Treatment methods for cysteamine sensitivity disorders

Abstract

This invention provides a method for treating cysteamine sensitivity disorders in the target population. [Solution] A method is provided for the treatment of cystinosis and other cysteamine-sensitive disorders in a subject, comprising the administration of a disulfide convertible to cysteamine in vivo. The method may include separately administering a reducing agent to the subject to enhance the bioavailability of cysteamine produced after disulfide administration and to extend the plasma pharmacokinetic profile. The method allows for sustained plasma cysteamine concentrations in the subject. In one embodiment, compound (1) is administered at a dose of 50-150 milligrams / kilogram of body weight (mg / kg), TIFF2026065004000032.tif23170 A method is provided which includes administering to the subject at least once a day a pharmaceutically acceptable salt thereof.

Description

[Technical Field]

[0001] The present invention features compositions and methods for treating cysteamine-sensitive symptoms, syndromes, and diseases. [Background technology]

[0002] Cysteamine is a naturally occurring aminothiol that is produced in vivo via the catabolism of pantetheine. Preclinical and early clinical studies suggest that cysteamine may be therapeutically active in a variety of diseases, but extensive clinical development has been hindered by the lack of convenient dosing regimens and inadequate toxicology.

[0003] Cysteamine has several mechanisms of action, most of which are related to the reducing ability of its thiol moiety. Cysteamine was first clinically studied in the 1950s as a radioprotective agent for cancer patients undergoing radiation therapy and as a treatment for radiation poisoning. The thiol group of cysteamine can reduce free radicals and other oxidative compounds that can be harmful to cells, thereby contributing to redox homeostasis. Cysteamine can also indirectly neutralize harmful oxidants by increasing the levels of other antioxidant thiols such as glutathione and cysteine. For example, cysteamine can participate in thiol-disulfide exchange with cystine (a dimeric oxidative form of cysteine) to form cysteamine-cysteine ​​disulfide and free cysteine. Cysteamine can also form disulfides with cysteine ​​residues in proteins, thereby affecting protein structure and function. Cysteamine can inhibit enzymes including transglutaminase, caspase, matrix metalloproteinase, and glutaminylcyclase. Cysteamine is a chelating agent with a particular affinity for copper. Cysteamine also blocks the secretion of certain peptide hormones, including somatostatin.

[0004] Diseases for which there is preclinical or clinical evidence of the therapeutic effects of cysteamine include neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, and Parkinson's disease; inflammatory and fibrotic diseases of the kidneys, liver, and lungs; metabolic diseases, including the spectrum of diabetes, metabolic syndromes, and fatty liver disease; infectious diseases, including viral, bacterial, and parasitic infections; hypercholesterolemia; ischemic diseases, including ischemic heart disease or seizures; sickle cell anemia; genetic mitochondrial disorders; genetic disorders caused by mutations of arginine to cysteine; and cancer.

[0005] Unfortunately, cysteamine has very unpleasant sensory properties (foul odor and bitter taste) and, when taken in therapeutically effective amounts (more than 1 gram per day in adolescents and adults), can cause body odor and bad breath. Most patients also experience gastrointestinal side effects, including loss of appetite, nausea, vomiting, and / or stomach pain. Bad breath, body odor, and gastrointestinal side effects are all associated with high peak cysteamine blood levels (often more than 50 times higher than endogenous cysteamine levels in healthy subjects). Furthermore, the elimination half-life of cysteamine is only about 25 minutes, which necessitates frequent administration. In summary, existing oral formulations of cysteamine have problems with sensory properties (bitter taste, foul odor), pharmacology (mostly below therapeutic blood concentrations between dose intervals), toxicology (gastrointestinal and other side effects), and stability (short half-life due to oxidation). Many of these problems are inherent in the drug being a volatile thiol compound. As a result, many cystinosis patients do not fully adhere to cysteamine therapy and consequently suffer from disease progression.

[0006] Clinical development of cysteamine formulations is hindered by the impossibility of delivering therapeutic levels of the drug over a sustained period while possessing acceptable toxicology. Therefore, improved treatment regimens are needed, including improved cysteamine-producing compounds, improved formulations, and improved dosing regimens that can reduce peak concentrations while producing sustained elevated blood cysteamine levels, and minimize side effects while increasing trough concentrations to provide improved efficacy. Furthermore, considering the known inter-patient variability of cysteamine pharmacokinetics, compositions are needed that allow for individualization of dosing regimens to improve efficacy and reduce toxicity. [Overview of the project]

[0007] In a first aspect, the present invention provides compound 1 in doses of 50 to 150 milligrams / kilogram of body weight (mg / kg) (for example, 60±10, 70±10, 80±10, 90±10, 100±25, 110±20, 120±10, 130±10, or 140±10 mg / kg), The present invention relates to a method for treating cysteamine-impaired sensitivity in a subject, comprising administering TIFF2026065004000001.tif23170 or a pharmaceutically acceptable salt thereof to the subject at least once daily (e.g., once, twice, or three times daily). In certain embodiments, the reducing agent is not administered to the subject within two hours of dose administration (e.g., within 30 minutes, 1 hour, 90 minutes, or 2 hours). In certain embodiments, the reducing agent is administered to the subject between 2 and 8 hours after dose administration. In certain embodiments, the reducing agent is administered 3 ± 1 hours, 4 ± 1 hours, 5 ± 1 hours, 6 ± 1 hours, 7 ± 1 hours, or 4 ± 2 hours after dose administration of compound 1 or a pharmaceutically acceptable salt thereof. In one embodiment, the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid. In certain embodiments, compound 1 or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, compound 1 or a pharmaceutically acceptable salt thereof is formulated as a powder, and the dosage form is a sachet. In certain embodiments, a pantetheinase inducer selected from the group including PPAR alpha agonists, PPAR gamma agonists, or Nrf2 inducers is administered to the subject. In one embodiment, the pantetheinase inducer is isothiocyanates, sulforaphane, S-allyl-cysteine, diallyl trisulfide, oxidized fats, omega-3 fatty acids, or oleylethanolamide found in cruciferous vegetables. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered to the subject at a dose of 10–50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg) within 30 minutes (e.g., 5, 10, 15, 20, 25, or 30 minutes) of compound 1 or a pharmaceutically acceptable salt thereof. In one embodiment, cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of compound 1 or a pharmaceutically acceptable salt thereof.

[0008] In certain embodiments, within 30 minutes (e.g., 5, 10, 15, 20, 20, or 25 minutes) of administration of compound 1 or a pharmaceutically acceptable salt of compound 3, a dose of 10-50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg) of compound 3 is administered. TIFF2026065004000002.tif23170 or a pharmaceutically acceptable salt thereof is administered to the subject. Optionally, compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, compound 3 or a pharmaceutically acceptable salt thereof is administered concurrently with the administration of compound 1 or a pharmaceutically acceptable salt thereof.

[0009] In any of the above methods, the cysteamine sensitivity disorder may be selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, liver, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD), or any other cysteamine sensitivity disorder described herein.

[0010] In a related embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising a reducing agent; and (iii) instructions for administering the second pharmaceutical composition at least two hours after the first pharmaceutical composition has been administered to a subject for the treatment of cysteamine sensitivity disorder.

[0011] In another embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising a pantethinase inducer; and (iii) instructions for administering the first and second pharmaceutical compositions to a subject for the treatment of cysteamine sensitivity disorder.

[0012] In another related embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising cystamine or a pharmaceutically acceptable salt thereof; and (iii) instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

[0013] In another embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof; and (iii) instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

[0014] In any of the above kits, the instructions may include instructions for carrying out a method for administering compound 1 described above.

[0015] In another embodiment, the present invention relates to compound 2 in doses of 50 to 150 milligrams / kilogram of body weight (mg / kg) (e.g., 60±10, 70±10, 80±10, 90±10, 100±25, 110±20, 120±10, 130±10, or 140±10 mg / kg), The present invention relates to a method for treating cysteamine-impaired sensitivity in a subject, comprising administering TIFF2026065004000003.tif24170 or a pharmaceutically acceptable salt thereof to the subject at least once daily (e.g., once, twice, or three times daily). In certain embodiments, the reducing agent is not administered to the subject within two hours of dose administration (e.g., within 30 minutes, 1 hour, 90 minutes, or 2 hours). In certain embodiments, the reducing agent is administered to the subject between 2 and 8 hours after dose administration. In certain embodiments, the reducing agent is administered 3 ± 1 hours, 4 ± 1 hours, 5 ± 1 hours, 6 ± 1 hours, 7 ± 1 hours, or 4 ± 2 hours after dose administration of compound 2 or a pharmaceutically acceptable salt thereof. In one embodiment, the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid. In certain embodiments, compound 2 or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, compound 2 or a pharmaceutically acceptable salt thereof is formulated as a powder, and the dosage form is a sachet. In certain embodiments, a pantetheinase inducer selected from the group including PPAR alpha agonists, PPAR gamma agonists, or Nrf2 inducers is administered to the subject. In one embodiment, the pantetheinase inducer is isothiocyanates, sulforaphane, S-allyl-cysteine, diallyl trisulfide, oxidized fats, omega-3 fatty acids, or oleylethanolamide found in cruciferous vegetables. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered to the subject at a dose of 10–50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg) within 30 minutes (e.g., 5, 10, 15, 20, 25, or 30 minutes) of compound 2 or a pharmaceutically acceptable salt thereof. In one embodiment, cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of compound 2 or a pharmaceutically acceptable salt thereof.

[0016] In certain embodiments, within 30 minutes (e.g., 5, 10, 15, 20, 20, or 25 minutes) of administration of compound 2 or a pharmaceutically acceptable salt thereof, compound 3 is administered in doses of 10-50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg). TIFF2026065004000004.tif22170 or a pharmaceutically acceptable salt thereof is administered to the subject. Optionally, compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, compound 3 or a pharmaceutically acceptable salt thereof is administered concurrently with the administration of compound 2 or a pharmaceutically acceptable salt thereof.

[0017] In any of the above methods, the cysteamine sensitivity disorder may be selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, liver, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD), or any other cysteamine sensitivity disorder described herein.

[0018] In a related embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising a reducing agent; and (iii) instructions for administering the second pharmaceutical composition at least two hours after the first pharmaceutical composition has been administered to a subject for the treatment of cysteamine sensitivity disorder.

[0019] In another aspect, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising a pantetheinase inducer; and (iii) instructions for administering the first pharmaceutical composition and the second pharmaceutical composition to a subject for the treatment of a cysteamine-sensitive disorder.

[0020] In yet another aspect, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising cystamine or a pharmaceutically acceptable salt thereof; and (iii) instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of a cysteamine-sensitive disorder.

[0021] In yet another aspect, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof; and (iii) instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of a cysteamine-sensitive disorder.

[0022] In any of the above kits, the instructions can include instructions for carrying out a method of administering the above compound 2.

[0023] The present invention relates to compound 3, A pharmaceutical composition comprising TIFF2026065004000005.tif22170 or a pharmaceutically acceptable salt thereof. The pharmaceutical composition can comprise Compound 3 or a pharmaceutically acceptable salt thereof formulated for immediate release, for delayed release, or for sustained release. In certain embodiments, the pharmaceutical composition further comprises a second active agent comprising a cysteamine precursor or a pharmaceutically acceptable salt thereof. Optionally, the second active agent is formulated for immediate release. In certain embodiments, the second active agent is formulated for delayed release or for sustained release. In one particular embodiment, Compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release and the second active agent is formulated for delayed release.

[0024] In related aspects, the invention features a method for treating a cysteamine-sensitive disorder in a subject, comprising administering to the subject a pharmaceutical composition comprising a therapeutically effective amount of Compound 3 or a pharmaceutically acceptable salt thereof. The cysteamine-sensitive disorder can be selected from cystinosis; neurodegenerative diseases; neurodevelopmental diseases; neuropsychiatric diseases; mitochondrial diseases; fibrotic diseases of the kidney, liver, or lung; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or stroke; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD), or any other cysteamine-sensitive disorder described herein.

[0025] In another aspect, the invention provides Compound 3 at a dose of 50 to 150 milligrams per kilogram of body weight (mg / kg) (e.g., 60 ± 10, 70 ± 10, 80 ± 10, 90 ± 10, 100 ± 25, 110 ± 20, 120 ± 10, 130 ± 10, or 140 ± 10 mg / kg) The present invention relates to a method for treating cysteamine-impaired sensitivity in a subject, comprising administering TIFF2026065004000006.tif22170 or a pharmaceutically acceptable salt thereof to the subject at least once daily (e.g., once, twice, or three times daily). In certain embodiments, the reducing agent is not administered to the subject within two hours of dose administration (e.g., within 30 minutes, 1 hour, 90 minutes, or 2 hours). In certain embodiments, the reducing agent is administered to the subject between 2 and 8 hours after dose administration. In certain embodiments, the reducing agent is administered 3±1 hours, 4±1 hours, 5±1 hours, 6±1 hours, 7±1 hours, or 4±2 hours after dose administration of compound 3 or a pharmaceutically acceptable salt thereof. In one embodiment, the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid. In certain embodiments, compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, compound 3 or a pharmaceutically acceptable salt thereof is formulated as a powder, and the dosage form is a sachet. In certain embodiments, a pantetheinase inducer selected from the group including PPAR alpha agonists, PPAR gamma agonists, or Nrf2 inducers is administered to the subject. In one embodiment, the pantetheinase inducer is isothiocyanates, sulforaphane, S-allyl-cysteine, diallyl trisulfide, oxidized fats, omega-3 fatty acids, or oleylethanolamide found in cruciferous vegetables. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered to the subject at a dose of 10–50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg) within 30 minutes (e.g., 5, 10, 15, 20, 25, or 30 minutes) of compound 3 or a pharmaceutically acceptable salt thereof. In one embodiment, cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of compound 3 or a pharmaceutically acceptable salt thereof.

[0026] In any of the above methods, the cysteamine sensitivity disorder may be selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, liver, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD), or any other cysteamine sensitivity disorder described herein.

[0027] In a related embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising a reducing agent; and (iii) instructions for administering the second pharmaceutical composition at least two hours after the first pharmaceutical composition has been administered to a subject for the treatment of cysteamine sensitivity disorder.

[0028] In another embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising a pantethinase inducer; and (iii) instructions for administering the first and second pharmaceutical compositions to a subject for the treatment of cysteamine sensitivity disorder.

[0029] In yet another embodiment, the present invention features a kit comprising: (i) a first pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof; (ii) a second pharmaceutical composition comprising cystamine or a pharmaceutically acceptable salt thereof; and (iii) instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

[0030] In any of the above kits, the instructions may include instructions for carrying out the method of administering compound 3 described above.

[0031] In another embodiment, the present invention is characterized by an acid addition salt of compound 1, wherein the acid is hydrochloric acid, acetic acid, trifluoroacetic acid, or tartaric acid. In a particular embodiment, the acid is acetic acid or tartaric acid. In a particular embodiment, the acid is acetic acid.

[0032] In one embodiment, the acid addition salt has the following formula. In some embodiments, the acid addition salt has the following formula: TIFF2026065004000008.tif23170

[0033] In certain embodiments, the acid is tartaric acid.

[0034] In one embodiment, the acid addition salt has the following formula. In one embodiment, the acid addition salt has the following formula. In one embodiment, the acid addition salt has the following formula. TIFF2026065004000011.tif23170

[0035] In another embodiment, the present invention is characterized by a method for treating cysteamine sensitivity impairment in a subject, comprising administering an effective amount of any of the aforementioned acid addition salts to the subject.

[0036] In certain embodiments, the reducing agent is not administered to the subject within 2 hours after dose administration (e.g., 30 minutes, 1 hour, 90 minutes, or 2 hours). In certain embodiments, the reducing agent is administered to the subject between 2 and 8 hours after dose administration. In certain embodiments, the reducing agent is administered 3±1 hours, 4±1 hours, 5±1 hours, 6±1 hours, 7±1 hours, or 4±2 hours after dose administration of compound 1 or a pharmaceutically acceptable salt thereof. In one embodiment, the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid.

[0037] In certain embodiments, any of the aforementioned acid addition salts are formulated for immediate release. In certain embodiments, any of the aforementioned acid addition salts are formulated as a powder, and the dosage form is either a sachet or formulated in a bottle for resuspending in an aqueous solution suitable for drinking. In certain embodiments, a pantetheinase inducer selected from the group including PPAR alpha agonists, PPAR gamma agonists, or Nrf2 inducers is administered to the subject. In one embodiment, the pantetheinase inducer is isothiocyanates, sulforaphane, S-allyl cysteine, diallyl trisulfide, oxidized fats, omega-3 fatty acids, or oleylethanolamide found in cruciferous vegetables. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered to the subject at a dose of 10–50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg) within 30 minutes (e.g., 5, 10, 15, 20, 25, or 30 minutes) of any of the aforementioned acid addition salts. In one embodiment, cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of any of the aforementioned acid addition salts.

[0038] In certain embodiments, within 30 minutes (e.g., 5, 10, 15, 20, 20, or 25 minutes) of administration of compound 1 or a pharmaceutically acceptable salt of compound 3, a dose of 10-50 mg / kg (e.g., 15±5, 20±5, 25±5, 30±5, 35±5, 40±5, or 45±5 mg / kg) of compound 3 is administered. TIFF2026065004000012.tif22170 or a pharmaceutically acceptable salt thereof is administered to the subject. Optionally, compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release. In certain embodiments, compound 3 or a pharmaceutically acceptable salt thereof is administered concurrently with the administration of compound 1 or a pharmaceutically acceptable salt thereof.

[0039] In any of the above methods, the cysteamine sensitivity disorder may be selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, liver, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD), or any other cysteamine sensitivity disorder described herein.

[0040] In yet another embodiment, the disclosure features a method for synthesizing an asymmetric disulfide, the method comprising combining (a) 1 molar equivalent of an organic carboxylic acid or a salt thereof, (b) 2 to 4 molar equivalents (e.g., 2, 2.5, 3, 3.5, or 4 molar equivalents) of a cystamine or a salt thereof, and (c) an amide coupling reagent, wherein more than 90% (e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.5%) of the organic carboxylic acid or salt thereof is converted to an asymmetric disulfide of formula (A), and less than 10% (e.g., 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5%) of the organic carboxylic acid remains unreacted or is converted to a symmetric disulfide of formula (B), thereby forming a mixture. In formula TIFF2026065004000013.tif21170, R is an organic radical. In certain embodiments, the group RC(O)- is a portion of less than 1,000 daltons, 700 daltons, 400 daltons, or 200 daltons. In some embodiments, RC(O)- is a natural or synthetic amino acid, or an ester or amide thereof.

[0041] In some embodiments, the organic carboxylic acid or a salt thereof is selected from pantothenic acid, 4-phosphopantothenic acid, acetic acid, or salts thereof. In certain embodiments, the organic carboxylic acid or a salt thereof is pantothenic acid or a salt thereof. In some embodiments, the amide coupling reagent is hydroxybenzotriazole. In some embodiments, the amide coupling reagent is N,N'-dicyclohexylcarbodiimide. In some embodiments, the coupling is in one or more solvents selected from dichloromethane, tetrahydrofuran, acetonitrile dimethylformamide, water, and combinations thereof.

[0042] In another aspect, the present disclosure features a method for synthesizing an asymmetric disulfide, the method comprising an organic solvent: (a) 2 to 4 molar equivalents (e.g., 2 to 2.3, 2.2 to 3, 2.7 to 3.3, or 3.1 to 4 molar equivalents) of thiols selected from cysteamine, N-acetylcysteamine, cysteine, N-acetylcysteine, N-acetylcysteinamide, or salts thereof, and (b) comprising combining in 1 molar equivalent of a disulfide selected from cystamine, pantethine, or salts thereof.

[0043] In some embodiments, the thiol-to-disulfide molar ratio is about 2:1 to about 4:1 (e.g., about 2:1 to about 2.5:1, about 2.5:1 to about 3.5:1, about 2.7:1 to about 3.3:1, about 2.5:1 to about 3:1, about 3:1 to about 3.5, or about 3:1 to about 3.5, about 4:1, about 3.5:1 to about 4:1). In certain embodiments, the thiol-to-disulfide molar ratio is about 2.5:1 to about 3.5:1 (e.g., about 2.5:1 to about 2.7:1, about 2.7:1 to about 3.3:1, or about 3.3:1 to about 3.5:1). In other embodiments, the thiol-to-disulfide molar ratio is approximately 2.7:1 to approximately 3.3:1 (for example, approximately 2.7:1 to approximately 3.1:1, or approximately 3.1 to approximately 3.3).

[0044] In some embodiments, the thiol is N-acetylcysteamine or a salt thereof.

[0045] In some embodiments, the disulfide is a cystamine or a salt thereof.

[0046] In some embodiments, the organic solvent is methanol or ethanol. In certain embodiments, the organic solvent is methanol.

[0047] definition "Immediate release" means the release of an active agent (e.g., a cysteamine precursor or a pharmaceutically acceptable salt thereof) formulated in a unit dosage form having a dissolution-release profile in artificial gastric fluid, with at least 55%, 65%, 75%, 85%, or 95% of the drug released within the first two hours of testing using USP-compliant equipment.

[0048] "Controlled release" refers to a mode of release of an activator (e.g., a cysteamine precursor or a pharmaceutically acceptable salt thereof) from a formulation in a manner that allows control of either the anatomical release site, the rate of release, or both. Generally, the objective of controlled-release formulations is to extend the duration of therapeutic drug levels in the body (e.g., compared to immediate-release formulations) and / or to optimize drug delivery to cysteamine absorption sites, thereby reducing the number of doses that must be administered in 24 hours. Gastric retention, delayed-release, sustained-release, and colon-targeted formulations are all examples of controlled-release formulations. Controlled-release formulations can also allow for a reduction in the peak concentration of the drug (Cmax) compared to that observed with immediate-release formulations administered at the same dose level (i.e., a reduced cysteamine Cmax in the case of the cysteamine precursor of this invention). A controlled-release formulation of an activator can be achieved, for example, by embedding the activator in a matrix material that is slow to dissolve or erode, thereby allowing the active ingredient to slowly and regularly leach out of the coating by either diffusion from the matrix, erosion of the matrix surface, or both, or by the formation of a gel with a semipermeable surface through which the drug slowly exits the semipermeable layer.

[0049] "Delayed release" means an oral formulation in which a pharmaceutical preparation, for example, passes substantially intact through the acidic environment of the stomach and dissolves in the more basic environment of the small intestine, thereby having a elucidate-release profile in artificial gastric fluid where less than 25%, 20%, 15%, 10%, or 5% of the active ingredient (e.g., cysteamine precursor or a pharmaceutically acceptable salt thereof) formulated in the unit dosage form is released within the first hour of the test, and additionally, has a elucidate-release profile in artificial intestinal fluid at pH 6.0, 65%, 75%, 85%, or 95% of the active ingredient is released within the first two hours of the test. In some embodiments, the delayed release of the active ingredient (e.g., cysteamine precursor or a pharmaceutically acceptable salt thereof) results from the use of a pH-sensitive enteric coating on the oral dosage form. The enteric coating can be combined with, for example, rapid-release or slow-release formulations, or a combination of the two, to extend the period over which the drug is released.

[0050] The term "sustained-release" (also referred to as "extended-release" in the literature) refers to a drug formulation that, compared to an immediate-release formulation of the same drug, provides sustained release of the drug over a longer period, for example, 6 to 12 hours or more, thereby having a dissolution-release profile in artificial gastric or intestinal fluid where at least 10 to 45% (i.e., 15 to 45%, 20 to 45%, 25 to 45%, 35 to 45%, 30 to 45%, or 40 to 45%) of the active agent (e.g., cysteamine precursor or a pharmaceutically acceptable salt thereof) in the unit dosage form is released within the first 3 hours of the test, and 65%, 75%, 85%, 90%, 93%, 95%, or 97% or more of the drug is released within 8 hours when in artificial small intestinal fluid. Preferably, though not necessarily, sustained release results in substantially constant blood levels of the drug that remain within the therapeutic range of the disease being treated over a longer period. Preferably, the sustained-release formulation of the cysteamine precursor produces plasma cysteamine levels that fall within a concentration range of, for example, 5-50 μM, 5-40 μM, 5-35 μM, 5-30 μM, 5-25 μM, 5-20 μM, or 10-50 μM, 10-45 μM, 10-40 μM, 10-35 μM, 10-30 μM, 10-25 μM, or 10-20 μM.

[0051] The term "colon-targeted" refers to formulations or compositions that deliver drug release to the colon (where the density of the gut microbiota is much higher than in the small intestine) and optionally to the distal ileum (which tends to be the most alkaline region of the gastrointestinal tract). One method for targeting drug release to the distal ileum and colon is to use a pH-sensitive coating that dissolves around pH 7 (e.g., pH 6.8, pH 6.9, pH 7.0), which is typical pH in the ileum. Formulations designed for pH-dependent drug release in the ileum are very likely to also release the drug in the colon (especially if the drug is embedded in a sustained-release matrix), and / or some of the cysteamine precursor released in the ileum can still migrate to the colon in its precursor form (i.e., not yet converted to cysteamine). Another type of colon-targeted formulation relies on enzymes produced by gut bacteria to break down drug-encapsulating polymers that cannot be broken down by salivary, gastric, or pancreatic enzymes, thereby resulting in drug delivery in the colon. The density of the gut microbiota is also high in the distal ileum, and therefore the gut microbiota begins to digest the polymer, thus allowing the drug to be released in the distal ileum. Ileal and colon-targeted formulations are collectively referred to as colon-targeted formulations in this specification.

[0052] The term “unit dosage form” refers to physically distinct units suitable as a single dosage form, such as pills, tablets, caplets, rigid capsules, or flexible capsules, each containing a predetermined amount of cysteamine precursor or a pharmaceutically acceptable salt thereof. “Rigid capsule” means a capsule containing a membrane that forms a two-part capsule-shaped container capable of carrying a solid or liquid payload of a drug and excipients. “Flexible capsule” means a capsule molded into a single container that carries a liquid or semi-solid or solid payload of a drug and excipients. Granules, powders, and liquids can also be provided in “unit dosage forms” by using appropriate packaging. For example, granules or powders can be administered in sachets, and liquids in ampoules, vials, or plastic containers.

[0053] The term “microparticles,” as used herein, refers to microbeads, microspheres, micropellets, nanoparticles, nanobeads, nanospheres, or other fine particles used in drug formulations, each microparticle having an average diameter between 0.05 and 999 micrometers. Dozens, hundreds, or thousands of such microparticles can be used in a single unit dosage form, for example, by filling them into capsules, formulating them as a powder, or suspending them in a liquid.

[0054] When used herein, the term “effective dose” of a drug means a quantity sufficient to produce a beneficial or desired outcome in a patient, such as disease remission, and such “effective dose” depends on the context in which it is applied, including the patient’s age and weight, the nature of the disease including the affected organ(s), the state or level of activity of the disease, the patient’s sensitivity to cysteamine, and other factors.

[0055] As used herein, “pantetheine,” “4-phosphopantetheine,” “dephosphocoenzyme A,” and “coenzyme A,” as well as any analogs or derivatives convertible to one of these compounds in the gastrointestinal tract, all refer to D enantiomers (sometimes also called R enantiomers using recent nomenclature). Each of these compounds contains a chiral carbon in the pantothenoyl moiety, which may exist in either the D (dextro) or L (revo) form, also called the (R) or (S) form, respectively. Only the D-pantetheine enantiomer is the only pantetheine enantiomer that is a substrate of pantetheinase and therefore a cysteamine precursor. Similarly, only the D-enantiomers of compounds convertible to pantetheine, such as 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A, are useful in the compositions and methods of the present invention.

[0056] As used herein, a "disulfide compound" is a compound containing a sulfur atom chemically bonded to a second sulfur atom in the form of R1-S-S-R2, where R1 and R2 are organic compounds. R1 and R2 may be the same or different. Disulfide compounds are generally formed by the oxidation of two thiols (i.e., R1-S-H + R2-S-H yields R1-S-S-R2 + 2H + ), and can be reversibly converted to two thiols by reduction (i.e., R1-S-S-R2 + 2H + yields R1-S-H + R2-S-H). Disulfide compounds can also be formed by reacting one or two thiols with a dithiol (e.g., R1-S-H + R2-S-H + H-S-R3-S-H yields R1-S-S-R3-S-S-R2 + 4H + , where R1, R2, and R3 are organic compounds and H + is a hydrogen ion). The disulfide compounds of the present invention are 1) cysteamine mixed disulfide compounds of the formula C2H6NS-S-R1, where R1 is an organic moiety, 2) pantethine disulfide compounds of the formula C 11 H 21 N2O4S-S-R1, (where R1 is an organic moiety), 3) 4-phosphopantethine disulfide compounds of the formula C 11 H 22 N2O7PS-S-R1 (where R1 is an organic moiety), 4) dephospho coenzyme A disulfide compounds of the formula C 21 H 34 N7O 13 P2S-S-R1 (where R1 is an organic moiety), 5) compounds of the formula C 21 H 35 N7O 16The bioactive sulfur-containing compound includes a coenzyme A disulfide compound of formula P3S-S-R1 (wherein R1 is the organic part), or an N-acetylcysteamine compound of formula C4H8NOS-S-R1 (wherein R1 is the organic part). Additional disulfides can be formed using dithiols, which are compounds capable of forming two disulfide bonds. At least one, and optionally both, disulfide bonds are with cysteamine or a compound that can be broken down to cysteamine in the gastrointestinal tract. Alternatively, a dithiol may be disulfide-bonded to just one such compound, and the second thiol of the dithiol may remain in thiol form, or the second thiol may be disulfide-bonded to any thiol, including any thiols listed in Figure 17, for example. Compounds that can be broken down to cysteamine in the gastrointestinal tract include, in addition to pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine, or any analogues or derivatives that can be converted to one of these five compounds in the gastrointestinal tract (e.g., by chemical or enzymatic processes). Any such analogue or derivative referred to herein as “suitable analogue or derivative” is a thiol of the present invention and may substitute for one of these five compounds. A “mixed disulfide” is a disulfide formed from two different thiols. A “cysteamine mixed disulfide” means a disulfide that connects cysteamine to another (non-cysteamine) thiol. A “pantetheine mixed disulfide” means a disulfide that connects pantetheine to another (non-pantetheine) thiol, and so on. Generally, mixed disulfides are classified by the simplicity of their two constituent thiols (for example, cysteamine-pantetheine is called a cysteamine mixed disulfide). Useful thiols for forming disulfide-cysteamine precursors include, for example, L-cysteine, N-acetylcysteine, glutathione, any thiols listed in Figure 17, and other thiols described herein. Several exemplary mixed disulfides are shown in Figures 2–10.The tables in Figures 18–21 show how the thiols in Figure 17 can be usefully combined to form disulfides. For brevity and clarity, the names of the two thiols linked via a disulfide bond are used herein to indicate the disulfide name, rather than their formal chemical names (e.g., using IUPAC nomenclature). Thus, cysteamine-pantetheine refers to the disulfide formed from these two compounds. Three important exceptions to this rule are: the disulfide formed by reacting two pantetheines is generally called pantethine, the disulfide formed by reacting two cysteines is generally called cystine, and the disulfide formed by reacting two cysteamines is generally called cysteamine.

[0057] Where used herein, the terms “disulfide formed by reacting…” or “compound formed by reacting…” refer in particular to a disulfide formed between two specified thiols. For example, the disulfide formed by reacting cysteamine with pantetheine (called cysteamine-pantetheine) means the heterodimer formed between the cysteamine molecule and the pantetheine molecule. This definition does not reflect what can actually happen when two specified thiols react. That is, when cysteamine is reacted with pantetheine under oxidative conditions, three disulfides can be formed in varying proportions depending on the chemical conditions: cysteamine-cysteamine (i.e., cystamine), cysteamine-pantetheine (also pantetheine-cysteamine, which is identical for the purposes of this invention), and pantetheine-pantetheine (i.e., pantethine). When the text means the actual reaction product (i.e., a mixture of the three disulfides), it clearly states so.

[0058] A "cysteamine precursor" means a compound that can be converted to at least one cysteamine under physiological conditions. Means of conversion include reduction in the case of cysteamine-containing disulfides (i.e., cysteamine mixed disulfides), enzymatic hydrolysis in the case of pantetheine substrates (pantetheine and compounds that can be metabolically converted to pantetheine in the gastrointestinal tract, such as 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A, and appropriate analogs or derivatives thereof), or both reduction and enzymatic cleavage. Examples of precursors include, but are not limited to, cysteamine mixed disulfides, pantetheine disulfide, 4-phosphopantetheine disulfide, dephosphocoenzyme A disulfide, coenzyme A disulfide, and N-acetylcysteamine disulfide, as well as pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, and N-acetylcysteamine. The chemical relationships between cysteamine, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A (the latter four compounds are cysteamine precursors) are shown below. Since all constituent thiols are cysteamine precursors, homodimers of two pantetheine molecules (i.e., pantethine), or two 4-phosphopantetheine molecules, or two dephosphocoenzyme A molecules, or two coenzyme A molecules, or two N-acetylcysteamine molecules are also disulfide cysteamine precursor compounds.

