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.

The Pharmacokinetics Of Turoctocog Alfa Are Consistent Over Different Concentrations and Production Lots

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4783-4783 ◽  
Author(s):  
Víctor Jiménez-Yuste ◽  
Sandra Lejniece ◽  
Robert Klamroth ◽  
Trine Saugstrup ◽  
Judi Moss
Keyword(s):  
Half Life ◽  
Research Funding ◽  
Fixed Effects ◽  
Hemophilia A ◽  
Severe Hemophilia ◽  
Pooled Data ◽  
One Stage ◽  
Chromogenic Assay ◽  
The One ◽  
Pharmacokinetic Difference

Introduction Turoctocog alfa is a B domain truncated human recombinant FVIII for treatment of patients with hemophilia A. The production yields a highly homogenous product with the same tyrosine sulphation as human FVIII. In order to confirm the consistency of turoctocog alfa pharmacokinetics (PK) over different production lots and vial strengths, a clinical trial was performed in 15 patients with severe hemophilia A. Aim To compare the PK of 3 lots of 2000 IU/vial and 1 lot of 3000 IU/vial of turoctocog alfa after i.v. administration of 50 IU/kg in patients with severe haemophilia A. Methods This was a multi-centre, open-label trial investigating the PK of 4 lots of turoctocog alfa (3 lots of 2000 IU/vial; Lots A, B and C, and 1 lot of 3000 IU/vial; Lot D) in patients with severe hemophilia A (FVIII<1%). The trial was performed as a two-period, incomplete block, cross-over trial, in which each patient was allocated at random to a predefined sequence of 2 different lots of turoctocog alfa. The FVIII activity was assessed using both the one-stage clot and chromogenic assays. Both the primary endpoint, normalized AUC (AUC*(planned dose/actual dose)), and the secondary PK endpoints were analyzed by ANCOVA on the log transformed values, with lot, visit and patient as fixed effects. Each of the three 2000 IU/vial lots was compared and tested against the 2 other 2000 IU/vial lots. If not significantly different on a 5% level, the 3 lots were pooled together and tested against the 3000 IU/vial lot. Results Fifteen patients with a mean age of 38.6 years (ranging from 21 to 60 years) were included from 3 hemophilia centres in 3 different countries. Three adverse events (AEs) were reported in the trial by 2 separate patients; all AEs were judged to be unlikely related to the trial product. There was no development of inhibitors. There was no pharmacokinetic difference observed between Lots A, B, C (2000 IU/vials) and there was no pharmacokinetic difference observed between the pooled data from lot A, B and C (2000 IU/vial) and lot D (3000 IU/vial) based on normalized AUC, half-life, incremental recovery and clearance. The estimated mean values (with 90% CI) for the PK parameters based on the chromogenic assay are presented in Table 1. The results were similar for the one-stage clot assay and the chromogenic assay. Conclusions No pharmacokinetic differences were observed between the three 2000 IU/vial lots (Lot A, Lot B and Lot C), nor were there pharmacokinetic differences between Lot D (3000 IU/vial) and pooled data from Lots A, B and C, based on normalized AUC, half-life, incremental recovery and clearance. There were no safety concerns and no inhibitor development in the trial. Disclosures: Jiménez-Yuste: Novo Nordisk: Consultancy, Research Funding, Speakers Bureau. Klamroth:Novo Nordisk, CSL Behring, Bayer, Baxter, Pfizer: Honoraria, Research Funding. Saugstrup:Novo Nordisk: Employment. Moss:Novo Nordisk: Employment.

