Citations

Abstract We examined the prevalence and prognostic relevance of bone marrow reticulin fibrosis in 526 patients with World Health Organization–defined polycythemia vera evaluated at the time of initial diagnosis. Seventy-four patients (14%) displayed mostly grade 1 reticulin fibrosis, with only 2 cases showing higher-grade fibrosis. Presenting clinical and laboratory characteristics, including JAK2V617F allele burden, between patients with and without fibrosis were similar for the most part, with the exception of a higher prevalence of palpable splenomegaly in patients with fibrosis (P < .01). Patients with fibrosis were less prone to experience thrombosis during their clinical course (1.1 vs 2.7 per 100 patient-years; P = .03) and more prone to develop post-polycythemia vera myelofibrosis (2.2 vs 0.8 per 100 patient-years; P = .01). There was no significant difference between the 2 groups in terms of overall or leukemia-free survival. The present study clarifies the incidence, degree, and prognostic relevance of bone marrow fibrosis obtained at time of initial diagnosis of polycythemia vera.

SF3B1 mutations were recently reported in myelodysplastic syndromes (MDSs), especially in the presence of ring sideroblasts (RSs). We sought to define the interaction between SF3B1 mutations, morphology, karyotype, and prognosis in MDS with more than or equal to 15% RS (MDS-RS). We studied 107 patients with MDS-RS, including 48 with refractory anemia with RS (RARS), 43 with refractory cytopenia with multilineage dysplasia (RCMD)-RS, 11 with refractory anemia with excess blasts-1 (RAEB1)–RS, and 5 with RAEB2-RS. SF3B1 mutations were detected in 53 (∼ 50%) patients: 35 RARS (73%), 16 RCMD-RS (37%), and 2 RAEB1-RS (18%). In univariate analysis, the presence of SF3B1 mutations was associated with better overall (P < .01) and leukemia-free (P < .01) survival; however, in both instances, significance was completely accounted for by World Health Organization morphologic risk categorization. In other words, when RARS and RCMD-RS were analyzed separately, there was no additional prognostic value from the presence or absence of SF3B1 mutations.

Abstract DIPSS-plus (the Dynamic International Prognostic Scoring System-plus) includes 8 risk factors for survival in primary myelofibrosis. In the present study of 884 karyotypically annotated patients with primary myelofibrosis, we sought to identify 1 or 2 parameters that can reliably predict death in the first 2 years of disease. After a median of 8.2 years from time of referral to the Mayo Clinic, 564 deaths (64% of patients in the study) had been recorded. Risk factors associated with > 80% 2-year mortality included monosomal karyotype, inv(3)/i(17q) abnormalities, or any 2 of the following: circulating blasts > 9%, leukocytes ≥ 40 × 109/L, or other unfavorable karyotype. Patients with any 1 of these risk profiles (n = 52) displayed significantly shorter overall survival than those otherwise belonging to a high-risk category per DIPSS-plus (n = 298); respective median survivals were 9 and 23 months (hazard ratio 2.2, 95% confidence interval 1.6-3.1; P < .01). The present information complements DIPSS-plus in the selection of primary myelofibrosis patients for high-risk treatment approaches.

Purpose The WHO diagnostic criteria underscore the role of bone marrow (BM) morphology in distinguishing essential thrombocythemia (ET) from early/prefibrotic primary myelofibrosis (PMF). This study examined the clinical relevance of such a distinction. Methods Representatives from seven international centers of excellence for myeloproliferative neoplasms convened to create a clinicopathologic database of patients previously diagnosed as having ET (N = 1,104). Study eligibility criteria included availability of treatment-naive BM specimens obtained within 1 year of diagnosis. All bone marrows subsequently underwent a central re-review. Results Diagnosis was confirmed as ET in 891 patients (81%) and was revised to early/prefibrotic PMF in 180 (16%); 33 patients were not evaluable. In early/prefibrotic PMF compared with ET, the 10-year survival rates (76% and 89%, respectively) and 15-year survival rates (59% and 80%, respectively), leukemic transformation rates at 10 years (5.8% and 0.7%, respectively) and 15 years (11.7% and 2.1%, respectively), and rates of progression to overt myelofibrosis at 10 years (12.3% and 0.8%, respectively) and 15 years (16.9% and 9.3%) were significantly worse. The respective death, leukemia, and overt myelofibrosis incidence rates per 100 patient-years for early/prefibrotic PMF compared with ET were 2.7% and 1.3% (relative risk [RR], 2.1; P < .001), 0.6% and 0.1% (RR, 5.2; P = .001), and 1% and 0.5% (RR, 2.0; P = .04). Multivariable analysis confirmed these findings and also identified age older than 60 years (hazard ratio [HR], 6.7), leukocyte count greater than 11 × 10 9 /L (HR, 2.01), anemia (HR, 2.95), and thrombosis history (HR, 2.81) as additional risk factors for survival. Thrombosis and JAK2V617F incidence rates were similar between the two groups. Survival in ET was similar to the sex- and age-standardized European population. Conclusion This study validates the clinical relevance of strict adherence to WHO criteria in the diagnosis of ET and provides important information on survival, disease complication rates, and prognostic factors in strictly WHO-defined ET and early/prefibrotic PMF.

