Citations

Abstract Introduction: Mutations localized in the tyrosine kinase domain activation loop of FLT3 (FLT3-TKD), representing point mutations in codon D835/I836 and rarely deletions of codon I836, induce constitutive tyrosine phosphorylation and activation of the receptor tyrosine kinase similarly to FLT3 internal tandem duplication (ITD) mutations. However, the prognostic role of FLT3-TKD in AML, particularly in the presence of NPM1 mutations, is not well established. The phase 3 RATIFY trial [NCT00651261; Stone et al. N Engl J Med. 2017] showed that in combination with standard chemotherapy, midostaurin (PKC412) improved survival outcomes across all 3 FLT3 stratification subgroups (ITD high allelic ratio [≥ 0.7], ITD low allelic ratio [< 0.7], and TKD) vs placebo in patients with newly diagnosed FLT3-mutated AML. Here, we evaluated the prognostic impact of FLT3-TKD and NPM1 mutations in a post hoc analysis from the RATIFY trial. Methods: In RATIFY, newly diagnosed patients with AML 18-60 years old were randomly assigned to receive midostaurin or placebo together with standard induction and consolidation therapy followed by 12 28-day cycles of maintenance therapy with midostaurin or placebo. FLT3-TKD mutation was detected by PCR and capillary electrophoresis at 9 reference laboratories. Patients were categorized as NPM1 mutated (mut) or NPM1 wild-type (WT) using PCR. Efficacy outcomes included complete remission (CR), overall survival (OS), event-free survival (EFS) and disease-free survival (DFS). EFS and DFS analyses were performed considering CR within a 60-day window. P values presented have not been adjusted for multiplicity. Results: Of the total randomized 162 FLT3-TKD patients, 134 with available NPM1 data had consented for exploratory analysis and thus were included in this study (see Table for subgroup distribution). Overall, 47.8% of patients were male, and the median age was 49 years (95% CI, 45.5-51.1 years). The median white blood cell (WBC) count was higher in patients with NPM1-mut than in patients with NPM1-WT (34.1 vs 15.5 × 109/L, P = .0011). CR rates (during the first 60 days) were higher in patients with FLT3-TKD/NPM1-mut vs FLT3-TKD/NPM1-WT (66% vs 53%); however, this was driven by the higher rate of CR in the midostaurin arm (76% NPM1-mut vs 44% NPM1-WT) rather than the placebo arm (53% NPM1-mut vs 60% NPM1-WT). The overall CR rate (regardless of NPM1 genotype) was 64% for midostaurin and 56% for placebo in FLT3-TKD patients. The prognostic effect of the NPM1 mutation concurrent with FLT3-TKD was seen for all endpoints consistently with hazard ratios (HRs) around 0.50 or lower (Figures 1 and 2 and Table). Overall (regardless of treatment) OS, EFS, and DFS estimates at 3 years were 73% vs 52%, 48% vs 25%, and 74% vs 47%, respectively, in patients with FLT3-TKD/NPM1-mut vs FLT3-TKD/NPM1-WT. Whereas the HRs for midostaurin vs placebo were 0.73 for both OS and EFS, the impact of treatment on outcomes varied between the individual NPM1/TKD subgroups and was not consistently observed when endpoints were censored at stem cell transplant (SCT) (Table). It should be noted that the number of patients in each subgroup was small and therefore the HRs with 95% CIs should be interpreted with caution. Multivariate analyses in these FLT3-TKD patients revealed that NPM1 genotype was an independent prognostic factor for OS, EFS and DFS (2-sided P < .05), whereas study drug, age, sex, WBC at baseline and SCT (no/yes) did not reach this level of significance in the Cox model. Conclusions: This post hoc analysis of the FLT3-TKD patient subset in the RATIFY trial showed the high prognostic value of NPM1 mutational status. Whereas midostaurin showed an overall benefit in the FLT3-TKD patients for OS, EFS, CR and DFS, the impact of treatment on outcome varied between the individual NPM1 subgroups within these FLT3-TKD patients and was not consistently observed.Further analyses using additional endpoints and additional multivariate analyses are planned. Support: U10CA180821, U10CA180882, U10CA180820, U10CA180791, U10CA180888, U10CA180863, (CCSRI) #704970, U24CA196171; ClinicalTrials.gov Identifier: NCT00651261 Disclosures Voso: Celgene: Research Funding, Speakers Bureau. Larson:Ariad/Takeda: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding. Heuser:Janssen: Consultancy; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; StemLine Therapeutics: Consultancy; Astellas: Research Funding; BergenBio: Research Funding; Karyopharm: Research Funding; Bayer Pharma AG: Consultancy, Research Funding; Tetralogic: Research Funding; Sunesis: Research Funding; Daiichi Sankyo: Research