1.
A randomized trial of factor VIII and neutralizing antibodies in hemophilia A
Peyvandi F, Mannucci PM, Garagiola I, El-Beshlawy A, Elalfy M, Ramanan V, Eshghi P, Hanagavadi S, Varadarajan R, Karimi M, et al
The New England Journal of Medicine. 2016;374((21)):2054-64.
Abstract
BACKGROUND The development of neutralizing anti-factor VIII alloantibodies (inhibitors) in patients with severe hemophilia A may depend on the concentrate used for replacement therapy. METHODS We conducted a randomized trial to assess the incidence of factor VIII inhibitors among patients treated with plasma-derived factor VIII containing von Willebrand factor or recombinant factor VIII. Patients who met the eligibility criteria (male sex, age <6 years, severe hemophilia A, and no previous treatment with any factor VIII concentrate or only minimal treatment with blood components) were included from 42 sites. RESULTS Of 303 patients screened, 264 underwent randomization and 251 were analyzed. Inhibitors developed in 76 patients, 50 of whom had high-titer inhibitors (≥5 Bethesda units). Inhibitors developed in 29 of the 125 patients treated with plasma-derived factor VIII (20 patients had high-titer inhibitors) and in 47 of the 126 patients treated with recombinant factor VIII (30 patients had high-titer inhibitors). The cumulative incidence of all inhibitors was 26.8% (95% confidence interval [CI], 18.4 to 35.2) with plasma-derived factor VIII and 44.5% (95% CI, 34.7 to 54.3) with recombinant factor VIII; the cumulative incidence of high-titer inhibitors was 18.6% (95% CI, 11.2 to 26.0) and 28.4% (95% CI, 19.6 to 37.2), respectively. In Cox regression models for the primary end point of all inhibitors, recombinant factor VIII was associated with an 87% higher incidence than plasma-derived factor VIII (hazard ratio, 1.87; 95% CI, 1.17 to 2.96). This association did not change in multivariable analysis. For high-titer inhibitors, the hazard ratio was 1.69 (95% CI, 0.96 to 2.98). When the analysis was restricted to recombinant factor VIII products other than second-generation full-length recombinant factor VIII, effect estimates remained similar for all inhibitors (hazard ratio, 1.98; 95% CI, 0.99 to 3.97) and high-titer inhibitors (hazard ratio, 2.59; 95% CI, 1.11 to 6.00). CONCLUSIONS Patients treated with plasma-derived factor VIII containing von Willebrand factor had a lower incidence of inhibitors than those treated with recombinant factor VIII. (Funded by the Angelo Bianchi Bonomi Foundation and others; ClinicalTrials.gov number, NCT01064284; EudraCT number, 2009-011186-88.).
2.
Source of factor VIII replacement (PLASMATIC OR RECOMBINANT) and incidence of inhibitory alloantibodies in previously untreated patients with severe hemophilia a: the multicenter randomized sippet study
Peyvandi F, Mannucci PM, Garagiola I, Elalfy M, El-Beshlawy A, Ramanan MV, Eshghi P, Hanagavadi S, Varadarajan R, Karimi M, et al
Blood. 2015;126((23)): Abstract No. 5.
3.
Home treatment of haemarthroses using a single dose regimen of recombinant activated factor VII in patients with haemophilia and inhibitors. A multi-centre, randomised, double-blind, cross-over trial
Kavakli K, Makris M, Zulfikar B, Erhardtsen E, Abrams ZS, Kenet G, NovoSeven trial investigators
Thrombosis and Haemostasis. 2006;95((4):):600-5.
Abstract
The aim was to evaluate the efficacy and safety of two recombinant factor VIIa (rFVIIa) dose regimens for treating haemarthroses in patients with congenital haemophilia A or B and inhibitors. This was a multicentre, randomised, cross-over, double-blind trial. Patients were randomly allocated to treat a first joint bleeding episode with one 270 microg/kg rFVIIa dose followed by two doses of placebo at 3-hour intervals and a second joint bleed with three single doses of 90 microg/kg rFVIIa at 3-hour intervals, or vice versa. Efficacy was evaluated using a novel and robust treatment response-rating scale based on patient-assessment of pain and joint mobility. Outcome was rated at different timepoints, and an effective or ineffective treatment response was determined. Treatment preferencewas defined as effective treatment with one regimen and ineffective with the other. Patients with equally effective or ineffective treatments had no preference. Treatment was rated as effective for 65% of patients using the 270 microg/kg dose versus 70% for the 90 microg/kg x 3 regimen. An equal preferencewas noted for the two regimens (21% for each; p = 0. 637); most patients (58%) had no preference. 37/42 bleeding episodes (88%) were successfully treated with rFVIIa; additional haemostatic medications were administered for five episodes. No safety issues were identified. Administration of rFVIIa as a single 270 microg/kg dose to treat haemarthroses in patients with haemophilia and inhibitors was at least as efficacious and safe as the 90 microg/kg x 3 regimen.