Compounds, Compositions, and Methods for Treating Diseases

Abstract

To provide compounds and compositions for activation or induction of expression of a pattern recognition receptor.SOLUTION: The invention provides a compound of Formula (I) in the figure, or a pharmaceutically acceptable salt or stereoisomer thereof. [Z, X1, X2, Y1 and Y2 are each O, S, or the like; B1 and B2 are each a purinyl nucleobase or the like; and L1, L2, R1 to R4 are each C1-C6 alkyl or the like.]SELECTED DRAWING: None

Description

[Technical field]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 664,493, filed April 30, 2018; and U.S. Provisional Patent Application No. 62 / 552,473, filed August 31, 2017, the contents of each of which are incorporated by reference in their entirety.

[0002] Disclosed are compounds and compositions that activate the innate immune defense system and induce expression of pattern recognition receptors in a host, and methods of using them for the treatment of microbial infections or proliferative diseases (e.g., cancer). [Background technology]

[0003] A key feature of the innate immune system is the recognition and elimination of foreign bodies. Identification of these pathogenic invaders occurs through host recognition of evolutionarily conserved microbial structures known as pathogen-associated molecular patterns (PAMPs) (Jensen, S. and Thomsen, AR J Virol (2012) 86:2900-2910). These PAMPs can be widely shared by multiple microbial species and include a wide range of molecular structures, such as nucleic acids, lipopolysaccharides, and glycoproteins, that are critical for their survival and / or virulence. Host recognition can occur through multiple pathways, such as activation of pattern recognition receptors (PRRs), which ultimately result in downstream signaling events and ultimately in enhanced immune responses.

[0004] To date, several PRRs have been identified that serve as sensors of pathogenic infection. For example, the retinoic acid-inducible gene I (RIG-I) protein is an RNA helicase that also functions as a sensor of microbial-derived RNA. RIG-I is a key factor in host recognition of RNA viruses from a variety of different virus families, including Flaviviridae (e.g., West Nile virus, Hepatitis C virus, Japanese encephalitis virus, Dengue virus), Paramyxoviridae (e.g., Sendai virus, Newcastle disease virus, respiratory syncytial virus, measles virus), Rhabdoviridae (e.g., rabies virus), Orthomyxoviridae (e.g., influenza virus type A, influenza virus type B), and Arenaviridae (e.g., Lassa virus). Stimulator of interferon genes (STING) is a cytoplasmic adaptor protein that activates the TBK1-IRF3 signaling complex, resulting in the induction of type I interferons (IFN-β and IFN-α) and other immune pathway proteins. Other PRRs also play a role in sensing microbial-derived nucleic acids, including NOD2, LGP2, MDA5, and several Toll-like receptors (TLRs), which are expressed on the cell surface and in endosomal compartments. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Jensen, S. and Thomsen, AR J Virol (2012) 86:2900-2910 Summary of the Invention [Problem to be solved by the invention]

[0006] A drawback of many current antiviral therapies is the emergence of drug-resistant mutants that occur with widespread use. Moreover, many available treatments require sustained and long-term therapy, which often results in undesirable side effects and a risk of relapse at the end of treatment. Furthermore, many viruses can be subdivided into different genotypes, and certain drugs developed against one genotype may be inactive against other genotypes. In contrast, the use of small molecule mimetics of virus-derived RNA that can induce PRRs may provide an alternative approach to the treatment of viral infections, since these compounds may be agonistic across genotypes and may have both direct antiviral activity as well as the ability to activate the host immune response, limiting the development of drug resistance and toxicity. Thus, a new generation of therapies that induce the expression of PRRs for use in disease treatment and as diagnostic tools is needed.

[0007] Furthermore, RIG-I serves as a biomarker for predicting the prognosis of certain types of cancer, such as hepatocellular carcinoma (Hou, J. et al, Cancer Cell (2014) 25:49-63). Recent publications have highlighted the importance of RIG-I and STING as mediators of innate and adaptive immunity, and agonists of RIG-I and STING have been recognized as immuno-oncology drugs in cancer therapy (Li, XY et al, Mol Cell Oncol (2014) 1:e968016; Woo, SR Trends in Immunol (2015) 36:250-256). In particular, RIG-I is involved in regulating fundamental cellular processes, such as hematopoietic proliferation and differentiation, maintenance of leukemic stemness, and hepatocellular carcinoma tumorigenesis, indicating that RIG-I plays a crucial function as a tumor suppressor. Importantly, the cytosolic DNA sensing STING pathway has been shown to play a key mechanistic role in innate immune sensing, driving type I IFN production that is relevant in cancer and for immuno-oncology applications such as therapeutic and diagnostic agents. [Means for solving the problem]

[0008] Described herein are cyclic dinucleotide compounds, compositions comprising cyclic dinucleotide compounds, and related methods of use.

[0009] In one aspect, the disclosure features a compound of formula (I):

[0010] [ka] During the ceremony, Z is S or O; B 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5 is hydrogen or C1-C 20Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20 Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20 Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R 5)C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 and each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 It is heteroalkyl, halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0011] In some embodiments, the compound is a compound of Formula (Ia), (Ib), (Ic), or (Id): or a pharma- ceutically acceptable salt thereof:

[0012] [ka] In the formula, Z, B 1 , B 2 , X 1 , X 2 , Y 1 , Y 2 , L 1 , L 2 , R 1 , R 2 , R 3 , R 4 and each of their subvariables are as described above.

[0013] In one aspect, the present disclosure describes a method of inducing expression of a pattern recognition receptor in a subject suffering from a microbial infection, comprising administering to the subject an effective amount of a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof.

[0014] [ka] During the ceremony, Z is S or O; B 1 and B. 2each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; X 1 and X 2 each is independently O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 and; L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each C-C alkyl and C-C heteroalkyl is independently selected from R 6 may be substituted with; R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 and; R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g. C1-C6 heteroalkyl), cycloalkyl, heterocycle, OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), aryl, or heteroaryl, each C1-C 20 Alkyl, C1-C 20 Heteroalkyl, cycloalkyl, heterocycle, aryl, OC(O)OC1-C 20 Alkyl (e.g. C 1-6 alkyl), and heteroaryl are each 1 to 5 R 8 may be substituted with; Each R 5 are independently hydrogen or C1-C 20 is alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each C-C 20Alkyl, cycloalkyl, heterocycle, aryl, or heteroaryl is 1 to 5 R 9 may be substituted with; R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each C1-C 20 Alkyl, cycloalkyl, heterocycle, aryl, or heteroaryl is 1 to 5 R 9 may be substituted with; Each R 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, OC(O)NR5-C1-C 20 Alkyl (e.g., C1-C6 alkyl), S(O)2NR5-aryl, NR5C(O)-aryl, NR5R5C(O)-aryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, or OC(O)-heteroaryl, OC(O)-C1-C 20 Alkyl (e.g. C1-C6), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6), where each C1-C 20 Alkyl, O-aryl, OC(O)NR5-C1-C 20 Alkyl, S(O)2NR5-aryl, NR5C(O)-aryl, CH2NR5C(O)-aryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, or OC(O)-heteroaryl, OC(O)-C1-C 20 Alkyl (e.g. C1-C6), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6) is 1 to 5 R 9 may be replaced by; Each R 9 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), halo, -CN, OH, O-C1-C 20 Alkyl, O-C1-C 20 Heteroalkyl, O-aryl, O-heteroaryl.

[0015] In another aspect, the disclosure features a method of treating cancer in a subject, the method including administering to the subject a therapeutically effective amount of a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof.

[0016] [ka] During the ceremony, Z is S or O; B 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5 is hydrogen or C1-C 20 Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20 Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20 Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R 5 )C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9Each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 It is heteroalkyl, halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0017] In another aspect, the disclosure features a composition that includes a vaccine and a vaccine adjuvant that includes a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof.

[0018] [ka] During the ceremony, Z is S or O; B 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5 is hydrogen or C1-C 20 Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20 Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20 Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R 5 )C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 Each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 It is heteroalkyl, halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0019] In another aspect, the disclosure features a method of inducing expression of a pattern recognition receptor (PRR) for immune regulation in a subject, the method comprising administering to the subject an effective amount of a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof.

[0020] [ka] During the ceremony, Z is S or O; B 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5 is hydrogen or C1-C 20 Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20 Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R 5 )C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 Each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 It is heteroalkyl, halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0021] In another aspect, the disclosure features a method of inducing expression of pattern recognition receptors (PRRs) for immune regulation and therapeutic response induction in a subject having cancer, the method comprising administering to the subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt or stereoisomer thereof.

[0022] [ka] During the ceremony, Z is S or O; B 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5 is hydrogen or C1-C 20 Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20 Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20 Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R 5 )C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 Each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 Heteroalkyl, O-C1-C 20 -NR 10 R10 , halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0023] In another aspect, the disclosure features a method of eliciting an immune response in a subject, the method including administering to the subject a therapeutically effective amount of a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof.

