[Application of activated recombinant factor VII (rFVIIa, NovoSeven) in neonatology]

Recombinant activated factor VII is vitamin K dependent glycoprotein, similar as the same in the human blood plasma. First has been described in application for hemophilia, where are presented inhibitors of factors VIII and IX, later was proved that it has effectiveness in hemorrhage with different etiology. Clinical experience with this medicine in neonatology is still small, but in the latest years there is some data about its effectiveness in hemorrhage in term and preterm newborns. The data shows that there is low risk of side effects of the recombinant activated factor VII in neonatal period. But still has been described as a experimental treatment.

Randomized, prospective clinical trial of recombinant factor VIIa for secondary prophylaxis in hemophilia patients with inhibitors

BACKGROUND

Hemophilic patients with factor VIII (FVIII) and FIX inhibitors suffer from frequent bleeding episodes and reduced quality of life.

OBJECTIVES

To evaluate whether secondary prophylaxis with activated recombinant factor VII (rFVIIa) can safely and effectively reduce bleeding frequency as compared to conventional on-demand therapy.

METHODS

Thirty-eight male patients entered a 3-month preprophylaxis period to confirm high baseline bleeding frequency (mean > or = 4 bleeds per month). Twenty-two patients were randomized 1:1 to receive daily rFVIIa prophylaxis with either 90 or 270 microg kg(-1) for 3 months, followed by a 3-month postprophylaxis period.

RESULTS

Bleeding frequency was reduced by 45% and 59% during prophylaxis with 90 and 270 microg kg(-1), respectively (P < 0.0001); however, there was no significant difference detected between doses. The majority of this reduction was maintained during the postprophylaxis period. Although all types of bleed were similarly reduced, the effect was most pronounced for spontaneous joint bleeds. Patients reported significantly fewer hospital admissions and days absent from work/school during prophylaxis as compared to the preprophylaxis period. No thromboembolic events were reported during prophylaxis.

CONCLUSION

Clinically relevant reductions in bleeding frequency during prophylaxis as compared to conventional on-demand therapy were achieved without raising safety concerns. These results provide evidence for the concept of secondary rFVIIa prophylaxis in inhibitor patients with frequent bleeds.

Factor VII activado recombinante

Recombinant activated factor VII is a drug that should be considered when there is massive bleeding. Its activation after it is bond to the tissue factor expressed triggers the coagulation cascade by action sequence of the different factors. Since its approval as treatment for bleeding episodes in patients with hemophilia, its indications have been increasing. It is a drug is indicated in non-traumatic intracranial bleeding, in patients with severe multiple traumas, and in those bleeding conditions that may affect patient viability. Although the adverse effects are well characterized, it is still a newly used drug. Thus, the potential risks of its use in each patient must be weighed.

Dosing factor VIIa (recombinant) in nonhemophiliac patients with bleeding after cardiac surgery

PURPOSE

The dosing of factor VIIa (recombinant) in nonhemophiliac patients with cardiac-surgery-associated bleeding (CSAB) is discussed.

SUMMARY

Factor VIIa (recombinant) is a vitamin K-dependent glycoprotein that is FDA-approved for use in patients with hemophilia A or B with inhibitors to factor VIII or IX and for patients with factor VII deficiency. Case reports and observational studies indicate that factor VIIa (recombinant) may be efficacious for the treatment of acute bleeding episodes related to trauma, surgery, and coagulopathies. The use of factor VIIa (recombinant) for CSAB is increasing. No controlled clinical trials have been conducted to determine the safety and efficacy of factor VIIa (recombinant) in the treatment of CSAB; therefore, the appropriate dosing scheme remains unclear. In addition, thromboembolic events associated with factor VIIa (recombinant) have been reported, so the safety of factor VIIa (recombinant) in patients with normal coagulation systems is unclear. Data from one randomized, controlled, clinical trial of the use of factor VIIa (recombinant) in intracerebral hemorrhage showed a dose-related trend toward adverse events when factor VIIa (recombinant) was compared with placebo.