Funding. Wei:Novartis: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau; Pfizer: Honoraria, Other: Advisory committee; Amgen: Honoraria, Other: Advisory committee, Research Funding; Abbvie: Honoraria, Other: Advisory board, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Other: Advisory committee, Research Funding; Celgene: Honoraria, Other: Advisory committee, Research Funding. Brandwein:Lundbeck: Consultancy; Celgene: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Boehringer Ingelheim: Consultancy, Research Funding. de Witte:Novartis: Research Funding; Amgen: Consultancy, Research Funding; Celgene: Honoraria, Research Funding. Medeiros:Celgene: Consultancy, Research Funding; Genentech: Employment. Tallman:Cellerant: Research Funding; Orsenix: Other: Advisory board; BioSight: Other: Advisory board; ADC Therapeutics: Research Funding; AROG: Research Funding; AbbVie: Research Funding; Daiichi-Sankyo: Other: Advisory board. Schlenk:Pfizer: Research Funding, Speakers Bureau. Ganser:Novartis: Membership on an entity's Board of Directors or advisory committees. Cheng:Novartis: Employment. Gathmann:Novartis: Employment. Tiecke:Novartis: Employment. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding. Döhner:AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Sunesis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Celator: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Agios: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Pfizer: Research Funding; Pfizer: Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Stone:Otsuka: Consultancy; Argenx: Other: Data and Safety Monitoring Board; Amgen: Consultancy; Agios: Consultancy, Research Funding; Orsenix: Consultancy; Ono: Consultancy; Novartis: Consultancy, Research Funding; Astellas: Consultancy; Arog: Consultancy, Research Funding; Merck: Consultancy; Cornerstone: Consultancy; Fujifilm: Consultancy; Jazz: Consultancy; Celgene: Consultancy, Other: Data and Safety Monitoring Board, Steering Committee; Pfizer: Consultancy; Sumitomo: Consultancy; AbbVie: Consultancy.

Abstract Background: The oral BTK inhibitor ibrutinib is the only approved therapy for patients with symptomatic Waldenström macroglobulinemia (WM). Bing-Neel syndrome (BNS) is a rare complication of WM that results from infiltration of malignant lymphoplasmacytic cells into the central nervous system (CNS) causing neurological deficits. Treatment options in patients with BNS are limited to agents with CNS penetration. Ibrutinib can penetrate into the CNS, but data on its efficacy in BNS is lacking outside case reports. Methods: We performed a multicenter retrospective study evaluating the efficacy of ibrutinib in patients with BNS. The diagnosis of BNS was established in patients with a clinicopathological diagnosis of WM by radiological and/or cytological evidence of CNS involvement by WM, and response was assessed based on recently published criteria. Ibrutinib was given orally at doses of 420-560 mg PO once daily until disease progression or intolerable toxicity. Response was assessed using criteria from the 8th International Workshop for WM (Minnema et al. Haematologica 2017). Events were defined as death from any cause, progression of disease and stopping ibrutinib from any reason. Time to events was estimated using the Kaplan-Meier method. Results: We present data on 24 patients with BNS treated with ibrutinib. The median age at diagnosis of WM was 60 years (range 38-76 years) and 14 patients (58%) were men. The median lines of therapy for WM prior to BNS diagnosis was 1 (range 0-7 lines), and 9 patients (38%) were untreated for WM at the time of BNS diagnosis. Previous WM therapies included anti-CD20 antibodies (n=15), alkylators (n=13), nucleoside analogues (n=8), proteasome inhibitors (n=3), immunomodulators (n=2), and autologous transplant (n=1). The median age at BNS diagnosis was 65 years (range 38-80). The median time from WM to BNS diagnosis was 4 years (range 0-27 years). In 2 patients, the diagnosis of BNS was made concurrently with WM diagnosis. The median number of BNS lines prior to ibrutinib was 1 (range 0-5 lines). Previous BNS therapies included intrathecal chemotherapy (n=9), high-dose methotrexate (n=6), bendamustine (n=3) and radiation therapy (n=3). In 7 patients (29%), ibrutinib was the first line of treatment for BNS. The most common symptoms at BNS presentation were cognitive deficits (n=10), sensory deficits (n=8), ataxia/falls (n=8), motor deficits (n=6), headache (n=5) and seizures (n=5). MRI findings included leptomeningeal enhancement (n=16) and brain masses (n=5). Cerebrospinal fluid (CSF) flow cytometry confirmed the presence of clonal CD19+ in 19 patients (79%). Biopsies were performed in 5 patients (21%) and confirmed presence of WM cells. 