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Polycythemia vera (PV) is a relatively indolent myeloid neoplasm with median survival that exceeds 35 years in young patients, but its natural history might be interrupted by thrombotic, fibrotic, or leukemic events, with respective 20-year rates of 26%, 16%, and 4%. Current treatment strategies in PV have not been shown to prolong survival or lessen the risk of leukemic or fibrotic progression and instead are directed at preventing thrombotic complications. In the latter regard, two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). All patients require phlebotomy to keep hematocrit below 45% and once-daily low-dose aspirin, in the absence of contraindications. Cytoreductive therapy is recommended for high-risk or symptomatic low-risk disease; our first-line drug of choice in this regard is hydroxyurea but we consider pegylated interferon as an alternative in certain situations, including in young women of reproductive age, in patients manifesting intolerance or resistance to hydroxyurea therapy, and in situations where treatment is indicated for curbing phlebotomy requirement rather than preventing thrombosis. Additional treatment options include busulfan and ruxolitinib; the former is preferred in older patients and the latter in the presence of symptoms reminiscent of post-PV myelofibrosis or protracted pruritus. Our drug choices reflect our appreciation for long-term track record of safety, evidence for reduction of thrombosis risk, and broader suppression of myeloproliferation. Controlled studies are needed to clarify the added value of twice- vs once-daily aspirin dosing and direct oral anticoagulants. In this invited review, we discuss our current approach to diagnosis, prognostication, and treatment of PV in general, as well as during specific situations, including pregnancy and splanchnic vein thrombosis.

Anemia is a frequent manifestation of myelofibrosis (MF) and there is an unmet need for effective treatments in anemic MF patients. The REALISE phase 2 study (NCT02966353) evaluated the efficacy and safety of a novel ruxolitinib dosing strategy with a reduced starting dose with delayed up-titration in anemic MF patients. Fifty-one patients with primary MF (66.7%), post-essential thrombocythemia MF (21.6%), or post-polycythemia vera MF (11.8%) with palpable splenomegaly and hemoglobin

We report the clinical presentation and risk factors for survival in 175 patients with myeloproliferative neoplasms (MPN) and COVID-19, diagnosed between February and June 2020. After a median follow-up of 50 days, mortality was higher than in the general population and reached 48% in myelofibrosis (MF). Univariate analysis, showed a significant relationship between death and age, male gender, decreased lymphocyte counts, need for respiratory support, comorbidities and diagnosis of MF, while no association with essential thrombocythemia (ET), polycythemia vera (PV), and prefibrotic-PMF (pre-PMF) was found. Regarding MPN-directed therapy ongoing at the time of COVID-19 diagnosis, Ruxolitinib (Ruxo) was significantly more frequent in patients who died in comparison with survivors (p=0.006). Conversely, multivariable analysis found no effect of Ruxo alone on mortality, but highlighted an increased risk of death in the 11 out of 45 patients who discontinued treatment. These findings were also confirmed in a propensity score matching analysis. In conclusion, we found a high risk of mortality during COVID-19 infection among MPN patients, especially in MF patients and/or discontinuing Ruxo at COVID-19 diagnosis. These findings call for deeper investigation on the role of Ruxo treatment and its interruption, in affecting mortality in MPN patients with COVID-19.

Somatic mutations in splicing factor genes frequently occur in myeloid neoplasms. While SF3B1 mutations are associated with myelodysplastic syndromes (MDS) with ring sideroblasts, SRSF2P95 mutations are found in different disease categories, including MDS, myeloproliferative neoplasms (MPN), myelodysplastic/myeloproliferative neoplasms (MDS/MPN), and acute myeloid leukemia (AML). To identify molecular determinants of this phenotypic heterogeneity, we explored molecular and clinical features of a prospective cohort of 279 SRSF2P95-mutated cases selected from a population of 2663 patients with myeloid neoplasms. Median number of somatic mutations per subject was 3. Multivariate regression analysis showed associations between co-mutated genes and clinical phenotype, including JAK2 or MPL with myelofibrosis (OR = 26.9); TET2 with monocytosis (OR = 5.2); RAS-pathway genes with leukocytosis (OR = 5.1); and STAG2, RUNX1, or IDH1/2 with blast phenotype (MDS or AML) (OR = 3.4, 1.9, and 2.1, respectively). Within patients with SRSF2-JAK2 co-mutation, JAK2 dominance was invariably associated with clinical feature of MPN, whereas SRSF2 mutation was dominant in MDS/MPN. Within patients with SRSF2-TET2 co-mutation, clinical expressivity of monocytosis was positively associated with co-mutated clone size. This study provides evidence that co-mutation pattern, clone size, and hierarchy concur to determine clinical phenotype, tracing relevant genotype-phenotype associations across disease entities and giving insight on unaccountable clinical heterogeneity within current WHO classification categories.

