anagrelide, approved immunomodulators, or observation without pharmacological treatment. The primary endpoint, composite response (patients who achieved both haematocrit control without phlebotomy and 35% or more reduction from baseline in spleen volume) at 32 weeeks was previously reported. Patients receiving best available therapy could cross over to ruxolitinib after week 32. We assessed the durability of primary composite response, complete haematological remission, overall clinicohaematological response, overall survival, patient-reported outcomes, and safety after 5-years of follow-up. This study is registered with ClinicalTrials.gov, NCT01243944.

FINDINGS

We enrolled patients between Oct 27, 2010, and Feb 13, 2013, and the study concluded on Feb 9, 2018. Of 342 individuals screened for eligibility, 222 patients were randomly assigned to receive ruxolitinib (n=110, 50%) or best available therapy (n=112, 50%). The median time since polycythaemia vera diagnosis was 8·2 years (IQR 3·9-12·3) in the ruxolitinib group and 9·3 years (4·9-13·8) in the best available therapy group. 98 (88%) of 112 patients initially randomly assigned to best available therapy crossed over to receive ruxolitinib and no patient remained on best available therapy after 80 weeks of study. Among 25 primary responders in the ruxolitinib group, six had progressed at the time of final analysis. At 5 years, the probability of maintaining primary composite response was 74% (95% CI 51-88). The probability of maintaining complete haematological remission was 55% (95% CI 32-73) and the probability of maintaining overall clinicohaematological responses was 67% (54-77). In the intention-to-treat analysis not accounting for crossover, the probability of survival at 5 years was 91·9% (84·4-95·9) with ruxolitinib therapy and 91·0% (82·8-95·4) with best available therapy. Anaemia was the most common adverse event in patients receiving ruxolitinib (rates per 100 patient-years of exposure were 8·9 for ruxolitinib and 8·8 for the crossover population), though most anaemia events were mild to moderate in severity (grade 1 or 2 anaemia rates per 100 patient-years of exposure were 8·0 for ruxolitinib and 8·2 for the crossover population). Non-haematological adverse events were generally lower with long-term ruxolitinib treatment than with best available therapy. Thromboembolic events were lower in the ruxolitinib group than the best available therapy group. There were two on-treatment deaths in the ruxolitinib group. One of these deaths was due to gastric adenocarcinoma, which was assessed by the investigator as related to ruxolitinib treatment.

INTERPRETATION

We showed that ruxolitinib is a safe and effective long-term treatment option for patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea. Taken together, ruxolitinib treatment offers the first widely approved therapeutic alternative for this post-hydroxyurea patient population.

FUNDING

Novartis Pharmaceuticals Corporation.

Second cancer in Philadelphia negative myeloproliferative neoplasms (MPN-K). A nested case-control study

We conducted a large international nested case-control study including 1881 patients with Philadelphia-negative myeloproliferative neoplasms (MPN). Cases (n = 647) were patients with second cancer (SC: carcinoma, non-melanoma skin cancer, hematological second cancer, and melanoma) and controls (n = 1234) were patients without SC, matched with cases for sex, age at MPN diagnosis, date of MPN diagnosis, and MPN disease duration. The aim was to evaluate the risk of SC after exposure to cytoreductive drugs. Patients exposed to hydroxyurea (HU) (median: 3 years) had a risk of SC similar to unexposed patients (OR = 1.06, 95% CI 0.82-1.38). In contrast, in cancer-specific stratified multivariable analysis, HU had two-fold higher risk of non-melanoma (NM) skin cancer (OR = 2.28, 95% CI 1.15-4.51). A significantly higher risk of NM-skin cancer was also documented for pipobroman (OR = 3.74, 95% CI 1.00-14.01), ruxolitinib (OR = 3.87, 95% CI 1.18-12.75), and for drug combination (OR = 3.47, 95% CI 1.55-7.75). These three drugs did not show excess risk of carcinoma and hematological second cancer compared with unexposed patients. Exposure to interferon, busulfan, and anagrelide did not increase the risk. In summary, while it is reassuring that no excess of carcinoma was documented, a careful dermatologic active surveillance before and during the course of treatments is recommended.

