A phase 1b/2 clinical study of marstacimab, targeting human tissue factor pathway inhibitor, in haemophilia.

A phase 1b/2, three-month study of marstacimab, a human monoclonal antibody targeting tissue factor pathway inhibitor (TFPI), was conducted in participants with haemophilia A or B, with or without inhibitors. Participants assigned to four cohorts received escalating weekly doses based on inhibitor status (without inhibitors: 300 mg, a single 300-mg loading dose with subsequent 150-mg doses, or 450 mg; with inhibitors: 300 mg). Safety outcomes were treatment-emergent adverse events (TEAEs), injection site reactions, clinical and laboratory parameter changes. Efficacy was assessed by annualised bleeding rates (ABRs). Pharmacokinetics and pharmacodynamics (PD) were also evaluated. Among 26 treated participants [haemophilia A without inhibitor, n = 16 (61.5%); haemophilia A with inhibitor, n = 7 (26.9%); haemophilia B, n = 3 (11.5%)], 24 completed the study. Overall, 80.8% experienced TEAEs. ABR during treatment was significantly reduced versus an external on-demand control group (p < 0.0001) and versus pretreatment ABR (p < 0.0001), with significant reductions observed across all dose cohorts. Marstacimab exposure generally increased in a dose-related manner, with steady-state concentration reached by day 57. Changes in pharmacodynamic biomarkers occurred across all dose cohorts. Marstacimab was safe and well tolerated. Clinically meaningful reductions in ABR and treatment-related changes for all PD biomarkers indicated effective targeting of TFPI. (Clinicaltrials.gov identifier, NCT02974855).

Long-term safety and efficacy of the anti-tissue factor pathway inhibitor marstacimab in participants with severe haemophilia: Phase II study results.

Marstacimab, an investigational human monoclonal antibody targeting tissue factor pathway inhibitor, demonstrated safety and efficacy in preventing bleeding episodes in patients with haemophilia. This multicentre, open-label study investigated safety, tolerability, and efficacy of long-term weekly prophylactic marstacimab treatment in participants with severe haemophilia A and B, with or without inhibitors. Adult participants were enrolled from a previous phase Ib/II study or de novo and assigned to one of two subcutaneous (SC) marstacimab doses: once-weekly 300 mg or a 300-mg loading dose followed by once-weekly 150-mg doses, for up to 365 days. Study end-points included safety assessments and annualised bleeding rates (ABRs). Of 20 enrolled participants, 18 completed the study. Overall, 70% of participants had treatment-emergent adverse events, including injection site reactions, injection site haematoma, and haemarthrosis. No treatment-related serious adverse events or thrombotic events occurred. Across all dose cohorts, mean and median on-study ABRs ranged from 0 to 3.6 and 0 to 2.5 bleeding episodes/participant/year respectively, demonstrating comparable efficacy to that observed in the short-term parent study. No treatment-induced anti-drug antibodies were detected. Once-weekly SC marstacimab prophylaxis was well tolerated, with an acceptable safety profile, and maintained long-term efficacy up to 365 days. (Clinicaltrials.gov identifier, NCT03363321).

Activated protein C has a regulatory role in factor VIII function.

Mechanisms thought to regulate activated factor VIII (FVIIIa) cofactor function include A2-domain dissociation and activated protein C (APC) cleavage. Unlike A2-domain dissociation, there is no known phenotype associated with altered APC cleavage of FVIII, and biochemical studies have suggested APC plays a marginal role in FVIIIa regulation. However, the in vivo contribution of FVIIIa inactivation by APC is unexplored. Here we compared wild-type B-domainless FVIII (FVIII-WT) recombinant protein with an APC-resistant FVIII variant (FVIII-R336Q/R562Q; FVIII-QQ). FVIII-QQ demonstrated expected APC resistance without other changes in procoagulant function or A2-domain dissociation. In plasma-based studies, FVIII-WT/FVIIIa-WT demonstrated dose-dependent sensitivity to APC with or without protein S, whereas FVIII-QQ/FVIIIa-QQ did not. Importantly, FVIII-QQ demonstrated approximately fivefold increased procoagulant function relative to FVIII-WT in the tail clip and ferric chloride injury models in hemophilia A (HA) mice. To minimize the contribution of FV inactivation by APC in vivo, a tail clip assay was performed in homozygous HA/FV Leiden (FVL) mice infused with FVIII-QQ or FVIII-WT in the presence or absence of monoclonal antibody 1609, an antibody that blocks murine PC/APC hemostatic function. FVIII-QQ again demonstrated enhanced hemostatic function in HA/FVL mice; however, FVIII-QQ and FVIII-WT performed analogously in the presence of the PC/APC inhibitory antibody, indicating the increased hemostatic effect of FVIII-QQ was APC specific. Our data demonstrate APC contributes to the in vivo regulation of FVIIIa, which has the potential to be exploited to develop novel HA therapeutics.

