Tefferi, Ayalew

Abstract Abstract 3895 Poster Board III-831 A genome-wide single nucleotide polymorphism (SNP) screen led to the identification of 11q aUPD in patients diagnosed with various subtypes of myeloproliferative neoplasms (MPN), e.g. chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (aCML) and myelofibrosis (MF) (Grand et al., Blood 2009;113:6182). Further molecular analyses revealed acquired activating point and length mutations in CBL exons 8 and 9 in 10% of CMML, 8% of aCML and 6% of MF cases. Most variants were missense substitutions in the RING or linker domains that abrogated CBL ubiquitin ligase activity and conferred a proliferative advantage to 32D cells overexpressing FLT3. In this study, 160 patients with BCR-ABL and JAK2 V617F negative MPNs were screened for CBL mutations by PCR and direct sequencing. Eighteen known (Y371H, L380P [2x], C381R, C381Y [2x], C384Y, C396Y, H398P, H398Q, W408C, P417H, F418L, R420Q [5x]) and four new (F378L, G397V, I423N, V430M) missense mutations affecting fourteen residues were identified in 20 patients. Two patients harbored two different mutations. The clinical phenotype could be characterized more precisely in 17 patients. Median age was 68 years (range 59–85) with a slight female predominance (f, n=10; m, n=7). Striking hematological features were leukocytosis (14/17; 82%; median 29,000/μl, range 4,500-141,000) with continuously left-shifted granulopoiesis (blasts, promyelocytes, myelocytes, metamyelocytes) in 85% and elevated monocytes (median 2,500/μl, range 630-10,656) >1,000/μL in 88% (15/17) of patients. Eosinophilia (>1,500/μL) was rare (3/17, 18%). Anemia (normal values: f, Hb <12g/dL; m, Hb <14g/dL) was present in all 17 patients (f, median 10g/dL, range 8.7-11.8; m, median 11.2g/dL, range 8.6-12.9). Platelets did not exceed 300,000/μL in any patient while 11/17 (65%) patients presented with thrombocytopenia (median 125,000/μL, range 18,000-271,000). Splenomegaly was present in 11/17 patients (65%) and LDH was elevated (median 304U/L, range 189-729) in 9/17 patients (52%). Bone marrow histology and immunohistochemistry were available from 12 patients. Relevant features were hypercellularity, marked granulopoiesis and microlobulated megakaryocytes without clusters in 11/12 patients (92%), respectively. Increased fibres were seen in 8/12 (67%) patients of whom one showed severe fibrosis. Clinical follow-up was available from 17 patients. Thirteen patients (76%) have died because of progression to secondary acute myeloid leukemia/blast phase (n=7), cytopenia-related complications (n=2) or for unknown reasons (n=4) after a median of 23 months (range 3-60) following diagnosis. In conclusion, point mutations of CBL exons 8 and 9 are present in approximately 6-12% of BCR-ABL and JAK2 V617F negative MPNs. They are associated with a distinct clinical and hematological phenotype presenting with myeloproliferative features allowing diagnosis of a proliferative subtype of CMML rather than aCML or MF in the majority of cases. Patients with left-shifted leukocytosis, monocytosis, anemia and lack of thrombocytosis who are negative for BCR-ABL and point or length mutations of JAK2 should be routinely screened for CBL mutations. Disclosures: No relevant conflicts of interest to declare.

