Immunomodulators

1. A method of enhancing, stimulating, and/or increasing an immune response in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

A is W

wherein:

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

m is 1;

w is 0, 1, or 2;

R 14 and R 15 are hydrogen;

R 16a is hydrogen;

R 16 is selected from

—CH 2 C(O)NHCH(R 17 )C(O)NH 2 ;

—CH 2 C(O)NHCH(R 17 )C(O)NHCH(R 17a )C(O)NH 2 ; and

—CH 2 C(O)NHCH(R 17 )CO 2 H;

wherein:

X is selected from

—(CH 2 ) 2 CH(CO 2 H)NHC(O)(CH 2 ) p ;

—(CH 2 CH 2 O) q ; and

—(CH 2 CH 2 O) q CH 2 CH 2 NHC(O)CH 2 CH 2 CH(CO 2 H)NHC(O)CH 2 ) p ;

wherein q is 3, 4, 5, 6, 7, 8, 9, 10, or 11; and

wherein p is 14, 15, or 16;

each R 17a is independently selected from hydrogen and —CH 2 CO 2 H;

each R 17 is —(CH 2 ) z -triazolyl-X—R 35 , wherein z is 1 and R 35 is selected from —CO 2 H and CH 3 ;

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

R a , R e , and R j are hydrogen;

R b , R k , and R L are methyl;

R 1 is phenylC 1 -C 3 alkyl wherein the phenyl part is optionally substituted with hydroxy, halo, or methoxy;

R 2 is C 1 -C 7 alkyl;

R 3 is amidoC 1 -C 3 alkyl or carboxyC 1 -C 3 alkyl;

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

R 5 is selected from imidazolylC 1 -C 3 alkyl, aminoC 1 -C 3 alkyl, and aminobutyl;

R 6 is selected from amidoC 1 -C 3 alkyl, aminoC 1 -C 3 alkyl, aminobutyl, and C 1 -C 7 alkyl;

R 7 and R g , together with the atoms to which they are attached, form a pyrrolidine ring optionally substituted with hydroxy;

R 8 and R 10 are indolylC 1 -C 3 alkyl optionally substituted with carboxyC 1 -C 3 alkyl;

R 9 is hydroxyC 1 -C 3 alkyl or aminoC 1 -C 3 alkyl;

R 11 is C 1 -C 7 alkyl;

R 12 is C 1 -C 7 alkyl; and

R 13 is selected from C 1 -C 7 alkyl, carboxyC 1 -C 3 alkyl, and —(CH 2 ) 3 NHC(NH)NH 2 .

2. The method of claim 1 , further comprising administering an additional agent prior to, after, or simultaneously with the compound of formula (I), or the therapeutically acceptable salt thereof.

3. The method of claim 2 , wherein the additional agent is an antimicrobial agent, an antiviral agent, a cytotoxic agent, and/or an immune response modifier.

4. The method of claim 1 , wherein the compound of formula (I) is:

or a pharmaceutically acceptable salt thereof.

5. A method of inhibiting growth, proliferation, or metastasis of cancer cells in a subject in need thereof, said method comprising administering to the subject a therapeutically effective amount a compound having the formula:

or a pharmaceutically acceptable salt thereof; wherein said cancer cells are mediated by the interaction of PD-L1 with PD-1.

6. The method of claim 5 , wherein the cancer is selected from melanoma, renal cell carcinoma, squamous non-small cell lung cancer (NSCLC), non-squamous NSCLC, colorectal cancer, castration-resistant prostate cancer, ovarian cancer, gastric cancer, hepatocellular, carcinoma, pancreatic carcinoma, squamous cell carcinoma of the head and neck, carcinomas of the esophagus, gastrointestinal tract and breast, and hematological malignancies.

7. A method blocking the interaction of PD-L1 with PD-1 and/or CD80 in a subject, said method comprising administering to the subject a therapeutically effective amount of a compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

A is

wherein:

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

m is 1;

w is 0;

R 14 and R 15 are hydrogen;

R 16a is hydrogen;

R 16 is selected from

—CH 2 C(O)NHCH(R 17 )C(O)NH 2 ;

—CH 2 C(O)NHCH(R 17 )C(O)NHCH(R 17a )C(O)NH 2 ; and

—CH 2 C(O)NHCH(R 17 )CO 2 H;

wherein:

X is selected from

—(CH 2 ) 2 CH(CO 2 H)NHC(O)(CH 2 ) p ;

—(CH 2 CH 2 O) q ; and

—(CH 2 CH 2 O) q CH 2 CH 2 NHC(O)CH 2 CH 2 CH(CO 2 H)NHC(O)CH 2 ) p ;

wherein q is 3, 4, 5, 6, 7, 8, 9, 10, or 11; and

wherein p is 14, 15, or 16;

each R 17a is independently selected from hydrogen and —CH 2 CO 2 H,

each R 17 is —(CH 2 ) z -triazolyl-X—R 35 , wherein z is land R 35 is selected from —CO 2 H and CH 3 ;

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

R a , R e , and R j are hydrogen;

R b , R k , and R L are methyl;

R 1 is phenylC 1 -C 3 alkyl wherein the phenyl part is optionally substituted with hydroxy, halo, or methoxy;

R 2 is C 1 -C 7 alkyl;

R 3 is amidoC 1 -C 3 alkyl or carboxyC 1 -C 3 alkyl;

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

R 5 is selected from imidazolylC 1 -C 3 alkyl, aminoC 1 -C 3 alkyl, and aminobutyl;

R 6 is selected from amidoC 1 -C 3 alkyl, aminoC 1 -C 3 alkyl, aminobutyl, and C 1 -C 7 alkyl;

R 7 and R g , together with the atoms to which they are attached, form a pyrrolidine ring optionally substituted with hydroxy;

R 8 and R 10 are indolylC 1 -C 3 alkyl optionally substituted with carboxyC 1 -C 3 alkyl;

R 9 is hydroxyC 1 -C 3 alkyl or aminoC 1 -C 3 alkyl;

R 11 is C 1 -C 7 alkyl;

R 12 is C 1 -C 7 alkyl; and

R 13 is selected from C 1 -C 7 alkyl, carboxyC 1 -C 3 alkyl, and —(CH 2 ) 3 NHC(NH)NH 2 .

8. The method of claim 7 , wherein the compound of formula (I) is:

or a pharmaceutically acceptable salt thereof.