[0024] [ka] During the ceremony, Z is S or O; B 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2 each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5is hydrogen or C1-C 20 Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20 Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20 Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R5 )C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 Each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 It is heteroalkyl, halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0025] In some embodiments, the immune response comprises anti-tumor immunity. In some embodiments, the immune response comprises induction of a PRR (e.g., STING, RIG-I, MDA5). [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 depicts SZ14 cells treated with either compound 2 or compound 4 and digitonin for 5.5 hours [ISG54 ISRE-luciferase activity was determined and normalized to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant).] [Diagram 2] FIG. 1 depicts SZ14 cells treated with compound 3 and digitonin for 6 hours [ISG54 ISRE-luciferase activity was determined and normalized to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant).] [Figure 3A] FIG. 1 depicts NK-92 cells stimulated with compound 4 alone for 23 hours in the absence of IL-2. [Levels of IFN-γ in culture supernatants were quantified using ELISA and results were shown as pg / mL. Cells were also treated with control DMSO and cultured with medium in the presence / absence of IL-2.] [Figure 3B] FIG. 1 depicts that NK-92 cell proliferation is IL-2 dependent [the presence of IL-2 can induce the production of IFN-γ.]. [Figure 4]FIG. 1 depicts RAW-Lucia-ISG-WT and RAW-Lucia-ISG-STING KO cells stimulated with compound 2 or compound 4 alone for 19 hours. [The activity of secreted luciferase (IRF type I IFN activity) in cell culture supernatants was measured using Quanti-luc from Invivogen. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). EC50 values ​​were calculated using XLfit. Neither compound induced IRF activity in STING KO cells.] [Diagram 5] FIG. 1 depicts human endothelial cells isolated from pulmonary microvessels, hepatic sinusoidal microvessels, and colonic microvessels plated in 96-well plates and stimulated with compound 4 alone. [Cell culture supernatants were collected 6 and 23 hours after treatment. Levels of RANTES in culture supernatants were quantified using ELISA, and results are shown as pg / mL. Concentrations (1.25, 2.5, 5, and 10 micromolar) increase from left to right within each of the six bars.] [Figure 6A] Figure 1 depicts THP1-Dual-KI-STING-R232 cells stimulated with compounds alone for 20 hours. [The activities of secreted luciferase (IRF-type I IFN activity) (upper panel) and NF-κB (lower panel) in cell culture supernatants were measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). EC50 values ​​were calculated using XLfit. THP1-Dual-KI-STING-R232 reporter cell line was generated from THP-Dual-STINGKO cells by rescuing the STING signaling pathway by inserting STING-R232 (STING-WT). Compounds did not induce IRF activity in STING KO cells.] [Figure 6B]Figure 1 depicts THP1-Dual-KI-STING-R232 cells stimulated with compounds alone for 20 hours. [The activities of secreted luciferase (IRF-type I IFN activity) (upper panel) and NF-κB (lower panel) in cell culture supernatants were measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). EC50 values ​​were calculated using XLfit. THP1-Dual-KI-STING-R232 reporter cell line was generated from THP-Dual-STINGKO cells by rescuing the STING signaling pathway by inserting STING-R232 (STING-WT). Compounds did not induce IRF activity in STING KO cells.] [Figure 7A] Figure 1 depicts THP1-Dual-WT cells stimulated with compounds alone for 20 hours. [Secreted luciferase (IRF type I IFN activity) (upper panel) and NF-κB (lower panel) activities in cell culture supernatants were measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). EC50 values ​​were calculated using XLfit. THP1-Dual-WT cells express STING-HAQ mutant. Compounds did not induce IRF activity in STING KO cells.] [Figure 7B] Figure 1 depicts THP1-Dual-WT cells stimulated with compounds alone for 20 hours. [Secreted luciferase (IRF type I IFN activity) (upper panel) and NF-κB (lower panel) activities in cell culture supernatants were measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). EC50 values ​​were calculated using XLfit. THP1-Dual-WT cells express STING-HAQ mutant. Compounds did not induce IRF activity in STING KO cells.] [Figure 8A] FIG. 1 depicts THP1-Dual-WT cells stimulated with compound 4 alone in triplicate for 20 hours [IRF-driven secreted luciferase activity in cell culture supernatants was measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold increase compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant).] [Figure 8B] FIG. 1 depicts THP1-Dual-WT cells stimulated with compound 4 alone in triplicate for 20 hours. [NF-κB activity in cell culture supernatants was measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold increase compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant).] [Figure 8C] FIG. 1 depicts THP1-Dual-WT cells stimulated with compound 4 alone in triplicate for 20 hours. [Levels of RANTES in culture supernatants were quantified using ELISA and results were expressed as pg / mL.] [Figure 8D] FIG. 1 depicts THP1-Dual-WT cells stimulated with compound 4 alone in triplicate for 20 hours. [Levels of IL-29 in culture supernatants were quantified using ELISA and results were expressed as pg / mL.] [Figure 9A] Figure 1 depicts THP1-Dual (WT) cells stimulated with compound 3 alone (upper panel) or compound / lipo mixture (lower panel) for 20 hours. [The activity of secreted luciferase (IRF type I IFN activity) in cell culture supernatants was measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). EC50 was calculated using XLfit.] [Figure 9B]Figure 1 depicts THP1-Dual (WT) cells stimulated with compound 3 alone (upper panel) or compound / lipo mixture (lower panel) for 20 hours. [Activity of sNF-κB in cell culture supernatants was measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold induction compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant), EC50 was calculated using XLfit.] [Figure 10] Figure 1 depicts THP1 double & STING KO THP1 double cells grown in complete medium and treated with various concentrations of Compound 2 or DMSO control and Lipofectamine LTX. [Dual cells harbor both a secreted embryonic alkaline phosphatase (SEAP) reporter gene under the control of an IFN-b minimal promoter fused to five copies of the NF-κB consensus transcription response element to measure NF-κB activity and a Lucia reporter gene under the control of an ISG54 minimal promoter to measure IRF activity. After 20 hours of incubation, IRF activity was assessed using QUANTI-luc to measure the levels of Lucia, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from the fold change in emission / absorbance compared to DMSO-treated samples.] [Figure 11] FIG. 1 depicts SZ14 reporter cells (HEK293-derived type I IFN-inducible reporter cell line) treated with compounds and digitonin. [ISG54 ISRE-luciferase activity was determined and normalized to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant).] [Figure 12]FIG. 1 depicts THP1-Dual-WT cells in 96-well plates stimulated with eight concentrations of compound 4 in triplicate for 20 hours. [IRF-driven secreted luciferase and NF-κB-driven SEAP activities in cell culture supernatants were measured using Quanti-luc and Quanti-blue from Invivogen, respectively. Data are presented as fold increase compared to DMSO-treated cells (mean ± standard deviation of triplicate wells / stimulant). Compound 4 did not induce IRF activity in THP1-STING KO cells.] [Figure 13] FIG. 1 depicts treatment of groups of 5 Balb / C mice (female, 8 weeks old) with saline control or Compound 4 administered intravenously via the tail vein at 9 mg / kg. [Serum, spleen and liver samples were collected 2, 4 and 24 hours after treatment. Levels of RANTES (A, C, E) and TNF-α (B, D, F) were measured using ELISA. Results are shown as pg / mL for serum samples and pg / g tissue for spleen and liver samples.] [Figure 14] FIG. 1 depicts treatment groups of 5 Balb / C mice (female, 10 weeks old) administered saline control or Compound 3 intravenously via the tail vein at 9 mg / kg. [Serum, spleen and liver samples were collected 2 and 24 hours after treatment. RANTES and TNF-α levels were measured using ELISA and results are shown as pg / mL for serum samples and pg / g tissue for spleen and liver samples.] [Figure 15] Response summary in a study to determine efficacy of compound 4 in CT26 murine colon carcinoma using female balb / c mice [treated mice took at least 10 days longer to reach the endpoint compared to the vehicle group]. [Figure 16] Figure 1 shows tumor growth inhibition in a study to determine the efficacy of compound 4 in the CT26 murine colon cancer model using female BALB / c mice [treated mice showed at least an 89% increase in tumor growth inhibition when compared to the vehicle group]. [Figure 17]FIG. 1 depicts the time to individual endpoints for mice in a study to determine the efficacy of compound 4 in the CT26 mouse colon cancer model using female balb / c mice [treated mice took longer to reach the endpoint when compared to the vehicle group]. [Figure 18] FIG. 1 depicts tumor volume distribution on day 18 in a study to determine the efficacy of compound 4 in the CT26 mouse colon cancer model using female balb / c mice [mice in the treatment group had significantly smaller tumor volumes compared to the vehicle group.] [Figure 19] FIG. 1 depicts a Kaplan-Meier plot for a study to determine the efficacy of compound 4 in the CT26 mouse colon cancer model using female BALB / c mice [Treatment groups had a higher percentage of mice remaining at day 21 than the vehicle group.] [Figure 20] FIG. 1 depicts compound 4 administered intravenously at 1 mg / kg and 3 mg / kg to mice in a CT26 colon cancer model [tumor growth was slowed in the compound 4 