Clinical and Biological Characteristics According to the Burden of JAK2V617F Mutated Allele in BCR-ABL Negative MPNs

Abstract Abstract 1437 JAK2 mutation testing and karyotye are routinely used for diagnosis of myeloproliferative neoplasms (MPNs) but they have not been incorporated into risk stratification. Although JAK2V617F mutation in MPNs has been one of the most seminal medical discoveries in recent years, it is not clear the importance of the amount of JAK2V617F allele. Some studies correlate the JAK2 allele burden with a higher hemoglobin level, leukocyte count, splenomegaly and thrombosis and more probability of transformation to MF or AML. The aim of this study was to determine whether cytogenetic data, JAK2 mutation status and allele burden correlates with cytological subtypes, clinical complications or provide prognostic information. Methods A retrospective study was conducted with samples centralized in a unique laboratory since 2005. A total of 526 patients were included (median age 63; 243 males) with classic MPNs (348 ET, 135 PV, 43 PMF) fulfilling 2008 WHO criteria and in accordance with the Declaration of Helsinki. Conventional cytogenetic was performed in bone marrow samples obtained at diagnosis (n=205) and at progression to MF or AML (n=46). DNA was extracted from peripheral blood using QIAamp DNA mini kit (Qiagen). All samples were coded and assayed blindly in duplicate to detect JAK2V617F mutation with an allele-specific PCR using TaqMan allelic discrimination, with 2 specific probes to measure the respective fluorescence of each allele. Then, JAK2 MutaQuant assay (Ipsogen, Luminy Biotech) was used to detect the JAK2V617F quantity by real-time PCR, detecting fluorescent signals using double-dye hyrolysis oligonucleotide probes with calibration standards at 4 different concentrations. Homozygous (HOZ) ratio was considered when percentage was higher than 50. Laboratory (hemoglobin, WBC and platelet counts) and clinical data (constitutional symptoms, splenomegaly, complications, OS and DFS) were collected. For continuous variables parametric and non parametric statistics were used. Survival analysis was performed using Kaplan-Meier estimate and log-rank tests were used for comparisons. The χ2 and Fisher's exact tests were used to analyze differences in the distribution of variables among patient subsets. p-value less than 0.05 were considered statistically significant. Results Aberrant karyotypes were seen in 15/205 (7%) cases at diagnosis (4% in ET and PV and 40% in PMF). At progression to MF or AML we have cytogenetic studies in 22 patients, and 10 (45%) harbor alterations. A total of 283 patients (64%) were JAK2V617F, 61% ET (4% HOZ), 75% PV (28% HOZ) and 55% PMF (16% HOZ). The median value of JAK2V617F was 26% (range, 1–99.9%). No correlation was seen between JAK2 and karyotype at diagnosis, but 7/9 patients with aberrant karyotype at progression had JAK2V617F mutation. JAK2 correlations with laboratory and clinical data are summarized in Table 1 and 2. Conclusions JAK2V617F is associated with a more pronounced myeloproliferative phenotype (higher hemoglobin level, platelet or leukocyte count). Patients with JAK2V617F HOZ have a higher probability of splenomegaly. Hematological complications do not depend on JAK2 ratio but mutated patients have more probability of thrombosis or hemorrhage. OS and PFS do not depend on JAK2 status, but patients with JAK2V617F heterozygous seem to have a slightly better outcome. Disclosures: No relevant conflicts of interest to declare.

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Latent Myeloproliferative Neoplasm May Underlie Retinal Vein Occlusion In Older Patients

Blood ◽

10.1182/blood.v122.21.5242.5242 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5242-5242

Author(s):

Katerina Zoi ◽

Christine Zoi ◽

Andreas Giannopoulos ◽

Argyri Gialeraki ◽

Kassiani Giannaki ◽

...

Keyword(s):

