Methods and compositions for preventing, treating, or ameliorating myocardial injury using neuregulins - Patent Application 20070233334

Abstract

Methods and compositions for preventing, treating, or delaying myocardial damage in mammals using neuregulin. Methods, frequency, and dosages of administration of pharmaceutical formulations or compositions for reducing myocardial damage. It has been demonstrated in a rat myocardial injury model that neuregulin can improve cardiac function after myocardial infarction, suggesting that neuregulin can be used to prevent, treat, or delay damage caused by myocardial infarction.

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to the use of neuregulin (NRG) for the manufacture of a medicament for preventing, treating, or alleviating myocardial damage in a mammal. The present invention also relates to a method, frequency, and dosage of a pharmaceutical preparation or composition comprising NRG for preventing, treating, or alleviating myocardial damage in a mammal. In particular, the present invention relates to a method for preventing, treating, or alleviating myocardial damage, a pharmaceutical composition comprising NRG for that purpose, and a method, frequency, and dosage of a pharmaceutical preparation or composition comprising NRG for preventing, treating, or alleviating myocardial damage in a mammal. [Background technology]

[0002] BACKGROUND OF THEINVENTION Cardiovascular problems are a serious threat to people's lives and health worldwide. There are many types of cardiovascular diseases, including heart failure, myocardial infarction, coronary arteriosclerotic heart disease, arrhythmia, cardiomyopathy, valvular heart disease, infective endocarditis, pericardial disease, ischemic heart disease, congenital heart disease, etc. Cardiovascular diseases tend to cause myocardial damage and affect cardiac function, which makes the human body unwell. Myocardial infarction is a cardiovascular disease that seriously endangers human health. As people's living conditions continue to improve, the incidence of ischemic myocardial infarction is steadily increasing. Myocardial infarction is a type of ischemic myocardial necrosis induced by severe and chronic myocardial ischemia, which is mainly caused by the sudden reduction or interruption of coronary blood supply due to persistent occlusion of the coronary artery. Ischemic myocardial infarction causes myocardial cell necrosis and scarring, thereby affecting cardiac function.

[0003] When myocardial infarction occurs, the coronary artery is occluded for 20-30 minutes, which results in the necrosis of some of the myocardial cells due to lack of blood, and the pathological process of myocardial infarction begins. As myocardial necrosis becomes more and more severe, most of the affected myocardial cells gradually undergo coagulative necrosis after 2 hours, and at the same time the myocardial interstitium becomes congested and edematous with a large amount of inflammatory cell infiltration. The myocardial necrotic process ends approximately after 6-12 hours. Myocardial fibers dissolve after 1-2 weeks, i.e., they are engulfed by macrophages and gradually decomposed into fibrils, and finally after 6 weeks the necrotic zone is completely replaced by a dense scar of fibers. This is known as old or recovered myocardial infarction.

[0004] Normal left ventricular function is significantly affected after the occurrence of myocardial infarction. When the heart undergoes massive ischemia, the pumping function of the left ventricle is impaired, resulting in reduced cardiac output, stroke volume, and blood pressure, with a concomitant increase in end systolic volume and elevated end diastolic volume that may occur within weeks after infarction.

[0005] Ventricular remodeling is a significant pathological behavior that occurs after myocardial infarction. Post-infarction ventricular remodeling refers to the changes that occur in the structure and morphology of the ventricular infarcted and non-infarcted regions after the occurrence of myocardial infarction: the changes in the infarcted region mainly include the expansion of the infarct, while the changes in the non-infarcted region mainly manifest as ventricular hypertrophy. The typical sign of ventricular remodeling is ventricular decompensated hypertrophy: the change in ventricular mass, volume increase, and morphological change cause the dysfunction of the ventricular pump, which may progress to heart failure. The underlying mechanism that causes the occurrence and progression of heart failure is ventricular remodeling. This condition is a persistent and progressive change secondary to myocardial infarction. Its severity determines the patient's cardiac function and prognosis. Post-infarction ventricular remodeling is one of the major cardiovascular diseases that affect the patient's cardiac function and endanger human life.

[0006] Currently, the main treatments for myocardial infarction include early reperfusion (including thrombolytic therapy and interventional therapy), angiotensin (ANG) II receptor blockers, angiotensin-converting enzyme (ACE) inhibitors, β-receptor blockers, etc. These are effective in reducing infarct size, decreasing recurrent myocardial ischemia, improving revascularization, and inhibiting excessive ventricular dilation, thereby reducing the incidence of chronic heart failure.

[0007] Symptoms of myocardial infarction are closely related to the size and location of the infarction and the status of coronary collateral vessels. The main symptoms include pain, fever, tachycardia, nausea, vomiting, hypotension, shock, arrhythmia, etc. The main complications of myocardial infarction include papillary muscle dysfunction or rupture, cardiac rupture, ventricular aneurysm, embolism, and post-infarction syndrome (PMIS).

[0008] Most of the existing drugs or interventional therapies can only alleviate the symptoms of myocardial infarction, but cannot repair the damage of cardiac tissue. For patients with advanced myocardial infarction, heart transplantation can improve cardiac function as the last therapeutic option and save terminal patients, but due to the shortage of donors, the complexity of surgery, immune rejection, and high treatment costs, it is difficult to apply widely in clinical practice.

[0009] In summary, myocardial damage caused by cardiovascular diseases poses serious harm to human health. In particular, myocardial infarction, a fatal disease that seriously endangers human health, needs to be treated with safer and more effective drugs in clinical practice.

[0010] Neuregulin (NG) or heregulin (HRG), a member of the EGF-like family, refers to a group of structurally similar growth and differentiation factors (GDFs) including NRG1, NRG2, NRG3, and NRG4 and their isomers, which have been shown to stimulate breast cancer cell differentiation and milk protein secretion (Lessor T et al., J Cell Biochem. 1998; 70 (4):587-595); induce neural crest cell differentiation into Schwann cells (Topilko et al., Mol Cell Neurosci, 1996; 8 (2-3): 71-75); stimulate synthesis of acetylcholine receptors in skeletal muscle cells (Altiok N et al., EMBO.J. 1995; 14 (17): 4258-4266); promote cardiomyocyte survival and DM synthesis (Zhao YY et al., I Biol Cher. 1998; 273 (17): 4266-4270). NRG exerts a range of biological effects in the development of the heart and the nervous system (10261-10269). In vivo studies performed in mouse embryos with a severe NRG gene deficiency demonstrated that NRG is required for cardiac and neural development.

