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As life expectancy in individuals with congenital hemophilia approaches that of the general population, we hypothesize that public health risks, including overweight and obesity, also follow a similar trend.A search of the literature included terms relating to overweight, sequelae of being overweight, and hemophilia. Studies were included if they reported the frequency or clinical significance of known complications of overweight and obesity, including musculoskeletal disease, aerobic capacity, cardiovascular disease, diabetes, hyperlipidemia, decreased quality of life, and change in pharmacokinetics of infused clotting factor in hemophilia. Recommendations from medical organizations were searched for preventive and management strategies applicable to this population.Overweight and obesity are now more prevalent in the hemophilia population than previous generations, with rates similar to and, in certain subsets even higher, than that of the general population. Increased BMI leads to limitations in joint range of motion in the general population and even more so in persons with hemophilia.Overweight and obesity in hemophilia are an increasing problem. Simple steps can be taken to encourage patients to decrease caloric intake and increase physical activity. Prevention and management of overweight, obesity, and their sequelae must be addressed in clinical practice in order to maximize the overall health of the hemophilia population.

Thrombocytopenia and anemia are the two most common hematologic conditions seen in the pediatric emergency department. Providers of emergency pediatric care must have an understanding of the causes and therapies for the various conditions that result from thrombocytopenia and anemia. This article reviews the common causes of isolated thrombocytopenia and anemia in infancy and childhood.

Type 3 von Willebrand disease (VWD) is a rare bleeding disorder with markedly decreased or absent von Willebrand factor (VWF) protein, accompanied by a parallel decrease in VWF function and factor VIII (FVIII) activity. The goal of this study was to describe the population of patients enrolled in the USA Centers for Disease Control Universal Data Collection (UDC) study with type 3 VWD, defined as a VWF:Ag of

BDDrFVIII is a B-domain deleted recombinant factor VIII (rFVIII) product for haemophilia A. Manufacture uniquely includes purification chromatography by synthetic-affinity ligand rather than murine-based monoclonal antibody, as well as an albumin-free cell culture process. BDDrFVIII was studied in 204 patients, including 62 subjects

Osteoporosis in adult males is an under-recognized problem. Patients with haemophilia have several predisposing factors for developing decreased bone mineral density (BMD) including prolonged periods of immobility, reduced weight bearing and co-morbidities associated with bone loss. To establish prevalence and risk factors associated with decreased BMD in patients with haemophilia. Adults with moderate or severe haemophilia A or B underwent dual-energy X-ray absorptiometry (DXA). BMD was correlated to laboratory values, joint mobility measurements and physical activity questionnaires. Thirty patients completed evaluations. The median age was 41.5 years (range 18-61). Median lowest T-score by DXA was -1.7 (range: -5.8 to +0.6), with the femoral neck being the site of the lowest T-scores. Based on World Health Organization criteria, 70% of patients had decreased BMD. Twenty-seven per cent of the participants (n = 8) had osteoporosis and 43% (n = 13) had osteopenia. Variables associated with increased bone loss included lower serum 25-hydroxyvitamin D levels (P = 0.03), lower body mass index (P = 0.047), lower activity scores (P = 0.02), decreased joint range of motion (P = 0.046), HIV (P = 0.03), HCV (P = 0.02), history of inhibitor (P = 0.01) and age (P = 0.03). Adults with haemophilia are at increased risk for developing osteoporosis. A history of HCV and HIV infections, decreased joint range-of-motion, decreased activity levels, history of an inhibitor and low body weight predict bone loss and suggest a population to target for screening. A high prevalence of vitamin D insufficiency was observed. Future studies should investigate interventions, including vitamin D supplementation, to prevent bone loss and fractures for this at-risk population.

Immune tolerance induction (ITI) is the most common approach used to eliminate inhibitors that develop in hemophilia A patients following exposure to factor (F) VIII therapy. ITI generally requires ongoing long-term exposure to factor replacement therapy using FVIII or FIX. Although plasma-derived products have been the mainstay of ITI therapy in the past, recent data indicate that high-purity (i.e., recombinant) rFVIII products are probably equally effective. For patients who have failed to respond to ITI treatment, or for those at high risk to do so, immunosuppressive therapy may be helpful. Rituximab has demonstrated a possible clinical benefit in hemophilic and nonhemophilic patients developing FVIII inhibitors, but benefit in those with congenital hemophilia and inhibitors has not been established and more extensive clinical studies are needed. More recently, research on reducing the incidence of inhibitor development has included mutagenizing key epitopes of the FVIII antigenic molecule to alter its immunogenicity without affecting biological activity, as well as induction of tolerance by gene therapy with immunodominant A2 and C2 domains of FVIII presented by B cells as immunoglobulin fusion proteins.

Introduction & Objectives: Given the longer life expectancy for people with hemophilia today, an increase in diseases such as obesity (defined as body mass index [BMI] ≥30 kg/m2) (Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults – The Evidence Report. National Institutes of Health. Obes Res 1998;6 Suppl 2:51S–209S), diabetes, and cardiovascular disease poses an increasing challenge to their care. Obesity may be of special relevance in hemophilia, both in terms of dosing as well as in impact on general health, yet little is known and published on this topic. Factor (F) VIII dosing is based on body weight (BW) and it has been shown that in vivo recovery increases with BMI due to a decrease in volume of distribution (Blanchette VS, et al. J Thromb Haemost 2008;6:1319–1326). Consequently, dosing based on ideal BW instead of actual BW has been suggested (Hanley MJ, et al. Clin Pharmacokinet 2010;49:71–87; Henrard S, et al. Haematologica 2013;98:1481–1486). In addition to negative effects on general health, obesity can also affect joint health. Intuitively, an increased BMI can have a deleterious effect on joints and aggravate arthropathy, which could theoretically be reflected in higher annualized bleeding rates (ABRs). However, published data are scarce, and conflicting or inconclusive. We performed a post hoc analysis of prevalence, dosing, and outcomes recorded in obese patients in clinical trials of turoctocog alfa (NovoEight®), a new B-domain–truncated recombinant FVIII product. Materials & Methods: Previously treated patients with severe hemophilia A without FVIII inhibitors participated in the phase 3a guardian™1 trial (Lentz SR, et al. Haemophilia 2013;19:691–697), and most continued in the extension trial, guardian™2, which is currently ongoing. Adult patients with BW >120 kg were not eligible (in guardian™1), but there were otherwise no restrictions regarding BMI. Prophylactic treatment with turoctocog alfa was given every other day or 3 times weekly. All patients started with an actual body–weight based dose of 20 IU/kg, which could be increased at the investigator’s discretion. Dosing based on ideal BW was not used. Patients who participated in either guardian™1 or guardian™2 and who were ≥18 years old at entry to the latest of the 2 studies (i.e., at entry to guardian™2 unless the patient only participated in guardian™1) were included in this analysis. Data were included up to 30 June 2013. Results: Mean age at the time of enrollment in the guardian™2 trial was 32 years for obese and 31 years for non-obese patients. Mean duration of observation was 2.23 years per patient for obese and 2.16 years for non-obese patients. Twenty-two of 137 patients (16.1%) had a BMI of ≥30 kg/m2 at some point during the observation period. Of these, 13 patients were from the US (comprising 46% of the total adult US patient cohort), which is approximately double the percentage reported in data compiled by the Centers for Disease Control and Prevention in 2005 (Report on the Universal Data Collection Program. 2005;7[1]:30–39). Mean turoctocog alfa dose/kg BW used for prevention per administration was 25.9 IU/kg in obese and 28.3 IU/kg in non-obese patients (p=0.20). The mean annualized consumption of turoctocog alfa was 4154 IU/kg/year in obese and 4393 IU/kg/year in non-obese patients (p=0.39). The estimated mean ABR was 3.28 and 3.85 bleeds/patient/year in the obese and non-obese patients, respectively (p=0.57). Conclusions: In the guardian™ clinical trial population examined in this analysis, 16.1% of the total and 46% of US patients were obese, thus highlighting the importance of this co-morbidity in modern hemophilia care. Dosing was similar for both non-obese and obese patients, which was expected given the setting of relatively rigid (and body-weight based) dosing in these trials. Importantly, no statistically significant difference in ABR between obese and non-obese patients was found in the guardian™ trials. These findings could be related to the small subgroup population size and exclusion of patients with BW >120 kg. Given the high prevalence of obesity and its potential effect on pharmacokinetic parameters, joint health, and overall health status, more research is needed on this topic. Disclosures Recht: Novo Nordisk: Research Funding. Lentz:Novo Nordisk: Consultancy; Novo Nordisk: Research Funding. Matytsina:Novo Nordisk A/S: Employment. Landorph:Novo Nordisk A/S: Employment. Saugstrup:Novo Nordisk A/S: Employment.

