Axitinib prodrug

Abstract

In certain embodiments, the present invention provides a compound of formula I: [Formula 1] JPEG2024537839000018.jpg65165 (in the formula, X 1 is N or N + Y 1 Selected from X 2 NH or NY 2 Selected from X 3 NH or NY 3 is selected from Y 1 is -CH2OCO(OCH2CH2)n 1 O.M. 1 or -CH2OCO(CH2)n 1a COOH, Y 2 is -CH2OCO(OCH2CH2)n2OM2 or -CH2OCO(CH2)n 2a COOH, Y 3 is -CH2OCO(OCH2CH2)n 3 O.M. 3 or -CH2OCO(CH2)n 3a COOH, n 1 , n 1a n 2a , n 3 and n 3a are independently 0 or an integer from 1 to 8; M 1 , M 2 and M 3 are independently H, optionally substituted C 1-6 is selected from alkyl and optionally substituted aryl; 1 , X 2 and X 3 at least one of is not N or NH), and pharma- ceutically acceptable salts thereof.

Description

[Technical field]

[0001] The present application relates to prodrugs of axitinib, pharmaceutical compositions containing the axitinib prodrugs disclosed herein, and corresponding methods of treatment. [Background technology]

[0002] Tyrosine kinase inhibitors have been developed as chemotherapeutic drugs to block signal transduction of receptor tyrosine kinases (RTKs), a family of tyrosine protein kinases. RTKs span the cell membrane with an intracellular (inside) and an extracellular (outside) portion. Upon ligand binding to the extracellular portion, the receptor tyrosine kinases dimerize and initiate an intracellular signaling cascade driven by autophosphorylation using the coenzyme messenger adenosine triphosphate (ATP). Many of the RTK ligands are growth factors, such as VEGF. VEGF is related to a family of proteins that bind to the VEGF receptor (VEGFR) types, namely VEGFR1-3 (all RTKs), thereby inducing angiogenesis. VEGF-A, which binds to VEGFR2, is the target of the anti-VEGF drugs mentioned above. In addition to VEGFR1-3, several other RTKs are known to induce angiogenesis, such as platelet-derived growth factor receptor (PDGFR), which is activated by PDGF, and stem cell factor receptor / type III receptor tyrosine kinase (c-Kit), which is activated by stem cell factor.

[0003] The TKI axitinib is used alone to treat advanced renal cell carcinoma (RCC, a type of cancer that begins in the cells of the kidney) in patients who have not responded to other drugs. Axitinib is used in combination with avelumab or pembrolizumab to treat advanced renal cell carcinoma.

[0004] Several TKIs have been evaluated for the treatment of age-related macular degeneration (AMD) through various routes of administration, including eye-drop administered pazopanib (GlaxoSmithKline: NCT00463320), regorafenib (Bayer: NCT02348359), and PAN90806 (PanOptica: NCT02022540), as well as the oral TKI X-82 (Tyrogenex; NCT01674569, NCT02348359). However, topical eye drops tend to have low solution concentrations of TKIs that tend to be poorly water-soluble, and the residence time of TKIs on the ocular surface is short, resulting in poor penetration into the vitreous and limited distribution to the retina. Furthermore, the drug concentration during topical administration is difficult to control due to washout and user error. Furthermore, systemic administration of TKIs is not practical because high doses are required to achieve effective concentrations of the drug in the eye, especially in the desired tissues. This results in unacceptable side effects due to high systemic exposure. Moreover, drug concentrations are difficult to control. Alternatively, intravitreal injection of TKI suspensions has been performed. However, this administration method requires frequent repeated injections, such as daily or at least monthly, due to the rapid clearance of the drug. Furthermore, some TKIs are poorly soluble, so aggregates may form upon intravitreal injection and migrate or deposit on the retina, causing local contact toxicity or holes, such as macular or retinal holes.

[0005] Thus, there is a need in the art for new compounds, pharmaceutical compositions and methods of treatment for treating diseases such as renal cell carcinoma and ocular diseases, such as AMD, diabetic macular edema (DME) and retinal vein occlusion (RVO), with TKI therapy.

[0006] All references cited herein are incorporated by reference in their entirety for all purposes. Summary of the Invention

[0007] It is an object of certain embodiments of the present invention to provide compounds for the treatment of a disease or condition.

[0008] It is an object of certain embodiments of the present invention to provide pharmaceutical compositions comprising the compounds disclosed herein.

[0009] It is an object of certain embodiments of the present invention to provide methods of treatment using the compounds and pharmaceutical compositions disclosed herein.

[0010] It is an object of certain embodiments of the present invention to provide methods for preparing the compounds and pharmaceutical compositions disclosed herein.

[0011] It is an object of certain embodiments of the present invention to provide axitinib prodrugs that are more soluble than axitinib, e.g., at least 2-fold, 10-fold, 25-fold, 50-fold, 75-fold, 100-fold, 150-fold, 200-fold, 250-fold, 500-fold or 1000-fold, or in any range of values, e.g., 2-200-fold, 10-100-fold, or 50-about 150-fold.

[0012] It is an object of certain embodiments of the present invention to provide a method of modulating the release of an active agent from a hydrogel or organogel comprising incorporating a prodrug as disclosed herein into the hydrogel or organogel dosage form.

[0013] It is an object of certain embodiments of the present invention to provide prodrugs of axitinib for the treatment of diseases or conditions with axitinib therapy.

[0014] It is an objective of certain embodiments of the present invention to provide a prodrug of axitinib in a hydrogel or xerogel (converted to a hydrogel in vivo) matrix to form an implant for sustained delivery of the prodrug to local tissue where it is enzymatically converted to axitinib. The increased solubility of the prodrug serves to speed up the release of the drug from the hydrogel implant compared to the more hydrophobic active drug form of axitinib.

[0015] In certain embodiments, the present invention provides a compound of formula I: [ka] (In the formula, X 1 is N or N + Y 1 is selected from X 2 NH or NY 2 is selected from X 3 NH or NY 3 is selected from Y 1 -CH 2 OCO(OCH 2 CH 2 )n 1 O.M. 1 or -CH 2 OCO(CH 2 )n 1a COOH, Y 2 -CH 2 OCO(OCH 2 CH 2 )n 2 O.M. 2 or -CH 2 OCO(CH 2 )n 2a COOH, Y 3 -CH 2 OCO(OCH 2 CH 2 )n 3 O.M. 3 or -CH 2 OCO(CH 2 )n 3a COOH, n 1 , n 1a , n 2 n 2a , n 3 and n 3a are independently 0 or an integer from 1 to 8, M 1 , M 2 and M 3 are independently H, optionally substituted C 1-6selected from alkyl and optionally substituted aryl; X 1 , X 2 and X 3 at least one of which is not N or NH; and pharma- ceutically acceptable salts thereof.

[0016] In another embodiment, Y 1 , Y 2 and Y 3 are independently -(CH 2 )z 1 OCO(O(CH 2 )z 2 )n 1 OM or -(CH 2 )z 1 OCO(CH 2 )q 1 COOH, Z 1 and Z 2 is independently selected from an integer of 1 to 4; q 1 are independently selected from integers of 0 to 4.

