Shannon Jackson

Long-acting recombinant factor IX Fc fusion protein (rFIXFc) for perioperative management of subjects with haemophilia B in the phase 3 B-LONG study

In the phase 3 B‐LONG (Recombinant Factor IX Fc Fusion Protein [rFIXFc] in Subjects With Haemophilia B) study, rFIXFc demonstrated a prolonged half‐life compared with recombinant factor IX (rFIX), and safety and efficacy for prophylaxis and treatment of bleeding in subjects with moderately‐severe to severe haemophilia B. In this B‐LONG sub‐analysis, rFIXFc was evaluated for efficacy in subjects requiring major surgery. Dosing was investigator‐determined. Assessments included dosing, consumption, bleeding, transfusions and haemostatic response. A population pharmacokinetics model of rFIXFc was used to predict FIX activity. Twelve subjects underwent 14 major surgeries (including 11 orthopaedic surgeries); most subjects (11/12) received rFIXFc prophylaxis before surgery (range, ~2 weeks–12 months). Investigators/surgeons rated haemostatic responses as excellent (n = 13) or good (n = 1). In most surgeries (85·7%), haemostasis from the pre‐surgical dose until the end of surgery was maintained with a single rFIXFc infusion. Blood loss was consistent with similar surgeries in subjects without haemophilia. The strong correlation (R2 = 0·9586, P < 0·001) between observed and population pharmacokinetic model‐predicted FIX activity suggests surgery did not impact rFIXFc pharmacokinetics. No unique safety concerns or inhibitors were observed. In conclusion, rFIXFc was safe and efficacious, with prolonged dosing intervals and low consumption, when used perioperatively in haemophilia B. Surgery did not appear to alter rFIXFc pharmacokinetics.

Helicobacter pylori Activates Calpain via Toll-Like Receptor 2 To Disrupt Adherens Junctions in Human Gastric Epithelial Cells

ABSTRACT Helicobacter pylori is a risk factor for the development of gastritis, gastroduodenal ulcers, and gastric adenocarcinoma. H. pylori-induced disruption of epithelial adherens junctions (AJs) is thought to promote the development of severe disease; however, the mechanisms whereby H. pylori alters AJ structure remain incompletely understood. The present study demonstrates that H. pylori infection in human patients is associated with elevated serum levels of an 80-kDa E-cadherin ectodomain, whose presence is independent of the presence of serum antibodies against CagA. In vitro, a heat-labile H. pylori surface component activates the host protease calpain in human gastric MKN45 cells independently of the virulence factors CagA and VacA. H. pylori-induced calpain activation results in cleavage of E-cadherin to produce a 100-kDa truncated form and induce relocalization of E-cadherin and β-catenin. Stimulation of MKN45 cells with the toll-like receptor 2 (TLR2) ligand P3C activated calpain and disrupted E-cadherin and β-catenin in a pattern similar to that induced by H. pylori. Inhibition of TLR2 prevented H. pylori-induced calpain activation and AJ disassembly. Together, these findings identify a novel pathway whereby H. pylori activates calpain via TLR2 to disrupt gastric epithelial AJ structure.

Long-term safety and efficacy of recombinant factor VIII Fc fusion protein (rFVIIIFc) in subjects with haemophilia A

The safety, efficacy and prolonged half‐life of recombinant factor VIII Fc fusion protein (rFVIIIFc) in previously treated patients with severe haemophilia A was demonstrated in the phase 3 A‐LONG and Kids A‐LONG studies. Here, we report interim safety and efficacy data from the rFVIIIFc extension study, ASPIRE (ClinicalTrials.gov #NCT01454739).

Recognizing the need for personalization of haemophilia patient-reported outcomes in the prophylaxis era.

