Pharmaceutically acceptable salts of sepiapterin

Abstract

To provide new pharmaceutical salts and / or co-crystals of sepiapterin which exhibit improved properties.SOLUTION: A pharmaceutically acceptable salt and / or co-crystal of sepiapterin is provided which is a methanesulfonate salt and / or co-crystal, a nicotinate salt and / or co-crystal, a toluenesulfonate salt and / or co-crystal, a benzenesulfonate salt and / or co-crystal, a sulfate salt and / or co-crystal, a phosphate salt and / or co-crystal, a malonate salt and / or co-crystal, a tartrate salt and / or co-crystal, a fumarate salt and / or co-crystal, a gentisate salt and / or co-crystal, or a glycolate salt and / or co-crystal.SELECTED DRAWING: None

Description

[Background technology]

[0001] Primary tetrahydrobiopterin deficiency (PBD) is caused by deficiencies of GTP cyclohydrolase I (GTP-CH), 6-pyruvoyltetrahydropterin synthase (PTPS), or sepiapterin reductase (SR), which impair the biosynthesis of tetrahydrobiopterin (BH4), or by defects in BH4 recycling (pterin-4a-carbinolamine dehydratase (PCD) or dihydropteridine reductase (DHPR) deficiency). PBD accounts for 1-3% of all cases of hyperphenylalaninemia (HPA), with nearly all remaining cases being due to phenylalanine hydroxylase deficiency.

[0002] BH4 is an essential cofactor for phenylalanine hydroxylase, tyrosine hydroxylase, tryptophan hydroxylase, fatty acid glyceryl ether oxygenase, and nitric oxide (NO) synthase.

[0003] In PBD, HPA results from impaired hydroxylation of phenylalanine (Phe) to tyrosine (Tyr). Decreased synthesis of Tyr and decreased activity of Tyr and tryptophan hydroxylase result in decreased formation of neurotransmitters, which in turn leads to neuromotor disorders.

[0004] Phenotypically, BH4 deficiency manifests as deficiency of the HPA and the neurotransmitter precursors L-dopa and 5-hydroxytryptophan, and is detected by screening programs that measure Phe to detect phenylalanine hydroxylase deficiency (the exception being individuals with SR deficiency who have normal Phe concentrations).

[0005] Current treatment for BH4 deficiency involves lowering blood Phe concentrations through oral administration of BH4 (in cases of GTP-CH and PTPS deficiency) and / or a low-Phe diet (mainly in cases of DHPR deficiency), as well as administration of the neurotransmitter precursors L-dopa and 5-hydroxytryptophan (5HTP).

[0006] There are few reported long-term follow-up studies of patients with BH4 deficiency. Treatments vary between physicians and clinics, are far from clinical evidence-based, and include pharmacological agents, none of which have marketing approval for this indication. Thus, there is a need for new therapies for BH4 deficiency. Summary of the Invention

[0007] The present invention features novel pharmaceutical salts of sepiapterin that exhibit improved properties. In particular, the present invention features salts of sepiapterin with improved stability, such as the nicotinic acid, phosphoric acid, tartaric acid, fumaric acid, or hydrochloric acid salts. The present invention also features pharmaceutical compositions comprising a pharma- ceutical effective amount of one or more sepiapterin salts, and methods for treating tetrahydrobiopterin-associated disorders comprising administering a sepiapterin salt of the present invention to a subject in need thereof.

[0008] In one aspect, the invention features salts and / or co-crystals of sepiapterin. In some embodiments, the salts and / or co-crystals of sepiapterin include methanesulfonate and / or co-crystals, nicotinate and / or co-crystals, p-toluenesulfonate and / or co-crystals, benzenesulfonate and / or co-crystals, phosphate and / or co-crystals (e.g., 1:1 phosphate and / or co-crystals, i.e., one molecule of sepiapterin for one molecule of phosphoric acid), malonate and / or co-crystals (e.g., 1:1 malonate and / or co-crystals, i.e., one molecule of sepiapterin for one molecule of malonic acid), tartrate and / or co-crystals (e.g., 1:1 tartrate and / or co-crystals, i.e., one molecule of sepiapterin for one molecule of tartaric acid), or the like. In some embodiments, the salt is a co-crystal with an acid. In some embodiments, the salt is a co-crystal with an acid. In some embodiments, the salt and / or co-crystal of sepiapterin has improved properties, such as improved stability, purity, exposure, and / or bioavailability.

[0009] In some embodiments, the salt and / or co-crystal of sepiapterin is a methanesulfonate salt and / or co-crystal.

[0010] In some embodiments, the salt and / or co-crystal of sepiapterin is a nicotinic acid salt and / or co-crystal.

[0011] In some embodiments, the salt and / or co-crystal of sepiapterin is a p-toluenesulfonate salt and / or co-crystal.

[0012] In some embodiments, the salt and / or co-crystal of sepiapterin is a benzenesulfonate salt and / or co-crystal.

[0013] In some embodiments, the salts and / or co-crystals of sepiapterin are phosphate salts and / or co-crystals, where the phosphate counterion is H2PO4 - In some embodiments, the salt and / or co-crystal of sepiapterin is a phosphate salt and / or co-crystal, wherein the phosphate counterion is HPO4 2- In some embodiments, the salts and / or co-crystals of sepiapterin are phosphate salts and / or co-crystals, where the phosphate counterion is PO4 3- In some embodiments, the salts and / or co-crystals of sepiapterin are 1:1 phosphates and / or co-crystals, i.e., one molecule of sepiapterin for every molecule of phosphate. In some embodiments, the salts and / or co-crystals of sepiapterin are 2:1 phosphates and / or co-crystals, i.e., two molecules of sepiapterin for every molecule of phosphate.

[0014] In some embodiments, the salts and / or co-crystals of sepiapterin are 1:1 malonate and / or co-crystals, i.e., one molecule of sepiapterin for every molecule of malonate, hi some embodiments, the salts and / or co-crystals of sepiapterin are 2:1 malonate and / or co-crystals, i.e., two molecules of sepiapterin for every molecule of malonic acid.

[0015] In some embodiments, the salts and / or co-crystals of sepiapterin are 1:1 tartrate salts and / or co-crystals, i.e., one molecule of sepiapterin for every molecule of tartrate salt, hi some embodiments, the salts and / or co-crystals of sepiapterin are 2:1 tartrate salts and / or co-crystals, i.e., two molecules of sepiapterin for every molecule of tartaric acid.

[0016] In some embodiments, the sepiapterin salt and / or co-crystal is a 1:1 gentisate salt and / or co-crystal, i.e., one molecule of sepiapterin for every one molecule of gentisate. In some embodiments, the sepiapterin salt and / or co-crystal is a 2:1 gentisate salt and / or co-crystal, i.e., two molecules of sepiapterin for every one molecule of gentisate.

[0017] In some embodiments, the salts and / or co-crystals of sepiapterin are 1:1 fumarate salts and / or co-crystals, i.e., one molecule of sepiapterin for every molecule of fumaric acid, hi some embodiments, the salts and / or co-crystals of sepiapterin are 2:1 fumarate salts and / or co-crystals, i.e., two molecules of sepiapterin for every molecule of fumaric acid.

[0018] In some embodiments, the salt and / or co-crystal of sepiapterin is a 1:1 glycolate and / or co-crystal, i.e., one molecule of sepiapterin for every molecule of glycolic acid. In some embodiments, the salt and / or co-crystal of sepiapterin is a 2:1 glycolate and / or co-crystal, i.e., two molecules of sepiapterin for every molecule of glycolic acid. In some embodiments, the salt and / or co-crystal of sepiapterin is a 3:1 glycolate and / or co-crystal, i.e., three molecules of sepiapterin for every molecule of glycolic acid.

[0019] In some embodiments, the salt and / or co-crystal of sepiapterin is a sulfate salt and / or co-crystal, wherein the sulfate counterion is HSO4. - In some embodiments, the salt and / or co-crystal of sepiapterin is a sulfate salt and / or co-crystal, wherein the sulfate counterion is SO4 2- In some embodiments, the salts and / or co-crystals of sepiapterin are 1:1 sulfate salts and / or co-crystals, i.e., one molecule of sepiapterin for every molecule of sulfate. In some embodiments, the salts and / or co-crystals of sepiapterin are 2:1 sulfate salts and / or co-crystals, i.e., two molecules of sepiapterin for every molecule of sulfate.

[0020] In some embodiments, the salt and / or co-crystal of sepiapterin is an acetate salt and / or co-crystal.

[0021] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal is crystalline. In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal contains less than 40% by weight (e.g., less than 30%, less than 20%, less than 10%, less than 5%, less than 1%, or between 30-40%, 25-35%, 20-30%, 15-25%, 10-20%, 5-15%, or 1-10%) of amorphous compound. In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal is substantially free of amorphous compound. In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal is substantially free of other salts or crystalline forms of sepiapterin.

[0022] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal is stable. For example, in some embodiments, upon exposure to 25° C. and 60% relative humidity and / or 40° C. and 75% relative humidity for 2 weeks, the pharma- ceutically acceptable salt and / or co-crystal maintains at least 90% purity (e.g., at least 95% purity, at least 96% purity, at least 97% purity, at least 98% purity, at least 99% purity) and / or does not undergo morphological change (e.g., the salt and / or co-crystal remains substantially free of free base and / or there is no polymorphic form change of the salt and / or co-crystal and / or free base).

[0023] In some embodiments, the pharma- ceutically acceptable salts and / or cocrystals provide increased exposure (e.g., at least 5%, at least 10%, at least 15%, at least 25%, at least 50%, at least 75%, at least 95%, at least 99%, at least 100%) in a subject (e.g., increased exposure as measured by BH4 and / or sepiapterin levels in the subject's plasma, CSF, and / or brain) compared to other salts and / or cocrystals of sepiapterin and / or sepiapterin free base.

[0024] In some embodiments, the pharma- ceutically acceptable salts and / or cocrystals provide increased bioavailability in a subject (e.g., at least 5%, at least 10%, at least 15%, at least 25%, at least 50%, at least 75%, at least 95%, at least 99%, at least 100%) compared to other salts and / or cocrystals of sepiapterin and / or sepiapterin free base.

[0025] In some embodiments, the pharma- ceutically acceptable salts and / or cocrystals have improved crystallinity compared to other salts and / or cocrystals of sepiapterin and / or sepiapterin free base.

[0026] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a hydrochloride salt and / or a co-crystal. In some embodiments, the hydrochloride salt and / or co-crystal has an endothermic onset temperature of about 218° C. (e.g., 216° C. to 220° C., e.g., 217° C. to 219° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the hydrochloride salt and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31° C. to 150° C. as measured by thermogravimetric analysis.