INTRODUCTION: Patients with GT, a rare congenital platelet disorder due to ­an abnormality of glycoprotein IIb/IIIa expression, experience frequent and severe mucocutaneous bleeding. Little is known about how and where US GT patients receive care, or about its impact on patients and their families. This first survey is aimed to capture their experience and perspectives. METHODS: A web-based structured quantitative survey (~45 min) was distributed in 1Q 2014 to adult patients (≥18 years old) and parents of affected children ( RESULTS: Respondents included 14 adults with GT (mean age 39.3 years, range 19-55, 86% female) and 9 parents (mean age 42.1 years, range 29-54, 89% female) of children with GT (mean age 9.3 years, range 1-17, 33% female). Respondents had post-high school education (92%), were employed (65%) or students (13%), and had health insurance (87%). Age at diagnosis was 6.2 (2) years and was higher for adults (9.3 [5]) than children (1.7 [0.5]). Frequent presenting symptoms were skin bleeding/bruising (83%), gum/mouth/tooth bleeding (46%), epistaxis (58%), and abnormal menstrual cycles (21%). Time from first bleed to hematology referral was 23 (5) months (38% Treatment team included hemophilia treatment center (HTC)-based hematologist (50%), non-HTC hematologist/oncologist (41%), pediatrician (38%), OB/GYN (33%), internist (25%) and ENT (17%). Most bleeds required none (59%) or local (25%) treatment. Nearly all patients (83%) received a transfusion at some point (67% blood; 75% platelets); 70% received it at a hospital near home. Most patients (78%) reported platelet transfusions controlled bleeds in the past; 56% reported platelet transfusions controlled bleeds currently. Nearly half (44%) were told they were “refractory”; 50% were told they were tested for antibodies and of those tested, 56% were told they had “antibodies” to platelets. Median perceived disease control (0-10 scale, 10=very well controlled) was 6.83 (adults 6.33, parents 7.67). Most adults (93%) and majority of children (67%) found GT impacted school, with issues including absence, bullying, and falling behind. Both adults (87%) and children (78%) reported GT impacted participation in activities/sports in childhood due to restrictions, triggered bleeds, and embarrassment. Half of the adult patients reported still being impacted with activities. GT also impacted relationships with friends and peers for children (56%) and adults (40% during childhood, 20% currently); issues included being teased, marginalized, and called “abused” due to constant bruising. Parents reported having a child with GT impacted their (44%) or their spouses (22%) employment, including frequent absences resulting in reprimands and terminations; 27% of adults reported impacts on employment including fatigue, bleeds, and lost work days. Most respondents were very/quite satisfied with support of spouses (79%), family (76%), and friends (83%), but less so with support of schools (56%) and employers (50%). Hematologists (91%) and websites (91%) were the most common sources of information. Most useful (1-5, 5=most useful) sources of information were other patients (5), other caregivers (5), nurses (4.2), hematologists (4.1), websites (4.1) and national organizations (3.6). Many noted major consumer organizations related to the bleeding disorders population have little or no information on GT. Looking to the future, adults and parents desired increased education of the medical community, more immediate treatment in the ER, focus on pre-activity treatment to prevent bleeding, and improved coordination of care. CONCLUSION: While limited in scope, these data provide directional insight into the burden of living with or caring for one or more children with GT. In particular, the psychosocial impact of frequent mucocutaneous bleeding in childhood deserves further study. These results highlight the need for better resources for families and healthcare providers. Disclosures Cooper: Novo Nordisk: Employment.

