RU2737799C1 - Inhaled hexapeptide for treating respiratory diseases associated with interleukin-6 - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine, namely to infectious and internal diseases, and aims to treat COVID-19. Hexapeptide of formula (I): H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I) or a pharmaceutically acceptable salt thereof is used in the treatment of a respiratory disease associated with interleukin-6, where the respiratory disease is COVID-19, by pulmonary administration to a mammal in need thereof. Also for treating respiratory disease associated with interleukin-6, where the respiratory disease is COVID-19, using an aqueous pharmaceutical composition containing said hexapeptide or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable adjuvant, by pulmonary administration to a mammal in need thereof. Furthermore, a method of treating respiratory disease associated with interleukin-6, where the respiratory disease is COVID-19, involves a stage of pulmonary administration of an effective amount of said hexapeptide or its pharmaceutically acceptable salt to a mammal in need thereof.

EFFECT: using the group of inventions enables providing more effective prevention, reduction or elimination of the symptoms of respiratory disease associated with IL-6, where the respiratory disease is COVID-19.

9 cl, 10 ex, 6 tbl, 4 dwg

Description

Scope of invention

[0001] the Present invention relates to the field of health care. More specifically, the invention relates to the use of an inhaled hexapeptide in the treatment of respiratory diseases associated with increased production of interleukin-6.

Background of the invention

[0002] Respiratory diseases, also known as lung diseases, are a group of diseases that affect the respiratory system. According to the International Classification of Diseases 10th edition of the World Health Organization (WHO), diseases of the respiratory system are classified as acute upper respiratory tract infections (J00-J06), influenza and pneumonia (J09-J18), other acute lower respiratory infections (J20- J22), other diseases of the upper respiratory tract (J30-J39), chronic diseases of the lower respiratory tract (J40-J47), lung diseases caused by external agents (J60-J70), other respiratory diseases mainly affecting the interstitium (J80-J84 ), purulent and necrotic conditions of the lower respiratory tract (J85-J86), other diseases of the pleura (J90-J94) and other diseases of the respiratory system (J95-J99). Respiratory diseases are the leading causes of death and disability worldwide. Chronic obstructive pulmonary disease (COPD) affects more than 200 million people worldwide. Asthma affects up to 334 million people worldwide. Lower respiratory tract infections and pneumonia are the two leading causes of death, causing more than 4 million deaths each year. Forum of International Respiratory Societies. Forum of International Respiratory Societies. The Global Impact of Respiratory Disease. 2 ^nd Edition. Sheffield, European Respiratory Society, 2017 .

[0003] Interleukin-6 (IL-6) is a small cytokine (21 kDa) that is produced by cells of the innate immune system and epithelial cells of the lungs. IL-6 is the main regulator of the acute phase of the immune process and antibody production. However, the overproduction of IL-6 contributes to the development of various respiratory diseases and is associated with the severity of these diseases. Increased expression of IL-6 in lung epithelial cells was observed in patients with asthma and other respiratory diseases. Rincon M., Irvin CG. Role of IL-6 in asthma and other inflammatory pulmonary diseases. Int J Biol Sci. 2012; 8 (9): 1281-90 . Elevated levels of IL-6 have been found in patients with asthma. Yokoyama A. et al. Am J Respir Crit Care Med. 1995 May; 151 (5): 1354-8 . Elevated IL-6 levels are predictors of increased mortality in patients with COPD. Celli BR et al .. Am J Respir Crit Care Med. 2012, 185 (10): 1065-72 . Elevated IL-6 levels have been associated with acute respiratory distress syndrome (ARDS) and pneumonia caused by various viral infections. McGonagle D. et al. Autoimmun Rev. 2020, 19 (6): 102537 . Liu B. et al. J Autoimmun. 2020, 111: 102452 . Elevated levels of IL-6 have been observed in influenza A / H1N1 pneumonia. Davey RT Jr et al. PLoS One. 2013; 8 (2): e57121 . Elevated IL-6 levels predicted disease severity in patients with community-acquired pneumonia. Ramírez P. et al. Crit Care Med. 2011, 39 (10): 2211-7 . High concentrations of IL-6 in serum and bronchoalveolar lavage fluid have been associated with disease severity and poor outcome in patients with pneumonia. Bordon J. et al. Int J Infect Dis. 2013, 17 (2): e76-83 . Higher IL-6 levels have been associated with early mortality in patients with community-acquired pneumonia. Bacci MR et al. J Med Biol Res. 2015, 48 (5): 427-32 . The increase in IL-6 concentration reflects the severity of the disease in patients with community-acquired pneumonia. Zobel K. et al. BMC Pulm Med. 2012, 12: 6 . IL-6 concentrations were lower in surviving patients than in non-surviving patients with community-acquired pneumonia. Lee YL et al. J Crit Care. 2010, 25 (1): 176.e7-13 . Elevated IL-6 levels have been associated with pulmonary fibrosis. Papiris SA et al. Cytokine. 2018, 102: 168-172 . Elevated levels of IL-6 increased the risk of death in hospitalized patients with pneumonia. Andrijevic I. et al. Ann Thorac Med. 2014, 9 (3): 162-7 . Thus, overexpression of IL-6 contributes to the development of the severity of respiratory diseases. Therefore, there is a great need for safe and effective approaches to counter the activity of IL-6 in patients with respiratory diseases.

[0004] Coronavirus infection 2019 (COVID-19) is caused by the SARS-CoV-2 virus and is characterized by diffuse alveolar lung injury, microthrombosis and cytokine release syndrome. Elevated IL-6 levels are associated with acute respiratory distress syndrome (ARDS) and SARS-CoV-2 pneumonia. McGonagle D. et al. Autoimmun Rev. 2020, 19 (6): 102537 . An early rise in IL-6 levels predicted in-hospital mortality in COVID-19 patients. Luo M. et al. JCI Insight. 2020: 139024 . Elevated IL-6 levels in COVID-19 patients were predictive of more severe disease and the need for intensive care. Gubernatorova EO et al. Cytokine Growth Factor Rev. 2020, 53: 13-24 . A meta-analysis of a number of COVID-19 studies has shown that the IL-6 threshold of 1.7 pg / ml in the serum of COVID-19 patients can be used as a differentiator between severe and non-severe forms of the disease. Henry BM et al. Clin Chem Lab Med. 2020, 58 (7): 1021-1028 . Therefore, there is a great need for safe and effective approaches to reduce IL-6 activity in COVID-19 patients.