[0017] The term "slow-release, biodegradable drug delivery system" as used herein refers to one that contains an active agent and is administered, for example, as an implant, into a patient's body where it remains in place for a period of time while releasing the active agent to the surrounding environment. The drug delivery system may be of any predetermined shape (e.g., rod-shaped, spherical, oblate spheroidal, ellipsoidal, disk-shaped, tubular, hemispherical, or irregular shape) prior to insertion or administration, and this shape may be maintained to some extent upon placement of the system at a desired location, although the dimensions (e.g., length and / or diameter) of the system may change after administration due to hydration and / or biodegradation as further disclosed herein. The drug delivery system may be designed to be biodegradable over time (as disclosed below), and thus may soften, change shape, and / or decrease in size, and eventually be eliminated by either dissolution or disintegration.

[0018] The term "biodegradable" refers to a material or object (such as the drug delivery system according to the present invention) that degrades in vivo, i.e., when placed in the human or animal body, or in vitro, when immersed in an aqueous solution under physiological conditions, such as pH 7.2-7.4 at 37°C. In the context of the present invention, as disclosed in detail herein below, a drug delivery system comprising an organogel containing an active agent slowly biodegrades over time when administered or deposited in the human or animal body. In certain embodiments, biodegradation is at least partially achieved by ester hydrolysis in the aqueous environment of the body. Biodegradation may be achieved by covalent crosslinking and / or hydrolysis or enzymatic cleavage within the polymer units. The drug delivery system slowly softens and disintegrates, resulting in clearance via physiological pathways. In certain embodiments, the organogel of the present invention retains its shape for an extended period of time (e.g., about 1 month, 3 months, or 6 months). In certain embodiments, the shape is maintained by covalent crosslinking of the polymeric components forming the organogel, for example, until the active agent, or at least a major amount thereof (e.g., at least 50%, at least 75%, or at least 90%) has been released.

[0019] An "organogel" in the present invention is a solid or semi-solid system that forms a covalently crosslinked three-dimensional network of one or more hydrophilic or hydrophobic natural or synthetic polymers (as disclosed herein) containing a hydrophobic organic liquid as disclosed herein. Thus, in the present invention, "organogel" is limited to so-called chemical organogels, in which the intermolecular interactions between the organogelating molecules are chemical bonds (e.g., covalent bonds) formed during gelation by a chemical reaction that induces crosslinking. As used herein, "organogel" refers to a three-dimensional polymer network of at least two precursors / gelators / precursors, including a hydrophobic organic liquid and, optionally, a hydrophobic organic liquid, covalently crosslinked to each other in the presence of an organic solvent and contained within the covalently crosslinked polymer network.

[0020] The term "polymer network" describes a structure formed from polymer chains (of the same or different molecular structure and of the same or different molecular weight) that are covalently crosslinked with each other. Types of polymers suitable for the purposes of the present invention are disclosed herein below. The term "polymer network" is used interchangeably with the term "matrix".

[0021] For purposes of this disclosure, the term “alkyl” used by itself or as part of another group refers to alkyl groups having 1 to 12 carbon atoms (i.e., C 1~12 alkyl) or a specified number of carbon atoms (i.e., C such as methyl) 1 C such as alkyl and ethyl 2 C such as alkyl, propyl or isopropyl 3 In one embodiment, the alkyl group refers to a straight-chain or branched-chain aliphatic hydrocarbon containing a straight-chain C 1~10 In another embodiment, the alkyl group is selected from the branched chain C 1~10 In another embodiment, the alkyl group is selected from a linear C 1~6 In another embodiment, the alkyl group is selected from the branched chain C 1~6 In another embodiment, the alkyl group is selected from a linear C 1~4 In another embodiment, the alkyl group is selected from the branched chain C 1~4 In another embodiment, the alkyl group is selected from the group consisting of straight or branched chain C 2~4 Non-limiting exemplary C alkyl groups are selected from the group consisting of C 1~10 Alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, iso-butyl, 3-pentyl, hexyl, heptyl, octyl, nonyl, decyl, and the like. 1~4 Alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, and iso-butyl.

[0022] For purposes of this disclosure, the term "optionally substituted alkyl" used by itself or as part of another group means that the alkyl as defined above is either unsubstituted or substituted with one, two or three substituents independently selected from nitro, haloalkoxy, aryloxy, aralkyloxy, alkylthio, sulfonamido, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, ureido, guanidino, carboxy, carboxyalkyl, cycloalkyl, etc. In one embodiment, the optionally substituted alkyl is substituted with two substituents. In another embodiment, the optionally substituted alkyl is substituted with one substituent. Non-limiting exemplary optionally substituted alkyl groups are -CH 2 CH 2 NO 2 , -CH 2 CH 2 CO 2 H, -CH 2 CH 2 SO 2 CH 3 , -CH 2 CH 2 COPh, -CH 2 C 6 H 11 etc.

[0023] For purposes of this disclosure, the term “aryl” used by itself or as part of another group refers to a monocyclic or bicyclic aromatic ring system having 6 to 14 carbon atoms (i.e., C 6~14 aryl). Non-limiting exemplary aryl groups include phenyl (abbreviated as "Ph"), naphthyl, phenanthryl, anthracyl, indenyl, azulenyl, biphenyl, biphenylenyl, and fluorenyl. In one embodiment, the aryl group is selected from phenyl or naphthyl.

[0024] For purposes of this disclosure, as used herein, the term "optionally substituted aryl" used by itself or as part of another group means that the aryl as defined above is either unsubstituted or substituted with 1 to 5 substituents independently selected from halo, nitro, cyano, hydroxy, amino, alkylamino, dialkylamino, haloalkyl, hydroxyalkyl, alkoxy, haloalkoxy, aryloxy, aralkyloxy, alkylthio, carboxamido, sulfonamido, alkylcarbonyl, arylcarbonyl, alkylsulfonyl, arylsulfonyl, ureido, guanidino, carboxy, carboxyalkyl, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclo, alkoxyalkyl, (amino)alkyl, hydroxyalkylamino, (alkylamino)alkyl, (dialkylamino)alkyl, (cyano)alkyl, (carboxamido)alkyl, mercaptoalkyl, (heterocyclo)alkyl, or (heteroaryl)alkyl. In one embodiment, the optionally substituted aryl is an optionally substituted phenyl. In one embodiment, the optionally substituted phenyl has four substituents. In another embodiment, the phenyl that may be substituted has three substituents. In another embodiment, the phenyl that may be substituted has two substituents. In another embodiment, the phenyl that may be substituted has one substituent. Non-limiting exemplary substituted aryl groups include 2-methylphenyl, 2-methoxyphenyl, 2-fluorophenyl, 2-chlorophenyl, 2-bromophenyl, 3-methylphenyl, 3-methoxyphenyl, 3-fluorophenyl, 3-chlorophenyl, 4-methylphenyl, 4-ethylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 2,6-di-fluorophenyl, 2,6-di-chlorophenyl, 2-methyl, 3-methoxyphenyl, 2-ethyl, 3-methoxyphenyl, 3,4-di-methoxyphenyl, 3,5-di-fluorophenyl, 3,5-di-methylphenyl, 3,5-dimethoxy, 4-methylphenyl, 2-fluoro-3-chlorophenyl, and 3-chloro-4-fluorophenyl.The term optionally substituted aryl is meant to include optionally substituted fused cycloalkyl, and groups having optionally substituted fused heterocyclo rings. Examples include: [ka]

[0025] The term "pharmaceutically acceptable salts" as used herein can include, but is not limited to, inorganic acid salts such as hydrochloride, hydrobromide, sulfate, phosphate, etc., organic acid salts such as formate, acetate, trifluoroacetate, maleate, tartrate, etc., sulfonate salts such as methanesulfonate, benzenesulfonate, p-toluenesulfonate, etc., metal salts such as sodium, potassium, cesium salts, alkaline earth metal salts such as calcium, magnesium salts, and organic amine salts such as triethylamine, pyridine, picoline, ethanolamine, triethanolamine, dicyclohexylamine, N,N'-dibenzylethylenediamine, etc. In certain embodiments, the therapeutically active agent is a free base. [Brief description of the drawings]

[0026] [Figure 1] 1 shows a synthesis scheme for the prodrug of Example 1. [Diagram 2] 1H-NMR of Example 1 is shown. [Diagram 3] LCMS of Example 1 is shown. [Figure 4] LCMS of Example 1 is shown. [Diagram 5] HPLC of Example 1 is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] In certain embodiments, the present invention relates to compounds that are convertible in vivo to compounds of formula II, and that are more hydrophilic than compounds of formula II.

