Citations

Abstract In multiple myeloma, the neoplastic plasma cells are either dispersed throughout the red marrow spaces of the axial and proximal appendicular skeleton or concentrated in discrete, well vascularlized plasmacytomas that stimulate osteoclastic bone resorption and erode into cortical bone. Interactions between bone marrow stromal cells (BMSC) and myeloma cells are clearly important in the pathogenesis of myeloma that diffusely infiltrates the bone marrow and where plasmacytomas are in contact with the bone marrow space. However, these interactions cannot be of major relevance at the centers of expanding plasmacytomas since these sites are devoid of osteoclasts, osteoblasts and other BMSC. Histological sections of skeletal plasmacytomas from 22 patients with multiple myeloma were therefore examined after immunostaining with anti-macrophage antibodies. Hematoxylin and eosin stained sections showed sheets of plasma cells interspersed with numerous small blood vessels. Immunostained sections revealed abundant CD68+, CD163+ macrophage infiltrates in all tumors, and scattered collections of CD3+ T lymphocytes. Tumor-associated macrophages (TAM) accounted for 2 to 12 percent of nucleated cells in these plasmacytomas and were evenly distributed through the parenchyma or clustered around CD34+ blood vessels. In general the TAM had dendritic morphology, and each dendrite was in close contact with multiple plasma cells. In a small percentage of cases, there was a subpopulation of TAM strikingly clustered around CD34+ positive blood vessels. However, vascular mimicry was not seen. Abundant murine CD68+ TAM were also found in subcutaneous KAS6/1 and MM1 myeloma xenografts in SCID mice. To determine whether cells of the monocytic lineage might be exploitable as carriers for systemic delivery of therapeutic agents to plasmacytomas, monocyte-derived dendritic cells were infected with oncolytic measles viruses and administered intravenously to SCID mice bearing subcutaneous KAS6/1 xenografts. Immunostaining for human MHC II antigen revealed that the infused DCs could localize to the KAS6/1 tumors where they heterofused with and transferred MV infection to the myeloma cells. This is the first report of TAM in skeletal plasmacytomas of myeloma patients. Further research into the role of TAM in supporting myeloma growth is warranted since they may offer many potential opportunities for the development of novel approaches to myeloma therapy.

Abstract Background: MV-NIS is an Edmonston-lineage measles virus that expresses the human sodium-iodide symporter (hNIS). The virus is oncolytic, and its activity can be monitored by noninvasive imaging of radioiodine uptake by hNIS. The receptor is CD46, a membrane regulator of complement activation that is overexpressed on myeloma cells. Methods: Formal studies were done in collaboration with the RAID program to assess the efficacy, biodistribution and safety of MV-NIS in transgenic, measles susceptible mice and in non-human primates. The protocol therapy for the animal studies was modeled on the planned human clinical trial. Mouse efficacy studies were done in irradiated 6-week old female CB17 ICR SCID mice implanted subcutaneously with human KAS-6/1 cells. Mouse toxicity & biodistribution were done in 184 6–8 week IfnarKO x CD46 Ge mice treated with 105–107 TCID50 MV-NIS. Squirrel monkey toxicity studies were done in 12 measles-naïve adults with 108 TCID50. The clinical trial is a 3 patient/cohort dose escalation study which allows for 1 dose of MV-NIS/patient. Once MTD of MV-NIS is reached, subsequent cohorts will be treated with CTX 10 mg/kg 2 days prior to MV-NIS at MTD/100. Immune response to measles is tested pre & post therapy. PK & biodistribution are tested by measurements of MV-N in blood, urine, & gargle samples and by serial nuclear imaging, respectively. BM myeloma cells are tested for CD46 expression and MV infectivity. Results: Preclinical studies: The minimum effective dose in the mouse model was 4 x 106 TCID50 /kg. The MTD for MV-NIS with CTX was