[0005] Interleukin-6 antagonists are a class of therapeutic agents that are directed against IL-6 itself (eg, siltuximab) or the IL-6 receptor (eg, tocilizumab). Tocilizumab is a recombinant humanized monoclonal antibody to the human interleukin-6 receptor subclass of IgG1 immunoglobulin with a molecular weight of approximately 148 kDa. European patent 0628639B; US Patent 5,795,965; Japanese patent 3370324B. Tocilizumab binds to both membrane (mIL-6R) and soluble (sIL-6R) interleukin-6 receptors (IL-6R), thereby reducing the effects of IL-6. China's National Health Commission has included the use of tocilizumab in guidelines for treating patients with COVID-19. Tocilizumab has been shown to reduce COVID-19 disease severity and mortality in a group of COVID-19 patients. Zhang C. et al. Int J Antimicrob Agents. 2020, 55 (5): 105954 . Xu X. et al. Proc Natl Acad Sci USA. 2020, 117 (20): 10970-10975 . However, the efficacy and safety of interleukin-6 antagonists in the treatment of COVID-19 has not yet been demonstrated in a critical phase 3 multicenter clinical trial.

[0006] Hexapeptide H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH is an analogue of dynorphin A (1-6) with Gly replaced by D-Ala at position 2 of the amino acid sequence. The hexapeptide is a strong base and is used in the form of non-toxic acid addition salts. Hexapeptide diacetate salt is a commercially available injectable drug in the Russian Federation called dalargin for the treatment of diseases of the digestive system, in particular acute pancreatitis, gastric and duodenal ulcers, with a history of clinical use for more than 30 years. The hexapeptide has demonstrated a wide spectrum of biological activities in the dose range from 1 to 1000 μg / kg of mammalian body weight. The use of the hexapeptide in the form of intramuscular injection or intravenous infusion is disclosed in patents RU 2032422, 2241488, 2198641, 2104717, 2270025, 2351334, 2343885, 2405534, 2363455, 2515550, 2180598, 2635083, 2436588, 2148465, 2230000, 2635083, 2436588, 2148465, 2230000, 2155608, 2185176, 2139725, 2266130, 2326661, 2299742, 2218896, 2416398, 2318503, 2430753, 2299438, 2258529, 2099077, 2122415, 2261713, 2006039, 2366416, 2228762, 21858498 219676493, 2228762, 21858498 219676493, 2228762, 21858498 219676493 2290203, 2286793, 2366432, 2299065, 2429002, 2196603, 2142814, 2285522, 2203693, 2230549, 2180591, 2142736, 2113856, 2217139, 2266752, 2261722, 2362580, 2223741, 2228666869, 221718 2416398, 2318503, 2430753, 2299438, 2258529, 2099077, 2122415, 2261713, 2006039, 2366416. Hexapeptide injections have been shown to be useful in lowering plasma IL-6 levels in patients suffering from coronary artery disease. Dontsov AV. Klin Med (Mosk). 2017, 95 (2): 127-31 . Patent RU 2672888 discloses the use of intranasal hexapeptide as an agent with direct antiviral activity in the treatment of acute respiratory viral infections. Intramuscular injections of hexapeptide have been used to treat pneumonia in adults. Borovskaya et al. Bulletin physiology and pathology of respiration. 2004, 17: 85-88 . Intravenous infusions of hexapeptide have been used to treat respiratory distress syndrome in newborns. Bichenov R.G. The role of dalargin in the complex treatment of newborns with respiratory distress syndrome. 14.00.37. Anesthesiology and resuscitation. PhD thesis. Rostov-on-Don, 2000 . However, the effectiveness of treatment of respiratory diseases using injectable forms of hexapeptide is limited, firstly, by the very rapid removal of the hexapeptide from the circulation with a half-life of several minutes due to the rapid cleavage by peptidases and, secondly, by the very low absorption of the hexapeptide by the lung tissues, which is 0, 4% of the total dose of the drug administered by intravenous injection. Kalenikova EI et al. Pharmacokinetics of dalargin. Problems of Biological, Medical and Pharmaceutical Chemistry. 1988, 34 (1): 75-83 .

[0007] Intrapulmonary drug delivery is a route of administration that provides direct local treatment of respiratory diseases. Compared to intravenous or intramuscular injection, this method provides a painless and safe alternative. However, an increase in the concentration of peptidases such as elastase and cathepsin G from neutrophils in the lungs arising from inflammation has been identified as a potential barrier to inhaled peptide delivery for the treatment of respiratory diseases, since these enzymes promote rapid hydrolytic degradation of peptides in the lung. Fellner RC et al. Mol Cell Pediatr. 2016, 3 (1): 16 . Abnormal high concentrations of IL-6 have been found to cause neutrophil degranulation and significant dose-dependent release of neutrophil peptidases. Bank U. et al. Inflammation. 1995, 19 (1): 83-99 . In this context, the increased activity of neutrophil peptidases in the lungs caused by increased concentrations of IL-6 is a potential barrier to the delivery of peptides by inhalation for the treatment of respiratory diseases associated with increased production of IL-6.

[0008] From the prior art nothing is known about the effectiveness of the hexapeptide of the formula H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH or its salts introduced into the lungs in the treatment of respiratory diseases associated with increased production of IL-6.

Brief description of the invention

[0009] The inventors have surprisingly found that an intrapulmonary administered hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

significantly more effective in preventing, reducing or eliminating the symptoms of respiratory diseases associated with IL-6 in a mammal compared to the same hexapeptide at the same dose, but administered by injection.

[0010] A first aspect of the invention relates to the use of a hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

or a pharmaceutically acceptable salt thereof in the treatment of a respiratory disease associated with interleukin-6 by pulmonary administration to a mammal in need thereof.

[0011] In another aspect, the invention relates to the use of an aqueous pharmaceutical composition comprising a hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable adjuvant in the treatment of a respiratory disease associated with interleukin-6 by pulmonary administration to a mammal in need thereof.