Sudden-onset gallbladder rupture due to Ceftriaxone-associated pseudolithiasis in a patient with acquired hemophilia A.

We herein report a 76-year-old man with acquired hemophilia A (AHA) who developed gallbladder rupture due to Ceftriaxone (CTRX)-associated pseudolithiasis. The patient was admitted for an examination of systemic subcutaneous bleeding. A blood test showed a prolonged activated partial thromboplastin time and sequentially revealed low factor VIII activity (<1%) and a high factor VIII inhibitor level of 143 BU/mL. The patient was thus diagnosed with AHA. After admission, he developed a high-grade fever and was administered intravenous CTRX, considering the possibility of psoas abscess or cellulitis. Although his high-grade fever was improved, computed tomography incidentally showed a high-density lesion in the gallbladder, suggestive of CTRX-associated pseudolithiasis without clinical symptoms. Despite cessation of CTRX, the pseudolithiasis never disappeared, and the patient suddenly died after rapid progression of abdominal bloating. An autopsy revealed that the gallbladder was severely swollen and had ruptured with hemorrhaging because of hemorrhagic cholecystitis, caused by CTRX-associated pseudolithiasis with AHA. Our case demonstrated that CTRX-associated pseudocholelithiasis can unexpectedly induce gallbladder hemorrhaging and rupture in a patient with a bleeding diathesis, including AHA. CTRX-associated pseudocholelithiasis can cause a fatal outcome in patients with a bleeding disorder, even if CTRX is ceased as soon as pseudocholelithiasis is detected.

[Acquired hemophilia A following BNT162b2 mRNA COVID-19 vaccination].

Acquired hemophilia A (AHA) is a rare disease characteized by bleeding symptoms caused by decreased factor VIII activity due to the appearance of inhibitors to factor VIII triggered by malignancy or collagen disease. An 86-year-old woman developed purpura on her extremities after the first dose of the BNT162b2 mRNA COVID-19 vaccine. This symptom subsided after a few days. After the second dose of the BNT162b2 mRNA COVID-19 vaccine, purpura appeared again, and the patient was referred to our hospital Her APTT was remarkably prolonged to 110 seconds, and a cross-mixing test revealed an inhibitor pattern. Since FVIII activity was <1% and FVIII inhibitor was 51.6 BU, she was diagnosed with AHA. Prednisolone therapy was started, and coagulative complete remission was achieved. Because acquired hemophilia can develop after mRNA COVID-19 vaccination, as in this case, it is critical to monitor the appearance of bleeding symptom.

[Acquired hemophilia A that developed after BNT162b2 mRNA COVID-19 vaccination and worsened following re-vaccination].

An 86-year-old Japanese male patient visited a nearby hospital with painful swelling in his left upper and lower limbs 35 days after the second dose of the BNT162b2 mRNA coronavirus disease-2019 (COVID-19) vaccine. He was referred to our hematological department due to a prolonged activated partial thromboplastin time and was urgently admitted. He was diagnosed with acquired hemophilia A (AHA) based on factor VIII (FVIII) activity of 1.7%, FVIII inhibitor of 152.3 BU/ml, and FVIII-binding antibodies detected by enzyme-linked immunosorbent assay. Immunosuppressive therapy with prednisolone (PSL) at 0.5 mg/kg/day was started owing to the risk of infection due to old age and poor activities of daily living. Hemostasis treatment with bypass hemostatic preparations (rFVIIa preparation, FVIIa/FX) was administered for each bleeding event, such as intramuscular and knee joint bleeding, resulting in good hemostatic effects. Coagulative complete remission was achieved on day 69 with PSL treatment; however, FVIII activity decreased with PSL tapering. AHA relapse with rectus abdominis muscle hematoma was observed after the third vaccination. This is the first Japanese report of AHA after COVID-19 vaccination and the world's first case, in which the presence of anti-FVIII-binding antibodies were observed.

