Evaluation of chromogenic factor <scp>IX</scp> assays by automated protocols

Kershaw, Geoffrey; Dissanayake, Keerthie; Chen, Vivien; Khoo, Teh‐Liane

doi:10.1111/hae.13446

Cited by 13 publications

(23 citation statements)

References 20 publications

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“…Kershaw et al previously evaluated automated chromogenic FIX assays and found between-run CVs ranged from 1.8% to 4.5% using a Sysmex CS-2500 analyser. 8 Small differences were present, but the current study performed analyses in only a small number of assays (n = 5), so this represents a limitation.…”

Section: Discussionmentioning

confidence: 88%

“…In normal plasma, the relationships between CSA and OSA showed differences, especially in high levels of FIX activity. Although a recent study showed a similar variation in the normal range of FIX:C, 8 we should consider increasing the dilution when testing FIX within the normal range or in levels exceeding the upper limit of normal range. Throughout the correlation analyses, we evaluated single-dilution analyses of Revohem FVIII and FIX.…”

Section: Revohem Fviii Includes Human Recombinant Protein Whereas Simentioning

confidence: 83%

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Performance evaluation of Revohem^™ FVIII chromogenic and Revohem^™ FIX chromogenic in the CS‐5100 autoanalyser

Suzuki

Kanematsu

et al. 2019

Int J Lab Hematology

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Introduction Chromogenic substrate assay (CSA) reagents Revohem™ FVIII and Revohem™ FIX are now available as in vitro diagnostic reagents for autoanalysers in Japan. In this study, we evaluated the performance of these reagents in the CS‐5100 automated coagulation analyser. Methods We assessed within‐run and between‐day imprecision, on‐board stability and frozen‐storage stability of Revohem FVIII and FIX. Sensitivity to lupus anticoagulant (LA) was examined using LA‐positive patient plasma. Correlations were analysed using plasma samples from normal individuals and patients with haemophilia A (HA) or B (HB) or von Willebrand disease (VWD). Results Imprecision was <2% for Revohem FVIII and <6.5% for Revohem FIX. On‐board storage of Revohem FVIII resulted in a <10% decrease in FVIII levels from baseline at 24 hours, whereas Revohem FIX showed a >10% decrease at 8 hours. Revohem FVIII showed good stability while frozen for 22 days. Although Revohem FIX showed degradation due to freeze‐thawing, a new calibration improved stability up to 22 days. Interference from LA was not observed with Revohem FVIII or FIX. The FVIII CSA‐CSA correlation was excellent in normal (r = 0.9924), HA (r = 0.9945) and VWD (r = 0.9914). The FVIII CSA‐OSA correlation was good in normal (r = 0.8468) and excellent in HA (r = 0.975) and VWD (r = 0.9936). The FIX CSA‐OSA correlation was fair in normal (r = 0.4791) and excellent in HB (r = 0.9501). Conclusion Revohem FVIII and FIX both showed excellent performance in the CS‐5100 analyser. These reagents could be useful in routine laboratory testing for diagnosing and treating haemophilia.

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Section: Discussionmentioning

confidence: 88%

Section: Revohem Fviii Includes Human Recombinant Protein Whereas Simentioning

confidence: 83%

Performance evaluation of Revohem^™ FVIII chromogenic and Revohem^™ FIX chromogenic in the CS‐5100 autoanalyser

Suzuki

Kanematsu

et al. 2019

Int J Lab Hematology

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“…The authors also acknowledge that it would have been ideal to base the primary analysis on a one‐stage clotting assay that used the same aPTT reagent for both products; however, unfortunately, there is not a single aPTT reagent that could be used to measure both products and allow a more robust head‐to‐head comparison. A previously published field study by Sommer et al showed that a one‐stage clotting assay using SynthAFax overestimates FIX activity for rFIXFc in spiked hemophilia B plasma samples, and a recent study by Kershaw et al also reported over‐recovery for rFIXFc with this aPTT reagent . Meanwhile, the field study by Sommer et al demonstrated that a one‐stage clotting assay with Actin FSL accurately reproduces the activity of rFIXFc .…”

Section: Discussionmentioning

confidence: 99%

“…Normal human plasma (NHP) standards, calibrated against the World Health Organization international FIX standard, were used to calibrate all assays. For the one‐stage clotting assays, the activated partial thromboplastin time (aPTT) reagents were selected by referring to the product label and/or published literature recommendations for each product; SynthAFax (Instrumentation Laboratory, Bedford, MA) was used for N9‐GP and Actin FSL (Siemens, Marburg, Germany) for rFIXFc. To date, chromogenic assays had not been used in any clinical trials with rFIXFc; however, given that the ROX factor IX (Rossix AB, Mölndal, Sweden) kit has been previously qualified for measuring N9‐GP, it was subsequently qualified for measuring rFIXFc in the current trial and selected as the chromogenic assay for both products.…”

Section: Methodsmentioning

confidence: 99%

Favorable pharmacokinetics in hemophilia B for nonacog beta pegol versus recombinant factor IX‐Fc fusion protein: A randomized trial