[0059] "Appropriate analogues or derivatives" means compounds that can be converted in the gastrointestinal tract, whether by chemical or enzymatic processes, to pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine, which are cysteamine precursors, or disulfides containing any of these.

[0060] "Compounds convertible to pantetheine" means compounds such as 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A that can be broken down to pantetheine in the gastrointestinal tract, as well as analogs or derivatives of compounds that can be converted to the parent compound in the gastrointestinal tract.

[0061] In relation to disulfides, the term "constituent thiol" refers to a thiol (and optionally dithiol) compound that reacts to form a disulfide.

[0062] "Cysteamine content" refers to the weight fraction of cysteamine precursors that can be converted to cysteamine in vivo during chemical and / or enzymatic degradation.

[0063] The term "pharmaceutically acceptable salt," as used herein, refers to a salt that, within the bounds of appropriate medical judgment, is suitable for use in contact with human and animal tissues without causing excessive toxicity, irritation, allergic reactions, etc., and that provides a reasonable benefit-to-risk ratio. Pharmacologically acceptable salts are well known in the art. For example, pharmaceutically acceptable salts are described in Berge et al., J. Pharmaceutical Sciences 66:1-19, 1977, and Pharmaceutical Salts: Properties, Selection, and Use (eds. PHStahl and CGWermuth), Wiley-VCH, 2008. These salts can be prepared in situ during the final isolation and purification of the compounds of the present invention, or separately by reacting free base groups with appropriate organic or inorganic acids. Typical acid addition salts include acetate, adipine, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, tartrate, borate, butyrate, camphorate, camphor sulfonate, citrate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, fumarate, glucoheptoneate, glycerophosphate, hemisulfate, heptaneate, hexanoate, hydrobromide, hydrochloride, hydroiodide, and 2-hydroxyethanesulfate. Examples include nitrates, lactobionates, lactates, laurates, lauryl sulfates, malates, maleates, malons, methanesulfonates, 2-naphthalenesulfonates, nicotinates, nitrates, oleates, oxalates, palmitates, pamoates, pectins, persulfates, 3-phenylpropionates, phosphates, picrates, pivalates, propions, stearates, succinates, sulfates, tartrates, thiocyanates, toluenesulfonates, undecanoates, valersates, etc.Typical alkali metal salts or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, etc., as well as non-toxic ammonium, quaternary ammonium, and amine cations, including but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, and ethylamine.

[0064] "Gastric retention," "gastric retention," etc., refers to a pharmaceutical composition that can remain in the stomach of a mammal, preferably a human, for an extended period, preferably for the same duration as food, and more preferably for a longer period than food. Therefore, "gastric retention" is the retention of a drug composition in the stomach for a longer period than the retention time when delivered in free form, for example, in an oral delivery vehicle not considered gastric retention. Gastric retention formulations may be characterized by gastric retention for a longer period than the normal emptying time from the stomach, i.e., longer than about 2 hours, particularly longer than about 3 hours, and usually longer than about 4, 6, 8, or 10 hours. Gastric retention formulations typically remain in the stomach for about 3, 4, 6, 8, 10 hours, or sometimes 18 hours or more, after ingestion of food. However, it should be noted that, according to the present invention, retention in controlled-release gastric retention drug delivery systems is not observed more than 48 hours, preferably 24 hours, after administration on a non-fasting state. Examples of gastric retention formulations include floating or buoyant formulations, swelling or distending formulations, bioadherent or mucosal-adhering formulations, dispersible formulations, and magnetic formulations, or any combination thereof. Since it has been found that it is difficult to maintain gastric retention with only one mechanism, a combination of two or more gastric retention formulations is common. Gastric retention formulations are preferably administered with food.

[0065] The interchangeable terms “floating,” “floating,” and “buoyant” refer to a type of formulation that has the ability to position the composition of the present invention on or near the surface of the gastric contents, which are a porridge-like liquid in a feeding state (gastric juice in a fasted state or after gastric emptying). By floating on the gastric contents, the formulation has less opportunity to be propelled into the duodenum through the pylorus during contraction of the gastric muscles, and the pylorus is located at the bottom of the stomach in a seated or upright state. Floating formulations may consist of small (e.g., micron scale), medium (e.g., milliscale), or large (e.g., centimeter scale) particles. Larger compositions may act simultaneously via swelling / expanding mechanisms, as described herein. Formulations of any size may act simultaneously via mucosal adhesion mechanisms.

[0066] The interchangeable terms “swellable” and “expandable” refer to the ability of a composition to increase its dimensions upon contact with a fluid-containing medium such as gastric juice or abrasive liquid. Preferably, “swellable” is characterized by increasing the dimensions of the initial tablet to a size that will not be easily removed from the stomach. Gastric emptying involves passage through the pylorus. The average resting diameter of the pylorus in humans varies between fed and fasted states. It is approximately 1 centimeter or less when fed and approximately 1.28 centimeters ± 7 millimeters when fasted. Preferably, “swellable” requires increasing the dimensions of the composition to 14 mm, 16 mm, 18 mm, 20 mm, or 22 mm or more in at least two dimensions, or alternatively, if only one dimension is so, until both the second and third dimensions are greater than 12 mm, 14 mm, or 16 mm.

[0067] "Mucosal adhesion" refers to the ability of a composition to adhere to the layer of mucus lining the gastrointestinal tract. In the case of gastric retention formulations, "mucosal adhesion" refers to adhesion to the mucus layer lining the stomach. Mucosal adhesion is one of several techniques for extending gastric retention time, but the gastric mucosa undergoes slow but continuous metabolic turnover, limiting the duration of mucosal adhesion. Therefore, mucosal adhesion is usually combined with other gastric retention techniques to achieve a longer gastric retention time. "Bioadhesion" refers to the ability of a composition to adhere to other molecules lining the gastrointestinal tract, including molecules on the surface of intestinal cells.

[0068] The interchangeable terms “unfolding” or “shape-changing” refer to the ability of a composition to unfold, stretch, unwind, loosen, or otherwise open up in the stomach to transform into a composition of a size and / or geometric shape that does not easily pass through the pylorus and thus remains in the stomach for an extended period. “Unfolding” or shape-changing formulations may be formulated within capsules. Ideally, though not required, the dimensions of the unfolded or unfolded formulation in its unpackaged state should be greater than 16mm, 18mm, 20mm, or 22mm in at least two dimensions, or alternatively, if only one dimension is so, the second and third dimensions should be 12mm, 14mm, or 16mm or greater.

[0069] A “magnetic formulation” means a composition containing a magnet or dispersible magnetized material that can interact with an externally applied magnetic field formed by an externally placed magnet(s) to cause the composition to remain in the stomach or small intestine for an extended period. Compositions targeting the stomach preferably remain in the stomach for at least as long as food remains there, more preferably longer than food remains there. Compositions targeting the small intestine preferably remain until substantially complete drug dissolution or until sufficient magnetic strength to hold the composition in place is lost, whichever comes first. The magnet or magnetic material used must be safe for human ingestion. While external magnets can also be used to place a pharmaceutical composition containing a magnet in other areas of the gastrointestinal tract, such as the colon, in most cases magnetic formulations are a type of gastric retention formulation or small intestine target formulation.

[0070] As used herein, “therapeutic dose” refers to the amount that must be administered to a patient (human or non-human mammal) to improve the disease or modulate a biomarker that surrogates disease activity. Clinical endpoints for a wide range of diseases, including neurodegenerative, metabolic, fibrous, ischemic, infectious, neoplastic, and genetic disorders, vary widely but are generally well known in the field. Specific biomarkers include, for example, (i) white blood cell (WBC) cystine levels that surrogate disease control in patients with cystinosis; (ii) Clinical Global Assessment (CGI) score, Assessment of Change Based on Clinician Interviews and Caregiver Inputs (CIBIC-Plus), Alzheimer’s Disease Collaborative – Clinician Global Assessment of Change (ADCS-CCGIC) score, Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-Cog) score, and Alzheimer’s Disease Collaborative – Modified Activities of Daily Living for Severe Dementia (iii) Biochemical measures of neurodegenerative disease activity include AD biomarkers (e.g., plasma beta-amyloid protein) or brain-derived neurotrophic factor (BDNF) levels. (iv) Measures of metabolic and fibrotic liver disease include anatomical examinations such as the (NAFLD) activity score (NAs) and liver fibrosis score (NAs), and anatomical examinations such as the liver fibrosis score (UDHRS), MATTIS test, Hopkins Trailmaking test, categorical fluency task, unified Parkinson's disease rating scale (UPDRS) score, or Parkinson's disease sleep scale (PDSS-2) total score. (iii) Biochemical measures of neurodegenerative disease activity include AD biomarkers (e.g., plasma beta-amyloid protein) or brain-derived neurotrophic factor (BDNF) levels. (iv) Measures of metabolic and fibrotic liver disease include anatomical examinations such as the (NAFLD) activity score (NAs) and liver fibrosis score, as well as measurements of liver fibrosis based on liver biopsy. (v) Biochemical indicators of liver health, including hepatic and adipose tissue insulin sensitivity, as measured by HOMA-IR and Adipo-IR indices, serum aminotransferase and gamma-glutamyl transpeptidase (GGT) levels, and CK-18-derived fragments in the blood relating to NAFLD, NASH, ASH, or hereditary liver disease.(vi) Indicators of disease status for mitochondrial diseases include the Newcastle Pediatric Mitochondrial Disease Scale (NPMDS) score as a clinical endpoint, and (vii) biomarkers including levels of glutathione, total serum thiols, acetacetate, beta-hydroxybutyrate, lactate, or malondialdehyde (a marker of oxidative stress). Other surrogate disease markers include modulation of the immune response, modulation of gene or protein expression, or modulation of confirmed radiological disease measures (e.g., assessed by X-ray, CT scan, MRI scan, or PET scan). Methods for determining the therapeutically effective dose of cysteamine precursors are highly disease-specific and well-known to clinicians specializing in each of the above diseases.

[0071] As used herein, “pharmaceutically acceptable excipients” are natural or synthetic substances included (together with the active ingredient) in formulations of compositions suitable for use in humans and / or non-human mammals without excessive adverse side effects (such as toxicity, irritation, or allergic reactions). Examples of excipients include anti-adhesion agents, antioxidants, binders, coatings, compression aids, disintegrants, dyes (colors), emollients, emulsifiers, fillers (diluents), film-forming agents or coatings, flavorings, fragrances, lubricants (flow enhancers), moisteners, preservatives (including antioxidants), printing inks, adsorbents, suspending or dispersing agents, solvents, colloidal stabilizers, sweeteners, and water. The US FDA maintains a database of “inactive ingredients” containing information on thousands of substances commonly used in drug formulations. This database can be used to search for excipients commonly used in controlled-release, delayed-release, sustained-release, or extended-release formulations. Excipients include, but are not limited to, butylated hydroxytoluene (BHT), calcium carbonate, dibasic calcium phosphate, calcium stearate, carbomer, croscarmellose, cross-linked polyvinylpyrrolidone, citric acid, crospovidone, ethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, or cellulose derivatives including hypromellose, sodium doxate, gelatin, gelucire 43 / 01, lactose, magnesium stearate, maltitol, mannitol, methylcellulose, methylparaben, microcrystalline cellulose, polyethylene glycol, poly(ethylene oxide), polyvinylpyrrolidone, povidone, pregelatinized starch, propylparaben, shellac, silicon dioxide, sodium carboxymethylcellulose, sodium starch glycolate, sorbitol, starch (corn), stearic acid, sucrose, talc, titanium dioxide, vegetable oil, waxes including white, yellow, or beeswax, and xylitol.Excipients also include diluents (e.g., physiological saline and aqueous buffers), aqueous and non-aqueous carriers such as water, ethanol, polyols (e.g., glycerol, propylene glycol, polyethylene glycol, etc.), and suitable mixtures thereof, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Excipients useful for formulating compositions having specific properties are specifically described in the detailed description of the invention.

[0072] "Enteric coating" means a drug or compound added to the formulations described herein that protects the active ingredient(s) described herein (e.g., cysteamine precursors, and promoters of the breakdown and absorption of cysteamine precursors) as they pass through the stomach. Enteric coatings also protect the stomach from irritating pharmaceutical ingredients (e.g., cysteamines). Examples of commercially available enteric coating technologies include, but are not limited to, AcrylEZE, Opadry, Nutrateric and Sureteric products (Colorcon, West Point PA), Advantia Performance Specialty Coatings (International Specialty Products, Wayne NJ), Kollicoat product line (BASF Corporation, Ludwigshafen Germany), Aquacoat products (FMC BioPolymer), Eastman CAP (Eastman Chemical Co., Kingsman TN), Eudragit product line (Evonik Industries), and AQOAT, HP-50, and HP-55 product lines (Shin Etsu Pharma). Ashland Specialty Ingredients, Encap Drug Delivery, and Sanyo Chemical Industries, Ltd. also sell enteric coating systems.Examples of pH-sensitive film-forming polymers commonly used in enteric-coated formulations include: (i) cellulose-based polymers such as cellulose acetate phthalate (e.g., Aquacoat CPD, FMC;CAP, Eastman Chemical Co.), cellulose acetate succinate, cellulose acetate trimellitate, hydroxypropyl methylcellulose phthalate, and hydroxypropyl methylcellulose acetate succinate (e.g., AquaSolve, Ashland Specialty Ingredients, Wilmington DE); and (ii) polymethacrylates such as poly(methacrylate-ethyl acrylate) in 1:1 and 1:2 ratios (e.g., Eudragit L30D-55 and Eudragit L100-55 (Evonik Industries), AcrylEZE (Colorcon), Kollicoat MAE 30 DP and Kollicoat MAE 100P (BASF Pharma Ingredients and Services), and Polyquid PA-30 (Sanyo Chemical)). Examples of enteric coatings include polyvinyl derivatives such as (iii) poly(vinyl acetate) phthalate (e.g., Sureteric, Colorcon), and (iv) other copolymers such as semi-esters of styrene and maleic acid copolymers, semi-esters of vinyl ether and maleic acid copolymers, and vinyl acetate and crotonic acid copolymers. Enteric coatings are also made using shellac (e.g., PROTECT, Sensient Pharmaceutical Coating Systems) or sodium alginate and zein (Encap Drug Delivery). Hydroxypropyl methylcellulose is also called hypromellose or HPMC. Examples of other excipients commonly used in enteric coating formulations include wet microcrystalline cellulose, wet powdered cellulose, gellan gum, and stearic acid. Enteric coatings can be applied to a variety of formulations, including tablets, capsules, and microparticles.

[0073] As used herein, “combination therapy” means that a patient (or non-human mammal) requiring treatment according to the present invention receives, in addition to those disclosed herein, any pharmacotherapy not fully described herein or, in some cases, not intended herein. Combination therapy may be performed sequentially (before or after) or concurrently with the cysteamine precursor therapy of the present invention.

[0074] "To treat" means to subject a patient to a management regimen with the aim of treating a disease or disorder and obtaining a beneficial or desirable outcome, such as improvement of disease signs or symptoms, or improvement of biochemical, radiological, behavioral or physical markers of disease activity or disease state. Examples of beneficial or desirable outcomes include, but are not limited to, reduction of inflammation, correction of biochemical imbalances, improvement of quality of life, improvement of cognitive and behavioral status, improvement of motor function, improvement of emotional and mood status, improvement of sleep, or, more generally, relief or improvement of one or more symptoms or conditions, reduction of disease severity, stabilization of disease state, prevention of disease transmission, delay or slowing of disease progression, improvement or relief of disease, disorder, or condition, and partial or complete remission of major disease manifestations.

[0075] The term "mammal" is intended to refer to both humans and non-human mammals.

[0076] "To deliver" means to provide and / or administer by oral administration of the active ingredient(s) described herein by the active ingredient(s) and (optionally) one or more carriers and / or diluents and / or adjuvants or other excipients, such as tablets, capsules, liquids, powders, granules, microparticles, sachets, suppositories, etc. (collectively referred to as the "Pharmaceutical Composition" or simply the "Composition"). The Composition may be provided with any color coding or alphanumeric text description on the surface or packaging of the Composition, as well as instructions for delivery, including instructions on whether the Composition should be taken at a specific time of day or with food (e.g., (a specific type or amount of food)), liquids, meals (including details regarding the type of meal) or other pharmacotherapy, and whether the patient should remain upright or seated for a period of time after drug administration.

[0077] Some disease acronyms, gene names, and other medical terms are represented by abbreviations. Disease acronyms include MELAS (mitochondrial cerebral cardiomyopathy, lactic acidosis, and stroke-like episodes) and MERFF (myoclonus epilepsy with red rag fibers). Gene names include POLG (DNA polymerase gamma, encoding the catalytic subunit of mitochondrial DNA polymerase); OCT1, OCT2, and OCT3 (encoding organic cation transporters 1, 2, and 3, respectively) (also known as SLC22A1, SLC22A2, and SLC22A3, respectively); PANK2 (encoding pantothenate kinase 2); VNN1 (encoding vanin 1, also known as pantetheinase); and VNN2 (encoding vanin 2, also known as GPI-80 and pantetheinase).

[0078] As used herein, “cysteamine-sensitive disorders” means disorders for which there is evidence that cysteamine may be an effective treatment. This evidence may be derived from clinical or preclinical studies of the disease in mammals (e.g., humans, dogs, mice, rats, monkeys, rabbits) or from in vitro studies of the disease mechanism. Cysteamine-sensitive disorders constitute a broad, heterogeneous group of diseases with widely varying signs and etiologies. Diseases and disorders for which there is evidence of cysteamine efficacy may be classified by etiology, with the important caveat that the mechanism of cysteamine efficacy is not always clear and there may be unknown mechanisms of action. Important categories of cysteamine-sensitive disorders include: (i) disorders of cystine transport (cystinosis being the most well-known); (ii) disorders related to oxidative damage, including neurodegenerative and hepatic diseases; (iii) disorders related to pathological enzyme activity, including neurodegenerative diseases, hereditary mitochondrial diseases, and diseases associated with mutant MECP2 and POLG; (iv) fibrotic disorders, including fibrosis of the kidneys, liver, or lungs; (v) metabolic disorders, including metabolic syndrome X, diabetes mellitus, and the spectrum of non-alcoholic fatty liver diseases leading to non-alcoholic steatohepatitis (NASH); (vi) infectious diseases, including certain viral infections (e.g., influenza), bacterial infections (e.g., Pseudomonas aeruginos), and parasitic infections (e.g., malaria); (vii) ischemic diseases, including ischemia-reperfusion injury of the heart and other organs; (viii) disorders related to abnormal adiponectin metabolism; and (ix) cancer and the improvement of adverse effects of cancer treatment.

[0079] As used herein, the term “approximately” means ±20% of the listed values. [Brief explanation of the drawing]

[0080] [Figure 1] The chemical structure of coenzyme A is shown, which can be induced by an enzyme-catalyzed reaction (shown in Figure 11) from a dephosphocoenzyme A molecule, a 4-phosphopantotheine molecule, a pantetheine molecule, a pantothenic acid molecule, or a cysteamine molecule. [Figure 2]Two chemical structures of the disulfide of the present invention are shown. The upper chemical structure shows a mixed cysteamine disulfide molecule having cysteamine on the left and a second thiol (indicated as RS-) on the right. The lower chemical structure shows pantetheine disulfide having pantetheine on the left and a second thiol (indicated as RS-) on the right. Figures 3, 4, and 5 show exemplary mixed cysteamine disulfides. Other mixed cysteamine disulfides can be formed with the thiols listed in Figure 17, as schematically shown in Figures 18 and 21. [Figure 3] The four chemical structures of cysteamine mixed disulfides are shown. Specifically, as shown on the label, mixed cysteamine disulfides with partner thiol allyl mercaptan, L-cysteine, L-cysteine ​​ethyl ester, and N-acetylcysteine ​​are shown. [Figure 4] Two exemplary cysteamine mixed disulfide chemical structures and one exemplary N-acetylcysteamine mixed disulfide chemical structure are shown. The two cysteamine mixed disulfides are formed between cysteamine and N-acetylcysteamine, and between cysteamine and N-acetylcysteineamide. A mixed disulfide formed between N-acetylcysteamine and N-acetylcysteineamide is also shown (indicated on the label). [Figure 5] As shown on the label, two exemplary cysteamine mixed disulfide structures are shown: one formed between cysteamine and pantetheine, and another between cysteamine and glutathione. [Figure 6] The chemical structure of an exemplary cysteamine mixed disulfide formed between cysteamine and coenzyme A is shown. [Figure 7] Two chemical structures are shown. The top one is an exemplary pantetheine mixed disulfide formed between pantetheine and cysteine. The bottom one is an exemplary N-acetylcysteamine mixed disulfide formed with pantetheine. [Figure 8]The chemical structures of two exemplary mixed disulfides are shown, as indicated on the label: one is formed between pantetheine and N-acetylcysteine, and the other is formed between dithiol dihydrolipoic acid and two cysteamines (one disulfide bonded to each of the two thiols of dihydrolipoic acid). [Figure 9] The chemical structure of an exemplary pantetheine mixed disulfide formed between pantetheine and glutathione is shown. [Figure 10] The chemical structure of an exemplary 4-phosphopantetheine mixed disulfide formed between 4-phosphopantetheine and coenzyme A is shown. [Figure 11] This is a schematic diagram of a portion of the coenzyme A, pantetheine, and cysteamine metabolic pathway, including both intracellular metabolism (solid lines) and catabolic reactions occurring in the gastrointestinal tract (dotted lines). Several reactions occur at both locations (e.g., phosphatases are present in both the cytoplasm and the gastrointestinal tract). Compounds are shown in regular font, and enzymes in italics. Both compounds and enzymes have various alternative names for those shown in the diagram. This diagram is not a complete depiction of coenzyme A, pantetheine, and cysteamine metabolism, but is simply intended to convey that coenzyme A, dephosphocoenzyme A, 4-phosphopantetheine, and pantetheine can be catabolized into cysteamine (and pantothenate) in the intestines. [Figure 12]A schematic diagram of the gastrointestinal (GI) tract is shown (above). Below is a table summarizing certain anatomical and physiological parameters for each segment of the GI tract related to the in vivo production and uptake of cysteamine from the cysteamine precursor of the present invention. In particular, this table shows the anatomical sites where cysteamine formation and uptake occur, as well as the levels of physiological variables that affect the in vivo production rate of cysteamine from the cysteamine precursor (e.g., via reduction of disulfide bonds and cleavage by pantethinase) and the absorption rate of cysteamine along the GI tract (e.g., by organic cation transporters 1, 2, and 3). For example, pH affects the disulfide exchange reaction. The level of glutathione (GSH) is a proxy for the redox environment that affects the equilibrium between oxidized and reduced disulfides and thiols, including the reduction of disulfide-cysteamine precursors. Absorption surface area and transit time, along with levels of pantetheine digestive enzymes and cysteamine transporters, influence the rate of cysteamine production from pantetheine and subsequent cysteamine absorption. Other physiological variables in this figure affect the performance of certain types of formulations. For example, some types of gastric retention formulations swell to a size that prevents them from passing through the pylorus. Some pH-sensitive pharmaceutical coatings dissolve in the duodenum at around pH 5.5, pH 6, or pH 6.5, while others dissolve in the ileum at around pH 7, which is typical. Some types of colon-targeted formulations are refractory to digestion by human (or mammalian) enzymes but consist of polymers that can be broken down by enzymes produced by intestinal bacteria, thereby resulting in the release of cysteamine precursors co-formulated with the aforementioned polymers. The values ​​or ranges provided in the table are derived from literature sources and may not encompass the full range of normal human variability. Nevertheless, the degree of variability shown can, in part, explain the wide inter-individual variability in clinically observed cysteamine uptake and metabolism. [Figure 13]This table shows the classification of cysteamine precursors and some of their notable pharmacological properties. Cysteamine precursors are classified on the left (bottom) side of the table according to (i) whether they are thiols or disulfides, (ii) if they are disulfides, whether they are cysteamine-containing mixed disulfides (including cysteamine-pantetheine), pantetheine-containing mixed disulfides (excluding cysteamine-pantetheine), or contain other thiols that can be broken down to pantetheine in the gastrointestinal tract, and (iii) how many cysteamines are produced upon chemical reduction and / or enzymatic degradation (under the # symbol). "Other thiols or dithiols" means any dithiol, as well as any thiol that is not cysteamine, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine. (See Figure 17 for exemplary thiols and dithiols). While the decomposition of disulfidecysteamine precursors containing "other thiols" yields only one cysteamine, disulfidecysteamine precursors containing dithiols can yield one or two cysteamines upon decomposition, because one dithiol can bind to, for example, two cysteamines (see Table 21 for a summary of how thiols and dithiols can be combined). This table further shows, under "Steps to Produce Cysteamine," which chemical and / or enzymatic steps are required to produce cysteamine from each class of cysteamine precursors. For example, a cysteamine mixed disulfide containing cysteamine + another thiol (e.g., cysteine) requires only one step: reduction of the disulfide bond. Similarly, thiol pantetheine requires only one step: panteinase cleavage. Other cysteamine precursors require two steps. For example, the pantetheine homodimer pantethine requires panteinase cleavage following reduction of the disulfide bond. Furthermore, other cysteamine precursors require three or more steps. For example, 4-phosphopantetheine homodimers require reduction of the disulfide bond, phosphatase cleavage, and pantetheinase cleavage.Dephospho-coenzyme A and disulfides containing coenzyme A require additional steps. For some disulfide-cysteamine precursors, the number of decomposition steps to cysteamine between the two thiols produced by the reduction of the disulfide bond differs, as shown in the table. Furthermore, this table shows the classes of compounds that can be co-formulated or co-administered with cysteamine precursors to promote in vivo cysteamine formation, and which classes of accelerators are useful for each class of cysteamine precursor. For example, any disulfide-cysteamine precursor can be productively co-formulated or co-administered with a reducing agent (abbreviated as RA in the table) to promote the reduction of the disulfide bond. Cysteamine precursors that are or contain pantetheine, or any thiols that can be decomposed to pantetheine, can be productively co-formulated or co-administered with an inducer of the enzyme pantetheinase (abbreviated as PI in the table). Pantetheine disulfide can be productively co-formulated or co-administered with both reducing agents and pantetheinase inducers. Since such compounds can be productively co-formulated or administered concurrently with all classes of cysteamine precursors, cysteamine absorption enhancers (e.g., cysteamine transporter inducers such as organic cation transporters) or cysteamine catabolism inhibitors are not shown in the table. At the far right (top), this table summarizes in a few words the notable pharmacological properties of different classes of cysteamine precursors, which may be influenced by the number of degradation steps required to produce cysteamine, the yield of cysteamine, or the presence of enhancers of in vivocysteamine production. The very brief descriptions provided are not exhaustive and should not be construed as limitations. [Figure 14]This is a diagram of an exemplary pharmaceutical composition. It shows notable characteristics of the exemplary composition, including: (i) type of dosage form (e.g., tablet, capsule, powder, liquid), (ii) formulation characteristics relating to the anatomical localization of drug release (e.g., an intragastric formulation stays in the stomach; an enteric-coated formulation may be designed to release the drug in the small intestine; a colon-targeted formulation is designed to release the drug in the ileum or colon), as well as (iii) duration of drug release (immediate release: IR, or sustained-release SR), (iv) type of cysteamine precursor(s), (v) dose(s) (provided as a range), ( vi) the type of co-compounding accelerator(s) for in vivo cysteamine production, if present, (vii) the dose(s) of the accelerator compound(s) (provided as a range), (viii) recommendations for administering the composition with food(s) (e.g., applesauce or yogurt) or a meal(s) (e.g., dinner), or whether food(s) are optional ("food OK"), (ix) the site(s) of cysteamine precursor release in the gastrointestinal tract, and (vii) the site where cysteamine is produced in vivo (e.g., by reduction of disulfide bonds or pantetheinase cleavage). The compositions in Figure 13 are each limited to a single type of formulation with respect to the site and time of drug release. Such compositions (including many variants not shown in the figure) can be administered in various combinations, providing flexibility for individualizing administration. Other exemplary compositions with more active ingredients and / or more complex formulations are shown in Figures 14 and 15. [Figure 15] This figure illustrates exemplary pharmaceutical compositions having (i) one or two drug release profiles (for example, composition G includes an immediate-release component and a sustained-release component), and (ii) at least two cysteamine precursors and up to two accelerators. Recommendations for administration with or without food are provided, as well as the sites of drug release and in vivo conversion of cysteamine precursors to cysteamine. Exemplary compositions, and many other compositions not illustrated, can be combined in various ratios. [Figure 16]This figure shows exemplary multi-dose regimens in which two or more compositions are administered together or consecutively at short intervals. Notable characteristics of exemplary compositions are shown in Figures 14 and 15. Examples of compositions that provide cysteamine precursor degradation accelerators (e.g., reducing agents) but do not provide cysteamine precursors are included. Separate formulations of accelerators allow for co-administration with cysteamine precursor-containing compositions in various ratios to optimize cysteamine production or uptake in vivo. Separate formulations of accelerators further allow for control over the site and timing of accelerator release to optimize cysteamine production or uptake in vivo. [Figure 17] This is a list of exemplary thiols and dithiols that can be combined to produce thiol-type cysteamine precursors (compounds 2-6) or disulfide-type cysteamine precursors. The chemical formula, CAS (Chemical Abstracts Service) registry number, and formula molecular weight of each thiol or dithiol are shown. In some cases, the CAS number is specific to a particular enantiomer. Each thiol is numbered (leftmost column in Figure 17) to facilitate a concise reference of these thiols in Figures 18-21. [Figure 18]Figure 17 includes two tables showing how thiols and dithiols can be combined to produce two classes of disulfide cysteamine precursors, cysteamine mixed disulfides, and pantetheine disulfides. The five columns in each of the two tables, from left to right, list the following: (i) The two thiols that react to form a disulfide are indicated by numbers in the leftmost column of Figure 17 (thiols are numbered 1-29, and dithiols are numbered 30-35). For example, the notation "1+28" represents the disulfide formed by reacting thiol 1 (cysteamine) with thiol 28 (thiopronine). All disulfides in the left table contain cysteamine (compound 1) + a second thiol (any of compounds 2-35). All disulfides in the right table contain pantetheine (compound 2) + a second thiol (any of compounds 2-35). (ii) The formula molecular weight (MW) of the disulfide shown in the first column. For example, the MW of disulfide 1+28 is 238.35 daltons (the sum of the masses of the two constituent thiols minus 2 to account for the two lost protons). Note that for thiols 13 and 14 (L-cysteine ​​ethyl ester HCl and L-cysteine ​​methyl ester HCl), the mass of the salt form is used. The actual mass of free disulfide is 36.46 daltons less than the mass shown. (iii) The number of cysteamines that can be produced upon decomposition of the cysteamine precursor in vivo. Disulfides are sorted into those that produce two cysteamines listed above the horizontal thick line and those that produce one cysteamine listed below. (iv) The fraction of cysteamine precursors that can be converted to free cysteamine in vivo. For example, the fraction of disulfide 1+28 that can be converted to 238.35 daltons of cysteamine is 32.4%. Disulfides that produce one cysteamine are ranked from highest to lowest molecular weight according to the fraction of their molecular weights that can be converted to cysteamine. (v) The number of decomposition steps (chemical or enzymatic) required to obtain cysteamine from a disulfide cysteamine precursor.For disulfides above the horizontal thick line where both thiols are diced into cysteamine (or where one of the two thiols is cysteamine itself), two numbers are shown indicating the number of steps for each thiol component of the disulfide. The order of the two numbers corresponds to the order in which the two thiols are listed in the first column of the table. For disulfides where only one of the thiols is diced into cysteamine (below the horizontal thick line), only one number is shown, indicating the number of steps for the decomposition of that thiol. For example, in Disulfide Table 1B, the disulfide represented as "2+5" means pantetheine (thiol 2) disulfide bound to coenzyme A (thiol 5). The MW of this disulfide is 1,352.36. When broken down in the intestine, this disulfide produces two cysteamines. The combined weight of the two cysteamines is 154.3 daltons, which is 11.4% of the mass of the disulfide, as shown in the fourth column. The decomposition pathway from disulfide to the two cysteamines involves two steps in the case of the pantetheine moiety (step 1: reduction of the disulfide bond, step 2: cleavage by pantetheinase) and four or more steps (indicated by 4+) in the case of the coenzyme A moiety (step 1: reduction of the disulfide bond, step 2: ectonucleotide diphosphatase-catalyzed elimination of the nucleotide (other catabolic pathways are possible), step 3: dephosphorylation to pantetheine, step 4: cleavage by pantetheinase). Therefore, the numbers in the fifth column: 2 / 4+ indicate the number of decomposition steps from disulfide to cysteamine for pantetheine and coenzyme A moiety, respectively. [Figure 19] Figure 17 includes two tables showing how to combine thiols and dithiols to produce two classes of disulfide cysteamine precursors: 4-phosphopantetheine disulfide and dephosphocoenzyme A disulfide. The five columns in each of the two tables provide the same information as in Figure 18. Again, note that in the case of thiols 13 and 14 (L-cysteine ​​ethyl ester HCl and L-cysteine ​​methyl ester HCl), the mass of the salt form is used. The actual mass of the free disulfide is 36.46 daltons less than the mass shown. [Figure 20] Figure 17 includes two tables showing how thiols and dithiols can be combined to produce two classes of disulfide cysteamine precursors, coenzyme A disulfide and N-acetylcysteamine disulfide. The five columns in each of the two tables provide the same information as in Figure 18. Again, note that for thiols 13 and 14 (L-cysteine ​​ethyl ester HCl and L-cysteine ​​methyl ester HCl), the masses of the salt forms are used. The actual mass of the free disulfide is 36.46 daltons less than the mass shown. [Figure 21] This document includes two tables illustrating methods for producing disulfides that can yield two cysteamines (top table) or one cysteamine (bottom table) upon in vivo decomposition by joining a dithiol to two thiols. The numbering of thiols and dithiols is shown in Figure 17. Within each table, various possible dithiol-thiol-thiol combinations are grouped by the dithiol moiety (compounds 30-35) for brevity, and the molecular weight and cysteamine yield for each group are provided as ranges. Three exemplary dithiol-thiol-thiol combinations are shown at the bottom of each table, including the specific MW, the percentage of MW convertible to cysteamine, and the number of decomposition steps to cysteamine (see explanation of Figure 18 above). Additional details are provided in the explanatory text below the two tables. [Figure 22] This shows the initial thiol activation step used in the chemical synthesis of mixed (asymmetric) disulfides. [Figure 23]This shows one synthetic scheme used to prepare cysteamine-pantetheine disulfide (referred to as TTI-0102, where 01 refers to cysteamine, which is thiol 1 in Figure 17, and 02 refers to pantetheine, which is thiol 2 in Figure 17). The primary amine of cysteamine is first protected with tert-butyloxycarbonyl (Boc), and then the -SH group of cysteamine-Boc is activated with bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphospholinane-2-yl)disulfane (abbreviated as PDTA) in dichloromethane (DCM) in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The Boc group is then removed with acid, and the activated cysteamine is reacted with (R)-pantetheine. [Figure 24] A second synthetic scheme used to produce cysteamine-pantetheine disulfide (TTI-0102) is shown. (R)-pantetheine is activated with bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphospholinan-2-yl)disulfane (abbreviated as PDTA) in dichloromethane (DCM) in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The activated (R)-pantetheine is then reacted with cysteamine in sodium hydride (NaH) and tetrahydrofuran (THF). [Figure 25] The synthetic scheme used to produce N-acetylcysteamine-pantetheine disulfide (referred to as TTI-0602, where the numbers 6 and 2 refer to the two combined thiols, as shown by the numbering in Figure 17) is shown. N-acetylcysteamine is activated with bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphospholinane-2-yl)disulfane (PDTA) in dichloromethane (DCM) in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The activated N-acetylcysteamine is then reacted with (R)-pantetheine in triethanolamine (TEA) in DCM. [Figure 26]The synthetic scheme used to prepare N-acetylcysteine-pantetheine disulfide (referred to as TTI-1502, where numbers 15 and 2 refer to the two combined thiols, as numbered in Figure 17) is shown. N-acetylcysteine ​​is activated with bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphospholinane-2-yl)disulfane (PDTA) in dichloromethane (DCM) in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The activated N-acetylcysteine ​​is then reacted with (R)-pantetheine in sodium hydride (NaH) and tetrahydrofuran (THF). [Figure 27] This includes the nuclear magnetic resonance (NMR) spectrum of TTI-0102 obtained on a Varian INOVA 500. The inset structure of TTI-0102 is denoted by letters a-i to indicate specific bonds, and these are highlighted in the NMR spectrum. [Figure 28] This includes the nuclear magnetic resonance (NMR) spectrum of TTI-0602 obtained on a Varian INOVA 500. The inset structure of TTI-0602 is denoted by letters a-g to indicate specific bonds, and these are highlighted in the NMR spectrum. [Figure 29] This includes the nuclear magnetic resonance (NMR) spectrum of TTI-1502 obtained on a Varian INOVA 500. The inset structure of TTI-1502 is denoted by letters a-i to indicate specific bonds, and these are highlighted in the NMR spectrum. [Figure 30A] The graph includes plasma cysteamine concentration-time curves after forced oral administration of cysteamine hydrochloride (30 mg / kg, Figure 30A) or compound 2 (also known as TTI-0602) (120 mg / kg, Figure 30B) to Sprague-Dawley rats, as described in Example 10. The values ​​in both curves are the mean values ​​from three rats. The standard deviation is indicated by error bars. [Figure 30B]The graph includes plasma cysteamine concentration-time curves after forced oral administration of cysteamine hydrochloride (30 mg / kg, Figure 30A) or compound 2 (also known as TTI-0602) (120 mg / kg, Figure 30B) to Sprague-Dawley rats, as described in Example 10. The values ​​in both curves are the mean values ​​from three rats. The standard deviation is indicated by error bars. [Figure 31A] The following are included in the examples: the plasma cysteamine concentration-time curve (Figure 31A) after forced oral administration of compound 2 (also known as TTI-0602) at doses of 30 mg / kg, 60 mg / kg, or 120 mg / kg to Sprague-Dawley rats (3 rats per dose); and the plasma cysteamine, N-acetylcysteamine, and pantothenic acid concentration-time curve (Figure 31B) after forced oral administration of 120 mg / kg of compound 2 (also known as TTI-0602) to Sprague-Dawley rats, as described in Example 10. [Figure 31B] The following are included in the examples: the plasma cysteamine concentration-time curve (Figure 31A) after forced oral administration of compound 2 (also known as TTI-0602) at doses of 30 mg / kg, 60 mg / kg, or 120 mg / kg to Sprague-Dawley rats (3 rats per dose); and the plasma cysteamine, N-acetylcysteamine, and pantothenic acid concentration-time curve (Figure 31B) after forced oral administration of 120 mg / kg of compound 2 (also known as TTI-0602) to Sprague-Dawley rats, as described in Example 10. [Figure 32] As described in Example 10, the chart includes the concentrations of cysteamine (micromolar) in the liver and kidneys 10.5 hours after administration of 120 mg / kg of Compound 2 (also known as TTI-0602) to Sprague-Dawley rats by forced oral administration. [Figure 33]As described in Example 1, (i) cysteamine hydrochloride (30 mg / kg), cystamine dihydrochloride (30 mg / kg), pantethine (30 mg / kg), or compound 1 (also known as TTI-0102) (100 mg / kg) were administered orally to male Sprague-Dawley rats, resulting in the plasma cysteamine concentration-time curve. The concentrations are the mean values ​​from three rats, and the error bars indicate the standard deviation. [Figure 34A] As described in Examples 11-13, the plasma cysteamine concentration-time curves (Figure 34A) and pharmacokinetic parameters (Figure 34B) are shown after forced oral administration of compound 1 (also known as TTI-0102) at doses of 30 mg / kg, 60 mg / kg, or 100 mg / kg to male Sprague-Dawley rats. Abbreviations: Cmax = maximum cysteamine concentration; Tmax = time to reach maximum cysteamine concentration; AUC last = area under the drug concentration-time curve from 0 to 6 hours; T1 / 2 = half-life of cysteamine in plasma; MRT last = mean residence time based on 6-hour data. [Figure 34B] As described in Examples 11-13, the plasma cysteamine concentration-time curves (Figure 34A) and pharmacokinetic parameters (Figure 34B) are shown after forced oral administration of compound 1 (also known as TTI-0102) at doses of 30 mg / kg, 60 mg / kg, or 100 mg / kg to male Sprague-Dawley rats. Abbreviations: Cmax = maximum cysteamine concentration; Tmax = time to reach maximum cysteamine concentration; AUC last = area under the drug concentration-time curve from 0 to 6 hours; T1 / 2 = half-life of cysteamine in plasma; MRT last = mean residence time based on 6-hour data. [Figure 35A]The bar graphs show the concentrations of cysteamine (Figure 35A) and pantetheine (Figure 35B) in the gastrointestinal tract of male Sprague-Dawley rats 6 hours after forced oral administration of cysteamine hydrochloride (30 mg / kg) or compound 1 (also known as TTI-0102) at doses of 30 mg / kg, 60 mg / kg, or 100 mg / kg. Gastrointestinal contents obtained from the stomach, proximal small intestine, distal small intestine, and cecum / colon were analyzed as described in Examples 11-13. All samples from the four intestinal segments were reduced with TCEP. Proximal and distal small intestinal contents were also analyzed without TCEP. The numbers above each bar indicate the value for that sample. Samples are placed in the upper and lower panels to facilitate comparison of cysteamine and pantetheine levels in the same sample. [Figure 35B] The bar graphs show the concentrations of cysteamine (Figure 35A) and pantetheine (Figure 35B) in the gastrointestinal tract of male Sprague-Dawley rats 6 hours after forced oral administration of cysteamine hydrochloride (30 mg / kg) or compound 1 (also known as TTI-0102) at doses of 30 mg / kg, 60 mg / kg, or 100 mg / kg. Gastrointestinal contents obtained from the stomach, proximal small intestine, distal small intestine, and cecum / colon were analyzed as described in Examples 11-13. All samples from the four intestinal segments were reduced with TCEP. Proximal and distal small intestinal contents were also analyzed without TCEP. The numbers above each bar indicate the value for that sample. Samples are placed in the upper and lower panels to facilitate comparison of cysteamine and pantetheine levels in the same sample. [Figure 36A] This diagram shows the synthetic scheme for the hemiacylation of cystamine to produce compound 1 (cysteamine-pantetheine asymmetric disulfide). DCC is an abbreviation for the coupling reagent N,N'-dicyclohexylcarbodiimide. HOBt is an abbreviation for 1-hydroxybenzotriazole hydrate. DMF is an abbreviation for the solvent dimethylformamide. [Figure 36B]The synthesis scheme for compound 1 by thiol-disulfide exchange is shown. The illustrated reaction involving cysteamine (thiol) and pantetheine (disulfide) is one of two thiol-disulfide exchange reactions discussed in Example 14. [Figure 37] The proton nuclear magnetic resonance (1H NMR) spectrum of TTI-0102, produced by hemiacylation of cystamine (shown in Figure 36A), is shown. The structure of TTI-0102 is shown, with lowercase annotations corresponding to the peaks in the 1H NMR spectrum. This table shows the numerical values ​​of all peaks, their delta values ​​(expressed as parts per million, or ppm), and peak heights. [Figure 38] The relationship between predicted and observed proton peak heights in the 1H NMR spectrum shown in Figure 37 is presented in a table format, with protons labeled (a, b, c, d, e, f, g, h, i) as shown in Figure 37. [Modes for carrying out the invention]

