WHO/BS/2015.2261 Collaborative study report on Blood Coagulation Factor IX

Overview

There are three main aims for this collaborative study:

1. to add a FIX antigen value to the 4th International Standard for Blood Coagulation Factors II, VII, IX and X, Plasma, Human (09/172);

2. to value assign a World Health Organisation (WHO) replacement International Standard (IS) for Blood Coagulation Factor IX, Concentrate, Human and a replacement Pharmacopoeial (Ph Eur) Biological Reference Preparation (BRP) for Blood Coagulation FIX, and

3.To investigate the suitability of the 4th International Standard for Blood Coagulation Factor IX, Concentrate as a potency standard for purified full length recombinant FIX.

Assignment of antigen value to the 4th International Standard for Blood Coagulation Factors II, VII, IX and X, Plasma, Human (09/172) relative to local normal plasma pool was carried out by 15 laboratories returning 17 sets of data in total for analysis. Only 5 sets of data gave intralaboratory GCVs greater than 10%. There was good inter-laboratory agreement, GCV was 7.9%. It was clear that local pools or the 4th IS for FIX Plasma could not be used as an antigen measurement standard for recombinant products since some reagent kits gave much lower results than other kits and this is reflected in the high inter-laboratory variation (GCVs A: 26.6%; D; 31.5%). It is recommended that a FIX antigen value of 0.90 IU/ampoule be added to the label of the 4th IS for International Standard for Blood coagulation Factors II, VII, IX, X, Plasma.