News Column

Patent Issued for Prevention and Reduction of Blood Loss

May 12, 2014



By a News Reporter-Staff News Editor at Biotech Business Week -- According to news reporting originating from Alexandria, Virginia, by NewsRx journalists, a patent by the inventors Ladner, Robert C. (Ijamsville, MD); Ley, Arthur C. (Newton, MA); Hirani, Shirish (Arlington, MA); Williams, Anthony (Melrose, MA), filed on November 22, 2010, was published online on April 29, 2014 (see also Biotechnology Companies).

The assignee for this patent, patent number 8710007, is Dyax Corp. (Cambridge, MA).

Reporters obtained the following quote from the background information supplied by the inventors: "Proteases are involved in a broad range of biological pathways. In particular, serine proteases such as kallikrein, plasmin, elastase, urokinase plasminogen activator, thrombin, human lipoprotein-associated coagulation inhibitor, and coagulation factors such as factors VIIa, IXa, Xa, XIa, and XIIa have been implicated in pathways affecting blood flow, e.g., general and focal ischemia, tumor invasion, fibrinolysis, perioperative blood loss, and inflammation. Inhibitors of specific serine proteases, therefore, have received attention as potential drug targets for various ischemic maladies.

"One such inhibitor, aprotinin (also called bovine pancreatic trypsin inhibitor or BPTI), obtained from bovine lung, has been approved in the United States for prophylactic use in reducing perioperative blood loss and the need for transfusion in patients undergoing cardiopulmonary bypass (CPB), e.g., in the course of a coronary artery bypass grafting procedure. Aprotinin is commercially available under the trade name TRASYLOL.RTM. (Bayer Corporation Pharmaceutical Division, West Haven, Conn.) and was previously approved for use to treat pancreatitis. The effectiveness of aprotinin is associated with its relatively non-specific abilities to inhibit a variety of serine proteases, including plasma kallikrein and plasmin. These proteases are important in a number of pathways of the contact activation system (CAS).

"CAS is initially activated when whole blood contacts the surface of foreign substrates (e.g., kaolin, glass, dextran sulfate, or damaged bone surfaces). Kallikrein, a serine protease, is a plasma enzyme that initiates the CAS cascade leading to activation of neutrophils, plasmin, coagulation, and various kinins. Kallikrein is secreted as a zymogen (pre-kallikrein) that circulates as an inactive molecule until activated by a proteolytic event early in the contact activation cascade. Clearly, specific inhibition of kallikrein would be a very attractive approach to control blood loss associated with CPB and the onset of systemic inflammatory response (SIR) as would be encountered during, for example, various invasive surgical procedures.

"Despite being the only licensed compound for preventing perioperative blood loss in CPB for coronary artery bypass grafting (CABG) procedures, aprotinin is not as widely used as would be expected. There are serious concerns regarding the use of this bovine polypeptide in patients who require CPB, and in particular the use of this compound in CABG procedures. Aprotinin is not specific for kallikrein, but interacts with additional enzymes (e.g., plasmin) in multiple pathways. Thus, the mechanism of action of aprotinin is largely speculative, and the lack of precise understanding of what is affected during aprotinin treatment produces the risk of complications during treatment. One frequently cited complication is uncontrolled thrombosis, due to aprotinin's actions upon the fibrinolytic pathway. There is concern not only over such hyperacute events as major vessel thrombosis in the perioperative period, but also over graft patency after the CABG procedure. Furthermore, as a naturally occurring protein obtained from bovine lung, administration of aprotinin in humans can elicit severe hypersensitivity or anaphylactic or anaphylactoid reactions after the first and, more often, after repeat administration to patients. This is particularly of concern in the large number of patients who have repeat CABG procedures. In addition, there is an increasing public concern regarding use of material derived from bovine sources as a potential vector for the transmission of bovine spongiform encephalopathy to humans.

"These concerns make clear that a need remains for more effective and more specific means and methods for preventing or reducing perioperative blood loss and the onset of SIR in a patient subjected to surgery resulting in activation of the CAS, such as CABG procedures in patients of CPB, or hip replacement."

