Tefferi, Ayalew

Abstract Background : Myelofibrosis (MF) is characterized by progressive bone marrow dysfunction, extramedullary hematopoiesis, massive splenomegaly, elevated levels of inflammatory cytokines, severe constitutional symptoms, cachexia and premature death. INCB018424 is a potent, selective inhibitor of JAK 1 and 2 which has demonstrated impressive clinical activity in the early portion of a phase 1/2 study in patients with PMF and Post-PV/ET MF. Methods : Following the initial dose escalation phase with a BID schedule (N=11), both twice daily (10 mg BID to 25 mg BID, N=56) and once daily (25 mg QD to 200 mg QD, N= 37) dose regimens were explored. Endpoints included spleen size assessed by manual palpation, constitutional symptoms assessed using the Modified Myelofibrosis Symptom Assessment Form (MFSAF) and JAK2 allele burden. Exercise capacity is being assessed using the Six Minute Walk Test (6MWT), and body mass and composition are being assessed using standard methods. Safety was assessed by collection of adverse events and monitoring of laboratory data. Results : Over 100 patients are currently enrolled in the study, with a mean exposure to drug of > 5 months. Twenty percent of patients have received INCB018424 for > 9 months. INCB018424 is associated with a rapid reduction of splenomegaly in over 93% of patients from a mean baseline spleen size >20 cm, with 50% or greater reduction being observed in 35% of patients dosed with 10 mg BID or 50 mg QD, and 59% of patients dosed with 25mg BID regimens. These declines nearly always occur within the first month of therapy, with further, slower decreases often observed thereafter. In responding patients, spleen size reduction persists for the duration of therapy (currently up to one year follow-up). Constitutional symptoms are reported with high frequency in the study population as assessed by the MFSAF: night sweats, pruritis and fatigue were reported by >60%, >45% and >90% of patients respectively. Improvements in self-assessed symptom scores (mean % improvement of 40% to 60%) occurred by the first assessment at week 2. Activity limitations are also reported by a high proportion of MF patients; 70% of respondents reported impaired ability to exercise or get around, with a mean score >5 on the 11-point MFSAF scale; INCB018424 therapy was associated with rapid (within 2 weeks) and marked (40% or more) improvement in self-assessed score. There was a dose-dependent weight gain, most pronounced in patients with the lowest body mass index (BMI) values at baseline. Profound reductions in inflammatory cytokines were observed by the first evaluation at week 2 in virtually all patients, and were maintained during therapy. INCB018424 is generally well tolerated with the primary toxicity being dose-dependent grade 3 or 4 reversible thrombocytopenia which occurred in 0%, 18% and 32% of patients dosed with 10 mg BID, 50 mg QD or 25 mg BID. Conclusions : INCB18424 shows unprecedented and durable clinical efficacy in reducing spleen size and improving constitutional symptoms in patients with MF. Results from proactive dose modification regimens, assessments of exercise capacity, MRI-based spleen volume assessment and body composition determination will be presented.