Introduction: The laboratory work-up of von Willebrand Disease includes measurement of Von Willebrand Factor (VWF) antigen (VWF:Ag), VWF activity (ristocetin cofactor activity, VWF:RCo), and factor VIII Activity (FVIII), where VWF:Ag and VWF:RCo below 30-40% in the appropriate clinical setting are consistent with VWD. Accurate diagnosis of type 2 VWD, marked by a qualitative deficiency in the VWF protein, is imperative for appropriate therapeutic interventions. Exon 28 sequencing is frequently pursued to confirm the diagnosis of type 2 VWD. An exon 28 polymorphism, D1472H, results in impaired VWF binding to ristocetin, affecting the clinical assay of VWF activity as measured by ristocetin cofactor activity, but not resulting in impaired VWF function in vivo. This polymorphism is common in the healthy population and does not result in a hemorrhagic phenotype. We reviewed our institution’s experience with exon 28 sequencing with regard to the D1472H polymorphism, laboratory phenotype, and ultimate clinical diagnosis. Methods: Following IRB approval, patients who underwent exon 28 sequencing during evaluation for clinically significant bleeding between the years of 2003-2013 were identified. A retrospective chart review was conducted: patient demographics, VWF:RCo (lowest recorded), VWF:Ag (obtained on same day as the lowest VWF:RCo), and clinical diagnosis were collected. Descriptive statistics were employed to analyze the data. Results: Seventy-three patients underwent exon 28 sequencing during their work up for symptomatic bleeding between 2003-2013. The median age at testing was 7 years (10 months – 56 years), 41% were females. Of the 73 patients tested, D1472H polymorphism results for 65 patients were available for review. Fourteen patients (21.5%) were found to be heterozygous for the D1472H polymorphism. No patients were found to be homozygous. There was no difference between the mean VWF:RCo/VWF:Ag ratio for the D1472H heterozygous group (64% [47-81%]) and the group without the polymorphism (64% [48-80%]). VWF:RCo was lower in the heterozygotes with type 1 VWD (23.5% [14.5%-32.5%]) than in the group without the polymorphism (31% [18.5%-43.5]) (Table 1). In the group heterozygous for the D1472H polymorphism, 5/14 were diagnosed with type 1 VWD (Table 2). Two were diagnosed with type 2M VWD. One patient was diagnosed with type 1 VWD and mild hemophilia, 1 had type 1 VWD and Factor XI deficiency, 1 had type 2B VWD, 1 had chronic thrombocytopenia. Three patients did not have bleeding disorders. Conclusion: At our institution, heterozygosity for the exon 28 D1472H polymorphism was not associated with decreased VWF:RCo or VWF:RCo/VWF:Ag ratios as compared to patients without this polymorphism in all patients tested. For patients diagnosed with type 1 VWD, the VWF:RCo was lower in the group heterozygous for the D1472H mutation. These patients had sub-normal levels of VWF:Ag and VWF:RCo in the setting of clinically significant bleeding. Thus, the provisional diagnosis of VWD was appropriate despite the potential effect of the polymorphism on the VWF:RCo. These results are inconsistent with previously reported studies where presence of the D1472 polymorphism resulted in lower VWF:RCo/VWF:Ag ratios and inaccurate diagnosis of VWD. This study highlights the challenges associated with the laboratory diagnosis of VWD and the importance of continued research into the development of reliable VWD testing that more closely mimics the protein’s in vivoactivity. Abstract 2849. Table 1.VWF Assay Results for patients with and without the D1472 polymorphismD1472H+ all comersD1472H - all comersD1472H + no VWDD1472H + type 1 VWDD1472H - no VWDD1472H - type 1 VWDNumber of patients1451371420VWF Ag52%54%90%38%117%47%VWF:RCo37%37%72%23%100%31%VWF:RCo/VWF:Ag0.640.640.80.60.850.65Abstract 2849. Table 2.Patients with D1472H + and type 1 VWDPatient No.Age at testing (years)SexVWF:AgVWF:RCoVWF:RCo/VWF:AgDiagnosis118M47%27%0.57type 1 VWD23M23%14%0.61Type 1 VWD339F23%16%0.70type 1 VWD416F25%13%0.52type 1 VWD56M57%31%0.54type 1 VWD656M40%27%0.68type 1 VWD, factor XI deficiency74M53%37%0.70type 1 VWD, mild hem A Disclosures No relevant conflicts of interest to declare.

BACKGROUND: Bone disease is increasingly being clinically recognized in hemophilia. We previously demonstrated bone disease in factor VIII (FVIII)-deficient mice at peak bone mass that was independent of activity, hemarthroses, and weight compared to wild-type littermates. These findings are consistent with the hypothesis that FVIII-deficiency directly impacts skeletal health. However, the impact of FVIII-deficiency on skeletal health at different stages of growth and aging remains unknown. Addressing this issue is critical for understanding the potential underlying mechanisms as well developing therapeutic interventions to ameliorate bone disease in hemophilia. METHODS: The skeletal health of FVIII-deficient and wild-type littermate controls were characterized during growth (10 weeks of age), peak bone mass (20 weeks), and during aging (40 weeks). Characterization included micro computerized tomography (CT) imaging, bone mineral density, biomechanical testing, histomorphometry (quantitative histology), gene expression using reverse transcription polymerase chain reaction (RT-PCR), and bone biomarker evaluation. RESULTS: Femoral bone mineral density in FVIII-deficient mice is decreased compared to wild-type littermate controls with increasing statistical significance with age; p = 0.108 at 10 weeks (12 FVIII-deficient and 15 wild-type mice), p = 0.064 at 20 weeks (19 FVIII-deficient and 22 wild-type mice) and p= 0.017 at 40 weeks (18 FVIII-deficient and 23 wild-type mice) of age. Cortical bone (outer hard bone) thickness differences decrease with age, with FVIII-deficient mice having statistically thinner cortices at 10 weeks (p = 0.0004) compared to 20 (p = 0.008) and 40 weeks (p = 0.079). Trabecular bone (softer inner bone), measured by trabecular number, decreased in FVIII-deficient mice, has a similar trend: 10 weeks (p = 0.035), 20 weeks (p = 0.048), and 40 weeks (p = 0.643). Histomorphometry also shows an age-dependent pattern. At 10 weeks in the FVIII-deficient mice there is higher osteoclast (cells that break down bone) (p = 0.0010) and no change in osteoblast (cells that build bone) numbers; at 20 weeks there is higher osteoclast (p = 0.0011) and lower osteoblast (p = 0.027) numbers; while at 40 weeks there is no difference in osteoclast and lower osteoblast (p = 0.0017) numbers. Dynamic histomorphometry demonstrates lower bone formation rate at 40 weeks (p = 0.002) but no difference at 20 weeks. Biomechanical strength, as measured by ultimate force, is decreased in FVIII-deficient mice at 20 weeks (p = 0.017) and 40 weeks (p= 0.023). 10 week bones were not evaluated for biomechanical strength due to small size. No statistical difference in CTX-1 (biomarker for bone resorption) or osteocalcin (biomarker for bone formation) is observed at any age group. Levels of gene expression using RT-PCR was characterized from the bone marrow cells in the 20 week cohorts evaluating genes related to bone metabolism. Normalized to beta-actin and glyceraldehyde 3-phosphate dehydrogenase, differential gene expression is not seen in osteocalcin, tumor necrosis factor-alpha, receptor activator of nuclear factor-kappa B (RANK), RANK ligand, interferon-beta or tartrate-resistant acid phosphatase. There is lower FBJ osteosarcoma oncogene (c-fos) gene expression (p < 0.01), a transcriptional regulator of osteoclast formation, in the bone marrow from FVIII-deficient mice. There is also a trend for lower osteoprotegerin gene expression (p < 0.10). CONCLUSIONS: Evidence for bone disease is present in growing, mature and aging bones in FVIII-deficient mice compared to littermate controls but the form of bone disease differs with age. Differences in imaging parameters are most pronounced at 10 weeks while BMD is most pronounced in bones of older mice. Furthermore, FVIII-deficient mice have an age-dependent pattern of osteoblast and osteoclast numbers with a relative increase in osteoclasts during growth and relative decrease in osteoblasts with aging. Even with these changes, the decreases in biomechanical strength, measured against aged-matched wild-type controls, are similar at both 20 and 40 weeks. The observed bone pathology is not associated with global changes in biomarkers of bone formation or bone resorption at any age. These results suggest that FVIII-associated bone disease is a complex age-dependent process that begins during development and continues throughout life. Disclosures Taylor: Baxter BioScience: Research Funding; Novo Nordisk: Research Funding.

