scholarly journals Role of Non-Driver Mutations and JAK2V617F Allele Burden in Myelofibrotic and Acute Myeloid Transformation of Patients with Polycythemia Vera and Essential Thrombocythemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1952-1952 ◽  
Author(s):  
Alicia Senín ◽  
Conchi Fernández ◽  
Beatriz Bellosillo ◽  
Laura Camacho ◽  
Raquel Longaron ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Essential Thrombocythemia ◽  
Chronic Phase ◽  
Progressive Increase ◽  
Driver Mutations ◽  
Evolutionary Pattern ◽  
Allele Burden ◽  
Jak2v617f Allele Burden ◽  
Acute Myeloid

Abstract Background: Non-driver mutations and JAK2V617F allele burden have been involved in progression to myelofibrosis (MF) or acute myeloid leukemia (AML) in patients with polycythemia vera (PV) and essential thrombocythemia (ET). It is unknown if both mechanisms play a different role in disease transformation and if they are useful in routine clinical practice. Methods: JAK2V617F allele burden was monitored in 208 patients (PV n=106, ET n=102) for a median of 6.5 years (range: 1-13). Quantification of JAK2V617F allele burden was assessed on the first available sample and every year thereafter. The evolutionary pattern of JAK2V617F allele burden was categorized as persistently low (<50%), persistently high (>50%), progressive increase (> 25% from baseline) or unexplained decrease (not therapy related). Next generation sequencing (NGS) analysis of 51 myeloid-related genes was performed in 100 patients with a median molecular follow-up of 10 years including all cases with transformation to AML or MF. Detected mutations by NGS in the last sample were studied in first paired sample obtained in the chronic phase (median time from diagnosis: 1.6 years). Time to myelofibrosis and time to AML were calculated according to the presence of non-driver mutations or the JAK2V617F evolutionary pattern. Multivariate analysis was performed by Cox regression. Results: With a median follow-up of 13 years (range: 1-30) 32 patients died whereas 24 and 12 patients progressed to MF and AML, respectively. Median age at diagnosis was 63 years (range: 20-94), 115 were women (55%) and 173 (83%) received cytoreduction. A persistently low JAK2V617F allele burden was observed in 62% of patients whereas the remainder presented a persistently high (25%), a progressive increase (11%) or a non-therapy-related decrease of JAK2V617F allele burden (2%). Non-driver mutations were detected in last sample in 48% of