Abstract Background: Systemic mastocytosis (SM) and hypereosinophilic syndrome (HES) are JAK2V617F-negative orphan diseases without effective long-term therapeutic options. Both of these diseases share clinical and laboratory features with FIP1L1-PDGFRA-positive chronic eosinophilic leukemia (CEL). SM is associated with KITD816V or other KIT mutations. HES is currently not molecularly characterized. The exquisite sensitivity of FIP1L1-PDGFRA to inhibition by imatinib mesylate (IM) underlies the efficacy of this agent in treating FIP1L1-PDGFRA-positive CEL. In contrast, KITD816V is resistant to inhibition by IM, and is only moderately sensitive to dasatinib (cellular IC50=micromolar concentrations), which may explain the relatively disappointing clinical responses in SM with these agents. TG101348 is an orally bioavailable JAK2-selective inhibitor that is currently being tested in a Phase 1 clinical trial for the treatment of myelofibrosis. The aim of the current study was to evaluate TG101348 (relative to the tyrosine kinase inhibitors IM, dasatinib, and sorafenib) for its ability to: inhibit growth of leukemic cell lines that carry KITD816V and FIP1L1-PDGFRA; and inhibit the in vitro growth of eosinophil colonies derived from progenitor cells from HES patients. Methods: The following cell lines were used for in vitro experiments: HMC-1, a mast cell leukemia line (KITD816V-positive); EOL-1, a CEL derived line (FIP1L1-PDFRA-positive), Ba/F3 T674I, a Ba/F3 line that express the IM-resistant FIP1L1-PDFRAT674I mutation, and HEL, a human erythroleukemia line (JAK2V617F-positive). Cell proliferation assays were performed in triplicate using the XTT assay (Leukemia. 2007 21:1658). Drug concentrations in these experiments ranged from 2.9 × 10−12 M to 10−4 M. JAK Inhibitor I (Calbiochem) is a non-selective JAK inhibitor tool compound. Eosinophil colonies were obtained by plating PBMCs from healthy controls or HES patients in methylcellulose, in the presence of IL-3, IL-5, and GM-CSF. Effects of IM and TG101348 on eosinophil colony growth were studied in parallel experiments. Results: Consistent with prior observations, the HMC-1 cell line was resistant to inhibition by IM (IC50>10 mM), but was moderately sensitive to dasatinib (Table). In contrast, TG101348 inhibited HMC-1 growth at nanomolar concentrations, similar to its effect on HEL cells that harbor the JAK2V617F mutation. TG101348 inhibited HMC-1 growth 53-fold and 4-fold more potently than IM and dasatinib, respectively (Figure). Sorafenib, a multikinase inhibitor that reportedly has activity against KIT kinase (enzyme IC50=68 nM), had only a limited effect on HMC-1 growth (IC50=4000 nM). In contrast to HMC-1, EOL-1 growth was inhibited by IM, dasatinib, sorafenib, and TG101348 at picomolar concentrations (Table). The T674I mutation (in the context of FIP1L1-PDGFRA) corresponds to the T315I mutation in BCR-ABL – it occurs infrequently in CEL and is usually found in the context of transformation to acute leukemia. Growth of Ba/F3 cells harboring FIP1L1-PDFGRA-T674I has been shown to be inhibited by sorafenib (confirmed in this report; Table) and nilotinib, at nanomolar concentrations. TG101348 is less potent at inhibiting growth of these cells, with cellular IC50 of ~2 mM – pharmacokinetic data from the ongoing Phase I study of TG101348 shows that this concentration is achievable in plasma with once daily dosing. Drug Cellular IC50 HMC-1 (nM) EOL-1 (pM) Ba/F3 T674I (nM) HEL (nM) Imatinib 18800 4 10700 - Dasatinib 1300 <1 30900 - Sorafenib 4000 2 16 - Jak Inhibitor I 926 30 4300 ? TG101348 355 <1 1950 300 Figure Figure Conclusions: The JAK2-selective inhibitor TG101348 is a potent inhibitor of KITD816V and FIP1L1-PDGFRA, warranting clinical trials using this drug in SM and FIP1L1- PDGFRA-positive CEL. Data regarding TG101348 effects on signaling intermediates in leukemic cell lines and on eosinophil colony growth will be presented at the meeting – data from the latter experiments may indicate a therapeutic role for TG10134 in the treatment of patients with HES.