Retinal Vein Occlusion ◽

Older Patients ◽

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Significant Risk ◽

Jak2v617f Mutation ◽

Thrombotic Complication ◽

Allele Burden ◽

Vein Occlusion ◽

Increased Risk

Abstract Background Myeloproliferative neoplasms (MPNs) have been associated with a high incidence of thrombosis and bleeding episodes, which significantly contribute to disease-related morbidity and mortality. Clinical data indicate an association of the JAK2V617F mutation, seen in nearly all polycythemia vera (PV) cases and almost 60% of those with essential thrombocythemia (ET) and myelofibrosis (MF). The mutation is also seen in 37% of patients with in splachnic vein thrombosis (SVT) and its presence was associated with an increased risk for SVT. However, the prevalence of JAK2V617 seems to be low in patients with other thromboembolic events in unusual sites such as cerebral sinus, upper limb deep venous thrombosis (DVT). Additionally, activating mutations of MPL gene, seen in 3% of ET and 5% of MF patients, are considered as a significant risk factor for microvessel disturbances and have been associated with an increased risk of arterial thrombosis. Retinal vein occlusion (RVO) is a thrombotic complication in an uncommon site that may result in sight threatening disease. In this study we investigated the prevalence of JAK2V617F and MPLW515L/K mutations in a prospectively assembled cohort of patients with RVO, hypothesizing that some cases may be associated with an underlying undiagnosed MPN. Patients and Methods We studied 52 (23 males and 29 females) consecutive patients with no evidence of an underlying MPN who had been diagnosed with RVO confirmed with fluorangiography from January 2007 to September 2011. The mean age was 70 years (range: 49-85) Twenty eight patients (53.8%) presented with central RVO and 24 patients with branched RVO (46.5%). DNA was extracted from peripheral blood samples by standard procedures. The JAK2V617F mutation was detected using a tetra-primer amplification refractory mutation system (ARMS) polymerase chain reaction (PCR) assay with a sensitivity of 1% and the allele burden was estimated with a semi-quantitative method. MPLW515L/K were detected using allele-specific PCR (AS-PCR) assays with a sensitivity of 1%. Results Overall, MPN associated mutations were detected in 5/52 cases. JAK2V617F was detected in 2/52 cases (3.8%; 95%CI-1.4%-9%), while MPL exon 10 mutations were detected in 3/52 (5.7%; 95%CI-0.6%-12%). The JAK2V617F allele burden in the two positive patients was 45% and 52% respectively. Both patients who carried the JAK2V617F mutation were female. The first patient had been already diagnosed with ET according to the WHO criteria at the time of RVO screening. She was receiving hydroxyurea and aspirin and her platelet count was normal. The second patient who also carried the JAK2V617F mutation had a PLT count of 850.000/μl at the time of screening and was diagnosed with ET within the 3 following months. The patients with MPL mutations presented with normal blood counts. Conclusions Our findings indicate that a latent MPN could underlie RVO even in the absence of conventional diagnostic criteria. Our results represent the first report that MPL mutations could underlie RVO cases and suggest that routine screening of RVO cases for MPN mutations may be useful, especially in older patients. Disclosures: No relevant conflicts of interest to declare.

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Clinical Relevance of JAK2V617F Allele Burden in Primary and Post-Polycythemic/Post-Thrombocythemic Myelofibrosis

Blood ◽

10.1182/blood.v112.11.2799.2799 ◽

2008 ◽

Vol 112 (11) ◽

pp. 2799-2799

Author(s):

Paola Guglielmelli ◽

Giovanni Barosi ◽

Alessandro Pancrazzi ◽

Giovanni Longo ◽

Elisabetta Antonioli ◽

...

Keyword(s):