not reached in the mouse study. Pre-treatment with CTX changed the biodistribution of MV-NIS infected cells and the kinetics of virus elimination from infected tissues in mice and monkeys. In monkeys, MV-N mRNA was detected at day 1 in the buccal cavity with levels declining on day 2, then surging on day 8, suggesting viral replication. There were no unscheduled deaths or treatment related lesions on necropsy. Patients: Three patients were treated with a dose of 106 TCID50 (Table). No DLT was observed. Two patients had MV-N amplified from their gargle specimen. Accrual to dose level 2 has begun. Conclusions: IV administration of MV-NIS is feasible. The virus is capable of traveling to a distant site and replicating before being cleared by the immune system. Patient 2 Patient 2 Patient 3 *copies per microgram RNA of cells derived from gargle sample at each time point: day +3, +8, +15, +22, and +29; no MV-N detected in urine or blood Anti-measles neutralizing Ab titer, pre-Rx / post Rx 1:10 / 1:160 < 1:10 / 1:20 < 1:10 / 1:10 AEs possibly related Gr 2 plts Gr 1 plts, cough, fever, rigors Gr 2 Incr aPTT CD46 copies/cell CD138+ / CD138- BMPC 79,771 / 10,322 140,187 / 10,145 28,258 / 11,228 MV-N QRT-PCR: d3/ d8/ d15/ d22/ d29 (cp/ug RNA)* −/ −/ −/ nd / nd −/ −/ 16,440 / 1405 / − 123-I uptake on SPECT No Uptake day 8 No

Abstract Background In the primary analysis of the phase III COMFORT-I study, the JAK1/JAK2 inhibitor ruxolitinib (RUX) significantly improved splenomegaly, myelofibrosis (MF)-related symptoms, and quality of life (QoL) measures in patients (pts) with MF versus placebo (PBO). An additional analysis (median follow-up 51 weeks [wks)]) showed RUX was associated with a survival advantage versus PBO (Verstovsek et al. N Engl J Med2012). Longer term follow-up (median 102 wks) showed durable SV reductions and QoL improvements. At this time point, RUX continued to be associated with a survival advantage, despite all pts originally randomized to PBO having discontinued or crossed over to ruxolitinib shortly after the primary analysis (Verstovsek et al. ASH 2012. abstract 800). We report additional longer-term follow-up of pts from COMFORT-I. Methods In COMFORT-I, 309 pts were randomized (1:1) to RUX or PBO. RUX starting dose depended on baseline platelet count (100–200´109/L: 15 mg BID; >200´109/L: 20 mg BID). Doses could be titrated for lack of efficacy or excess toxicity as specified in the protocol. Pts receiving PBO could crossover to RUX after the primary analysis (ie, when all pts completed 24 wks and half the pts completed 36 wks of therapy) or at any time if they met protocol-specified criteria for worsening splenomegaly. The primary endpoint was the proportion of pts who achieved a ≥35% reduction in spleen volume (SV) at wk 24. Symptoms were assessed up to wk 24 using the modified MF Symptom Assessment Form v2.0. QoL continued to be evaluated beyond wk 24 using the EORTC QoL Questionnaire-Core 30 (QLQ-C30). Survival was estimated by Kaplan-Meier analysis according to original randomized treatment. To better understand the effect of crossover on the PBO arm, statistical modeling of survival was conducted using a generalized Gamma distribution. Results Median follow-up was 149 wks at the time of this updated analysis. Of 155 pts originally randomized to RUX, 77 remain on therapy. Of 154 pts originally randomized to PBO, 111 crossed over to RUX; the median time to crossover was 41.1 wks (range, 5.1–65.4). At wk 24, pts originally randomized to RUX had a mean SV reduction of −31.6%; this was durable for pts who continued on RUX, where the mean SV reduction at wk 144 was −34.1%. Fifty-nine percent (91/155) of pts originally randomized to RUX achieved a ≥35% SV reduction at any time during study; for these pts, the probability of maintaining this response for >132 weeks from the time of their initial response was 0.53. Pts originally randomized to RUX who continued on therapy experienced durable improvements in the Global Health Status/QoL and functional domains of the EORTC QLQ-C30. Overall survival