Article

Abshire T, Kenet G. Recombinant factor VIIa: review of efficacy, dosing regimens and safety in patients with congenital and acquired factor VIII or IX inhibitors

Emory University, Atlanta, Georgia, United States
Journal of Thrombosis and Haemostasis (Impact Factor: 5.55). 07/2004; 2(6):899-909. DOI: 10.1111/j.1538-7836.2004.00759.x
Source: PubMed

ABSTRACT Recombinant factor (rF)VIIa has been available to clinicians since 1996 and has an excellent safety record after almost three-quarters of a million doses have been administered. This paper will review the current clinical experience with rFVIIa dosing in acquired and congenital hemophilia with inhibitors and chronicle all spontaneous and clinical trial reports of thrombotic adverse events as of April 2003. Standard dosing of rFVIIa (90 micro g kg(-1)) allows binding of FVIIa to the surface of an activated platelet and can directly activate factor X in the absence of tissue factor. Experience with bolus dosing suggests that higher dosing (>200 micro g kg(-1)) may be more efficacious in treating hemophilia patients. Clinical trials are ongoing to validate this observation. Continuous infusion dosing may be efficacious for major surgery but high infusion rates (50 micro g kg(-1) h(-1)) might be needed. The relationship between dose of rFVIIa, amount of thrombin generated and measurable FVIIa level is still not known and perhaps newer testing which measures thrombin generation might be more advantageous. Relatively few thrombotic events have been associated with rFVIIa. Known factors predisposing to thrombosis were present in 20 of the 25 (80%) hemophilia patients who were reported spontaneously or who developed a thrombosis during a clinical trial. Additionally, thrombotic events have not increased despite a growing experience with higher dosing of rFVIIa.