Abstract Background: Essential thrombocythemia (ET) frequently occurs in women of childbearing age. Recently, an increased risk of pregnancy complications was reported in patients with ET carrying the JAK2V617F mutation (Passamonti et al. Blood. 2007;110:485). In the current study, we sought to validate this observation as well as identify other predictors of pregnancy loss in ET. Methods: Data was abstracted from the medical records of a consecutive cohort of patients with WHO-defined ET seen at the Mayo Clinic. Patient characteristics and pregnancy outcome are summarized using descriptive statistics. The analysis of risk factors associated with pregnancy complications was carried out by both univariate and multivariate analyses. Results: i) Patient characteristics at ET diagnosis A total of 63 pregnancies were recorded in 36 women at or after their diagnosis of ET. At diagnosis of ET, median (range) values were: age 26 years (15–36), platelet count 1350 x 109/L (683–3300), hemoglobin level 13.3 g/dL (10.5–16) and leukocyte count 9.3 x109/L (5–26.9). JAK2V617F mutation analysis was performed in 20 patients; half were positive. Only 5 patients had a history of thrombosis at diagnosis. Follow-up after ET diagnosis was for a median of 82.9 months (range, 6.5–340.8 months). ii) Outcome of first pregnancy at or after diagnosis of ET A total of 36 first pregnancies were documented at or after the diagnosis of ET. At the time, median (range) values were: time from diagnosis 25.5 months (0–155), age 28 years (20–36), platelet count 840 x 109/L (255–1998), hemoglobin 12.9 g/dl (9–16.6) and leukocyte count 8.4 x109/L (6.6–19.8). Seven of the 36 (19%) women were receiving cytoreductive therapy at time of conception: anagrelide (n=4), interferon (n=1), hydroxyurea (n=1) and radiophosphorus (n=1). Aspirin therapy was documented in 53% of the women at time of conception and in 69% during the first trimester of their pregnancy. Among the 36 first pregnancies, 61% (n=22) resulted in live birth and 39% (n=14) in fetal loss. Twelve of the 14 pregnancy losses occurred during the first trimester (10 spontaneous miscarriages, 1 ectopic pregnancy and 1 therapeutic abortion) and the remaining two during the second trimester. Maternal complications occurred in 11% (n=4) of pregnancies and included pre-eclampsia (n=1), hematoma after Cesarean-section (n=2) and post-partum hemorrhage (n=1). iii) Predictors of first pregnancy outcome in ET Pregnancy outcome, in terms of live birth versus miscarriage did not correlate with age (p=0.27), presence of cardiovascular risk factor (p=0.76), platelet count (p=0.49), leukocyte count (p=0.67) or hemoglobin level (p=0.31). Similarly, pregnancy loss was similar between JAK2V617F-positive (4 of 10 pregnancies) and JAK2V617F-negative (4 of 10 pregnancies) patients (p>0.9). Furthermore, among 5 cases of 3 consecutive miscarriages, 4 were JAK2V617F-negative. Interestingly, the rate of pregnancy loss was only 21% among 24 patients receiving aspirin therapy during the first trimester as compared to 75% among the 12 patients in whom no such treatment was documented (p=0.002). iv) Second and subsequent pregnancy outcome Seventeen second pregnancies were recorded; 71% (n=12) resulted in live birth that included 8 of 9 patients with successful and 4 of 8 with unsuccessful first pregnancies (p=0.07). The trend was similar among 7 third pregnancies, which resulted in only one live birth; 5 of the 6 fetal losses occurred in women with history of first pregnancy loss (p=0.09). Conclusion: The current study does not support the recently communicated association between the presence of JAK2V617F and increased risk of pregnancy loss in ET. Instead, two parameters of potential importance for predicting pregnancy outcome in ET were identified; the occurrence of a miscarriage might be a marker for a similar event during subsequent pregnancies whereas aspirin therapy during the first trimester might be beneficial.