Essential thrombocythemia (ET) and polycythemia vera (PV) are myeloproliferative neoplasms (MPNs) characterized by an increased risk of developing venous and arterial thromboses and of evolution to myelofibrosis or acute leukemia (1). MPNs are recognized as a major cause of splanchnic vein thromboses (SVT), which include hepatic, splenic, portal and mesenteric vein thromboses (2). Patients with SVT are at an increased risk of developing bleeding events and arterial thrombotic events (3), as well as recurrent SVT and the use of anticoagulation and cytoreduction do not clearly modify this risk (3–5). Management of SVT in MPN patients remains a challenge and most therapeutic recommendations are based on retrospective analyses (6). Recently, De Stefano reported that hydroxyurea failed to prevent recurrent thromboses in the splanchnic vasculature in patients with a prior SVT (7). We conducted a prospective, open-label, multi-center phase II clinical trial of Pegylated Interferon Alfa-2a (PEG) in 20 subjects with SVT and an MPN, who represented a cohort of patients who participated in the Myeloproliferative Disorders - Research Consortium (MPD-RC) 111 trial (). MPD-RC 111 was a prospective study of patients with high-risk ET/PV who were resistant or intolerant to hydroxyurea (HU), but prior HU therapy was not a requirement for patients to enter the SVT cohort. Here we report the outcomes of the 20 SVT patients who were treated with PEG.

No abstract available.

A total of 410 patients with blast phase myeloproliferative neoplasm (MPN-BP) were retrospectively reviewed: 248 from the Mayo Clinic and 162 from Italy. Median survival was 3.6 months, with no improvement over the last 15 years. Multivariable analysis performed on the Mayo cohort identified high risk karyotype, platelet count 65 years and transfusion need as independent risk factors for survival. Also in the Mayo cohort, intensive chemotherapy resulted in complete remission (CR) or CR with incomplete count recovery (CRi) rates of 35 and 24%, respectively; treatment-specified 3-year/5-year survival rates were 32/10% for patients receiving allogeneic stem cell transplant (AlloSCT) (n = 24), 19/13% for patients achieving CR/CRi but were not transplanted (n = 24), and 1/1% in the absence of both AlloSCT and CR/CRi (n = 200) (p

Loss-of-function TET2 mutations (TET2

Ruxolitinib is a Janus kinase (JAK) (JAK1/JAK2) inhibitor that has demonstrated superiority over placebo and best available therapy (BAT) in the Controlled Myelofibrosis Study with Oral JAK Inhibitor Treatment (COMFORT) studies. COMFORT-II was a randomized (2:1), open-label phase 3 study in patients with myelofibrosis; patients randomized to BAT could crossover to ruxolitinib upon protocol-defined disease progression or after the primary end point, confounding long-term comparisons. At week 48, 28% (41/146) of patients randomized to ruxolitinib achieved ⩾35% decrease in spleen volume (primary end point) compared with no patients on BAT (PP=0.06); the crossover-corrected HR was 0.44 (95% CI, 0.18–1.04; P=0.06). There was no unexpected increased incidence of adverse events with longer exposure. This final analysis showed that spleen volume reductions with ruxolitinib were maintained with continued therapy and may be associated with survival benefits.