Thromboembolic events in polycythemia vera

Thromboembolic events and cardiovascular disease are the most prevalent complications in patients with polycythemia vera (PV) compared with other myeloproliferative disorders and are the major cause of morbidity and mortality in this population. Moreover, a vascular complication such as arterial or venous thrombosis often leads to the diagnosis of PV. The highest rates of thrombosis typically occur shortly before or at diagnosis and decrease over time, probably due to the effects of treatment. Important risk factors include age (≥ 60 years old) and a history of thrombosis; elevated hematocrit and leukocytosis are also associated with an increased risk of thrombosis. The goal of therapy is to reduce the risk of thrombosis by controlling hematocrit to < 45%, a target associated with reduced rates of cardiovascular death and major thrombosis. Low-risk patients (< 60 years old with no history of thrombosis) are managed with phlebotomy and low-dose aspirin, whereas high-risk patients (≥ 60 years old and/or with a history of thrombosis) should be treated with cytoreductive agents. Interferon and ruxolitinib are considered second-line therapies for patients who are intolerant of or have an inadequate response to hydroxyurea, which is typically used as first-line therapy. In this review, we discuss factors associated with thrombosis and recent data on current treatments, including anticoagulation, highlighting the need for more controlled studies to determine the most effective cytoreductive therapies for reducing the risk of thrombosis in patients with PV.

Differenzialdiagnose der Erythrozytose – Ursachen und klinische Bedeutung

Due to its rare incidence, erythrocytosis frequently represents a challenge for the treating doctors. The erythropoiesis (= production of erythrocytes) is located in the bone marrow, and the hormone erythropoietin (EPO) takes control in its regulation. Therefore, measurement of EPO in serum is one of the main diagnostic steps. In erythrocytosis, congenital causes have to be distinguished from acquired ones. Furthermore, there are primary and secondary forms. Congenital causes of erythrocytoses occur very infrequently, are mainly diagnosed in young age and should be treated in specialized centers. Polycythemia vera (PV), a clonal disorder and one of the main myeloproliferative neoplasms (beside essential thrombocythemia and primary myelofibrosis), represents the most frequent primary acquired cause of erythrocytosis. Clinically, increased thrombophilia and microvascular disturbance occur. The first-line treatment in patients with PV includes administration of aspirin and phlebotomies. Secondary acquired forms of erythrocytosis mainly occur due to hypoxia triggered by nicotine abuse or chronic heart and lung diseases. Regarding other differential diagnoses, a cancer-associated EPO production, kidney diseases or exogenous supply with EPO (= EPO doping) have to be considered.

Leukemic transformation and second cancers in 3649 patients with high-risk essential thrombocythemia in the EXELS study

EXELS, a post-marketing observational study, is the largest prospective study of high-risk essential thrombocythemia (ET) patients, with an observation time of 5 years. EXELS found higher event rates of acute leukemia transformation in patients treated with hydroxycarbamide (HC). In the current analysis, we report age-adjusted rates of malignant transformation from 3460 EXELS patients exposed to HC, anagrelide (ANA), or both. At registration, 481 patients had ANA treatment without HC exposure, 2305 had HC without ANA exposure, and 674 had been exposed to both. Standard incidence ratios (SIRs) were calculated using data from the Cancer Incidence in Five Continents database to account for differences in age-, gender-, and country-specific background rates. SIRs for acute myelogenous leukemia (AML) were high in ET patients. SIRs for AML were high in HC-treated patients, but AML was rare in ANA-treated patients; no cases of AML were found in patients only treated with ANA. No statistically significant difference was seen between SIRs for ANA and HC treatment for AML or skin cancer. SIRs for other cancers were similar in the HC and ANA groups and close to 1, indicating little difference in risk. Although statistically inconclusive, this study strengthens concerns regarding possible leukemogenic risk with HC treatment. (NCT00202644).