Abstract Background: Systemic mastocytosis (SM) sometimes coexists with an associated clonal hematological non mast cell lineage disease and such an occurrence is recognized by the 2001 World Health organization (WHO) classification system as SM-AHNMD (Leuk Res. 2001 25:603). However, SM-AHNMD has not been further stratified into prognostically relevant subgroups. This was the major objective of the current study, which also provides information on prevalence and relevance of detecting KITD816V and JAK2V617F mutations. Methods: Patient records in the institutional electronic database from January 1976 to October 2007 were reviewed and SM patients 18 years of age or older identified; the date of diagnosis ranged from July 1964 to October 2007. Only those cases where diagnosis was confirmed by bone marrow (BM) histology were included in the analysis. SM- and AHNMD-components were classified according to WHO criteria. Results: AHNMD sub-classification: Of 342 consecutive cases of SM that were screened, 138 (40%) were identified as having SM-AHNMD (median age 65 years, range 20–87). The most frequent AHNMD was chronic myelomonocytic leukemia (SM-CMML) seen in 38 (28%) patients. 23 (17%) patients had SM associated with myelodysplastic syndrome (SM-MDS), 22 (16%) with hypereosinophilic syndrome/chronic eosinophilic leukemia (SM-HES/CEL) and 33 (24%) with another myeloproliferative neoplasm (SM-MPN). The number of cases with other SM-AHNMD was much lower and included lymphoma 8 (6%), acute leukemia 3 (2%), MDS/MPN 3 (2%), and 8 (6%) cases of multiple myeloma, primary amyloidosis or chronic lymphocytic leukemia. Of the 33 SM-MPN patients, 2 had polycythemia vera, 6 essential thrombocythemia, and 2 myelofibrosis; the remaining 23 patients had an unclassified MPN in association with SM. Clinical characteristics at presentation: The combined incidence of urticaria pigmentosa (UP) was 18%, mast cell mediator release symptoms 28% and constitutional symptoms 62%. 76 patients (57%) had palpable splenomegaly. 99 patients (72%) had anemia, 18 (13%) leukopenia (43% with SM-MDS; p<0.0001) and 76 (55%) thrombocytopenia. 70 (51%) patients had leukocytosis and 63 (55%) displayed circulating immature myeloid cells (78% with CMML; p=0.001). 59 (54%) patients had elevated serum alkaline phosphatase level: SM-CMML 70%, SM-MPN 60%, SM-HES/CEL 40%, and SM-MDS 30% (p=0.01). Where evaluated, serum tryptase was elevated in 92% of the patients (median=75 ng/mL; range=4–1360). BM blasts were ≥5% in 25 patients (22%), including 48% with SM-MDS (p=0.004). 12 of 35 patients tested carried the FIP1L1-PDGFRA mutation (all had SM-HES/CEL; p<0.0001). Disease course and prognostic factors At a median follow up of 15 months (range 0–182), 99 deaths were recorded and the combined median survival was 24 months: SM-CMML 15 months; SM-MDS 15 months, SM-MPN 30 months; and SM-HES/CEL 87 months (p=0.003). Fifteen patients (11%) transformed to acute leukemia or mast cell leukemia. Multivariate analysis of parameters at the time of diagnosis showed a significant and independent association between inferior survival and SM-AHNMD sub-type (p=0.007), presence of constitutional symptoms (p=0.04), thrombocytopenia (p=0.01), presence of circulating immature myeloid cells (p=0.006), and hypoalbuminemia (p<0.0001). In SM-CMML, hypoalbuminemia was associated with inferior survival (p=0.03). KIT D816V and JAK2 V617F analysis: Archived BM was available in 88 patients for KITD816V and JAK2V617F analysis. By DNA sequencing, overall KITD816V detection rate was 33%: SM-CMML 48%, SM-MDS 21%, SM-HES 8%, and SM-MPN 45% (p=0.03). In patients with SM-HES/CEL (p=0.0009) and SM-MPN (p=0.04), detection of KITD816V was associated with inferior survival. Greater than 1% (range 5–57) JAK2V617F allele burden was detected in 6 patients (9%): 4 in SM-MPN, 1 in SM-CMML and 1 in SM-MDS. Conclusions: The WHO-defined SM-AHNMD comprises prognostically diverse subcategories among which SM-CMML is the most frequent. Survival is favorable in SM-HES/CEL and significantly worse in SM-CMML and SM-MDS. Additional independent predictors of inferior survival include constitutional symptoms, thrombocytopenia, circulating immature myeloid cells, and hypoalbuminemia. In SM-HES/CEL and SM-MPN, BM KITD816V allele burden may influence survival. JAK2V617F occurs infrequently in SM-AHNMD and when it does, it clusters with SM-MPN.

