How I use bypassing therapy for prophylaxis in patients with hemophilia A and inhibitors

Primary prophylaxis implementation and long-term joint outcomes in Swedish haemophilia A patients

INTRODUCTION

Primary prophylaxis is the gold standard in severe haemophilia A (SHA) but time to escalate the prophylaxis regimen varies.

AIM

Assess prophylaxis implementation and long-term joint health outcomes in SHA with primary prophylaxis.

METHODS

Adult male patients born after 1980, with SHA on primary prophylaxis, started before the age of 3 years and second joint bleed, and no history of FVIII inhibitors, were enrolled. Repeated joint-health examinations were performed with HJHS or HEAD-US; VERITAS-PRO assessed adherence.

RESULTS

Thirty patients were enrolled with, at inclusion, median age 33.5 years, annualized bleed rate and joint bleed rate 0, and FVIII consumption 4232 IU/kg/year, respectively. The median age was 1.2 years, at prophylaxis start once weekly with a median FVIII dose of 47.7 IU/kg, and 1.7 years, by the time escalation to a final regimen had occurred, with a median infusion frequency of thrice weekly and FVIII dose 41.7 IU/kg, respectively. Older age correlated with later transition to escalated prophylaxis (p < .001). Longer time to escalated prophylaxis correlated to more bleeds (p < .001). Median HJHS increased slowly, reaching 4 at 35-40 years. HJHS at 15-20 years correlated with higher HJHS afterwards. Median total HEAD-US score was 1 and correlated with HJHS (p < .001). Median VERITAS-PRO score was 36, indicating good treatment adherence.

CONCLUSION

Primary prophylaxis is effective but does not completely prevent the gradual development of arthropathy in SHA. Joint assessments with HJHS should start at an early age, as they correlate with arthropathy in later life. Prophylaxis escalation should proceed expeditiously to prevent bleeds.

Hemoperitoneum as a Life-Threatening Complication of an Acute Cholecystitis in a Patient with Hemophilia A with Inhibitors: A Case Report

We present the case of a 52-year-old male with severe hemophilia A with inhibitors, who was diagnosticated with acute lithiasic cholecystitis that required surgical intervention due to lack of favorable response to conservatory treatment. During surgery, hemostatic support was performed with activated recombinant factor VII (rFVIIa, NovoSeven®). The surgery was performed first laparoscopically with adhesiolysis, followed by subcostal laparotomy and cholecystectomy because of the findings of a pericholecystic plastron with abscess and massive inflammatory anatomical modifications. The patient presented postoperative complications, requiring a second surgical intervention, due to the installation of a hemoperitoneum. Hemostatic treatment with rFVIIa was given for a further 3 weeks postoperatively, and the patient was discharged in safe condition. A surgical intervention increases the risk of bleeding in hemophilic patients, which may have vital complications in the absence of adequate hemostatic support and the support of a multidisciplinary team with experience in hemophilic surgery.

A multicentre real-world data study to assess the bleeding rate and management of patients with haemophilia A and factor VIII inhibitors in Argentina

The development of inhibitors against factor VIII (FVIII) concentrates is a severe complication of treatment for patients with haemophilia. We investigated annualized bleeding rates (ABRs) in patients in Argentina with haemophilia A with inhibitors and analysed potential differences between treatment strategies. This multicentre, retrospective, real-world data, cohort design study comprised ambulatory paediatric and adult patients with congenital haemophilia A and FVIII inhibitors treated according to standard clinical practice, with 12-months follow-up. Of 69 included patients, 39 (56.5%) received on-demand treatment, 13 (18.8%) received prophylactic treatment, and 17 (24.6%) received immune tolerance induction (ITI) therapy. The mean overall ABR was 7.68 ± 8.18, with similar rates for on-demand (8.59 ± 9.69), prophylaxis (5.54 ± 4.71), and ITI (7.24 ± 6.23) subgroups. In the negative binomial regression model, prophylactic treatment [incidence rate ratio (IRR) 0.41, 95% confidence interval (CI): 0.21-0.79, P < 0.01] and ITI (IRR 0.47, 95% CI: 0.27-0.81, P < 0.01) therapy were significantly associated with a decrease in the ABR compared with on-demand treatment. Age (IRR 0.96, 95% CI: 0.94-0.97, P < 0.01), number of target joints (IRR 1.21, 95% CI: 1.11-1.31, P < 0.001), and history of recurring bleeding (IRR 2.3, 95% CI: 1.19-4.57, P = 0.012) were significantly and independently associated with ABR. The ABR in standard clinical practice was lower than that reported in controlled clinical trials. Patients undergoing prophylaxis and ITI therapy showed reduced ABRs compared with on-demand treatment, after controlling for bleeding predictor variables.