[0028] In certain embodiments, the compound of formula I is converted in vivo to the compound of formula II (axitinib). [ka]

[0029] In certain embodiments, the present invention provides a compound of formula I: [ka] (In the formula, X 1 is N or N + Y 1 is selected from X 2 NH or NY 2 is selected from X 3 NH or NY 3 is selected from Y 1 is -CH 2 OCO(OCH 2 CH 2 )n 1 O.M. 1 or -CH 2 OCO(CH 2 )n 1a COOH, Y 2 is -CH 2 OCO(OCH 2 CH 2 )n 2 O.M. 2 or -CH 2 OCO(CH 2 )n 2a COOH, Y 3 is -CH 2 OCO(OCH 2 CH 2 )n 3 O.M. 3 or -CH 2 OCO(CH 2 )n 3a COOH, n 1 , n 1a , n2 n 2a , n 3 and n 3a are independently 0 or an integer from 1 to 8, M 1 , M 2 and M 3 are independently H, optionally substituted C 1-6 selected from alkyl and optionally substituted aryl; X 1 , X 2 and X 3 at least one of which is not N or NH; and pharma- ceutically acceptable salts thereof.

[0030] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1 is N + Y 1 and X 2 is NH, X 3 is NH, Y 1 -CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 It is.

[0031] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1 is N, X 2 is NY 2 and X 3 is NH, Y 2 -CH 2 OCO(CH 2 )n 2 COOH 。

[0032] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1 is N, X 2 is NH, X 3 is NY 3 and Y 3 -CH 2 OCO(CH 2 )n 4 COOH 。

[0033] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1 is N, X 2 is NY 2 and X 3 is NY 3 and Y 2 and Y 3 are -CH 2 OCO(CH 2 )n 2 It is COOH.

[0034] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1 is N + Y 1 and X 2 is NY 2 and X 3 is NH, Y 1 -CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 and Y 2 -CH 2 OCO(CH 2 )n 2 COOH 。

[0035] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1is N + Y 1 and X 2 is NH, X 3 is NY 3 and Y 1 -CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 and Y 3 -CH 2 OCO(CH 2 )n 2 COOH 。

[0036] In certain embodiments, the present invention relates to a compound of formula I, wherein X 1 is N + Y 1 and X 2 is NY 2 and X 3 is NY 3 and Y 1 -CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 and Y 2 and Y 3 are -CH 2 OCO(CH 2 )n 2 COOH 。

[0037] In certain embodiments, the present invention relates to a compound of formula I, wherein n 1 is 0, 1, 2, 3, 4, 5, 6, 7 or 8, or 1 to 3 or 4 to 6 or 7 to 8.

[0038] In certain embodiments, the present invention relates to a compound of formula I, wherein n 2is 0, 1, 2, 3, 4, 5, 6, 7 or 8, or 1 to 3 or 4 to 6 or 7 to 8.

[0039] In certain embodiments, the present invention relates to a compound of formula I, wherein n 3 is 0, 1, 2, 3, 4, 5, 6, 7 or 8, or 1 to 3 or 4 to 6 or 7 to 8.

[0040] In certain embodiments, the present invention relates to a compound of formula I, wherein n 1a is 0, 1, 2, 3, 4, 5, 6, 7 or 8, or 1 to 3 or 4 to 6 or 7 to 8.

[0041] In certain embodiments, the present invention relates to a compound of formula I, wherein n 2a is 0, 1, 2, 3, 4, 5, 6, 7 or 8, or 1 to 3 or 4 to 6 or 7 to 8.

[0042] In certain embodiments, the present invention relates to a compound of formula I, wherein n 3a is 0, 1, 2, 3, 4, 5, 6, 7 or 8, or 1 to 3 or 4 to 6 or 7 to 8.

[0043] In certain embodiments, M 1 is methyl, ethyl, propyl or phenyl.

[0044] In certain embodiments, M 2 is methyl, ethyl, propyl or phenyl.

[0045] In certain embodiments, M 3 is methyl, ethyl, propyl or phenyl.

[0046] In certain embodiments, the compound of formula 1 is axitinib-N-succinoyloxymethyl or a pharma- ceutically acceptable salt thereof. In other embodiments, the compound is axitinib-N-succinoyloxymethyl.

[0047] In certain embodiments, the present invention relates to a pharmaceutical composition comprising a compound of Formula I disclosed herein and a pharma- ceutically acceptable excipient.

[0048] In certain embodiments, the pharmaceutical composition is in the form of an oral solid dosage form, such as a tablet, capsule, or powder.

[0049] In certain embodiments, the pharmaceutical composition is in the form of an ophthalmic formulation, such as an implant, an injection, a solution, a suspension, or an ointment. The formulation can be administered intravitreally, topically, or to the anterior or posterior part of the eye of a mammal (e.g., a human).

[0050] In certain embodiments, the prodrugs disclosed herein are contained in a hydrogel (eg, a polyethylene glycol-based system disclosed herein) or organogel, for example for ocular administration.

[0051] In certain embodiments, the increased solubility of the axitinib prodrug allows for the tailoring of the release of the active agent from the hydrogel compared to the base drug (i.e., axitinib). For example, the release rate can be at least 1.1 times, at least 1.2 times, at least 1.5 times, at least 2 times, at least 5 times, at least 10 times, at least 20 times, at least 50 times, at least 100 times, at least 250 times, at least 500 times, or at least 1000 times higher, including all ranges between any of the preceding values.

[0052] In certain embodiments, the present invention relates to a method of treating a disease or condition comprising administering a compound of formula I or a pharmaceutical composition disclosed herein.

[0053] In certain embodiments, the disease or condition is cancer, such as advanced renal cell carcinoma.

[0054] In certain embodiments, the disease or condition is an ocular disease or condition, such as AMD, DME or RVO.

[0055] In certain embodiments, after administration to a patient or subject, the compound of formula I is converted in vivo to the compound of formula II. [ka]

[0056] In certain embodiments, the present invention relates to a method of treating a disease or condition with axitinib therapy comprising administering a compound or pharmaceutical composition disclosed herein.

[0057] In certain embodiments, the present invention relates to hydrogels comprising the compounds disclosed herein.

[0058] In certain embodiments, the present invention relates to xerogels comprising the compounds disclosed herein.

[0059] In certain embodiments, hydrogels or xerogels may be formed from precursors that have functional groups that form crosslinks to form a polymer network. These crosslinks between polymer strands or arms may be chemical (i.e., may be covalent) and / or physical (e.g., ionic bonds, hydrophobic associations, hydrogen bridges, etc.) in nature.