[0012] In accordance with another aspect, the invention relates to a method for the treatment of a respiratory disease associated with interleukin-6, which comprises the step of pulmonary administration of an effective amount of a hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

or a pharmaceutically acceptable salt thereof in a mammal in need thereof.

[0013] In a preferred embodiment of the invention, the pharmaceutically acceptable salt of the hexapeptide of formula (I) is diacetate.

[0014] In preferred embodiments of the invention, the interleukin-6-associated respiratory disease is selected from the group consisting of acute respiratory distress syndrome, acute lower respiratory tract infection, pneumonia, pulmonary edema, bronchitis, tracheobronchitis, chronic obstructive pulmonary disease, and asthma. More preferably, the acute lower respiratory tract infection is COVID-19.

[0015] In preferred embodiments of the invention, a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof is administered to the lungs in the form of an aerosol with a particle size of 0.1 to 10 microns, more preferably 1 to 5 microns.

[0016] In preferred embodiments of the invention, an aqueous pharmaceutical composition containing a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof is administered to the lungs in the form of an aerosol with a particle size of 0.1 to 10 microns, more preferably 1 to 5 microns.

[0017] In preferred embodiments of the invention, the effective amount of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof for use in the method of the invention is 0.001 to 1.00 mg per kg of mammalian body weight.

[0018] Due to the pulmonary route of administration of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof, the present invention provides a painless and safe alternative to hexapeptide injections in the treatment of interleukin-6-associated respiratory diseases.

[0019] Due to the direct local delivery of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof to the lungs, the present invention provides a particularly advantageous method for achieving therapeutically effective levels of hexapeptide (I) in the lung that cannot be achieved with injections of hexapeptide (I) ...

[0020] Because of the improved delivery of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof to the lungs by pulmonary administration, this invention provides particularly advantageous compositions and methods over injections of the hexapeptide for preventing, ameliorating or eliminating the symptoms of interleukin-related respiratory diseases. 6, in mammals in need of it.

Brief Description of Figures

[0021] FIG. 1 shows representative histological preparations of mouse lungs stained with hematoxylin-eosin obtained before (0 h) and after (24, 72 and 120 h) induction of acute lung injury characterized by increased levels of interleukin-6 in the lungs.

[0022] FIG. 2 shows the mean mRNA levels ± error of the mean for interleukin-6 in the lungs of healthy mice ("Intact"); mice with acute lung injury caused by sequential administration of α-galactosylceramide and lipopolysaccharide ("LPS"); mice with acute lung injury caused by sequential administration of α-galactosylceramide and lipopolysaccharide treated with intramuscular injections of hexapeptide (I) diacetate ("LPS + GP (I) im"); and mice with acute lung injury caused by sequential administration of α-galactosylceramide and lipopolysaccharide, treated with inhalation of hexapeptide (I) diacetate ("LPS + GP (I) ing.").

[0023] FIG. 3 shows Kaplan-Meier survival curves for mice with acute lung injury caused by sequential administration of α-galactosylceramide and lipopolysaccharide ("LPS"); mice with acute lung injury caused by sequential administration of α-galactosylceramide and lipopolysaccharide, which received intramuscular injections of hexapeptide (I) diacetate ("LPS + GP (I) IM"); and mice with acute lung injury caused by sequential administration of α-galactosylceramide and lipopolysaccharide, treated with inhalation administration of hexapeptide (I) diacetate ("LPS + GP (I) ing.") to the lungs.

[0024] FIG. 4 shows the percentage of patients with severe COVID-19 responding to standard therapy ("Control") or intrapulmonary inhalation of hexapeptide (I) diacetate ("GP (I) ing"). A patient with a serum IL-6 level of less than 1.7 pg / ml after treatment was considered to be responding to therapy (a "responder"), and a patient with a serum IL-6 level above 1.7 pg ml was considered refractory to therapy (a "non-responder ").

Detailed description of the invention

[0025] The inventors have surprisingly discovered that an intrapulmonary administered hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

significantly more effective in preventing, reducing or eliminating the symptoms of respiratory diseases associated with IL-6 in a mammal compared to the same hexapeptide at the same dose, but administered by injection.

[0026] A first aspect of the invention relates to the use of a hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

or a pharmaceutically acceptable salt thereof in the treatment of a respiratory disease associated with interleukin-6 by pulmonary administration to a mammal in need thereof.

[0027] Hexapeptide of formula (I), short name hexapeptide (I), has the chemical name tyrosyl-D-alanyl-glycyl-phenylalanyl-leucyl-arginine, chemical formula C ₃₅ H ₅₁ N ₉ O ₈ , molecular weight 725.84 daltons and CAS registration number 81733-79-1 as an identifier.

[0028] The present invention relates to all pharmaceutically acceptable salts and solvates of the hexapeptide of formula (I). Non-exclusive examples of such pharmaceutically acceptable salts include chloride, bromide, sulfate, acetate, pyruvate, malate, fumarate, and citrate.

[0029] In a preferred embodiment, the pharmaceutically acceptable salt of the hexapeptide of formula (I) is diacetate, chemical name tyrosyl-D-alanyl-glycyl-phenylalanyl-leucyl-arginine diacetate.

[0030] The hexapeptide of formula (I) can be prepared by any method known in the art, in particular by solid phase synthesis. The hexapeptide of formula (I) and its salts and solvates are commercially available, for example, in Bachem catalog No. 4030569.0100 (https://shop.bachem.com/4030569.html). Hexapeptide (I) diacetate is a commercially available active pharmaceutical ingredient produced by several manufacturers in the Russian Federation, for example. OOO "Berakhim" (Obninsk, Russia).

[0031] As used herein, the term "interleukin-6", the short name "IL-6", refers to native interleukin-6 of any species, including mouse, rat, bovine and human, preferably human.

[0032] As used herein, the term "respiratory disease" refers to a disease affecting the respiratory system. The term "respiratory system" refers to the airways and lungs.

[0033] As used herein, the term "interleukin-6-associated respiratory disease" refers to a respiratory disease associated with the overproduction of interleukin-6. Such respiratory diseases include acute respiratory distress syndrome (ARDS); ARDS associated with COVID-19; an acute lower respiratory tract infection such as COVID-19; pneumonia; viral pneumonia; pneumonia associated with COVID-19; pulmonary edema; bronchitis; tracheobronchitis; chronic obstructive pulmonary disease (COPD); and asthma.