Abstract BACKGROUND: Both thalidomide (Br J Haematol2002;117:288) and lenalidomide (Blood2006;108:1158) are effective for alleviating anemia in approximately 20% of patients with myelofibrosis (MF). However, the value of these drugs is undermined by their respective potential for peripheral neuropathy and severe myelosuppression. In the current study, we evaluated the safety and efficacy of the new immunomodulatory drug, pomalidomide (POM) in MF. METHODS: This is a phase-2 randomized, multicenter, double-blind, active-control, parallel-group study to determine safety and select a “Best” dose of POM alone or combined with prednisone (PRED). Patients were equally randomized to 4 treatment groups: POM (2 mg/day) + placebo, PRED (30 mg/day) + placebo, POM (2 mg/day) + PRED (30 mg/day), and POM (0.5 mg/day) + PRED (30 mg/day). POM therapy was given for up to twelve 28-day treatment cycles. PRED therapy was given in a tapering dose schedule during the first three of these 12 treatment cycles. Protocol eligibility criteria included absolute neutrophil count of ≥ 1 × 109/L, platelet count of ≥ 50 × 109/L and hemoglobin level of < 10 g/dL including red blood cell (RBC) transfusion requirement. Patients with prior thalidomide or lenalidomide therapy and/or venous thrombosis were excluded from study participation. Response was assessed by the International Working Group for Myelofibrosis Research and Treatment (IWG-MRT) criteria (Blood.2006;108:1497) and by independent analysis of the component variables. RESULTS: A total of 104 patients with MF were assessed for eligibility; 85 were randomized and 84 received the assigned therapy. Blinded data for the first 82 patients are presented here; median age was 67 years and MF subtype was PMF in 70% of the patients and post-PV/ET MF in 30%. All patients belonged to either intermediate or high risk disease category (Blood1996;88:1013); 42 (51%) were RBC transfusion-dependent. Median duration of disease before randomization was 3 years (range 2–14). The number of patients assigned to each arm was relatively balanced: 21, 20, 19 and 22, respectively. After a median treatment duration of 3 months, 42 (51%) patients have discontinued protocol therapy because of lack of therapeutic effect (n=19), withdrawal of consent (n=11), adverse event (n=11) or death (n=2). Grade 3/4 adverse events (regardless of attribution) included anemia (10%), thrombocytopenia (9%), leukopenia (9%), fatigue (7%), dyspnea (5%), thrombosis (4%), diarrhea (4%) and hyperglycemia (4%). Combined response rate using IWG-MRT criteria was 25% (95% CI, 16–34%) and ranged between 11% and 42% among the four treatment arms. CONCLUSION: Pomalidomide, with or without concomitant prednisone therapy, is well tolerated in patients with MF, especially from the standpoint of myelosuppression. Response rates are high. Additional, unblinded, information regarding response details, remission duration and laboratory correlative studies will be presented at the meeting.

Abstract Abstract 3918 Poster Board III-854 BACK GROUND We have previously demonstrated that the myeloproliferative neoplasms (MPNs) of primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocythemia (ET) can lead to weight loss, splenomegaly and constitutional symptoms (Cancer 2007;109:68–76). Additionally we have demonstrated that hypocholesterolemia in MPN patients is associated with decreased survival (Blood 2007;110:a2548). Given that current JAK2 inhibitor trials are demonstrating the ability to reverse MPN associated splenomegaly (Haematologica 2009;94(Suppl 2)439 a1088) and cachexia (Blood 2008;112(11):a1760) we sought to determine the baseline natural history for these variables in patients treated prior to the JAK2 inhibitor era. METHODS We analyzed the Mayo MPN database for patients (not treated with JAK2 inhibitors) with information on disease prognosis, presentation, therapies, height and weight at diagnosis, and outcomes. Additionally, when available, we analyzed additional weights during the clinical course, the body mass index (BMI- (weight/(height*height)), spleen size, and peripheral blood studies including lipids. Results: Patients 783 patients with MPNs (followed for a median of 51 months (range 1-871 months); 60% having expired) were identified for the analysis (PV=158, ET=255, PMF=370) with 541 (69%) having a weight at the time of diagnosis, the remainder had a weight obtained a median of 7.8 months after diagnosis. Additionally, 508 patients (65%) had a weight value available from 1–3 additional time points during the course of their disease. Corresponding measurements of splenomegaly, or absence thereof, were noted in 766 cases (98%). Lipid panels (obtained within 18 months of diagnosis) were available in 264 patients. Results by MPN disease type are listed in the Table. Impact on prognosis Univariate analysis of variables discussed which negatively impacted survival included the subtype of MPN (not surprisingly worse for PMF p<0.001), weight loss of greater than 10% during the course of follow-up (P<0.001), or development of splenomegaly of >10 cm below the left costal margin (p=0.004) whereas hypocholesterolemia was significant only for the subset of PMF patients (P=0.03). The IWG-MRT International Prognostic Score (IPSS - Cervantes et. al. Blood 2009) was the only variable prognostically relevant in multivariate analysis (P<0.001). Conclusions Progressive splenomegaly, weight loss, and hypocholesterolemia are common across all MPNs but are most prognostically detrimental in PMF. Ongoing and future trials of JAK2 inhibitors will answer whether reversal of these latter hypercatabolic and proliferative manifestations of disease will improve outcomes for MPN patients. Disclosures: No relevant conflicts of interest to declare.