[0027] In some embodiments, the hydrochloride salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 7.8±0.5 as measured by powder X-ray diffraction. In some embodiments, the hydrochloride salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 7.8±0.5, 12.9±0.5, and / or 26.2±0.5 as measured by powder X-ray diffraction. In some embodiments, the hydrochloride salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 1 as measured by powder X-ray diffraction. In some embodiments, the hydrochloride salt and / or co-crystal has all of the peaks listed in Table 1 as measured by powder X-ray diffraction. [Table 1]

[0028] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a methanesulfonate salt and / or co-crystal. In some embodiments, the methanesulfonate salt and / or co-crystal has an endothermic onset temperature of about 182°C (e.g., 180°C to 184°C, e.g., 181°C to 183°C) in a differential scanning calorimetry (DSC) profile. In some embodiments, the methanesulfonate salt and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31°C to 150°C as measured by thermogravimetric analysis.

[0029] In some embodiments, the methanesulfonate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 23.5±0.5 as measured by powder X-ray diffraction. In some embodiments, the methanesulfonate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 7.9±0.5, 23.5±0.5, and / or 29.0±0.5 as measured by powder X-ray diffraction. In some embodiments, the methanesulfonate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 2 as measured by powder X-ray diffraction. In some embodiments, the methanesulfonate salt and / or co-crystal has all of the peaks listed in Table 2 as measured by powder X-ray diffraction. [Table 2]

[0030] In some embodiments, the methanesulfonate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 7.9±0.5 as measured by powder X-ray diffraction. In some embodiments, the methanesulfonate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 7.9±0.5, 23.4±0.5, and / or 28.9±0.5 as measured by powder X-ray diffraction. In some embodiments, the methanesulfonate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 3 as measured by powder X-ray diffraction. In some embodiments, the methanesulfonate salt and / or co-crystal has all of the peaks listed in Table 3 as measured by powder X-ray diffraction. [Table 3]

[0031] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a nicotinate salt and / or co-crystal. In some embodiments, the nicotinate salt and / or co-crystal has an endothermic onset temperature of about 220° C. (e.g., 218° C. to 222° C., e.g., 219° C. to 221° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the nicotinate salt and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31° C. to 150° C. as measured by thermogravimetry analysis.

[0032] In some embodiments, the nicotinate and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 24.5±0.5 as measured by powder X-ray diffraction. In some embodiments, the nicotinate and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 9.9±0.5, 23.2±0.5, and / or 24.5±0.5 as measured by powder X-ray diffraction. In some embodiments, the nicotinate and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 4 as measured by powder X-ray diffraction. In some embodiments, the nicotinate and / or co-crystal has all of the peaks listed in Table 4 as measured by powder X-ray diffraction. [Table 4]

[0033] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a toluenesulfonate salt. In some embodiments, the toluenesulfonate salt and / or co-crystal has an endothermic onset temperature of about 190° C. (e.g., 188° C. to 192° C., e.g., 189° C. to 191° C.) and / or 263° C. (e.g., 261° C. to 265° C., e.g., 262° C. to 264° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the toluenesulfonate salt and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31° C. to 150° C. as measured by thermogravimetry.

[0034] In some embodiments, the toluene sulfonate and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 6.5±0.5 as measured by powder X-ray diffraction. In some embodiments, the toluene sulfonate and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 6.5±0.5, 15.1±0.5, and / or 23.4±0.5 as measured by powder X-ray diffraction. In some embodiments, the toluene sulfonate and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 5 as measured by powder X-ray diffraction. In some embodiments, the toluene sulfonate and / or co-crystal has all of the peaks listed in Table 5 as measured by powder X-ray diffraction. [Table 5]

[0035] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a benzenesulfonate and / or co-crystal. In some embodiments, the benzenesulfonate and / or co-crystal has an endothermic onset temperature of about 193°C (e.g., 191°C to 195°C, e.g., 192°C to 194°C) and / or 206°C (e.g., 204°C to 208°C, e.g., 205°C to 207°C) in a differential scanning calorimetry (DSC) profile. In some embodiments, the benzenesulfonate and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31°C to 150°C as measured by thermogravimetric analysis.

[0036] In some embodiments, the benzenesulfonate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 6.5±0.5 as measured by powder X-ray diffraction. In some embodiments, the benzenesulfonate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 6.5±0.5, 14.8±0.5, and / or 19.6±0.5 as measured by powder X-ray diffraction. In some embodiments, the benzenesulfonate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 6 as measured by powder X-ray diffraction. In some embodiments, the benzenesulfonate salt and / or co-crystal has all of the peaks listed in Table 6 as measured by powder X-ray diffraction. [Table 6]

[0037] In some embodiments, the salt and / or co-crystal of sepiapterin is a sulfate salt. In some embodiments, the sulfate salt and / or co-crystal has an endothermic onset temperature of about 196° C. (e.g., 194° C. to 198° C., e.g., 195° C. to 197° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the sulfate salt and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31° C. to 150° C. as measured by thermogravimetry analysis.

[0038] In some embodiments, the sulfate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 5.1±0.5 as measured by powder X-ray diffraction. In some embodiments, the sulfate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 5.1±0.5, 7.8±0.5, and / or 23.0±0.5 as measured by powder X-ray diffraction. In some embodiments, the sulfate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 7 as measured by powder X-ray diffraction. In some embodiments, the sulfate salt and / or co-crystal has all of the peaks listed in Table 7 as measured by powder X-ray diffraction. [Table 7]

[0039] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a phosphate salt. In some embodiments, the phosphate salt and / or co-crystal has an endothermic onset temperature of about 144°C (e.g., 142°C to 146°C, e.g., 143°C to 145°C) and / or 207°C (e.g., 205°C to 209°C, e.g., 206°C to 208°C) in a differential scanning calorimetry (DSC) profile. In some embodiments, the phosphate salt and / or co-crystal has a weight loss of less than 12% (e.g., less than 10%, less than 5%, less than 2%, or less than 1%) from 31°C to 150°C as measured by thermogravimetry.

[0040] In some embodiments, the phosphate and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 25.6±0.5 as measured by powder X-ray diffraction. In some embodiments, the phosphate and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 16.6±0.5, 22.2±0.5, and / or 25.6±0.5 as measured by powder X-ray diffraction. In some embodiments, the phosphate and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 8 as measured by powder X-ray diffraction. In some embodiments, the phosphate and / or co-crystal has all of the peaks listed in Table 8 as measured by powder X-ray diffraction. [Table 8]

[0041] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a malonate and / or co-crystal. In some embodiments, the malonate and / or co-crystal has an endothermic onset temperature of about 175° C. (e.g., 173° C. to 177° C., e.g., 174° C. to 176° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the malonate and / or co-crystal exhibits less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) weight loss from 31° C. to 150° C. as measured by thermogravimetric analysis.

[0042] In some embodiments, the malonate and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 6.9±0.5 as measured by powder X-ray diffraction. In some embodiments, the malonate and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 6.9±0.5, 23.8±0.5, and / or 25.5±0.5 as measured by powder X-ray diffraction. In some embodiments, the malonate and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 9 as measured by powder X-ray diffraction. In some embodiments, the malonate and / or co-crystal has all of the peaks listed in Table 9 as measured by powder X-ray diffraction. [Table 9]

[0043] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a tartrate salt (e.g., an L-tartrate salt). In some embodiments, the tartrate salt and / or co-crystal has an endothermic onset temperature of about 156° C. (e.g., 154° C. to 158° C., e.g., 155° C. to 157° C.) and / or 175° C. (e.g., 173° C. to 177° C., e.g., 174° C. to 176° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the tartrate salt and / or co-crystal exhibits less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) weight loss from 31° C. to 150° C. as measured by thermogravimetric analysis.

[0044] In some embodiments, the tartrate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 7.4±0.5 as measured by powder X-ray diffraction. In some embodiments, the tartrate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 7.4±0.5, 21.8±0.5, and / or 23.9±0.5 as measured by powder X-ray diffraction. In some embodiments, the tartrate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 10 as measured by powder X-ray diffraction. In some embodiments, the tartrate salt and / or co-crystal has all of the peaks listed in Table 10 as measured by powder X-ray diffraction. [Table 10]

[0045] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a fumarate and / or co-crystal. In some embodiments, the fumarate and / or co-crystal has an endothermic onset temperature of about 77°C (e.g., 75°C to 79°C, e.g., 76°C to 78°C), 133°C (e.g., 131°C to 135°C, e.g., 132°C to 134°C), and / or 190°C (e.g., 188°C to 192°C, e.g., 189°C to 191°C) in a differential scanning calorimetry (DSC) profile. In some embodiments, the fumarate and / or co-crystal has a weight loss of less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%) from 31°C to 150°C as measured by thermogravimetry.

[0046] In some embodiments, the fumarate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 24.0±0.5 as measured by powder X-ray diffraction. In some embodiments, the fumarate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 11.4±0.5, 11.9±0.5, and / or 24.0±0.5 as measured by powder X-ray diffraction. In some embodiments, the fumarate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 11 as measured by powder X-ray diffraction. In some embodiments, the fumarate salt and / or co-crystal has all of the peaks listed in Table 11 as measured by powder X-ray diffraction. [Table 11]

[0047] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a gentisate salt and / or co-crystal. In some embodiments, the gentisate salt and / or co-crystal has an endothermic onset temperature of about 83° C. (e.g., 81° C. to 85° C., e.g., 82° C. to 84° C.), 134° C. (e.g., 132° C. to 136° C., e.g., 133° C. to 135° C.), and / or 149° C. (e.g., 147° C. to 151° C., e.g., 148° C. to 150° C.) in a differential scanning calorimetry (DSC) profile. In some embodiments, the gentisate salt and / or co-crystal has a weight loss of less than 7% (e.g., less than 5%, less than 3%, less than 2%, or less than 1%) from 31° C. to 150° C. as measured by thermogravimetry.

[0048] In some embodiments, the gentisate salt and / or cocrystal has at least one peak at a diffraction angle 2θ (°) of 7.1±0.5 as measured by powder X-ray diffraction. In some embodiments, the gentisate salt and / or cocrystal further has at least one peak at a diffraction angle 2θ (°) of 7.1±0.5, 8.7±0.5, and / or 26.7±0.5 as measured by powder X-ray diffraction. In some embodiments, the gentisate salt and / or cocrystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 12 as measured by powder X-ray diffraction. In some embodiments, the gentisate salt and / or cocrystal has all of the peaks listed in Table 12 as measured by powder X-ray diffraction. [Table 12]

[0049] In some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin is a glycolate and / or co-crystal. In some embodiments, the glycolate and / or co-crystal has an endothermic onset temperature of about 79°C (e.g., 77°C to 81°C, e.g., 78°C to 80°C), 90°C (e.g., 88°C to 92°C, e.g., 89°C to 91°C), 132°C (e.g., 130°C to 134°C, e.g., 131°C to 133°C), and / or 152°C (e.g., 130°C to 134°C, e.g., 131°C to 133°C) in a differential scanning calorimetry (DSC) profile. In some embodiments, the glycolate and / or co-crystal has a weight loss of less than 21% (e.g., less than 15%, less than 10%, less than 5%, or less than 1%) from 31°C to 150°C as measured by thermogravimetry.