patients. Median number of mutations was 1 (range: 1-5). Mutational frequencies were: TET2 12%, DNMT3A 12%, TP53 9%, ASXL1 7%, RUNX1 4%, SF3B1 4%, SRSF2 4%, IDH1/2 4%, SH2B3 3 % and <2% for EZH2, ZRSR2, SETBP1, FLT3, NPM, BCOR, CBL, PTPN11, KAT6A, NF1, U2AF1, GNAS, PHF6, KTM2A, JAK2, BCORL1, NOTCH1, MPL and PRPF40B. Mutations were detected in first sample in 28% of patients (58% of those with mutations in last sample). Frequencies of mutations in first sample were: TET2 10%, DNMT3A 5%, TP53 5%, ASXL1 4%, SRSF2 4%, IDH1/2 3%, and < 2% for SF3B1, SH2B3, KMT2A and ZRSR2. The evolutionary pattern of JAK2V617F allele burden was not associated with the presence of mutations in first or last sample. Twelve patients progressed to AML (post-PV n=7, post-ET n=5), nine of them presented mutations in first sample. AML transformation at 15 years was 27% and 6.8% for patients with and without additional mutations in first sample, respectively (p=0.001). Mutated genes associated with a higher probability of AML transformation were DNMT3A (p<0.0001), SRSF2 (p<0.0001) and IDH (p<0.0001). Other variables associated with a higher probability of AML were age > 65 years (p=0.012) and exposure to busulfan (p=0.003). Evolutionary JAK2V617F pattern was not associated with the probability of AML (p=0.667). In multivariate analysis, an increased risk of AML transformation was observed for patients with additional mutations in the chronic phase (HR: 6.3; 95%CI 1.6-24.7, p=0.008) after adjusting for initial diagnosis, age and exposure to busulfan. Twenty-four MF transformations were documented (post-PV n= 18, post-ET n=6). Presence of additional mutations was not associated with the probability of MF (p=0.189). Patients with persistently high or a progressive increase of the JAK2V617Fallele burden showed a higher probability of MF transformation (24% versus 1.5% at 10 years, p<0.0001) that persisted in multivariate analysis after correction for age and initial diagnosis (HR 13.9, 95%CI: 2.9-65.6, p=0.001). Conclusion: Non-driver mutations are involved in the progression of PV and ET to AML but not to MF. NGS could be useful for identifying patients with PV or ET at risk of AML transformation. Acknowledgment:This work was supported by grants from the Instituto de Salud Carlos III, Spanish Health Ministry, FISPI13/00557, FISPI1300393, RD012/0036/0004, 2014 SGR567. Alicia Senín received a grant from Sociedad Española de Hematología y Hemoterapia. Disclosures No relevant conflicts of interest to declare.

