Shire Pharmaceuticals Research Articles

PTU-123 Factors that Anticipate Clinical/Therapeutic Outcomes to Prucalopride

IntroductionChronic constipation (CC) is a prevalent disorder that has a significant negative impact on quality of life. Traditional management has focused on lifestyle measures and laxative. Prucalopride, a selective high...

Combination of Cytoreductive Therapies in Patients with Essential Thrombocythemia: A Preliminary Report From the E.X.E.L.S. Study.

AbstractAbstract 2842 Background:As some patients (pts) with essential thrombocythemia (ET) may discontinue their cytoreductive treatment because of drug intolerance/inefficacy, combinations of drugs with different activity/tolerability patterns are being utilized in clinical practice. Objectives:To evaluate the clinical relevance and patterns of cytoreductive combination treatment in ET in Evaluation of Xagrid™ Efficacy and Long-term Safety (EXELS), an observational study in 3643 European pts with high-risk ET. Patients and Methods:Data on pts receiving cytoreductive treatments in combination for ≥30 days (COMB) were collected from a planned data cut in September 2011. This timepoint was 2.5 years after enrollment completed. Results:COMB was recorded in 347 pts (9.5%), the vast majority (87.6%) of whom received anagrelide + hydroxycarbamide (ANA+HC). Other combinations were anagrelide + interferon-α (ANA+IFN), anagrelide + pipobroman (ANA+PIPO; Table). Six patients also received anagrelide + other drugs (ANA+OTH).In 333 pts, the initial drug was HC (n=167; 50.2%), ANA (n=138; 41.4%), IFN (n=14; 4.2%), PIPO (n=9; 2.7%), or OTH (n=5; 1.5%), while the added drug was ANA (n=195; 58.6%), HC (n=123; 36.9%), IFN (n=12; 3.6%), PIPO (n=2; 0.6%), or OTH (n=1; 0.3%). Fourteen pts started ANA+HC concomitantly. The median duration of monotherapy treatment before COMB start was 139 months for HC, 53 months for ANA, 71 months for IFN, and 237 months for PIPO.In pts receiving ANA+HC, the median weekly dose of the initial drug, both before and during COMB, was 10.5 mg for ANA and 7.0 g for HC, while the median weekly dose of the added drug during COMB was 7.0 mg for ANA and 3.5 g for HC. In these pts, the median platelet count ≤6 months before COMB start, during COMB (first test), and during COMB (last test) was 581, 411, and 434 ×109/L, respectively (with counts ≤600 ×109/L in 52.9%, 79.2%, and 77% of cases, respectively); the median white blood cell count was 6.9, 6.8, and 6.8 ×109/L, respectively; the median hematocrit was 38.0%, 36.3%, and 39.0%, respectively; and median hemoglobin was 11.9, 11.6, and 12.0 g/dL respectively. Similar laboratory results were obtained in pts receiving ANA+IFN or ANA+PIPO.Before, during and after COMB, anti-aggregatory treatment, usually low-dose aspirin, was given in 66.3%, 71.8%, and 33.1% of pts, respectively. In the same time periods, thrombotic (3, 11, and 11 cases, respectively) and hemorrhagic events (1, 2, and 5 cases, respectively) occurred.The COMB discontinuation rate was 54.5% globally (186/341 pts). COMB was discontinued by stopping ANA in 67 cases (36.0%), HC in 76 (40.9%), IFN in 8 (4.3%), PIPO in 4 (2.2%), both ANA and HC in 19 (10.2%), both ANA and IFN in 3 (1.6%), both ANA and PIPO in 3 (1.6%), or by adding a third drug in 6 cases (3.2%).In the 158 pts who discontinued ANA+HC, reasons were: intolerance/side effects (n=79, 50.0%), lack of efficacy (n=35, 22.2%), investigator decision (n=34, 21.5%, mainly with switch to ANA monotherapy), patient preference (n=10, 6.3%), missing, other (including economic) or unknown (n=17, 10.2%). Similarly, intolerance/side effects was the most frequent reason for discontinuing ANA+IFN (12/20; 60.0%).Overall, there were 63 patients with suspected severe adverse reactions (SSARs) and 45 with predefined events (PDEs) during COMB. The most frequent SSARs were myelofibrosis, palpitations, myocardial infarction and tachycardia. The most frequent PDEs included cardiovascular symptoms, myocardial infarction, stroke and transformation. Pts on COMB, the majority of whom received ANA+HC, accounted for 3.8% of all pts at registration and 5.0–5.8% of all pts in the following 5 years. Conclusion:COMB was performed in almost 10% of the 3643 pts with ET in the EXELS study, mainly with use of ANA+HC (87.6%). COMB appears to be a useful approach to treating patients for whom monotherapy was not well tolerated or ineffective since platelet levels were reduced to <600 ×109/L in almost 80% of pts, and a switch to monotherapy with the added drug, usually ANA, frequently followed.Tablen (%)ANA+HCANA+IFNANA+PIPOPatients304 (87.6%)26 (7.5%)11 (3.2%)Median age at treatment start, years614660Median duration of combination, weeks913245Duration of treatment in patients who did not discontinue, weeks15378185Patients who discontinued COMB158 (52%)20 (76.9%)8 (72.7%)NB: Six pts received ANA+OTH (busulphan or anagrelide [Thromboreductin®] or HC+INT) Disclosures:Gugliotta:Shire: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Besses:Shire: Honoraria; Novartis: Honoraria. Griesshammer:Shire: Honoraria. Harrison:Novartis: Consultancy, Honoraria, Research Funding; YM Biosciences: Consultancy; S*Bio: Consultancy; Shire: Honoraria, Research Funding; Sanofi Avensis: Honoraria. Kiladjian:Shire: Membership on an entity’s Board of Directors or advisory committees; Incyte: 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; Celgene: Research Funding. Coll:Shire Pharmaceuticals: Employment. Smith:Shire Pharmaceuticals: Employment. Abhyankar:Shire Pharmaceuticals: Employment. Birgegård:Shire Pharmaceuticals: Honoraria; Pharmacosmos: Research Funding; Shire Pharmaceuticals Sweden: Consultancy.

Comparison of Pharmacokinetic Parameters of Anagrelide in Healthy Japanese and Caucasian Volunteers

