Experience with use of recombinant activated factor VII

Rare inherited coagulation disorders: no longer orphan and neglected

Rare inherited coagulation disorders due to the deficiency or dysfunction of coagulation factors have until recently received less clinical attention than hemophilias and von Willebrand disease. This situation has changed in the last decades, mainly due to therapeutic progress with the availability of more and safer products for replacement therapy produced by plasma fractionation or recombinant DNA technology. This narrative review, based on the latest literature and expert opinion, emphasizes the progress achieved for each of the rare deficiencies, mentions the still unmet therapeutic needs, and sketches the perspectives for further progress.

Pharmacological management of rare coagulation factor deficiencies besides hemophilia

INTRODUCTION

Rare coagulation factor deficiencies are less-known disorders with variable effects on the patient's life. Management of such patients is a challenge due to the paucity of evidence-based data, more so when patients with these rare disorders encounter a more rare, related condition, like inhibitor development or thrombosis.

AREA COVERED

A comprehensive literature search related to RCFDs and management was performed in PubMed in order to discuss therapeutic options and challenges, prophylaxis, management of minor and major surgeries, obstetric and gynecological complications, inhibitor development, and thrombosis.

EXPERT OPINION

Although significant changes have occurred in the management of RCFDs in recent years, more evidence-based studies besides expert opinion are needed for optimal management.

Continuous infusion of recombinant activated factor VII: a review of data in congenital hemophilia with inhibitors and congenital factor VII deficiency

Introduction

Continuous infusion (CI) of clotting factors as a replacement therapy for perioperative hemostatic protection has been performed for many years, including with factors VIII and IX and recombinant activated factor VII (rFVIIa). This approach provides steady factor levels without requiring frequent administration of bolus doses.

Aim

To review safety, efficacy, and dosing data regarding CI of rFVIIa for hemostatic management of patients with congenital hemophilia with inhibitors (CHwI) or congenital factor VII deficiency (C7D).

Materials and methods

A literature review identified instances of CI of rFVIIa in patients with CHwI or C7D undergoing surgery or experiencing bleeding episodes. Data regarding safety, efficacy, and dosing were extracted.

Results

The safety and efficacy of 50 mcg/kg/h CI of rFVIIa following a 90 mcg/kg bolus injection, vs a standard bolus injection regimen, was reported for 24 patients with CHwI undergoing elective surgery in an open-label, randomized, Phase III trial. Efficacy was similar between CI and bolus injection groups at all postoperative time points assessed. Additionally, a postmarketing surveillance study reported effective (80%) and partially effective (20%) CI of rFVIIa in a Japanese cohort of ten patients with CHwI who underwent 15 surgical procedures. Finally, the safety and dosing of rFVIIa CI in 193 and 26 patients with CHwI and C7D, respectively, were reported in 11 prospective studies, 10 retrospective studies, and 30 case reports. No unexpected safety findings were reported.

Conclusion

rFVIIa CI has been performed safely and effectively in patients with CHwI and C7D undergoing surgery and during bleeding episodes in patients with CHwI.

Hereditary Blood Coagulation Disorders: Management and Dental Treatment

Patients with hereditary hemostatic disorders, characterized by a tendency to bleeding or thrombosis, constitute a serious challenge in the dental practice. Advances in the medical diagnosis of hemostatic disorders have exposed dental professionals to new patients not amenable to the application of the management protocols associated with other, more well-known, disorders. It is the aim of this paper to review the evidence, to highlight the areas of major concern, and to suggest management regimens for patients with hereditary hemostatic disorders. An extensive review has been made (PubMed, Science Direct, Web of Knowledge, etc.) of literature pertaining to hereditary disorders affecting blood coagulation factors and how they affect the practice of dentistry. Several aspects relating to the care of such patients must be recognized and taken into consideration when dental treatment is planned. Replacement of deficient coagulation factors ensures that safe dental treatment will be carried out. However, the half-life of such coagulation factors requires that dental treatment be specifically planned and adapted to the type of pathology involved.

Future of coagulation factor replacement therapy

Over a million patients worldwide currently suffer from hemophilia and other congenital clotting factor deficiencies. Patients affected with hemophilia A and B are treated by intravenous replacement therapy of factor VIII and factor IX, respectively. Current hemophilia treatments have favorably supported their efficacy, tolerability, and safety profiles. The onset of alloantibodies inactivating the infused coagulation factor is the main problem in hemophilia patients rendering replacement therapies ineffective; another disadvantage is the short half-life of the infused clotting factors with the need for multiple and frequent infusions to manage a bleeding episode. Now, the challenge in the management of hemophilia treatment is the prolongation of the half-life and reduction in the immunogenicity of recombinant clotting factors. The bioengineering strategies, previously applied successfully to other therapeutic proteins, encourage the current efforts to produce novel coagulation factors with more prolonged bioavailability, with increased potency and resistance to inactivation and potentially reduced immunogenicity.

A review of long-term prophylaxis in the rare inherited coagulation factor deficiencies

The rare inherited coagulation factor deficiencies (deficiencies of factors I, II, V, VII, XI, XIII, combined FV + FVII deficiency, combined deficiency of the vitamin K dependent factors and von Willebrand disease type 3) have an aggregate prevalence of approximately 1:100,000. They may cause recurrent life or function threatening haemorrhage. In this article we review the available literature on long-term prophylaxis and, where possible, make recommendations on this important area.