Hematopoietic Clonal Dominance and Evolutionary Pattern Of JAK2V617F Allele Burden In Polycythemia Vera Patients

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2832-2832
Author(s):  
Anna Angona ◽  
Alberto Alvarez-Larrán ◽  
Beatriz Bellosillo ◽  
Luz Martínez-Avilés ◽  
Laura Camacho ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Conflicts Of Interest ◽  
Chronic Phase ◽  
Progressive Increase ◽  
Absolute Difference ◽  
Evolutionary Pattern ◽  
Allele Burden ◽  
Cd34 Cells ◽  
The Relationship ◽  
Jak2v617f Allele Burden

Abstract Introduction The JAK2V617F allele burden at progenitor levels increases over time in polycythemia vera (PV), with the dominance of the JAK2V617F-positive clone at the CD34+ compartment being an important modifier of the disease phenotype. The relationship between clonal dominance and the evolutionary pattern of JAK2V617F granulocytic load is presently unknown. Objective To analyze the relationship between clonal dominance of CD34+ cells with the evolution of the granulocytic JAK2V617F mutant load in PV patients. Methods A total of 37 patients with PV were included in the study. At time of the study, 30 patients corresponded to the chronic phase of the disease, whereas 7 patients had evolved to myelofibrosis (post-PV MF). Seventeen patients were in early chronic phase (less than 5 years from diagnosis) and 13 patients in late chronic phase (more than 5 years from diagnosis). Granulocytes were isolated from peripheral blood by density gradient, whereas CD34+ cells were purified by immunomagnetic positive selection. Stem cells (CD34+, CD38-) and progenitors (CD34+, CD38+) populations were further separated by fluorescence-activated cell sorting. JAK2V617F allele burden was measured by quantitative PCR in all three cell fractions. Clonal dominance was defined as an absolute difference ≤ 10% in JAK2V617F between granulocytes and CD34+ populations. Granulocytic JAK2V617F mutant load was measured every year with the evolutionary pattern of the JAK2V617F allele burden being stratified as follows: stable < 50%, stable ≥ 50%, progressive increase and unexplained decrease. The study was approved by the local Ethics Committee and informed consent was obtained according to the Declaration of Helsinki. Results JAK2V617F allele burden in CD34+/CD38- cells was 8%, 24.9% and 71.4% in early chronic phase, late chronic phase and post-PV MF, respectively (p < 0.001). Similar results were observed in CD34+/CD38+ cells (JAK2V617F allele burden: 19.1%, 36.1% and 71.8% in early chronic phase, late chronic phase and post-PV MF, respectively, p < 0.001). No significant differences were observed among the three groups in granulocyte JAK2V617F allele burden. Six patients (16.2%) presented clonal dominance. According to disease status, clonal dominance was observed in 5 out of 7 (71.4%) patients with post-PV MF and in 1 out of 13 (7.7%) patients in late chronic phase, whereas no patient in early chronic phase showed clonal dominance. JAK2V617F monitoring was performed in 29 patients. According to their granulocytic JAK2V617F evolutionary patterns, 9 patients remained with a stable JAK2V617F below 50%, 13 patients showed a stable JAK2V617F ≥ 50%, 6 patients experienced a progressive increase of the JAK2V617F mutant load and 1 case presented an unexplained decrease of JAK2V617F. Clonal dominance was observed in 5 out of 20 (25%) patients with a stable JAK2V617F >50% or a changing profile in comparison to 0 out of 9 patients with stable JAK2V617F < 50% (p=0.05). Conclusion Clonal dominance correlates with JAK2V617F allele burden evolutionary pattern.This may be a factor to be taken into account in the therapeutic strategy of PV patients and supports the need to monitor JAK2V617F burden during clinical follow-up. Funding this study was supported by grants from the Ministry of Education and Science of Spain and Instituto de Salud Carlos III FEDER (EC10-136, FIS PI10/018087, RD09/0076/00036 and RD12/0036/0010), 2009SGR929 and by grant from Asociación Española Contra el Cáncer Catalunya. 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.