Abstract Background: Activating mutations in the pseudokinase domain of JAK2 occur at a high frequency in Philadelphia chromosome-negative myeloproliferative disorders (MPDs). Increasing JAK2 V617F allele burden has been shown to correlate with disease severity (bone marrow dysfunction, organomegaly and constitutional symptoms), which is consistent with exaggerated JAK2 signaling playing a central role in MPDs. INCB018424 is a potent and selective JAK1/2 inhibitor currently being evaluated in the clinic for the treatment of MPDs including primary myelofibrosis (PMF), post-polycythemia vera and essential thrombocythemia myelofibrosis (Post-PV/ET MF). Methods: The percentage of mutant JAK2 V617F relative to wild-type JAK2 was determined in peripheral blood using a quantitative single-nucleotide extension assay. The assay is based on the single nucleotide extension of a DNA primer that anneals adjacent to the V617F mutation. The percentage of JAK2 V617F in bone marrow was determined using pyrosequencing as previously described. The relationship between JAK2 V617F allele burden and clinical phenotype was assessed with samples obtained at study entry. JAK2 V617F allele burden was assessed in nineteen PMF and Post-PV/ET MF patients treated with 25 mg BID INCB018424 for a minimum of three months using peripheral blood and bone marrow. Results: There is an excellent correlation in the JAK2 V617F allele burden between samples obtained from bone marrow and peripheral blood, suggesting that the fraction of cells bearing the mutant clone remains stable during hematopoiesis in this patient group. The mean %V617F values were 59%, 80% and 86% for Post-ET MF (n=2), Post-PV MF (n=8) and PMF (n=9) patients. V617F allele burden correlated with spleen size, absolute neutrophil count (ANC) and Body Mass Index (BMI) in this patient population (R2 values if 0.61, 0.17 and 0.44, respectively), with a higher allele burden predicting larger spleen size, a higher ANC and a lower BMI. Eighteen of the nineteen evaluable JAK2 V617F-positive patients had baseline JAK2 V617F values above 50%, with the mean %V617F value for all evaluable patients being 81%, implying that the majority of hematopoietic stem cells contain the mutant allele in this patient population. During INCB018424 therapy (at least 3 months of treatment) in these patients, profound improvements in clinical endpoints including reduction or resolution of splenomegaly and constitutional symptoms are observed, yet only a modest decrease in JAK2 V617F allele burden is seen in both bone marrow and peripheral blood (13% and 9 % decrease from baseline, respectively, at 3 months). Conclusions: While the patient group is small and heterogeneous in nature, clinical correlates of V617F allele burden observed in myelofibrosis patients in this study are similar to those reported in PV. In addition, despite profound clinical improvements in these patients, V617F allele burdens do not change dramatically suggesting that the clinical activity of INCB018424 might involve inhibition of downstream signaling in cells harboring activating JAK2 mutations rather than changing the allele burden.

Abstract BACKGROUND: We sought to determine the prognostic relevance of aberrant serum lipid values in the myeloproliferative disorders (MPDs) of primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocythemia (ET). METHODS: The Mayo MPD patient institutional database was queried to identify clinical history and lipid profiles (within a year of diagnosis). Serum cholesterol (CHOL), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), and triglycerides (TRI) were assessed compared to clinical outcomes. RESULTS: 558 patients with MPDs (PMF 28%, PV 27%, and ET 45%) (median age at diagnosis of 56 (range18–81)) were identified. A lipid profile obtained a median of 0.0 months from diagnosis (range (-8 to 12 months) from MPD patients displayed low CHOL, LDL-C, and higher HDL-C than typical for the USA. Amongst MPD disease types PMF patients had lower CHOL (p<0.001) and HDL (p<0.001) compared to ET and PV (see table). Amongst PMF patients, although hypocholesterolemia was not a surrogate for malnutrition (p=0.13) median serum albumin 4.1 g/dL (range 2.7–4.8)), there was correlation with the presence of weight loss, hypercatabolic symptoms, and worse Mayo-CBC myelofibrosis prognostic scores (Cancer2006;106:623; p<0.01). Amongst the study group PMF patients had the