Perioperative continuous infusions of factor VIII versus factor IX for patients with hemophilia A or B undergoing major surgery.

Continuous factor VIII (FVIII) or factor IX (FIX) infusions are commonly used for patients with hemophilia A (HA) or B (HB) undergoing surgery to secure perioperative hemostasis. To describe differences between the initial recovery and subsequent FIX and FVIII levels, and describe clinical outcomes among HB and HA patients receiving perioperative continuous infusion (CI) of recombinant FVIII and FIX concentrates. Retrospective chart review was conducted on 8 consecutive patients with HB and 7 consecutive patients with HA who underwent major surgery between 2014 and 2018 and received continuous infusions of standard half-life factor concentrate. Median initial bolus dose per kilogram was higher for HB compared to HA patients [90.8 (IQR 78.0-98.7) vs. 52.1 (IQR 48.6-55.6) IU/kg], while initial CI dose-rates were similar [4.3 (IQR 3.8-4.6) vs. 4.2 (IQR 3.8-4.4) IU/kg/h]. Median post-bolus recovery was higher for FVIII compared to FIX [1.70 (IQR 1.23-1.75) vs. 0.88 (IQR 0.75-1.00) IU/mL]. Median factor levels also were higher for FVIII on post-operative days 1 to 3. HB patients had greater mean intraoperative estimated blood loss [285.7 (range 0-1000) vs. 142.8 (range 0-400) mL] and longer median length of hospital stay [9 (IQR 8-12) vs. 5 (IQR 4-6.5) days]. Our initial evidence suggests greater in vivo yield of rFVIII compared to rFIX in the perioperative setting. We identified poorer clinical outcomes in this small cohort of perioperative HB patients indicating that they may benefit from a higher CI rate for adequate surgical hemostatic coverage.

Hemophilia B Gene Therapy with a High-Specific-Activity Factor IX Variant.

BACKGROUND: The prevention of bleeding with adequately sustained levels of clotting factor, after a single therapeutic intervention and without the need for further medical intervention, represents an important goal in the treatment of hemophilia. METHODS: We infused a single-stranded adeno-associated viral (AAV) vector consisting of a bioengineered capsid, liver-specific promoter and factor IX Padua (factor IX-R338L) transgene at a dose of 5×1011 vector genomes per kilogram of body weight in 10 men with hemophilia B who had factor IX coagulant activity of 2% or less of the normal value. Laboratory values, bleeding frequency, and consumption of factor IX concentrate were prospectively evaluated after vector infusion and were compared with baseline values. RESULTS: No serious adverse events occurred during or after vector infusion. Vector-derived factor IX coagulant activity was sustained in all the participants, with a mean (±SD) steady-state factor IX coagulant activity of 33.7±18.5% (range, 14 to 81). On cumulative follow-up of 492 weeks among all the participants (range of follow-up in individual participants, 28 to 78 weeks), the annualized bleeding rate was significantly reduced (mean rate, 11.1 events per year [range, 0 to 48] before vector administration vs. 0.4 events per year [range, 0 to 4] after administration; P=0.02), as was factor use (mean dose, 2908 IU per kilogram [range, 0 to 8090] before vector administration vs. 49.3 IU per kilogram [range, 0 to 376] after administration; P=0.004). A total of 8 of 10 participants did not use factor, and 9 of 10 did not have bleeds after vector administration. An asymptomatic increase in liver-enzyme levels developed in 2 participants and resolved with short-term prednisone treatment. One participant, who had substantial, advanced arthropathy at baseline, administered factor for bleeding but overall used 91% less factor than before vector infusion. CONCLUSIONS: We found sustained therapeutic expression of factor IX coagulant activity after gene transfer in 10 participants with hemophilia who received the same vector dose. Transgene-derived factor IX coagulant activity enabled the termination of baseline prophylaxis and the near elimination of bleeding and factor use. (Funded by Spark Therapeutics and Pfizer; ClinicalTrials.gov number, NCT02484092 .).

International recommendations on the diagnosis and treatment of acquired hemophilia A.

