Verstovšek, Srđan

Abstract Allogeneic hematopoietic cell transplantation (HCT) is the only curative therapy for myelofibrosis (MF). In this large multicenter retrospective study, overall survival (OS) in MF patients treated with allogeneic HCT (551 patients) and without HCT (non-HCT) (1377 patients) was analyzed with Cox proportional hazards model. Survival analysis stratified by the Dynamic International Prognostic Scoring System (DIPSS) revealed that the first year of treatment arm assignment, due to upfront risk of transplant-related mortality (TRM), HCT was associated with inferior OS compared with non-HCT (non-HCT vs HCT: DIPSS intermediate 1 [Int-1]: hazard ratio [HR] = 0.26, P < .0001; DIPSS-Int-2 and higher: HR, 0.39, P < .0001). Similarly, in the DIPSS low-risk MF group, due to upfront TRM risk, OS was superior with non-HCT therapies compared with HCT in the first-year post treatment arm assignment (HR, 0.16, P = .006). However, after 1 year, OS was not significantly different (HR, 1.38, P = .451). Beyond 1 year of treatment arm assignment, an OS advantage with HCT therapy in Int-1 and higher DIPSS score patients was observed (non-HCT vs HCT: DIPSS-Int-1: HR, 2.64, P < .0001; DIPSS-Int-2 and higher: HR, 2.55, P < .0001). In conclusion, long-term OS advantage with HCT was observed for patients with Int-1 or higher risk MF, but at the cost of early TRM. The magnitude of OS benefit with HCT increased as DIPSS risk score increased and became apparent with longer follow-up.

Abstract Background: Debate continues as to the clinical relevance of subclassifying patients with the myeloproliferative disorder (MPD) MMM into the subgroups of agnogenic myeloid metaplasia (AMM), post-polycythemic myeloid metaplasia (PPMM), and post-thrombocythemic myeloid metaplasia (PTMM). We looked to validate previously described phenotypic variability amongst subtypes, and explore relevant and differences in constitutional symptoms. Methods: An detailed analysis of patients with MMM whom responded to an international web based survey of MPD patients which registered responses regarding diagnosis, disease course, complete blood counts, co-morbidities (Charlson Co-morbidity index), symptoms, and fatigue (Fact-An and Brief Fatigue Inventory (BFI)). Results: A total of 456 patients self described as MMM responded of which 32.3% had AMM (n = 148), 38.0% % had PPMM (n = 174), and 29.7% had PTMM (n = 136). Detailed breakdown of differences in demographics, clinical course, current laboratory studies, treatment history, and current symptoms are outlined in the table below. Phenotypic Variability Amongst 458 MMM Patients Category AMM (N=148; 32.3%) PPMM (N=174; 38.0%) PTMM (N=136; 29.7%) MMM Total (N=458) Δ between groups (p = ) Hb = Hemoglobin; SCT = Stem Cell Transplant Age (Median) 61 57 57 58 0.09 Sex (% Males) 60% 49% 30% 47% <0.01 Yrs from MPD Dx 5 6 8 6 <0.01 Labs/ Prior History Hb (g/dL) 11.0 13.7 11.6 12.1 <0.01 % with RBC Tx 43% 6% 11% 20% <0.01 Leukocytes (×10(9)/L) 8.0 7.6 7.2 7.7 0.64 Platelets (×10(9))/L) 200 352 396 321 <0.01 % with Splenomegaly 76% 49% 41% 54% <0.01 % with Prior Thrombosis 10% 22% 31% 21% <0.01 % with Prior Bleed 16% 20% 31% 22% 0.01 Treatment History for the MMM % with Prior Tx for MPD 64% 88% 77% 77% <0.01 % Medical Therapy 57% 70% 75% 67% <0.01 # Meds (Median (Range)) 1 (0–8) 2 (0–6) 2 (0–6) 2 (0–8) <0.01 % with Splenectomy 8% 5% 6% 6% 0.48 % with SCT 6% 1% 1% 3% <0.01 MMM Associated Constitutional Symptoms % with Fatigue 85% 81% 85% 84% 0.56 % with Bone Pain 51% 46% 44% 47% 0.51 % with Fevers 19% 17% 18% 18% 0.87 % with Pruritus 39% 69% 39% 50% <0.01 % with Night Sweats 55% 58% 53% 56% 0.67 % with Weight Loss 30% 15% 16% 20% <0.01 Overall the data suggests patients with AMM are more likely male, with greater burdens of anemia, splenomegaly, and weight loss. However they are less likely to have experienced thrombohemorrhagic complications and have received fewer MPD medications. In contrast PPMM patients (not unsurprisingly) have little trouble from anemia, but have the most pruritus. Patients with PTMM are most likely female, with the highest platelet counts, and the greatest likelihood of thrombohemorrhagic complications. Additionally, all three subgroups of MMM had significant fatigue compared to published controls for both fatigue instruments (P<0.0001) yet there was no difference between MMM subtypes for the severity of fatigue. Conclusions: A large unselected series of MMM patients supports that although constitutional symptoms are significant and similar amongst MMM subgroups, these patients have variable burdens of other MPD manifestations.