CONCLUSION

No particular dose of factor VIIa (recombinant) is strongly supported in the literature for off-label use, and thromboembolic events may be dose dependent. Use of the smallest possible dose is warranted because of the high cost of factor VIIa (recombinant) and the potential for thromboembolic events. A single dose of 2.4 or 4.8 mg or 45 microg/kg should be considered.

The use of recombinant activated factor VII in trauma patients: Experience from the Australian and New Zealand haemostasis registry

BACKGROUND

There is increasing use of rFVIIa (eptagog alpha, Novoseven) in injured patients with critical bleeding. The role of rFVIIa is not defined in this group of patients. Registries provide an opportunity to review the patients, reported response and adverse events for rFVIIa.

AIM

To determine the pattern of use, reported response and adverse events in patients receiving rFVIIa following injury using the Australian and New Zealand Haemostasis Registry (ANZHR).

METHODS

The ANZHR (commenced May 2005) collects data from 53 hospitals on all patients receiving rFVIIa in those hospitals.

RESULTS

Of 695 cases in the registry, 108 patients from 19 hospitals were submitted with a primary trauma diagnosis. Most (88) patients received one 90microg/kg dose of rFVIIa. There was a significant reduction in the use of all blood products following rFVIIa (p<0.001) and rFVIIa was thought to have decreased or stopped bleeding in 59% of cases. There was wide variation in the timing of rFVIIa use. There were two adverse events that were considered possibly linked and a total of three thromboembolic events. Following multivariate analysis, pH provided the best model of response to rFVIIa. Patients with a pH<7.05 were significantly less likely to respond (OR=0.3, 95% CI=0.0-0.3). Only two patients would fit the criteria for the present prospective study of rFVIIA in trauma patients.

CONCLUSION

The best approach to managing critical bleeding in trauma patients is not agreed. The role of rFVIIa will only be clarified if there is a standardised approach to fluid management and transfusion of blood products. The registry allows tracking of current practice, outcomes and adverse events and will complement present phase 2 and 3 trials.

Recombinant activated factor VII for refractory bleeding after acute aortic dissection surgery: A propensity score analysis*

OBJECTIVE

The aim of this study was to assess safety and effectiveness of recombinant activated factor VII (rFVIIa) in patients with refractory bleeding undergoing acute aortic dissection surgery with deep hypothermic circulatory arrest.

DESIGN

Propensity score-matched analysis.

SETTING

University hospital.

PATIENTS

Twenty-three cardiac surgery patients receiving rFVIIa compared with 23 matched controls.

INTERVENTIONS

An intravenous bolus of rFVIIa (70 microg/kg) was administered at the end of a complete transfusion protocol. Five patients received rFVIIa in the operating room, and 18 patients received rFVIIa in the intensive care unit. Four of the intensive care unit patients required a second dose.

MEASUREMENTS AND MAIN RESULTS

Blood loss and transfusion requirements were significantly reduced in the period after rFVIIa administration. A highly significant reduction in hourly blood loss was found at -1 hr vs. 0 hrs and 0 hrs vs. 1 hr (-194 and -77.5 mL, respectively; both adjusted p < .001). In addition, significant improvements of international normalized ratio (p < .001), partial thromboplastin time (p < .001), platelet count (p < .001), fibrinogen (p < .001), and antithrombin (p < .001) were detected after rFVIIa administration. The two groups did not differ regarding adverse events.

CONCLUSIONS

rFVIIa was successfully used as an additional therapy both during and after acute aortic dissection surgery with deep hypothermic circulatory arrest, when bleeding was refractory to conventional methods. Randomized studies are necessary to confirm the safety and efficacy of rFVIIa in this setting.

Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia

BACKGROUND

Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies. It is also increasingly being used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means.

OBJECTIVES

To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding, or prophylactically to prevent (excessive) bleeding in patients without haemophilia.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's Specialised Register, CENTRAL, MEDLINE, EMBASE and other specialised databases up to March 2006. We also searched reference lists of articles and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population with the exception of those with haemophilia. There was no restriction by outcomes examined, but this review focuses on mortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed potentially relevant studies for inclusion. Data were extracted and methodological quality was examined. Studies using rFVIIa prophylactically and those using rFVIIa therapeutically have been considered separately. Data were pooled using fixed and random effects models, but random effects models were preferred because of the variability in clinical features of the included studies.

