# US 2019/0167793 A1 · Near-ir light-cleavable conjugates and conjugate precursors

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- Number: US 2019/0167793 A1
- Document ID: US20190167793A1
- Status: Published application
- Kind: A1
- Application number: 16/323,747
- Filed: 2017-08-07
- Published: 2019-06-06
- Earliest claimed: 2016-08-11
- Assignees: The United States of America, as represented by the Secretary, Dept. of Health and Human Service
- Applicants: The United States of America, as represented by the Secretary, Dept. of Health and Human Service
- Inventors: Martin John Schnermann; Roger Rauhauser Nani; Alexander Patrick Gorka; Hisataka Kobayashi
- Web page: https://patentgrep.com/patent/US20190167793A1

## CPC

- A61K 41/0042: {Photocleavage of drugs in vivo, e.g. cleavage of photolabile linkers in vivo by UV radiation for releasing the pharmacologically-active agent from the administered agent; photothrombosis or photoocclusion}
- A61K 47/545: {Heterocyclic compounds (A61K47/558 takes precedence)}
- A61K 47/6803: {Drugs conjugated to an antibody or immunoglobulin, e.g. cisplatin-antibody conjugates}
- A61K 47/6809: {Antibiotics, e.g. antitumor antibiotics anthracyclins, adriamycin, doxorubicin or daunomycin}
- A61K 47/6829: {Bacterial toxins, e.g. diphteria toxins or Pseudomonas exotoxin A}
- A61K 47/6845: {the antibody targeting a cytokine, e.g. growth factors, VEGF, TNF, a lymphokine or an interferon}
- A61K 49/0032: {Methine dyes, e.g. cyanine dyes}
- A61K 49/0058: {Antibodies}
- A61P 35/00: Antineoplastic agents
- 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)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS

## Abstract

Embodiments of near-infrared light-cleavable heptamethine cyanine-based conjugates, particularly targeting agent-drug conjugates, according to Formula I and conjugate precursors are disclosed. The disclosed targeting agent-drug conjugates are useful for targeted delivery and release of a drug. Methods of making and using the conjugates and precursors also are disclosed.

## Claims

### Claim 1

A conjugate having a chemical structure according to Formula I, or a pharmaceutically acceptable salt thereof:
wherein m is 1, 2, 3, 4, or 5;
each n independently is 1, 2, or 3;
R1 and R4 independently are alkyl, haloalkyl, cycloalkyl, alkoxy, —ROH, —RC(O)OH, —C(O)—R, or —C(O)—O—R, wherein R is alkyl;
R2 is C(Re)2 wherein each RC independently is H, halo, alkyl, or aryl, or (R2)m collectively is phenyl;
R3 is -L1-C(O)—X2-drug, where L1 is absent or a linker moiety and X2 is O, N(H), or N(CH3);
R5 is —(CH2)x-L2-Ra, where x is an integer≥1, L2 is a linker moiety or is absent, and Ra is —C(O)N(H)Rb, —N(H)C(O)Rb, —N(H)Rb, —SRb,
where y is an integer≥1 and Rb is a targeting agent,
X1 is O, N, or CH2;
G1 is
G2 is
R6 and R7 independently are alkyl sulfonate, H, alkyl, alkoxy, or substituted aminoalkyl;
R8-R19 independently are H, alkyl, amino, alkoxy, or alkyl sulfonate;
each Y independently is C(Rd)2, S, O, Se, or N(Rd) wherein each Rd independently is alkyl or H; and
each ring A independently is a 6-membered fused aryl, aliphatic, heteroaliphatic, or heteroaryl ring.

### Claim 2 (depends on 1)

The conjugate according to claim 1, wherein R1 and R4 independently are C1-C4 alkyl, —ROH, —RCOOH, or —RCF3, where R is C1-C4 alkyl.

### Claim 3 (depends on 1)

The conjugate according to claim 1, wherein ring A is a fused phenyl ring substituted with optionally substituted sulfonate.

### Claim 4 (depends on 1)

The conjugate according to claim 1, wherein:
G1 is
and G2 is
or
G1 is
and G2 is
or
G1 is
and G2 is
wherein each Y is the same,
R6 and R7 are identical, and
R8-R11 and R16-R17 are identical to R12-R15 and R18-R19, respectively.

### Claim 5 (depends on 1)

The conjugate according to claim 1, wherein:
(i) each Y is C(CH3)2;
(ii) R6 and R7 are —(CH2)pSO3− or —(CH2)pN(CH3)3+, where p is 1, 2, 3, 4, or 5;
(iii) R8-R19 are H; or
(iv) any combination of (i), (ii), and (iii).

### Claim 6 (depends on 1)

The conjugate according to claim 1, having a structure according to Formula II:

### Claim 7 (depends on 1)

The conjugate according to claim 1, wherein R3 is
where R20-R27 independently are H, alkyl, —NO2, —NRe2, —NRe3, alkoxy, or sulfonate, wherein each Re independently is H, halo, or alkyl.

### Claim 8 (depends on 1)

The conjugate according to claim 1, wherein —X2-Drug is
where R′ is C1-C10 alkyl or alkyl sulfonate.

### Claim 9 (depends on 1)

The conjugate according to claim 1, wherein R5 is
where q and r independently are 1, 2, 3, 4, or 5.

### Claim 10 (depends on 1)

The conjugate according to claim 1, wherein Rb is a targeting agent.

