scholarly journals The one‐stage assay or chromogenic assay to monitor baseline factor VIII levels and desmopressin effect in non‐severe haemophilia A: Superiority or non‐inferiority?

Haemophilia ◽  
2020 ◽  
Vol 26 (5) ◽  
pp. 916-922
Author(s):  
Lisette M. Schütte ◽  
Luca S. Hodes ◽  
Iris Moort ◽  
Sara C. M. Stoof ◽  
Frank W. G. Leebeek ◽  
...  
Keyword(s):  
Factor Viii ◽  
Haemophilia A ◽  
Severe Haemophilia ◽  
One Stage ◽  
Chromogenic Assay ◽  
The One ◽  
Baseline Factor

scholarly journals Assessing the Performance of Extended Half-Life Coagulation Factor VIII, FC Fusion Protein by Using Chromogenic and One-Stage Assays in Saudi Hemophilia A Patients

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Tarek M. Owaidah ◽  
Hazzaa A. Alzahrani ◽  
Nouf S. Al-Numair ◽  
Abdulmjeed O. Alnosair ◽  
Amelita M. Aguilos ◽  
...  
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
Hemophilia A ◽  
Coagulation Factor ◽  
Time Interval ◽  
One Stage ◽  
Chromogenic Assay ◽  
Significant Difference ◽  
Mean Differences ◽  
The One

Background. The one-stage assay is the most common method to measure factor VIII activity (FVIII : C) in hemophilia A patients. The chromogenic assay is another two-stage test involving purified coagulation factors followed by factor Xa-specific chromogenic substrate. Aim. This study aimed to assess the discrepancy and correlation between the chromogenic and one-stage assays in measuring FVIII : C levels in hemophilia patients receiving Extended Half-Life Elocta® as a recombinant extended half-life coagulation factor. Methods. We performed a study comparing the measurements of FVIII : C levels by the chromogenic versus the one-stage assays at different drug levels. Data of FVIII : C levels, dosage, and the time interval from administration to measurement were retrieved from the hospital records. The correlation, mean differences, and discrepancy between the two assays were calculated. The linear regression analysis was used to predict the time interval till reaching 1% FVIII : C. Results. Fourteen patients with 56 samples were included in the study. Of them, 13 patients were receiving Elocta® as a prophylactic, while one was receiving Elocta® on demand. One-third of these samples showed a discrepancy between the chromogenic and one-stage assays. The two assays were well correlated. Mean differences were significant at the individual and the time interval level. The time since the last Elocta® injection could significantly predict FVIII : C levels (β = 0.366, P<0.001). Conclusion. Our findings suggested a significant difference between both methods; the FVIII : C levels measured by the one-stage assay were less than those estimated by the chromogenic assay. However, the measurements of FVIII levels by the two assays were well correlated but discrepant in one-third of the samples. The levels of FVIII : C reach 1% after 5.4 days since the last Elocta® administration.

Validation of a Procedure for Potency Assessing of a High Purity Factor VIII Concentrate -Comparison of Different Factor VIII Coagulant Assays and Effect of Prediluent

1990 ◽  
Vol 64 (02) ◽  
pp. 251-255 ◽  
Author(s):  
Claudine Mazurier ◽  
Armelle Parquet-Gernez ◽  
Maurice Goudemand
Keyword(s):  
Factor Viii ◽  
Specific Activity ◽  
Assay Method ◽  
One Stage ◽  
Chromogenic Assay ◽  
Coagulant Activity ◽  
The One ◽  
In Vitro Data

SummaryThe assessment of factor VIII coagulant activity (FVTII: C) in recently available highly purified and concentrated FVTII therapeutic products calls for careful evaluation of assay methodologies. We assayed more than 130 batches of a concentrate with a specific activity of about 150 FVTII :C units/mg protein, using one-stage and two-stage clotting and chromogenic methods. There was good agreement between the potency estimates obtained with the different methods. We also compared the FVTII :C potencies obtained after predilution in buffer or FVIII-deficient plasma using either calibrated plasma or FVTII concentrate as references. With the one-stage assay we found a marked discrepancy between the potency values obtained with buffer and with FVTII-deficient plasma used as prediluents. In order to validate our “in vitro” data we performed 6 “in vivo” analyses in severe haemophilia A patients. On the basis of the overall data obtained we chose to label FVIII potency by using FVIII-deficient plasma as prediluent, reference plasma as standard and the chromogenic assay method.

