Four Decades of Carrier Detection and Prenatal Diagnosis in Hemophilia A: Historical Overview, State of the Art and Future Directions.

Hemophilia A (HA), a rare recessive X-linked bleeding disorder, is caused by either deficiency or dysfunction of coagulation factor VIII (FVIII) resulting from deleterious mutations in the F8 gene encoding FVIII. Over the last 4 decades, the methods aimed at determining the HA carrier status in female relatives of HA patients have evolved from phenotypic studies based on coagulation tests providing merely probabilistic results, via genetic linkage studies based on polymorphic markers providing more accurate results, to next generation sequencing studies enabling highly precise identification of the causative F8 mutation. In parallel, the options for prenatal diagnosis of HA have progressed from examination of FVIII levels in fetal blood samples at weeks 20-22 of pregnancy to genetic analysis of fetal DNA extracted from chorionic villus tissue at weeks 11-14 of pregnancy. In some countries, in vitro fertilization (IVF) combined with preimplantation genetic diagnosis (PGD) has gradually become the procedure of choice for HA carriers who wish to prevent further transmission of HA without the need to undergo termination of pregnancies diagnosed with affected fetuses. In rare cases, genetic analysis of a HA carrier might be complicated by skewed X chromosome inactivation (XCI) of her non-hemophilic X chromosome, thus leading to the phenotypic manifestation of moderate to severe HA. Such skewed XCI may be associated with deleterious mutations in X-linked genes located on the non-hemophilic X chromosome, which should be considered in the process of genetic counseling and PGD planning for the symptomatic HA carrier. Therefore, whole exome sequencing, combined with X-chromosome targeted bioinformatic analysis, is highly recommended for symptomatic HA carriers diagnosed with skewed XCI in order to identify additional deleterious mutations potentially involved in XCI skewing. Identification of such mutations, which may profoundly impact the reproductive choices of HA carriers with skewed XCI, is extremely important.

The potential role of emicizumab prophylaxis in severe von Willebrand disease.

BACKGROUND: Severe von Willebrand disease (VWD) may be associated with chronic joint damage and may require prophylactic therapy. Emicizumab is a humanized bispecific antibody, which mimics the function of coagulation factor VIII (FVIII), and it has been approved for prophylaxis in hemophilia A. METHODS: This is the first study assessing the potential future role of emicizumab as an alternative prophylactic treatment in patients with severe VWD, based upon a thrombin generation (TG) ex vivo analysis. We report 51 weeks of successful off label emicizumab prophylaxis in a child with severe VWD and recurrent hemarthroses and progressive arthropathy despite adherence to previous prophylaxis with replacement therapy. RESULTS AND CONCLUSIONS: Our work demonstrated that ex vivo spiking with emicizumab increased TG in plasma from patients with type 3 VWD. Similar TG results were observed in our treated patient, whose therapy was well tolerated without any adverse events. Both in vitro and ex vivo TG data support sufficient hemostasis without exceeding the range seen in healthy volunteers. Further collaborative studies on the efficacy and safety of emicizumab prophylaxis in severe VWD is warranted.

Confirmed long-term safety and efficacy of prophylactic treatment with BAY 94-9027 in severe haemophilia A: final results of the PROTECT VIII extension study.

INTRODUCTION: The phase 2/3 PROTECT VIII main study demonstrated efficacy and safety of BAY 94-9027 (damoctocog alfa pegol; Jivi® ), a B-domain-deleted recombinant factor VIII (FVIII), site-specifically PEGylated to extend its half-life. AIM: To report the final efficacy and safety data for BAY 94-9027 from the PROTECT VIII extension. METHODS: Previously treated males aged 12-65 years with severe haemophilia A (FVIII <1%) who completed the multicentre, open-label PROTECT VIII main study were eligible for the extension. Patients received either on demand or prophylaxis treatments (30-40 IU/kg twice weekly [2 × W], 45-60 IU/kg every 5 days [E5D], or 60 IU/kg every 7 days [E7D]) and could switch to any prophylaxis regimen (variable frequency) as needed. Annualised bleeding rates (ABR), zero bleeds and safety outcomes were included in this final analysis. RESULTS: At extension completion, patients (n = 121) received BAY 94-9027 for a median (range) total time of 3.9 (0.8-7.0) years. Median (Q1; Q3) total ABR was 1.49 (0.36; 4.80) for prophylaxis patients (n = 107), compared with 34.09 (20.3; 36.6) for on-demand patients (n = 14). Median total ABRs for 2 × W (n = 23), E5D (n = 33), E7D (n = 23) and variable frequency (n = 28) groups were 1.57, 1.17, 0.65 and 3.10, respectively. Of prophylaxis patients, 20.6% were bleed-free during the entire extension (median time, 3.2 years) and 50.0% were bleed-free during the last 6 months. No patient developed FVIII inhibitors. No deaths or thrombotic events were reported. CONCLUSIONS: Efficacy and safety of BAY 94-9027 was confirmed, with extension data supporting its use as a long-term treatment option for patients with haemophilia A.