Abstract Survival of patients with primary myelofibrosis (PMF) is highly variable, ranging from months to even decades. Although treatment of PMF remains mostly palliative, the increasing use of allogeneic hemopoietic stem cell transplantation and introduction of newer therapies has raised the need for a better prognostic stratification of these patients. The initial features of 1,054 patients (638M/416F; median age 64 years, range 10–90) consecutively diagnosed with PMF in seven institutions from Europe and USA between 1980 and 2007 were evaluated for prognostic significance. Patients with the so-called “pre-fibrotic” form of PMF were not considered. The variables assessed were those previously shown to be of prognostic value in PMF, those clinically meaningful, and possible confounders (namely, diagnostic period and series of origin). The effect of the potential prognostic factors on survival was evaluated by the Cox proportional hazards regression and the proportional hazards assumption checked in every model by graphical methods and the Grambsch-Therneau test. A prognostic model was identified through a stepwise selection process, based on a z-test of the regression coefficients, and evaluated by calculating its discriminating power (measured by Harrell’s C concordance index), as compared to that of current PMF prognostic systems, and its positive predictive accuracy for actual survival longer (or shorter) than definite periods of time from diagnosis. The replicability of both the prognostic variables and the new prognostic score was tested by bootstrap re-sampling, in which 1,000 samples of the same size than the original series were built by random extraction with reposition. Median survival of the overall series was 69 months (95% CI: 61–76), with 49% of patients having died at the time of study. At multivariate analysis, five initial variables were associated with shorter survival: age > 65 years, constitutional symptoms (weight loss, fever, sweats), Hb < 10 g/dL, leukocyte count > 25×109/L, and blood blasts 1%. The hazard ratios of these variables did not differ substantially, ranging from 2.89 (95% CI: 2.46–3.61) for Hb < 10 g/dL to 1.80 (95% CI: 1.50–2.17) for blood blasts 1% and, therefore, one point was assigned to each one. Based on this, among the 1,001 patients of the series with all the necessary data available, four risk groups were identified with no overlapping in the 95% CI of their survival curves (figure): low risk (no factor, 22% of patients; median survival 135 months); intermediate risk-1 (one factor, 29% of patients; median survival 95 months); intermediate risk-2 (two factors; 28% of patients; median survival 48 months); and high risk (three factors, 21% of patients; median survival 27 months). The new prognostic score showed high predictive accuracy and replicability and had higher discriminating power than current risk-based PMF classifications. In the 409 patients with assessable metaphases, presence of cytogenetic abnormalities (observed in 30% of cases) was associated with shorter survival and contributed to prognosis, but only in patients in the intermediate-risk groups. No prognostic influence for either JAK2 V617F mutational status (n= 345) or blood CD34+ cell count (n= 150) was noted. This new prognostic scoring system substantially improves existing risk-based classifications of PMF and may help in treatment-decision making and in the design and analysis of newer therapies for the disease. Figure Figure

Abstract A 73-year-old woman with metastatic transitional cell carcinoma of the bladder developed vaginal bleeding a few days after undergoing radical cystectomy. She had no other signs of mucocutaneous bleeding. Coagulation studies revealed a markedly prolonged thrombin time (greater than 600 seconds), a slightly prolonged reptilase time (20 seconds), and mildly elevated fibrinogen (4.39 g/L), and fibrin D-dimer (200 to 500 ng/mL) levels. Treatment of the patient's plasma in vitro with protamine or barium sulfate normalized the thrombin time. The anticoagulant activity corresponded to 0.15 heparin U/mL when measured by a thrombin time assay using normal plasma as substrate and standardized with porcine heparin. The anticoagulant was quantitatively bound to and subsequently eluted with 1 mol/L NaCl from quaternary aminoethyl (QAE) Sephadex, and then isolated by affinity chromatography on immobilized antithrombin III. The isolated anticoagulant was shown to be sensitive to heparinase digestion. Therefore, the inhibitor has functional and chemical properties similar to those of high-affinity heparin. Thus far, this is the only anticoagulant of this type isolated from the plasma of a patient bearing a tumor other than plasma cell myeloma.

