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Claire N. Harrison

Other affiliations: St Thomas' Hospital, National Health Service, Queensland Health  ...read more
Bio: Claire N. Harrison is an academic researcher from Guy's and St Thomas' NHS Foundation Trust. The author has contributed to research in topics: Ruxolitinib & Myelofibrosis. The author has an hindex of 66, co-authored 424 publications receiving 19843 citations. Previous affiliations of Claire N. Harrison include St Thomas' Hospital & National Health Service.


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Journal ArticleDOI
TL;DR: Somatic mutations in the endoplasmic reticulum chaperone CALR were found in a majority of patients with myeloproliferative neoplasms with nonmutated JAK2, a finding consistent with its role as an initiating mutation in some patients.
Abstract: Background Somatic mutations in the Janus kinase 2 gene (JAK2) occur in many myeloproliferative neoplasms, but the molecular pathogenesis of myeloproliferative neoplasms with nonmutated JAK2 is obscure, and the diagnosis of these neoplasms remains a challenge. Methods We performed exome sequencing of samples obtained from 151 patients with myeloproliferative neoplasms. The mutation status of the gene encoding calreticulin (CALR) was assessed in an additional 1345 hematologic cancers, 1517 other cancers, and 550 controls. We established phylogenetic trees using hematopoietic colonies. We assessed calreticulin subcellular localization using immunofluorescence and flow cytometry. Results Exome sequencing identified 1498 mutations in 151 patients, with medians of 6.5, 6.5, and 13.0 mutations per patient in samples of polycythemia vera, essential thrombocythemia, and myelofibrosis, respectively. Somatic CALR mutations were found in 70 to 84% of samples of myeloproliferative neoplasms with nonmutated JAK2, in 8...

1,529 citations

Journal ArticleDOI
TL;DR: Continuous ruxolitinib therapy, as compared with the best available therapy, was associated with marked and durable reductions in splenomegaly and disease-related symptoms, improvements in role functioning and quality of life, and modest toxic effects.
Abstract: Background Treatment options for myelofibrosis are limited. We evaluated the efficacy and safety of ruxolitinib, a potent and selective Janus kinase (JAK) 1 and 2 inhibitor, as compared with the best available therapy, in patients with myelofibrosis. Methods We assigned 219 patients with intermediate-2 or high-risk primary myelofibrosis, post–polycythemia vera myelofibrosis, or post–essential thrombocythemia myelofi brosis to receive oral ruxolitinib or the best available therapy. The primary end point and key secondary end point of the study were the percentage of patients with at least a 35% reduction in spleen volume at week 48 and at week 24, respectively, as assessed with the use of magnetic resonance imaging or computed tomography. Results A total of 28% of the patients in the ruxolitinib group had at least a 35% reduction in spleen volume at week 48, as compared with 0% in the group receiving the best available therapy (P<0.001); the corresponding percentages at week 24 were 32% and 0% (P<0.001). At 48 weeks, the mean palpable spleen length had decreased by 56% with ruxolitinib but had increased by 4% with the best available therapy. The median duration of response with ruxolitinib was not reached, with 80% of patients still having a response at a median follow-up of 12 months. Patients in the ruxolitinib group had an improvement in overall quality-of-life measures and a reduction in symptoms associated with myelofibrosis. The most common hematologic abnormalities of grade 3 or higher in either group were thrombocytopenia and anemia, which were managed with a dose reduction, interruption of treatment, or transfusion. One patient in each group discontinued treatment owing to thrombocytopenia, and none discontinued owing to anemia. Nonhematologic adverse events were rare and mostly grade 1 or 2. Two cases of acute myeloid leukemia were reported with the best available therapy. Conclusions Continuous ruxolitinib therapy, as compared with the best available therapy, was associated with marked and durable reductions in splenomegaly and disease-related symptoms, improvements in role functioning and quality of life, and modest toxic effects. An influence on overall survival has not yet been shown. (Funded by Novartis Pharmaceuticals; ClinicalTrials.gov number, NCT00934544.)

