To cite this article: Konkle BA, Ebbesen LS, Erhardtsen E, Bianco RP, Lissitchkov T, Rusen L, Serban MA. Randomized, prospective clinical trial of recombinant factor VIIa for secondary prophylaxis in hemophilia patients with inhibitors. J Thromb Haemost 2007; 5: 1904-13. Summary. 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 ‡ 4 bleeds per month). Twenty-two patients were randomized 1:1 to receive daily rFVIIa prophylaxis with either 90 or 270 lg 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 lg kg , 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.

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BackgroundBAY 81-8973 is a new full-length human recombinant factor VIII product manufactured with technologies to improve consistency in glycosylation and expression to optimize clinical performance.ObjectivesTo demonstrate superiority of prophylaxis vs. on-demand therapy with BAY 81-8973 in patients with severe hemophilia A.Patients/MethodsIn this multinational, randomized, open-label crossover study (LEOPOLD II; ClinicalTrials.gov identifier: NCT01233258), males aged 12–65 years with severe hemophilia A were randomized to twice-weekly prophylaxis (20–30 IU kg−1), 3-times-weekly prophylaxis (30–40 IU kg−1), or on-demand treatment with BAY 81-8973. Potency labeling for BAY 81-8973 was based on the chromogenic substrate assay or adjusted to the one-stage assay. Primary efficacy endpoint was annualized number of all bleeds (ABR). Adverse events (AEs) and immunogenicity were also assessed.ResultsEighty patients (on demand, n = 21; twice-weekly prophylaxis, n = 28; 3-times-weekly prophylaxis, n = 31) were treated and analyzed. Mean ± SD ABR was significantly lower with prophylaxis (twice-weekly, 5.7 ± 7.2; 3-times-weekly, 4.3 ± 6.5; combined, 4.9 ± 6.8) vs. on-demand treatment (57.7 ± 24.6; P < 0.0001, anova). Median ABR was reduced by 97% with prophylaxis (twice-weekly, 4.0; 3-times-weekly, 2.0; combined, 2.0) vs. on-demand treatment (60.0). Median ABR was higher with twice-weekly vs. 3-times-weekly prophylaxis during the first 6-month treatment period (4.1 vs. 2.0) but was comparable in the second 6-month period (1.1 vs. 2.0). Few patients reported treatment-related AEs (4%); no treatment-related serious AEs or inhibitors were reported.ConclusionsTwice-weekly or 3-times-weekly prophylaxis with BAY 81-8973 reduced median ABR by 97% compared with on-demand therapy, confirming the superiority of prophylaxis. Treatment with BAY 81-8973 was well tolerated.

Summary. Background: Vatreptacog alfa, a recombinant human factor VIIa (rFVIIa) analog developed to improve the treatment of bleeds in hemophilia patients with inhibitors, differs from native FVIIa by three amino acid substitutions. In a randomized, double-blind, crossover, confirmatory phase III trial (adept TM 2), 8/72 (11%) hemophilia A or B patients with inhibitors treated for acute bleeds developed anti-drug antibodies (ADAs) to vatreptacog alfa. Objectives: To characterize the formation of anti-vatreptacog alfa ADAs in hemophilia patients with inhibitors. Methods/patients: This was a post hoc analysis of adept TM 2. Immunoglobulin isotype determination, specificity analysis of rFVIIa cross-reactive antibodies, epitope mapping of rFVIIa single mutant analogs and pharmacokinetic (PK) profiling were performed to characterize the ADAs. Results: Immunoglobulin isotyping indicated that the ADAs were of the immunoglobulin G subtype. In epitope mapping, none of the rFVIIa single mutant analogs (V158D, E296V or M298Q) contained the complete antibody epitope, confirming that the antibodies were specific for vatreptacog alfa. In two patients, for whom PK profiling was performed both before and after the development of ADAs, vatreptacog alfa showed a prolonged elimination phase following ADA development. During the follow-up evaluation, the rFVIIa cross-reactivity disappeared after the last vatreptacog alfa exposure, despite continued exposure to rFVIIa as part of standard care. Conclusions: Results from the vatreptacog alfa phase III trial demonstrate that the specific changes made, albeit relatively small, to the FVIIa molecule alter its clinical immunogenicity.

Children with haemophilia often experience limitations in activities of daily life. Recently the Paediatric Haemophilia Activities List (PedHAL) has been developed and tested in Dutch children with intensive replacement therapy. The psychometric properties of the PedHAL in children not receiving intensive replacement therapy are not known. The objective was to gain further insight into the psychometric properties of the PedHAL and to study the functional health status of Romanian children and adolescents with haemophilia. Children attending to the rehabilitation centre of Buzias in Romania were sampled consecutively. Construct validity of the PedHAL was evaluated by concurrent testing with objective and subjective measures of physical function and functional ability. Reproducibility was tested by a 3-day test-retest by intraclass correlation coefficient (ICC) and limits of agreement (LOA). Responsiveness to rehabilitation was assessed by Haemophilia Joint Health Score (HJHS) and PedHAL. Twenty-nine children with severe (n = 25) or moderate (n = 4) haemophilia participated. Mean age was 13.2 years (SD 4.0). Median score of the PedHAL was 83.5 (IQR 47.9-90.5). The PedHAL correlated moderately with HJHS (rho = -0.59), Functional Independence Score in& Haemophilia (rho = 0.65) and Child Health Questionnaire-physical function (rho = 0.40) and not with Child Health Questionnaire-mental health, Child Health Questionnaire-behaviour and 6MWT. Test-retest reliability was good (ICC = 0.95). LOA was 17.4 points for the sum score. HJHS scores improved slightly after rehabilitation, whereas PedHAL scores did not change. In general, construct validity and test-retest reliability were good, test-retest agreement showed some variability. Therefore, currently the PedHAL may be more appropriate for research purposes than for individual patient monitoring in clinical practice.