International collaborations over the years have produced a series of prognostic models for primary myelofibrosis (PMF), including the recently unveiled mutation-enhanced international prognostic scoring systems for transplant-age patients (MIPSS70 and MIPSS70-plus). In the current study, we considered the feasibility of a genetically inspired prognostic scoring system (GIPSS) that is exclusively based on genetic markers. Among 641 cytogenetically annotated patients with PMF and informative for previously recognized adverse mutations, multivariable analysis identified “VHR” karyotype, “unfavorable” karyotype, absence of type 1/like CALR mutation and presence of ASXL1, SRSF2, or U2AF1Q157 mutation, as inter-independent predictors of inferior survival; the respective HRs (95% CI) were 3.1 (2.1–4.3), 2.1 (1.6–2.7), 2.1 (1.6–2.9), 1.8 (1.5–2.3), 2.4 (1.9–3.2), and 2.4 (1.7–3.3). Based on HR-weighted risk points, a four-tiered GIPSS model was devised: low (zero points; n = 58), intermediate-1 (1 point; n = 260), intermediate-2 (2 points; n = 192), and high (≥3 points; n = 131); the respective median (5-year) survivals were 26.4 (94%), 8.0 (73%), 4.2 (40%), and 2 (14%) years; the model was internally validated by bootstrapping and its predictive accuracy was shown to be comparable to that of MIPSS70-plus. GIPPS offers a low-complexity prognostic tool for PMF that is solely dependent on genetic risk factors and, thus, forward-looking in its essence.

Disease-specific mutations facilitate diagnostic precision and drug target discovery. In myeloproliferative neoplasms (MPN), this is best exemplified by the chronic myeloid leukemia-associated BCR-ABL1. No other mutation in MPN has thus far shown a similar degree of diagnostic accuracy or therapeutic relevance. However, JAK2 and KIT mutations are detected in more than 90% of patients with polycythemia vera and systemic mastocytosis, respectively, and are therefore used as highly sensitive clonal markers in these diseases. JAK2 and MPL mutations also occur in essential thrombocythemia (ET) and primary myelofibrosis (PMF), but their diagnostic value is limited by suboptimal sensitivity and specificity. The molecular diagnostic gap in JAK2/MPL-unmutated ET/PMF is now partially addressed by the recent discovery of calreticulin (CALR) mutations in the majority of such cases. However, bone marrow morphology remains the central diagnostic platform and is essential for distinguishing ET from prefibrotic PMF and diagnosing patients those do not express JAK2, MPL or CALR (triple-negative). The year 2013 was also marked by the description of CSF3R mutations in the majority of patients with chronic neutrophilic leukemia (CNL). Herein, we argue for the inclusion of CALR and CSF3R mutations in the World Health Organization classification system for ET/PMF and CNL, respectively.

The aim of this review is to critically address the validity and clinical applicability of three major diagnostic classification systems for polycythemia vera (PV), that is, those proposed by the Polycythemia Vera Study Group (PVSG), the British Committee for Standards in Haematology (BCSH) and the World Health Organization (WHO). Special focus is on which one of the three red cell parameters (hemoglobin-HB, hematocrit-HCT and red cell mass-RCM) should be used as the diagnostic hallmark of PV. The revised BCSH employed a persistently raised HCT level as the first diagnostic criterion in combination with the presence of a JAK2V617F mutation. On the other hand, the WHO classification used a raised HB value as a surrogate for increased RCM in association with molecular markers and for the first time, the bone marrow (BM) morphology was included as a minor criterion. Ongoing controversy and discussion regards the use of certain threshold values for HCT and HB as surrogates for RCM as well as the existence of prodromal-latent disease, so-called masked PV (mPV). It has been shown that mPV can be recognized in patients not meeting the required HB or HCT threshold levels by both the WHO and BCSH criteria. These cases present with the same baseline clinical features as overt PV but present worsened survival. A critical reappraisal of the WHO criteria may suggest either to reduce the thresholds for HB or to consider HCT values as major diagnostic criterion, as in the BCSH, in association with JAK2V617F mutation. The clinical utility of using HCT as reference variable is supported also by results of clinical trials which explicitly recommend to use the HCT threshold for monitoring treatment. In questionable cases as in mPV, BM biopsy examinations should be mandated together with mutation analysis.