[0011] NRG receptor is a member of the EF receptor family, which includes FR, ErbB2, ErbB, and ErbB4, and plays an important role in cell proliferation, differentiation, survival, etc. NRG receptor is a tyrosine kinase receptor composed of an extracellular ligand-binding domain, a transmembrane domain, and an intracellular tyrosine kinase domain. When NRG binds to the extracellular domain of ErbB3 or ErbB4, a conformational change occurs there, which leads to the formation of ErbB3 / ErbB4 or ErbB2 / ErbB3 heterodimers or ErbB4 / ErbB4 homodimers, and phosphorylation of their C-terminus. The phosphorylated C-terminus can further bind to downstream signaling proteins in cells to activate the AKT and / or EK signaling pathways, and ultimately cause a series of cellular responses, such as cell proliferation, cell differentiation, cell apoptosis, cell migration, or stimulation or inhibition of cell adhesion. Of these receptors, ErbB2 and ErbB4 are expressed primarily in cardiac tissue (Zhao YY et al., Circ Res. 1999; 84 (12): 1380-1387).

[0012] Existing evidence indicates that the EGF-like domain of NRG-1, which contains amino acids 50-64, has a high capacity to bind and activate the receptor (Culousoou JM et al., J Biol Chem. 1995; 270 (21): 12857-12863). NRG-1β can bind ErbB3 and ErbB4 with high affinity. ErbB2 can form heterodimers with ErbB3 or ErbB4, and its affinity for its ligands is higher than that of the homodimers of ErbB3 or ErbB4. Neurodevelopmental studies have confirmed that signaling through NRG-1β, ErbB2, and ErbB3 is required for the formation of the sympathetic nervous system (Britsch S et al., Dienes Dev. 1998; 12 (12): 1825-1836). Lack of expression of NRG-1β or ErbB2 or ErbB4 leads to embryonic lethality due to cardiac developmental defects (Gassmann M et al. Nature, 1995; 378(6555): 390-394). Recent studies have shown that NRG-1β, ErbB2, and ErbB4 are not only essential for cardiac development but also play a crucial role in maintaining adult cardiac function (Kuramochi Y et al. J Mol Cell Cardiol. 2006; 41 (2): 228-235). It has been demonstrated that NRG-1β can enhance the formation of cardiac sarcomeres in adults. It has been found that ingestion of NRG-1β EGF-like domain can improve cardiac function and prevent cardiac dysfunction in various animal models of heart failure (Liu et al. J Am Coll Cardiol. 2006; 48: 1438-1447). In clinical trials, NRG has also shown therapeutic effects on chronic heart failure caused by various etiologies, significantly enhancing cardiac function (CN200910057390.5).In an animal model of cerebral ischemia-reperfusion, NRG-1 has shown significant protective effects on brain cells, inhibiting brain cell apoptosis, enhancing neurological function, and reducing infarct size (Li Q et al., Neurosci Lett. 2008; 443 (3): 155-159).There is evidence that cardiac ischemia-reperfusion induces the release of NRG-1 and activates the NRG / ErbB signaling pathway in cardiomyocytes (Kuramochi Y et al., J Biol Chem. 2004; 279 (49): 51141-51147), and that NRG-1 plays a role in the prevention, treatment or mitigation of cardiac ischemia-reperfusion injury (WO2011091723).

[0013] Myocardial injury is a fatal disease that seriously endangers human health, but the administration method, administration frequency, and dosage of NRG-1 for the treatment of myocardial injury have not yet been clearly determined. The present invention provides a method for addressing the above needs and a pharmaceutical composition comprising NRG therefor. It is worth mentioning that the present invention provides a particularly optimized administration frequency, the present invention provides a particularly optimized dosage, and the present invention provides a particularly optimized administration method. The present invention further relates to the use of NRG for the manufacture of a drug for preventing, treating, or alleviating myocardial injury in a mammal. For the treatment of myocardial infarction, the present invention provides a particularly optimized administration frequency, the present invention provides a particularly optimized dosage, and the present invention provides a particularly optimized administration method. Summary of the Invention

[0014] (Detailed Description) (A. Overview) The present invention provides the use of NRG for the manufacture of a drug for preventing, treating or alleviating myocardial injury in a mammal.The present invention further relates to the use of NRG for the manufacture of a drug for preventing, treating or alleviating myocardial injury in a mammal, the mammal being preferably a human.NRG can improve cardiac function affected by myocardial injury and reduce cardiac remodeling.

[0015] Many cardiovascular diseases, such as heart failure, myocardial infarction, coronary arteriosclerosis, arrhythmia, myocarditis, valvular heart disease, infective endocarditis, pericardial disease, ischemic heart disease, congenital heart disease, etc., can cause myocardial damage. Myocardial damage affects cardiac function and endangers human health. Myocardial infarction is accompanied by persistent coronary artery occlusion, and is usually accompanied by apoptosis and necrosis of myocardial cells, infiltration of large amounts of inflammatory cells, and myocardial fibrosis, which induce myocardial damage. The damage of myocardial infarction tends to cause cardiac dysfunction, thus affecting human health.

[0016] The present invention is based on the scientific discovery that NRG is essential for cardiac development and plays a critical role in maintaining adult cardiac function; the present invention is based on the scientific discovery that NRG can enhance the formation of sarcomeres, cytoskeleton, and cell-cell junctions in cardiac myocytes; the present invention is based on the scientific discovery that NRG can enhance cardiac function in animals or patients with heart failure in various animal models and clinical trials; the present invention is based on the scientific discovery that NRG exerts a protective effect on brain cells in an animal model of cerebral ischemia-reperfusion; the present invention is based on the scientific discovery that NRG exerts a protective effect on brain cells in an animal model of cardiac ischemia-reperfusion; NRG, NRG polypeptides, and mutants of NRG, or other complexes having NRG-like functions, are all within the scope of the present invention.

[0017] In a first aspect, the present invention provides a pharmaceutical preparation for preventing, treating, or alleviating myocardial damage in a mammal. The present invention further provides a pharmaceutical preparation for preventing, treating, or alleviating damage due to myocardial infarction in a mammal, the mammal being preferably a human. The pharmaceutical preparation includes an effective amount of NRG or a functional fragment thereof, or a nucleic acid encoding NRG or a functional fragment thereof, or a substance that increases the production and / or function of NRG, and a pharma- ceutical acceptable carrier, excipient, and the like. The pharmaceutical preparation can be used in combination with other drugs or therapies for preventing, treating, or alleviating myocardial damage. In one embodiment, the pharmaceutical preparation comprising NRG is effective for increasing the EF value of the mammalian left ventricle. In another embodiment, the pharmaceutical preparation comprising NRG is effective for decreasing the left ventricular end diastolic volume (LVEDV) or the left ventricular end systolic volume (LVESV). In another embodiment, the pharmaceutical preparation comprising NRG is subcutaneously injected via a syringe or another device. In another embodiment, the pharmaceutical preparation comprising NRG is subcutaneously injected via a pump, such as an injection pump. In some embodiments, the syringe pump is a micropump. In a further embodiment, the micropump is an insulin pump.It is worth mentioning that the present invention is suitable for any preparation that can be used as a medicament, and the pharmaceutical preparation comprises the above-mentioned NRG or comprises NRG and a medicament-acceptable excipient, diluent, or carrier.The pharmaceutical preparation used in the present invention includes, but is not limited to, the contents of the present application.

