High Rates of Molecular Response After Long-Term Follow-up of Patients with Advanced Essential Thrombocythemia (ET) or Polycythemia Vera (PV) Treated with Pegylated Interferon-ALFA-2A (PEG-IFN-α-2A; PEGASYS)

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 461-461
Author(s):  
Alfonso Quintás-Cardama ◽  
Ross Levine ◽  
Taghi Manshouri ◽  
Outi Kilpivaara ◽  
Hagop M. Kantarjian ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Covalent Attachment ◽  
Molecular Response ◽  
Molecular Responses ◽  
Allele Burden ◽  
Mutational Status ◽  
Starting Dose ◽  
Jak2v617f Allele Burden

Abstract Abstract 461 Background: The use of IFN-α in polycythemia vera (PV) and essential thrombocythemia (ET) has been hampered by poor tolerance and inconvenient dosing schedules. The covalent attachment of polyethylene glycol to IFN-α renders a molecule with prolonged serum half-life, which can be administered weekly. Objectives: We conducted a phase II study of subcutaneous PEG-IFN-α-2a (Pegasys) in 84 patients (pts) with high-risk PV (n=44) or ET (n=40). We performed high throughput mutational analysis of JAK2, MPL, TET2, and ASXL1 in all pts. Patients and Therapy: Median age was 51 years (range, 18–79), time from diagnosis to PEG-IFN-α-2a 51 months (range, 0–355), and number of prior therapies was 1 (range, 0–6), including hydroxyurea (HU; n=47), anagrelide (AG; n=26), IFN-α (n=12: 5 oral and 7 sc), imatinib (n=7), and dasatinib (n=1). PEG-IFN-α-2a was initial therapy in 16 (19%) pts (7 PV) that refused HU. JAK2V617F was detected in 19/40 (48%) ET and in 42/44 (95%) PV pts. Nine (11%) pts had abnormal cytogenetics. Initial PEG-IFN-α-2a starting dose was 450 mcg/wk, but that was modified to the current starting dose of 90 mcg/wk. Results: After a median follow-up of 40 months (range, 8–62), 66/83 (80%) assessable pts have responded. Median time to response was 4 weeks (range, 0.5–26). Complete response (CR) was achieved by 62 (75%) pts (for ET: platelets <440×109/L, in the absence of thromboembolic events; for PV: Hb <15 g/dL, no phlebotomy, disappearance of splenomegaly) whereas 4 (5%) pts (2 PV, 2 ET) had a partial response ([PR]; no phlebotomy, off HU and AG, still palpable spleen). Of 5 pts with abnormal karyotype at study entry who were evaluable for response, 2 reverted to diploid cytogenetics. JAK2V617F to total JAK2 ratio was determined by quantitative pyrosequencing assay in all 84 pts prior to PEG-IFN-α-2a. Sixty-one (73%) pts carried the JAK2V617F mutation, which was quantitated at least once on therapy in 54 (64%). Overall, 29 (54%) had >20% reduction in JAK2V617F allele burden, including 10 (19%) in whom the mutation became undetectable (complete molecular response [CMR]) and 15 (28%) who had a >50% reduction (partial molecular response). Molecular responses have not yet reached a plateau among pts with PV. We also analyzed pts for mutations in exon 12 of JAK2, MPL, and the tumor suppressors TET2 and ASXL1 to determine their impact on response to PEG-IFN-α-2a. No pts carried JAK2 exon 12 mutations. One JAK2V617F−negative pt with ET had a MPLW515L mutation, achieved CHR but did not achieve a molecular response. Full length resequencing of all exons of TET2 and ASXL1 genes identified somatic TET2 mutations in 9/71 (13%) and somatic ASXL1 mutations in 3/71 (4%) pts; we identified TET2 (3 JAK2V617F− ET, 2 JAK2V617F+ ET, 3 JAK2V617F+ PV, 1 JAK2V617F− PV) and ASXL1 (1 pt with ET JAK2V617F+, ET JAK2V617F−, and PV JAK2V617F+) mutations in PV and ET pts who were JAK2V617F–positive and negative. TET2 or ASXL1 mutational status did not impact the likelihood of achievement of JAK2 molecular responses, and there was no difference in JAK2V617F allele burden with PEG-IFN-α-2a according to TET2 or ASXL1 mutational status. One pt with baseline mutations in JAK2, TET2, and ASXL1 became JAK2V617F–negative on PEG-IFN-α-2a. Most pts had grade 1–2 toxicities but at doses ≤90 mcg/wk, grade 3–4 toxicity was infrequent. Twenty-five (30%) patients were taken off study after a median of 9 months (range, 3–36) but only 13 (15%) of them due to therapy-related toxicity: g3 neutropenia, anorexia, depression (n=3), ischemic retinopathy, g2 fatigue (n=5), dyspnea, g2 neuropathy. The remaining 59 pts are currently receiving 450 mcg/wk (n=1), 360 mcg/wk (n=1), 240 mcg/wk (n=1), 180 mcg/wk (n=2), 135 mcg/wk (n=3), 90 mcg every 1 (n=8), 2 (n=12), 3 (n=2), or 4 wks (n=1), 45 mcg every 1 (n=9), 2 (n=5), 3 (n=6), or 4 wks (n=8). Conclusion: PEG-IFN-α-2a is remarkably active and acceptably safe in advanced, previously treated PV and ET. Clinical responses are frequently accompanied by significant reduction of JAK2V617F allele burden, which becomes undetectable in a proportion of them suggesting selective targeting of the JAK2V617F clones. Quantitative analysis of ASXL1 and TET2 mutational allele burden during PEG-IFN-α-2a therapy to determine clonal evolution, and methylcellulose-based clonogenic assays in pts who achieved CMR to assess for the presence of erythropoietin independent colony formation are ongoing and will be presented. Disclosures: No relevant conflicts of interest to declare.