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.

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

Platelet Count Predicts Co-occurrence of Driver Mutations in Essential Thrombocythemia and Myelofibrosis with a Low JAK2 Allele Burden

2019 ◽  
Vol 19 ◽  
pp. S352-S353
Author(s):  
Barbara Mora ◽  
Margherita Maffioli ◽  
Daniela Barraco ◽  
Michele Merli ◽  
Rosario Casalone ◽  
...  
Keyword(s):  
Platelet Count ◽  
Essential Thrombocythemia ◽  
Driver Mutations ◽  
Allele Burden

Long-Term Follow-Up of Allogeneic Stem Cell Transplantation (SCT) with Reduced Intensity Conditioning (RIC) for Patients (pts) with Chronic Myeloid Leukemia (CML).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2898-2898
Author(s):  
Partow Kebriaei ◽  
Michelle Detry ◽  
Antonio Carrasco-Yalan ◽  
Athanasios Anagnostopoulos ◽  
Daniel Couriel ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Stem Cell ◽  
Acute Gvhd ◽  
Advanced Disease ◽  
Chronic Phase ◽  
Disease Stage ◽  
Disease Group ◽  
Blast Phase

Abstract Allogeneic SCT remains an effective strategy for inducing durable remission in CML. RIC regimens are less myelosuppressive, but adequately immunosuppressive, allowing for engraftment with acceptable treatment-related mortality (TRM) in older pts who otherwise would not be candidates for SCT. The long-term antitumor effect of this approach is not well-established. This is relevant in CML, since many pts present for SCT with advanced disease after failing tyrosine kinase inhibitors (TKI). Patients, Methods: We evaluated outcomes of 64 CML pts (40 M/24 F) with median age 52 yrs (range 18–72) treated from June 1996 to April 2005 with FAI (fludarabine 120 mg/m2, Ara-C 8 gm/m2, idarubicin 36 mg/m2), FM140 (fludarabine 120 mg/m2, melphalan 140 mg/m2 +/− Ara-C 2 gm/m2) or FM180 (fludarabine 120 mg/m2, melphalan 180 mg/m2) and unmanipulated stem cells. Disease stage at time of study entry was first chronic (n=13), second chronic (n=17), accelerated (n=29), or blast phase (n=5), with median time from diagnosis to SCT of 2.6 yrs (range 0.5–20.3). Stem cell source was bone marrow (n=38) or peripheral blood (n=26), and donor type was matched related (n=30), 1 Ag mismatched related (n=4), or matched unrelated (n=30). Graft vs. host disease (GVHD) prophylaxis consisted of tacrolimus and mini-dose methotrexate in all but 6 pts (CSA-based). Anti-thymocyte-globulin was added to all pts other than matched related. Maintenance therapy with TKIs following SCT was not used. Multivariate analysis was done using Cox proportional hazards regression. Results: 22 pts were alive at a median follow up of 7 yrs from SCT (range 0.8–9.8). OS and PFS were 48% and 30%, respectively, at 2 yrs, and 33% and 30%, respectively, at 5 yrs. The cumulative incidence of acute GVHD grades II–IV and III–IV were 31% and 14%, respectively, and chronic GVHD was 32% (22% for extensive). TRM at 100 days, 1-, 2-, and 5- yrs were 2%, 14%, 20%, and 33%, respectively. There was no association between pt age, donor source, preparative regimen, or time to SCT and TRM. Disease recurrence accounted for 12 of 42 deaths. There were 3 cases of graft rejection, with 1 death from graft rejection. Only disease stage at time of SCT was significantly predictive in multivariate analysis for both OS and PFS. Pts with advanced disease had worse OS (HR 2.36, 95%CI 1.25–4.46, p=0.008, see figure) and PFS (HR 1.91, 95%CI 1.05–3.49, p=0.035) than pts in chronic phase. In multivariate for PFS, pts who developed grade I or II acute GVHD were less likely to progress compared to pts who did not develop any GVHD: grade I (HR 0.324, 95%CI 0.13–0.84, p=0.027) and grade II (HR 0.286, 95%CI 0.11–0.78, p=0.014). Conclusion: RIC SCT provides adequate disease control in chronic phase CML pts. The development of some GVHD is protective in this setting. TRM rates are acceptable but continue to increase over time. Alternative treatment strategies need to be explored in pts with accelerated or blast phase disease. Results may be improved with addition of TKI therapy post SCT. Survival by Disease Group Survival by Disease Group

SAR302503: Interim Safety, Efficacy and Long-Term Impact on JAK2 V617F Allele Burden in a Phase I/II Study in Patients with Myelofibrosis,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3838-3838 ◽  
Author(s):  
Animesh Pardanani ◽  
Jason Gotlib ◽  
Catriona Jamieson ◽  
Jorge E. Cortes ◽  
Moshe Talpaz ◽  
...  
Keyword(s):  
Platelet Count ◽  
Research Funding ◽  
Jak2 V617f ◽  
Intermediate Risk ◽  
Spleen Size ◽  
Safety And Efficacy ◽  
Allele Burden ◽  
Jak2v617f Allele Burden