Jennifer Maahs,1 Jennifer Donkin,2 Michael Recht,3 David L Cooper4 1Indiana Hemophilia and Thrombosis Center, Indianapolis, IN, 2Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, CA, 3Oregon Hemophilia Center, Oregon Health and Science University, Portland, OR, 4Novo Nordisk, Princeton, NJ, USA Abstract: DOSE (Dosing Observational Study in Hemophilia) was a prospective, observational diary study designed to evaluate the use of bypassing agents in patients prescribed recombinant activated factor VII (rFVIIa) as first-line treatment in the home setting. Patients with congenital hemophilia with inhibitors and caregivers participated, and as part of the study, the time spent preparing and administering product was recorded for bypassing agent (BPA) infusions. The aim of this manuscript is to present the results of the analysis of the time spent preparing and administering a single dose of either rFVIIa or plasma-derived activated prothrombin complex concentrate (pd-aPCC). Diaries were completed for 18 adult patients and 19 caregivers of 21 children with 176 BPA-treated bleeding episodes and 1,350 BPA infusions (1,270 rFVIIa, 80 pd-aPCC). The median preparation and administration times were 5.0 minutes and 5.0 minutes for rFVIIa and 29.0 minutes and 24.5 minutes for pd-aPCC, respectively. Preparation and administration times were significantly shorter with rFVIIa than pd-aPCC (P

Drug-induced immune hemolytic anemia (DIIHA) is an uncommon side effect of pharmacologic intervention. A rare mediator of DIIHA, carboplatin is an agent used to treat many pediatric cancers. We describe here, the first case of fatal carboplatin induced DIIHA in a pediatric patient and a brief review of the literature. Our patient developed acute onset of multi-organ failure with evidence of complement activation, secondary to a drug induced red cell antibody. Early recognition of the systemic insult associated with carboplatin induced hemolytic anemia may allow for future affected patients to receive plasmapheresis, a potentially effective therapy.

The Joint Outcome Study (JOS) was a randomized controlled clinical trial in boys with severe factor VIII deficiency comparing prophylaxis consisting of 25 IU/kg factor VIII every other day begun prior to age 30 months with an enhanced episodic regimen given only in response to bleeding. At JOS exit at age 6 years, joint outcome by sensitive magnetic resonance image (MRI) and joint physical examination (PE) of 6 index joints (both ankles, knees and elbows) determined superiority of prophylaxis over episodic therapy (p < 0.05). At JOS end, all parents were informed of the study results and boys in the episodic arm were counseled to initiate prophylaxis therapy; all but 1 JOS participant on episodic therapy switched to prophylaxis. The JOS Continuation Study is being performed to determine the results of early prophylaxis on joint development until the age of 18 years and to determine the impact of delaying prophylaxis initiation until age 6 years. All boys in the original JOS were eligible to enroll in the continuation study. Study data collected includes cumulative number of index joint and total hemorrhages, joint PE score of 6 index joints using the Colorado Pediatric Joint Assessment Scale as previously described (Haemophilia 6:649) and MRI soft tissue, osteochondral and total scores of 6 index joints using the expanded MRI 45 Scale as recently presented (ISTH OP Mon 7/1/13, 9 am). Additional data are collected on prophylaxis adherence, activities, surgeries, quality of life and replacement factor utilization. To date, results of 26 (40%) of the original 65 boys (16 on early and 10 on delayed prophylaxis) including 156 index joints are available for analysis. Results, expressed as a cumulative score for all 6 index joints, are shown in Table 1. While still enrolling, the JOS Continuation Study is documenting an ongoing disparity in joint outcome in children with initiation of prophylaxis delayed until age 6 years, compared with prophylaxis started before 30 months of age. Following delayed initiation of prophylaxis, adolescents manifest increased numbers of hemarthroses and increased MRI damage particularly affecting bone and cartilage. Joint PE is less sensitive than MRI in determination of joint outcome in hemophilia. Disclosures: Manco-Johnson: Bayer HealthCare: Membership on an entity’s Board of Directors or advisory committees, Research Funding; CSL Behring: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees; NovoNordisk: Membership on an entity’s Board of Directors or advisory committees; Eisai: Research Funding. Manco-Johnson:Bayer HealthCare: Research Funding. Lane:Bayer HealthCare: Honoraria; Baxter BioScience: Paid travel to attend a meeting, Paid travel to attend a meeting Other. Shapiro:Bayer HealthCare: Research Funding; Baxter BioScience: Research Funding; Biogen Idec: Research Funding; Cangene: Research Funding. Valentino:Baxter BioScience: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Bayer HealthCare: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; CSL Behring: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; GTC Biotherapeutics: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Inspiration Bioscience: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; NovoNordisk: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding. Brown:Baxter BioScience: Research Funding; Biogen Idec: Research Funding; CSL Behring: Research Funding.

Background The hemostatic system is developmentally regulated, resulting in qualitative and quantitative differences in the mediators of primary and secondary hemostasis as well as fibrinolysis. Age-dependent values of pro- and anti-coagulant proteins have been determined. However, the task of defining age-dependent normal values of neonatal platelet function has been met with challenges owing to difficulties in obtaining adequate blood volumes for functional assays and inconsistent results amongst varying testing methods. In order to overcome many of these challenges, cord blood is often used as a source of neonatal platelets. Platelet aggregometry comparing adult and cord blood derived platelets has demonstrated a near lack of platelet response to epinephrine, collagen, and thromboxane in cord blood samples. In contrast, other studies of platelet function, such as flow cytometry, have failed to demonstrate this phenotypic difference. Assays of primary hemostasis reveal that neonatal blood mediates primary hemostasis as effectively as adult blood. In order to overcome the challenges associated with studying neonatal platelets, we have developed a novel platelet function assay employing small volumes of blood obtained directly from the neonate in order to assess platelet adhesion, activation, and aggregation simultaneously. Methods Eight-well slide chambers were coated with either fibrillar collagen or fibrinogen and allowed to adsorb at room temperature for one hour. Blood was obtained from healthy adult controls via venipuncture and neonatal samples via heelstick into sodium citrate. The blood was separated into two 200 µl aliquots, and TRAP (Thrombin Receptor Activating Peptide: 30 mM) was added to one aliquot. 100 µl of plain whole blood was added to both a collagen and a fibrinogen coated well and 100 µ of whole blood plus TRAP was added to a fibrinogen coated well. The samples were then incubated at 37°C for 30 minutes. Non-adherent cells were washed three times with modified HEPES-Tyrode buffer. FITC-P-selectin was then added (10 µg/ml), and the samples were incubated at 37 oC for 10 minutes and subsequently washed. Samples were imaged with differential interference contrast (DIC) and fluorescence microscopy on a Zeiss Axiovert 200 M microscope. Results Platelet adhesion, activation, and aggregation were assessed for 3 neonatal samples and 3 adult control samples. Both adult and neonatal platelets adhered to fibrinogen and collagen equally. Exposure to collagen and fibrinogen (+/- TRAP) resulted in alpha granule release and P-selectin expression in both neonatal and adult platelets. In addition, both adult and neonatal platelets were observed to undergo the characteristic cytoskeletal changes that result in platelet spreading on fibrinogen (+/- TRAP) and collagen surfaces. Both neonatal and adult platelets were observed to form platelet aggregates on both surfaces under static conditions. (Figure 1) Conclusions We have successfully developed a novel platelet function assay using small volumes of whole blood to assess three key platelet functions: adhesion, activation, and aggregation. This is the first study to demonstrate that neonatal platelets spread on adhesive and extracellular matrix proteins and suggests that neonatal platelets contain the cytoskeletal machinery necessary to undergo this change in platelet formation. This assay fills a critical need in clinical pediatric hematology where efforts to diagnose and treat neonatal platelet dysfunction are often met with technical challenges related to conventional platelet function assays. Disclosures: No relevant conflicts of interest to declare.