AbstractAbstract 5066 Aim:Currently, it is not fully elucidated how ethnicity influences the pharmacokinetic (PK) profile of anagrelide. The aim of this retrospective analysis was to compare the PK profile of anagrelide in healthy Japanese and Caucasian volunteers. Methods:Retrospective analyses were conducted on two phase I studies with anagrelide: a study of healthy Japanese volunteers (study A) and healthy Caucasian volunteers (study B). In study A, healthy males received anagrelide (0. 5, 1. 0 or 2. 0 mg) or placebo under fasted or fed conditions. In study B, healthy volunteers received a single 1. 0 mg dose under fasted conditions. PK analysis of anagrelide was conducted as part of these original studies. The calculated PK parameters were maximum plasma concentration (Cmax), time for Cmax (tmax), area under plasma concentration from time zero to time infinity (AUC0-inf) and terminal-phase disposition half-life (t1/2). Results:PK data for healthy Japanese males (n=6) aged 20–35 years, with a body weight of 50–80 kg and receiving 1. 0 mg anagrelide in study A were compared with PK data for healthy Caucasian volunteers (n=10, 8 male and 2 female) aged 40–69 years, with a body weight of 56–100 kg and receiving 1. 0 mg anagrelide in study B. Single-dose PK parameters under fasted conditions across both studies are shown in the Table for anagrelide and its metabolite 2-amino-5, 6-dichloro-3, 4-dihydroquinazilone (RL603).TableSingle-dose PK parameters (mean ± SD) in healthy Japanese (n=6) and Caucasian (n=10) volunteers receiving anagrelide, 1 mg fasted administrationAnalyte/PopulationCmax (ng/mL)tmax (h)AUC0-inf (ng·h/mL)t1/2 (h)AnagrelideJapanese4.86±2.401.25±0.6112.82±5.431.42±0.51Caucasian4.88±2.151.15±0.6311.30±3.731.35±0.21RL603Japanese8.55±1.183.00±1.1073.25±13.855.86±0.98Caucasian1.64±0.402.10±0.5718.20±3.866.84±1.58Compared with Caucasian volunteers, healthy Japanese volunteers exhibited similar Cmax, and slightly higher AUC0-inf for anagrelide. In contrast, Cmax and AUC0-inf for the inactive metabolite RL603 were considerably higher in Japanese volunteers. Five adverse events (AEs) were reported in 3 volunteers in study A and 9 AEs in 3 volunteers in study B: 5 and 3 AEs, respectively, were considered possibly related to treatment. The most commonly reported AEs were headache and nausea. No serious AEs were observed during either study. Discussion:The PK analyses conducted on volunteers receiving a single 1 mg dose showed that under fasted conditions anagrelide was rapidly absorbed with similar Cmax and tmax between Japanese and Caucasian volunteers. The slightly higher AUC0-inf of anagrelide in Japanese volunteers may be an artefact of the high inter-subject variability, which is common with drugs such as anagrelide that exhibit extensive pre-systemic metabolism. It remains unclear as to why Japanese volunteers had higher RL603 Cmax and AUC0-inf values than Caucasian individuals.Analyses of PK data from studies of patients with essential thrombocythaemia (ET) (Okamoto et al, manuscript in preparation; Besses et al, Int J Clin Pharmacol Ther, 2012, manuscript in press) noted that compared with non-Japanese patients, Japanese patients also had slightly higher Cmax (2. 81±0. 99 vs 5. 88±4. 58 ng/mL) and AUC (6. 8±2. 4 vs 16. 3±6. 5 ng·h/mL) for anagrelide. Overall, across both ethnic groups, patients with ET had higher anagrelide exposures than healthy volunteers. However, within the Japanese population, Cmax and AUC0-inf values were only slightly higher in patients with ET than in volunteers, which may suggest that the PK exposures of anagrelide did not differ substantially between these Japanese cohorts. Conclusion:Anagrelide exhibits high inter- and intra-subject variability, which makes it difficult to compare PK exposures in studies with small populations. The PK data across all these studies indicate that the first-pass metabolism of anagrelide may be marginally lower in the Japanese population than in Caucasian individuals; however these differences do not translate to different clinical outcomes with respect to the observed treatment-related AEs associated with anagrelide therapy. Despite the small differences observed in metabolism of anagrelide, it is well tolerated in Japanese populations and ethnicity-specific dosing regimens are not required. Disclosures:Kanakura:Shire: Consultancy. Hodgson:Shire Pharmaceutical Development Ltd: Employment. Troy:Shire Development, LLC: Employment. Abhyankar:Shire Pharmaceuticals: Employment. Smith:Shire Pharmaceuticals: Employment. Besses:Shire: Honoraria; Novartis: Honoraria.

A Sensitized Whole Genome ENU Mutagenesis Screen Identifies an Arp2 Missense Mutation As a Novel Suppressor of Lethal Thrombosis in the Factor V Leiden Mouse

Abstract 493Only ∼10% of individuals carrying the common risk factor, Factor V Leiden (FVL), will develop venous thrombosis. In order to identify potential FVL modifier genes, we performed a sensitized dominant ENU mutagenesis screen based on the perinatal synthetic lethal thrombosis observed in mice homozygous for FVL (FVQ/Q) and hemizygous for tissue factor pathway inhibitor deficiency (Tfpi+/−). The screen was performed by crossing ENU-treated male FVQ/Q mice with FVQ/+ Tfpi+/− females. Surviving G1 offspring were analyzed to identify survivors with the lethal FVQ/Q Tfpi+/− genotype. Analysis of 7,128 G1 offspring (∼2X genome coverage) identified 98 FVQ/Q Tfpi+/− mice that survived to weaning. Fourteen FVQ/Q Tfpi+/− G1 mice exhibited successful transmission of a putative suppressor mutation to two or more FVQ/Q Tfpi+/− G2 offspring. Whole exome sequencing was performed on a progeny tested member of 8 of the 14 lines using the Agilent SureSelect mouse whole exome capture kit resulting in ∼100 fold coverage. Variant analysis revealed a small number of high confidence novel heterozygous (dominant) single nucleotide variants (SNVs) in each sample. Sanger re-sequencing of all 11 SNVs in a cohort of mice from line 1 confirmed that the G to C mutation (chromosome 11 base 19,977,300) in the Actr2 gene (present in 15/16 re-sequenced progeny p<0.0001) is the dominant FVL modifier in this line. This mutation resulted in an R286G substitution in a highly conserved amino acid in the Arp2 protein, which is essential for the function of the Arp2/3 complex. Arp2/3 is responsible for intracellular actin branching and polymerization, which is critical for the regulation of cell shape. Analysis of 31 progeny from an Arp2 R/G × Arp2 R/G cross revealed only one live Arp2 G/G mouse (p<0.05), suggesting that R286G is a loss of function mutation and that homozygous deficiency is lethal. Complete blood counts (Advia 2120) performed on 14 Actr2 heterozygous and 10 wildtype littermates revealed no significant differences in platelet count, red and white blood cell counts, hematocrit or hemoglobin. However, measurements of platelet size and size distribution including mean platelet dry mass, platelet volume distribution width and the platelet component distribution width were significantly altered in Actr2 heterozygous mutant mice (p<0.05 for each measure). Thus, partial deficiency of Arp2 appears to alter platelet structure/function resulting in a shift in hemostatic balance facilitating survival of the otherwise lethal FVQ/Q Tfpi+/− phenotype. These results suggest that variation in Arp2 or related genes could potentially modify thrombosis risk in humans, and might also identify novel therapeutic targets for the treatment of this class of disorders. Disclosures:Ginsburg:Shire Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees; Portola Pharmaceuticals: Consultancy; Catalyst Biosciences: Consultancy; Baxter Pharmaceuticals: benefit from payments to Children’s Hosptial, Boston, and the University of Michigan Patents & Royalties; Merck Pharmaceuticals: Consultancy.

Essential Thrombocythaemia in Young Adults: Clinical Characteristics and Outcomes – a Single Center Experience