[0050] In some embodiments, the glycolate salt and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 7.6±0.5 as measured by powder X-ray diffraction. In some embodiments, the glycolate salt and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 7.6±0.5, 10.7±0.5, and / or 24.0±0.5 as measured by powder X-ray diffraction. In some embodiments, the glycolate salt and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 13 as measured by powder X-ray diffraction. In some embodiments, the glycolate salt and / or co-crystal has all of the peaks listed in Table 13 as measured by powder X-ray diffraction. [Table 13]

[0051] In some embodiments, the acetate and / or co-crystal has at least one peak at a diffraction angle 2θ (°) of 6.2±0.5 as measured by powder X-ray diffraction. In some embodiments, the acetate and / or co-crystal further has at least one peak at a diffraction angle 2θ (°) of 6.2±0.5, 12.0±0.5, and / or 18.1±0.5 as measured by powder X-ray diffraction. In some embodiments, the acetate and / or co-crystal has one or more (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, or 14 or more) peaks listed in Table 14 as measured by powder X-ray diffraction. In some embodiments, the acetate and / or co-crystal has all of the peaks listed in Table 14 as measured by powder X-ray diffraction. [Table 14]

[0052] In another aspect, the invention features a composition (e.g., a solid composition) comprising any of the pharma- ceutically acceptable salts and / or cocrystals described above and a pharma- ceutically acceptable excipient. In some embodiments, the composition is stable at room temperature for at least 6 months. For example, when the composition is stored at room temperature for 6 months, the level of sepiapterin or its pharma- ceutically acceptable salts and / or cocrystals in the composition decreases by less than 5% (e.g., less than 4%, less than 3%, less than 2%, less than 1%), and / or when the composition is stored at room temperature for 6 months, the level of lactoylpterin in the composition increases by less than 5% (e.g., less than 4%, less than 3%, less than 2%, or less than 1%). In some embodiments, the pharma- ceutically acceptable salts and / or cocrystals comprise less than 10% by weight (e.g., less than 5%, or less than 1%) of amorphous compounds. In some embodiments, the pharma- ceutically acceptable salts and / or cocrystals are substantially free of amorphous compounds.

[0053] In some embodiments of any of the above compositions, the composition comprises an antioxidant (e.g., ascorbic acid), where the ratio of the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin and the antioxidant by weight (e.g., weight of salt and / or co-crystal to antioxidant) is greater than 4:1 (e.g., greater than 5:1, greater than 6:1, greater than 7:1, greater than 8:1, greater than 9:1, greater than 10:1, greater than 15:1, or greater than 20:1).

[0054] In some embodiments of any of the above compositions, the composition comprises an antioxidant, and wherein the pharmaceutical composition comprises a greater amount by weight of a pharma- ceutically acceptable salt of sepiapterin than the antioxidant. For example, in some embodiments, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin and the antioxidant (e.g., ascorbic acid) are present in a weight ratio of at least 1:1 (e.g., 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1).

[0055] In some embodiments of any of the above compositions, the composition comprises an antioxidant, wherein the composition comprises less than 10% (e.g., less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%) of antioxidant (e.g., ascorbic acid) by total weight. In some embodiments, the pharmaceutical composition is substantially free of antioxidants.

[0056] In some embodiments of any of the above compositions, the composition comprises less than 10% (e.g., less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%, or less than 0.2%) lactoylpterin by total weight. In some embodiments, the pharmaceutical composition comprises less than 1.3% lactoylpterin. In some embodiments, the pharmaceutical composition further comprises an antioxidant (e.g., ascorbic acid). In other embodiments, the pharmaceutical composition does not comprise an antioxidant.

[0057] In some embodiments of any of the above compositions, the composition is formulated for use in a suspension.

[0058] In some embodiments of any of the above pharmaceutical compositions, the antioxidant is 4-chloro-2,6-di-tert-butylphenol, tocopherol, α-tocopherol, alkylated diphenylamines, ascorbic acid, ascorbyl myristate, ascorbyl palmitate, ascorbyl stearate, β-carotene, butylated hydroxyanisole, butylated hydroxytoluene, citric acid, cysteine, D-α-tocopheryl polyethylene glycol 1000 succinate, deferoxamine mesylate, dodecyl gallate, ethylparaben, folic acid, fumaric acid, gallic acid, glutathione, lecithin, malic acid, methyl The antioxidant is selected from the group consisting of ruparaben, monothioglycerol, N-acetylcysteine, nordihydroguaiaretic acid, octyl gallate, p-phenylenediamine, potassium ascorbate, potassium metabisulfite, potassium sorbate, propionic acid, propyl gallate, retinol, sorbic acid, sodium ascorbate, sodium bisulfite, sodium hydrosulfite, sodium isoascorbate, sodium metabisulfite, sodium sulfite, sodium thiosulfate, tartaric acid, tert-butylhydroquinone, tocopheryl acetate, vitamin A, vitamin B6, vitamin B12, or vitamin E, or a combination thereof. In some embodiments of any of the above pharmaceutical compositions, the antioxidant is ascorbic acid, tocopherol, retinol, ascorbyl palmitate, N-acetylcysteine, glutathione, butylated hydroxytoluene, and / or butylated hydroxyanisole.

[0059] In some embodiments of any of the above compositions, the pharmaceutical composition comprises about 20-95% (e.g., about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or about 20-30%, about 25-45%, about 40-60%, about 50-75%, about 70-90%, about 85-95%) sepiapterin, or a pharma- ceutically acceptable salt and / or cocrystal thereof, by total weight.

[0060] In some embodiments of any of the above compositions, the pharmaceutical composition further comprises a dispersing agent (e.g., carboxymethylcellulose or a pharma- ceutically acceptable salt thereof, such as croscarmellose sodium, and / or a cocrystal thereof). In some embodiments of any of the above compositions, the pharmaceutical composition comprises 0.1-1.5% (e.g., 0.1-0.3%, 0.2-0.4%, 0.3-0.5%, 0.4-0.6%, 0.5-0.7%, 0.6-0.8%, 0.7-0.9%, 0.8-1%, 0.9-1.1%, 0.9-1.1%, 1-1.2%, 1.1-1.3%, 1.2-1.4%, or 1.3-1.5%) of a dispersing agent (e.g., croscarmellose sodium) by total weight.

[0061] In some embodiments of any of the above compositions, the pharmaceutical composition comprises at least one anti-caking agent or bulking agent (e.g., bulking agent and anti-caking agent). In some embodiments, the at least one anti-caking agent or bulking agent is colloidal silicon dioxide or microcrystalline cellulose. In some embodiments, the pharmaceutical composition comprises 60-80% (e.g., about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, or about 80%) of the anti-caking agent and / or bulking agent by total weight. In some embodiments of any of the above compositions, the pharmaceutical composition comprises both colloidal silicon dioxide and microcrystalline cellulose. In some embodiments of any of the above compositions, the pharmaceutical composition comprises 60-65% (e.g., about 60%, about 61%, about 62%, about 63%, about 64%, or about 65%) microcrystalline cellulose by total weight and 2-15% (e.g., about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, or about 15%) colloidal silicon dioxide by total weight.

[0062] In some embodiments of any of the above compositions, the sepiapterin is formulated in particles less than 200 μm in size (e.g., less than 180 μm, less than 160 μm, less than 140 μm, less than 120 μm, less than 100 μm, or less than 80 μm).

[0063] In some embodiments of any of the above compositions, the pharmaceutical composition is formulated as particles (e.g., particles for use in a suspension). In some embodiments, the particles are less than 200 μm in size (e.g., less than 180 μm, less than 160 μm, less than 140 μm, less than 120 μm, less than 100 μm, or less than 80 μm).

[0064] In some embodiments of any of the above compositions, the pharmaceutical composition comprises less than 50% by weight of lactoylpterin (e.g., less than 40%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than 0.3%, or less than 0.2%) of the combined amount of sepiapterin or a salt thereof and lactoylpterin. In some embodiments, the pharmaceutical composition comprises less than 1.3% lactoylpterin.

[0065] In some embodiments of any of the above compositions, the pharmaceutical composition further comprises an administration vehicle (eg, an administration vehicle having a viscosity of about 50 to 1750 centipoise).

[0066] In some embodiments of any of the above compositions, the pharmaceutical composition, upon administration to a subject, results in greater plasma or hepatocyte levels of tetrahydrobiopterin (e.g., at least 1.1-fold, at least 1.2-fold, at least 1.3-fold, at least 1.4-fold, at least 1.5-fold, at least 2-fold, at least 3-fold, or at least 4-fold) than that resulting from administration of a pharmaceutical composition containing the same amount of tetrahydrobiopterin (e.g., as measured by Tmax, Cmax, AUC, or plasma concentration 15 minutes after administration).

[0067] In some embodiments of any of the above compositions, the pharmaceutical composition, upon administration to a subject, results in a plasma or hepatocyte level of tetrahydrobiopterin that is greater (e.g., at least 1.1-fold, at least 1.2-fold, at least 1.3-fold, at least 1.4-fold, at least 1.5-fold, at least 2-fold, at least 3-fold, or at least 4-fold) than that resulting from administration of a pharmaceutical composition comprising the same amount of sepiapterin or a pharma- ceutically acceptable salt thereof and more than 10% antioxidant (e.g., as measured by Tmax, Cmax, AUC, or plasma concentration 15 minutes after administration).

[0068] In one aspect, the invention features a method of making a pharmaceutical composition including sepiapterin, or a pharma- ceutically acceptable salt and / or co-crystal thereof, the method including: a) mixing microcrystalline cellulose and colloidal silicon dioxide, b) adding a pharma- ceutically acceptable salt and / or co-crystal of sepiapterin, a dispersing agent, and an antioxidant to the mixture of step a, and c) mixing the microcrystalline cellulose, colloidal silicon dioxide, the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin, the dispersing agent, and the antioxidant to produce a pharmaceutical composition including a pharma- ceutically acceptable salt and / or co-crystal of sepiapterin.

[0069] In some embodiments, the mixture of microcrystalline cellulose and colloidal silicon dioxide is passed through a filter having pores of less than 200 μm (e.g., less than 180 μm, less than 160 μm, less than 140 μm, less than 120 μm, less than 100 μm, or less than 80 μm) prior to step b.

