Immunomodulators acting as antagonists of PD-1

1. A compound of formula (I)

or a pharmaceutically acceptable salt thereof, wherein:

A is selected from

wherein:

denotes the point of attachment to the carbonyl group and denotes the point of attachment to the nitrogen atom;

n is 0 or 1;

m is 1 or 2;

m′ is 0 or 1;

w is 0, 1, or 2;

R X is selected from hydrogen, amino, hydroxy, and methyl;

R 14 and R 15 are independently selected from hydrogen and methyl;

R 16a is selected from hydrogen and C 1 -C 6 alkyl;

R 16 is selected from

—(C(R 17a ) 2 ) 2 —X—R 30 ,

—C(R 17a ) 2 C(O)N(R 16a )C(R 17a ) 2 —X′—R 31 ,

—C(R 17a ) 2 [C(O)N(R 16a )C(R 17a ) 2 ] w′ —X—R 31 ,

—(C(R 17a )(R 17 )C(O)NR 16a ) n′ —H; and

—(C(R 17a )(R 17 )C(O)NR 16a ) m′ —C(R 17a )(R 17 )—CO 2 H;

wherein:

w′ is 2 or 3;

n′ is 1-6;

m′ is 0-5;

X is a chain of between 1 and 172 atoms wherein the atoms are selected from carbon and oxygen and wherein the chain may contain one, two, three, or four groups selected from —NHC(O)NH—, and —C(O)NH— embedded therein; and wherein the chain is optionally substituted with one to six groups independently selected from —CO 2 H, —C(O)NH 2 , —CH 2 C(O)NH 2 , and —(CH 2 )CO 2 H;

X′ is a chain of between 1 and 172 atoms wherein the atoms are selected from carbon and oxygen and wherein the chain may contain one, two, three, or four groups selected from —NHC(O)NH—, and —C(O)NH— embedded therein; and wherein the chain is optionally substituted with one to six groups independently selected from —CO 2 H, —C(O)NH 2 , and —CH 2 CO 2 H, provided that X′ is other than unsubstituted PEG;

R 30 is selected from —CO 2 H, —C(O)NR W R X , and —CH 3 wherein R W and R X are independently selected from hydrogen and C 1 -C 6 alkyl, provided that when X is all carbon, R 30 is other than —CH 3 ;

R 31 is —CO 2 H, —C(O)NR W R X , —CH 3 , alexa-5-SDP, and biotin;

each R 17a is independently selected from hydrogen, C 1 -C 6 alkyl, —CH 2 OH, —CH 2 CO 2 H, —(CH 2 ) 2 CO 2 H,

each R 17 is independently selected from hydrogen, —CH 3 , (CH 2 ) z N 3 , —(CH 2 ) z NH 2 , —X—R 31 , —(CH 2 ) z CO 2 H, —CH 2 OH, CH 2 C═CH, and —(CH 2 ) z -triazolyl-X—R 35 , wherein z is 1-6 and R 35 is selected from —CO 2 H, —C(O)NR W R X , CH 3 , biotin, -2-fluropyridine, —C(O)—(CH 2 ) 2 —C(O)O-vitamin E, —C(O)O-vitamin E; and

provided at least one R 17 is other than hydrogen, —CH 3 , or —CH 2 OH;

R c , R f , R h , R i , R m , and R n are hydrogen;

R a and R j are each independently selected from hydrogen and methyl;

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 11 , R 12 , and R 13 are independently selected from a natural amino acid side chain and an unnatural amino acid side chain or form a ring with the corresponding vicinal R group as described below;

