ALBERT

Description: Abstract Significant amounts of methane reside in sediments along the continental margins and slope of the Arctic Ocean. Methanotrophic bacteria oxidize methane to bicarbonate and also assimilate some methane‐derived carbon into biomass. Their metabolism transforms methane to other forms of carbon and sequesters it within the system, reducing its emission to the atmosphere. Increases in water temperatures driven by global climate change may accelerate the methane flux from the benthos into the water column, potentially increasing the importance of methanotrophic consumption as a methane sink. We report methane concentrations and oxidation rates in the water column of the Chukchi Sea from August 2017. This area is characterized by seasonally high nutrient concentrations that fuel high rates of pelagic primary productivity and subsequent sedimentation of organic matter, which stimulates benthic methanogenesis. Methane concentrations in the study area ranged from 6 to 72 nmol L−1, consistent with previously published measurements. Methane oxidation rates were as high as 580 pmol L−1 d−1, similar to the rates measured in the East Siberian Arctic Shelf. Depth‐integrated methane oxidation rates were lower than methane efflux rates, suggesting that physiochemical factors prevent the methanotrophic microbial community from efficiently removing methane from the ecosystem. Still, methanotrophic bacteria provide an ecosystem service by removing a fraction of methane prior to its efflux to the atmosphere.

Description: Background: Polycythemia vera (PV) is characterized by erythrocytosis, thrombocytosis, and/or leukocytosis and a broad range of disease-related symptoms. In high-risk patients, the most common first-line treatment is hydroxyurea (HU). The open-label RESPONSE trial demonstrated that ruxolitinib (RUX), a JAK1/JAK2 inhibitor, provided superior efficacy compared with best available therapy in patients with PV who were resistant to or intolerant of HU according to modified European LeukemiaNet (ELN) criteria. This study (RELIEF) was conducted in patients receiving a stable dose of HU and who were generally well controlled but reporting disease-associated symptoms, comparing the change in PV-related symptom burden in patients continuing their HU therapy with those switching to RUX treatment. Methods: RELIEF was a randomized, multicenter, double-blind, double-dummy, phase 3b study of patients with PV aged ≥18 years on a stable dose of HU monotherapy and reporting PV-related symptoms. Patients were required to be receiving HU for ≥12 weeks prior to enrollment and on the same dose level for the last 4 weeks, and have a score ≥8 on the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) cytokine total symptom score (TSS-C). The TSS-C comprised symptoms of itching, tiredness, muscle ache, night sweats, and sweats while awake; each symptom was rated on a scale of 0=absent to 10=worst imaginable, with a maximum TSS-C score of 50. Patients also had to meet one of the following: ≤1 phlebotomy in the previous 6 months or no palpable splenomegaly. Those eligible were randomized 1:1 to receive RUX 10 mg BID and HU-placebo, or HU at the same dose/schedule and RUX-placebo. Dose adjustments were permitted for safety and efficacy. After Week 16, patients could receive open-label RUX until Week 48. The primary endpoint was the proportion of patients with a ≥50% reduction in TSS-C at Week 16; secondary endpoints included proportion of patients with a ≥50% reduction in individual TSS-C symptoms and safety. Results: Overall, 54 and 56 patients were randomized to RUX and HU, respectively; 87.0% and 89.3% remained on treatment through Week 16. At baseline, the median age (range) was 64 (36-87) in the RUX group and 66 (19-85) in the HU group; 44% and 61% were men. The majority of patients in the RUX and HU groups did not have baseline platelet counts or WBC above ELN thresholds: platelets 〉400 and ≤600 x 109/L (RUX 31.5%, HU 28.6%), 〉600 x 109/L (3.7%, 8.9%); WBC 〉10 and ≤15 x 109/L (16.7%, 16.1%), 〉15 x 109/L (11.1%, 14.3%). In the RUX and HU groups, the mean TSS-C at screening (22.4, 23.1) was higher than that at baseline (16.7, 18.0); the ratio of screening to baseline TSS-C was 1.7 and 1.6. The proportion of patients achieving a ≥50% reduction