With the intent of dissecting the molecular complexity of Philadelphia-negative myeloproliferative neoplasms (MPN), we designed a target enrichment panel to explore, using next-generation sequencing (NGS), the mutational status of an extensive list of 2000 cancer-associated genes and microRNAs. The genomic DNA of granulocytes and in vitro-expanded CD3+T-lymphocytes, as a germline control, was target-enriched and sequenced in a learning cohort of 20 MPN patients using Roche 454 technology. We identified 141 genuine somatic mutations, most of which were not previously described. To test the frequency of the identified variants, a larger validation cohort of 189 MPN patients was additionally screened for these mutations using Ion Torrent AmpliSeq NGS. Excluding the genes already described in MPN, for 8 genes (SCRIB, MIR662, BARD1, TCF12, FAT4, DAP3, POLG and NRAS), we demonstrated a mutation frequency between 3 and 8%. We also found that mutations at codon 12 of NRAS (NRASG12V and NRASG12D) were significantly associated, for primary myelofibrosis (PMF), with highest dynamic international prognostic scoring system (DIPSS)-plus score categories. This association was then confirmed in 66 additional PMF patients composing a final dataset of 168 PMF showing a NRAS mutation frequency of 4.7%, which was associated with a worse outcome, as defined by the DIPSS plus score.

Patient outcome in primary myelofibrosis (PMF) is significantly influenced by karyotype. We studied 879 PMF patients to determine the individual and combinatorial prognostic relevance of somatic mutations. Analysis was performed in 483 European patients and the seminal observations were validated in 396 Mayo Clinic patients. Samples from the European cohort, collected at time of diagnosis, were analyzed for mutations in ASXL1, SRSF2, EZH2, TET2, DNMT3A, CBL, IDH1, IDH2, MPL and JAK2. Of these, ASXL1, SRSF2 and EZH2 mutations inter-independently predicted shortened survival. However, only ASXL1 mutations (HR: 2.02; P

Reproducibility and clinical usefulness of the WHO classification of chronic myeloproliferative neoplasm (MPN) persist to be a controversial issue. Major arguments are focused on the critical impact of histopathology, particularly concerning the distinction between essential thrombocythemia (ET) versus early/prefibrotic primary myelofibrosis (PMF). Regarding bone marrow morphology, WHO guidelines strictly require the recognition of characteristic histological patterns based on standardized features and a consensus of clinical and molecular-genetic data. Molecular-genetic findings as JAK2V617F, may aid to exclude reactive thrombocytosis, although in ET and PMF only 50-60% of the cases show these aberrations. Considerable doubts over the existence of early/prefibrotic PMF have been expressed with the consequence to include this entity in the ET category. On the other hand, it has to be argued that some of the critical studies failed to adhere very strictly to the WHO guidelines. Contrasting this situation, recently published retrospective and prospective clinico-pathological studies featuring the WHO criteria provided an important information on disease outcomes supporting the existence of early/prefibrotic PMF as a distinct clinico-pathologic entity in patients presenting clinically with ET. Therefore, this controversy suggests a scientific project, including the community of pathologists and hematologists, for providing sound, objective and reproducible criteria for diagnosing early/prefibrotic PMF.

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms with variable risk of evolution into post-PV and post-ET myelofibrosis, from now on referred to as secondary myelofibrosis (SMF). No specific tools have been defined for risk stratification in SMF. To develop a prognostic model for predicting survival, we studied 685 JAK2, CALR, and MPL annotated patients with SMF. Median survival of the whole cohort was 9.3 years (95% CI: 8-not reached-NR-). Through penalized Cox regressions we identified negative predictors of survival and according to beta risk coefficients we assigned 2 points to hemoglobin level

In a multi-institutional collaborative project, 1473 patients with myeloproliferative neoplasms (MPN) were screened for isocitrate dehydrogenase 1 (IDH1)/IDH2 mutations: 594 essential thrombocythemia (ET), 421 polycythemia vera (PV), 312 primary myelofibrosis (PMF), 95 post-PV/ET MF and 51 blast-phase MPN. A total of 38 IDH mutations (18 IDH1-R132, 19 IDH2-R140 and 1 IDH2-R172) were detected: 5 (0.8%) ET, 8 (1.9%) PV, 13 (4.2%) PMF, 1 (1%) post-PV/ET MF and 11 (21.6%) blast-phase MPN (P