Molecular Mechanisms of Skewed X-Chromosome Inactivation in Female Hemophilia Patients-Lessons from Wide Genome Analyses.

INTRODUCTION: Hemophilia A (HA) is an X-linked bleeding disorder caused by factor VIII (FVIII) deficiency or dysfunction due to F8 gene mutations. HA carriers are usually asymptomatic because their FVIII levels correspond to approximately half of the concentration found in healthy individuals. However, in rare cases, a carrier may exhibit symptoms of moderate to severe HA primarily due to skewed inactivation of her non-hemophilic X chromosome. AIM: The aim of the study was to investigate X-chromosome inactivation (XCI) patterns in HA carriers, with special emphasis on three karyotypically normal HA carriers presenting with moderate to severe HA phenotype due to skewed XCI, in an attempt to elucidate the molecular mechanism underlying skewed XCI in these symptomatic HA carriers. The study was based on the hypothesis that the presence of a pathogenic mutation on the non-hemophilic X chromosome is the cause of extreme inactivation of that X chromosome. METHODS: XCI patterns were studied by PCR analysis of the CAG repeat region in the HUMARA gene. HA carriers that demonstrated skewed XCI were further studied by whole-exome sequencing (WES) followed by X chromosome-targeted bioinformatic analysis. RESULTS: All three HA carriers presenting with the moderate to severe HA phenotype due to skewed XCI were found to carry pathogenic mutations on their non-hemophilic X chromosomes. Patient 1 was diagnosed with a frameshift mutation in the PGK1 gene that was associated with familial XCI skewing in three generations. Patient 2 was diagnosed with a missense mutation in the SYTL4 gene that was associated with familial XCI skewing in two generations. Patient 3 was diagnosed with a nonsense mutation in the NKAP gene that was associated with familial XCI skewing in two generations. CONCLUSION: Our results indicate that the main reason for skewed XCI in our female HA patients was negative selection against cells with a disadvantage caused by an additional deleterious mutation on the silenced X chromosome, thus complicating the phenotype of a monogenic X-linked disease. Based on our study, we are currently offering the X inactivation test to symptomatic hemophilia carriers and plan to expand this approach to symptomatic carriers of other X-linked diseases, which can be further used in pregnancy planning.

BAY 81-8973 demonstrated efficacy, safety and joint status improvement in patients with severe haemophilia A in the LEOPOLD I extension for ≤2 years.

OBJECTIVES: BAY 81-8973 (Kovaltry® ), a full-length, unmodified, recombinant human factor VIII, provided excellent bleeding control for patients with haemophilia A in the pivotal 1-year LEOPOLD I trial. The LEOPOLD I extension evaluated long-term efficacy and safety of BAY 81-8973 prophylaxis. METHODS: After completing LEOPOLD I, patients continued receiving 20-50 IU/kg BAY 81-8973 two- or three-times weekly in the extension. Outcomes included annualised bleeding rate (ABR) and haemostasis during surgery. RESULTS: Fifty-five patients aged 12-65 years participated in the extension. Median (range) exposure days during the 2-year total study period was 309 (115-355). No patient switched regimens. Median (Q1; Q3) ABR for all bleeds was 2.0 (1.0; 6.1) during the pivotal study, 2.0 (0.0; 5.2) during the extension, and 2.0 (0.5; 5.5) combined. The proportion of joint bleeds affecting target joints decreased (pivotal study: 90.9%, extension: 60.0%). Haemostasis was assessed as excellent/good in all five major surgeries. One serious adverse event (myocardial infarction) occurred in a patient with cardiovascular risk factors. No patients developed inhibitors. CONCLUSIONS: BAY 81-8973 prophylaxis efficacy outcomes in the pivotal study were maintained or, in the case of joint protection, improved during the extension, with a safety and tolerability profile consistent with previous experience.

