- The Fiix-prothrombin time (Fiix-PT; pronounced 'fix PT') is a new modified prothrombin time sensitive to only factors II and X. It is intended for monitoring oral anticoagulation with vitamin K antagonist but with a possible application to measure other oral anticoagulants.
- A patent for the invention has been granted in the USA and China in 2016 with patent pending status elsewhere.
- The patent is owned by a start-up company, Fiix Diagnostics Ltd (Fiix Greining ehf) founded late in the year 2013. The company is owned by Pall T. Onundarson, Brynja R. Gudmundsdottir, the Landspitali National University Hospital and University of Iceland in Reykjavik, Iceland. Fiix Diagnostics Ltd is supported by the Technology Development Fund of the The Icelandic Centre for Research (email@example.com).
- Fiix is a registered trademark.
- The aim of Fiix Diagnostics Ltd is to provide manufacturing and distribution of the Fiix test. For this purpose Fiix Diagnostics Ltd is collaborating with Hart Biologicals Ltd in Hartlepool, England, on the commercialisation of the Fiix test, aiming for a marketable kit for use in clinicl laboratories in 2018.
In a publication in the Journal of Thrombosis and Thrombolysis it was demonstrated that stabilization of anticoagulation by Fiix-PT monitoring associated with reduced thromboembolism compared to standar PT (INR) monitoring.
Reduced anticoagulation variability in patients on warfarin monitored with Fiix-prothrombin time associates with reduced thromboembolism: The Fiix-trial.
Oskarsdottir AR, Gudmundsdottir BR, Indridason OS, Lund SH, Arnar DO, Bjornsson ES, Magnusson MK, Jensdottir HM, Vidarsson B, Francis CW, Onundarson PT.
J Thromb Thrombolysis. 2017 May;43(4):550-561. doi: 10.1007/s11239-017-1482-4.
This publication published in January 2017 in the Journal of Thrombosis and Haemostasis demonstrates that the Fiix-PT reflects thrombin generation better than does the standard prothrombin time in samples from patients on warfarin. Thus, the results support the hypothesis that the practice of using a monitoring test that is affected by FVII should be abandonded.
During warfarin induction, the Fiix-prothrombin time reflects the anticoagulation level better than the standard prothrombin time.
Jonsson PI, Letertre L, Juliusson SJ, Gudmundsdottir BR, Francis CW, Onundarson PT.
J Thromb Haemost. 2017 Jan;15(1):131-139. doi: 10.1111/jth.13549. Epub 2016 Nov 30.
July 24 2016:
A meta-analysis published in the International Journal of Laboratory Haematology suggests that monitoring warfarin with Fiix-PT reduces risk of vascular events in NVAF patients at least as much as DOACs.
Compared to traditionally INR monitored warfarin, Fiix-warfarin (warfarin monitored with Fiix-PT) is an improved anticoagulant.
June 7 2016:
A publication in the May 2016 issue of the Journal of Thrombosis and Haemastasis demonstrates that the dilute Fiix prothrombin time may be suitable as a stat test to assess all oral anticoagulants as well as unfractionated and fractionated heparin.