Collaborative study for the establishment of replacement batches for human coagulation factor IX concentrate...

Area of Science:

• Biotechnology and Pharmaceutical Sciences
• Hematology and Coagulation
• Regulatory Affairs and Standardization

Background:

• Existing European Pharmacopoeia (Ph. Eur.), World Health Organisation (WHO), and FDA reference standards for human blood coagulation Factor IX concentrate (established 1996) were nearing depletion.
• A collaborative study was initiated by WHO, European Directorate for the Quality of Medicines & HealthCare (EDQM), and FDA to establish new, replacement reference batches.

Purpose of the Study:

• To establish new biological reference preparations (BRP) and international standards (IS) for human blood coagulation Factor IX concentrate.
• To assign accurate potency values to candidate Factor IX concentrate preparations using collaborative laboratory testing.
• To evaluate the performance of clotting versus chromogenic assays and the impact of pre-diluents on potency estimations.

Main Methods:

• Thirty laboratories from fourteen countries participated in a collaborative study.
• Candidate preparations (recombinant and plasma-derived Factor IX) were assayed against existing 3rd IS for Factor IX concentrate (96/854) and plasma (99/826).
• Both clotting and chromogenic assay methods were employed, with analysis of intra- and inter-laboratory variability (geometric coefficient of variation, GCV).

Main Results:

• Significant differences in potency estimates were observed between clotting and chromogenic assays for the recombinant candidate and plasma IS.
• Plasma-derived Factor IX products showed similar potency values across both assay methods.
• Clotting assays demonstrated good intra- and inter-laboratory agreement, with most GCVs below 10%. Pre-diluent choice (plasma vs. buffer) did not significantly alter results.

Conclusions:

• Sample C (07/182), a plasma-derived Factor IX concentrate, was established as the Human coagulation Factor IX concentrate BRP batch 2 with a potency of 7.9 IU/ampoule.
• The same sample (07/182) was adopted as the 4th International Standard for Blood Coagulation Factor IX, Concentrate, Human by WHO and as a replacement FDA standard.
• The study successfully ensured the continued availability of essential reference standards for human Factor IX concentrate.