[0081] The present invention features compositions and methods that enable in vivo production of cysteamine from a precursor compound (cysteamine precursor) in a controlled amount and at a controlled location in the gastrointestinal tract, as well as methods for treating cysteamine-sensitive symptoms, syndromes, and diseases. The methods and compositions of the present invention may contain any one of the compounds 1 to 3 shown below, or a pharmaceutically acceptable salt thereof. Compounds 1-3 can be administered to a subject alone, in combination with a second activator which is a cysteamine precursor, or in combination with an agent which modifies the release or reuptake of cysteamine, following the administration of a compound such as a reducing agent or a pantethinase inducer.

[0082] Cysteamine is a small, highly reactive thiol molecule (NH2-CH2-CH2-SH) found in all living organisms, from bacteria to humans. Its IUPAC name is 2-aminoethanethiol. Other common names include mercaptamine, beta-mercaptoethylamine, 2-mercaptoethylamine, decarboxycysteine, and thioethanolamine. In humans, cysteamine is produced by the enzyme pantetheinase (also known as pantothenate or vitamin B5), which cleaves pantetheine into cysteamine and pantothenic acid. Human pantetheinase is encoded by the Vanin 1 and Vanin 2 genes (abbreviated as VNN1 and VNN2) and is widely expressed, including in the gastrointestinal tract. Therefore, dietary pantetheine, found in many foods (e.g., nuts and dairy products), is cleaved in the gastrointestinal lumen to produce cysteamine and pantothenic acid, which are then absorbed. In particular, cysteamine can be transported across the gastrointestinal epithelium by organic cation transporters (OCTs), a family of transporters including organic cation transporters 1 (OCT1), OCT2, and OCT3, which have been shown to transport cysteamine within intestinal cells. Based on its ability to be converted to cysteamine in the gastrointestinal tract, pantetheine is a cysteamine precursor. Cysteamine precursors represent a class of compounds that may have advantages over cysteamine salts with respect to (i) tolerability and side effects, (ii) pharmacokinetics and administration interval, (iii) manufacturing, and (iv) product stability. More generally, administering cysteamine precursors that can generate cysteamine in vivo at various rates, and using formulation methods to deliver those precursors to selected sites in the gastrointestinal tract at selected times, may be useful in therapeutic regimens by providing much better control of cysteamine pharmacokinetics, which has been a major obstacle to the widespread use of cysteamine and other thiols to date.

[0083] Cysteamine precursor Pantetheine and its catabolic products, cysteamine and pantothenate, are intermediates in the biosynthesis of coenzyme A in plants and animals (see Figure 11 for diagrams of the relevant metabolic and catabolic pathways). Several compounds in the coenzyme A biosynthesis pathway, such as 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A, can be catabolized to pantetheine, and then to cysteamine and pantothenate, in the human gastrointestinal tract. Therefore, 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A are cysteamine precursors because they can be converted to cysteamine in the intestine. N-acetylcysteamine is also a cysteamine precursor by deacetylation by intestinal or cellular deacetylases (e.g., deacetylases that convert N-acetylcysteine ​​to cysteine ​​in vivo).

[0084] Pantethine is a dimer of two pantetheine molecules joined by a disulfide bond. In other words, pantethine is the oxidized form of pantetheine. The interconversion of pantethine to the two pantetheine molecules is not enzymatically mediated and does not require ATP. This reaction is instead primarily controlled by the redox environment in the gut. In vivo, pantetheine is dominant in the reducing environment, which tends to be dominant, especially intracellularly, but in more oxidative environments such as the stomach, the equilibrium shifts towards pantethine. A small clinical study by Wittwer (Wittwer et al., J.Exp.Med.76:4 (1985)) showed that when administered orally, a significant fraction of pantethine is chemically reduced to pantetheine in the human gastrointestinal tract, and subsequently cleaved into cysteamine and pantothenate. Therefore, pantethine is a cysteamine precursor. Pantetheine as used herein refers to the D-enantiomer.

[0085] The pantothenoyl moiety of pantetheine contains a chiral carbon. Therefore, there are two enantiomers of pantetheine, traditionally called D-pantetheine and L-pantetheine (also known as R-pantetheine and S-pantetheine). Only the D-enantiomer of pantetheine can be cleaved by pantetheinase; therefore, only the D-enantiomer is suitable as a cysteamine precursor. The two enantiomers of pantetheine can be combined in four ways (D-,D-;D-,L-;L-,D-; and L-,L-pantetheine) to form disulfide pantetheine. Only D-,D-pantetheine can be chemically reduced to two D-pantetheines and then cleaved to produce two cysteamines. Therefore, the D-,D-form of pantetheine is extremely preferred, and the term pantetheine, as used herein, refers to the D-,D-enantiomer. Pantetheine-related compounds, such as 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A, must also be in a D-stereoisomer configuration in order to produce D-pantetheine (and therefore cysteamine) upon intestinal degradation. Thus, "4-phosphopantetheine," "dephosphocoenzyme A," and "coenzyme A," as well as any analogues or derivatives thereof, refer herein to D-enantiomers. None of pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A are absorbed by intestinal cells; rather, each compound must be catabolized into the absorbed pantothenate and cysteamine (see Shibata et al., J.Nutr. 113:2107 (1983)).

[0086] Thiol or disulfide-type cysteamine precursors can also be formed using pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, or analogs or derivatives of D-stereoisomers of coenzyme A, which can be converted to the parent compound in the gastrointestinal tract (e.g., by natural enzymatic or chemical processes), and are referred to herein as “suitable analogs or derivatives.” For example, there are numerous physiological forms of coenzymes that are readily broken down into coenzyme A in the intestine (e.g., acetyl-CoA, succinyl-CoA, malonyl-CoA, etc.). Any acetylation, alkylation, phosphorylation, lipidation, or other analogues can be used as cysteamine precursors. Pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, or analogues of coenzyme A, as well as methods for producing them, are described in the literature (van Wyk et al., Chem Commun 4:398 (2007)).

[0087] Pantetheine can form disulfides with other thiols, known as pantetheine mixed disulfides, which constitute another class of cysteamine precursors. The thiols reacted with pantetheine are preferably naturally occurring thiols or unnatural thiols known to be safe in humans based on their history of human or animal use. For example, mixed disulfides can be formed by reacting pantetheine with 4-phosphopantetheine, dephospho coenzyme A, or coenzyme A, compounds present in the human body and many foods. Such mixed disulfides produce two cysteamines upon reduction and degradation in the intestines. Pantetheine linked to N-acetylcysteamine also produces two cysteamines upon reduction and degradation in the intestines. In certain embodiments, disulfide-cysteamine precursors capable of producing two cysteamines are preferred. Figures 18-21 show the cysteamine yields of different classes of disulfide-cysteamine precursors. 4-phosphopantetheine, dephosphocoenzyme A, or analogs or derivatives of coenzyme A, which can be converted to the parent compound in the gastrointestinal tract via chemical or enzymatic processes (i.e., appropriate analogs or derivatives), can also be linked to pantetheine to form a pantetheine mixed disulfide cysteamine precursor, or can be linked to other thiols.

[0088] Pantetheine mixed disulfides can also be formed by reacting pantetheine with thiols that are not themselves decomposable into cysteamines, such as L-cysteine, homocysteine, N-acetylcysteine, N-acetylcysteinamide, N-acetylcysteine ​​ethyl ester, N-acetylcysteamine, L-cysteine ​​ethyl ester hydrochloride, L-cysteine ​​methyl ester hydrochloride, thiocysteine, allyl mercaptan, furfuryl mercaptan, benzyl mercaptan, thioterpineol, 3-mercaptopyruvate, cysteinyl glycine, gamma-glutamylcysteine, gamma-glutamylcysteine ​​ethyl ester, glutathione, glutathione monoethyl ester, glutathione diethyl ester, mercaptoethylgluconamide, thiosalicylic acid, thiocysteine, thiopronine, or diethyldithiocarbamic acid. For the Chemical Abstracts Service (CAS) registry numbers, molecular formulas, and molecular weights of exemplary thiol compounds that can react with pantetheine to form pantetheine mixed disulfides, see Figure 17. Disulfides formed by pantetheine and any of thiols 6-35 (see Figure 17 for thiol numbering) yield one cysteamine upon reduction of the disulfide bond and cleavage by pantetheinase. Although these second thiols are not convertible to cysteamine in the intestine, they can nevertheless promote cysteamine production, for example by stimulating pantetheinase activity or by participating in disulfide exchange with cysteamine-containing disulfides, or they can provide therapeutic benefits that complement those offered by cysteamine, for example by acting as a reducing agent or by other mechanisms.

[0089] Dithiol compounds such as dihydrolipoic acid (DHLA), meso-2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropanesulfonic acid (DMPS), 2,3-dimercapto-1-propanol, bucillamine, or N,N′-bis(2-mercaptoethyl) isophthalamide can also react with pantetheine to form either a pantetheine mixed disulfide having one free thiol group, or a ternary compound having two disulfide bonds connecting two pantetheine molecules to a dithiol. Mixed pantetheine disulfides of the former category produce one cysteamine upon reduction of the disulfide bond and cleavage by pantetheinase, while the latter category produces two cysteamines. See Figure 21 for a table showing methods for producing useful cysteamine precursors by combining cysteamine, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine with various dithiols. Alternatively, two different thiols can be combined with a dithiol to obtain a cysteamine precursor, i.e., a compound that can ultimately be broken down to cysteamine in the gastrointestinal tract, as long as one of the thiols is cysteamine, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine. Tables 2A and 2B in Figure 21 show some of the notable properties of such cysteamine precursors, including the molecular weight and cysteamine yield range (i.e., the percentage of cysteamine precursors convertible to cysteamine in vivo), and for selected examples, the number of in vivo degradation steps from cysteamine precursor to cysteamine.

[0090] Similar to pantetheine, any of 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine, or a suitable analogue or derivative, can (i) react with itself to form a homodimeric disulfide, (ii) react with each other in various pairs to form a mixed disulfide, or (iii) react with other thiols (not convertible to cysteamine in vivo) to form a mixed disulfide. All such disulfides are cysteamine precursors. The first two categories may produce two cysteamines upon reduction and degradation in the intestines, while the third category may produce only one cysteamine.

[0091] For example, any of the thiols listed in Figure 17 can be reacted with 4-phosphopantetheine (as shown in Figure 19), dephosphocoenzyme A (Figure 19), coenzyme A (Figure 20), or N-acetylcysteamine (Figure 20) to form a mixed disulfide cysteamine precursor. Similarly, other naturally occurring chitoles can be used, as well as non-natural thiols known to be safe in humans. Figures 18–21 schematically show some of the combinations of thiols and dithiols that can react to form disulfide cysteamine precursors. The conversion of such compounds to cysteamine in the human gastrointestinal tract requires (i) reduction of the disulfide bond to produce a free thiol, (ii) degradation by intestinal enzymes (e.g., phosphatases, diphosphatases, phosphodiesterases) to produce pantetheine in the case of 4-phosphopantetheine, dephosphocoenzyme A, a disulfide containing coenzyme A, or a suitable analogue or derivative thereof, and (iii) cleavage of pantetheine by pantetheinase. N-acetylcysteamines containing disulfide must be reduced and deacetylated in the intestines, blood, or tissues.

[0092] Cysteamine itself can also be reacted with other thiols to form mixed disulfidecysteamine precursors. For example, cysteamine can be reacted with pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, or N-acetylcysteamine with analogs or derivatives of five thiols that can be broken down to the parent compound in the gastrointestinal tract, or with any of the other thiols listed in Figure 17, to form any of the disulfides in Figures 18-20. Two cysteamines can be joined to a dithiol via two disulfide bonds to produce another type of disulfidecysteamine precursor (Figure 21). Figure 8 shows the chemical structure of such a cysteamine precursor, i.e., a dihydrolipoate disulfide bonded to two cysteamines. Upon reduction of the disulfide bond, the two cysteamines are released along with dihydrolipoic acid, a potent reducing agent, which may complement the therapeutic properties of cysteamine in certain disease settings.

[0093] In summary, cysteamine precursors can be classified into three main categories: (i) cysteamine-degradable thiols, (ii) cysteamine-containing mixed disulfides including disulfides formed with dithiols, (iii) pantetheine-containing disulfides, (iii) 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A-containing disulfides, or appropriate analogues or derivatives. Each of the latter three categories may be further degraded depending on a second thiol: (a) pantetheine, or appropriate analogues or derivatives, (b) 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A, or appropriate analogues or derivatives, or (c) thiols that are not cysteamine precursors themselves (e.g., L-cysteine, homocysteine, N-acetylcysteine, N-acetylcysteinamide, N-acetylcysteine ​​ethyl ester, N-acetylcysteamine, L-cysteine ​​ethyl ester). (Glutathione hydrochloride, L-cysteine ​​methyl hydrochloride, thiocysteine, allyl mercaptan, furfuryl mercaptan, benzyl mercaptan, 3-mercaptopyruvate, thioterpineol, glutathione, cysteinyl glycine, gamma-glutamylcysteine, gamma-glutamylcysteine ​​ethyl ester, glutathione monoethyl ester, glutathione diethyl ester, mercaptoethylgluconamide, thiosalicylic acid, thiocysteine, thiopronine, or diethyldithiocarbamate). Dithiol compounds such as dihydrolipoic acid, meso-2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropanesulfonic acid (DMPS), 2,3-dimercapto-1-propanol, bucillamine, or N,N′-bis(2-mercaptoethyl)isophthalamide can also be combined with cysteamine, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A, or suitable analogs or derivatives to form disulfides.

[0094] Pharmacological properties of cysteamine precursors The temporal and spatial patterns of in vivo cysteamine production from cysteamine precursors can vary widely depending on the type of cysteamine precursor. Cysteamine precursors that require multiple chemical and enzymatic reactions to produce cysteamine will, on average, produce cysteamine later than those that require only one step. This property of cysteamine precursors can be used to design a variety of pharmaceutical compositions that vary the rate and duration of in vivo cysteamine production. Furthermore, pharmaceutical compositions can be administered in combinations and ratios that result in the desired pharmacological outcome. For example, a cysteamine mixed disulfide may be administered to provide elevated plasma cysteamine levels immediately after drug administration. The only step required to produce cysteamine from the cysteamine mixed disulfide is the reduction of the disulfide bond. Depending on the identity of the second thiol, a second cysteamine may be produced following one or more degradation steps. The second cysteamine can only be produced after the reduction of the disulfide bond and another step, and therefore is inevitably produced later than the first cysteamine, thereby extending the time during which cysteamine is produced in the intestines and absorbed into the bloodstream. Since free cysteamine bases and cysteamine salts (e.g., Cystagon® and Procysbi®) have very short half-lives, this extension of in vivo cysteamine production from cysteamine precursors represents a significant advance over current therapies.

[0095] One approach involves a pantetheinase cleavage step to produce a second cysteamine, where the second thiol is pantetheine (i.e., cysteamine-pantetheine disulfide). Since pantetheinase is generally located on the surface of intestinal cells, it is always in contact with some of the intestinal contents, thereby extending the period of cysteamine production. This combination of early and late cysteamine production from a single disulfide molecule offers several advantages: (i) cysteamine becomes available upon reduction of the disulfide bond, providing an early therapeutic benefit; (ii) pantetheine cleavage occurs over time (pantetheinase is expressed at varying levels throughout the gastrointestinal tract), extending the duration of the therapeutic effect; (iii) the temporally and spatially extended cysteamine production via both bond reduction and pantetheine cleavage reduces high peak cysteamine concentrations strongly associated with side effects; and (iv) avoids saturation of pantetheinase or cysteamine uptake mechanisms such as OCT transport. In other words, long-term elevated blood cysteamine levels offer patients both more effective drug therapies and less toxic, more convenient dosage forms.

[0096] Alternatively, if the second thiol is L-cysteine ​​(i.e., cysteamine-L-cysteine ​​disulfide), only one cysteamine is produced upon reduction of the disulfide, and there is no prolonged cysteamine production. However, as described below, cysteamine-L-cysteine ​​disulfide can be formulated for release in substantially any part of the gastrointestinal tract, including the ileum or colon, where a cysteamine precursor capable of rapid cysteamine release may be useful. Furthermore, cysteine ​​has also been shown to promote pantethinase activity and have beneficial effects in several disease models. Therefore, cysteamine-L-cysteine ​​disulfide may be a useful complement to another cysteamine precursor or may be useful in the treatment of diseases that respond to both cysteamine and cysteine.

[0097] Disulfides containing thiols that require two or more catabolic reactions to produce cysteamine, such as 4-phosphopantetheine, dephospho-coenzyme A, or coenzyme A, or suitable analogues or derivatives thereof, are more efficiently broken down in the small intestine, where they are exposed to digestive enzymes present in pancreatic juice than in the stomach or large intestine. Disulfides produced by reacting two such thiols with each other or with a thiol other than cysteamine begin at a later time point, producing cysteamine over a longer period than, for example, cysteamine-L-cysteine ​​disulfide. On average, 4-phosphopantetheine, dephospho-coenzyme A, or coenzyme A, or suitable analogues produce cysteamine more slowly than pantetheine, and similarly for disulfides containing these compounds.

[0098] Cysteamine precursors such as pantetheine, compounds that can be broken down into pantetheine in the intestines, and disulfides containing any of these compounds all produce pantothenate along with cysteamine when cleaved by pantetheinase. Pantothenate, or vitamin B5, is a water-soluble compound that is present in food and synthesized by intestinal bacteria. When pantothenate is administered in large doses, excess amounts are excreted in the urine. A review of pantothenate by the Panel on Folate, Other B Vitamins, and Choline of the US Institute of Medicine Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (National Academies Press (US), 1998) states that "there have been no reports of adverse effects of oral pantothenate in humans or animals."

[0099] Mixture of cysteamine precursors The methods and compositions of the present invention may include mixtures of cysteamine precursors to utilize their different pharmacological properties. In particular, individualized improvement of cysteamine plasma levels (or personalization to a given patient's needs) can be achieved by using mixtures of cysteamine precursors. For example, the above-mentioned cysteamine-pantetheine mixed disulfide fixes the ratio of cysteamine to pantetheine at 1:1. However, cysteamine is rapidly absorbed and removed from the body (elimination half-life: approximately 25 minutes), resulting in a sharp peak in blood levels, while pantetheine provides cysteamine over several hours (via pantetheinase cleavage). Therefore, because cysteamine production from pantetheine spreads over a long period, a dose of cysteamine-pantetheine mixed disulfide that yields therapeutic cysteamine levels early (from cysteamine released upon reduction of the disulfide bond) may later yield levels below therapeutic cysteamine levels. Thus, a 1:1 ratio of cysteamine:pantetheine may not be ideal for a particular patient or purpose. Adding more pantetheine to the dosage form maintains blood cysteamine within the therapeutic range for a longer period. To increase the ratio of pantetheine to cysteamine, either thiolpantetheine, disulfidepantethine, or another pantetheine-containing disulfide can be co-compounded or administered concurrently with, for example, a cysteamine-pantetheine mixed disulfide to achieve blood cysteamine levels within the therapeutic range for a longer period. By adjusting the ratio of the two cysteamine precursors, desired pharmacokinetic parameters, such as maximizing the area under the cysteamine concentration-time curve (AUC), minimizing the peak concentration (Cmax) of cysteamine, maximizing the trough concentration (Cmin), or maintaining cysteamine blood levels above a threshold, or any combination of such parameters, can be achieved.

[0100] Cysteamine precursors such as 4-phosphopantetheine, dephospho-coenzyme A, or coenzyme A, and the disulfides formed from these three compounds, require more catabolic steps to produce cysteamine than pantetheine. Therefore, the rate of cysteamine production from these precursors is, on average, slower and longer-lasting than that from pantetheine or certain pantetheine disulfides. Thus, the co-administration or co-combination of 4-phosphopantetheine, dephospho-coenzyme A, or coenzyme A, or their disulfides with cysteamine-pantetheine, and optionally pantetheine or pantethine, provides another method for controlling cysteamine pharmacokinetics by selecting an appropriate cysteamine precursor. In particular, the use of such cysteamine precursors can be used to further extend the time over which cysteamine is produced in the gastrointestinal tract.

[0101] 4-Phosphopantethine, dephosphocoenzyme A, and disulfide containing coenzyme A The formal biosynthetic pathway for coenzyme A, schematically shown in Figure 11, requires five steps catalyzed by four enzymes (CoA synthase catalyzes the last two steps). The initial step of phosphorylation of pantothenate by pantothenate kinase controls the flow through the pathway. Until recently, it was thought that none of the intermediates in the coenzyme A synthesis (or catabolism) pathway were efficiently absorbed in the gastrointestinal tract. Rather, only the catabolic products of pantetheine (pantothenate and cysteamine) are absorbed in the intestines. Two important consequences of our understanding of the coenzyme A pathway for cysteamine precursor therapy are that (i) cysteamine precursors must be broken down into cysteamine in the intestines and then absorbed and transported to the site of therapeutic effect (e.g., liver, central nervous system), and (ii) cellular coenzyme A synthesis necessarily begins with pantothenate (since other metabolic intermediates do not cross the cell membrane).

[0102] However, 4-phosphopantetheine efficiently crosses the cell membrane (Srinivasan et al., Nature Chemical Biology 11:784 (2015)). This observation is significant for the design and use of the cysteamine precursors described herein for treating a variety of diseases and disorders. Firstly, it enables therapeutic approaches involving in-situ cysteamine production in multiple tissues and organs, including diseased tissue (as opposed to the intestine alone). Secondly, it enables cellular delivery of the coenzyme A precursor (4-phosphopantetheine) downstream of an initial synthesis step catalyzed by pantothenate kinase, which can be used to treat pantothenate kinase-deficient subjects. Methods for using cysteamine precursors to treat these two categories of diseases are described below, illustrated with several examples.

[0103] In one approach, since all of these organs (and others) contain pantethinase expressed from either the VNN1 or VNN2 gene, diseases of the kidneys, liver, lungs, and connective tissue, as well as infectious diseases, can be effectively treated. This method involves (i) administering a cysteamine precursor that can be broken down in the intestines to the patient to produce one or two molecules of 4-phosphopantetheine, some of which can be (ii) absorbed by intestinal cells and enter the bloodstream (4-phosphopantetheine is relatively stable), then (iii) pass through the diseased organ via circulation, and (iv) broken down by phosphatases and pantethinases to produce cysteamine at the site of the disease.