[0060] The polymer network may be prepared from either one type of precursor or from two or more types of precursors that are allowed to react. The precursor is selected with consideration of the properties desired for the resulting hydrogel. There are a variety of suitable precursors for use in the preparation of hydrogels and xerogels. Generally, any medicamentously acceptable crosslinkable polymer that forms a hydrogel may be used for the purposes of the present invention. The hydrogel and the components incorporated therein (including the polymers used to create the polymer network) should be physiologically safe, e.g., so as not to induce an immune response or other adverse effects. The hydrogels and xerogels may be formed from natural polymers, synthetic polymers, or biosynthetic polymers. Natural polymers may include glycosaminoglycans, polysaccharides (e.g., dextran), polyamino acids, proteins, or mixtures or combinations thereof.

[0061] Synthetic polymers can generally be any polymers that are synthetically produced from a variety of feedstocks by different types of polymerization, including free radical polymerization, anionic or cationic polymerization, chain growth or addition polymerization, condensation polymerization, ring-opening polymerization, etc. Polymerization may be initiated by some initiators, light and / or heat, and can be mediated by a catalyst.

[0062] Generally, for the purposes of the present invention, one or more synthetic polymers from the group comprising one or more units of polyalkylene glycol can be used, including, for example, polyethylene glycol (PEG), polypropylene glycol, poly(ethylene glycol)-block-poly(propylene glycol) copolymers, or polyethylene oxide, polypropylene oxide, polyvinyl alcohol, poly(vinylpyrrolidinone), polylactic acid, polylactic acid-co-glycolic acid, random or block copolymers, or any combination / mixtures thereof, although this list is not intended to be limiting.

[0063] The precursors may be covalently crosslinked to one another to form a covalently crosslinked polymer network. In certain embodiments, precursors having at least two reactive centers (e.g., in free radical polymerization) can function as crosslinkers because each reactive group can participate in the formation of a different growing polymer chain.

[0064] The precursors may have a biologically inert and hydrophilic portion, e.g., a core. In the case of branched polymers, the core refers to a continuous portion of the molecule connected to arms extending from the core, the arms bearing functional groups often at the termini of the arms or branches. Multi-arm PEG precursors are examples of such precursors, and are further disclosed herein below.

[0065] Thus, the hydrogels used in the present invention can be prepared, for example, from one multi-arm precursor having a (set of) first functional group(s) and another multi-arm precursor having a (set of) second functional group(s). By way of example, the multi-arm precursor may have hydrophilic arms such as polyethylene glycol units terminated with primary amines (nucleophilic) or may have activated ester end groups (electrophilic). The polymer networks according to the present invention may comprise identical or different polymer units crosslinked to each other.

[0066] Certain functional groups can be prepared with high reactivity by using activating groups. Such activating groups include, but are not limited to, carbonyldiimidazole, sulfonyl chloride, aryl halides, sulfosuccinimidyl esters, N-hydroxysuccinimidyl esters, succinimidyl esters, epoxides, aldehydes, maleimides, imidoesters, acrylates, and the like. N-hydroxysuccinimide esters (NHS) are useful groups for crosslinking nucleophilic polymers, such as primary amine- or thiol-terminated polyethylene glycols. The NHS-amine crosslinking reaction may be carried out in aqueous solution in the presence of buffers, such as phosphate buffers (pH 5.0-7.5), triethanolamine buffers (pH 7.5-9.0), borate buffers (pH 9.0-12), or sodium bicarbonate buffers (pH 9.0-10.0).

[0067] In certain embodiments, each precursor may contain only nucleophilic or only electrophilic functional groups, so long as both nucleophilic and electrophilic precursors are used in the crosslinking reaction. Thus, for example, if the crosslinker has only nucleophilic functional groups, such as amines, the precursor polymer may have electrophilic functional groups, such as N-hydroxysuccinimide. On the other hand, if the crosslinker has electrophilic functional groups, such as sulfosuccinimide, the functional polymer may have nucleophilic functional groups, such as amines or thiols. Thus, functional polymers (e.g., proteins, poly(allylamine), or amine-terminated di- or multifunctional poly(ethylene glycol)) can also be used to prepare the polymer networks of the present invention.

[0068] In one embodiment, the first reactive precursors each have about 2 to about 16 nucleophilic functional groups (referred to as functionality), and the second reactive precursors that react with the first reactive precursors to form the polymer network each have about 2 to about 16 electrophilic functional groups. Reactive precursors having a number of reactive (nucleophilic or electrophilic) groups that is a multiple of 4, thus, for example, 4, 8, and 16 reactive groups, are particularly suitable for the present invention. Any number of functional groups (e.g., containing any of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 groups) is possible in order to ensure that the functionality is sufficient for the formation of a suitable crosslinked network for the precursor to be used in accordance with the present invention.

[0069] In certain embodiments of the invention, the polymer network forming the hydrogel comprises polyethylene glycol (PEG) units, which are known in the art to form hydrogels when crosslinked, and these PEG hydrogels are suitable for pharmaceutical applications, for example as matrices for drugs intended to be administered to any part of the human or animal body.

[0070] The polymer network of the hydrogel implants of the invention may include one or more multi-armed PEG units having 2-10 arms, or 4-8 arms, or 4, 5, 6, 7, or 8 arms. The PEG units may have different or the same number of arms. In certain embodiments, the PEG units used in the hydrogels of the invention have 4 and / or 8 arms. In certain embodiments, a combination of 4-armed and 8-armed PEG units is utilized.

[0071] The number of PEG arms used helps control the flexibility or softness of the resulting hydrogel. For example, hydrogels formed by crosslinking 4-armed PEGs are generally softer and more flexible than those formed from 8-armed PEGs of the same molecular weight. A softer hydrogel, e.g., a 4-armed PEG, may be used, optionally in combination with another multi-armed PEG, e.g., an 8-armed PEG as disclosed above, particularly when it is desired to stretch the hydrogel before or after drying, as described below in the section on implant manufacture herein.

[0072] In certain embodiments of the present invention, the polyethylene glycol units used as precursors have an average molecular weight in the range of about 2,000 to about 100,000 daltons, or in the range of about 10,000 to about 60,000 daltons, or in the range of about 15,000 to about 50,000 daltons. In certain embodiments, the polyethylene glycol units have an average molecular weight in the range of about 10,000 to about 40,000 daltons, or in the range of about 20,000 daltons. PEG precursors of the same average molecular weight may be used, or PEG precursors of different average molecular weights may be combined with each other. The average molecular weight of the PEG precursors used in the present invention is given as the number average molecular weight (Mn), which in certain embodiments may be determined by MALDI.

[0073] In a 4-arm PEG, each of the arms may have an average arm length (or molecular weight) that is the total molecular weight of the PEG divided by 4. Thus, one precursor that can be used in the present invention, the 4a20k PEG precursor, has four arms, each with an average molecular weight of about 5,000 Daltons. Thus, the 8a20k PEG precursor that can be used in the present invention in addition to the 4a20k PEG precursor, has eight arms, each with an average molecular weight of 2,500 Daltons. Longer arms may be more flexible than shorter arms. PEGs with longer arms may swell more than PEGs with shorter arms. Also, PEGs with fewer arms may swell and be more flexible than PEGs with more arms. In certain embodiments, combinations of PEG precursors with different numbers of arms, such as a combination of a 4-arm PEG precursor and an 8-arm precursor, may be utilized in the present invention. Additionally, longer PEG arms have a higher melting point when dry, which may provide greater dimensional stability during storage. For example, an 8-arm PEG of molecular weight 15,000 daltons cross-linked with trilysine may not maintain an extended conformation at room temperature, whereas a 4-arm PEG of 20,000 daltons cross-linked with an 8-arm PEG of 20,000 daltons is dimensionally stable in an extended conformation at room temperature.