First observation of inhibitor development against efmoroctocog alfa in France

In patients with severe haemophilia receiving clotting factor concentrates, the risk of immunisation against their usual treatment is still patent and feared. New haemophilia drug treatments with an extended half-life have become available over the past few years. The risk of inhibitor development to these new treatments is unclear. We report the case of a 51-year-old man with severe haemophilia A, who was previously treated with no history of inhibitor development. Soon after a switch in his treatment to efmoroctocog alfa he developed an inhibitor against this recombinant Fc fusion extended half-life FVIII (rFc-FVIII) product. The patient was on an on-demand treatment regimen and was treated for mucosal bleeding. The inhibitor was characterised as type I, with classical epitope mapping. The spontaneous evolution of this inhibitor was favourable, but an anamnestic response led to a switch in his treatment to emicizumab.

Thrombin-like serine protease, antiquorin from Euphorbia antiquorum latex induces platelet aggregation via PAR1-Akt/p38 signaling axis

Plant latex proteases (PLPs) are pharmacologically essential and are integral components of traditional medicine in the management of bleeding wounds. PLPs are known to promote blood coagulation and stop bleeding by interfering at various stages of hemostasis. There are a handful of scientific reports on thrombin-like enzymes characterized from plant latices. However, the role of plant latex thrombin-like enzymes in platelet aggregation is not well known. In the present study, we attempted to purify and characterize thrombin-like protease responsible for platelet aggregation. Among tested plant latices, Euphorbia genus latex protease fractions (LPFs) induced platelet aggregation. In Euphorbia genus, E. antiquorum LPF (EaLPF) strongly induced platelet aggregation and attenuated bleeding in mice. The purified thrombin-like serine protease, antiquorin (Aqn) is a glycoprotein with platelet aggregating activities that interfere in intrinsic and common pathways of blood coagulation cascade and alleviates bleeding and enhanced excision wound healing in mice. In continuation, the pharmacological inhibitor of PAR1 inhibited Aqn-induced phosphorylation of cPLA₂, Akt, and P38 in human platelets. Moreover, Aqn-induced platelet aggregation was inhibited by pharmacological inhibitors of PAR1, PI3K, and P38. These data indicate that PAR1-Akt/P38 signaling pathways are involved in Aqn-induced platelet aggregation. The findings of the present study may open up a new avenue for exploiting Aqn in the treatment of bleeding wounds.

Emicizumab prophylaxis among infants and toddlers with severe hemophilia A and inhibitors-a single-center cohort

BACKGROUND

Emicizumab is a bispecific antibody that bridges factor IXa and factor X to restore hemostasis in patients with hemophilia A (HA). Its efficacy and safety have been proven in multicenter trials. However, real world data regarding its use in very young children are currently lacking. Ancillary test results for monitoring emicizumab's hemostatic effect and their clinical correlations are scarce.

METHODS

Children with HA and inhibitors treated by emicizumab were prospectively followed at our center. Laboratory follow-up included rotational thromboelastometry (ROTEM) and thrombin generation (TG), prior to and during treatment.