0 Followers
 · 
62 Views
 · 
112 Downloads
  • Source
    • "rFVIIa was first approved in Europe in 1996. It has proved to be an effective and safe therapeutic agent for the management of bleeding in hemophiliac patients with inhibitors, with adverse thrombotic events occurring in less than 1% of patients.28 Data collected in a database demonstrated that rFVIIa dosed in a range of less than or equal to 200 μg/kg had a bleeding cessation rate of 84% compared with 97% for those receiving over 200 μg/kg. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In developing countries, the treatment of hemophilia patients with inhibitors is presently the most challenging and serious issue in hemophilia management, direct costs of clotting factor concentrates accounting for >98% of the highest economic burden absorbed for the health care of patients in this setting. In the setting of chronic diseases, cost-utility analysis, which takes into account the beneficial effects of a given treatment/health care intervention in terms of health-related quality of life, is likely to be the most appropriate approach. The aim of this study was to assess the incremental cost-effectiveness ratios of immune tolerance induction (ITI) therapy with plasma-derived factor VIII concentrates versus on-demand treatment with recombinant-activated FVIIa (rFVIIa) in hemophilia A with high titer inhibitors from an Iranian Ministry of Health perspective. This study was based on the study of Knight et al, which evaluated the cost- effectiveness ratios of different treatments for hemophilia A with high-responding inhibitors. To adapt Knight et al's results to the Iranian context, a few clinical parameters were varied, and cost data were replaced with the corresponding Iranian estimates of resource use. The time horizon of the analysis was 10 years. One-way sensitivity analyses were performed, varying the cost of the clotting factor, the drug dose, and the administration frequency, to test the robustness of the analysis. Comparison of the incremental cost-effectiveness ratios between the three ITI protocols and the on-demand regimen with rFVIIa shows that all three ITI protocols dominate the on-demand regimen with rFVIIa. Between the ITI protocols the low-dose ITI protocol dominates both the Bonn ITI protocol and the Malmö ITI protocol and would be the preferred ITI protocol. All of the three ITI protocols dominate the on-demand strategy, as they have both a lower average lifetime cost and higher quality-adjusted life-years (QALYs) gained. The cost per QALY gained for the Bonn ITI protocol compared with the Malmö ITI protocol was $249,391.84. The cost per QALY gained for the Bonn ITI protocol compared with the low-dose ITI protocol was $842,307.69. The results of data derived from our study suggest that the low-dose ITI protocol may be a less expensive and/or more cost-effective option compared with on-demand first-line treatment with rFVIIa.
    ClinicoEconomics and Outcomes Research 11/2011; 3:207-12. DOI:10.2147/CEOR.S25909
  • Source
    • "Identified published reports on parallel use of aPCC ( FEIBA ) and r - FVIIa ( NovoSeven ) . Diagnosis Case ( s ) Age ( years ) , sex aPCC / r - FVIIa infusions Doses administered Complication Reference HA + inhibitor haematomas 1 2 2# Sequential 90 lg / kg r - FVIIa / 2 h 75 iu / kg aPCC / 12 h PE Rosenfeld et al ( 2002 ) HA + inhibitor 1 26 # Sequential 84 lg / kg r - FVIIa aPCC dose unknown AMI Abshire and Kenet ( 2004 ) Acquired HA 1 57 $ Sequential 20 – 48 lg / kg r - FVIIa aPCC dose unknown DVT + PE Abshire and Kenet ( 2004 ) Acquired HB 1 70 # Sequential r - FVIIa dose unknown aPCC dose unknown DIC Abshire and Kenet ( 2004 ) Acquired HA 1 55 # Sequential 80 lg / kg r - FVIIa aPCC dose unknown Cerebral thrombosis Abshire and Kenet ( 2004 ) Acquired HA 1 56 $ Sequential r - FVIIa dose unknown aPCC dose unknown DIC Abshire and Kenet ( 2004 ) "
    [Show abstract] [Hide abstract]
    ABSTRACT: In the absence of new outbreaks of transfusion-related infections, the occurrence of neutralizing antibodies currently remains the most prominent complication in haemophilia. Coagulation factor products that may circumvent the inadequate activation of factor X in classical haemophilia, often referred to as bypassing agents, have demonstrated a high degree of efficacy. A smaller number of patients have been described in whom either bypassing agent, or both, demonstrate diminished efficacy. In those cases, the use of both bypassing agents in parallel was attempted, either using simultaneous (combined) or alternating (sequential) infusion of the two drugs, reportedly with successful haemostasis. We speculated whether such treatment might cause thromboembolism. A thorough literature search disclosed 17 reports regarding the parallel use of bypassing agents in the same bleeding episode in 49 patients; reporting nine patients with acquired haemophilia and forty patients with congenital haemophilia with inhibitors. Notable incidences of thromboembolic manifestations were observed: in nine patients with acquired haemophilia, five and in 40 patients with congenital haemophilia five suffered from significant thrombotic complications, and overall four cases were fatal. Although efficacy of parallel treatment was reported excellent in most cases, thromboembolism is rare in haemophilia and parallel treatment with activated prothrombin complex concentrate and activated recombinant human factor VII appears to increase the risk of thrombosis in these patients.
    British Journal of Haematology 09/2011; 155(2):256-62. DOI:10.1111/j.1365-2141.2011.08854.x · 4.96 Impact Factor
  • Source
    • "Meanwhile, in the study by Pruthi et al,20 1 patient in the BI group developed thrombosis of the popliteal and proximal peroneal veins, documented by Doppler ultrasonography on day 10 after surgery. Additionally, 2 reviews reported adverse thromboembolic events following rFVIIa treatment in patients with hemophilia from 1996 to April 200342 and from May 2003 to 2006.43 In total, 55 thromboem-bolic events are reported among approximately 1.5 million standard doses (90 μg/kg) administered to a 40-kg individual. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Recombinant activated factor VII (rFVIIa, NovoSeven) was introduced in 1996 for the treatment of hemophilic patients with antibodies against coagulation factor VIII or IX. To review the evidence supporting the use of rFVIIa for the treatment of patients with congenital bleeding disorders. English-language databases were searched in September 2009 for reports of randomized controlled trials (RCTs) evaluating the ability of rFVIIa to restore hemostasis in patients with congenital bleeding disorders. Eight RCTs involving 256 hemophilic patients with antibodies against coagulation factors, also known as inhibitors, were identified. The evidence supporting the use of rFVIIa in these patients was weak with regard to dose, clinical setting, mode of administration, efficacy, and adverse events, given the limited sample size of each RCT and the heterogeneity of the studies. The authors suggest that rFVIIa therapy in hemophilic patients with inhibitors should be based on the individual's ability to generate thrombin and form a clot, and not on the patient's weight alone. Therefore, assays for thrombin generation, such as whole-blood thromboelastography, have the potential to significantly improve the treatment of these patients.
    Drug Design, Development and Therapy 07/2010; 4:107-16. DOI:10.2147/DDDT.S11764 · 3.03 Impact Factor
Show more