The aim of this study was to determine whether the burden of JAK2(V617F) allele correlated with major clinical outcomes in patients with polycythemia vera (PV). To this end, we determined JAK2 mutant allele levels in granulocytes of 173 PV patients at diagnosis. The mean (+/-s.d.) mutant allele burden was 52% (+/-29); 32 patients (18%) had greater than 75% mutant allele. The burden of JAK2(V617F) allele correlated with measurements of stimulated erythropoiesis (higher hematocrit, lower mean cell volume, serum ferritin and erythropoietin levels) and myelopoiesis (higher white cell count, neutrophil count and serum lactate dehydrogenase) and with markers of neutrophil activation (elevated leukocyte alkaline phosphatase and PRV-1 expression). As compared to those with less than 25% mutant allele, patients harboring greater than 75% JAK2(V617F) allele were at higher relative risk (RR) of presenting larger spleen (RR 4.7; P

The optimal duration of treatment with vitamin K antagonists (VKA) after venous thromboembolism (VTE) in patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) is uncertain. To tackle this issue, we retrospectively studied 206 patients with MPN-related VTE (deep venous thrombosis of the legs and/or pulmonary embolism). After this index event, we recorded over 695 pt-years 45 recurrences, venous in 36 cases, with an incidence rate (IR) of 6.5 per 100 pt-years (95% confidence interval (CI): 4.9-8.6). One hundred fifty-five patients received VKA; the IR of recurrent thrombosis per 100 pt-years was 4.7 (95% CI: 2.8-7.3) on VKA and 8.9 (95% CI: 5.7-13.2) off VKA (P=0.03). In patients receiving VKA, the IR of recurrent thrombosis per 100 pt-years was 5.3 (95% CI: 3.2-8.4) among 108 patients on long-term VKA and 12.8 (95% CI: 7.3-20.7) after discontinuation among the 47 who ceased treatment (P=0.008), with a doubled risk of recurrence after stopping VKA (hazard ratio: 2.21, 95% CI: 1.19-5.30). The IR of major bleeding per 100 pt-years was 2.4 (95%: CI: 1.1-4.5) on VKA and 0.7 (95% CI: 0.08-2.5) off VKA (P=0.08). In conclusion, in MPN patients with VTE recurrent thrombosis is significantly reduced by VKA and caution should be adopted in discontinuation; however, the incidence of recurrence on treatment remains high, calling for clinical trials aimed to improve prophylaxis in this setting.

We report the results of two prospective phase II studies investigating the role of high-dose sequential chemotherapy, followed by autologous stem cell transplantation (ASCT) in 62 patients with advanced stage peripheral T-cell lymphomas (PTCLs) at diagnosis. Conditioning regimen consisted of mitoxantrone (60 mg/m2) and melphalan (180 mg/m2) or carmustine, etoposide, Ara-C and melphalan followed by peripheral blood stem cell autografting. In an intent-to-treat analysis, 46 out of 62 patients (74%) completed the whole programme, whereas 16 patients did not undergo ASCT, mainly because of disease progression. At a median follow-up of 76 months, the estimated 12-year overall (OS), disease-free and event-free survival (EFS) were 34, 55 and 30%, respectively. OS and EFS were significantly better in patients with anaplastic lymphoma-kinase (ALK)-positive anaplastic large-cell lymphoma (ALCL), as compared with the remaining PTCL. Multivariate analysis showed that patients attaining complete remission (CR) before ASCT had a statistically significant benefit in terms of OS and EFS (P

Elevated C-reactive protein is associated with shortened leukemia-free survival in patients with myelofibrosis

The rate of transformation from JAK2-mutated ET to PV is influenced by an accurate WHO-defined clinico-morphological diagnosis

No role for CXCL12–G801A polymorphism in the development of extramedullary disease in acute myeloid leukemia

The size of duplication does not add to the prognostic significance of FLT3 internal tandem duplication in acute myeloid leukemia patients