Pharmacokinetic In Vivo Comparison Using 1-Stage and Chromogenic Substrate Assays with Two Formulations of Hemofil-M

1996 ◽  
Vol 76 (06) ◽  
pp. 0950-0956 ◽  
Author(s):  
Christine Lee ◽  
Trevor Barrowcliffe ◽  
Gordon Bray ◽  
Ed Gomperts ◽  
Anthony Hubbard ◽  
...  
Keyword(s):  
Factor Viii ◽  
Pharmacokinetic Studies ◽  
Chromogenic Substrate ◽  
Single Centre ◽  
One Stage ◽  
Chromogenic Assay ◽  
The Usa ◽  
The Mean ◽  
The One

SummaryIn a study to demonstrate the safety and pharmacokinetics (half-life and recovery) of two different method M purified AHF (Hemofil-M) concentrates processed in the USA and Spain, two different methods of factor VIII assay (one-stage clotting and chromogenic) have been compared in vivo. The study was a single centre blinded, randomised, crossover study. Twelve patients with severe haemophilia A (VIII: C <2 u/dl) were divided into two subgroups of six. None had received factor VIII concentrate within 48 h preceding the study. Twenty-four pharmacokinetic studies were performed in the 12 patients. Each subgroup received two different lots of study material (US and Spanish) at a dose of 50 u/kg seven days apart. A second randomisation was nominal potency, high: 1000 u or mid: 500 u per vial. The potency label was a one-stage clotting assay using the mega I standard. A standard pharmacokinetic study was performed over 24 h and each blinded sample was analysed in duplicate by a one-stage clotting (aPTT) and a chromogenic (Chromogenix AB; CS) assay at the Royal Free and NIBSC. Pharmacokinetic modelling was performed. The mean label for Hemofil-M using the chromogenic substrate assay was 79% that using the one stage assay (Mega I standard). The recovery was 17-28% higher measured by chromogenic compared to the clotting assay. Since most clinicians use the clotting assay, potency labelling using the chromogenic assay, will overestimate predicted Hemofil-M recovery by as much as 25%.

Efficacy, Immunogenicity, Pharmacokinetics, and Safety Of Human-cl rhFVIII – a GCP Study In Children With Severe Haemophilia A

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3594-3594
Author(s):  
Raina Liesner ◽  
Martina Jansen ◽  
Anna Klukowska ◽  
Vladimir Vdovin ◽  
Tomasz Szczepanski ◽  
...  
Keyword(s):  
Age Groups ◽  
Human Cell Line ◽  
Haemophilia A ◽  
Severe Haemophilia ◽  
Central Laboratory ◽  
One Stage ◽  
Previously Treated ◽  
Bleeding Episodes ◽  
The One

Abstract Introduction Human-cl rhFVIIIis the first recombinant factor VIII concentrate expressed in a human cell line (Human Embryonic Kidney 293F cells). Studies in adolescent and adult pre-treated patients with severe haemophilia A showed a favorable PK profile with a median half-life of 17.1 hours (one stage assay) and indicated safety and efficacy in preventing and treating bleeding episodes (BE). Aims The objectives of this international GCP study were to evaluate the efficacy, safety, immunogenicity and pharmacokinetic (PK) properties of Human-cl rhFVIIIin previously treated children between 2 and 12 years of age. Methods All patients started with an in-vivo recovery (IVR) investigation and in a subset of patients, the PK of Human-cl rhFVIII was assessed in comparison to the patient’s previously used FVIII product. After an injection of 50 IU/kg, blood samples were collected up to 48 hours for PK analysis and up to 2 hours for IVR. IVR was repeated in all patients after 3 and 6 months. FVIII plasma levels were measured by chromogenic and one-stage assay in a central laboratory. Patients were treated prophylactically with Human-cl rhFVIII every other day or 3x weekly, injecting 30-40 IU Human-cl rhFVIIIper kg for at least 6 months and > 50 exposure days. Inhibitors were measured before, during and at the end of the study by modified Nijmegen Bethesda assay in a central laboratory. Adverse events were recorded throughout the study. Results 59 patients (29: 2-5 years; 30: 6-12 years) were enrolled from 15 specialized sites in Europe. 13 children of each age group participated in the comparative PK investigation. Mean PK parameters of Human-cl rhFVIII were similar in both age groups for both the chromogenic and the one-stage assay: AUCnorm 0.23 vs. 0.24 h*IU/mL/[IU/kg]); IVR 1.88 vs. 1.61% per IU/kg; T1/2 9.7 vs. 12.5 h. IVR remained stable throughout the study. A total of 108 BEs in 32/59 patients were treated with Human-cl rhFVIII. The majority of treated BEs were traumatic (60.2%) and minor (56.5%). The mean ± SD monthly bleeding rate of all types of BEs/patient was 0.34±0.43 (spontaneous BEs: 0.12±0.27; traumatic BEs: 0.19±0.29). No inhibitor development was reported; no patient discontinued the study because of an AE. Conclusion The data indicate that Human-cl rhFVIII is efficacious and safe in preventing and treating BEs in previously treated children. The PK of Human-cl rhFVIII was comparable in both studied age groups. Disclosures: Liesner: Octapharma AG: Consultancy, Investigator Other. Jansen:Octapharma AG: Employment. Klukowska:Octapharma AG: Investigator Other. Vdovin:Octapharma AG: Investigator Other. Szczepanski:Octapharma AG: Investigator Other. Knaub:Octapharma AG: Employment.