Acquired hemophilia A (AHA), a rare bleeding disorder caused by neutralizing autoantibodies against coagulation factor VIII (FVIII), occurs in both men and women without a previous history of bleeding. Patients typically present with an isolated prolonged activated partial thromboplastin time due to FVIII deficiency. Neutralizing antibodies (inhibitors) are detected using the Nijmegen-modified Bethesda assay. Approximately 10% of patients do not present with bleeding and, therefore, a prolonged activated partial thromboplastin time should never be ignored prior to invasive procedures. Control of acute bleeding and prevention of injuries that may provoke bleeding are top priorities in patients with AHA. We recommend treatment with bypassing agents, including recombinant activated factor VII, activated prothrombin complex concentrate, or recombinant porcine FVIII in bleeding patients. Autoantibody eradication can be achieved with immunosuppressive therapy, including corticosteroids, cyclophosphamide and rituximab, or combinations thereof. The median time to remission is 5 weeks, with considerable interindividual variation. FVIII activity at presentation, inhibitor titer and autoantibody isotype are prognostic markers for remission and survival. Comparative clinical studies to support treatment recommendations for AHA do not exist; therefore, we provide practical consensus guidance based on recent registry findings and the authors' clinical experience in treating patients with AHA.

Clinical evaluation of bleeds and response to haemostatic treatment in patients with acquired haemophilia: A global expert consensus statement.

BACKGROUND: Acquired haemophilia (AH) is a rare bleeding disorder with significant morbidity and mortality. Most patients initially present to physicians without experience of the disease, delaying diagnosis and potentially worsening outcomes. Existing guidance in AH is limited to clinical opinion of few experts and does not address monitoring bleeds in specific anatomical locations. AIM: Derive consensus from a large sample of experts around the world in monitoring bleeding patients with AH. METHODS: Using the Delphi methodology, a structured survey, designed to derive consensus on how to monitor bleeding patients with AH, was developed by a steering committee for completion by a group of haematologists with an interest in AH. Consensus was defined as ≥75% agreement with a given survey statement. After three rounds of survey refinement, a final list of consensus statements was compiled. RESULTS: Thirty-six global specialists in AH participated. The participants spanned 20 countries and had treated a median of 12.0 (range, 1-50) patients with AH within the preceding 5 years. Consensus was achieved in all items after three survey rounds. In addition to statements on general management of bleeding patients, consensus statements in the following areas were presented: urinary tract, gastrointestinal tract, muscles, skin, joints, nose, pharynx, mouth, intracranial and postpartum. CONCLUSIONS: Here, we present consensus statements derived from a broad sample of global specialists to address monitoring of location-specific bleeds and evaluating efficacy of bleeding treatment in patients with AH. These statements could be applied in practice by treating physicians and validated by individual population surveys.

Treatment and prevention of bleeding in congenital hemophilia A patients with inhibitors.

The treatment of bleeding in hemophilia A patients with persistent inhibitory antibodies to factor VIII is problematic. The current standard hemostatic agents for inhibitor patients are recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrate (APCC). These "inhibitor bypassing agents" are less reliably effective than are replacement therapies for patients without inhibitors, and there are no validated laboratory assays to monitor their efficacy. Furthermore, only single rFVIIa and APCC products are available worldwide, and their use can be complicated, albeit rarely, by thrombotic events. For all these reasons, new approaches to treat bleeding in inhibitor patients are eagerly awaited. These new approaches include replacement therapy with porcine factor VIII concentrate (currently approved for use in acquired hemophilia patients), bispecific antibodies to simulate the biologic function of factor VIII (already in use in some jurisdictions), pegylated forms of activated factor VII, and strategies targeting the natural anticoagulants TFPI and antithrombin, which create a hypercoagulable phenotype to counterbalance the hypocoagulability imposed by hemophilia.

Thrombotic microangiopathy in a patient with adult-onset Still's disease.

BACKGROUND: Since there are many disorders that can present with thrombotic microangiopathy (TMA), establishing a correct diagnosis is important to offer the most appropriate therapy. CASE REPORT: A 26-year-old woman was transferred to our hospital with fragmentation hemolytic anemia, thrombocytopenia, and acute kidney failure. History revealed that she was recently diagnosed with adult-onset Still's disease (AOSD) and received intraocular injections of bevacizumab to treat acute retinal artery occlusion. At our hospital, she underwent extensive investigations and was treated with high-dose steroids, hemodialysis, and therapeutic plasma exchange. For recurrent disease, she received a single dose of eculizumab. RESULTS: The patient's ADAMTS13 activity was normal and she had evidence of complement activation. Genetic testing identified a benign polymorphism in the C3 gene. Pathophysiology of TMA in AOSD is briefly discussed and an overview of the literature is presented. CONCLUSION: Work-up of a new fragmentation hemolytic anemia and thrombocytopenia should include careful review of past history, including medications, as well as relevant laboratory investigations with aim to establish a correct diagnosis. Occasionally, the correct diagnosis is not the obvious one and there could be multiple contributors to the pathogenesis. Establishing diagnosis is important for counseling patient on disease prognosis and to guide treatment.

Lymphoma-associated acquired von Willebrand syndrome responsive to splenectomy: A case report.