favored RUX (HR=0.69; 95% CI: 0.46, 1.03; P= 0.067; Fig 1), with 42 and 54 deaths among pts originally randomized to RUX and PBO, respectively. Modeling of the hazard function of death over time to explore the effect of crossover to RUX in pts originally randomized to PBO showed a decrease in hazard for these pts, which corresponded to an increased proportion of pts crossing over to RUX. In pts originally randomized to RUX who continued on therapy, there was no substantial change in the rate, distribution, or severity of nonhematologic adverse events (AEs) with longer-term therapy; most nonhematologic AEs were grade 1 or 2. Mean and median hemoglobin and platelet count remained stable with longer-term therapy. Consistent with this, the incidence of new onset grade 3 or 4 anemia and thrombocytopenia observed after the first 6 months of RUX therapy decreased relative to that seen in the first 6 months of therapy (Fig 2). With approximately 1 year of additional follow up, 4 new cases of acute myeloid leukemia were reported: 2 pts originally randomized to PBO (376 and 666 days after crossover to RUX) and 2 pts originally randomized to RUX (848 and 1143 days after starting RUX). Conclusions After a median follow-up of 149 wks, the hazard ratio for overall survival favored pts originally randomized to RUX over those originally randomized to PBO, the majority of whom crossed over to RUX. The hazard of death for pts originally randomized to PBO decreased as pts crossed over to RUX. SV reductions and QoL improvements were sustained with longer-term therapy. The incidence of new onset grade 3 or 4 anemia and thrombocytopenia decreased with longer-term therapy. Collectively, these data reinforce the durable efficacy and longer-term safety of RUX in pts with MF. Disclosures: Verstovsek: Incyte Corporation: Research Funding. Mesa:Genentech: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding; Incyte Corporation: Research Funding; Lilly: Research Funding. Gotlib:Incyte Corporation: Travel support, Travel support Other; Incyte Corporation: Membership on an entity’s Board of Directors or advisory committees; Incyte Corporation: Research Funding. Levy:Incyte Corporation: Equity Ownership; Incyte Corporation: Employment. Gupta:Incyte Corporation: Consultancy; Novartis: Consultancy; Inctye Corporation: Research Funding; Novartis: Research Funding; Novartis: Speakers Bureau. Deininger:BMS, ARIAD, NOVARTIS: Consultancy; BMS, NOVARTIS, CELGENE, GILEAD: Research Funding; ARIAD, NOVARTIS: Advisory Boards, Advisory Boards Other. Miller:Novartis: Consultancy; Incyte Corporation: Consultancy; Novartis: Research Funding; Incyte Corporation: Research Funding; Novartis: Honoraria; Incyte Corporation: Honoraria. Talpaz:Ariad: Consultancy; Novartis: Consultancy; BMS: Consultancy; Pfizer: Consultancy; Ariad: Membership on an entity’s Board of Directors or advisory committees; Novartis: Membership on an entity’s Board of Directors or advisory committees; BMS: Membership on an entity’s Board of Directors or advisory committees; Pfizer: Membership on an entity’s Board of Directors or advisory committees. Winton:Incyte Corporation: Research Funding; Incyte Corporation: Membership on an entity’s Board of Directors or advisory committees. Arcasoy:Incyte Corporation: Research Funding. Lyons:Lilly: Research Funding; Amgen: Research Funding; Celgene: Research Funding; Incyte Corporation: Research Funding; Gilead: Consultancy; Seattle Genetics: Research Funding; Gilead: Research Funding; Ariad: Research Funding; GlaxoSmithKline: Research Funding; Novartis: Research Funding. Paquette:Incyte Corporation: Consultancy. Raza:Novartis: Speakers Bureau; Onconova Inc: Research Funding. Vaddi:Incyte Corporation: Employment; Incyte Corporation: Equity Ownership. Sun:Incyte: Employment; Incyte: Equity Ownership. Peng:Incyte Corporation: Employment; Incyte Corporation: Equity Ownership. Sandor:Incyte: Employment; Incyte: Equity Ownership. Kantarjian:Ariad: Research Funding; Novartis: Research Funding; BMS: Research Funding; Pfizer: Research Funding.