group compared to vehicle]. [Figure 21] Figure 1 depicts cells stably expressing reporters for measuring IRF and / or NF-κB activity treated with a wide range of concentrations of compound 1 or DMSO control for 20 hours. [IRF activity was assessed using QUANTI-luc to measure Lucia levels, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from fold change in emission / absorbance compared to DMSO-treated samples. EC50 values ​​are obtained by curve fitting with Xl fit. Compound 1 did not induce IRF or NF-κβ activity in STING KO cells. Compound 1 has STING-dependent activity.] [Figure 22]Figure 1 depicts cells stably expressing reporters for measuring IRF and / or NF-κB activity treated with a wide range of concentrations of compound 2 or DMSO control for 20 hours. [IRF activity was assessed using QUANTI-luc to measure Lucia levels, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from fold change in emission / absorbance compared to DMSO-treated samples. EC50 values ​​were obtained by curve fitting with Xl fit. Compound 2 did not induce IRF activity or NF-κβ in STING KO cells. Compound 2 has activity against wild-type STING, the R71H-G230A-R293Q (HAQ) mutant of hSTING, and wt-mSTING.] [Diagram 23] FIG. 1 depicts cryopreserved mouse bone marrow-derived dendritic cells (DCs) and macrophages treated with a wide range of concentrations of Compound 2 or DMSO control for 20 hours. [Cell pellets were harvested and total RNA was obtained. Gene expression levels of ISGs were measured by Taqman assay. Compound 2 induces ISG expression in mouse bone marrow-derived DCs and macrophages.] [Figure 24] Figure 1 depicts cells stably expressing both or either reporters for measuring IRF and NF-κB activity treated with a wide range of concentrations of compound 3 or DMSO control for 20 hours. [IRF activity was assessed using QUANTI-luc to measure Lucia levels, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from fold change in emission / absorbance compared to DMSO-treated samples. EC50 values ​​were obtained by curve fitting with Xl fit. Compounds did not induce IRF activity or NF-κβ in STING KO cells. Compound 3 has activity against wild-type STING, STING-HAQ and wt-mSTING.] [Diagram 25]FIG. 1 depicts freshly isolated peripheral blood mononuclear cells (PBMCs) treated with a wide range of concentrations of Compound 3 or DMSO control for 20 hours. (Supernatants were collected to measure IFNb and TNFa secretion by Verikine-Human IFNβ serum ELISA kit and Human TNFα ELISA kit, respectively. The amount of cytokines released into the supernatant was calculated by standard curve. Compound 3 induces IFNβ and TNFα secretion in PBMCs after treatment.) [Figure 26] FIG. 1 depicts compound 3 administered intravenously at 3 mg / kg to mice in a CT26 colon cancer model [tumor growth was slowed in the compound 3 group compared to vehicle]. [Figure 27] Figure 1 depicts cells stably expressing both or either reporters for measuring IRF and NF-κB activity treated with a wide range of concentrations of compound 4 or DMSO control for 20 hours. [IRF activity was assessed using QUANTI-luc to measure Lucia levels, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from fold change in emission / absorbance compared to DMSO-treated samples. EC50 values ​​are obtained by curve fitting with Xl fit. Compound 4 did not induce IRF activity or NF-κβ in STING KO cells. Compound 4 has activity against wild-type STING, R71H-G230A-R293Q (HAQ), the R232H mutant of hSTING, MYD88 knockout cells, and wt-mSTING.] [Figure 28] FIG. 1 depicts cells stably expressing both or either reporters for measuring IRF and NF-κB activity treated with a wide range of concentrations of compound 4 or DMSO control for 20 hours. [IRF activity was assessed using QUANTI-luc to measure Lucia levels, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from fold change in emission / absorbance compared to DMSO-treated samples. EC50 values ​​were obtained by curve fitting with X1 fit. RIG-I is not involved in the mechanism of action of compound 4.] [Figure 29] FIG. 1 depicts freshly isolated PBMCs treated with a wide range of concentrations of Compound 4 or DMSO control for 20 hours. [Supernatants were collected to measure IFNb and TNFa secretion by Verikine-Human IFNβ serum ELISA kit and Human TNFα ELISA kit, respectively. The amount of cytokines released into the supernatant was calculated by standard curve. Compound 4 induces IFNβ and TNFα secretion in PBMCs after treatment.] [Diagram 30] FIG. 1 depicts that intravenously administered (9 mg / kg) Compound 3 potently induced elevated ISG / type I IFN responses in normal Balb / C mice. [Figure 31A] FIG. 1 depicts cells treated for 20 hours with various concentrations of compound 3 and two of its diastereomers (3A and 3B), or DMSO control. [Cells stably expressed one or both of the reporters used to measure IRF activity. IRF activity was assessed using QUANTI-luc to measure levels of Lucia. % induction was calculated from the fold change in luminescence / absorbance compared to DMSO-treated samples.] [Figure 31B] FIG. 1 depicts cells treated for 20 hours with various concentrations of compound 3 and two of its diastereomers (3-A and 3-B), or DMSO control. [Cells stably expressed one or both of the reporters used to measure NF-κB activity. NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from the fold change in emission / absorbance compared to DMSO-treated samples.] [Figure 31C] FIG. 1 depicts cells treated for 20 hours with various concentrations of compound 3 and two of its diastereomers (3-A and 3-B), or DMSO control. [Cells stably expressed one or both of the reporters used to measure NF-κB activity. Levels of Lucia were measured by assessing IRF activity using QUANTI-luc. % induction was calculated from the fold change in luminescence / absorbance compared to DMSO-treated samples.] [Diagram 32]FIG. 1 depicts that compound 3 and its diastereomers (3-A and 3-B) bind to STING with high affinity. [Thermal shift assays were performed using various dilutions of compound 3 and two of its diastereomers (3-A and 3-B) from 2 mM to 0.05 μM in 10 mM HEPES (pH 7.5), 140 mM NaCl, and 5-fold dilutions of SYPRO Orange dye (Invitrogen) with 0.1 mg / mL STING CTD. Fluorescence as a function of temperature was recorded using a Real Time PCR instrument (Thermo Fisher). A temperature gradient was run from 25 to 80 °C with a ramp of 0.2 °C over 60 min. Data were analyzed using Thermal Shift software (Thermo Fisher) and DSF analysis. Fluorescence data was fitted using a differential model to obtain the midpoint temperature (Tm) of the thermal protein unfolding transition using the curve fitting software Prism.] [Figure 33-1] FIG. 1 depicts that compound 3 and its diastereomers (3-A and 3-B) bind to STING with high affinity. [Isothermal calorimetry was performed on a MicroCal Itc200 at 25° C. Compound 3 and two of its diastereomers (3-A and 3-B) at 1.5 mM were titrated against 132.5 μM human wtSTING-CTD (with a SUMO tag). After buffer subtraction, the resulting binding curves were fitted using either two binding sites (3-A) or one binding site (3-B).] [Figure 33-2] FIG. 1 depicts that compound 3 and its diastereomers (3-A and 3-B) bind to STING with high affinity. [Isothermal calorimetry was performed on a MicroCal Itc200 at 25° C. Compound 3 and two of its diastereomers (3-A and 3-B) at 1.5 mM were titrated against 132.5 μM human wtSTING-CTD (with a SUMO tag). After buffer subtraction, the resulting binding curves were fitted using either two binding sites (3-A) or one binding site (3-B).] [Figure 33-3]FIG. 1 depicts that compound 3 and its diastereomers (3-A and 3-B) bind to STING with high affinity. [Isothermal calorimetry was performed on a MicroCal Itc200 at 25° C. Compound 3 and two of its diastereomers (3-A and 3-B) at 1.5 mM were titrated against 132.5 μM human wtSTING-CTD (with a SUMO tag). After buffer subtraction, the resulting binding curves were fitted using either two binding sites (3-A) or one binding site (3-B).] [Figure 34A] FIG. 1 depicts compound 4 and its diastereomers (4-A and 4-B) are effective in inducing IRF signaling. [Cells were treated with various concentrations of compound 3 and two of its diastereomers (4-A and 4-B), or DMSO control for 20 hours. Cells stably expressed one or both reporters used to measure IRF activity. IRF activity was assessed using QUANTI-luc to measure the levels of Lucia. % induction was calculated from the fold change in luminescence / absorbance compared to DMSO-treated samples.] [Figure 34B] FIG. 1 depicts the efficacy of compound 4 and its diastereomers (4-A and 4-B) in inducing NF-κB signaling. [Cells were treated with various concentrations of compound 4 and its two diastereomers (4-A and 4-B), or DMSO control for 20 hours. Cells stably expressed one or both reporters used to measure NF-κB activity. NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from the fold change in emission / absorbance compared to DMSO-treated samples.] [Figure 34C]FIG. 1 depicts the efficacy of compound 4 and its diastereomers (4-A and 4-B) in inducing IRF signaling. [Cells were treated with various concentrations of compound 4 and its two diastereomers (4-A and 4-B), or DMSO control for 20 hours. Cells stably expressed one or both reporters used to measure IRF activity. IRF activity was assessed using QUANTI-luc to measure the levels of Lucia. % induction was calculated from the fold change in luminescence / absorbance compared to DMSO-treated samples.] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present disclosure relates to a method for activating and / or inducing expression of a PRR (e.g., STING) in a subject, in particular a method for treating a microbial infection or a proliferative disease (e.g., cancer). In some embodiments, the method comprises administering a compound of formula (I) or a pharma- ceutically acceptable salt thereof. It should be noted that the induction of any PRR using these compounds can stimulate interferon and / or NF-KB production, which can induce the expression of various PRRs, which are inducible genes, by a feedback mechanism.