In Vivo Recovery of Factor VIII: A Comparison of One-Stage and Two-Stage Assay Methods

1979 ◽  
Vol 42 (04) ◽  
pp. 1230-1239 ◽  
Author(s):  
I M Nilsson ◽  
T B L Kirkwood ◽  
T W Barrowcliffe
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
In Vitro Assays ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference ◽  
Assay Methods ◽  
The One ◽  
Fraction I

SummaryThe recovery and half-life of VIII: C in the plasma of severely haemophilic patients was measured by one-stage and two-stage assays after injection of two Factor VIII concentrates (Hemofil, Hyland and Fraction I-O, Kabi). Plasma volumes were measured with an Evans� Blue technique, and both concentrates and post-infusion samples were measured against the same plasma standard.There was a highly significant difference in recoveries estimated by the two assay methods. The one-stage assays gave the most consistent results, in that the average recovery was 100%, whereas the two-stage assays gave only about 80% of the value expected from in vitro assays. There was no difference in recoveries between the two concentrates.The two-stage assays gave a slightly shorter half-life than the one-stage assays, and the half-life of Hemofil was also shorter than that of Fraction I-O.

Factor VIII: C (FVIII: C) Recovery and Half-Life After Infusion of Steam-Treated High Purity Factor VIII Concentrate in Severe Hemophilia A - Comparison of One-Stage Assay, Two-Stage Assay and a Chromogenic Substrate Assay

1986 ◽  
Vol 56 (03) ◽  
pp. 353-359 ◽  
Author(s):  
Peter Hellstern ◽  
Ralf Kiehl ◽  
Chieko Miyashita ◽  
Holger Schwerdt ◽  
Gerhard von Blohn ◽  
...  
Keyword(s):  
Factor Viii ◽  
High Purity ◽  
Plasma Levels ◽  
Half Life ◽  
Hemophilia A ◽  
Least Square ◽  
Chromogenic Substrate ◽  
Two Stage ◽  
One Stage ◽  
The One

SummaryFactor VIII :C recovery and half-life was measured in 16 hemophilia A patients under comprehensively standardized conditions. Each patient received the same lot of a steam-treated high purity FVIII concentrate at a dose of 19-33 U/kg body weight. A comparison was made between the one-stage assay, the two-stage assay and a chromogenic substrate test for FVIII :C determination using a FXa-sensitive chromogenic substrate. Factor VIII :C potency of the administered FVIII concentrate was measured using calibration curves derived from a concentrate standard and FVIII: C plasma levels were read from calibration curves derived from a plasma standard. The chromogenic assay showed a good reproducibility at FVIII: C levels between 0.015 and 0.50 U/ml. The FVIII :C recoveries calculated from the results of the one-stage assay, the two-stage assay and the chromogenic substrate test were 109 ± 20, 92 ± 14 and 81 ± 11% (x ± SD), respectively. The elimination half-lives of FVIII :C were calculated by non-linear least square analysis using a modified computerized Gauss-Newton algorithm. The half-lives calculated from the FVIII: C plasma levels measured by the one-stage assay, the two-stage assay and the chromogenic test were 23.8 ± 6.4, 22.2 ± 5.7 and 17.1 ± 4.8 h (x ± SD), respectively. No previous study has reported such long half-life values. Our findings indicate that measurements of recoveries and half-lives by the chromogenic FVIII :C assay and by computerized nonlinear least square analysis allow the possibility of individualized FVIII replacement therapy.

Characterization of PEGylated Factor VIII Molecules.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4024-4024
Author(s):  
Joanne Severs ◽  
Nicole Samuels ◽  
John Teare ◽  
Amy Tollner ◽  
Lisa Regan
Keyword(s):  
Mass Spectrometry ◽  
Factor Viii ◽  
Half Life ◽  
Hemophilia A ◽  
Maldi Mass Spectrometry ◽  
Potency Assay ◽  
One Stage ◽  
Thrombin Activation ◽  
The One