JAK2V617F Complete Molecular Remission in Long-Term Follow-up of Patients with Polycythemia Vera and Essential Thrombocythemia Treated with Ruxolitinib

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3185-3185
Author(s):  
Lisa Pieri ◽  
Alessandro Pancrazzi ◽  
Annalisa Pacilli ◽  
Claudia Rabuzzi ◽  
Giada Rotunno ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Research Funding ◽  
Jak2v617f Mutation ◽  
Prolonged Treatment ◽  
Molecular Response ◽  
Molecular Remission ◽  
Allele Burden ◽  
Jak2v617f Allele Burden

Abstract Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) characterized by the presence of JAK2V617F mutation in >95% and 60% of patients (pts), respectively. This mutation usually affects one allele in ET while most PV pts are homozygous due to mitotic recombination. Acquisition of the JAK2V617F mutation is strongly associated with the germline 46/1 predisposition haplotype. Ruxolitinib is a JAK1/JAK2 inhibitor recently approved for myelofibrosis (MF) and under investigation in PV and ET pts intolerant or resistant to hydroxyurea. We enrolled 24 pts, 11 with PV and 13 with ET, in the phase II INCB18424-256 trial that overall included 34 PV and 39 ET pts. 21/24 pts were still on treatment at 5 years (yr), of which 19 JAK2V617F mutated. Results of the PV cohort have been reported recently (Verstovsek et al. Cancer, 2014): with a median follow up of 35 months (mo), the JAK2V617F allele burden decreased by a mean of 8%, 14%, and 22%, respectively, after 12, 24 and 36 mo. The proportion of pts who achieved a reduction ≥50 % at any time during the 1st yr, 2nd yr, and 3rd yr were 5.9%, 14.7%, and 23.5%, respectively, but no patients achieved a complete remission. In our series of pts we evaluated the JAK2V617F allele burden by two RTQ-PCR methods, according to Lippert (sensitivity, 0.8%) and to Larsen (sensitivity, 0.08%) method. We also analysed by next generation sequencing (NGS; Ion Torrent platform) a series of MPN-associated mutations including TET2, ASXL1, IDH1/2, LNK, CBL, SRSF2, EZH2 and MPL at baseline and at 5 yr of treatment in ruxolitinib treated pts who achieved a >25% JAK2V617F allele burden reduction at 5 yr (n=13/19). JAK2V617F allele burden decreased by a mean of 7%, 11%, and 19% at 12, 24 and 36 mo, and decreased further by a mean of 28% after 60 mo. Three (1 PV, 2 ET) of 19 pts (16%) achieved a 50% or greater allele burden reduction after 2 yr; no additional pts achieved this degree of allele burden reduction even in prolonged follow up. These 3 pts further improved their molecular response to a complete molecular response (CMR) after 5 yr of treatment. Their mean JAK2V617F allele burden was 46.6% at baseline, 28.3%, 16.3%, 8.7% and 0% after 1 yr, 2 yr, 3 yr and 5 yr, respectively. The JAK2 CMR was confirmed in at least one independent sample at 3 mo after first discovery. At this last timepoint, the PV pt was in complete haematological remission according to ELN criteria, the 2 ET pts were in partial remission due to platelet count still >400x109/L: 422x109/L and 812x109/L, respectively. BM histopathology in the 2 ET pts at 5 yr, while they were in CMR, showed still evidence of megakaryocyte hyperplasia. In the PV pt, histopathology at 5 yr is pending; evaluation at 3 yr, a time when she was in complete hematologic remission and JAK allele burden had decreased from 69 to 8%, showed normalization of cellularity, megakaryocyte and myeloid lineage compared to baseline but still slight erythroid hyperplasia. All 3 pts had normal karyotype at baseline that remained unchanged thereafter. CMR for JAK2V617F was confirmed by NGS. The 2 ET pts achieving CMR did not show any additional mutations, while the PV pts presented a TET2 Y867H mutation with an allele burden of 48.9% and 52%, respectively at baseline and 5 yr. No recurrent mutations in genes other than JAK2 were found in all other examined cases at baseline or at 5 yr. In 3 informative pts, we also analysed the proportion of JAK2V617F homozygous, heterozygous and wild type clones by the method of Hasan et al (Leukemia 2013) based on allelic discrimination of 46/1 haplotype and JAK2. We found that JAK2V617F/V617F clones were reduced by a mean of 95.5%, JAK2V617F/WT showed an uneven trend with a mean reduction of 45.54% while JAK2WT/WT conversely increased (mean 61.43%) at 5 yr, suggesting that in a subset a patients who present significant reduction of VF allele burden ruxolitinib may preferentially target the homozygous clones. Until now, complete molecular remission in PV pts has been described only in patients treated with interferon. Our data suggest that a subset of pts who present a rapid and sustained reduction of the JAK2V617F allele burden under ruxolitinib may eventually reach a condition of CMR with prolonged treatment. However, similar to findings with interferon, mutations establishing clonality, such as in TET2, may still persist in patients who eventually show the disappearance of JAK2V617F mutated subclones. Disclosures Verstovsek: Incyte: Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Efficacy and Safety of Pegylated Interferon Alpha-2a in Patients with Essential Thrombocythemia and Polycythemia Vera: Results after a Median 7-Year Follow-up of a Phase 2 Study