[0074] When referring to a PEG precursor having a particular average molecular weight, such as a 15k PEG or 20k PEG precursor, the indicated average molecular weight (i.e., Mn of 15,000 or 20,000, respectively) refers to the PEG portion of the precursor before end groups are added (where "20k" means 20,000 daltons and "15k" means 15,000 daltons; the same abbreviations are used herein for other average molecular weights of PEG precursors). In certain embodiments, the Mn of the precursor PEG portion is determined by MALDI. The degree of substitution with the end groups disclosed herein is determined after end group functionalization. 1 It may be determined by H-NMR.

[0075] In certain embodiments, electrophilic end groups for use with PEG precursors for the preparation of hydrogels of the invention are N-hydroxysuccinimidyl (NHS) esters, including, but not limited to, "SAZ" (referring to succinimidyl azelaic acid end groups), "SAP" (referring to succinimidyl adipic acid end groups), "SG" (referring to succinimidyl glutarate end groups), and "SS" (referring to succinimidyl succinic acid end groups).

[0076] In certain embodiments, nucleophilic end groups for use with PEG precursors for the preparation of hydrogels of the present invention are amines ("NH 2 ") end groups. Thiol (-SH) end groups or other nucleophilic end groups are also possible.

[0077] In certain preferred embodiments, a 4-arm PEG having an average molecular weight of about 20,000 Daltons and electrophilic end groups as disclosed above, and an 8-arm PEG having an average molecular weight of about 20,000 Daltons and nucleophilic end groups as disclosed above, are crosslinked to form a polymer network and thus a hydrogel according to the present invention.

[0078] Reaction of nucleophilic group-containing PEG units with electrophilic group-containing PEG units, such as amine end group-containing PEG units and active ester group-containing PEG units, results in multiple PEG units being crosslinked with a hydrolyzable linker having the formula: [ka] where m is an integer from 0 to 10, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In one particular embodiment, for example when SAZ end-group containing PEG is used, m is 6. For SAP end-groups, m will be 3, for SG end-groups, m will be 2, and for SS end-groups, m will be 1. All crosslinks in the polymer network may be the same or different.

[0079] In certain preferred embodiments, SAZ end groups are utilized in the present invention. This end group may provide extended duration in the eye, and certain embodiments of the implants of the present invention comprising hydrogels comprising PEG-SAZ units may biodegrade in the eye, e.g., in the vitreous humor of the human eye, after an extended period of time, e.g., 9-12 months as further disclosed below, and may persist even longer in certain circumstances. SAZ groups are more hydrophobic than SAP, SG, SS, etc. end groups due to the high number of carbon atoms in the chain (m is 6, and the total number of carbon atoms in the amide and ester groups is 7).

[0080] In certain preferred embodiments, a 20,000 dalton 4-arm PEG precursor is combined with a 20,000 dalton 8-arm PEG precursor, e.g., a 20,000 dalton 4-arm PEG precursor having SAZ groups (as defined above) is combined with a 20,000 dalton 8-arm PEG precursor having amine groups (as defined above). These precursors are referred to herein as 4a20kPEG-SAZ and 8a20kPEG-NH, respectively. 2 The chemical structure of 4a20kPEG-SAZ is as follows: [ka] In the formula, R represents the pentaerythritol core structure. 2 The chemical structure of (having a hexaglycerol core) is as follows: [ka]

[0081] In the above formula, n is determined by the molecular weight of the individual PEG arms.

[0082] In certain embodiments, the molar ratio of nucleophilic and electrophilic end groups reacting with each other is about 1:1, i.e., one amine group is provided for every SAZ group. 2In the case of PEG, the weight ratio is about 2:1 since the 8-arm PEG contains twice the amount of end groups as the 4-arm PEG. However, an excess of either the electrophilic end group (e.g., NHS end group such as SAZ) or the nucleophilic end group (e.g., amine) may be used. In particular, an excess of the nucleophile, e.g., an amine end group-containing precursor, may be used, i.e., 4a20kPEG-SAZ and 8a20kPEG-NH 2 may be less than 2:1 by weight.

[0083] Each and any combination of electrophile- and nucleophile-containing PEG precursors disclosed herein can be used to prepare implants according to the invention. For example, any 4-arm or 8-arm PEG-NHS precursor (e.g., with SAZ, SAP, SG, or SS end groups) can be combined with any 4-arm or 8-arm PEG-NHS precursor. 2 The electrophilic and nucleophilic group-containing precursors may be combined with the PEG units of the precursor (or any other PEG precursor having a nucleophilic group). Additionally, the PEG units of the electrophilic and nucleophilic group-containing precursors may have the same average molecular weight or different average molecular weights.

[0084] Instead of PEG-based crosslinkers, other nucleophilic group-containing crosslinkers can be used, for example low molecular weight amine linkers such as trilysine (or trilysine salts or derivatives such as trilysine acetate) or other low molecular weight multi-arm amines.

[0085] In certain embodiments, the nucleophilic group-containing crosslinker may be bound or conjugated to a visualization agent. A visualization agent is an agent that contains a fluorophore or other visualization group. For example, fluorescent dyes such as fluorescein, rhodamine, coumarin, cyanine, etc. may be used as visualization agents. The visualization agent may be bound to the crosslinker, for example, via some of the nucleophilic groups of the crosslinker. Because a sufficient amount of nucleophilic groups is required for crosslinking, generally "conjugated" or "conjugate" includes partial conjugates, meaning that only some of the nucleophilic groups are used for conjugation with the visualization agent, for example, about 1% to about 20%, or about 5% to about 10%, or about 8% of the nucleophilic groups of the crosslinker may be conjugated to the visualization agent. In other embodiments, the visualization agent may be conjugated to the polymer precursor, for example, via a specific reactive (such as electrophilic) group of the polymer precursor.

[0086] The disclosure herein regarding hydrogels is also applicable to xerogels.

[0087] Extruded dosage form The materials for hydrogels disclosed herein can also be extruded with a prodrug. Certain embodiments relate to a method of preparing a sustained release biodegradable ophthalmic insert comprising extruding a polymer composition and a prodrug to form an insert suitable for ocular administration.

[0088] In other embodiments, the method includes feeding the polymer composition and the prodrug to an extruder, mixing the ingredients in the extruder, extruding strands, and cutting the strands into unit dose inserts or implants.

[0089] In certain embodiments, the polymer composition and the prodrug are fed separately into the extruder. In other embodiments, the polymer composition and the prodrug are fed simultaneously into the extruder. In certain embodiments, the polymer composition is premixed, e.g., melt blended, prior to introduction into the extruder.

[0090] In certain embodiments, the method further includes cooling the strands, for example, prior to cutting the strands.

[0091] In certain embodiments, the method further comprises stretching the strands, eg, prior to cutting the strands.

[0092] In certain embodiments, stretching is performed under wet conditions, heated conditions, or a combination thereof, while in other embodiments, stretching is performed under dry conditions, heated conditions, or a combination thereof.

[0093] In certain embodiments, the extruded composition is subjected to a curing step, such as exposure to moisture, etc. In certain embodiments, curing crosslinks the polymer composition.

[0094] In certain embodiments, the method further comprises drying the strands after stretching the strands.

[0095] In other embodiments, all of the steps of the methods disclosed herein may be performed simultaneously or sequentially in any order.

[0096] In certain embodiments, the method further comprises melting the polymer in the extruder at a temperature below the melting point of the prodrug. The temperature can be, for example, less than about 100°, less than about 90°, less than about 80°, less than about 70°, less than about 60°, less than about 50°. In some embodiments, the temperature is from about 50° C. to about 80° C. In certain embodiments, the extrusion is performed at a temperature above the melting points of the polymer and the prodrug.