Abstract Idiopathic HES is a myeloproliferative disorder (MPD) characterized by persistent overproduction of eosinophils resulting in organ damage. In a small subset of patients (pts), the disease is caused by the FIP1L1-PDGFR-α fusion tyrosine kinase. Its expression has been associated with complete clinical responses to therapy with tyrosine kinase inhibitor (TKI) imatinib mesylate. In contrast, there is no specific therapy for pts with HES lacking FIP1L1-PDGFR-α expression and corticosteroids are used for palliation. Alemtuzumab (Campath-1H™) is a humanized rat monoclonal antibody directed against the CD52 antigen. Since CD52 is expressed on eosinophils, we evaluated its efficacy in pts with FIP1L1-PDGFR-α-negative symptomatic HES. A total of 9 pts (5 male, 4 female) received alemtuzumab in weekly cycles at the dose of 30 (8 pts) or 10 (1 pt) mg 3 times a week intravenously or subcutaneously. During the first week alemtuzumab was given in escalating doses (3→10→30mg) to assure tolerance. Median age was 53 years (range 24–70), time from HES diagnosis to alemtuzumab therapy 34 months (range 4–195), median WBC 17×109/L (range 6.9–82.4), absolute eosinophil count (AEC) 9×109/L (range 0.7–30), and bone marrow eosinophils 23% (range 10–68). Three pts had abnormal cytogenetics: del11(q23), +8, and t(5;6). Pts had received a median of 3 prior therapies (range 2–6), including corticosteroids (prednisone; n=9), imatinib (n=7), dasatinib (n=3), interferon-alpha (n=3), hydroxyurea (n=3), nilotinib (n=2), and cladribine (n=2). A total of 121 weekly cycles have been administered (median 13 cycles) thus far. A complete hematologic response (CHR; i.e. AEC normalization) was observed in 8 pts (89%) within 4 weeks of therapy; peripheral blood eosinophils were undetectable in 6 of 8 CHR pts. Follow-up bone marrow specimens were available in 3 pts while in CHR (after a median of 5.5 weekly alemtuzumab cycles) showing complete response in 2 and partial response in 1 pt. In addition, 3 pts that were on prednisone and 2 on hydroxyurea at the start of alemtuzumab discontinued them within 2 weeks into therapy. One pt had a remarkable partial response with reduction of AEC from 47.5 to 1×109/L after 8 weekly cycles of alemtuzumab; this patient was on 3g of hydroxyurea and 80mg of prednisone at the start of alemtuzumab and was able to discontinue hydroxyurea and decrease prednisone to 10mg while on alemtuzumab. Five pts who stopped alemtuzumab experienced relapse after a median time of 3.5 weeks (range, 1 to 10) and 1 relapsed while receiving alemtuzumab after 14 weekly cycles. Three pts are currently on alemtuzumab: 2 receiving 30 mg weekly as maintenance while in CHR after 8+ and 19+ weeks, respectively, and 1 with partial response is receiving 30mg 3 times a week. One relapsed pt was rechallenged with alemtuzumab and normalized AEC again. Alemtuzumab was generally well tolerated. Grade 3–4 drug-related toxicities occurred in 2 pts, 1 with neutropenia and 1 with infusion-related fever, which led to transient and complete alemtuzumab discontinuation, respectively. Two pts experienced CMV reactivation that required therapy. In summary, alemtuzumab was well tolerated and has remarkable activity in pts with FIP1L1-PDGFR-α-negative HES. Different dose schedules of alemtuzumab that include prolonged maintenance therapy are warranted to improve the response duration. Updated clinical results will be presented.