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 60-60 ◽  
Author(s):  
Lucia Masarova ◽  
Srdan Verstovsek ◽  
Keyur P. Patel ◽  
Kate J Newberry ◽  
Jorge E. Cortes ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Interferon Alpha ◽  
Essential Thrombocythemia ◽  
Research Funding ◽  
Pegylated Interferon ◽  
Molecular Remission ◽  
Molecular Responses ◽  
Pegylated Interferon Alpha ◽  
Allele Burden

Abstract Introduction: It has been previously reported that pegylated interferon alpha-2a can induce hematologic and molecular responses in patients with essential thrombocythemia "ET" and polycythemia vera "PV", but the follow up in these studies were relatively short. Objective: We present longer-term efficacy and safety results of a prospective phase II study of pegylated interferon alpha-2a in patients with ET and PV after a median follow up of 82.5 months (range, 8-107). Methods: Patients with a diagnosis of ET or PV, in a need of therapy, either newly diagnosed or previously treated, were eligible for this study. Median interferon starting dose of 180 mcg/week SQ (range, 450-90; 39% started on 90mcg/week) was modified in majority of the patients based on toxicity or lack of efficacy. Clinical and molecular responses were assessed every 3 to 6 months. Results: Among 83 enrolled patients (43 PV, 40 ET), 32 patients (39%) are still on study (but in 8 therapy is on hold: 5 due to toxicity, and 3 for financial reasons). Median age was 53 years (range, 19-78). Overall 37% of patients did not receive prior cytoreductive treatment. The overall median exposure to therapy was 87 months (range, 58-107) and was no different for patients still enrolled on the study and those who stopped study participation. Nine (28%) patients still on study are currently on a dose equal or higher than 90 mcg/week and 15 (47%) are on dose equal or smaller than 45mcg/week. JAK2 status or allele burden had no impact on achievement of response (clinical or molecular), time to response or duration of therapy. 55 of 59 (71%) JAK2V617F positive patients were evaluable for molecular response (Figure); 8 patients carried CARL mutation, 3 carried MPL and in 13 were triple negative. Median duration of hematologic and molecular response was 66 and 53 months, respectively; and directly correlated with treatment length and type of response (CMR had the longest duration of response). Overall yearly discontinuation rate were gradually decreasing for first 5 years, from 17% to 5%, and slowly increasing afterward to 10%. Of the 51 patients not on the study anymore, 27 (35% of the total) discontinued therapy primarily due to treatment toxicity. New late (≥24 months from start of therapy) G3/4 toxicity occurred in 17% of patients. Among patients in complete hematologic response treatment failure due to vascular adverse event or disease transformation was seen in 5 patients each. Three patients died on study (not related to therapy or disease), and 8 after stopping participation. Mean changes in allele burden over time in JAK2 positive patients are depicted in figure. Conclusions: Although pegylated interferon alpha-2a can induce significant hematologic and molecular responses; toxicity still limits its use over longer period of time and loss of response or transformation is encountered. Table.ResponseCharacteristicsFirst responseLast responseHem Resp, N. of patients (No), (%)CHR62 (76)25 (40)aPHR4 (5)1 (25)ORR66 (79)26 (39)aMol Resp, No, (%)CMR10 (18)9 (90)PMR20 (36)5 (25)*mMR5 (9)2 (40)ORR35 (74)16 (46)SafetyAny gradeGrade≥3Overall Adverse Events (AE), No, (%)any AE83 (100)57 (67)recurrent AE74 (89)13 (16)AE subtypes, No, (%)musculoskeletal73 (88)6 (8)neurological53 (64)2 (4)psychiatric38 (46)4 (11)gastrointestinal54 (65)11 (20)LFT elevation27 (33)5 (18)skin18 (22)2 (11)infection/fever26 (31)3 (12)respiratory23 (28)2 (9)cardiovascular13 (16)3 (23)metabolic16 (19)2 (13)neutropenia37 (45)21 (57)thrombocytopenia18 (22)a1 (6)anemia36 (43)1 (3)Autoimmune toxicity, No, (%)hepatitis1 (2.5)CNS vasculitis1 (2.5)lupus nephritis1 (2.3)Sjogren sy & dermatitis1 (2.5)Vascular AE (TEE/bleeding),Unprovoked6 (7)5 (83)No, (%)Provoked4 (5)3 (75)Disease transformation, No, (%)Myelofibrosis6 (7)AML1 (1)Safety over ≥24 months**Any gradeGrade≥3New AE, No (%)3th year10 (17)4 (40)4th year6 (11)4 (67)5th year5 (10)1 (20)≥ 6th year10 (24)1 (10)**Effective sample size for patients on therapy/year: Initial number of patients at risk at the beginning of period minus half of patients censored during that period*% calculated from 19 patientsastatistically significant differences by Fisher's exact testAbbr. CMR= complete molecular remission (undetectable JAK2 allele burden), PMR= partial molecular remission (>50% decrease in allele burden), mMR= minor molecular remission (20-49% decrease in allele burden) Figure 1. Figure 1. Disclosures Off Label Use: Pegylated Interferon alfa-2a used for patients with essential thrombocythemia and polycythemia vera. Cortes:Novartis: Consultancy, Research Funding; BerGenBio AS: Research Funding; Teva: Research Funding; BMS: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy. Konopleva:Novartis: Research Funding; AbbVie: Research Funding; Stemline: Research Funding; Calithera: Research Funding; Threshold: Research Funding.