Abstract 5060Less than 20% of patients with essential thrombocythemia (ET) are diagnosed below the age of 60. Patients with ET have increased risk of thrombosis and bleeding and potential for progression to myelofibrosis (MF) or acute myeloid leukaemia (AML). In limited studies of young patients, the clinical course has been relatively benign with low rates of transformation to AML or MF. Thrombohemorrhagic events are generally few, but higher than that of the general population. This study aims to characterize of a group ET patients diagnosed at age ≤40, their thrombotic and hemorrhagic events, disease progression and treatment given.Patients were identified through a single institution MPN registry. This is an IRB approved registry that captures comprehensive information about patients with ET. Data on patient demographics, treatment, and disease-related events were obtained. Patients were diagnosed from 1975–2011, using either WHO or PVSG criteria depending on date of diagnosis. Kaplan-Meier method was used for survival analysis.59 patients were diagnosed with ET at age ≤40. Median age of diagnosis was 31. 5years (range 16–40), with a median follow up of 7. 7years (0. 4–33. 8). All were of Asian descent: 81. 4% Chinese, 11. 9% Malay, 3. 4% Indian and 3. 4% Filipino. 40. 7% were male. JAK2 V617F mutation was screened for in 61%. Of these patients, 11 were positive, 25 negative for the mutation. Mean presenting counts were: WBC 10. 7 × 109/L (5. 9–21. 3), Hb 13. 6g/dL (9. 7–16. 4), platelets 957 × 109/L (449–2377). Splenomegaly was noted in 3 patients. 20. 3% had underlying hypertension, 16. 9% hyperlipidemia and 5. 1% diabetes mellitus. One patient had a prior stroke. Another had prior portal vein thrombosis.At diagnosis, 23. 7% were symptomatic, with microvascular symptoms of headache (11. 9%) and giddiness (6. 8%) being most common. The remainder were diagnosed incidentally, on health screening or when seeking medical attention for unrelated conditions. One patient presented with a myocardial infarction at diagnosis, while another had a significant bleeding post hemorrhoidectomy with drop in Hb by >2g/dL (platelet 2457 × 109/L). Based on a history of prior thrombosis, 3 patients were defined as high risk for thrombotic events. 67. 8% of patients had cytoreduction, indications being platelets ≥1500 × 109/L (n=16), presence of risk factors for atherosclerotic disease (n=11) and history/onset of thrombosis (n=5). In 8, the reason for cytoreduction could not be ascertained. Hydroxyurea was most commonly used (62. 7%), followed by anagrelide in 52. 5% and interferon 25. 4%. 5. 1% received busulphan, and 1. 7% 32P. Use of antiplatelet therapy was noted in 83. 8%, most frequently aspirin (76. 5%) and ticlopidine (11. 9%). On follow up, 2 arterial thromboses occurred (stroke, TIA), giving a thrombosis rate of 0. 39%/patients/year. Neither was a recurrent thrombosis. No venous thrombosis or major bleeds occurred. 20. 4% had minor mucocutaneous bleeding; 5 had platelets ≥1500 × 109/L at that time. 3. 4% had disease progression due to MF and another 3. 4% had AML. 3. 4% of patients died due to AML. Median survival was 33. 8years (95% confidence interval 30. 3–35. 5). Initial blood counts, presence of JAK2 and high risk disease status did not correlate with thrombotic risk, risk of death or disease progression. Use of antiplatelet agents and a platelet count ≥1500 × 109/L did not correlate with bleeding risk.Few studies have looked exclusively at young patients with ET. In this group, most patients were asymptomatic and well, ET being diagnosed incidentally. They were predominantly at low risk for thrombosis and other ET-related complications. The period of follow up was comparable to that of other studies and during that time, the rate of complications and risk of disease progression was low. The thrombosis rate of 0. 39% per patient year was less than that reported by other groups (2. 2–2. 6 thromboses/100patients/year) (Leukaemia 2007;21:1218–1223, Clin Appl Thrombosis/Hemostasis 2000;6(1):31–35) but similar to the 0. 74%/patient year reported by Barbui (Blood. Epub. June 13 2012). Overall findings generally complemented those reported by other groups. No risk factors were found to influence the occurrence of complications, but the number of events was small. Follow up of this group of patients over time is essential to see if their disease course remains benign or if complications will increase with time.Soli Deo Gloria Disclosures:Kam:Shire Pharmaceuticals: Consultancy, grant to support the MPN registry Other.

Partial in Vivo FVIII Stabilization by VWF Fragments

Abstract 15Plasma factor VIII (fVIII) circulates in complex with von Willebrand factor (VWF) and is rapidly cleared in the absence of VWF. Previous in vitro studies have 1) localized the fVIII-binding region of VWF to the N-terminus, comprised of the contiguous D’ and D3 domains and 2) observed reduced affinity for fVIII upon alterations to the tertiary structure of VWF. To gain insight into the structure-function of VWF for fVIII stabilization, we tested VWF fragments for in vivo fVIII stabilization and investigated the architecture of a VWF fragment in complex with fVIII. For the in vivo study, fragments of murine Vwf cDNA were cloned into the hepatic-specific expression vector, pLIVE, and modified to fuse tandem E and FLAG tags to the C-terminus. The following VWF fragments were expressed in vivo by hydrodynamic tail vein injection into Vwf−/− mice: 1) a monomer of the VWF D’D3 domains (monoD’D3; M1-C22, S764-P1274); 2) a truncation of monomeric D’D3 (truncD’D3; M1-C22, S764-R1035); 3) dimers of D’D3 (diD’D3; M1-P1274); 4) multimers of D’D3 (multiD’D3; M1-P1274, G2713-K2813); 5) dimers of mature VWF subunits (DPro, M1-C22, S764-K2813); or 6) full length, multimeric VWF (wtVWF, M1-K2813). Expression of all VWF fragments persisted throughout the period of observation (4 weeks) with peak antigenic levels at 1 or 3 days post-injection. Prolonged elevation of plasma fVIII activity (fVIIIa) from ∼10% to ∼50–200% were observed (100% defined as the fVIIIa level of pooled platelet poor plasma from 10 wild type C57BL/6 mice) for all but the truncated monomer of D’D3 (Figure 1). Significantly increased fVIIIa levels (p<0.05, relative to pre-injection) were first observed at 1 day, peaked at 3 days, and persisted for the duration of observation. A minimal VWF fragment (S764-R1035, truncD’D3) reported to bind fVIII in vitro significantly increased plasma fVIIIa to 34% only at 3 days post-injection. Clearance of VWF fragments from circulation were determined from injections of pooled platelet poor plasma containing recombinant VWF fragments derived from hydrodynamically injected mice into naïve Vwf−/− mice. Nonlinear regression estimated the half-life for monoD’D3 (3.4hr), diD’D3 (2.1hr), multiD’D3 (2.3hr), DPro (2.8hr), and wtVWF (3.5hr). To examine how dimers of D’D3 bind fVIII, diD’D3 from HepG2 conditioned media was purified either alone or with recombinant fVIII, and negative stained samples were visualized by electron microscopy (EM). Single-particle EM analysis revealed that each subunit of the dimer binds 1 fVIII molecule. 3D EM reconstructions indicate that the light chain of fVIII directly interacts with, and potentially induces torsion in the flexible D’D3 domains of VWF. Together, these results emphasize the importance of VWF’s tertiary structure in fVIII stabilization and that the N-terminal D’D3 alone is sufficient to support fVIII survival in vivo. These findings could lead to improved methods of recombinant fVIII production and the development of novel approaches to treatment for hemophilia and von Willebrand disease. [Display omitted] Disclosures:Ginsburg:Shire Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees; Portola Pharmaceuticals: Consultancy; Catalyst Biosciences: Consultancy; Baxter Pharmaceuticals: benefit from payments to Children’s Hosptial, Boston, and the University of Michigan Patents & Royalties; Merck Pharmaceuticals: Consultancy.