Abstract Background: Scant data exists regarding the burden of fatigue and constitutional symptoms in patients with myeloproliferative disorders (MPDs) (essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis with myeloid metaplasia (MMM)). Methods: An Internet based survey of MPD patients regarding clinical course, blood counts, constitutional symptoms, and fatigue (FACT-AN and Brief Fatigue Inventory (BFI)). Results: Patient Demographics: A total of 1179 MPD patients (median age 56; 41.4% male) internationally (76% USA: 50 states, 30 countries, 6 continents) responded to the survey. Self reported diagnoses were PV (35%), ET (26%), or MMM (39%). Clinical History: 1025 patients (87%) had undergone MPD therapy (drugs 70.5%, phlebotomy 44.1%, other 16%). Thrombosis (n=261, 22%), hemorrhage (N=272; 23%), and splenomegaly (N=478 (43%) were frequently reported. Blood tests (available in 917) showed 39% were anemic, 7% transfusion dependent. Symptoms: Fatigue, pruritus, night sweats and bone pain were present across the majority of MPD patients (see table). Additionally it was observed that these symptoms appeared with nearly equal frequency in PV as in MMM patients. However MMM patients displayed more advanced features (fevers, night sweats and weight loss). MPD Associated Constitutional Symptoms in 1179 Patients SYMPTOM PV (N=405) ET (N=304) MMM (N=456) MISSING (N=14) TOTAL (N=1179) P VALUE Fatigue 344 (84.9%) 220 (72.4%) 381 (83.6%) 7 945 (81.1%) <0.0001 Pruritus 265 (65.4%) 120 (39.5%) 228 (50.0%) 3 613 (52.6%) <0.0001 Night Sweats 199 (49.1%) 123 (40.5%) 254 (55.7%) 4 576 (49.4%) 0.0002 Bone Pain 174 (43.0%) 125 (41.1%) 214 (46.9%) 4 513 (44%) 0.2480 Fevers 53 (13.1%) 26 (8.6%) 81 (17.8%) 2 160 (13.7%) 0.0013 Weight Loss 39 (9.6%) 22 (7.2%) 93 (20.4%) 0 154 (13.2%) <0.0001 Spleen Pain 17 (4.2%) 27 (8.9%) 30 (6.6%) 4 74 (6.3%) <0.0001 Fatigue (82% MPD linked) was significantly increased across all MPD subtypes compared to published controls for both the BFI (P<0.0001) and Fact-An (P<0.0001). Additionally 69% curtail social activity because of fatigue, 35% need assistance with activities of daily living, and 11% reported MPD associated medical disability. Fatigue strongly correlated with multiple MPD disease features including: anemia, bone pain, constitutional symptoms, pruritus, splenic pain, smoking, thrombosis, and hemorrhagic events (all p<0.0001). Interestingly, even in “asymptomatic” MPD patients (those without anemia, splenomegaly, or thrombohemorrhagic complications) (n=279)) 24% (41% PV, 31% ET, 28% MMM) described significant fatigue worse than published controls. Conclusions: Fatigue and other constitutional symptoms are a significant burden to MPD patients, despite current therapies employed. Additionally fatigue is also a significant problem even in MPD patients lacking other advanced disease features. Clearly, direct attempts to improve fatigue (through pharmacologic and non-pharmacologic interventions) are necessary.