Background Individuals with hemophilia have abnormally low bone density, despite prophylactic factor infusion with the associated reduction in the joint disabling complications of bleeding. Previously, we demonstrated decreased bone mineral density, skeletal strength, and increased bone resorption in factor VIII (FVIII)-deficient mice without differences in physical activity or joint bleeding compared to control mice. Thus, we hypothesize that factor deficiency is an independent risk factor for decreased skeletal health. Methods To test this hypothesis, we evaluated platelet-poor plasma from 80 male subjects with severe FVIII deficiency, 20 male patients with severe factor IX (FIX) deficiency and 52 healthy male controls. Samples were assessed for three markers of bone turnover: receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG) and carboxy-terminal collagen crosslinks (CTX-1). RANKL binding to the RANK receptor induces the proliferation and differentiation of osteoclasts resulting in increased bone resorption. OPG competitively inhibits RANKL binding to RANK, blocking these osteoclastic effects. CTX-1 is formed through the degradation of bone and thus is a direct marker of bone resorption. Results No differences in RANKL levels are seen between any of the groups. A significant increase in OPG is identified in plasma from FIX-deficient subjects compared to FVIII-deficient subjects (p = 0.0046) and control subjects (p = 0.0095), without differences seen between FVIII-deficient and control subjects (p = 0.920). CTX-1 is higher in samples from FVIII-deficient subjects compared to FIX-deficient subjects (p = 0.020) and control subjects (p = 0.0024), without differences seen between FIX-deficient and control subjects (p = 0.947) samples. In a subset analysis, subjects receiving FVIIII concentrate replacement within 12 hours of plasma collection have decreased CTX-1 (p = 0.022) but not OPG (p= 0.850) compared to those subjects receiving factor concentrate replacement greater than12 hours from plasma collection. We are currently evaluating other plasma markers of bone turnover and cytokine expression in the same cohort of samples. Conclusions Subjects with FVIII deficiency but not FIX deficiency have evidence of increased bone resorption compared to control samples. Increased OPG levels are present in FIX-deficient plasma and may contribute to the differences seen in CTX-1 production between subjects with FIX and FVIII deficiency. Furthermore, FVIII replacement within 12 hours of plasma collection reverses CTX-1 elevation seen in FVIII-deficiency. This study suggests that bone disease is intrinsic to FVIII-deficiency and that aggressive FVIII replacement may ameliorate this pathology. Disclosures: Manco-Johnson: Novo Nordisk: Membership on an entity’s Board of Directors or advisory committees; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees; Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees; CSL Behring: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Bayer HealthCare: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Eisai: Research Funding. Taylor:Novo Nordisk: Research Funding; Baxter BioScience: Research Funding.

Abstract 2218 Autoimmune lymphoproliferative syndrome (ALPS), often due to an inherited defect in the FAS gene, presents with chronic non-malignant lymphadenopathy, splenomegaly, and autoimmune cytopenias (Oliveira JB et al. “Revised diagnostic criteria and classification for the autoimmune lymphoproliferative syndrome (ALPS): report from the 2009 NIH International Workshop”. Blood. 2010 Oct 7;116(14):e35-40). Thrombocytopenia has been noted in approximately 23% of ALPS patients. These patients, especially those with massive splenomegaly and hypersplenism, are often refractory to standard dose short-term corticosteroid regimens and intravenous immunoglobulins (IVIG). Mycophenolate mofetil (MMF) has been used for persistent thrombocytopenia as a steroid sparing long-term measure in 40 out of 245 ALPS patients in our cohort. The median age at initiation of MMF was 10.5 years (range 7 months to 43 years) with an average follow-up of 3.8 years on MMF (range 3 months to 11 years). Here we share our experience over the last 7 months related to the use of thrombopoietin receptor agonists in 3 ALPS patients who have persistent, severe, MMF-refractory thrombocytopenia (platelets Patient 1 is a 21 year old man with ALPS-FAS and splenomegaly who has been on MMF for 2 years. He presented with monthly episodes of thrombocytopenia requiring high dose corticosteroids and IVIG followed by four weeks of rituximab and daily prednisone without any durable improvement in his thrombocytopenia. He was started on eltrombopag 50mg daily and was able to taper off prednisone in one month with sustained stable platelet count. Three months after starting eltrombopag, he was able to survive surgical intervention for a spontaneous pneumothorax while on eltrombopag and MMF. Patient 2 is an 18 year old woman with ALPS-FAS and surgical asplenia who has been on MMF for approximately 7 years. She began having significant, symptomatic thrombocytopenia refractory to high-dose corticosteroids with transient responses to IVIG. She was started on eltrombopag 50mg daily with MMF and initially responded. However, when MMF was discontinued her platelet count plummeted. Despite reinitiating MMF, her platelet counts never recovered on eltrombopag and she continued to require monthly IVIG. She was eventually switched to romiplostim, and was incrementally increased to the maximum dose of 10mcg/kg/week. Her platelet counts continue to fluctuate, but she has not required any IVIG in over one month. Patient 3 is a 19 year old man with ALPS-U and surgical asplenia who has been on MMF for the last 9 years. During the past year he has had episodes of symptomatic thrombocytopenia requiring monthly courses of high dose corticosteroids and IVIG. After initiation of eltrombopag, he had a significant rise in his platelet counts. However, upon discontinuation of MMF, his platelet counts plummeted. MMF was restarted and he was trialed on multiple, different eltrombopag dosing regimens leading to supratherapeutic responses with platelet counts over 1,000,000/uL. Eltrombopag was held during these periods to allow for the significant thrombocytosis to resolve, but withholding eltrombopag led to platelet counts to eventually fall precipitously. Furthermore, he also developed severe headaches due to MMF and MMF had to be discontinued. After multiple dosing regimens, he eventually maintained a stable platelet count on eltrombopag 50mg daily for 5 days alternating with eltrombopag 25mg for 2 days without the concomitant use of MMF. Recently, there has been increasing evidence supporting the use of thrombopoietin receptor agonists in the treatment of refractory immune thrombocytopenia. MMF continues to be well tolerated as a long-term corticosteroid sparing drug for patients with ALPS complicated by chronic, refractory thrombocytopenia. Our preliminary experience suggests that there may be a role for thrombopoietin receptor agonists, most likely in combination with an immunosuppressive agent such as MMF, in the treatment of refractory thrombocytopenia in patients with ALPS. However, schedule and duration of therapy with this class of drugs needs further long term evaluation. Disclosures: No relevant conflicts of interest to declare.