Abstract Abstract 3838 Background: SAR302503 (SAR503, formerly TG101348), a potent, oral JAK2-selective inhibitor was studied in a Phase I/II trial for the treatment of patients with high- or intermediate-risk primary, post-polycythemia vera (PV) and post-essential thrombocythemia (ET) myelofibrosis (MF). SAR503 was administered orally once daily in 28-day cycles. Eligibility criteria included platelet count of ≥50 × 109/L. Interim safety and efficacy data from this study up to April 2010 have been previously published (JCO 2011, 29(7):789–796). The aim of this presentation is to report updated safety and efficacy of ongoing patients as well as an analysis of the JAK2V617F allele burden in this cohort. Results: Overall, 59 subjects (median age 64 years) were treated. Forty four patients had PMF, 12 post-PV MF and 3 post-ET MF; 86% were JAK2 V617F-positive. Median palpable spleen size was 18 cm at study enrollment. Twenty eight patients were treated in the dose-escalation cohort (30–800 mg administered as a single daily dose); thirty one patients were treated at the MTD (680 mg) in the dose confirmation cohort. 43/59 patients (73%) completed 6 cycles of treatment and continued treatment on the extension study. Currently, 22 patients (37%) remain on treatment with a median number of 28.5 cycles (24–41 range) and a median of last dose of 440 mg/day. Safety: Treatment-emergent toxicities in cycle 1–6 have been previously reported; toxicities were dose-dependent and generally alleviated with dose-reduction. Five patients discontinued treatment beyond cycle 6 for treatment-related adverse events: thrombocytopenia, depression, mental status changes, creatinine elevation and subdural hematoma. For the subgroup of patients with a baseline platelet count between 50–100 × 109/L (n =13; median 73, range 51–94); the platelet count at defined times points during follow up was: cycle 3; median 50, range 21–138 (p=0.09) and cycle 6; median 47, range 13–85 (p=0.01). Despite 7 of the 13 patients being treated at ≥680 mg/day, only 2 instances of Grade 4 thrombocytopenia were noted in this group Spleen response: As previously reported, spleen responses were seen early, usually within first 3 cycles, with half or more patients in each dose level ≥240 mg/day showing a durable ≥50% decrease in palpable spleen size. Spleen size (mean, median, range, and proportion with ≥50% reduction) at the following time points was: Baseline (n=58; 18.33cm, 18cm, 4–38cm, NA) ; 6 months (n=57; 9.05cm, 9cm, 0–30cm, 54.4%;) 12 months (n=42; 8.55cm, 9cm, 0–28cm, 66.7%) 18 months (n=36; 8.03cm, 8.5cm, 0–33cm, 52.8%); 24 months (n=31; 8.10cm, 8cm, 0–30cm, 54.8%,) 30 months (n=18; 6cm, 7.5cm, 0–16cm, 61.1%,and) 36 months (n=9; 5.89cm, 3cm, 0–16cm, 66.7%). JAK2V617F allele burden: We previously reported a significant decrease in JAK2V617F allele burden at the end of cycles 6 and 12. A durable decrease was also demonstrable after 24 cycles of treatment (n =21; median 9%, range 0–100%) relative to baseline (n =51; median 20%, range 3–100%) (p=0.03). Similarly, for patients with JAK2 V617F allele burden >20% at baseline; there was a significant decrease after cycle 24 (n =12; median 21%, range 6–100%) relative to baseline (n =23; median 60%, range 23–100%) (p=0.03). Conclusions: SAR503 is safe and efficacious treatment with long term effect on spleen size and JAK2V617F allele burden in patients with high- and intermediate-risk myelofibrosis. Additional follow up information will be updated at the time of meeting. Disclosures: Jamieson: Wintherix: Equity Ownership; Pfizer Oncology: Research Funding; Celgene: Research Funding; Novartis: Honoraria. Gao:Sanofi-Aventis: Employment. Zhang:Sanofi-Aventis: Employment. Neumann:Sanofi-Aventis: Employment.

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.

A Heterogeneous Response Pattern to Interferon-alpha2 with Induction of a Significant Decrease in the Calreticulin Mutant Allele Burden in a Subset of Patients with Essential Thrombocythemia and Primary Myelofibrosis

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4057-4057
Author(s):  
Sabrina Cordua ◽  
Lasse Kjaer ◽  
Morten Orebo Holmström ◽  
Niels Pallisgaard ◽  
Vibe Skov ◽  
...  
Keyword(s):  
Essential Thrombocythemia ◽  
Mutant Allele ◽  
Myeloproliferative Neoplasms ◽  
Primary Myelofibrosis ◽  
Allele Burden ◽  
Travel Grant ◽  
Ifn Treatment