[0028] definition As used herein, the articles "a" and "an" refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

[0029] "About" and "approximately" generally refer to an acceptable degree of error for the quantity measured, given the nature or precision of the measurement. Exemplary degrees of error are within 20 percent (%), typically within 10%, and more typically within 5% of a given value or range of values.

[0030] As used herein, the terms "obtain" or "obtaining", as these terms are used herein, refer to possession of a physical entity (e.g., a sample, e.g., a blood sample or a liver biopsy sample) or obtaining a value, e.g., a numerical value, by "directly obtaining" or "indirectly obtaining" a physical entity or value. "Directly obtaining" means performing a process (e.g., an analytical method) to obtain a physical entity or value. "Indirectly obtaining" refers to receiving a physical entity or value from another party or source (e.g., a third party laboratory that directly obtained the physical entity or value). Directly obtaining a value includes performing a process that involves a physical change of a sample or another substance, e.g., performing an analytical process that involves a physical change of a substance, e.g., a sample, performing an analytical method, e.g., a method described herein, e.g., by mass spectrometry, e.g., LC-MS, analysis of a sample of a bodily fluid such as blood.

[0031] As used herein, the term "induce" or "induction of" refers to an increase or enhancement of a function, e.g., an increase or enhancement of expression of a pattern recognition receptor (e.g., STING). In some embodiments, "induction of PRR expression" refers to an induction of transcription (e.g., mRNA, e.g., an increase or enhancement) of a PRR RNA, e.g., STING RNA, or a translation (e.g., an increase or enhancement) of a PRR protein, e.g., STING protein. In some embodiments, induction of PRR expression (e.g., STING expression) refers to, for example, an increase or enhancement of the concentration of a PRR RNA, e.g., STING RNA (e.g., mRNA) or STING protein in a cell. In some embodiments, induction of PRR expression (e.g., STING expression) refers to, for example, an increase in the copy number of a PRR RNA, e.g., STING RNA (e.g., mRNA), or a PRR protein, e.g., STING protein, in a cell. In some embodiments, inducing expression of a PRR (e.g., STING) can refer to the initiation or translation of a PRR RNA (e.g., STING RNA (e.g., mRNA)), or the translation of a PRR protein (e.g., STING protein). In some embodiments, inducing expression of a PRR (e.g., STING) can refer to an increase in the rate of PRR RNA (e.g., STING RNA (e.g., mRNA)) transcription, or an increase in the rate of expression of a PRR protein (e.g., STING protein).

[0032] As used herein, the term "activate" or "activation" refers to the stimulation or induction of a function, e.g., a downstream pathway, e.g., a downstream signaling pathway. In some embodiments, activation of a pattern recognition receptor (PRR) (e.g., STING) refers to the stimulation of a particular protein or pathway, e.g., through interaction with a downstream signaling partner (e.g., IFN-β promoter stimulator 1 (IPS-1), IRF3, IRF7, NF-kB, interferons (e.g., IFN-α or IFN-β), and / or cytokines). In some embodiments, activation is distinct from induction of expression of a PRR. In some embodiments, a PRR may be activated without resulting in induction of PRR expression (e.g., expression of STING). In some embodiments, activation may include induction of expression of a PRR (e.g., STING). In some embodiments, activation of a PRR may induce induction of expression of a PRR (e.g., STING) by about 0.1%, about 0.5%, about 1%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or more) compared to a reference standard (e.g., a basal expression level of a PRR (e.g., STING)).

[0033] As used herein, an amount of a compound, complex, or substance effective to treat a disorder (e.g., a disorder described herein), a "therapeutically effective amount," "effective amount," or "effective course" refers to an amount of a compound, substance, or composition that, upon single or multiple administrations to a subject, is effective in treating the subject or in curing, alleviating, ameliorating, or ameliorating a subject suffering from a disorder (e.g., a microbial infection) beyond that expected in the absence of such treatment.

[0034] As used herein, the terms "prevent" or "preventing" in the context of a disorder or disease refers to the administration of an agent to a subject, e.g., the administration of a compound of the present disclosure (e.g., a compound of Formula (I)) to a subject, such that the onset of at least one symptom of the disorder or disease is delayed compared to that which would be observed in the absence of administration of the agent.

[0035] As used herein, the term "reference treatment" or "reference standard" refers to a standardized level or standardized treatment used as a basis for comparison. In some embodiments, the reference standard or reference treatment is a standard or treatment that is accepted, well known, or well characterized in the art. In some embodiments, the reference standard describes the outcome of the methods described herein. In some embodiments, the reference standard describes the level of a marker (e.g., the level of induction of a PRR, e.g., STING) in a subject or sample, e.g., before the start of treatment, e.g., with a compound or composition described herein. In some embodiments, the reference standard describes a measure of the presence, progression, or severity of a disease or a symptom thereof (e.g., before the start of treatment, e.g., with a compound or composition described herein).

[0036] As used herein, the term "subject" is intended to include humans and non-human animals. Exemplary human subjects include human patients suffering from a disorder, e.g., a disorder described herein, or normal subjects. The term "non-human animals" includes all vertebrates, e.g., non-mammals (e.g., chickens, amphibians, reptiles, etc.) and non-human primates, domestic animals and / or agriculturally useful animals, e.g., mammals such as sheep, dogs, cats, pigs, etc. In an exemplary embodiment of the present disclosure, the subject is a woodchuck (e.g., Eastern Woodchuck (Marmota monax)).

[0037] As used herein, the term "treat" or "treating" a subject suffering from a disorder or disease refers to subjecting the subject to a treatment regimen, such as administration of a compound or composition of formula (I), or a pharma- ceutically acceptable salt thereof, or a composition comprising formula (I) or a pharma- ceutically acceptable salt thereof, such that at least one symptom of the disorder or disease is cured, healed, alleviated, relieved, altered, remedied, ameliorated, or improved. Treating includes administering an amount effective to alleviate, relieve, alter, remedy, ameliorate, improve, or affect the disorder or disease, or the symptoms of the disorder or disease. Treatment may inhibit the deterioration or worsening of the symptoms of the disorder or disease.

[0038] As used herein, the term "Cmd" refers to the words "compound" or "Compound," either of which are used interchangeably.

[0039] Numerous ranges are provided herein, e.g., ranges for the amount of drug administered per day. In some embodiments, the ranges include both endpoints. In other embodiments, the ranges exclude one or both endpoints. By way of example, a range can exclude a lower limit. Thus, in such embodiments, a range of 250-400 mg / day, excluding the lower limit, would be considered to encompass amounts greater than 250 that are equal to or less than 400 mg / day.

[0040] As used herein, the term "alkyl" refers to any C-C 12 Alkyl, C1-C 10Alkyl refers to a monovalent saturated straight or branched hydrocarbon, such as straight or branched groups of 1 to 12, 1 to 10, or 1 to 6 carbon atoms, referred to as C1-C6 alkyl. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, sec-pentyl, isopentyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, sec-hexyl, and the like.

[0041] The terms "alkenyl" and "alkynyl" are art-recognized and refer to unsaturated aliphatic groups analogous in length and possible substitution to the alkyls described above, but which contain at least one double or triple bond respectively. Exemplary alkenyl groups include, but are not limited to, -CH=CH2 and -CH2CH=CH2.

[0042] The term "alkylene" refers to a diradical of an alkyl group.

[0043] The terms "alkenylene" and "alkynylene" refer to diradicals of alkenyl and alkynyl groups, respectively.

[0044] The term "methylene unit" refers to a divalent -CH2- group present in an alkyl, alkenyl, alkynyl, alkylene, alkenylene, or alkynylene moiety.

[0045] As used herein, the term "carbocyclic ring system" means a monocyclic, or a fused, spiro-fused, and / or bridged, bicyclic or polycyclic hydrocarbon ring system, in which each ring is either fully saturated or contains one or more units of unsaturation, but in which no ring is aromatic.

[0046] The term "carbocyclic" refers to a radical of a carbocyclic ring system. Representative carbocyclic groups include cycloalkyl groups (e.g., cyclopentyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.), and cycloalkenyl groups (e.g., cyclopentenyl, cyclohexenyl, cyclopentadienyl, etc.).

[0047] The term "aromatic ring system" is art-recognized and refers to a monocyclic, bicyclic, or polycyclic hydrocarbon ring system in which at least one ring is aromatic.

[0048] The term "aryl" refers to a radical of an aromatic ring system. Representative aryl groups include fully aromatic ring systems such as phenyl, naphthyl, and anthracenyl, as well as ring systems in which an aromatic carbocyclic ring is fused to one or more non-aromatic carbocyclic rings, such as indanyl, phthalimidyl, naphthymidyl, or tetrahydronaphthyl.

[0049] The term "heteroalkyl" refers to an "alkyl" moiety in which at least one of the carbon atoms has been replaced with a heteroatom such as O, S, or N.

[0050] The term "heteroaromatic ring system" is art-recognized and refers to a monocyclic, bicyclic, or polycyclic ring system in which at least one ring is aromatic and contains a heteroatom, and no other ring is a heterocycle (as defined below). In certain cases, a ring that is aromatic and contains a heteroatom contains 1, 2, 3, or 4 independently selected ring heteroatoms in such ring.

[0051] The term "heteroaryl" refers to the radical of a heteroaromatic ring system. Representative heteroaryl groups include (i) ring systems in which the rings each contain a heteroatom and are aromatic, such as imidazolyl, oxazolyl, thiazolyl, triazolyl, pyrrolyl, furanyl, thiophenylpyrazolyl, pyridinyl, pyrazinyl, pyridazinyl, pyrimidinyl, indolizinyl, purinyl, naphthyridinyl, and pteridinyl; (ii) rings each are aromatic or carbocyclic, with at least one aromatic ring containing a heteroatom and at least one other ring being a hydrocarbon ring, or (iii) rings each are aromatic or carbocyclic, with at least one aromatic ring containing a heteroatom and at least one other ring being a hydrocarbon ring, such as indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, isoindol ... The ring system includes dazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, pyrido[2,3-b]-1,4-oxazin-3(4H)-one, 5,6,7,8-tetrahydroquinolinyl and 5,6,7,8-tetrahydroisoquinolinyl, and (iii) ring system in which each ring is aromatic or carbocyclic, and at least one aromatic ring shares a bridgehead heteroatom with another aromatic ring, such as 4H-quinolizinyl.In certain embodiments, heteroaryl is a monocyclic or bicyclic ring, each of the rings contains 5 or 6 ring atoms, and 1, 2, 3 or 4 of the ring atoms are heteroatoms independently selected from N, O and S.