scholarly journals JAK2V617F allele burden and thrombosis: A direct comparison in essential thrombocythemia and polycythemia vera

2009 ◽  
Vol 37 (9) ◽  
pp. 1016-1021 ◽  
Author(s):  
Alessandra Carobbio ◽  
Guido Finazzi ◽  
Elisabetta Antonioli ◽  
Paola Guglielmelli ◽  
Alessandro M. Vannucchi ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Allele Burden ◽  
Jak2v617f Allele Burden

Sequential Analysis By Next Generation Sequencing of 18 Genes in Polycythemia Vera and Essential Thrombocythemia Reveals a Association Between Mutational Status and Clinical Outcome after 3-Year Follow-up

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2808-2808
Author(s):  
Damien Luque Paz ◽  
Aurelie Chauveau ◽  
Caroline Buors ◽  
Jean-Christophe Ianotto ◽  
Francoise Boyer ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Jak2 V617f ◽  
Primary Myelofibrosis ◽  
Jak2 V617f Mutation ◽  
Poor Prognostic Factor ◽  
Disease Evolution ◽  
Allele Burden ◽  
V617f Mutation

Abstract Introduction Myeloproliferative neoplasms (MPN) are molecularly characterized by driver mutations of JAK2, MPL or CALR. Other somatic mutations may occur in epigenetic modifiers or oncogenes. Some of them have been shown to confer a poor prognosis in primary myelofibrosis, but their impact is less known in Polycythemia Vera (PV) and Essential Thrombocythemia (ET). In this study, we investigated the mutational profile using NGS technology in 50 JAK2 V617F positive cases of MPN (27 PV and 23 ET) collected at the time of diagnosis and after a 3 year follow-up (3y). Patients and Methods All patients were JAK2 V617F positive and already included in the prospective cohort JAKSUIVI. All exons of JAK2, MPL, LNK, CBL, NRAS, NF1, TET2, ASXL1, IDH1 and 2, DNMT3A, SUZ12, EZH2, SF3B1, SRSF2, TP53, IKZF1 and SETBP1 were covered by an AmpliseqTM custom design and sequenced on a PGM instrument (Life Technologies). CALR exon 9 mutations were screened using fragment analysis. Hotspots that mutated recurrently in MPN with no sequencing NGS coverage were screened by Sanger sequencing and HRM. A somatic validation was performed for some mutations using DNA derived from the nails. The increase of a mutation between diagnosis and follow-up has been defined as a relative increase of twenty percent of the allele burden. An aggravation of the disease at 3y was defined by the presence of at least one of the following criteria: leukocytosis &gt;12G/L or immature granulocytes &gt;2% or erythroblasts &gt;1%; anemia or thrombocytopenia not related to treatment toxicity; development or progressive splenomegaly; thrombocytosis on cytoreductive therapy; inadequate control of the patient's condition using the treatment (defined by at least one treatment change for reasons other than an adverse event). Results As expected, the JAK2 V617F mutation was found in all patients with the use of NGS. In addition, we found 27 other mutations in 10 genes out of the 18 genes studied by NGS (mean 0.54 mutations per patient). Overall, 29 of 50 patients had only the JAK2 V617F mutation and no other mutation in any of the genes analysed. No CALR mutation was detected. Nine mutations that were not previously described in myeloid malignancies were found. The genes involved in the epigenetic regulation were those most frequently mutated: TET2, ASXL1, IDH1, IDH2 and DNMT3A. In particular, TET2 mutations were the most frequent and occurred in 20% of cases. There was no difference in the number or in the presence of mutations between PV and ET. At 3y, 4 mutations appeared in 4 patients and 15 out of 50 patients (9 PV and 6 ET) were affected by an allele burden increase of at least one mutation. At 3y, 24/50 patients suffered an aggravation of the disease as defined by the primary outcome criterion (16 PV and 8 ET). The presence of a mutation (JAK2 V617Fomitted) at the time of the diagnosis was significantly associated with the aggravation of the disease (p=0.025). Retaining only mutations with an allele burden greater than 20%, the association with disease aggravation is more significant (p=0.011). Moreover, a mutation of ASXL1, IDH1/2 or SRSF2, which is a poor prognostic factor in primary myelofibrosis, was found in 8 patients, all having presented an aggravation of their disease (p=0.001). Only 4 patients had more than one somatic mutation other than JAK2 V617F and all of them also had an aggravation at 3y (p=0.046). In this cohort, appearance of a mutation at 3y was not associated with the course of the disease. Conversely, the increase of allele burden of at least one mutation was associated with an aggravation (p=0.019). Discussion and conclusion Despite the short follow-up and the limited number of patients, this study suggests that the presence of additional mutations at the time of the diagnosis in PV and TE is correlated to a poorer disease evolution. The increase of mutation allele burden, which reflects clonal evolution, also seems to be associated with the course of the disease. These results argue for a clinical interest in large mutation screening by NGS at the time of the diagnosis and during follow-up in ET and PV. Disclosures Ugo: Novartis: Membership on an entity's Board of Directors or advisory committees, Other: ASH travel.

