CALR-mutated patients with low allele burden represent a specific subtype of essential thrombocythemia: A study on behalf of FIM and GBMHM.

A low allele burden (i.e., <20%) of the CALR driver mutation is found in 10.8% of CALR-mutated MPNs, mostly in essential thrombocythemia, and correlates with a milder phenotype and a more indolent evolution compared to patients with an allele burden ≥20%.

Transfusion-Transmitted Hepatitis A Virus, France, 2018.

We report a transfusion-transmitted hepatitis A virus infection in an immunocompromised patient in France, detected shortly after a transfusion of pathogen-reduced pooled platelets. This case raises questions about the efficacy of donor screening methods. Additional safety measures, such as routine donation screening, should be considered.

Sequential mutational evaluation of CALR -mutated myeloproliferative neoplasms with thrombocytosis reveals an association between CALR allele burden evolution and disease progression.

In myeloproliferative neoplasms (MPN), JAK2V617F allele burden measurement has an impact on prognosis that helps in patient monitoring. Less is known about its usefulness in CALR-mutated cases. Additional mutations found by next-generation sequencing have also shown an impact on prognosis that may drive therapeutic choices, especially in myelofibrosis, but few studies focused on CALR-mutated patients. We performed a molecular evaluation combining next-generation sequencing with a myeloid panel and CALR allele burden measurement at diagnosis and during follow-up in a cohort of 45 patients with CALR-mutated essential thrombocythaemia. The bone marrow histology was also blindly reviewed in order to apply the WHO2016 classification. The most frequently mutated gene was TET2 (11/21 mutations). CALR type 1-like patients appear to have a more complex molecular landscape. We found an association between disease progression and CALR allele burden increase during follow-up, independently of additional mutations and WHO2016-reviewed diagnosis. Patients with disease progression at the time of follow-up showed a significant increase in CALR allele burden (+16·7%, P = 0·005) whereas patients without disease progression had a stable allele burden (+3·7%, P = 0·194). This result argues for clinical interest in CALR allele burden monitoring.

WT1 gene is overexpressed in myeloproliferative neoplasms, especially in myelofibrosis.

Classical Philadelphia-negative myeloproliferative neoplasms include Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF). They are characterized by the presence of driver mutations of JAK2, CALR or MPL genes. Overexpression of WT1 is used as a marker of minimal residual disease in acute myeloid leukemia, especially after allogeneic stem cell transplantation (SCT). We investigated WT1 expression at diagnosis in 152 MPN patients and showed that the WT1 transcript was overexpressed in PMFs and PVs compared to controls. In particular, WT1 transcript levels were higher in PMF than in ET and PV. WT1 transcript levels were significantly increased during myelofibrotic transformation of ET or PV. Using multivariate linear regression, high WT1 transcript levels in PMF were associated with age over 65, splenomegaly and thrombocytopenia. The ROC curve analysis showed that a level of WT1 transcript >10 WT1 copies/104ABL1 enabled the diagnosis of PMF with a specificity of 95.8% (PMF vs ET; ROC AUC = 0.91). In myelofibrosis, studying follow-ups of WT1 transcript showed that this marker is of interest after allogeneic SCT. These results demonstrate that WT1 overexpression is a simple marker of myelofibrosis in MPN and could be used during patient follow-up.

Sequential analysis of 18 genes in polycythemia vera and essential thrombocythemia reveals an association between mutational status and clinical outcome.

Philadelphia-negative classical myeloproliferative neoplasms (MPN) are clonal diseases characterized by driver mutations of JAK2, MPL, or CALR. Additional mutations may occur in epigenetic regulators, signaling, or splicing genes that may be useful in the prognostic assessment of MPN patients. In primary myelofibrosis, molecular-based prognostic scoring systems have been recently proposed, but few data are available to date for polycythemia vera (PV) and essential thrombocythemia (ET). In this study, we used a next generation sequencing-based 18-gene panel in 50 JAK2V617F positive PV and JAK2V617F positive ET patients from an institutional cohort investigated at diagnosis and at 3-year follow-up (3y). Disease progression at 3y was defined by a composite criterion. Patients (28 PV and 22 ET) were included according to their clinical status, with or without disease progression. At diagnosis, we found 28 additional mutations in 21 of the 50 patients. Patients with disease progression were more likely to have at least one additional mutation. There was no difference between PV and ET. All patients with two or more additional mutations exhibited disease progression at 3y. No novel mutations appeared at 3y. The allele burden increase by at least one mutation at 3y was more frequent in patients with disease progression. Our data suggest that screening for additional mutations in PV and ET could identify patients at a higher risk of disease progression. © 2017 Wiley Periodicals, Inc.

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.

Efficacy and safety of ruxolitinib in patients with myelofibrosis and low platelet count (50 × 109/L to <100 × 109/L) at baseline: the final analysis of EXPAND.