MAIN RESULTS

Thirteen trials met the inclusion criteria; all were placebo-controlled double-blind RCTs. Six trials involving 724 participants examined the prophylactic use of rFVIIa; 379 received rFVIIa. There were no outcomes by which any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There were trends in favour of rFVIIa for a number of outcomes, particularly the number of participants transfused, pooled RR 0.85 (95% CI 0.72 to 1.01) but this was balanced by a trend against rFVIIa with respect to thromboembolic adverse events, pooled RR 1.25 (95% CI 0.76 to 2.07). Seven trials involving 1214 participants examined the therapeutic use of rFVIIa; 687 received rFVIIa. There were no outcomes where any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality, RR 0.82 (95% CI 0.64 to 1.04), although no other clear trends in favour of rFVIIa were noted for other desired outcomes. Interpretation of these results must take into account one study which could not be included in the quantitative summary but which showed results strongly in favour of rFVIIa for the treatment of intra-cerebral haemorrhage. There was a trend against rFVIIa with respect to thromboembolic adverse events; the RR 1.50 (95% CI 0.86 to 2.62).

AUTHORS' CONCLUSIONS

Although rFVIIa has a role in the management of patients with haemophilia, its effectiveness as a more general haemostatic drug, either prophylactically or therapeutically, remains uncertain. Its effectiveness as a therapeutic agent, particularly for intra-cerebral haemorrhage, looks more encouraging than prophylactic use. The use of rFVIIa outside its current licensed indications should be very limited and its wider use await the results of ongoing and possibly newly commissioned RCTs. In the interim, rFVIIa use should be restricted to clinical trials.

Thromboembolic Complications Associated With Factor VIIa Administration

BACKGROUND

Factor VIIa (FVIIa) is given to promote hemostasis in coagulopathic trauma patients at high risk for death. FVIIa is associated with thromboembolic complications, but the incidence is not known, nor is which patients are at risk. We examined our experience with FVIIa to better understand this issue.

METHODS

Medical records of patients who received FVIIa from 2001 to 2006 were reviewed for evidence of thromboembolic events, including ischemic cardiovascular accident, myocardial ischemia or infarct, mesenteric infarct, peripheral arterial thromboembolism, deep venous thrombosis, or pulmonary embolus. Indication for FVIIa dosing, timing of complication, and clinical outcome were recorded. Each event was assessed by a panel of experienced clinicians to determine the contribution of FVIIa to the event and to patient outcome.

RESULTS

Two hundred eighty-five medical records were reviewed. Twenty-seven patients (9.4%) had thromboembolic complications after administration of FVIIa. Nine events were thought to be highly related to FVIIa, and 10 of 14 deaths were, in part, caused by the thrombotic complication. Eighteen of the events, including all cardiovascular accidents and most cases of mesenteric ischemia, were attributed to a combination of FVIIa and a definable, high-energy vascular injury.

CONCLUSION

FVIIa is a potent procoagulant, with the potential for adverse thromboembolic events in susceptible patients. Our experience suggests that caution should be exercised in administration of FVIIa to patients with arterial injuries. Injured mesenteric and cerebral vessels may be especially susceptible to thrombosis.

Recombinant human activated factor VII is thrombogenic in a rabbit model of cyclic flow reduction and does not reduce intra-abdominal bleeding