4 patients had normal MRI but had abnormal CSF cytology and/or flow cytometry. Tissue was not obtained in 1 patient in whom MRI showed leptomeningeal enhancement. Interestingly, 2 patients were diagnosed with lymphoplasmacytic lymphoma secreting IgG paraprotein. The median serum IgM (n=20) prior to ibrutinib initiation was 1,294 mg/dl (range 125-5,938 mg/dl), and the median hemoglobin level was 11.9 g/dl (7.7-15.2 g/dl). Ten patients (42%) received ibrutinib 560 mg PO once daily, and 14 (58%) received ibrutinib 420 mg PO once daily. At best response, median serum IgM and hemoglobin levels were 340 mg/dl (82-3,330 mg/dl) and 14.6 g/dl (range 9.2-16.0 g/dl). Based on consensus BNS response criteria, complete response was attained in 2 patients (8%), partial response in 14 (58%) and clinical improvement in 3 patients (13%). With a median follow-up time of 13 months (95% CI 8-21 months), 5 patients have stopped ibrutinib, 3 due to BNS progression, 1 due to grade 3 muscle cramps and 1 due to arrhythmia, and 3 patients have died, 2 from infection and 1 from BNS progression. The median event-free survival (EFS) from ibrutinib initiation was not yet reached. The 1-year and 2-year EFS rates were 71% (95% CI 46-86%) and 52% (23-75%), respectively. Conclusion: Ibrutinib is a safe and effective treatment option for patients with BNS. Disclosures Palomba: Pharmacyclics: Consultancy; Celgene: Consultancy. Talaulikar:Amgen: Consultancy, Honoraria; Takeda: Research Funding; Janssen: Honoraria, Speakers Bureau; Roche: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Buske:Janssen: Honoraria, Research Funding; Bayer: Research Funding; Roche: Honoraria, Research Funding. Tedeschi:Gilead: Consultancy; AbbVie: Consultancy; Janssen: Consultancy, Speakers Bureau. Simpson:Pharmacyclics LLC, an AbbVie Company: Research Funding; Acerta: Research Funding; Merck: Honoraria, Research Funding; BeiGene: Research Funding; Sanofi: Research Funding; Bristol-Myers Squibb: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Novartis: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; MSD: Honoraria; Roche: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Amgen: Research Funding, TRAVEL, ACCOMMODATIONS, EXPENSES; Janssen: Honoraria, Research Funding. Tam:Janssen: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BeiGene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Ansell:Affimed: Research Funding; Takeda: Research Funding; Merck & Co: Research Funding; Pfizer: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Celldex: Research Funding; LAM Therapeutics: Research Funding. Treon:Johnson & Johnson: Consultancy; BMS: Research Funding; Pharmacyclics: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Janssen: Consultancy, Other: Travel, Accommodations, Expenses. Castillo:Millennium: Research Funding; Genentech: Consultancy; Abbvie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Beigene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding.

Background: Based on an established classification system of Apert syndrome subtypes, detailed regional morphology and volume analysis may be useful to provide additional clarification to individual Apert cranial structure characteristics, and treatment planning. Methods: Computed tomography scans of 32 unoperated Apert syndrome and 50 controls were included and subgrouped as: type I, bilateral coronal synostosis; type II, pansynostosis; type III, perpendicular combination synostosis. Three-dimensional analysis of craniometric points was used to define structural components using Materialise Mimics and 3-Matics software. Results: Occipitofrontal circumference of all subtypes of Apert syndrome patients is normal. Intracranial volumes of types I and II were normal, but type III was 20% greater than controls. Middle cranial fossa volume was increased in all 3 types, with the greatest increase in type II (86%). Type II developed a 69% increase in anterior cranial fossa volume, whereas type III had 39% greater posterior cranial fossa volume. Increased cranial fossa depth contributed most to above increased volume. The anteroposterior lengths of middle and posterior cranial fossae were reduced in type I (15% and 17%, respectively). However, only the anterior cranial fossa was significantly shortened in type III. Conclusions: Occipitofrontal circumference and overall intracranial volume is not always consistent in individual subunits of Apert syndrome. Detailed and segmental anterior, middle, and posterior cranial fossae volumes and morphology should be analyzed to see what impact this may have related to surgical planning.