A previously healthy 33-year-old female presented with a large hematoma over her right knee after kneeling. She was found to have pancytopenia and massive splenomegaly. Von Willebrand Factor (VWF) antigen level was 0.38 units/ml, ristocetin cofactor activity 0.13 units/ml, and VWF multimeric distribution was normal. Bone marrow examination revealed an indolent B-cell lymphoma. Diagnosis was consistent with acquired von Willebrand syndrome as an autoimmune epiphenomenon of a lymphoma. Diagnostic and therapeutic splenectomy under hemostatic coverage was performed. VWF antigen levels and activities immediately normalized postoperatively and remained within the normal range several months later. Splenic pathology confirmed hairy cell leukemia with a BRAF mutation.

Invisible bleeds: Lived experiences and barriers to care for men with hemophilia.

INTRODUCTION: Guidelines of the World Federation of Hemophilia support the provision of equitable, optimal care for people with hemophilia (PWH). However, limited research exists examining the lived experiences of PWH or the barriers to care they may encounter. The primary objective of this exploratory study was to describe the experiences of men with hemophilia in Canada. METHODS: We conducted a qualitative descriptive study using a semistructured interview guide and analyzed transcribed interviews using inductive thematic content analysis. Inclusion criteria were: age ≥18 years, English-speaking, and confirmed diagnosis of inherited hemophilia A or B. RESULTS: A total of 11 participants were interviewed. Median age was 39 years old (29-73 years old), and diagnoses included severe hemophilia A (n = 5), mild hemophilia A (n = 2), and severe hemophilia B (n = 4). Three primary themes arose: (1) impact on identity and daily life; (2) dynamic changes in treatment; and (3) barriers to care and identified needs. Major subthemes included chronic pain and activity limitation, psychosocial burden, and symptom normalization. Multidisciplinary care, coordinated surgical care, improved emergency care, and clear care plans were identified as ongoing needs. DISCUSSION: Men with hemophilia described significant symptom burden and areas of ongoing need. Collaborative efforts between hematologists, emergency room physicians, and surgeons to establish hospital-specific testing, treatment and referral guidelines, and regular hemophilia treatment center audits may help address these care gaps, providing more person-centered, equitable care. Future work is required to implement these strategies and monitor their effects.

Switching to nonacog beta pegol in hemophilia B: Outcomes from a Canadian real-world, multicenter, retrospective study.

Background: The Canadian Bleeding Disorders Registry (CBDR) captures data from 24 hemophilia treatment centers and patients directly. Nonacog beta pegol (N9-GP) was approved in Canada in 2018. Objectives: To assess treatment outcomes following switching to N9-GP in a real-world setting. Methods: CBDR data for Canadian male patients (aged 7-72 years) with hemophilia B receiving prophylactic N9-GP for ≥6 months as of March 31, 2021, were included. To allow comparison with the previously used products, only patients for whom data were available in the CBDR for at least 6 months before the switch to N9-GP were included in this retrospective analysis. Results: Forty-two patients were included in the analysis (total observation period: 148.0 patient-years). The distribution of disease severity was 62% severe, 36% moderate, 2% mild, with 62% of patients previously receiving recombinant factor IX-Fc-fusion protein (rFIXFc) and 38% previously receiving standard half-life (SHL) recombinant factor IX (rFIX). During a median follow-up period of 2.3 years on N9-GP prophylaxis, 232 bleeds were reported in 30 patients, 29% of patients reported zero bleeds. The median overall annualized bleeding rate on N9-GP was 0.73 for patients switching from rFIXFc (previously 1.44) and 2.10 for patients switching from SHL rFIX (previously 6.06). Median total annualized factor consumption (IU/kg) was lower with N9-GP than with previous SHL rFIX (2152 vs 3018) and previous rFIXFc (1766 vs 2278). Conclusions: Results from this first real-world study of N9-GP in patients with hemophilia B suggest optimal bleeding control with low factor consumption after switching to N9-GP, irrespective of the previous product.

Extended half-life factor VIII concentrates in adults with hemophilia A: Comparative pharmacokinetics of two products.