[0018] In a second aspect, the present invention provides a method for preventing, treating, or alleviating myocardial damage in a mammal. The present invention further provides a method for preventing, treating, or alleviating damage due to myocardial infarction in a mammal, the mammal being preferably a human. The method comprises the use of an effective amount of NRG or a functional fragment thereof, a nucleic acid encoding NRG or a functional fragment thereof, or a substance that increases the production and / or function of NRG required for the prevention, treatment, or alleviation of myocardial damage in a mammal. Other drugs can be used in combination with the method, particularly with an effective amount of NRG or a functional fragment thereof, a nucleic acid encoding NRG or a functional fragment thereof, or a substance that increases the production and / or function of NRG to prevent, treat, or alleviate myocardial damage in a mammal.

[0019] In a third aspect, the present invention provides a composition for preventing, treating, or alleviating myocardial damage in a mammal. The present invention further provides a pharmaceutical composition for preventing, treating, or alleviating damage due to myocardial infarction in a mammal, the mammal being preferably a human. The pharmaceutical composition comprises a form of NRG provided by the present invention for preventing, treating, or alleviating myocardial damage in a mammal, and another drug for preventing, treating, or alleviating myocardial damage. The pharmaceutical composition comprises an EGF-like domain, which has been demonstrated to be capable of binding to and activating a receptor. In particular, and not by way of limitation, the NRG provided by the present invention is, by way of example, a fragment of the NRG-1β2 isomer, which comprises amino acids 177-237. The amino acid sequence of this fragment is as follows: [ka]

[0020] In a fourth aspect, the present invention provides a dosage of a pharmaceutical preparation comprising NRG for use in preventing, treating, or alleviating myocardial damage in a mammal. The present invention further provides a dosage of a pharmaceutical preparation comprising NRG for use in preventing, treating, or alleviating damage due to myocardial infarction in a mammal, the mammal being preferably a human. An effective dose means that one or more beneficial effects can be achieved when a dose of NRG is applied to a mammal. The beneficial effects can improve cardiac function in a patient with myocardial damage, prevent further deterioration of the cardiac function, or inhibit the worsening of cardiac dysfunction that may be caused by myocardial damage. The dosage provided to a mammal by the present invention is 0.1 μg / kg / day (protein / body weight) to 360 μg / kg / day (protein / body weight). In one embodiment, the dose is between 0.3 μg / kg / day (protein / body weight) and 50 μg / kg / day (protein / body weight); in one embodiment, an effective dose is 7.5 μg / kg / day; in one embodiment, an effective dose is 15 μg / kg / day, and in another embodiment, an effective dose is 30 μg / kg / day.

[0021] In a fifth aspect, the present invention provides a method for administering a pharmaceutical preparation comprising NRG to prevent, treat, or alleviate myocardial damage in a mammal. The present invention further provides a method for administering a pharmaceutical preparation comprising NRG to prevent, treat, or alleviate myocardial infarction damage in a mammal, the mammal being preferably a human. The pharmaceutical preparation can be administered orally, rectally, topically, by inhalation, bucally (e.g., sublingually), parenterally (e.g., subcutaneously, intramuscularly, intradermally, or intravenously), transdermally, or in any other suitable manner. In one embodiment, NRG is administered only once a day. In another embodiment, NRG is administered multiple times a day. In one embodiment, NRG is administered in one day. In another embodiment, this tolerated dose of NRG is administered within a few days. In another embodiment, NRG is administered multiple times a day for many consecutive days. In another embodiment, NRG is administered two days a week, multiple times a day for many consecutive weeks. In another embodiment, NRG is subcutaneously injected 2 days a week, 3 times a day, for many consecutive weeks. In another embodiment, NRG is subcutaneously injected 3 times a day, for many consecutive days. In another embodiment, NRG is subcutaneously injected 3 times a day, for 35 consecutive days. In another embodiment, NRG is subcutaneously injected 3 times a day, for 38 consecutive days. In another embodiment, NRG is subcutaneously injected 3 times a day, for 49 consecutive days. In another embodiment, NRG is subcutaneously injected 3 times a day, for 60 consecutive days. In another embodiment, NRG is subcutaneously injected 3 times a day, for more than 35 consecutive days. In another embodiment, NRG is administered multiple times a day, for many consecutive days, and then slowly discontinued. In another embodiment, NRG is administered multiple times a day, for many consecutive days, and then slowly discontinued over 3 weeks: week 1 is administered every other day, week 2 is administered every 3rd day; week 3 is administered every 4th day subcutaneously. In another embodiment, NRG is injected subcutaneously three times daily for more than 38 consecutive days and then slowly discontinued.In another embodiment, NRG is subcutaneously injected three times a day for 49 consecutive days, then slowly discontinued over three weeks: the first week is administered every other day; the second week is administered every third day; the third week is administered every fourth day. In another embodiment, NRG is administered multiple times a day for many consecutive days, then slowly tapered off the daily dose. In another embodiment, NRG is administered three times a day for many consecutive days, then slowly tapered off the daily dose. In another embodiment, NRG is subcutaneously injected three times a day for more than 60 consecutive days, then slowly tapered off the daily dose. In another embodiment, NRG is subcutaneously injected three times a day for 60 consecutive days, then slowly tapered off the daily dose. In another embodiment, NRG is subcutaneously injected three times a day for 60 consecutive days, then slowly discontinued over three weeks: the first week daily dose is half the dose administered continuously; the second week daily dose is one-fourth the dose administered continuously; the third week daily dose is one-eighth the dose administered continuously.

[0022] The present invention also provides a kit for preventing, treating or alleviating myocardial damage in a mammal. The present invention also provides a kit for preventing, treating or alleviating damage due to myocardial infarction in a mammal, the mammal being preferably a human. The kit includes a single dose or multiple doses of said pharmaceutical preparation or composition for preventing, treating or alleviating myocardial injury, and instructions on how to use the pharmaceutical preparation or composition.

[0023] The pharmaceutical preparation or composition provided by the present invention can be administered before, during or after the onset of cardiac disease. When used for prevention, the pharmaceutical preparation or composition is generally administered before the onset of cardiac disease. When used for treatment, the pharmaceutical preparation or composition is generally administered during or after the onset of cardiac disease. In one embodiment, the pharmaceutical preparation or composition provided by the present invention is administered before the onset of cardiac disease. In another embodiment, the pharmaceutical preparation or composition provided by the present invention is administered when myocardial infarction occurs. In another embodiment, the pharmaceutical preparation or composition provided by the present invention is administered after the onset of cardiac disease.