[0104] The advantages of this treatment method include (i) higher cysteamine concentrations at the site of the disease that can be achieved using cysteamine absorbed from the intestines per equivalent dose, (ii) lower plasma cysteamine concentrations resulting in lower toxicity (4-phosphopantetheine is a circulating delivery vehicle), (iii) a longer blood half-life than cysteamine (approximately 25 minutes for cysteamine compared to more than 3 hours for 4-phosphopantetheine), which allows for longer dosing intervals and thereby improves patient convenience, and (iv) the ability to selectively target cysteamine to disease tissues where panteteinase overexpression is pathogenic, including metabolic diseases such as NASH (Sato W. et al., Hepatol Res. 34:256 (2006)) and certain inflammatory diseases (Naquet P. et al., Biochem Soc Trans. 42:1094 (2014)). Since inflammation is often present at the site of infection, selective cysteamine production at the site of infection is possible, and cysteamine is useful in environments where it has antibacterial, antiviral, or antiparasitic activity. Therefore, 4′-phosphopantetheine can be absorbed in the intestines, circulate in the bloodstream, and then broken down to cysteamine in organs or diseased tissues expressing pantetheinase, either constitutively, as in the kidneys, or as an active disease presentation, as in inflammation.

[0105] 4-Phosphopantethine - produces disulfide in cases of kidney disease. As mentioned above, pantetainase (encoded by both the VNN1 and VNN2 genes) is highly expressed in the kidneys. Therefore, some circulating 4-phosphopantetheine is broken down in the kidneys to produce cysteamine. The advantages of kidney-specific cysteamine production include higher tissue levels than those achieved through cysteamine absorption by the gastrointestinal tract, and fewer side effects associated with elevated blood levels of cysteamine (e.g., foul-smelling respiration and sweating, nausea, vomiting, loss of appetite, and stomach pain). Renal diseases responsive to cysteamine therapy include fibrous diseases (e.g., glomerulonephritis), as well as metabolic diseases including nephrotic cystinosis (renal failure is a major complication that can be delayed by cysteamine therapy for up to 10 years).

[0106] Cystinuria is another hereditary kidney disorder associated with recurrent kidney stones (nephrolithiasis). On average, adult patients require surgical intervention every three years due to pain, infection, or other complications associated with kidney stones, and the average patient has undergone seven surgical interventions for nephrolithiasis by middle age. Patients with cystinuria are at high risk of kidney loss and require nephrectomy. A small but significant proportion of cases (1-3%) develop end-stage renal disease and require treatment with dialysis or kidney transplantation.

[0107] Cystinuria is caused by a mutation in one of two genes (SLC3A1 and SLC7A9) that encode the low-affinity cystine transporter rBAT (heterodimer). Disease transmission is autosomal recessive, meaning that individuals who inherit two deletion copies of either gene develop cystinuria.

[0108] In healthy individuals, only 0.4% of cystine filtered through the glomeruli is ultimately excreted in the urine. The remaining 99.6% is reabsorbed into the proximal tubule by rBAT (and to a lesser extent by another transporter). In cases of rBAT deficiency, cystine accumulates in the renal pelvis, resulting in high concentrations of cystine remaining in the urine. Cystine can precipitate as stones, potentially causing ureteral obstruction and severe pain. Kidney stones also increase the risk of infection. (Not all patients with cystinuria develop stones, and the disease spectrum is quite broad).

[0109] Initial treatment for patients with cystinuria who develop stones is dietary therapy, including drinking up to 5 liters of fluids per day and alkalizing the urine to approximately pH 7.5, which increases the solubility of cystine. Second-line therapy is the administration of thiol compounds that can form a mixed disulfide with cysteine. The mixed disulfide remains dissolved in the urine because it is more soluble than cystine. Thiols of penicillamine and thiopronine have been used in this way, but are not well tolerated by most patients. Alpha-mercaptopropionylglycine is also approved by the US FDA for cystinuria, but is not tolerated by about one-third of patients.

[0110] Orally administered cysteamine precursors, which are broken down to 4-phosphopantetheine in the intestines, then absorbed, enter circulation, and ultimately broken down to pantetheine, and then to cysteamine by pantetheinase in the kidneys, are a useful class of therapeutic compounds for cystinuria. Cysteamine readily forms a mixed disulfide with cysteine ​​via disulfide exchange with cystine, and the cysteamine-cysteine ​​disulfide is more soluble than cystine in aqueous solutions (e.g., urine). This therapeutic approach requires a lower dose of cysteamine precursor than is needed for the cysteamine formed in the intestines and absorbed from there (only a small portion of which reaches the kidneys), as it involves the formation of cysteamine in the kidneys.

[0111] Other kidney diseases suitable for cysteamine therapy, including oxidative damage and fibrous diseases associated with genetic disorders, including those caused by mutations that change arginine codons to cysteine ​​codons, can be treated using a similar approach. Renal blood supply is a major part of cardiac output and ensures that a significant portion of absorbed 4-phosphopantethene is delivered to the kidneys.

[0112] More generally, cysteamine precursors that can be broken down to 4-phosphopantetheine (including 4-phosphopantetheine disulfide) are useful for delivering therapeutic doses of cysteamine to all organs that express significant levels of phosphatase and pantetheinase. For example, they can be used to treat lung diseases associated with oxidative damage.

[0113] Useful cysteamine precursors for these therapeutic methods include disulfides containing coenzyme A, dephosphocoenzyme A, and 4′-phosphopantetheine, each of which can be broken down to 4′-phosphopantetheine in the gastrointestinal tract by reduction of the disulfide bond (in the case of disulfides containing 4′-phosphopantetheine) or by enzymatic degradation following reduction of the disulfide bond (in the case of disulfides containing coenzyme A and dephosphocoenzyme A). In some embodiments, cysteamine precursors providing two molecules of 4′-phosphopantetheine are preferred over those providing one. For example, 4′-phosphopantetheine-dephosphocoenzyme A mixed disulfide, or homodimeric 4′-phosphopantetheine disulfide, can deliver more in-situ cysteamine-producing capacity than cysteine-4-phosphopantetheine mixed disulfide. Another useful class of cysteamine precursors includes dithiols bonded to one or two thiols that can be broken down to 4′-phosphopantetheine. For example, dihydrolipoic acid can be linked to one or two molecules of 4′-phosphopantetheine via a disulfide bond.

[0114] More generally, any disulfide consisting of 4′-phosphopantetheine, dephosphocoenzyme A, or coenzyme A and another thiol can be a source of 4′-phosphopantetheine after reduction of the disulfide bond and (in the case of dephosphocoenzyme A or coenzyme A) partial degradation in the gastrointestinal tract. After being transported through the gastrointestinal epithelium and reaching circulation, 4′-phosphopantetheine can be broken down to pantetheine by serum phosphatases (however this is a slow reaction), and then broken down in the blood to cysteamine and pantothenate by panteinase (a fast reaction), or 4′-phosphopantetheine can be broken down upon contact with tissues expressing phosphatases and panteinase. Phosphatases are (collectively) widely expressed, including, for example, acid phosphatases encoded by the ACP1, ACP2, ACP5, and ACPT genes, as well as alkaline phosphatases encoded by the ALPI, ALPL, ALPP, and ALPPL2 genes. Tissues that express panteteinase encoded by VNN1 include the liver, kidneys, heart, and gastrointestinal tract, while panteteinase encoded by VNN2 is expressed in the kidneys, bladder, pancreas, spleen, lungs, hematopoietic system (e.g., bone marrow, lymph nodes, tonsils), connective tissue (smooth muscle, adipose tissue), and to a lower degree in the thyroid gland, adrenal gland, heart, and reproductive organs (testes, ovaries, fallopian tubes, endometrium). Although the VNN3 gene is described as a pseudogene, several reports describe different VNN3 expressions that suggest a functional role. VNN3 is widely expressed. Data on the expression of vanillin family genes in tissues and cell lines can be found in public databases such as Protein Atlas (www.proteinatlas.org) and in several publications (e.g., Jansen, PAM et al. Expression of the Vanin Gene Family in Normal and Inflamed Human Skin: Induction by Proinflammatory Cytokines. J. Investigative Dermatology 129:2167-2174, 2009).

[0115] Pantothenate kinase-associated neurodegeneration (PKAN) A second therapeutic approach that may utilize disulfide cysteamine precursors to deliver 4-phosphopantetheine is exemplified by diseases known as pantothenate kinase-associated neurodegeneration (PKAN). Cysteamines have preclinical and clinical evidence of therapeutic efficacy in several neurodegenerative diseases, including Parkinson's disease, Huntington's disease, and neurodegeneration due to cerebral iron accumulation (NBIA). NBIA refers to a group of rare, clinically heterogeneous diseases variably associated with progressive extrapyramidal signs, delayed motor development, and cognitive decline, among other symptoms. Age of onset ranges from infancy to late adulthood. The appearance of symptoms, as well as the rate of progression, varies considerably. Consequently, diagnosis is usually suggested by the observation of abnormal iron accumulation in the basal ganglia on MRI scans of the brain. Cerebellar atrophy may also be present. NBIA is associated with mutations in one of ten genes: PANK2, PLA2G6, C19orf12, FA2H, ATP13A2, WDR45, COASY, FTL, CP, and DCAF17. Except for mutations in the WDR45 gene located on the X chromosome, NBIA is transmitted as an autosomal recessive disorder.

[0116] The most common type of NBIA (30–50% of all cases) is pantothenate kinase-associated neurodegeneration (PKAN), caused by mutations in the gene encoding pantothenate kinase 2 (PANK2). Mitochondrial-localized pantothenate kinase 2 phosphorylates pantothenate to produce 4-phosphopantothenate, which is then converted to 4-phosphopantothenoylcysteine ​​and subsequently decarboxylated to 4-phosphopantetheine (see Figure 11). Providing a source of 4′-phosphopantetheine, a downstream metabolite of the PANK2 catalytic step, overcomes the requirements of a functional PANK2 enzyme. Both coenzyme A and dephosphocoenzyme A can be degraded to 4′-phosphopantetheine in the gastrointestinal tract. Therefore, 4′-phosphopantetheine, dephosphocoenzyme A, or any disulfide consisting of coenzyme A and another thiol can complement PANK2 deficiency.

[0117] In certain embodiments, 4′-phosphopantetheine, dephospho-coenzyme A, or a disulfide containing coenzyme A can be administered to patients suffering from PANK2 deficiency to improve disease symptoms. Specifically, the disulfides are shown in Figure 19 (Tables 1C and 1D), Figure 20 (Table 1E), and Figure 21 (a subset of compounds containing at least one 4′-phosphopantetheine, one dephospho-coenzyme A, or one coenzyme A; thiols 3, 4, and 5, respectively, in the nomenclature of the figures).

[0118] The disulfide-cysteamine precursors of this application are particularly suitable for carrying out the therapeutic methods outlined above. Disulfides provide an effective method for delivering 4′-phosphopantetheine (and ultimately cysteamine) because (i) disulfides are stable in air (i.e., stable to oxygen) and therefore easier to formulate and store and more stable for longer periods than thiols; (ii) the thiol group is protected until the disulfide is reduced in the small intestine near the absorption site; and (iii) a second thiol having additional or complementary therapeutic properties can be delivered simultaneously. For example, in some embodiments, cysteamine-4-phosphopantetheine mixed disulfide, cysteamine-dephosphocoenzyme A mixed disulfide, and cysteamine-coenzyme A mixed disulfide are useful therapeutic compounds.

[0119] N-acetylcysteamine disulfide (compound 3) In certain embodiments, the cysteamine precursor is compound 3 or a pharmaceutically acceptable salt thereof. The homodimer of the two N-acetylcysteamines is an efficient delivery vehicle of cysteamine that can be used in two ways: administered as a monotherapy or in combination with one or more other cysteamine precursors. In either case, the goal is to provide sustained serum N-acetylcysteamine and cysteamine levels within the therapeutic range (e.g., greater than 5 micromoles but less than 75 micromoles in plasma, or greater than 10 micromoles but less than 65 micromoles) for as long as possible.

[0120] In embodiments in which compound 3 is administered as a monotherapy agent, it is preferably formulated in a manner that provides at least two release profiles: an early-release profile and a late-release profile. The early-release formulation (also known as immediate-release) begins releasing compound 3 within 10 minutes after oral administration. The late-release formulation begins releasing a substantial amount of compound 3 about 2–4 hours later. The two formulations can be mixed so that they can be taken together in a single dosage form. The ratio of the dose of compound 3 formulated for early-release to the dose formulated for late-release is at least 1:2 and can range up to 1:8 (e.g., 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8). In one embodiment, both the early-release and late-release dose components are formulated as microbeads. Microbeads with the two release profiles can be manufactured separately and then mixed together in the desired ratio to produce a dosage form (e.g., a sachet). This approach facilitates the manufacture of doses with different ratios of early-to-late-release microbeads. By using different ratios of two types of microbeads, treatment can be personalized for each patient.

[0121] In some embodiments, compound 3 is formulated with three release profiles: early, mid, and late. The early-release component begins releasing compound 3 within 10 minutes of oral administration, the mid-release component begins releasing a significant amount of compound 3 approximately 2–4 hours after ingestion, and the late-release formulation begins releasing approximately 3–6 hours after ingestion. The three release components can be mixed so that they can be taken together in a single dosage form. The ratio of compound 3 in the three dose components (early:mid:late) is at least 1:2:2. The compound 3 in the mid and late-release components may independently vary between 2 and 8 times the amount of the early-release component, but the late-release component is at least equal to the mid-release component (e.g., 1:2:8, 1:4:6, 1:4:4, 1:5:5, 1:6:8, etc.). In one embodiment, the early, mid, and late-release dose components can all be formulated as microbeads, manufactured separately, and then mixed together in a desired ratio (e.g., a ratio customized to the physiology of the gastrointestinal and hepatic regions) to produce a dosage form (e.g., a sachet).

[0122] In certain embodiments, the late-dose component, or both the mid- and late-dose components, are formulated for prolonged retention in the stomach (gastric retention formulation). In other embodiments, the late-dose component, or both the mid- and late-dose components, are formulated for sustained release. In certain embodiments, the two- or three-component formulation is taken with a meal, preferably containing at least 500 calories, more preferably at least 700 calories. Preferably, the meal is nutritionally complex (e.g., containing several types of natural foods) and at least 25% of the calorie content comes from fat.

[0123] In these embodiments in which compound 3 is administered co-administered with at least one additional cysteamine precursor, it is formulated to provide a release profile that complements the release profile of at least one other cysteamine precursor, so that the cysteamine precursors together provide a therapeutically ranged plasma cysteamine concentration for as long as possible. In preferred embodiments, compound 3 provides cysteamine in the first 1–3 hours after administration, and at least one additional cysteamine precursor provides cysteamine for 3–6, 3–8, 4–10, or 3–12 hours, for example, with a 12-hour dosing interval. In such embodiments, compound 3 may be formulated for immediate release. In particular embodiments, the at least one additional cysteamine precursor administered co-administered with compound 3 is compound 1 or a pharmaceutically acceptable salt thereof.

[0124] Accelerator for cysteamine production from cysteamine precursors The methods and compositions of the present invention can utilize cysteamine production promoters. Additional flexibility in controlling blood levels of cysteamine can be achieved by combining cysteamine precursors with promoters of the steps necessary for chemically and enzymatically breaking down the cysteamine precursors into cysteamine in the intestines, for cysteamine absorption into the bloodstream, and for preventing rapid catabolism of cysteamine in the intestines, blood, or tissues. Promoters specific to each of these steps exist. Thus, any of the cysteamine precursors described herein can optionally be co-administered, concurrently, or sequentially with agents that promote cysteamine production or intestinal uptake, or slow cysteamine breakdown.

[0125] The first step in converting disulfide-cysteamine precursors to cysteamine is the reduction of the disulfide to produce two thiols. The redox environment in the gastrointestinal tract may not contain sufficient reducing equivalents to quantitatively reduce the cysteamine precursors to their respective thiols, thereby limiting cysteamine production. For example, the concentrations of reducing agents glutathione and cysteine ​​in gastric juice are very low or undetectable (Nalini et al., Biol Int. 32:449 (1994)). Furthermore, small clinical studies on high doses of pantetheine have shown that much of the pantetheine is excreted unchanged in the stool, clearly reflecting incomplete reduction of the disulfide bond (see Wittwer et al., J. Exp. Med. 76:4 (1985)). To address this potential limitation, reducing agents can be administered co-administered or concomitantly combined with the disulfide-cysteamine precursor, or administered before or after the cysteamine precursor, thereby making them available at the required time and place. A reducing agent may promote the reduction of the disulfide bond, thereby freeing two thiols, or it may promote a thiol-disulfide exchange reaction in which thiol (A) and disulfide (BC) react to produce a new disulfide (AB or AC) and thiol (B or C), thereby releasing one of the thiols in the original disulfide (e.g., cysteamine, pantetheine, or a compound that can be broken down into cysteamine).

[0126] Various reducing agents can be used to promote the reduction of disulfides or thiol-disulfide exchange in the gastrointestinal tract. Reducing agents can directly reduce disulfide-cysteamine precursors, or sequentially reduce disulfide-cysteamine precursors, or reduce other disulfides, such as glutathione disulfide, that are involved in thiol-disulfide exchange. In some embodiments, physiological compounds with reducing ability (i.e., substances normally found in the body) or food-derived compounds can be used to promote the reduction of disulfide-cysteamine precursors or to promote the thiol-disulfide exchange reaction. Physiological reducing agents such as thiol glutathione or cysteine ​​(both present in the small intestine as a result of bile and intestinal cell secretion) may be used, as well as other compounds that are normally present in the body and in food, such as ascorbic acid (vitamin C), tocopherol (vitamin E), or dithiol dihydrolipoic acid, which are potent reducing agents. Other widely available reducing agents can also be used, including thiols such as N-acetylcysteine ​​and non-thiols such as nicotinamide adenine dinucleotide (NADH), as listed in Figure 17. Preferred reducing agents are those known to be safe at doses required to bring about a change in the local gastrointestinal tract redox environment. Up to several grams of reducing agent may be required per administration period, for example, 0.5 to 5 grams. Disulfide cysteamine precursors that can benefit from the co-administration of reducing agents are shown in Figure 13. In particular, compounds 1 to 3 can benefit from the co-administration of one or more reducing agents or from an appropriate number of subsequent administrations, as described herein. Two or more reducing agents may be combined. Preferably, the reducing agents have a molecular weight of less than 300 daltons.

[0127] Adults produce 400 to 1,000 milliliters (mL) or more of bile daily, with an estimated average of 750 mL (Boyer, Compr. Physiol. 3:32 (2013)). Bile is produced in the liver throughout the day. Some is stored in the gallbladder, but the remainder provides a steady, slow flow of bile even in fasting conditions (bile performs excretory functions and aids in digestion and fat absorption). Diet stimulates the duodenal secretion of the peptide hormones secretin and cholecystokinin, which in turn stimulate bile production and gallbladder contraction, respectively. The concentration of thiols in bile is approximately 4 mM, and it mainly consists of glutathione, but also contains gamma-glutamylcysteine, cysteinylglycine, and cysteine ​​(Eberle et al., J Biol. Chem. 256:2115 (1981), Abbott and Meister, J. Biol. Chem 258:6193 (1984)).

[0128] Cysteine, and to a lower degree, glutathione, are also secreted into the lumen of the gastrointestinal tract by intestinal cells to regulate intraluminal redox capacity. Thiol concentrations in intestinal fluid from the rat jejunum have been measured directly, independently of contributions from bile. In fasted rats, the range is 60–200 μM, and in feeding animals, it is 120–300 μM (Hagen et al., Am.J.Physiol.259:G524 (1990), Dahm and Jones, Am.J.Physiol.267:G292 (1994)). Furthermore, unlike bile secretion, the maintenance of luminal thiol levels is a dynamic process, thereby increasing intestinal levels of oxidizing molecules (e.g., disulfide cysteamine precursors) can be counteracted, at least to some extent, by increased cysteine ​​production by intestinal cells (Dahm and Jones, J.Nutr.130:2739 (2000)). The human small intestine secretes approximately 1.8 liters of fluid per day, and the colon secretes approximately 0.2 liters, for a total of about 2 liters. The concentration of thiols (mainly cysteine) in the secretions varies depending on the region of the gastrointestinal tract, the oxidation-reduction capacity of the lumen, and the diet.

[0129] The total concentration of gastrointestinal thiols (both from bile and intestinal cells) influences the rate and extent of disulfide bond reduction and / or thiol-disulfide exchange required to convert cysteamine precursors to thiols, which is an essential first step in the breakdown to cysteamine. The amount of reducing equivalents available in the upper gastrointestinal tract after a meal can be estimated by making several assumptions. For example, assuming that (i) 200 mL of bile is secreted in the first hour after a large meal, and another 100 mL 2-3 hours later, and (ii) the thiol concentration in the bile is 4 mM, then the milliequivalent of thiol reducing power in the bile would be 0.3 L × 0.004 mol / L = 0.0012 moles of thiol (1.2 mmol). Furthermore, we assume that intestinal cells in the small intestine secrete an additional 400 milliliters during the 4 hours following a meal, bringing an additional 0.4 liters × 0.0002 moles / liter = 80 micromoles of luminal thiols at a thiol concentration of 200 μM. Combined with bile thiols, a total of approximately 1.28 millimoles is available to reduce food disulfides and maintain the intestinal redox potential. This is a normal level of thiols in the small intestine several hours after a meal, not an estimate of the upper limit of thiol secretion (which can be quite high).

[0130] A 0.5-gram dose of cysteamine-(R)-pantetheine disulfide (MW: 353.52 g / L) contains approximately 1.41 mmol of disulfide bonds and, therefore, can, in principle, be converted to thiols by endogenous levels of thiols (disregarding the need for lumen thiols for other physiological purposes) (either through reduction of disulfide bonds or thiol-disulfide exchange).

[0131] More generally, a dose of cysteamine precursor in excess of 1.25 mmol can benefit from the co-administration of an exogenous reducing agent. Many natural products commonly found in food can provide reducing power to promote the reduction of cysteamine precursors or thiol-disulfide exchange, including the major endogenous intestinal thiols cysteine ​​or glutathione. Cysteine ​​or glutathione analogs such as N-acetylcysteine, N-acetylcysteine ​​ethyl ester, or N-acetylcysteinamide can also be used. Ascorbic acid is another agent that can reduce disulfide bonds (Giustarini et al. Nitric Oxide 19:252 (2008)). For example, the dose of ascorbic acid required to provide the same reducing power as 1 gram of the disulfide cysteamine precursor cysteamine-(R)-pantetheine disulfide can be calculated as follows:

[0132] The molecular weight of ascorbic acid (176.12 g / mol) is approximately half that of cysteamine-(R)-pantetheine disulfide (353.52 g / mol), also known as compound 1. Therefore, 1 gram of ascorbic acid has an equimolar reducing equivalent to the number of disulfide bonds in 2 grams of compound 1. The U.S. Food and Nutrition Board recommends a daily intake of vitamin C of only 75 milligrams for women and 90 milligrams for men, but many people take much higher doses, including doses of 1 gram or more per day, with significantly fewer or no adverse effects.

[0133] A similar line of reasoning leads to the amount of other reducing agents needed to match the molar dose of compound 1. For example, cysteine ​​(molecular weight: 121.15 daltons) is approximately 34% of the mass of compound 1, N-acetylcysteine ​​(molecular weight: 163.195 daltons) is approximately 46% of the mass of compound 1, alpha-lipoic acid (molecular weight: 208.34 daltons) is approximately 59% of the mass of compound 1, and so on. Alpha-lipoic acid and N-acetylcysteine ​​are widely available in 600 and 1,000 mg capsules and tablets, respectively, including sustained-release formulations that are unregulated, in vitamin stores and online. Similar calculations can be performed for other disulfide cysteamine precursors based on their molecular weights.

[0134] Bile is the primary source of thiols, and because bile is continuously diluted along the length of the small and large intestines, the extra reducing power for reducing cysteamine precursors may be more useful in the jejunum, ileum, or colon than in the duodenum. Therefore, formulations designed to release reducing agents in the distal small and / or large intestines may be particularly useful supplements for disulfide cysteamine precursors. Sustained-release formulations of ascorbic acid and other reducing agents are commercially available. Alternatively, ascorbic acid can be co-compounded with cysteamine precursors to ensure simultaneous delivery of both drugs.

[0135] The electrochemical capabilities (reducing power) associated with different biological reducing agents are known and provide guidance for their use, but the ability of such agents to reduce different disulfide cysteamine precursors is best determined empirically.

[0136] The reaction rate of thiol-disulfide exchange reactions is strongly affected by pH (i.e., slower at lower pH). Such exchange reactions are an alternative mechanism to the reduction of disulfide bonds for the liberation of cysteamine from cysteamine mixed disulfides or pantetheine from pantetheine disulfides. To increase the reaction rate of thiol-disulfide exchange reactions, basic compounds may be administered or compounded with disulfide-cysteamine precursors, thereby making them available at the required time and place. Physiological compounds such as bicarbonates are present in high concentrations in pancreatic juice and can be used to regulate local gastrointestinal pH.

[0137] A crucial step in converting many cysteamine precursors to cysteamine is the enzyme pantetheinase, encoded by the human VNN1 and VNN2 genes. Pantetheine and pantetheine disulfide (including pantethine) require this enzyme to produce cysteamine. Pantetheinase is also ultimately required for cysteamine production from compounds convertible to pantetheine in the gastrointestinal tract, such as 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, and appropriate analogues and derivatives. Normal levels of pantetheinase in the gastrointestinal tract may not be sufficient to quantitatively cleave all pantetheine molecules provided by pharmacological doses. To address this limitation, compounds that induce pantetheinase expression can be co-administered or concomitantly combined with cysteamine precursors containing pantetheine or pantetheine-convertible compounds to increase the amount of pantetheinase in the gastrointestinal tract at the required time and place (i.e., when and where pantetheine is present). Drugs that induce pantethinase expression include both physiological substances, such as certain food components, and FDA-approved drugs. Physiological inducers of VNN1 include various substances that act via the transcription factor NF-E2-related factor-2 (more commonly acronymized Nrf2), peroxisome proliferator-activated receptor alpha (PPAR alpha), and peroxisome proliferator-activated receptor gamma (PPAR gamma).

[0138] Factors that induce Nrf2 activation (via translocation to the nucleus) include both natural products and certain drugs. For example, sulforaphane, an isothiocyanate found in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, and cauliflower, induces VNN1 expression via Nrf2. Sulforaphane-rich foods (e.g., Brussels sprouts) can be used to induce pantethinase expression, or sulforaphane can be administered as a pure substance in a pharmaceutical composition. Certain food-derived thiols, including S-allyl cysteine ​​and diallyl trisulfide (both found in onions, garlic, and garlic extracts), also induce Nrf2 and can be included in a diet administered with cysteamine precursors. Alternatively, either compound can be obtained in its pure form and administered in a pharmaceutical composition. Lipids present in certain foods, including some polyunsaturated fatty acids, oxidized fats, omega-3 fatty acids, and naturally occurring lipid oleylethanolamide (OEA), also induce Nrf2 and / or PPAR alpha. Foods rich in oxidized fats include french fries and other fried foods, which can be administered concurrently with cysteamine precursors that require pantethinase cleavage to produce cysteamine. Omega-3 fatty acids are present in fish and are available in fish oil extracts and in pure forms for use in pharmaceutical compositions.

[0139] Naturally occurring PPAR alpha-ligands include endogenous compounds such as leukotriene B4, 8-hydroxyeicosatetraenoic acid, and arachidonic acid and arachidonic acid metabolites, including certain family members. Pharmacological PPAR alpha-ligands include fibrates (e.g., benzafibrate, cyprofibrate, clinofibrate, clofibrate, fenofibrate, gemfibrozil), pyrinixic acid (Wy14643), and di(2-ethylhexyl) phthalate (DEHP). Any natural or synthetic PPAR alpha-ligand may be co-compounded or administered concurrently with cysteamine precursors that require pantetheinase cleavage to produce cysteamine. For an overview of PPAR ligands, see Grygiel-Gorniak, B. Nutrition Journal 13:17 (2014).

[0140] Natural and synthetic PPARG agonists can also be used to stimulate Nrf2-mediated transcription of the pantetainase genes VNN1 and / or VNN2. Natural product PPARG agonists include arachidonic acid and its metabolites, such as 15-hydroxyeicosatetraenoic acid (15(S)-HETE, 15(R)-HETE, and 15(S)-HpETE), 9-hydroxyoctadecadienoic acid, 13-hydroxyoctadecadienoic acid, 15-deoxy-(delta)12,14-prostaglandin J2, and prostaglandin PGJ2, as well as honokiol, amorphurtin 1, amorphurtin B, and amorphous stilballs. Other natural products that activate both PPARG and PPARA include genistein, biochanin A, sargacinic acid, sargacinhydroquinic acid, resveratrol, and amorphous stilballs. Natural product PPARG agonists are described and outlined in Wang et al., Biochemical Pharmacology 92:73 (2014). Pharmacological PPAR gamma agonists include thiazolidinediones (also known as glitazone, e.g., pioglitazone, rosiglitazone, robeglitazone). Heme derived from red meat also induces VNN1 expression. PPARA or PPARG agonists that stimulate pantetheinase expression can be co-administered or combined with cysteamine precursors containing pantetheine or compounds that can be broken down to pantetheine in the intestine. Combining two or more inducers of pantetheinase expression can promote expression or reduce the dose of any single agent.

[0141] Another crucial step in making cysteamine biologically available throughout the body is its absorption across the intestinal epithelium. Cysteamine uptake from the lumen is mediated by transporters, the native levels of which may not be high enough to transport all cysteamine within the lumen. Therefore, compounds that induce the expression of cysteamine transporters can be co-administered or combined with cysteamine precursors to enhance cysteamine absorption. Cysteamine is transported across the intestinal epithelium by organic cation transporters 1, 2, and 3 (encoded by the OCT1, OCT2, and OCT3 genes, also known as the SLC22A1, SLC22A2, and SLC22A3 genes), as well as possibly other transporter proteins. Inducers of organic cation transporter expression include the transcription factors PPAR alpha and PPAR gamma, the pregnane X receptor (PXR), the retinoic acid receptor (RAR), and (in the case of OCT1) the RXR receptor, as well as the glucocorticoid receptor. Therefore, either native or synthetic ligands of these receptors can be used to increase OCT expression, thereby promoting cysteamine uptake by intestinal epithelial cells. Agents that stimulate the expression of cysteamine transporters may be administered or combined with any type of cysteamine precursor.

[0142] The elimination half-life of cysteamine in the human body (time from Cmax to half-Cmax after intravenous bolus) is approximately 25 minutes. A portion of the cysteamine dose is converted to various disulfides, including mixed disulfides with free cysteine, protein cysteinyl residues, and glutathione. Pharmacological interventions cannot prevent this mode of elimination, and in any case, the cysteamine pool remains available for further disulfide exchange. However, there is a cysteamine catabolic pathway that irreversibly converts cysteamine and effectively removes it from the body. The enzyme cysteamine dioxygenase, which oxidizes cysteamine to hypotaurine, is a key factor in cysteamine elimination. Hypotaurine is then further oxidized to taurine. Co-administration of cysteamine precursors and one or both of these catabolic products may slow cysteamine catabolism by inhibiting the final product. Therefore, in certain embodiments, the cysteamine precursor is concomitantly formulated, administered, or given in an optimal temporal sequence with hypotaurine and / or taurine.

[0143] Figure 13 shows a classification of cysteamine precursors based on thiol constituents, the number of cysteamine molecules that can be produced, the metabolic steps required to produce cysteamine, potentially useful promoters of in vivocysteamine production, and cysteamine release profiles. Compounds that induce higher expression of cysteamine transporters (not shown in Figure 13) are useful for all types of cysteamine precursors. Compounds that alkalize intestinal contents and thereby promote thiol-disulfide exchange and / or reduction of disulfide bonds (not shown in Figure 13) are useful for disulfidecysteamine precursors.

[0144] In summary, flexibility in controlling cysteamine blood levels can be achieved by (i) using one or more cysteamine precursors with selected properties, (ii) one or more enhancers of in vivocysteamine precursor degradation and / or cysteamine absorption, (iii) one or more inhibitors of cysteamine catabolism, (iv) one or more formulations (e.g., immediate, delayed, sustained, intragastric, or colon-targeted, or combination thereof), and (v) co-combination or co-administration of a dosing schedule that allows for optimal simultaneous delivery of the cysteamine precursor(s) and enhancers(s) to targeted segments of the gastrointestinal tract in amounts that can be effectively degraded and absorbed. The result of the personalized application of these tools is the maintenance of cysteamine blood levels within the therapeutic range for extended periods and superior pharmacological effects on the disease compared to existing compounds and formulations.