Abstract Introduction The discovery of mutations in the calreticulin (CALR) gene in the majority of JAK2 -V617F negative patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF) (Klampfl et al., 2013; Nangalia et al., 2013) has improved the diagnostic accuracy considerably, and most recently distinct clinical and hematological characteristics according to mutational status have been described (Park et al., 2015). The perspective is to personalize and optimize treatment according to the molecular and clinical landscape. This may be achieved by obtaining more information on responses in myeloproliferative neoplasms (MPN) to existing treatment strategies as assessed by the allele burden. Mutations in the CALR gene have proven to play a major role in oncogenic and immunologic processes (Lu, Weng, & Lee, 2015). In this context, it is highly relevant to explore the effectiveness of interferon-alpha2 (IFN) in reducing the CALR -mutated clone. Until now, only one paper has reported a decrease in allele burden in two patients during IFN treatment (Cassinat, Verger, & Kiladijan, 2014). The objective of this report is to expand current knowledge on this important topic by describing the mutant CALR allele burden over time in a larger group of IFN-treated patients. Method Clinical data were collected retrospectively from a single institution on all IFN-treated CALR positive MPN patients with sequential determinations of the mutant allele burden. Type 1 and type 2 mutations were initially identified by a previously published fragment analysis (Klampfl et al 2013). We have developed a Taqman qPCR assay for precise determination of the mutant allele burden of type 1 and type 2 mutations. Stored DNA was subsequently analysed to increase follow-up time. Results Twenty-one patients were included. Fifteen patients had a diagnosis of PMF; 7 of these were diagnosed with prefibrotic myelofibrosis. Six patients had ET. The type 1 and 2 mutations were found in 15 and 6 patients, respectively. Median age was 60 years (range 42-79) and the sex ratio (M/F) was 8/13. Fifteen patients (71%) were in ongoing treatment with IFN, whereas treatment was discontinued in 6 (29%) because of side effects. Median time of IFN treatment was 756 days (range 42-3927). The IFN prescribed was either subcutaneous injection of Pegasys® (median: 45 microgram (ug) per week), PegIntron® 25-50 ug per week, or Multiferon® 3 x 3 million IU per week. Median follow up time since the first CALR measurement was 756 days (range 294-2108). Fourteen patients (67%) maintained an unchanged allele burden during follow up; 1 patient (5%) presented a temporary decrease (from 39% to 27% in allele burden) but increased to the initial level within months while still on IFN treatment (presumably due to low compliance); 1 patient (5%) displayed an increase in allele burden during transformation to acute myelogenous leukemia (Figure 1); and 5 patients (24%) exhibited a marked decrease in allele burden (median decrease: 32%, range 18-45) during treatment with IFN (Figure 2). All 5 patients with decreasing allele burden (Table 1) normalized their platelet counts within a median time of 5 weeks (range 4-20) after initiating treatment with IFN. Conclusion Using a novel sensitive assay for the CALR mutant allele burden, we have demonstrated and substantiated the effectiveness of IFN to reduce the allele burden in a larger series of CALR positive patients with PMF and ET. Importantly, we report for the first time on highly heterogeneous response patterns. Our observation of one fourth of the CALR positive patients responding to treatment with IFN strongly suggests that IFN significantly influences the CALR mutational load. Further clinical and molecular studies are urgently needed to explore the mechanisms behind the heterogeneous response patterns and the clinical implications in regard to clonal evolution and disease progression in non-responding patients. We are currently analysing these issues to assess the definite role of IFN in future treatment strategies in CALR positive MPN patients. Table 1. Patients responding to interferon-alpha2 Characteristics Number/median (range) Patients 5 Age, years 53 (42-62) Sex (M/F) 1/4 Diagnosis- Essential thrombocythemia- Primary myelofibrosis- Prefibrotic myelofibrosis 221 Calreticulin mutation type- type 1- type 2 50 Duration of interferon-alpha2 treatment, days 960 (177-2790) Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Cordua: Janssen-Cilag: Other: travel grant. Off Label Use: interferon alpha2 for myeloproliferative neoplasms. Holmström:La Roche Ltd: Other: travel grant. Pallisgaard:Qiagen: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel grant, Speakers Bureau; Bristol Meyer Squibb: Speakers Bureau; Novartis: Other: travel grant, Research Funding, Speakers Bureau; Roche: Other: travel grant. Hasselbalch:Novartis: Research Funding.

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