[0097] In certain embodiments, the extruded composition is dried when in strand form or unit dose. In certain embodiments, drying occurs after stretching the strand. Drying can be, for example, evaporative drying at ambient temperature, or can include heat, vacuum, or a combination thereof.

[0098] In certain embodiments, the hydrogel strands are stretched by a stretch factor ranging from about 0.25 to about 10, 0.5 to about 6, or about 1 to about 4.

[0099] In certain embodiments, the strands are cut into segments having an average length of about 20 mm, 17 mm, 15 mm, 12 mm, 10 mm, 8 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, or 0.5 mm or less.

[0100] In certain embodiments, the prodrug is suspended in the polymer composition.

[0101] In certain embodiments, the prodrug is homogeneously dispersed in the polymer composition.

[0102] In certain embodiments, the extrusion process is carried out without the use of a solvent (eg, water).

[0103] In certain embodiments, solvents are used in amounts less than about 10% w / w, less than about 5% w / w, or less than about 1% w / w.

[0104] In certain embodiments, the content uniformity of the unit dose inserts is within 10%, within 5%, or within 1%.

[0105] In certain embodiments, the dosage form has a sustained release of from about 7 days to about 6 months after intraocular administration.

[0106] In certain embodiments, the polymorphic form of the prodrug is unchanged or substantially unchanged, hi certain embodiments, the purity of the prodrug after curing is greater than 99%, greater than 99.5%, or greater than 99.9% compared to the prodrug before extrusion.

[0107] In certain embodiments, the prodrug has an average particle size of less than about 100 μm, less than about 50 μm, less than about 25 μm, or less than about 10 μm.

[0108] In certain embodiments, the prodrug has a D50 particle size of less than about 10 μm and / or a D99 particle size of less than about 50 μm, or a D90 particle size of about 5 μm or less and / or a D98 particle size of about 10 μm or less.

[0109] Organogel In certain embodiments, the prodrugs herein can be used in organogels.

[0110] In certain embodiments, the present invention provides a sustained release biodegradable drug delivery system comprising an organogel and a prodrug, wherein the organogel comprises a hydrophobic organic liquid and a biodegradable, covalently crosslinked polymer network, and wherein the hydrophobic organic liquid and the prodrug are contained in the biodegradable, covalently crosslinked polymer network. In certain embodiments, a sustained release biodegradable drug delivery system is provided comprising an organogel and a prodrug, wherein the organogel comprises a hydrophobic organic liquid and a biodegradable, covalently crosslinked polymer network, and wherein the hydrophobic organic liquid and the prodrug are immobilized in the biodegradable, covalently crosslinked polymer network.

[0111] In certain embodiments, the sustained release biodegradable drug delivery system comprises at least three components: a biodegradable covalently crosslinked polymer network, a hydrophobic organic liquid, and a prodrug.

[0112] In certain embodiments, organogels are formed by polymerization of non-linear, multifunctional monomers or polymer precursor components, as described herein below, to form a covalently crosslinked polymer network containing a hydrophobic organic liquid, which remains immobilized within the polymer network until it is released from the network, for example, in vivo. Thus, organogels of the present invention are like hydrophobic analogs of hydrogels, which contain water instead of a hydrophobic organic phase. Organogels are similar to hydrogels in that the matrix is ​​composed of a polymeric component (gelling agent) that forms a network and a non-reactive component. The non-reactive component is water in hydrogels, whereas in organogels of the present invention, it is a hydrophobic organic compound, such as oil, that has a glass transition temperature (Tg) and melt transition temperature (Tm) below body temperature.

[0113] In certain embodiments, the covalent crosslinking of the polymer network forming the precursor restricts the mobility of the hydrophobic organic liquid (e.g., oil) component. This may provide continuous control of drug release by restricting drug delivery to diffusion through the organogel and / or eliminating the occurrence of defects that provide a quick escape route for the drug. In certain embodiments, the drug delivery system of the present invention is a fully or partially diffusion-controlled delivery system, i.e., the release of the oil and / or prodrug is controlled primarily by diffusion processes. Degradation of the polymer matrix may additionally occur in the organogels of the present invention, but does not primarily control the release of the prodrug. In non-crosslinked gels, such as extruded linear polymers, the release of the prodrug is primarily controlled by the degradation of the polymer matrix, which releases the prodrug in a degradation-controlled system. The network-forming precursor must be miscible with the hydrophobic organic liquid component and, upon crosslinking, "holds" the component to form a solid or semi-solid to form the organogel. In certain embodiments, the compatibility of the hydrophobic organic liquid with the polymer network influences the rate at which the hydrophobic organic liquid escapes into the surrounding tissue fluids in vivo and may be gradually replaced by aqueous fluids, providing an additional method of control over prodrug solubility and drug release kinetics relative to network degradation.

[0114] In certain embodiments, the use of organogels in the sustained release biodegradable drug delivery systems of the present invention thus allows the release of the prodrug from the drug delivery system to be modified by adjusting or appropriately selecting the precursor components forming the crosslinked polymer network according to their hydrophilic and / or hydrophobic properties. Furthermore, in certain embodiments, the release of the prodrug from the drug delivery system can be modified or controlled by appropriately selecting the hydrophobic organic liquid according to its properties such as hydrophobicity, viscosity, compatibility with the prodrug, solubility or insolubility of the prodrug in the hydrophobic organic phase, etc.

[0115] Organogel-based drug delivery systems according to certain embodiments of the present invention offer several advantages over hydrogels, including the ability to stabilize water-degradable (hydrolyzable) components, such as water-sensitive prodrugs, over long periods of storage due to the anhydrous nature of certain organogels and the lack of need for hydration upon implantation.

[0116] Water-soluble compounds have low solubility or are insoluble in the organogel, allowing drugs to be incorporated as particulate solids embedded in the organogel matrix. The low solubility of drugs in the organogel matrix provides a mechanism for controlling the rate of drug release. This property greatly increases the range of compounds that can be included in the implant.

[0117] Manipulating the lipophilicity / hydrophilicity of the organogel can tune the drug release rate and affect the diffusion rate. This is not possible with pure hydrogels as they are water-based, and therefore in these systems, tuning the drug / matrix solubility requires modifying the drug itself into a prodrug form. With organogels, this can be avoided. Furthermore, changing the lipophilicity / hydrophilicity of the organogel can affect the degradation rate of the polymer matrix, which can have an additional effect on the drug release rate.

[0118] Organogels can be designed to slowly release hydrophobic organic liquids (e.g., oils) from the matrix in vivo, allowing for their slow transformation into hydrogels that are subsequently degraded, thus offering a new mode of controlled drug release and improving biocompatibility.

[0119] Solvents can be optionally added to the organogel during manufacture to overcome component compatibility problems, and the solvent can be removed to obtain an organogel with immobilized oil. The solvent can be removed by heat treatment, which is not possible for materials that melt or undergo glass transition at high temperatures. Solvent removal can also be achieved by methods typically used for non-crosslinked polymers, such as water extraction, vacuum drying, freeze drying, and evaporation. The manufacturing process is greatly simplified as the need for careful removal of the solvent is eliminated.

[0120] In certain embodiments, organogels have the physical properties of low modulus, dimensional stability, and good drug release kinetics. In certain embodiments, organogels are dimensionally stable to heat and do not melt. Thus, implant manufacturing processes such as hot melt extrusion can be used to form certain organogels of the invention.

