Congenital haemophilia A (factor VIII deficiency) and B (factor IX deficiency) are X-linked bleeding disorders. Replacement therapy has been the cornerstone of the management of haemophilia, aiming ...to reduce the mortality and morbidity of chronic crippling arthropathy. Frequent intravenous injections are burdensome and costly for patients, consequently with poor adherence and restricted access to therapy for many patients worldwide. Bioengineered clotting factors with enhanced pharmacokinetic profiles can reduce the burden of treatment. However, replacement therapy is associated with a risk for inhibitor development that adversely affects bleeding prevention and outcomes. Novel molecules that are subcutaneously delivered provide effective prophylaxis in the presence or absence of inhibitors, either substituting for the procoagulant function of clotting factors (eg, emicizumab) or targeting the natural inhibitors of coagulation (ie, antithrombin, tissue factor pathway inhibitor, or activated protein C). The ultimate goal of haemophilia treatment would be a phenotypical cure achievable with gene therapy, currently under late phase clinical investigation.
Emicizumab is a bispecific monoclonal antibody that bridges activated factor IX and factor X to replace the function of missing activated factor VIII, thereby restoring hemostasis. In a phase 3, ...multicenter trial, we investigated its use as prophylaxis in persons who have hemophilia A without factor VIII inhibitors.
We randomly assigned, in a 2:2:1 ratio, participants 12 years of age or older who had been receiving episodic treatment with factor VIII to receive a subcutaneous maintenance dose of emicizumab of 1.5 mg per kilogram of body weight per week (group A) or 3.0 mg per kilogram every 2 weeks (group B) or no prophylaxis (group C). The primary end point was the difference in rates of treated bleeding (group A vs. group C and group B vs. group C). Participants who had been receiving factor VIII prophylaxis received emicizumab at a maintenance dose of 1.5 mg per kilogram per week (group D); intraindividual comparisons were performed in those who had participated in a noninterventional study.
A total of 152 participants were enrolled. The annualized bleeding rate was 1.5 events (95% confidence interval CI, 0.9 to 2.5) in group A and 1.3 events (95% CI, 0.8 to 2.3) in group B, as compared with 38.2 events (95% CI, 22.9 to 63.8) in group C; thus, the rate was 96% lower in group A and 97% lower in group B (P<0.001 for both comparisons). A total of 56% of the participants in group A and 60% of those in group B had no treated bleeding events, as compared with those in group C, who all had treated bleeding events. In the intraindividual comparison involving 48 participants, emicizumab prophylaxis resulted in an annualized bleeding rate that was 68% lower than the rate with previous factor VIII prophylaxis (P<0.001). The most frequent adverse event was low-grade injection-site reaction. There were no thrombotic or thrombotic microangiopathy events, development of antidrug antibodies, or new development of factor VIII inhibitors.
Emicizumab prophylaxis administered subcutaneously once weekly or every 2 weeks led to a significantly lower bleeding rate than no prophylaxis among persons with hemophilia A without inhibitors; more than half the participants who received prophylaxis had no treated bleeding events. In an intraindividual comparison, emicizumab therapy led to a significantly lower bleeding rate than previous factor VIII prophylaxis. (Funded by F. Hoffmann-La Roche and Chugai Pharmaceutical; HAVEN 3 ClinicalTrials.gov number, NCT02847637 .).
Emicizumab (ACE910) bridges activated factor IX and factor X to restore the function of activated factor VIII, which is deficient in persons with hemophilia A. This phase 3, multicenter trial ...assessed once-weekly subcutaneous emicizumab prophylaxis in persons with hemophilia A with factor VIII inhibitors.
We enrolled participants who were 12 years of age or older. Those who had previously received episodic treatment with bypassing agents were randomly assigned in a 2:1 ratio to emicizumab prophylaxis (group A) or no prophylaxis (group B). The primary end point was the difference in bleeding rates between group A and group B. Participants who had previously received prophylactic treatment with bypassing agents received emicizumab prophylaxis in group C.
A total of 109 male participants with hemophilia A with inhibitors were enrolled. The annualized bleeding rate was 2.9 events (95% confidence interval CI, 1.7 to 5.0) among participants who were randomly assigned to emicizumab prophylaxis (group A, 35 participants) versus 23.3 events (95% CI, 12.3 to 43.9) among those assigned to no prophylaxis (group B, 18 participants), representing a significant difference of 87% in favor of emicizumab prophylaxis (P<0.001). A total of 22 participants in group A (63%) had zero bleeding events, as compared with 1 participant (6%) in group B. Among 24 participants in group C who had participated in a noninterventional study, emicizumab prophylaxis resulted in a bleeding rate that was significantly lower by 79% than the rate with previous bypassing-agent prophylaxis (P<0.001). Overall, 198 adverse events were reported in 103 participants receiving emicizumab prophylaxis; the most frequent events were injection-site reactions (in 15% of participants). Thrombotic microangiopathy and thrombosis were reported in 2 participants each (in the primary analysis) who had received multiple infusions of activated prothrombin complex concentrate for breakthrough bleeding. No antidrug antibodies were detected.