Abstract Background Despite improvements in outcome following the addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) (R-CHOP), patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) and International Prognostic Index (IPI) scores of 3-5 at diagnosis have a poor outcome. Enzastaurin is a potent inhibitor of PKCβ, a component of the B-cell receptor signaling complex, with preclinical activity and clinical activity in a phase II trial in patients with relapsed DLBCL, providing the rationale for this study in the primary therapy setting. Methods PRELUDE was a multi-national, randomized, double-blinded, placebo-controlled study. Patients were required to have a histologic diagnosis of DLBCL, pre-treatment IPI score ≥3, and a complete response (CR) or CRu by International Working Group Criteria, or a negative FDG-PET scan after 6–8 cycles of R-CHOP. Patients were randomly assigned in a 2:1 ratio to receive either enzastaurin 500 mg daily or an identical placebo as maintenance therapy, for a planned treatment duration of 3 years. The primary endpoint was DFS, defined as lack of disease progression or death. Assuming a 2-year DFS rate in the control group of 70%, the primary analysis had 80% power to detect a HR of 0.67, eg, a 2-year DFS rate of 79% in the enzastaurin group. Secondary endpoints included overall survival (OS) and event-free survival (EFS). Data were analyzed 3 years after the last enrolled patient initiated treatment. Results From May 2006–April 2010, 758 patients were enrolled (enzastaurin, n=504; placebo, n=254). Median age at enrollment was 64 years (range 21-89); at diagnosis, 65% of patients had stage IV disease, 48% had B symptoms, and 25% had a mass >10 cm; baseline disease and patient characteristics were well balanced between treatment arms. Fifty-seven percent had a negative PET scan following completion of R-CHOP. Median follow-up time for all patients was 48 months (range 0.03–80). At the time of analysis, 209 events had occurred. The DFS HR for enzastaurin vs. placebo was 0.92 (95% CI: 0.69, 1.22; 2-sided log-rank p=0.54). DFS at 24 and 48 months were 79% and 70% for the enzastaurin arm, and 75% and 71% for placebo, respectively. OS at 24 and 48 months was 87% and 81% for enzastaurin, and 89% and 82% for placebo; HR for enzastaurin vs. placebo was 1.04 (95% CI: 0.74, 1.47; 2-sided log-rank p=0.81). Percent of ITT population patients on therapy at 12, 24, and 36 months was 70.6%, 60.6%, and 20.1% for enzastaurin; 72.3%, 60.6%, and 22.1% for placebo. Biomarker subgroup analysis was performed and will be available at time of presentation. Treatment emergent AEs (all grades) that were possibly study drug-related and significantly different between enzastaurin and placebo included chromaturia (18.5% vs. 0.4%), QTc prolongation (10.8% vs. 3.6%), and diarrhea (10.3% vs. 2.8%). There were no significant differences in number of patients with at least 1 grade 3 or higher AE between treatment arms. No significant differences were observed in the frequency of deaths while on therapy. Conclusion Enzastaurin did not improve DFS, EFS, or OS in patients with high-risk DLBCL and CR following R-CHOP treatment. Disclosures: Crump: Roche: Honoraria; Jansen-Ortho: Honoraria; Celgene: Honoraria; Lundbeck: Honoraria; Novartis: Research Funding; Seattle Genetics: Honoraria. Off Label Use: rituximab for maintenance therapy post autolgous transplant for lymphoma. Leppä:Eli Lilly: Research Funding. Ogura:Eli Lilly: Research Funding. Rifkin:Millenium, Celgene, ONYX: Membership on an entity’s Board of Directors or advisory committees. Mackensen:Eli Lilly: Consultancy. Offner:Eli Lilly: Membership on an entity’s Board of Directors or advisory committees. Smith:Genentech, Celgene, Spectrum, Seattle Genetics, Gilead, Amgen/Micronet: Consultancy. Tobinai:Eli Lilly: Research Funding. Hahka-Kemppinen:Eli Lilly: Employment. Thornton:Eli Lilly: Employment. Shi:Eli Lilly: Employment. Lin:Eli Lilly: Employment. Kahl:Genentech: Consultancy. Savage:Eli Lilly: Consultancy.