from baseline in TSS-C at Week 16 (primary endpoint) was 43.4% in the RUX group and 29.6% in the HU group (P=0.139; OR, 1.82; 95% CI, 0.82-4.04). The proportions of patients in the RUX vs HU groups achieving a ≥50% reduction in scores for itching and tiredness at Week 16 were 40.0% vs 26.4% and 54.2% vs 32.0%, respectively. Median percentage changes in individual TSS-C symptoms are shown in Table 1. Additional analyses found no correlation between individual changes in HU dose from baseline to Weeks 13-16 and percentage change in TSS-C in the HU arm (r2=0.030). Even patients maintaining the same HU dose from prior to study entry through Week 16 reported symptom improvement: 12/35 (34.3%) with no dose change, 4/12 (33.3%) with a dose increase, and 0/9 (0%) with a dose decrease had a ≥50% reduction in TSS-C. The most common nonhematologic adverse events in the RUX arm on randomized treatment were fatigue (20.4% RUX vs 10.7% HU), headache (16.7% vs 5.4%), and dizziness (13.0% vs 8.9%). The most common adverse events on HU were diarrhea (9.3% RUX vs 19.6% HU) and constipation (7.4% vs 12.5%); most events were grade 1 or 2. Grade 3 or 4 anemia or thrombocytopenia (lab values) were not reported in the RUX group; two patients in the RUX group had grade 3 or 4 neutropenia. Conclusion: In generally well controlled PV patients receiving a stable dose of HU, there was a positive trend in symptom improvement for patients switched to RUX therapy versus those continuing on HU therapy, although this was not statistically significant. The 34% response rate among patients who continued to receive a stable HU dose suggests a placebo effect that led to an underpowered study. Further analyses are required to better interpret these findings. Disclosures Off Label Use: Ruxolitinib is a JAK1/JAK2 inhibitor approved for the treatment of patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Vannucchi:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Yacoub:Alexion Pharmaceutical: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Sanofi Aventis: Membership on an entity's Board of Directors or advisory committees. Koschmieder:Novartis Pharmaceuticals: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Byrne:Novartis Pharmaceuticals: Honoraria. Verstovsek:Incyte Corporation: Research Funding. Hunter:Incyte Corporation: Employment, Equity Ownership. Jones:Incyte Corporation: Employment, Equity Ownership. He:Incyte Corporation: Employment, Equity Ownership. Morozov:Novartis Pharmaceuticals: Employment, Equity Ownership.

Description: Abstract 795FN2 Background: Ruxolitinib (INC424), a potent and selective oral JAK1 and JAK2 inhibitor, demonstrated rapid and durable reductions in splenomegaly and improved disease-related symptoms, role functioning, and quality of life (QoL) in 2 phase 3 studies in patients with myelofibrosis (MF) (the COMFORT studies). Per-protocol, patient-reported, health-related QoL (HRQoL) and symptoms analyses in the COMFORT-II study are limited. Here we report on additional post hoc analyses of these outcomes. The COMFORT-II study includes 219 patients (ruxolitinib, n=146; best available therapy [BAT], n=73). At entry, all patients were classified into intermediate 2-risk or high-risk prognostic groups (Cervantes F, et al. Blood, 2009;113(13):2895-2901) and had palpable splenomegaly ≥5 cm below the costal margin. Patients could have received prior therapy for MF. On BAT, doses and schedules or no therapy were selected by the investigator; therapy adjustments were permitted during the randomized treatment phase at the investigator's discretion. Patients in both arms continued in the randomized treatment phase as long as there was no protocol-defined disease progression. Methods: The European Organisation for the Research and Treatment of Cancer (EORTC) QoL Questionnaire–Core 30 (QLQ-C30) and Functional Assessment of Cancer Therapy–Lymphoma (FACT-Lym) questionnaires were assessed at baseline and weeks 8, 16, 24, and 48. EORTC QLQ-C30 consists of 30 items combined into 15 subscales (Global Health Status/QoL, 5 functioning subscales, and 9 symptom subscales; scores range from 0 to 100, and higher scores indicate better HRQoL and functioning but a worsening of symptoms). FACT-Lym consists of 42 items combined into 8 subscales (4 well-being