We recently defined a high-molecular risk category (HMR) in primary myelofibrosis (PMF), based on the presence of at least one of the five 'prognostically detrimental' mutated genes (ASXL1, EZH2, SRSF2 and IDH1/2). Herein, we evaluate the additional prognostic value of the 'number' of mutated genes. A total of 797 patients were recruited from Europe (n=537) and the Mayo Clinic (n=260). In the European cohort, 167 (31%) patients were HMR: 127 (23.6%) had one and 40 (7.4%) had two or more mutated genes. The presence of two or more mutations predicted the worst survival: median 2.6 years (hazard ratio (HR) 3.8, 95% confidence interval (CI) 2.6-5.7) vs. 7.0 years (HR 1.9, 95% CI 1.4-2.6) for one mutation vs 12.3 years for no mutations. The results were validated in the Mayo cohort and prognostic significance in both cohorts was independent of International Prognostic Scoring System (IPSS; HR 2.4, 95% CI 1.6-3.6) and dynamic IPSS (DIPSS)-plus (HR 1.9, 95% CI 1.2-3.1), respectively. Two or more mutations were also associated with shortened leukemia-free survival (HR 6.2, 95% CI 3.5-10.7), also Mayo validated. Calreticulin mutations favorably affected survival, independently of both number of mutations and IPSS/DIPSS-plus. We conclude that the 'number' of prognostically detrimental mutations provides added value in the combined molecular and clinical prognostication of PMF.

Current prognostication in primary myelofibrosis (PMF) is based on the dynamic international prognostic scoring system (DIPSS)-plus, which employs clinical and cytogenetic variables. We recently reported DIPSS-plus independent prognostic significance for calreticulin (CALR) (favorable) and ASXL1 (unfavorable) mutations. In the current study, 570 PMF patients were recruited for derivation (n=277) and validation (n=293) of a molecular prognostic model based on these two mutations. Survival was the longest in CALR(+)ASXL1(-) (median 10.4 years) and shortest in CALR(-)ASXL1(+) patients (median, 2.3 years; hazard ratio (HR), 5.9; 95% confidence interval (CI), 3.5-10.0). CALR(+)ASXL1(+) and CALR(-)ASXL1(-) patients had similar survival and were grouped together in an intermediate-risk category (median survival, 5.8 years; HR, 2.5; 95% CI, 1.5-4.0). The CALR/ASXL1 mutations-based prognostic model was DIPSS-plus independent (P0.0001) and effective in identifying low-/intermediate-1-risk patients with shorter (median, 4 years) or longer (median 20 years) survival and high-/intermediate-2-risk patients with shorter (median, 2.3 years) survival. Multivariable analysis distinguished CALR(-)ASXL1(+) mutational status as the most significant risk factor for survival: HR 3.7 vs 2.8 for age65 years vs 2.7 for unfavorable karyotype. These observations signify immediate clinical relevance and warrant i) CALR and ASXL1 mutation determination in all patients with PMF and ii) molecular revision of DIPSS-plus.

Abstract 3833 Background: Survival in primary myelofibrosis (PMF) is assessed by the Dynamic International Prognostic Scoring System (DIPSS) (Blood 2010;115:1703) and DIPSS-plus (JCO 2011;29:392). The latter is based on eight risk factors including age>65 years, constitutional symptoms, hemoglobin 25 × 109/L, platelet count Methods: A combination of multivariable and receiver operating characteristic (ROC) analyses were applied to a Mayo Clinic database of 884 karyotypically-annotated patients with PMF, in order to define karyotype-dependent and karyotype-independent risk models for LT. The karyotype-independent model was further validated in a separate cohort of 525 PMF patients from an international database (Blood 2010;115:1703). Patients in the Mayo cohort were evaluated at time of referral and those of the international database at time of initial diagnosis. Results I: Sixty cases of LT were documented. Karyotype (categorized into MK, inv(3)/i(17q) abnormalities, other unfavorable, and favorable), PB blast percentage (as a continuous variable), and platelet count (as a continuous variable) were the most reliable (p Results II: The karyotype-independent model was based on PB blast percentage and platelet count only; low-risk (no adverse points; n =525), intermediate-risk (one adverse point; n =311) and high-risk (two adverse points; n =48); the corresponding 3-year LT rates were 3%, 12% (HR 3.1, 95% CI 1.8–5.4; p Conclusions: The current leukemia risk models are applicable at diagnosis or during follow-up, in the presence or absence of cytogenetic information, and complement DIPSS-plus in the comprehensive prognostication of patients with PMF. Disclosures: Vannucchi: Novartis: Honoraria.