High risk of recurrent venous thromboembolism in BCR-ABL-negative myeloproliferative neoplasms after termination of anticoagulation

Venous thromboembolism (VTE) is a major burden in patients with BCR-ABL-negative myeloproliferative neoplasms (MPN). In addition to cytoreductive treatment anticoagulation is mandatory, but optimal duration of anticoagulation is a matter of debate. In our single center study, we retrospectively included 526 MPN patients. In total, 78 of 526 MPN patients (14.8%) had 99 MPN-associated VTE. Median age at first VTE was 52.5 years (range 23-81). During a study period of 3497 years, a VTE event rate of 1.7% per patient/year was detected. 38.4% (38/99) of all VTEs appeared before or at MPN diagnosis and 55.6% (55/99) occurred at "uncommon" sites like splanchnic or cerebral veins. MPN patients with VTEs were significantly more female (p = 0.028), JAK2 positive (p = 0.018), or had a polycythemia vera (p = 0.009). MPN patients without VTEs were more often CALR positive (p = 0.023). Total study period after first VTE was 336 years with 20 VTE recurrences accounting for a recurrence rate of 6% per patient/year. In 36 of 71 MPN patients with anticoagulation therapy after first VTE event (50.7%), prophylactic anticoagulation was terminated after a median time of 6 months (range 1-61); 13 of those 36 patients (36.1%) had a VTE recurrence after a median of 13 months (range 4-168). In contrast, only three of 35 (8.6%) patients with ongoing anticoagulation had a VTE recurrence (p = 0.0127). Thus, termination of prophylactic anticoagulation was associated with a significantly higher risk of VTE recurrence. Our data suggest that in MPN patients with VTE, a prolonged duration of anticoagulation may be beneficial.

Contemporary management of patients with BCR-ABL1-negative myeloproliferative neoplasms during pregnancy

INTRODUCTION

The management of pregnancy during the course of BCR-ABL1-negative myeloproliferative neoplasms (MPN) is an increasingly relevant problem. This is mostly due to earlier and better diagnosis of MPN together with the trend in modern society toward delaying pregnancy until later life. Areas Covered: The present review aims to provide an overview of the available literature data concerning outcome of pregnancy in MPN. Possible therapeutic modalities are discussed and a management algorithm is suggested. Expert Commentary: Most data are available for women with essential thrombocythemia and we present 793 published pregnancies. Live birth rate is 68.5% with 31.5% miscarriages. Spontaneous abortion is the most frequent complication with 26.5%, followed by stillbirth with 4.8%. Maternal complications are relatively low with 1.8% major thrombotic and 2.4% major bleeding events. In polycythemia vera the situation is clinically more complex and roughly 150 pregnancy reports are available. There is very limited information in primary myelofibrosis with less than 20 reported pregnancies. With active management including control of blood counts, aspirin, low molecular weight heparin and in higher risk cases interferon alpha pregnancy in MPN is manageable with a success rate not far below the normal situation with 80%.

Recommendations for the diagnosis and treatment of patients with polycythaemia vera

OBJECTIVES

To present the Central European Myeloproliferative Neoplasm Organisation (CEMPO) treatment recommendations for polycythaemia vera (PV).

METHODS

During meetings held from 2015 through 2017, CEMPO discussed PV and its treatment and recent data.

RESULTS

PV is associated with increased risks of thrombosis/thrombo-haemorrhagic complications, fibrotic progression and leukaemic transformation. Presence of Janus kinase (JAK)-2 gene mutations is a diagnostic marker and standard diagnostic criterion. World Health Organization 2016 diagnostic criteria for PV, focusing on haemoglobin levels and bone marrow morphology, are mandatory. PV therapy aims at managing long-term risks of vascular complications and progression towards transformation to acute myeloid leukaemia and myelodysplastic syndrome. Risk stratification for thrombotic complications guides therapeutic decisions. Low-risk patients are treated first line with low-dose aspirin and phlebotomy. Cytoreduction is considered for low-risk (phlebotomy intolerance, severe/progressive symptoms, cardiovascular risk factors) and high-risk patients. Hydroxyurea is suspected of leukaemogenic potential. IFN-α has demonstrated efficacy in many clinical trials; its pegylated form is best tolerated, enabling less frequent administration than standard interferon. Ropeginterferon alfa-2b has been shown to be more efficacious than hydroxyurea. JAK1/JAK2 inhibitor ruxolitinib is approved for hydroxyurea resistant/intolerant patients.