subscales; 1 symptom subscale [LymS]; and 3 total scale scores: FACT-General [G], FACT-Lym trial outcome index [TOI], and FACT-Lym total; scores for the different subscales vary from 0–28 to 0–168, and higher scores indicate better outcomes). This analysis includes evaluable patients in the randomized treatment phase and assesses changes from baseline in HRQoL and MF symptom scores, including the EORTC subscales, LymS, and FACT total scores, which incorporate well-being and/or symptom subscales. Mixed-model analyses, adjusted for age, sex, baseline score, and prognostic risk category, are used to evaluate treatment differences at each time point and overall across time. Results: HRQoL and MF symptoms, on average, improved compared with baseline for patients receiving ruxolitinib, but remained the same or worsened for patients receiving BAT. Based on the EORTC QLQ-C30, the treatment differences in physical functioning, role functioning, fatigue, and appetite loss significantly favored ruxolitinib starting at week 8 (P

Description: Background: Janus kinases (JAKs), including JAK1 and JAK2, mediate the signaling of cytokines and growth factors implicated in the pathogenesis of myelofibrosis (MF). Suppression of JAK2 leads to cytopenias due to its involvement in the signaling pathways of thrombopoietin and erythropoietin. Purpose: The objective of this ongoing study is to evaluate the efficacy and safety of INCB039110, a selective JAK1 inhibitor, in patients with MF with the goal of improving MF-related symptoms with less myelosuppression than seen with JAK1/JAK2 inhibition. Here, we report the 12- and 24-week efficacy and safety of INCB039110 in a phase II trial. Methods: Adults with intermediate-1 or higher (per Dynamic International Prognostic Scoring System [DIPSS]) primary MF (PMF), post–polycythemia vera MF (PPV-MF), or post–essential thrombocythemia MF (PET-MF) were eligible regardless of JAK2V617F mutation status. A platelet count of ≥ 50 × 109/L, hemoglobin ≥ 8.0 g/dL (transfusions permitted), and a palpable spleen or prior splenectomy were required. Patients assessed the severity of 19 disease-related symptoms daily using the modified Myelofibrosis Symptom Assessment Form v3.0 electronic diary. Spleen volume (SV) was evaluated by magnetic resonance imaging or computed tomography at baseline, week 12, and week 24. The primary endpoint was the proportion of patients with a ≥ 50% reduction from baseline in total symptom score (TSS, consisting of the sum of 6 individual symptom scores: night sweats, itchiness, abdominal discomfort, pain under left ribs, early satiety, and bone/muscle pain) at week 12. Other endpoints included the proportion of patients with a ≥ 50% reduction from baseline in TSS at week 24, percentage change from baseline in TSS at week 12 and 24, percentage change from baseline in SV at week 12 and 24, and safety. The study used a Simon 2-stage design to assess 3 separate dose cohorts (100 mg twice daily [BID], 200 mg BID, and 600 mg once daily [QD]). A dose cohort could be expanded if ≥ 3 of the first 10 patients met the primary endpoint (intent-to-treat method). Results: Enrollment is complete and 87 patients have been treated with INCB039110: 10 in the 100 mg BID, 45 in the 200 mg BID, and 32 in the 600 mg QD groups; 10, 42, and 31 patients, respectively, were evaluable for the primary endpoint. The 200 mg BID and 600 mg QD cohorts met criteria for expansion. Enrolled patients (mean age, 64 years) had PMF (55%), PPV-MF (26%), or PET-MF (18%), and most had intermediate-1 (37%) or intermediate-2 (47%) risk by DIPSS. Mean SV at baseline was 2442.7 cm3, mean hemoglobin was 10.2 g/dL, and mean platelet count was 246.7 × 109/L. Reductions in TSS were similar between the 200 mg BID and 600 mg QD groups, and largely maintained through week 24 (Table). Modest reductions in spleen volume were attained in the 200 mg BID and 600 mg QD groups. TableINCB039110 Dose100 mg BID200 mg BID600 mg QD Patients with ≥ 50% improvement in TSS,* n/N (%)Week 122/10 (20)15/42 (36)10/31 (32)Week 242/10 (20)12/42 (29)11/31 (35) Median change from baseline in TSS,† %Week 12−28.5−45.8−37.2Week 24−57.2−48.6−46.7Median change in SV,† %Week 12−0.5−14.1−14.5Week 24−31.1−17.4−17.1 * Patients who discontinued prior to the week 12 or 24 visit were considered