[0070] In some embodiments, the mixture of microcrystalline cellulose, colloidal silicon dioxide, sepiapterin, dispersing agent, and antioxidant is passed through a filter having pores of less than 200 μm (e.g., less than 180 μm, less than 160 μm, less than 140 μm, less than 120 μm, less than 100 μm, or less than 80 μm).

[0071] In some embodiments of any of the above compositions, the weight percentages are measured on a dry composition (eg, prior to suspension in a liquid such as water).

[0072] In some embodiments of any of the above methods, the antioxidant is ascorbic acid. In some embodiments of any of the above methods, the dispersing agent is croscarmellose sodium.

[0073] In one aspect, the invention features a method for treating a tetrahydrobiopterin-associated disorder (e.g., phenylketonuria or tetrahydrobiopterin deficiency) in a subject in need thereof, the method including administering an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0074] In one aspect, the invention features a method of increasing tetrahydrobiopterin levels in a subject in need thereof, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0075] In one aspect, the invention features a method of reducing phenylalanine levels in a subject in need thereof, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0076] In one aspect, the invention features a method of increasing activity of phenylalanine hydroxylase in a subject, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0077] In one aspect, the invention features a method of treating phenylketonuria in a subject in need thereof, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals or pharmaceutical compositions described above.

[0078] In one aspect, the invention features a method of treating gastroparesis in a subject in need thereof, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals or pharmaceutical compositions described above.

[0079] In one aspect, the invention features a method of increasing serotonin levels in a subject in need thereof, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0080] In one aspect, the invention features a method of increasing activity of tryptophan hydroxylase in a subject, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0081] In one aspect, the invention features a method of increasing dopamine levels in a subject in need thereof, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0082] In one aspect, the invention features a method of increasing tyrosine hydroxylase activity in a subject, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0083] In one aspect, the invention features a method of increasing nitric oxide synthase activity in a subject, the method including administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0084] In one aspect, the invention features a method of increasing activity of alkylglycerol monooxygenase in a subject, comprising administering to the subject an effective amount of any of the pharma- ceutically acceptable salts and / or cocrystals, or pharmaceutical compositions described above.

[0085] In one aspect, the invention features a method for increasing the level of homovanillic acid and / or 5-hydroxyindoleacetic acid in a subject, comprising administering an effective amount of any of the pharmaceutically acceptable salts and / or co-crystals or pharmaceutical compositions described above. In one embodiment, the pharmaceutically acceptable salts and / or co-crystals are methanesulfonate and / or co-crystals, nicotinate and / or co-crystals, toluenesulfonate and / or co-crystals, benzenesulfonate and / or co-crystals, sulfate and / or co-crystals, phosphate and / or co-crystals, malonate and / or co-crystals, tartrate and / or co-crystals, fumarate and / or co-crystals, gentisate and / or co-crystals, or glycolate and / or co-crystals. In some embodiments, the level of homovanillic acid and / or 5-hydroxyindoleacetic acid in the cerebrospinal fluid (CSF) of the subject is increased. In some embodiments, the level of homovanillic acid and / or 5-hydroxyindoleacetic acid in the subject (e.g., in the subject's CSF) is increased by at least 5% compared to the level before administration (e.g., the level is increased by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 100%, at least 150%, at least 200%, at least 250%, at least 300% compared to the level before administration).

[0086] In some embodiments, prior to administration of sepiapterin or a pharma- ceutically acceptable salt thereof, the subject has homovanillic acid and / or 5-hydroxyindoleacetic acid levels that are less than 50% (e.g., less than 40%, less than 30%) of the levels of an average subject (e.g., the subject has a CSF level of homovanillic acid less than 15 ng / ml and / or a CSF level of 5-hydroxyindoleacetic acid less than 5 ng / ml). In some embodiments, the subject has not been diagnosed with a BH4-related disease. In some embodiments, the subject does not have symptoms of a BH4-related disease. In some embodiments, after administration of sepiapterin or a pharma-ceutically acceptable salt thereof, the homovanillic acid and / or 5-hydroxyindoleacetic acid levels in the subject are greater than 50% of the levels of an average subject (e.g., the subject has a CSF level of homovanillic acid greater than 15 ng / ml and / or a CSF level of 5-hydroxyindoleacetic acid greater than 5 ng / ml).

[0087] In some embodiments of any of the above methods, the effective amount of any of the above pharma- ceutically acceptable salts and / or cocrystals or pharmaceutical compositions comprises an amount sufficient to increase the level of tetrahydrobiopterin in the subject's plasma one hour after administration by at least 2-fold (e.g., at least 3, 4, 5, 6, 7, 9, or 10-fold) compared to the level of tetrahydrobiopterin before administration.

[0088] In some embodiments of any of the above methods, the effective amount of any of the above pharma- ceutically acceptable salts and / or cocrystals or pharmaceutical compositions comprises an amount sufficient to increase the level of tetrahydrobiopterin in the CSF and / or brain of the subject one hour after administration by at least 2-fold (e.g., at least 3, 4, 5, 6, 7, 9, or 10-fold), compared to the level of tetrahydrobiopterin before administration.

[0089] In some embodiments of any of the above methods, the subject is a human. In some embodiments of any of the above methods, the method comprises combining any of the above pharma- ceutically acceptable salts and / or cocrystals or pharmaceutical compositions with an administration vehicle prior to administration.

[0090] definition In this application, unless otherwise clear from the context, (i) the term "a" may be understood to mean "at least one," (ii) the term "or" may be understood to mean "and / or," (iii) the terms "comprising" and "including" may be understood to include the listed components or steps, whether presented by themselves or with one or more additional components or steps, and (iv) the terms "about" and "approximately" may be understood to allow for standard variations as understood by one of ordinary skill in the art, and (v) when ranges are provided, the endpoints are included.

[0091] The term "administration" as used herein refers to administration of a composition to a subject. Administration to an animal subject (e.g., administration to a human) may be by any suitable route. For example, in one embodiment, administration includes bronchial (including bronchial instillation), buccal, enteral, intradermal, intraarterial, intradermal, intragastric, intramedullary, intramuscular, intranasal, intraperitoneal, intrathecal, intravenous, intraventricular, mucosal, nasal, oral, rectal, subcutaneous, sublingual, topical, intratracheal (including intratracheal instillation), transdermal, intravaginal, or intravitreal.

[0092] The term "anti-caking agent" refers to an additive added to a powdered or granular pharmaceutical formulation to prevent the formation of lumps. Exemplary anti-caking agents include colloidal silicon dioxide, microcrystalline cellulose, tricalcium phosphate, microcrystalline cellulose, magnesium stearate, sodium bicarbonate, sodium ferrocyanide, potassium ferrocyanide, calcium ferrocyanide, calcium phosphate, sodium silicate, colloidal silicon dioxide, calcium silicate, magnesium trisilicate, talcum powder, sodium aluminosilicate, potassium aluminosilicate, calcium aluminosilicate, bentonite, aluminosilicate, stearic acid, and polydimethylsiloxane.

[0093] The term "antioxidant" refers to an active pharmaceutical ingredient that can minimize the oxidative degradation of a pharmaceutical active ingredient. Examples of antioxidants include ascorbic acid, tocopherol, retinol, ascorbyl palmitate, N-acetylcysteine, glutathione, ethylenediaminetetraacetic acid, sodium bisulfite, sodium metabisulfite, thiourea, butylated hydroxytoluene, butylated hydroxyanisole, vitamin E, 4-chloro-2,6-di-tert-butylphenol, alkylated diphenylamines, ascorbyl myristate, ascorbyl stearate, beta-carotene, citric acid, cysteine, D-alpha-tocopheryl polyethylene glycol 1000 succinate, deferoxamine methanesulfonate, and the like. Ingredients include: ethylparaben, dodecyl gallate, ethylparaben, folic acid, fumaric acid, gallic acid, lecithin, malic acid, methylparaben, monothioglycerol, nordihydroguaiaretic acid, octyl gallate, p-phenylenediamine, potassium ascorbate, potassium metabisulfite, potassium sorbate, propionic acid, propyl gallate, sorbic acid, sodium ascorbate, sodium hydrosulfite, sodium isoascorbate, sodium sulfite, sodium thiosulfate, tartaric acid, tert-butylhydroquinone, tocopheryl acetate, vitamin A, vitamin B6, and vitamin B12.

[0094] As used herein, the term "BH4-related disease" or "tetrahydrobiopterin-related disease" refers to any disease or disorder that may derive therapeutic benefit from modulating (e.g., increasing) levels of BH4, e.g., phenylketonuria.

[0095] "Measuring the level of a compound" means detecting the compound directly or indirectly by methods known in the art. "Measuring directly" means performing a process to obtain a physical entity or value (e.g., performing an assay or test on a sample, or "analyzing a sample" as that term is defined herein). "Measuring indirectly" means receiving a physical entity or value from another party or source (e.g., a third-party testing laboratory that obtains the physical entity or value directly). Methods for measuring the level of a compound generally include, but are not limited to, liquid chromatography (LC)-mass spectrometry.

[0096] The term "dispersing agent" refers to an agent used in pharmaceutical formulations to separate particles in the formulation, e.g., to release its medicinal substance upon contact with moisture. Examples include cross-linked polyvinylpyrrolidone, carboxymethylcellulose (e.g., croscarmellose salts, e.g., croscarmellose sodium), starch (e.g., sodium starch glycolate), or alginic acid.

[0097] An "effective amount" of a compound may vary depending on factors such as the individual's medical condition, age, sex, weight, and the ability of the compound to elicit a desired response. A therapeutically effective amount includes an amount in which any toxic or detrimental effects of the compound are outweighed by the therapeutically beneficial effects. A therapeutically effective amount also includes an amount sufficient to provide a benefit, e.g., a clinical benefit.

[0098] "Increasing the activity" of an enzyme means increasing the level of an activity associated with the enzyme, e.g., phenylalanine hydroxylase, or an associated downstream effect. A non-limiting example of increasing the activity of an enzyme includes increasing the activity of phenylalanine hydroxylase, which results in a decrease in the level of phenylalanine. The activity level of an enzyme can be measured using any method known in the art.

[0099] "Level" refers to the level of a compound as compared to a reference. The reference can be any useful reference, as defined herein. A "decreased level" or "increased level" of a compound refers to a decrease or increase in the level of a compound as compared to a reference (e.g., about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 100%, about 150%, about 200%, about 300%, about 400%, about 500%, or more decrease or increase, as compared to a reference). about 10%, about 15%, about 20%, about 50%, about 75%, about 100%, or about 200% or greater decrease or increase, about 0.01 fold, about 0.02 fold, about 0.1 fold, about 0.3 fold, about 0.5 fold, about 0.8 fold or less decrease or increase, or about 1.2 fold, about 1.4 fold, about 1.5 fold, about 1.8 fold, about 2.0 fold, about 3.0 fold, about 3.5 fold, about 4.5 fold, about 5.0 fold, about 10 fold, about 15 fold, about 20 fold, about 30 fold, about 40 fold, about 50 fold, about 100 fold, about 1000 fold or greater increase). The level of the compound may be expressed as mass / volume (e.g., g / dL, mg / ml, μg / ml, ng / ml) or as a relative percentage of the total compound in the sample.