Multivariate Analysis ◽

Clinical Relevance ◽

Leukocyte Count ◽

Group Analysis ◽

Hemoglobin Level ◽

Jak2v617f Mutation ◽

Risk Category ◽

Allele Burden ◽

Mutational Status

Abstract The JAK2V617F mutation is found in 60% of patients (pts) with primary myelofibrosis (PMF) and >90% with post-polycythemia vera MF (PPV-MF); few pts with post-essential thrombocythemia MF (PET-MF) have been reported. There are conflicting results about clinical relevance of V617F mutational status and/or burden in PMF, while no study specifically addressed this point yet in PPV/PET-MF. An association of mutation with poorer survival in PMF has been reported (Campbell P et al, Blood, 2006), while Tefferi A et al (Leukemia, 2008) found a reduced survival only for pts with lowest allele burden. Barosi G et al (Blood, 2007) found that JAK2V617F mutation independently predicted evolution towards large splenomegaly, splenectomy and leukemic transformation. We separately evaluated 2 groups of pts, 240 pts with PMF and 65 pts with secondary forms of MF (PPV-MF n=43, PET-MF n=22); the V617F allele burden was measured in granulocytes by RT-PCR. Diagnosis of PMF satisfied the 2008 WHO criteria, and that of PPV- or PET-MF the IWG-MRT criteria. PMF: 150 pts (63%) were JAK2V617F-pos, median V617F allele burden 45% (range, 1–100%); percentage of pts in the four allele quartiles was 16%, 50%, 15%, and 19%. Median interval from diagnosis to genotyping was 21 months. In multivariate analysis, JAK2V617F mutated patients had significantly higher leukocyte count (P=.02) and hemoglobin level (P<.0001), that were both positively correlated with V617F burden (P= .03 and P=.01, respectively). Pts with Hb <10g/dL were significantly less among JAK2V617-pos (12% vs 26%; P<.007), accounting for a significantly greater proportion of mutated pts in the Lille low risk category (P=.04). Nor a mutated JAK2 genotype nor the V617F burden had any influence on presence or degree of palpable splenomegaly, thrombosis, hemorrhage, AML evolution, or cytoreductive treatment. 29 pts died (12.0%); survival was independent of JAK2 genotype, and was associated (multivariate analysis) only with age (95% CI, 1.07–1.18) and leukocyte count (95% CI, 1.02–1.10). Since we previously observed a time-dependent accumulation of mutated alleles in PMF, we performed a sub-group analysis in 90 pts in whom quantitation of V617F burden was performed within six months from diagnosis: 56 pts (62%) were mutated, median V617F burden was 36% (range, 10–100%); percentage of pts in the four allele quartiles was 27%, 50%, 16%, and 7%. Similar to the whole pts series, the only parameters significantly associated with allele burden were hemoglobin level, (P=.03), leukocyte count (P=.04) and low Lille score (P=.04). However, we found a statistically significant association (multivariate analysis) of lowest V617F burden quartile with shortened survival compared to patients having greater than 25% V617F allele or to JAK2V671F unmutated patients, corroborating finding from Tefferi et al (Leukemia, 2008). Using Cox analysis, reduced survival was associated with low V617F burden (P=.008), leukocytosis (P=−003) and age (P=.03). These findings indicate that a low V617F burden, measured at the time of diagnosis, has a negative impact on survival, and might represent a novel criterion for risk stratification in PMF. PPV/PET-MF: 49 pts (75.3%) were JAK2V617F mutated, median V617F allele burden 73% (10–100%). All 43 PPV-MF were mutated compared to 6/22 (27%) of PET-MF (P<.01). Median V617F burden was significantly greater in PPV-MF than in 173 control PV pts (72% vs 52%; P<.01), as well as in PET-MF (57% vs 26% in 200 control ET pts; P<.001), supporting that accumulation of V617F alleles is a mechanism of evolution toward MF in JAK2V617F-positive PV or ET pts. However, since JAK2V617F mutation frequency was significantly lower in PET-MF pts (27.2%) than in ET pts (63.4%; P<.01), genetic mechanisms other than JAK2V617F may have a dominant role in MF transformation of ET. A part for lower platelet count (P=.04) in JAK2V617F-pos PPV/PET-MF pts no other difference with unmutated pts was found. In the analysis of quartiles, we found a correlation of allele burden with age, leukocyte count and circulating CD34+ cell count (all P<.05), while there was no impact on clinical characteristics including spleen size, thrombosis, hemorrhage, AML transformation or overall survival (median follow-up, 40 months). Therefore, both presence and burden of JAK2V617F seem to have little influence on disease phenotype in pts with PPV- or PET-MF, although larger series and longer follow-up might be warranted.

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The JAK2 46/1 Haplotype Analysis In Essential Thrombocythaemia and Polycythaemia Rubra Vera Reveals That CC Genotype Is Associated with a Higher JAK2V617F and c-MPL W515 Allele Burden

Blood ◽

10.1182/blood.v116.21.1977.1977 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1977-1977

Author(s):

Shameem Mahmood ◽

Louise Mellish ◽

Nicholas Lea ◽

Austin G Kulasekararaj ◽

Atiyeh Abdallah ◽

...

Keyword(s):