BAY 81-8973, a Full-Length Recombinant Factor VIII: Results from Assay Field Study

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3539-3539
Author(s):  
Monika Maas Enriquez ◽  
Horst Beckmann ◽  
Yvonne Katterle ◽  
Stefan Bruns ◽  
Despina Tseneklidou-Stoeter ◽  
...  
Keyword(s):  
Factor Viii ◽  
Field Study ◽  
Full Length ◽  
Recombinant Factor Viii ◽  
One Stage ◽  
Chromogenic Assay ◽  
Clinical Laboratories ◽  
Interlaboratory Variability ◽  
The One ◽  
Plasma Control

Abstract Background: BAY 81-8973 is a full-length unmodified recombinant factor VIII (rFVIII) in development for the treatment of hemophilia A. BAY 81-8973 has the same amino acid sequence as Bayer's sucrose-formulated rFVIII but is manufactured using the latest technologies. Potency labeling is based on the chromogenic assay. BAY 81-8973 has demonstrated an excellent safety and efficacy profile in the clinical development program. This field study was conducted to evaluate assay variability in BAY 81-8973 measurements compared with a marketed rFVIII (Advate®, Baxter, Westlake Village, CA) using the methods, reference standards, and reagents typically used in clinical laboratories. Methods: Clinical laboratories in North America, Europe, Israel, and South Africa were invited to participate in the study. Each laboratory was provided with 21 blinded samples to analyze using their routine assay (one-stage, chromogenic, or both), reagents, and standards. The 21 samples consisted of 3 aliquots each of spiked hemophilia plasma containing normal von Willebrand factor levels with BAY 81-8973 at 3 different levels: <10 IU/dL (low), 10-50 IU/dL (medium), >50 IU/dL (high); 3 aliquots each of spiked hemophilia plasma with Advate at the same levels (low, medium, high); and 3 aliquots of commercially available positive control sample (normal human plasma). Samples were identified by unique numbers and by target FVIII levels (low, medium, high). The nominal spiked target levels of FVIII concentration were 0.043 IU/mL (low), 0.375 IU/mL (medium), and 0.865 IU/mL (high) for BAY 81-8973 and Advate and 0.960 IU/mL for the plasma control. Results were analyzed statistically for intra- and interlaboratory variability. Results: Of 82 laboratories contacted, 41 in 11 countries participated. Thirty-one laboratories used the one-stage assay only, 1 used the chromogenic assay only, and 9 used both assays. Intralaboratory variability was <11% for both assays at all FVIII levels and was similar for BAY 81-8973, Advate, and the plasma control. Interlaboratory variability was highest for the lowest concentration using the chromogenic assay (percent coefficient of variation: 60% for BAY 81-8973, 51% for Advate) and decreased to 14% for BAY 81-8973 (Advate, 12%; plasma control, 10%) with the one-stage assay and 5% (Advate, 6%; plasma control, 7%) with the chromogenic assay at the highest concentration. For the 9 laboratories that used both the one-stage and chromogenic assays, the chromogenic:one-stage ratio for mean values for BAY 81-8973 at low, medium, and high concentrations was 1.04, 1.04, and 1.14, respectively; for Advate, the ratios were 1.02, 1.07, and 1.21. Conclusions: The laboratories participating in this field study used a wide range of methods and reagents for FVIII measurements. The variability of the results was similar for both BAY 81-8973 and Advate and highest for low concentrations. There was no relevant difference in the results between the one-stage and chromogenic assays. Disclosures Maas Enriquez: Bayer Pharma AG: Employment. Beckmann:Bayer Pharma AG: Employment. Katterle:Bayer Pharma AG: Employment. Bruns:Winicker Norimed: Employment. Tseneklidou-Stoeter:Bayer Pharma AG: Employment. Kitchen:Bayer Pharma AG: Other: Advisory fees, Speakers Bureau.