[0024] The pharmaceutical preparations or compositions provided by the invention may be administered orally, rectally, topically, by inhalation, bucally (e.g., sublingually), parenterally (e.g., subcutaneous, intramuscular, intradermal, or intravenous injection), transdermally, or in any other suitable manner. Subcutaneous injection may be performed using a syringe, a pump (microinjection pump), or another administration device. Dosage forms of the pharmaceutical preparations or compositions provided by the invention include, but are not limited to, tablets, troches, cachets, dispersions, suspensions, solutions, capsules, ointments, and the like.

[0025] (B. Definition) Unless otherwise defined, all scientific and technical terms used herein have the same meaning as understood by those skilled in the art. All patent documents, patent application documents, published patent documents, and other publications are cited by reference. If any definitions covered in this section have a different meaning from that explained in the above documents, the explanation given in this section shall prevail.

[0026] Unless otherwise specified, as used herein, "a / an" means "at least one" or "one or more."

[0027] As used herein, "mammal" refers to non-human primates (cows, pigs, horses, cats, dogs, rats, mice, etc.) or primates (monkeys, humans), preferably humans.

[0028] "Myocardial injury" as used herein refers to certain types of myocardial injury caused by pathological heart disease, such as heart failure, myocardial infarction, coronary arteriosclerotic heart disease, arrhythmia, cardiomyopathy, valvular heart disease, infective endocarditis, pericardial disease, ischemic heart disease, or congenital heart disease. Myocardial injury tends to cause cardiac dysfunction, thereby affecting human health. The pathogenesis of myocardial injury is related to multiple pathophysiological changes, including the production of oxyradicals, calcium overload, inflammatory response due to neutrophil infiltration into the damaged area, apoptosis or necrosis of cardiomyocytes, metabolic disorders of tissues caused by energy supply imbalance, abnormalities in cardiac signaling, cholesterol accumulation, and the formation of atherosclerotic plaques.

[0029] As used herein, "neuregulin" or "NRG" refers to a protein or polypeptide that can bind to and activate ErbB2, ErbB3, ErbB4, or heterodimers or homodimers. NRG includes isoforms of NRG, EGF-like domains of NRG, polypeptides containing the EGF-like domains of NRG, mutants or derivatives of NRG, and other gene products of NRG that can activate the above receptors. NRG also includes NRG-1, NRG-2, NRG-3, and NRG-4, polypeptides, fragments, and complexes with NRG-like functions. Preferably, NRG is a type of protein or polypeptide that can bind to and activate ErbB2 / ErbB4 or ErbB2 / ErbB3 heterodimers. By way of example and not of limitation, NRG (rhNRG) provided by the present invention is a fragment of the NRG-1β2 isomer that contains the EGF-like domain, i.e., the 177-237 amino acid fragment. The amino acid sequence of this fragment is as follows: [ka] The NRG used in the present invention can activate the above-mentioned receptor and regulate its biological function. For example, it can stimulate skeletal muscle cells to synthesize acetylcholine receptors; and promote the differentiation, survival, and DNA synthesis of cardiomyocytes. NRG also includes conservative NRG mutants that do not substantially affect biological function. As is clear to those skilled in the art, mutation of a single amino acid in a non-critical zone does not cause changes in the biological function of a protein or polypeptide (Watson et al., Molecular Biology of the Gene, 4th edition, 1987, The Bejacmin / Cummings Pub. co., p.224). The NRG used in the present invention can be extracted from natural sources or obtained by recombinant technology, artificial synthesis, or other means.

[0030] As used herein, an "EGF-like domain" refers to an EGF-like domain that is capable of binding to and activating ErbB2, ErbB3, ErbB4, or heterodimers or homodimers thereof, and is described in WO 00 / 64400; Holmes et al., Science, 256: 1205-1210 (1992); U.S. Pat. Nos. 5,530,109 and 5,716,930; Hijazi et al., Int. J. Oncol., 13: 1061-1067 (1998); Chang et al., Nature, 387: 509-512 (1997); Carraway et al., Nature, 387: 512-516 (1997); Higashiyama et al., J. Biochem., 122: 675-680 (1997); and WO 97 / 023666. 09425. In some embodiments, the EGF-like domain binds to and activates ErbB2 / ErbB4 or ErbB2 / ErbB3 heterodimers. In some embodiments, the EGF-like domain comprises amino acids in the receptor binding zone of NRG-1. In some embodiments, the EGF-like domain refers to amino acids 177-226, 177-237, or 177-240 of NRG-1. In some embodiments, the EGF-like domain comprises amino acids in the receptor binding zone of NRG-2. In some embodiments, the EGF-like domain comprises amino acids in the receptor binding zone of NRG-3. In some embodiments, the EGF-like domain comprises amino acids in the receptor binding zone of NRG-4. In some embodiments, the EGF-like domain comprises the amino acid sequence set forth in U.S. Pat. No. 5,834,229: Ala Glu Lys Glu Lys Thr Phe Cys Val Asn Gly Gly Glu Cys Phe Met Val Lys Asp Leu Ser Asn Pro.

[0031] The NRG can be a drug that can be administered orally, rectally, topically, by inhalation, bucally (e.g., sublingually), parenterally (e.g., subcutaneous, intramuscular, intradermal, or intravenous injection), transdermally, or in any other suitable manner. In all modes of administration, the most suitable route of administration must be selected depending on the condition and severity to be treated, and the characteristics of the particular NRG used. The NRG can be administered alone. Or, more preferably, the NRG can be administered with some pharma- ceutically acceptable carrier or excipient. Any suitable pharma-ceutically acceptable carrier or excipient is applicable to the present method (Remington: The Science and Practice of Pharmacy, Alfonso R. Gennaro (ed.) Mack Publishing Company, April 1997).

[0032] A "pump" as used herein is an administration device for subcutaneous injection of medicinal liquids, drugs, proteins, and / or other compositions. The pump can be used for continuous, precise, and metered administration. The pump is provided with a subcutaneous catheter for continuous subcutaneous infusion. The catheter can be placed externally or a catheter port can be embedded in the pump mechanism. A microinfusion pump is a portable, easy-to-use device that can be used for precise infusion. For example, an insulin pump is a medical device used to administer insulin or other drugs during the treatment of diabetes or other diseases. Insulin pumps may also be used to continuously deliver insulin subcutaneously. An insulin pump may be fitted with a disposable thin-walled plastic pipe or catheter so that the insulin or other drug can enter the tissue. The catheter can be inserted subcutaneously and moved as needed. The pump can be attached to an external device that can be connected to the patient or a device that can be implanted in the patient's body. An external pump refers to a device designed to be used in a fixed location such as a hospital, clinic, or similar location. It particularly refers to a mobile or portable device such as a pump or similar device that can be carried by the patient. The external pump includes a reservoir capable of storing a fluid medium, such as, but not limited to, a fluid medium including NRG.

