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Measuring factor IX activity of nonacog beta pegol with commercially available one-stage clotting and chromogenic assay kits : A two-center study

Bowyer, A. E.; Hillarp, A. LU ; Ezban, M.; Persson, P. LU and Kitchen, S. (2016) In Journal of Thrombosis and Haemostasis
Abstract

Essentials: Validated assays are required to precisely measure factor IX (FIX) activity in FIX products. N9-GP and two other FIX products were assessed in various coagulation assay systems at two sites. Large variations in FIX activity measurements were observed for N9-GP using some assays. One-stage and chromogenic assays accurately measuring FIX activity for N9-GP were identified. Summary: Background: Measurement of factor IX activity (FIX:C) with activated partial thromboplastin time-based one-stage clotting assays is associated with a large degree of interlaboratory variation in samples containing glycoPEGylated recombinant FIX (rFIX), i.e. nonacog beta pegol (N9-GP). Validation and qualification of specific assays and conditions... (More)

Essentials: Validated assays are required to precisely measure factor IX (FIX) activity in FIX products. N9-GP and two other FIX products were assessed in various coagulation assay systems at two sites. Large variations in FIX activity measurements were observed for N9-GP using some assays. One-stage and chromogenic assays accurately measuring FIX activity for N9-GP were identified. Summary: Background: Measurement of factor IX activity (FIX:C) with activated partial thromboplastin time-based one-stage clotting assays is associated with a large degree of interlaboratory variation in samples containing glycoPEGylated recombinant FIX (rFIX), i.e. nonacog beta pegol (N9-GP). Validation and qualification of specific assays and conditions are necessary for the accurate assessment of FIX:C in samples containing N9-GP. Objectives: To assess the accuracy of various one-stage clotting and chromogenic assays for measuring FIX:C in samples containing N9-GP as compared with samples containing rFIX or plasma-derived FIX (pdFIX) across two laboratory sites. Methods: FIX:C, in severe hemophilia B plasma spiked with a range of concentrations (from very low, i.e. 0.03 IU mL-1, to high, i.e. 0.90 IU mL-1) of N9-GP, rFIX (BeneFIX), and pdFIX (Mononine), was determined at two laboratory sites with 10 commercially available one-stage clotting assays and two chromogenic FIX:C assays. Assays were performed with a plasma calibrator and different analyzers. Results: A high degree of variation in FIX:C measurement was observed for one-stage clotting assays for N9-GP as compared with rFIX or pdFIX. Acceptable N9-GP recovery was observed in the low-concentration to high-concentration samples tested with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays. Similar patterns of FIX:C measurement were observed at both laboratory sites, with minor differences probably being attributable to the use of different analyzers. Conclusions: These results suggest that, of the reagents tested, FIX:C in N9-GP-containing plasma samples can be most accurately measured with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays.

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author
organization
publishing date
type
Contribution to journal
publication status
in press
subject
keywords
Blood coagulation test, Factor IX, Hemophilia B, Nonacog beta pegol, Poly(ethylene glycol)
in
Journal of Thrombosis and Haemostasis
publisher
Federation of European Neuroscience Societies and Blackwell Publishing Ltd
external identifiers
  • Scopus:84977104377
ISSN
1538-7933
DOI
10.1111/jth.13348
language
English
LU publication?
yes
id
01fe584c-bca0-41c6-b9ea-a5dd9e59239f
date added to LUP
2016-07-21 12:09:05
date last changed
2016-10-21 12:39:34
@misc{01fe584c-bca0-41c6-b9ea-a5dd9e59239f,
  abstract     = {<p>Essentials: Validated assays are required to precisely measure factor IX (FIX) activity in FIX products. N9-GP and two other FIX products were assessed in various coagulation assay systems at two sites. Large variations in FIX activity measurements were observed for N9-GP using some assays. One-stage and chromogenic assays accurately measuring FIX activity for N9-GP were identified. Summary: Background: Measurement of factor IX activity (FIX:C) with activated partial thromboplastin time-based one-stage clotting assays is associated with a large degree of interlaboratory variation in samples containing glycoPEGylated recombinant FIX (rFIX), i.e. nonacog beta pegol (N9-GP). Validation and qualification of specific assays and conditions are necessary for the accurate assessment of FIX:C in samples containing N9-GP. Objectives: To assess the accuracy of various one-stage clotting and chromogenic assays for measuring FIX:C in samples containing N9-GP as compared with samples containing rFIX or plasma-derived FIX (pdFIX) across two laboratory sites. Methods: FIX:C, in severe hemophilia B plasma spiked with a range of concentrations (from very low, i.e. 0.03 IU mL<sup>-1</sup>, to high, i.e. 0.90 IU mL<sup>-1</sup>) of N9-GP, rFIX (BeneFIX), and pdFIX (Mononine), was determined at two laboratory sites with 10 commercially available one-stage clotting assays and two chromogenic FIX:C assays. Assays were performed with a plasma calibrator and different analyzers. Results: A high degree of variation in FIX:C measurement was observed for one-stage clotting assays for N9-GP as compared with rFIX or pdFIX. Acceptable N9-GP recovery was observed in the low-concentration to high-concentration samples tested with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays. Similar patterns of FIX:C measurement were observed at both laboratory sites, with minor differences probably being attributable to the use of different analyzers. Conclusions: These results suggest that, of the reagents tested, FIX:C in N9-GP-containing plasma samples can be most accurately measured with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays.</p>},
  author       = {Bowyer, A. E. and Hillarp, A. and Ezban, M. and Persson, P. and Kitchen, S.},
  issn         = {1538-7933},
  keyword      = {Blood coagulation test,Factor IX,Hemophilia B,Nonacog beta pegol,Poly(ethylene glycol)},
  language     = {eng},
  publisher    = {ARRAY(0x9461cb8)},
  series       = {Journal of Thrombosis and Haemostasis},
  title        = {Measuring factor IX activity of nonacog beta pegol with commercially available one-stage clotting and chromogenic assay kits : A two-center study},
  url          = {http://dx.doi.org/10.1111/jth.13348},
  year         = {2016},
}