### Claim 11 (depends on 1)

The conjugate according to claim 1, wherein R5 is —(CH2)x-L2-Ra, where x is an integer≥1, L2 is a linker moiety or is absent, and Ra is —C(O)N(H)Rb, —N(H)C(O)Rb, —N(H)Rb, or —SRb where Rb is a targeting agent, the conjugate further comprising one or more additional moieties bound to Rb, each of the additional moieties independently having a chemical structure according to Formula III:
wherein m, n, x, R1-R4, X1, G1, G2, and L2 are as defined in claim 1, and Z is —C(O)N(H)—, —N(H)C(O)—, —N(H)—, or —S—.

### Claim 12 (depends on 1)

The conjugate according to claim 1, wherein Rb is an antibody and R3 is
where —X2-Drug is

### Claim 13 (depends on 1)

The conjugate according to claim 1, wherein the conjugate is:
where R1 and R4 are methyl, ethyl, n-propyl, i-propyl, t-butyl, or —(CH2)2OH;
R6 and R7 are —(CH2)4SO3− or —(CH2)4N(CH3)3+; and
Rb is an antibody.

### Claim 14 (depends on 1)

A pharmaceutical composition comprising a conjugate according to claim 1, wherein Rb is a targeting agent and a pharmaceutically acceptable carrier.

### Claim 15

A precursor compound having a structure according to Formula IV, or a salt thereof:
wherein m is 1, 2, 3, 4, or 5;
each n independently is 1, 2, or 3;
R1 and R4 independently are alkyl, haloalkyl, cycloalkyl, alkoxy, —ROH, —RC(O)OH, —C(O)—R, or —C(O)—O—R, wherein R is alkyl;
R2 is C(Rc)2 wherein each RC independently is H, halo, alkyl, or aryl, or (R2)m collectively is phenyl;
X1 is O, N, or CH2;
G1 is
G2 is
R6 and R7 independently are alkyl sulfonate, H, alkyl, alkoxy, or substituted aminoalkyl;
R8-R19 independently are H, alkyl, amino, alkoxy, or alkyl sulfonate;
each Y independently is C(Rd)2, S, O, Se, or N(Rd) wherein each Rd independently is alkyl or H;
each ring A independently is a 6-membered fused aryl, aliphatic, heteroaliphatic, or heteroaryl ring;
R28 is hydrogen or a protecting group; and
R29 is —(CH2)u—C≡CH where u is 1, 2, 3, 4, or 5.

### Claim 16 (depends on 15)

The precursor compound of claim 15, wherein the precursor compound is
wherein R1 and R4 are methyl, ethyl, n-propyl, i-propyl, t-butyl, or —(CH2)2OH; and
R6 and R7 are —(CH2)pSO3− or —(CH2)pN(CH3)3+, where p is 1, 2, 3, 4, or 5.

### Claim 17 (depends on 1)

A method, comprising:
providing a conjugate according to claim 1, wherein Rb is a targeting agent; and
subsequently irradiating the conjugate with targeted application of an effective quantity of light having a selected wavelength in the near-infrared range and a selected intensity to induce a cleavage reaction and release the drug from the conjugate.

### Claim 18 (depends on 17)

The method of claim 17, wherein irradiating the conjugate with targeted application of light comprises irradiating the conjugate with a laser that produces light having a wavelength of 650-900 nm.

### Claim 19 (depends on 17)

The method of claim 17, further comprising:
monitoring a level of fluorescence of the conjugate; and
ceasing irradiation when the level of fluorescence falls below a target level.

### Claim 20 (depends on 17)

The method of claim 17, further comprising:
providing a biological sample including, or suspected of including, a target molecule;
contacting the biological sample with the conjugate, wherein the targeting agent of the conjugate is capable of recognizing and binding to the target molecule; and
subsequently irradiating the biological sample with the targeted application of light.

### Claim 21 (depends on 17)

The method of claim 17, further comprising:
identifying a subject as having a condition that may be treated with the drug;
administering a therapeutically effective amount of the conjugate or a pharmaceutical composition comprising the conjugate to the subject; and
subsequently irradiating the conjugate by targeted application of the effective quantity of light having a wavelength in the near-infrared range and a selected intensity to a targeted portion of the subject, thereby releasing the drug from at least some molecules of the conjugate.

### Claim 22 (depends on 21)

The method of claim 21, wherein the subject has a tumor and the targeted portion of the subject includes an area proximate a location of the tumor.

### Claim 23 (depends on 17)

The method of claim 17, further comprising:
administering a therapeutically effective amount of the conjugate or a pharmaceutical composition comprising the conjugate to a subject suspected of having a condition that may be treated with the drug;
subsequently irradiating the conjugate by targeted application of a quantity of light having a wavelength in the near-infrared range and a selected intensity to a targeted portion of the subject, wherein the quantity of light is sufficient to produce fluorescence of the conjugate but insufficient to induce cleavage of the conjugate and release the drug from the conjugate;
detecting any fluorescence from the conjugate in the targeted portion of the subject; and
subsequently irradiating the conjugate, if fluorescence is detected, by targeted application of the effective quantity of light having a wavelength in the near-infrared range and a selected intensity to the targeted portion of the subject, thereby releasing the drug from at least some molecules of the conjugate.

### Claim 24 (depends on 23)

The method of claim 23, wherein the condition is a tumor that may be treated with the drug and the targeted portion of the subject includes the tumor site, the method further comprising:
excising at least a portion of the tumor from the subject before administering the therapeutically effective amount of the conjugate.

### Claim 25 (depends on 23)

The method of claim 23, wherein (i) the condition is a tumor that may be treated with the drug, (ii) the targeted portion of the subject includes the tumor site, and (iii) fluorescence is detected in the targeted portion of the subject, the method further comprising:
excising at least a portion of the tumor from the subject after detecting the fluorescence in the targeted portion of the subject; and
subsequently irradiating the conjugate by targeted application of the effective quantity of light to the targeted portion of the subject.