Abstract 21 Background: Low bone mineral density (BMD) and increased risk of fracture are increasingly being identified in patients with hemophilia. Multiple clinical studies have shown that both children and adults with hemophilia have significantly decreased BMD, with up to 70% of adult patients affected. Decreased BMD in this population has previously been attributed to inactivity due to hemophilic arthropathy and comorbid conditions including infection with HIV and hepatitis C. The factor VIII (FVIII) knockout (KO) mouse model has been extensively characterized with respect to bleeding and the development of inhibitors. However, the skeletal status of these animals has not been described. Therefore, the purpose of this study is to examine the skeletal phenotype of FVIII deficient mice and measure serum markers of bone turnover and regulation. Methods: We compared the skeletal phenotype of 11 male FVIII KO mice and 8 matched wild-type (WT) controls at 20 weeks of age. BMD was measured using dual energy x-ray absorptiometry (DXA), bone geometry was examined by μCT and, after sacrifice, femoral breaking strength was measured by three-point bending until failure (ultimate force). In a second group of 24 mice (12 KO and 12 WT), serum was obtained under uniform conditions at 20 weeks of age via cardiac puncture. Serum levels of receptor activator of nuclear factor kappa-B ligand (RANK-L), osteoprotegerin (OPG), interleukin 1α (IL-1α) and osteocalcin were measured using commercially available ELISAs. Alkaline phosphatase (alk phos) activity was measured using a colorimetric assay. The RANK-L/OPG system regulates bone turnover, osteocalcin and alk phos are markers of bone turnover and IL-1α is an inflammatory cytokine. Results: No differences in body weight, length, percent fat, or femoral length were observed between FVIII KO and WT mice (data not shown). No spontaneous bleeding was observed in any animal. As shown in Table I, KO mice had significantly decreased BMD, cortical thickness and stiffness compared to WT mice. This resulted in decreased resistance to fracture as measured via ultimate force. The data presented here demonstrate that adult FVIII KO male mice exhibit lower cortical bone mass resulting in femora less resistant to fracture compared with WT controls. Because FVIII KO mice do not have spontaneous joint hemorrhages and exhibit normal behavior and activity levels, these data suggest that there is an underlying connection between the coagulation system and bone metabolism that results in lower BMD and bone strength. To understand why KO mice have decreased BMD, we measured serum levels of regulators of bone metabolism, markers of bone turnover and inflammatory cytokines. There was no difference in RANK-L, OPG or the RANK-L/OPG ratio between the KO and WT mice. In addition, there was no observed difference in osteocalcin and alk phos. However, WT animals had significantly higher levels of IL-1α expression (P = 0.008). All of the KO animals had undetectable IL-1α levels under physiologic conditions whereas the mean IL-1α level in WT mice was 32.2 pg/ml. Thrombin production is reduced in hemophilia and thrombin has previously been shown to stimulate inflammatory cytokine production. Therefore, these data suggest that thrombin may be necessary for IL-1α production under non-stress conditions and that lower levels of IL-1α may be detrimental to bone health. Although increased inflammatory cytokines are typically associated with decreased BMD, prior research has shown that physiologic levels of cytokines are necessary to maintain bone health. Conclusions: These data provide compelling evidence that the link between FVIII deficiency and impaired skeletal health is real and independent of differences in physical activity and other medical co-morbidities. In addition, the decreased levels of IL-1α observed in KO mice suggest that inflammatory cytokines are involved in this pathophysiology. Ongoing work in our laboratory is aimed at further exploring these connections. Disclosures: No relevant conflicts of interest to declare.

Abstract 2509 Background: Chronic pediatric immune thrombocytopenia (ITP) has an incidence of 1–2/100,000. Due to its low incidence, large studies in pediatric chronic ITP are difficult. This registry includes patients from 16 sites in the US and Canada and represents one of the largest longitudinal datasets of children/adolescents with chronic ITP. Objective: To describe the North American Chronic ITP Registry (NACIR) study population and evaluate univariate predictors of platelet count response to therapies, including IVIG, anti-D globulin (anti-D), steroids (5–14 day course), and splenectomy. Registry methods and patient characteristics: After local IRB approval, 550 patients with chronic ITP enrolled in the NACIR between January 2004 and June 2010. Eligibility included: ages 6 months-18 years at ITP diagnosis, clinical diagnosis of ITP, and ITP duration >6 months. Primary ITP was defined as isolated thrombocytopenia without associated conditions. Secondary ITP included those patients with immune thrombocytopenia associated with other immune-mediated medical conditions, including Evans Syndrome. Treatment response was defined as a post-treatment platelet count ≥50,000/uL within 7 days of IVIG, 10 days of anti-D, 14 days of steroids, and 30 days of splenectomy. 365 subjects had at least one 6 month follow-up report after enrollment; median duration of follow-up was 2.1 yrs. Demographics of participants include: 46% male; 84% Caucasian, 7% Black, and 7% Asian; and 20% Hispanic. Mean age at diagnosis of acute ITP was 8.7 ± SD 5.2 years. At the time of enrollment in NACIR, subjects had received a median of 2 prior treatments (range 0–7). Results: The median platelet count at diagnosis of acute ITP was 11,000/uL (IQR 6,000–31,000/uL) and at chronic ITP was 35,000/uL (IQR 18,000–66,000/uL). 69 (12.5%) patients had secondary ITP or Evans syndrome. Of those tested, 25.6% (98/359) of patients had a positive ANA (titer > 1:40), and 75/337 (22.3%) had a positive direct anti-globulin test (DAT). 27.5% of patients had an antecedent viral illness. Of the 550 subjects, 2 (0.4%) experienced life-threatening bleeding. Patients were treated as follows: 259 (47.1%) with steroids, 253 (46%) with IVIG, 189 (34.4%) with anti-D, and 64 (11.6%) with splenectomy. Overall responses to therapy included: 69.1% response to steroids, 74.3% response to IVIG, 66.7% response to anti-D, and 85.9% response to splenectomy. Univariate predictors of response to treatments are shown in Table I. Higher platelet count at chronic ITP diagnosis and DAT positive predicted a platelet response to a short course of steroids in univariate analysis. This was confirmed in multivariable analysis of potential confounders, using logistic regression with a backwards elimination procedure. Response to one type of therapy was often strongly associated with a response to a second therapy. Gender, ethnicity, race, older age, and platelets ≥20,000/uL at acute ITP diagnosis were not associated with response to any single therapy. Conclusion: The demographics and laboratory findings of the large, well characterized NACIR population are consistent with other reports of young people with chronic ITP. The novel finding that DAT positivity predicts steroid response, even with multivariable adjustment for confounders, provides evidence that the NACIR is a robust and useful tool for trying to predict response to ITP treatment strategies. Disclosures: Klaassen: Novartis: Research Funding; Cangene: Research Funding. Lambert: Cangene: Membership on an entity's Board of Directors or advisory committees.