Disparate SEC23B Deficient Phenotypes in Humans and Mice

Abstract 974SEC23 is a core component of the COPII coated vesicle that mediates the transport of cargo proteins from the endoplasmic reticulum to the Golgi apparatus. Mutations in human SEC23B, one of two mammalian SEC23 paralogs, results in the autosomal recessive disease, congenital dyserythropoietic anemia type II (CDAII). In contrast, SEC23B deficient mice were recently reported to die perinatally with massive pancreatic degeneration, with no evidence of anemia at birth (Tao, et al., 2012. Proc.Natl.Acad.Sci.U.S.A. 109:E2001–9.) To examine the impact of SEC23B deficiency on hematopoietic function in mice surviving beyond the immediate perinatal period, lethally irradiated C57BL/6J mice were transplanted with fetal liver cells (FLC) collected from E17.5 embryos that were either wild-type (WT) or homozygous for the previously reported Sec23b gene trap allele (Sec23bgt/gt). Recipients of Sec23bgt/gt FLC were indistinguishable from their WT transplant controls and exhibited none of the phenotypic characteristics of CDAII (anemia, increased bi/multi-nucleated RBC precursors, narrower band size and increased shift of the membrane protein band 3 on SDS gel electrophoresis, or RBC double membrane appearance by electron microscopy). To test for a more subtle defect in hematopoietic reconstitution, Sec23bgt/gt FLCs were co-transplanted with WT GFP+ FLC in a 1:1 ratio, with no competitive difference observed over the course of 18 weeks of follow-up. Transplant of marrow from these chimeric animals into secondary recipients demonstrated continued equivalence of Sec23bgt/gt and WT hematopoietic stem cells. To rule out an incidental mutation in a nearby gene (“passenger gene”) as the cause of the pancreatic phenotype in SEC23B-deficient mice, two Sec23b bacterial artificial chromosome transgenes were crossed into the Sec23bgt line, with both demonstrating complete rescue of the Sec23bgt/gt pancreatic phenotype, with normal survival to adulthood. Sec23bgt/gt murine embryonal fibroblasts express a SEC23B/βGEO fusion protein consistent with the gene trap insertion into Sec23b intron 19, and this fusion protein co-immunoprecipitates with SEC24A (Tao, et al., 2012. Proc.Natl.Acad.Sci.U.S.A. 109:E2001–9). To rule out a contribution of the SEC23B/βGEO fusion protein to the disparate human and mouse SEC23B-deficient phenotypes, a second, conditional SEC23B allele was analyzed, in which exons 5 and 6 are flanked by loxP sites (Sec23bfl). Deletion of exons 5 and 6 results in frame shift and stop codon in exon 7. Mice with an erythroid-specific deficiency of SEC23B were generated by crossing the Sec23bfl allele to an EpoR-Cre transgene. Sec23bfl/-/EpoR-CreTg+ mice exhibit no anemia compared to their WT litter mates. Transplant recipients of FLCs from E16.5 embryos homozygous for a germline deletion of Sec23b exons 5 and 6 (Sec23b−/−) were also indistinguishable from mice receiving WT FLCs. Pancreas-specific knock-out generated by crossing the Sec23bfl allele to a p48-Cre or Pdx1-Cre transgene confirmed the pancreatic phenotype observed. This suggests that the perinatal lethality in Sec23b deficient mice may be the result of the loss of pancreatic Sec23b expression. To explore the mechanism for the disparate human and mouse SEC23B-deficient phenotypes, the expression patterns for SEC23A and SEC23B were examined in mice and humans by RT PCR and western blotting. The ratio of SEC23B/SEC23A expression is higher in mouse pancreas (12.7) compared to bone marrow (2.6), whereas in humans, the ratio is higher in the bone marrow (7.8) relative to pancreas (5.5) (normalized to liver). Taken together with the high degree of sequence similarity between SEC23A and SEC23B (∼ 85% identity at the amino acid level), we hypothesize that these 2 SEC23 paralogs overlap extensively at the level of protein function, with the disparate deficiency phenotypes due primarily to differences in tissue and developmentally-specific gene expression programs that have shifted extensively during recent mammalian evolution. These findings have important implications for the comparative function of other closely related paralogous genes. Further studies of the overlapping functions of SEC23A and SEC23B and their relevant protein cargos should provide new insight into the pathogenesis of CDAII and potential therapeutic approaches. Disclosures:Ginsburg:Shire Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees; Portola Pharmaceuticals: Consultancy; Catalyst Biosciences: Consultancy; Baxter Pharmaceuticals: benefit from payments to Children’s Hosptial, Boston, and the University of Michigan Patents & Royalties; Merck Pharmaceuticals: Consultancy.

In Vivo Genome Editing of Liver Albumin for Therapeutic Gene Expression: Rescue of Hemophilic Mice Via Integration of Factor 9

AbstractAbstract 751Gene correction using zinc finger nuclease (ZFN) technology can be applied to target virtually any locus in the human genome. Beyond correcting mutated genes causative of disease, ZFNs can also be utilized to target transgene insertion into genomic “safe harbors.” Ideally, specific gene targeting to such “safe harbor” sites would (i) ensure therapeutically relevant levels of transgene expression and (ii) tolerate transgene addition without deleterious effect on the host organism. For liver-derived protein replacement, albumin represents an attractive target locus. Firstly, albumin is very highly expressed exclusively in the liver, thus targeting of a relatively small percentage of alleles should yield therapeutically relevant levels of liver-specific transgene expression. Second, the reduction or complete absence of albumin in animals and even humans (analbuminemia) produces surprisingly few symptoms. Here, we sought to investigate whether ZFN-mediated targeted insertion of a promoter-less copy of the human F9 cDNA at the mouse albumin locus could result in human Factor IX production and successfully correct the hemophilic phenotype in mice.To address this question, we constructed an AAV vector encoding a pair of ZFNs targeting intron 1 of the mouse albumin locus (AAV8-mAlb-ZFN) and a donor AAV vector (AAV8-Donor) harboring a partial cDNA cassette containing exons 2–8 of the wild-type human F9 gene flanked by sequences lacking significant homology to the mouse genome. Co-delivery of 1e11 vg of AAV8-mAlb-ZFN along with 5e11vg of AAV8-Donor resulted in stable (>12wk) circulating F.IX levels of 1600–3200 ng/mL (32–64% of normal). As a control, mice injected with the AAV8-Donor along with an AAV vector encoding a ZFN pair targeting an unrelated locus exhibited background F.IX levels (∼50 ng/mL). A dose-response study was performed by administering a fixed dose of donor (5e11 vg/mouse) with decreasing doses of AAV8-mAlb-ZFN (1e11, 1e10 and 1e9 vg/mouse). Human F.IX levels increased as a function of ZFN dose in the range tested (3260±480, 225±43 and 31±4 ng/mL at the high, medium and low dose, respectively). Importantly, these results showed that donor homology to the target site is not required to achieve robust levels of gene addition to the albumin locus in adult mice, thus permitting the design of donor vectors harboring corrective copies of transgenes up to the maximum AAV packaging capacity of ∼4.7 Kb.Albumin and factor IX are both synthesized as pre-propeptides and turned into propeptides after the signal peptide is removed. Expression of human F9 exons 2–8 spliced with mouse albumin exon 1 is expected to yield a chimeric propeptide. The first 2 N-terminal amino acids would originate from proalbumin, followed by a Val to Leu mutation at position −17 of the hF.IX propeptide and 16 aa encoded by human F9. To evaluate whether this chimeric human F.IX derived from gene addition to the albumin locus would be processed correctly and normalize the prolonged clotting times in hemophilia B (HB) mice, we injected 1e11 vg of AAV8-mAlb-ZFN and 5e11vg of AAV8-Donor into HB animals. Two weeks post-treatment, hF.IX antigen levels were in the range of 20% of normal and activated partial thromboplastin time, a measurement of clot formation, was corrected to wild-type levels (42 seconds), from an average of 70 seconds pre-treatment. Thus expression of a therapeutic protein (F.IX) from the albumin locus is shown to correct the HB disease phenotype in vivo.In summary, these data provide the first demonstration of ZFN-mediated in vivo genome editing of a safe harbor locus for therapeutic protein production. While we provide here a proof of principle establishing phenotypic correction of hemophilia B, appropriately designed donors could expand this strategy. Most importantly the magnitude of albumin expression (>15 g / day) should enable production of a diverse range of transgenes at therapeutically consequential levels. Disclosures:Anguela:The Children’s Hospital of Philadelphia: Patents & Royalties. Sharma:The Children’s Hospital of Philadelphia: Patents & Royalties. Doyon:Sangamo BioSciences, Inc.: Employment. Wong:Sangamo BioSciences, Inc.: Employment. Paschon:Sangamo BioSciences, Inc.: Employment. Gregory:Sangamo BioSciences, Inc.: Employment. Holmes:Sangamo BioSciences, Inc.: Employment. Rebar:Sangamo BioSciences, Inc.: Employment. High:Shire Pharmaceuticals: Consultancy; Sangamo Biosciences, Inc: Collaborator, Collaborator Other; Novo Nordisk: Visiting Professor, Visiting Professor Other; Genzyme, Inc: Membership on an entity’s Board of Directors or advisory committees; The Children’s Hospital of Philadelphia: Patents & Royalties; Bluebird Bio, Inc: Membership on an entity’s Board of Directors or advisory committees.