In addition to obtaining background information on this patent, NewsRx editors also obtained the inventors' summary information for this patent: "This invention is based on the discovery of peptides that inhibit serine proteases. Serine proteases such as, for example, kallikrein, are involved in, for example, pathways leading to excessive perioperative blood loss and the onset of systemic inflammatory response. Preferred kallikrein peptide inhibitors include those described in U.S. Pat. Nos. 6,333,402 and 6,057,287 to Markland et al., the contents of which are incorporated herein by reference in their entirety. The invention is directed in part to the use of the peptides in therapeutic methods and compositions suitable for use in eliminating or reducing various ischemias, including but not limited to perioperative blood loss, and the onset of systemic inflammatory response. Perioperative blood loss results from invasive surgical procedures that lead to contact activation of complement components and the coagulation/fibrinolysis systems. More specifically, the invention provides methods of using kallikrein inhibitors to reduce or prevent perioperative blood loss and a systemic inflammatory response in patients subjected to invasive surgical procedures, especially cardiothoracic surgeries.

"In one embodiment, the invention is directed to a method for preventing or reducing ischemia in a patient comprising administering to the patient a composition comprising a polypeptide comprising the amino acid sequence: Xaa1 Xaa2 Xaa3 Xaa4 Cys Xaa6 Xaa7 Xaa8 Xaa9 Xaa10 Xaa11 Gly Xaa13 Cys Xaa15 Xaa16 Xaa17 Xaa18 Xaa19 Xaa20 Xaa21 Xaa22 Xaa23 Xaa24 Xaa25 Xaa26 Xaa27 Xaa28 Xaa29 Cys Xaa31 Xaa32 Phe Xaa34 Xaa35 Gly Gly Cys Xaa39 Xaa40 Xaa41 Xaa42 Xaa43 Xaa44 Xaa45 Xaa46 Xaa47 Xaa48 Xaa49 Xaa50 Cys Xaa52 Xaa53 Xaa54 Cys Xaa56 Xaa57 Xaa58 (SEQ ID NO:1), wherein Xaa1, Xaa2, Xaa3, Xaa4, Xaa56, Xaa57 or Xaa58 are each individually an amino acid or absent; Xaa10 is an amino acid selected from the group consisting of: Asp and Glu; Xaa11 is an amino acid selected from the group consisting of: Asp, Gly, Ser, Val, Asn, Ile, Ala and Thr; Xaa13 is an amino acid selected from the group consisting of: Arg, His, Pro, Asn, Ser, Thr, Ala, Gly, Lys and Gln; Xaa15 is an amino acid selected from the group consisting of: Arg, Lys, Ala, Ser, Gly, Met, Asn and Gln; Xaa16 is an amino acid selected from the group consisting of: Ala, Gly, Ser, Asp and Asn; Xaa17 is an amino acid selected from the group consisting of: Ala, Asn, Ser, Ile, Gly, Val, Gln and Thr; Xaa18 is an amino acid selected from the group consisting of: His, Leu, Gln and Ala; Xaa19 is an amino acid selected from the group consisting of: Pro, Gln, Leu, Asn and Ile; Xaa21 is an amino acid selected from the group consisting of: Trp, Phe, Tyr, His and Ile; Xaa22 is an amino acid selected from the group consisting of: Tyr and Phe; Xaa23 is an amino acid selected from the group consisting of: Tyr and Phe; Xaa31 is an amino acid selected from the group consisting of: Glu, Asp, Gln, Asn, Ser, Ala, Val, Leu, Ile and Thr; Xaa32 is an amino acid selected from the group consisting of: Glu, Gln, Asp Asn, Pro, Thr, Leu, Ser, Ala, Gly and Val; Xaa34 is an amino acid selected from the group consisting of: Thr, Ile, Ser, Val, Ala, Asn, Gly and Leu; Xaa35 is an amino acid selected from the group consisting of: Tyr, Trp and Phe; Xaa39 is an amino acid selected from the group consisting of: Glu, Gly, Ala, Ser and Asp; Xaa40 is an amino acid selected from the group consisting of: Gly and Ala; Xaa43 is an amino acid selected from the group consisting of: Asn and Gly; Xaa45 is an amino acid selected from the group consisting of: Phe and Tyr; and wherein the polypeptide inhibits kallikrein.

"In a particular embodiment, the ischemia is perioperative blood loss due to a surgical procedure performed on the patient. The surgical procedure can be a cardiothoracic surgery, such as, for example, cardiopulmonary bypass or coronary artery bypass grafting.