Abstract The FIP1L1-PDGFR-α fusion kinase induces hypereosinophilic syndrome (HES) in a subset of patients (pts). Imatinib is a potent inhibitor of PDGFR-α and has been associated with durable hematologic responses in pts with HES. However, development of kinase domain mutations may hamper TKI activity, underscoring the need for novel agents to prevent or overcome resistance. We evaluated the efficacy of the novel TKI EXEL-0862 in FIP1L1-PDGFR-α-expressing cells. In 72-hour MTS assay, EXEL-0862 inhibited EOL-1 cell proliferation with an IC50 of 1.0 nM and markedly decreased phosphorylation of STAT3 and Erk1/2, suggesting inhibition of downstream targets of PDGFR-α. More important, EXEL-0862 induced dose-dependent inhibition of PDGFR-α phosphorylation in peripheral blood mononuclear cells from a pt with HES. Exposure of EOL-1 cells to EXEL-0862 10 nM for 24 hours caused apoptosis as evidenced by flow cytometry (annexin-V/PI staining) and transmission electron microscopy. This was coupled with time-dependent cleavage of caspases-3, caspase-9, and PARP and with mitochondrial damage as reflected by cytochrome c translocation into the cytosol, and a diminished mitochondrial transmembrane potential. Of note, apoptotic features were not evident after 16 hours of EXEL-0862 exposure. Immunoblots showed marked downregulation of Mcl-1, but not of Bcl-2, Bcl-XL, or Bax. To elucidate the mechanism of Mcl-1 cleavage, EOL-1 cells were exposed to 10 nM EXEL-0862 for 6 hours followed by cycloheximide (5 μg/ml), a potent translation inhibitor, which resulted in marked Mcl-1 turnover. Treatment with the proteasome inhibitor MG-132 failed to abrogate EXEL-0862-induced Mcl-1 cleavage, suggesting proteasome-independent degradation. Rather, a decrease of pro-form Mcl-1 (p42) and increase of the cleaved Mcl-1 peptide form of Mcl-1 (p28) coincided with caspase-3 activation. Pretreatment with 20 μM pan-caspase inhibitor Z-VAD abolished EXEL-0862-induced Mcl-1 cleavage, pointing to a caspase--dependent mechanism. Collectively, our results establish EXEL-0862 as a solid candidate for the targeted treatment of pts with FIP1L1-PDGFR-α-positive HES.

Abstract Background: Little objective data exists regarding the impact that myeloproliferative disorders (MPDs) (essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis with myeloid metaplasia (MMM)) have on quality of life. Methods: An Internet based survey of MPD patients regarding clinical course, co-morbidities (through the Charlson Co-Morbidity Index), fatigue (through two validated fatigue instruments (FACT-AN and Brief Fatigue Inventory (BFI)), and exercise tolerance (Godin Leisure-Time Questionnaire). Results: Patient Demographics: A total of 830 MPD patients (median age 56; 60.8% male) from a broad geographic distribution (77% USA: 50 states, 30 countries, 5 continents) responded to the survey. Self reported diagnoses were PV (N=272; 33%), ET (N=221; 27%), or MMM (N=329; 40%) for a median of 5 years (range (0–53). Clinical History: 708 patients (87%) had undergone treatment for their MPD (drugs 84.6%, phlebotomy 49.5%, other 16%). A history of thrombotic (n=195, 24%) or hemorrhagic events (N=214; 26%) were frequently reported. Blood tests (available in 597 a median 1.65 months prior to survey) showed 37% were anemic (7% transfusion dependent). Additionally, 347 (44%) had splenomegaly, painful in 21%. Symptoms: Frequent symptoms reported included fatigue (90%), pruritus (57%), night sweats (54%), bone pain (48%), undesired weight loss (15%), and/or fevers (15%). 41% felt restricted in their activities, and 89 (11%) were medically disabled secondary directly to their MPD. 82% of patients felt their fatigue was linked to their MPD. Additionally 69% curtail social activity because of fatigue, and 41% need some degree of assistance with activities of daily living. Charlson co-morbidity index demonstrated 722 (87%) had minimal co-morbidities strengthening the association between fatigue and their MPD. The burden of fatigue decreased from MMM to PV to ET respectively (p=0.0002). Results from both fatigue assessment tools (FACT-AN and BFI) were highly correlated. Fatigue (FACT-AN fatigue subscale) strongly correlated with multiple MPD disease features including: anemia, bone pain, constitutional symptoms, pruritus, splenic pain, hemorrhagic events (all p<0.0001) and thrombosis(p=0.01). Additionally, currently smoking (as opposed to being a prior smoker) was highly associated with increased fatigue (p<0.0001). Interestingly, even in “asymptomatic” patients (those without anemia, splenomegaly, or thrombohemorrhagic complications (n=187)) 73% (n=128; 40% PV, 32% ET, 27% MMM; p=N.S.) described moderate to severe MPD associated fatigue. Reported physical activity was diminished (Godin Leisure Score) between MPD patients and published norms, with 38% describing minimal to no exercise. Overall, 86% stated fatigue was the major obstacle to exercise. Conclusions: Fatigue is an extremely common problem in patients with MPDs despite current therapies, and a minimal burden of co-morbidities in the majority of patients. Fatigue is also common in patients lacking advanced MPD disease features, or thrombohemorrhagic complications. Clearly, direct attempts to improve fatigue (through pharmacologic and non-pharmacologic interventions) are necessary.