poorest survival (followed by PV then ET; p<0.001). Decreased cholesterol (CHOL <150mg/dL, or HDL <60 mg/dL) was associated with decreased survival (P<0.001), but only in PMF patients (see figure). Decreased PMF survival was also associated with traditional PMF risk factors of hemoglobin <10g/dL, leukocytes <4 or >30 × 10(9)/L, platelets <100 × 10(9)/L, and circulating blasts. In multivariate analysis (Cox-Proportional Hazard) only the Mayo-CBC score, hemoglobin <10g/dL, circulating blasts and decreased CHOL remained significant for decreased survival (p<0.001). CONCLUSIONS: The presence of hypocholesterolemia is very common in patients with PMF and is independently associated with inferior survival. Survival by HDL-C and Serum Cholesterol (CHOL) in 154 patient’s with Primary Myelofibrosis Survival by HDL-C and Serum Cholesterol (CHOL) in 154 patient’s with Primary Myelofibrosis Lipid Distributions in 558 MPD patients VALUE/ NCEP CATEGORY PMF (N=154) PV (N=149) ET (N=255) NHANES (USA MEANS;95th CI) NCEP: National Cholesterol Education Program: NHANES (National Health and Nutrition Examination Survey (values for all races ages 65–74) Serum Cholesterol (Median) 149 mg/dL 179 mg/dL 199 mg/dL 221 mg/dL (153–301) −>200mg/dl (Desirable) 10% 31% 48% −150–200mg/dL (Desirable) 39% 25% 41% −100–149mg/dL (Desirable) 41% 41% 9% −<100mg/dL (Low) 10% 3% 2% LDL Cholesterol (Median) 33 mg/dL 41 mg/dL 49 mg/dL 149 mg/dL (87–217) −>100mg/dL (Low to high risk) 1% 1% 1% −<100mg/dL (Optimal) 99% 99% 99% HDL Cholesterol (Median) 79 mg/dL 118 mg/dL 108 mg/dL 45.7 mg/dL (29–71) −>60mg/dL (Optimal) 74% 90% 91% −40–60mg/dL (Normal) 16% 10% 8% −<40mg/dL (Low) 10% 0% 1% Triglycerides (Median) 151 mg/dL 89 mg/dL 116 mg/dL 145 mg/dL (62–285) −>200mg/dL (High) 28% 0% 3% −150–199mg/dL (Borderline) 23% 6% 14% −<150mg/dL (low) 49% 94%% 83%

Abstract Background: Peripheral blood (PB) is sometimes used in place of bone marrow (BM) for cytogenetic studies in either primary (PMF) or post-polycythemia vera/essential thrombocythemia (post-PV/ET MF) myelofibrosis. In a retrospective study, we examined overall yield from PB cytogenetic studies in MF and where possible compared the results with those obtained by BM cytogenetic analysis. Methods: Standard laboratory techniques were used to perform cytogenetic studies in both the PB and BM. A successful study constituted the acquisition of at least two analyzable metaphases and an abnormal clone required the presence of a specific cytogenetic abnormality in at least two metaphases. Clinical and laboratory correlations were made using variables collected at the time of cytogenetic studies. Results I: A total of 242 PB cytogenetic studies were reviewed to identify 59 MF cases; 39 were PMF and 20 post-PV/ET MF. Median age was 60 years (range 36–77) and 37 were male patients. The median duration of the disease at the time of PB cytogenetic studies was 3.5 years (range 0.2–35). At least two analyzable metaphases (median 20, range 2–31) were obtained in 49 (81%) of the 59 study patients; in univariate analysis, this was predicted by presence and degree of circulating myeloid progenitor cells (p < 0.0001), higher PB CD34 count (p < 0.0001), higher leukocyte count (p = 0.0008), and absence of myeloid growth factor therapy (p = 0.005). In multivariable analysis, only the presence of circulating myeloid progenitor cells sustained its significance. Results II: Twenty two cases had concomitant PB and BM cytogenetic studies performed. Of these, 9 patients had abnormal BM cytogenetic findings; the concomitant PB cytogenetic studies were also abnormal in 5 (56%) patients but normal in the other 4. Conversely, PB cytogenetic studies were abnormal in 12 patients; the concomitant BM cytogenetic studies were abnormal in 5 (41%) and normal in the remaining 7. PB cytogenetic studies were not successful in 4 of the 22 total cases; BM studies were successful in 3 of these 4 cases and the results were normal in all. Conclusion: In the presence of circulating myeloid progenitor cells, PB can be considered as an alternative to BM for cytogenetic studies in MF patients, especially in view of the difficulty getting BM aspirates in this disease. However, considering the prognostic value of specific cytogenetic abnormalities in MF, the non-trivial discordance between the BM and PB cytogenetic findings, observed in the current study, warrants a prospective evaluation for further clarification.