INTRODUCTION: The etiology of acute liver failure (ALF) remains an important prognostic factor. The Acute Liver Failure Study Group recently reported that 150 of 2,718 adult patients with ALF (5.5%) had an indeterminate etiology. Our aim was to use whole exome sequencing to identify genetic variants associated with phenotypic, biochemical, and histologic features among patients with indeterminate ALF. METHODS: This effort has defined a cohort of well-pedigreed patients with indeterminate ALF; DNA samples extracted from whole blood samples were obtained from 26 respective patients with indeterminate ALF. These samples were kept at the Acute Liver Failure Study Group repository at the NIDDK, Bethesda. Whole exome sequencing and bioinformatics analysis were performed at the Mayo Clinic Center of Individualized Medicine in Rochester, MN. RESULTS: Of the 26 patients, 8 survived spontaneously, 6 died, and 12 underwent a liver transplantation; all those transplanted were alive at 21 days after enrollment in the study. Twenty-two of the 26 patients presented as ALF. We found 12 variants associated with 11 genes. The most common variant was rs4940595 in the SERPINB11 gene which was found in 23 of the 26 patients. This variant had a stop codon; no reports of disorders have been associated with this variant. The next most commonly found variant was rs1135840 in the CYP2D6 gene; this mutation is a missense_variant and has been reported to be associated with hepatotoxicity of antituberculous therapy. None of our patients were receiving this therapy. We also found a significant asymmetric distribution of rs1800754 of the CYP2D7 gene and rs1135840 of the CYP2D6 gene between patients who survived spontaneously (75%) and those who died or underwent liver transplantation (30.5% and 25%, respectively). DISCUSSION: We found 12 variants of 11 genes significantly associated with ALF among adults with i ndeterminate etiology. We also found a significant asymmetric distribution of 2 variants belonging to the CYP2D7 and CYP2D6 genes, respectively, between those who survived spontaneously and those who died or underwent liver transplantation. The 2 most common variants, rs4940595 and rs1135840, of the SERPINB11 and CYP2D6 genes, respectively, found in our patients with ALF have been described as potentially important in the adaptive response combating the emergence of infectious diseases and associated with hepatotoxicity of antituberculous therapy, respectively. Our findings need to be expanded to include more patients with indeterminate ALF as well as viral, drug toxicity, and autoimmune etiologies to determine whether our findings are associated with the specific etiology, indeterminate, or with the overall ALF syndrome itself.

Abstract Multiple myeloma (MM) is characterized by clonal proliferation of a neoplastic plasma cell and its production of a monoclonal immunoglobulin; evolving from an asymptomatic pre-malignant stage named monoclonal gammopathy of undetermined significance (MGUS). At the time of diagnosis with MM, lytic lesions are present in approximately 70-80% of patients. Lytic lesions increase the risk for skeletal related events as well as treatment costs, while lowering quality of life and overall survival. Metastatic bone surveys underestimate bone disease since plain radiographs demonstrate abnormalities until at least 30% of trabecular bone has been lost and cannot provide information about ongoing bone remodeling. Bone scintigraphy lacks usefulness in following bone disease due to decreased osteoblast activity in MM, while Dual-energy X-ray absorptiometry scans produce heterogeneous local bone mineral density changes and are not recommended to evaluate bone disease in these patients. Biomarkers (eg, N- and C-terminal telopeptides of type I collagen) have been used to assess bone metabolism balance (BMB; ie, the difference between bone formation and resorption) in MM prior and subsequent to specific therapies, however, consensus is still lacking and their clinical utility is uncertain. Calcium in nature consists of six isotopes, and the relative abundance of the isotopes varies measurably. The strength of molecular bonds depends on atomic weight of the participating atoms. Calcium (Ca) containing compounds react at different rates depending on atomic mass. Bone formation favors lighter isotopes of Ca, depleting soft tissue of light Ca isotopes, while bone resorption releases this isotopically light Ca back into soft tissue with little or no selectivity. As a result of this difference in isotope fractionation, Ca isotopic composition in soft tissue should shift to heavier Ca isotope values in positive BMB and lighter values in negative BMB. In order to identify whether Ca isotopic composition can be used as a marker of myeloma-induced bone disease, we first set out to determine its association with MM disease activity. Using multiple collector inductively coupled plasma mass spectrometry, we determined the Ca isotopic composition in 108 peripheral blood samples from 54 patients with monoclonal gammopathies. Ca isotopic composition was determined as the ratio between the naturally occurring 44Ca and 42Ca isotopes (δ44/42Ca) relative to a standard in parts per ten thousand units, as previously described by Morgan et al. Disease activity was determined at the time of δ44/42Ca determination by assessing disease status and response to treatment, as described by the International Myeloma Working Group uniform response criteria, defining progressive or relapsed disease as active disease, and stable or responsive disease as non-active. Categorical variables were analyzed using chi squared or Fisher’s exact test, interval variables were analyzed using a one-tailed t-test. A repeated measures logistic regression model was developed using a cross-sectional time-series generalized estimating equation. All statistical analysis was done using Stata/SE 12.0. Fifty-four adult patients (61% male) diagnosed with monoclonal gammopathy, ranging from MGUS (n=1) to SMM (n=4) to MM (n=49), were assessed at different time points, with 7 patients being assessed once, 41 were assessed twice, 5 were assessed 3 times, while 1 patient was assessed 4 times. Mean age at the time of first assessment was 66, ranging from 45 to 84. Mean δ44/42Ca was statistically lower in the active disease group as compared to the non-active group (-0.7536 vs -0.6564, p=0.0466). In a statistically significant repeated measurement logistic regression model (p= 0.0239), δ44/42Ca is associated with active disease (OR=0. 