Abstract BACKGROUND: MF is a progressive illness associated with cachexia and weight loss (Mesa et al, Cancer2007;109: 68). These clinical signs, resulting from both hypercatabolism (secondary to increased pro-inflammatory cytokines) and MF associated splenomegaly, are associated with decreased survival (Dupriez et al., Blood1996;88:1013). Currently, there is no therapy that decreases the progressive cachexia of MF. INCB018424 is a selective JAK1/2 inhibitor which has the potential to improve both the aberrant myeloproliferation in MF through decreasing constitutively active JAK-STAT signaling, and nutritional status by decreasing both splenomegaly and the pathologically increased cytokines. METHODS: Symptomatic patients with MF enrolled in a phase I/II trial (www.ClinicalTrials.gov, NCT00509899) with INCB018424, were analyzed for the impact of therapy on nutritional status and cachexia. Specifically, in addition to traditional endpoints of IWG-MRT response (reported elsewhere) patients were assessed for changes in body mass index (BMI), serum cholesterol values, spleen size, and patient reports of early satiety and anorexia. Additionally, leptin, an adipose-derived protein hormone that plays a key role in regulating energy balance and circulates at levels proportional to body fat in health and disease (Mantovani et al, J Mol Med2001; 79:406), was assessed serially. RESULTS: Patients: Thirty four MF patients, treated for at least 2 months with 25 mg twice daily of INCB018424, were included in this analysis. Among this group 85% demonstrated splenomegaly (median 20 cm below left costal margin, range 4 cm to 32 cm; 2 patients had prior splenectomy) and had a median BMI of 24.8 (range 17.9 to 49.7). Although the median BMI at baseline would be considered in the “normal range” (18.5–24.9), loss of lean body mass at enrollment would be underestimated by the contribution of splenomegaly or edema. Appetite: At enrollment, a clearly positive correlation between the presence of anorexia and early satiety (by patient’s report) and significant splenomegaly was observed. Treatment with INCB018424 led to resolution of the symptoms of poor appetite and early satiety, along with the reduction in splenomegaly. Weight: MF patients on therapy initially lost weight, which reflects resolution of excess extravascular water (based on investigators reported decreases in peripheral edema, ascites, or splenomegaly). As the trial progressed MF patients on INCB018424 treatment progressively gained weight (mean increase of 0.40 kg @ 1 month, 2.93 kg @ 2 mo, 3.70 @ 3 mo), and exhibited improved appetite. Importantly, weight gain was more consistent, of greater magnitude and more durable in patients who entered the study in the lowest quartile for BMI. Cholesterol: We previously reported that hypocholesterolemia (total cholesterol <150 or 100 mg/dL; HDL < 60mg/dL) is associated with decreased survival in MF patients (Mesa et al, Blood2007; 2007;110:a2548), potentially from hypercatabolism and splenic consumption of lipids. At enrollment, median total cholesterol was 95 mg/dl (range), with 94% and 55% below 150 mg/dl and 100 mg/dl, respectively. Following treatment with INCB018424, median total cholesterol increased to 145 mg/dl (range 72–289 mg/dL) with 73% increasing to an improved range above their baseline (either to the >100mg/dl or >150 mg/dl range). Leptin: At enrollment, MF patients had very low leptin levels (mean = 2.55 ng/mL with 50% below 1 ng/mL vs. a range of 6–12 ng/mL for normal volunteers). Low plasma levels are associated with shortened survival in cancer patients. The plasma leptin levels increased 176% on average after one month of treatment with INCB018424, and continued to increase to levels matching healthy volunteers with time on study (mean = 7.04 ng/mL (range 0.25 – 35 ng/mL) after 2 months on INCB018424) and correlated to weight increases. CONCLUSIONS: Therapy with INCB018424 improves the nutritional status of MF patients, including improving pathologic weight loss, hypercatabolism associated hypocholesterolemia, and pathologically decreased serum leptin. The improved nutritional status of MF patients treated with INCB018424 may reflect the ability of JAK inhibition to target the underlying pathophysiology of MF cachexia by reducing the organomegaly, levels of pro-inflammatory cytokines, and pro-inflammatory cytokine signaling.

