Direct oral anticoagulants in antiphospholipid syndrome with venous thromboembolism: Impact of the European Medicines Agency guidance

Hemophilia Gene Therapy: The End of the Beginning?

Extensive preclinical research over the past 30 years has culminated in the recent regulatory approval of several gene therapy products for hemophilia. Based on the efficacy and safety data in a recently conducted phase III clinical trial, Roctavian® (valoctocogene roxaparvovec), an adeno-associated viral (AAV5) vector expressing a B domain deleted factor VIII (FVIII) complementary DNA, was approved by the European Commission and Food and Drug Administration (FDA) for the treatment of patients with severe hemophilia A. In addition, Hemgenix® (etranacogene dezaparvovec) was also recently approved by the European Medicines Agency and the FDA for the treatment of patients with severe hemophilia B. This product is based on an AAV5 vector expressing a hyper-active factor IX (FIX) transgene (FIX-Padua) transgene. All AAV-based phase III clinical trials to date show a significant increase in FVIII or FIX levels in the majority of treated patients, consistent with a substantial decrease in bleeding episodes and a concomitant reduction in factor usage obviating the need for factor prophylaxis in most patients. However, significant interpatient variability remains that is not fully understood. Moreover, most patients encountered short-term asymptomatic liver inflammation that was treated by immune suppression with corticosteroids or other immune suppressants. In all phase III trials to date, FIX expression has appeared relatively more stable than FVIII, though individual patients also had prolonged FVIII expression. Whether lifelong expression of clotting factors can be realized after gene therapy requires longer follow-up studies. Further preclinical development of next-generation gene editing technologies offers new prospects for the development of a sustained cure for hemophilia, not only in adults, but ultimately in children with hemophilia too.

Direct Oral Anticoagulants vs Vitamin K Antagonists in Patients With Antiphospholipid Syndromes: Meta-Analysis of Randomized Trials

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs) for patients with thrombotic antiphospholipid syndrome remain controversial.

OBJECTIVES

The authors performed a systematic review and meta-analysis of randomized controlled trials that compared DOACs with vitamin K antagonists (VKAs).

METHODS

We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials through April 9, 2022. The 2 main efficacy outcomes were a composite of arterial thrombotic events and venous thromboembolic events (VTEs). The main safety outcome was major bleeding. Random effects models with inverse variance were used.

RESULTS

Our search retrieved 253 studies. Four open-label randomized controlled trials involving 472 patients were included (mean control-arm time-in-therapeutic-range 60%). All had proper random sequence generation and adequate allocation concealment. Overall, the use of DOACs compared with VKAs was associated with increased odds of subsequent arterial thrombotic events (OR: 5.43; 95% CI: 1.87-15.75; P < 0.001, I2 = 0%), especially stroke, and the composite of arterial thrombotic events or VTE (OR: 4.46; 95% CI: 1.12-17.84; P = 0.03, I2 = 0%). The odds of subsequent VTE (OR: 1.20; 95% CI: 0.31-4.55; P = 0.79, I2 = 0%), or major bleeding (OR: 1.02; 95% CI: 0.42-2.47; P = 0.97; I2 = 0%) were not significantly different between the 2 groups. Most findings were consistent within subgroups.

CONCLUSIONS

Patients with thrombotic antiphospholipid syndrome randomized to DOACs compared with VKAs appear to have increased risk for arterial thrombosis. No significant differences were observed between patients randomized to DOACs vs VKAs in the risk of subsequent VTE or major bleeding.

An Update on Antiphospholipid Syndrome

PURPOSE OF REVIEW

To review the recent available evidence on epidemiology, pathogenesis, clinical phenotypes, and management of antiphospholipid syndrome (APS) and summarize potential future research perspectives.

