# US 12,594,345 B2 · Degradable hyaluronic acid hydrogels

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- Number: US 12,594,345 B2
- Document ID: US12594345B2
- Status: Granted
- Kind: B2
- Application number: 17/280,760
- Filed: 2019-09-25
- Published: 2021-11-04
- Granted: 2026-04-07
- Earliest claimed: 2018-09-26
- Assignees: Ascendis Pharma A/S
- Applicants: Ascendis Pharma A/S
- Inventors: Sebastian Stark; Burkhardt Laufer; Thomas Knappe; Tobias Voigt; Nicola Bisek
- Web page: https://patentgrep.com/patent/US12594345B2

## CPC

- A61K 47/6903: {the form being semi-solid, e.g. an ointment, a gel, a hydrogel or a solidifying gel}
- A61K 47/61: the organic macromolecular compound being a polysaccharide or a derivative thereof
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)

## Abstract

The present invention relates to conjugates comprising crosslinked hyaluronic acid to which a plurality of drug moieties are covalently and reversibly conjugated, wherein the hyaluronic acid exhibits a certain degree of modification and comprises degradable crosslinked moieties. It also relates to their use as medicaments and their use in the diagnosis, prevention and treatment of diseases.

## Claims

### Claim 1

A conjugate comprising crosslinked hyaluronic acid strands to which a plurality of drug moieties are covalently and reversibly conjugated, wherein the conjugate comprises a plurality of connected units selected from the group consisting of
wherein
an unmarked dashed line indicates a point of attachment to an adjacent unit at a dashed line marked with #or to a hydrogen;
a dashed line marked with #indicates a point of attachment to an adjacent unit at an unmarked dashed line or to a hydroxyl;
a dashed line marked with § indicates a point of connection between at least two units Z3 via a moiety -CL-;
each -D is independently a drug moiety;
each -L1- is independently a linker moiety to which -D is covalently and reversibly conjugated; wherein the bond between -L1- and -D is cleaved in aqueous buffer at pH 7.4 and 37° C. with a half-life ranging from 12 hours to three months and -D is released non-enzymatically in its unmodified, pharmacologically active form;
each -L2-, -L3- and -L4- is independently either absent or a spacer moiety;
each —CL- is independently a moiety connecting at least two units Z3 and wherein there is at least one degradable bond in the direct connection between any two carbon atoms marked with the * connected by a moiety —CL-;
each —SP— is independently absent or a spacer moiety;
each —Ra1 is independently selected from the group consisting of —H, C1-4 alkyl, an ammonium ion, a tetrabutylammonium ion, a cetyl methylammonium ion, an alkali metal ion and an alkaline earth metal ion;
each —Ra2 is independently selected from the group consisting of —H and C1-10 alkyl;
each —X0A—, —X0B—, —X0C and —X0D is independently either absent or a linkage;
each —X0E— is
wherein the unmarked dashed line indicate attachment to —SP— and the dashed line marked with an asterisk indicate attachment to the carbonyl of the hyaluronic acid, wherein R01 is independently selected from the group consisting of halogen, —H, —CN, -T0, C1-50 alkyl, C2-50 alkenyl, and C2-50 alkynyl: wherein -T0, C1-50 alkyl, C2-50 alkenyl, and C2-50 alkynyl are optionally substituted with one or more —R02, which are the same or different, and wherein C1-50 alkyl, C2-50 alkenyl, and C2-50 alkynyl are optionally interrupted by one or more groups selected from the group consisting of -T0, —C(O)O—, —O—, C(O)—, —C(O)N(R03)—, —S(O)2N(R03)—, —S(O)N(R03)—, —S(O)2—, —S(O)—, N(R03)S(O)2N(R03a)—, —S—, —N(R03)—, —OC(OR03)(R03a), —N(R03)C(O)N(R03a)—, and —OC(O)N(R03) wherein each T0 is independently selected from the group consisting of phenyl, naphthyl, indenyl, indanyl, tetralinyl, C3-10 cycloalkyl, 3- to 10-membered heterocyclyl, and 8- to 11-membered heterobicyclyl; wherein each T0 is independently optionally substituted with one or more R02, which are the same or different; and wherein each —R02, —R03 and —R03a is independently selected from the group consisting of H and C1-6 alkyl: wherein C1-6 alkyl is optionally substituted with one or more halogen, which are the same or different;
each —X0F- is
