Chemistry: natural resins or derivatives; peptides or proteins; – Proteins – i.e. – more than 100 amino acid residues – Blood proteins or globulins – e.g. – proteoglycans – platelet...
Reexamination Certificate
1999-06-08
2001-11-20
Low, Christopher S. F. (Department: 1653)
Chemistry: natural resins or derivatives; peptides or proteins;
Proteins, i.e., more than 100 amino acid residues
Blood proteins or globulins, e.g., proteoglycans, platelet...
C530S383000, C530S384000, C530S829000, C530S333000, C514S002600, C514S021800
Reexamination Certificate
active
06320029
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the preparation and use of liquid formulations of plasma proteins, particularly blood coagulation factors. More specifically, the present invention relates to stable liquid formulations of Factor VIII and Factor IX and to the treatment of congenital or acquired deficiencies of plasma proteins by continuous injection or infusion of these formulations to provide a constant level of the coagulation factor in the blood.
BACKGROUND OF THE INVENTION
Coagulation
Coagulation of blood occurs by either the “intrinsic pathway” or the “extrinsic pathway”, whereby certain blood proteins interact in a cascade of proteolytic activations to ultimately convert soluble fibrinogen to insoluble fibrin. These threads of fibrin are cross-linked to form the scaffolding of a clot; without fibrin formation, coagulation cannot occur.
The intrinsic pathway consists of seven steps: (1) the proteolytic activation of Factor XII; (2) activated Factor XII cleaves Factor XI to activate it; (3) activated Factor XI cleaves Factor IX, thereby activating it; (4) activated Factor IX interacts with activated Factor VIII to cleave and activate Factor X; (5) activated Factor X binds to activated Factor V on a membrane surface, which complex proteolytically cleaves prothrombin to form thrombin; (6) thrombin proteolytically cleaves fibrinogen to form fibrin; (7) fibrin monomers assemble into fibrils, which are then cross-linked by Factor XIII.
The extrinsic pathway consists of the following steps: (1) upon rupture of a blood vessel, Factor VII binds to tissue factor, a lipoprotein present in tissues outside the vascular system; (2) Factor VII is activated to Factor VIIa by proteolytic cleavage; and (3) the Factor VIIa-tissue factor complex cleaves and activates Factor X. Thereafter, the extrinsic pathway is identical to the intrinsic pathway, i. e. the two pathways share the last three steps described above.
One of the plasma proteins, coagulation Factor IX (“CFIX”) is synthesized in the liver by hepatocytes as a 415 amino-acid polypeptide and then post-translationally modified to a glycoprotein of molecular weight 56,000 Daltons by a carboxylase requiring vitamin K as a cofactor. CFIX is thus one of the group of “vitamin K-dependent” plasma proteins.
Factor VII is another vitamin K-dependent clotting protein that is similar to CFIX in size and structure.
Factor VIII, a non-vitamin K-dependent protein, is a much larger protein, with a molecular wieght of near 300,000 daltons (300 kDa). It is activated by thrombin, which cleaves the molecule in several places to form Factor VIIIa (the activated form). In plasma, Factor VIII binds to von Willebrand Factor (vWF) and circulates as complexes with vWF, which stabilizes the labile Factor VIII molecule.
Disturbing the balance of the cascade involved in the intrinsic pathway results in various coagulation disorders. The absence or reduction of an intrinsic Factor X-activating moiety (a “tenase”) at step (4) results in the defective-coagulation condition known as hemophilia. Hemophilia A, the most common, results from a mutation in the gene for Factor VIII; Hemophilia B, also known as Christmas Disease, results from a mutation in the gene for Factor IX. Hemophilia B, like Hemophilia A, is X-linked and accounts for approximately 12% of hemophilia cases. The symptoms are identical to those of Hemophilia A: excessive bleeding upon injury; and spontaneous bleeding, especially into weight-bearing joints, soft tissues, and mucous membranes. Repeated bleeding into joints results in hemarthroses, causing painful crippling arthropathy that often necessitates joint replacement. Hematomas in soft tissues can result in pseudo tumors composed of necrotic coagulated blood; they can obstruct, compress, or rupture into adjacent organs and can lead to infection. Once formed the hematomas are difficult to treat, even with surgery. Recovery of nerves after compression is poor, resulting in palsy. Those bleeding episodes that involve the gastrointestinal tract, central nervous system, or airway/retroperitoneal space can lead to death if not detected. Intracranial bleeding is a major cause of death in hemophiliacs.