[0034] In preferred embodiments of the invention, the interleukin-6-associated respiratory disease is selected from the group consisting of acute respiratory distress syndrome; acute lower respiratory tract infection; pneumonia; pulmonary edema; bronchitis; tracheobronchitis; chronic obstructive pulmonary disease; and asthma. More preferably, the acute lower respiratory tract infection is COVID-19.

[0035] As used herein, the term "pulmonary administration" refers to the administration of a drug through the lungs by inhalation. The term "inhalation" as used in relation to the formulations and compositions of the invention is synonymous with "pulmonary administration". As used herein, the term "inhalation" refers to the inhalation of a vapor or dispersion of solid or liquid particles containing a drug. In specific examples, inhalation may be via a nebulizer or other aerosol delivery device.

[0036] In some embodiments, a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof may be administered pulmonary in the form of an aerosol. Numerous methods and devices are well known in the art that can be used to generate said aerosols in therapeutically useful ranges of sizes and concentrations. In particular, these are nebulizers, metered-dose inhalers (MDI) and dry powder inhalers (DPI). Pilcer G. et al. Int J Pharm. 2010, 392 (1-2): 1-19 . Nebulizers such as jet nebulizers or ultrasonic nebulizers are used to deliver aqueous pharmaceuticals. The MDI metered-dose inhaler suspends or dissolves drug powders in liquid propellants, and when a metered amount of propellant is released from the storage container, the propellant vaporizes and rapidly expands to disperse the powder drug or liquid drug with droplets. Such propellants include, but are not limited to, chlorofluorocarbons, hydrochlorofluorocarbons, or hydrocarbons. The DPI Dry Powder Inhaler delivers a precisely metered dose of medication to the lungs in dry powder form. It is designed to create an aerosol of the medicinal powder in the inhalation air stream. In carrying out the invention, any methods and devices, including nebulizers, MDIs and DPIs, can be used to pulmonary delivery of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof to a patient in need thereof.

[0037] As used herein, the term "aerosol" refers to a suspension of liquid or solid particles in a gaseous medium. In carrying out the invention, the hexapeptide (I) or a pharmaceutically acceptable salt thereof may be administered pulmonary as an aerosol in the form of liquid formulations and dry powders.

[0038] In a preferred embodiment, the hexapeptide (I) or a pharmaceutically acceptable salt thereof is administered to the lungs in the form of an aerosol with a particle size of 0.1 to 10.0 microns, more preferably 1 to 5 microns.

[0039] As used herein, the term "treatment" means preventing, reducing, or inhibiting the development of the disease to which the term applies, or one or more symptoms of that disease. The term "treatment" refers to both therapeutic treatment and prophylactic measures. Those who need treatment include those who already have the disorder, those who are prone to have the disorder, those who are diagnosed with the disorder, or those who have the disorder to be prevented.

[0040] As used herein, the term "mammal" refers to any animal classified as a mammal, such as a mouse, a rat, and a human. The preferred mammal is humans.

[0041] In carrying out the invention, a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof can be used as an active pharmacological ingredient in a pharmaceutical composition, which can be prepared as a solid, semi-solid or liquid.

[0042] In another aspect, the invention relates to the use of an aqueous pharmaceutical composition comprising a hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable adjuvant in the treatment of a respiratory disease associated with interleukin-6 by pulmonary administration to a mammal in need thereof.

[0043] In carrying out the invention, the aqueous pharmaceutical composition contains from 0.1 to 100 mg / ml of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof.

[0044] In a preferred embodiment, the aqueous pharmaceutical composition contains 0.9 to 1.1 mg / ml of hexapeptide (I) diacetate.

[0045] As used herein, the term "excipient" describes any ingredient other than hexapeptide (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the compositions may contain an excipient in an amount of 0.001 to 99.999%.

[0046] Non-exclusive examples of excipients for use in the aqueous pharmaceutical composition of the invention include purified water, water for injection, buffer systems for maintaining pH 3.0-8.5, tonicity regulators, antimicrobial preservatives, surfactants such as nonionic and amphiphilic surfactants, stabilizers and emulsifiers.

[0047] As used herein, the term "aqueous pharmaceutical composition" means that pharmaceutical water, such as purified water or water for injection, is a necessary adjuvant to the composition of the invention.

[0048] As used herein, the term "pharmaceutical water" refers to water that meets the requirements of regulatory documents of the Russian Federation and / or other countries, for example, the requirements of FS.2.2.0020.15 "Purified water" and the requirements of FS.2.2.0019.15 "Water for injection »Pharmacopoeia of the Russian Federation; and / or CPMP / QWP / 158/01 "Note for Guidance on Quality of Water for Pharmaceutical Use", EMEA, 2002. Preferably, the pharmaceutical water is selected from the group consisting of purified water and water for injection.

[0049] As used herein, the term "buffer system" describes a combination of acid and base in amounts sufficient to maintain the desired pH. Non-exclusive examples of pharmaceutically acceptable buffer systems for maintaining the pH in the range from 3.0 to 8.5 are described in the Pharmacopoeia of the Russian Federation (OFS.1.3.0003.15 "Buffer solutions") and include acetate buffer, citrate buffer, succinate buffer, phosphate buffer and imidazole buffer.

[0050] Non-exclusive examples of tonicity regulators include a suitable osmotically active inorganic agent such as sodium, calcium or magnesium chlorides, sulfates or phosphates; a suitable osmotically active organic agent such as sugars and sugar alcohols, in particular trehalose, mannitol and sorbitol. The preferred tonicity regulator is sodium chloride in an amount of 0.1 to 0.9% of the specified composition.

[0051] In carrying out the invention, an aqueous pharmaceutical composition is administered intrapulmonary in the form of vapors or dispersions of liquid particles in a gaseous medium, thereby delivering from 0.1 to 50 mg of hexapeptide (I) or a pharmaceutically acceptable salt thereof to the lung of a mammal. Preferably, the composition is administered in an amount that delivers 10 mg of hexapeptide (I) diacetate to the lung of a mammal.

[0052] In carrying out the invention, the aqueous pharmaceutical composition is administered to the lungs using a nebulizer or metered dose inhaler (MDI).