054, p=0.031, 95% CI=0.004-0.765) after adjusting for age, gender, presence of anemia, serum creatinine, free light chain ratio, current bisphosphonate and current anti-myeloma therapy. A lower δ44/42Ca in the active disease group might suggest a link between a more intense level of bone resorption and myeloma activity. Ca isotopic composition can become part of the clinician’s arsenal to determine disease status in a patient with MM. In order to further characterize δ44/42Ca to specifically infer myeloma-induced bone disease activity, further studies that include serum biomarkers and dynamic imaging should be performed. Disclosures: Gordon: Arizona State University: “Application of Ca isotope analysis to the early detection of metastatic cancer” (AzTE reference number M13-117) Patents & Royalties; Arizona State University: “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L), “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L) Patents & Royalties. Skulan:AZTE: “Application of Ca isotope analysis to the early detection of metastatic cancer” (AzTE reference number M13-117) Patents & Royalties; AZTE: “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L), “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L) Patents & Royalties. Anbar:Arizona State University: “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L), “Isotopic biomarkers for rapid assessment of bone mineral balance in biomedical applications” (US Application #PCT/US2011/039780; AzTE reference number M10-102L) Patents & Royalties; Arizona State University: “Application of Ca isotope analysis to the early detection of metastatic cancer” (AzTE reference number M13-117) Patents & Royalties. Fonseca:AMGEN: Consultancy; Millennium: Consultancy; Binding Site: Consultancy; Onyx: Consultancy, Research Funding; Lilly: Consultancy; BMS: Consultancy; Genzyme: Consultancy; Celgene: Consultancy; Medtronic: Consultancy; Otsuka: Consultancy; Cylene: Research Funding; Prognostication of MM based on genetic categorization of the disease: Patents & Royalties.

Abstract Background: A mutation in the Janus tyrosine kinase 2 gene (JAK2 V617F) has been recognized in Philadelphia chromosome-negative myeloproliferative disorders, including PV (∼95% of patients), ET (∼50%) and PMF (∼50%). INCB018424 is a potent and orally bioavailable selective JAK2 inhibitor with >80-fold selectivity against a broad panel of kinases, including JAK3. INCB018424 potently inhibits JAK2 V617F mediated signaling and malignant cell survival in vitro and in vivo in mice. Preclinical safety studies with INCB018424 demonstrated an excellent safety profile with no off-target toxicities. Methods: A phase I/II trial of INCB018424 given orally BID is being conducted in patients with PMF and Post-PV/ET MF. Both JAK2 V617F and JAK2 wild type patients are eligible. PK and PD data are being collected. Responses are being evaluated using the International Working Group (IWG) consensus criteria for treatment response in myelofibrosis with myeloid metaplasia, for the IWG for Myelofibrosis Research and Treatment (IWG-MRT) (Tefferi et al., Blood, 108, 1497–1503, 2006). Results: The initial dose of 25 mg PO BID resulted in a rapid and marked reduction in splenomegaly. All 3 patients in the first cohort of patients achieved a reduction in spleen size that is consistent with a clinical improvement response provided it is sustained for 8 weeks; spleen sizes of 25, 22, and 7 cm below the left costal margin have decreased to 8, 10, and 0 cm in the first month of therapy. At two months follow-up, the patient with a baseline spleen size of 22 cm is now down to 2 cm. All 3 patients also noted significant symptomatic improvement. The second cohort of 3 patients started therapy at an increased dose (50 mg PO BID) and at one week follow-up, the initial two patients (one JAK2 wild type, one JAK2 V617F) had decreases in spleen size from 22 cm to 17 cm and from 22 cm to 16 cm, respectively. No dose-limiting toxicities or other significant adverse events occurred in any patients to date. PK/PD analyses demonstrated that administration of INCB018424 resulted in plasma drug concentrations sufficient to markedly inhibit JAK2, as shown by suppression of phosphorylated STAT3 (a substrate of JAK2) in whole blood cells in all 3 patients in the first cohort. The 3 patients in the first cohort were all JAK2 V617F mutation positive: percentages of JAK2 V617F positive whole blood cells before therapy were 79%, 49% and 91%, and after one month of therapy, they were 59%, 48% and 78%, respectively. Conclusions: Initial results show marked reduction in splenomegaly and symptomatic improvement, without significant toxicity. The percentage of blood cells with JAK2 V617F mutation appears to be decreasing in patients on therapy. Updated results on current and future patients will be presented at the meeting.

