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  5. Study of the regulation of blood coagulation by factors VIIa and IXa
  1. Biologics Research Projects

Study of the regulation of blood coagulation by factors VIIa and IXa

Principal Investigator: Mikhail V. Ovanesov, PhD
Office / Division / Lab: OTAT / DPPT / HB

General Overview

CBER regulates products that prevent life-threatening blood loss in individuals who lack certain proteins that the body uses to coagulate blood (form clots). These products include Factor VII (activated), Factor IX, and Factor XI.

Blood coagulation (clotting) is a complex, multi-step process that requires many different coagulation factors. These factors must work together in a precise sequence to produce a blood clot when there is damage to the blood vessels. The clotting process is very fast and efficient; however, if left unchecked, clotting can lead to thrombosis (excessive clotting that blocks blood flow). Therefore, there is a separate system of proteins, called coagulation inhibitors, to control clotting. When the delicate balance between clotting (pro-coagulation) and inhibition (anti-coagulation) shifts to pro- or anticoagulation, the result can be a life-threatening thrombosis or spontaneous bleeding (insufficient clotting).

Our laboratory is currently refining the tools and tests we use to determine the potency of protein coagulation factors that CBER regulates in order to be better able to ensure that such products are safe and effective. This will facilitate the review of genetically or chemically engineered products with properties that are different from those of natural coagulation factors. This knowledge will enhance our ability to evaluate new therapies for coagulation disorders and to improve the treatment of patients who suffer from these devastating conditions.

We also aim to clarify the roles of activated Factors VII, IX and XI in the development of stroke and heart attack which are serious adverse events caused by abnormal blood clot formation. Although these activated factors have been amply studied, their thrombotic activity is still not fully understood.

Currently available tests used to diagnose blood coagulation disorders represent individual (isolated) steps of the complex process, and therefore can only diagnose the lack of just one specific coagulation factor or inhibitor in a patient’s blood. Therefore, these tests do not indicate the state of balance between the pro-coagulant and anti-coagulant systems. Thus, these tests cannot assess the severity of the disease in patients, monitor the treatment to determine if it is working, or predict adverse events of treatment, such as too much clotting in a bleeding patient. Our laboratory is developing coagulation tests that better represent the complexity of the blood coagulation system and will design them based on recent discoveries on the biological activity of current and developing coagulation factor products.

One such assay, the Thrombin Generation Test, allows continuous monitoring of the pro-coagulation and anti-coagulation events over a long period of time in several plasma samples simultaneously. Another tool we use to study clotting is the video-microscope, which records the growth of clot size in an artificial model of a damaged blood vessel.

Scientific Overview

Imbalance in the blood coagulation system can cause life-threatening thrombosis or bleeding. Unfortunately, existing assays of blood coagulation have poor predictive value for many pathological states and are not useful for diagnosis and treatment monitoring. We believe that coagulation testing can be improved through the consideration of physiological processes that are not represented by the traditional assays. We are developing tests based on recent findings on the biological activity of existing and emerging coagulation factor products. The use of these tools will improve the treatment of and care received by patients suffering from disorders of blood coagulation.

The potential benefits and risks of existing and emerging blood coagulation-related products should be studied with assays that are physiologically relevant. Our research on the regulation of blood clotting will provide the basis for developing better coagulation testing and assay validation. The knowledge gained from our research will facilitate the evaluation of, and enhance the assurance of the efficacy, safety and quality of blood
coagulation products.

The research program is designed to further our understanding of the mechanisms of action of blood clotting through the use of novel assays that measure the ‘global’ coagulation function. The thrombin/fibrin generation and video-microscopy-based clot growth techniques can evaluate many aspects of blood coagulation as it occurs in vivo, such as activation with low levels of physiological activator, continuous kinetics of enzymatic activities and clotting, and limited dilution of test plasma. However, these new assays are not yet optimized or validated specifically for the determination of the potency of coagulation factors, such as Factor (F) VIII. Validation of these tests is one of our research goals.

Another goal of our research program is to elucidate the roles of activated factors VII, IX and XI in hemostasis and thrombosis, which are well documented but still not fully understood. The current licensed dose of FVIIa exceeds the physiological level of FVIIa in blood by several orders of magnitude and yet the treatment appears to be relatively safe, at least in the target population of hemophilia patients with inhibitory antibodies to Factors IX and VIII. In contrast, only trace amounts of FIXa in FIX concentrates and FXIa in plasma-derived immune globulin products are attributed to serious adverse thrombotic events. To better understand the mechanisms of action of these molecules, we are looking for analytical conditions that can predict the duration of their clinical effect in vivo. These studies will be useful in the evaluation of the safety and efficacy of products that treat disorders in blood coagulation.

Furthermore, enhancing our understanding of how the balance of blood coagulation is maintained will facilitate the regulation of current and emerging products, especially those that are genetically or chemically engineered to have characteristics that differ from those of their wild-type counterparts.