[0052] The term "heterocyclic ring system" refers to monocyclic, or fused, spiro-fused, and / or bridged bicyclic and polycyclic ring systems in which at least one ring is saturated or partially unsaturated (but not aromatic) and contains a heteroatom. The heterocyclic ring system can be attached to its pendant group at any heteroatom or carbon atom that results in a stable structure, and any of the ring atoms can be optionally substituted.

[0053] The term "heterocycle" refers to the radical of a heterocyclic ring system. Representative heterocycles include: (i) ring systems in which all rings are non-aromatic and at least one ring contains a heteroatom, such as tetrahydrofuranyl, tetrahydrothienyl, pyrrolidinyl, pyrrolidonyl, piperidinyl, pyrrolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and quinuclidinyl; (ii) ring systems in which at least one ring is non-aromatic and and (iii) ring systems in which at least one ring is non-aromatic and contains a heteroatom and at least one other ring is aromatic and contains a heteroatom, such as 3,4-dihydro-1H-pyrano[4,3-c]pyridine and 1,2,3,4-tetrahydro-2,6-naphthyridine. In certain embodiments, the heterocycle is a monocyclic or bicyclic ring, where each of the rings contains 3 to 7 ring atoms, and 1, 2, 3, or 4 of the ring atoms are heteroatoms independently selected from N, O, and S.

[0054] The term "saturated heterocycle" refers to a radical of a heterocyclic ring system in which all rings are saturated, for example, tetrahydrofuran, tetrahydro-2H-pyran, pyrrolidine, piperidine, and piperazine.

[0055] "Partially unsaturated" refers to a group that contains at least one double or triple bond. "Partially unsaturated" ring systems are further intended to encompass rings with multiple sites of unsaturation, but are not intended to include aromatic groups (e.g., aryl or heteroaryl groups) as defined herein. Similarly, "saturated" refers to a group that does not contain double or triple bonds, i.e., all single bonds.

[0056] The term "nucleobase" as used herein refers to nucleosides, nitrogen-containing biological compounds found attached to sugars in the basic building blocks of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). The primary, or natural, nucleobases are cytosine (DNA and RNA), guanine (DNA and RNA), adenine (DNA and RNA), thymine (DNA) and uracil (RNA), abbreviated as C, G, A, T, and U, respectively. Because A, G, C, and T occur in DNA, these molecules are called DNA bases, and A, G, C, and U are called RNA bases. Adenine and guanine belong to the double-ring class of molecules called purines (abbreviated as R). Cytosine, thymine, and uracil are all pyrimidines. Other nucleobases that do not function as normal parts of the genetic code are called non-natural.

[0057] As described herein, the compounds of the present disclosure may contain "optionally substituted" moieties. In general, the term "substituted" means that one or more hydrogens of the specified moiety are replaced with suitable substituents, regardless of whether the term "optionally" is present. Unless otherwise stated, an "optionally substituted" group may have suitable substituents at each substitutable position of the group, and when multiple positions in a given structure may be substituted with multiple substituents selected from a specified group, the substituents may be the same or different at each position. The combination of substituents envisioned under the present disclosure is preferably one that results in the formation of a stable or chemically feasible compound. As used herein, the term "stable" refers to a compound that is substantially unchanged when placed under conditions that allow for the production, detection, and, in certain embodiments, recovery, purification, and use of the compound for one or more of the purposes disclosed herein.

[0058] As used herein, the definition of each expression, e.g., alkyl, m, n, etc., when this expression occurs more than once in any structure, is independent of the definition of this expression elsewhere in the same structure.

[0059] As described herein, the compounds of the present disclosure may contain "optionally substituted" moieties. In general, the term "substituted" means that one or more hydrogens of the specified moiety are replaced with suitable substituents, regardless of whether the term "optionally" is present. Unless otherwise stated, an "optionally substituted" group may have suitable substituents at each substitutable position of the group, and when multiple positions in a given structure may be substituted with multiple substituents selected from a specified group, the substituents may be the same or different at each position. The combination of substituents envisioned under the present disclosure is preferably one that results in the formation of a stable or chemically feasible compound. As used herein, the term "stable" refers to a compound that is substantially unchanged when placed under conditions that allow for the production, detection, and, in certain embodiments, recovery, purification, and use of the compound for one or more of the purposes disclosed herein.

[0060] Pattern Recognition Receptors The disclosure presented herein features methods for activating and inducing PRR expression (e.g., STING expression) in a subject, for example, a subject suffering from a microbial infection (e.g., viral, bacterial, fungal, or parasitic infection) or a proliferative disease (e.g., cancer). Pattern recognition receptors (PRRs) are a broad class of proteins that recognize pathogen-associated molecular patterns (PAMPs) that are conserved within pathogenic invaders. PAMPs are typically products of biosynthetic pathways essential for pathogen survival and / or infectivity, such as lipopolysaccharides, glycoproteins, and nucleic acids. Recognition of PAMPs by their cognate PRRs activates signaling pathways that lead to the production of immune defense factors, such as pro- and anti-inflammatory cytokines, type I interferons (IFN-α, IFN-β), and / or interferon-stimulated genes (ISGs). It is also well known that induction of innate immune signaling results in activation of T cell responses as well as induction of adaptive immunity. These downstream immune effects are essential for the clearance of viruses via apoptosis and killing of infected cells through cytotoxic T lymphocytes, as well as other defense mechanisms. It is also well known that interferons act on ISREs (interferon response elements) that can induce the production of ISGs, which play an important role in antiviral cellular defense.

[0061] Stimulator of interferon genes (STING) is a cytoplasmic microbial-derived DNA sensor that has been shown to be particularly sensitive to double-stranded DNA and cyclic dinucleotides (e.g., cyclic di-GMP) (Burdette, DL and Vance, RE (2013) Nat Immuno l14:19-26). Two molecules of STING form homodimers mediated by an α-helix present in the C-terminal dimerization domain, and molecular binding studies have revealed that each STING dimer binds one molecule of microbial nucleic acid, e.g., DNA or cyclic dinucleotides. Upon ligand binding, STING activates the innate immune response through interactions with RIG-I and IPS-1, resulting in interferon production (e.g., IFN-α and IFN-β) and other downstream signaling events. Since its discovery, STING has been shown to function as an important sensor of viruses (e.g., adenovirus, herpes simplex virus, hepatitis B virus, vesicular stomatitis virus, and hepatitis C virus), bacteria (e.g., Listeria monocytogenes, Legionella pneumopholia, Mycobacterium tuberculosis), and protozoa (Plasmodium falciparum and Plasmodium berghei). In addition, STING has been shown to play a key role in the innate immune response to tumor antigens, driving dendritic cell activation and subsequent T cell priming in several cancers (Woo, SR et al. Trends in Immunol(2015) 36:250-256).

[0062] Another class of PRRs includes RIG-I, which is the first member of a family of PRRs called RIG-I-like receptors (RLRs), which primarily detect RNA from foreign sources. It is an important sensor of microbial infection (e.g., viral infection) in most cells and is constitutively expressed at low levels in the cytosol. After ligand binding, expression of RIG-I is rapidly enhanced, resulting in increased RIG-I concentrations in the cell (Jensen, S. and Thomsen,AR J Virol(2012) 86:2900-2910, Yoneyama M. et al. Nat Immunol(2004) 5:730-737). RIG-I is an ATP-dependent helicase that contains a central DExD / H box ATPase domain and tandem N-terminal caspase recruitment domains (CARDs) that mediate downstream signaling. The C-terminus of RIG-I contains a ssRNA / dsRNA binding domain that acts to silence CARD function at the N-terminus when unbound. Without wishing to be bound by theory, upon recognition of the target RNA structure, two N-terminal CARDs are exposed, allowing interaction with downstream binding partners CARD and with mitochondrial antiviral signaling molecule (MAVS) and IFN-β promoter stimulator factor 1 (IPS-1), also known as CARDIF, which in turn triggers further downstream signaling, such as induction of IRF3, IRF7, NF-κB, IFN, and cytokine production, which ultimately results in the initiation of a host immune response.

[0063] Other RLRs, including MDA5, LGP2, and RNase L, are homologous to RIG-I and function in a similar manner. MDA5 is highly homologous to RIG-I and has been shown to be crucial for eliciting cytokine responses during infection with picornaviruses (e.g., encephalomyocarditis virus (EMCV), Taylor virus, and mengovirus), Sendai virus, rabies virus, West Nile virus, rabies virus, rotavirus, mouse hepatitis virus, and murine norovirus. LPG2 lacks the CARD domain found in RIG-I and MDA5, which causes direct interaction with IPS-1 to initiate downstream signaling. As such, LPG2 is believed to behave as a regulator of innate immune responses along with other CARD-bearing RLRs such as RIG-I and MDA5.

[0064] Another class of PRRs encompasses the nucleotide-binding receptor and oligomerization domain (NOD)-like receptor, or NLR, family (Caruso, R. et al, Immunity (2014) 41:898-908), which includes the microbial sensor NOD2. NOD2 is composed of an N-terminal CARD, a centrally located nucleotide-binding oligomerization domain, and a C-terminal leucine-rich repeat domain that is responsible for binding microbial PAMPs, such as bacterial peptidoglycan fragments and microbial nucleic acids. Ligand binding is thought to activate NOD2, driving its interaction with the CARD-containing kinase RIPK2, which in turn activates a number of downstream proteins, including NF-κB, MAPK, IRF7, and IRF3, the latter of which results in the induction of type 1 interferons. NOD2 is expressed in a diverse set of cell types, including macrophages, dendritic cells, Paneth cells, epithelial cells (e.g., lung epithelial cells, intestinal epithelium), and osteoblasts. NOD2 binds to a wide range of pathogens, including protozoa (e.g., Toxoplasma gondii and rodent malaria parasites (Plasmodium berghei)), bacteria (e.g., Bacillus anthracis, Borrelia burgdorferi, Burkholderia pseudomallei, Helicobacter hepaticus, Legionella pneumophilia, Mycobacterium tuberculosis, Propionibacterium acnes, Porphyromonas gingivalis, Salmonella enterica, and Streptococcus pneumoniae). pneumonia), and viruses (e.g., respiratory syncytial virus and murine norovirus 1) (Moreira, LO and Zamboni, DS Front Immunol (2012) 3:1-12).Recent studies have revealed that mutations in NOD2 may contribute to inflammatory diseases such as Crohn's disease, resulting in an aberrant inflammatory response upon stimulation.