[0033] The external pump can be connected to the patient, for example, via a fluid flow through a suitable hollow tube. The hollow tube can be connected to a hollow needle, which is used to pierce the patient's skin for injection. Alternatively, the hollow tube can be directly connected to the patient via a cannula or similar object. The external pump can be worn by the patient, attached to the patient's clothing, or attached under the patient's clothing. Suitable pumps include, but are not limited to, microinjection pumps that can be used for high frequency injections, such as the MiniMed Paradigm 522 insulin pump, the MiniMed Paradigm 722 insulin pump, the MiniMed Paradigm 515 insulin pump, the MiniMed Paradigm 715 insulin pump, the MiniMed Paradigm 512R insulin pump, the MiniMed Paradigm 712R insulin pump, the MiniMed Paradigm 508 insulin pump, and the MiniMed Paradigm 508R insulin pump (Medtronic, Northridge, Canada), and other similar devices known to those skilled in the art.

[0034] U.S. Patent 11 / 211,095 (filing date: 8 / 23 / 2005, publication number: US2006 / 0264894, registration number US7686787) and published PCT applications WO01 / 70307 (PCT / US01 / 09139), WO04 / 030716 (PCT / US2003 / 028769), WO04 / 030717 (PCT / US2003 / 029019) and WO2013075622 (PCT / CN2012 / 0849 36), U.S. Patents US2005 / 0065760 (Method for Advising Patients Concerning Doses of Insulin) and US6,589,229 An example of an administration device, such as an external pump described in (Wearable Self-Containing Drug Infusion Device), is referenced in this section.

[0035] As used herein, "other drugs or therapies that can be used to prevent, treat, or alleviate myocardial damage" refers to drugs and interventional therapies that are generally applicable to the treatment of myocardial damage and drugs and interventional therapies that are generally applicable to the treatment of damage caused by myocardial infarction. Among them, drugs for treating myocardial infarction include antiplatelet drugs (such as aspirin, clopidogrel), anticoagulants (such as heparin, bivalirudin), thrombolytic agents (such as alteplase, tenecteplase, urokinase, recombinant human pro-urokinase), lipid-lowering drugs (statins, cholesterol absorption inhibitors), angiotensin-converting enzyme inhibitors / ANG II receptor blockers, beta-receptor blockers, calcium channel blockers, nitrates, phosphatase inhibitors, diuretics, renin-angiotensin-aldosterone system (RAS) antagonists, myocardial energy optimizers, ischemic tissue metabolism improvers, free radical scavengers, etc. Interventional therapies include coronary interventional therapy. [Brief description of the drawings]

[0036] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] 1 shows echocardiographic results of the effect of chronic subcutaneous administration of NRG at various doses in treating rats with acute myocardial infarction. [Diagram 2] 1 shows echocardiographic results of the effect of NRG by chronic subcutaneous administration at various frequencies in treating rats with acute myocardial infarction. [Diagram 3] 1 shows the therapeutic effect of NRG on acute myocardial infarction in rats through chronic subcutaneous administration followed by discontinuation due to reduced frequency. [Figure 4] 1 shows the therapeutic effect of NRG on acute myocardial infarction in rats through chronic subcutaneous administration followed by discontinuation with dose reduction. EXAMPLES

[0037] (Example) (Example 1: Therapeutic effect of chronic subcutaneous administration of various doses of rhNRG on acute myocardial infarction in rats - Study on the dose-effect relationship of NRG) (1. Purpose) To investigate the dose-effect relationship of NRG for the treatment of acute myocardial infarction in rats by observing the therapeutic effects of various doses of rhNRG on acute myocardial infarction in rats in a rat model of myocardial infarction induced by left coronary artery ligation. (2. Experimental Drugs) (2.1 Excipients: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.) (2.2 rhNRG: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.)

[0038] (3. Laboratory Animals) (3.1 Strain and source: Wistar rats, provided by Shanghai Sippe-Bk Lab Animal Co., Ltd.) (3.2 Sex, weight and certificate: Male, 200-270g)

[0039] (4. Experimental materials and equipment) Anesthesia equipment, isoflurane evaporator manufactured by MSS INTERNATIONAL LTD. Isoflurane, 100ml / bottle, manufactured by RWD Life Technologies Co., Ltd. Cardiac ultrasound detector Vivid E95. Ningbo Lingqiao suture needle (with thread) manufactured by Ningbo Medical Needle Co., Ltd.

[0040] (5. Experimental Method) 5.1 Establishment of a rat model of heart failure induced by coronary artery ligation The rats were anesthetized with isoflurane through a gas anesthesia machine. The rats were then fixed in a supine position. After shaving the chest, the skin was disinfected with 75% alcohol. After incision of the left anterior chest skin, the pectoral muscles were bluntly separated to expose the 4th and 5th ribs. The muscle between the 4th and 5th ribs was bluntly cut using a hemostat. The heart was pushed out of the thoracic cavity using both hands to completely expose the heart for observation of lung expansion and heartbeat. The left atrial appendage and pulmonary artery cone were completely exposed, and the left anterior descending coronary artery (LADCA) between them was ligated with a surgical suture. After ligation, the heart was quickly returned to its original position. The pectoral muscles and skin were then sutured. After surgery, the rats were returned to their cages and fed and observed in detail.

[0041] 5.2 Grouping and Administration Table 1. Grouping of experimental animals and administration schedule [Table 1] Administration began the day after the animal model of myocardial infarction was established.

[0042] (5.3 Observation Indicators) After anesthesia with 4% isoflurane, the rat was fixed on the operating table in a left lateral position. The head of the rat was fixed to a breathing mask of a gas anesthesia machine, and anesthesia was maintained with isoflurane. After shaving the chest, the skin was disinfected with 75% alcohol and covered with a coupling agent. An echocardiogram probe was used to detect any echo signals from the rat's left ventricle. The left ventricular end-diastolic and end-systolic diameters (D) were measured. The left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV) were calculated. In addition, the ejection fraction (EF) value was obtained. EF = (EDV-ESV) / EDV × 100%.

[0043] (5.3.2 Data Processing) All experimental data are expressed as ±SD.

[0044] (6. Experimental Results) (6.1 Echocardiogram Results) Echocardiography was performed 60 days after continuous administration of NRG. The results showed that the LVEDd, LVEDs, and EF values ​​for the vehicle group were 0.971±0.07 cm, 0.832±0.08 cm, and 34.6±7.00%, respectively; the LVEDd, LVEDs, and EF values ​​for the 15 μg / kg-NRG group were 0.975±0.07 cm, 0.794±0.10 cm, and 42.9±11.32%, respectively; the LVEDd, LVEDs, and EF values ​​for the 7.5 μg / kg-NRG group were 0.965±0.07 cm, 0.808±0.11 cm, and 38.4±12.17%, respectively; and the LVEDd, LVEDs, and EF values ​​for the 3.75 μg / kg-NRG group were 0.994±0.08 cm, 0.839±0.12 cm, and 37.0±12.23%, respectively. According to the data of LVEDd and LVEDs, LVEDd and LVEDs can be decreased in the high-dose NRG group. According to the data of EF value, the cardiac functions of rats in the high-dose, medium-dose and low-dose groups were all improved after 60 days of continuous administration, and there was a dose-effect relationship among the three groups. For details, please refer to Table 2 and Figure 1. Table 2. Echocardiographic results of the efficacy of various doses of NRG administered subcutaneously for 60 days in treating rats with acute myocardial infarction. (x±SD) [Table 2]

[0045] (7. Conclusion) After 60 days of treatment with rhNRG, the EF values ​​of the treatment groups receiving subcutaneous injections of 5 μg / kg, 2.5 μg / kg, and 1.25 μg / kg of NRG three times a day were higher than those of the control group, and there was a certain dose-effect relationship among the three doses.