RECENT FINDINGS

Accumulating evidence has further expanded our understanding of the disease, including new data about the incidence and prevalence of APS, novel pathways supporting the role of thrombo-inflammation in APS including platelet, monocyte and endothelial cell activation, pro-inflammatory cytokine and chemokine production, complement activation, neutrophil extracellular trap release, and type I interferon gene expression that could yield to new potential treatment targets, better identification of criteria and non-criteria clinical phenotypes, antiphospholipid antibody profiles and their associations with clinical outcomes, prognostic tools, and treatment strategies based on recent evidence-based recommendations for patients with thrombotic and obstetric APS, with or without systemic lupus erythematosus. Ongoing research efforts and international collaborations enhance our knowledge of this rare and often devastating syndrome and help improve patient care and health outcomes.

International multicenter, multiplatform study to validate Taipan snake venom time as a lupus anticoagulant screening test with ecarin time as the confirmatory test: Communication from the ISTH SSC Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies

BACKGROUND

Lupus anticoagulant (LA) assays are compromised in anticoagulated patients, and existing strategies to overcome the interferences have limitations. The prothrombin-activating Taipan snake venom time (TSVT) screening test and ecarin time (ET) confirmatory test are innately insensitive to vitamin K antagonists (VKA) and direct factor Xa inhibitors (DFXaI).

OBJECTIVES

Validate standardized TSVT/ET reagents for LA detection, in a multicenter, multiplatform study.

PATIENTS/METHODS

Six centers from four countries analyzed samples with TSVT/ET from 81 nonanticoagulated patients with LA, patients with established antiphospholipid syndrome (APS), and proven persistent LA who were either not anticoagulated (n = 120) or were anticoagulated with VKAs (n = 180) or DFXaIs (n = 71). Additionally, 339 nonanticoagulated LA-negative patients, and 575 anticoagulated non-APS patients (172 VKA, 403 DFXaI) were tested. Anticoagulant spiking experiments were performed and 112 samples containing potential interferences (i.e., direct thrombin inhibitors) were tested. Results were evaluated against locally derived cutoffs. Imprecision was evaluated.

RESULTS

Cutoffs were remarkably similar despite use of different analyzers and donor populations. Cutoffs for TSVT ratio, ET ratio, percent correction, and normalized TSVT ratio/ET ratio ranged between 1.08 and 1.10, 1.09 and 1.12, 9.3% and 14.8%, and 1.10 and 1.15, respectively. Coefficients of variation for TSVT and ET ratios were ≤5.0%. TSVT/ET exhibited sensitivity, specificity, and negative and positive predictive values of 78.2%/95.0%/86.3%/91.5%, respectively, with established APS as the LA-positive population, and 86.9%/95.0%/76.8%/97.4%, respectively, with triple-positive APS. Interference was seen with direct thrombin inhibitors, unfractionated heparin, and low molecular weight heparins, but not VKAs or DFXaIs.

CONCLUSIONS

TSVT/ET are validated for LA detection in nonanticoagulated patients and those on VKAs or DFXaIs.

Acute coronary syndrome as the first presentation of antiphospholipid antibody syndrome

We describe a case of a 42-year-old man who presented with anginal chest pain. He had objective evidence of ongoing cardiac injury. After initial treatment for coronary arterial disease, cardiac catheterisation revealed diffuse coronary arterial thrombosis with embolisation. Follow-up testing implicated new-onset antiphospholipid antibody syndrome as the aetiology.

Treatment and Secondary Prevention of Venous Thromboembolism in Real Clinical Practice Based on Health Care Professional Survey

Aim. To assess the duration of the anticoagulant treatment of venous thromboembolism (VTE) in various categories of patients in real clinical practice through survey of practitioners, as well as correspondence of the duration with current clinical guidelines.

Material and methods. Data obtained from electronic survey of practicing surgeons as part of a commercial brand assessment (Brand Adoption Monitor) was studied. Survey was carried out by the "Validata” analytical agency at the request and with the financial support of Bayer. Inpatient and outpatient vascular surgeons, as well as general outpatient surgeons were invited to complete the electronic questionnaire. The number of interviewed specialists was 100: 50 inpatient vascular surgeons and 50 outpatient specialists, among whom the share of vascular surgeons (phlebologists, angi-ologists) was about 20%. The study was completed in 20 cities of Russia with a population of at least 200,000 people from all federal districts except the North Caucasus and the Republic of Crimea. The selection criteria for participants were: work experience in the specialty ≥3 years, work experience at the current organization >6 months, ≥5 patients with VTE during in the last month.