Genetic Determinants of Plasma Von Willebrand Factor (VWF) and VWF Propeptide Levels

Abstract 3313Plasma VWF levels vary by approximately five-fold in healthy populations and are influenced by both environmental and inherited factors. Low levels of VWF are associated with bleeding and elevated levels with increased risk for thrombosis. Increased levels of VWF occur with age, may rise acutely due to inflammation or infection, and may serve as a biomarker for endothelial dysfunction and atherosclerosis. Genetic factors are thought to account for 60 – 70% of the variance in VWF antigen levels with ∼30% of this effect due to ABO blood type. VWF multimers are assembled in the Golgi apparatus where the VWF propeptide is cleaved to form mature VWF. Because the half life of plasma VWF propeptide (ppVWF) is ∼5X faster than the mature VWF antigen, the ratio of ppVWF/VWF:Ag in plasma primarily reflects clearance rates of mature VWF while alterations in biosynthesis and/or secretion of VWF affect the level of both ppVWF and VWF:Ag. In order to identify additional quantitative trait loci (QTL) for VWF antigen variation and altered clearance of VWF:Ag, we performed genetic analyses in a healthy young sibling cohort, the Genes and Blood Clotting Study (GABC, n=1,152). The cohort was SNP genotyped with an Illumina Omni-1 array resulting in 763,195 SNPs available for analysis after extensive QC. Plasma VWF antigen (VWF:Ag) and VWF propeptide levels were determined by AlphaLISA (Perkin Elmer, Waltham, MA), using polyclonal anti-human VWF antibodies (DAKO, Glostrup, Denmark) or monoclonal anti-ppVWF antibodies (Blood Center of Wisconsin, Milwaukee, WI). The median levels were 108.1 IU/dL, 99.97 IU/dL and 1.0 for VWF:Ag, ppVWF and ppVWF/VWF:Ag respectively. The estimated heritability (h2) was 64.5%, 55.72%, and 64.26% for VWF:Ag, ppVWF, and ppVWF/VWF:Ag respectively. A genome-wide association study (GWAS) for VWF:Ag in this cohort revealed significant signals at the ABO and VWF loci, consistent with previously published reports. However, GWAS for ppVWF levels demonstrated a signal only at 12p13, overlying the VWF gene itself. The top SNP, rs1800378 (beta 4.297, p-value 1.58E–11), encodes a nonsynonymous substitution (His484Arg) in the VWF propeptide. In contrast, GWAS for ppVWF/VWF:Ag showed a strong signal at 9q34, the ABO locus, (top SNP rs687289, beta −0.2131, p-value 1.88E–62) and no significant signal at 12p13. These results suggest that ABO is the major common determinant of variability in VWF clearance rates and a common SNP, rs1800378, is associated with VWF propeptide levels. We next utilized the sibling structure in this cohort to perform linkage analyses. Linkage analysis for VWF:Ag identified a novel locus at 2p12-2q13 in addition to the expected signal at ABO. The effect size of this chromosome 2 locus on VWF variation (19.2% variance explained) was comparable to the effect of the ABO locus (24.5%). Linkage analysis for ppVWF demonstrated novel loci at 7q21 (LOD score 5.03) and at 11q21 (LOD score 4.12), with no significant signal on chromosome 2. In contrast, linkage analysis for ppVWF/VWF:Ag identified signals at 2p12 (LOD score 3.17), 8p22 (LOD score 3.48) and 11q22 (LOD score 3.41). Taken together, these results identify a number of potential candidate loci for genetic regulation of plasma VWF through alteration of synthesis, storage, secretion or clearance mechanisms. We hypothesize that signals present in linkage but not association are due to VWF regulatory genes with high allelic heterogeneity, harboring many genetic variants that are individually rare, but in aggregate present in a large portion of sibships. Segregation of these variants among sibs could then explain the strong signal by linkage, but lack of signal by association in unrelated individuals. Replication of the strong 2p12-2q13 signal in both VWF:Ag and ppVWF/VWF:Ag linkage studies suggests that the responsible variants at this locus affect VWF levels through altered clearance. The novel QTLs for ppVWF/VWF:Ag levels on chromosome 8p22 and 11q22 are also likely to work through altered clearance mechanisms while the novel signals for ppVWF levels on 7q21 and 11q21, not significant in the VWF:Ag linkage study, may affect efficiency of cleavage or clearance of ppVWF. Identification of the underlying genes at these novel loci and their mechanism of action could lead to improved understanding of the severity, penetrance and treatment for von Willebrand Disease as well as the risk for venous thromboembolic disease associated with elevated VWF. Disclosures:Ginsburg:Shire Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees; Portola Pharmaceuticals: Consultancy; Catalyst Biosciences: Consultancy; Baxter Pharmaceuticals: benefit from payments to Children’s Hosptial, Boston, and the University of Michigan Patents & Royalties; Merck Pharmaceuticals: Consultancy.

In Vivo Model to Evaluate Loss of Liver-Derived Factor IX Expression Caused by AAV Capsid-Specific CD8+ T Cells

Abstract 2046Long-term partial correction of severe hemophilia B following peripheral vein delivery of an AAV8-factor IX vector in human subjects has recently been reported. However, the two patients in the high-dose cohort experienced a rise in liver transaminases and drop in circulating F.IX levels that was halted with steroid treatment. In both the AAV8 and in an earlier AAV2-based trial, a dose of 2×1012 vg/kg seemed above a threshold for the activation of capsid specific memory CD8+ cytotoxic T lymphocytes (CTL). Therefore, reaching a target of > 5% sustained F.IX level (for a change to mild disease) is currently limited by activation of T cell immunity against capsid. New clinical trials are in the pipeline with AAV8 vectors expressing hyperactive F.IX variants that provide therapeutic F.IX expression at lower vector doses, with a goal of avoiding activation of CD8+ T cell memory response. Lack of a preclinical model to study CTL-mediated loss of AAV gene therapy has hampered efforts at clinical development. Neither mice nor non-human primates have recapitulated the human experience, making it difficult to evaluate, prior to clinical trial design, the effect of the serotype, vector dose, and other parameters of the protocol on targeting by capsid-specific T cells. To solve this problem, we have recently developed a murine model, in which male BALB/c RAG −/− mice receive hepatic AAV gene transfer followed by intravenous administration of in vitro expanded strain-matched capsid-specific CD8+ T cells (specific to an MHC I capsid epitope conserved between AAV2 and AAV8 serotypes shared between BALB/c mice and humans expressing the B*0702 molecule). In this model, AAV2-F.IX transduced mice showed a rise in liver enzymes, loss of circulating F.IX, and loss of F.IX expressing hepatocytes, following adoptive transfer of the CTL one day but not 7 or 14 days after gene transfer. CD8+ T cell infiltrates were observed 7 days following adoptive transfer and were absent at 28 days, suggesting a small window for optimal AAV2 capsid antigen presentation in the liver. Additionally, mice were protected from capsid specific CD8+ T cells when treated with the proteasome inhibitor bortezomib, which impairs the generation of peptide epitopes for MHC I antigen presentation. We next tested in our model AAV8 vectors, which in mice show superior tropism for liver. Published pre-clinical data by others suggested lack of capsid-specific CD8+ cell activation with this serotype. While this was not borne out in a clinical trial, the onset of T cell responses and of transaminitis in humans appeared to be delayed for AAV8 vector (8–9 weeks after gene transfer) compared to AAV2 (3–4 weeks). In comparison to AAV2, CD8+ T cell transfer in AAV8 injected mice had a milder impact on circulating F.IX levels (<50% loss of expression as opposed to 4-fold loss with AAV2), and CD8+ T cell infiltrates were largely absent at day 7. In two different experiments, 25–40% of F.IX expressing hepatocytes were lost compared to AAV8-F.IX transduced mice that received no or control CD8+ T cells. However, when the T cells were transferred 7 or 14 days after AAV8 administration, a more robust loss of systemic F.IX expression was observed (3- to 5-fold), with a 45% and 32% reduction in F.IX expressing hepatocytes, respectively (Fig 1 A-C). CD8+ T cell infiltrates were prevalent by day 42 in the livers of these animals. Together, these data suggest that optimal AAV8 capsid presentation in the murine liver occurs between days 28 and 42 following gene transfer. This delay in targeting of AAV8 transduced murine liver is consistent with the delay observed between the AAV2 and AAV8 F.IX clinical trials. This murine model should be useful to (1) evaluate novel AAV serotypes and capsid variants, (2) test the effect of the vector dose, (3) test the effect of pharmacological modulation on capsid presentation and targeting by capsid-specific CTL, and (4) provide guidance for the timing for immune suppression. [Display omitted] Disclosures:High:Amsterdam Molecular Therapeutics: ; Baxter Healthcare: Consultancy; Biogen Idec: Consultancy; bluebird bio, Inc.: Membership on an entity’s Board of Directors or advisory committees; Genzyme, Inc.: Membership on an entity’s Board of Directors or advisory committees; Novo Nordisk: ; Sangamo Biosciences: ; Shire Pharmaceuticals: Consultancy. Herzog:Genzyme Corp.: Royalties, AAV-FIX technology, Royalties, AAV-FIX technology Patents & Royalties.