Abstract Acquired pure red cell aplasia (APRCA) is associated with a number of conditions including malignancies, infections and autoimmune disorders. APRCA also occurs in patients with T-LGLL. It is postulated that suppression of erythropoiesis in T-LGLL is related to the immune destruction of erythroid precursors by the LGL clone. We hypothesize that APRCA can be associated with clonal T-cell expansion without pathological evidence of T-LGLL. Methods: We identified patients who were diagnosed with APRCA and had clonal TCR gene rearrangements. Clinical course, bone marrow pathology and flow cytometry data were reviewed. Immunohistochemical studies were performed on available bone marrow biopsies using antibodies to CD3, CD8, CD20 and the cytotoxic granule proteins TIA-1 and granzyme B. Clonal TCR gene rearrangements were detected by PCR and Southern blot. The diagnosis of APRCA was based on the absence of erythroid progenitors, with intact granulo- and thrombopoiesis. A pathologic diagnosis of T-LGL leukemia was established by the presence of clonal TCR gene rearrangements and an immunophenotypically distinct CD8 positive T-cell population as previously described. The diagnostic flow cytometric features included abnormal patterns of T-cell antigen expression and aberrant co-expression of NK-cell antigens. Immunoperoxidase features supportive of a diagnosis of LGL were the presence of interstitial clusters or intravascular staining of cells positive for CD8 and TIA-1 and/or granzyme B. Results: We identified 28 patients with APRCA and the presence of clonal TCR gene rearrangements seen at Mayo Clinic Rochester between 7/1/1991 to 6/1/03. All patients presented with a transfusion dependent anemia (median hemoglobin 7.8 g/dL, range 3.6–10.3). Tissue was available for immunohistochemical studies for 21 cases. 13 of 21 patients (61%) had an immunophenotypically abnormal T-cell population which, in conjunction with the clonal TCR gene rearrangements were considered diagnostic of T-LGL. 8 patients (39%) had no pathological evidence of T-LGLL despite clonal TCR gene rearrangement studies. The most commonly used treatment consisted of oral cyclophosphamide which was used in 14 of 21 patients (8 and 6 in patients with and without pathological evidence of T-LGLL respectively). A normalization of hemoglobin was seen in 11 patients (6 and 5 in patients with and without evidence of T-LGLL respectively). Median duration of response was 30 months (range 22–120). None of 8 patients with APRCA and clonal TCR gene rearrangements without evidence of LGLL at the the time of initial diagnosis developed overt T-LGLL during follow up (median 64 months, range 30–118). Discussion: 39 % of patients with APRCA and evidence of clonal TCR gene rearrangements did not meet pathological criteria for diagnosis of T-LGLL. There was no apparent difference in disease presentation and response to therapy in patients with or without pathological evidence of LGLL. The significance of the presence of clonal TCR gene rearrangements in the absence of a detectable immunophenotypically abnormal T-cell population is unclear. It is possible that T-LGL was present which could not be detected by our analyses. Alternatively, the clonal TCR gene rearrangements could be indicative of a pertubation of the T-cell compartment related to an autoimmune disorder causing the APRCA. The fact that none of the patients developed progression to overt LGLL supports the latter possibility.