Results. In total, 104 doctors were surveyed during the period from December 11, 2019 to January 20, 2020, of which 50 were inpatient vascular surgeons and 54 were from outpatient setting. According to the survey of vascular surgeons in hospitals, 75% (6 [5;10]) of patients were hospitalized with a primary episode of VTE and 25% (2 [1;4]) with a recurrent thrombotic event. In an outpatient surgeon, 27.5% (3 [2;5]) of patients were treated in an outpatient setting without hospitalization, 34.7% (3 [2;5]) came to an appointment immediately after discharge from the hospital and 38.8% (2 [1;4]) were a repeat visit regarding a previous VTE. Most often, surgeons observed episodes of clinically unprovoked VTE in 27.3% of cases, thrombotic events provoked by major transient risk factors were 12.2%, event provoked by small transient risk factors were 13.3% and events provoked by small persistent risk factors were 12.6%, while cancer-associated thrombosis represented 13.5%. Most surgeons chose to prescribe anticoagulant therapy beyond 3 months. About half of the specialists prescribed therapy for a year or longer for cancer-associated thrombosis and recurrent VTE. When treating the first episode of clinically unprovoked VTE, about half of the respondents chose anticoagulation for a period of 3 to 6 months. About 60% of specialists prescribed anticoagulant therapy for a period of 3 to 6 months to patients with minor transient or persistent risk factors and patients with VTE provoked by major transient risk factor (trauma or surgery).

Conclusion. Correspondence of the duration of anticoagulant therapy in real clinical practice with the international clinical guidelines varies within 450% range and, on average, does not exceed 30%. This discrepancy was both in situations when the duration of therapy was lower than recommended, but also in situations when treatment extension would not have been recommended.

Neurologic Manifestations of the Antiphospholipid Syndrome - an Update

PURPOSE OF REVIEW

In recent years, the spectrum of neurological manifestations of antiphospholipid syndrome (APS) has been growing. We provide a critical review of the literature with special emphasis on presentation, proposed mechanisms of disease, and treatment of neurological involvement in APS.

RECENT FINDINGS

Although stroke is the most common cause of neurological manifestations in patients with APS, other neurological disorders have been increasingly associated with the disease, including cognitive dysfunction, headache, and epilepsy. Direct oral anticoagulants have failed to show non-inferiority compared to vitamin K antagonists for the prevention of major thrombotic events. Antiphospholipid antibodies are often found in patients with acute COVID-19 but clear evidence supporting an association between these antibodies and the risk of thrombotic events, including stroke and cerebral venous thrombosis, is still lacking. APS patients may present with several distinct neurological manifestations. New criteria will facilitate the classification of patients presenting with increasingly recognized non-criteria neurological manifestations.

Direct oral anticoagulants in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) represents the later stage consequence of at least one or more unresolved episodes of acute pulmonary embolism; thus, indefinite anticoagulation is strongly recommended by current practice guidelines. Historically, vitamin K antagonists have been widely used in these patients. However, recent data indicate a shift toward direct oral anticoagulants (DOACs), despite lack of data on the safety and efficacy in this patient population. Herein, we briefly discuss the current rationale for oral anticoagulation use in CTEPH, addressing important issues and controversies involved with the use of DOACs, opening a strategy for further clinical research in the field of oral anticoagulation.