Emicizumab prophylaxis was associated with a significantly lower rate of bleeding events than no prophylaxis among participants with hemophilia A with inhibitors. (Funded by F. Hoffmann-La Roche and Chugai Pharmaceutical; HAVEN 1 ClinicalTrials.gov number, NCT02622321 .).
Hemophilia A and B predominantly attracts clinical attention in males due to X‐linked inheritance, introducing a bias toward female carriers to be asymptomatic. This common misconception is ...contradicted by an increasing body of evidence with consistent reporting on an increased bleeding tendency in hemophilia carriers (HCs), including those with normal factor VIII/IX (FVIII/IX) levels. The term HC can hamper diagnosis, clinical care, and research. Therefore, a new nomenclature has been defined based on an open iterative process involving hemophilia experts, patients, and the International Society on Thrombosis and Haemostasis (ISTH) community. The resulting nomenclature accounts for personal bleeding history and baseline plasma FVIII/IX level. It distinguishes five clinically relevant HC categories: women/girls with mild, moderate, or severe hemophilia (FVIII/IX >0.05 and <0.40 IU/ml, 0.01–0.05 IU/ml, and <0.01 IU/ml, respectively), symptomatic and asymptomatic HC (FVIII/IX ≥0.40 IU/ml with and without a bleeding phenotype, respectively). This new nomenclature is aimed at improving diagnosis and management and applying uniform terminologies for clinical research.
Requirements to participate in haemophilia clinical trials Mahlangu, Johnny N.
Haemophilia : the official journal of the World Federation of Hemophilia,
April 2020, 2020-Apr, 2020-04-00, 20200401, Letnik:
26, Številka:
S3
Journal Article
Recenzirano
Odprti dostop
Introduction
Clinical trials in haemophilia product development are expanding rapidly however, the number of sites and expertise in the clinical trial conduct is limited. Guidance on the requirement ...for conducting clinical trials is required
Aim
The aim of this paper is to outline generic requirements to participate in clinical trials in haemophilia
Materials
This paper describes three elements which are the requirements for success conduct of haemophilia clinical trials. These are the study product, study participant, and the global regulatory and ethics framework
Results and conclusion
In haemophilia clinical trials, requirements for participate in studies are many and include considerations of study product, study participant and ethical and regulatory framework. When these elements are in place, it is possible to conduct haemophilia clinical trials anywhere in the world.
Current unmet needs in haemophilia A patients with inhibitors include the need for intravenous infusion of replacement therapy and the high burden of treatment associated with prophylaxis. Emicizumab ...is a humanised bispecific monoclonal antibody designed to address these unmet needs and has completed phase III clinical trials in adolescents/adults (HAVEN 1) and paediatric (HAVEN 2) inhibitor populations. In HAVEN 1, there was an 80% bleed reduction across all bleeds, 89% reduction in treated joint bleeds, 92% reduction in treated spontaneous bleeds, and 95% reduction in treated target joint bleeds on emicizumab compared with no prophylaxis. In HAVEN 2, there was a 63% reduction in all bleeds, 94.7% reduction in treated bleeds, 94.7% reduction in treated spontaneous bleeds, 100% reduction in treated joint bleeds, and 100% reduction in treated target joint bleeds on emicizumab prophylaxis when compared with no prophylaxis. For patients on bypassing agent prophylaxis, emicizumab resulted in a 68% reduction in bleeds in HAVEN 1 and a 100% reduction in bleed rates in HAVEN 2. In HAVEN 1, three patients developed thrombotic microangiopathy (TMA) and two developed thrombosis when emicizumab was used together with an activated prothrombin complex concentrate (aPCC) at high or frequent doses. When the combination was avoided in HAVEN 2, no patient developed TMA or thrombosis. In both studies, no anti-emicizumab antibodies developed and the pharmacokinetic profile of emicizumab was similar. Emicizumab use is currently being explored in haemophilia A patients without inhibitors as well as in combination with other haemophilia A replacement therapies. The role of emicizumab in combination with current factor VIII replacement therapies and evolving non-replacement therapies remains to be established.
Redefining prophylaxis in the modern era Mahlangu, Johnny N.; Blanchette, Victor; Klamroth, Robert
Haemophilia : the official journal of the World Federation of Hemophilia,
February 2021, 2021-Feb, 2021-02-00, 20210201, Letnik:
27, Številka:
S3
Journal Article
Recenzirano
Odprti dostop
Prophylaxis is the globally accepted standard of care for persons with haemophilia and presents many advantages over episodic treatment. The prophylaxis benefits include bleed reduction, reduction in ...musculoskeletal complications and improvement in the quality of life. The currently evolving novel therapies for the management of haemophilia has ushered a new era characterized by improved prophylaxis targets and outcomes. These redefined targets and outcomes have necessitated the need to also redefine prophylaxis. In this state‐of‐the‐art review, we redefine prophylaxis in the modern era by revisiting its definition, presenting data to support higher trough levels to achieve with prophylaxis and introducing steady‐state haemostasis as a possible new target for prophylaxis.