Current treatment of these symptoms consists of intravenous replacement therapy with Factor VIII or Factor IX concentrates. Treatment of major bleeding episodes is by bolus injection of concentrate. As described above, however, tissue damage remains even after prompt detection and treatment. Prophylactic treatment is recommended to prevent this pain and debilitation. Upon injection, 50% of Factor IX is immediately bound to vascular endothelial cells and/or diffuses into the extravascular space. The remaining 50% has a half life in circulation of approximately 24 hours. These infusion kinetics result in the need for injections once to twice per week or more to maintain minimal therapeutic levels in the plasma. While this regimen is inconvenient and stressful for the patient, it is also not totally effective. Progressive, cumulative tissue damage continues with each bleeding episode prior to the onset of treatment.
Vitamin K-dependent Plasma Proteins
The group that comprises the vitamin K-dependent plasma proteins consists to date of Factor II, Factor VII, Factor IX, Factor X, Protein C, Protein S, and Protein Z. These proteins exhibit significant homology on all levels: gene organization, amino acid sequence (primary structure), protein folding (secondary structure), post-translational modifications, activation, and function (Hedner and Davie, Chapter 84: Introduction to Hemostasis and the Vitamin K-Dependent Coagulation Factors, in C. R. Scriver et al. (Eds.),
Metabolic Basis of Inherited Disease,
6th edition, McGraw-Hill, New York N.Y., (1989), pp. 2107-2134). A comparison of the features of the six- well-characterized vitamin K-dependent plasma proteins follows (Protein Z is excluded due to a paucity of information regarding its properties and function):
Feature
Factor II
Factor VII
Factor IX
Factor X
Protein C
Protein S
No. gla domains
10
10
12
11
9
11
No. EGF's (w/&bgr;)
2 Kringle
2
2
2
2
4 &bgr;‘s
Activation
2 by Xa
1 by Xa
2 by XIa
2 by IXa
1 by IIa
—
cleavage
Function
serine
serine
serine
serine
serine
cofactor,
protease
protease
protease
protease
protease
Protein C
Catalytic domain
His43
His41
His41
His42
His42
—
Asp99
Asp90
Asp89
Asp88
Asp88
Ser205
Ser192
Ser185
Ser185
Ser191
No. carbohydrates
3
3
2
2
4
3
The “gla” domains consist of the first 40 to 45 amino acid residues with multiple &ggr;-carboxyglutamic acid residues that are formed by the carboxylation of the amino acid glutamic acid by a membrane-bound complex requiring vitamin K. They are required for the calcium-dependent binding of the protein to phospholipid surfaces.
The “EGF” domains are composed of 40 to 50 amino acids that show considerable sequence similarity to Epidermal Growth Factor (EGF) and its precursor. The first EGF domain in each of these proteins contains a &bgr;-hydroxyaspartic acid modification. While Protein S does not contain these EGF domains, it does contain three &bgr;-hydroxyaspartic acid residues and one &bgr;-hydroxyasparagine residue. Factor II, also known as prothrombin, contains 2 Kringle regions in the place of these EGF domains. These Kringle domains are also found in Factor XII, Plasminogen, Tissue Plasminogen Activator, and Urokinase, which while not vitamin K-dependent proteins, are plasma proteins with proteolytic activity that are involved in coagulation.
Five of the six vitamin K-dependent plasma proteins are activated by proteolytic cleavage by the preceding member of the coagulation cascade. Three have two cleavages, releasing an activation peptide that shielded the catalytic domain. Activation of Factor X by Factor IXa involves a single cleavage that releases an activation peptide from the heavy chain of this two-chain protein. Factor VII is activated by a single cleavage of the single chain of the polypeptide, without the release of an activation peptide.
Five of the six vitamin K-dependent plasma proteins are serine
Drohan William N.
Jameson Thomas R.
Miekka Shirley I.
Singh Manish S.
Taylor, Jr. John R.
Low Christopher S. F.
Mohamed Abdel A.
Sterne, Kessler, Goldtein & Fox PLLC
The American National Red Cross
LandOfFree
Methods of production and use of liquid formulations of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods of production and use of liquid formulations of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods of production and use of liquid formulations of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2606966