Abstract Background: Patients with polycythemia vera (PV) can have a pronounced symptom burden that negatively impacts their quality of life (QoL). Traditional treatment options such as phlebotomy, hydroxyurea, and interferon provide clinical benefit but frequently do not alleviate symptoms. The ongoing REVEAL study is being conducted to describe contemporary demographics, burden of disease, clinical management, patient-reported outcomes, and healthcare resource utilization among patients with PV in the US. This preliminary analysis describes the burden of PV based on patient-reported outcomes (PROs), including health-related QoL and work productivity. Methods: REVEAL is a multicenter, noninterventional, nonrandomized, prospective, observational study. Eligible patients are ≥18 years of age with a PV diagnosis and currently under active management by a physician in the US. PROs are being collected at study enrollment and every 3 months thereafter. Each of the 10 items on the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) are graded from 0 (absent) to 10 (worst imaginable), with individual symptom scores ≥7 considered severe; total symptom score (TSS) ranges from 0-100. Raw scores for items on the 30-item European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire-Core 30 (EORTC QLQ-C30) are standardized by linear transformation to 0-100. Higher scores on the EORTC QLQ-C30 indicate better functioning for global health status/QoL and functional subscales and worse severity for symptom subscales. Outcomes with the 6-item Work Productivity and Activity Impairment Specific Health Problem questionnaire (WPAI-SHP) are presented as a proportion from 0% (minimal/no impairment) to 100% (maximal impairment/productivity loss). Analyses of these preliminary data were descriptive. Results: At the time of data cutoff (June 9, 2015), REVEAL had enrolled 865 patients (total planned enrollment, n=2000), the majority were male (55.5%) and white (89.5%), with a median age of 67 (range, 22-95) years. 782 patients had completed the PRO questionnaires at the enrollment visit. A majority of patients reported ≥1 PV-related symptom. Mean (SD) MPN-SAF symptom scores were highest for fatigue (3.5 [2.7]), early satiety (2.7 [2.8]), inactivity (2.7 [2.9]), itching (2.6 [3.1]), and concentration problems (2.1 [2.6]). The mean (SD) MPN-SAF TSS (sum of 10 symptom scores) was 19.6 (16.1). The most frequently reported severe symptoms were fatigue, itching, inactivity, early satiety, night sweats, concentration problems, and bone pain (Table 1). Mean (SD) global health status/QoL reported on the EORTC QLQ-C30 was 72.8 (23.4); functional subscales were as follows: cognitive functioning, 80.3 (24.5); emotional functioning, 80.7 (24.0); physical functioning, 83.1 (20.6); role functioning, 84.3 (26.1); and social functioning, 85.0 (25.0). The most severe mean (SD) symptom subscale scores were fatigue (30.7 [28.5]), insomnia (29.5 [34.5]), pain (20.9 [29.3]), and dyspnea (17.3 [28.6]). Among patients who were employed at baseline (n=273), mean (SD) PV-related WPAI-SHP scores were as follows: absenteeism (ie, work time missed), 2.9% (10.6%); presenteeism (ie, impairment at work/reduced on-the-job effectiveness), 10.7% (20.4%); work productivity loss (ie, absenteeism plus presenteeism), 12.0% (22.2%); and activity impairment, 21.0% (28.0%). Conclusion: Preliminary descriptive data from patients currently enrolled in REVEAL suggest that patients with PV have notable impairment in QoL because of their disease; patient-reported scores on the MPN-SAF and EORTC QLQ-C30 were similar to those reported previously for patient populations with MPNs. Similarly, PV is associated with marked work productivity loss among patients who are currently employed. Subsequent analyses from REVEAL will evaluate changes over time in PROs and investigate correlations with disease progression and treatment. REVEAL can provide novel insights into questions related to the contemporary real-world QoL burden and its impact on PV-related symptoms and work productivity. Disclosures Mesa: Pfizer: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Incyte Corporation: Research Funding; CTI Biopharma: Research Funding; Promedior: Research Funding. Boccia:Incyte Corporation: Honoraria. Moliterno:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees. Naim:Incyte Corporation: Employment, Equity Ownership. Cordaro:Incyte Corporation: Employment, Equity Ownership. Peng:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Stein:Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Abstract Background: Patients with polycythemia vera (PV) have an increased symptom burden (eg, fatigue, pruritus, and splenomegaly-related symptoms) and an increased risk of mortality compared with the general