Recombinant human activated factor VII (rHuFVIIa) can reduce bleeding but may be associated with arterial thrombosis. We hypothesized that rHuFVIIa would increase the occurrence of cyclic flow reductions (CFR) and reduce intra-abdominal bleeding in an experimental model. An adapted Folts' model of carotid artery lesion and stenosis was used. Twenty four rabbits were randomized to receive rHuFVIIa (group F) or placebo (group P) in a double-blind fashion. A standardized injury to the common carotid artery resulted in CFR and/or thrombosis. Hematological values, coagulation and thromboelastographic (TEG) variables were compared. Intra-abdominal bleeding was evaluated by measuring blood loss from standardized hepatosplenic lesions. The median number (range) of spontaneous CFR [group P: 6 (0-15); group F: 8 (0-16)] was comparable between groups. The number of induced CFR (by "shaking" of the artery) needed to avert thrombosis (group F: 2; group P: 0; p < 0.05) and the incidence of complete carotid artery thrombosis (group F: 3; group P: 0; p < 0.05) were higher in group F. Intra-abdominal bleeding was similar in both groups. TEG analysis demonstrated a hypercoagulable state in both groups but the magnitude of the change was statistically more important in group F. rHuFVIIa increases thrombosis in a rabbit model of carotid artery injury. The bleeding from hepatic and splenic lesions is not reduced by administration of rHuFVIIa despite a hypercoagulable state confirmed by standard TEG analysis.

Systemic venous thrombosis after recombinant factor VIIa in the control of bleeding after cardiac surgery

Recombinant factor VIIa has been licensed in the United Kingdom since 1996 for the control of bleeding in hemophilic patients who are actively bleeding or are about to undergo surgery. Medical practitioners are also applying recombinant factor VIIa toward the control of bleeding in patients without hemophilia. Although the efficacy of recombinant factor VIIa has been shown in many patients, concerns have arisen about the risk of thrombotic adverse events. Herein, we report the case of a 73-year-old woman who underwent major coronary surgery and developed fatal systemic venous thrombosis after recombinant factor VIIa was used in an attempt to control her severe postoperative bleeding. We review the medical literature and discuss the risks of using recombinant factor VIIa to control severe bleeding after cardiac surgery.

Recombinant factor VIIa (eptacog alfa): a pharmacoeconomic review of its use in haemophilia in patients with inhibitors to clotting factors VIII or IX

Recombinant factor VIIa (NovoSeven; also known as recombinant activated factor VII or eptacog alfa) is indicated as an intravenous haemostatic agent in haemophilia patients with inhibitors to clotting factors VIII or IX. In noncomparative trials in haemophilia patients with inhibitors, on-demand home treatment with recombinant factor VIIa was effective in controlling episodes of mild to moderate bleeding and well tolerated, with early treatment being associated with a greater rate of success and the need for fewer doses than delayed treatment. Prophylactic treatment with recombinant factor VIIa was also effective in maintaining haemostasis in patients with this indication undergoing surgery. Relative to prior treatment with plasma-derived agents, treatment with recombinant factor VIIa was associated with improvements in health-related quality of life in a cost-utility study in haemophilia patients with inhibitors in Australia. In well designed decision-model cost analyses conducted from a healthcare payer perspective in several countries, on-demand treatment with recombinant factor VIIa to control mild to moderate bleeding episodes in this patient population was predicted to be cost saving or cost neutral relative to on-demand treatment with intravenous activated prothrombin complex concentrate (aPCC). Although the acquisition cost of recombinant factor VIIa was greater than that of aPCC in some studies, the greater initial efficacy of recombinant factor VIIa than aPCC resulted in lower predicted total medical costs. Results were generally robust to plausible changes in key parameters. Orthopaedic surgery with recombinant factor VIIa to maintain haemostasis in haemophilia patients with inhibitors was generally predicted to be cost saving, relative to not having surgery, over the medium to long term in modelled cost analyses from a healthcare payer perspective in the UK and US. The initial cost of surgery was high, but the difference in costs between patients undergoing or not undergoing surgery was predicted to decline over time, as savings were realised from the decrease in the number of bleeding episodes requiring treatment in patients who underwent surgery. In haemophilia patients with inhibitors, recombinant factor VIIa is clinically effective in controlling mild to moderate bleeds, and in maintaining haemostasis in patients undergoing orthopaedic surgery. Available pharmacoeconomic data from several countries, despite inherent limitations, support the use of recombinant factor VIIa as a treatment option that is at least cost neutral relative to aPCC in treating mild to moderate bleeds in this patient population. In addition, orthopaedic surgery with recombinant factor VIIa to maintain haemostasis in haemophilia patients with inhibitors is generally cost saving relative to not having surgery over the medium to long term, as the acquisition costs of recombinant factor VIIa are offset by cost savings resulting from the decrease in the number of joint-related bleeds.