[0046] Example 2: Therapeutic effect of chronic subcutaneous administration of rhNRG at various frequencies on acute myocardial infarction in rats (1. Purpose) To investigate the therapeutic effects of a specific dose of rhNRG on acute myocardial infarction in rats by chronic subcutaneous administration at various frequencies in a rat model of myocardial infarction induced by left coronary artery ligation.

[0047] (2. Experimental Drugs) (2.1 Excipients: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.)

[0048] (2.2 rhNRG: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.)

[0049] (3. Laboratory Animals) (3.1 Strain and source: Wistar rats, provided by Shanghai Sippe-Bk Lab Animal Co., Ltd.)

[0050] (3.2 Sex, weight and certificate): Male, 200-270g.

[0051] (4. Experimental materials and equipment) This is the same as "4. Experimental materials and equipment" in Example 1.

[0052] (5. Experimental Method) 5.1 Establishment of a rat model of heart failure induced by coronary artery ligation This is the same as "5.1 Establishment of a rat model of heart failure induced by coronary artery ligation" in Example 1.

[0053] 5.2 Grouping and Administration Table 3. Grouping of experimental animals and administration schedule [Table 3]

[0054] All experimental animals were randomly divided into groups after coronary artery ligation. Following survival after ligation, rats were randomly divided into four groups according to body weight: vehicle group (control group), NRG 30μg / kg / day group, NRG 30μg / kg / BIW group, and NRG 30μg / kg / day×7+QW group. Administration began the day after the animal model of myocardial infarction was established. For the first three and fourth groups, rats were injected subcutaneously three times a day for the first seven days and weighed once a day. Animals were dosed according to body weight, with a dose of 30μg / kg / day. For the fourth group, rats were injected with NRG one day a week for the final four weeks, with a daily dose of 30μg / kg.

[0055] (5.3 Observation Indicators) 5.3.1 Cardiac Function Tests After anesthesia with 4% isoflurane, the rats were fixed on the operating table in a left lateral position. The head of the rat was fixed to a breathing mask of a gas anesthesia machine, and isoflurane was used to maintain anesthesia. After shaving the chest, the skin was disinfected with 75% alcohol and covered with a coupling agent. An echocardiographic probe was used to detect any echo signals from the rat's left ventricle. The left ventricular end-diastolic and end-systolic diameters (D) were measured. The left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV) were calculated. In addition, the ejection fraction (EF) value was obtained: EF-(EDV-ESV) / EDV×100%. The cardiac function of the rats was evaluated by echocardiography at the 1st, 2nd, 3rd, and 5th weeks after the onset of myocardial infarction.

[0056] (5.3.2 Data Processing) All experimental data are expressed as ±SD.

[0057] (6. Experimental Results) (6.1 Echocardiogram Results) Echocardiography was performed after 35 days of continuous administration of NRG. The LVEDd, LVEDs, and EF values ​​in the control group were 0.925±0.084cm, 0.756±0.107cm, and 42.5±10.174%, respectively; the LVEDd, LVEDs, and EF values ​​in the NRG / 30 μg / kg / day group were 0.879±0.058cm, 0.694±0.077cm, and 47.9±8.342%, respectively; The LVEDd, LVEDs, and EF values ​​in the NRG / 30 μg / kg / BIW group were 0.928 ± 0.084 cm, 0.746 ± 0.110 cm, and 45.2 ± 10.248%, respectively; the LVEDd, LVEDs, and EF values ​​in the NRG / 30 μg / kg / day × 7 + QW group were 0.931 ± 0.070 cm, 0.760 ± 0.097 cm, and 42.7 ± 9.892%, respectively.

[0058] As shown by the data of LVEDd and LVEDs, after 35 days of continuous administration, NRG / 30μg / kg / day can significantly reduce LVEDd and LVEDs; according to the data of EF value, EF value is significantly higher in NRG / 30μg / kg / day group than in the control group; EF value shows an upward trend in NRG / 30μg / kg / BIW group compared with the control group, and during the first 7 days of continuous administration, the cardiac function of rats in NRG / 30μg / kg / day×7+QW group was improved to some extent compared with the control group, that is, the cardiac function showed an upward trend. Then, injections were given every 7 days to maintain the effect. Please refer to Table 4 and Figure 2 for the results.

[0059] Table 4. Echocardiographic results of the therapeutic effect of NRG through chronic subcutaneous administration at different frequencies on myocardial infarction in rats (x ± SD). [Table 4]

[0060] Example 3: Therapeutic effect of rhNRG on acute myocardial infarction in rats through chronic subcutaneous administration followed by discontinuation due to reduced frequency. (1. Purpose) To observe the therapeutic effect of rhNRG on acute myocardial infarction in rats through chronic administration followed by discontinuation with reduced frequency in a rat model of myocardial infarction induced by left coronary artery ligation.

[0061] (2. Experimental Drugs) (2.1 Excipients: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.) (2.2 rhNRG: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.)

[0062] (3. Laboratory Animals) (3.1 Strain and source: Wistar rats, provided by Shanghai Sippe-Bk Lab Animal Co., Ltd.) (3.2 Sex, weight and certificate): Male, 200-270g.

[0063] (4. Experimental materials and equipment) This is the same as "4. Experimental materials and equipment" in Example 1.

[0064] (5. Experimental Method) 5.1 Establishment of a rat model of heart failure induced by coronary artery ligation This is the same as "5.1 Establishment of a rat model of heart failure induced by coronary artery ligation" in Example 1.

[0065] 5.2 Grouping and Administration Rats were randomly divided into groups and dosed after coronary artery ligation. Following survival after ligation, rats were randomly divided into two groups, including vehicle group and NRG 30 μg / kg group. There were 19 rats in the vehicle group and 18 rats in the NRG group. Continuous administration of the drug was started from the day after model creation by subcutaneous administration at a dose of 10 μg / kg three times a day. Echocardiography was performed on the 14th day after model creation. All animals were continuously dosed until day 38, and animals in the NRG group were examined by echocardiography. Animals in the NRG group were divided into two subgroups on average, with animals in one subgroup continuing to be dosed and animals in the other subgroup being prematurely discontinued from dosing. The vehicle group was continuously dosed. For the subgroup that received continuous NRG treatment, a 3-week withdrawal schedule was implemented on day 49: every other day dosing in week 1, every 3 days dosing in week 2, and every 4 days subcutaneous injection of NRG in week 3. In terms of dosing method, rats were subcutaneously injected with NRG 3 times a day, exactly as described above. For the NRG withdrawal subgroup, rats were observed for clinical symptoms. All animals underwent weekly echocardiography to monitor changes in cardiac function.