CONCLUSIONS

Greater understanding of PV is serving as a platform for new therapy development and treatment response predictors.

Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas (PETAL): A Multicenter, Randomized Phase III Trial

Purpose Interim positron emission tomography (PET) using the tracer, [¹⁸F]fluorodeoxyglucose, may predict outcomes in patients with aggressive non-Hodgkin lymphomas. We assessed whether PET can guide therapy in patients who are treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Patients and Methods Newly diagnosed patients received two cycles of CHOP-plus rituximab (R-CHOP) in CD20-positive lymphomas-followed by a PET scan that was evaluated using the ΔSUV_max method. PET-positive patients were randomly assigned to receive six additional cycles of R-CHOP or six blocks of an intensive Burkitt's lymphoma protocol. PET-negative patients with CD20-positive lymphomas were randomly assigned or allocated to receive four additional cycles of R-CHOP or the same treatment with two additional doses rituximab. The primary end point was event-free survival time as assessed by log-rank test. Results Interim PET was positive in 108 (12.5%) and negative in 754 (87.5%) of 862 patients treated, with statistically significant differences in event-free survival and overall survival. Among PET-positive patients, 52 were randomly assigned to R-CHOP and 56 to the Burkitt protocol, with 2-year event-free survival rates of 42.0% (95% CI, 28.2% to 55.2%) and 31.6% (95% CI, 19.3% to 44.6%), respectively (hazard ratio, 1.501 [95% CI, 0.896 to 2.514]; P = .1229). The Burkitt protocol produced significantly more toxicity. Of 754 PET-negative patients, 255 underwent random assignment (129 to R-CHOP and 126 to R-CHOP with additional rituximab). Event-free survival rates were 76.4% (95% CI, 68.0% to 82.8%) and 73.5% (95% CI, 64.8% to 80.4%), respectively (hazard ratio, 1.048 [95% CI, 0.684 to 1.606]; P = .8305). Outcome prediction by PET was independent of the International Prognostic Index. Results in diffuse large B-cell lymphoma were similar to those in the total group. Conclusion Interim PET predicted survival in patients with aggressive lymphomas treated with R-CHOP. PET-based treatment intensification did not improve outcome.

Benefit-risk profile of cytoreductive drugs along with antiplatelet and antithrombotic therapy after transient ischemic attack or ischemic stroke in myeloproliferative neoplasms

We analyzed 597 patients with myeloproliferative neoplasms (MPN) who presented transient ischemic attacks (TIA, n = 270) or ischemic stroke (IS, n = 327). Treatment included aspirin, oral anticoagulants, and cytoreductive drugs. The composite incidence of recurrent TIA and IS, acute myocardial infarction (AMI), and cardiovascular (CV) death was 4.21 and 19.2%, respectively at one and five years after the index event, an estimate unexpectedly lower than reported in the general population. Patients tended to replicate the first clinical manifestation (hazard ratio, HR: 2.41 and 4.41 for recurrent TIA and IS, respectively); additional factors for recurrent TIA were previous TIA (HR: 3.40) and microvascular disturbances (HR: 2.30); for recurrent IS arterial hypertension (HR: 4.24) and IS occurrence after MPN diagnosis (HR: 4.47). CV mortality was predicted by age over 60 years (HR: 3.98), an index IS (HR: 3.61), and the occurrence of index events after MPN diagnosis (HR: 2.62). Cytoreductive therapy was a strong protective factor (HR: 0.24). The rate of major bleeding was similar to the general population (0.90 per 100 patient-years). In conclusion, the long-term clinical outcome after TIA and IS in MPN appears even more favorable than in the general population, suggesting an advantageous benefit-risk profile of antithrombotic and cytoreductive treatment.