[0121] The drug delivery systems of the invention comprising organogels can be used to deliver a variety of drugs including steroids, nonsteroidal anti-inflammatory drugs (NSAIDS), ocular hypotensive drugs, antibiotics, peptides, etc. The organogels can be used to deliver drugs and therapeutic agents such as anti-inflammatory drugs (e.g., diclofenac), analgesics (e.g., bupivacaine), calcium channel blockers (e.g., nifedipine), antibiotics (e.g., ciprofloxacin), cell cycle inhibitors (e.g., simvastatin), proteins or peptides (e.g., insulin), enzymes, anti-tumor agents, local anesthetics, hormones, angiogenic agents, anti-angiogenic agents, growth factors, antibodies, neurotransmitters, psychotropic drugs, anti-cancer drugs, chemotherapeutic agents, drugs that affect the reproductive organs, genes, oligonucleotides, or other configurations, and viruses such as AAV for gene delivery. The release rate from the organogel may depend on one or more properties of the prodrug, the hydrophobic organic liquid, and the polymer network, among other possible factors including one or more of the size of the drug, the relative hydrophobicity, the density of the organogel, the solids content of the organogel, and the like.

[0122] The drug delivery system of the present invention may be in the form of an implant, a medical implant or a pharma- ceutically acceptable implant, an implant coating, or an oral dosage form, or the like.

[0123] Treatment method In certain embodiments, the prodrugs disclosed herein are utilized in the treatment of ocular diseases associated with neovascularization.

[0124] In other embodiments, the ocular disease may be mediated by one or more receptor tyrosine kinases (RTKs), such as VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-α / β, and / or c-Kit.

[0125] In some embodiments, the ocular disease is a retinal disease including choroidal neovascularization, diabetic retinopathy, diabetic macular edema, retinal vein occlusion, acute macular neuroretinopathy, central serous chorioretinopathy, and cystoid macular edema, and the ocular disease is acute multifocal macular pigment epitheliopathy, Behcet's disease, birdshot retinochoroidopathy, infectious (syphilis, Lyme, tuberculosis, toxoplasmosis), intermediate uveitis (pars planitis), multifocal choroiditis, multiple ephemeral white dot syndrome (MEWDS), ocular sarcoidosis, posterior scleritis, serpentine choroiditis, subretinal ocular ... The eye disease is a vascular or exudative disease including Coats' disease, parafoveal telangiectasia, papillophlebitis, dendritic vasculitis, sickle cell retinopathy and other hemoglobinopathies, vascularoid streaks, and familial exudative vitreoretinopathy; or the eye disease is due to trauma or surgery including sympathetic ophthalmia, uveitic retinal disease, retinal detachment, trauma, photodynamic laser therapy, photocoagulation, intraoperative hypoperfusion, radiation retinopathy, or bone marrow transplant retinopathy.

[0126] In another embodiment, the prodrugs utilized herein may be utilized to treat tumor-associated eye diseases, including, for example, tumor-associated retinal diseases, solid tumors, tumor metastases, benign tumors such as hemangiomas, neurofibromas, trachoma, and pyogenic granulomas, congenital RPE hypertrophy, posterior uveal melanoma, choroidal hemangiomas, choroidal osteomas, choroidal metastases, complex hamartomas of the retina and retinal pigment epithelium, retinoblastoma, angioproliferative tumors of the fundus, retinal astrocytomas, or intraocular lymphomas.

[0127] In other embodiments, the prodrugs of the present invention can be used to treat any eye disease associated with vascular leakage.

[0128] In certain embodiments, the ocular disease is selected from neovascular age-related macular degeneration (AMD), diabetic macular edema (DME) and retinal vein occlusion (RVO).

[0129] In certain embodiments, the ocular disease is neovascularization-related age-related macular degeneration, hi other embodiments, the ocular condition is dry eye.

[0130] The compounds and pharmaceutical compositions disclosed herein can be administered by any route, such as oral, parenteral, ocular, transdermal, nasal, pulmonary or rectal. In certain embodiments, they can be administered into the vitreous or other sites. Other spaces include, for example, the punctum (canaliculus, superior / inferior canaliculus), fornix, superior / inferior fornix, sub-Tenon space, choroid, suprachoroid, Tenon, cornea, cancer tissue, organ, prostate, breast, surgically created space or lesion, empty space and potential space. In certain embodiments, the dosage form is a punctal plug, an intracanalicular insert, an anterior chamber insert, or an intravitreal insert.

[0131] In certain embodiments, the prodrugs and formulations herein are used by intravitreal, suprachoroidal, subretinal, subconjunctival, or subtenon administration (eg, for tumor treatment).

[0132] In certain embodiments, the present invention relates to a prodrug (e.g., a prodrug of axitinib disclosed herein) administered in combination with a base drug (e.g., axitinib) in the same formulation (e.g., an ophthalmic formulation) or in a different formulation to provide a more rapid releasing loading dose when there is a lag time in the release or therapeutic effect of the base drug. In embodiments where the prodrug has a slower release than the base drug, the combination can provide a longer duration of effect than administration of the base drug alone.

[0133] In certain embodiments, axitinib prodrugs can be formulated and / or administered according to US Pat. No. 11,439,592 B2. EXAMPLES

[0134] Example 1: Axitinib-N-succinoyloxymethyl prodrug The compound of Example 1 was prepared according to the following scheme.

[0135] [ka]

[0136] For each step in the process, sample numbers, batch sizes, conditions, yields and discussion are provided below. [Table 1-1] [Table 1-2]

[0137] Example 2 Solubility Experiments The solubility test was carried out using the following test materials and conditions. Test articles: Axitinib (99.99% purity by HPLC); Axitinib-N-succinoyloxymethyl prodrug (94.3% purity by HPLC); Test medium: Phosphate buffered saline pH 7.4 Incubation conditions: 22°C, 24 hours with continuous shaking Test concentration: 1mg / mL Data Analysis: The solubility of the test articles was determined by HPLC analysis using a calibration curve.

[0138] The HPLC conditions were as follows: [Table 2]

[0139] The results are as follows: [Table 3]

[0140] The solubility of axitinib reported in the literature is about 0.2 mcg / mL. The results showed that the N-succinoyloxymethyl prodrug improved the solubility of the prodrug by about 1100-fold.

[0141] Example 3 (Prophetic) Conversion of the axitinib-N-succinoyloxymethyl prodrug to axitinib is shown below.

[0142] method A concentration (1 μM in the final incubation) of prodrug was incubated with hrCES (combination of hrCES-1 and hrCES-2, 0.1 mg protein / mL per hrCES) in phosphate buffer (100 mM, pH 7.4) containing MgCl2 (5 mM). The incubation mixture was equilibrated at 37 °C for 5 min in a shaking water bath. The reaction was initiated by the addition of prodrug and then incubated at 37 °C. Aliquots of the incubation solution were sampled at 0, 15, 30, 60, and 120 min. The reaction was terminated by the addition of 50% ice-cold acetonitrile (ACN) / 0.1% formic acid containing an internal standard (IS, 0.2 μM metoprolol or 0.2 μM tolbutamide for positive or negative ionization mode of mass spectrometry, respectively). After centrifugation at 1,640g (3,000 rpm) for 10 min at 4 °C to remove proteins, the supernatant was transferred to an HPLC autosampler plate and stored at -20 °C until analysis. The remaining prodrug (expressed as the peak area ratio of prodrug to IS) and the formation of acid product per prodrug (final hydrolysis product of each prodrug) were measured by LC-MS / MS (Appendix 1). The CES activity of the hrCES used in this study was verified in parallel by using 1 mM of the nonspecific esterase probe substrate PNPB and measuring the time-dependent formation of PNP (0, 3, 5, 10 min) based on the absorbance at 410 nm. The experimental conditions for phenotyping of the CES reaction and sample analysis are summarized below. [Table 4]

[0143] Data analysis The residual percentage of the prodrug is calculated using the following formula: Prodrug remaining rate (%) = 100 × At / A0 where At is the peak area ratio (prodrug to IS) at time t and A0 is the peak area ratio (prodrug to IS) at time zero.