Abstract Symptomatic burden in myeloproliferative neoplasms is present in most patients and compromises quality of life. We sought to validate a broadly applicable 18-item instrument (Myeloproliferative Neoplasm Symptom Assessment Form [MPN-SAF], coadministered with the Brief Fatigue Inventory) to assess symptoms of myelofibrosis, essential thrombocythemia, and polycythemia vera among prospective cohorts in the United States, Sweden, and Italy. A total of 402 MPN-SAF surveys were administered (English [25%], Italian [46%], and Swedish [28%]) in 161 patients with essential thrombocythemia, 145 patients with polycythemia vera, and 96 patients with myelofibrosis. Responses among the 3 administered languages showed great consistency after controlling for MPN subtype. Strong correlations existed between individual items and key symptomatic elements represented on both the MPN-SAF and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30. Enrolling physicians' blinded opinion of patient symptoms (6 symptoms assessed) were highly correlated with corresponding patients' responses. Serial administration of the English MPN-SAF among 53 patients showed that most MPN-SAF items are well correlated (r > 0.5, P < .001) and highly reproducible (intraclass correlation coefficient > 0.7). The MPN-SAF is a comprehensive and reliable instrument that is available in multiple languages to evaluate symptoms associated with all types of MPNs in clinical trials globally.

AbstractJAK-STAT signaling is involved in the regulation of cell survival, proliferation, and differentiation. JAK tyrosine kinases can be transiently activated by cytokines or growth factors in normal cells, whereas they become constitutively activated as a result of mutations that affect their function in tumors. Specifically, the JAK2V617F mutation is present in the majority of patients with myeloproliferative disorders (MPDs) and is implicated in the pathogenesis of these diseases. In the present study, we report that the kinase CK2 is a novel interaction partner of JAKs and is essential for JAK-STAT activation. We demonstrate that cytokine-induced activation of JAKs and STATs and the expression of suppressor of cytokine signaling 3 (SOCS-3), a downstream target, are inhibited by CK2 small interfering RNAs or pharmacologic inhibitors. Endogenous CK2 is associated with JAK2 and JAK1 and phosphorylates JAK2 in vitro. To extend these findings, we demonstrate that CK2 interacts with JAK2V617F and that CK2 inhibitors suppress JAK2V617F autophosphorylation and downstream signaling in HEL92.1.7 cells (HEL) and primary cells from polycythemia vera (PV) patients. Furthermore, CK2 inhibitors potently induce apoptosis of HEL cells and PV cells. Our data provide evidence for novel cross-talk between CK2 and JAK-STAT signaling, with implications for therapeutic intervention in JAK2V617F-positive MPDs.

Abstract In an international collaborative study, a central histologic review identified 891 patients with essential thrombocythemia, strictly defined by World Health Organization criteria. After a median follow-up of 6.2 years, 109 (12%) patients experienced arterial (n = 79) or venous (n = 37) thrombosis. In multivariable analysis, predictors of arterial thrombosis included age more than 60 years (P = .03; hazard ratio [HR] = 1.7), thrombosis history (P = .003; HR = 2.1), cardiovascular risk factors including tobacco use, hypertension, or diabetes mellitus (P = .007; HR = 1.9), leukocytosis (> 11 × 109/L; P = .04; HR = 1.7), and presence of JAK2V617F (P = .009; HR = 2.6). In contrast, only male gender predicted venous thrombosis. Platelet count more than 1000 × 109/L was associated with a lower risk of arterial thrombosis (P = .007; HR = 0.4). These associations, except the one with leukocytosis, remained significant (or near significant) when analysis was restricted to JAK2V617F-positive cases. The current study clarifies the contribution of specific disease and host characteristics to the risk of arterial versus venous thrombosis in essential thrombocythemia.

Abstract Survival in cytogenetically high-risk patients with acute myeloid leukemia or myelodysplastic syndromes is significantly worse in the presence of a monosomal karyotype (MK). The objective of the present study was to determine whether the same held true for primary myelofibrosis. Among 793 primary myelofibrosis patients seen at our institution, 62 displayed an unfavorable karyotype by way of complex karyotype (n = 41) or sole trisomy 8 (n = 21). Seventeen (41%) of the 41 patients with complex karyotype were classified as having an MK. Median survival was 6, 24, and 20 months in patients with MK, complex karyotype without monosomies, and sole trisomy 8, respectively (P < .0001). The corresponding 2-year leukemic transformation rates were 29.4%, 8.3%, and 0 (P < .0001); hazard ratios (95% confidence intervals) were 6.9 (1.3-37.3) and 14.8 (1.7-130.8). The prognostic relevance of MK was not accounted for by the Dynamic International Prognostic Scoring System. We conclude that MK in primary myelofibrosis is associated with extremely poor overall and leukemia-free survival.