"In a particular embodiment, individual amino acid positions of SEQ ID NO:1 can be one or more of the following: Xaa10 is Asp, Xaa11 is Asp, Xaa13 is Pro, Xaa15 is Arg, Xaa16 is Ala, Xaa17 is Ala, Xaa18 is His, Xaa19 is Pro, Xaa21 is Trp, Xaa31 is Glu, Xaa32 is Glu, Xaa34 is Ile, Xaa35 is Tyr, Xaa39 is Glu.

"In another embodiment, the invention is directed to a method for preventing or reducing the onset of systemic inflammatory response associated with a surgical procedure in a patient comprising administering to the patient a composition comprising a polypeptide comprising the amino acid sequence: Xaa1 Xaa2 Xaa3 Xaa4 Cys Xaa6 Xaa7 Xaa8 Xaa9 Xaa10 Xaa11 Gly Xaa13 Cys Xaa15 Xaa16 Xaa17 Xaa18 Xaa19 Xaa20 Xaa21 Xaa22 Xaa23 Xaa24 Xaa25 Xaa26 Xaa27 Xaa28 Xaa29 Cys Xaa31 Xaa32 Phe Xaa34 Xaa35 Gly Gly Cys Xaa39 Xaa40 Xaa41 Xaa42 Xaa43 Xaa44 Xaa45 Xaa46 Xaa47 Xaa48 Xaa49 Xaa50 Cys Xaa52 Xaa53 Xaa54 Cys Xaa56 Xaa57 Xaa58 (SEQ ID NO:1), wherein Xaa1, Xaa2, Xaa3, Xaa4, Xaa56, Xaa57 or Xaa58 are each individually an amino acid or absent; Xaa10 is an amino acid selected from the group consisting of: Asp and Glu; Xaa11 is an amino acid selected from the group consisting of: Asp, Gly, Ser, Val, Asn, Ile, Ala and Thr; Xaa13 is an amino acid selected from the group consisting of: Arg, His, Pro, Asn, Ser, Thr, Ala, Gly, Lys and Gln; Xaa15 is an amino acid selected from the group consisting of: Arg, Lys, Ala, Ser, Gly, Met, Asn and Gln; Xaa16 is an amino acid selected from the group consisting of: Ala, Gly, Ser, Asp and Asn; Xaa17 is an amino acid selected from the group consisting of Ala, Asn, Ser, Ile, Gly, Val, Gln and Thr; Xaa18 is an amino acid selected from the group consisting of: His, Leu, Gln and Ala; Xaa19 is an amino acid selected from the group consisting of: Pro, Gln, Leu, Asn and Ile; Xaa21 is an amino acid selected from the group consisting of: Trp, Phe, Tyr, His and Ile; Xaa22 is an amino acid selected from the group consisting of: Tyr and Phe; Xaa23 is an amino acid selected from the group consisting of: Tyr and Phe; Xaa31 is an amino acid selected from the group consisting of Glu, Asp, Gln, Asn, Ser, Ala, Val, Leu, Ile and Thr; Xaa32 is an amino acid selected from the group consisting of: Glu, Gln, Asp Asn, Pro, Thr, Leu, Ser, Ala, Gly and Val; Xaa34 is an amino acid selected from the group consisting of: Thr, Ile, Ser, Val, Ala, Asn, Gly and Leu; Xaa35 is an amino acid selected from the group consisting of: Tyr, Trp and Phe; Xaa39 is an amino acid selected from the group consisting of: Glu, Gly, Ala, Ser and Asp; Xaa40 is an amino acid selected from the group consisting of: Gly and Ala; Xaa43 is an amino acid selected from the group consisting of: Asn and Gly; Xaa45 is an amino acid selected from the group consisting of: Phe and Tyr; and wherein the polypeptide inhibits kallikrein. In a particular embodiment, the surgical procedure can be a cardiothoracic surgery, such as, for example, cardiopulmonary bypass or coronary artery bypass grafting. In a particular embodiment, individual amino acid positions of SEQ ID NO:1 can be one or more of the following: Xaa10 is Asp, Xaa11 is Asp, Xaa13 is Pro, Xaa15 is Arg, Xaa16 is Ala, Xaa17 is Ala, Xaa18 is His, Xaa19 is Pro, Xaa21 is Trp, Xaa31 is Glu, Xaa32 is Glu, Xaa34 is Ile, Xaa35 is Tyr, Xaa39 is Glu.