Background: Thrombocytopenia is a common feature of myelofibrosis (MF), a myeloproliferative neoplasm driven by dysregulated JAK/STAT signaling; however, pivotal trials assessing the efficacy of ruxolitinib (a JAK1/2 inhibitor) excluded MF patients with low platelet counts (<100 × 109/L). Objectives: Determination of the maximum safe starting dose (MSSD) of ruxolitinib was the primary endpoint, with long-term safety and efficacy as secondary and exploratory endpoints, respectively. Design: EXPAND (NCT01317875) was a phase 1b, open-label, ruxolitinib dose-finding study in patients with MF and low platelet counts (50 to <100 × 109/L). Methods: Patients were stratified according to baseline platelet count into stratum 1 (S1, 75 to <100 × 109/L) or stratum 2 (S2, 50 to <75 × 109/L). Previous analyses established the MSSD at 10 mg twice daily (bid); long-term results are reported here. Results: Of 69 enrolled patients, 38 received ruxolitinib at the MSSD (S1, n = 20; S2, n = 18) and are the focus of this analysis. The incidence of adverse events was consistent with the known safety profile of ruxolitinib, with thrombocytopenia (S1, 50%; S2, 78%) and anemia (S1, 55%; S2, 44%) the most frequently reported adverse events and no new or unexpected safety signals. Substantial clinical benefits were observed for patients in both strata: 50% (10/20) and 67% (12/18) of patients in S1 and S2, respectively, achieved a spleen response (defined as ⩾50% reduction in spleen length from baseline) at any time during the study. Conclusion: The final safety and efficacy results from EXPAND support the use of a 10 mg bid starting dose of ruxolitinib in patients with MF and platelet counts 50 to <100 × 109/L. Registration: ClinicalTrials.gov NCT01317875.

Ruxolitinib before allogeneic hematopoietic transplantation in patients with myelofibrosis on behalf SFGM-TC and FIM groups.

This multicenter prospective phase 2 trial analyzed disease-free survival (DFS) in myelofibrosis patients receiving ruxolitinib for 6 months before transplantation. Seventy-six patients were recruited. Age-adjusted dynamic international prognostic scoring system was intermediate-1, intermediate-2, and high in 27 (36%), 31 (41%), and 18 (24%) patients. All patients received ruxolitinib from inclusion to conditioning regimen (fludarabine-melphalan) or to progression. A donor was found in 64 patients: 18 HLA-matched sibling donor (MSD), 32 HLA-matched unrelated (UD10/10), and 14 HLA mismatched unrelated donor (UD9/10. Among 64 patients with a donor, 20 (31%) achieved a partial response before transplantation and 59 (92%) could be transplanted after ruxolitinib therapy (18/18 MSD, 30/21 UD10/10, 11/34 UD9/10), of whom 19 (32%) were splenectomized. Overall survival from inclusion was 68% at 12 months. One-year DFS after transplantation was 55%: 83%, 40%, and 34% after MSD, UD10/10 or UD9/10, respectively. Cumulative incidence of grade 2-4 acute graft-versus-host disease (GVHD) was 66% and non-relapse-mortality was 42% at 12 months. Short course of ruxolitinib before transplantation is followed by a high rate of transplantation. With the platform used in this protocol, outcome was much better in patients transplanted with HLA-matched sibling donor as compared to unrelated donor.

Genomic analysis of primary and secondary myelofibrosis redefines the prognostic impact of ASXL1 mutations: a FIM study.

We aimed to study the prognostic impact of the mutational landscape in primary and secondary myelofibrosis. The study included 479 patients with myelofibrosis recruited from 24 French Intergroup of Myeloproliferative Neoplasms (FIM) centers. The molecular landscape was studied by high-throughput sequencing of 77 genes. A Bayesian network allowed the identification of genomic groups whose prognostic impact was studied in a multistate model considering transitions from the 3 conditions: myelofibrosis, acute leukemia, and death. Results were validated using an independent, previously published cohort (n = 276). Four genomic groups were identified: patients with TP53 mutation; patients with ≥1 mutation in EZH2, CBL, U2AF1, SRSF2, IDH1, IDH2, NRAS, or KRAS (high-risk group); patients with ASXL1-only mutation (ie, no associated mutation in TP53 or high-risk genes); and other patients. A multistate model found that both TP53 and high-risk groups were associated with leukemic transformation (hazard ratios [HRs] [95% confidence interval], 8.68 [3.32-22.73] and 3.24 [1.58-6.64], respectively) and death from myelofibrosis (HRs, 3.03 [1.66-5.56] and 1.77 [1.18-2.67], respectively). ASXL1-only mutations had no prognostic value that was confirmed in the validation cohort. However, ASXL1 mutations conferred a worse prognosis when associated with a mutation in TP53 or high-risk genes. This study provides a new definition of adverse mutations in myelofibrosis with the addition of TP53, CBL, NRAS, KRAS, and U2AF1 to previously described genes. Furthermore, our results argue that ASXL1 mutations alone cannot be considered detrimental.