The unprecedented progress in addressing unmet needs in haemophilia care to date includes developing several novel therapies that rebalance haemostasis by restoring thrombin generation in patients ...with haemophilia A or B with and without inhibitors. These novel therapies are FVIII mimetics, antithrombin interference RNA therapy and several monoclonal antibodies directed against the tissue factor pathway inhibitor (anti-TFPI). In this review, we provide an update on the progress made in developing anti-TFPI therapie. Phase 1 data from the three anti-TFPI studies showed acceptable safety profiles, and currently, available phase 2 data are encouraging. While these data support these molecules' further development progression, there is uncertainty on several aspects of their evolution. Two of the three anti-TFPIs have shown drug-related thrombosis, with one study consequently terminated. None of the thrombotic events is predictable with current monitoring tools, and none correlate with known coagulation parameters. All three anti-TFPIs undergo target mediated drug disposition, which impacts the formulation of dosing regimen fo these therapies. They would require more frequent dosing than some of the extended half-life clotting factor products and antithrombin RNAi therapy. There is no assay to measure the TFPI as the physiological levels are very low, which makes monitoring the impact of the anti-TFPI a challenge. The anti-TFPIs have several advantages, including their bioavailability when administered subcutaneously, their stable pharmacokinetics and their ability to prevent bleeds in haemophilia A or B patients with and without inhibitors. Whether these advantages can be realized will depend on the outcome of the currently ongoing studies.
The Phase 3 A-LONG and Kids A-LONG studies demonstrated the prolonged half-life of rFVIIIFc compared with rFVIII, and the safety and efficacy of rFVIIIFc in subjects with severe haemophilia A. ...Eligible subjects from A-LONG and Kids A-LONG continued rFVIIIFc treatment by enrolling in ASPIRE, an ongoing extension study. Based on combined data from the primary studies and ASPIRE interim data, the safety and efficacy of rFVIIIFc in subjects requiring surgery were evaluated. Perioperative dosing regimens were determined by investigators with guidance based on pharmacokinetic data and recommendations from a clinical dosing committee. In addition to dosing frequency, factor consumption, blood loss, transfusions, bleeding episodes, and haemostatic response were assessed. Across studies, 21 subjects underwent 23 evaluable major surgeries, including 19 orthopaedic surgeries; 41 subjects underwent 52 minor surgeries, including 30 dental procedures. No major and 10 minor surgeries were performed in paediatric subjects. Of the major (n = 22) and minor (n = 32) surgeries assessed for haemostatic response, all were rated as excellent or good by the investigator/surgeon. During most major surgeries (95.7 %), haemostasis was maintained with one rFVIIIFc infusion. Blood loss in major surgeries was consistent with similar surgeries in subjects without haemophilia. Across studies, rFVIIIFc was well tolerated; no subject developed an inhibitor.
Background
Surgical procedures impose hemostatic risk to people with hemophilia, which may be minimized by optimal factor (F) replacement therapy.
Methods
This analysis evaluates the efficacy and ...safety of extended half‐life factor replacement recombinant FVIII and FIX Fc fusion proteins (rFVIIIFc and rFIXFc) during surgery in phase 3 pivotal (A‐LONG/Kids A‐LONG and B‐LONG/Kids B‐LONG) and extension (ASPIRE and B‐YOND) studies. Dosing regimens were determined by investigators. Injection frequency, dosing, blood loss, transfusions, and hemostatic response were assessed.
Results
Forty‐five major (n = 31 subjects) and 90 minor (n = 70 subjects) procedures were performed in hemophilia A; 35 major (n = 22) and 62 minor (n = 37) procedures were performed in hemophilia B. Unilateral knee arthroplasty was the most common major orthopedic procedure (hemophilia A: n = 15/34; hemophilia B: n = 8/24). On the day of surgery, median total dose in adults/adolescents was 81 IU/kg for rFVIIIFc and 144 IU/kg for rFIXFc; most major procedures required ≤2 injections (including loading dose). Through days 1–14, most major procedures had ≤1 injection/day. Hemostasis was rated excellent (rFVIIIFc: n = 39/42; rFIXFc: n = 29/33) or good (n = 3/42; n = 4/33) in evaluable major surgeries, with blood loss comparable with subjects without hemophilia. Most minor procedures in adults/adolescents required one injection on the day of surgery, including median loading dose of 51 IU/kg (rFVIIIFc) and 80 IU/kg (rFIXFc). No major treatment‐related safety concerns were identified. No subjects developed inhibitors or serious vascular thromboembolic events.
Conclusions
rFVIIIFc and rFIXFc were efficacious and well tolerated for the management of perioperative hemostasis across a wide spectrum of major and minor surgeries in hemophilia.
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