R 10 is indolylC 1 -C 3 alkyl, wherein the indolyl part is optionally substituted with one group selected from C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkoxycarbonylC 1 -C 3 alkyl, (C 1 -C 6 alkyl)S(O) 2 NHC(O)C 1 -C 3 alkyl, arylS(O) 2 NHC(O)C 1 -C 3 alkyl, arylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, C 3 -C 6 cycloalkylS(O) 2 NHC(O)C 1 -C 3 alkyl, C 3 -C 6 cycloalkylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, cyano, haloC 1 -C 3 alkoxy, haloC 1 -C 3 alkyl, heteroarylS(O) 2 NHC(O)C 1 -C 3 alkyl, heteroarylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, —NR p R q , (NR p R q )C 1 -C 3 alkyl, and tetrazolylC 1 -C 3 alkyl, or with two groups selected from C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkoxycarbonylC 1 -C 3 alkyl, C 1 -C 3 alkyl, (C 1 -C 6 alkyl)S(O) 2 NHC(O)C 1 -C 3 alkyl, arylS(O) 2 NHC(O)C 1 -C 3 alkyl, arylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, carboxy, carboxyC 1 -C 3 alkyl, cyano, C 3 -C 6 cycloalkylS(O) 2 NHC(O)C 1 -C 3 alkyl, C 3 -C 6 cycloalkylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, halo, haloC 1 -C 3 alkoxy, haloC 1 -C 3 alkyl, heteroarylS(O) 2 NHC(O)C 1 -C 3 alkyl, heteroarylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, hydroxy, —NR p R q , (NR p R q )C 1 -C 3 alkyl, tetrazolyl, tetrazolylC 1 -C 3 alkyl, and phenyl, wherein the phenyl is further optionally substituted by one, two, or three groups independently selected from C 1 -C 3 alkoxy, C 1 -C 3 alkyl, and halo; or

R 10 is azaindolylC 1 -C 3 alkyl wherein the azaindolyl part of the azaindolylC 1 -C 3 alkyl is substituted with one or two other groups independently selected from C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkoxycarbonylC 1 -C 3 alkyl, C 1 -C 3 alkyl, (C 1 -C 6 alkyl)S(O) 2 NHC(O)C 1 -C 3 alkyl, arylS(O) 2 NHC(O)C 1 -C 3 alkyl, arylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, carboxy, carboxyC 1 -C 3 alkyl, cyano, C 3 -C 6 cycloalkylS(O) 2 NHC(O)C 1 -C 3 alkyl, C 3 -C 6 cycloalkylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, halo, haloC 1 -C 3 alkoxy, haloC 1 -C 3 alkyl, heteroarylS(O) 2 NHC(O)C 1 -C 3 alkyl, heteroarylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, hydroxy, —NR p R q , (NR p R q )C 1 -C 3 alkyl, tetrazolyl, tetrazolylC 1 -C 3 alkyl, and phenyl, wherein the phenyl is further optionally substituted by one, two, or three groups independently selected from C 1 -C 3 alkoxy, C 1 -C 3 alkyl, and halo; or

R 10 is —(CH 2 ) n Q′, wherein n is 1-3 and Q′ is a five, six-fused saturated or unsaturated ring system containing one, two, three, or four nitrogen atoms, wherein said ring system is optionally substituted with one, two, or three groups selected from C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkoxycarbonylC 1 -C 3 alkyl, C 1 -C 3 alkyl, (C 1 -C 6 alkyl)S(O) 2 NHC(O)C 1 -C 3 alkyl, arylS(O) 2 NHC(O)C 1 -C 3 alkyl, arylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, carboxy, carboxyC 1 -C 3 alkyl, cyano, C 3 -C 6 cycloalkylS(O) 2 NHC(O)C 1 -C 3 alkyl, C 3 -C 6 cycloalkylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, halo, haloC 1 -C 3 alkoxy, haloC 1 -C 3 alkyl, heteroarylS(O) 2 NHC(O)C 1 -C 3 alkyl, heteroarylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, hydroxy, —NR p R q , (NR p R q )C 1 -C 3 alkyl, tetrazolyl, tetrazolylC 1 -C 3 alkyl, and phenyl, wherein the phenyl is further optionally substituted by one, two, or three groups independently selected from C 1 -C 3 alkoxy, C 1 -C 3 alkyl, and halo; provided Q′ is other than azaindolyl or indolyl; or

R 10 is —(CH 2 ) n Z′, wherein n is 1-3 and Z′ is a six, six-fused saturated or unsaturated ring system containing one, two, three or four nitrogen atoms, wherein said ring system is optionally substituted with one, two, or three groups selected from C 1 -C 6 alkoxy, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkoxycarbonylC 1 -C 3 alkyl, C 1 -C 3 alkyl, (C 1 -C 6 alkyl)S(O) 2 NHC(O)C 1 -C 3 alkyl, arylS(O) 2 NHC(O)C 1 -C 3 alkyl, arylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, carboxy, carboxyC 1 -C 3 alkyl, cyano, C 3 -C 6 cycloalkylS(O) 2 NHC(O)C 1 -C 3 alkyl, C 3 -C 6 cycloalkylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, halo, haloC 1 -C 3 alkoxy, haloC 1 -C 3 alkyl, heteroarylS(O) 2 NHC(O)C 1 -C 3 alkyl, heteroarylC 1 -C 3 alkylS(O) 2 NHC(O)C 1 -C 3 alkyl, hydroxy, —NR p R q , (NR p R q )C 1 -C 3 alkyl, tetrazolyl, tetrazolylC 1 -C 3 alkyl, and phenyl, wherein the phenyl is further optionally substituted by one, two, or three groups independently selected from C 1 -C 3 alkoxy, C 1 -C 3 alkyl, and halo;