Abstract Abstract 532 Primary Plasma cell leukemia (PCL) is a rare plasma cell disorder characterized by an aggressive clinical course. The efficacy of autologous and allogeneic HCT in PCL is uncertain due to the small number of patients that have been reported in the literature. To determine the potential for long-term disease control using HCT in PCL, we performed a retrospective review of 160 patients with primary PCL who received autologous (n=107), allogeneic (n=52) or syngeneic (n=1) HCT and were reported to the CIBMTR between 1995 and 2006. Kaplan–Meier analysis was used for overall survival (OS) and progression free survival (PFS). Cumulative incidence estimates of non-relapse mortality (NRM), relapse, acute and chronic GVHD were calculated. Median age at the time of autologous HCT was 57 years (range, 32-74 years) and allogeneic HCT was 48 years (range, 24-62 years). Median time from initial treatment to autologous HCT was 7 months and allogeneic HCT was 6 months. At the time of transplant, in the autologous HCT group, 19% patients were in complete remission, 56% in partial remission and 1% had relapsed/progressive disease; in the allogeneic HCT group, 17% were in complete remission, 46% in partial remission and 10% had relapsed/progressive disease. In the allogeneic HCT group, 83% of the patients received myeloablative conditioning regimens and 17% received nonmyeloablative/reduced-intensity conditioning. The rate of acute GVHD was 35% (95% confidence interval [CI], 22%-49%) and the rate of chronic GVHD at 3 years was 27% (95% CI, 13%-40%). After a median follow-up of 38 months, 20 of the 52 patients (38%) are alive in the allogeneic HCT group and 68 of the 107 pts (64%) are alive in the autologous HCT group (Figure 1). Progressive disease accounted for 38% of the deaths in the allogeneic HCT group and 86% of the deaths in the autologous HCT group. The outcomes are summarized in table 1. The remarkable overall survival of patients after autologous HCT in this analysis is noteworthy and indicates that autologous HCT is a safe and acceptable treatment option for patients with primary PCL. Although relapse rates are lower, allogeneic HCT carries a much higher risk of NRM and should be considered primarily in the context of a clinical trial. Disclosures: Lonial: Celgene: Consultancy; Millennium: Consultancy, Research Funding; BMS: Consultancy; Novartis: Consultancy; Gloucester: Research Funding.