[0100] The term "pharmaceutical composition" as used herein refers to a composition in which a compound described herein is formulated with a pharma- ceutically acceptable excipient. A pharmaceutical composition may be manufactured or sold with the approval of a government regulatory agency as part of a therapeutic regimen for the treatment of a disease in a mammal. A pharmaceutical composition may be formulated, for example, for oral administration in a unit dosage form (e.g., tablet, capsule, caplet, gelcap, suspension, solution, or syrup), for topical administration (e.g., cream, gel, lotion, or ointment), for intravenous administration (e.g., a sterile solution in a solvent system suitable for intravenous use, without particulate embolism), or any other pharma- ceutical acceptable formulation.

[0101] The term "pharmaceutically acceptable salt" as used herein means any pharmaceutically acceptable salt of sepiapterin. Pharmaceutically acceptable salts include ion pairs of sepiapterin in the solid state and / or in solution. Pharmaceutically acceptable cocrystals include free base sepiapterin and an acid in the solid state. A mixture of salt forms and cocrystal forms may be present in the same composition. For example, pharmaceutically acceptable salts of sepiapterin include those that are within the scope of sound medical judgment, suitable for use in contact with human and animal tissues without undue toxicity, irritation, or allergic reaction, and commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, pharmaceutically acceptable salts are described in Remington (Remington: The Science and Practice of Pharmacy, (22nd ed.) ed. LV Allen, Jr., 2013, Pharmaceutical Press, Philadelphia, PA). The salts can be prepared in situ during the final isolation and purification of the compounds described herein, or can be prepared separately by reacting the free base groups with a suitable organic acid.

[0102] Sepiapterin can be prepared as pharmaceutically acceptable salts and / or co-crystals. These salts may be acid addition salts, including inorganic or organic acids. Suitable pharmaceutically acceptable acids and methods for preparing suitable salts are well known in the art.

[0103] By "reference" is meant a useful reference used to compare the levels of a compound. A reference can be any sample, standard, standard curve, or level used for comparison purposes. A reference can be a normal reference sample or a reference standard or level. A "reference sample" can be, for example, a control, e.g., a predefined negative control value such as a "normal control", or a prior sample taken from the same subject, a sample taken from a normal healthy subject, such as a normal cell or normal tissue, a sample (e.g., cell or tissue) from a subject without a disease, a sample from a subject diagnosed with a disease but not yet treated with a compound of the invention, a sample from a subject treated with a compound of the invention, or a sample of a purified compound (e.g., any of those described herein) of known normal concentration. By "reference standard or level" is meant a value or numerical value obtained from a reference sample. A "normal control value" is a pre-determined value indicative of a non-disease state, e.g., a value expected in a healthy control subject. Typically, a normal control value is expressed as a range ("between X and Y"), a high threshold value ("not higher than X"), or a low threshold value ("not lower than X"). A subject having a measured value within the normal control value of a particular biomarker is typically referred to as "within the normal range" for that biomarker. The normal reference value or level can be a value or value derived from a normal subject without a disease or disorder (e.g., cancer), a subject treated with a compound of the invention. In a preferred embodiment, the reference sample, standard, or level is matched to the subject sample in at least one of the following criteria: age, weight, sex, disease stage, and overall health. A standard curve of levels of a purified compound (e.g., any of those described herein) within the normal reference range can also be used as a reference.

[0104] The term "subject" or "patient" as used herein refers to any organism to which the compositions of the invention can be administered, e.g., for experimental, diagnostic, prophylactic, and / or therapeutic purposes. Exemplary subjects include any animal (e.g., mammals such as mice, rats, rabbits, non-human primates, and humans). A subject may be a human or animal that is seeking or in need of treatment, is undergoing treatment, is potentially undergoing treatment, or is receiving care by a trained professional for a particular disease or condition.

[0105] As used herein, the terms "treat", "treated" or "treating" refer to both therapeutic and prophylactic or preventative treatments, the purpose being to prevent or slow (alleviate) an undesirable physiological condition, disorder, or disease, or to obtain a beneficial or desired clinical outcome. Beneficial or desired clinical outcomes include, but are not limited to, alleviation of symptoms, reduction in the extent of a condition, disorder, or disease, stabilization (i.e., not worsening) of a condition, disorder, or disease, delay in onset or slowing of progression of a condition, condition, disorder, or disease, improvement or reversal (whether partial or total) of the condition, disorder, or disease (whether detectable or undetectable), improvement in at least one measurable physical parameter (not necessarily discernible by the patient), or enhancement or amelioration of a condition, disorder, or disease. Treatment includes eliciting a clinically significant response without excessive levels of side effects. Treatment also includes prolonging survival compared to expected survival in the absence of treatment.

[0106] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs. Methods and materials are described herein for use in the disclosure of this specification, but other suitable methods and materials known in the art can also be used. The materials, methods, and examples are illustrative only and are not intended to be limiting. All publications, patent applications, patents, sequences, database entries, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control.

[0107] The details of one or more embodiments of the invention are set forth in the description below. Other features, objects, and advantages of the invention will become apparent from the description and the claims. [Brief description of the drawings]

[0108] [Figure 1] FIG. 1 is an IR spectrum of the free base of sepiapterin. [Diagram 2] FIG. 2 is an IR spectrum of the hydrochloride salt and / or co-crystals of sepiapterin. [Diagram 3] FIG. 3 is an IR spectrum of the methanesulfonate salt and / or co-crystal of sepiapterin. [Figure 4] FIG. 4 shows IR spectra of nicotinic acid salts and / or co-crystals of sepiapterin. [Diagram 5] FIG. 5 shows IR spectra of the toluenesulfonate salt and / or co-crystals of sepiapterin. [Figure 6] FIG. 6 is an IR spectrum of the co-crystals of benzenesulfonate and / or sepiapterin. [Figure 7] FIG. 7 shows IR spectra of sulfate and / or co-crystals of sepiapterin. [Figure 8] FIG. 8 shows IR spectra of phosphate salts and / or co-crystals of sepiapterin. [Figure 9]FIG. 9 shows IR spectra of L-tartrate salt and / or co-crystals of sepiapterin. [Figure 10] FIG. 10 shows IR spectra of the glycolate salt and / or co-crystals of sepiapterin. [Figure 11] FIG. 11 shows IR spectra of sepiapterin malonate and / or co-crystals. [Figure 12] FIG. 12 is an IR spectrum of gentisate salt and / or co-crystals of sepiapterin. [Figure 13] FIG. 13 shows IR spectra of the fumarate salt and / or co-crystals of sepiapterin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0109] The present invention features pharma- ceutically acceptable salts and / or cocrystals of sepiapterin, compositions thereof, and methods of treating tetrahydrobiopterin-associated diseases using such compositions. The inventors have surprisingly found that some salts and / or cocrystals of sepiapterin have improved properties, such as improved stability, purity, exposure, and / or bioavailability.

[0110] compound Sepiapterin The pharmaceutical compositions of the present invention comprise sepiapterin, or a pharma- ceutically acceptable salt and / or co-crystal thereof. Sepiapterin has the following structure: JPEG2024063143000015.jpg3061

[0111] In some embodiments, the pharma- ceutically acceptable salts and / or co-crystals of sepiapterin described herein are present in the pharmaceutical compositions of the present invention in crystalline form.

[0112] In some embodiments, the pharmaceutical composition of the present invention comprises 20-30% (e.g., 20%, 22%, 25%, 27%, or 30%) of a pharma- ceutically acceptable salt and / or cocrystal of sepiapterin by total weight. In some embodiments, the pharmaceutical composition comprises more than 20% (e.g., more than 25%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, or more than 90%) of a pharma- ceutically acceptable salt and / or cocrystal of sepiapterin by total weight.

[0113] Tetrahydrobiopterin When sepiapterin is administered to a subject, it is converted to tetrahydrobiopterin, which has the structure: JPEG2024063143000016.jpg3065

[0114] Lactoylpterin An impurity that may be present in sepiapterin preparations is lactoylpterin, which may result from oxidation of sepiapterin. Lactoylpterin has the following structure: JPEG2024063143000017.jpg3161

[0115] Excipients Antioxidants Sepiapterin has a tendency to oxidize rapidly when exposed to air. Therefore, the pharmaceutical composition of the present invention may contain an antioxidant. The antioxidant can minimize the oxidative degradation of sepiapterin. Examples of antioxidants include 4-chloro-2,6-di-tert-butylphenol, tocopherol, α-tocopherol, alkylated diphenylamines, ascorbic acid, ascorbyl myristate, ascorbyl palmitate, ascorbyl stearate, beta-carotene, butylated hydroxyanisole, butylated hydroxytoluene, citric acid, cysteine, D-α-tocopheryl polyethylene glycol 1000 succinate, deferoxamine methanesulfonate, dodecyl gallate, ethylparaben, folic acid, fumaric acid, gallic acid, glutathione, lecithin, malic acid, methylparaben, monothioglucose, methylparaben ... The antioxidants include glycerol, N-acetylcysteine, nordihydroguaiaretic acid, octyl gallate, p-phenylenediamine, potassium ascorbate, potassium metabisulfite, potassium sorbate, propionic acid, propyl gallate, retinol, sorbic acid, sodium ascorbate, sodium bisulfite, sodium hydrosulfite, sodium isoascorbate, sodium metabisulfite, sodium sulfite, sodium thiosulfate, tartaric acid, tert-butylhydroquinone, tocopheryl acetate, vitamin A, vitamin B6, vitamin B12, or vitamin E. In some embodiments, the pharmaceutical compositions of the present invention include ascorbic acid, tocopherol, retinol, ascorbyl palmitate, N-acetylcysteine, glutathione, butylated hydroxytoluene, and / or butylated hydroxyanisole as antioxidants.

[0116] In some embodiments, the pharmaceutical composition comprises less than 10% (e.g., less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%) antioxidant by total weight. In some embodiments, the pharmaceutical composition comprises 2-9% (e.g., 2-4%, 3-5%, 4-6%, 5-7%, 6-8%, or 7-9%) antioxidant by total weight. In some embodiments, the pharmaceutical composition comprises 5-100% of the USP maximum daily dose of the antioxidant, e.g., in some embodiments, the pharmaceutical composition comprises 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the USP maximum daily dose of the antioxidant. In some embodiments, the ratio of sepiapterin or its pharma- ceutically acceptable salt and / or cocrystal to antioxidant is at least 1:1, e.g., 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1 wt / wt. In some embodiments of any of the above compositions, the composition comprises an antioxidant (e.g., ascorbic acid), wherein the ratio of the pharma- ceutically acceptable salt and / or cocrystal of sepiapterin to antioxidant by weight (e.g., weight of salt to antioxidant) is greater than 4:1 (e.g., greater than 5:1, greater than 6:1, greater than 7:1, greater than 8:1, greater than 9:1, greater than 10:1, greater than 15:1, or greater than 20:1).