[0145] Pharmaceutical composition The present invention provides compositions formulated to achieve therapeutically effective plasma concentrations of cysteamine over a long period of time in order to (i) reduce side effects associated with high peak concentrations of cysteamine, (ii) reduce insufficiency caused by trough concentrations of cysteamine below therapeutic levels, and (iii) improve patient convenience and thus adhere to the treatment by reducing the number of daily doses. The compounds and formulations of the present invention are also designed to (i) provide improved sensory stimulation properties compared to existing cysteamine formulations, (ii) reduce contact between free cysteamine and gastric epithelium, which is a known cause of gastrointestinal side effects, and (ii) minimize the dose of cysteamine precursor required to achieve therapeutic cysteamine blood levels by matching the dose and delivery site(s) with the relevant digestive and absorption processes in the gastrointestinal tract, the objective of which can be achieved by (iii) optimizing the degradation and absorption of cysteamine precursors by co-combination or co-administration with accelerators of those processes.

[0146] In the compositions of the present invention, all formulations contain a pharmaceutical excipient to prevent oral exposure of the cysteamine precursor or a salt thereof. A formulation method for masking bitterness or other unpleasant tastes includes a coating that can be applied in several layers. Flavoring agents and dyes may also be used. Methods for producing pharmaceutical compositions having an acceptable mouthfeel and / or taste are known in the art (see, for example, the textbook on pharmaceutical formulations cited elsewhere). Patent documents also provide methods for producing sensorily acceptable pharmaceutical compositions (see, for example, U.S. Patent Publication No. 2010 / 0062988).

[0147] Gastric retentive composition The first composition provides a cysteamine precursor or a salt thereof in an intragastric retentive formulation. Various intragastric retentive techniques are known in the field, some of which are well used in commercially available products. For an overview, see, for example, Pahwa et al., Recent Patents in Drug Delivery and Formulation, 6:278 (2012), and Hou et al., Gastric retentive dosage forms: a review. Critical Reviews in Therapeutic Drug Carrier Systems 20:459 (2003).

[0148] Intragastric retention formulations provide sustained release of cysteamine precursors in the stomach. Depending on the type of cysteamine precursor subsequently in vivo, cysteamine production may begin in the stomach or in the small intestine, which is the tissue where cysteamine is most efficiently absorbed. Some cysteamine precursors may continue to be converted to cysteamine in the large intestine, even if released from the pharmaceutical composition in the stomach or small intestine. For example, disulfide cysteamine precursors released in the stomach may remain in an oxidized state, mainly in the acidic, oxidizing environment of the stomach, and begin releasing cysteamine after encountering a reducing agent (e.g., bile glutathione) in the small intestine. Intragastric retention compositions produce elevated blood cysteamine levels 1 to 4 hours, preferably 1 to 6 hours, more preferably 1 to 8 hours, 1 to 10 hours, or longer, after ingestion.

[0149] Contrary to recommendations for cysteamine tartrate (see, for example, the Procysbi® FDA full prescribing information), gastric retention formulations of cysteamine precursors should be administered with food, preferably with a diet containing sufficient calories and nutrient density to delay gastric emptying. Nutrient-dense diets induce osmoreceptors and chemoreceptors in the small intestine (and to a lesser extent in the stomach), which have the effect of stimulating nerve and hormonal signals that reduce gastric motility and thereby delay emptying. Delaying gastric emptying is a mechanism for extending the effect of gastric retention compositions. However, filling the stomach with a large amount of food or liquid tends to promote gastric motility and increase the rate of emptying; therefore, nutrient density is a more important dietary characteristic than volume. Solid foods that must be broken down into small particles in the pyloric sulcus and pylorus before being emptyed into the duodenum prolong gastric retention compared to liquid or semi-liquid foods. Among liquid foods, high-viscosity liquids can delay gastric emptying compared to low-viscosity liquids. Foods with high osmotic pressure contents induce duodenal osmolality receptors, which transmit signals that slow gastric emptying. The release of cysteamine precursors into the stomach (e.g., from gastric retention preparations) can increase the osmotic pressure of gastric contents, and therefore duodenal contents.

[0150] In certain embodiments, disulfide cysteamine precursors are preferred for gastric retention formulations because the acidic, oxidative environment of the stomach tends to maintain the disulfide in an oxidized form, thereby limiting the exposure of gastric epithelium to cysteamine, which is considered one of the causes of cysteamine toxicity. Upon entering the duodenum and mixing with bile containing high (millimole) concentrations of glutathione, cysteine, and other reducing agents, the disulfide is reduced, thereby producing free thiols at the sites where it is exposed to pantethinase and where cysteamine transporters are expressed on intestinal cells.

[0151] The presence of fat in the small intestine is the most potent known inhibitor of gastric emptying, leading to reduced relaxation and contraction of the proximal stomach in the pyloric region. Once the fat is absorbed in the small intestine and no longer triggers inhibitory signals to the stomach, gastric motility resumes its normal pattern. Therefore, gastric retention formulations can ideally be administered with a meal containing fatty foods. Protein-rich meals also slow gastric emptying to a lesser degree, and carbohydrate-rich meals to an even lesser degree.

[0152] Gastric retention compositions can also be administered with compounds that slow gastric emptying, including certain lipids. For example, fatty acids having at least 12 carbon atoms stimulate cholecystokinin release from enteroendocrine cells and reduce gastric motility, while fatty acids with shorter carbon chains are less effective. In some embodiments, food or diet may be supplemented with fatty acids or triglycerides containing fatty acids with 12 or more carbon chains (e.g., oleic acid, myristic acid, myristate triethanolamine, fatty acid salts).

[0153] When fats and proteins reach the duodenum, they stimulate the secretion of several intestinal hormones, including ghrelin, cholecystokinin (CCK), and glucagon-like peptide 1 (GLP1). CCK delays gastric emptying by binding to the CCK1 receptor (CCK1R, formerly called the CCK-A receptor). In some embodiments, orally active CCK agonists or mimics, positive allosteric modulators of CCK1R, or agents that promote the release of endogenous CCK or inhibit CCK degradation, or agents that otherwise prolong CCK action by some combination of these mechanisms or other mechanisms, are administered with gastric retention compositions to delay gastric emptying and prolong the gastric retention of the compositions. CCK is a peptide that exists in several forms ranging from 8 to 53 amino acids (e.g., CCK-8, CCK-53). Oral administration of peptides is ineffective because they are digested in the gastrointestinal tract. Small molecule CCK agonists have been developed and tested by several research groups. For example, SR-146, 131 and related compounds were developed by scientists at Sanofi (U.S. Patents 5,731,340 and 6,380,230, incorporated herein by reference).

[0154] Certain protease inhibitors induce CCK production or release, prolong its half-life, or otherwise enhance its effects, including both food-derived mixtures and pure compounds. For example, ingestion of potato-derived protease inhibitor concentrates, as well as ingestion of soy peptone and soy beta-conglycinin peptone, is associated with elevated CCK levels. Camostat is a synthetic protease inhibitor with pleiotropic effects, including stimulation of endogenous CCK release and consequently slowing gastric emptying. Camostat mesylate is a widely used pharmaceutical salt in humans. FOY-251 is an active metabolite of camostat. In some embodiments, agents that stimulate CCK production or release, prolong CCK half-life, or otherwise enhance CCK effects are concomitantly formulated or administered with a gastric retention composition in an amount that slows gastric emptying. In some embodiments, camostat, FOY-251, or a prodrug, derivative, or active metabolite of camostat, or a pharmaceutically acceptable salt thereof, is co-compounded with or administered co-administered with an intragastric composition in amounts ranging from 50 to 300 mg / kg or 100 to 250 mg / kg.

[0155] Gastric emptying is also slowed by the acidification of the porridge. For example, citric acid and acetic acid have been shown to delay gastric emptying. In some embodiments, the food or meal may be a natural source of citric acid (e.g., the pulp or juice of oranges, lemons, limes, grapefruits, or other citrus-rich fruits), or acetic acid (e.g., vinegar, pickles, or other pickled vegetables), or lactic acid (e.g., sauerkraut or kimchi). In some embodiments, an amount of acidic food or liquid sufficient to lower the pH of the porridge below pH 4 or below pH 3.5 is administered along with the gastric retention composition.

[0156] Glucagon-like peptide-1 (GLP1) is another intestinal hormone released by cells in the duodenum in response to food, particularly ingested fats, and affects gastric emptying. Orally administered GLP1 receptor agonists have been discovered by several research groups (e.g., Sloop et al., Diabetes 59:3099 (2010)). Positive allosteric modulators of the GLP1 receptor (those that enhance endogenous GLP1, but are not agonists themselves) belong to a different category of GLP1R agonists (see, for example, Wootten et al., J. Pharmacol. Exp. Ther. 336:540 (2011), Eng et al., Drug Metabolism and Disposition 41:1470 (2013), and also U.S. Patents 2006 / 0287242, 2007 / 0021346, 2007 / 0099835, 2013 / 0225488, and 2013 / 0178420, each incorporated herein by reference). Among the compounds that positively modulate GLP-1 receptor signaling in the presence of endogenous GLP-1 is quercetin, which acts by binding to an allosteric site on the GLP-1 receptor and positively influencing receptor signaling upon binding of the endogenous ligand (GLP-1, a peptide, exists in several forms). Several quercetin analogs are also positive modifiers of endogenous GLP-1. Quercetin is a flavonol found in many fruits, vegetables, leafy greens, and grains. It is used as an ingredient in health supplements, beverages, and foods. In some embodiments, a GLP-1 receptor agonist or positive allosteric modifier of GLP-1 is co-compounded or administered co-administered with an intragastric retention composition in sufficient quantities to delay gastric emptying. In some embodiments, the GLP-1 receptor agonist or positive allosteric modifier is quercetin or a quercetin analog, derivative, or active metabolite. Certain small molecule drugs can also delay gastric emptying time and can be administered or combined with gastric retention compositions.

[0157] Gastric emptying is also slowed by the acidification of the porridge. For example, citric acid and acetic acid have been shown to delay gastric emptying. In some embodiments, the food or meal may be a natural source of citric acid (e.g., oranges, grapefruits, or other citrus-rich fruits), or acetic acid (e.g., vinegar, pickles, or other pickled vegetables), or lactic acid (e.g., sauerkraut or kimchi). In some embodiments, the pH of the porridge is lowered to below 4 or below 3.5 by administering an acidic food or liquid together with the gastric retention composition.

[0158] U.S. Patent No. 8,741,885 describes a method for extending the gastric retention of an intragastric pharmaceutical composition (e.g., a floating, swelling, or mucosal-adhering composition) by combining an active pharmacochemical component with an opioid. The purpose of co-combining opioids is to delay gastric emptying. Gastric paresis, or severe congestive gastrointestinal motility, is a well-known potentially serious complication of opioid therapy.

[0159] Sustained-release composition The second composition provides a cysteamine precursor or a salt thereof in a non-gastric sustained-release formulation. Sustained-release formulations are well known in the art: Wen, H. and Park, K. (eds.) Oral Controlled Release Formulation Design and Drug Delivery: Theory to Practice. Wiley, 2010; Augsburger, LL and Hoag, SW (eds.) Pharmaceutical Dosage Forms-Tablets, Vol. 3: Manufacture and Process Control. CRC Press, 2008. The sustained-release component may be a tablet, powder, or a capsule filled with microparticles. Optionally, the particles may differ in size, composition (e.g., type or concentration of sustained-release polymer), or type or thickness of coating agent, or, if coated with multiple layers of coating agent, the number and composition of layers, thereby providing a longer-lasting drug release in aggregates compared to formulations in which all particles are substantially identical, as the drug is released from individual particles at different rates or at different start times. The sustained-release formulation may optionally be coated with a pH-sensitive material (called an enteric coating) that prevents dissolution in the stomach. The microparticles in a single composition may differ in the type or thickness of one or more coating agents. For example, the pH at which the coatings dissolve may differ. Two or more microparticles used in such a mixed composition may be manufactured separately according to strict specifications and then blended in a ratio that achieves long-term drug release in vivo.

[0160] Sustained-release compositions result in the prolonged release of cysteamine precursors in the stomach and / or small intestine (but not the former if enteric-coated), thereby sustaining cysteamine production in vivo. Sustained-release formulations can be designed to release the drug for a period approximately equal to the sum of the mean gastric and small intestinal transit times, for example, 3–5 hours when administered on a fast, or 5–8 hours when administered with food or a meal. Alternatively, sustained-release formulations can be designed to release the drug for a longer period than the sum of the mean gastric and small intestinal transit times, allowing for continued release of cysteamine precursors in the large intestine. In some embodiments, such sustained-release compositions can release cysteamine precursors for 4–8 hours when administered on a fast, or for 6–10 hours or longer when administered with a meal.

[0161] Sustained-release formulations can cause an increase in blood cysteamine levels for 1 to 4 hours, preferably 1 to 6 hours, more preferably 1 to 8 hours, and even more preferably 1 to 10 hours or longer, after ingestion. Sustained-release formulations of cysteamine precursors can be administered with or between meals, and optionally with cysteamine precursor breakdown agents or cysteamine absorption enhancers. Foods tend to inhibit the absorption of free cysteamine, especially fatty foods, and it is generally recommended to take cysteamine salts on an empty stomach, although small amounts of applesauce or similar foods are acceptable.

[0162] Mixed formulation Some compositions inevitably have two types of formulation elements: those that primarily control the rate of drug release and those that primarily control the anatomical site of drug release. For example, a gastric retention formulation always contains the drug in a sustained-release formulation; otherwise, long-term gastric retention would be meaningless. However, there are ways to combine immediate-release and sustained-release components in a single gastric retention formulation. For example, the immediate-release component may rapidly dissolve in the stomach or form an outer layer that rapidly disintegrates, leaving a core sustained-release component that remains in the stomach by one or more of the gastric retention mechanisms described herein. However, not all types of formulations can be combined productively. For example, an enteric-coated gastric retention formulation is counterproductive because the gastric retention formulation is designed to release the drug in the stomach, and the gastric release is blocked by the coating, which is resistant to dissolution in acidic media.

[0163] Compositions having different temporal or anatomical drug release profiles, when combined with a suitable cysteamine precursor and optionally with a cysteamine production or absorption enhancer, deliver therapeutically ranged blood cysteamine levels over 0.5–6 hours, more preferably 0.5–8 hours, most preferably 0.5–12 hours, 0.5–15 hours, or longer. Examples of productive combinations of formulations include mixed formulations containing up to two drug-release components, as well as separately formulated compositions that can be combined in various amounts and ratios to adjust the amount and timing of in vivo cysteamine production and absorption to the needs of individual patients.

[0164] The third composition provides a mixed formulation comprising a first enteric-coated component formulated for the delayed release of a cysteamine precursor or a salt thereof in the small intestine, and a second component of enteric-coated microparticles formulated for the sustained release of a cysteamine precursor or a salt thereof throughout the small and proximal portions of the large intestine. The mixed formulation provides the first component to initially achieve elevated cysteamine levels in the blood, and the second component to maintain cysteamine levels in the blood over time.

[0165] The fourth composition provides a mixed formulation comprising (i) a sustained-release intragastric formulation of a cysteamine precursor or a salt thereof, and (ii) an immediate-release formulation of a cysteamine precursor or a salt thereof designed to release the drug in the stomach. The second component of the mixed formulation is on the outer surface of the composition and begins to dissolve immediately upon contact with gastric contents. It is the first to produce cysteamine, though not necessarily in the stomach. The first (intragastric) component results in the long-term release of the cysteamine precursor in the stomach, followed by in vivo cysteamine production throughout the small intestine and production in the large intestine depending on the properties of the cysteamine precursor. The combined in vivo production and absorption of cysteamine from the two components begins within one hour after administration of the mixed composition and continues for at least five hours, preferably eight, ten, twelve hours, or longer, within the therapeutic concentration range.

[0166] In the fifth composition, the first component is formulated for immediate release in the stomach and comprises a cysteamine precursor, preferably a cysteamine mixed disulfide or pantetheine disulfide, or a salt thereof, and the second component is formulated for sustained release of the cysteamine precursor, or a salt thereof. The first component is located on the outer surface of the composition such that the second component remains intact after the dissolution or disintegration of the first component. The mixed formulation of this fifth composition produces an initial increase in plasma cysteamine concentration from the immediate-release component and can maintain the elevated level of cysteamine from the second (sustained-release) component through continued in vivo cysteamine production for 6, 8, 10 hours, or longer. The release of the cysteamine precursor (or several different cysteamine precursors) along the gastrointestinal tract from the stomach to the large intestine allows the amount of cysteamine precursor to match the levels of pantehetinase and cysteamine transporters in all segments of the intestine, thereby maximizing cysteamine production and absorption. The continuous small intestinal production and absorption of cysteamine avoids reliance on high Cmax to prolong exposure, thereby reducing cysteamine-related side effects associated with high peak levels. Therefore, mixed formulations of cysteamine precursors allow for the administration of cysteamine to a wide range of disorders sensitive to its effects.

[0167] In the sixth composition, the first component is formulated for immediate release in the stomach and comprises a cysteamine precursor, preferably a cysteamine mixed disulfide or pantetheine disulfide, or a salt thereof, and the second component is formulated for sustained release of the cysteamine precursor, or a salt thereof, in the ileum and / or colon. This mixed formulation of the sixth composition can result in an initial increase in plasma cysteamine levels from the immediate-release component, as well as a second increase in plasma cysteamine levels from the ileum and colon target components, around the time the first peak rapidly decreases. The second component may begin releasing the cysteamine precursor 4 to 8 hours after administration, depending on whether it is administered with or without food. Controlled release of the cysteamine precursor (or different cysteamine precursors) along the gastrointestinal tract from the stomach to the large intestine allows the amount of cysteamine precursor to match the levels of pantehetinase and cysteamine transporters in all segments of the intestine, maximizing cysteamine production and absorption.

[0168] compound The pharmaceutically acceptable compositions of the present invention comprise one or more cysteamine precursors or pharmaceutically acceptable salts thereof. Examples of salts of the present invention include, but are not limited to, salts of alkali metals, e.g., sodium and potassium; salts of alkaline earth metals, e.g., calcium, magnesium, and barium; and salts of organic bases, e.g., amine bases and inorganic bases. Exemplary salts are found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418; Berge et al., J. Pharmaceutical Sciences 66:1 (1977); and Pharmaceutical Salts: Properties, Selection, and Use (edited by PHStahl and CGWermuth), Wiley-VCH, 2008, each of which is incorporated herein by reference in whole.

[0169] The compositions of the present invention may contain a cysteamine precursor or a salt thereof in the components of an intragastric or mixed formulation to achieve a therapeutically effective plasma concentration of cysteamine within the first four hours after administration, preferably within the first two hours after administration, and most preferably within the first hour. The cysteamine plasma concentration preferably remains within the therapeutic range for at least five hours, preferably six hours, more preferably eight hours, ten hours, or longer. The formulation may contain a thiolcysteamine precursor that can be enzymatically broken down to produce cysteamine such as pantetheine, or a compound that can be broken down in the gastrointestinal tract to pantetheine (and thereafter to cysteamine), such as 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A, or a derivative thereof or prodrug that can be broken down in the gastrointestinal tract to pantetheine (and then to cysteamine). Alternatively, the cysteamine precursor may be formed by reacting cysteamine or a compound that can be broken down to produce cysteamine with another thiol-containing organic sulfur compound to form a disulfide compound. Disulfide cysteamine precursors or salts thereof are produced by reacting cysteamine with thiol cysteamine precursors such as pantetheine, 4-phosphopantetheine, dephospho coenzyme A, coenzyme A, or N-acetylcysteamine, or by reacting cysteamine with N-acetylcysteine ​​(NAC), N-acetylcysteinamide, N-acetylcysteine ​​ethyl ester, homocysteine, glutathione (GSH), allyl mercaptan, furfuryl mercaptan, benzyl mercaptan, or thioterpineol. It can be formed by reacting grapefruit mercaptan with other thiols, including 3-mercaptopyruvic acid, L-cysteine, L-cysteine ​​ethyl ester, L-cysteine ​​methyl ester, thiocysteine, cysteinylglycine, gamma-glutamylcysteine, gamma-glutamylcysteine ​​ethyl ester, glutadione monoethyl ester, glutathione diethyl ester, mercaptoethylgluconamide, thiosalicylic acid, thiopronine, or diethyldithiocarbamic acid.Thiol-cysteamine precursors or cysteamines can also be reacted with dithiols such as dihydrolipoic acid, meso-2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropanesulfonic acid (DMPS), 2,3-dimercapto-1-propanol (dimercaprole), bucillamine, or N,N′-bis(2-mercaptoethyl) isophthalamide (BDTH2) to form disulfide-cysteamine precursors. See Figure 17 for a list of thiols that can be used to form disulfide-cysteamine precursors, and Figures 18-21 for tables summarizing thiol pairs that can be bound to form disulfide-cysteamine precursors. Other thiols suitable for forming cysteamine precursors are known in the art. For example, PCT Patent Publication WO1993 / 006832, which is incorporated herein by whole reference in its entirety, discloses additional useful thiols not shown in Figure 17, including, among others, N,N-dimethylcysteine, thiocholine, aminopropanethol, aminobutanethiol, and aminopentanethiol.

[0170] The formed disulfides may delay the release of cysteamine in the stomach and / or promote its in vivo production and absorption in the small intestine, depending on the properties of the cysteamine precursor used (e.g., the number of degradation steps required to form cysteamine). Figure 13 shows a classification of cysteamine precursors and summarizes the pharmacologically relevant properties of the selected precursors. Figures 18–21 provide information on the cysteamine yield of many disulfide cysteamine precursors. The stomach is generally a more oxidative and acidic environment than the small intestine. When stomach contents enter the duodenum, they mix with pancreatic juice containing bicarbonates that neutralize stomach acid, and bile containing millimolar concentrations of the physiological reducing agent glutathione and related thiols including cysteine. As a result, disulfides tend to remain oxidized in the stomach and are more likely to be reduced in the small intestine or participate in disulfide exchange reactions with thiols. Disulfide exchange reactions are generally catalyzed by thiolate ions, which are far more nucleophilic than thiol ions, and the formation of thiolate ions is undesirable in the acidic environment of the stomach.

[0171] For example, pantetheine, a thiolcysteamine precursor, can form a homodimeric disulfide, where two pantetheines covalently bond to form pantethine (a disulfidecysteamine precursor). In some preferred embodiments, the cysteamine precursor provides a plurality of cysteamines, for example, by a mixed cysteamine disulfide formed by conjugating cysteamine with pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A, or by a corresponding mixed pantetheine disulfide formed by oxidizing pantetheine with 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A, or by a suitable prodrug or analog that can be converted to the parent compound in the gastrointestinal tract. Furthermore, 4-phosphopantetheine can be disulfide-bonded to dephosphocoenzyme A or coenzyme A, or dephosphocoenzyme A can be disulfide-bonded to allow the cysteamine precursor to produce two types of cysteamine in vivo. Figure 13 shows the number of cysteamines that can be produced in vivo from different classes of cysteamine precursors. Figures 18–21 show specific disulfide cysteamine precursors. Those that produce two cysteamines in vivo are listed at the top of the table, and the fractional yield (percent) of cysteamine for each disulfide is also shown, as well as the number of decomposition steps required to produce the cysteamine. In some embodiments, the reactive thiol group of the cysteamine or organosulfur can be modified to include substituents such as acetyl groups, ester groups, glutamyl, succinyl, phenylalanyl, polyethylene glycol (PEG), and / or folate.

[0172] In preferred embodiments, the compositions of the present invention contain pantetheine, pantetheine-containing pantetheine, or salts thereof in components of an intragastric formulation and / or a mixed formulation, which can sustain elevated blood levels of cysteamine for 5 to 10 hours or more after administration. The composition may be a cysteamine precursor that requires chemical reduction or enzymatic conversion to at least one cysteamine of the parent compound, thereby delaying the release of cysteamine. The formulation may contain pantetheine or a compound that can be broken down to pantetheine in the gastrointestinal tract (e.g., 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A; collectively referred to as pantetheine precursors), in which the thiol group of pantetheine or the pantetheine precursor reacts with the thiol group of another organosulfur compound to form a disulfide compound. Since pantetheinase is expressed at higher levels in the intestines than in the stomach, and the lumen of the small intestine is a more reducing environment than the stomach, the pantetheine component of the disulfide cysteamine precursor is converted to cysteamine in the small intestine and then absorbed. For example, pantetheine can form a homodimeric disulfide in which two pantetheines are covalently bonded to form pantethine. Pantetheine-containing cysteamine precursors can also contain a pantetheine mixed disulfide, where pantethein thiol reacts with a thiol group to form a disulfide. In preferred embodiments, the pantetheine precursor provides two or more cysteamines, such as those provided by a mixed disulfide formed from cysteamine and pantetheine (which, when reduced and subsequently cleaved by pantetheinase, yields two cysteamines and one pantothenic acid), or by a mixed disulfide pantetheine-coenzyme A (which, when reduced and subsequently degraded and then cleaved by pantetheinase, yields two cysteamines, two pantothenic acids, and ADP). Other disulfide cysteamine precursors that yield two cysteamines when degraded in the intestine are shown in Figures 18-21.In some embodiments, the reactive thiol group of pantetheine or an organosulfur compound may be modified to include substituents such as an acetyl group, a methyl ester, an ethyl ester, glutamyl, succinyl, phenylalanyl, polyethylene glycol (PEG), and / or folate.

[0173] The distinction between cysteamine precursors that require pantetheinase cleavage to produce cysteamine and cysteamine precursors that require only chemical reduction to produce cysteamine (cysteamine mixed disulfides) is important because, provided that a suitable reducing environment is present in the intestines (or can be pharmacologically created), the reaction rate of conversion of the precursor compound to cysteamine is generally faster in the second category. A further distinction can be made between cysteamine precursors that require reduction followed by pantetheinase cleavage (e.g., pantethine) and cysteamine precursors that require first reduction, then degradation to pantetheine, and then pantetheinase cleavage (e.g., 4-phosphopantethine, dephosphocoenzyme A, or disulfides containing coenzyme A). The additional degradation step(s) required by the latter class of disulfide cysteamine precursors slows and prolongs the duration of cysteamine production over a longer period.

[0174] The compounds of the present invention can be prepared by various methods known to those skilled in the art of chemical synthesis. Methods for preparing thiols, including cysteamine, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, or coenzyme A and other thiols (see Figure 17), are well known in the art. Coenzyme A, pantethine, N-acetylcysteamine, and glutathione are commercially available as dietary supplements. Most of the other thiols in Figure 17 are readily available from chemical companies.

[0175] Synthesis of cysteamine precursors The compounds of the present invention, comprising both thiols and disulfide cysteamine precursors, can be prepared from readily available starting materials using methods and procedures known in the art, such as those described in Mandel et al., Organic Letters, 6:4801 (2004). Methods for producing pantethene are described in U.S. Patents 3,300,508 and 4,060,551, each of which is incorporated herein by reference. Methods for converting liquid pantetheine to a solid are disclosed in Japanese Patent Publications JP-A-S50-88215 and JP-A-S55-38344. Where typical or preferred process conditions (i.e., reaction temperature, time, molar ratio of reactants, solvent, pressure, etc.) are indicated, it will be understood that other process conditions may also be used unless otherwise stated. Optimal reaction conditions may vary depending on the specific reactants or solvent used, but such conditions can be determined by routine optimization procedures for those skilled in the art.

[0176] In preferred embodiments, the composition of the present invention comprises one or more disulfide cysteamine precursors. Disulfides, which are oxidized thiols, are readily formed from constituent thiols without expensive reagents or equipment. Furthermore, disulfides are not affected by oxidation, which can limit the long-term stability of thiol compounds exposed to air. Therefore, with respect to manufacturing, cost, storage costs, shipping, and patient convenience (i.e., long shelf life), cysteamine precursors in disulfide form are preferable to thiol form.

[0177] In some embodiments, mixed disulfide cysteamine precursors are synthesized by the conjugation of two different thiols to form three reaction products, where thiols A and B can conjugate to form disulfides AA, AB, and BB. For example, disulfides formed by reacting cysteamine with pantetheine include cysteamine-cysteamine (called cystamine), cysteamine-pantetheine, and pantetheine-pantetheine (called pantethine). All three compounds are useful in providing cysteamine, and the different steps involved in actually converting each compound to cysteamine may be pharmacologically beneficial by extending the time it takes for cysteamine to be produced in vivo by reduction of the disulfide bond or by a combination of reduction and enzymatic degradation steps. Therefore, the simultaneous formulation of all three oxidation products without purification (except for removing unwanted impurities such as unreacted thiols and / or solvents) may be pharmacologically beneficial. This is particularly true when the two reacted thiols are each convertible to cysteamines (e.g., pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, N-acetylcysteine, or appropriate analogues and prodrugs), or when cysteamine itself is reacted with a cysteamine-convertible thiol. As a result, in certain embodiments, three disulfides formed by reacting two different thiols, each convertible to cysteamine (or one of which is cysteamine), are all co-formulated in a single composition. This method of synthesis and formulation does not require more complex synthesis steps or post-synthesis purification steps necessary to separate the mixed disulfide from the two homodimeric disulfides simultaneously produced in the oxidation reaction. (Unreacted thiols and other impurities must, of course, be removed before the pharmaceutical composition is formulated.)

[0178] The advantages of producing and simultaneously compounding a mixture of three disulfides are not fully realized in the case of disulfide cysteamine precursors produced by reacting a cysteamine-convertible thiol with a second thiol that is not cysteamine-convertible. For example, the three disulfides formed by reacting pantetheine with N-acetylcysteine ​​(NAC) are pantetheine-pantetheine (pantethine), pantetheine-NAC, and NAC-NAC. The first two compounds are cysteamine precursors, while the third (NAC-NAC) is not. Nevertheless, NAC-NAC may have beneficial pharmacological properties in terms of modulating the enteric redox environment or beneficial medical properties, as it results in the yielding of two NAC molecules upon chemical reduction. Therefore, in certain embodiments, all three disulfide products formed by reacting a cysteamine or a thiol convertible to cysteamine in vivo with a second thiol that is not convertible to cysteamine in vivo are simultaneously incorporated into a single composition.

[0179] The expected ratio of reaction products when two different thiols are oxidized depends on the molar ratio of the two thiols, their absolute concentrations, the pH, and / or the chemical environment surrounding the sulfhydryl groups of each thiol. If the ratio of thiol A to thiol B is 1:1, the expected molar ratio of reaction products AA, BB, and AB is approximately 1:1:2. (Deviations from the expected ratio may result from differences in adjacent chemical bonds to the thiols, which can affect the reaction rate of disulfide bond formation, for example, by the electronegativity of the atomic bonds to the sulfhydryls. Any deviation can be predicted or measured using methods known in the art.) The ratio of reaction products can be altered by changing the molar ratio of the two thiols. For example, the molar concentration of thiol A may be increased relative to the molar concentration of thiol B to increase the proportion of AA and AB relative to BB. When reacting two thiols, one may be a cysteamine or a compound that can decompose into a cysteamine (thiol A), and the other may be a cysteamine-indegradable thiol (thiol B). The molar concentration of the first thiol can be increased relative to the molar concentration of the second thiol to increase the proportion of the cysteamine precursor produced. For example, reacting thiols A and B in a 2:1 molar ratio increases the ratio of AA and AB (both cysteamine precursors) to BB (not a cysteamine precursor).

[0180] In certain embodiments, the inclusion of a catalyst can facilitate the oxidation of two different thiols and / or alter the mixture of reaction products (as outlined in Musiejuk and Witt (2015)). For example, an oxidizing agent such as hydrogen peroxide or dimethyl sulfoxide (DMSO), or a metal such as copper, manganese, or telluride, or iodine, diethyl azodicarboxylate (or related compounds), or dichlorodicyanoquinone (DDQ) can be added. Optimal catalyst performance can be achieved by empirically determining the optimal solvent system, catalyst concentration, and reaction conditions.

[0181] In other embodiments, asymmetric disulfides can be produced via thiol-disulfide exchange reactions between thiols and symmetric disulfides. This type of reaction, like the oxidation of two different thiols, provides a mixture of all possible products (symmetric and asymmetric disulfides). However, the formation of asymmetric disulfides is sometimes favored, and may even become the primary reaction product under optimized conditions, by providing a molar excess of symmetric disulfides compared to thiols. Examples 15 and 16 describe the synthesis of pantetheine-cysteamine disulfides via thio-disulfide exchange. This method uses cysteamine as the thiol and pantetheine as the disulfide, and pantetheine as the thiol and cystamine as the disulfide. In preferred embodiments of the thiol-disulfide exchange reaction, the molar ratio of thiol to disulfide (e.g., cysteamine:pantetheine) is 2:1 to 4:1, 2.5:1 to 3.5:1, and 2.7:1 to 3.3:1. In certain embodiments, the solvent is methanol, and the reaction time is 1 to 20 hours, or 1 to 12 hours, or 1 to 6 hours. In certain embodiments, the product of the thiol:disulfide exchange reaction (e.g., TTI-0102) is then precipitated (e.g., as described in Example 17).