Abstract Abstract 3917 Poster Board III-853 Background Patients with Myelofibrosis (MF) suffer from significant fatigue, constitutional symptoms and splenomegaly (Mesa et. al. Cancer 2007) not improved by current therapy. The MF-SAF is a 19 item self administered instrument specific to MF associated symptoms previously validated for use at a single time point (Mesa et. al. Leukemia Research 2009). We sought to assess the performance characteristics of the MF-SAF when administered sequentially in the context of a prospective clinical trial. Methods Sequential MF patients enrolled in the prospective, uncontrolled Phase II, trial were given a 15 item modified MF-SAF to complete at enrollment, and after 15 days, 1 month, 2 months, 3 months and every 3 months thereafter. The MF-SAF was scored as previously published on a 0 (absent) to 10 (maximal) scale. Cross validation of serial change in MF-SAF scores was undertaken by comparison to objective measurements made as part of the therapeutic drug trial. Results Patients Eighty six MF patients were enrolled and had 2 or more MF-SAF instruments completed to allow for sequential analysis. Patients were of a median age (65 years), gender distribution (35 % females), and disease subtype (53 % PMF) typical for a clinical trial in MF. Baseline MF-SAF Responses: Baseline assessment of the most frequent MF abnormalities reported by patients completing the MF-SAF (see Table 1) confirmed the wide prevalence of MF associated symptoms, and their significant severity. General fatigue was the most frequent symptom cited (91%), while cough was the least frequently observed symptom (44%). 95% of patients had at least 2 symptoms present on the MF-SAF. Serial MF-SAF Changes in Response to Therapy Therapy with INCB018424 resulted in a significant and rapid reduction in MF associated symptoms with 46% to 85% of patients experiencing improvement in a given symptom. The greatest improvements in MFSAF score improvements were reported by patients experiencing abdominal discomfort, night sweats, pruritus and fever (see Table 1), and corresponded to significant improvements in the individual MF symptom scales as well as the patient's overall assessment of quality of life (QOL). Correlation of MF-SAF to Objective Changes during INCB018424 Therapy Objective measurements obtained on the INCB018424 trial included MRI measurements of splenic reduction, the six minute walk test (6MWT) for inactivity, and serial weights. Reduction in spleen size (by ≥ 35% by volume or ≥ 50% by palpable length) corresponded to improvement in MF-SAF scores of abdominal discomfort and fatigue (50% of patients, median score decrease of -1.2, and -1.8, respectively). Improvement in the 6MWT by > 50 meters was associated with a 2-fold greater improvement in inactivity score on the MF-SAF compared to subjects who improved 6MWT performance by <50 meters. Finally, improvements in weight loss and fever were corroborated by objective measurements made at physician visits on the trial. Conclusions The MF-SAF is a brief, easily self administered, MF specific instrument which was successfully administered sequentially in the conduct of a large Phase II clinical trial. The significant symptomatic improvements reported by patients in the open label trial of INCB018424 corresponded to both improvements in symptom specific scores on the MF-SAF and objective measurements. Further validation of the MF-SAF will be possible by inclusion in upcoming randomized placebo controlled trials in MF patients. Parallel trials performed in MF patients should consider use of this instrument to allow for comparisons. Disclosures: Levy: Incyte Corporation: Employment, Equity Ownership. Vaddi:Incyte Corporation: Employment, Equity Ownership. Erickson-Viitanen:Incyte Corporation: Employment, Equity Ownership. Verstovsek:Incyte: Research Funding.

Abstract Prompted by the activity of lenalidomide (Revlimid®) in pts with chronic idiopathic myelofibrosis (CIMF), we sought to evaluate the safety and efficacy of the combination of lenalidomide and prednisone in a phase II study for pts with CIMF. The rationale for this combination is that the anti-angiogenic and anti-TNFa effects of lenalidomide may be potentiated by the effects of prednisone to reduce marrow fibrosis and improve hematopoiesis in CIMF. Initial therapy consisted of lenalidomide 10 mg/d (dose level [DL] 0) on days 1–21 of a 28–day cycle for 6 cycles, in combination with prednisone 30 mg/d orally during cycle 1, 15 mg/d orally during cycle 2, and 15 mg/d every other day during cycle 3. The lenalidomide dose could be reduced to 5 mg/d (DL -1) or to 5 mg/d every other day (DL -2), or increased to 15 mg/d (DL +1) or 20 mg/d (DL +2) depending upon toxicity or lack of response, respectively. A total of 40 pts (23 male, 17 female) have been enrolled. The median age was 62 years (range, 41–86), time from CIMF diagnosis to the study treatment 10 months (range, 0–269), WBC count 87x109/L (range, 