wherein R04 is independently selected from the group consisting of halogen, —H, CN, T0, C1-50 alkyl, C2-50 alkenyl, and C2-50 alkynyl: wherein T0, C1-50 alkyl, C2-50 alkenyl, and C2-50 alkynyl are optionally substituted with one or more R06, which are the same or different, and wherein C1-50 alkyl, C2-50 alkenyl, and C2-50 alkynyl are optionally interrupted by one or more groups selected from the group consisting of T0, —C(O)O—, —O—, —C(O)—, —C(O)N(R07)—, —S(O)2N(R07)—, —S(O)N(R07)—, —S(O)2—, —S(O)—, —N(R07)S(O)2N(R07a)—, —S—, N(R07)—, —OC(OR07)(R07a), —N(R07)C(O)N(R07a)—, and —OC(O)N(R07); wherein each T0 is independently selected from the group consisting of phenyl, naphthyl, indenyl, indanyl, tetralinyl, C3-10 cycloalkyl, 3- to 10-membered heterocyclyl, and 8- to 11-membered heterobicyclyl;
wherein each T0 is independently optionally substituted with one or more R06, which are the same or different; and wherein each R06, R07 and R07a is independently selected from the group consisting of H and C1-6 alkyl; wherein C1-6 alkyl is optionally substituted with one or more halogen, which are the same or different;
optionally —X0A— and/or —X0B- form together with -L4- or parts of -L4- one or more ring structure selected from the group consisting of 4- to 7-membered heterocyclyl, 8- to 11-membered heterobicyclyl and adamantyl;
optionally —X0B— and/or —X0C— form together with -L3- or parts of -L3- one or more ring structure selected from the group consisting of 4- to 7-membered heterocyclyl, 8- to 11-membered heterobicyclyl and adamantyl;
optionally, —X0C— and/or —X0D— form together with -L2- or parts of -L2- one or more ring structure selected from the group consisting of 4- to 7-membered heterocyclyl, 8- to 11-membered heterobicyclyl and adamantyl;
optionally —X0E— and/or —X0F— form together with —SP— or parts of —SP— one or more ring structure selected from the group consisting of 4- to 7-membered heterocyclyl, 8- to 11-membered heterobicyclyl and adamantyl;
wherein
all units Z1 present in the conjugate may be the same or different;
all units Z2 present in the conjugate may be the same or different;
all units Z3 present in the conjugate may be the same or different;
at least one unit Z3 is present per hyaluronic acid strand which is connected to at least one unit Z3 on a different hyaluronic acid strand; and
the conjugate comprises at least one unit Z2;
wherein —CL- is a moiety of formula (D)
wherein
the dashed lines indicate attachment to a moiety —X0F—; and
m2, m3 and m4 are independently an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and 25;
and
wherein -L1- is of formula (I):
wherein
the dashed line indicates the attachment to a nitrogen, hydroxyl or thiol of -D;
—X— is selected from the group consisting of —C(R4R4a)—, —N(R4)—, —O—, —C(R4R4a)—C(R5R5a)—, —C(R5R5a)—C(R4R4a)—, —C(R4R4a)—N(R6)—, —N(R6)—C(R4R4a)—, —C(R4R4a)—O—, —O—C(R4R4a)—, and —C(R7R7a)—,
X1 is selected from the group consisting of C and S(O);
—X2— is selected from the group consisting of —C(R8R8a)— and —C(R8R8a)—C(R9R9a)—;
═X3 is selected from the group consisting of ═O, ═S, and ═N—CN;
—R1, —R1a, —R2, —R2a, —R4, —R4a, —R5, —R5a, —R6, —R8, —R8a, —R9 and —R9a are independently selected from the group consisting of —H and C1-6 alkyl;
—R3 and —R3a are independently selected from the group consisting of —H and C1-6 alkyl, provided that in case one of —R3 and —R3a or both are other than —H they are connected to N to which they are attached through an sp3-hybridized carbon atom;
—R7 is selected from the group consisting of —N(R10R10a) and —NR10—(C═O)—R11;
—R7a, —R10, —R10a and —R11 are independently selected from the group consisting of —H and C1-6 alkyl;
alternatively, one or more of the pairs —R1a/—R4a, —R1a/—R5a, —R1a/—R7a, —R4a/—R5a and —R8a/—R9a form a chemical bond;
alternatively, one or more of the
pairs —R1/—R1a, —R2/—R2a, —R4/—R4a, —R5/—R5a, —R8/—R8a and —R9/—R9a are joined together with the atom to which they are attached to form a C3-10 cycloalkyl or 3- to 10-membered heterocyclyl;
alternatively, one or more of the pairs —R1/—R4, —R1/—R5, —R1/—R6, —R1/—R7a, —R4/—R5, —R4/—R6, —R8/—R9 and —R2/—R3 are joined together with the atoms to which they are attached to form a ring A;
alternatively, —R3/—R3a are joined together with the nitrogen atom to which they are attached to form a 3- to 10-membered heterocycle;
A is selected from the group consisting of phenyl; naphthyl; indenyl; indanyl;
tetralinyl; C3-10 cycloalkyl; 3- to 10-membered heterocyclyl; and 8- to 11-membered heterobicyclyl; and
wherein -L1- is substituted with —X0D-L2- and wherein -L1- is optionally further substituted, provided that the hydrogen marked with the asterisk in formula (I) is not replaced by —X0D-L2- or a substituent.