No Benefit to Platelet-rich Plasma Over Placebo Injections in Terms of Pain or Function in Patients with Hemophilic Knee Arthritis: A Randomized Trial.

BACKGROUND: Hemophilic knee arthritis is one of the most common presenting symptoms of hemophilia, and its management continues to be challenging to practitioners. Preliminary research has suggested that platelet-rich plasma (PRP) may have short-term efficacy in the treatment of hemophilic knee arthritis, but evidence for this treatment is limited. QUESTIONS/PURPOSES: What is the effectiveness of PRP compared with placebo in (1) reducing pain and improving knee joint function (as measured by WOMAC, VAS, and Hemophilia Joint Health Score [HJHS]) and (2) improving quality of life (as measured by SF-36 scores) in patients with hemophilic knee arthritis through 24 months of follow-up? METHODS: This was a prospective, parallel-group, double-blinded, single-center, placebo-controlled randomized clinical trial that included participants from a tertiary care center starting January 1, 2019, with follow-up completed on November 30, 2021. Participants were older than 18 years and had hemophilic knee arthritis confirmed by MRI, and they were randomly allocated to interventions in a 1:1 ratio. The investigators were not informed of the randomization sequence generated by the computer. Patient groups were comparable with respect to age, gender, BMI, hemophilia type, and disease severity at baseline. Physicians delivered three sessions (one per week) of a standard intraarticular injection of PRP (n = 95) or placebo (n = 95). The rate of successful blinding was balanced across the groups, which was assessed by asking participants which injection they thought they had received. The primary outcome was the WOMAC score (range 0 to 96; higher scores indicate more pain and worse function; minimum clinically important difference, 6.4 points) over 24 months. Among the 190 patients assigned to PRP or saline injections (mean age 31 ± 7 years), 100% (190) of patients were men). There was no between-group difference in the proportion of patients who completed the trial; 97% (92 of 95) of patients in the PRP group and 94% (89 of 95) of patients in the placebo group completed the trial. The most common adverse events were injection site discomfort 8% (8 of 95) in the PRP group and 4% (4 of 95) in the placebo group. An intention-to-treat analysis was planned, but there was no crossover between groups. All patients were included in the analyses. With 95 patients in each group, the study was powered a priori at 90% to detect a difference in WOMAC score of 6.4 points, which was considered a clinically important difference. RESULTS: There were no clinically important differences in the mean WOMAC, VAS pain, HJHS, SF-36, and MRI scores between groups at any timepoint. Intraarticular PRP did not ameliorate function, symptoms, and quality of life in patients with hemophilic knee arthritis. At 24 months of follow-up, the mean difference between the PRP and placebo groups in the WOMAC score was -1 (95% CI -5 to 2; p = 0.42). The mean difference in the VAS pain score was -0.3 (95% CI -0.8 to 0.2; p = 0.19), in the HJHS was -0.6 (95% CI -1.4 to 0.1; p = 0.10), in the SF-36 physical component summary was 0 (95% CI -2 to 3; p = 0.87), and in the SF-36 mental component summary was -1 (95% CI -3 to 2; p = 0.64). The mean differences in the MRI scores of soft tissue and osteochondral subscore were 0.1 (95% CI -0.3 to 0.5; p = 0.59) and -0.3 (95% CI -0.7 to 0.1; p = 0.19), respectively. CONCLUSION: Among patients with hemophilic knee arthritis, three intraarticular PRP injections, compared with placebo injections, did not improve hemophilic knee symptoms, function, and quality of life over 24 months. The results of this study do not support the use of PRP injections in patients who have hemophilic knee arthritis. LEVEL OF EVIDENCE: Level I, therapeutic study.

[Hemostatic management of hemophilia].