The BCR-ABL1-negative myeloproliferative neoplasms: a review of JAK inhibitors in the therapeutic armamentarium

INTRODUCTION

The classical BCR-ABL1-negative myeloproliferative neoplasms (MPN) include primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET). They are characterized by stem cell-derived clonal proliferation, harbor Janus kinase 2 (JAK2), or calreticulin (CALR), or myeloproliferative leukemia virus oncogene (MPL) driver mutations and exert an over activated JAK-signal transducer and activator of transcription (STAT) pathway. Therefore JAK inhibiting strategies have been successfully investigated in MPN clinical trials. Areas covered: The present review aims to provide a concise overview of the current and future role of JAK inhibitors in the therapeutic armamentarium of MPN. Expert opinion: The JAK1/JAK2 inhibitor ruxolitinib has clearly enriched the therapeutic armamentarium of MPN and is now licenced for more than five years in MF and over three years as second line in PV. Momelotinib, although of limited activity in MPN trials, demonstrated unique property of improving MF associated anemia. Less myelosuppressive or more selective JAK inhibitors like pacritinib, NS-01872 or Itacitinib are new promising agents tested in MF. JAK inhibition has become a cornerstone of MPN therapy and future efforts focus on ruxolitinib-based combinations and new JAK inhibitors.

[Thrombocytosis and thrombocytopenia - background and clinical relevance]

Due to the central role of platelets in hemostasis, the clinical relevance of quantitative changes in platelet counts (< 150 G/l or > 450 G/l) may be significant. Thrombopoesis (= production of platelets) occurs in the bone marrow, and the hormone thrombopoetin takes control on its regulation.In thrombocytosis, primary causes have to be distinguished from the far more common reactive (= secondary) reasons. The most important form of primary thrombocytosis occurs in myeloproliferative neoplasms especially in essential thrombocythemia (ET). Clinically, increased thrombophilia, microcirculatory disturbances as well as an increased hemorrhagic diathesis occur in patients with myeloproliferative neoplasms. According to the WHO diagnosis criteria 2016 standard diagnostic procedure in myeloproliferative neoplasms includes bone marrow biopsy and the detection of one of the acquired and typical MPN mutations in the JAK2, MPL or CALR gene.In contrast, patients with thrombocytopenia more often suffer from bleeding complications, however, in antiphospholipid syndrome or thrombotic microangiopathy (TMA) thrombotic events occur in spite of a low platelet count. Generally it makes sense to differentiate between pathological changes in thrombopoesis and the various causes of increased peripheral platelet turnover. Concerning differential diagnosis a careful anamnesis is very important in order to get hints like drugs associated with thrombocytopenia, signs of infection or autoimmune disorders. As an initial diagnostic approach we recommend examination of the blood smear in order to exclude pseudothrombocytopenia or disorderes like thrombotic microangiopathy, myelodysplasia or other hematological diseases.

Treatment of essential thrombocythemia in Europe: a prospective long-term observational study of 3649 high-risk patients in the Evaluation of Anagrelide Efficacy and Long-term Safety study

Evaluation of Anagrelide (Xagrid^®) Efficacy and Long-term Safety, a phase IV, prospective, non-interventional study performed in 13 European countries enrolled high-risk essential thrombocythemia patients treated with cytoreductive therapy. The primary objectives were safety and pregnancy outcomes. Of 3721 registered patients, 3649 received cytoreductive therapy. At registration, 3611 were receiving: anagrelide (Xagrid^®) (n=804), other cytoreductive therapy (n=2666), or anagrelide + other cytoreductive therapy (n=141). The median age was 56 vs. 70 years for anagrelide vs. other cytoreductive therapy. Event rates (patients with events/100 patient-years) were 1.62 vs. 2.06 for total thrombosis and 0.15 vs. 0.53 for venous thrombosis. Anagrelide was more commonly associated with hemorrhage (0.89 vs. 0.43), especially with anti-aggregatory therapy (1.35 vs. 0.33) and myelofibrosis (1.04 vs. 0.30). Other cytoreductive therapies were more associated with acute leukemia (0.28 vs. 0.07) and other malignancies (1.29 vs. 0.44). Post hoc multivariate analyses identified increased risk for thrombosis with prior thrombohemorrhagic events, age ≥65, cardiovascular risk factors, or hypertension. Risk factors for transformation were prior thrombohemorrhagic events, age ≥65, time since diagnosis, and platelet count increase. Safety analysis reflected published data, and no new safety concerns for anagrelide were found. Live births occurred in 41/54 pregnancies (76%). clinicaltrials.gov Identifier: 00567502.