[0065] Representative compounds The disclosure features compounds and methods for inducing PRR expression (e.g., STING expression) in a subject (e.g., a subject suffering from a microbial infection (e.g., a viral, bacterial, fungal, or parasitic infection) or a proliferative disease (e.g., cancer)) comprising administration of an effective amount of a compound of Formula (I) or a pharmaceutically acceptable salt or stereoisomer thereof.

[0066] In some embodiments, the disclosure features a compound of Formula (I), wherein the 3'-OH terminus of a first nucleoside is linked to the 5'-OH of a second nucleoside via a second linkage; and the 2'-OH terminus of the second nucleoside is linked to the 5'-OH of the first nucleoside via a linkage.

[0067] In some embodiments, the compound is of formula (I): or a pharma- ceutically acceptable salt or stereoisomer thereof:

[0068] [ka] wherein Z is S or O; 1 and B. 2 each is independently a purinyl nucleobase or a pyrimidinyl nucleobase; 1 and X 2 each independently is O or S; Y 1 and Y 2 each independently represents O, S, or NR 5 And;L 1 and L 2 is independently absent, C-C alkyl, or C-C heteroalkyl, and each alkyl and heteroalkyl is independently selected from R 6 may be substituted with R 1 and R 2each independently represents hydrogen, halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), or OR 7 ;R 3 and R 4 each independently represents hydrogen, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl (e.g., C1-C6 heteroalkyl), OC(O)OC1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 8 may be substituted with R 5 is hydrogen or C1-C 20 Alkyl (e.g., C1-C6 alkyl); R 6 is halo, -CN, C1-C 20 Alkyl (e.g. C1-C6 alkyl), OR 7 , oxo, cycloalkyl, heterocycle, aryl, or heteroaryl, each of which is selected from the group consisting of one or more R 9 may be substituted with R 7 is hydrogen, C1-C 20 alkyl (e.g., C1-C6 alkyl), cycloalkyl, heterocycle, aryl, or heteroaryl, each of which may be one or more R 9 Each R may be substituted with 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl (e.g. C1-C6 alkyl), C(O)O-C1-C 20 Alkyl (e.g. C1-C6 alkyl), OC(O)O-C1-C 20 Alkyl (e.g., C1-C6 alkyl), C(O)N(R 5 )-C1-C 20Alkyl (e.g., C1-C6 alkyl), N(R 5 )C(O)-C1-C 20 Alkyl (e.g., C1-C6 alkyl), OC(O)N(R 5 )-C1-C 20 Alkyl (e.g. C1-C6 alkyl), O-aryl, O-heteroaryl, C(O)-aryl, C(O)-heteroaryl, OC(O)-aryl, C(O)O-aryl, OC(O)-heteroaryl, C(O)O-heteroaryl, C(O)O-aryl, C(O)O-heteroaryl, C(O)N(R 5 )-aryl, C(O)N(R 5 )-heteroaryl, N(R 5 )C(O)-aryl, N(R 5 )2C(O)-aryl, or N(R 5 )C(O)-heteroaryl, S(O)2N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 Each R 9 are independent, C1-C 20 Alkyl, O-C1-C 20 Alkyl, C1-C 20 It is heteroalkyl, halo, -CN, OH, oxo, aryl, heteroaryl, O-aryl, or O-heteroaryl.

[0069] In some embodiments, Z is S. In some embodiments, Z is O. In some embodiments, B 1 Or B 2 At least one of B is a purinyl nucleobase. 1 Or B 2 Each of B is independently a purinyl nucleobase. 1 is a purinyl nucleobase. In some embodiments, B 2 is a pyrimidinyl nucleobase. In some embodiments, B 1 is a purinyl nucleobase, and B 2 is a pyrimidinyl nucleobase.

[0070] In some embodiments, Z is S. In some embodiments, Z is O.

[0071] In some embodiments, B 1 Or B 2 At least one of B is a purinyl nucleobase. 1 Or B 2 Each of B is independently a purinyl nucleobase. 1 is a purinyl nucleobase. In some embodiments, B 2 is a pyrimidinyl nucleobase. In some embodiments, B 1 is a purinyl nucleobase, and B 2 is a pyrimidinyl nucleobase. In some embodiments, B 1 is a pyrimidinyl nucleobase. In some embodiments, B 2 is a purinyl nucleobase. In some embodiments, B 1 is a pyrimidinyl nucleobase, B 2 is a purinyl nucleobase.

[0072] In some embodiments, B 1 Or B 2 Each of B is selected from a natural nucleobase or a modified nucleobase. 1 Or B 2 Each of B is selected from adenosinyl, guanosinyl, cytosinyl, thyminyl, uracilyl, 5'-methylcytosinyl, 5'-fluorouracilyl, 5'-propynyluracilyl, and 7-deazaadenosinyl. 1 Or B 2 Each of the

[0073] [ka] Selected from "

[0074] [ka] " indicates the linkage of the nucleobase to the ribose ring.

[0075] In some embodiments, B 1 Or B 2 is selected from natural nucleobases, 1 Or B 2 The other of B is a modified nucleobase. 1 Or B 2 is adenosinyl, guanosinyl, thyminyl, cytosinyl, or uracilyl, and B 1 Or B 2 the other is 5'-methyluracilyl, 5'-fluorouracilyl, 5'-propynyluracilyl, or 7-deazaadenosinyl.

[0076] In some embodiments, B 1 is adenosinyl or guanosinyl. 2 is cytosinyl, thyminyl, or uracilyl. 1 is adenosinyl or guanosinyl, B 2 is cytosinyl, thyminyl, or uracilyl. 2 is adenosinyl or guanosinyl. 1 is cytosinyl, thyminyl, or uracilyl. 2 is adenosinyl or guanosinyl, B 1 is cytosinyl, thyminyl, or uracilyl.

[0077] In some embodiments, B 1 and B. 2 Each of B is independently uracilyl. 1 and B. 2 Each of is independently adenosinyl.

[0078] In some embodiments, R 1 and R 2each independently is hydrogen, halo, or OR 7 In some embodiments, R 1 and R 2 Each of R is independently halo (e.g., fluoro). 1 and R 2 Each of these is hydrogen or 7 But no.

[0079] In some embodiments, X 1 is O. In some embodiments, X 2 is O. In some embodiments, X 1 and X 2 each independently is O.

[0080] In some embodiments, Y 1 is O or S. In some embodiments, Y 2 is O or S. In some embodiments, Y 1 and Y 2 Each of Y is independently O or S. 1 Or Y 2 One of the groups is O and the other is Y 1 Or Y 2 and the other is S. In some embodiments, Y 1 Or Y 2 Each of Y is independently S. 1 Or Y 2 each independently is O.

[0081] In some embodiments, L 1 is C1-C6 alkyl (e.g., CH2). In some embodiments, L 2 is C1-C6 alkyl (e.g., CH2). In some embodiments, L 1 and L 2 Each of is independently C1-C6 alkyl (e.g., CH2).

[0082] In some embodiments, R 3is hydrogen, aryl, or heteroaryl, and the aryl and heteroaryl are each independently selected from 1 to 5 R 8 In some embodiments, R 3 is aryl or heteroaryl, each of which is selected from 1 to 5 R 8 In some embodiments, R 3 is one R 8 is a phenyl substituted with

[0083] In some embodiments, R 4 are independently hydrogen, aryl, or heteroaryl, and the aryl and heteroaryl are each independently selected from 1 to 5 R 8 In some embodiments, R 4 is aryl or heteroaryl, each of which is selected from 1 to 5 R 8 In some embodiments, R 4 is one R 8 is a phenyl substituted with

[0084] In some embodiments, R 3 and R 4 each independently is hydrogen, aryl, or heteroaryl, and the aryl and heteroaryl are each independently selected from 1 to 5 R 8 In some embodiments, R 3 is aryl or heteroaryl, each of which is selected from 1 to 5 R 8 may be substituted with R 4 is hydrogen. In some embodiments, R 3 is one R 8 phenyl substituted with R 4 is hydrogen. In some embodiments, R 3 and R 4 Each of the following is independently one R 8 is a phenyl substituted with

[0085] In some embodiments, Y 1 and Y 2Each of these is O and R 3 and R 4 Each of Y is independently hydrogen. 2 is O and R 4 is hydrogen. In some embodiments, Y 1 and Y 2 each of which is independently S, and R 3 and R 4 Each of these independently represents one R 8 In some embodiments, Y 1 is S and R 3 is one R 8 has been replaced with.