Abstract Background: Deletion 5q is a lenalidomide-sensitive cytogenetic abnormality seen usually in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). In the current study, we looked into the occurrence and clinicopathologic correlates of del(5q) in myeloproliferative neoplasms (MPNs) defined according to the World Health Organization (WHO) criteria. Methods: Patients with del(5q)-positive MPN were identified through database query involving over 2000 patients with myeloproliferative neoplasms (MPD) including no less than 500 patients with primary myelofibrosis (PMF), 600 patients with essential thrombocytosis (ET), 500 patients with polycythemia vera (PV), and the remaining comprised of patients with molecularly-undefined chronic eosinophilic leukemia, hypereosinophilic syndrome, systemic mastocytosis (SM), chronic neutrophilic leukemia, and “MPN, unclassifiable”. Results: A total of 23 patients with del(5q) were identified (12 at time of initial diagnosis), suggesting an overall prevalence rate of 1%. A central pathological review was conducted to confirm the diagnosis in each instance. Specific diagnoses included PMF (n=14; estimated prevalence of 3%), MPN, unclassifiable (n=4), PV (n=2), ET (n=1), post ET-myelofibrosis (n=1) and SM (n=1). Del(5q) was a sole abnormality in 5 patients, accompanied by one other abnormality in 6 patients, and part of a complex karyotype in 12 patients. The most common breakpoint was q13q33 (n=10) followed by q15q33 (n=6). Based on sample size adequacy, we focused on del(5q)-positive PMF patients and compared their bone marrow histological and clinical features with their del(5q)-negative counterparts seen at the Mayo Clinic during the same period of time (n=311). There was no difference in gender or age distributions. Histopathological review did not show the typical tight clusters of megakaryocytes seen in classic PMF. The megakaryocytes were not the predominate feature of the biopsy, in general were less lobulated and smaller in size, and had a higher grade of fibrosis (med = 3+) than classic PMF. Furthermore, del(5q)-positive PMF patients presented with significantly lower hemoglobin level (p=0.0009) and platelet count (p=0.0003). The percentage of patients presenting with a hemoglobin level of < 10 g/dL or a platelet count of < 100 × 109/L were 70% and 92% in del(5q)-positive patients as opposed to 43% and 18% in del(5q)-negative patients. However, the presence of del(5q) did not significantly affect either overall survival (Figure) or leukemic transformation in PMF (14% vs 9%). Conclusions: Del(5q) is generally rare in MPNs but might occur in as much as 3% of patients with PMF. The presence of del(5q) does not appear to affect overall survival in PMF despite its clustering with adverse prognostic features for the disease including anemia and thrombocytopenia. Finally, megakaryocyte morphology and distribution in del(5q)-associated PMF are characteristically different from classic PMF. Figure Figure

Abstract This phase 1 clinical trial evaluated the safety and effects of autologous dendritic cells (DC) injected to patients in late chronic or accelerated phase of chronic myelogenous leukemia (CML). Seven patients with a median age of 63 years (range 55–78) entered the trial. Median time from diagnosis to registration was 38 months (range 16–94). Two patients were in the accelerated phase of disease based on the presence of additional bone marrow chromosomal abnormalities, all other patients were in chronic phase. Prior therapies included hydroxyurea and alpha interferon with or without cytosine arabinoside. Four patients were on therapy with imatinib mesylate during the course of the trial, two were treated before imatinib became available and one was previously intolerant of imatinib. CD14+ monocytes were selected from a leukapheresis product by clinical grade immunoadsorption (Miltenyi Biotec). The monocytes were matured to CD83+ and bcr-abl+ DC after 10 days in culture with X-VIVO 15 medium with 1% human AB serum, GM-CSF, IL-4, as the base culture media followed by maturation mediated by TNF-alpha, IL-6 and prostaglandin E2. The first patient entered had a positive mycoplasma reaction by polymerase chain reaction at the time of his first DC injection, the cells were not given and he was withdrawn from the study. The other six patients were treated in two cohorts of three patients and received four injections each of 3x106 DC and 15x106 DC per injection, respectively. CML-DC injections were generally well tolerated and all non-hematologic toxicities were ≤ grade 2. All injections were given intra-nodally into a cervical lymph node except in the first patient where the DCs were injected subcutaneously. We observed no major clinical responses, but the white blood cell counts normalized or were maintained at normal level in four patients during therapy. Three patients experienced a transient reduction in the percentage of bcr-abl+ cells suggesting that the treatment may have affected the cells in a leukemia specific manner. We detected vascular endothelial growth factor (VEGF) in the plasma prior to therapy. In four of five patients, VEGF levels decreased by more than 75 percent during therapy. T cells isolated from patients’ blood and incubated with autologous CML DC before, during and after therapy showed increased proliferation and secretion of interferon gamma during the course of therapy. DCs from three patients were transfected with a recombinant replication-defective adenovirus carrying the gene for IL-2 under a constitutively active promoter. IL-2 secreted by transfected dendritic cells enhanced in vitro T cell proliferation and interferon gamma release and these effects increased with increasing numbers of DC injections. This study demonstrates that CML-DC can be prepared from the blood of patients treated with imatinib mesylate, that they can be administered safely and that progress of therapy is accompanied by an increase in DC-specific T cell reactivity and a decrease in circulating VEGF.