BACKGROUND: The use of pharmacokinetic (PK) studies to help design personalized prophylaxis regimens for factor VIII (FVIII) concentrate in individuals with hemophilia A has been recognized for many years but only became practical for routine clinical use with the availability of web-accessible population PK applications based on Bayesian analysis. OBJECTIVE: To compare PK variables using population PK studies done on 2 extended half-life recombinant FVIII concentrates in 23 individuals with hemophilia A after switching from one product to the other. METHODS: We retrospectively analyzed PK parameters derived from the Web-Accessible Population Pharmacokinetic Service-Hemophilia (WAPPS-HEMO) application on 23 individuals with severe or moderately severe hemophilia A who were required to switch from recombinant FVIII Fc (Eloctate; Biogen, Cambridge, MA, USA) to recombinant antihemophilic factor PEGylated (Adynovate; Takeda Pharmaceutical Company, Osaka, Japan) between 2016 and 2017. RESULTS: There were minor PK differences between Eloctate and Adynovate, but some parameters did reach statistical significance, namely in vivo recovery (mean, 2.73 IU/dL per IU/kg vs 2.41 IU/dL per IU/kg), clearance (mean, 0.163 mL/h vs 0.194 mL/h), and volume of distribution at steady state (mean, 42.5 ml/kg vs 49.8 mL/kg). Smaller nonsignificant trends toward higher values for Adynovate were seen in terminal half-life, area under the curve, and predicted times to 5% and 1% residual FVIII after infusion. CONCLUSION: Population PK analysis revealed differences between the two extended half-life FVIII concentrates, reaching significance for in vivo recovery, clearance, and volume of distribution.

Final Results of the Prospective ADVATE® Immune Tolerance Induction Registry (PAIR) Study with Plasma- and Albumin-Free Recombinant Factor VIII.

INTRODUCTION: Neutralizing antibodies to coagulation factor VIII (FVIII) remain a major complication associated with FVIII replacement therapy. AIM: To assess safety and efficacy of immune tolerance induction (ITI) therapy with ADVATE® (antihemophilic factor [recombinant] [rAHF]) in patients who participated in the Prospective ADVATE Immune Tolerance Induction Registry (PAIR) study. METHODS: The PAIR study was an international, multicenter, open-label, prospective, observational study in patients with hemophilia A and inhibitors, prescribed rAHF ITI therapy in clinical practice. The primary endpoint was adverse event (AE) reporting; the secondary endpoints included incidence of central venous access device-related complications and success rates of ITI therapy. Maintenance of immune tolerance was monitored for 12 months post-ITI therapy. RESULTS: Of 44 patients, 36 completed ITI therapy, including 31 completing the 12-month follow-up. Most patients received rAHF 90-130 IU/kg/day (59.1%) and a mean of 6.0 doses/week; the median duration of rAHF ITI therapy during the PAIR study was 600 days. Overall, 284 AEs were reported; 56 AEs were serious, of which none were considered rAHF-related. Of 228 nonserious AEs, 14 (in six patients) were deemed rAHF-related: increase of FVIII inhibitors titer due to anamnestic response, nausea, catheter site pain, pyrexia, urticaria, upper respiratory tract infection, arthralgia, and hemarthrosis. None were severe or led to ITI discontinuation. Eighteen patients experienced ≥1 central venous access device-related complication, and 21 of 36 completers achieved a negative inhibitor titer. The Kaplan-Meier estimate of success for achievement of first negative titer at 18 months of ITI therapy was 68.3% (95% confidence interval 51.8-83.6%) among completers. Of patients with partial or complete success post-ITI, 87% (20/23) maintained immune tolerance at 12-month follow-up. CONCLUSION: Data suggest that rAHF ITI therapy in the PAIR study was effective, with no unexpected safety signals reported.

"They don't really take my bleeds seriously": Barriers to care for women with inherited bleeding disorders.

INTRODUCTION: Women with inherited bleeding disorders experience excessive bleeding that may impair their quality of life, making early diagnosis and treatment critical. However, the experiences of these women regarding access to care has been minimally described. The primary objective of this study was to evaluate and describe barriers to care for women with bleeding disorders. This study was a continuation of our previous work describing the lived experiences of these women. METHODS: We undertook a qualitative descriptive study. Inclusion criteria for study enrollment were the following: age ≥18 years, English-speaking, and confirmed diagnosis of an inherited bleeding disorder. Women were recruited across Canada by treating health-care providers and members of the Canadian Hemophilia Society. Telephone interviews were conducted using a semi-structured interview style, transcribed verbatim, and analyzed using descriptive thematic analysis. RESULTS: A total of 15 participants were interviewed. Median age was 31 years (range 24-70 years). Four primary themes surrounding barriers to care emerged: (1) lack of health-care provider awareness of bleeding disorders, (2) health-care provider dismissal of symptoms, (3) limited access to specialized care and treatment plans, and (4) need for self-education and advocacy. DISCUSSION: We found that women with inherited bleeding disorders experience tension with the health-care system, feeling unheard and poorly understood. Based on our findings, we identified key knowledge and care gaps that could be addressed with awareness and educational initiatives: patient education on vaginal blood loss, updated medical curricula, clear referral guidelines, and telehealth initiatives for patients residing far from hemophilia treatment centers.