RESULTS

Eleven children whose median age was 26 months were treated by emicizumab and followed for a median of 36 weeks. During follow-up, none experienced hemarthrosis or any other spontaneous bleeds. For 7/11 patients, emicizumab prophylaxis was sufficient to maintain hemostasis without additional supplemental therapy. Only 4/11 patients were occasionally treated with recombinant activated FVII for trauma. Two minor surgeries were safely performed without supplemental therapy while another procedure was complicated by major bleeding. TG parameters improved for all patients, correlating with their clinical status. Interestingly, the lowest TG values were obtained for patients experiencing bleeding episodes, while ROTEM parameters in all patients were close to the normal range.

CONCLUSIONS

This study confirms the safety and efficacy of emicizumab in reducing bleeds in young children with HA with inhibitors, including infants. However, surgeries warrant caution as emicizumab prophylaxis may not be sufficient for some procedures. TG may more accurately reflect the hemostasis state than ROTEM in pediatric patients treated with emicizumab.

Increased Accumulation and Retention of rhFVIIa (eptacog beta) in Knee Joints of Hemophilia A Mice Compared to Wild-Type Mice

Our earlier studies showed that recombinant human factor VIIa (rhFVIIa) administered intravascularly in mice disappeared rapidly from the circulation. However, a small fraction of rhFVIIa that entered extravascular remained functionally active for an extended period. The present study aims to investigate the dose-dependency of rhFVIIa accumulation and retention in mouse knee joints and test whether the hemophilic condition affects rhFVIIa sequestration in joints. Wild-type and FVIII^-/- mice were injected with three doses of rhFVIIa (eptacog beta, 90, 250, and 500 μg/kg) via the tail vein. At varying times following rhFVIIa administration, blood and knee joints were collected to measure FVIIa activity and antigen levels in plasma and joint tissues. Joint tissue sections were analyzed by immunohistochemistry for the presence of rhFVIIa. Vascular permeability was assessed by either Evans Blue dye or fluorescein dextran extravasation. The study showed that rhFVIIa accumulated in knee joints of wild-type and FVIII^-/- mice in a dose-dependent manner. rhFVIIa antigen and FVIIa activity could be detectable in joints for at least 7 days. Significantly higher levels of rhFVIIa accumulation were observed in knee joints of FVIII^-/- mice compared with that of wild-type mice. Immunohistochemical analyses confirmed higher levels of rhFVIIa retention in FVIII^-/- mice compared with wild-type mice. Additional studies showed that FVIII^-/- mice were more permissible to vascular leakage. In conclusion, the present data demonstrate a dose-dependent accumulation of rhFVIIa in knee joints, and the hemophilic condition enhances the entry of rhFVIIa from circulation to the extravascular. The present data will be useful in improving rhFVIIa prophylaxis.

Thromboembolic event rate in patients exposed to anti-inhibitor coagulant complex: a meta-analysis of 40-year published data

Anti-inhibitor coagulant complex (AICC), an activated prothrombin complex concentrate, has been available for the treatment of patients with inhibitors since 1977, and thromboembolic events (TEEs) have been reported after infusion of AICC in patients with congenital or acquired hemophilia. With the aim of estimating the TEE incidence rate (IR) related to AICC exposure in these patients, a systematic review of the literature was carried out in Medline, according to PRISMA guidelines, from inception date to March 2017. The IR of TEEs was estimated through a meta-analytic approach by using a generalized linear mixed model based on a Poisson distribution. Thirty-nine studies were included (1980-2016). Overall, 46 TEEs were reported; of these, 13 were reported as disseminated intravascular coagulations, 11 as myocardial infarctions, and 3 as thrombotic cerebrovascular accidents. The pooled TEE IR was 2.87 (95% confidence interval [CI], 0.32-25.40) per 100 000 AICC infusions (5.42 in retrospective studies [95% CI, 0.92-31.82]; 1.09 in prospective studies [95% CI, 0.01-238.77]). The TEE rate was 5.09 (95% CI, 0.01-1795.60) per 100 000 AICC infusions administered on demand, whereas no TEEs were reported with prophylaxis. Interestingly, the estimated IR in patients with congenital hemophilia was <0.01 per 100 000 infusions. These findings provide robust evidence of safety of AICC over almost 40 years of published studies.