The use of factor VIIa in haemorrhagic shock and intracerebral bleeding

Factor VIIa is a revolutionary new pharmaceutical that promises to change the anaesthesia and critical care approach to major trauma. It is an extremely potent pro-coagulant agent, and while it enables haemostasis at the site of tissue injury, it also has the possibility of producing life-threatening thromboembolic complications. New data regarding FVIIa use is published almost every month, leading to a rapidly evolving clinical understanding of the potential indications, and potential pitfalls, of off-label use. Determination of appropriate practice, including the ability to judge the risks and benefits of FVIIa therapy for individual cases, is still some years in the future, and will depend in large part on clinical trials which are just getting underway.

The use of recombinant–activated factor VII in von Willebrand disease: a case series

Spontaneous and surgery-associated bleeding in patients with von Willebrand disease (vWD) cannot always be controlled with desmopressin or replacement therapy. This paper presents results on the use of recombinant-activated factor VII (rFVIIa) in patients with vWD included in the internet registry Haemostasis.com. Twenty-eight reports on the use of rFVIIa in vWD were identified from the database and included in this analysis. The bleeding episodes were classified as mild (n = 7), moderate (n = 16), or severe (n = 2), and were unspecified in three cases. The median dose of rFVIIa administered was 94 microg/kg body weight (40-127.3 microg/kg). Bleeding stopped in 23 of 27 evaluable patients (85%) and markedly decreased in three patients; the total response rate was 96% (26/27 patients). Response did not correlate with the type of vWD, the site or severity of the initial bleed, or the rFVIIa dose. Other replacement therapies were infrequently used, and their use was similar in the 24 h before and after rFVIIa administration. Eighteen patients also received antifibrinolytic treatment, but its impact on response was not recorded. Only one adverse event (mild fever) was observed. These cases suggest a role for rFVIIa as a safe and effective therapy for vWD.

Recombinant activated factor VIIa in uncontrolled bleeding: a haemostasis laboratory study in non-haemophilia patients

Extensive surgery and massive tissue trauma are often associated with severe bleeding. We present retrospective data on the use of recombinant factor VIIa in haemostatic emergencies in13 non-hemophilia patients with uncontrolled bleeding. Recombinant factor VIIa was administered in doses ranging from 16 mug/kg bodyweight to 60 microg/kg bodyweight. Blood loss during 24 h before and after the infusion was registered, showing that 10 out of 13 patients (77%) had a 70% or greater reduction in transfusion requirement decreasing significantly in mean from 28.1 to 9.9 red blood cell units. Coagulation parameters were studied in blood samples collected 10 min before and 10-15 min after the injection of recombinant factor VIIa. Factors VII:C, II:C, and X:C increased significantly while the activated partial thromboplastin time, platelet numbers, and concentration of fibrinogen and D-dimers were unchanged. The dose of rFVIIa correlated significantly with the rise in factor X:C and inversely with transfusion requirements. Dynamic clot velocity of whole blood was recorded before and after rFVIIa infusion in four patients. Judged from red blood cell usage no improvement in haemostasis was seen in one patient suffering thrombocytopenia and low fibrinogen. This patient died 6 h after recombinant factor VIIa infusion, and three other patients died before 1 month. None of the fatalities appeared to be related to recombinant factor VIIa usage. No thromboembolic complications were seen. In conclusion, 12 out of 13 patients survived the first 24 h after treatment with relatively low doses of recombinant factor VIIa for large-scale bleeding. Recombinant factor VIIa was well tolerated and safe in these non-hemophilia patients. With quite low doses of recombinant factor VIIa (<or= 60 microg/kg), the dose of recombinant factor VIIa correlated positively with efficacy. Activation of factor X appeared to predict haemostatic efficacy.