ALBERT

Beschreibung: Joint arthropathy secondary to recurrent hemarthroses remains a debilitating complication of hemophilia despite the use of prophylactic factor concentrates. Increased vascularity and neoangiogenesis have been implicated in the progression of musculoskeletal disorders and tumor growth. We hypothesized that de novo blood vessel formation could play a major role in the pathogenesis of hemophilic joint disease (HJD). We observed a 4-fold elevation in proangiogenic factors (vascular endothelial growth factor-A [VEGF-A], stromal cell–derived factor-1, and matrix metalloprotease-9) and proangiogenic macrophage/monocyte cells (VEGF+/CD68+ and VEGFR1+/CD11b+) in the synovium and peripheral blood of HJD subjects along with significantly increased numbers of VEGFR2+/AC133+ endothelial progenitor cells and CD34+/VEGFR1+ hematopoietic progenitor cells. Sera from HJD subjects induced an angiogenic response in endothelial cells that was abrogated by blocking VEGF, whereas peripheral blood mononuclear cells from HJD subjects stimulated synovial cell proliferation, which was blocked by a humanized anti-VEGF antibody (bevacizumab). Human synovial cells, when incubated with HJD sera, could elicit up-regulation of HIF-1α mRNA with HIF-1α expression in the synovium of HJD subjects, implicating hypoxia in the neoangiogenesis process. Our results provide evidence of local and systemic angiogenic response in hemophilic subjects with recurrent hemarthroses suggesting a potential to develop surrogate biologic markers to identify the onset and progression of hemophilic synovitis.

Beschreibung: The growing awareness to screen women with menorrhagia for an underlying bleeding disorder has led to an increase in enrollment of identified cases in Hemophilia Treatment Centers (HTCs). However, the outcome of menorrhagia management in these women has not been well-described. Objective : To determine the efficacy/outcome of the management of bleeding disorder-related menorrhagia in patients enrolled within the HTC network. Patients and Methods : Registry study of initial data collection of retrospective obstetrical and gynecological events with prospective yearly follow-up for 5 years for new obstetrical and gynecological events. Results : 99 women from five HTCs in New York-New Jersey Region II have been registered to date, mean age 38±16.3, median age 40. Diagnoses are: von Willebrand disease (VWD) in 71%; thrombocytopathy in 6%; factor deficiency in 23%. Menstrual status and outcomes presently: ⇒32/99 (32%) are not menstruating due to hysterectomy or post/peri-menopausal status; 13/99 have undergone a hysterectomy (n=10) or endometrial ablation (n=3) for menorrhagia control; in 7/10 of the women undergoing a hysterectomy for menorrhagia control, the diagnosis of VWD was previously established; 6/7of these women attempted medical treatment prior to hysterectomy ⇒68/99 (68%) are presently menstruating. Of those menstruating, menstrual status is as follows: Normal menses: 23.5% (16/68) Menorrhagia under control: 23.5% (16/68); of these patients; 11/16 have achieved control with oral contraceptive(OC), the remaining 5 patients have achieved control with intranasal DDAVP or Amicar Menorrhagia presently: 53% (36/68); 22/36 (61%) have undergone a course of ineffective menorrhagia treatment including intranasal DDAVP in 17/22 Conclusions : The majority of women with menorrhagia enrolled in HTCs have persistent menorrhagia despite evaluation and management within the HTC network. Only a small proportion have menorrhagia control due to intranasal DDAVP use and a proportion still necessitate hysterectomy for menorrhagia control. The value in United States HTCs of hemostatic measures alone such as intranasal DDAVP in the management of bleeding disorder related menorrhagia is uncertain at this time. Further study of combined therapy (intranasal DDAVP and Amicar ± OC) and novel approaches (levonorgestrel-intrauterine device) is warranted as are efforts to procure tranexamic acid for use in the U.S.