[0086] In some embodiments, each R 8 are independent, C1-C 20 Alkyl (e.g. C1-C6 alkyl), C1-C 20 Heteroalkyl, C(O)-C1-C 20 Alkyl, O-C(O)-C1-C 20 Alkyl, O-C(O)O-C1-C 20 Alkyl, OC(O)N(R 5 )-C1-C 20 Alkyl, O-aryl, C(O)-aryl, OC(O)-aryl, or C(O)N(R 5 )-aryl, each alkyl, heteroalkyl, aryl, and heteroaryl being selected from one or more R 9 may be substituted by:

[0087] In some embodiments, R 8 is 1 to 5 R 9 (Example: 1 R 9 In some embodiments, R 8 is 1 to 5 R 9 (Example: 1 R 9 ) is optionally substituted by OC(O)-aryl.

[0088] In some embodiments, R 9 is O-C1-C 12alkyl (e.g., O-CH2(CH2)8CH3). In some embodiments, R 9 is O-C1-C 10 alkyl (e.g., O-CH2(CH2)8CH3). In some embodiments, R 9 is O-C1-C8 alkyl (e.g., O-CH2(CH2)6CH3). In some embodiments, R 9 is 1 to 5 R 9 O-C1-C6 alkyl (e.g., O-CH2(CH2)4CH3) substituted with; 9 are independently O-C1-C 20 It is an alkyl.

[0089] In some embodiments, the compound of formula (I) is selected from those depicted in Table 1.

[0090] Table 1 (unless otherwise stated in the table, formula C n H (2n+1) refers to an n-alkyl group. For example, C 10 H 21 refers to n-decyl unless otherwise noted.)

[0091] [Table 1] TIFF0007673118000013.tif199162TIFF0007673118000014.tif237162TIFF0007673118000015.tif233162TIFF0007673118000016.tif205161TIFF0007673118000017.tif213160TIFF0007673118000018.tif217160TIFF0007673118000019.tif245160TIFF0007673118000020.tif216160TIFF0007673118000021.tif218159TIFF0007673118000022.tif192161TIFF0007673118000023.tif204160TIFF0007673118000024.tif236160TIFF0007673118000025.tif202160TIFF0007673118000026.tif220160TIFF0007673118000027.tif219160TIFF0007673118000028.tif207161TIFF0007673118000029.tif221160TIFF0007673118000030.tif210160TIFF0007673118000031.tif228160TIFF0007673118000032.tif249160TIFF0007673118000033.tif242161TIFF0007673118000034.tif194161TIFF0007673118000035.tif231160TIFF0007673118000036.tif190160TIFF0007673118000037.tif191160TIFF0007673118000038.tif205163TIFF0007673118000039.tif234161TIFF0007673118000040.tif196160TIFF0007673118000041.tif241160TIFF0007673118000042.tif217161TIFF0007673118000043.tif196160TIFF0007673118000044.tif207160TIFF0007673118000045.tif216162TIFF0007673118000046.tif213160TIFF0007673118000047.tif207160TIFF0007673118000048.tif210160TIFF0007673118000049.tif250160TIFF0007673118000050.tif244161TIFF0007673118000051.tif209160TIFF0007673118000052.tif199160TIFF0007673118000053.tif192161TIFF0007673118000054.tif198160TIFF0007673118000055.tif204160TIFF0007673118000056.tif197160TIFF0007673118000057.tif229161TIFF0007673118000058.tif244160TIFF0007673118000059.tif240160TIFF0007673118000060.tif235161TIFF0007673118000061.tif243160TIFF0007673118000062.tif244160TIFF0007673118000063.tif231160TIFF0007673118000064.tif232162TIFF0007673118000065.tif243162TIFF0007673118000066.tif244161TIFF0007673118000067.tif233161TIFF0007673118000068.tif208162TIFF0007673118000069.tif211161TIFF0007673118000070.tif216160TIFF0007673118000071.tif216161TIFF0007673118000072.tif211161TIFF0007673118000073.tif211160TIFF0007673118000074.tif215160TIFF0007673118000075.tif214160TIFF0007673118000076.tif215160TIFF0007673118000077.tif216161TIFF0007673118000078.tif205161TIFF0007673118000079.tif200161TIFF0007673118000080.tif211160TIFF0007673118000081.ti f248160TIFF0007673118000082.tif208160TIFF0007673118000083.tif189160TIFF0007673118000084.tif22 7160TIFF0007673118000085.tif199161TIFF0007673118000086.tif220160TIFF0007673118000087.tif1951 62TIFF0007673118000088.tif241160TIFF0007673118000089.tif205161TIFF0007673118000090.tif112161.

[0092] wherein X is a pharma- ceutically acceptable counterion, e.g., lithium, sodium, potassium, calcium, magnesium, aluminum, ammonium, ethylamine, diethylamine, ethylenediamine, ethanolamine, diethanolamine, piperazine, and the like (see, e.g., Berge et al., supra); the designation "n" indicates that the associated alkyl chain is "normal" (i.e., unbranched). In some embodiments, the compound of Table 1 is not a salt (i.e., it is a free acid or free base).

[0093] In one embodiment, the compounds described herein are in the form of a pharma- ceutically acceptable salt. Examples of salts are described herein, e.g., ammonium salts. In some embodiments, the compounds are mono-salts. In some embodiments, the compounds are di-salts. In some embodiments, the compounds described herein (e.g., compounds in Table 1) are not salts (e.g., free acids or free bases).

[0094] Without wishing to be bound by theory, the compounds of formula (I) are small molecule nucleic acid hybrid (cyclic dinucleotide) compounds that combine both antiviral and immunomodulatory activity. The latter activity mediates controlled apoptosis of virus-infected hepatocytes via stimulation of the innate immune response, similar to that achieved by IFN-α therapy in patients suffering from viral infections. The mechanism of action of the compounds of formula (I) involves their host immune stimulatory activity, which can induce endogenous IFN through activation of PRRs, such as RIG-I, NOD2, and STING. Activation can occur by binding of the compounds of formula (I) to the nucleotide binding domain of PRRs (e.g., STING), as described above, which can further result in the induction of PRR expression (e.g., STING expression).

[0095] The compounds provided herein may contain one or more asymmetric centers and may occur as racemates and racemic mixtures, single enantiomers, individual diastereomers, and diastereomeric mixtures. All such isomeric forms of these compounds are expressly included within the scope of the present invention. When a compound is named or depicted by structure without specifying the stereochemistry and has one or more chiral centers, it is understood to represent all possible stereoisomers of the compound unless otherwise stated. The compounds provided herein may also include restrictions resulting from the presence of bonds (e.g., carbon-carbon bonds, phosphorus-oxygen bonds, or phosphorus-sulfur bonds) or substituents that may restrict bond rotation, such as rings or double bonds. In some embodiments, the compounds of formula (I) include isomers (e.g., Rp-isomers or Sp-isomers) or isomeric mixtures (e.g., Rp-isomers or Sp-isomers) of the compounds of formula (I).

[0096] Usage example The present disclosure relates to a method of inducing expression of a PRR (e.g., STING) in a subject by administering an effective amount of a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof, hi some embodiments, the subject may be suffering from a condition as described below, e.g., a viral infection (e.g., viral latency), a bacterial infection, a cancer (e.g., a proliferative disease).

[0097] Treating viral infections Pattern recognition receptors such as STING, RIG-I, and NOD2 have been shown to be important elements in host recognition of many RNA viruses from a variety of different virus families. In some embodiments, the method of inducing expression of a PRR (e.g., STING) disclosed herein comprises administering to a subject infected with a microbial agent an effective amount of a compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof. In some embodiments, the microbial infection is a virus. In some embodiments, the virus is an RNA virus (e.g., a double-stranded RNA (dsRNA) virus, a single-stranded RNA (ssRNA) virus (e.g., a positive-strand (sense) ssRNA virus or a negative-strand (antisense) ssRNA virus), or a ssRNA retrovirus) or a DNA virus (e.g., a dsDNA virus, a ssDNA virus, or a dsDNA retrovirus). In some embodiments, the virus can be, for example, a Group I, Group II, Group III, Group IV, Group V, Group VI, or Group VII virus according to the Baltimore classification system.

[0098] In some embodiments, the virus is a dsRNA virus, such as a Group III virus. In some embodiments, expression of a PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is a dsRNA virus and is a member of the Birnaviridae, Chrysoviridae, Cystoviridae, Endornaviridae, Hypoviridae, Partitiviridae, Picobirnaviridae, Reoviridae, or Totiviridae, or other families of dsRNA viruses. Examples of dsRNA viruses and viral genera include, but are not limited to, picobirnavirus, rotavirus, ceadorna, coltivirus, orbivirus, and orthoreovirus, or subtypes, species, or variants thereof.