BACKGROUND: Development of inhibitory antibodies that limit replacement therapy with factor VIII (FVIII) is one of the most difficult complications of hemophilia A. Although 70–90% of children achieve immune tolerance (IT) with regular FVIII therapy, children with refractory inhibitors remain a challenge to manage. METHODS: Boys with hemophilia A were evaluated for the development and treatment of inhibitors (COMIRB 97–178). Children with refractory inhibitors following failure of IT or failure to achieve Table 1: Immune Modulation Protocol employed for Compassionate Care Throughout Protocol FVIII 100-200 U/kg IV daily Months 1 and 3 Rituximab 375/m2 IV once weekly x 4 Months 5 through 10 Cyclophosphamide 500-1000 mg/m2 IV once monthly Month 11 to sustained tolerization x 1 year, then taper as tolerated over 6 months. Mycophenylate mofetil 400-600 mg/m2/dose orally twice daily; Pneumocystis prophylaxis with Trimethoprim/Sulfamethoxazole twice weekly Persistent/Refractory Inhibitor Repeat course of Rituximab (once weekly x 4 more doses) RESULTS: Six children were treated on this protocol; results are shown on Table 2. Table 2: Results of Salvage Therapy Protocol for Refractory FVIII Inhibitors. Patient Peak Titer (BU) Current Titer (BU) Time on Protocol Current Therapy Den 1 175.4 0.5 23 months Mycophenylate mofetil, FVIII Den 2 5600 1.1 13 months Mycophenylate mofetil, FVIII Den 3 17.4 0.1 7 months Mycophenylate mofetil, FVIII Phx 1 1206 1.9 12 months Rituximab, Mycophenylate mofetil, FVIII Phx 2 180 115 12 months Rituximab, Mycophenylate mofetil, FVIII Phx 3 204.8 2.1 5 months Rituximab, Mycophenylate mofetil, FVIII Two children (Den 1 and Den 3) achieved a negative BU (0.2, 0.1, respectively) after 9 and 4 months of therapy although Den 1 had a relapse to 1.5 BU at 17 months and required further Rituximab. All children have experienced decreased bleeding and pain, and no child required further hospitalization for bleeding complications. CD 20 cell counts decreased to near zero in all treated children but no child experienced reduction in CD 20 count for more than 6 months beyond cessation of rituximab therapy. One child (Phx 1) had transient neutropenia (ANC=350) for which mycophenylate mofetil was withheld and decreased immunoglobulins (IgG ≥ 100 mg/dL) for which IGIV was infused. No child had infection related to neutropenia or lymphopenia. This protocol has been well-tolerated and no major adverse events have occurred. CONCLUSION: These findings provide the first evidence that multiple agent immune modulatory therapy consisting of intravenous rituximab and cyclophosphamide followed by oral mycophenylate mofetil may be safe and effective to reduce BU titers and improve clinical status in children with hemophilia A and refractory inhibitors. Future clinical trials are needed to confirm and extend these observations and to explore other strategies for IT.

ReFacto AF (Albumin-Free Cell Culture Process) is a BDDrFVIII manufactured using an albumin-free cell culture process and purified using a chemically synthesized peptide affinity ligand instead of a murine monoclonal antibody. A virus-retaining filtration step has been included as an additional safety precaution during manufacture. The potency assignment of ReFacto AF has been aligned to the one-stage clotting assay, to permit routine clinical monitoring, as for other rFVIII products, without specialized standards. The pharmacokinetic (PK) profile of ReFacto AF vs. Advate was assessed in a randomized double blind crossover fashion, in 30 previously treated patients (PTPs) (≥ 12 years; FVIII:C ≤1%) using the standard bioequivalence approach based upon the one-stage clotting assay. Safety and efficacy of ReFacto AF was also assessed in a total of 94 PTPs (FVIII ≤2%), which included the PK subjects, during 6 months of open label routine prophylaxis supplemented with on-demand treatment as necessary. A follow-up PK assessment with ReFacto AF was performed in the PK subjects after 6 months. Pharmacokinetic equivalence of ReFacto AF and Advate was demonstrated (n = 30 subjects). The ratios of geometric least-square means for K-value, AUCt, AUC∞ were 100%, 89.8%, and 88.0%, respectively, and associated 90% confidence intervals were within the bioequivalence window of 80%–125%. Twenty five (25) subjects had a baseline and 6 month follow-up PK assessment with ReFacto AF. Mean K-value and t1/2 for ReFacto AF were 2.23 (± 0.39) IU/dL per IU/kg and 11.8 (± 5.1) hours, respectively at baseline and the 6 month follow-up PK profile was unchanged. Of the 94 patients, 89 accrued at least 50 ReFacto AF exposure days. Median routine prophylaxis dose was 30.2 IU/kg. During routine prophylaxis, the median annualized bleed rate was 1.9 (mean 3.9, range 0 to 42.1), and 43 of 94 (45.7%) patients experienced no bleeding episodes. A total of 187 bleeding episodes were treated on-demand with a median dose of 30.6 IU/kg, and 92.5% resolved with 1 or 2 infusions. The overall adverse event (AE) profile was consistent with the AE profile of ReFacto and other rFVIII products. Two of the 94 patients had transient, low-titer, clinically silent inhibitors (0.98 BU/mL and 1.21 BU/mL), each detected by routine surveillance on a single occasion and each was negative on follow-up testing. The corresponding ELISAs for FVIII antibodies were negative for both patients. No patient in the study had a positive ELISA immune response to CHO cell protein or to the peptide affinity ligand used for ReFacto AF purification. ReFacto AF is pharmacokinetically equivalent to Advate based on one-stage FVIII activity assessments, and ReFacto AF PK is stable over 6 months of use. The product is effective in the prevention and treatment of bleeding episodes. Inhibitor safety results show no evidence of neoantigenicity and the AE profile demonstrates safety in PTPs with hemophilia A.

Background: Osteoporosis among adult males is a major and under-recognized problem in the United States. Patients with hemophilia have several predisposing risks for developing decreased bone mineral density (BMD) and osteoporosis, and may represent an important group to target for screening and treatment for fracture prevention. Patients and Methods: Patients over the age of 18 with moderate or severe hemophilia A or B (as defined by factor activity < 5%) and no history of prophylactic factor use prior to age 10 were eligible. Bone mineral densities were obtained using DEXA scans (DXA) along with measurements of joint mobility and physical activity and laboratory parameters. Results: Twenty-eight patients have been consented with accrual ongoing. 21 have undergone DXA scans. Median age of 39 (range 18–61), 86% HCV positive, 26% HIV positive. Median T-score for all sites (lumbar, femoral neck, hip, and other) was −1.7 (−5.8–0.6), with the most effected area being the femoral neck, T-score −1.7 (−5.8–0.8). Based on WHO criteria, 76% of patients had decreased BMD, 33% (n=7) with osteoporosis, and 43% (n=9) with osteopenia. Trends associated with decreased BMD included decreased serum 25-hydroxy-vitamin D levels, increased alkaline phosphatase, and decreased weight. All patients with osteoporosis were HCV positive, and all HIV positive patients had decreased BMD. Median activity scores were lower among osteoporotic patients vs normal BMD. Joint range-of-motion in the lower extremities was limited to 59.5% of predicted values in patients with osteoporosis, 84% in osteopenia, and 93% in patients with normal BMD. Summary: Patients with hemophilia are at markedly increased risk for developing osteoporosis and osteopenia. Potential predictors of risk for decreased BMD are concurrent HCV and HIV infection, low vitamin D levels, elevated alkaline phosphatase, lower weight, decreased range of motion and lower activity scores. More aggressive screening for decreased BMD among moderate and severe hemophilia patients with initiation of therapy is appropriate. Median Values Worst T-Score Activity Score (1–5) Joint ROM (% Pred) Weight (kg) 25-Hydroxy-D (ng/mL) Alk Phos (IU/L) Normal BMD 0.1 5 94.0 91.6 28.0 59 Osteopenia −1.6 4 85.0 80.7 23.0 86 Osteoporosis −3.0 3 68.5 73.0 21.8 99