Beschreibung: Abstract 2231 Background: PNH arises from a genetic mutation of hematopoietic stem cells which leads to the acquired nonmalignant clonal expansion of cells lacking glycosyl phosphatidylinositol-anchored proteins (GPI-APs). Lack of GPI-APs translates into PNH's most significant clinical features: bone marrow failure, intravascular hemolysis and thrombosis. PNH rarely occurs in children and has been reported to have a distinct clinical presentation compared to the adult population. Results: We provide a clinical description of 11 consecutive pediatric patients (pts) aged 11–17 years (median age 13.9 years) diagnosed with PNH since 1993 at a single institution. Bone marrow failure was the presenting clinical finding in 10 pts, including aplastic anemia (AA) (N = 9), hypoplastic myelodysplastic syndrome (MDS) (N = 1), and isolated red cell anemia (N = 1). This rate of bone marrow failure at presentation is higher than the reported rate of 24–33% seen in adult pts. Immunosuppressive therapy was the initial treatment for 8 patients with aplastic anemia and this included: antithymocyte globulin (N = 8), Cyclosporine (N = 8) and prednisone (N = 6). Partial response to immunotherapy was seen in all pts. Five pts had evidence of myelodysplastic features, including one at diagnosis. These included dysplasia with monosomy 7 for 2 pts, 5q deletion for one pt, and dysplasia with normal cytogenetics for 2 pts. The monosomy 7 abnormality was transient and resolved spontaneously for the 2 pts, while the pt with 5q deletion proceeded to transplantation. None of these pts developed excessive blasts or leukemic transformation. Thrombosis occurred in six pts with four of the pts experiencing several sites and episodes of thrombosis. Diagnosis of thrombosis occurred at presentation in one patient. Thrombosis in the remaining five pts first occurred 5–88 months from diagnosis (mean 58.8 months). This rate of thrombosis (55%) is similar to the reported rate of thrombosis in adult pts (40%) but is higher than recent reports of pediatric PNH in the literature. Treatment of thrombosis included anticoagulation and thrombolysis when appropriate. Intermittent episodes of intravascular hemolysis occurred in all 11 pts. Gross hemoglobinuria occurred in only one patient at initial presentation. This rate of gross hemoglobinuria at presentation is similar to other series of pediatric PNH, but much lower than the reported rate of 33–50% in adult pts. Of the 11 pts, 4 underwent hematopoietic stem cell transplant (HSCT) of whom 2 pts are alive and disease free. Eculizumab, a monoclonal antibody directed against the complement protein C5 was initiated in 3 pts of whom 2 pts currently have stable disease; the third non-compliant patient developed progression of thrombotic disease but has since restarted eculizumab therapy. Two pts died following complications related to thrombosis and two patients are transfusion independent with stable disease. Conclusions: This series represents a large single center cohort of pediatric pts diagnosed with PNH. This report highlights the high rate of bone marrow failure in pediatric pts with PNH. This differs from the adult population, and emphasizes the need for PNH testing in all children with AA or MDS, as well as children with unexplained Coombs-negative hemolysis or thrombosis. Both the high prevalence of hemolysis and high risk of thrombosis should warrant early treatment with eculizumab for pediatric pts with PNH. HSCT remains the only curative option for pediatric pts with PNH but its risk must be considered relative to the patient's disease severity, compliance and response to long-term treatment with anticoagulant and/or anticomplement therapy. Disclosures: No relevant conflicts of interest to declare.

Beschreibung: Abstract 3668 Background: Congenital FVII deficiency, the most common of the autosomal recessive rare coagulation disorders (RCDs), is characterized by genotypic variability as well as phenotypic heterogeneity ranging from absent to severe hemorrhage, and rarely thrombosis. Prothrombin time (PT) and FVII activity assays do not reliably predict bleeding phenotype. Global assays of coagulation and fibrinolysis may better characterize overall hemostatic balance and could aid in the assessment of hemorrhagic and thrombotic risk in RCDs. Objective: We sought to investigate whether a global assay might better predict bleeding phenotype in FVII deficiency. Methods: Four North American centers enrolled 24 known FVII deficient subjects (21 heterozygotes (FVII:C 20–60 U/dl) and 3 homozygotes/compound heterozygotes (FVII:C 〈 .01U/dL)) at asymptomatic baseline in a collaborative cross-sectional study. Venipuncture was performed for determination of baseline factor VII activity (FVII:C) and prothrombin time (PT) in plasma. The Clot Formation and Lysis (CloFAL) global assay and the Simultaneous Thrombin and Plasmin generation (STP) assay were performed centrally at the University of Colorado by previously described methods (Goldenberg et. al, Haemophilia 2008 and Grunzke et al., J Thromb Haemost 2009 (abstract)). Bleeding history data were obtained retrospectively and locally using a standardized case report form, in order to assign each subject a bleeding score (0-3.2) as previously described by Mariani et al. (Thromb Haemost, 2005), but slightly modified as follows: 0 (asymptomatic); 1 (mild): 1–2 symptoms excluding hemarthrosis, CNS and GI bleeding; 2 (moderate): 〉/=3 symptoms excluding hemarthrosis, CNS or GI bleeding; 3 (severe): hemarthrosis, CNS or GI bleeding. Within each score, decimals indicated the # of symptoms. Results: Median values (ranges) for age, FVII:C, and bleeding score were as follows: age, 12 years (3-36 years); FVII:C, 39 U/dL (