BAY 94-9027 prophylaxis is efficacious and well tolerated for up to >5 years with extended dosing intervals: PROTECT VIII extension interim results.

INTRODUCTION: BAY 94-9027 is an extended-half-life, site-specifically PEGylated, B-domain-deleted recombinant factor VIII (FVIII). The PROTECT VIII main study demonstrated efficacy of bleed control using extended-interval prophylaxis with BAY 94-9027 for 36 weeks. AIM: To report long-term efficacy and safety of prophylaxis with BAY 94-9027 in a descriptive analysis of the ongoing PROTECT VIII extension with a total treatment time of up to >5 years. METHODS: Previously treated males aged 12-65 years with severe haemophilia A who completed the PROTECT VIII main study were eligible for the open-label extension. Patients received on-demand treatment or prophylaxis (30-40 IU/kg twice weekly, 45-60 IU/kg every 5 days, or 60 IU/kg every 7 days) and could switch regimens as needed. RESULTS: Patients (N = 121; on demand, n = 14; prophylaxis, n = 107) accumulated a median (range) of 3.9 years (297-1965 days) and 223 (23-563) total exposure days by 31 January 2018. During the extension, median (quartile [Q]1; Q3) annualized bleeding rates (ABRs) for total bleeds were 1.6 (0.3; 4.6) for patients receiving prophylaxis and 34.1 (20.3; 36.6) for patients receiving on-demand treatment. ABRs for twice-weekly (n = 23), every-5-days (n = 33), every-7-days (n = 23) and variable frequency (n = 28) treatments were 1.7, 1.2, 0.7 and 3.1, respectively. Of prophylaxis patients, 20.6% were bleed-free throughout the extension (median time, 3.2 years), and 44.5% were bleed-free during the last 6 months. No patients developed FVIII inhibitors. CONCLUSIONS: BAY 94-9027 prophylaxis was efficacious and well tolerated with dosing intervals up to every 7 days for a median (range) of 3.9 years (0.8-5.4 years).

Efficacy and safety of damoctocog alfa pegol prophylaxis in patients ⩾40 years with severe haemophilia A and comorbidities: post hoc analysis from the PROTECT VIII study.

Background: Advances in treatment have enabled patients with haemophilia A to live longer and therefore may be subjected to comorbidities associated with ageing, in addition to disease-associated morbidities. There have been few reports to date on efficacy and safety of treatment specifically in patients with severe haemophilia A and comorbidities. Objective: To explore the efficacy and safety of damoctocog alfa pegol prophylaxis in patients with severe haemophilia A aged ⩾40 years with comorbidities of interest. Design: A post hoc analysis of data from the phase 2/3 PROTECT VIII study and its extension. Methods: Bleeding and safety outcomes were analysed in a subgroup of patients aged ⩾40 years with ⩾1 comorbidity receiving damoctocog alfa pegol (BAY 94-9027; Jivi®) prophylaxis. Results: Thirty-four patients with severe haemophilia A were included in this analysis, with a mean age of 49.4 years at time of enrolment. The most prevalent comorbidities were hepatitis C (n = 33; chronic, n = 23), hepatitis B (n = 8) and hypertension (n = 11). Four patients had human immunodeficiency virus. All received damoctocog alfa pegol prophylaxis for the entire study [median (range) time in study = 3.9 (1.0-6.9) years]. During the main study and extension, median total annualised bleeding rates (ABRs) (Q1; Q3) were 2.1 (0.0; 5.8) and 2.2 (0.6; 6.0), respectively; median joint ABRs were 1.9 (0.0; 4.4) and 1.6 (0.0; 4.0), respectively. Mean adherence with prophylaxis schedule was greater than 95% throughout the study. No deaths or thrombotic events were reported. Conclusion: Efficacy, safety and adherence of damoctocog alfa pegol were confirmed in patients aged ⩾40 years with haemophilia A and one or more comorbidities, with data for up to 7 years supporting its use as a long-term treatment option in this group. Plain language summary: Advances in treatment mean that people with haemophilia A are now living longer and, as a result, may have additional medical conditions that occur with ageing. We aimed to investigate the efficacy and safety of the long-acting replacement factor VIII damoctocog alfa pegol in people with severe haemophilia A who had additional medical conditions. To do this, we investigated the recorded information about patients aged 40 years of age or older who had been treated with damoctocog alfa pegol in a previously completed clinical trial. We found that the treatment was well-tolerated; no deaths or thrombotic events (undesirable clotting events) were reported. Treatment was efficacious in reducing bleeding in this group of patients. The findings support the use of damoctocog alfa pegol as a long-term treatment for older patients with haemophilia A and coexisting conditions.