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Association Studies ◽

Statistical Significance ◽

Jak2 V617f ◽

Tagging Snp ◽

Jak2 Mutation ◽

Allele Burden ◽

Significant Difference ◽

Jak2v617f Allele Burden

Abstract Abstract 1977 First 2 authors contributed equally. Background: Genomic-wide association studies have identified the germline 46/1 haplotype as a predisposing allele associated with JAK2V617F positive myeloproliferative neoplasms (MPN). The present study analysed data on 856 JAK2V617F positive patients, 326 of which had complete clinical data. Aims: To evaluate the JAK2 46/1 haplotype frequencies, JAK2V617F allele burden, c-MPL 515 mutation and risk of transformation. Methods: Genomic DNA from whole peripheral blood or bone marrow patient samples was analysed as follows: JAK2V617F allele burden by Q-PCR, JAK2 exon 12 mutations by Q-PCR and PCR fragment analysis, MPL W515 L and K mutations by allele specific PCR. The 46/1 JAK2 mutation susceptibility haplotype (46/1) tagging SNP rs12343867 (susceptibility allele C) were analysed by pyrosequencing. Results: The allele frequency for the 46/1 tag SNP rs1234867 in the 856 patients was calculated for the total JAK2V617F cohort (0.48) and the clinical entities ET (0.34) and PRV (0.44) confirming that the 46/1 haplotype is greatly over represented in JAK2V617F MPD patients as compared to published the control population (Wellcome Trust Case Control Consortium (WTCCC) (0.24). The Analysis of the 856 patients demonstrated that JAK2V617F and c-MPL W515L/K mutations co-existed in 16 patients(1.9%), the incidence of c-MPL W515L being twice as common as the c-MPL W515K mutations. There was no correlation between these mutations and age or 46/1 haplotype status. The JAK2V617F allele burden (AB) was lower in the c-MPL mutant patients, the average JAK2AB 31%. 3 out 4 c-MPL patients for which clinical information was available had a diagnosis of ET. No JAK2 exon 12 mutations were found in any of the 859 JAK2V617F positive samples suggesting that co-existing JAK2 exon 14 and exon 12 mutations are extremely rare. The genotypic data in ET patients showed: C/C 12%, C/T 44%, T/T 44% and their respective JAK2V617 allele burden (AB) were 46%, 32%, 29%. The genotype data in PRV patients: C/C 18%, C/T 53%, T/T 28.6% and their respective AB were 47%, 31% and 39%. The median AB was 32% (n=121) for ET and 37% (n=103) for PRV. Within a cohort of 255 patients (ET=138, PRV=117) 4% of ET and 6% of PRV patients transformed to acute myeloid leukaemia or myelofibrosis with no predominant haplotype association. In the ET patients, the median AB was 35%, there was no significant difference in the JAK2 V617F AB between those who transformed or not (p=0.45). Interestingly, on the whole ET group C/C genotype patients were more likely to have an allele burden >50% (p=0.058). In the PRV patients, the median AB was 48%. Again, the C/C genotype, PRV patients were more likely to have an AB>50% (p=0.06), although not reaching statistical significance. Conclusions: The 46/1 haplotype in both clinical entities ET and PRV demonstrated a higher allele burden in the C/C genotype in comparison to the other genotypes. No predominant haplotype predicted the risk of transformation to a more aggressive disease such as MF or AML. The analysis also showed that c-MPL W515K/L mutations can co-exist with JAK2V617F. The c-MPL W515K/L mutations did not exhibit a positive correlation with a preferential 46/1, but was associated with a lower allele burden. No co-existing exon 12 and exon 14 mutations were found, suggesting the rarity of this occurrence. Disclosures: No relevant conflicts of interest to declare.

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JAK2 Mutation Analysis and Function of Bone Marrow Mesenchymal Stem Cells in Myeloproliferative Neoplasms

Blood ◽

10.1182/blood.v118.21.5179.5179 ◽

2011 ◽

Vol 118 (21) ◽

pp. 5179-5179

Author(s):

Hong Tian ◽

Yang Xu ◽

Guanghua Chen ◽

Man Qiao ◽

Wu Depei

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Jak2v617f Mutation ◽

Primary Study ◽

Jak2 Mutation ◽

Healthy Donors ◽

Marrow Mesenchymal Stem Cells

Abstract Abstract 5179 Background: JAK2V617F and JAK2 exon12 mutations in haematopoietic cells were partially responsible for the pathogenesis of myeloproliferative neoplasms (MPN).But it was still unclear whether bone marrow mesenchymal stem cells (BMSCs), the significant component of hemopoiesis microenvironment, were participated in the pathogenesis of MPN. Objective: To study the physiopathology characteristics and analyze JAK2 mutation in BMSCs from MPN patients. Methods: By searched for the JAK2V617F mutation and exon 12 mutation in 135 MPN patients' blood /bone marrow samples, 20 patients with JAK2V617F mutation, 10 patients with JAK2 exon 12 mutation, 5 JAK2-mutation-negetive patients and 10 healthy donors were recruited. The phenotype, mesenchymal differentiation capacity, expression of hematopoietic and immune molecules and JAK2 mutation of isolated bone marrow BMSCs were detected. Results: BMSCs derived from the four groups were found to be similar in morphology, differentiation ability and expression of hematopoietic and immune molecules. Primary study indicated that the isolated BMSCs from patients groups were not able to harbor JAK2 mutation in spite of positive or negative JAK2 mutation in blood /bone marrow samples. Conclusion: BMSCs from MPN patients had similar biological characteristics to healthy donors, and BMSCs were not likely involved in pathogenesis of MPN. Disclosures: No relevant conflicts of interest to declare.

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Comparison of Real-Time PCR and Droplet Digital PCR for the Determination of JAK2V617F Mutation in Ph'-Negative Myeloproliferative Neoplasms

Blood ◽

10.1182/blood.v124.21.5548.5548 ◽

2014 ◽

Vol 124 (21) ◽

pp. 5548-5548

Author(s):

Giulia Fontanelli ◽

Claudia Baratè ◽

Elena Ciabatti ◽

Francesca Guerrini ◽

Riccardo Morganti ◽

...