Beschreibung: Background: Among the most serious complications of hemophilia A is anti-VIII inhibitor formation, which occurs in ~25% of patients, typically in childhood within the first 20 exposures. Morbidity is high, hospitalization is frequent, and healthcare cost is high. Thus, immune tolerance induction (ITI), a program of regular F.VIII therapy, is used to eradicate the inhibitor. A landmark study demonstrated ITI was equally effective with high-dose (HD) (200 IU/kg/day) or low-dose (LD) (50 IU/kg 3x/week) F.VIII, but found a bleeding rate 2-fold greater in the LD arm. As the inhibitor neutralizes F.VIII, no difference in bleeding was expected. We hypothesized that thrombin generation assay (TGA), a global measure of tissue factor-induced thrombin generation that predicts bleeding in hemophilia better than F.VIII, might clarify this question. Methods: Following IRB approval, TGA was performed on thawed, re-calcified CTI /citrate plasma samples from the ITI repository, using re-lipidated tissue factor and a BioTek Synergy 4 fluorescence plate reader. TGA parameters, i.e. peak thrombin (peak T), estimated thrombin potential (ETP), maximum rate (MaxR), lag time (LAG), were compared by dose group, and repeated after F.VIII spike to neutralize the inhibitor and enhance TGA sensitivity. Significance was calculated by fitting generalized estimating equations linear models to account for serial measurements, with log-transformed TGA as outcome and dose group as predictor. Wilcoxon rank sum test was used to compare bleeds by dose group. Spearman correlation was used to compare TGA and bleeds, and TGA and inhibitor titer. The first TGA sample per subject was used in the analysis; and, separately, all TGA samples per subject. Sensitivity analysis was performed by 95% bootstrap confidence intervals to account for multiple measurements per subject. Total F.VIII antibody (NNA+NA) was analyzed by fluorescent immunoassay (FLI) and compared with anti-VIII (BU/ml) by Pearson correlation. Results: Samples (n=83) from 31 subjects, 14 LD and 17 HD, were available. There was no difference in peak T, ETP, MaxR, or LAG between LD and HD; after VIII spike (Table); nor between non-tolerized (n=56) and tolerized (n=27) subjects, all p〉.05. There was no correlation between TGA and bleeding, nor between TGA and anti-VIII titer, all p〉.05. In 19 subjects in whom anti-VIII fell to

Beschreibung: Background: Retrospective reviews of hemophilia therapy correlate normal joint X-ray (XR) and physical exam (PE) with early institution of routine infusions of FVIII dosed to prevent bleeding. Although the National Hemophilia Foundation recommended prophylaxis for all persons with severe hemophilia in 1995, fewer than half of affected persons in the US have adopted prophylaxis due to cost, effort, lack of perceived need and complications. Objective: The “Joint Outcome Study” was constructed as a multi-center, open-label, two-arm, prospective, randomized clinical trial to compare full prophylaxis with an intensive treatment regimen for joint hemorrhage. Methods: A regimen of every other day infusions of FVIII at 25 U/kg to prevent hemorrhage (prophylaxis, P) was compared with intensive therapy using ≥ 3 infusions totaling ≥ 80 U/kg FVIII at the time of each joint hemorrhage to minimize joint damage (enhanced episodic, EE). Primary outcome was the proportion of boys in each arm with bone or cartilage damage on XR or magnetic resonance imaging (MR) of index joints (elbows, knees, and ankles). Outcomes were judged independently by two research radiologists who were blinded to treatment arm and bleed history, with a third for discrepant readings. Other outcomes included joint function on a physical exam scale validated for young children (PE), # of joint hemorrhages and factor utilization. Boys were followed from entry between 12 and 30 months until age 6 years. At entry all children had normal joints on XR and MR and had no more than two hemorrhages into any one joint. Results: Sixty-five boys were randomized to P (32) or EE (33). The study has been completed. While adjudication of XR and MR outcomes is still ongoing, clinical study results show the following: Children on P consumed more FVIII (mean 163 vs 47 infusions/year, P 〈 0.001) and had fewer joint hemorrhages per year (0.47 vs 4.9, p 〈 0.001) than boys on EE. PE scores for the six index joints were lower on the P arm compared with EE (mean score 4.7 vs. 8.6, p〈 0.01). Conclusion: This first randomized clinical trial of prophylaxis in young children with FVIII deficiency showed improved joint function by age 6 years in children on early every other day prophylaxis in comparison to an aggressive program of multiple infusions administered promptly at the time of joint hemorrhage. Joint structural outcome confirmation will be based on MR and XR.