Abstract Background: Myelofibrosis (MF) shortens survival but also compromises quality of life from disease associated splenomegaly and constitutional symptoms (fatigue, weight loss, night sweats, and bone pain). No current validated instrument of patient reported outcomes (PRO) captures the spectrum of MF associated symptoms. In an era of rapid development and testing of therapeutic agents which may impact the natural history and symptoms associated with MF (such as JAK2 inhibitors) a uniform and validated instrument for capturing the presence, severity (and potentially improvement) of MF symptoms is needed. We sought to develop and validate such an instrument, the myelofibrosis symptom assessment form (MFSAF). Methods: Based upon the results in our MF QOL survey (Cancer2007;109(1):68–76), we developed the MFSAF to assess fatigue (via the brief fatigue inventory (BFI-Cancer1999;85:1186)), additional symptoms were independently assessed for presence and severity on a scale from 0 (absent) to 10 (worst possible) for splenomegaly associated symptoms (early satiety, pain, inactivity, cough) night sweats, itching, bone pain, fever, unintentional weight loss as well as an estimate of overall quality of life. Additionally, patients provided feedback on the quality and nature of the MFSAF, and also completed for comparison validated instruments including the Memorial Symptom Assessment Scale (MSAS), the Insomnia Severity Index (ISI), and the Brief Pain Index. Physician input was included including their assessment of patient’s fatigue, spleen symptoms, and quality of life (blinded to patient’s responses) as well as clinical history, lab and exam findings. Results: MFSAF Results 34 MPD patients were enrolled (24 MF, 10 in the comparison group (4 polycythemia vera (PV), 6 essential thrombocythemia (ET)). the MFSAF was rated by patients as easy to understand (median score 1, range 0–6), and “addressed most of my symptoms” (median score 1, range 0–6) both on a scale of 0 (as good as possible to 10 as bad as possible). When asked if a symptom was not addressed (open ended response) no single symptom was named more than once. As we have previously reported fatigue was common with BFI scores (median 3.6 (0–10) for MF and 2.5 (range 0.2–3.8) for the ET/PV group (increasing BFI score associated with worsening fatigue) worse than median score of published “healthy” controls 2.2. Additional MF associated symptoms were captured well by the MFSAF with splenic, constitutional symptoms, and QOL (median 3 (range 0–7) MF, median 2 (0–3) ET/PV) documented easily and worse than ET/PV controls. Physicians estimation of QOL was excellent (median 3 (0–8) for MF, median 2 (0–4) for ET/PV). MFSAF Comparison to other Instruments: The MSAS demonstrated more adverse values for MF (than ET/PV) in the PSYCH (psychologic stress; mean-1.27 (STD DEV 0.80), PHYS (physical symptoms; mean 0.90 (STD DEV 0.53)), GDI (Global Distress Index mean-1.29 (STD DEV 0.77)) and a total MSAS symptom score (mean 0.85 (std dev (0.49)) comparable with advanced renal disease (PSYCH 0.99, PHYS 0.99, GDI 1.27, and MSAS of 0.81; J of Pall Med2007;10(6):1266), as well as advanced lung disease, AIDS, and various advanced malignancies. Individual, previously validated MSAS questions were all highly correlated (all p<0.01) with MFSAF (in italic) counterparts including lack of energy (fatigue), cough (same), pain (both abdominal pain and bone pain), sweats (night sweats), itching (same), and weight loss (same). Further validation of pain measurements in the MFSAF came from comparison to the BPI where both individually the presence, and intensity of pain (both abdominal and bone) were highly correlated (all p<0.01). Insomnia, not yet included in the MFSAF, was present in 68% and 63% of patients (MSAS and ISI, respectively). Additionally, problems with sexual interest, or activity, was noted in 35% of patients to the MSAS. Conclusions: Currently available instruments of PRO and symptoms are lengthy, and individually incomplete for assessing the presence and severity of the diverse nature of symptoms associated with MF. The proposed MFSAF, was comprehensive and well understood by patients and the results for the individual symptoms assessed were highly correlated with previously validated instruments for other conditions as well as with physicians perceptions of fatigue and QOL. The MFSAF, with the addition of questions regarding insomnia and sexuality, should be utilized in all trials of therapeutic agents in MF patients in which symptomatic improvements are an endpoint.