[0053] As used herein, the term "nebulizer" refers to an inhalation device that converts a liquid drug for nebulization into a dispersion in an atmosphere to deliver an active pharmaceutical ingredient to the lungs. Non-exclusive examples of nebulizers include compressors, ultrasonic or other types of nebulizers.

[0054] In some embodiments, the aqueous pharmaceutical composition is pressurized in a package with a dispensing valve-nebulizer system (aerosols and sprays) for subsequent nebulization.

[0055] In a preferred embodiment, the aqueous pharmaceutical composition is administered to the lungs in the form of an aerosol with a particle size of 0.1 to 10.0 microns, more preferably 1 to 5 microns.

[0056] In carrying out the invention, the aqueous pharmaceutical composition may be in the form of a unit dosage form suitable for single pulmonary administration of a precise dose. As used herein, the term "unit dosage form" refers to a physically discrete unit of a composition of the invention suitable for administration to a mammal by the pulmonary route. The level of a particular effective dose for any particular mammal depends on many factors, including the species of the mammal; the disease and its severity, the specific composition used; the age, weight, general health and sex of the subject; duration of administration; duration of treatment; combination with other drugs and / or additional therapies, and other similar factors well known in the medical technology.

[0057] In some embodiments of the invention, the unit dosage form contains hexapeptide (I) or a pharmaceutically acceptable salt thereof in an amount of 1.0 to 10.0 mg.

[0058] In carrying out the present invention, the composition of the present invention can be prepared using procedures well known in the art. Such procedures include, but are not limited to, mixing the hexapeptide (I) or a pharmaceutically acceptable salt thereof with the other ingredients of the composition by conventional means. Manual preparation of the compositions of the invention may be found in "Remington: The science and practice of pharmacy" 20 ^th ed. Mack Publishing, Easton PA, 2000 ISBN 0-912734-04-3 and "Encyclopaedia of Pharmaceutical Technology", edited by Swarbrick, J. & JC Boylan, Marcel Dekker, Inc., New York, 1988 ISBN 0-8247-2800- 9 or later editions.

[0059] In accordance with another aspect, the invention relates to a method for the treatment of a respiratory disease associated with interleukin-6, which comprises the step of pulmonary administration of an effective amount of a hexapeptide of formula (I):

H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I)

or a pharmaceutically acceptable salt thereof in a mammal in need thereof.

[0060] As used herein, the term "effective amount" refers to an amount of an active pharmaceutical ingredient that is sufficient to cause a decrease, reversal, amelioration, or inhibition of the development of the disease to which the term applies, or one or more symptoms of that disease.

[0061] In a preferred embodiment, the effective amount of the hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof is 0.001 to 1.00 mg / kg per kg of body weight of the mammal.

[0062] In carrying out the invention, an effective amount of a hexapeptide of formula (I), or a pharmaceutically acceptable salt thereof, can be administered to the lungs by continuous inhalation over a period of 1 minute to 2 hours, preferably 30 to 60 minutes.

[0063] In carrying out the invention, an effective amount of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof may be administered to the lungs once or twice a day for one day or longer.

[0064] Due to the pulmonary route of administration of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof, the present invention provides a painless and safe alternative to hexapeptide injection in the treatment of interleukin-6-associated respiratory diseases.

[0065] Due to the direct local delivery of a hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof to the lungs, the present invention provides a particularly advantageous method for achieving therapeutically effective levels of hexapeptide (I) in the lung that cannot be achieved with injections of hexapeptide (I) ...

[0066] Because of the improved pulmonary delivery of a hexapeptide of formula (I), or a pharmaceutically acceptable salt thereof, to the lungs, this invention provides particularly advantageous compositions and methods over injections of the hexapeptide for preventing, ameliorating or eliminating the symptoms of interleukin-related respiratory diseases 6, in mammals in need of it.

[0067] The following examples are presented to demonstrate the invention. The examples are illustrative only and are not intended to limit the scope of the invention in any way.

Example 1

[0068] The example shows a pharmaceutical composition for pulmonary administration.

[0069] Table 1.

Ingredient Content in 1 ml Hexapeptide (I) diacetate 0.1-100.0 mg Purified water up to 1 ml Phosphate buffer pH 3.0-8.5

[0070] An aqueous pharmaceutical composition is prepared as follows. Commercially available hexapeptide (I) diacetate, pharmacopoeial quality (OOO Berahim, Obninsk, Russia), is dissolved in purified water in the amounts indicated in Table 1, and the pH of the solution is adjusted to 3.0-8.5 using a phosphate buffer. The solution is filtered through a 0.22 µm filter to prepare a sterile solution without preservatives. The solution is poured into vials. The aqueous pharmaceutical composition is administered to the lungs by inhalation using a nebulizer at the recommended dose to treat an IL-6-associated respiratory disease in a subject in need thereof.

Example 2

[0071] This example shows a preferred aqueous pharmaceutical composition for pulmonary administration.

[0072] Table 2.

Ingredient Content in 1 ml Hexapeptide (I) diacetate 1 mg Purified water up to 1 ml

[0073] An aqueous pharmaceutical composition is prepared as follows. Commercially available pharmacopoeial grade hexapeptide (I) diacetate (Berahim LLC, Obninsk, Russia) is dissolved in purified water in the amounts indicated in Table 2. The solution is filtered through a filter with a pore size of 0.22 μm to prepare a sterile solution without preservatives with a pH of about 4.8. The solution is filled into ampoules and sealed in a sterile atmosphere. The aqueous pharmaceutical composition is administered to the lungs at a dose of 10 mg per subject using a nebulizer to treat an IL-6 associated respiratory disease.

Example 3

[0074] This example shows an aqueous pharmaceutical composition for pulmonary administration in a unit dosage form.

[0075] Table 3.