Keyword(s):

Real Time ◽

Standard Method ◽

Real Time Pcr ◽

Myeloproliferative Neoplasms ◽

Digital Pcr ◽

Droplet Digital Pcr ◽

Jak2v617f Mutation ◽

Rt Pcr ◽

Jak2 Mutation ◽

Allele Burden

Abstract Myeloproliferative neoplasms (MPNs) are a group of clonal diseases associated with JAK2 mutation (V617F) in a percentage varying from 50% (Essential Thrombocytemia ET, and Primary Myelofibrosis PMF) to 95% (Polycitemia Vera, PV). The standard method for determining the V617F mutation is today represented by the Real Time PCR (RT-PCR). However, in recent years some studies have focused attention on a new method, the Droplet Digital PCR (DD-PCR), that allows an absolute quantitation of the mutated allele without any reference curve. The main objective of this study was the comparison of two PCR methods (RT-PCR and DD-PCR) for the analysis of the JAK2V617F mutation in order to assess the sensitivity, specificity and feasibility of the two techniques. In the study 225 patients with MPNs JAK2V617F-positive were enrolled; in 99 cases, DNA was still available for further assays and so DD-PCR tests were performed and compared with the results coming from RT-PCR (MutaQuant kit, Ipsogen, Luminy Biotech, Marseille, France). The results show a good sensitivity for both methods; nevertheless, after appropriate dilution tests, the DD-PCR was able to detect the JAK2V617F mutation in the 5x10-4 dilution versus 5x10-3 for the RT-PCR, in front of a fully comparable specificity. A linear regression analysis showed an absolute correlation between the 2 methods (R2=0.91), and the median mutated allele burden was not different when measured by the DD-PCR or the RT-PCR (p=0.67), with the highest median allele burden observed in secondary myelofibrosis (86% by RT-PCR and 91% by DD-PCR) and the lowest one in ET (23% by RT-PCR and 25% by DD-PCR) (see Figure 1 and Figure 2), as expected. Figure 1 Figure 1. Figure 2 Figure 2. Our study demonstrates that a new molecular technique, the DD-PCR, may represent a new frontier in the world of molecular techniques for the detection of JAK2 mutation with a high sensitivity and specificity. In addition the method allows obtain two types of information, qualitative and quantitative, with one analysis, saving time and at a lower cost than the standard method. Disclosures No relevant conflicts of interest to declare.

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The Behavior of Cytogenetic/Molecular Markers Associated with JAK2 Mutation Status Before and After Primary Myelofibrosis Progression Supports the Hypothesis of the Leukemic Clone's Independence From the JAK2 Mutation

Blood ◽

10.1182/blood.v120.21.5058.5058 ◽

2012 ◽

Vol 120 (21) ◽

pp. 5058-5058

Author(s):

Francesco Albano ◽

Antonella Zagaria ◽

Luisa Anelli ◽

Nicoletta Coccaro ◽

Giuseppina Tota ◽

...

Keyword(s):

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Chronic Phase ◽

Primary Myelofibrosis ◽

Jak2v617f Mutation ◽

Wild Type ◽

Jak2 Mutation ◽

Cytogenetic Abnormalities ◽

Qrt Pcr ◽

Leukemic Clone

Abstract Abstract 5058 Leukemic transformation has been reported in 15–30% of primary myelofibrosis (PMF). However, very little is known about the molecular bases responsible for acute myeloid leukemia (AML) transformation. JAK2 status analysis of paired chronic myeloproliferative neoplasms (MPN) and AML samples showed that during AML transformation the JAK2 mutation could be lost. Two probable models have been proposed to explain the MPN evolution to AML: a) JAK2-mutated AML usually arose from PMF or myelofibrotic transformation of ET/PV as a consequence of genetic instability conferred by the presence of JAK2 mutations; b) JAK2 wild-type AML generally developed in patients with chronic-phase ET or PV, frequently as a consequence of a clone selection driven by the therapy (Thoennissen NH et al. Blood 2010, 115:2882; Beer PA et al., Blood 2010, 115:2891; Spivak JL, Blood 2010, 115:2727). In this report we describe two PMF cases with the JAK2V617F mutation associated with molecular/cytogenetic abnormalities who developed JAK2-wild type AML characterized by a leukemic clone bearing a new cytogenetic aberration. At the PMF diagnosis, Case #1 showed a normal karyotype 46, XY[20] and resulted JAK2V617F positive. Molecular analyses performed at the time of AML transformation revealed the presence of a JAK2V617F negative clone bearing a novel t(12;18)(p13;q12) rearrangement. As the t(12;18) breakpoints were located centromerically to SETBP1 (18q12. 3), quantitative real-time PCR (qRT-PCR) experiments were made, showing SETBP1 overexpression. To investigate the occurrence of SETBP1 dysregulation and the presence of t(12;18) at PMF onset, qRT-PCR and Fluorescence in situ hybridization were performed, revealing gene overexpression and absence of the chromosomal translocation, respectively. At PMF onset, Case #2 harbored a novel t(3;5)(q27. 1;q31. 1) in addition to the JAK2V617F mutation. At the time of AML evolution, disappearance of the t(3;5)(q27. 1;q31. 1) and leukemic clone expansion of t(3;3)(q21. 3;q26. 2) was associated with disappearance of the JAK2V617F mutation. In contrast to literature data showing that JAK2 mutation loss is commonly associated with AML transformation after PV and ET, our findings suggest that evolution to JAK2-wild type AML could also occur in JAK2V617F PMF patients. The presence of different cytogenetic abnormalities associated with PMF and AML allowed us to follow the sequence of molecular events that lead to JAK2V617F disappearance, indicating that MPN and AML are clonally unrelated and probably generated by the transformation of different stem cell levels. Moreover, the well-documented clonal heterogeneity landscape in our cases demonstrated that the genomic instability responsible for AML transformation already existed at PMF onset and was not generated either by JAK2V617F mutation expression or by the therapy. Disclosures: No relevant conflicts of interest to declare.