Res Pract Thromb Haemost 2020 Jun 12;4(5):944-5
Effect of pH on thrombin activity measured by calibrated automated thrombinography.
Jackson JW, Surov SS, Liang Y, Parunov LA, Ovanesov MV

Blood Adv 2019 Sep 10;3(17):2668-78
Mitigation of T-cell dependent immunogenicity by reengineering factor VIIa analogue.
Jankowski W, McGill J, Lagasse HAD, Surov S, Bembridge G, Bunce C, Cloake E, Fogg MH, Jankowska KI, Khan A, Marcotrigiano J, Ovanesov MV, Sauna ZE

J Thromb Haemost 2019 Apr;17(4):695-7
Establishment of the WHO 2nd International Standard Factor V, plasma (16/374): communication from the SSC of the ISTH.
Hubbard AR, Thelwell C, Rigsby P, Subcommittee on Factor VIII, Factor IX and Rare Coagulation Disorders

Cell Mol Life Sci 2018 Oct;75(20):3781-801
Dissecting the biochemical architecture and morphological release pathways of the human platelet extracellular vesiculome.
De Paoli SH, Tegegn TZ, Elhelu OK, Strader MB, Patel M, Diduch LL, Tarandovskiy ID, Wu Y, Zheng J, Ovanesov MV, Alayash A, Simak J

Haemophilia 2017 May;23(3):466-75
Can the diagnostic reliability of the thrombin generation test as a global haemostasis assay be improved? The impact of calcium chloride concentration.
Parunov LA, Surov SS, Liang Y, Lee TK, Ovanesov MV

Am J Hematol 2017 Apr;92(4):E44-5
Association of immune globulin intravenous (IGIV) and thromboembolic adverse events (TEEs).
Ovanesov MV, Menis MD, Scott DE, Forshee R, Anderson S, Bryan W, Golding B

J Thromb Haemost 2017 Apr;15(4):709-20
Expression and characterization of a codon-optimized blood coagulation factor VIII.
Shestopal SA, Hao JJ, Karnaukhova E, Liang Y, Ovanesov MV, Lin M, Kurasawa JH, Lee TK, McVey JH, Sarafanov AG

Arterioscler Thromb Vasc Biol 2016 Dec;36(12):2334-45
Synergy between tissue factor and exogenous factor XIa in initiating coagulation.
Leiderman K, Chang WC, Ovanesov M, Fogelson AL

Haemophilia 2016 Sep;22(5):780-9
Optimization of the thrombin generation test components to measure potency of factor VIII concentrates.
Jha NK, Shestopal SA, Gourley MJ, Woodle SA, Liang Y, Sarafanov AG, Weinstein M, Ovanesov MV

J Extracellular Vesicles 2016 May 4;5:30422
Characterization of procoagulant extracellular vesicles and platelet membrane disintegration in DMSO-cryopreserved platelets.
Tegegn TZ, De Paoli SH, Orecna M, Elhelu OK, Woodle SA, Tarandovskiy ID, Ovanesov MV, Simak J

Thromb Res 2016 Apr;140:132-9
Interconnectedness of global hemostasis assay parameters in simultaneously evaluated thrombin generation, fibrin generation and clot lysis in normal plasma.
Xin KZ, Chang WC, Ovanesov MV

J Pharm Sci 2016 Mar;105(3):1023-7
Subvisible particle content, formulation, and dose of an erythropoietin peptide mimetic product are associated with severe adverse postmarketing events.
Kotarek J, Stuart C, De Paoli SH, Simak J, Lin TL, Gao Y, Ovanesov M, Liang Y, Scott D, Brown J, Bai Y, Metcalfe DD, Marszal E, Ragheb JA

J Thromb Haemost 2015 Dec;13(12):2168-79
Clotting factor product administration and same-day occurrence of thrombotic events, as recorded in large healthcare database during 2008-2013.
Ekezue BF, Sridhar G, Ovanesov MV, Forshee RA, Izurieta HS, Selvam N, Parunov L, Jain N, Mintz PD, Epstein J, Anderson SA, Menis M

J Thromb Haemost 2015 Aug;13(8):1527-30
No effect of corn trypsin inhibitor on factor XIa-dependent thrombin generation assay: comment.
Parunov LA, Surov SS, Tucker E, Ovanesov MV

Birth Defects Res C Embryo Today 2015 Sep;105(3):167-84
Epidemiology of venous thromboembolism (VTE) associated with pregnancy.
Parunov LA, Soshitova NP, Ovanesov MV, Panteleev MA, Serebriyskiy II

Biochemistry 2015 Jan;54(2):481-9
Cluster III of low-density lipoprotein receptor-related protein 1 binds activated blood coagulation factor VIII.
Kurasawa JH, Shestopal SA, Woodle SA, Ovanesov MV, Lee TK, Sarafanov AG


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