Practical application and clinical impact of the WHO histopathological criteria on bone marrow biopsy for the diagnosis of essential thrombocythemia versus prefibrotic primary myelofibrosis.

AIMS: To evaluate the feasibility of the histopathological diagnosis of prefibrotic-early primary myelofibrosis (PM) as described in the World Health Organization (WHO) classification and to evaluate the clinical implications of prefibrotic-early PM in a series of patients previously diagnosed as having essential thrombocythemia (ET) according to the Polycythemia Vera Study Group criteria. METHODS AND RESULTS: WHO criteria were applied to bone marrow biopsy specimens by two pathologists who then reclassified 127 cases as 102 ET (80.3%), 18 prefibrotic-early PM (14.2%) and seven fibrotic PM (5.5%). In 45 cases (35%), the final diagnosis was only reached by consensus. The megakaryocytic criteria that best discriminated between ET and prefibrotic-early PM were an increased nucleo-cytoplasmic ratio, presence of cloudlike nuclei, hyperchromatic-dysplastic nuclei, paratrabecular megakaryocytes and tight clusters. A histological score discriminated between ET (score < or =3) and PM (score > or =6), but 21 cases showed an intermediate ambiguous score. No significant differences were observed at diagnosis and at follow-up (median time 93 months) for thrombosis, major haemorrhage, laboratory data, transformation into overt myeloid metaplasia and survival. CONCLUSIONS: The distinction between ET and prefibrotic-early PM is impaired by subjectivity in pathological practice and is of questionable clinical relevance, at least when considering individual patients.

Leukemic evolution of polycythemia vera and essential thrombocythemia: genomic profiles predict time to transformation.

Among myeloproliferative neoplasms, polycythemia vera (PV) and essential thrombocythemia (ET) are the 2 entities associated with the most chronic disease course. Leukemic evolution occurs rarely but has a grim prognosis. The interval between diagnosis and leukemic evolution is highly variable, from a few years to >20 years. We performed a molecular evaluation of 49 leukemic transformations of PV and ET by targeted next-generation sequencing. Using a hierarchical classification, we identified 3 molecular groups associated with a distinct time to leukemic transformation. Short-term transformations were mostly characterized by a complex molecular landscape and mutations in IDH1/2, RUNX1, and U2AF1 genes, whereas long-term transformations were associated with mutations in TP53, NRAS, and BCORL1 genes. Studying paired samples from chronic phase and transformation, we detected some mutations already present during the chronic phase, either with a significant allele burden (short-term transformation) or with a very low allele burden (especially TP53 mutations). However, other mutations were not detected even 1 year before leukemic transformation. Our results suggest that the leukemic transformation of PV and ET may be driven by distinct time-dependent molecular mechanisms.

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.

Thalidomide versus placebo in myeloid metaplasia with myelofibrosis: a prospective, randomized, double-blind, multicenter study.

BACKGROUND AND OBJECTIVES: In non-randomized studies, thalidomide appeared to be effective in myeloid metaplasia with myelofibrosis (MMM). We compared thalidomide to placebo for treatment of anemia in MMM. DESIGN AND METHODS: A prospective phase II B, randomized double-blind multicenter trial comparing thalidomide 400 mg/d with placebo for 180 days was conducted in 52 anemic patients (hemoglobin pounds Sterling 9 g/dL or transfused). The main outcome measure was a 2 g/L increase in hemoglobin or 20% reduction in transfusions. RESULTS: In the thalidomide group only 10 patients completed 6 months of treatment. At 180 days, in an intention-to-treat analysis, no difference was observed between the thalidomide and placebo groups as regards improvement of hemoglobin levels (one patient in each group) or reduction of red blood cell transfusions (three vs five patients, respectively). The spleen size, determined by ultrasonography, increased significantly less in the thalidomide group than in the placebo group (p < 0.05). Thalidomide had no apparent benefit on the Dupriez score, the severity score, survival, death, or any other clinical or biological parameter. Somnolence, gastro-intestinal signs, weight gain, and edema were significantly more frequent in the thalidomide group. Outpatient discontinuation of thalidomide was significantly correlated with a high severity score > 4 (odds ratio, OR = 16; p < 0.01), and g-glutamyl transferase levels > 40 IU/L (OR = 12; p < 0.05). INTERPRETATION AND CONCLUSIONS: Thalidomide (200-400 mg/d) does not demonstrate substantial efficacy in anemic MMM patients. The natural history of disease in the placebo group revealed spontaneous periods of remission of anemia. Tolerance of thalidomide was significantly correlated wih the severity and liver involvement of the disease.