1.1–89), hemoglobin 9.8 g/dL (range, 7.8–17.3), platelets 137x109/L (range, 8–1183). Pts had received a median of 1 prior therapy (range 0–4): hydroxyurea (HU; n=14), anagrelide (AG; n=4), azacitidine (n=6), steroids (n=5), thalidomide (n=4), and interferon (n=3). Ten (25%) pts had not received any prior therapy. JAK2 V617F mutation was detected in 18 (50%) of 36 tested pts and 20 (50%) of 40 had abnormal cytogenetics. A total of 260 cycles have been administered. All 40 pts are evaluable for response and toxicity. Responses have been observed in 12 (30%) pts, including complete response (CR) in 2 (normal blood counts and <5% bone marrow blasts, off HU, AG, growth factors, and no transfusions); partial response (PR) in 7 (at least 2 of the following: Hb increase by ≥2 g/dL, 50% increase in platelets, decrease of bone marrow blasts or organomegaly by ≥50%, normalization of WBC count without blasts, or reduction in bone marrow fibrosis; off HU, AG, growth factors, and transfusion independence); and hematologic improvement (HI) in 3 (at least 2 of the following: decrease by ≥25% of pretreatment leukocytosis, splenomegaly, or marrow blasts, or increase of Hb by ≥1g/dl without growth factor or transfusion support or platelets by ≥25%; off HU, AG, growth factors). Median time to response was 12 weeks (range, 2–32). Responses have been sustained for a median of 15 wks (range, 5–36) and are ongoing in all 12 responders. Overall, 21 (53%) pts experienced grade 3–4 toxicity, being the most frequent neutropenia, anemia, musculoskeletal pain, and fatigue. Twenty-four (60%) pts have required dose reduction to DL -1, of which 5 (12.5%) further reduced to DL -2. One (2.5%) pt dose-escalated to DL +1, while 15 (25%) remained at DL 0. Twenty-one (53%) pts discontinued lenalidomide due to: lack of response (n=8), pt’s decision (n=7), grade 3–4 toxicity (n=5), and poor compliance (n=1). No deaths or transformation to acute myeloid leukemia occurred. In summary, the combination of lenalidomide and prednisone is an active and generally well-tolerated regimen for pts with CIMF. Longer follow-up is warranted to evaluate the durability of ongoing responses. Updated results will be presented at the meeting.

Abstract Introduction: Several groups are developing orally bioavailable small molecule JAK2 inhibitors as an approach to targeted therapy of myeloproliferative disorders. We previously reported that one such inhibitor (TG101209) potently inhibits JAK2V617F in vitro, and was effective in reducing tumor growth in a mouse xenograft model (Leukemia, 2007 Aug;21(8):1658–68). Here, we expand our analysis using TG101348, a highly selective JAK2 inhibitor currently in preclinical development, using cell lines and primary cells harboring JAK2V617F, MPLW515L/K, or JAK2 exon 12 mutations. Methods: Cell proliferation was assessed using the XTT assay. For primary cell experiments, PBMCs were plated in methylcellulose medium at 0, 300nM, 600nM, and 1200nM TG101348, both with and without erythropoietin (Epo). Hematopoietic colonies were scored after 12–16 days culture, and harvested for genotyping. Results: TG101348 inhibits growth of human erythroleukemia (HEL) and Ba/F3-V617F cells (IC50=300nM and 580nM, respectively), as well as Ba/F3-(MPL)W515L cells (IC50=620nM). JAK2:JAK3 selectivity of TG101348 was demonstrated by its 10-fold more potent inhibition of CHRF (JAK2T875N) as compared to CMK (JAK3A572V) cell proliferation. TG101348’s inhibitory effect on ex vivo hematopoietic colony growth was studied in 12 MPD patients (JAK2V617F=9, MPLW515L/K=1, JAK2 exon 12 mutation [N542-E543del]=1, no mutation=1), and 2 healthy controls (Table). Conclusions: (1) TG101348 inhibits colony growth from MPD patients more potently than healthy controls, reflecting its potential therapeutic window. (2) Endogenous colony growth is inhibited at nanomolar concentrations in all cases, with some alleles showing greater sensitivity than others (MPLW515K = exon 12 mutation > JAK2V617F). The corresponding Epo-supported erythroid colonies are less potently inhibited, reflecting the generally lower prevalence of JAK2 mutations in such colonies. (3) EEC growth in the absence of known JAK2 or MPLW515 mutations is also inhibited, indicating a similar dependence on dysregulated JAK-STAT signaling in such cases. (4) The ability of TG101348 to selectively suppress mutation-positive hematopoietic colonies will be discussed. Inhibitor effect on ex vivo hematopoietic colony growth Paient Mutation IC50 (nM) % Mutation-positive colonies Epo No Epo Epo No Epo (EEC) Normal 1 None >1200 n/a n/a n/a Normal 2 None >1200 n/a n/a n.a PV1 V617F 600 <300 5 40 PV2 V617F 600 300 33 50 PV3 V617F 600–1200 300–600 9 70 PV4 V617F 300–600 600 0 15 PV5 V617F 600–1200 300 80 100 PV6 V617F 600 300–600 7 19 PV7 V617F 600–1200 600 32 36 PV8 V617F 600–1200 <300 45 37 PV9 V617F 600 600–1200 20 12 PV10 Exon 12 (N542–E543del) 900 <300 9 60 PMF1 W515K 300–600 <300 100 33 PMF2 None >1200 300 n/a n/a