[0144] The elimination rate constant of the prodrug is estimated from first-order kinetics: Ct = C0·e-kt where C0 and Ct are the concentrations of the prodrug (expressed as the peak area ratio of the prodrug to IS) at time zero and incubation time t (min), and k is the elimination rate constant (min-1).

[0145] The elimination half-life of the prodrug (if applicable) before the plot begins to flatten is calculated using the following formula: t1 / 2=0.693 / k where t1 / 2 is the half-life (min) and k is the elimination rate constant (min-1).

[0146] The in vitro intrinsic clearance of the prodrug (if applicable) is calculated using the following formula: CLint=k / P where CLint is the in vitro intrinsic clearance, k is the elimination rate constant (min-1), and P is the enzyme concentration in the incubation medium (mg protein / mL).

[0147] All intrinsic clearance parameters are estimated using GraphPad® Prism (GraphPad Software, San Diego, CA, USA) and Microsoft Office Excel (Microsoft Corporation, Redmond, WA, USA).

[0148] Example 4 (Prophetic) The test article is prepared in suspension in a mixture of DMSO (5%) and 0.5%-CMC-Na (95%, v / v) at a concentration of 3 mg / mL of the axitinib molar equivalent of the prodrug of the present invention. Male ICR mice (64 mice, weighing 18-22 g) are randomly divided into 4 groups (16 mice per group). After fasting the animals for 12 hours, the test article is administered to the animals by oral gavage at a molar equivalent of 30 mg / kg axitinib. Blood samples are collected via the orbit into heparinized EP tubes at 0.25, 0.5, 1, 2, 4, 6, and 8 hours after administration of the dosing solution. The blood samples are centrifuged at 5,000 rpm at 4°C for 10 minutes, and plasma samples are collected and stored at -80°C. Sample analysis: Plasma samples (10 μL) are mixed thoroughly with acetonitrile (110 μL). The samples are then centrifuged at 12,000 rpm at 4° C. The supernatant is analyzed by LC-MS / MS instrumentation, and the target analytes are axitinib and its corresponding prodrug molecules.

[0149] Example 5 (Prophetic) Male ICR mice (body weight: 18-22 g) are randomly divided into 6 groups, with 6 mice per group, and blood is collected from 6 mice at each time point, for a total of 6 time points. The dosing solution of the test article is prepared by dissolving or suspending the compound in the solvent system. For all compounds, the concentration of the dosing solution is 3 mg / mL in axitinib molar equivalent, and the dose is 30 mg / kg in axitinib molar equivalent. After fasting the animals for 12 hours, the test article is administered in the dosing vehicle at a dose calculated according to the above information. After dosing, blood samples are collected at the pre-set time points of 0.5, 1, 2, 4, 6, and 8 hours. The blood samples are centrifuged at 5,000 rpm and 4 °C for 10 minutes, and plasma samples are collected and stored at -80 °C. Sample analysis: The plasma sample (20 μL) is mixed well with acetonitrile (220 μL). The samples were then centrifuged at 12,000 rpm at 4° C. The supernatants are analyzed on an LC-MS / MS instrument to obtain the target analytes.

Claims

1. Compounds of Formula I: 【Chemical 1】 (In the formula, X １ is N or N ＋ Y １ is selected from X ２ is NH or NY ２ is selected from X ３ is NH or NY ３ is selected from Y １ is -CH ２ OCO (OCH ２ CH ２ ) n １ O.M. １ or -CH ２ OCO (CH ２ ) n １ａ COOH, Y ２ is -CH ２ OCO (OCH ２ CH ２ ) n ２ O.M. ２ or -CH ２ OCO (CH ２ ) n ２ａ COOH, Y ３ is -CH ２ OCO (OCH ２ CH ２ ) n ３ O.M. ３ or -CH ２ OCO (CH ２ ) n ３ａ COOH, n １ , n １ａ , n ２ n ２ａ , n ３ and n ３ａ are independently 0 or an integer from 1 to 8, M １ , M ２ and M ３ are independently H, optionally substituted C １－６ selected from alkyl and optionally substituted aryl; X １ , X ２ and X ３ at least one of is not N or NH), and pharmaceutically acceptable salts thereof.

2. X １ is N ＋ Y １ and X ２ is NH, X ３ is NH, Y １ is -CH ２ OCO (OCH ２ CH ２ ) n １ OCH ３ is, or X 1 is N; X 2 is NY 2 ; X 3 is NH; Y 2 is —CH 2 OCO(CH 2 )n 2 COOH, or X 1 is N; X 2 is NH; X 3 is NY 3 ; Y 3 is —CH 2 OCO(CH 2 )n 3 COOH, or X 1 is N; X 2 is NY 2 ; X 3 is NY 3 ; Y 2 and Y 3 are each —CH 2 OCO(CH 2 )n 2 COOH, or X 1 is N + Y 1 ; X 2 is NY 2 ; X 3 is NH; Y 1 is —CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 ; Y 2 is —CH 2 OCO(CH 2 )n 2 COOH, or X 1 is N + Y 1 ; X 2 is NH; X 3 is NY 3 ; Y 1 is —CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 ; Y 3 is —CH 2 OCO(CH 2 )n 2 COOH, or X 1 is N + Y 1 ; X 2 is NY 2 ; X 3 is NY 3 ; Y 1 is —CH 2 OCO(OCH 2 CH 2 )n 1 OCH 3 ; Y 2 and Y 3 are each —CH 2 OCO(CH 2 )n 2 COOH; The compound of claim 1.

3. n １ 10. The compound of claim 1, wherein n 1 , n 2 , n 3 , n 1a , n 2a or n 2a is 2.

4. The compound described in claim 1, which is axitinib-N-succinoyloxymethyl.

5. A pharmaceutical composition comprising a compound of formula I according to any one of claims 1 to 4 and a pharmaceutically acceptable excipient.

6. 6. The pharmaceutical composition of claim 5, in the form of an oral solid dosage form, a tablet, an ophthalmic formulation, an implant, an injectable, a solution, a suspension, or an ointment.

7. A pharmaceutical composition according to claim 5 for treating a disease or symptom.

8. 8. The pharmaceutical composition of claim 7, wherein the disease or condition is advanced renal cell carcinoma.

9. 8. The pharmaceutical composition of claim 7, wherein the disease or condition is an ocular disease or condition.

10. 10. The pharmaceutical composition of claim 9, wherein the ocular disease or condition is diabetic retinopathy, AMD, DME, or RVO.

11. When said compound of formula I is reacted in vivo with a compound of formula II 【Chemistry 2】 The pharmaceutical composition of claim 7, wherein

12. A hydrogel comprising the compound according to any one of claims 1 to 4.

13. The hydrogel of claim 12 further comprising a polyethylene glycol compound.

14. A xerogel comprising the compound according to any one of claims 1 to 4.

15. 15. The xerogel of claim 14, further comprising a polyethylene glycol compound.

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