1,483 citations

Journal ArticleDOI
TL;DR: Four somatic gain-of-function mutations affecting JAK2 exon 12 define a distinctive myeloproliferative syndrome that affects patients who currently receive a diagnosis of polycythemia vera or idiopathic erythrocytosis.
Abstract: BACKGROUND The V617F mutation, which causes the substitution of phenylalanine for valine at position 617 of the Janus kinase (JAK) 2 gene (JAK2), is often present in patients with polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. However, the molecular basis of these myeloproliferative disorders in patients without the V617F mutation is unclear. METHODS We searched for new mutations in members of the JAK and signal transducer and activator of transcription (STAT) gene families in patients with V617F-negative polycythemia vera or idiopathic erythrocytosis. The mutations were characterized biochemically and in a murine model of bone marrow transplantation. RESULTS We identified four somatic gain-of-function mutations affecting JAK2 exon 12 in 10 V617F-negative patients. Those with a JAK2 exon 12 mutation presented with an isolated erythrocytosis and distinctive bone marrow morphology, and several also had reduced serum erythropoietin levels. Erythroid colonies could be grown from their blood samples in the absence of exogenous erythropoietin. All such erythroid colonies were heterozygous for the mutation, whereas colonies homozygous for the mutation occur in most patients with V617F-positive polycythemia vera. BaF3 cells expressing the murine erythropoietin receptor and also carrying exon 12 mutations could proliferate without added interleukin-3. They also exhibited increased phosphorylation of JAK2 and extracellular regulated kinase 1 and 2, as compared with cells transduced by wild-type JAK2 or V617F JAK2. Three of the exon 12 mutations included a substitution of leucine for lysine at position 539 of JAK2. This mutation resulted in a myeloproliferative phenotype, including erythrocytosis, in a murine model of retroviral bone marrow transplantation. CONCLUSIONS JAK2 exon 12 mutations define a distinctive myeloproliferative syndrome that affects patients who currently receive a diagnosis of polycythemia vera or idiopathic erythrocytosis.

1,218 citations

Journal ArticleDOI
TL;DR: Hydxyurea plus low-dose aspirin is superior to anagrelideplus low- dose aspirin for patients with essential thrombocythemia at high risk for vascular events.
Abstract: background We conducted a randomized comparison of hydroxyurea with anagrelide in the treatment of essential thrombocythemia. methods A total of 809 patients with essential thrombocythemia who were at high risk for vascular events received low-dose aspirin plus either anagrelide or hydroxyurea. The composite primary end point was the actuarial risk of arterial thrombosis (myocardial infarction, unstable angina, cerebrovascular accident, transient ischemic attack, or peripheral arterial thrombosis), venous thrombosis (deep-vein thrombosis, splanchnicvein thrombosis, or pulmonary embolism), serious hemorrhage, or death from thrombotic or hemorrhagic causes. results After a median follow-up of 39 months, patients in the anagrelide group were significantly more likely than those in the hydroxyurea group to have reached the primary end point (odds ratio, 1.57; 95 percent confidence interval, 1.04 to 2.37; P=0.03). As compared with hydroxyurea plus aspirin, anagrelide plus aspirin was associated with increased rates of arterial thrombosis (P=0.004), serious hemorrhage (P=0.008), and transformation to myelofibrosis (P=0.01) but with a decreased rate of venous thromboembolism (P=0.006). Patients receiving anagrelide were more likely to withdraw from their assigned treatment (P<0.001). Equivalent long-term control of the platelet count was achieved in both groups.

793 citations

Journal ArticleDOI
TL;DR: A review of critical concepts and recommendations on the management of Philadelphia-negative classical myeloproliferative neoplasms, including monitoring, response definition, first- and second-line therapy, and therapy for special issues are presented.
Abstract: We present a review of critical concepts and produce recommendations on the management of Philadelphia-negative classical myeloproliferative neoplasms, including monitoring, response definition, fi ...

731 citations


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29 Sep 2017
TL;DR: Thank you very much for reading who classification of tumours of haematopoietic and lymphoid tissues, and maybe you have knowledge that, people have look hundreds of times for their chosen readings like this, but end up in malicious downloads.
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30 Jul 2009-Blood
TL;DR: The classification of myeloid neoplasms and acute leukemia is highlighted with the aim of familiarizing hematologists, clinical scientists, and hematopathologists not only with the major changes in the classification but also with the rationale for those changes.

4,274 citations

Journal ArticleDOI
TL;DR: Genetic evidence and in vitro functional studies indicate that V617F gives hematopoietic precursors proliferative and survival advantages and a high proportion of patients with myeloproliferative disorders carry a dominant gain-of-function mutation of JAK2.
Abstract: background Polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis are clonal myeloproliferative disorders arising from a multipotent progenitor. The loss of heterozygosity (LOH) on the short arm of chromosome 9 (9pLOH) in myeloproliferative disorders suggests that 9p harbors a mutation that contributes to the cause of clonal expansion of hematopoietic cells in these diseases. methods We performed microsatellite mapping of the 9pLOH region and DNA sequencing in 244 patients with myeloproliferative disorders (128 with polycythemia vera, 93 with essential thrombocythemia, and 23 with idiopathic myelofibrosis). results Microsatellite mapping identified a 9pLOH region that included the Janus kinase 2 ( JAK2 )

3,391 citations

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TL;DR: HIF plays a central role in the transcriptional response to changes in oxygen availability and is modulated by FIH1-mediated asparagine hydroxylation, and HIF-modulatory drugs are now being developed for diverse diseases.

2,623 citations

Journal ArticleDOI
09 Feb 2017-Cell
TL;DR: It is suggested that bold approaches to drug development, harnessing the adaptive properties of the immune-microenvironment while limiting those of the tumor, combined with advances in clinical trial-design, will improve patient outcome.

1,800 citations