Testing for antiphospholipid antibodies: Advances and best practices

The diagnosis of antiphospholipid syndrome (APS) relies on the detection of circulating antiphospholipid antibodies (aPL). Currently, lupus anticoagulant (LAC), anticardiolipin (aCL), and antibeta2-glycoprotein I antibodies (aβ2GPI) IgG or IgM are included as laboratory criteria if persistently present. Progress has been made on the standardization of tests as guidelines on LAC testing and immunological assays for aCL and aβ2GPI are published. However, LAC measurement remains a complicated procedure with many pitfalls and interfered by anticoagulant therapy. Solid-phase assays for aCL and aβ2GPI still show interassay differences. These methodological issues make the laboratory diagnosis of APS challenging. In the interpretation of aPL results, antibody profiles help in identifying patients at risk. Noncriteria aPL, such as antibodies against the domain I of beta2-glycoprotein (aDI) and antiphosphatidylserine-prothrombin (aPS/PT) antibodies have been studied in the last years and may be useful in risk stratification of APS patients. But, aDI and aPS/PT are not included in the current diagnostic criteria and testing in daily practice is not recommended as these antibodies have no added value in the diagnosis of APS. This review will focus on the technical aspects of the laboratory methods, the clinical relevance of assays and interpretation of aPL results in the diagnosis of APS.

Use of direct oral anticoagulants in patients with thrombotic antiphospholipid syndrome: Guidance from the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis

Clarity and guidance is required with regard to the use of direct oral anticoagulants in antiphospholipid syndrome (APS) patients, within the confines of the recent European Medicines Agency recommendations, discrepant recommendations in other international guidelines and the limited evidence base. To address this, the Lupus Anticoagulant/Antiphospholipid Antibodies Scientific and Standardization Committee (SSC) chair and co-chairs together with SSC Control of Anticoagulation members propose guidance for healthcare professionals to help them manage APS patients. Uncertainty in this field will be addressed. This guidance will also serve as a call and focus for research.

How to Interpret Antiphospholipid Laboratory Tests

PURPOSE OF THE REVIEW

This review focuses on the laboratory tests necessary for the diagnosis of antiphospholipid syndrome (APS). For the interpretation of the results of the tests for antiphospholipid antibodies (aPL), understanding of all pitfalls and interferences is necessary.

RECENT FINDINGS

Progress has been made on the standardization of aPL tests and current guidelines for detection of lupus anticoagulant (LAC), anticardiolipin antibodies (aCL), and antibeta2-glycoprotein I antibodies (aβ2GPI) are useful tools. LAC measurement remains a complex procedure with many pitfalls and interference by anticoagulant therapy. Solid phase assays for aCL and aβ2GPI still show inter-assay differences. Measuring LAC, aCL, and aβ2GPI allows making antibody profiles that help in identifying patients at risk. Other aPL, such as antibodies against domain I of beta2-glycoprotein I (aDI) and antiphosphatidylserine-prothrombin (aPS/PT) antibodies, may be useful in risk stratification of APS patients, but are not included in the current diagnostic criteria as no added value in the diagnosis of APS has been illustrated so far. The laboratory diagnosis of APS remains challenging. LAC, aCL, aβ2GPI IgG, and IgM should be performed to increase diagnostic efficacy, with an integrated interpretation of all results and an interpretative comment. A close interaction between clinical pathologists and clinicians is mandatory.

Thromboendarterectomy in a patient with Systemic Lupus and antiphospholipid Syndrome, lessons learned from a complex disease interaction

Systemic lupus erythematosus (SLE) is the prototypic multisystem autoimmune disorder with a broad spectrum of clinical presentations encompassing almost all organs and tissues¹. Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of venous and/or arterial thrombosis and pregnancy morbidity in the presence of pathogenic autoantibodies known as antiphospholipid antibodies (aPL)². Chronic thromboembolism is one of the well-known established pathogenesis of pulmonary hypertension, known as chronic thromboembolic pulmonary hypertension (CTEPH)³. APS may be also associated with other diseases, mainly systemic lupus erythematosus (SLE). The presence of secondary APS in SLE patients further aggravate the condition due to recurrent venous thromboembolic showers to the pulmonary vasculature. Pulmonary endarterectomy (PEA) is the treatment of choice for CTEPH with lifelong anticoagulation⁴. We herein report a rare cause of CTEPH in a 42-year-old Egyptian man who presented with dyspnea WHO-FC III. The patient was diagnosed as a case of CTEPH due to secondary APS. He underwent PEA and was discharged on lifelong anticoagulation. Clinical follow-ups thereafter showed improvement of functional capacity and pulmonary artery pressures. In conclusion, management of such cases was combination of standard treatment of CTEPH, in addition to specific management of secondary APS to avoid recurrence of the disease.