Abstract Background: Peripheral blood (PB) is sometimes used in place of bone marrow (BM) for cytogenetic studies during the evaluation of hematologic malignancies. We looked for clinical or laboratory features that predict success in obtaining analyzable metaphases during PB chromosome studies. Methods: The Mayo Clinic cytogenetics database was queried to identify adult cases (age > 18 years) with suspected or established hematologic neoplasm in whom PB cytogenetic studies were performed. Success defined as the acquisition of at least two metaphases, was correlated with clinical and laboratory information corresponding to the time of the PB cytogenetic study. Results: A total of 242 PB cytogenetic studies were performed: clinical diagnosis was a myeloid neoplasm in 169 patients (70%), lymphoid neoplasm in 50 (21%), and unexplained cytopenia or leukocytosis in 23 (9%). The 169 myeloid cases included 59 patients with either primary (n=39) or post-polycythemia vera/essential thrombocythemia (post-PV/ET MF) myelofibrosis (n=20), 42 with acute myeloid leukemia (AML), 15 with chronic myeloid leukemia, 9 with myelodysplastic syndrome (MDS), 8 with ET, 6 with PV, and 30 with other MPDs. The 50 lymphoid cases included 19 with chronic lymphocytic leukemia, 12 with lymphoma, 11 with acute lymphocytic leukemia (ALL), and 8 with plasma cell proliferative disorders. PB cytogenetic studies resulted in at least two analyzable metaphases (median 20, range 2–31) in 142 of the 242 study cases (59%); in univariate analysis, this was predicted by the specific clinical diagnosis (p<0.0001), presence and degree of circulating myeloid progenitor cells (p<0.0001), higher leukocyte count (p<0.001), lower platelet count (p=0.003), lower hemoglobin level (p=0.002), and presence of palpable splenomegaly (p=0.002). In multivariable analysis, only the presence of circulating myeloid progenitor cells sustained its significance and this was consistent with the high yield rates seen in PMF (80%), post-PV/ET MF (85%), AML (76%), and ALL (80%) as opposed to the low rates seen in ET (0%) and PV (2%). In 104 cases, BM cytogenetic studies were performed within one month of the PB cytogenetic studies; an abnormal BM cytogenetic finding was another independent predictor of a successful PB study (p=0.002). Conclusion: PB cytogenetic studies are most appropriate in diseases characterized by presence of circulating myeloid progenitors or blasts (e.g. PMF, AML, ALL); the yield otherwise is too small to be cost-effective. The current study also suggests a higher likelihood of a successful PB cytogenetic study in the presence of an abnormal bone marrow karyotype.

Abstract Background: In both polycythemia vera (PV) and essential thrombocythemia (ET), aspirin and/or hydroxyurea therapy provide adequate protection from thrombosis but not from disease transformation into acute myeloid leukemia/myelodysplastic syndrome (AML/MDS) or myelofibrosis (MF). In designing clinical trials with new drugs, including the use of small molecule JAK2 inhibitors, in either ET or PV, it is important to identify patients who are at a higher risk of early transformation into AML/MDS/MF as well as those in whom the long-term risk of these complications is too low to justify exposure to experimental drugs with unknown short-term and long-term toxicity profile. Methods: Information on an institutional database of 1061 patients with either PV (n=458) or ET (n=603) was updated in July of 2007. The World Health Organization criteria were used for diagnosis of PV, ET, AML, MDS, and MF. Two different approaches were used to assess both early and overall risk of AML/MDS/MF development in both ET and PV. In the first approach, three distinct groups were delineated and their presenting features compared; group A was comprised of patients who have remained AML/MDS/MF free after a minimum follow-up of 20 years whereas groups B and C included patients who developed either AML/MDS or MF, respectively, in the first decade of their disease. In the second approach, prognostic factors for AML/MDS/MF-free survival were examined among the entire cohort of 1061 patients. Results : In ET, the number of patients that fulfilled the above-mentioned criteria for inclusion in groups A, B, and C were 40, 12, and 8; the three groups displayed significant differences in the prevalence, at diagnosis, of lower than normal hemoglobin level (8% vs. 58% vs. 38%; p=0.0004), male sex (18% vs. 58% vs. 50%; p=0.01), and arterial thrombosis at diagnosis (p=0.03), respectively. However, only the former two remained significant during multivariable analysis that included age as a covariate. In PV, the number of patients in groups A, B, and C were 23, 18, and 12; the only difference between the three groups was the association between group B and leukocytosis (p=0.02). Cox regression analysis of the entire 1061 ET/PV patients cohort, including 65 AML/MDS/MF events in ET and 36 AML/MDS events in PV, confirmed the inferior AML/MDS/MF-free survival in ET associated with lower than normal hemoglobin and AML/MDS-free survival in PV associated with leukocytosis (Figure). Conclusion : The current study identifies PV patients with leukocytosis as being the most appropriate and ET patients without anemia as the least appropriate for consideration of participation in experimental drug treatment trials. Figure Figure Figure Figure

Polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) are myeloproliferative disorders (MPDs) associated with activating mutations of Janus tyrosine kinase 2 (JAK2) gene. The most common mutation, JAK2 V617F, has been reported in ∼97% of patients with PV, ∼50% with ET, and ∼50% with PMF. The resultant JAK2 protein is continuously autophosporylated and therefore always active. It is believed that this mutated tyrosine kinase contributes to the existence and progression of MPDs. CEP701 is an orally available potent low nanomolar inhibitor of wild type and mutated JAK2 tyrosine kinase in enzymatic and cellular assays. Significant inhibition (growth stasis) was observed following CEP-701 subcutaneous administration to V617F-mutated JAK2-dependent HEL.92 xenografts grown in immunocompromised mice. These results indicate that CEP-701 is an attractive candidate for clinical evaluation in patients with MPD carrying a mutated, constitutively activated JAK2. CEP701 is also a potent inhibitor of FLT3 and is being evaluated as FLT3 inhibitor in Phase II/III studies in patients with acute myeloid leukemia, at the starting dose of 80mg PO BID. We designed a Phase II study of CEP701, at the dose of 80 mg PO BID, in patients with PMF and post PV/ET MF, who harbor JAK2 V617F mutation. Eleven patients have been treated so far, seven males, median age 56 years (range, 38–69), median 3 prior therapies (range 0–6); 7 with abnormal cytogenetics; 8 with enlarged spleen (2 had splenectomy); 4 with enlarged liver; 5 transfusion dependent. Five patients have been followed for at least 1 month and have had stable disease. Response will be evaluated using International Working Group for MF Consensus Response Criteria. JAK2 V617F allele burden is being measured monthly. Except for Grade 2 nausea in one patient, no toxicities have been noted so far. Updated results will be presented at the meeting.

In a 20-year period, 223 patients (median age, 64.8 years) with myelofibrosis with myeloid metaplasia (MMM) had therapeutic splenectomy at our institution. Primary indications for surgery were transfusion-dependent anemia (45.3%), symptomatic splenomegaly (39.0%), portal hypertension (10.8%), and severe thrombocytopenia (4.9%). Operative mortality and morbidity rates were 9% and 31%, respectively. The 203 survivors of surgery had a median postsplenectomy survival time (PSS) of 27 months (range, 0-155). Among preoperative variables, thrombocytopenia (platelet count less than 100 × 109/L) and nonhypercellular bone marrow were identified as independent risk factors for decreased PSS. Durable remissions in constitutional symptoms, transfusion-dependent anemia, portal hypertension, and severe thrombocytopenia were achieved in 67%, 23%, 50%, and 0% of the patients, respectively. Histologic or cytogenetic features of bone marrow obtained before splenectomy did not predict a response in cytopenias. After splenectomy, substantial enlargement of the liver and marked thrombocytosis occurred in 16.1% and 22.0% of the patients, respectively. The thrombocytosis was associated with an increased risk of perioperative thrombosis and decreased PSS. The rate of blast transformation (BT) was 16.3%, and the risk of BT was higher in the presence of increased spleen mass and preoperative thrombocytopenia. However, the PSS of patients with BT was not significantly different from that of patients without BT. We conclude that presplenectomy thrombocytopenia in MMM may be a surrogate for advanced disease and is associated with an increased risk of BT and inferior PSS. However, the development of BT after splenectomy may not affect overall survival and does not undermine the palliative role of the procedure for the other indications.