Management of surgery in persons with hemophilia A receiving emicizumab prophylaxis: data from a national hemophilia treatment center.

Background: Persons with hemophilia A may require surgical procedures. Real-world data on invasive procedures in persons with hemophilia A receiving emicizumab prophylaxis are limited. Objectives: To evaluate the safety of invasive procedures in persons with hemophilia A receiving emicizumab prophylaxis and their outcomes in a longitudinally followed cohort. Methods: Data from medical records of persons with hemophilia A with and without factor VIII (FVIII) inhibitors longitudinally followed at our tertiary center, who received emicizumab prophylaxis and underwent all types of invasive procedures, were retrieved. Outcomes of interest were bleeding and thrombotic complications. Results: Overall, 35 patients underwent 56 invasive procedures, 18 (32.1%) were major. The median age was 36.3 years (IQR, 8.8-55.9 years); 12 patients (34.3%) were younger than 18 years at the time of procedure; 17 (48.6%) were patients with FVIII inhibitors. Among major procedures, orthopedic surgeries prevailed. All patients who underwent major procedures received factor replacement with either recombinant activated factor VII (patients with inhibitors) or FVIII (patients without inhibitors). Factor concentrates were administered prior to 32 (84.2%) of the minor procedures. Repeated doses were given according to international expert opinion recommendations and patients' condition.There were 7 bleeding events in 6 patients, 5 were major bleeds, including 1 patient who underwent a minor procedure without factor replacement. None of the patients experienced a thrombotic complication. Conclusion: Invasive procedures can be performed safely in patients receiving emicizumab prophylaxis with close surveillance after surgery. Factor concentrates may be advised in selected patients undergoing minor procedures.

Women with Hemophilia: Case Series of Reproductive Choices and Review of Literature.

Aim Very little is known regarding reproductive choices, pregnancy, and delivery of women with moderate to severe hemophilia. Our aim was to describe our experience with three hemophiliac women and their journey to achieve motherhood. Methods Medical charts of women with moderate to severe hemophilia A treated at our center were evaluated. Data regarding choices of conception, pregnancy course, mode of delivery, and pregnancy outcomes were obtained. Results Three women are presented. Whereas patient 1 chose to adopt her first child and later had twins through egg donations and a surrogate mother, patient 2 underwent spontaneous pregnancy and delivered via cesarean section. Patient 3 preferred in vitro fertilization and preimplantation genetic diagnosis to avoid hemophilia and hemophilia carriership in her offspring. Conclusion The appropriate means to achieve parenthood for women with moderate to severe hemophilia should be individualized and requires support of a comprehensive multidisciplinary team.

Comparing Physician and Patient Perspectives on Prophylactic Treatment with BAY 94-9027 for Severe Haemophilia A: A Post Hoc Analysis.