[0117] Previous formulations of sepiapterin have contained 50% or more antioxidants (e.g., ascorbic acid), so it is surprising that compositions containing less than 10% antioxidant, or even no antioxidant, are effective in stabilizing pharma- ceutically acceptable salts and / or co-crystals of sepiapterin.

[0118] Dispersants In some embodiments, the pharmaceutical composition of the present invention includes at least one dispersing agent. The dispersing agent may separate particles in the formulation, for example, releasing its medicinal agent upon contact with moisture. Examples of dispersing agents include, but are not limited to, cross-linked polyvinylpyrrolidone, carboxymethylcellulose (e.g., croscarmellose salts, e.g., croscarmellose sodium), starch (e.g., sodium starch glycolate), or alginic acid. In some embodiments, the dispersing agent in the pharmaceutical composition is carboxymethylcellulose, such as a pharma- ceutically acceptable salt of croscarmellose. In some embodiments, the pharmaceutical composition may include 0.1-1.5% (e.g., 0.1%, 0.5%, 1%, or 1.5%) of dispersing agent by total weight. In some embodiments, the pharmaceutical composition includes less than 1.5% (e.g., less than 1%, less than 0.5%, or less than 0.1%) of dispersing agent.

[0119] Anti-caking Agent Sepiapterin has been found to clump when added to an aqueous solution. Anti-caking agents are often added to pharmaceutical compositions, for example, to prevent the formation of lumps in the solution. Thus, in some embodiments, the pharmaceutical composition of the present invention comprises at least one anti-caking agent. In some embodiments, the pharmaceutical composition of the present invention comprises at least two anti-caking agents. Exemplary anti-caking agents include colloidal silicon dioxide, microcrystalline cellulose, tricalcium phosphate, microcrystalline cellulose, magnesium stearate, sodium bicarbonate, sodium ferrocyanide, potassium ferrocyanide, calcium ferrocyanide, calcium phosphate, sodium silicate, colloidal silicon dioxide, calcium silicate, magnesium trisilicate, talcum powder, sodium aluminosilicate, potassium aluminosilicate, calcium aluminosilicate, bentonite, aluminosilicate, stearic acid, and polydimethylsiloxane. In some embodiments, the at least one anti-caking agent is colloidal silicon dioxide or microcrystalline cellulose. In some embodiments, the pharmaceutical composition may comprise 65-75% (e.g., 65%, 67%, 70%, 73%, or 75%) of the anti-caking agent by total weight. In some embodiments, the pharmaceutical composition comprises both colloidal silicon dioxide and microcrystalline cellulose. In some embodiments, the pharmaceutical composition comprises 60-65% microcrystalline cellulose by total weight and 5-7% colloidal silicon dioxide by total weight.

[0120] Dosing Vehicle In some embodiments, a pharmaceutical composition of the invention is combined with a dosing vehicle prior to administration. In some embodiments of any of the above compositions, the composition may be administered in a dosing vehicle having a viscosity of, for example, about 50 to 1750 centipoise (cP) to aid in suspension and administration of the pharmaceutical composition. One type of suspending agent that can be used is a combination of glycerin and sucrose in water (e.g., MEDISCA 2.5% glycerin and 27% sucrose in water). (R)An appropriate amount of the composition can be added to the dosing vehicle mixture and stirred to suspend the composition immediately prior to administration.

[0121] Other suspending agents may also be used as administration vehicles. Exemplary suspending agents include agar, alginic acid, sodium carboxymethylcellulose, carrageenan, dextrin, gelatin, guar gum, hydroxyethylcellulose, hydroxypropylcellulose, hypromellose, methylcellulose, polyethylene glycol, povidone, tragacanth, xanthan gum, or other suspending agents known in the art.

[0122] In some embodiments, the invention features a pharmaceutical composition that further includes a pharma- ceutically acceptable salt and / or co-crystal of sepiapterin, e.g., less than 10% (e.g., 9%, 7%, 5%, 3%, 1%, 0.5%, 0.25%, or 0.1%) of an antioxidant by total weight. The antioxidant can be ascorbic acid. In some embodiments, the ratio of the pharma- ceutically acceptable salt and / or co-crystal of sepiapterin to the antioxidant is 1:1, e.g., 2:1, 5:1, 7:1, or 10:1 wt / wt. In some embodiments of any of the above compositions, the composition comprises an antioxidant (e.g., ascorbic acid), wherein the ratio of the pharma- ceutically acceptable salt and / or cocrystal of sepiapterin to the antioxidant is greater than 4:1 by weight (e.g., weight of salt to antioxidant) (e.g., greater than 5:1, greater than 6:1, greater than 7:1, greater than 8:1, greater than 9:1, greater than 10:1, greater than 15:1, or greater than 20:1). The pharmaceutical composition may comprise 20-30% of the pharma- ceutically acceptable salt and / or cocrystal of sepiapterin by total weight, e.g., 20%, 22%, 25%, 27%, or 30%. The pharmaceutical composition may further comprise a dispersing agent, e.g., croscarmellose sodium. The pharmaceutical composition may comprise 0.1-1.5% of the dispersing agent by total weight, e.g., 0.1%, 0.5%, 1%, or 1.5%. In some embodiments, the pharmaceutical composition comprises at least one anti-caking agent, such as colloidal silicon dioxide or microcrystalline cellulose. The pharmaceutical composition may comprise 65-75% of the anti-caking agent by total weight, such as 65%, 67%, 70%, 73%, or 75%. In some embodiments, the pharmaceutical composition comprises both colloidal silicon dioxide and microcrystalline cellulose. In some embodiments, the pharmaceutical composition comprises 60-65% of the microcrystalline cellulose by total weight, and 5-7% of the colloidal silicon dioxide by total weight. In some embodiments, the pharma- ceutically acceptable salt and / or cocrystal of sepiapterin is formulated as particles with a size of less than 140 μm, such as 120 μm, 110 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, or 5 μm.In some embodiments, the pharmaceutical composition contains less than 1.3%, e.g., less than 1%, of impurities such as lactoylpterin, e.g., the composition contains less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%, or less than 0.2%.

[0123] Pharmaceutically acceptable salts and / or co-crystals of sepiapterin are useful in treating diseases associated with low intracellular BH4 levels or diseases such as primary tetrahydrobiopterin deficiency, GTPCH deficiency, 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency, DHPR deficiency, sepiapterin reductase deficiency, dopamine-responsive dystonia, Segawa syndrome, tyrosine hydroxylase deficiency, phenylketonuria, DNAJC12 deficiency, Parkinson's disease, depression due to Parkinson's disease, impulsivity in Parkinson's disease patients, major depression, autism spectrum disorder, and other conditions. Sepiapterin in various forms of the present invention may be useful as a treatment for diseases associated with the dysfunction of various BH4-dependent metabolic pathways, including but not limited to, spectrum, ADHD, schizophrenia, bipolar disorder, cerebral ischemia, restless leg syndrome, obsessive-compulsive disorder, anxiety, aggression in Alzheimer's disease, cerebrovascular disorder, spasm after subarachnoid hemorrhage, myocarditis, coronary vasospasm, cardiac hypertrophy, arteriosclerosis, hypertension, thrombosis, infection, endotoxin shock, liver cirrhosis, hypertrophic pyloric stenosis, gastric mucosal damage, pulmonary hypertension, renal dysfunction, impotence, and hypoglycemia. Therefore, the various forms of sepiapterin of the present invention may be administered to a patient in an effective amount to obtain treatment or improvement of a disease, disorder, or condition.

[0124] In some embodiments, the salts and / or co-crystals are salts and / or co-crystals of sepiapterin with sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, malonic acid, tartaric acid (e.g., L-tartaric acid), phosphoric acid, gentisic acid, fumaric acid, glycolic acid, acetic acid, or nicotinic acid.

[0125] In some embodiments, the pharmaceutical composition comprises a crystalline sepiapterin salt and / or cocrystal. The crystalline sepiapterin salt and / or cocrystal can occur as an anhydrate (e.g., without any bound water or solvent or hydration or solvation), or as a hydrate, partial hydrate (e.g., hemihydrate, sesquihydrate), dihydrate, trihydrate, where the crystalline form binds water of hydration or solvent molecules associated with the crystalline form of sepiapterin or its salt and / or cocrystal. In one embodiment, the crystalline sepiapterin salt and / or cocrystal occurs as a monohydrate or hemihydrate.

[0126] The present invention provides pharmaceutical compositions comprising a pharma- ceutically acceptable carrier and an effective amount (e.g., a therapeutically effective amount, including a prophylactically effective amount) of a pharma- ceutically acceptable salt and / or co-crystal of sepiapterin.

[0127] The pharma- ceutically acceptable carrier may be any of those conventionally used, limited only by chemical and physical considerations, such as solubility and lack of reactivity with the compound, and the route of administration. It will be understood by those skilled in the art that, in addition to the pharmaceutical compositions described below, the pharma- ceutically acceptable salts and / or cocrystals of sepiapteprin can be formulated as cyclodextrin inclusion complexes, or liposomes.

[0128] The pharma- ceutically acceptable carriers described herein, such as vehicles, adjuvants, excipients, or diluents, are well known to those skilled in the art and are readily available. Preferably, the pharma-ceutically acceptable carrier is chemically inert to the active compounds and has no detrimental side effects or toxicity under the conditions of use.

[0129] dose The pharma- ceutically acceptable salts of sepiapterin can be used in any suitable dose. Appropriate doses and dosing regimens can be determined within the skill of the art. Generally, treatment is initiated with a dose that is less than optimal. Thereafter, the dosage is increased in small increments until the optimum effect under the circumstances is obtained. For convenience, the total daily dose can be administered in divided doses throughout the day, if desired. At appropriate doses and appropriate administration of a particular compound, the present invention provides a wide range of responses. Typically, the dosage ranges from about 2.5 to about 150 mg / kg body weight / day of the patient being treated. For example, in embodiments, a pharma- ceutically acceptable salt of sepiapterin can be administered at about 20 mg / kg to about 200 mg / kg, about 40 mg / kg to about 150 mg / kg, about 60 mg / kg to about 120 mg / kg, about 80 mg / kg to about 100 mg / kg, about 40 mg / kg to about 60 mg / kg, about 2.5 mg / kg to about 20 mg / kg, about 2.5 mg / kg to about 10 mg / kg, or about 2.5 mg / kg to about 5 mg / kg of subject body weight per day, one or more times per day, to obtain the desired therapeutic effect.