Beschreibung: Abstract 4169 The randomized controlled trial (RCT) is the gold-standard clinical trial design by which safety and efficacy of new medical therapies are evaluated in comparison to placebo or established treatments. Randomization serves as a primary means of ensuring equal distribution of confounding factors, minimizing selection bias, and upholding key assumptions of the statistical analysis. In some circumstances, when prognostic heterogeneity is hypothesized but evidence is not definitive, lack of equipoise among experts in the field may preclude randomization in a particular subgroup. In traditional RCT designs, patients in this subpopulation are then excluded from trial participation. However, these patients often constitute an important subgroup of the disease population. By taking advantage of existing RCT infrastructure, efforts to evaluate such patients in a parallel cohort arm – using a “parallel-cohort RCT” design – would provide an efficient means of generating multi-center prospective data on natural history, toward the development of future RCTs involving these subgroups. A current example of the parallel-cohort RCT design is the Kids-DOTT trial, an ongoing investigator-initiated multi-center randomized trial of the duration of anti-thrombotic therapy for venous thrombosis in children. The target population is children with first-episode acute VTE (excluding pulmonary embolism) in whom a reversible prothrombotic clinical risk factor has been identified and comprehensive laboratory assessment reveals no severe or multi-trait thrombophilia. Children meeting eligibility criteria and in whom no persistent occlusive thrombosis at the six-week follow-up time point are randomized to shortened-duration (six weeks) versus conventional-duration (three months) anticoagulant therapy (Figure 1). The primary endpoint is the cumulative incidence (i.e., risk) of recurrent VTE at two years, and will be compared between the two arms. Secondary outcomes include cumulative incidence of post-thrombotic syndrome (PTS) at two years and of major hemorrhage during anticoagulant therapy. The primary hypothesis of the study is that shortened-duration anticoagulation is non-inferior to conventional-duration therapy. The study also evaluates two groups of patients in parallel cohorts (Figure 1). The first group is comprised of patients with a persistent occlusive thrombosis following the first six weeks of anticoagulation; this cohort is allocated to a conventional course of anticoagulation. The second parallel cohort in the Kids-DOTT trial consists of patients with persistent antiphospholipid antibodies, who are allocated to a course of anticoagulation ranging from 3 months to lifelong. For each of these subpopulations, there was lack of equipoise toward inclusion in the randomization to shortened- versus conventional-duration therapy, due to perception of possible increased recurrence risk. The specific aims involving the parallel cohorts are to determine whether: (1) persistent thrombotic veno-occlusion is a prognostic indicator of recurrent VTE and/or PTS, among children treated with a three month conventional course of anticoagulation (comparison of randomization arm B vs. parallel cohort arm C in Figure 1); and (2) duration of therapy influences risk of recurrent VTE and/or PTS among children with persistent APA, when anticoagulated for a minimum duration of three months (within parallel cohort arm D in Figure 1). In this way, the parallel-cohort RCT model of the Kids-DOTT trial provides additional efficiency in trial design, maximizing the information gained from subpopulations of interest that are excluded from randomization. Broader application of the parallel-cohort RCT design should be considered, particularly in rare disease areas, where efforts to maximize inclusion of the diseased population are critical to trial feasibility and applicability. Disclosures: Off Label Use: The presentation refers to the use of anticoagulants as a drug class in general in the treatment of venous thromboembolism (VTE) in children. Despite their use in the standard care for pediatric VTE, all anticoagulants remain off-label for this indication in children.

Beschreibung: According to the CDC’s 2006 National Hemophilia Data Set, females comprise 0.7% of the moderately and severely affected hemophilia A (HA) population and 1.3% of those similarly affected with hemophilia B (HB) in the US. Since no comprehensive data have been published on this patient group since 1978, we conducted this study to collect and analyze epidemiological, clinical, psychosocial, and molecular genetic data on females with severe (s) or moderate (mod) HA or HB. Potential subjects with factor VIII or IX activity levels