Discrepancies Between ABO Genotype and ABO Glycan Phenotypes

Abstract 274The ABO(H) carbohydrate blood group system is highly polymorphic in humans, with >200 ABO alleles described to date. The ABO gene encodes the glycosyltransferase, ABO, which has two main isoforms which generate blood group A or blood group B. Blood group O is the result of a non-functional ABO glycosyltransferase. ABO blood group is commonly imputed in genome-wide association studies where ABO is associated with phenotypes such as von Willebrand Factor level or myocardial infarction. We sought to determine the accuracy of a common ABO genotyping algorithm in a repository of 1092 individuals from a healthy sibling cohort study, the Genes and Blood Clotting Cohort (GABC). We utilized three published single nucleotide variants (SNVs) to assign ABO blood group (A2, B, and O) relative to the A1 reference allele: rs8176704 (G/A) to annotate A2, rs8176749 (C/T) to annotate B, and rs687289 (A/G) to annotate O. We detected ABO glycans in red blood cell-rich buffy coat samples using an adaptation of published ABO forensic dried blood spot techniques. Briefly, samples were diluted and applied to a nitrocellulose membrane, blotted with murine monoclonal anti-A (Immucor) or murine monoclonal anti-B (Immucor) antibodies followed by and streptavidin-conjugated donkey anti-mouse IgG HRP secondary (Jackson ImmunoResearch). Blots were developed, imaged using ImageQuant 350 (GE), and scored semi-quantitatively by two blinded independent observers relative to red blood cell-rich buffy coat reference panels from normal blood donors.Comparison of ABO imputed genotype to detected ABO glycans in red blood cell-rich buffy coat identified discrepancies in the predicted major ABO blood group assignment (i.e. blood group O, A, B, or AB) in 4.4% of individuals. Interestingly, A glycan density was generally low in individuals with a discrepant A phenotype, suggesting that these individuals harbor a less robust blood group A enzyme variant. There was no common pattern for genotype-phenotype discrepancies. Multiple types of errors (both presence and absence of ABO glycans) were observed, and divergent patterns of ABO glycans were observed between homozygotes for ABO SNVs, suggesting multiple ABO alleles or other genetic modifiers underlie the discordant calls. Interrogation of the Exome Variant Server (http://evs.gs.washington.edu/EVS/) found one-third of ABO nonsynonymous polymorphisms in the exome data set are novel, indicating a large proportion of the genetic variation at ABO has not been previously described. Furthermore, the majority of nonsynonymous variants in the EVS database for the genes encoding H antigen (the ABO acceptor structure), FUT1 and FUT2, were also novel.In summary, ABO(H) is more variable genetically than previously suspected. A commonly applied ABO SNV genotyping algorithm resulted in 4.4% frequency of major ABO blood group glycan discrepancy as detected in red blood cell-rich buffy coats, likely due in large part to the underlying genetic diversity at ABO. Further work is needed to deeply characterize the genetic diversity at ABO, FUT1, and FUT2 and correlate the spectrum of allelic variants with ABO(H) carbohydrate phenotypes. Such high resolution ABO and H classification would likely advance our understanding of the complex physiologic processes influenced by ABH blood groups, including disorders of hemostasis and thrombosis, vascular disease, infectious disease susceptibility, complications of pregnancy, and allogeneic exposures. Disclosures:Ginsburg:Shire Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees; Portola Pharmaceuticals: Consultancy; Catalyst Biosciences: Consultancy; Baxter Pharmaceuticals: benefit from payments to Children’s Hosptial, Boston, and the University of Michigan Patents & Royalties; Merck Pharmaceuticals: Consultancy.

Stable Factor IX Activity Following AAV-Mediated Gene Transfer in Patients with Severe Hemophilia B

AbstractAbstract 752 Introduction:We are conducting a phase I/II clinical trial of factor IX gene transfer for severe hemophilia B. In the trial we are using a serotype-8 pseudotyped self-complementary adeno-associated virus (scAAV) vector expressing a codon-optimized coagulation factor IX (FIX) transgene (scAAV2/8-LP1-hFIXco). We have previously reported the early safety and efficacy of our novel gene transfer approach in six patients with severe hemophilia B following a single peripheral vein infusion of one of three vector doses (low [2×1011 vector particles (vp)/kilogram weight (kg)], intermediate [6×1011 vp/kg], or high dose [2×1012 vp/kg]) (Nathwani et al, NEJM 365:2357–65, 2011). AAV-mediated expression of FIX at 1–6% of normal was established in all six participants with an initial follow-up of between 6–14 months following gene transfer. We now report longer follow-up of these participants, as well as data from two additional participants recently enrolled at the high dose level. Methods:We have now infused scAAV2/8-LP1-hFIXco in eight subjects with severe hemophilia B (FIX activity, <1% of normal values). Vector was administered without immunosuppressive therapy, and participants have now been followed for 3 months to 2½ years. FIX activity, serum transaminases, vector genomes in secretions/excretions, antibodies to FIX and AAV8, and AAV8 capsid-specific T-cells were monitored during the follow-up. Results:Each of the participants currently has AAV-mediated activity of FIX at 1 to 6% of normal levels. These levels have been stable in each during the follow-up period which is now greater than 1½ years for the first six participants. Five of the eight participants have discontinued FIX prophylaxis and remain free of spontaneous hemorrhage; in the other three, the interval between prophylactic injections has increased. None of the participants in the low or intermediate dose cohorts had evidence of transaminitis; each currently has FIX activity of 1–3% for over 1½ years. Of the four participants who received the high dose of vector, one had a transient, asymptomatic elevation of serum aminotransferase levels, which was associated with the detection of AAV8-capsid-specific T cells in the peripheral blood; two others had a slight increase in liver-enzyme levels, the cause of which was less clear. Each of these three participants received a short course of glucocorticoid therapy, which rapidly normalized their aminotransferase levels and maintained FIX levels in the range of 4 to 6% of normal values. The fourth participant has not had transaminitis three months after vector administration. Conclusions:This represents the first successful, long-term, gene therapy-mediated expression of a therapeutic protein from an AAV vector delivered to human liver. Although immune-mediated clearance of AAV-transduced hepatocytes remains a concern, this process may be controlled with a short course of glucocorticoids without loss of transgene expression. Larger numbers of patients followed for longer periods of time are necessary to fully define the benefits and risks and to optimize dosing. However, this gene therapy approach, even with its risk of mild, transient transaminitis, has the potential to convert the bleeding phenotype of patients with severe hemophilia B into a mild form of the disease or to reverse it entirely for a prolonged period of time following vector administration. (ClinicalTrials.gov number, NCT00979238). Disclosures:Chowdary:Novo Nordisk: Consultancy. High:Amsterdam Molecular Therapeutics: ; Baxter Healthcare: Consultancy; Biogen Idec: Consultancy; bluebird bio, Inc.: Membership on an entity's Board of Directors or advisory committees; Genzyme, Inc.: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: ; Sangamo Biosciences: ; Shire Pharmaceuticals: Consultancy.