Symptom burden profile in myelofibrosis patients with thrombocytopenia: Lessons and unmet needs

Myelofibrosis is a myeloproliferative neoplasm associated with progressive cytopenias and high symptom burden. MF patients with thrombocytopenia have poor prognosis but the presence of thrombocytopenia frequently precludes the use of JAK2 inhibitors. In this study, we assessed quality of life and symptom burden in 418 MF patients with (n=89) and without (n=329) thrombocytopenia using prospective data from the MPN-QOL study group database, including the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and Total Symptom Score (MPN10). Thrombocytopenia, defined as platelet count <100×10⁹/L (moderate 51-100×10⁹/L; severe ≤50×10⁹/L), was associated with anemia (76% vs. 45%, p<0.001), leukopenia (29% vs. 11%, p<0.001), and need for red blood cell transfusion (35% vs. 19%, p=0.002). Thrombocytopenic patients had more fatigue, early satiety, inactivity, dizziness, sad mood, cough, night sweats, itching, fever, and weight loss; total symptom scores were also higher (33 vs. 24, p<0.001). Patients with severe thrombocytopenia were more likely to have anemia (86% vs. 67%, p=0.04), leukopenia (40% vs. 20%, p=0.04), and transfusion requirements (51% vs. 20%, p=0.002) but few differences in symptoms when compared to patients with moderate thrombocytopenia. These results suggest that MF patients with thrombocytopenia experience greater symptomatic burden than MF patients without thrombocytopenia and may benefit from additional therapies.

A phase 2 study of momelotinib, a potent JAK1 and JAK2 inhibitor, in patients with polycythemia vera or essential thrombocythemia

Momelotinib is a potent inhibitor of JAK1 and JAK2 that demonstrated efficacy in patients with primary and secondary myelofibrosis. This phase 2, open-label, randomized study evaluated the efficacy and safety of oral once-daily momelotinib (100mg and 200mg) for the treatment of polycythemia vera (PV) and essential thrombocythemia (ET). The primary endpoint for PV was overall response rate (ORR), defined as the proportion of patients with hematocrit <45%, white blood cell count <10×10⁹/L, platelet count ≤400×10⁹/L, and resolution of palpable splenomegaly, each lasting ≥4 weeks. The definition of ORR for ET excluded the hematocrit component. A total of 39 patients (28 PV, 11 ET) were enrolled, with 28 patients receiving ≥12 weeks of treatment. The study was terminated due to limited efficacy. Two patients (ORR 5.1%) met the primary efficacy endpoint (both PV 200mg). Predose plasma levels of momelotinib were stable over time. A total of 31 (79.5%) patients experienced momelotinib-related adverse events (AEs), the most frequent being headache (23.1%), dizziness (18.0%), somnolence (15.4%), nausea (15.4%), and fatigue (15.4%). Three patients experienced serious AEs (7.7%), with 1 considered related to momelotinib (dyspnea). Peripheral neuropathy occurred in 7 (17.9%) patients (4 PV, 3 ET).

Ruxolitinib reduces JAK2 p.V617F allele burden in patients with polycythemia vera enrolled in the RESPONSE study