Similar Rate of Thrombosis in Essential Thrombocythemia and Polycythemia Vera Patients after Stratification for JAK2 V617F Allele Burden.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1745-1745
Author(s):  
Alessandra Carobbio ◽  
Guido Finazzi ◽  
Elisabetta Antonioli ◽  
Paola Guglielmelli ◽  
Alessandro M. Vannucchi ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Vascular Complications ◽  
Jak2 V617f ◽  
Similar Rate ◽  
Wild Type ◽  
Allele Burden ◽  
Real Time Quantitative Pcr ◽  
Venous Thromboembolic

Abstract Patients with Essential Thrombocythemia (ET) can be categorized as either JAK2 V617F mutated (V617F+) or wild type (V617F−). Mutated patients display multiple features resembling Polycythemia Vera (PV), with significantly higher hemoglobin level and neutrophil counts, lower platelet count, more pronounced bone marrow erythropoiesis and granulopoiesis and higher tendency to transform in PV. Presence of the mutation and/or allele burden has been variably associated with the rate of vascular complications in ET and PV, but a direct comparison between the two disorders under this respect has not been performed. To tackle this issue, we compared the rate of major thrombosis in 867 ET patients (57% were JAK2 V617F+) with that in 415 PV patients (all V617F+). The median follow-up was 4.9 (0 – 39) and 3.8 (0 – 26) years in ET and PV, respectively. High risk ET patients (age ≥ 60 years and/or previous thrombosis) received Hydroxyurea whereas the vast majority of low-risk remained untreated. PV patients were treated according to the current risk-stratified recommendations. Thrombotic episodes were recorded over time and calculated as rates % per patient/year (pt/yr). After adjusting for age, the thrombosis-free survival curves of JAK2 V617F+ and V617F− ET patients were superimposable until 10 years after the diagnosis, then they diverged so that the actuarial probability of major thrombosis in mutated ET patients reached that of PV (48% vs 55%, test for trend p=0.05). We found that JAK2 V617F+ allele burden measured by real-time quantitative PCR influenced these rates in a comparable way in both ET and PV. Actually, in JAK2 wild type ET (n=376, 43%) the rate was 1.4% pt/yr. In ET patients with JAK2 V617F+ allele burden ranging from 1 to 25% (N=190; 49%) the rate was 1.9 % pt/yr compared to 1.2 in PV patients (N=64, 19%); in the group with 26–50% the rate was 2.0 % pt/yr in ET (N=177; 45%) and 3.0 in PV patients (N=118, 36%); in cases of V617F+ allele burden greater than 50% the rate was 3.8 % pt/yr in ET (N=23; 6%) and 2.9 in PV patients (N=147, 45%). In conclusion, from this retrospective analysis, we conclude that in patients with ET harboring JAK2 V617F mutation the rate of stroke, myocardial infarction and venous thromboembolic complications is similar to that of PV patients and increases in dependence of V617F allele burden, supporting the hypothesis that ET and PV may be viewed as a continuum also in terms of vascular complications

scholarly journals JAK2V617F allele burden is associated with thrombotic mechanisms activation in polycythemia vera and essential thrombocythemia patients