### Claim 2 (depends on 1)

The conjugate of claim 1, wherein the conjugate comprises crosslinked hyaluronic acid strands to which a plurality of drug moieties are covalently and reversibly conjugated, wherein the conjugate comprises a plurality of connected units selected from the group consisting of
wherein
an unmarked dashed line indicates a point of attachment to an adjacent unit at a dashed line marked with #or to a hydrogen;
a dashed line marked with #indicates a point of attachment to an adjacent unit at an unmarked dashed line or to a hydroxyl;
a dashed line marked with § indicates a point of connection between at least two units Z3 via a moiety —CL-;
-D, -L1-, -L2-, -L3-, -L4-, —SP—, —CL-, —X0A—, —X0B—, —X0C—, —X0D—, —X0E—, —X0F—, —Ra1 and —Ra2 are used as in claim 1;
wherein
all units Z1 present in the conjugate may be the same or different;
all units Z2 present in the conjugate may be the same or different;
all units Z3 present in the conjugate may be the same or different;
the number of Z1 units ranges from 1% to 98% of the total number of units present in the conjugate;
the number of Z2 units ranges from 1% to 98% of the total number of units present in the conjugate, provided at least one unit Z2 is present in the conjugate;
the number of Z3 units ranges from 1% to 97% of the total number of units present in the conjugate, provided that at least one unit Z3 is present per strand; and
wherein at least 70% of all hyaluronic acid strands comprise at least one moiety Z2 and at least one moiety Z3.

### Claim 3 (depends on 2)

The conjugate of claim 2, wherein the number of units Z2 ranges from 1% to 70% of all units present in the conjugate.

### Claim 4 (depends on 2)

The conjugate of claim 2, wherein the number of units Z3 ranges from 1% to 30%.

### Claim 5 (depends on 2)

The conjugate of claim 2, wherein the number of units Z1 ranges from 10% to 97%.

### Claim 6 (depends on 1)

The conjugate of claim 1, wherein -D is an antibiotic moiety.

### Claim 7 (depends on 1)

The conjugate of claim 1, wherein -D is an anti VEGF antibody moiety or fragment thereof.

### Claim 8 (depends on 1)

A pharmaceutical composition comprising at least one conjugate of claim 1 and at least one excipient.

### Claim 9 (depends on 1)

A method of treating a patient suffering from a disease b that can be treated with D-H or D-OH, comprising administering an effective amount of the conjugate of claim 1 to the patient.

### Claim 10 (depends on 1)

A method of preparing a pharmaceutical formulation comprising a conjugate of claim 1, wherein the method comprises the steps of
(a) providing said conjugate;
(b) subjecting the conjugate of step (a) to a solution comprising a buffering agent, a surfactant and a salt comprising multivalent ions to which a swelling agent is added after addition of said solution;
(c) homogenizing the admixture of step (b);
(d) deswelling the conjugate of step (c) in a deswelling solution comprising at least a deswelling agent;
(e) isolating the conjugate from the admixture of step (d);
(f) subjecting the conjugate of step (e) to a solution comprising a buffering agent, a surfactant, a salt comprising bivalent ions, a hydrophilic polymer of a molecular weight higher than 10 kDa, a density-modifying agent and a polarity-modifying agent, to which a swelling agent is added after addition of said solution;
(g) homogenizing the admixture of step (f);
(h) deswelling the conjugate of step (g) in a deswelling solution comprising at least a deswelling agent;
(i) isolating the conjugate from the admixture of step (h); and
wherein, there may be optional washing steps between steps (c) and (d), (f) and (g), and (g) and (h).