The safety and efficacy of treatment options for patients with haemophilia have significantly improved over the last two decades, particularly with greater utilization of prophylactic approaches. Consequently, it is becoming increasingly difficult to differentiate the treatment benefits of available choices based on standard endpoints such as annualized bleeding rates and joint health scores. Patient‐reported outcomes (PROs) have shown limited ability to discriminate between treatment outcomes, in part because of their comprehensive nature; i.e. differences in specific outcomes meaningful to individual patients are masked by a global scoring system based on a fixed set of items, many of which may be unimportant for any given patient. There is a clear need for new outcome measures. Initiatives to develop patient‐centric outcomes that capture clinically meaningful change are ongoing. One such approach, goal attainment scaling (GAS), allows patients, in collaboration with a trained clinician, to select goals from a medical condition‐specific menu of options and subsequently facilitates quantitative assessment of goal realization. Thus, it is fully personalized and sensitive to small, often idiosyncratic, treatment benefits, such as improvements in functional capacity. In this paper, we present the underlying rationale for GAS and one other novel approach to PRO personalization, and discuss their potential to augment current outcome measures by reliably detecting and quantifying treatment effects in individuals with haemophilia on prophylaxis.

Cardiovascular disease (CVD) in Canadians with haemophilia: Age‐Related CVD in Haemophilia Epidemiological Research (ARCHER study)

Improvements in haemophilia care have increased life expectancy in persons with haemophilia (PWH). This ageing population presents clinicians with management challenges as they develop age‐related comorbidities such as cardiovascular disease (CVD).

Suspected collagen disorders in the bleeding disorder clinic: A case–control study

Disorders of collagen are associated with a mild bleeding tendency because of the potential abnormal interaction of collagen, von Willebrand factor (VWF) and platelets required during primary haemostasis and due to generalized soft tissue fragility. Abnormal collagen may contribute to bleeding in existing mucocutaneous bleeding disorders, but the prevalence in this setting is unknown. Generalized symptomatic joint hypermobility (SJH) is common in collagen disorders and may be objectively measured. To assess the association between symptomatic joint hypermobility and mucocutaneous bleeding disorders, we performed a case–control study in which case subjects were 55 consecutive individuals who had visited our bleeding disorder clinic with a diagnosis of von Willebrand disease, low von Willebrand factor levels, mild platelet function disorder or undefined bleeding disorder. Controls were 50 subjects without a bleeding disorder, and were age and gender matched to the cases. All subjects were assessed with: (i) Beighton score for joint hypermobility, (ii) revised Brighton criteria, (iii) Condensed MCMDM1‐VWD bleeding questionnaire, and (iv) haemostasis laboratory studies. The prevalence of SJH/suspected collagen disorder in the bleeding disorder clinic was 24% (13/55) compared with 2% (1/50) in the control population (OR 15, 95% CI 2–121). Seventy‐seven per cent of bleeding disorder clinic SJH subjects (10/13) had a prior personal or family history of Ehlers‐Danlos, Benign Joint Hypermobility Syndrome or Osteogenesis Imperfecta (OI). Symptomatic joint hypermobility was associated with increased odds of an underlying mucocutaneous bleeding disorder. These findings suggest that a collagen disorder is common and often unrecognized in the bleeding disorder clinic as a potential contributor to the bleeding symptoms.

Patterns of tertiary prophylaxis in Canadian adults with severe and moderately severe haemophilia B

From a young age patients with severe and moderately severe FIX deficiency (haemophilia B) can experience spontaneous or traumatic bleeding and joint destruction may result. The use of coagulation factor IX concentrate to prevent anticipated bleeding, as primary or secondary prophylaxis, has become a common and recommended practice in children. The current practice of using tertiary prophylaxis, in the presence of established joint arthropathy, in adults with haemophilia B is not well characterized. This observational study was conducted to gain a better understanding of the recent Canadian experience with tertiary prophylaxis in adults with severe and moderately severe haemophilia B. Data were collected from all eligible adult (≥ 18 years of age) males with baseline FIX:C ≤ 2% from seven Canadian Hemophilia Treatment centres over a 2‐year observation period from 2009 to 2011. Thirty‐four per cent of the 67 subjects with moderately severe haemophilia B were exposed to prophylaxis with the majority as continuous prophylaxis (≥45 weeks year‐1). The severe subgroup (FIX:C < 1%) demonstrated a 52% exposure rate. None had primary prophylaxis exposure in childhood. Eighty‐one per cent used once or twice weekly infusion regimens and reported a median annual bleeding rate of five bleeds per year versus four bleeds per year for those using on‐demand treatment. Annual median factor utilization for all subjects using prophylaxis was 196 283 U year‐1 compared to 46 361 U year‐1 for on demand. Approximately 50% of adults with severe haemophilia B are using continuous tertiary prophylaxis in Canada, a practice likely to increase which warrants further study.