Treatment of acquired haemophilia with recombinant activated FVII: a critical appraisal

Acquired haemophilia is a rare bleeding disorder usually caused by the spontaneous formation of inhibitory antibodies to coagulation FVIII. The disease occurs most commonly in the elderly, and although acquired haemophilia may be associated with a variety of underlying conditions, up to 50% of reported cases are idiopathic. Treatment options have traditionally involved human FVIII or FIX replacement therapy (if the inhibitor titre allows), porcine FVIII or the use of activated pro-thrombin complex concentrates. Recombinant activated coagulation FVII (rFVIIa) was available on an emergency and compassionate use basis from 1988 to 1999 at sites in Europe and North America. It has been registered in Europe for use in treating acquired haemophilia since 1996 and has recently been licensed for this indication in the United States. By directly activating FX on the surface of activated platelets at the site of injury (thereby bypassing FVIII and FIX), rFVIIa can circumvent the actions of inhibitory antibodies present in acquired haemophilia patients. This paper provides an overview of experiences with rFVIIa for the treatment of acquired haemophilia from the NovoSeven compassionate and emergency use programmes (1989-1999), the Hemophilia and Thrombosis Research Society Registry, and independent published reports from January 1999 to September 2005. rFVIIa has been reported to provide safe and effective haemostasis as a first line therapy in patients of all ages for a variety of surgical and non-surgical bleeding situations.

Human recombinant factor VII for emergency reversal of coagulopathy in neurosurgical patients: a retrospective comparative study

OBJECTIVE

Severe coagulopathy in a neurosurgical patient with intracranial hemorrhage is a common and serious problem. Current therapy with vitamin K and fresh-frozen plasma (FFP) may be too slow in certain situations. There are reports of rapid reversal of coagulopathy using human recombinant factor VII. We present a retrospective controlled study of our experience with factor VII.

METHODS

We used factor VII as a second-line therapy after initial attempts at reversal with FFP had failed. Factor VII was given to 29 patients in the neurosurgical intensive care unit; 24 patients treated before the introduction of factor VII were control subjects. The groups were matched by age, sex, cause of coagulopathy, and presence of intracranial hemorrhage.

RESULTS

After initial FFP administration, the international normalized ratio (INR) changed from a mean of 2.57 to 1.67 in the factor VII group and from 2.17 to 1.85 in control subjects. In all patients, INR tended to rebound. Before administration of factor VII, the mean INR was 2.206. After 1.4 mg of factor VII, mean INR decreased to 1.12 (P < 0.05). Measured from admission, INR in the factor VII group normalized within 6.78 +/- 2.68 hours, and in control subjects, within 47.44 +/- 9.88 hours (P < 0.0005). Six factor VII patients and six control subjects died. The number of patients with good functional outcome (Glasgow Outcome Scale score of 5) was greater among patients treated with factor VII compared with those who received only vitamin K and FFP (nine versus two, P = 0.04). None of the deaths were the result of a thrombotic complication. There were no thrombotic complications in the factor VII group.

CONCLUSION

Factor VII is safe and highly effective when emergency reversal of coagulopathy is desired and may improve the functional outcome. We speculate that the use of factor VII as first choice may result in decreased use of FFP and thus increase patient safety.

Use of recombinant factor VIIa for refractory hemorrhage during extracorporeal membrane oxygenation

OBJECTIVE

To describe the outcome and treatment of two patients with recombinant factor VIIa (rFVIIa) for severe hemorrhage associated with extracorporeal membrane oxygenation (ECMO).

DESIGN

Case report.

SETTING

A 38-bed pediatric intensive care unit and 20-bed pediatric cardiac intensive care unit at a tertiary care children's hospital.

PATIENT

Two patients with life-threatening hemorrhagic complications associated with ECMO requiring massive transfusion of blood products.

INTERVENTIONS

Administration of repeated doses of rFVIIa at 90 microg/kg/dose.

MEASUREMENT AND MAIN RESULTS

PATIENT 1 was an 11-yr-old male with a dilated cardiomyopathy who had undergone an orthotopic heart transplant treated with venoarterial ECMO postoperatively for right ventricular dysfunction. PATIENT 2 was a 13-yr-old male treated with venoarterial ECMO for cardiopulmonary failure from necrotizing staphylococcal pneumonia. Both patients had severe hemorrhage from the cannulation sites and thoracostomy tubes requiring massive transfusion to maintain intravascular blood volume and replace clotting factors. Both patients were treated with rFVIIa every 2-4 hrs and attained hemostasis. PATIENT 1 was administered three doses and PATIENT 2 was administered ten doses. No evidence of abnormal thrombus formation was noted in their respective ECMO circuits.

CONCLUSIONS

The efficacy of rFVIIa in reducing intractable bleeding postcardiac surgery and in other coagulopathic states is being investigated. Despite theoretical concerns of thrombosis, these cases illustrate that there may be a role for the cautious use of rFVIIa in treating severe and intractable hemorrhage associated with ECMO.

The use of activated recombinant coagulation factor VII during haemarthroses and synovectomy in a patient with congenital severe factor V deficiency

Factor V deficiency is a rare hereditary bleeding disorder. Currently, FV concentrates are not available, and the treatment of spontaneous bleeding or bleeding associated with invasive procedures is transfusion of fresh frozen plasma (FFP). However, FFP transfusion can lead to the development of inhibitor to FV, and is associated with several potential transfusion reactions including allergic reactions. We report a patient with congenital severe FV deficiency with repeated haemarthroses of a shoulder joint, and progressively severe allergic reactions to FFP transfusions. In addition, the patient also developed acute pulmonary oedema. Activated recombinant coagulation factor VII (rFVIIa) was used as an alternative haemostatic agent to FFP. We describe the use of rFVIIa in this patient during haemarthroses, synovectomy, and physiotherapy.