[0182] Alternatively, in another embodiment, the ratio of cysteamine precursors used in a pharmaceutical composition can be adjusted by combining the three reaction products of a mixed disulfide oxidation reaction with a pure disulfide. For example, if cysteamine (C) and pantetheine (P) of thiols are oxidized in a 1:1 molar ratio, they are combined to form three products: CC, PP, and CP in approximately a 1:1:2 ratio. Pure pantethine (PP) can be added to the mixture in any desired amount to extend the in vivo cysteamine-forming properties of the mixture. Doubling the starting amount of pantethine yields a 1:2:2 ratio. Adding four times the starting amount of pantethine yields a 1:2:5 ratio.

[0183] Novel ratios of cysteamine precursors can also be achieved by combining two independently generated mixed disulfide reaction products. For example, when cysteamine-pantetheine reaction products (CC, PP, and CP) are combined with equimolar reaction products from the N-acetylcysteine ​​(NAC)-cysteamine (C) oxidation reaction (CC, NAC-NAC, and C-NAC in a 1:1:2 ratio), the mixture will contain five compounds, one of which, NAC-NAC, cannot be converted to cysteamine. The other four disulfides, PP, CC, CP, and C-NAC, are present in a molar ratio of approximately 1:2:2:2. Optionally, pantetheine can be added to change the ratio to, for example, 2:2:2:2 (or more simply, 1:1:1:1), or in larger quantities to achieve a ratio of 1:1:1:5. Thus, the molar ratio of disulfides in a pharmaceutical composition can be controlled in various ways. In another example, the cysteamine-pantetheine reaction products (CC, PP, and CP) may be combined with the 4-phosphopantetheine (4P)-cysteamine (C) oxidation reaction (i.e., CC, 4P-4P, and C-4P in a 1:1:2 ratio) to produce a mixture of five disulfides in a 1:1:1:2:2 ratio.

[0184] In summary, when one thiol is oxidized to produce a cysteamine precursor disulfide, only one product exists (e.g., pantetheine + pantetheine = pantethine). When two thiols are oxidized, three products exist, two or three of which are cysteamine precursors, depending on whether one or both of the thiols are decomposable to cysteamine or are cysteamines themselves. Mixtures of cysteamine precursors are most easily produced by combining the products of these two types of reactions. The mixtures may contain pure disulfides or three-component disulfide mixtures in various molar ratios. However, heterodimeric cysteamine precursors can also be used in their pure form, after purification, or in combination with other homodimeric cysteamine precursors.

[0185] Alternatively, specific mixed disulfides (also known as asymmetric disulfides) can be selectively synthesized using more sophisticated chemical methods (for example, cysteamine and pantetheine can be combined to form virtually only disulfidecysteamine-pantetheine). These methods employ a wide range of sulfur protecting groups and strategies for their removal. The most widely used methods involve substituting sulfenyl derivatives with thiols or their derivatives. Commonly used sulfenyl derivatives include sulfenyl chloride, S-alkylthiosulfate and S-arylthiosulfate (Bunte salt), S-(alkylsulfanyl)isothiourea, benzothiazole-2-yl disulfide, benzotriazolyl sulfide, dithioperoxyester, (alkylsulfanyl)dialkylsulfonium salt, 2-pyridyl disulfide and derivatives, N-alkyltetrazolyl disulfide, sulfenamide, sulfenyl dimethylamine, sulfenyl thiocyanate, 4-nitroalene sulfenanilide, thiol sulfinate and thiol sulfonate, sulfanylsulfinamidin, thionitrite, sulfenylthiocarbonate, thioimide, thiophosphonium salt, and 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-yl disulfide. Further procedures include the reaction of thiols with sulfinylbenzimidazole, rhodium-catalyzed disulfide exchange, electrochemical methods, and the use of diethyl azodicarboxylate. These and other methods are outlined by Musiejuk, M. and D. Witt. Organic Preparations and Procedures International 47:95 (2015). Thus, with reasonable effort, specific mixed (asymmetric) disulfides of interest can be prepared. Examples 1 and 2 provide the synthesis procedures for the mixed disulfides of the present invention.

[0186] In further embodiments, mixed disulfides can be synthesized from symmetric disulfides by preferentially attaching substituents (e.g., acyl groups) to one end of the symmetric disulfide (i.e., hemiacylation). For example, since cysteamine and pantetheine have different pantothenate moieties, disulfidecystamine can be hemiacylated with pantothenate to produce cysteamine-pantetheine disulfide. By optimizing the reactant concentrations and adding coupling agents to promote acylation, this procedure can yield over 95%. Cystamine is an attractive starting point for producing asymmetric disulfides because it contains reactive amino groups at both ends. Example 14 describes the efficient synthesis of pantetheine-cysteamine disulfide via hemiacylation of cystamine with substituted pantothenic acid through a reactive intermediate. In certain embodiments, the molar ratio of the acyl group to the disulfide is 1:2 to 1:4. In certain embodiments, the acylation reaction is accelerated by the addition of N,N'-dicyclohexylcarbodiimide (DCC) in a DCC:acyl group molar ratio of 3:1 to 5:1. In certain embodiments, the acylation reaction is accelerated by the addition of 1-hydroxybenzotriazole (HOBt) in an HOBt:acyl group molar ratio of 1:1 to 1:3.

[0187] stereochemistry Some of the compounds of the present invention exist in multiple enantiomer forms. In particular, pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A contain a chiral carbon in the pantothenoyl moiety. Therefore, each of these compounds can exist as a D- or L-enantiomer, or as a racemic mixture of two with respect to the pantethenoyl group. However, human pantetheinase (encoded by the VNN1 and VNN2 genes) is specific to D-pantetheine (Bellussi et al., Physiological Chemistry and Physics 6:505 (1974)). Hence, only D-pantetheine (and not L-pantetheine) is a cysteamine precursor, and therefore the present invention relates only to D-pantetheine, and to the D-enantiomers of 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A, as well as analogs or prodrugs convertible to these compounds in the gastrointestinal tract. Similarly, for all disulfides containing pantetheine, 4-phosphopantetheine, dephosphocoenzyme A, and coenzyme A, or any suitable analogue or prodrug, only the D-enantiomer should be used.

[0188] L-enantiomers of amino acids and amino acid derivatives are preferred. Therefore, in this specification, "cysteine" refers to L-cysteine, homocysteine, and L-homocysteine, and cysteine ​​derivatives such as N-acetylcysteine, N-acetylcysteinamide, N-acetylcysteine ​​ethyl ester, cysteine ​​methyl ester, cysteine ​​ethyl ester, cysteinylglycine, and gamma-glutamylcysteine ​​are all formed using L-enantiomers of cysteine.

[0189] In the case of dihydrolipoic acid, the R enantiomer is preferred because it is an enantiomer produced in the human body. Generally, for compounds that are normally present in the human body or in food, naturally occurring enantiomers are preferred.

[0190] Salt form and crystallization The pharmaceutically active properties of any compound containing the cysteamine precursor of the present invention may be improved by association with a counterion or salt. Specific properties that may be improved include stability (e.g., low hygroscopicity, less susceptible to oxidation, high resistance to extreme changes in heat, humidity, and pH), improved tendency to form crystals, and ease of formulation (with respect to the properties of the solid form of the compound, such as a powder).

[0191] Crystallization is a less expensive, faster, and more scalable purification method than, for example, column chromatography; therefore, the potential for salt forms to improve the crystallization properties of compounds is particularly important. Methods for inducing the precipitation of small molecules are known in this field (see, for example, the overview by Chen et al. in Crystal Growth and Design, 11(4), 2011). Crystallization can be induced by cooling a saturated solution of the target compound, by adding an antisolvent (a liquid in which the target compound is poorly soluble) to the solution of the compound (Mostafa et al., Chemical Engineering Science 63:5457-5467, 2008), by introducing a surface that promotes crystal formation (e.g., scratched glass), by adding a crystal species, or by adding a compound that will cocrystallize with the target compound, including a polymer (Edueng et al., Journal of Controlled Release 256:193-202, 2017) (Korotkova and Karatchvil, Procedia Chemistry 10:473-476, 2014). Industrial crystallization processes can be carried out in batch form or increasingly via continuous processes (Zhang et al., Engineering 3:354-364, 2017).

[0192] Crystallization can be carried out in one of two ways: the desired disulfide compound can be selectively crystallized in the presence of impurities (which remain in the solution and can therefore be easily removed after crystallization), or one or more impurities can be crystallized while the desired compound remains in the solution. The two approaches can be combined sequentially.

[0193] Since cysteamine precursors are often administered in relatively large doses (more than 1 gram per day, or up to 10 grams in adults), any salts must be safe. Therefore, salts that are natural products, present in significant levels in the diet, and possess pleasant sensory stimulating properties are preferred. Examples of such salts include, but are not limited to, acetates, citrates, and tartrates. The salt form of a cysteamine precursor that induces crystallization may not overlap with the pharmaceutically preferred salt form; in such cases, the salt form may be specifically generated to aid crystallization, and then redissolved in a solvent to convert the salt to the preferred pharmaceutically preferred salt. Large salts that tend to promote crystallization include benzoates and naphthoates (naphthoic acid).

[0194] Separation method Most of the synthetic routes outlined above cannot produce mixed disulfides with a purity exceeding 99% (i.e., within the range required by drug regulatory agencies). Crystallization may also not be sufficiently selective to reduce drug impurities to an acceptable level. Therefore, robust separation methods may be required. Thus, in certain embodiments, any synthetic method can be combined with an efficient scheme for separating the desired product (i.e., mixed disulfide cystamine precursor) from other compounds (including other disulfides) produced in the synthesis. Useful separation methods other than crystallization include various chromatographic procedures, including resins that separate small molecules based on size, charge, hydrophobicity, affinity, or other properties.

[0195] formulation When used as a pharmaceutical, cysteamine precursors, or their pharmaceutically acceptable salts, solvates, or prodrugs, can be administered in the form of pharmaceutical compositions. These compositions can be prepared in various ways known in the pharmaceutical industry and can be formulated to release the drug to a specific part of the gastrointestinal tract at a time controlled by various excipients and formulation techniques. For example, formulations may be formulated to provide a set of compositions having various drug-release properties that can address specific diseases, achieve the necessary blood levels of cysteamine to achieve therapeutic efficacy, allow for a desired duration of drug effect, and be administered in different combinations to account for interpatient variability in cysteamine metabolism. Administration is primarily by oral route and may be supplemented by suppositories. Cysteamine precursors can also be co-formulated with agents that promote the production or absorption of cysteamine in vivo, such as reducing agents, buffers, pantethinase inducers, or inducers of cysteamine uptake by intestinal epithelial cells.

[0196] The pharmaceutical composition may contain one or more pharmaceutically acceptable carriers. In the preparation of pharmaceutical compositions for use in the method of the present invention, a cysteamine precursor, its pharmaceutically acceptable salt, solvate, or prodrug is typically mixed with an excipient, diluted with an excipient, or encapsulated in a carrier in the form of, for example, a capsule, tablet, sachet, paper, vial, or other container. The active ingredient of the present invention may be administered alone or in mixture with a pharmaceutically acceptable excipient or carrier. The excipient or carrier is selected based on the mode and route of administration, the target region of the gastrointestinal tract for drug release, and the intended time profile of drug release. When the excipient acts as a diluent, the excipient may be a solid, semi-solid, or liquid substance (e.g., saline solution) acting as a vehicle, carrier, matrix, or other medium for the active ingredient. Therefore, the composition may be in the form of tablets, powders, granules, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, and soft and hard gelatin capsules. As is known in the art, the type and amount of excipients vary depending on the intended drug-release properties. The resulting composition may contain additional agents such as preservatives or coatings.

[0197] Suitable pharmaceutical carriers and pharmaceutical essentials for use in pharmaceutical formulations are described in the well-known references in this field, Remington: The Science and Practice of Pharmacy, 21st Ed., Gennaro, Ed., Lippencott Williams & Wilkins (2005), and the USP / NF (United States Pharmacopeia and National Medicines), or the corresponding European or Japanese references. Examples of suitable excipients are lactose, dextrose, sucrose, sorbitol, mannitol, starch, acacia gum, calcium carbonate, calcium phosphate, alginate, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, cellulose derivatives, polyvinylpyrrolidone, poly(lactic acid-glycolic acid copolymer) (PLGA), cellulose, water, syrup, methylcellulose, vegetable oil, polyethylene glycol, hydrophobic inert matrix, carbomer, hypromellose, gelucire 43 / 01, docusate sodium, and white wax. Other possible excipients include lubricants such as talc, magnesium stearate, and mineral oil; wetting agents; emulsifiers and suspending agents; preservatives such as methyl and propyl hydroxybenzoates; sweeteners; and flavoring agents. Further details of other exemplary excipients and their uses are described in Handbook of Pharmaceutical Excipients, 6th Edition, Rowe et al., Eds., Pharmaceutical Press (2009).

[0198] The pharmaceutical composition may contain a cysteamine precursor salt that is optionally co-compounded or administered with other agents that promote the in vivo degradation of the cysteamine precursor to cysteamine or that promote the intestinal absorption of cysteamine. The pharmaceutical composition may also contain other therapeutic agents that complement the pharmacological effects of cysteamine in a target disease. Exemplary promoters of in vivo cysteamine production or absorption, and exemplary therapeutic agents that may be included in the compositions described herein, are provided herein.

[0199] The compositions of the present invention may contain a single active ingredient (i.e., a single cysteamine precursor), or a combination of a first and second active ingredient in a single unit dosage form, or a combination of a first, second, third, and optionally fourth active ingredient and optionally a fifth ingredient in a single unit dosage form. In a composition having two active ingredients, both ingredients may be cysteamine precursors, or one ingredient may be an in vivo cysteamine production promoter (e.g., a reducing agent that promotes the reduction of disulfide cysteamine precursors or an agent that induces increased intestinal expression of pantethinase), or an intestinal absorption promoter of cysteamine (e.g., an agent that induces increased expression of one or more organic cation transporters such as OCT1, OCT2, or OCT3). In a composition having three or four active ingredients, all ingredients may be cysteamine precursors, or one or two ingredients may be in vivo cysteamine production and / or intestinal absorption promoters. In compositions having two or more cysteamine precursors, the types of cysteamine precursors are selected to achieve in vivo cysteamine production over a sustained period. For example, a mixed disulfide cysteamine precursor that requires only the reduction of a disulfide bond to produce one cysteamine and will therefore begin producing cysteamine immediately upon reaching the region of the gastrointestinal tract having a redox environment contributing to the reduction of the disulfide bond can be mixed with pantetheine or with pantetheine disulfide, which requires both the reduction of the disulfide bond and pantetheinase cleavage to produce cysteamine, and can optionally be combined with a compound that is digestible to pantetheine in the intestine, or with a disulfide containing such a compound that requires additional steps to produce pantetheine and therefore cysteamine. Examples of compounds digestible to pantetheine in the intestine include 4-phosphopantetheine, dephosphocoenzyme A, coenzyme A, and preferred analogs and derivatives. The time course of in vivo cysteamine production varies depending on the number of degradation steps between the cysteamine precursor and cysteamine.In some embodiments, compositions containing multiple cysteamine precursors are formulated as powders, granules, or liquids, i.e., in formulations capable of containing large quantities of the drug.

[0200] A pharmaceutical composition may also contain one or more agents that enhance the performance of the formulation. For example, a gastric retention composition may contain compounds that slow gastric emptying in order to prolong the retention of the composition in the stomach.

[0201] In a composition containing two cysteamine precursor components, the first and second components may be present in a ratio of, for example, about 1:1.5 to about 1:4. In a composition containing three cysteamine precursor components, the first, second, and third components may be present in a ratio of, for example, about 1:1:2 to about 1:4:4. In a composition containing four active components, the first to fourth active components may be present in a ratio of, for example, about 1:1:1:2 to about 1:2:5:5. In a composition containing five active components, the first to fifth active components may be present in a ratio of, for example, about 1:1:2:2:2 to about 1:1:2:5:5:8.

[0202] In some embodiments, a composition containing two or more cysteamine precursors includes one precursor selected for rapid in vivo cysteamine production (e.g., requiring only reduction of a disulfide bond) and a second precursor selected for a more moderate or slower in vivo conversion to cysteamine (e.g., requiring chemical reduction and at least one enzymatic degradation step). In some embodiments, a pharmaceutical composition containing two or more cysteamine precursors includes at least one precursor being a cysteamine mixed disulfide, which can produce cysteamine upon reduction of a disulfide bond. In more relevant embodiments, at least one additional component is disulfide-containing pantetheine or a compound that can be broken down to pantetheine in the gastrointestinal tract.

[0203] The composition can be formulated in solid unit dosage forms (e.g., tablets or capsules), and each dose contains, for example, 50 to 800 mg of the first active ingredient. For example, doses may range from approximately 50 mg to approximately 800 mg, approximately 50 mg to approximately 700 mg, approximately 50 mg to approximately 600 mg, approximately 50 mg to approximately 500 mg, approximately 75 mg to approximately 800 mg, approximately 75 mg to approximately 700 mg, approximately 75 mg to approximately 600 mg, approximately 75 mg to approximately 500 mg, approximately 100 mg to approximately 800 mg, approximately 100 mg to approximately 700 mg, approximately 100 mg to approximately 600 mg, It may contain the first active ingredient in amounts of approximately 100mg to 500mg, 250mg to 800mg, 250mg to 700mg, 250mg to 600mg, 250mg to 500mg, 400mg to 800mg, 400mg to 700mg, 400mg to 600mg, 450mg to 700mg, and 450mg to 600mg.

[0204] In alternative embodiments, the composition may be formulated in liquid or powder unit dosage forms, with each dosage unit containing approximately 250 mg to approximately 10,000 mg of cysteamine precursor. For example, dosages of approximately 250 mg to approximately 10,000 mg, approximately 250 mg to approximately 8,000 mg, approximately 250 mg to approximately 6,000 mg, approximately 250 mg to approximately 5,000 mg, approximately 500 mg to approximately 10,000 mg, approximately 500 mg to approximately 8,000 mg, approximately 500 mg to approximately 6,000 mg, approximately 500 mg to approximately 5,000 mg, approximately 750 mg to approximately 10,000 mg, approximately 750 mg to approximately 8,000 mg, approximately 750 mg to approximately 6,000 mg, and approximately 750 mg It may contain the active ingredient of the first component in the following amounts: mg to approximately 5,000 mg, approximately 1,250 mg to approximately 10,000 mg, approximately 1,250 mg to approximately 8,000 mg, approximately 1,250 mg to approximately 6,000 mg, approximately 1,250 mg to approximately 5,000 mg, approximately 2,000 mg to approximately 10,000 mg, approximately 2,000 mg to approximately 8,000 mg, approximately 2,000 mg to approximately 6,000 mg, approximately 2,000 mg to approximately 5,000 mg, and approximately 3,000 mg to approximately 6,000 mg.

[0205] In compositions having first and second cysteamine precursor components, the amount of the second active ingredient in the solid unit dosage form can vary, for example, from 50 to 700 mg. For example, the dosage may contain approximately 50mg to 700mg, 50mg to 600mg, 50mg to 500mg, 50mg to 450mg, 75mg to 700mg, 75mg to 600mg, 100mg to 700mg; 100mg to 600mg, 100mg to 500mg, 100mg to 400mg, 250mg to 700mg, 250mg to 600mg, 250mg to 500mg, 250mg to 400mg, 400mg to 700mg, 400mg to 600mg, 400mg to 500mg, 450mg to 700mg, 450mg to 600mg, and 450mg to 500mg. In a composition having a cysteamine precursor as a first active ingredient and an in vivo cysteamine production promoter as a second active ingredient, the amount of the second active ingredient in a unit dosage form can vary, for example, from 0.1 mg to 400 mg.

[0206] In alternative embodiments comprising the first and second ciseamine precursor components, the amount of the second active ingredient in the liquid or powder unit dosage form may vary, for example, from about 250 mg to about 6,000 mg. For example, the dosage per dose may be about 250 mg to about 6,000 mg, about 250 mg to about 5,000 mg, about 250 mg to about 4,000 mg, about 250 mg to about 3,000 mg, about 250 mg to about 2,000 mg; about 500 mg to about 6,000 mg, about 500 mg to about 5,000 mg, about 500 mg to about 4,000 mg, about 500 mg to about 3,000 mg, about 750 mg to about 6,000 mg, about 750 mg to about 5,000 mg, about 750 mg to about 4 It may contain the following amounts of the second active ingredient: 1,000 mg, approximately 750 mg to approximately 3,000 mg, approximately 1,250 mg to approximately 6,000 mg, approximately 1,250 mg to approximately 5,000 mg, approximately 1,250 mg to approximately 4,000 mg, approximately 1,250 mg to approximately 3,000 mg, approximately 2,000 mg to approximately 6,000 mg, approximately 2,000 mg to approximately 5,000 mg, approximately 2,000 mg to approximately 4,000 mg, approximately 2,000 mg to approximately 3,000 mg, and approximately 2,500 mg to approximately 5,000 mg.

[0207] In a solid composition containing a third, or third and fourth, cysteamine precursor component, the unit dose may contain approximately 50 mg to approximately 400 mg of each of the third active component and, if present, the fourth active component. For example, the dose may contain approximately 50 mg to approximately 400 mg, approximately 50 mg to approximately 350 mg, approximately 50 mg to approximately 300 mg, approximately 50 mg to approximately 250 mg, approximately 75 mg to approximately 400 mg, approximately 75 mg to approximately 350 mg, approximately 75 mg to approximately 300 mg, approximately 75 mg to approximately 250 mg, approximately 100 mg to approximately 400 mg, approximately 100 mg to approximately 350 mg, approximately 100 mg to approximately 300 mg, approximately 100 mg to approximately 250 mg, approximately 250 mg to approximately 400 mg, approximately 250 mg to approximately 350 mg, or approximately 250 mg to approximately 300 mg. In a composition having five active ingredients, the unit dose of the five ingredients may range from approximately 50 mg to approximately 300 mg. In a composition having a fourth active ingredient, and optionally a third active ingredient, as an in vivo cysteamine production promoter, the amount of the fourth active ingredient and optionally the third active ingredient in the unit dosage form may vary, for example, from 0.1 mg to 400 mg.

[0208] In alternative embodiments comprising a third, or third and fourth, cysteamine precursor component in a liquid or powder unit dosage form, the unit dose of the third and optionally fourth active component may vary, for example, from about 250 mg to about 4,000 mg per dose. For example, the dosage per dose may be about 250 mg to about 4,000 mg, about 250 mg to about 3,000 mg, about 250 mg to about 2,000 mg, about 250 mg to about 1,000 mg, about 500 mg to about 4,000 mg, about 500 mg to about 3,000 mg, about 500 mg to about 2,000 mg, about 500 mg to about 1,000 mg, about 750 mg to about 4,000 mg, about 750 mg to about 3,000 mg, about 750 mg to about 2,000 mg, or about 750 mg It may contain a third and optionally fourth active ingredient in amounts of approximately 1,000 mg, 1,000 mg to 4,000 mg, 1,000 mg to 3,000 mg, 1,000 mg to 2,000 mg, 1,000 mg to 1,500 mg, 1,500 mg to 4,000 mg, 1,500 mg to 3,000 mg, 1,500 mg to 2,000 mg, 2,000 mg to 4,000 mg, and 2,000 mg to 3,000 mg.

[0209] Pharmaceutical compositions can be formulated, by means of procedures known in the art, to provide immediate, delayed, gastric retention, sustained, or colonic release (collectively referred to as controlled release) of the active ingredient after administration to a patient.

[0210] To prepare solid compositions such as tablets, the active ingredient(s) (e.g., several cysteamine precursors) can be mixed with one or more pharmaceutically acceptable excipients to form a solid bulk formulation composition containing a homogeneous mixture of the compounds of the present invention. When these bulk formulation compositions are homogeneous, the active ingredients are typically uniformly dispersed throughout the composition, thereby allowing the composition to be easily subdivided into equally effective unit dosage forms such as tablets, capsules, or microparticles. The solid bulk formulation is then subdivided into the above-mentioned unit dosage forms.

[0211] Alternatively, two homogeneous batches of active ingredient(s) mixed with one or more pharmaceutical excipients can be prepared, each using different concentrations of the active ingredient(s). The first mixture can then be used to form a core, and the second mixture to form a shell around the core, thereby forming a composition with variable drug-release properties. If the higher-concentration batch is located in the core and the lower-concentration batch is located in the shell, once the shell is substantially dissolved or eroded, a faster drug-release rate follows an initial moderate rate of drug release. In some embodiments, the pharmaceutical composition contains a higher concentration of the active ingredient(s) in the core than in the shell. The ratio of cysteamine precursor concentrations in the core:shell can range, for example, from about 1.5:1 to 4:1. Excipients may also differ in type or concentration between the two batches to affect the drug-release rate. In some embodiments, polymer(s) or other matrix-forming components in the core release the active ingredient(s) more slowly than those from the shell. In such embodiments, higher concentrations of cysteamine precursors in the core are partially or completely equilibrated by slower drug release, extending the duration of cysteamine precursor release and therefore the duration of cysteamine production in vivo, intestinal absorption, and elevated blood levels. One or more coatings may be applied to the core before the shell layer is applied, and additional coatings may be applied to the shell to enable an efficient manufacturing process and / or help provide desired pharmacological properties, including the timing and location of drug release in the gastrointestinal tract.

[0212] The pharmaceutical compositions of the present invention include those formulated to release a mixture of cysteamine precursors with different mechanisms or number of degradation steps leading to cysteamine production. Specifically, a mixture of two, three, four, or five cysteamine precursors, each comprising one, two, three, or more chemical and / or enzymatic degradation steps separate from the release of cysteamine. For example, one step may be reduction of a disulfide bond (in the case of a cysteamine mixed disulfide) or pantetheinase cleavage (in the case of pantetheine). A second step may be reduction of a disulfide bond followed by pantetheinase cleavage (in the case of pantetheine disulfide), or phosphatase cleavage followed by pantetheinase cleavage (in the case of 4-phosphopantetheine). A third step may be reduction of a disulfide bond followed before or after degradation to pantetheine (e.g., by phosphatase), followed by pantetheinase cleavage (e.g., in the case of 4-phosphopantetheine disulfide). The four steps may be reduction of the disulfide bond, followed by two degradation steps to pantetheine (e.g., removal of the adenine nucleotide moiety by ectonucleotide diphosphatase, followed by removal of the 4′ phosphate by phosphatase), and then pantetheinase cleavage (e.g., coenzyme A or dephosphocoenzyme A disulfide). The purpose of combining cysteamine precursors having different chemical and / or enzymatic degradation pathways to cysteamine is to extend the time that cysteamine is produced from the intestines and absorbed from the intestines, thereby extending the duration of therapeutically effective cysteamine blood levels. In some embodiments, the pharmaceutical composition of the present invention comprises at least two cysteamine precursors, and in further embodiments, the pharmaceutical composition comprises three cysteamine precursors.

[0213] The pharmaceutical compositions of the present invention can be formulated for mixed release, meaning that one composition contains two drug release profiles. For example, an immediate-release formulation can be combined with a sustained-release formulation. (See, for example, compound F in Figure 14.) In such a composition, the first active ingredient may be formulated for immediate release, which begins between approximately 5 and 30 minutes after ingestion. For example, the first active ingredient may be released 5, 10, 15, 20, 25, 30, or 45 minutes after ingestion of the composition. The first active ingredient is formulated so that a therapeutic plasma cysteamine concentration is achieved between approximately 15 minutes and 3 hours, preferably between 30 minutes and 2 hours, after ingestion. For example, a therapeutic plasma cysteamine concentration may be reached 0.5 hours, 1 hour, 2 hours, or 3 hours after ingestion of the composition. The type of cysteamine precursor used (e.g., thiols, cysteamine mixed disulfides, pantothecin disulfide, coenzyme A disulfide, N-acetylcysteamine disulfide, etc.) affects the time it takes to reach therapeutic blood concentrations of cysteamine and the duration for which those concentrations are maintained.

[0214] In compositions having two, three, and optionally four or five active ingredients (e.g., multiple cysteamine precursors and / or enhancers of cysteamine production and absorption in vivo), each of the second, third, and / or fourth, and / or fifth active ingredients is formulated to initiate controlled release from the composition between approximately 1 hour and 8 hours after ingestion. Controlled-release compositions may include delayed-release and / or sustained-release formulations. For example, the second, third, and / or fourth active ingredients may be released at 1, 1.5, 2, 3, 4, 5, 6, 7, or 8 hours after ingestion of the composition. The second, third, and / or fourth active ingredients are formulated so that the plasma concentration of cysteamine (reflecting the contribution of all active ingredients) begins to be maintained within a therapeutic range between approximately 30 minutes and 2 hours after ingestion and is extended for 6 to 10 hours, more preferably 8 to 12 hours, or longer. For example, plasma cysteamine concentrations may remain within a therapeutic range for 6, 8, 10, 12, 15, 20, or 24 hours after ingestion of the active ingredient of the composition. Depending on the patient's age and size, the disease being treated, and the patient's cysteamine metabolic rate, two or more compositions may be required to deliver sufficient cysteamine precursors to achieve therapeutic blood levels over several hours.

[0215] In some embodiments, compositions consisting of single formulations can be produced as substitutes or complements to pharmaceutical compositions containing mixed formulations. That is, time-based formulations, such as immediate-release or sustained-release formulations, and anatomically targeted formulations, such as gastric retention, delayed-release, and colon-targeted formulations, can be prepared for administration as separate compositions. Formulating a collection of pharmaceutical compositions with different drug-release properties (whether time-based or anatomical / physiological) offers certain advantages. For example, such compositions can be administered to different patients in different combinations and ratios to result in therapeutically within-range blood cysteamine levels over extended periods. That is, a therapeutic regimen consisting of one, two, three, or more compositions administered on a specific schedule can be tailored to the individual patient's cysteamine production, absorption, and metabolic capacity. Since these capabilities are known to vary among patients, formulations of multiple homogeneous compositions containing different cysteamine precursors and different drug-release properties can be combined in different ratios for different patients, addressing the known limitations of existing cysteamine formulations.

[0216] Preferably, a combination of two or more pharmaceutical compositions can maintain cysteamine blood levels within a therapeutic range for at least 2 to 8 hours after ingestion, more preferably 1 to 8 hours after ingestion, even more preferably 2 to 10 hours, most preferably 1 to 10 hours, 1 to 12 hours, 1 to 14 hours, or longer. Separately formulated pharmaceutical compositions containing different cysteamine precursors with different drug release profiles provide the dosing flexibility necessary to individualize the administration regimen to achieve therapeutically effective cysteamine blood concentrations over a long period.

[0217] Gastric emptying time and colonic transit time are frequently reported to vary significantly (by more than twofold) among healthy individuals. The levels of the intestinal redox environment and pantethinase activity are also known to vary between individuals. These and other factors are thought to explain the wide inter-individual variability in plasma cysteamine levels observed after cysteamine administration. For example, in a study of the pharmacokinetics of immediate-release cysteamine bietartrate in healthy volunteers, peak cysteamine blood levels (Cmax) after oral administration of 600 mg with food changed more than eightfold, from 7 micromoles to 57.3 micromoles (Dohil R. and P. Rioux, Clinical Pharmacology in Drug Development 2:178 (2013)). In the same study, Cmax following 600 mg of delayed-release cysteamine bietartrate administered with food changed 12fold, from 2.1 μM to 25.4 μM. Inter-patient variability in cysteamine plasma levels was not extreme when cysteamine was administered to fasting patients, but still reached up to fourfold. (When cysteamine is administered every 6 hours, as in the case of Cystagon®, or every 12 hours, as in the case of Procysbi®, it is difficult to completely avoid meal times.)

[0218] Current cysteamine formulations and administration methods offer only one tool to address inter-subject variability: increasing or decreasing the dose. The cysteamine precursors, in vivo cysteamine synthesis and absorption enhancers, drug formulations, and drug administration methods of the present invention provide multiple tools for achieving therapeutic blood cysteamine levels by adjusting compounds, dosage forms, and administration regimens for individual patients without leading to unacceptable toxicity often associated with high Cmax or inadequate therapeutic effects associated with blood levels below long-term therapeutic thresholds.

[0219] Another advantage of separately formulated compositions is that they can be administered at different times in relation to meals. This is a useful option because different classes and types of formulations of cysteamine precursors interact differently with meals. For example, to maximize gastric retention time, gastric retention formulations should be administered with or immediately after a meal, preferably with a nutrient-rich meal. Conversely, immediate-release formulations containing cysteamine mixed disulfides that can be rapidly converted to cysteamine by reduction of the disulfide bond should preferably not be administered with large meals. Large meals interfere with cysteamine absorption in some individuals, but meals are compatible with certain cysteamine precursors, such as pantetheine disulfide, which produce little cysteamine (if present) in the stomach and tend to be converted to cysteamine in the small intestine.

[0220] The individualized dosing regimens possible with the compounds and formulations of the present invention are particularly useful because, while the wide inter-individual variability in the intestinal absorption of cysteamine is well documented, the relatively moderate intra-individual variability is equally well established. That is, a given subject absorbs and metabolizes substantially similar doses of cysteamine when administered on multiple occasions under similar circumstances. Therefore, individualized dosing regimens to produce therapeutically ranged blood cysteamine levels for a particular patient should be relatively stable and yield predictable results over time.