nonresponders at that time point. † Only patients with baseline and week 12 or 24 data were included. Negative change = improvement. Mean platelet count is shown in Figure 1. Mean hemoglobin levels in patients who entered the study without transfusion requirements and did not receive post-baseline blood transfusions are shown in Figure 2. In these patients, the mean percent change from baseline in hemoglobin at week 24 increased by 5.6% in the 200 mg BID group and 8.6% in the 600 mg QD group. The most common nonhematologic adverse events (occurring in 〉 15% of enrolled patients overall regardless of causality) were fatigue (29%), nausea (21%), upper respiratory tract infection (18%), constipation (17%), diarrhea (17%), and cough (16%); most of these events were grade 1 or 2 and did not appear to be dose dependent. New or worsening grade 3 or 4 anemia occurred in 33% and 0% of patients, respectively, and thrombocytopenia in 24% and 5% of patients, respectively. Conclusions: Patients with MF treated with the JAK1 inhibitor INCB039110 (200 mg BID or 600 mg QD) continued to show meaningful improvements in MF-related symptoms and modest decreases in spleen size, while preserving mean hemoglobin levels over time through week 24. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Mascarenhas: Incyte Corporation: Consultancy. Talpaz:ARIAD, BMS, Sanofi. Incyte, Pfizer: Research Funding. Gupta:Novartis: Consultancy, Honoraria, Research Funding; Incyte Corporation: Consultancy, Research Funding. Foltz:Novartis: Consultancy, Honoraria, Research Funding; Incyte Corporation: Research Funding; Gilead: Research Funding; Promedior: Research Funding; Janssen: Consultancy. Savona:Karyopharm: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Gilead : Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees; Celgene : Membership on an entity's Board of Directors or advisory committees. Paquette:Incyte Corporation: Speakers Bureau. Coughlin:Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Eastern Health: Employment. Winton:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Hunter:Incyte Corporation: Employment. Assad:Incyte Corporation: Employment. Clark:Incyte Corporation: Employment. O'Neill:Incyte Corporation: Employment. Hoffman:All Cells LLC: Consultancy, Membership on an entity's Board of Directors or advisory committees; Geron: Consultancy, Membership on an entity's Board of Directors or advisory committees. Verstovsek:Incyte Corporation: Research Funding.

Description: Background: Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk subtype occurring in 15-30% of older children and adolescents/young adults (AYAs) with B-ALL. Ph-like ALL is associated with high relapse rates and poor survival despite intensive multi-agent cytotoxic chemotherapy. Development of successful treatment strategies to decrease relapse and improve cure rates in patients with Ph-like ALL remains a major therapeutic gap. Rearrangements of cytokine receptor-like factor 2 (CRLF2-R) with frequent concomitant JAK2 point mutations occur in 50% of Ph-like ALL cases and induce constitutive JAK/STAT and other kinase signaling. An additional 15-20% of Ph-like ALL harbors other JAK pathway alterations, such as JAK2 or EPOR rearrangements, that similarly activate JAK/STAT signaling. Ruxolitinib is a potent, selective JAK1/JAK2 inhibitor with demonstrated activity in preclinical Ph-like ALL models and clinical safety as monotherapy in children with relapsed/refractory cancers. We report the initial safety of ruxolitinib in combination with post-induction chemotherapy in children and AYAs with newly-diagnosed high-risk (HR) Ph-like ALL with CRLF2-R or other JAK pathway alterations treated on the non-randomized, 2-part phase 2 study INCB18424-269 (AALL1521; NCT02723994). Methods: Patients aged 1-21 years at time of diagnosis with HR B-ALL and eligible Ph-like genetic lesions who had completed 4-drug induction chemotherapy as per the Children's Oncology Group (COG) AALL1131 study (NCT02883049) were eligible to participate. Patients were stratified into 4 cohorts by genetic alterations and end-induction flow cytometric minimal residual disease (MRD) status: cohort A = CRLF2-R JAK-mutant, MRD+; B = CRLF2-R JAK-wild-type, MRD+; C = other JAK pathway alterations, MRD+, D = any CRLF2-R or JAK