Unplanned Hospital Readmissions in IBD Patients: Predictive Factors

Purpose: Hospitalizations for exacerbations of IBD are common. However, it is unknown which factors are associated with unplanned readmissions in IBD patients. The aim of this study was to determine the predictive factors of unplanned readmissions at 3-mos and 1-yr. Methods: We retrospectively reviewed the electronic database of our institution (3 large academic hospitals) to identify consecutive pts admitted between Jan 2009 to Sept 2010 with primary discharge diagnosis of either UC or CD. Index admission was defined as first unplanned admission during this period. Readmission was defined as unplanned admission (due to any cause) occurring within 3 mos and 1 yr from the index admission. To identify factors predictive of readmissions, we compared social, demographic and clinical features at index admission of pts with readmission and those with no readmissions. The following data was extracted: demographics (age, sex, race, insurance), BMI, tobacco use, source of admission (ED, transfer, direct admit), type of IBD, yrs of disease, surgery prior to index admission, surgery during index admission, medications during index admission and at discharge (antibiotics, steroids, mesalamine, immunomodulators, biologics), colonoscopy, use of TPN, ICU stay, number of comorbities (>3 or <3), history of psychiatric illness. The statistical analysis was done by chi square test and Fisher Exact test. p<0.05 was considered significant. Results: A total of 558 pts with IBD accounted for 1056 admissions within this time period. 209 pts had an index admission with a primary discharge diagnosis of either UC or CD. There were 160 unplanned readmissions. The unplanned readmission rates were-18% at 3 mos and 36.4% at 1 yr. 102 of 209 consecutive pts were analyzed. Their demographic information is:mean age 37.6 yrs, 58% females, 68% Whites, 73 had CD, 29 had UC, mean duration of IBD 8.5 yrs, median length of stay 6 days.24 pts were readmitted at least once within 3 mos and 51 were readmitted at least once within 1 yr. Male sex was predictive of 3-mo readmission (p=0.021) but not 1-yr readmission (p=0.071). None of the other demographic, clinical or social factors analyzed were predictive of either 3-mo or 1-yr readmissions. Conclusion: Based on our results we conclude that despite high rates of both 3-mo and 1-yr unplanned readmissions in IBD patients, there were no demographic, clinical or social factors predictive of unplanned readmissions except male sex. Since frequent admissions are currently deemed to be indicators of poor quality of care, future prospective studies on large number of patients are needed to identify why males are more likely to be readmitted within 3 mos and further help identify modifiable factors to prevent readmissions and thereby conserve healthcare costs. Disclosure: Dr. Gary R. Lichtenstein - Consultant: Abbott Corporation, Consultant, Research: Alaven, Research: Bristol-Myers Squibb, Consultant, Research: Centocor Orthobiotech, Consultant: Elan, Consultant, Research: Ferring, Consultant: Hospira, Consultant: Meda Pharmaceuticals, Consultant: Millenium Pharmaceuticals, Consultant: Pfizer Pharmaceuticals, Consultant, Research: Proctor and Gamble, Consultant, Research: Prometheus Laboratories, Inc.,Consultant, Research: Salix Pharmaceuticals, Consultant: Santarus, Consultant: Schering-Plough Corporation, Consultant, Research: Shire Pharmaceuticals, Consultant: Takeda, Consultant, Research: UCB, Consultant, Research: Warner Chilcotte, Consultant: Wyeth.

Unplanned Hospital Readmission Rates and Causes in Patients with Inflammatory Bowel Disease: A Critical Analysis

Purpose: IBD is a chronic inflammatory disease characterized by periods of relapses and remissions. Hospitalizations for exacerbations of IBD are common. Readmission has been deemed a marker of poor quality of care. The aim of this study was to better understand and characterize the rates of unplanned readmissions in IBD patients at 30 days, 90 days, 180 days and 1 yr and to identify the reasons for the unplanned readmissions. Methods: We retrospectively reviewed the electronic database of our institution (3 large urban academic hospitals) to identify consecutive patients admitted between Jan 2009 to Sept 2010 with a primary discharge diagnosis of either UC or CD. Index admission was defined as first unplanned admission with primary discharge diagnosis of either UC or CD during this period. Readmission was defined as unplanned admission (due to any cause) occurring within 30 days, 90 days, 180 days or 1 year from the index admission. Data collected included demographics, type of IBD, length of stay, and primary discharge diagnosis for both index and readmission. Results: A total of 558 pts with IBD accounted for 1,056 admissions to the health system within this time period. Of these a total of 209 pts had an index admission with primary discharge diagnosis of either UC or CD. The demographics of the cohort were-mean age 37.5 yrs, 115 females, 149 whites, 150 had CD and 59 had UC. There were a total of 160 unplanned readmissions during the study period. The unplanned readmission rates were - 8.6% (18/209) at 30 days, 18% (37/209) at 90 days, 30.6% (64/209) at 180 days and 36.4% at 1 year. The mean length of stay (LOS) of all index admissions was 7.5 days and mean LOS of all readmissions was 7 days. Among the 76 pts readmitted at least once at 1 year, 38 were females, 47 were whites and 56 pts had CD. At 1 year, 33 pts were readmitted at least twice and 17 were readmitted more than 2 times. Eighty-five of the 160 readmissions had a primary discharge diagnosis of IBD (either CD or UC), while the rest of the 75 had other diagnoses at discharge. Infection was the most common other discharge diagnosis of readmissions (28/160), followed by postoperative complications (10/160), abdominal pain (5/160), bowel obstruction (4/160), pancreatitis (4/160), cholecystitis (4/160). Conclusion: The unplanned readmission rate in IBD pts is high, with more than one third of pts being readmitted at least once within 1 yr of discharge. The most common reasons for readmissions were IBD exacerbations and infections. Future large studies are needed to define national rates of readmission and risk factors for readmissions in IBD pts. This has the potential to better understand and possibly alter the standard of care. Disclosure: Dr. Gary R. Lichtenstein - Consultant: Abbott Corporation, Consultant, Research: Alaven, Research: Bristol-Myers Squibb, Consultant, Research: Centocor Orthobiotech, Consultant: Elan, Consultant, Research: Ferring, Consultant: Hospira, Consultant: Meda Pharmaceuticals, Consultant: Millenium Pharmaceuticals, Consultant: Pfizer Pharmaceuticals, Consultant, Research: Proctor and Gamble, Consultant, Research: Prometheus Laboratories, Inc., Consultant, Research: Salix Pharmaceuticals, Consultant: Santarus, Consultant: Schering-Plough Corporation, Consultant, Research: Shire Pharmaceuticals, Consultant: Takeda, Consultant, Research: UCB, Consultant, Research: Warner Chilcotte, Consultant: Wyeth.