INTRODUCTION: BAY 94-9027 is a newly developed extended half-life product to treat haemophilia, allowing for fewer injections than with standard products. This post hoc analysis aimed to compare physicians' and patients' opinions on BAY 94-9027 prophylaxis, and explore how qualitative interview data is aligned with the data from the Haemophilia-specific Quality of Life questionnaire for Adults (Haemo-QoL-A). METHODS: Exploratory qualitative interviews were conducted with physicians and patients by phone upon the exit of patients from the PROTECT VIII extension phase following a semi-directed guide. In this post hoc analysis, all transcripts were reviewed and reported concepts were compared to assess the level of concordance between physicians and patients. These qualitative data were compared with the Haemo-QoL-A mean global and subscale scores at baseline and end of main phase (36 weeks later). RESULTS: Ten physicians and 16 patients (mean age 47 years) from Israel, the Netherlands and the USA were interviewed. Significant improvements were reported by all physicians from baseline [e.g. lower frequency of bleeds (80%), improvement in emotional functioning (90%)], which is in concordance with patients' reports. The improved confidence reported by physicians cascaded to greater participation in various activities, resulting in a better perceived emotional state and a significant improvement on the Haemo-QoL-A emotional impact subscale score (p = 0.04) between baseline and end of main phase. Most physicians (80%) reported improvement in bleed frequency, as patients did (88%). Improvement in physical functioning or mobility was not consistently reported in this 8-month study. CONCLUSION: Interviewed physicians and patients generally agreed on the beneficial impact of BAY 94-9027, specifically regarding the increased level of self-confidence in patients and its subsequent positive impact on patients' lives. These findings supported the observed improvement on the Haemo-QoL-A emotional impact subscale. Overall, this study highlights the concordance between physician and patient perspective on the positive experience with BAY 94-9027.

Safety and efficacy of BAY 94-9027, an extended-half-life factor VIII, during surgery in patients with severe hemophilia A: Results of the PROTECT VIII clinical trial.

INTRODUCTION: Ensuring hemostasis during invasive procedures is a challenge in patients with severe hemophilia A. This analysis evaluated efficacy and safety of BAY 94-9027, an extended-half-life recombinant factor VIII (FVIII), in the surgical setting. MATERIALS AND METHODS: Patients participating in an open-label BAY 94-9027 clinical trial who underwent major surgery were included in the analysis. Investigator/surgeon assessment of hemostasis during surgery was the primary outcome. In addition, information about FVIII use, FVIII levels during perioperative period, bleeding complications and FVIII inhibitor development were collected. RESULTS: Data were analyzed for 26 major surgeries (orthopedic, n = 21) in 20 patients aged 13-61 years. BAY 94-9027 provided effective hemostasis during all procedures. FVIII levels 6-8 h post preoperative infusion and prior to the first follow-up infusion were in the range expected to maintain protection in the major surgery setting. The median time from preoperative infusion to the first follow-up infusion (the first infusion administered after the preoperative infusion) was 12.33 (3.6-49.9) h. No intraoperative bleeding complications occurred, and no new inhibitors developed following any surgery. CONCLUSIONS: The results of the study demonstrate that BAY 94-9027 was efficacious and well tolerated in the treatment of patients undergoing major surgeries. Advantages of BAY 94-9027 include the potential for less frequent infusion and reduced factor consumption, which should simplify the management of patients during major surgery.

Allele-specific replication associated with aneuploidy in blood cells of patients with hematologic malignancies.

We hypothesize that coordination between the two DNA parental sets in somatic cells is essential for the stability of the diploid genome, and that its disruption is associated with the many alterations observed in the various cancerous phenotypes. As coordination between two allelic counterparts is well exemplified by synchrony in replication timing, we examined, in blood cells of patients suffering from various hematologic malignancies, replication patterns of five loci. These loci were three cancer-implicated genes (TP53, AML1, and RB1) and two nontranscribed sequences engaged in chromosome segregation. All five loci normally display synchrony in allelic replication timing. In addition, in order to exemplify an asynchronous mode of allelic replication, we followed the replication of allelic counterparts of an imprinted gene (SNRPN), which is distinguished by its asynchronous mode of allelic replication (allele-specific replication). Allelic replication patterns were studied by fluorescence in situ hybridization (FISH), which has been shown to distinguish between nonreplicated and replicated regions of the genome in interphase cells, based on the structure of the specific hybridization signals that are being detected. Using the FISH replication assay we observed, for all loci which normally exhibit synchrony in allelic replication, loss of synchrony when present in blood cells of patients with hematologic malignancies. The loss of synchrony in allelic replication in patients' cells was accompanied by aneuploidy (chromosome losses and gains), the hallmark of cancer. We were able to reinstate the normal pattern of replication in the patients' cells by introducing an inhibitor of DNA methylation. It thus appears loss of allelic coordination is an epigenetic alteration characterizing cancer, which is easily identified by simple cytogenetic means and has a potential use in both cancer investigation and detection.