pathway alteration, MRD-. Patients commenced treatment on the INCB18424-269/AALL1521 study at consolidation with ruxolitinib orally twice daily in combination with augmented Berlin-Frankfurt-Münster (aBFM) post-induction chemotherapy as per AALL1131. Five discontinuous dose levels (10-50 mg/m2/dose 14-days-on/14-days-off per cycle [DL-2 to DL2]) and one continuous DL1b (40 mg/m2/dose × 28 days per cycle) of ruxolitinib with aBFM chemotherapy were explored via a standard rolling 6 design. Dose-limiting toxicities (DLTs) were assessed through Day 29 of delayed intensification (DI) and defined as hematologic and non-hematologic toxicity with higher grade or more prolonged duration than observed in children with treated with identical chemotherapy (without ruxolitinib) on other COG HR B-ALL trials. Pharmacokinetic (PK) and pharmacodynamic (PD) analyses were conducted using serial blood samples obtained from patients during consolidation therapy. Results: Forty patients (pts) were enrolled in Part 1 (cohort A, n=10; B, n=9; C, n=5; D, n=16). Four patients discontinued study treatment before the Day 29 DI timepoint, 3 of whom were replaced. Patients had a median age of 14 years, and 67.5% were male. Treatment-emergent adverse events occurred in all patients and included anemia (75%), platelet count decrease and/or thrombocytopenia (65%), febrile neutropenia (72.5%), and AST or ALT increase (57.5%). Thirty-three patients had Grade 3/4 events deemed possibly related to ruxolitinib without identified DLTs. Eleven patients in Part 1 (27.5%) discontinued study therapy for various reasons: CNS relapse (2 pts), end-consolidation MRD+ (4 pts), multi-system organ dysfunction (MSOD; 2 pts), elective MRD- stem cell transplantation (1 pt), psychosocial/compliance issues (2 pts). One patient died of septic shock and MSOD not attributed to ruxolitinib. Preliminary analysis of plasma drug levels at 4 hours post-dose was consistent with the known PK profile of ruxolitinib. PD studies demonstrated dose-dependent inhibition of target phosphoproteins and, importantly, sustained inhibition of phosphorylated STAT5 with continuous ruxolitinib dosing at DL1b. Discussion: These findings demonstrate safety and tolerability of ruxolitinib in combination with intensive multi-agent chemotherapy in children and AYAs with newly-diagnosed HR CRLF2-R/JAK pathway-mutant Ph-like ALL and support continued investigation of treatment efficacy in Part 2 of this trial. Disclosures Tasian: Aleta Biopharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Research Funding; Incyte Corporation: Research Funding. Assad:Incyte Corporation: Employment, Equity Ownership. Hunter:Incyte Corporation: Employment. Du:Incyte Corporation: Employment.

Description: Abstract 801 Background: Ruxolitinib is a potent JAK1 & 2 inhibitor that has demonstrated superiority over traditional therapies for the treatment of MF. In the two phase 3 COMFORT studies, ruxolitinib demonstrated rapid and durable reductions in splenomegaly and improved MF-related symptoms and quality of life. COMFORT-II is a randomized, open-label study evaluating ruxolitinib versus BAT in patients (pts) with MF. The primary and key secondary endpoints were both met: the proportion of pts achieving a response (defined as a ≥ 35% reduction in spleen volume) at wk 48 (ruxolitinib, 28.5%; BAT, 0%; P 〈 .0001) and 24 (31.9% and 0%; P 〈 .0001), respectively. The present analyses update the efficacy and safety findings of COMFORT-II (median follow-up, 112 wk). Methods: In COMFORT-II, 219 pts with intermediate-2 or high-risk MF and splenomegaly were randomized (2:1) to receive ruxolitinib (15 or 20 mg bid, based on baseline platelet count [100-200 × 109/L or 〉 200 × 109/L, respectively]) or BAT. Efficacy results are based on an intention-to-treat analysis; a loss of spleen response was defined as a 〉 25% increase in spleen volume over on-study nadir that is no longer a ≥ 35% reduction from baseline. Overall survival was estimated using the Kaplan-Meier method. Results: The median follow-up was 112 wk (ruxolitinib, 113; BAT, 108), and the median duration of exposure 83.3 wk (ruxolitinib, 111.4 [randomized and extension phases]; BAT, 45.1 [randomized treatment only]). Because the core study has completed, all pts have either entered the extension phase