Abstract Background: Current evidence links some of the disease manifestations in myelofibrosis (MF) to abnormal cytokines, likely produced by clonally involved megakaryocytes and monocytes. Furthermore, the recent discovery of JAK2/MPL mutations in MF suggests the contribution of abnormal JAK-STAT signaling to both clonal myeloproliferation and cytokine-driven debility. In order to gain additional pathogenetic insight regarding cytokine-phenotype correlations in MF, we looked into the plasma cytokine profile of MF before and after treatment with INCB018424, a selective JAK1/2 inhibitor. Methods: The current study includes subjects with MF enrolled in an ongoing phase 1–2 study of oral INCB018424 (doses ranging from 25 mg/day to 50 mg BID). Plasma samples were obtained prior to treatment and at intervals of 2 weeks, 1 month and 2 months following INCB018424 dosing. Samples were submitted to Rules Based Medicine Human MAP multiplexed immunoassay system to obtain plasma levels on a range of protein analytes. Results: Plasma cytokine levels in MF patients (n=53) vs. normal healthy volunteers (n=15): Compared to normal controls, plasma levels of pro-inflammatory cytokines and markers of inflammation were significantly increased in MF patients (Table; mean +/− SD values). Furthermore, the observed inflammatory cytokine levels in MF were often higher than those seen in patients with rheumatoid arthritis or cancer-associated cachexia (data to be presented at the meeting). Correlation of plasma cytokine levels in MF with JAK2 V617F mutational status, MF subtype and/or constitutional symptoms/cachexia: Comparison of JAK2V617F positive (n=40) and negative (n=13) MF cases suggested significantly (p<0.01) higher IL-1RA (mean +/− SD = 5575 +/− 917 vs. 1291 +/− 359 pg/ml) and CRP (17.4 +/− 1.6 vs. 6.7 +/− 1.9 μg/ml) levels for the former whereas the other cytokines were elevated to a similar extent. Plasma cytokine levels in PMF (n=30) vs. post-PV MF (n=15) vs. post-ET MF (n=8) were not significantly different. The presence of prior splenectomy did not appear to alter the specific MF cytokine profile (Table 1); the abnormal cytokine profile in MF is, therefore, not necessarily a consequence of marked splenomegaly. There was a direct correlation between the levels of pro-inflammatory cytokines and the presence or absence of constitutional symptoms/cachexia (Figure). Similarly, increased inflammatory cytokine levels in MF were accompanied with significantly decreased leptin levels, a surrogate for nutritional status (Table). Post-INCB018424 treatment cytokine levels: Treatment with INCB018424 induced a rapid decrease in MF-associated inflammatory cytokine levels, in parallel with the observed clinical benefit of both reduced splenomegaly and improvement in constitutional symptoms/cachexia (data to be presented at the meeting). Conclusion: The plasma cytokine profile of MF is reminiscent of a chronic inflammatory state with levels of pro-inflammatory cytokines that are possibly higher than those seen in other inflammatory/malignant conditions. Furthermore, the current study suggests a fundamental link between these cytokines and MF-associated constitutional symptoms/cachexia. Cytokine modulation through JAK-STAT inhibition appears to be a mechanism of action for INCB018424 in MF. Cytokine Normal volunteer (N = 15) MF with splenectomy (N = 6) MF without splenectomy (N = 47) IL-1b (pg/ml) 0.6 +/− 0.04 44 +/− 36 41 +/− 25 IL-1RA (pg/ml) 103 +/− 10 7759 +/− 3939 4111 +/− 763 IL-6 (pg/ml) 0 9.7 +/− 3.3 53.6 +/− 22.5 IL-8 (pg/ml) 7.6 +/− 1.17 1618 +/− 1165 2376 +/− 451 TNFa (pg/ml) 2.6 +/− 0.21 38 +/− 6.8 45 +/− 8.8 TNFRII (ng/ml) 3.1 +/− 0.12 27.3 +/− 7.4 24.7 +/− 2.5 CRP (mg/ml) 1.5 +/− 0.49 21.7 +/− 4.5 13.9 +/− 1.6 Leptin (ng/ml) 10.8 +/− 3.5 3.8 +/− 0.9 2.74 +/− 0.6