R b is methyl or, R b and R 2 , together with the atoms to which they are attached, form a ring selected from azetidine, pyrollidine, morpholine, piperidine, piperazine, and tetrahydrothiazole; wherein each ring is optionally substituted with one to four groups independently selected from amino, cyano, methyl, halo, and hydroxy;

R d is hydrogen or methyl, or, R d and R 4 , together with the atoms to which they are attached, can form a ring selected from azetidine, pyrollidine, morpholine, piperidine, piperazine, and tetrahydrothiazole; wherein each ring is optionally substituted with one to four groups independently selected from amino, cyano, methyl, halo, hydroxy, and phenyl;

R e is hydrogen or methyl, or R e and R 5 , together with the atoms to which they are attached, can form a ring selected from azetidine, pyrollidine, morpholine, piperidine, piperazine, and tetrahydrothiazole; wherein each ring is optionally substituted with one to four groups independently selected from amino, cyano, methyl, halo, and hydroxy;

R g is hydrogen or methyl, or R g and R 7 , together with the atoms to which they are attached, can form a ring selected from azetidine, pyrollidine, morpholine, piperidine, piperazine, and tetrahydrothiazole; wherein each ring is optionally substituted with one to four groups independently selected from amino, benzyl optionally substituted with a halo group, benzyloxy, cyano, cyclohexyl, methyl, halo, hydroxy, isoquinolinyloxy optionally substituted with a methoxy group, quinolinyloxy optionally substituted with a halo group, and tetrazolyl; and wherein the pyrrolidine and the piperidine ring are optionally fused to a cyclohexyl, phenyl, or indole group;

R k is hydrogen or methyl, or R k and R 11 , together with the atoms to which they are attached, can form a ring selected from azetidine, pyrollidine, morpholine, piperidine, piperazine, and tetrahydrothiazole; wherein each ring is optionally substituted with one to four groups independently selected from amino, cyano, methyl, halo, and hydroxy; and

R 1 is methyl or, R 1 and R 12 , together with the atoms to which they are attached, form a ring selected from azetidine and pyrollidine, wherein each ring is optionally substituted with one to four independently selected from amino, cyano, methyl, halo, and hydroxy.

2. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein A is

3. A compound of claim 2 , or a pharmaceutically acceptable salt thereof, wherein

m is 1;

w is 0;

R 16a is hydrogen; and

R 16 is selected from

—C(R 17a ) 2 C(O)N(R 16a )C(R 17a ) 2 —X′—R 31 , and

—(C(R 17a )(R 17 )C(O)NR 16a ) m′ —C(R 17a )(R 17 )—CO 2 H.

4. A compound of claim 3 , or a pharmaceutically acceptable salt thereof, wherein

R b is methyl;

R g and R 7 , together with the atoms to which they are attached, form a pyrollidine ring, wherein said ring is optionally substituted with one hydroxy group; and

R k is methyl.

5. A compound of claim 4 , or a therapeutically acceptable salt thereof, wherein:

R a , R e , and R j hydrogen;

R L is methyl;

R n is hydrogen;

R 1 is phenylmethyl wherein the phenyl is optionally is substituted with one hydroxy group;

R 2 is methyl;

R 3 is —CH 2 C(O)NH 2 ;

R 4 is hydrogen, or, R 4 and R d , together with the atoms to which they are attached, form a pyrrolidine ring;

R 5 is-CH 2 NH 2 ;

R 6 is —CH 2 CH(CH 3 ) 2 ;

R 8 is —CH 2 (indolyl);

R 9 is —(CH 2 ) 2 NH 2 ;

R 11 and R 12 are —(CH 2 ) 3 CH 3 ; and

R 13 is —CH 2 CH(CH 3 ) 2 .

6. A compound of claim 5 , or a pharmaceutically acceptable salt thereof, wherein R 10 is selected from