2013 ◽  
Vol 99 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Margarida Coucelo ◽  
Gonçalo Caetano ◽  
Teresa Sevivas ◽  
Susana Almeida Santos ◽  
Teresa Fidalgo ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Allele Burden ◽  
Jak2v617f Allele Burden

scholarly journals The Impact of the Mutational Landscape upon the Molecular Responses to Interferon-Alfa2 in Calr-Mutated MPN Patients

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4327-4327
Author(s):  
Vibe Skov ◽  
Lasse Kjær ◽  
Mads Thomassen ◽  
Steffen Koschmieder ◽  
Julia Czech ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Median Number ◽  
Driver Mutations ◽  
Molecular Response ◽  
Molecular Responses ◽  
Allele Burden ◽  
Ifn Therapy ◽  
Ifn Treatment ◽  
The Impact

Abstract Introduction: The Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are associated with driver mutations in JAK2, CALR, and MPL genes. Non-driver mutations involved in epigenetic regulation, signaling, and splicing are suggested to affect disease progression and treatment response. Interferon-alpha2 (IFN) induces hematologic and molecular responses in patients (pts) with MPNs. We studied 20 CALR positive pts by targeted next generation sequencing (NGS) of 68 genes and investigated the impact of somatic mutations on the molecular response to IFN. Methods: Twenty JAK2V617F negative CALR mutated pts (type 1 (n=14), type 2 (n=4), and other (n=2)) with ET (n=3), pre-PMF (n=5) and PMF (n=12) treated with IFN participated in the study. Targeted NGS was performed on DNA from peripheral blood at baseline and during IFN therapy. Libraries were prepared using an in-house gene panel covering 68 genes (Table 1). NGS was performed on the Ion Torrent platform and data were analyzed using Biomedical Genomics workbench and VarSeq. Variants with coverage <100x, variant allele frequency (VAF) <3%, introns, germline and synonymous variants, and SNPs with minor allele frequency >1% were excluded. A mutation with VAF <3% in either a pre- or post-treatment sample was retained if VAF was >3% in the paired sample. Statistical analysis was done in R and a p-value <0.05 was considered significant. Results: Mean average coverage per base was 2749 (range:1964-3874). In all pts, median CALR allele burden (%CALR) was 41.5% (range: 30-53) and 40% (range: 5.7-54) at baseline and follow-up, respectively. The median duration of IFN treatment from NGS at baseline to follow-up was 33 months (range: 7-100). Median number of non-driver mutations was 3 (range: 0-9) in all pts. Nineteen (95%) pts had at least one non-driver mutation, 14 (70%) >1, and 12 (60%) ³3. Stratified according to molecular response (MR) and non-MR, 4 (20%) achieved MR and 16 (80%) non-MR. Median %CALR at baseline was 42 (30-53) and 39 (33-49) in non-MR and MR, respectively, and 44 (25-54) and 10 (6-15) in non-MR and MR, respectively, during treatment with IFN. Median number of non-driver mutations was 2 (range: 0-6) in MR and 3 (range: 1-9) in non-MR. In all pts, there were 64 non-driver mutations in 18 genes at baseline and during IFN therapy. Of the 20 pts analyzed, TET2 occurred in 50% of pts, CUX1 in 45%, DNMT3A in 40%, GATA2 in 35%, ASXL1 in 30%, and SH2B3 in 10%. Each of the mutations - CBL, IKZF1, VEGFA and XPC occurred in 10% and EZH2, JAK2S523del, NF1, NFE2, PHIP, SF3B1, SRSF2, and TGFB1 in 5%. Interestingly, the epigenetic regulator genes ASXL1, DNMT3A, and TET2 were frequently mutated. Notably, TET2 occurred exclusively in pre-PMF and PMF. To examine if non-driver mutations were associated with a response to treatment with IFN, %CALR was evaluated in TET2, ASXL1, CUX1, DNMT3A, and GATA2 wild type (wt) and mutated pre- and post-treatment samples. Patients with mutations in CUX1 had a significantly higher post-IFN-treatment %CALR compared to CUX1 wt pts (p<0.03). Moreover, CUX1 wt pts had a significant reduction in %CALR during treatment (p<0.04) (Figure 2). Different scenarios were observed when comparing the evolution of the mutant allele burden in non-driver mutations and the CALR mutation during treatment (Figure 3). An ASXL1 mutation was present in one MR with VAF decreasing from 3 to 0.5 in response to IFN. Five non-MRs carried an ASXL1 mutation with increasing or unchanged VAF in 4 of 5 pts and decreasing VAF in one pt. Discussion and Conclusions: In the present study, ASXL1, DNMT3A, and TET2 were frequently mutated possibly due to the high number of pts with pre-PMF and PMF. An association between poor response to IFN and ASXL1 mutations was recently reported in PMF. Indeed, we found a possible association between ASXL1 mutations and non-MR with increased or unchanged %ASXL1 during IFN therapy. However, in one MR and one non-MR, we recorded a marked decline in %ASXL1 but a sustained decrease or increase in %CALR, respectively. These results might imply a pt specific clonal heterogeneity. CUX1 is a transcription factor regulating TP53. We show that pts without CUX1 mutations had a significant reduction in %CALR and a significantly lower %CALR compared to CUX1 mutated pts during treatment. Our finding of a blunted response to IFN in CALR/CUX1 mutated pts deserves further studies in larger cohorts of CALR mutated MPNs. Disclosures Hasselbalch: Novartis: Research Funding.