[0066] (5.3 Observation Indicators) 5.3.1 Cardiac Function Tests After anesthesia with 4% isoflurane, the rat was fixed on the operating table in a left lateral position. The head of the rat was fixed to a breathing mask of a gas anesthesia machine, and isoflurane was used to maintain anesthesia. After shaving the chest, the skin was disinfected with 75% alcohol and covered with a coupling agent. An echocardiographic probe was used to detect any echo signals from the rat's left ventricle. The left ventricular end-diastolic and end-systolic diameters (D) were measured. The left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV) were calculated. In addition, the ejection fraction (EF) value was obtained. EF = (EDV-ESV) / EDV × 100%.

[0067] (5.3.2 Data Processing) All experimental data were expressed ±SD. One-way ANOVA analysis was performed using GraphPad Prism6. P<0.05 indicates significant differences between groups. P<0.01 indicates highly significant differences between groups.

[0068] (6. Experimental Results) (6.1 Echocardiogram Results) Echocardiography was performed after 35 days of continuous administration of NRG. The LVEDd, LVEDs, and EF values ​​of the vehicle group were 0.988±0.08cm, 0.850±0.10cm, and 33.6±11.36%, respectively; the LVEDd, LVEDs, and EF values ​​of the NRG group were 0.953±0.05cm, 0.767±0.06cm, and 44.9±6.09%, respectively; the results indicate that NRG can significantly reduce LVEDd and LVEDs to enhance cardiac systolic function, thereby reversing left ventricular remodeling. After 49 days of continuous administration, the LVEDd, LVEDs, and EF values ​​of the vehicle group were 1.020±0.10cm, 0.881±0.15cm, and 33.1±14.55%, respectively; the LVEDd, LVEDs, and EF values ​​of the NRG interruption subgroup were 0.987±0.05cm, 0.807±0.06cm, and 42.2±5.48%, respectively, while the LVEDd, LVEDs, and EF values ​​of the NRG continuous administration subgroup were 0.973±0.07cm, 0.783±0.08cm, and 45.0±5.51%, respectively; this result indicates that the sudden interruption of NRG has some effect on the cardiac function of rats. A gradual interruption schedule was implemented in the NRG continuous administration subgroup, and echocardiography was performed at the second week after drug interruption. The LVEDd, LVEDs, and EF values ​​in the early NRG discontinuation subgroup were 1.043 ± 0.06 cm and 0.887 ± 0.06 cm, respectively. cm , 35.4±6.78%; LVEDd, LVEDs, and EF values ​​in the stepwise NRG interruption subgroup were 0.989±0.07cm, 0.814±0.08cm, respectively. cmand 41.3±4.92%. Significant differences from the vehicle group were observed. Echocardiography was performed at week 3 after discontinuation. The LVEDd, LVEDs, and EF values ​​of the early NRG discontinuation subgroup were 1.010±0.06cm, 0.842+0.06cm, and 38.9±5.04%, respectively; the LVEDd, LVEDs, and EF values ​​of the gradual NRG discontinuation subgroup were 0.976±0.06cm, 0.805±0.07cm, and 40.8±4.67%, respectively. Compared with the vehicle group, the effect of gradual discontinuation of NRG on cardiac function in rats was mitigated. See Tables 5 and 6 and Figure 3 for the results. Table 5. Echocardiographic results of the efficacy of NRG subcutaneous administration for 35 days in the treatment of myocardial infarction in rats (x±SD). [Table 5] ***: p<0.001 post-treatment subgroup compared with vehicle group; **: p<0.01 post-treatment subgroup compared with vehicle group; *: p<0.05 post-treatment subgroup compared with vehicle group Table 6. Echocardiographic results of efficacy in treating rats with myocardial infarction in two subgroups after 38 days of subcutaneous administration of NRG (x±SD). [Table 6] ***: p<0.001 post-treatment subgroup compared with vehicle group; **: p<0.01 post-treatment subgroup compared with vehicle group; *: p<0.05 post-treatment subgroup compared with vehicle group

[0069] (7. Conclusion) Through chronic subcutaneous administration followed by discontinuation with reduced frequency, rhNRG can improve cardiac function and reduce cardiac remodeling in rats with myocardial infarction.

[0070] Example 4: Therapeutic effect of rhNRG on acute myocardial infarction in rats through chronic subcutaneous administration followed by discontinuation with dose reduction. (1. Purpose) To observe the therapeutic effect of rhNRG on acute myocardial infarction in rats through chronic administration followed by discontinuation with reduced frequency in a rat model of myocardial infarction induced by left coronary artery ligation.

[0071] (2. Experimental Drugs) (2.1 Excipients: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.) (2.2 rhNRG: Developed by Zensun (Shanghai) Sci & Tech Co., Ltd.)

[0072] (3. Laboratory Animals) (3.1 Strain and source: Wistar rats, provided by Shanghai Sippe-Bk Lab Animal Co., Ltd.) (3.2 Sex, weight and certificate): Male, 200-270g.

[0073] (4. Experimental materials and equipment) This is the same as "4. Experimental materials and equipment" in Example 1.

[0074] (5. Experimental Method) 5.1 Establishment of a rat model of heart failure induced by coronary artery ligation This is the same as "5.1 Establishment of a rat model of heart failure induced by coronary artery ligation" in Example 1. 5.2 Grouping and Administration

[0075] (5.3 Observation Indicators) Rats were randomly divided into groups and dosed after coronary artery ligation. Following survival after ligation, rats were randomly divided into two groups according to body weight. Subcutaneous injections were given three times a day, and animals were weighed once a day. Animals were dosed according to body weight. Echocardiography was performed on the 10th day after model creation. All animals underwent echocardiography every 10 days, weekly after dose reduction, and every 2 weeks after completion of interruption. All animals were continuously dosed until day 60, after which a 3-week dose reduction interruption schedule was implemented. Dosage was reduced to 15 μg / kg, 7.5 μg / kg, and 3.75 μg / kg in weeks 1, 2, and 3, respectively. The drug was completely discontinued after 3 weeks of dose reduction to observe clinical symptoms.

[0076] 5.3.1 Cardiac Function Tests After anesthesia with 4% isoflurane, the rat was fixed on the operating table in a left lateral position. The head of the rat was fixed to a breathing mask of a gas anesthesia machine, and isoflurane was used to maintain anesthesia. After shaving the chest, the skin was disinfected with 75% alcohol and covered with a coupling agent. An echocardiographic probe was used to detect any echo signals from the rat's left ventricle. The left ventricular end-diastolic and end-systolic diameters (D) were measured. The left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV) were calculated. The ejection fraction (EF) value was obtained. EF = (EDV-ESV) / EDV × 100%.