A new formulation (rFIX-R) of BeneFIX has been developed to reduce the possibility of RBC agglutination, a phenomenon associated with the low ionic strength of the reconstituted drug product. The new formulation contains NaCl to increase the ionic strength and the recombinant factor IX concentration is increased for the 1000 IU strength and a new 2000 IU strength by reconstituting all strengths in 5 mL, facilitating the administration of larger doses in decreased volumes. Thirty-four (34) previously treated (≥150 exposure days [EDs]) males (≥12 years) with moderately severe/severe hemophilia B (FIX:C ≤2%) were enrolled and treated in this 2 part study. In the randomized, double-blind, crossover pharmacokinetic (PK) period of the study, the PK characteristics of rFIX-R were compared with those of the currently available formulation of BeneFIX. Subjects received either rFIX-R or BeneFIX as a 75 IU/kg bolus infusion over 10 minutes after a suitable washout. Blood samples were collected at defined times over 72 hours to measure pre-/post-infusion plasma factor IX activity. Subjects then received the alternate treatment following the same procedure. The mean plasma factor IX activity-versus-time profile after the infusion of rFIX-R was essentially identical to that seen with BeneFIX. From the 26 evaluable subjects, the mean PK parameter estimates of factor IX activity establish bioequivalence of the products since the 90% confidence intervals for rFIX-R to BeneFIX ratios of the geometric means of Cmax and AUCs fell within the bioequivalence interval of 80% to 125%. Figure Figure In the open-label treatment period, subjects used rFIX-R for on-demand control of bleeding, routine prophylaxis, and/or surgical prophylaxis for 6- to 12-months to achieve at least 30 EDs. The plasma factor IX activity-versus-time profile was recharacterized after 6 months of rFIX-R treatment and was unchanged compared with the baseline rFIX-R PK profile. Over 1000 infusions (>3,500,000 IU of rFIX-R) have been administered with no serious adverse events related to rFIX-R. No clinically significant adverse events related to rFIX-R have been reported, including FIX inhibitor development, allergic-type manifestations, or thrombotic complications. One subject, with a prior history of frequent RBC agglutination, reported two instances without any associated adverse events. The overall results of this study demonstrate the safety of rFIX-R and the bioequivalence of the new formulation and BeneFIX. Since bioequivalence is the most important surrogate endpoint for efficacy, these data predict a favorable rFIX-R efficacy profile, consistent with that of BeneFIX, but with increased convenience in that larger doses can be administered using decreased volumes relative to BeneFIX.

p38 MAP kinase is critical for the transcriptional regulation of the human interferon-γ gene. ♦ 58

INTRODUCTION: GT is a rare (~1:1 million) congenital platelet disorder characterized by a deficiency in or abnormality of GPIIb/IIIa and by predominantly mucocutaneous bleeding. Platelets are used to treat severe bleeding in individuals with GT and prevent bleeding during surgery; however, anti-platelet antibodies and/or refractoriness can occur. Few data exist on how and where US patients with GT receive care or how GT impacts patients and families. This first of its kind survey aims to capture healthcare professional (HCP) experience and perspectives on GT care. METHODS: An April 2014 web-based quantitative survey (~45 min) was distributed to 2280 HCPs including all 561 on the Center for Disease Control (CDC) hemophilia treatment center (HTC) list. Respondents had to be actively involved with the treatment of bleeding disorders. RESULTS: For 1726 successfully delivered emails, response rate was 8.7%.By target, 75 were physicians (9 self-classified as hematology only and 66 as hematology/oncology) and 75 were nurses (50 nurses, 25 nurse practitioners). The majority treated both adults and children; median 13 GT patients per center. Only 5% (7 of 21 CDC list respondents) reported working at federally-funded HTCs, with 41% from non-federally funded HTCs; the rest (54%) reported not being affiliated with an HTC. HCPs reported typical presentations including gum/mouth bleeds (67%), skin bleeds/bruising (66%), epistaxis (61%), and/or menorrhagia (39%). Mean (median) reported time to hematologist referral after first bleed was 18.4 (6) months (23% HCPs reported that 20% of bleeds received no treatment and 50% required some systemic (IV) treatment and/or transfusion (26% platelets only). In the prior 5 years, 81% of patients received platelets, 70% antifibrinolytics, and 36% of menstruating females received hormonal therapy. HCPs reported 75% of their patients received a pRBC transfusion at some point. Satisfaction with response to platelets (1-10, 10 = satisfied) was 7.3 (7). Transfusions are typically given in the HTC or hematologist’s hospital (86%), at a hospital near the patient’s house (63%) or at an infusion center (63%). HCPs reported 16% of patients were refractory and 32% had antibodies. HCPs reported that, for pediatric patients, 89% have issues at school and 87% have issues with activities/sports (71% limited participation). Most (65%) reported that children with GT have issues with peers and friends. Having children with GT also impacts parents’ work (66%), most commonly from missed time at work (31%). Emotional stress was also emphasized as an issue facing families. For adult patients, GT impacts activities/participation in sports (82%) and they face issues with employment (62%), most commonly from missed time (22%). HCPs reported relationships are impacted in 42% of patients. HCPs most frequently refer patients and families to hemophilia.org (63%) and curegt.org (56%) for additional information. HCPs indicated from their perspective quality of life for patients with GT and their families could be improved with increased focus on diagnosis/treatment (45%) and education/awareness (29%). Nurses tended to emphasize addressing education and the emotional and social impact on patients with GT; hematologists focused more on clinical aspects. Respondents noted it was most important that referring HCPs know how/when to refer to specialists (44%) and the importance of early diagnosis (36%). CONCLUSION: These data provide insights into the care of GT and other bleeding disorders in the US. While the World Federation of Hemophilia reported 103 US GT patients receiving their care in HTCs, the type of HCPs who responded here and patient/caregiver survey results suggest many GT patients receive care outside of the federally funded HTC network. Further cross-sectional and prospective studies may improve understanding of refractoriness/antibodies and psychosocial impact on patients and families. Disclosures Cooper: Novo Nordisk: Employment.