[0221] Sustained-release formulations can be designed to release drugs over a wide range of varying periods using methods known in the field. (Wen, H. and Park, K., eds.: Oral Controlled Release Formulation Design and Drug Delivery: Theory to Practice, Wiley, 2010; Wells, J.I. and Rubinstein, MH, eds.: Pharmaceutical Technology: Controlled Drug Release, Vol. I and II, Ellis and Horwood, 1991; and Gibson, M., ed.: Pharmaceutical Preformulation and Formulation: A Practical Guide from Candidate Drug Selection to Commercial Dosage Form, 2nd edition, Informa, 2009.)

[0222] Figures 14, 15, and 16 provide examples of pharmaceutical compositions of the present invention, intended to illustrate aspects such as active ingredients (cysteamine precursors, promoters of the conversion of cysteamine precursors to cysteamine, and promoters of enteric absorption of cysteamine), dose range (when all active ingredients are combined), type of formulation (including mixed formulations), combination of compositions, and method of administration (e.g., with food or with a meal). Examples of active ingredients include cysteamine precursors, as well as promoters of in vivo cysteamine production and promoters of enteric absorption of cysteamine.

[0223] Formulation for oral administration Pharmaceutical compositions intended by the present invention include those formulated for oral administration ("oral dosage forms"). Oral dosage forms may be, for example, tablets, capsules, liquid solutions or suspensions, powders, or liquid or solid crystals or granules, and these contain the active ingredient(s) in a mixture with non-toxic, pharmaceutically acceptable excipients. When formulated as a liquid, powder, crystal, or granule, the dosage may be packaged in a way that clearly defines the unit dose. For example, powders or granules or fine particles may be packaged in sachets. Liquids may be packaged in glass or plastic containers.

[0224] Excipients are selected from among other considerations known to those skilled in the fields of pharmacology, pharmaceuticals, and pharmaceutical manufacturing to provide acceptable sensory stimulation properties, control drug release properties, facilitate efficient manufacturing, and ensure the long-term stability of the pharmaceutical composition. Excipients may include, for example, inert diluents or fillers (e.g., sucrose, sorbitol, sugars, mannitol, microcrystalline cellulose, starch containing potato starch, calcium carbonate, sodium chloride, lactose, calcium phosphate, calcium sulfate, or sodium phosphate); granulators and disintegrants (e.g., cellulose derivatives containing microcrystalline cellulose, starch containing potato starch, croscarmellose sodium, alginate, or alginic acid); binders (e.g., sucrose, glucose, sorbitol, acacia, alginic acid, sodium alginate, gelatin, starch, pregelatinized starch, microcrystalline cellulose, aluminum magnesium silicate, sodium carboxymethylcellulose, hydroxypropyl methylcellulose, ethylcellulose, polyvinylpyrrolidone, or polyethylene glycol); as well as lubricants, anti-sticking agents (e.g., magnesium stearate, zinc stearate, stearic acid, silica, hydrogenated vegetable oil, or talc). Other pharmaceutically acceptable excipients may include colorants, flavorings, plasticizers, wetting agents, preservatives, buffers, and stabilizers. Many of these excipients are sold by multiple excipient manufacturers in various chemical forms and / or can be used in different concentrations and / or in various combinations with other excipients, ensuring differences in performance characteristics. Certain excipients can serve multiple purposes in a formulation.

[0225] Formulations for oral administration may also be presented as chewable tablets, as rigid gelatin capsules in which the active ingredient is mixed with an inert solid diluent (e.g., potato starch, lactose, microcrystalline cellulose, calcium carbonate, calcium phosphate, or kaolin), or as soft gelatin capsules in which the active ingredient is mixed with water or an oily medium, such as peanut oil, liquid paraffin, or olive oil. Powders, granules, and pellets may be prepared using the above-mentioned components in conventional methods below tablets and capsules, for example, using a mixer, fluidized bed apparatus, or spray dryer.

[0226] One category of useful formulations is important for the location of drug release, but primarily controls the rate of drug release (e.g., immediate and sustained-release formulations). A second category of useful formulations is important for the timing of release, but primarily controls the anatomical site of drug release (e.g., intragastric formulations for drug release in the stomach, colon-targeted formulations for the large intestine). Enteric-coated formulations are designed to remain intact in the acidic gastric environment and often to dissolve in the more alkaline small intestine, which is a type of anatomical target, and are often referred to as delayed-release formulations, emphasizing the time-controlled element. However, colon-targeted formulations may also have an enteric coating to prevent dissolution in the stomach, highlighting the complex relationship between anatomical targeting and control of drug release rate. Furthermore, there is extensive overlap between excipients used in time-based and anatomically or physiologically targeted formulations. These types of formulations can be combined in various ways to create multiple compositions with different drug release profiles in both time and space. Such compositions can be combined in different amounts and ratios to personalize treatment regimens to address biochemical and physiological variations among patients, as well as variations in disease type, severity, and activity.

[0227] Intragastric retention preparations Intragastric retention formulations may be used to release cysteamine precursors or salts thereof from the composition of the present invention in the stomach, and to control the release of the active ingredient(s) of the composition in the stomach over a prolonged period. In other words, since the point of intragastric retention formulations is prolonged intragastric retention, the accompanying excipients should provide sustained release of the active ingredient over the entire period that the intragastric retention formulation is expected to remain in the stomach, and optionally over a longer period including the time it takes to pass through the small intestine to the colon. Intragastric retention of the active ingredient of the present invention may be achieved by various mechanisms such as mucosal adhesion, buoyancy, sedimentation, swelling, and distension, and / or by the co-administration of pharmacological agents that delay gastric emptying. The excipients used in intragastric retention formulations, as well as the size and shape of the pharmaceutical composition, will vary depending on the mechanism of intragastric retention.

[0228] Mucosal-adherent / biodeadherent gastric retention preparations Mucosal adhesion refers to the adhesion of polymers used in a formulation to the gastrointestinal mucus layer until they are naturally removed from the surface as a result of ongoing mucus production. Bioadhesion, sometimes used interchangeably with mucosal adhesion, also encompasses the adhesion of polymers or other components of a pharmaceutical composition to molecules on the surface of gastrointestinal epithelial cells. The purpose of mucosal and bioadhesion is to increase the time that a pharmaceutical composition is in close proximity to gastrointestinal epithelial cells, including cell types capable of cysteamine precursor cleavage (i.e., cells expressing pantethinase on their surface) and cysteamine uptake and transport into circulation (e.g., cells expressing organic cation transporters). Mucosal-adherent polymers can be used when formulating large dosage forms such as tablets or capsules, and small dosage forms such as microparticles or microspheres. Various physiological factors such as peristalsis, mucin type, mucin turnover rate, gastrointestinal pH, fasting / feeding state, and type of food in the feeding state influence the degree and duration of mucosal adhesion. The mechanism of mucosal adhesion is thought to be due to the formation of electrostatic and hydrogen bonds at the interface between the polymer and mucus. Generally, mucosal adhesion is achieved with polymers that have affinity for the gastrointestinal mucosa, and is selected from synthetic or natural bioadherent materials such as polyacrylic acid, methacrylic acid and its derivatives or both, polybrene, polylysine, polycarbophil, carbomer, alginate, chitosan, cholestyramine, gum, lectin, polyethylene oxide, sucralfate, tragacanth, dextrin (e.g., hydroxypropyl beta-cyclodextrin), polyethylene glycol (PEG), gliadin, cellulose and cellulose derivatives, e.g., hydroxypropyl methylcellulose (HPMC), or mixtures thereof. For example, cross-linked acrylic and methacrylic acid copolymers available under trade names CARBOPOL (e.g., Carbopol 974P and 971P) and POLYCARBOPHIL have been used in mucosal adhesion formulations. (Hombach J. and A. Bernkop-Schnurch. Handbook of Experimental Pharmacology 197:251 (2010)).Other bioadherent cationic polymers include acidic gelatin, polygalactosamine, poly-amino acids such as polylysine, polyornithine, polyquaternary compounds, prolamins, polyimines, diethylaminoethyldextran (DEAE), DEAE-imines, polyvinylpyridine, polythiodiethylaminomethylethylene (PTDAE), polyhistidine, DEAE-methacrylate, DEAE-acrylamide, poly-p-aminostyrene, polyoxetane, Eudragit RL, Eudragit RS, GAFQUAT, polyamidoamine, cationic starch, DEAE-dextran, DEAE-cellulose, and copolymers of methacrylate (including copolymers of HPMA), N-(2-hydroxypropyl)-methacrylamide (see, for example, U.S. Patent No. 6,207,197).

[0229] Mucosal adhesion is most effective when applied to small particles (e.g., microparticles). Mucosal adhesion formulations can be combined with one or more other intragastric retention formulation methods, including floating formulations, swelling / bulging formulations, or any type of sustained-release formulation.

[0230] Floating gastric retention formulation Buoyancy as a gastric retention mechanism is effective in formulations of active ingredients (e.g., cysteamine precursors) having a lower bulk density than gastric juice and / or porridge (partially digested food in the stomach) to maintain buoyancy in the stomach. Generally, a density of less than 1 gram per cubic centimeter is desirable, and more preferably less than 0.9 grams per cubic centimeter. Buoyancy can be achieved by (i) using a low-density substance containing lipids, (ii) pre-forming bubbles(s) in the center of the composition, or (iii) using an effervescent excipient to generate bubbles in vivo. The latter type of pharmaceutical composition must be designed so that the gas produced by the effervescent excipient remains in the composition and thereby contributes to its buoyancy. For example, an effervescent excipient can be embedded in a polymer matrix to trap bubbles in the composition. The latter type of flotation formulation is generally prepared using a matrix containing a swelling polymer or polysaccharide and an effervescent couple (e.g., sodium bicarbonate and citrate or tartaric acid), or a chamber of trapped air, or a liquid that generates gas upon contact with liquid gastric contents at body temperature. Flotation gastric retention formulations have been extensively reviewed (e.g., Kotreka, UK Critical Reviews in Therapeutic Drug Carrier Systems, 28:47 (2011)).

[0231] Floating pharmaceutical compositions designed for intragastric retention have been known in the art for some time. For example, U.S. Patents 4,126,672, 4,140,755, and 4,167,558, each incorporated herein by reference, describe "hydrodynamically balanced" drug delivery systems (HBS) in tablet form having a density lower than that of gastric juice (i.e., less than 1 gram per cubic centimeter). As a result, the composition floats on gastric juice or porridge, thereby avoiding release through the pylorus during gastric muscle contractions. The drug is continuously released from a hydrophilic colloid derived from cellulose, such as methylcellulose, hydroxyalkylcellulose (e.g., hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose), or sodium carboxymethylcellulose, and upon contact with gastric juice, forms a water-impermeable barrier on the surface of the composition, which gradually erodes, slowly releasing the drug. A two-layer floating tablet having an outer layer formulated for immediate release and an inner layer formulated for sustained release is also disclosed in U.S. Patent No. 4,140,755, which is incorporated herein by reference.

[0232] Similar hydrodynamically balanced flotation formulations for sustained delivery of L-DOPA and decarboxylase inhibitors are also described (see U.S. Patent No. 4,424,235). Hydrophilic colloids such as gum arabic, tragacanth gum, locust bean gum, guar gum, karaya gum, agar, pectin, carrageenan, soluble and insoluble alginates, carboxypolymethylene, gelatin, casein, zein, and bentonite may be useful in the preparation of the flotation formulations of the present invention. The flotation formulations may contain up to about 60% fatty substances or mixtures of fatty substances selected from beeswax, cetyl alcohol, stearyl alcohol, glyceryl monostearate, hydrogenated castor oil, and hydrogenated cottonseed oil (lipids are less dense than gastric juice). The flotation formulations can promote the sustained release of cysteamine precursors and provide elevated plasma cysteamine levels over longer periods of time. Prolonged elevation of plasma cysteamine levels allows for less frequent administration.

[0233] The floating composition of the present invention may contain a gas generating agent. Methods for formulating floating compositions using gas generating compounds are known in the art. For example, floating capsules containing sodium bicarbonate are described in U.S. Patent No. 4,106,120. Similar floating granules based on gas generation are described in U.S. Patent No. 4,844,905. Floating capsules are described in U.S. Patent No. 5,198,229.

[0234] The floating composition may optionally contain an acid source and a gas-generating carbonate or bicarbonate agent, which together act as an effervescent couple to produce carbon dioxide gas that gives buoyancy to the formulation. The effervescent couple, consisting of a soluble organic acid and an alkali metal carbonate, forms carbon dioxide when the mixture comes into contact with water or when the alkaline component comes into contact with an acidic liquid (e.g., gastric juice). Typical examples of acids used include citric acid, tartaric acid, malic acid, fumaric acid, or adipic acid. Typical examples of gas-generating alkalis used include sodium bicarbonate, sodium carbonate, sodium glycine carbonate, sodium sesquicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, ammonium bicarbonate, sodium bisulfite, and sodium metabisulfite. The gas-generating agent interacts with the acid source, induced by contact with water or hydrochloric acid in gastric juice, to produce carbon dioxide or sulfur dioxide that is trapped in the matrix of the composition and improves its buoyancy properties. In one embodiment, the gas-generating agent is sodium bicarbonate and the acid source is citric acid.

[0235] Buoyancy is important because if a composition is not lighter than gastric juice and / or porridge immediately after reaching the stomach, it may be rapidly expelled through the pylorus. Some compositions, such as those containing pre-formed bubbles or low-density substances such as lipids, are lower in density than gastric juice and porridge at the time of ingestion. For buoyant compositions (i.e., effervescent formulations) that must achieve a density lower than that of gastric juice and / or porridge after reaching the stomach, a density of less than 1 gram per cubic centimeter is preferably achieved within 30 minutes, more preferably within 15 minutes, and most preferably within 10 minutes after contact with gastric juice. The buoyancy period is also important and should coincide with the drug release period. That is, if a composition is designed to release a drug for more than 6 hours, it must also be able to buoyant for 6 hours. Preferably, the buoyant composition maintains a density of less than 1 for at least 5 hours, more preferably 7.5 hours, and even more preferably 10 hours or more.

[0236] Large doses of cysteamine precursors (e.g., 2-10 grams) may be necessary to effectively treat some cysteamine-sensitive disorders and / or to achieve appropriate blood levels in adult subjects. Since the amount of any active ingredient that can be contained in a standard dosage form (e.g., tablets, capsules) is limited by the patient's ability to swallow large compositions, and administering multiple tablets or capsules can be inconvenient or unpleasant (impossible for patients with dysphagia), alternative dosage forms that do not limit the amount of active ingredient in a unit dosage form are useful. Powders, granules, and liquids are examples of dosage forms that are not limited in size, but can be delivered in unit doses by appropriate packaging (e.g., sachets or vials). In some embodiments of the present invention, the floating intragastric composition of the present invention is administered in liquid form. In further embodiments, the liquid composition contains an alginate. In other embodiments, the active pharmaceutical ingredient is delivered in the form of a powder or granules that can be sprinkled on food.

[0237] One type of liquid gastric retention floating drug delivery system utilizes alginates as excipients. Alginates are linear block polysaccharide copolymers made from beta-D-mannuronic acid and alpha-L-guluronic acid residues linked by 1,4-glycosidic bonds. They are used for a wide range of purposes in pharmaceutical compositions, including as a sustained-release polymer (see Murata et al., Eur J Pharm Biopharm 50:221 (2000)). Gaviscon is a brand name for floating liquid alginate formulations, including antacids. The safety of chronic alginate intake is well established, as it has been used for decades to treat gastroesophageal reflux. Floating formulations of alginates containing small molecule drugs have been described (see Katayama et al., Biol Pharm Bull. 22:55 (1999), and Itoh et al., Drug Dev Ind Pharm. 36:449 (2010)). Floating formulations that form a layer on the surface of gastric contents are sometimes referred to as raft-forming formulations. Raft-forming floating / gelling sustained-release compositions are described by Prajapati et al., J Control Release 168:151 (2013) and Nagarwal et al., Curr Drug Deliv. 5:282 (2008).

[0238] U.S. Patent No. 4,717,713, incorporated herein by reference, discloses a liquid (suitable for drinking) formulation that, upon contact with gastric contents, forms a semi-solid gel-like matrix in the stomach, thereby resulting in controlled release of a drug from the gelatinous matrix. A gel-forming vehicle is disclosed comprising xanthan gum, sodium alginate, gelatin or other polymers and complex coacervate pairs such as carrageenan, and thermogelled methylcellulose, all or subsets thereof, combined in various ratios, to influence the dissolution and / or diffusion rates of the suspended pharmaceutically active agent(s). Other excipients used include carbonate compounds such as calcium carbonate, which are effective both as gelation accelerators and as gas generators for suspending the gel. Xyloglucan and gellan gum can also be used as gelling agents or in combination with gelling agents.

[0239] Examples of liquid (drinkable) floating formulations include fine particles that can be provided as a liquid suspension (concentrate or ready for use) or as a powder that can be added to a liquid (e.g., water, juice, or other beverage). Floating gastric retention compositions may also be delivered in the form of a powder that is sprinkled on food or otherwise mixed in.

[0240] Examples of floating gastric retention formulations include mucosal adhesive polymers or other mucosal adhesive components (see U.S. Patents No. 6,207,197 and No. 8,778,396), and polymers such as polyethylene oxide, polyvinyl alcohol, sodium alginate, ethylcellulose, poly(lactic acid)coglycolic acid (PLGA), polylactic acid, polymethacrylate, polycaprolactone, polyester, polyacrylic acid, and polyamide can be used.

[0241] Swelling and expansion of gastric retention compositions Swelling and expansion are gastric retention mechanisms in which, upon contact with gastric juice, the composition swells to such an extent that it prevents it from passing through the pylorus and leaving the stomach. As a result, the composition remains in the stomach for a long period of time, for example, until the surface of the composition is eroded to a size smaller than the diameter of the pylorus, or until the stomach is substantially empty of food, at which point strong muscle contractions (sometimes called "housekeeper waves") sweep the stomach and remove its contents. The composition, in its swollen or expanded state, exceeds a diameter of approximately 14–16 mm and is therefore excluded from passing through the pyloric sphincter. Preferably, the composition exceeds a diameter of 16–18 mm. Swelling may be combined with buoyancy, which keeps the formulation away from the pylorus, especially in the feeding state.

[0242] The concept of formulations that swell upon contact with gastric juice and consequently remain in the stomach has been known since the 1960s. U.S. Patent No. 3,574,820 discloses a tablet that swells upon contact with gastric juice to a size that cannot pass through the pylorus and is therefore retained in the stomach. Similarly, U.S. Patent No. 5,007,790 describes a tablet or capsule made of a hydrophilic, water-swellable crosslinked polymer that swells rapidly to promote gastric retention while allowing for the slow dissolution of drug molecules mixed with the polymer.

[0243] U.S. Patent Publication 2003 / 0104053, incorporated herein by reference, discloses a unit dosage form tablet for drug delivery in which the active ingredient is dispersed in a solid unit matrix formed from a combination of poly(ethylene oxide) and hydroxypropyl methylcellulose. This combination is said to offer unique advantages in terms of release rate control and reproducibility, while also allowing both tablet swelling, which results in gastric retention, and tablet disintegration, which removes the tablet from the gastrointestinal tract after drug release has occurred. U.S. Patent 6,340,475, incorporated herein by reference and assigned to DepoMed, highlights a unit oral dosage form of an active ingredient developed by incorporating it into a polymer matrix consisting of a hydrophilic polymer that, upon absorbing water, swells to a sufficiently large size to promote gastric retention of the dosage form during feeding. The polymer matrix is ​​formed from polymers selected from the group consisting of poly(ethylene oxide), cellulose, crosslinked polyacrylic acid, xanthan gum, and alkyl-substituted celluloses such as hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, and microcrystalline cellulose.

[0244] Furthermore, gum-based swellable gastric retention systems have also been developed by DepoMed researchers. U.S. Patent No. 6,635,280, incorporated herein by reference, discloses a controlled-release oral dosage form of a highly water-soluble drug comprising one or more polymers that, upon absorbing water, swell to a sufficiently large size to promote retention of the dosage form in the stomach during feeding. The polymer matrix may be formed from polymers selected from poly(ethylene oxide), cellulose, alkyl-substituted cellulose, cross-linked polyacrylic acid, and xanthan gum. U.S. Patent No. 6,488,962, incorporated herein by reference, discloses an optimal tablet shape that prevents passage through the pylorus while remaining convenient for swallowing. The tablets are made using water-swellable polymers, including cellulose polymers and their derivatives, polysaccharides and their derivatives, polyalkylene oxides, polyethylene glycol, chitosan, poly(vinyl alcohol), xanthan gum, maleic anhydride copolymers, poly(vinylpyrrolidone), starch and starch-based polymers, maltodextrin, poly(2-ethyl-2-oxazoline), poly(ethyleneimine), polyurethane hydrogels, crosslinked polyacrylic acids and their derivatives, and copolymers of the listed polymers, including block copolymers and graft polymers.

[0245] U.S. Patent No. 6,723,340, incorporated herein by reference, discloses optimal polymer mixtures for producing swellable, gastric retention compositions. The mixtures provide optimal control of swelling and drug release parameters, as well as control of dissolution / erosion parameters, to ensure the composition passes into the small intestine during substantially complete drug release. Preferred polymer mixtures include combinations of poly(ethylene oxide) and hydroxypropyl methylcellulose. Preferred molecular weight and viscosity ranges are provided for the polymer mixtures.

[0246] The method described in the above patent publication has been used to formulate four USFDA-approved swelling-type gastric retention formulations, which have been described in multiple publications (for example, outlined in Berner et al., Expert Opin Drug Deliv. 3:541 (2006)).

[0247] U.S. Patent Publication 2008 / 0220060, incorporated herein by reference, discloses an intragastric retention formulation comprising an active substance granulated with a mixture of a weak gelling agent, a strong gelling agent, and a gas generating agent. Here, the strong gelling agent is selected from the group consisting of methylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose (excluding low-substituted hydroxypropylcellulose), hydroxyethylcellulose, ethylcellulose, sodium carboxymethylcellulose, xanthan gum, guar gum, carrageenan gum, locust bean gum, sodium alginate, agar-agar, gelatin, modified starch, copolymers of carboxyvinyl polymers, copolymers of acrylates, copolymers of oxyethylene and oxypropylene, and mixtures thereof. This patent also describes a method of manufacture. U.S. Patent 7,674,480 discloses a method for a swellable intragastric retention formulation that results in very rapid swelling using a mixture comprising a super-disintegrant, tannic acid, and one or more hydrogels. U.S. Patent Publication 2004 / 0219186, incorporated herein by reference, provides an expandable intragastric retention device comprising a gel formed from polysaccharides based on xanthan gum or locust bean gum or a combination thereof. U.S. Patent Publication 2006 / 0177497, incorporated herein by reference, discloses gellan gum-based orally controlled-release dosage forms as a platform technology for intragastric retention. The dosage forms further comprise hydrophilic polymers such as guar gum, hydroxypropyl methylcellulose, carboxymethylcellulose sodium salt, and xanthan gum.

[0248] U.S. Patent No. 6,660,300 discloses a biphasic swellable intragastric formulation technology suitable for delivering water-soluble drugs, wherein swelling and drug release are achieved by separate compartments of the composition, the inner solid granular phase comprising the drug and one or more hydrophilic polymers, one or more hydrophobic polymers and / or one or more hydrophobic materials (such as waxes, fatty alcohols and / or fatty acid esters). An outer solid continuous phase (in which the granules of the drug-containing inner phase are embedded) is formed using one or more hydrophobic polymers and / or one or more hydrophobic materials (such as waxes, fatty alcohols and / or fatty acid esters). Tablets and capsules are disclosed.

[0249] Other excipients useful for swellable or expandable matrix formulations include (i) water-swellable polymer matrices, and (ii) below: polyalkylene oxides, particularly poly(ethylene oxide), polyethylene glycol and poly(ethylene oxide)-poly(propylene oxide) copolymers; cellulose polymers; preferably acrylic acid and methacrylic acid polymers, their copolymers and esters, formed from acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and their copolymers, either with each other or with additional acrylate species such as aminoethyl acrylate; maleic anhydride copolymers; polymaleic acid; poly(acrylamide), poly(methacrylamide), poly(dimethylacrylamide and poly(N-isopropyl-acrylamide), such as poly(vinyl alcohol), poly(olefin alcohol), such as poly(vinylpyrrolidone), poly(N-vinyl lactam), poly(N-vinyl caprolactam and so on. Examples include copolymers of these; polyols such as glycerol, polyglycerol (especially highly branched polyglycerol), propylene glycol, and trimethylene glycol substituted with one or more polyalkylene oxides, e.g., mono-, di-, and tri-polyoxyethylene-modified glycerol, mono- and di-polyoxyethylene-modified propylene glycol, and mono- and di-polyoxyethyl-modified trimethylene glycol; polyoxyethylene-modified sorbitol and polyoxyethylene-modified glucose; polyoxazolines including poly(methyloxazoline) and poly(ethyloxazoline); polyvinylamines; polyvinyl acetates, including polyvinyl acetate itself and ethylene-vinyl acetate copolymers, polyvinyl acetate phthalate, etc.; polyimines such as polyethyleneimine; starch and starch-based polymers; polyurethane hydrogels; chitosan; polysaccharide gums; jelins; and hydrophilic polymers selected from shellac, shellac-acetyl alcohol, and shellac n-butyl stearate.The gastric retention formulation may also include any combination of floating formulations, mucoadhesive formulations, swelling matrix formulations, modified shape formulations, and / or magnetic formulations.

[0250] In some embodiments, the pharmaceutical composition of the present invention is a gastric retention composition that is retained in the stomach as a result of swelling to a size that inhibits passage through the pylorus. In further embodiments, the gastric retention composition is retained in the stomach by both swelling and floating mechanisms.

[0251] Developing, shape-changing gastric retention formulations Pharmaceutical compositions that expand, depressurize, or otherwise change in size and / or shape upon contact with liquid gastric contents are also described and are suitable delivery vehicles for the compounds and formulations of the present invention. Such compositions utilize the same principle as swelling / swelling gastric retention formulations in that they change the shape of the stomach to a size and / or geometry that is difficult to pass through the pylorus. Methods and materials for making expanding, stretching, or other shape-changing gastric retention compositions are known in the art. For example, U.S. Patent No. 3,844,285 describes various such devices intended for veterinary use in ruminants, but the basic principles are also applicable to human gastric retention formulations. U.S. Patent No. 4,207,890 describes a controlled-release drug delivery system consisting of a "disintegrated, expandable, non-porous polymer envelope containing an effective amount of an expanding agent that expands upon contact with gastric juice" and as a result remains retained in the stomach in an expanded state. The composition is administered inside a disintegrated capsule. Expanding and shape-changing gastric retention compositions have been reviewed (e.g., Klausner et al., Journal of Controlled Release 90:143 (2003)).

[0252] An exemplary unfolding intragastric retention technology called the “accordion pill” has been developed by Intec Pharma (Jerusalem, Israel). A multilayer planar structure of various shapes (with at least one layer containing the drug) folds into an accordion or step-like shape, as described in Kagan, L. Journal of Controlled Release 113:208 (2006), and is packaged within a capsule. Further features of the accordion pill and related technologies, including pharmaceutically acceptable excipients preferably used in their construction, are disclosed in U.S. Patent No. 6,685,962, incorporated herein by reference. The capsule dissolves upon contact with gastric contents, releasing the folded composition, which rapidly unfolds and subsequently remains in the stomach for up to 12 hours when administered with a normal meal.

[0253] Other gastric retention techniques include superporous hydrogels and ion exchange resin systems. Superporous hydrogels rapidly absorb water through numerous interconnected pores and swell rapidly (within 1 minute of liquid contact). Compositions can swell to more than 100 times their original size while maintaining sufficient mechanical strength to withstand gastric contraction forces when combined with hydrophilic polymers such as croscarmellose sodium (e.g., trade name: Ac-Di-Sol). Ion exchange resin beads can be filled with negatively charged drugs and suspended using a gas-generating agent (e.g., a bicarbonate that reacts with chloride ions in gastric juice to produce carbon dioxide gas). The beads are encapsulated in a semipermeable membrane that traps gas, resulting in long-term suspension of the beads.

[0254] Intragastric retention formulations may also include any combination of mucosal adhesive, floating, raft-forming, swelling, unfolding / shape-changing, superporous hydrogel, or ion-exchange resin formulations. Such combinations are known to those skilled in the art. For example, U.S. Patent No. 8,778,396 ("Multi-unit Intragastric Retention Pharmaceutical Dosage Formulations Containing Microparticles"), which is incorporated herein in whole by reference, describes a complex mucosal adhesive floating intragastric retention formulation comprising microparticles.

[0255] The compositions of the present invention may, but are not limited to, include hydrophilic polymers having swelling and / or mucosal adhesion properties to further promote gastric retention. Suitable hydrophilic polymers having swelling and / or mucosal adhesion properties for incorporation into the compositions of the present invention include, but are not limited to, polyalkylene oxides; cellulose polymers; acrylic and methacrylic acid polymers and their esters; maleic anhydride polymers; polymaleic acid; poly(acrylamide); poly(olefin alcohol); poly(N-vinyl lactam); polyols; polyoxyethylated sugars; polyoxazolines; polyvinylamines; polyvinyl acetates; polyimines; starch and starch-based polymers; polyurethane hydrogels; chitosan; polysaccharide gums; zein; shellac-based polymers; polyethylene oxide, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, methylcellulose, polyacrylic acid, maltodextrin, pregelatinized starch, and polyvinyl alcohol, their copolymers and mixtures.

[0256] The release of active ingredients from a composition can be achieved by using appropriate retarders, including excipients known in the pharmaceutical field for their release-delaying properties. Examples of such retarders include, but are not limited to, polymer release retarders, non-polymer release retarders, or any combination thereof.

[0257] Examples of polymer release retarders used for the purposes of the present invention include, but are not limited to, cellulose derivatives; polyhydric alcohols; sugars, gums, and their derivatives; vinyl derivatives, polymers, copolymers, or mixtures thereof; maleic acid copolymers; polyalkylene oxides or their copolymers; acrylic acid polymers and acrylic acid derivatives; or any combination thereof. Examples of cellulose derivatives include, but are not limited to, ethylcellulose, methylcellulose, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose (HPC), hydroxyethylcellulose, hydroxymethylcellulose, hydroxyethyl methylcellulose, carboxymethylcellulose (CMC), or combinations thereof. Examples of polyhydric alcohols include, but are not limited to, polyethylene glycol (PEG) or polypropylene glycol, or any combination thereof. Sugars, gums, and their derivatives include, but are not limited to, dextrin, polydextrin, dextran, pectin and pectin derivatives, alginic acid, sodium alginate, starch, hydroxypropyl starch, guar gum, locust bean gum, xanthan gum, karaya gum, tragacanth gum, carrageenan, acacia gum, gum arabic, fenugreek fiber, or gellan gum, or any combination thereof. Vinyl derivatives, polymers, copolymers, or mixtures thereof include, but are not limited to, polyvinyl acetate, polyvinyl alcohol, a mixture of polyvinyl acetate (8 w / w) and polyvinylpyrrolidone (2 w / w) (Kollidon SR), vinylpyrrolidone copolymer, vinyl acetate copolymer, polyvinylpyrrolidone (PVP), or combinations thereof. Examples of polyalkylene oxides or their copolymers include, but are not limited to, polyethylene oxide, polypropylene oxide, poly(oxyethylene)-poly(oxypropylene) block copolymer (poloxamer), or combinations thereof.Examples of maleic acid copolymers include, but are not limited to, vinyl acetate maleic anhydride copolymer, butyl acrylate styrene maleic anhydride copolymer, or any combination thereof. Examples of acrylic acid polymers and acrylic acid derivatives include, but are not limited to, carbomers, methacrylic acid, polymethacrylic acid, polyacrylate, polymethacrylate, or combinations thereof. Examples of polymethacrylates include, but are not limited to, a) copolymers formed from monomers selected from methacrylic acid, methacrylic acid esters, acrylic acid, and acrylic acid esters, and c) copolymers formed from monomers selected from ethyl acrylate, methyl methacrylate, and trimethylammonium ethyl methacrylate chloride, or any combination thereof. Examples of nonpolymeric release retarders used for the purposes of the present invention include, but are not limited to, fats, oils, waxes, fatty acids, fatty acid esters, long-chain monohydric alcohols, and esters thereof, or combinations thereof. Examples of nonpolymer release retarders used in the present invention include, but are not limited to, Cutina (hydrogenated castor oil), Hydrobase (hydrogenated soybean oil), Castorwax (hydrogenated castor oil), Croduret (hydrogenated castor oil), Carbowax, Compritol (glyceryl behenate), Sterotex (hydrogenated cottonseed oil), Lubritab (hydrogenated cottonseed oil), Apifil (yellow wax), Akofine (hydrogenated cottonseed oil), Softtisan (hydrogenated palm oil), Hydrocote (hydrogenated soybean oil), Corona (lanolin), Gelucire (macrogol glyceride draulic acid), Precirol (glyceryl palmitostearate), Emulcire (cetyl alcohol), Plurol diisostearyl (polyglyceryl diisostearate), and Geleol (glyceryl stearate), as well as mixtures thereof.