Desmopressin in moderate hemophilia A patients: a treatment worth considering

Desmopressin increases endogenous factor VIII levels in hemophilia A. Large inter-individual variation in the response to desmopressin is observed. Patients with a lower baseline factor VIII activity tend to show a reduced response, therefore, desmopressin is less frequently used in moderate hemophilia A patients (baseline factor VIII activity 1-5 international units/deciliter), even though factor VIII levels may rise substantially in some of them. We aim to describe the response to desmopressin in moderate hemophilia A patients and to identify predictors. We selected data on 169 patients with moderate hemophilia from the multicenter Response to DDAVP In non-severe hemophilia A patients: in Search for dEterminants (RISE) cohort study. Adequate response to desmopressin was defined as a peak factor VIII level ≥ 30, and excellent response as ≥ 50 international units/deciliter after desmopressin administration. We used univariate and multiple linear regression techniques to analyze predictors of the peak factor VIII level. Response was considered adequate in 68 patients (40%), of whom 25 showed excellent response (15%). Intravenous administration, age, pre-desmopressin factor VIII activity and von Willebrand factor antigen, peak von Willebrand factor activity and desmopressin-induced rise in von Willebrand factor antigen were significant predictors of peak factor VIII level and explained 65% of the inter-individual variation. In 40% of moderate hemophilia A patients, desmopressin response was adequate, thus it is important not to with-hold this group of patients from desmopressin responsiveness. Among the six predictors that we identified for desmopressin-induced factor VIII rise, factor VIII activity and desmopressin-induced rise in von Willebrand factor antigen had the strongest effect.

Haematuria is not a risk factor of hypertension or renal impairment in patients with haemophilia.

An increased prevalence of hypertension has been reported in patients with haemophilia compared to the age‐matched general population, although the causes were unclear. To date, there has been limited data implicating haemophilia‐specific risk factors such as renal bleeding.

Joining the patient on the path to customized prophylaxis: one hemophilia team explores the tools of engagement.

Background The relationship between hemophilia team interventions and achievement of optimal clinical outcomes remains to be elucidated. The British Columbia Hemophilia Adult Team has previously reported results of a comprehensive approach to individualize prophylaxis that has resulted in substantially reduced bleeding rates. In order to facilitate knowledge exchange and potential replication, it was important to gain a thorough understanding of the team’s approach. Methods A focus group of the British Columbia Hemophilia Adult Team was conducted to identify specific roles and processes that might be contributing to the prophylaxis regimen outcomes in this clinic. The focus group consisted of two workshops; one to describe the individual and collective roles of the clinic team in providing clinical care and guiding patients toward individualized prophylaxis; and the other to describe the patient journey from initial contact through reaching a successful engagement with the clinic. Results Analysis of the results revealed team roles and processes that underpinned a shared decision-making relationship with the patient with a particular focus on supporting the patient’s autonomy. Within this relationship, team focus shifts away from “adherence” toward the process whereby patients design and implement prophylaxis regimens resulting in reduction or elimination of bleeding episodes. Limitations Using the current methodology, it is not possible to demonstrate a causal link between specific team processes and improved bleeding rates in patients. Conclusion Through the active support of patient autonomy in all aspects of decisions related to hemophilia management, the British Columbia Hemophilia Adult Team approach de-emphasizes “adherence” as the primary goal, and focuses on a prophylaxis plan that is customized by the patient and aligned with his priorities. Adoption of this comprehensive team approach facilitates shared goals between the patient and the team that may optimize treatment adherence, but more importantly, reduce bleeding rates.