"In yet another embodiment, the invention is directed to a method for preventing or reducing the onset of systemic inflammatory response associated with a surgical procedure in a patient comprising administering to the patient a composition comprising a polypeptide consisting of the amino acid sequence: Glu Ala Met His Ser Phe Cys Ala Phe Lys Ala Asp Asp Gly Pro Cys Arg Ala Ala His Pro Arg Trp Phe Phe Asn Ile Phe Thr Arg Gln Cys Glu Glu Phe Ile Tyr Gly Gly Cys Glu Gly Asn Gln Asn Arg Phe Glu Ser Leu Glu Glu Cys Lys Lys Met Cys Thr Arg Asp (SEQ ID NO:2), wherein the polypeptide inhibits kallikrein. In one embodiment, the surgical procedure is a cardiothoracic surgery, such as, for example, cardiopulmonary bypass or coronary artery bypass grafting.

"In another embodiment, the invention is directed to a method for preventing or reducing ischemia in a patient comprising administering to the patient a composition comprising a polypeptide consisting of the amino acid sequence: Glu Ala Met His Ser Phe Cys Ala Phe Lys Ala Asp Asp Gly Pro Cys Arg Ala Ala His Pro Arg Trp Phe Phe Asn Ile Phe Thr Arg Gin Cys Glu Glu Phe Ile Tyr Gly Gly Cys Glu Gly Asn Gln Asn Arg Phe Glu Ser Leu Glu Glu Cys Lys Lys Met Cys Thr Arg Asp (SEQ ID NO:2), wherein the polypeptide inhibits kallikrein. In a particular embodiment, the ischemia can be perioperative blood loss due to a surgical procedure performed on the patient. In one embodiment, the surgical procedure is a cardiothoracic surgery, such as, for example, cardiopulmonary bypass or coronary artery bypass grafting.

"In yet another embodiment, the invention is directed to a method for preventing or reducing the onset of systemic inflammatory response associated with a surgical procedure in a patient comprising administering to the patient a composition comprising a polypeptide consisting of the amino acid sequence: Met His Ser Phe Cys Ala Phe Lys Ala Asp Asp Gly Pro Cys Arg Ala Ala His Pro Arg Trp Phe Phe Asn Ile Phe Thr Arg Gln Cys Glu Glu Phe Ile Tyr Gly Gly Cys Glu Gly Asn Gln Asn Arg Phe Glu Ser Leu Glu Glu Cys Lys Lys Met Cys Thr Arg Asp (amino acids 3-60 of SEQ ID NO:2), wherein the polypeptide inhibits kallikrein. In one embodiment, the surgical procedure is a cardiothoracic surgery, such as, for example, cardiopulmonary bypass or coronary artery bypass grafting.

"In another embodiment, the invention is directed to a method for preventing or reducing ischemia in a patient comprising administering to the patient a composition comprising a polypeptide consisting of the amino acid sequence: Met His Ser Phe Cys Ala Phe Lys Ala Asp Asp Gly Pro Cys Arg Ala Ala His Pro Arg Trp Phe Phe Asn Ile Phe Thr Arg Gln Cys Glu Glu Phe Ile Tyr Gly Gly Cys Glu Gly Asn Gln Asn Arg Phe Glu Ser Leu Glu Glu Cys Lys Lys Met Cys Thr Arg Asp (amino acids 3-60 of SEQ ID NO:2), wherein the polypeptide inhibits kallikrein. In a particular embodiment, the ischemia can be perioperative blood loss due to a surgical procedure performed on the patient. In one embodiment, the surgical procedure is a cardiothoracic surgery, such as, for example, cardiopulmonary bypass or coronary artery bypass grafting."

For more information, see this patent: Ladner, Robert C.; Ley, Arthur C.; Hirani, Shirish; Williams, Anthony. Prevention and Reduction of Blood Loss. U.S. Patent Number 8710007, filed November 22, 2010, and published online on April 29, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=85&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4208&f=G&l=50&co1=AND&d=PTXT&s1=20140429.PD.&OS=ISD/20140429&RS=ISD/20140429

Keywords for this news article include: Serine, Surgery, Ischemia, Peptides, Protease, Proteins, Cardiology, Dyax Corp., Kallikreins, Therapeutics, Neutral Amino Acids, Enzymes and Coenzymes, Cardiopulmonary Bypass, Biotechnology Companies, Blood Coagulation Factors, Cardiac Surgical Procedures, Cardiovascular Surgical Procedures.

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Source: Biotech Business Week


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