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POS0619 MODELLING OF DISEASE ACTIVITY IN PATIENTS WITH INFLAMMATORY ARTHROPATHIES TREATED WITH ETANERCEPT ORIGINATOR OR BIOSIMILAR AS FIRST-LINE BIOLOGIC IN AN AUSTRALIAN REAL-WORLD DATASET

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.2265 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 547.1-547

Author(s):

C. Deakin ◽

G. Littlejohn ◽

H. Griffiths ◽

T. Smith ◽

C. Osullivan ◽

...

Keyword(s):

Disease Activity ◽

Clinical Data ◽

Real World ◽

Rank Test ◽

P Value ◽

Continuous Variables ◽

Linear Quadratic ◽

First Line ◽

Modest Improvement ◽

Over Time

Background:The availability of biosimilars as non-proprietary versions of established biologic disease-modifying anti-rheumatic drugs (bDMARDs) is enabling greater access for patients with rheumatic diseases to effective medications at a lower cost. Since April 2017 both the originator and a biosimilar for etanercept (trade names Enbrel and Brenzys, respectively) have been available for use in Australia.Objectives:[1]To model effectiveness of etanercept originator or biosimilar in reducing Disease Activity Score 28-joint count C reactive protein (DAS28CRP) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) or ankylosing spondylitis (AS) treated with either drug as first-line bDMARD[2]To describe persistence on etanercept originator or biosimilar as first-line bDMARD in patients with RA, PsA or ASMethods:Clinical data were obtained from the Optimising Patient outcomes in Australian rheumatoLogy (OPAL) dataset, derived from electronic medical records. Eligible patients with RA, PsA or AS who initiated etanercept originator (n=856) or biosimilar (n=477) as first-line bDMARD between 1 April 2017 and 31 December 2020 were identified. Propensity score matching was performed to select patients on originator (n=230) or biosimilar (n=136) with similar characteristics in terms of diagnosis, disease duration, joint count, age, sex and concomitant medications. Data on clinical outcomes were recorded at 3 months after baseline, and then at 6-monthly intervals. Outcomes data that were missing at a recorded visit were imputed.Effectiveness of the originator, relative to the biosimilar, for reducing DAS28CRP over time was modelled in the matched population using linear mixed models with both random intercepts and slopes to allow for individual heterogeneity, and weighting of individuals by inverse probability of treatment weights to ensure comparability between treatment groups. Time was modelled as a combination of linear, quadratic and cubic continuous variables.Persistence on the originator or biosimilar was analysed using survival analysis (log-rank test).Results:Reduction in DAS28CRP was associated with both time and etanercept originator treatment (Table 1). The conditional R-squared for the model was 0.31. The average predicted DAS28CRP at baseline, 3 months, 6 months, 9 months and 12 months were 4.0 and 4.4, 3.1 and 3.4, 2.6 and 2.8, 2.3 and 2.6, and 2.2 and 2.4 for the originator and biosimilar, respectively, indicating a clinically meaningful effect of time for patients on either drug and an additional modest improvement for patients on the originator.Median time to 50% of patients stopping treatment was 25.5 months for the originator and 24.1 months for the biosimilar (p=0.53). An adverse event was the reason for discontinuing treatment in 33 patients (14.5%) on the originator and 18 patients (12.9%) on the biosimilar.Conclusion:Analysis using a large national real-world dataset showed treatment with either the etanercept originator or the biosimilar was associated with a reduction in DAS28CRP over time, with the originator being associated with a further modest reduction in DAS28CRP that was not clinically significant. Persistence on treatment was not different between the two drugs.Table 1.Respondent characteristics.Fixed EffectEstimate95% Confidence Intervalp-valueTime (linear)0.900.89, 0.911.5e-63Time (quadratic)1.011.00, 1.011.3e-33Time (cubic)1.001.00, 1.007.1e-23Originator0.910.86, 0.960.0013Acknowledgements:The authors acknowledge the members of OPAL Rheumatology Ltd and their patients for providing clinical data for this study, and Software4Specialists Pty Ltd for providing the Audit4 platform.Supported in part by a research grant from Investigator-Initiated Studies Program of Merck & Co Inc, Kenilworth, NJ, USA. The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck & Co Inc, Kenilworth, NJ, USA.Disclosure of Interests:Claire Deakin: None declared, Geoff Littlejohn Consultant of: Over the last 5 years Geoffrey Littlejohn has received educational grants and consulting fees from AbbVie, Bristol Myers Squibb, Eli Lilly, Gilead, Novartis, Pfizer, Janssen, Sandoz, Sanofi and Seqirus., Hedley Griffiths Consultant of: AbbVie, Gilead, Novartis and Lilly., Tegan Smith: None declared, Catherine OSullivan: None declared, Paul Bird Speakers bureau: Eli Lilly, abbvie, pfizer, BMS, UCB, Gilead, Novartis