Replacement therapy is the basic treatment for hemophilia by infusing deficient clotting factors, including replacement therapy for prophylaxis (i.e., prevention of breakthrough bleeding for physical activity), episodic replacement therapy, replacement therapy during and after procedures and surgery, and replacement therapy for physical activity, each administered at doses and intervals appropriate for the purpose and the product used. Although emicizumab is increasingly used for prophylaxis in severe hemophilia A, the combination of replacement therapy is necessary, especially during severe bleeding, highly invasive procedures, and major surgery. Furthermore, the usual APTT measurements cannot be used for monitoring the replacement therapy and detecting the presence of inhibitors while patients are receiving emicizumab. Hemostatic management of patients with inhibitors should be implemented based on the purpose of the therapy, the latest inhibitor titer, and the clinical response to the product, with the choice of inhibitor neutralization or bypass agent therapy. When bypassing agents are used in patients with hemophilia A with emicizumab inhibitor during and after bleeding, procedures, and surgery, the choice of agent and dose adjustment should be made with attention to thrombotic complications.

Acquired Hemophilia A Associated with NSAID: A Case Report.

Acquired hemophilia A (AHA) is a blood clotting disorder caused by the presence of autoantibodies (inhibitors) against factor VIII. The typical symptom of this disorder is bleeding under the skin and soft tissue (rarely in the joints), with no family or personal previous history of bleeding. This case reports is tended to build up awareness for better diagnosis and therapy. Woman, 39 years old, bruises on both forearms are intermittent for 2 months with a history of long term drug consumption for headache treatment. Hemostatic test showed the elongation of activated partial thromboplastin test (APTT) to 87.1 (normal 24.4-44.4 seconds) and the decreament of factor VIII (FVIII) activity to 5% (normal 60-150%). Provision of recombinant factor VIII lowered factor VIII activity to 2%. Factor VIII inhibitor titer was 21.12 BU and diagnosis AHA was made. Inhibitor eradication by methylprednisolone tablet 3x16mg which was given for 2 months, improved the APPT to 46.7 seconds and factor VIII activity to 36%. Acquired Hemophilia A should be suspected in an adult bleeding patient with history of taking a long time non-steroidal anti-inflammatory drugs (NSAIDs). This case is a rare case in Indonesia and therefore the procedure for diagnosis needs to be improved in order to avoid errors in delivering a therapy which can cause the decreament of factor VIII activity.

[Acquired hemophilia A with high-titer factor VIII inhibitor developing subsequent to clopidogrel administration].

An 80-year-old male was referred to our department for prolonged APTT (activated partial thromboplastin time) and subcutaneous hemorrhage. His medical history comprised alcoholic liver cirrhosis, hepatocellular carcinoma (HCC), and peripheral artery disease (PAD). For refractory HCC, he had received transcatheter arterial chemoembolization and was followed up regularly at our hospital. He underwent percutaneous transluminal angioplasty for PAD 10 months ago, and dual antiplatelet therapy with clopidogrel and cilostazol was initiated. Cilostazol was discontinued owing to subcutaneous hemorrhage 6 months ago. The prolonged APTT level, inhibitor pattern by cross-mixing test, and the presence of the inhibitor against factor VIII (449 Bethesda unit/ml) corroborated acquired hemophilia A (AHA). Thus, clopidogrel was discontinued for possible drug-induced AHA. After 4-week oral corticosteroid therapy, the APTT level recovered to normal. This case highlights two distinct features as follows: (1) possible relation to clopidogrel; and (2) despite extremely high titer of factor VIII inhibitor, his bleeding episodes were managed without antihemorrhagic agents. Here we present a case of clopidogrel-related AHA. Further accumulation of such cases is warranted to determine the potential correlation with clopidogrel and AHA.

Development of acquired hemophilia A during treatment of multiple myeloma with lenalidomide.