Decrease in JAK2V617F Allele Burden is Not a Prerequisite to Clinical Response in Patients with Polycythemia Vera (PV).

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1908-1908 ◽  
Author(s):  
Richard T. Silver ◽  
Katherine Vandris ◽  
Joshua J. Goldman ◽  
Fernando Adriano ◽  
Y. Lynn Wang ◽  
...  
Keyword(s):  
Clinical Response ◽  
Polycythemia Vera ◽  
Mutant Allele ◽  
Conflicts Of Interest ◽  
Kappa Coefficient ◽  
Molecular Response ◽  
Allele Burden ◽  
Hematologic Response ◽  
Complete Hematologic Response ◽  
Jak2v617f Allele Burden

Abstract Abstract 1908 Poster Board I-931 Previous studies of patients (pts) with polycythemia vera (PV) treated with pegylated interferon (peg-IFNá-2a) have shown an 83% complete hematologic response associated with an 89% molecular response over a median of 11 months (Kiladjian et al. Blood. 2008. 112(8):3065-3072) implying a causative relationship between molecular and hematologic responses. Our data show pts treated with rIFNá-2b or non-rIFNá-2b agents achieve hematologic response despite the absence of a molecular response suggesting that a molecular change is not a prerequisite to hematologic response. Thirty pts diagnosed with PV by the criteria of the Polycythemia Vera Study Group (PVSG) were followed clinically and hematologically with serial quantified JAK2V617F allele burden determined at six-month intervals over a mean of 21.6 months (mos) (range: 6.0 – 56.4 mos). These pts were treated with rIFNá-2b ranging from 0.5 mu to 3.0 mu three times per week depending upon clinical response. Primary clinical endpoints were hematocrit (hct) ≤45% men, ≤42% women, and no need for phlebotomy (PHL). Molecular and hematologic responses were graded according to the criteria of Barosi et al. (Blood. 2009. 113(20):4829-4833): complete hematologic response (CHR: hct ≤45% without PHL, platelets '400×109/L, WBC ≤10×109/L, normal spleen size, asymptomatic); partial hematologic response (PHR: hct ≤45% without PHL or response in 3 or more of the CHR categories); no hematologic response (NHR: failure to meet the criteria of CHR or PHR); complete molecular response (CMR: reduction of JAK2V617F marker to undetectable levels); partial molecular response (PMR: ≥50% reduction in pts with '50% mutant allele burden at baseline, or ≥25% reduction in pts with >50% mutant allele burden at baseline; applicable only to pts with ≥10% baseline allele burden); and no molecular response (NMR: failure to meet the criteria of CMR or PMR). Of the 30 pts treated with rIFNá-2b, 14 had a CHR, 13 had a PHR and 3 had NHR. Of 14 pts who had a CHR, 4 had a PMR and 10 had NMR. Of thirteen pts who had a PHR, 1 had a PMR and 12 had NMR. All 3 pts who had NHR also had NMR. Based on these data, the statistical agreement between hematologic response and molecular response was poor (kappa coefficient = 0.06, P=0.17). We then examined the hematologic responses (HR: CHR+PHR) of 25 non-rIFNá-2b treated pts, which included PHL ± anagrelide (3 pts: 2 HR/NMR, 1 NHR/NMR), dasatinib (5 pts: 5 HR/NMR), imatinib (9 pts: 3 HR/PMR, 4 HR/NMR, 2 NHR/NMR), and hydroxyurea (8 pts: 1 CHR/PMR, 7 HR/NMR). The minimal molecular response to dasatinib and hydroxyurea is noteworthy. Likewise, there was poor statistical agreement between hematologic response and molecular response for non-rIFNá-2b treated patients (kappa coefficient = 0.05, P=0.21). Of all 55 pts (rIFNá-2b and non-rIFNá-2b), those 9 patients with a PMR had a hematologic response (7 CHR and 2 PHR). Of 46 NMR's, 40 pts (87%) had a hematologic response (16 CHR, 24 PHR). Thus, NMR did not exclude the possibility of achieving CHR. Regardless of therapy, we demonstrate poor agreement between hematologic and molecular responses for these drugs (all pts: kappa = 0.05, P=0.13). This suggests a difference in action between peg-IFNá-2a, shown to cause molecular and hematologic responses concurrently, and several drugs we examined leading to clinical response without necessarily changing JAK2V617F allele burden. In this regard, other parameters such as bone marrow morphology and new biological markers may be useful in reconciling the differences. In summary, we find that a hematologic response is not always accompanied by a molecular response in PV pts treated with either rIFNá-2b or some non-rIFNá-2b drugs. We thus conclude that a reduction in JAK2V617F allele burden is not always required for patients to achieve hematologic response, and that following the JAK2V617F biomarker may be drug-dependent and may not always be a reliable measure of response. This warrants the importance of the randomized trial planned to compare peg-IFNá-2a to the current standard of treatment, hydroxyurea. Disclosures: No relevant conflicts of interest to declare.