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Is JAK2 Inducible by Cytotoxic Chemotherapy?

Blood ◽

10.1182/blood.v114.22.4979.4979 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4979-4979

Author(s):

Edmond A. Bendaly ◽

Saud S. Rahman ◽

Samiah Zafar ◽

Karen Haglof ◽

Sherif Ibrahim ◽

...

Keyword(s):

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Case Reports ◽

Lymphoblastic Leukemia ◽

Myeloproliferative Neoplasm ◽

Cytotoxic Chemotherapy ◽

Jak2v617f Mutation ◽

Platinum Based Chemotherapy ◽

History Of ◽

Increased Susceptibility

Abstract Abstract 4979 Introduction The JAK2V617F mutation accounts for most cases of myeloproliferative neoplasms (MPN). Only a few case reports of MPN following cytotoxic chemotherapy have been reported, and all of them were published prior to the discovery of the JAK2V617F mutation. We report a series of 6 patients who developed a JAK2V617F positive MPN following cytotoxic chemotherapy. Patients From 2006 to 2009, 6 patients with a history of a hematologic or an oncologic malignancy who developed an MPN were identified and their medical records retrospectively reviewed. One patient had acute lymphoblastic leukemia, 1 had Hodgkin lymphoma, 1 had squamous cell carcinoma of the head and neck, 1 had cervical cancer, and 2 had breast cancer. All patients were in remission from their primary malignancies at the time the MPN was diagnosed. Five were females. The median age at diagnosis was 72 years. Median time to development of the myeloproliferative neoplasm was 14 years. Type of chemotherapy exposure, MPN diagnosis and time to MPN in each case is shown in the table below. The JAK2V617F mutation was detected either in the peripheral blood or the bone marrow of all patients. There was no predominance of any specific MPN diagnosis. Patients who received platinum-based chemotherapy developed the MPN sooner than those who received alkylators (6 vs 17.5 years respectively). Treatment consisted of phlebotomy, hydroxyurea, anagrelide, aspirin or a combination as deemed appropriate by the treating hematologist. Conclusion These findings lead us to hypothesize whether the development of JAK2V617F positive MPN may be related to prior exposure to cytotoxic chemotherapy. Exposure to platinum-based chemotherapy may cause the disorder to appear sooner compared with exposure to alkylators. Recently, JAK2V617F positive MPN was found to be strongly associated with a specific constitutional haplotype, 46/11 suggesting increased susceptibility to this mutation. Chromosomal analyses are planned to show whether any of the reported patients exhibit this haplotype. Ref: 1.Jones et al, Nat Genet. 2009 Apr;41(4):446-9. 2009 Mar 15. The authors have no relevant disclosure. Disclosures No relevant conflicts of interest to declare.

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Epigenomic Profiling of Myeloproliferative Diseases Reveal Idiopathic Myelofibrosis as An Epigenetically Distinct Subgroup and Highlights the Epigenetic Effects of Jak2V617F Mutation

Blood ◽

10.1182/blood.v116.21.627.627 ◽

2010 ◽

Vol 116 (21) ◽

pp. 627-627

Author(s):

Sangeeta Nischal ◽

Li Zhou ◽

Yiting Yu ◽

Tushar Bhagat ◽

Yongkai Mo ◽

...

Keyword(s):