In patients with polycythemia vera (PV), an elevated JAK2 p.V617F allele burden is associated with indicators of more severe disease (e.g., leukocytosis, splenomegaly, and increased thrombosis risk); however, correlations between allele burden reductions and clinical benefit in patients with PV have not been extensively evaluated in a randomized trial. This exploratory analysis from the multicenter, open-label, phase 3 Randomized Study of Efficacy and Safety in Polycythemia Vera With JAK Inhibitor INCB018424 Versus Best Supportive Care trial evaluated the long-term effect of ruxolitinib treatment on JAK2 p.V617F allele burden in patients with PV. Evaluable JAK2 p.V617F-positive patients randomized to ruxolitinib (n = 107) or best available therapy (BAT) who crossed over to ruxolitinib at week 32 (n = 97) had consistent JAK2 p.V617F allele burden reductions throughout the study. At all time points measured (up to weeks 208 [ruxolitinib-randomized] and 176 [ruxolitinib crossover]), mean changes from baseline over time in JAK2 p.V617F allele burden ranged from −12.2 to −40.0% (ruxolitinib-randomized) and −6.3 to −17.8% (ruxolitinib crossover). Complete or partial molecular response was observed in 3 patients (ruxolitinib-randomized, n = 2; ruxolitinib crossover, n = 1) and 54 patients (ruxolitinib-randomized, n = 33; ruxolitinib crossover, n = 20; BAT, n = 1), respectively. Among patients treated with interferon as BAT (n = 13), the mean maximal reduction in allele burden from baseline was 25.6% after crossover to ruxolitinib versus 6.6% before crossover. Collectively, the data from this exploratory analysis suggest that ruxolitinib treatment for up to 4 years provides progressive reductions in JAK2 p.V617F allele burden in patients with PV who are resistant to or intolerant of hydroxyurea. The relationship between allele burden changes and clinical outcomes in patients with PV remains unclear.

Splanchnic vein thrombosis in myeloproliferative neoplasms: risk factors for recurrences in a cohort of 181 patients

We retrospectively studied 181 patients with polycythaemia vera (n=67), essential thrombocythaemia (n=67) or primary myelofibrosis (n=47), who presented a first episode of splanchnic vein thrombosis (SVT). Budd–Chiari syndrome (BCS) and portal vein thrombosis were diagnosed in 31 (17.1%) and 109 (60.3%) patients, respectively; isolated thrombosis of the mesenteric or splenic veins was detected in 18 and 23 cases, respectively. After this index event, the patients were followed for 735 patient years (pt-years) and experienced 31 recurrences corresponding to an incidence rate of 4.2 per 100 pt-years. Factors associated with a significantly higher risk of recurrence were BCS (hazard ratio (HR): 3.03), history of previous thrombosis (HR: 3.62), splenomegaly (HR: 2.66) and leukocytosis (HR: 2.8). Vitamin K-antagonists (VKA) were prescribed in 85% of patients and the recurrence rate was 3.9 per 100 pt-years, whereas in the small fraction (15%) not receiving VKA more recurrences (7.2 per 100 pt-years) were reported. Intracranial and extracranial major bleeding was recorded mainly in patients on VKA and the corresponding rate was 2.0 per 100 pt-years. In conclusion, despite anticoagulation treatment, the recurrence rate after SVT in myeloproliferative neoplasms is high and suggests the exploration of new avenues of secondary prophylaxis with new antithrombotic drugs and JAK-2 inhibitors.

Associations between gender, disease features and symptom burden in patients with myeloproliferative neoplasms: an analysis by the MPN QOL International Working Group

The myeloproliferative neoplasms, including polycythemia vera, essential thrombocythemia and myelofibrosis, are distinguished by their debilitating symptom profiles, life-threatening complications and profound impact on quality of life. The role gender plays in the symptomatology of myeloproliferative neoplasms remains under-investigated. In this study we evaluated how gender relates to patients' characteristics, disease complications and overall symptom expression. A total of 2,006 patients (polycythemia vera=711, essential thrombocythemia=830, myelofibrosis=460, unknown=5) were prospectively evaluated, with patients completing the Myeloproliferative Neoplasm-Symptom Assessment Form and Brief Fatigue Inventory Patient Reported Outcome tools. Information on the individual patients' characteristics, disease complications and laboratory data was collected. Consistent with known literature, most female patients were more likely to have essential thrombocythemia (48.6% versus 33.0%; P<0.001) and most male patients were more likely to have polycythemia vera (41.8% versus 30.3%; P<0.001). The rate of thrombocytopenia was higher among males than females (13.9% versus 8.2%; P<0.001) and males also had greater red-blood cell transfusion requirements (7.3% versus 4.9%; P=0.02) with shorter mean disease duration (6.4 versus 7.2 years, P=0.03). Despite there being no statistical differences in risk scores, receipt of most therapies or prior complications (hemorrhage, thrombosis), females had more severe and more frequent symptoms for most individual symptoms, along with overall total symptom score (22.8 versus 20.3; P<0.001). Females had particularly high scores for abdominal-related symptoms (abdominal pain/discomfort) and microvascular symptoms (headache, fatigue, insomnia, concentration difficulties, dizziness; all P<0.01). Despite complaining of more severe symptom burden, females had similar quality of life scores to those of males. The results of this study suggest that gender contributes to the heterogeneity of myeloproliferative neoplasms by influencing phenotypic profiles and symptom expression.