[0077] (5.3.2 Data Processing) All experimental data were expressed ±SD. One-way ANOVA analysis was performed using GraphPad Prism6. P<0.05 indicates significant differences between groups; P<0.01 indicates markedly significant differences between groups.

[0078] (6. Experimental Results) (6.1 Echocardiogram Results) Echocardiography was performed after 60 days of continuous administration of NRG. The LVEDd, LVEDs, and EF in the vehicle group were 1.048±0.07cm, 0.910±0.09cm, and 32.1±6.6%, respectively; the LVEDd, LVEDs, and EF in the NRG 30μg / kg / day group were 0.981±0.08cm, 0.794±0.08cm, and 43.8±8.0%, respectively. The LVEDd and LVEDs data showed that the LVEDd and LVEDs in the daily NRG administration group were significantly decreased, showing a significant difference from the control group (p<0.001). The EF value data showed that the EF value in the NRG group was significantly increased after 60 days of continuous administration, showing a significant difference from the control group (p<0.001). After 60 days, a treatment with a lower dose was performed without changing the frequency. Echocardiography was performed at week 3. The LVEDd, LVEDs, and EF values ​​in the control group were 1.038±0.07cm, 0.899±0.10cm, and 32.4±9.5%, respectively; the LVEDd, LVEDs, and EF values ​​in the NRG / 30 μg / kg / day group were 0.981±0.08 cm , 0.799±0.08cm, and 42.3±11.2%. For observation, the drug was completely discontinued after 3 weeks of dose reduction. The LVEDd, LVEDs, and EF values ​​in the control group were 1.065±0.07cm, 0.942±0.10cm, and 28.3±9.4%, respectively; the LVEDd, LVEDs, and EF values ​​in the NRG / 30μg / kg / day group were 0.994±0.08cm, 0.826±0.10cm, and 39.3±12.7%, respectively. Echocardiography was performed 9 weeks after discontinuation. The LVEDd, LVEDs, and EF values ​​of the control group were 1.137±0.08cm, 1.006±0.08cm, and 28.0±5.7%, respectively; the LVEDd, LVEDs, and EF values ​​of the NRG / 30μg / kg / day group were 1.104±0.08cm, 0.950±0.09cm, and 33.4±7.6%, respectively. Nine weeks after discontinuation, there was still a significant difference in LVEDd and LVEDs between the NRG daily administration group and the control group; the EF value still showed an upward trend compared with the control group. See Tables 7, 8, 9 and Figure 4 for the results.

[0079] (7. Conclusion) Considering a certain dose and various administration frequencies, rhNRG exerted some therapeutic effects on myocardial infarction in rats during continuous administration, resulting in enhancing cardiac function, improving ventricular remodeling, and postponing senescence caused by myocardial infarction in rats with acute myocardial infarction. rhNRG still exerted a significant improving effect on cardiac function in rats with myocardial infarction for a long period of time even after discontinuation. Table 7. Echocardiographic results of the efficacy of NRG administered subcutaneously for 60 days in the treatment of myocardial infarction in rats (x±SD). [Table 7] ***: p<0.001 post-treatment subgroup compared with vehicle group; **: p<0.01 post-treatment subgroup compared with vehicle group; *: p<0.05 post-treatment subgroup compared with vehicle group Table 8. Echocardiographic results of efficacy of NRG subcutaneous administration for 60 days and subsequent dose reduction in the treatment of rats with myocardial infarction 3 weeks after administration (x±SD). [Table 8] ***: p<0.001 post-treatment subgroup compared with vehicle group; **: p<0.01 post-treatment subgroup compared with vehicle group; *: p<0.05 post-treatment subgroup compared with vehicle group Table 9. Echocardiographic results of efficacy in treating rats with myocardial infarction after discontinuation of subcutaneous administration of NRG on day 81 (x±SD) [Table 9] ***: p<0.001 post-treatment subgroup compared with vehicle group; **: p<0.01 post-treatment subgroup compared with vehicle group; *: p<0.05 post-treatment subgroup compared with vehicle group The present application provides the following aspects of the invention. (Aspect 1) 20. The use of neuregulin (NRG) or a functional fragment thereof in the manufacture of a medicament for preventing, treating, or ameliorating myocardial damage in a mammal. (Aspect 2) The use of embodiment 1, wherein the NRG is NRG-1, NRG-2, NRG-3, or NRG-4. (Aspect 3) The use according to embodiment 1, wherein the NRG is NRG-1. (Aspect 4) The use according to embodiment 1, comprising the use of other drugs or therapies that can be used to prevent, treat or reduce damage from myocardial infarction in a mammal. (Aspect 5) The use according to embodiment 1, wherein said NRG enhances cardiac function and reduces cardiac remodeling in a mammal. (Aspect 6) The use according to embodiment 1, wherein the mammal is a human. (Aspect 7) A composition for preventing, treating, or alleviating myocardial damage in a mammal, comprising an effective amount of NRG or a functional fragment thereof. (Aspect 8) 1. A method for preventing, treating, or ameliorating myocardial damage in a mammal, comprising subcutaneously administering neuregulin (NRG) at a dose of 2.5 μg / kg / day to 50 μg / kg / day. (Aspect 9) 1. A method for preventing, treating, or ameliorating myocardial damage in a mammal, comprising administering neuregulin (NRG) multiple times per day for consecutive days. (Aspect 10) The method of embodiment 9, comprising administering said NRG multiple times per day for consecutive days, followed by slowly discontinuing said NRG.

Claims

1. 1. Use of neuregulin (NRG) in the manufacture of a medicament for use in a method for preventing, treating, or ameliorating myocardial injury in a mammal, comprising: the method comprising subcutaneously administering to the mammal the NRG at a dose of 2.5 μg / kg / day to 50 μg / kg / day for consecutive days; and The use comprising slowly discontinuing said NRG after said administration.

2. The use of claim 1, wherein the NRG is NRG-1, NRG-2, NRG-3, or NRG-4.

3. 2. The use according to claim 1, wherein the NRG is NRG-1.

4. 2. The use according to claim 1, wherein the medicament can be used in combination with other drugs or therapies to prevent, treat or alleviate myocardial damage in a mammal.

5. The use of claim 1, wherein the NRG enhances cardiac function and reduces cardiac remodeling in a mammal.

6. The use according to claim 1, wherein the mammal is a human.

7. 1. A composition for use in a method for preventing, treating, or ameliorating myocardial injury in a mammal, the composition comprising an effective amount of neuregulin (NRG), the method comprising: administering to the mammal subcutaneously the NRG at a dose of 2.5 μg / kg / day to 50 μg / kg / day for consecutive days; and the composition comprising slowly discontinuing said NRG after said administration.

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