Pegylated Interferon-ALFA-2A (PEG-IFN-α-2A; PEGASYS) Therapy Renders High Clinical and Molecular Response Rates in Patients with Essential Thrombocythemia (ET) and Polycythemia VERA (PV)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 658-658 ◽  
Author(s):  
Alfonso Quintas-Cardama ◽  
Hagop M. Kantarjian ◽  
Guillermo Garcia-Manero ◽  
Jorge Cortes ◽  
Marie Ann Richie ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Essential Thrombocythemia ◽  
Jak2 V617f ◽  
Clinical Activity ◽  
Molecular Response ◽  
Significant Activity ◽  
Recombinant Interferon ◽  
Starting Dose ◽  
Grade 3 ◽  
Initial Starting

Abstract Patients with high-risk essential thrombocythemia (ET) and polycythemia vera (PV) are typically managed with cytoreductive agents such as recombinant interferon-alpha (IFN-α), hydroxyurea (HU), and anagrelide (AG). Despite the significant activity of IFN-α in ET and PV, this agent is frequently hindered by poor tolerance and inconvenient dosing schedules. PEG-IFN-α is formulated by covalently attaching polymers of ethylene glycol to the native IFN-α molecule, resulting in decreased renal excretion and increased serum half-life that allows for weekly administration. On this basis, we are conducting a phase II study of subcutaneous PEG-IFN-α-2a (Pegasys) for patients with ET or PV. A total of 76 patients have been enrolled and treated thus far (36 ET, 40 PV). Median age is 53 years (range, 18–77), time from diagnosis to PEG-IFN-α-2a 49 months (range, 0–355), WBC count 8.7×109/L (range, 3.7–27.8), hemoglobin 13.5 g/dL (range, 8.9–18.8), and platelet count 554×109/L (range, 140–1641). Prior therapies (median 1; range 0–6) included HU (n=44), AG (n=29), IFN-α (n=11: 5 oral and 6 sc), imatinib (n=7), and dasatinib (n=1). PEG-IFN-α-2a was the initial therapy in 13 patients that refused therapy with HU. The JAK2 V617F mutation was detected in 20 (56%) of 36 ET and in 37 (92.5%) of 40 PV patients. Nine (12%) patients had abnormal cytogenetics. Initial starting dose of PEG-IFN-α-2a was 450 mcg/week, but that was modified to the current starting dose of 90 mcg/week. Dose modifications are allowed according to response or toxicity. Patients are currently receiving 450 mcg (n=1), 270 mcg (n=3), 180 mcg (n=14), 135 mcg (n=8), 90 mcg (n=27), and 45 mcg (n=7). After a median follow-up of 23 months (range, 2–38), 63 (85%) of 74 assessable patients have responded. The median time to response was 4 weeks (range, 0.5–26). Complete response (CR) was achieved by 60 (81%) patients (for ET: platelets <440×109/L, off HU and AG, in the absence of thromboembolic events; for PV: Hb <15 g/dL, off HU and AG, no phlebotomy, with disappearance of splenomegaly) whereas 3 (4%) patients (1 PV, 2 ET) had a partial response ([PR]; no phlebotomy, off HU and AG, but still palpable spleen). Of 5 assessable patients with abnormal karyotype at the start of the study, 2 reverted to diploid cytogenetics. The mutant JAK2 V617F to total JAK2 ratio was determined by quantitative pyrosequencing assay in all 76 patients prior to PEG-IFN-α-2a and was repeated at least once during therapy in 41 JAK2 V617F-positive patients. Overall, 23 (56%) had >10% reduction in JAK2 V617F expression, including 14 (34%) who had a >50% reduction. In 5 (11%) of the latter the mutant allele became undetectable. PEG-IFN-α-2a was well tolerated in most patients. Thirty-nine episodes of grade 3–4 toxicity were reported: neutropenia (n=15), elevated transaminases (n=5), infection (n=4), fatigue (n=3), pain (n=3), cardiac (n=2), and anemia, thrombocytopenia, depression, shortness of breath, pruritus, thrombosis, and dizziness in 1 case each. Sixteen (21%) patients were taken off study after a median of 8 months (range, 2–26) on PEG-IFN-α-2a but only 7 (9%) of them due to due to therapy-related toxicities: grade 3 neutropenia, anorexia, depression, ischemic retinopathy, dyspnea, confusion, and pruritic rash. In conclusion, PEG-IFN-α-2a therapy results in remarkable clinical activity with an acceptable toxicity profile in advanced, previously treated, patients with ET or PV. Clinical responses are frequently accompanied by significant reduction of JAK2 V617F allele burden, which becomes undetectable in a proportion of them, suggesting selective targeting of the malignant clone.

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