Abstract Dasatinib is approved as a second line therapy (Rx) for Philadelphia chromosome (Ph)-positive chronic myeloid leukemia, as it targets Bcr/Abl tyrosine kinase. Due to its activity against other kinases, like KIT and PDGFR, we conducted a Phase II study of dasatinib in patients with Ph-negative acute and chronic myeloid diseases. Sixty-eight patients were treated at the starting dose of 70mg PO BID (9 patients with SM received 140mg as a single dose daily); 4 weeks=1 cycle. All patients were assessed for response and toxicity (no Grade 4 toxicity was observed). The results by disease type are detailed. Systemic mastocytosis: 33 patients were treated (18 indolent, 9 aggressive, 6 with associated hematologic malignancy); median age 57 years (29–74); 14 were males, all PDGFRA−; # prior Rx 1 (0–4), 16 not previously treated; median # cycles 4 (1–20). Two achieved CR: one SM-MF (JAK2 V617F+, complex cytogenetics) and one SM-HES; both c-KIT mutation negative, low tryptase, anemic, failed erythropoietin, and had abnormal WBC differential. SM-MF patient progressed to AML after 8 months on Rx and died, and SM-HES is still in CR after 18+ months. Nine patients had improvement in symptoms related to SM, lasting from 3–18+ months. Nineteen Grade 3 toxicities were observed; dose was reduced to −1 level in 15, and to −2 level in 5 patients. Acute myeloid leukemia: 9 patients were treated; median age 70 years (51–91); 7 were males, 4 had abnormal cytogenetics; # prior Rx 2 (0–3); median # cycles 1 (1–18). CR was observed in an 80y old male with trisomy 8, previously treated with 3+7 chemotherapy with short CR. He relapsed on dasatinib Rx after 60 weeks. Eight patients had no response (4 stopped Rx within first month). Six Grade 3 toxicities were observed. Myelodysplastic syndrome/chronic myelomonocytic leukemia: 6 patients were treated (3+3); median age 68 years (51–75); 4 were males, 1 with abnormal cytogenetics; # prior Rx 1.5 (0–5); median # cycles 1 (1–2). No responses were observed (2 stopped Rx within first month); one Grade 3 toxicity was observed. Hypereosinophilic syndrome/chronic eosinophilic leukemia: 8 patients were treated (5+3); median age 58 years (23–75); 5 were males, 3 had abnormal cytogenetics, all PDGFRA-; # prior Rx 1.5 (0–3); median # cycles 3 (1–17). One female patient with HES achieved CR (previously Rx with gleevec without response). She relapsed after 58 weeks while off Rx due to toxicity. Other patients did not respond (1 stopped Rx within first month); 5 Grade 3 toxicities were observed. Polycythemia vera: one patient was treated; 50yr old female, with no prior Rx, had no response after 3 months of dasatinib Rx. Chronic idiopathic myelofibrosis: 11 patients were treated; median age 63 years (47–77); 10 were males, 2 had abnormal cytogenetics; # prior Rx 2 (0–7); median # cycles 6 (1–9). No responses were observed (1 stopped Rx within first month); 4 Grade 3 toxicities were observed. Conclusion: Dasatinib is active in systemic mastocytosis (overall response rate 33%). Updated clinical and molecular results will be presented.