Familial discrepancy between the one-stage and two-stage factor VIII methods in a subgroup of patients with haemophilia A

1994 ◽  
Vol 87 (4) ◽  
pp. 846-848 ◽  
Author(s):  
Elizabeth M. Duncan ◽  
Bruce M. Duncan ◽  
Lynn J. Tunbridge ◽  
John V. Lloyd
Keyword(s):  
Factor Viii ◽  
Haemophilia A ◽  
Two Stage ◽  
One Stage ◽  
The One

Discrepancy between one-stage and chromogenic factor VIII activity assay results can lead to misdiagnosis of haemophilia A phenotype

2010 ◽  
Vol 30 (04) ◽  
pp. 207-211 ◽  
Author(s):  
A. Pavlova ◽  
J. Oldenburg
Keyword(s):  
Factor Viii ◽  
Hemophilia A ◽  
Significant Proportion ◽  
Haemophilia A ◽  
Missense Mutations ◽  
One Stage ◽  
Chromogenic Assay ◽  
Fviii Activity ◽  
Mechanistic Basis

SummarySeverity of bleeding phenotype in hemophilia A (HA) depends on the underlying mutation in the F8 gene and, ultimately, on the concentration and functional integrity of the factor VIII (FVIII) protein in circulating plasma. Initial diagnosis for HA and monitoring of treatment is typically performed by measuring of FVIII activity by either one-stage assay or chromogenic assay.We review evidence for why both types of assay do not give comparable results in a significant proportion of patients with non-severe haemophilia A and why the discrepancy in results between both methods segregates with distinct subclasses of known missense mutations causing haemophilia A. The current understanding of the mechanistic basis for how FVIII:C assay discrepancies arise are discussed.We propose that both methods should be used in initial patient diagnosis along with follow-up genetic analysis to avoid potential misdiagnosis and to optimize treatment monitoring of patients with HA phenotypes.

Stability and Sterility of Sucrose-Formulated Recombinant Factor VIII (Kogenate® FS/Bayer) for Use during Continuous Infusion.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4004-4004
Author(s):  
Lisa Regan ◽  
Jordan Chew ◽  
Khang Vo ◽  
Joyce Leveque ◽  
Naji Khabbaz ◽  
...  
Keyword(s):  
Factor Viii ◽  
Continuous Infusion ◽  
Infusion Pump ◽  
Coagulation Activity ◽  
Excessive Bleeding ◽  
One Stage ◽  
Chromogenic Assay ◽  
Recombinant Fviii ◽  
The One

Abstract Continuous infusion of factor VIII (FVIII) is an alternative treatment approach to bolus dosing for providing hemostatic control in patients with hemophilia A undergoing surgery. Continuous infusion maintains consistent circulating FVIII, thus avoiding wastefully high or dangerously low levels. Potential advantages of continuous infusion include improved protection from excessive bleeding, reduced factor consumption, and easier monitoring. Continuous infusion requires FVIII usage parameters that are typically outside of the tested and approved ranges for the product, including extended time in an aqueous state at room temperature and exposure to a large surface area of tubing. Here we present in vitro data on the stability and sterility of a sucrose-formulated recombinant FVIII product (Kogenate® FS/Bayer; rFVIII-FS) under conditions comparable to those that would be experienced during the continuous infusion of patients. Three lots for each of 3 vial sizes (250, 500, and 1000 IU) were tested. Twenty vials of each size were reconstituted in Water for Injection, pooled into a 50 mL volume (100, 200, or 400 IU/mL for the 250, 500, and 1000 IU vial sizes, respectively), and aseptically transferred to pump reservoirs. Two mini-pumps were evaluated (WalkMed 350 Ambulatory Infusion Pump and CADD-Legacy PLUS Ambulatory Infusion Pump Model 6500) using a flow rate of 0.6 mL/hr. Reservoir bags containing reconstituted rFVIII-FS, pumps, and tubing were incubated at 30°C and samples were withdrawn to test coagulation activity via one-stage and chromogenic assays after 0.5, 1, 2, 3, 6, 12, 24, and 48 hours. Sample remaining in the reservoir after 48 hours was tested for sterility. The reservoirs and tubing used in this study were made from polyvinyl chloride (PVC), which has a high FVIII adsorption potential. Results for all 1000 IU lots based on the recoveries obtained at the first time point demonstrated &gt;80% activity at the end of the study using both the one-stage and chromogenic assays on both pumps. Results for all 500 IU lots showed similar recoveries (≥80%) for both pumps at study end using the chromogenic assay. However, the one-stage assay gave higher recovery values for the WalkMed pump (&gt;90%) compared to the CADD pump (&gt;75%). Results for all 250 IU lots demonstrated ≥79% activity at the end of the study using both pumps and both assays. All lots passed the sterility test. These findings indicate that rFVIII-FS is stable in both the WalkMed and CADD pumps and that sterility of rFVIII-FS is maintained for at least 48 hours. This suggests that rFVIII-FS is suitable for use in continuous infusion.

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