Clinical trial NCT04590950: Dosage and PD Study of Eftrenonacog-alfa
Official title: Monitoring and Pharmacodynamics Effect of Recombinant Factor IX Fc in Severe Haemophilia B Patients: a Real-life Study
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Severe Haemophilia B
Keywords: Chromogenic assay
Extended half-life product
Fc fusion protein
One-stage clotting assay
Pharmacodynamics
Lead sponsor: Assistance Publique - Hôpitaux de Paris
Sponsor class: OTHER
First posted: 2020-10-19
Enrollment: 15
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Severe haemophilia B patients

Brief summary: The purpose of this study is to evaluate the performance of different methods for measuring factor IX activity levels in haemophilia B patients treated with eftrenonacog-alfa and assess its pharmacodynamics (PD) in a real-life setting.

Detailed description: A recent European survey showed that increasing number of hemophilia B patients was switched from standard to extended half-life drugs. While some clinicians currently prefer to treat empirically rather than based on laboratory results, adoption of replacement therapy based on extended half-life products such as eftrenonacog-alfa may increase the interest in individualized pharmacokinetic assessments allowing the development of an initial dosing regimen. Thus inaccurate FIX activity measurements might be critical, especially when FIX trough level is used to tailor patient dosing regimens. It is therefore important that FIX activity levels are accurately determined allowing adequate recovery without increasing the cost of medical management of hemophilia B patients due to unnecessary dose corrections.

With the expansion of the prescription of eftrenonacog-alfa, the problem of accurately measuring its recovery has risen within hemostasis laboratories. Chronometric one-stage assays (OSA) are currently the most widely performed tests for FIX activity measurement. They are based on activated partial thromboplastin time (aPTT) reagent and factor-deficient plasma. Various aPTT reagents are commercialized. They could lead to a substantial variability in FIX results. Chromogenic two-stage assays (CSA) are less frequently used in clinical laboratories. They present fewer reagent choice compared to OSA. Several studies have evaluated OSA and CSA performances in samples spiked with eftrenonacog-alfa and have evidenced that some commonly used aPTT reagents would not be suitable for accurately monitoring this product. Whether these results are commutable to post-infusion samples collected from real-life patients remains unclear.

Unlike the measurement of a unique coagulation factor activity, thrombin generation assay (TGA) is a dynamic global test that explores the coagulation cascade as well as the anticoagulant pathways. TGA could be therefore a valuable tool to monitor replacement therapy in hemophilia B patients.

Hence the investigators sought in a real-life setting to compare 2 CSA and 1 OSA reagents to a product specific OSA in severe hemophilia B patients supplemented with eftrenonacog-alfa. The investigators also aimed to evaluate the pharmacodynamics (PD) of eftrenonacog-alfa using TGA.

Eligibility criteria: Inclusion Criteria:

* severe haemophilia B patients
* treated with eftrenonacog-alfa

Exclusion Criteria:

* any other haemostatic or replacement therapy

Primary outcomes:
measure: FIX activity levels
timeFrame: One month
Secondary outcomes:
measure: Thrombin generation assay
timeFrame: One month
measure: Thrombin generation assay
timeFrame: One month
measure: Thrombin generation assay
timeFrame: One month
measure: Thrombin generation assay
timeFrame: One month
measure: Thrombin generation assay
timeFrame: One month
Other outcomes:
Locations:
city: Paris
country: France
facility: Service d'hématologie biologique - Hôpital Cochin
Study officials:
References:
citation: Peyvandi F, Garagiola I, Boscarino M, Ryan A, Hermans C, Makris M. Real-life experience in switching to new extended half-life products at European haemophilia centres. Haemophilia. 2019 Nov;25(6):946-952. doi: 10.1111/hae.13834. Epub 2019 Aug 16.
citation: Sommer JM, Buyue Y, Bardan S, Peters RT, Jiang H, Kamphaus GD, Gray E, Pierce GF. Comparative field study: impact of laboratory assay variability on the assessment of recombinant factor IX Fc fusion protein (rFIXFc) activity. Thromb Haemost. 2014 Nov;112(5):932-40. doi: 10.1160/TH13-11-0971. Epub 2014 Aug 21.
citation: Kitchen S, Tiefenbacher S, Gosselin R. Factor Activity Assays for Monitoring Extended Half-Life FVIII and Factor IX Replacement Therapies. Semin Thromb Hemost. 2017 Apr;43(3):331-337. doi: 10.1055/s-0037-1598058. Epub 2017 Mar 6.
citation: Dargaud Y, Beguin S, Lienhart A, Al Dieri R, Trzeciak C, Bordet JC, Hemker HC, Negrier C. Evaluation of thrombin generating capacity in plasma from patients with haemophilia A and B. Thromb Haemost. 2005 Mar;93(3):475-80. doi: 10.1160/TH04-10-0706.
citation: Bowyer AE, Shepherd MF, Kitchen S, Maclean RM, Makris M. Measurement of extended half-life recombinant factor IX products in clinical practice. Int J Lab Hematol. 2019 Apr;41(2):e46-e49. doi: 10.1111/ijlh.12953. Epub 2018 Dec 7. No abstract available.
citation: Collins PW, Fischer K, Morfini M, Blanchette VS, Bjorkman S; International Prophylaxis Study Group Pharmacokinetics Expert Working Group. Implications of coagulation factor VIII and IX pharmacokinetics in the prophylactic treatment of haemophilia. Haemophilia. 2011 Jan;17(1):2-10. doi: 10.1111/j.1365-2516.2010.02370.x. Epub 2010 Aug 22.
citation: Srivastava A, Brewer AK, Mauser-Bunschoten EP, Key NS, Kitchen S, Llinas A, Ludlam CA, Mahlangu JN, Mulder K, Poon MC, Street A; Treatment Guidelines Working Group on Behalf of The World Federation Of Hemophilia. Guidelines for the management of hemophilia. Haemophilia. 2013 Jan;19(1):e1-47. doi: 10.1111/j.1365-2516.2012.02909.x. Epub 2012 Jul 6.