Beschreibung: The occurrence of inhibitors in severe hemophilia A can make replacement with factor VIII concentrates insufficient for treatment of acute hemorrhages. An alternative is use of bypassing agents. The FEIBA® NovoSeven® Comparative Study (FENOC) is a randomized multicenter equivalence trial conducted in Europe and North America to study the efficacy of two bypassing agents. The usual framework of testing for differences between effectiveness of two treatments is not the focus in an equivalency trial. Instead, one tests that there is no clinically significant difference between treatments. In FENOC, the goal was to show that FEIBA® and NovoSeven® differed by less than 15% in efficacy. Subjects age 2+ with factor VIII deficiency, a history of inhibitor and need for bypassing agents were eligible. An episode of ankle, elbow, or knee bleeding was treated with one dose of FEIBA® and two doses of NovoSeven® with crossover between the options for the following episode. Subjects reported evaluation of the hemostatic effect 2, 6, 12, 24, 36, and 48 hours after treatment. The primary endpoint was hemostatic effect at 6 hours. Differences in pain, rated using the visual analog scale (VAS), and subject’s evaluation of when bleeding had stopped were secondary endpoints. The target sample size was 60 pairs of treatments. Data were analyzed using a modified version of McNemar’s test proposed by Lee and Lusher (1991). The equivalence hypothesis was tested and an associated confidence interval was calculated. If the confidence interval was within plus or minus 15% (−15%, 15%) significance was declared at the 0.05 level.Sixty-six subjects in 25 sites were enrolled. Twelve withdrew prior to treatment, 2 had 1 treatment, and 4 had unresolved queries at study close. Forty-eight subjects completed both treatments. Results of the intent-to-treat analysis are reported. The median age was 27. Approximately 43% had knee bleeds, 32% elbow, and 20% ankle. The remaining 5% had bleeding episodes involving more than one joint (n=2) or hip (n=2) or shoulder (n=1) joints. One serious adverse event not related to study or treatment was reported. At 6 hours after treatment 80.9% of recipients of FEIBA® and 78.7% of recipients of NovoSeven® reported the treatment was effective. The confidence interval for the treatment difference was −11.4% to 15.7%, (p=0.059). About 32% of the recipients had effective relief with one treatment but not the other. The mean within pair difference in VAS scores at 6 hours (FEIBA®-NovoSeven®) was −2.3 mm. At 6 hours 76.1% of those treated with FEIBA® reported that bleeding had stopped compared to 65.2% of those treated with NovoSeven®. The confidence interval was −2.7%, 24.5% so we could not conclude that the difference between the two products was less than 15%. However, the treatments were determined to be equivalent with respect to subjects’ evaluation of cessation of bleeding at 24 and 48 hours. FEIBA® and NovoSeven® may have similar efficacy in the treatment of acute hemorrhages in patients with inhibitors, although this was not consistently demonstrated in the FENOC study. There appears to be variation among patients in response to each product.

Beschreibung: Abstract 217 Introduction: Both genetic and environmental factors have been implicated as potential risk factors for the development of inhibitory factor VIII (FVIII) antibodies. Previous studies suggest that genetic factors are of major importance. The causative FVIII mutation likely sets the stage for inhibitor risk, with other genetic markers important in determining the final outcome. Data suggest that the process of inhibitor development is complex, involving a variety of immune regulatory genes, several of which have the potential to modify risk. Through a collaboration among three multi-center studies: the Hemophilia Inhibitor Genetics Study (HIGS), the Malmö International Brother Study (MIBS), and the Hemophilia Growth and Development Study (HGDS), a combined cohort was formed to conduct an association study to test the hypothesis that antibody development to FVIII is mediated by immune response genes. Methods: The study includes clinical and laboratory data for 680 people with hemophilia A. Participants from Europe and North America account for 43% and 57% of the population, respectively. Eighty-five percent have severe (0.05 – 0.4 IU/mL) hemophilia. The cohort is predominately Caucasian, 81.0%, with 6.2% of African heritage, 8.8% Hispanic, and the remaining 4% of other races and ethnicities. Forty-nine percent have a current, or history of, an inhibitor ≥1 BU. Using the Illumina iSelect platform, 14,626 single nucleotide polymorphisms (SNPs) from 1,081 candidate genes were genotyped. These included immune response and immune modifier genes: cytokines and their receptors, chemokines and their receptors, and pathway genes involved in inflammatory and immune responses. Analyses were completed among the total group and the subgroup with severe hemophilia to identify SNPs associated with inhibitor status. The models were adjusted for population admixture, severity of hemophilia, type of mutation (high vs. low risk), year of birth, and geographic region. Meta analyses were used to obtain single odds ratios (OR) and p-values for the three cohorts. Results: 13,952 of the 14,626 (95.4%) SNPs were successfully genotyped. One hundred fourteen were associated with inhibitor status at the p