The Effect of Ulcerative Colitis (UC) Remission Status After Induction With MMX® Mesalamine on Long-Term Maintenance Therapy Outcomes (MOMENTUM Study): Induction Phase Results Presidential Poster

Purpose: 5-aminosalicylic acid therapy is the mainstay of treatment for mildly-to-moderately active UC. However, data are lacking for long-term outcomes with maintenance therapy and transitions from induction phase to maintenance phase. Methods: This is an open-label, prospective study evaluating 12-month results in UC patients who achieved complete (clinical and endoscopic) or partial remission after 8 weeks of induction therapy with MMX® mesalamine (NCT01124149). Adults with active mild-to-moderate UC (acute flare or newly diagnosed with modified UC Disease Activity Index [UC-DAI] total score 4-10, endoscopy score ≥1, and Physician's Global Assessment ≤2) received 8 weeks of MMX mesalamine 4.8 g/d QD during acute treatment. Those patients who achieved complete remission (modified UC-DAI ≤1; rectal bleeding and stool frequency scores of 0; ≥1-point reduction in endoscopy score) or partial remission (modified UC-DAI ≤3; combined stool frequency and rectal bleeding score ≤1; not in complete remission) at Week 8 continue to receive maintenance MMX mesalamine 2.4 g/d QD for 12 months (ongoing portion of the study). The primary endpoint is the percentage of patients in complete remission after 12 months of maintenance. Here we report results from the 8-week induction phase. Results: This pre-determined interim data cut included 672 patients, of whom 666 are included in the efficacy/safety population. The induction phase was completed by 610 patients and 467 entered the maintenance phase; 664 (99.7%) had histology compatible with UC. At Week 3, symptom improvement (≥1-point reduction from baseline) was observed in 43.1%, 38.9%, and 26.3% of patients for rectal bleeding, stool frequency, or both, respectively; at Week 8, these proportions increased to 63.4%, 62.2%, and 48.0%, respectively. Complete or partial remission was achieved by 27.9% and 42.2% of patients at Week 8, and complete mucosal healing (endoscopic subscore of 0) was achieved by 33.3%. Mean ± SD UC-DAI score decreased by 4.3 ± 2.24 points after the 8-week induction phase. The most common treatment-emergent adverse events during the induction phase were inefficacy of drug (6.5%), headache (1.8%), and fever (1.8%). Conclusion: This is the largest study of MMX mesalamine for mild to moderate UC and the 8 week induction results demonstrated a majority with partial or complete remission, and 33% with normal endoscopy (subscore of 0). There were no new safety signals. Unique to this study design is the enrollment of all patients during a flare with follow-through to maintenance phase (to be reported later). Disclosure: David T. Rubin - Financial Support for Research: Abbott, Elan, Warner Chilcott, Prometheus, Shire Development LLC; Lecture Fee(s): Merck; Consultancy: Abbott, Janssen, UCB, Elan, Shire, Exagen, Prometheus, Takeda. Geert D'Haens - Financial Support for Research: Abbott Laboratories, Jansen Biologics, Given Imaging, MSD, DrFalk Pharma, Photopill, Shire Development LLC; Lecture Fee(s): Abbott Laboratories, Tillotts, Tramedico, Ferring, MSD, UCB, Norgine, Shire; Consultancy: Abbott Laboratories, Actogenix, Centocor, Cosmo, Engene, Ferring Pharmaceuticals, GlaxoSmithKline, Jansen Biologics, Millenium Pharmaceuticals, MSD, Novonordisk, PDL Biopharma, Pfizer, SetPoint, Shire, Takeda, Teva, UCB Susi Inglis. Elizabeth Magee - Employees: Shire Pharmaceutical Development Ltd. Dory Solomon - Employee: Shire Development LLC. This research was supported by an industry grant. This study was funded by Shire Development LLC, Wayne, PA, USA.

Taking Note of Over-the-Counter Remedies for Adolescents With Cannabis Dependence

Taking Note of Over-the-Counter Remedies for Adolescents With Cannabis Dependence

Update on the management of ulcerative colitis: treatment and maintenance approaches focused on MMX&amp;reg; mesalamine

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon that typically manifests as diarrhea, abdominal pain, and bloody stool. Complications, such as colorectal cancer and extraintestinal manifestations, may also develop. The goals of management are to induce and maintain clinical remission and to screen for complications of this disease. Mesalamine is a 5-aminosalicylic acid compound that is the first-line therapy to induce and maintain clinical remission in patients with mild-to-moderate UC. For patients who are refractory to mesalamine or have more severe disease, steroids, azathioprine/mercaptopurine, cyclosporine, or infliximab may be used, induce and/or maintain remission. The various formulations of mesalamine available are primarily differentiated by the methods of delivery of the active compound of the drug to the colon. Mesalamine with Multi-Matrix System® (MMX) technology (Cosmo SpA, Milan, Italy) is an oral (1.2 g), once-daily tablet formulation of mesalamine used for the treatment of UC (Lialda® or Mezavant®, Shire Pharmaceuticals Inc, Wayne, PA). In clinical studies, MMX mesalamine (taken as a once-daily dose of 2.4 or 4.8 g) effectively induced and maintained clinical remission in patients with active mild-to-moderate UC. The overall safety profile of MMX mesalamine is similar to other oral mesalamine formulations. The use of such once-daily formulations has led to intense interest in whether simplified pill regimens can improve patient adherence to mesalamine therapy.

PWE-085 Age-related changes in diverticular disease admissions in Scottish hospitals 2000–2010

IntroductionRecent studies suggest that acute admissions for diverticular disease (DD) are increasing in younger age groups. Verification of this trend in Scotland and examination of treatment patterns by age will...

PWE-045 Gastroparesis—classifying severity and predicting response

IntroductionIdiopathic gastroparesis is a chronic disorder of the stomach characterised by delayed gastric emptying in the absence of recognisable causative pathology such as mechanical obstruction or diabetes. Presenting symptoms include...

Once-Daily MMX® Mesalamine for Endoscopic Maintenance of Remission of Ulcerative Colitis

Treatment with mesalamine to maintain endoscopic remission (mucosal healing) of ulcerative colitis (UC) has been shown to reduce the risk of relapse and is the recommended first-line maintenance therapy. To improve treatment adherence, a mesalamine formulation that can be administered once-daily, MMX(®) mesalamine (Lialda; Shire Pharmaceuticals LLC, Wayne, PA), was developed. This study was conducted to determine the efficacy and safety of once-daily MMX mesalamine compared with twice-daily delayed-release mesalamine (Asacol; Warner Chilcott, Dublin, Ireland) for maintaining endoscopic remission in patients with UC. A multicenter, randomized, double-blind, 6-month, active-control trial was conducted to assess the non-inferiority of once-daily MMX mesalamine 2.4 g/day compared with twice-daily delayed-release mesalamine at a total daily dose of 1.6 g/day in patients with UC in endoscopic remission. The primary end point was maintenance of endoscopic remission at month 6 in the per-protocol (PP) population. Overall, 826 patients were randomized and dosed. The primary objective (non-inferiority) was met. At month 6, 83.7 and 77.8% of patients receiving MMX mesalamine in the PP and intent-to-treat (ITT) populations, respectively, had maintained endoscopic remission compared with 81.5% (PP) and 76.9% (ITT) of patients receiving delayed-release mesalamine (95% confidence interval for difference: -3.9%, 8.1% (PP); -5.0%, 6.9% (ITT)). Time to relapse was not significantly different between the two treatment groups (log-rank test, P=0.5116 (PP); P=0.5455 (ITT)). The proportion of patients with adverse events was 37.1 and 36.0% in patients receiving MMX mesalamine and delayed-release mesalamine, respectively. Once-daily dosing of MMX mesalamine 2.4 g/day was shown to be well tolerated and non-inferior to twice-daily dosing with delayed-release mesalamine 1.6 g/day for maintenance of endoscopic remission in patients with UC.