Map Kinases ◽

Conflicts Of Interest ◽

Jak2v617f Mutation ◽

Striking Difference ◽

Idiopathic Myelofibrosis ◽

Jak2 Mutation ◽

Global Methylation ◽

Distinct Subgroup ◽

Global Hypomethylation ◽

Myeloproliferative Diseases

Abstract Abstract 627 Myeloproliferative diseases (MPD) are clonal hematologic disorders that present with increased numbers of functional, mature, terminally differentiated myeloid elements. Even though genetic, biochemical and functional studies have provided important insights into the pathogenesis of MPDs, the role of epigenetic changes in disease pathobiology is not well elucidated. We performed the HELP assay to study genome-wide methylation patterns in cases of Polycythemia Vera (PV), Essential Thrombocytosis (ET) and Idiopathic Myelofibrosis (IMF) and compared it with normal matched controls. The HELP assay uses differential methylation specific digestion by HpaII and MspI followed by amplification, two color labeling and hybridization to quantitatively determine individual promoter CpG methylation of 25636 loci. Analysis of 26 MPD neutrophil samples comprising 9 cases of ET, 6 cases of PV and 11 Cases of IMF was performed and compared to normal healthy controls. Unsupervised clustering based on global methylation profiles showed that IMF cases formed a distinct epigenetic cluster, while PV and ET cases were more similar to the normal controls. Further analysis of epigenetic differences between these groups showed that PV and ET samples were characterized by aberrant hypermethylation when compared to controls and had 143 genes that were uniformly hypermethylated. These genes are involved in pathways regulated by the NF-Kb and HNF-4alpha transcription factors. IMF on the other hand was characterized by both aberrantly hyper (n=162) and hypomethylated (n=95) loci when compared to controls. The pathways affected by hypomethylated genes were involved in cytokine cell signaling and MAP kinases. We subsequently validated these observations in an independent set of 8 IMF cases compared to 8 age matched controls. Methylation profiles obtained from whole blood by the HELP assay were able to clearly separate IMF cases from controls demonstrating the validity of our observations. These changes were quantified on a whole genome level by the Luminometric methylation assay (LUMA) that also revealed significantly more hypomethylation in IMF when compared to PV and ET cases (49% hypomethylation in IMF vs. 38% in PV/ET, p<0.05). Selected changes were validated by Mass Array sequencing. We next wanted to determine the epigenomic effects of Jak2V617F mutation and compared methylation profiles of MPD cases with and without the mutation. We observed that cases with Jak2 mutation had a higher number of differentially hypomethylated loci. This striking difference was seen by the LUMA assay also with 67% hypomethylation seen in mutant cases when compared to 48% in those without the mutation (p=0.02). This observation was validated in vitro in a cell line (FDCP) that expressed wither WT or mutant Jak2 kinase. We observed that expression of the mutant kinase led to global hypomethylation. This observation builds on recent data demonstrating nuclear binding of the mutant Jak2 kinase and its effects on the histone epigenetic machinery. In conclusion, we report that MPDs are characterized by various novel epigenetic alterations that affect important functional pathways and IMF is grossly epigenetically distinct from ET and PV. The Jak2 mutation also affects the methylome and leads to global hypomethylation that potentially contributes to the genomic instability and disease pathobiology. Disclosures: No relevant conflicts of interest to declare.

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Analysis of JAK2 V617F Mutation and Its Clinical Significance in Patients with Thrombocythemia and Other Myeloproliferative Neoplasms in Chinese

Blood ◽

10.1182/blood.v118.21.4687.4687 ◽

2011 ◽

Vol 118 (21) ◽

pp. 4687-4687

Author(s):

Yue Xu ◽

Changxin Yin ◽

Han He ◽

Lingling Shu ◽

Fuqun Wu ◽

...

Keyword(s):

Polycythemia Vera ◽

Essential Thrombocythemia ◽

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Jak2 V617f ◽

Jak2 V617f Mutation ◽

Jak2 Mutation ◽

Western Countries ◽

Arms Pcr ◽

V617f Mutation

Abstract Abstract 4687 JAK2 mutation is commonly found in Philadelphia-negative myeloproliferative neoplasms (MPNs). In Western countries, this mutation is found in approximately 96 percent of people with polycythemia vera, half of individuals with essential thrombocythemia or primary myelofibrosis. We used the method of amplification refractory mutation PCR (ARMS-PCR) to investigate MPN patients in China. We focused our study on patients with essential thrombocythemia (ET). ARMS-PCR was used to detect JAK2 V617F mutation in the bone barrow (BM) or peripheral blood of 37 MPN patients, which consisting of 7 ET, 5 polycythemia vera (PV), 5 chronic myeloid leukemia (CML), 5 chronic idiopathic myelofibrosis (CIMF), as well as 15 suspected MPNs. 17 cases of JAK2 V617F mutation (45.9%) were found in 37 patients, including 4 ET (57.1%), 4 PV (80.0%), 3 CIMF (60.0%), 6 suspected MPNs (40.0%). We did not find JAK2 V617F in the patients with CML. Our results indicated that the frequency of JAK2 V617F mutation in bcr/abl-negative MPNs in Chinese is similar to that in MPN patients in Western countries. At the same time, ARMS-PCR can distinguish the mutation is heterozygous or homozygous. Most patients were heterozygous for JAK2 but only a few were homozygous. In conclusion, our study showed that JAK2 V617F mutation frequency in Chinese MPN patients is similar to that in patients with this disorder in the West. It is the major molecular genetic abnormality in bcr-abl negative MPN and it can be used for diagnosis of MPN in China. Disclosures: No relevant conflicts of interest to declare.

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