# US 5,349,066 A · Bifunctional linking compounds, conjugates and methods for their production

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- Number: US 5,349,066 A
- Document ID: US5349066A
- Status: Granted
- Kind: A
- Application number: 07/865,062
- Filed: 1992-04-08
- Granted: 1994-09-20
- Earliest claimed: 1990-05-14
- Assignees: Bristol-Myers Squibb Company
- Inventors: Takushi Kaneko; David Willner; Ivo Monkovic; Robert S. Greenfield; Gary R. Braslawsky
- Web page: https://patentgrep.com/patent/US5349066A

## CPC

- C07H 15/252: Naphthacene radicals, e.g. daunomycins, adriamycins
- A61K 47/65: Peptidic linkers, binders or spacers, e.g. peptidic enzyme-labile linkers
- A61K 47/6809: {Antibiotics, e.g. antitumor antibiotics anthracyclins, adriamycin, doxorubicin or daunomycin}
- A61K 47/6889: {Conjugates wherein the antibody being the modifying agent and wherein the linker, binder or spacer confers particular properties to the conjugates, e.g. peptidic enzyme-labile linkers or acid-labile linkers, providing for an acid-labile immuno conjugate wherein the drug may be released from its antibody conjugated part in an acidic, e.g. tumoural or environment}
- A61P 35/00: Antineoplastic agents
- C07C 323/44: X or Y being nitrogen atoms
- C07D 213/71: to which a second hetero atom is attached
- C07H: SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS (derivatives of aldonic or saccharic acids C07C, C07D; aldonic acids, saccharic acids C07C59/105, C07C59/285; cyanohydrins C07C255/16; glycals C07D; compounds of unknown constitution C07G; polysaccharides, derivatives thereof C08B; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; sugar industry C13)
- 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
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

The present invention provides novel N-substituted hydrazine bifunctional compounds, novel N-substituted hydrazone derivatives of a cytotoxic reagent incorporating the bifunctional compounds, novel conjugates containing at least one cytotoxic reagent molecule reacted with the bifunctional compound and bound to a molecule reactive with a target cell population, methods for their production, and pharmaceutical compositions and methods for delivering cytotoxic reagents to a target population of cells. The hydrazone bonds of the conjugates of the invention permit the release of free cytotoxic reagent from the conjugates in the acidic external or internal environment of the target cells. The bifunctional compounds, derivatives, conjugates and methods of the invention are useful in antibody-or ligand-mediated drug delivery systems for the preferential killing of a target cell population to treat diseases such as cancers, infections and autoimmune disorders.

## Claims

### Claim 1

A conjugate formed by combining at least one molecule containing a free carbonyl group and at least one molecule containing a sulfhydryl group with at lease one of the following compounds:
(a) a bifunctional N-substituted hydrazine compound having the formula:
H.sub.2 NNHCONH(CH.sub.2).sub.n SSR.sup.8
wherein n is an integer from 1 to 10; and R.sup.8 is ##STR7## wherein X is NO.sub.2 or halogen; (b) a N-substituted hydrazine bifunctional compound having the formula:
H.sub.2 NNHCONHNHCONH(CH.sub.2).sub.n SSR.sup.8
wherein n is an integer from 1 to 10; and R.sup.8 is ##STR8## wherein X is H, NO.sub.2 or halogen; (c) a N-substituted hydrazine bifunctional compound having the formula:
H.sub.2 NNHCSNH(CH.sub.2).sub.m CH.dbd.CH(CH.sub.2).sub.n SSR.sup.8
wherein m, n are integers from 1 to 10, which are the same or different; and R.sup.8 is ##STR9## wherein X is H, NO.sub.2 or halogen; or (d) a N-substituted hydrazine bifunctional compound having the formula:
H.sub.2 NNHCOO(CH.sub.2).sub.n SSR.sup.8
wherein n is an integer from 1 to 10; and R.sup.8 is ##STR10## wherein X is H, NO.sub.2 or halogen; or (e) a N-substituted hydrazine bifunctional compound having the formula:
H.sub.2 NNH--Ar--CONH(CH.sub.2).sub.n SSR.sup.8
wherein n is an integer from 1 to 10; and R.sup.8 is ##STR11## wherein X is NO.sub.2 or halogen and Ar is ##STR12##

### Claim 2 (depends on 1)

The conjugate of claim 1, wherein said molecule containing a carbonyl group is a cytotoxic reagent.

### Claim 3 (depends on 2)

The conjugate of claim 2 wherein said cytotoxic reagent is an anthracycline.

### Claim 4 (depends on 1)

The conjugate of claim 1, wherein said molecule containing a sulfhydryl group is a molecule reactive with a target cell population.

### Claim 5 (depends on 4)

The conjugate of claim 4 wherein said molecule is a monoclonal antibody.

### Claim 6

A bifunctional compound comprising the compound of 1, wherein said compound is reduced by a reducing reagent to form a free sulfhydryl group.

### Claim 7 (depends on 6)

A conjugate formed by combining the compound of claim 6 with at least one molecule containing a free carbonyl group and at least one molecule having maleiimide groups attached.

### Claim 8 (depends on 7)

The conjugate of claim 7 wherein said molecule containing a free carbonyl group is an anthracycline and said molecule having maleiimide groups attached is an antibody.