[0258] The gastric retention composition of the present invention may, but is not limited to, a monolithic or multilayer dosage form or an inlay system. In one embodiment of the present invention, the gastric retention composition is in the form of a two- or three-layer solid dosage form. In an exemplary embodiment, a solid pharmaceutical composition in the form of an expandable two-layer system for oral administration is adapted to deliver the active pharmaceutical ingredient from the first layer immediately upon reaching the gastrointestinal tract, and to deliver a further pharmaceutical agent, which may be the same as or different from the second layer, in a modified manner over a specific period of time. The second layer may be formulated to expand in the composition, thereby extending the retention of the composition in the stomach.

[0259] In further exemplary embodiments, a solid pharmaceutical composition for oral administration comprises two layers, one layer containing the active ingredient along with a suitable release retarder, and the other layer containing a swelling agent in combination with other excipients. In another embodiment of the present invention, a solid pharmaceutical composition for oral administration comprises an inlay system, which is a special dosage form comprising a first tablet containing an active ingredient(s) placed inside a second tablet containing an excipient that ensures gastric retention. In this system, the tablet containing the active ingredient is small, and all sides except at least one side are coated with a blend of excipients containing a swelling polymer or a suspension system, or both, to ensure gastric retention.

[0260] In yet another embodiment of the present invention, the dosage form may be optionally coated. Surface coatings can be used for sensory stimulation purposes (particularly thiols or disulfides having an odor or unpleasant taste), for drug labeling purposes (e.g., color coding systems for dosage forms), for cosmetic purposes, for dimensional stabilization of compressed dosage forms, or for delaying drug release. The surface coating may be any conventional coating suitable for enteral use. The coating can be carried out using any prior art using conventional components. Surface coatings can be obtained using fast-dissolving films using conventional polymers, such as, but not limited to, hydroxypropyl methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, polyvinyl alcohol, and polymethacrylate. Coating excipients and methods for using them are well known in the art. See, for example, McGinity, James W. and Linda A. Felton, Aqueous Polymeric Coatings for Pharmaceutical Dosage Forms, 3rd edition, Informa Healthcare, 2008.

[0261] Furthermore, in another embodiment of the present invention, the composition may include, but is not limited to, pellets, microspheres, microcapsules, microbeads, microparticles, or nanoparticles that have long transit time in the intestinal tract in order to effectively deliver activators that require a longer residence time in the intestinal tract. The multiplicative system may (i) be bioadherent or mucoadherent, thereby delaying transit through the gastrointestinal tract, or (ii) be able to float on the gastric contents and optionally form a gel-like layer, or (iii) be coated with a pH-sensitive outer layer or a layer that dissolves in the mildly acidic environment of the small intestine or in the neutral to slightly basic environment of the ileum (typically the intestinal segment with the highest pH), or (iv) be formed using a polymer containing a drug that is not digested by human enzymes but is digested by enzymes produced by intestinal bacteria, leading to drug release in the distal ileum and colon. In embodiments, the composition of the present invention is in the form of multiplicative particles and is gastricly retentive. Such multiplicative systems may be prepared by methods including, but not limited to, pelletization, granulation, spray drying, spray setting, etc.

[0262] Appropriate polymer release control agents can be used in the compositions of the present invention. In one embodiment, the polymer release control agent is pH-independent, pH-dependent, or any combination thereof. In another embodiment, the polymer release control agent used in the compositions of the present invention may be swollen or non-swollen. In further embodiments, polymer release control agents that can be used in the compositions of the present invention include, but are not limited to, cellulose derivatives, sugars or polysaccharides, poly(oxyethylene)-poly(oxypropylene) block copolymers (poloxamers), vinyl derivatives or their polymers or copolymers, polyalkylene oxides and their derivatives, maleic acid copolymers, acrylic acid derivatives, etc., or any combination thereof.

[0263] Controlled-release compositions for oral use may be constructed to release the active drug by controlling the dissolution and / or diffusion of the active drug substance. To obtain controlled release and thereby optimize the plasma concentration-for-time profile, one of many strategies can be employed. In one example, controlled release is achieved by the appropriate selection of various formulation parameters and components, including, for example, various types of controlled-release compositions and coatings. Thus, drugs are formulated, along with appropriate excipients, into pharmaceutical compositions that release the drug in a controlled manner at administration. Examples include single or multiple unit tablet or capsule compositions, oily solutions, liquids, suspensions, emulsions, microcapsules, microspheres, nanoparticles, powders, and granules. In certain embodiments, the composition includes a biodegradable, pH, and / or temperature-sensitive polymer coating.

[0264] Dissolution or diffusion-controlled release can be achieved by appropriate coating of the compound in tablet, capsule, pellet, or granular formulation, or by incorporating the compound into an appropriate matrix. Examples of controlled-release coatings include one or more of the above-mentioned coating materials, and / or, for example, shellac, beeswax, glycowax, castor oil wax, carnauba wax, stearyl alcohol, glyceryl monostearate, glyceryl distearate, glycerol palmitostearate, ethylcellulose, acrylic resin, dipolylactic acid, cellulose acetate / butyrate, polyvinyl chloride, polyvinyl acetate, vinylpyrrolidone, polyethylene, polymethacrylate, methyl methacrylate, 2-hydroxymethacrylate, methacrylate hydrogel, 1,3-butylene glycol, ethylene glycol methacrylate, and / or polyethylene glycol. In controlled-release matrix formulations, examples of matrix materials may include hydrated methylcellulose, carnauba wax, and stearyl alcohol, carbopol 934, silicone, glyceryl tristearate, methyl acrylate-methyl methacrylate, polyvinyl chloride, polyethylene, and / or halogenated fluorocarbons.

[0265] Alternatively, a specific cysteamine precursor, or an enhancer of cysteamine production or absorption in vivo, may be formulated and administered as a medical food. Medical foods are regulated by the US FDA as foods, not drugs. Methods for formulating medical foods are known in the art. For a description of methods for preparing and administering active compounds in food or beverages, see, for example, U.S. Patent Publication 2010 / 0261791. Nutracia, a medical food company based in the Netherlands, has more than 250 patent applications and patents describing methods for combining pharmacologically active agents with food or beverages.

[0266] coating The pharmaceutical compositions formulated for oral delivery, such as tablets or capsules, according to the present invention can be coated or otherwise compounded to provide dosage forms that offer the advantages of delayed release or extended release. The coatings can be adapted to release the active drug substance in a predetermined pattern (for example, to achieve a controlled-release formulation), or they can be adapted to prevent the release of the active drug substance until after passage through the stomach by using, for example, enteric coatings (e.g., polymers that are pH-sensitive ("pH-controlled release"), polymers that have a slow or pH-dependent swelling rate, dissolution or erosion ("time-controlled release"), polymers that are broken down by enzymes ("enzyme-controlled release" or "biodegradable release"), and polymers that form a rigid layer that is broken down by increasing pressure ("pressure-controlled release")). Exemplary enteric coatings that can be used in the pharmaceutical compositions described herein include sugar coatings, film coatings (e.g., based on hydroxypropyl methylcellulose, methylcellulose, methylhydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, acrylate copolymers, polyethylene glycol, and / or polyvinylpyrrolidone), or coatings based on methacrylic acid copolymers, cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, hydroxypropyl methylcellulose acetate succinate, polyvinyl acetate phthalate, shellac, and / or ethylcellulose. Furthermore, time-delaying materials such as glyceryl monostearate or glyceryl distearate may be used.

[0267] For example, a tablet or capsule may contain an internal dose component and an external dose component, the latter in the form of an envelope relative to the former. The two components can be separated by an enteric coating, which resists disintegration in the stomach and allows the internal component to pass through the duodenum intact or its release to be delayed.

[0268] When an enteric coating is used, preferably a substantial amount of the drug is released in the lower gastrointestinal tract. Alternatively, a leak-through enteric coating can be used to provide a release profile intermediate between immediate-release and delayed-release formulations. For example, U.S. Patent Application No. 2008 / 0020041(A1) discloses a pharmaceutical formulation coated with an enteric material that releases at least a portion of the active ingredient upon contact with gastric fluid, along with the remaining component released upon contact with intestinal fluid.

[0269] In addition to coatings that provide delayed or extended release, solid tablet compositions may include coatings adapted to protect the composition from undesirable chemical changes (e.g., chemical decomposition before the release of the active drug substance). Coatings can be applied to solid dosage forms in a manner similar to that described in the Encyclopedia of Pharmaceutical Technology, Volumes 5 and 6, edited by Swarbrick and Boyland, 2000.

[0270] In controlled-release formulations, the active ingredient of the composition may be targeted for release in the small intestine. The formulation may include an enteric coating so that the composition is resistant to the lower pH environment found in the stomach but sensitive to the higher pH environment of the small intestine. To control the release of the active ingredient in the small intestine, multi-particle formulations may be used to prevent the simultaneous release of the active ingredient. A multi-particle composition may include a plurality of individual enteric-coated cores comprising a hydrophobic phase containing a cysteamine precursor or a salt thereof dispersed in a microcrystalline cellulose gel, and a hydrophilic phase containing a hydrogel. The microcrystalline cellulose (MCC) acts as a release-controlling polymer for the cysteamine precursor or salt while the core is dissolved or eroded in the intestine, preventing dose dumping and stabilizing the cysteamine precursor or salt. Two or more multi-particle compositions different with respect to excipients in the core or coating layer may be compounded into a single pharmaceutical composition (e.g., a capsule, powder, or liquid) to release the active ingredient (e.g., cysteamine precursor) over a longer period of time. Alternatively, the same effect can be achieved by using different concentrations of excipients in batches of two or more microparticles, and then combining the microparticles from the different batches in a ratio (e.g., 1:1) selected to yield a targeted drug release profile.

[0271] This composition comprises approximately 15% w / w to approximately 70% w / w of a cysteamine precursor or its salt, approximately 25% w / w to approximately 75% w / w of microcrystalline cellulose, and approximately 2% w / w to approximately 15% w / w of methylcellulose, where % w / w is the % w / w of the enteric-coated core.

[0272] In some cases, the proteinaceous subcoating layer may advantageously include a continuous proteinaceous subcoating layer that covers the individual cores and separates the individual cores from their respective enteric coatings in order to further enhance the stability of the cysteamine precursor or its salts. The continuous proteinaceous subcoating is adapted to prevent the cysteamine precursor or its salts from mixing with the enteric coating. Some preferred proteinaceous subcoatings have the following attributes: the subcoating can include a gelatin film attached to the core and / or the subcoating can include a dried proteinaceous gel.

[0273] In certain embodiments, the enteric-coated core releases no more than about 20% of the cysteamine precursor or its salts within about 2 hours when placed in a 0.1 N HCl solution and then releases at least about 85% of the cysteamine precursor or its salts within about 8 hours when placed in a substantially neutral pH environment.

[0274] Preferably, the enteric-coated core is an ellipsoid and has a diameter of 3 mm or less.

[0275] To prevent gastric adhesion of separately administered compositions, the compositions of the present invention can be coated with an anti-adhesive agent. The anti-adhesive agent may also be used to prevent the microparticles from sticking to each other. For example, the composition may be coated with a thin outermost layer of microcrystalline cellulose powder. Alternatively, adhesion can be prevented by coating with a polymer that is insoluble in gastric juice but is permeable and swellable. For example, a 30% polyacrylate dispersion (e.g., Eudragit NE30D, Evonik Industries) has been shown to prevent the adhesion of floating minitablets in the stomach (see Rouge et al., European Journal of Pharmaceutics and Biopharmaceutics 43:165 (1997)).

[0276] Commercial forms of the listed excipients used in enteric coatings include, for example, various brands of polymethacrylates (a group of chemically homogeneous compounds including aminomethacrylate copolymers, ammonia methacrylate copolymers, ethyl acrylate copolymer dispersions, methyl methacrylate copolymer dispersions, methacrylic acid copolymers, and methacrylic acid copolymer dispersions), which are marketed as product lines by companies including, but not limited to, Ashland, BASF Fine Chemicals (Kollicoat product line), ColorCon (Acryl-EZE product line), Eastman Chemical (Eastacryl product line), and Evonik Industries (Eudragit product line).

[0277] Formulations for drug release in the ileum and colon In some embodiments, ileal and / or colon-targeted formulations can be used to deliver cysteamine precursors to the distal ileum and colon. (The term “colon-targeted” is used herein to refer to both ileal and colon-targeted formulations. Any composition that begins releasing a drug in the ileum may also release a drug in the colon, and some drugs released in the ileum may reach the colon.) Advantages of drug delivery with colon-targeted compositions include prolonged contact with the colonic epithelium and the presence of colonic bacteria that can be utilized for site-specific delivery.

[0278] From a pharmacokinetic standpoint, colonic absorption of cysteamine is desirable because, due to its extremely short half-life, it must be continuously produced (and absorbed) in the gastrointestinal tract to maintain blood levels within the therapeutic range. An ingested pharmaceutical composition (otherwise a gastric-retaining composition) can reach the colon 3–5 hours after ingestion (on average, in most subjects) if ingested on a fast, or 6–10 hours after ingestion with food (on average, in most subjects). The only way to maintain blood cysteamine levels within the therapeutic range after the dosage form reaches the colon is to ensure that cysteamine is produced and absorbed in the colon. Some cysteamine precursors released into the small intestine can enter the colon intact and be broken down into cysteamine there. However, to provide robust cysteamine production in the colon, cysteamine precursors should be formulated to be released in the colon (or ileum), where they can be broken down and absorbed. Colon-targeted compositions are not intended for use alone as a treatment for cysteamine-sensitive diseases, but rather to complement formulations targeted at other areas of the gastrointestinal tract.

[0279] Two approaches to targeted delivery to the colon have been extensively developed and are described below.

[0280] The first approach involves utilizing enzymes produced in the colon by intestinal bacteria. Intestinal bacteria can digest various polymers that are not digested by human enzymes present in saliva, gastric juice, intestinal juice, or pancreatic juice. Pharmaceutical compositions containing such polymers are indigestible, and therefore, the active ingredients mixed with the polymers cannot escape until they encounter enzymes produced by intestinal bacteria in the distal ileum (where bacterial density begins to increase) or colon (where there can be 1 trillion bacteria per milliliter of colonic contents).

[0281] Cysteamine precursors and / or other active ingredients (e.g., in vivocysteamine synthesis or absorption enhancers) can be mixed with polymers that delay drug release and are digestible only by enzymes produced by enteric bacteria (in the human gastrointestinal tract). Polymers used for colon-targeted drug delivery based on selective degradation by enteric bacteria include dextran hydrogels (Hovgaard, L. and H. Brondsted, J. Controlled ReI. 36:159 (1995)), cross-linked chondroitin (Rubinstein et al., Pharm. Res. 9:276 (1992)), and hydrogels containing azo aromatic moieties (Brondsted, H. and J. Kopoecek, Pharm Res. 9:1540 (1992), and Yeh et al., J. Controlled ReI. 36:109 (1995)).

[0282] Covalent bonding of a drug to a carrier that forms a stable precursor in the stomach and small intestine and releases the drug in the large intestine upon enzymatic cleavage by the gut microbiota; examples of these precursors include azo complexes, cyclodextrin complexes, glycoside complexes, glucuronide complexes, dextran complexes, polypeptides, and polymer complexes. The basic principle is that the covalent bond linking the drug and the carrier must be indigestible by human enzymes but digestible by gut bacterial enzymes.

[0283] The second approach involves utilizing the higher pH in the ileum for the rest of the gastrointestinal tract. In healthy subjects, the pH of the gastrointestinal tract increases from the duodenum (approximately pH 5.5–6.6 from the proximal to distal duodenum) to the terminal ileum (approximately pH 7–7.5), then decreases in the cecum (approximately pH 6.4), and increases again from the right to the left side of the colon to a final value of approximately pH 7.

[0284] The composition can be coated with a pH-sensitive polymer that dissolves only at neutral to slightly alkaline pH levels (e.g., pH 6.5 or higher, pH 6.8 or higher, or pH 7 or higher). Beneath the pH-sensitive coating lies a sustained-release formulation from which the drug is gradually released by diffusion, erosion, or combination. This approach is described in U.S. Patent No. 5,900,252, which is incorporated herein by reference.

[0285] Colon targeting methods based on intestinal bacteria and pH can be combined. See, for example, Naeem et al., Colloids Surf B Biointerfaces S0927 (2014). This study describes coated nanoparticles formed using bacterial digestible polymers. Another technique combining pH and bacterial enzymatic digestion for delivering drug-containing liquid-filled capsules to the colon is described in U.S. Patent Publication 2007 / 0243253, which discloses formulations utilizing polymers including starch, amylose, amylopectin, chitosan, chondroitin sulfate, cyclodextrin, dextran, pullulan, carrageenan, scleroglucan, chitin, curduran, and levan, together with a pH-sensitive coating that dissolves at approximately pH 5 or higher.

[0286] Other approaches for colon-targeted drug delivery inclu...

Claims

1. A method for treating cysteamine sensitivity disorder in a subject, comprising compound 1 at a dose of 50 to 150 milligrams / kilogram of body weight (mg / kg), A method comprising administering to the subject at least once a day a pharmaceutically acceptable salt thereof.

2. The method according to claim 1, wherein the reducing agent is not administered to the subject within two hours of the administration of the aforementioned dose.

3. The method according to claim 1 or 2, wherein the reducing agent is administered to the subject between 2 and 8 hours after the administration of the aforementioned dose.

4. The method according to claim 3, wherein the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid.

5. The method according to any one of claims 1 to 4, wherein the compound 1 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

6. The method according to any one of claims 1 to 5, wherein the compound 1 or a pharmaceutically acceptable salt thereof is formulated as a powder and the dosage form is a sachet.

7. The method according to any one of claims 1 to 6, further comprising administering a pantethinase inducer selected from the group comprising a PPAR alpha agonist, a PPAR gamma agonist, or an Nrf2 inducer to the subject.

8. The method according to claim 7, wherein the pantethinase inducer is an isothiocyanate, sulforaphane, S-allyl cysteine, diallyl trisulfide, oxidized fat, omega-3 fatty acid, or oleylethanolamide found in cruciferous vegetables.

9. The method according to any one of claims 1 to 8, wherein 10 to 50 mg / kg of cystamine or a pharmaceutically acceptable salt thereof is administered to the subject within 30 minutes of administration of compound 1 or a pharmaceutically acceptable salt thereof.

10. The method according to claim 9, wherein the cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release.

11. The method according to any one of claims 9 or 10, wherein the cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of compound 1 or a pharmaceutically acceptable salt thereof.

12. Within 30 minutes of administering compound 1 or a pharmaceutically acceptable salt thereof, 10 to 50 mg / kg of compound 3, The method according to any one of claims 1 to 8, wherein a pharmaceutically acceptable salt thereof is administered to the subject.

13. The method according to claim 12, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

14. The method according to any one of claims 12 or 13, wherein the compound 3 or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of the compound 1 or a pharmaceutically acceptable salt thereof.

15. The method according to any one of claims 1 to 14, wherein the cysteamine sensitivity disorder is selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, livers, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic heart disease or ischemic disorders including seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD).

16. It's a kit, (i) A first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition containing a reducing agent, (iii) A kit comprising instructions for administering the second pharmaceutical composition at least two hours after the first pharmaceutical composition has been administered to a subject, for the treatment of cysteamine sensitivity disorder.

17. It's a kit, (i) A first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising a pantethinase inducer, (iii) A kit comprising instructions for administering the first pharmaceutical composition and the second pharmaceutical composition to a target for the treatment of cysteamine sensitivity disorder.

18. It's a kit, (i) A first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising cystamine or a pharmaceutically acceptable salt thereof, (iii) A kit comprising instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

19. It's a kit, (i) A first pharmaceutical composition comprising compound 1 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof, (iii) A kit comprising instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

20. The kit according to any one of claims 16 to 19, wherein the instruction manual is for carrying out the method described in any one of claims 1 to 15.

21. A method for treating cysteamine sensitivity disorder in a subject, comprising compound 2 at a dose of 50 to 150 milligrams / kilogram of body weight (mg / kg), A method comprising administering to the subject at least once a day a pharmaceutically acceptable salt thereof.

22. The method according to claim 21, wherein the reducing agent is not administered to the subject within two hours of the administration of the aforementioned dose.

23. The method according to claim 21 or 22, wherein the reducing agent is administered to the subject between 2 and 8 hours after the administration of the aforementioned dose.

24. The method according to claim 23, wherein the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid.

25. The method according to any one of claims 21 to 24, wherein the compound 2 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

26. The method according to any one of claims 21 to 25, wherein the compound 1 or a pharmaceutically acceptable salt thereof is formulated as a powder and the dosage form is a sachet.

27. The method according to any one of claims 21 to 26, further comprising administering a pantetainase inducer selected from the group comprising a PPAR alpha agonist, a PPAR gamma agonist, or an Nrf2 inducer to the subject.

28. The method according to claim 27, wherein the pantethinase inducer is an isothiocyanate, sulforaphane, S-allyl cysteine, diallyl trisulfide, oxidized fat, omega-3 fatty acid, or oleylethanolamide found in cruciferous vegetables.

29. The method according to any one of claims 21 to 28, wherein 10 to 50 mg / kg of cystamine or a pharmaceutically acceptable salt thereof is administered to the subject within 30 minutes of administration of compound 2 or a pharmaceutically acceptable salt thereof.

30. The method according to claim 29, wherein the cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release.

31. The method according to any one of claims 29 or 30, wherein the cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of compound 2 or a pharmaceutically acceptable salt thereof.

32. Within 30 minutes of administration of compound 2 or a pharmaceutically acceptable salt thereof, 10 to 50 mg / kg of compound 3, The method according to any one of claims 21 to 28, wherein a pharmaceutically acceptable salt thereof is administered to the subject.

33. The method according to claim 32, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

34. The method according to any one of claims 32 or 33, wherein the compound 3 or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of the compound 2 or a pharmaceutically acceptable salt thereof.

35. The method according to any one of claims 21 to 34, wherein the cysteamine sensitivity disorder is selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, livers, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD).

36. It's a kit, (i) A first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition containing a reducing agent, (iii) A kit comprising instructions for administering the second pharmaceutical composition at least two hours after the first pharmaceutical composition has been administered to a subject, for the treatment of cysteamine sensitivity disorder.

37. It's a kit, (i) A first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising a pantethinase inducer, (iii) A kit comprising instructions for administering the first pharmaceutical composition and the second pharmaceutical composition to a target for the treatment of cysteamine sensitivity disorder.

38. It's a kit, (i) A first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising cystamine or a pharmaceutically acceptable salt thereof, (iii) A kit comprising instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

39. It's a kit, (i) A first pharmaceutical composition comprising compound 2 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof, (iii) A kit comprising instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

40. The kit according to any one of claims 36 to 39, wherein the instruction manual is for carrying out the method described in any one of claims 21 to 55.

41. A pharmaceutical composition comprising compound 3, A pharmaceutical composition comprising a pharmaceutically acceptable salt thereof.

42. The pharmaceutical composition according to claim 41, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

43. The pharmaceutical composition according to claim 41, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for delayed release.

44. The pharmaceutical composition according to claim 41, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for sustained release.

45. The pharmaceutical composition according to any one of claims 41 to 44, further comprising a second active substance comprising a cysteamine precursor or a pharmaceutically acceptable salt thereof.

46. The pharmaceutical composition according to claim 45, wherein the second active substance is formulated for immediate release.

47. The pharmaceutical composition according to claim 45, wherein the second active substance is formulated for delayed release.

48. The pharmaceutical composition according to claim 45, wherein the second active substance is formulated for sustained release.

49. The pharmaceutical composition according to claim 45, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release, and the second active substance is formulated for delayed release.

50. A method for treating cysteamine sensitivity disorder in a subject, comprising administering to the subject a therapeutically effective amount of the pharmaceutical composition described in any one of claims 41 to 49.

51. The method according to claim 50, wherein the cysteamine sensitivity disorder is selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, livers, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD).

52. A method for treating cysteamine sensitivity disorder in a subject, comprising compound 3 in a dose of 50 to 150 milligrams / kilogram of body weight (mg / kg), A method comprising administering to the subject at least once a day a pharmaceutically acceptable salt thereof.

53. The method according to claim 52, wherein the reducing agent is not administered to the subject within two hours of the administration of the aforementioned dose.

54. The method according to claim 52 or 53, wherein the reducing agent is administered to the subject between 2 and 8 hours after the administration of the aforementioned dose.

55. The method according to claim 54, wherein the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid.

56. The method according to any one of claims 52 to 55, wherein the compound 2 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

57. The method according to any one of claims 52 to 56, wherein the compound 1 or a pharmaceutically acceptable salt thereof is formulated as a powder and the dosage form is a sachet.

58. The method according to any one of claims 52 to 57, further comprising administering a pantetainase inducer selected from the group comprising a PPAR alpha agonist, a PPAR gamma agonist, or an Nrf2 inducer to the subject.

59. The method according to claim 58, wherein the pantethinase inducer is an isothiocyanate, sulforaphane, S-allyl cysteine, diallyl trisulfide, oxidized fat, omega-3 fatty acid, or oleylethanolamide found in cruciferous vegetables.

60. The method according to any one of claims 52 to 59, wherein 10 to 50 mg / kg of cystamine or a pharmaceutically acceptable salt thereof is administered to the subject within 30 minutes of administration of compound 2 or a pharmaceutically acceptable salt thereof.

61. The method according to claim 60, wherein the cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release.

62. The method according to any one of claims 60 or 61, wherein the cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of the compound 2 or a pharmaceutically acceptable salt thereof.

63. The method according to any one of claims 52 to 62, wherein the cysteamine-sensitive disorder is selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, livers, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic heart disease or ischemic disorders including seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD).

64. It's a kit, (i) A first pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition containing a reducing agent, (iii) A kit comprising instructions for administering the second pharmaceutical composition at least two hours after the first pharmaceutical composition has been administered to a subject, for the treatment of cysteamine sensitivity disorder.

65. It's a kit, (i) A first pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising a pantethinase inducer, (iii) A kit comprising instructions for administering the first pharmaceutical composition and the second pharmaceutical composition to a target for the treatment of cysteamine sensitivity disorder.

66. It's a kit, (i) A first pharmaceutical composition comprising compound 3 or a pharmaceutically acceptable salt thereof, (ii) A second pharmaceutical composition comprising cystamine or a pharmaceutically acceptable salt thereof, (iii) A kit comprising instructions for administering the second pharmaceutical composition within 30 minutes after administering the first pharmaceutical composition to a subject for the treatment of cysteamine sensitivity disorder.

67. The kit according to any one of claims 64 to 66, wherein the instruction manual is for carrying out the method described in any one of claims 52 to 63.

68. An acid addition salt of compound 1, wherein the acid is hydrochloric acid, acetic acid, trifluoroacetic acid, or tartaric acid.

69. The acid addition salt according to claim 68, wherein the acid is acetic acid or tartaric acid.

70. The acid addition salt according to claim 69, wherein the acid is acetic acid.

71. The acid addition salt according to claim 70, wherein the acid addition salt has the following formula.

72. The acid addition salt according to claim 70, wherein the acid addition salt has the following formula.

73. The acid addition salt according to claim 69, wherein the acid is tartaric acid.

74. The acid addition salt according to claim 73, wherein the acid addition salt has the following formula.

75. The acid addition salt according to claim 73, wherein the acid addition salt has the following formula.

76. The acid addition salt according to claim 73, wherein the acid addition salt has the following formula.

77. A method for treating cysteamine sensitivity impairment in a subject, comprising administering to the subject an effective amount of the acid addition salt described in any one of claims 68 to 76.

78. The method according to claim 77, wherein the reducing agent is not administered to the subject within two hours of the administration of the aforementioned dose.

79. The method according to claim 77 or 78, wherein the reducing agent is administered to the subject between 2 and 8 hours after the administration of the aforementioned dose.

80. The method according to claim 79, wherein the reducing agent is selected from glutathione, glutathione diethyl ester, gamma-glutamylcysteine, dihydrolipoic acid, N-acetylcysteine, homocysteine, pantetheine, 4-phosphopantetheine, dephospho-coenzyme A, coenzyme A, vitamin E, and ascorbic acid.

81. The method according to any one of claims 77 to 80, wherein the acid addition salt is formulated for immediate release.

82. The method according to any one of claims 77 to 81, wherein the acid addition salt is formulated as a powder and the dosage form is a sachet, or the acid addition salt is formulated in a bottle for resuspending in an aqueous solution suitable for drinking.

83. The method according to any one of claims 77 to 82, further comprising administering a pantetainase inducer selected from the group comprising a PPAR alpha agonist, a PPAR gamma agonist, or an Nrf2 inducer to the subject.

84. The method according to claim 83, wherein the pantethinase inducer is an isothiocyanate, sulforaphane, S-allyl cysteine, diallyl trisulfide, oxidized fat, omega-3 fatty acid, or oleylethanolamide found in cruciferous vegetables.

85. The method according to any one of claims 77 to 84, wherein 10 to 50 mg / kg of cystamine or a pharmaceutically acceptable salt thereof is administered to the subject within 30 minutes of the administration of the acid addition salt.

86. The method according to claim 85, wherein the cystamine or a pharmaceutically acceptable salt thereof is formulated for immediate release.

87. The method according to any one of claims 85 or 86, wherein the cystamine or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of the acid addition salt.

88. Within 30 minutes of the administration of the acid addition salt, 10 to 50 mg / kg of compound 3, The method according to any one of claims 77 to 84, wherein a pharmaceutically acceptable salt thereof is administered to the subject.

89. The method according to claim 88, wherein the compound 3 or a pharmaceutically acceptable salt thereof is formulated for immediate release.

90. The method according to any one of claims 88 or 89, wherein the compound 3 or a pharmaceutically acceptable salt thereof is administered simultaneously with the administration of the acid addition salt.

91. The method according to any one of claims 77 to 90, wherein the cysteamine sensitivity disorder is selected from cystinosis; neurodegenerative diseases; neurodevelopmental disorders; neuropsychiatric disorders; mitochondrial diseases; fibrotic diseases of the kidneys, livers, or lungs; parasitic infections; sickle cell anemia; cancer; ischemic diseases including ischemic heart disease or seizures; chronic obstructive pulmonary disease (COPD); cystic fibrosis (CF); bacterial infections; viral infections; non-alcoholic steatohepatitis (NASH); alcoholic steatohepatitis; and non-alcoholic fatty liver disease (NAFLD).

92. A method for synthesizing an asymmetric disulfide, wherein the method is (a) 1 molar equivalent of an organic carboxylic acid or its salt, (b) 2 to 4 molar equivalents of cystamine or a salt thereof, (c) Combine amide coupling reagents, The process involves forming a mixture in which more than 90% of the organic carboxylic acid or its salt is converted to the asymmetric disulfide of formula (A), and less than 10% of the organic carboxylic acid remains unreacted or is converted to the symmetric disulfide of formula (B), A method in which R is an organic radical in the formula.

93. The method according to claim 92, wherein the organic carboxylic acid or a salt thereof is selected from pantothenic acid, 4-phosphopantothenic acid, acetic acid, or salts thereof.

94. The method according to claim 92, wherein the organic carboxylic acid or a salt thereof is pantothenic acid or a salt thereof.

95. The method according to any one of claims 92 to 94, wherein the amide coupling reagent is hydroxybenzotriazole.

96. The method according to any one of claims 92 to 94, wherein the amide coupling reagent is N,N'-dicyclohexylcarbodiimide.

97. The method according to any one of claims 92 to 96, wherein the combination is in one or more solvents selected from dichloromethane, tetrahydrofuran, acetonitrile dimethylformamide, water, and combinations thereof.

98. A method for synthesizing asymmetric disulfides, (a) 2 to 4 molar equivalents of thiols selected from cysteamine, N-acetylcysteamine, cysteine, N-acetylcysteine, N-acetylcysteinamide, or salts thereof, and (b) A method comprising combining one molar equivalent of a disulfide selected from cystamine, pantethine, or salts thereof in an organic solvent.

99. The method according to claim 98, wherein the molar ratio of the thiol to the disulfide is about 2:1 to about 4:

1.

100. The method according to claim 98, wherein the molar ratio of the thiol to the disulfide is about 2.5:1 to about 3.5:

1.

101. The method according to claim 98, wherein the molar ratio of the thiol to the disulfide is about 2.7:1 to about 3.3:

1.

102. The method according to any one of claims 98 to 101, wherein the thiol is N-acetylcysteamine or a salt thereof.

103. The method according to any one of claims 98 to 102, wherein the disulfide is cystamine or a salt thereof.

104. The method according to any one of claims 98 to 103, wherein the organic solvent is methanol or ethanol.

105. The method according to claim 104, wherein the organic solvent is methanol.

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