or discontinued from the study. The primary reasons for discontinuation were adverse events (AEs; ruxolitinib, 11.6%; BAT, 6.8%), consent withdrawal (4.1% and 12.3%), and disease progression (2.7% and 5.5%). Overall, 72.6% of pts (106/146) in the ruxolitinib arm and 61.6% (45/73) in the BAT arm entered the extension phase to receive ruxolitinib, and 55.5% (81/146) of those originally randomized to ruxolitinib remained on treatment at the time of this analysis. The primary reasons for discontinuation from the extension phase were progressive disease (8.2%), AEs (2.1%), and other (4.1%). Overall, 70 pts (48.3%) treated with ruxolitinib achieved a ≥ 35% reduction from baseline in spleen volume at any time during the study, and 97.1% of pts (132/136) with postbaseline assessments experienced a clinical benefit with some degree of reduction in spleen volume. Spleen reductions of ≥ 35% were sustained with continued ruxolitinib therapy (median duration not yet reached); the probabilities of maintaining the spleen response at wk 48 and 84 are 75% (95% CI, 61%-84%) and 58% (95% CI, 35%-76%), respectively (Figure). Since the last report (median 61.1 wk), an additional 9 and 12 deaths were reported in the ruxolitinib and BAT arms, respectively, resulting in a total of 20 (14%) and 16 (22%) deaths overall. Although there was no inferential statistical testing at this unplanned analysis, pts randomized to ruxolitinib showed longer survival than those randomized to BAT (HR = 0.52; 95% CI, 0.27–1.00). As expected, given the mechanism of action of ruxolitinib as a JAK1 & 2 inhibitor, the most common new or worsened grade 3/4 hematologic abnormalities during randomized treatment were anemia (ruxolitinib, 40.4%; BAT, 23.3%), lymphopenia (22.6%; 31.5%), and thrombocytopenia (9.6%; 9.6%). In the ruxolitinib arm, mean hemoglobin levels decreased over the first 12 wk of treatment and then recovered to levels similar to BAT from wk 24 onward; there was no difference in the mean monthly red blood cell transfusion rate among the ruxolitinib and BAT groups (0.834 vs 0.956 units, respectively). Nonhematologic AEs were primarily grade 1/2. Including the extension phase, there were no new nonhematologic AEs in the ruxolitinib group that were not observed previously (in ≥ 10% of pts), and only 1 pt had a new grade 3/4 AE (epistaxis). Conclusion: In COMFORT-II, ruxolitinib provided rapid and durable reductions in splenomegaly; this analysis demonstrates that these reductions are sustained over 2 years of treatment in the majority of pts. Ruxolitinib-treated pts showed longer survival than those receiving BAT, consistent with the survival advantage observed in previous (Verstovsek et al. NEJM. 2012) and current analyses of COMFORT-I, as well as with the comparison of pts of the phase 1/2 study with matched historical controls (Verstovsek et al. Blood. 2012). Disclosures: Cervantes: Sanofi-Aventis: Advisory Board, Advisory Board Other; Celgene: Advisory Board, Advisory Board Other; Pfizer: Advisory Board, Advisory Board Other; Teva Pharmaceuticals: Advisory Board, Advisory Board Other; Bristol-Myers Squibb: Speakers Bureau; Novartis: AdvisoryBoard Other, Speakers Bureau. Kiladjian:Shire: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Niederwieser:Novartis: Speakers Bureau. Sirulnik:Novartis: Employment, Equity Ownership. Stalbovskaya:Novartis: Employment, Equity Ownership. McQuity:Novartis: Employment, Equity Ownership. Hunter:Incyte: Employment. Levy:Incyte: Employment, stock options Other. Passamonti:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Barbui:Novartis: Honoraria. Gisslinger:AOP Orphan Pharma AG: Consultancy, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees. Knoops:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Harrison:Shire: Honoraria, Research Funding; Sanofi: Honoraria; YM Bioscience: Consultancy, Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau.

Description: 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 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.

Description: Key Points Long-term analysis of the COMFORT-II Trial shows that ruxolitinib treatment results in durable reductions in splenomegaly and is well tolerated. Patients randomized to ruxolitinib showed longer overall survival than those receiving the BAT.