Purpose Abnormal cytokine expression accompanies myelofibrosis and might be a therapeutic target for Janus-associated kinase (JAK) inhibitor drugs. This study describes the spectrum of plasma cytokine abnormalities in primary myelofibrosis (PMF) and examines their phenotypic correlates and prognostic significance. Patients and Methods Patients included in this study were required to have archived plasma, bone marrow biopsy, and cytogenetic information available at the time of first referral to the Mayo Clinic. Multiplex biometric sandwich immunoassay was used to measure plasma levels of 30 cytokines. Results In total, 127 PMF patients were studied; comparison with normal controls (n = 35) revealed significantly increased interleukin-1β (IL-1β), IL-1RA, IL-2R, IL-6, IL-8, IL-10, IL-12, IL-13, IL-15, tumor necrosis factor α (TNF-α), granulocyte colony-stimulating factor (G-CSF), interferon alfa (IFN-α), macrophage inflammatory protein 1α (MIP-1α), MIP-1β, hepatocyte growth factor (HGF), IFN-γ–inducible protein 10 (IP-10), monokine induced by IFN-γ (MIG), monocyte chemotactic protein 1 (MCP-1), and vascular endothelial growth factor (VEGF) levels and decreased IFN-γ levels. In treatment-naive patients (n = 90), increased levels of IL-8 (P < .001), IL-2R (P < .001), IL-12 (P < .001), IL-15 (P = .001), and IP-10 (P = .003) were independently predictive of inferior survival. A similar multivariable analysis that included all 127 study patients confirmed the prognostic value of these five cytokines, and IL-8, IL-2R, IL-12, and IL-15 remained significant when risk stratification, according to the recently revised Dynamic International Prognostic Scoring System (DIPSS plus), was added to the multivariable model. Leukemia-free survival was predicted by IL-8, which was also the only cytokine associated with ≥ 1% circulating blasts. Other cytokine-phenotype associations included increased IL-8 and constitutional symptoms; IL-2R, IL-12, and transfusion need; IL-2R, IL-8, and leukocytosis; IP-10 and thrombocytopenia; HGF, MIG, IL-1RA, and marked splenomegaly; and IL-1RA, IL-2R, IP-10, MIP-1β, and JAK2V617F. A two-cytokine (IL-8/IL-2R) –based risk categorization delineated prognostically different groups within specific DIPSS plus risk categories. Conclusion This study signifies the presence of specific cytokine-phenotype associations in PMF and a prognostically relevant plasma cytokine signature that might prove useful as a laboratory tool for predicting and monitoring treatment response.

Purpose Myelofibrosis is a myeloid malignancy associated with anemia, splenomegaly, and constitutional symptoms. Patients frequently harbor JAK-STAT activating mutations that are sensitive to TG101348, a selective small-molecule Janus kinase 2 (JAK2) inhibitor. Patients and Methods In a multicenter phase I trial, oral TG101348 was administered once a day to patients with high- or intermediate-risk primary or post–polycythemia vera/essential thrombocythemia myelofibrosis. Results Fifty-nine patients were treated, including 28 in the dose-escalation phase. The maximum-tolerated dose was 680 mg/d, and dose-limiting toxicity was a reversible and asymptomatic increase in the serum amylase level. Forty-three patients (73%) continued treatment beyond six cycles; the median cumulative exposure to TG101348 was 380 days. Adverse events included nausea, vomiting, diarrhea, anemia, and thrombocytopenia; corresponding grades 3 to 4 incidence rates were 3%, 3%, 10%, 35%, and 24%. TG101348 treatment had modest effect on serum cytokine levels, but greater than half of the patients with early satiety, night sweats, fatigue, pruritus, and cough achieved rapid and durable improvement in these symptoms. By six and 12 cycles of treatment, 39% and 47% of patients, respectively, had achieved a spleen response per International Working Group criteria. The majority of patients with leukocytosis or thrombocytosis at baseline (n = 28 and n = 10, respectively) achieved normalization of blood counts after six (57% and 90%, respectively) and 12 (56% and 88%, respectively) cycles. A significant decrease in JAK2 V617F allele burden was observed at 6 months in mutation-positive patients (n = 51; P = .04), particularly in the subgroup with allele burden greater than 20% (n = 23; P < .01); the decrease was durable at 12 months. Conclusion TG101348 is well tolerated and produces significant reduction in disease burden and durable clinical benefit in patients with myelofibrosis.