population, often resulting from thrombotic events, disease transformation to myelofibrosis, or secondary malignancies. There are limited data regarding PV burden and treatment patterns in a contemporary, real-world US setting. REVEAL is an ongoing observational study being conducted to describe contemporary demographics, burden of disease, clinical management, patient-reported outcomes, and healthcare resource utilization among patients with PV in the US. The objective of this assessment is to describe the clinical characteristics at enrollment among patients currently enrolled in REVEAL (enrollment from July 22, 2014 to June 9, 2015). Methods: REVEAL is a multicenter, noninterventional, nonrandomized, prospective, observational study. Eligible patients are ≥18 years of age with a PV diagnosis and currently under active management by a physician in the US. Data regarding disease and clinical characteristics, patient-reported outcomes, and health resource utilization are being collected at usual-care visits over a planned 36-month observation period. Analyses of these preliminary data were descriptive. Results: At data cutoff, 865 patients were enrolled (total planned enrollment, n=2000) from 174 sites (academic, n=27; community, n=147). Median (range) age at enrollment was 67 (22-95) years, 55.5% were male, 89.5% were white, and 45.4% had a history of smoking. Most patients (99.4%) had health insurance, including Medicare (56.0%), PPO (24.3%), or HMO (11.6%). Fifty-two percent were retired, 29.6% were employed, and 4.5% were unable to work or disabled. A total of 40.2% of patients completed a college/graduate degree, 19.9% had some college, and 32.5% completed high school or the equivalent. Documented major World Health Organization diagnostic criteria included JAK2V617F mutation in 50.9% of patients, elevated hemoglobin in 52.3%, and red cell mass in 5.5%. A bone marrow biopsy was conducted in 24.0% of patients, approximately half of whom (52.4% of the 24.0%) had trilineage myeloproliferation. Erythropoietin levels were abnormal in 19.7% of patients. Approximately half (46.6%) of patients had physician-reported PV-related symptoms at diagnosis, most frequently fatigue (25.2%) and pruritus (14.0%). At enrollment, median disease duration was 52.6 months; 42.3% of patients were diagnosed ≥5 years before enrollment. The most common comorbidities were hypertension (51.3%), obesity (14.2%), dyspnea (13.4%), myalgia (11.2%), and diabetes mellitus (11.1%). Mean hematocrit was 44.9%, hemoglobin was 14.5 g/dL, white blood cell count was 11.4×109/L, platelet count was 363.7×109/L, and absolute neutrophil count was 363.7×109/L. Twenty-one percent of patients had a history of thrombotic events, with 13.1% and 8.6% of patients experiencing ≥1 venous or arterial thromboembolic event, respectively. Of the 261 reported thrombotic events, 43.7% occurred after diagnosis of PV. The most common PV symptoms recorded at enrollment (using the Myeloproliferative Neoplasm Symptom Assessment Form) were fatigue (37.1%), pruritus (24.0%), headache (18.6%), insomnia (17.0%), dizziness (13.2%), bone pain (10.5%), and blurred vision (7.9%); 19.7% of 518 evaluable patients had palpable splenomegaly. Fewer than half of patients were receiving aspirin at enrollment (47.7%). The most common PV treatments ± aspirin were phlebotomy (PBT; 63.5%), hydroxyurea (HU; 42.2%), watchful waiting (5.3%), and ruxolitinib (3.1%); 23.0% of patients received PBT + HU. Conclusion: The REVEAL study is unique in that it captures data from both academic and community centers, and therefore includes a broader segment of the PV population typically not described in the literature. REVEAL can provide novel insights into questions related to the contemporary demographics of PV, practice patterns regarding diagnosis and therapy, and the real-world burden of PV and its impact on patients' quality of life and work productivity. Preliminary descriptive data from this early subset of patients suggest that a high proportion of patients report having PV-related symptoms at diagnosis, fewer patients are treated with aspirin than expected, and that thromboembolic event rates remain high after diagnosis. Disclosures Stein: Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees. Moliterno:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees. Boccia:Incyte Corporation: Honoraria. Naim:Incyte Corporation: Employment, Equity Ownership. Cordaro:Incyte Corporation: Employment, Equity Ownership. Peng:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Mesa:Promedior: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; NS Pharma: Research Funding; CTI Biopharma: Research Funding; Gilead: Research Funding; Pfizer: Research Funding; Incyte Corporation: Research Funding; Genentech: Research Funding.