Abstract Patients with hemophilia A typically require frequent treatment with replacement Factor VIII (FVIII) products due to the relatively short circulating half-life of FVIII. Increasing the half-life of FVIII would profound impact the lives of patients with hemophilia A, especially children, by reducing the frequency of infusions. The addition of polyethylene glutamate (PEG) to therapeutic molecules or their carriers has been demonstrated to increase the survival of such molecules in the circulation. To create a longer circulating product, we have developed novel FVIII molecules using site specific PEGylation techniques. We present a characterization of these PEGylated FVIII molecules in terms of the site of PEGylation, the binding of von Willebrand Factor (vWF), and the effect of PEGylation on thrombin digestion, and we compare the one-stage and chromogenic potency test results. The site of PEGylation was determined using MALDI-mass spectrometry. A vWF binding assay was developed using surface plasmon resonance technology (Biacore). The effect of PEGylation on thrombin digestion of the novel constructs was evaluated using MALDI-mass spectrometry, thrombin activation, and potency decay curves following thrombin activation. All novel constructs were PEGylated on the expected target site based on the site of introduced mutation. PEGylation of FVIII appeared to have a slight reduction on vWF-binding capability. The site of PEGylation reduced the ability of thrombin to digest FVIII, as assayed by MALDI-mass spectrometry analysis and by thrombin digestion and decay curves. The size and position of the PEG molecule influenced the extent of FVIII thrombin sensitivity. The one-stage potency assay was more sensitive to the size and position of the attached PEG molecule than the chromogenic potency assay. We report that some PEGylated FVIII molecules are less sensitive to thrombin activation than unmodified FVIII, and that the size and position of the PEG molecule can significantly affect the potency of FVIII. The findings of this study suggest that site-directed PEGylation of FVIII may be a useful technique for the development of FVIII molecules with extended activity in circulation and that careful choice of size and position of the PEG molecule is critical.

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

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%.

Pharmacokinetics of Recombinant Factor VIII (Recombinate) Using One-stage Clotting and Chromogenic Factor VIII Assay

1999 ◽  
Vol 82 (12) ◽  
pp. 1644-1647 ◽  
Author(s):  
D. Owens ◽  
G. Bray ◽  
P. Giangrande ◽  
P. Collins ◽  
C. Hay ◽  
...  
Keyword(s):  
Factor Viii ◽  
Clinical Situation ◽  
Recombinant Factor Viii ◽  
Pharmacokinetic Studies ◽  
Chromogenic Substrate ◽  
One Stage ◽  
Chromogenic Assay ◽  
Significant Difference ◽  
Post Infusion

SummaryIn a study designed to demonstrate the safety and pharmacokinetics of a recombinant factor VIII (Recombinate) manufactured in Andover, MA and Thousand Oaks, CA, two different methods of factor VIII assay (one-stage clotting and Chromogenic substrate) were compared in vivo. The study was performed in four centres in the UK: London, Oxford, Cardiff and Manchester. Two pharmacokinetic studies, at least one week apart, were performed in 30 patients with severe haemophilia A (VIII:C < 2 IU/dl). A dose of 50 IU/kg was administered with sampling pre-infusion, and +0.25, 0.5, 1, 3, 6, 9, 12 and 24 h post-infusion. The aggregate 60 pharmacokinetic study showed a half-life of 12.7 and 13.0 h (p = 0.28) and recovery of 127 and 161 IU/dl (p = 0.0001) using one-stage clotting or chromogenic substrate respectively. In a supplementary experiment, 20 post-infusion samples were re-assayed by 1-stage and chromogenic assay using two plasma (20th British plasma standard and an “in-house” pooled normal plasma) and two concentrate standards, derived from the same type, but different batch of infused concentrate (Recombinate) and pre-diluted in either individual pre-infusion sample or in pooled commercial haemophilic plasma. The use of the Recombinate concentrate standard overcame the significant difference in FVIII levels between 1-stage and chromogenic assay methods when a plasma standard was used (p <0.0001). It is concluded that where potency dosing designation is carried out by an assay system different to that used in the clinical situation, the use of the recombinant concentrate as a standard in post-infusion plasma samples is likely to give more reliable and reproducible results.

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