Ettingshausen

Hegemann

Simpson

et al. 2019

Research and Practice in Thrombosis and Haemostasis

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Background and Objective Nonacog beta pegol (N9‐GP) and recombinant factor IX‐Fc fusion protein (rFIXFc) are extended half‐life rFIX compounds. We report the first single‐dose pharmacokinetic trial of N9‐GP and rFIXFc. Patients/Methods Paradigm 7 was a multicenter, open‐label, randomized, crossover trial in previously treated (>150 exposure days) adults with congenital hemophilia B (FIX activity ≤2%). Patients received single intravenous injections (50 IU/kg) of N9‐GP and rFIXFc with at least 21 days between doses. Plasma FIX activity, predose, and at serial time points up to 240 hours postdose, was measured using validated one‐stage clotting assays (SynthAFax for N9‐GP; Actin FSL for rFIXFc) and a chromogenic assay (ROX factor IX) with normal human plasma as calibrator. The primary endpoint was area under the FIX activity–time curve from 0 to infinity, dose‐normalized to 50 IU/kg (AUC 0‐inf,norm ). Results Fifteen patients received study treatment. Based on FIX activity results from the one‐stage clotting assays, estimated AUC 0‐inf,norm was significantly greater for N9‐GP than rFIXFc (ratio: 4.39; P < 0.0001, based on a two‐sided test on 5% significance level). In addition, N9‐GP had a longer terminal half‐life, two times higher incremental recovery at 30 minutes and maximum FIX activity (dose‐normalized to 50 IU/kg) and six times higher FIX activity at 168 hours than rFIXFc. These findings were largely comparable with the chromogenic assay data and are consistent with published data for each compound. Conclusions In this comparison, N9‐GP demonstrated favorable pharmacokinetic characteristics versus rFIXFc, helping clinicians to understand differences between N9‐GP and rFIXFc. Registration This trial is registered with clinicaltrials.gov (NCT03075670) and the European Clinical Trials Database (EudraCT: 2016‐001149‐25).

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“…Potency for RB by ChA was ~30% lower than by OSCA, the OSCA/ChA discrepancy with recombinant FIX has been described in a number of other studies. 7,8,23,24 For DA in the OSCAs, there was a roughly 3-fold difference between the highest potency (CK Prest) and lowest potency (SynthFax) using both S1 and S2 standards. RB also showed lower potency when assayed using SynthaFax than the other APTT reagents, underestimation of Benefix with Synthfax has been previously reported.…”

Section: Discussionmentioning

confidence: 99%

Activity measurements of dalcinonacog alfa

Williams

Gray

2020

Haemophilia

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Introduction Many recombinant and modified FIX products have been, and continue to be, developed with the aim of improving treatment for patients with haemophilia B. One such new product is dalcinonacog alfa, a recombinant FIX with modifications to provide improved features such as subcutaneous administration. Aim In view of previously observed assay discrepancies with modified FIX therapeutics, the aim of this study was to assess potential discrepancies in potency measurement of dalcinonacog alfa between and within different assay methods. Methods Potency of dalcinonacog alfa was measured against the 5th International Standard (IS) for FIX Concentrate and the 4th IS for FIX Plasma by One‐Stage Clotting Assay, using 9 different APTT reagents and 2 commercially available FIX chromogenic kits. Plasma‐derived concentrate and recombinant FIX samples were also included for comparison in every assay. Results Substantial discrepancies were observed when assaying dalcinonacog alfa using the one‐stage clotting assay against both standards. No statistically valid results were obtained when testing dalcinonacog alfa using either chromogenic kit. Increasing the incubation time with the activation reagent in both chromogenic kits resulted in valid assays and increased the potency to become more in line with potencies by one‐stage clotting assays. Increasing the incubation time in the chromogenic kits had no effect on the potencies of the plasma‐derived or recombinant samples. However, incubation time influenced in the one‐stage clotting assay using Dapttin. Conclusions Within and between assay method discrepancy was found when assaying dalcinonacog alfa. Methods for potency labelling and clinical monitoring should be given careful consideration.

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Evaluation of chromogenic factor IX assays by automated protocols

Cited by 13 publications

References 20 publications

Performance evaluation of Revohem^™ FVIII chromogenic and Revohem^™ FIX chromogenic in the CS‐5100 autoanalyser

Performance evaluation of Revohem^™ FVIII chromogenic and Revohem^™ FIX chromogenic in the CS‐5100 autoanalyser

Favorable pharmacokinetics in hemophilia B for nonacog beta pegol versus recombinant factor IX‐Fc fusion protein: A randomized trial

Activity measurements of dalcinonacog alfa

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Evaluation of chromogenic factor IX assays by automated protocols

Cited by 13 publications

References 20 publications

Performance evaluation of Revohem™ FVIII chromogenic and Revohem™ FIX chromogenic in the CS‐5100 autoanalyser

Performance evaluation of Revohem™ FVIII chromogenic and Revohem™ FIX chromogenic in the CS‐5100 autoanalyser

Favorable pharmacokinetics in hemophilia B for nonacog beta pegol versus recombinant factor IX‐Fc fusion protein: A randomized trial

Activity measurements of dalcinonacog alfa

Contact Info

Product

Resources

About

Performance evaluation of Revohem^™ FVIII chromogenic and Revohem^™ FIX chromogenic in the CS‐5100 autoanalyser

Performance evaluation of Revohem^™ FVIII chromogenic and Revohem^™ FIX chromogenic in the CS‐5100 autoanalyser