Two-incision laparoscopic appendectomy for a severe hemophilia A child patient with coagulation factor VII deficiency: Case report and review of literature

RATIONALE

The main complication of patients with severe hemophilia is recurrent bleeding events that usually affected musculoskeletal contractures. And replacement therapy methods were continuously improved to minimize adverse impacts brought by those complications. However, only several cases reported about the appendectomy for hemophilia A. We report a case of acute appendicitis treated by two-incision laparoscopy in a boy with hemophilia A and coagulation factor VII deficiency for the first time.

PATIENT CONCERNS

An 8y7m-old Chinese boy presented with half a day of right sided abdominal pain, fever, nausea, and vomiting.

DIAGNOSES

He received a computed tomography (CT) scan which revealed an enlarged appendix, thickened wall and appendiceal fecalith, and had received a conservative anti-bacterial treatment for his acute appendicitis but failed. He was diagnosed with hemophilia A and coagulation factor VII deficiency.

INTERVENTIONS

Two-incision laparoscopic appendectomy was made in success with a careful management of perioperative period. We monitored the clotting factor FVIII level and gave him a replacement therapy.

OUTCOMES

The patient had an uneventful recovery.

LESSONS

It is important to exclude intraabdominal or retroperitoneal hemorrhage in patients suffering from hemophilia and acute abdominal pain. Pre-operative evaluation of validity of the FVIII replacement therapy is another effective strategy to assess the safety and feasibility of applying an operation procedure. The two-incision laparoscopic appendectomy is an effective treatment for this kind of patients for its minimal trauma and fast recovery characteristics. Our report shows that laparoscopic appendectomy is feasible in a child suffering from hemophilia after adequate blood clotting factor replacement treatment.

2017 Clinical trials update: Innovations in hemophilia therapy

A surge in therapeutic clinical trials over recent years is paving the way for transformative treatment options for patients with hemophilia. The introduction of recombinant factor concentrates in the early 1990s facilitated the use of prophylactic replacement as standard care for hemophilia rather than on-demand treatment. This has revolutionized health outcomes for hemophilia patients, enabling participation in physical activities and reducing debilitating, chronic joint damage. Challenges of prophylactic factor infusion include the frequency of infusions needed to maintain factor levels greater than 1%, patient adherence, reliable intravenous access, and development of neutralizing alloantibodies ("inhibitors"). Novel therapeutics seek to improve upon current factor concentrates by several different mechanisms: (1) extending the half-life of circulating exogenous factor protein, (2) replacing the gene necessary for production of endogenous factor protein, (3) employing bispecific antibody technology to mimic the coagulation function of factor VIII, (4) disrupting anticoagulant proteins, such as tissue factor pathway inhibitor (TFPI) or antithrombin (AT3) with antibodies, aptamers, or RNA interference technology. Emerging treatment options may reduce the frequency of (extended half-life products) or eliminate (gene therapy) the need for scheduled factor concentrate infusions, or provide a subcutaneous administration option (bispecific antibody, AT3, and TFPI targeting therapies). In addition, the nonfactor replacement strategies provide a promising treatment option for patients with inhibitors, presently the greatest unmet medical need in hemophilia. This review highlights current and recently completed clinical trials that are driving a paradigm shift in our approach to hemophilia care for patients with and without inhibitors. Am. J. Hematol. 91:1252-1260, 2016. © 2016 Wiley Periodicals, Inc.

Advances in the clinical management of inhibitors in hemophilia A and B

Inhibitors to factor (F)VIII or FIX are the most serious and challenging complication of hemophilia treatment, increasing morbidity and mortality because bleeds no longer respond to standard clotting factor replacement therapy. For patients with high-titer inhibitors, immune tolerance induction achieved through regular factor exposure is the only proven therapy capable of Inhibitor eradication and is almost always indicated for inhibitors of recent onset. Bypassing therapy is used to treat and prevent bleeding, but neither of the two currently available bypassing agents has the predictable hemostatic efficacy of factor replacement in hemophilia patients without inhibitors. Major research efforts are focused on the development of new, more potent therapies for the management of patients with inhibitors.