We describe a 67-year-old female demonstrating symptomatic multiple myeloma (MM) with anemia and bone lesions initially diagnosed in 2009. Although a partial response was achieved after bortezomib and dexamethasone treatment, MM recurred in 2012. Therefore, treatment with lenalidomide, cyclophosphamide, and dexamethasone was commenced. Coagulation tests conducted prior to the chemotherapy were normal. Lenalidomide was discontinued after 10 days due to exacerbation of renal dysfunction. Simultaneously, activated partial thromboplastin time (APTT) was prolonged to 89.5 seconds. The mixing test showed an inhibitor pattern, with factor VIII at 2% and factor VIII inhibitor at 4.85 BU/ml. A diagnosis of acquired hemophilia A was made, and treatment with prednisolone was started, after which APTT improved to 36.4 seconds and factor VIII inhibitor decreased to 1.09 BU/ml. The factor VIII inhibitor level again increased concomitantly with restarting lenalidomide, which was, therefore, discontinued, while immunosuppressive therapy was administered with the addition of cyclophosphamide. Factor VIII inhibitor gradually disappeared from the patient's blood over the next four months. To the best of our knowledge, this is the first description of lenalidomide as a possible cause of acquired hemophilia A. Our experience indicates that we need to pay attention to acquired hemophilia A after initiating lenalidomide therapy in patients with hematologic malignancies.

Case Report: Effective management of adalimumab-induced acquired hemophilia A with the CyDRI protocol.

Introduction: Acquired Hemophilia A (AHA) is a rare autoimmune disorder characterized by the emergence of inhibitors that specifically target coagulation Factor VIII, frequently resulting in severe bleeding episodes. Methods: We conducted a retrospective analysis of the medical records of a 68-year-old male patient who presented with adalimumab-induced AHA. Results: The patient received adalimumab, a tumor necrosis factor inhibitor antibody, as part of his treatment for rheumatoid arthritis. The patient's clinical journey, characterized by intense bleeding and coagulopathy, was effectively managed with the application of recombinant Factor VIIa (rFVIIa) and the CyDRi protocol. Discussion: The case emphasizes the importance of prompt coagulation assessment in patients with bleeding symptoms receiving disease-modifying therapy for rheumatoid arthritis that includes adalimumab therapy, considering the rare yet life-threatening nature of AHA. Additionally, this report provides an extensive review of the existing literature on drug-induced AHA, with a special emphasis on cases linked to immunomodulatory medications. Through this two-pronged approach, our report aims to enhance understanding and awareness of this severe complication among healthcare providers, promoting timely diagnosis and intervention.

Life-threatening chlorpromazine-induced acquired haemophilia A in a patient with a cavernous malformation involving the medulla oblongata.

INTRODUCTION: Chlorpromazine is a commonly used drug in several medical conditions associated with a wide range of side effects. Few cases of hemostatic disorder have been reported in the literature. CASE REPORT: A 39-year-old man had previously been diagnosed with a cavernous malformation of the medulla oblongata. Chlorpromazine was started to treat persistent hiccups. Twenty days later, the patient presented hepatitis and a pruritic rash. Haemostasis tests revealed a prolonged partial thromboplastin time associated with isolated decrease of factor VIII level and anti-factor VIII antibodies. Magnetic resonance imaging revealed recent asymptomatic bleeding. Introduction of eptacog alfa and prednisone allowed clinical and biological improvement as well as a prolonged remission after 12 months of follow-up.

Adalimumab-associated Acquired Hemophilia in a Patient with Scleritis.

Acquired hemophilia A (AHA) is a rare condition that may be drug-induced. In this case report, we describe a patient who presented with extensive subcutaneous bleeding three years after beginning treatment with adalimumab for necrotizing scleritis. His workup was compatible with drug-induced AHA. He was treated with high-dose corticosteroids, cyclophosphamide, and rituximab. Adalimumab was discontinued. We present this case as an example of a rare, but potentially life-threatening, complication of adalimumab.

Doxycycline-induced acquired haemophilia A.

An 80-year-old man with no personal or family history of bleeding, presented to hospital with extensive haematomas and skin bruising after using doxycycline. His basic lab workup was concerning for a coagulopathy with an elevated activated partial thromboplastin time and significant anaemia. Mixing studies and other factor levels were tested that led to the diagnosis of acquired haemophilia A with low factor VIII levels and high factor VIII antibodies. He was started on steroids, but his haemoglobin level continued to drop. Later, during his treatment, he was given multiple therapeutic agents, including cyclophosphamide, rituximab and recombinant factor VII (NovoSeven-R). Gradually factor VIII levels increased and haemoglobin stabilised. The hospital course was complicated by COVID-19 pneumonia leading to acute respiratory distress syndrome; the patient eventually expired due to respiratory failure.