Ingredient Containment in one bottle Hexapeptide (I) diacetate pharmacopoeial 10 mg Water for injections up to 10 ml pH 4.8

[0076] An aqueous pharmaceutical composition is prepared as follows. Commercially available pharmacopoeial quality hexapeptide (I) diacetate (OOO Berahim, Obninsk, Russia), dissolved in water for injection in the amount indicated in Table 3 to obtain a solution of hexapeptide (I) diacetate at a concentration of about 1 mg / ml, yield 100% ... The solution is filtered through a 0.22 µm filter (Merck Millipore) to prepare a sterile solution without preservatives, 99.9% yield. The solution is poured into sterile 10 ml vials in a stream of nitrogen or any other oxygen-free inert gas and hermetically sealed with a sterile butyl rubber stopper and aluminum crimp. The resulting aqueous pharmaceutical composition in unit dosage form is administered to the lungs of a subject suffering from a respiratory disease associated with IL-6, such as COVID-19.

Example 4

[0077] This example illustrates a model for evaluating the efficacy of hexapeptide (I) or a pharmaceutically acceptable salt thereof in the treatment of respiratory diseases associated with interleukin-6.

[0078] The efficacy of diacetate hexapeptide (I) was tested in a model of acute lung injury (APL) accompanied by acute respiratory distress syndrome (ARDS). The ALL / ARDS model is induced by intratracheal administration of lipopolysaccharide (LPS) as described in D'Alessio FR. Mouse Models of Acute Lung Injury and ARDS. Methods Mol Biol. 2018, 1809: 341-350 with some modifications to make the model more lethal. For this purpose, male C57Bl / 6 mice were pre-dosed with 1 μg / mouse of α-galactosylceramide (α-GalCer, KRN7000, Sigma-Aldrich) as described in Aoyagi T. et al. Int Immunol. 2011, 23 (2): 97-108 , and 24 hours later, mice were injected intratracheally with LPS (E. coli; 300 μg / mouse) supplemented with 10 μl / mouse of Freund's complete adjuvant and 100 μg / mouse of muramyl peptide. This model is characterized by an acute overproduction of interleukin-6 in the lungs, with overproduction of IL-6 associated with acute lung injury, pulmonary edema, acute respiratory distress syndrome, pneumonia, and high mortality. Other symptoms of simulated respiratory disease associated with IL-6 were inhibition of motor activity, impaired coordination, insufficient eyelid opening and drooping, low muscle tone, decreased appetite, water intake and urination; as well as respiratory failure. Figure 1 shows hematoxylin-eosin-stained histological preparations of healthy lung tissue before administration of α-galactosylceramide / LPS (0 h) and lung preparations obtained from animals 24, 72 and 120 hours after administration of LPS. Lung preparations in healthy animals are characterized by moderate blood supply, absence of pathological changes in the stroma and parenchyma, as well as in the walls of the bronchi and bronchioles. In contrast, lung preparations from animals induced by α-galactosylceramide / LPS are characterized by bronchopneumonia with areas of destruction of the walls of the bronchus and bronchioles, desquamated epithelium and accumulation of inflammatory infiltrate, that is, signs of acute lung damage caused by inflammation associated with the overproduction of IL-6.

[0079] To assess the dynamics of IL-6 production in the lungs, PLL / ARDS was induced in male C57Bl / 6 mice by sequential administration of α-galactosylceramide and LPS as described above. IL-6 levels were determined in an aqueous extract of lung homogenates obtained from animals at different times (n = 6 at each time point) after LPS injection ("LPS" group). For comparison, the levels of IL-6 in aqueous extracts of lung homogenates were determined in six healthy naive mice (group "Intact"). Measurements were performed using a Bio-Plex® MAGPIX ™ Multiplex Reader (Bio-Rad, SN: 12250707) and a commercially available standard panel (Bio-Plex Pro ™ Mouse Cytokine Th17 Panel A 6-Plex # M6000007NY) according to the manufacturer's instructions. The analysis of the obtained data was carried out using the Bio-Plex Data Pro software (version 1.0.0.06) by Bio-Rad. The results are presented in Table 4 as mean ± error of the mean of IL-6 concentrations in lung homogenates. For reference, the levels of IL-6 in aqueous extracts of lung homogenates in intact mice ("Intact") were 119 ± 9 pg / ml.

[0080] Table 4.

Group IL-6 levels in lung homogenates, pg / ml 2 h 7 h 12 h LPS 1876 ± 196 * 843 ± 93 434 ± 39

* Significant difference from Intact (p <0.05).

[0081] Table 4 shows that mice induced by the administration of α-galactosylceramide and LPS are characterized by an increase in the production of interleukin-6 in the lungs on average 15.7 times compared with healthy intact animals. Therefore, this model of APL / ARDS is useful for evaluating the effectiveness of drugs in the treatment of respiratory diseases associated with overproduction of IL-6.

[0082] In general, the APL / ARDS model reproduces the main features of respiratory diseases associated with interleukin-6 in humans, such as overproduction of IL-6 in the lungs, diffuse alveolar lung injury, acute respiratory distress syndrome, pulmonary edema and pneumonia.

Example 5

[0083] This example shows that pulmonary administration provides better delivery of diacetate hexapeptide (I) to the lungs compared to injection.

[0084] Male C57Bl / 6 mice were randomized into two groups of eighteen animals each. In the first group ("GP (I) IM") mice received 10 mg / kg of hexapeptide (I) diacetate in 50 μl of an aqueous solution by intramuscular injection. In the second group ("HP (I) ing.") Mice were received by inhalation of 10 mg / kg of hexapeptide (I) diacetate in 50 μl of an aqueous solution. Lungs were isolated before (0 min) and after (1, 5, 15, 60 min) administration of diacetate hexapeptide (I) from three animals at each time point in both groups. Concentrations of hexapeptide (I) in lung homogenates at each time point (0, 1, 5, 15, 60 min) were measured using an Aglient HPLC 1260 HPLC with an Agilent 6545XT Accurate mass Q-TOF LC / MS detector. The areas under the pharmacokinetic curves (AUC) of absorption of diacetate hexapeptide (I) by the lungs for 60 min were 6446 ng / ml and 2991 ng / ml for pulmonary administration and injections, respectively. Thus, pulmonary administration provides at least 2-fold increased delivery of diacetate hexapeptide (I) to the lungs compared to injections at the same dose.

Example 6

[0085] This example demonstrates that pulmonary administration of diacetate hexapeptide (I) inhibits overexpression of IL-6 in the lungs.