[0130] In some embodiments, the dose is sufficient to produce a level of BH4 in the CNS, e.g., as measured in the CSF and / or brain, and / or is sufficient to produce a therapeutic result, e.g., an increase in the level of serotonin or dopamine in the CNS. In some embodiments, the dose is sufficient to increase the level of BH4 to at least twice the level prior to administration, as measured in plasma or an organ of the subject, e.g., the liver of the subject.

[0131] In some embodiments, the pharma- ceutically acceptable salts and / or cocrystals of sepiapterin can be formulated as unit solid oral formulations, such as particles. In these embodiments, each unit solid oral formulation may contain any suitable amount of pharma- ceutically acceptable salts and / or cocrystals of sepiapterin. For example, each unit solid oral formulation may contain about 2.5 mg, about 5 mg, about 10 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 60 mg, about 70 mg, about 80 mg, about 90 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, or about 500 mg.

[0132] Route of administration The choice of carrier can be determined in part by the specific active agent as well as the specific method used to administer the composition.Therefore, suitable formulations of the pharmaceutical composition of the present invention are diverse.The following formulations for oral, aerosol, parenteral, subcutaneous, intravenous, intraarterial, intramuscular, intraperitoneal, intrathecal, rectal and vaginal administration are merely exemplary and are not limiting in any way.

[0133] The pharmaceutical composition may be a liquid preparation, such as a solution, suspension, or emulsion form. Formulations suitable for oral administration may consist of (a) solids or granules, such as capsules, sachets, tablets, lozenges, and troches, each containing a predetermined amount of active ingredient; (b) powders; (c) liquids, such as an effective amount of the compound dissolved in a diluent, such as water, saline, or orange juice; (d) suspensions in a suitable liquid; and (e) suitable emulsions. Preferred are solid oral preparations, such as capsule, tablet, and powder forms. Capsule forms may be of the usual hard- or soft-shelled gelatin type, containing, for example, surfactants, lubricants, and inert fillers, such as lactose, sucrose, calcium phosphate, and corn starch. Tablet forms may contain one or more of lactose, sucrose, mannitol, corn starch, potato starch, alginic acid, microcrystalline cellulose, acacia, gelatin, guar gum, colloidal silicon dioxide, croscarmellose sodium, talc, magnesium stearate, calcium stearate, zinc stearate, stearic acid, and other excipients, coloring agents, diluents, buffers, disintegrants, wetting agents, preservatives, flavoring agents, and pharmacologically compatible carriers.Lozenge forms may contain the active ingredient in a flavor (usually sucrose and acacia or tragacanth) in addition to the active ingredient, and similarly pastilles may contain the active ingredient in an inert base such as gelatin and glycerin, or sucrose and acacia, emulsions, gels, and such carriers are known in the art.

[0134] Formulations suitable for oral and / or parenteral administration include aqueous and non-aqueous isotonic sterile injection solutions which may contain antioxidants, buffers, bacteriostats, and solutes that render the formulation isotonic with the blood of the intended recipient, and aqueous and non-aqueous sterile suspensions which may contain suspending agents, solubilizing agents, thickening agents, stabilizers, and preservatives. The compounds of the present invention may be administered in a physiologically acceptable diluent in a pharmaceutical carrier such as water, saline, aqueous dextrose and related sugar solutions, alcohols such as ethanol, benzyl alcohol, or hexadecyl alcohol, glycols such as propylene glycol or polyethylene glycol and polyethylene alcohol, glycerol ketals such as 2,2-dimethyl-1,3-dioxolane-4-methanol, ethers such as poly(ethylene glycol) 400, oils, fatty acids, fatty acid esters or glycerides, or acetylated fatty acid glycerides with or without the addition of a pharma- ceutically acceptable surfactant such as a soap or detergent, suspending agents such as pectin, carbomers, methylcellulose, hydroxypropylmethylcellulose, or carboxymethylcellulose, or emulsifying agents, and other pharmaceutical adjuvants.

[0135] Oils that can be used in parenteral formulations include petroleum, animal, vegetable, synthetic oils, and the like. Specific examples of oils include peanut, soybean, sesame, cottonseed, corn, olive, petrolatum, and mineral. Fatty acids suitable for use in parenteral formulations include oleic acid, stearic acid, and isostearic acid. Ethyl oleate and isopropyl myristate are examples of suitable fatty acid esters. Suitable soaps for use in parenteral formulations include fatty acid alkali metal, ammonium, and triethanolamine salts, and suitable detergents include (A) cationic detergents (e.g., dimethyldialkylammonium halides, and alkylpyridinium halides, etc.), (b) anionic detergents (e.g., alkyl, aryl, and olefin sulfonates, alkyl, olefin, ether, and monoglyceride sulfates, and sulfosuccinates, etc.), (c) nonionic detergents (e.g., fatty amine oxides, fatty acid alkanolamides, and polyoxyethylene-polypropylene copolymers, etc.), (d) amphoteric detergents (e.g., alkyl-β-aminopropionates, and 2-alkyl-imidazoline quaternary ammonium salts, etc.), and (3) mixtures thereof.

[0136] Parenteral formulations may typically contain about 20% to about 30% by weight of sepiapterin or its pharma- ceutically acceptable salts and / or co-crystals in solution. Suitable preservatives and buffers can be used in such formulations. To minimize or eliminate irritation at the injection site, such compositions may contain one or more non-ionic surfactants having a hydrophilic-lipophilic balance (HLB) of about 12 to about 17. The amount of surfactant in such compositions ranges from about 5 to about 15% by weight. Suitable surfactants include polyethylene sorbitan fatty acid esters, such as sorbitan monooleate, and high molecular weight adducts of hydrophobic bases and ethylene oxide formed by the condensation of propylene oxide with propylene glycol. Parenteral formulations can be placed in unit-dose or multi-dose hermetically sealed containers, such as ampoules and vials, and can be stored in a lyophilized (lyophilized) condition requiring only the addition of a sterile liquid carrier for injection, e.g., water, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.

[0137] The pharmaceutical composition may be an injectable formulation.The requirements of effective pharmaceutical carriers for injectable compositions are well known to those of ordinary skill in the art.See Remington (The Science and Practice of Pharmacy, (22nd ed.) ed. LV Allen, Jr., 2013, Pharmaceutical Press, Philadelphia, PA).

[0138] Topical formulations, including those useful for transdermal drug release, are well known to those skilled in the art and are suitable for application to the skin in the context of the present invention. Topically applied compositions are typically in the form of liquids, creams, pastes, lotions and gels. Topical administration includes application to oral mucosa, including the oral cavity, oral epithelium, palate, gums, and nasal mucosa. In some embodiments, the composition comprises sepiapterin and a suitable vehicle or carrier. It may also include other ingredients, such as anti-irritants. The carrier may be a liquid, solid or semi-solid. In an embodiment, the composition is an aqueous solution. Alternatively, the composition may be a dispersion, emulsion, gel, lotion or cream vehicle of various components. In one embodiment, the primary vehicle is water or a biocompatible solvent that is substantially neutral or substantially neutralized. The liquid vehicle may include other materials, such as buffers, alcohols, glycerin, mineral oils, along with various emulsifiers or dispersants as known in the art, to obtain the desired pH, consistency and viscosity. The composition can be prepared as a solid, such as a powder or granules, which can be applied directly or dissolved in water or a biocompatible solvent to form a substantially neutral or substantially neutralized solution prior to use, which can then be applied to the target site. In embodiments of the present invention, vehicles for topical application to the skin can include water, buffer solutions, various alcohols, glycols such as glycerin, lipid materials such as fatty acids, mineral oils, phosphoglycerides, collagen, gelatin, and silicone-based materials.

[0139] The pharmaceutical compositions may be aerosol formulations administered via inhalation. Such aerosol formulations may be placed into pressurized acceptable propellants, such as dichlorodifluoromethane, propane, and nitrogen. They may also be formulated as pharmaceuticals for non-pressurized preparations, such as nebulizers or atomizers.

[0140] Further, the pharmaceutical composition may be a suppository. Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams, or spray formulations in addition to the active ingredient, such carriers being known in the art to be appropriate.

[0141] Oral solid dosage forms Formulations for oral use include particles containing the active ingredient in a mixture with non-toxic pharma- ceutically acceptable excipients, and such formulations are known to those skilled in the art (e.g., U.S. Patent Nos.: 5,817,307, 5,824,300, 5,830,456, 5,846,526, 5,882,640, 5,910,304, 6,036,949, 6,036,949, 6,372,218, which are incorporated herein by reference). The excipient may be, for example, an inert diluent or filler (e.g., sucrose, sorbitol, sugar, mannitol, microcrystalline cellulose, starch including potato starch, calcium carbonate, sodium chloride, lactose, calcium phosphate, calcium sulfate, or sodium phosphate), a granulating / disintegrating agent (e.g., cellulose derivatives including microcrystalline cellulose, starch including potato starch, croscarmellose sodium, alginates or alginic acid), a binder (e.g., sucrose, glucose, sorbitol, acacia, alginic acid, sodium alginate, gelatin, starch, pregelatinized starch, microcrystalline cellulose, magnesium aluminum silicate, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, ethylcellulose, polyvinylpyrrolidone ... Lidone, or polyethylene glycol), and lubricants, glidants, anti-adherents (e.g., magnesium stearate, zinc stearate, stearic acid, silica, hydrogenated vegetable oil, or talc), and anti-caking agents (e.g., colloidal silicon dioxide, microcrystalline cellulose, tricalcium phosphate, microcrystalline cellulose, magnesium stearate, sodium bicarbonate, sodium ferrocyanide, potassium ferrocyanide, calcium ferrocyanide, calcium phosphate, sodium silicate, colloidal silicon dioxide, calcium silicate, magnesium trisilicate, talcum powder, sodium aluminosilicate, potassium aluminosilicate, calcium aluminosilicate, bentonite, aluminosilicate, stearic acid, polydimethylsiloxane). Other pharma- ceutically acceptable excipients may be colorants, flavorings, plasticizers, humectants, and buffers. In some embodiments, the excipients (e.g., flavorings) are packaged with the composition.In some embodiments, excipients (eg, flavorings) are packaged separately from the composition (eg, combined with the composition prior to administration).

[0142] The solid compositions of the present invention may include a coating adapted to protect the composition from undesired chemical changes (e.g., chemical degradation prior to release of the active substance). The coating may be applied to the solid dosage form in a manner similar to that described in Remington (The Science and Practice of Pharmacy, (22nd ed.) ed. LV Allen, Jr., 2013, Pharmaceutical Press, Philadelphia, PA).

[0143] The above ingredients may be used to prepare powders or granules in a conventional manner, for example, using a mixer, a fluidized bed apparatus, a melt-solidification apparatus, a rotor granulator, an extrusion / spheronization apparatus, or a spray drying apparatus.