Safety and efficacy of ruxolitinib in an open-label, multicenter, single-arm phase 3b expanded-access study in patients with myelofibrosis: a snapshot of 1144 patients in the JUMP trial

JUMP is a phase 3b expanded-access trial for patients without access to ruxolitinib outside of a clinical study; it is the largest clinical trial to date in patients with myelofibrosis who have been treated with ruxolitinib. Here, we present safety and efficacy findings from an analysis of 1144 patients with intermediate- or high-risk myelofibrosis, as well as a separate analysis of 163 patients with intermediate-1-risk myelofibrosis - a population of patients not included in the phase 3 COMFORT studies. Consistent with ruxolitinib's mechanism of action, the most common hematologic adverse events were anemia and thrombocytopenia, but these led to treatment discontinuation in only a few cases. The most common non-hematologic adverse events were primarily grade 1/2 and included diarrhea, pyrexia, fatigue, and asthenia. The rates of infections were low and primarily grade 1/2, and no new or unexpected infections were observed. The majority of patients achieved a ≥50% reduction from baseline in palpable spleen length. Improvements in symptoms were rapid, with approximately half of all patients experiencing clinically significant improvements, as assessed by various quality-of-life questionnaires. The safety and efficacy profile in intermediate-1-risk patients was consistent with that in the overall JUMP population and with that previously reported in intermediate-2- and high-risk patients. Overall, ruxolitinib provided clinically meaningful reductions in spleen length and symptoms in patients with myelofibrosis, including those with intermediate-1-risk disease, with a safety and efficacy profile consistent with that observed in the phase 3 COMFORT studies. This trial was registered as NCT01493414 at ClinicalTrials.gov.

Antiplatelet therapy versus observation in low-risk essential thrombocythemia with a CALR mutation

The role of antiplatelet therapy as primary prophylaxis of thrombosis in low-risk essential thrombocythemia has not been studied in randomized clinical trials. We assessed the benefit/risk of low-dose aspirin in 433 patients with low-risk essential thrombocythemia (271 with a CALR mutation, 162 with a JAK2(V617F) mutation) who were on antiplatelet therapy or observation only. After a follow up of 2215 person-years free from cytoreduction, 25 thrombotic and 17 bleeding episodes were recorded. In CALR-mutated patients, antiplatelet therapy did not affect the risk of thrombosis but was associated with a higher incidence of bleeding (12.9 versus 1.8 episodes per 1000 patient-years, P=0.03). In JAK2(V617F)-mutated patients, low-dose aspirin was associated with a reduced incidence of venous thrombosis with no effect on the risk of bleeding. Coexistence of JAK2(V617F)-mutation and cardiovascular risk factors increased the risk of thrombosis, even after adjusting for treatment with low-dose aspirin (incidence rate ratio: 9.8; 95% confidence interval: 2.3-42.3; P=0.02). Time free from cytoreduction was significantly shorter in CALR-mutated patients with essential thrombocythemia than in JAK2(V617F)-mutated ones (median time 5 years and 9.8 years, respectively; P=0.0002) and cytoreduction was usually necessary to control extreme thrombocytosis. In conclusion, in patients with low-risk, CALR-mutated essential thrombocythemia, low-dose aspirin does not reduce the risk of thrombosis and may increase the risk of bleeding.