Abstract Abstract 2721 Poster Board II-697 The role of the CD40 pathway in B-cell cancers is rather enigmatic due to having polar opposite roles in tumor biology. Stimulation of the CD40 receptor can reduce cell viability of NHL cell lines and xenograft tumor models, whereas, in sharp contrast, constitutive CD40 stimulation can actually promote proliferation of NHL cell lines, as well as drive lymphomagenesis and transformation of primary B-cells. Therefore, targeting the CD40 pathway has been challenging due to a knowledge gap in understanding the factors that may dictate a pro- or anti-tumor role. To address this directly, we employed a large panel of NHL cell lines and xenografts models to simulate a patient population and to define the molecular parameters to test in the context of clinical trials. Using baseline gene expression profiling, we found that the in vitro activity of an antibody that stimulates the CD40 pathway, Dacetuzumab (SGN-40), correlated strikingly with a transcriptional profile that was representative of an inactive CD40 pathway. Resistant cells, on the other hand, displayed a transcriptional profile indicative of an activated CD40 pathway. Consistent with these observations, constitutive phosphorylation of ERK, a node downstream of CD40 signaling, was present predominantly in cell lines that were resistant to Dacetuzumab. Fifteen genes, based on their association with in vitro activity and their biology as components of the CD40 network, were selected as a classifier from these pre-clinical data and independently tested in a panel of cell lines and xenografts models. Testing the selected gene classifier by qRT-PCR from baseline fixed tumor tissue of 39 patients treated with Dacetuzumab in phase I and II clinical trials revealed the ability to predict sensitivity in patients, as determined by tumor shrinkage >10%, with an overall accuracy of 80%. Consistent with the observed tumor shrinkage, the classifier positive, predicted to respond to Dacetuzumab, patients also exhibited a prolonged progression free survival (PFS) compared to classifier negative patients, predicted not to respond to Dacetuzumab (HR = 0.23, p = 0.001). Finally, using a novel microarray approach to genome-wide expression profiling on fixed tumor tissue revealed that CD40 pathway activation was indeed an important predictor of response. Overall, these data suggest that sensitivity to Dacetuzumab can be predicted by pre-determining the CD40 pathway activation status of tumors. Disclosures: Dornan: Genentech, Inc.: Employment, Equity Ownership. Burington:Genentech, Inc.: Employment, Equity Ownership. Yue:Genentech, Inc.: Employment, Equity Ownership. Shi:Genentech, Inc.: Employment, Equity Ownership. Advani:Seattle Genetics, Inc.: Research Funding. Yu:Genentech, Inc.: Employment, Equity Ownership. Lau:Genentech, Inc.: Employment, Equity Ownership. Yu:Genentech, Inc.: Employment, Equity Ownership. De Vos:Seattle Genetics, Inc.: Research Funding. Forero-Torres:Seattle Genetics, Inc.: Research Funding. Modrusan:Genentech, Inc.: Employment, Equity Ownership. Koeppen:Genentech, Inc.: Employment, Equity Ownership. Yang:Genentech, Inc.: Employment, Equity Ownership. Du:Genentech, Inc.: Employment, Equity Ownership. Elkins:Genentech, Inc.: Employment, Equity Ownership. Polson:Genentech, Inc.: Employment, Equity Ownership. Offringa:Genentech, Inc.: Employment, Equity Ownership. Whiting:Seattle Genetics, Inc.: Employment, Equity Ownership. Ebens:Genentech, Inc.: Employment, Equity Ownership.