[0086] Male C57Bl / 6 mice were randomized into four groups of six animals each. The first group was intact ("Intact"). APL / ARDS was induced in groups 2 to 4 by sequential administration of α-galactosylceramide and LPS as described in Example 4 of the invention. In the second group ("LPS"), mice received 50 μl of saline by inhalation one hour after the administration of LPS. In the third group ("LPS + GP (I) IM") mice received 100 μg / kg of hexapeptide (I) diacetate in 50 μl of an aqueous solution by intramuscular injection one hour after LPS injection. In the fourth group ("LPS + GP (I) ing."), Mice received 100 μg / kg of hexapeptide (I) diacetate in 50 μl of an aqueous solution by inhalation one hour after the administration of LPS. After 3 hours, lungs were harvested from all groups of mice, and IL-6 mRNA content was measured in lung homogenates by quantitative real-time PCR. mRNA was isolated using RNA Extran Kit (Syntol, Russia) in accordance with the manufacturer's protocol. cDNA was synthesized using a supermix with Revept-L reagents (AmpliSens, Russia). Real-time PCR was performed using a CFX96 real-time PCR sensor system (BioRad, CA) and specific primers IL-6-F-5'-ATGAAGTTCCTCTCTGCAAG-3 'and IL-6-R-5'-GTGTAATTAAGCCTCCGACT-3'. Data have been normalized to GAPDH. Results are presented in FIG. 2 as fold change in mean lung IL-6 mRNA ± mean error. One-way ANOVA followed by Tukey's post-test shows statistically significant difference between groups. A significant 6.3-fold increase in the expression of IL-6 was found in mice of the LPS group as compared with mice in the Intact group (p <0.01). Pulmonary administration of hexapeptide (I) diacetate significantly inhibited LPS-induced IL-6 overproduction in mice in the LPS + GP (I) ing group (p <0.01), while the effect of injectable hexapeptide (I) diacetate was insignificant (p = 0.21) compared to mice of the "LPS" group. Thus, diacetate of hexapeptide (I) administered to the lungs inhibits the overexpression of IL-6 in the lungs associated with respiratory disease.

Example 7

[0087] This example shows the effect of inhalation of hexapeptide (I) on the levels of IL-6 in the lungs and serum.

[0088] Male C57Bl / 6 mice were randomized into three groups of six animals each. The first group was intact ("Intact"). APL / ARDS was induced in groups 2 and 3 by sequential administration of α-galactosylceramide and LPS as described in Example 4 of the invention. In the second group ("LPS"), mice received 50 μl of saline by inhalation one hour after LPS administration. In the third group ("LPS + GP (I) ing."), The mice received inhalation of 100 μg / kg of hexapeptide (I) diacetate in 50 μl of an aqueous solution one hour after the LPS injection. IL-6 levels were measured in serum and in aqueous extracts of lung homogenates obtained from animals seven hours after saline or LPS administration using a commercially available standard panel (Bio-Plex Pro ™ Mouse Cytokine Th17 Panel A 6-Plex # M6000007NY) as described in example 4 of the invention. The results are presented in Table 5 as mean ± error of mean IL-6 concentrations (pg / ml) in lung homogenates and serum.

[0089] Table 5.

Group IL-6 concentration, pg / ml Serum Lungs (1) Intact 61 ± 7 * 119 ± 9 * (2) LPS 191 ± 21 926 ± 106 (3) LPS + GP (I) ing. 29 ± 6 * 75 ± 10 *

* Significant difference from LPS (p <0.05).

[0090] Table 5 shows that LPS induced an increase in IL-6 levels by 7.8 (p <0.05) and 2.9 times (p <0.05) in the lungs and serum, respectively, compared to intact controls. ... Pulmonary administration of diacetate hexapeptide (I) to LPS-induced mice resulted in a 12.3 (p <0.05) and 6.5 (p <0.05) fold decrease in IL-6 levels in the lungs and serum, respectively, compared with untreated LPS-induced control. Thus, pulmonary administration of diacetate hexapeptide (I) significantly reduces the levels of IL-6 in the lungs and serum of mammals suffering from respiratory disease associated with the overproduction of interleukin-6.

Example 8

[0091] This example illustrates the dose-dependent effect of inhaled diacetate hexapeptide (I) in the treatment of respiratory disease associated with IL-6.

[0092] Male C57Bl / 6 mice were randomized into five groups of six animals each. APL / ARDS was induced in all groups by sequential administration of α-galactosylceramide and LPS as described in Example 4 of the invention. In the first group, mice were received by inhalation of 50 μl of saline. In other groups, mice received hexapeptide (I) diacetate at doses of 1, 10, 100, and 1000 μg / kg in the form of solutions in 50 μL of water. IL-6 levels were measured in aqueous extracts of lung homogenates obtained from animals six hours after LPS injection using a commercially available standard panel (Bio-Plex Pro ™ Mouse Cytokine Th17 Panel A 6-Plex # M6000007NY) as described in Example 4 inventions. The results are presented in Table 6 as mean ± error of mean of IL-6 concentrations in lung homogenates.

[0093] Table 6.

Dose of hexapeptide (I) diacetate, μg / kg IL-6 content in the lungs, pg / ml 0 (saline) 1043 ± 122 one 287 ± 49 * ten 106 ± 15 * one hundred 89 ± 9 * 1000 446 ± 72 *

* Reliably different from nat. solution (p <0.05).

[0094] Table 6 shows that pulmonary administration of hexapeptide (I) diacetate at doses of 1 to 1000 μg / kg (0.001 to 1 mg / kg) significantly reduces the overproduction of IL-6 in the lungs of animals suffering from IL-associated respiratory disease. -6.

Example 9

[0095] This example illustrates the therapeutic efficacy of inhaled diacetate hexapeptide (I) compared to injections.