[0144] Treatment method The present invention is characterized by, for example, a pharmaceutical composition in an orally acceptable formulation, comprising a therapeutically effective amount of a pharma- ceutically acceptable salt and / or cocrystal of sepiapterin, for example, and less than 10% of an antioxidant. In some embodiments, the pharmaceutical composition is a granular formulation dispersed in a pharma- ceutically acceptable carrier, for example, the composition can be mixed in water and ingested by the patient (e.g., within 5 to 10 minutes). Suitable formulations for use in the present invention are described in Remington (The Science and Practice of Pharmacy, (22nd ed.) ed. LV Allen, Jr., 2013, Pharmaceutical Press, Philadelphia, PA). Use of any conventional carrier in a pharmaceutical composition is contemplated unless incompatible with the active ingredient. In addition, it is understood that for animal (e.g., human) administration, the preparation should meet sterility, thermophilicity, general safety and purity standards as required by regulatory agencies.

[0145] The actual dosage of the composition of the present invention administered to a patient may be determined by physical and physiological factors such as body weight, severity of the condition, type of disease being treated, previous or concurrent therapeutic interventions, idiopathies of the patient, and route of administration. Depending on the dosage and route of administration, the preferred dosage and / or frequency of administration of an effective amount may vary depending on the subject's response. The person responsible for administration may in any case determine the concentration of active ingredient in the composition and the appropriate dosage for the individual subject.

[0146] In some embodiments, the patient receives 2.5 mg / kg / day, 5 mg / kg / day, 10 mg / kg / day, 20 mg / kg / day, 40 mg / kg / day, 60 mg / kg / day, or 80 mg / kg / day of salts and / or cocrystals of sepiapterin. The patient can receive a pharmaceutical composition containing sepiapterin once a day, twice a day, or three times a day during treatment. In some embodiments, the patient continues other current medications for BH4-related diseases (e.g., prescribed L-dopa / carbidopa, 5HTP, melatonin, MAO inhibitors, and dopamine receptor agonists) except for BH4 supplements (if taking BH4). The patient may not be allowed to take drugs known to inhibit folate synthesis (e.g., methotrexate, pemetrexed, trimetrexate, etc.).

[0147] In some embodiments, patients who have received BH4 therapy prior to study initiation will undergo a "washout" period during screening prior to administration of the pharmaceutical composition of the present invention. Patients may be instructed to maintain a consistent diet with respect to protein and phenylalanine (Phe) intake. Dietary records may be reviewed by a qualified dietitian. Three-day total Phe levels may be calculated and recorded by the dietitian.

[0148] In some embodiments, patients taking BH4 discontinue administration of BH4 (i.e., BH4 washout). Blood samples for Phe concentration may be obtained during the BH4 washout period 7 days, 5 days, 3 days, and 1 day prior to treatment with the pharmaceutical composition of the present invention, or at any time during the BH4 washout until blood Phe concentration is >360 μmol / L. In some embodiments, pre-administration blood samples are tested for sepiapteprin, Phe, BH4, and tyrosine (Tyr).

[0149] Production method of the drug product In some embodiments, the pharmaceutical compositions of the present invention can be produced by mixing sepiapterin or its pharma- ceutically acceptable salts and / or cocrystals and an antioxidant with one or more excipients, such as a dispersing agent, and one or more anti-caking agents. In some embodiments, each component of the composition is passed through a size exclusion filter (e.g., a filter having a pore size of 200 μm or less) before mixing. In some embodiments, the anti-caking agent is mixed together before adding each component of the composition (e.g., sepiapterin, a dispersing agent, and an antioxidant).

[0150] In some embodiments, the pharmaceutical composition is prepared by the steps of: (a) passing at least one anti-caking agent through a size exclusion filter (e.g., a filter having pores less than 200 μm), (b) combining (e.g., by mixing in a blender) a sepiapterin antioxidant, and optionally a dispersing agent, with the at least one anti-caking agent, and (c) passing the combination from step b through a size exclusion filter (e.g., a filter having pores less than 150 μm).

[0151] In some embodiments, the at least one anti-caking agent in step a comprises two or more anti-caking agents (eg, two anti-caking agents) mixed together before passing through the size exclusion filter. EXAMPLES

[0152] While certain features of the invention have been illustrated and described herein, those skilled in the art may recognize many modifications, substitutions, changes, and equivalents. It is therefore understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the invention. Thus, the following examples are provided to teach various aspects of the invention. These examples represent individual embodiments of aspects of the invention, and those skilled in the art will recognize that additional examples can be generated to equally teach aspects of the invention.

[0153] Example 1. Preparation of salts of sepiapterin Salts and / or cocrystals of sepiapterin with hydrochloric acid, methanesulfonic acid, toluenesulfonic acid, benzenesulfonic acid, nicotinic acid, sulfuric acid, phosphoric acid, malonic acid, L-tartaric acid, fumaric acid, gentisic acid, and glycolic acid were prepared by slurrying the free base of sepiapterin and the acids in acetone / water (9 / 1, v / v) or methanol for 2–17 days.

[0154] The resulting salts were analyzed by DSC, TGA, HPLC, IR and XRPD. The results are summarized in Table 15 below. The IR spectra are shown in Figures 1 to 13. [Table 15]

[0155] Example 2. Stability analysis of salts and / or cocrystals of sepiapterin The stability of the prepared salts and / or co-crystals was analyzed after 1 and 2 weeks at 25°C and 60% relative humidity and at 40°C and 75% relative humidity. The results are summarized in Table 16 below. Surprisingly, of all the salts and / or co-crystals tested, the phosphate salts and / or co-crystals, the tartrate salts and / or co-crystals, and the nicotinate salts and / or co-crystals were significantly more stable than the other salts and / or co-crystals. None of the phosphate salts, tartrate salts, or nicotinate salts and / or co-crystals underwent morphological changes during the stability test, and each retained 97% or more of its purity over the two weeks of testing. In fact, both the tartrate salts and nicotinate salts retained 99% or more of their purity. [Table 16] JPEG2024063143000020.jpg125157

[0156] Example 3: Solubility and disproportionation of various sepiapterin salts and / or cocrystals Dynamic solubility of sepiapterin nicotinate, phosphate, L-tartrate, fumarate and / or co-crystals was evaluated in water and in Medisca Oral Mix. X-ray powder diffraction (XRPD) was performed on the residual solids to confirm form change / disproportionation. The solids were suspended in media at a target concentration of ~7 mg / ml (calculated on free base). The suspensions were agitated at 25 rpm in a rolling incubator for 1, 4 and 24 hours. At each time point, 1 mL of the suspension was pipetted, centrifuged at 10000 rpm (2 min), filtered through a 0.45 μm membrane to obtain the supernatant for HPLC solubility and pH testing, and the residual solids were analyzed by XRPD. The solubility results are summarized in Tables 17-20. [Table 17] [Table 18] [Table 19] [Table 20]

[0157] Results: For the nicotinate, phosphate, L-tartrate and / or co-crystals, the residual solids changed to free base after 1 hour in water and in Medisca Oral Mix. For the fumarate and / or co-crystals, the residual solids did not change form in water and the crystallinity of the residual solids decreased after 1 hour in Medisca Oral Mix. Surprisingly, of the 12 different salt and / or co-crystal forms investigated, the fumarate and / or co-crystal was the only salt and / or co-crystal that was found to have high stability in the solid form stability test of Example 2 and to show no evidence of disproportionation in the disproportionation test.

[0158] Other forms While the invention has been described in relation to specific embodiments thereof, further modifications are possible, and this application is intended to cover any variations, uses, or adaptations of the invention which typically follow the principles of the invention, such departures from the disclosure herein being within known or customary practice in the art to which the invention pertains and which may be applied to the essential features described herein.

Claims

1. A pharmaceutically acceptable salt of sepiapterin, which is a 1:1.1 phosphate salt.

2. 10. The pharmaceutically acceptable salt of claim 1, which is crystalline.

3. 3. The pharmaceutically acceptable salt of claim 2, comprising less than 40% by weight of amorphous compound.

4. A pharmaceutical composition comprising the pharmaceutically acceptable salt of any one of claims 1 to 3 and a pharmaceutically acceptable excipient.

5. 10. A composition comprising the pharmaceutically acceptable salt of any one of claims 1 to 3 or the pharmaceutical composition of claim 4 for use in treating a tetrahydrobiopterin-associated disorder in a subject in need thereof, wherein an effective amount of the composition or pharmaceutical composition comprising the pharmaceutically acceptable salt is administered to the subject.

6. 6. The composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of claim 5, wherein the tetrahydrobiopterin-associated disorder is phenylketonuria or tetrahydrobiopterin deficiency.

7. 10. A composition comprising the pharmaceutically acceptable salt of any one of claims 1 to 3 or the pharmaceutical composition of claim 4 for use in increasing tetrahydrobiopterin levels in a subject in need thereof, decreasing phenylalanine levels in a subject in need thereof, increasing phenylalanine hydroxylase activity in a subject in need thereof, treating phenylketonuria in a subject in need thereof, increasing serotonin levels in a subject in need thereof, increasing tryptophan hydroxylase activity in a subject in need thereof, increasing dopamine levels in a subject in need thereof, increasing tyrosine hydroxylase activity in a subject in need thereof, increasing nitric oxide synthase activity in a subject in need thereof, increasing alkylglycerol monooxygenase activity in a subject, and / or increasing homovanillic acid and / or 5-hydroxyindoleacetic acid levels in a subject, wherein an effective amount of the composition or pharmaceutical composition comprising the pharmaceutically acceptable salt is administered to the subject.

8. A composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of any one of claims 5 to 7, wherein the composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of any one of claims 1 to 3 contains an effective amount sufficient to increase the level of tetrahydrobiopterin in the plasma of the subject by at least two-fold compared to the level of tetrahydrobiopterin before administration.

9. A composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of any one of claims 5 to 8, wherein the composition comprising the pharmaceutically acceptable salt of any one of claims 1 to 3 or the pharmaceutical composition of claim 4 contains an effective amount sufficient to increase the level of tetrahydrobiopterin in the CSF and / or brain of the subject by at least two-fold compared to the level of tetrahydrobiopterin before administration.

10. 8. A composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of claim 7, wherein the level of homovanillic acid and / or 5-hydroxyindoleacetic acid in the CSF of the subject is increased.

11. 11. A composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of claim 7 or 10, wherein the level of homovanillic acid and / or 5-hydroxyindoleacetic acid in the subject is increased by at least 100% compared to the level before administration.

12. 12. A composition or pharmaceutical composition comprising the pharmaceutically acceptable salt of any one of claims 5 to 11, wherein the subject is a human.

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