Abstract Abstract 2847 Background and Purpose: Myelofibrosis (MF) is a progressive Philadelphia-negative myeloproliferative neoplasm characterized by debilitating symptoms, massive splenomegaly, and anemia, which severely impairs quality of life. When medical therapy is not effective or tolerated, splenectomy may be required to ease symptoms in patients with symptomatic portal hypertension, massive splenomegaly, and/or frequent red blood cell transfusions (Barbui et al. J Clin Oncol. 2011;29:761–770). In a recent study (Tefferi et al. Mayo Clin Proc. 2012;87:25–33) up to 27% of patients diagnosed with MF eventually underwent splenectomy. However, splenectomy is associated with limited duration of symptom response, high rates of perioperative morbidity and mortality, and acceleration of hepatomegaly. Clinical studies in patients with MF have demonstrated that ruxolitinib, an oral JAK1/JAK2 inhibitor, provides significant and durable reductions in splenomegaly, the burden of MF-associated symptoms, and also improved quality of life. In this post hoc analysis of pooled data from these studies, we determined the incidence of splenectomy in patients treated with ruxolitinib and those who received placebo or best available therapy (BAT) to evaluate whether ruxolitinib therapy may affect the need for splenectomy. Methods: This analysis included patients who participated in the ruxolitinib phase I/II trial (N=153; Verstovsek et al. N Engl J Med. 2010;363:1117–1127); COMFORT-I, a phase III, 24-month placebo-controlled trial of ruxolitinib (N=309; Verstovsek et al. N Engl J Med. 2012;366:799–807); and COMFORT-II, a phase III, 48-month randomized trial comparing the effects of ruxolitinib and BAT (N=219; Harrison et al. N Engl J Med. 2012;366:787–798). Incidence of splenectomy while on treatment or during the protocol-specified follow-up period, adjusted for differences in the duration of follow up, was calculated for patients on ruxolitinib, placebo, or BAT. Results: As a result of the crossover rules and a higher discontinuation rate on the comparator arms in the phase III studies, mean follow-up duration for placebo (0.67 years) or BAT (0.95 years) overall was substantially shorter than mean follow-up duration for ruxolitinib (1.78 years). Baseline characteristics of the 14 patients who underwent splenectomy were as follows: median age=63 years; median time since initial diagnosis=7.8 years; median spleen length (n=13): 17.0 cm (range: 0–28.0 cm); median spleen volume (in those with measurement, n=11)=2924 cm3 (range: 1203–6807 cm3); IPSS high risk=50%, intermediate-2 risk=43%, intermediate-1=7%. Among patients originally randomized and treated with ruxolitinib, the incidence of splenectomy was 1.1 events per 100 patient years (Table). For patients treated with placebo or BAT in the phase III studies, the incidence of splenectomy was approximately three times higher at 2.9 events per 100 patient years, despite the fact that patients on placebo or BAT were allowed to crossover to ruxolitinib if they had worsening symptomatic splenomegaly. Conclusions: Although limited by small numbers, results of this analysis suggest that ruxolitinib reduces the need for splenectomy in patients with MF. Because of crossover to ruxolitinib and higher discontinuation rates in placebo and BAT, follow-up duration was shorter in these treatment arms compared with ruxolitinib. Further, ruxolitinib treatment in crossover patients may have prevented progression of symptomatic splenomegaly in some patients who may have otherwise become candidates for splenectomy. Our analysis may underestimate the true incidence of splenectomy among patients not receiving ruxolitinib therapy and therefore, the relative reduction in splenectomy rate in patients receiving this therapy. Longer-term follow up will better define the splenectomy rate in ruxolitinib-treated patients. Disclosures: Verstovsek: Incyte Corporation: Research Funding. Kiladjian:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees. Gotlib:Incyte Corporation: Consultancy, Honoraria, Support for travel to meeting for the study or other purposes from Incyte Other. Kantarjian:Incyte: grant support Other. Sirulnik:Novartis: Employment, Equity Ownership. Peng:Incyte Corporation: Employment, Equity Ownership. Sandor:Incyte Corporation: An employee of Incyte and receiving stock options as part of his compensation Other, Employment. Harrison:Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding.

Background: Percutaneous stellate ganglion blockade (SGB) has been used for drug-refractory electrical storm due to ventricular arrhythmia (VA); however, the effects and long-term outcomes have not been well studied. Methods: This study included 30 consecutive patients who had drug-refractory electrical storm and underwent percutaneous SGB between October 1, 2013, and March 31, 2018. Bupivacaine, alone or combined with lidocaine, was injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion (n=15) or both stellate ganglia (n=15). Data were collected for patient clinical characteristics, immediate and long-term outcomes, and procedure-related complications. Results: Clinical characteristics included age, 58±14 years; men, 73.3%; and left ventricular ejection fraction, 34±16%. At 24 hours, 60% of patients were free of VA. Patients whose VA was controlled had a lower hospital mortality rate than patients whose VA continued (5.6% versus 50.0%; P =0.009). Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in VA episodes from 26±41 to 2±4 in the 72 hours after SGB ( P <0.001). Patients who died during the same hospitalization (n=7) were more likely to have ischemic cardiomyopathy (100% versus 43.5%; P =0.03) and recurrent VA within 24 hours (85.7% versus 26.1%; P =0.009). There were no procedure-related major complications. Conclusions: SGB effectively attenuated electrical storm in more than half of patients without procedure-related complications. Percutaneous SGB may be considered for stabilizing ventricular rhythm in patients for whom other therapies have failed.