[0096] Male C57Bl / 6 mice were randomized into three groups of 15 animals each. APL / ARDS was induced in all mice by sequential administration of α-galactosylceramide and LPS as described in Example 4 of the invention. In the first group ("LPS"), mice received intramuscularly 50 μl of saline daily, once a day, starting from the day of the LPS injection. In the second group ("LPS + HP (I) IM") mice received intramuscularly hexapeptide (I) diacetate 100 μg / kg in 50 μl aqueous solution daily, once a day, starting from the day of LPS injection. In the third group ("LPS + HP (I) ing."), Mice received inhalation of 100 μg / kg of hexapeptide (I) diacetate in 50 μl of an aqueous solution daily, once a day, starting from the day of LPS injection. After 72 hours, LPS-induced APL / ARDS led to the death of 87% (13/15), 27% (4/15), and 7% (1/15) of animals in the LPS, LPS + HP (I) groups in .m. ", and" LPS + GP (I) ing. ", respectively. Figure 3 shows the Kaplan-Meier survival curves for 144 hours of observation after LPS administration. Kaplan-Meier analysis shows that there was a significant difference between the groups (p <0.0001; Mantel-Cox log rank test). Median survival was 24 hours in the LPS group. Hexapeptide (I) diacetate significantly reduced the death of animals as in the group "LPS + GP (I) IM" (p <0.0001), and in the group "LPS + GP (I) ing." (p <0.0001), compared to the LPS group. However, the therapeutic effect of inhaled hexapeptide diacetate (I) was higher than that achieved with injections of hexapeptide diacetate (I). The hazard ratio for the groups "LPS + HP (I) ing." / "LPS + HP (I) im." was 0.2295 (95% CI from 0.0397 to 1.372; logrank), that is, the probability of death of animals in the group of mice receiving inhaled hexapeptide (I) was 4.4 times lower than in the group of mice receiving hexapeptide injections (I). Thus, hexapepide (I) diacetate is more effective when administered to the lungs than hexapeptide (I) diacetate injections in reducing mortality associated with IL-6 overproduction.

Example 10

[0097] This example demonstrates that inhaled hexapeptide (I) diacetate was useful in the treatment of COVID-19.

[0098] A meta-analysis of COVID-19 clinical trials found that serum levels of 1.7 pg / ml interleukin-6 strongly distinguish severe (> 1.7 pg / ml) from mild COVID-19 (<1.7 pg / ml). Henry BM et al. Clin Chem Lab Med. 2020, 58 (7): 1021-1028 .

[0099] Inhalation of hexapeptide (I) diacetate has been used in the treatment of patients with COVID-19 in clinical trials approved by the human research ethics committee. Each research protocol complies with the ethical principles of the 1975 Declaration of Helsinki, as reflected in the prior approval of the Human Research Committee. Written informed consent was obtained from each participant included in the study. Patients with a confirmed diagnosis of COVID-19 who had blood levels of IL-6> 1.7 pg / ml were randomized into two groups. In the first group (control, n = 75), patients received daily standard therapy recommended by the Ministry of Health of the Russian Federation (versions 5 to 7 of the COVID-19 treatment guidelines). In the second group (GP (I), n = 11), patients received 10 mg of hexapeptide (I) diacetate by inhalation once a day every day for 5 days. Serum IL-6 levels were assessed using a commercially available ELISA assay before treatment (day 0) and after treatment (day 5). On day 0, there was no statistically significant difference between the groups (p = 0.8495; unpaired two-tailed Student's test), serum IL-6 levels (mean ± mean error) were 21.2 ± 3.3 and 19, 5 ± 6.2 pg / ml in groups 1 and 2, respectively. The cut-off value of 1.7 pg / ml for IL-6 in serum was used as a criterion for distinguishing between severe and mild COVID-19 in assessing an individual's response to treatment. A patient was considered a responder (responder) if the serum IL-6 level on the 5th day of treatment was below 1.7 pg / ml, and a non-responder (non-responder) if the level of IL-6 in serum blood on the 5th day of treatment was higher than 1.7 pg / ml. Five-day treatment with inhaled diacetate of hexapeptide (I) resulted in a 2.8-fold decrease in the IL-6 level from 19.5 ± 6.2 to 6.9 ± 2.3 pg / ml. At the same time, IL-6 levels less than 1.7 pg / ml were achieved in 54.5% of patients receiving inhaled hexapeptide diacetate (I), and only in 29.3% of patients in the control group. Thus, 54.5% of patients treated with inhaled hexapeptide (I) diacetate responded to treatment compared with 29.3% of patients in the control group (FIG. 4). Since the cut-off level of 1.7 pg / ml differentiates between severe and mild COVID-19, these results indicate that during the same treatment period, the severity of COVID-19 was reduced in 54.5% of patients treated with inhaled hexapeptide ( I) diacetate, compared with 29.3% of patients on standard therapy. Thus, Hexapeptide (I) diacetate, when administered pulmonary, has been beneficial in the treatment of COVID-19.

Claims (15)

1. Application of a hexapeptide of formula (I): H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I) or a pharmaceutically acceptable salt thereof in the treatment of a respiratory disease associated with interleukin-6, where the respiratory disease is COVID-19, by pulmonary administration to a mammal in need thereof. 2. The use of a hexapeptide of formula (I) according to claim 1, characterized in that the pharmaceutically acceptable salt is diacetate. 3. The use of an aqueous pharmaceutical composition containing a hexapeptide of formula (I): H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I) or a pharmaceutically acceptable salt and a pharmaceutically acceptable adjuvant thereof in the treatment of a respiratory disease associated with interleukin-6, wherein the respiratory disease is COVID-19, by pulmonary administration to a mammal in need thereof. 4. The use of an aqueous pharmaceutical composition according to claim 3, characterized in that the pharmaceutically acceptable salt is diacetate. 5. The use of an aqueous pharmaceutical composition according to claims 3, 4, characterized in that the composition is administered to the lungs in the form of an aerosol with a particle size of 1 to 5 microns. 6. A method of treating a respiratory disease associated with interleukin-6, wherein the respiratory disease is COVID-19, wherein the method comprises the step of pulmonary administration of an effective amount of a hexapeptide of formula (I): H-Tyr-D-Ala-Gly-Phe-Leu-Arg-OH (I) or a pharmaceutically acceptable salt thereof to a mammal in need thereof. 7. A method according to claim 6, wherein the pharmaceutically acceptable salt is diacetate. 8. A method according to claims 6, 7, characterized in that the hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof is administered in the form of an aqueous aerosol having a particle size of 1 to 5 microns. 9. The method according to claims 6-8, characterized in that the effective amount of the hexapeptide of formula (I) or a pharmaceutically acceptable salt thereof is from 0.001 to 1,000 mg per kg of body weight of the mammal.

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