[0099] In some embodiments, the virus is a ssRNA virus, e.g., a positive-strand (sense) ssRNA virus, e.g., a Group IV virus. In some embodiments, expression of a PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is a positive-stranded (sense) ssRNA virus and is a member of the Arteriviridae, Coronaviridae, Mesoniviridae, Roniviridae, Dicistroviridae, Ifraviridae, Marnaviridae, Picornaviridae, Secoviridae, Alphaflexiviridae, Betaflexiviridae, Gammaflexiviridae, Tymoviridae, Alphatetraviridae, Alvernaviridae, Astroviridae, Barnaviridae, Bromoviridae, Caliciviridae, Carmotetraviridae, Closteroviridae, Flaviviridae, Leviviridae, Luteoviridae, Narnaviridae, Nodaviridae, Permtotetraviridae, Potyviridae, Togaviridae, or Virugaviridae, or other families of positive-stranded (sense) ssRNA viruses.Examples of positive-stranded (sense) ssRNA viruses and virus genera include Yellow Fever Virus, West Nile Virus, Hepatitis C Virus, Dengue Fever Virus, Rubella Virus, Ross River Virus, Sindbis Virus, Chikungunya Virus, Norwalk Virus, Japanese Encephalitis Virus, Tick-Borne Encephalitis Virus, St. Louis Encephalitis Virus, Murray Valley Encephalitis Virus, Kyasanur Forest Disease Virus (e.g., Monkey Disease disease virus), Western equine encephalitis virus, Eastern equine encephalitis virus, Venezuelan equine encephalitis virus, Sapporovirus, Norovirus, Sapovirus, Calicivirus, Parechovirus, Hepatitis A virus, Rhinovirus (e.g., Rhinovirus A, Rhinovirus B, and Rhinovirus C), Enterovirus (e.g., Enterovirus A, Enterovirus B, Enterovirus C (e.g., Poliovirus), Enterovirus D, Enterovirus E, Enterovirus F, Enterovirus G, or Enterovirus H), Aphthovirus (e.g., Foot and Mouth Disease virus), Nidovirales (e.g., Cavally virus, Nam Dinh virus, Middle East Respiratory Syndrome coronavirus (MERS-CoV), coronavirus HKU1, coronavirus NL63, SARS-CoV, coronavirus OC43, and coronavirus 229E), Benivirus, Blune virus, Cile virus, virus), Hepevirus (e.g., Hepatitis E virus), Higre virus, Idaeovirus, Nege virus, Urmia virus, Polemo virus, Sobemo virus, or Umbra virus, or subtypes, species, or variants thereof.

[0100] In some embodiments, the virus is a member of the Norovirus genus, or a subtype, species, or variant thereof. In some embodiments, the virus is Norwalk virus, Hawaii virus, Snow Mountain virus, Mexico virus, Desert Shield virus, Southampton virus, Rosedale virus, or Wilkinson virus, or a subtype or variant thereof. In some embodiments, the virus is a member of the Norovirus genus and can be classified as genogroup GI, genogroup GII, genogroup GIII, genogroup GIV, or genogroup GV.

[0101] In some embodiments, the virus is a ssRNA virus, such as a negative strand (antisense) ssRNA virus, such as a group V virus. In some embodiments, the expression of a PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is a negative strand (antisense) ssRNA virus, and is a member of the Bornaviridae, Filoviridae, Paramyxoviridae, Rhabdoviridae, Nyamiviridae, Arenaviridae, Bunyaviridae, Ophioviridae, or Orthomyxoviridae, or other families of negative strand (antisense) ssRNA viruses. Examples of negative stranded (antisense) ssRNA viruses and virus genera include, but are not limited to, Borna disease virus, Ebola virus, Marburg virus, measles virus, mumps virus, Nipah virus, Hendra virus, respiratory syncytial virus, influenza and parainfluenza viruses, Metapneumovirus, Newcastle disease virus, Deltavirus (e.g., Hepatitis D virus), Dichoha virus, Emara virus, Nya virus, Tenuivirus, Varicosavirus, or subtypes, species, or variants thereof.

[0102] In some embodiments, the virus is a ssRNA retrovirus (ssRNA RT virus), such as a Group VI virus. In some embodiments, expression of the PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is a ssRNA RT virus and is a member of the Metaviridae, Pseudoviridae, or Retroviridae families, or other families of ssRNA RT viruses. Examples of ssRNA RT viruses and viral genera include, but are not limited to, Metavirus, Erranti virus, Alpharetrovirus (e.g., Avian Leukosis Virus, Rous Sarcoma Virus), Betaretrovirus (e.g., Mouse Mammary Tumor Virus), Gammaretrovirus (e.g., Murine Leukemia Virus, Feline Leukemia Virus), Deltaretrovirus (e.g., Human T-Lymphotropic Virus), Epsilonretrovirus (e.g., Walleye Cutaneous Sarcoma Virus), Lentivirus (e.g., Human Immunodeficiency Virus 1 (HIV)), or subtypes, species, or variants thereof.

[0103] In some embodiments, the virus is a DNA virus, such as a dsDNA virus or a ssDNA virus. In some embodiments, the virus is a dsDNA virus, such as a Group I virus, and expression of the PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is a dsDNA virus, and is selected from the family Myoviridae, Podoviridae, Siphoviridae, Alloherpesviridae, Herpesviridae, Oxyherpesviridae, Liposthrixviridae, Rudiviridae, Adenoviridae, Ampulaviridae, Ascoviridae, Asfarviridae, Baculoviridae, Bicaudaviridae, Clavaviridae, Corticoviridae, Fuseroviridae, Globloviridae, and the like. buloviridae, Guttaviridae, Hytrosaviridae, Iridoviridae, Marseilleviridae, Nimaviridae, Pandoraviridae, Papillomaviridae, Phycodnaviridae, Polydnavirus, Polyomaviridae, Poxviridae, Sphaerolipoviridae, Tectiviridae, or Turriviridae, or other families of dsDNA viruses. Examples of dsDNA viruses and virus genera include, but are not limited to, ZinoDNA virus, Nudi virus, smallpox, human herpes virus, Varicella-Zoster virus, Polyomavirus 6, Polyomavirus 7, Polyomavirus 9, Polyomavirus 10, JC virus, BK virus, KI virus, WU virus, Merkel cell polyomavirus, Trichodysplasia spinulosa-associated polyomavirus, MX polyomavirus, Simian virus 40, or subtypes, species, or variants thereof.

[0104] In some embodiments, the virus is an ssDNA virus, such as a Group II virus, and expression of the PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is an ssDNA virus and is a member of the Anelloviridae, Bacillariodnaviridiae, Bidnaviridae, Circoviridae, Geminiviridae, Inoviridae, Microviridae, Nanoviridae, Parvoviridae, or Spiraviridae, or other families of ssDNA viruses. Examples of ssDNA viruses and viral genera include, but are not limited to, Torque tenovirus, Torque teno midivirus, Torque teno minivirus, Gyrovirus, Circovirus, Parvovirus B19, Bocaparvovirus, Dependoparvovirus, Erythroparvovirus, Protoparvovirus, Tetraparvovirus, Silkworm densikonucleosis virus type 2, Lymphoidal parvo-like virus, Hepatopancreatic parvo-like virus, or subtypes, species, or variants thereof.

[0105] In some embodiments, the virus is a dsDNA reverse transcriptase (RT) virus, such as a Group VII virus, where expression of a PRR (e.g., STING) is induced by host-produced or virus-derived RNA. In some embodiments, the virus is a dsDNA RT virus and is a member of the Hepadnaviridae family, or Caulimoviridae family, or other families of dsDNA RT viruses. Examples of dsDNA RT viruses and viral genera include, but are not limited to, Hepatitis B virus, or subtypes, species, or variants thereof.

[0106] In some embodiments, the virus (e.g., a virus described herein) is latent, e.g., in a cell. In some embodiments, the virus is an RNA virus (e.g., a double-stranded RNA (dsRNA) virus, a single-stranded RNA (ssRNA) virus (e.g., a positive-strand (sense) ssRNA virus or a negative-strand (antisense) ssRNA virus), or a ssRNA retrovirus) or a DNA virus (e.g., a dsDNA virus, a ssDNA virus, or a dsDNA retrovirus), e.g., in a cell. In some embodiments, the virus is a Group I, Group II, Group III, Group IV, Group V, Group VI, or Group VII virus according to the Baltimore classification system, e.g., in a cell.

[0107] In some embodiments, the virus is an RNA virus (e.g., an RNA virus described herein), e.g., latent in the cell. In some embodiments, the virus is an ssRNA retrovirus (ssRNART virus), e.g., a Group VI virus, e.g., latent in the cell. In some embodiments, the virus is a human immunodeficiency virus 1 (HIV), or a subtype, species, or variant thereof, e.g., latent in the cell.

[0108] In some embodiments, the methods of inducing expression of a PRR (e.g., STING) in a subject suffering from a viral infection disclosed herein result in increased PRR expression (e.g., STING expression), hi some embodiments, expression of a PRR (e.g., STING) is induced by a factor of about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2, about 2.5, about 3, about 4, about 5, about 7.5, about 10, about 15, about 20, about 25, about 30, about 40, about 50, about 75, about 100, about 150, about 200, about 250, about 500, about 1000, about 1500, about 2500, about 5000, about 10,000, or more. In some embodiments, induction of PRR (e.g., STING) expression occurs within about 5 minutes of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof. In some embodiments, induction of PRR (e.g., STING) expression occurs within about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 1.5 hours, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 10 hours, about 12 hours or more of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof to a subject.

[0109] Treating bacterial infections Recent studies have revealed that PRRs (e.g., STING) play essential roles in host recognition of bacterial infections from diverse species (Dixit, E. and Kagan, JC Adv Immunol (2013) 117:99-125). In some cases, bacteria can secrete nucleic acids during the exponential growth phase (e.g., Listeria monocytogenes; Abdullah, Z. et al, EMBO J (2012) 31:4153-4164), which are then detected by PRRs such as RIG-I, thus promoting the induction of further PRR expression. In other cases, such as Legionella pneumophila, over the course of infection, bacterial DNA enters the cytosol and is transcribed into RNA ligands to RIG-I (Chiu, YH et al, Cell (2009) 138:576-591), thus triggering downstream PRR-mediated signaling events. Recognition of RNA released upon phagocytic uptake of bacteria can further trigger PRR expression (e.g., STING expression). Furthermore, bacterial cell wall components such as peptidoglycans (e.g., muramyl dipeptide, or MDP) can serve as ligands for the activation and induction of PRRs, i.e., NOD2, and bacterial-derived nucleic acids such as cyclic dinucleotides (e.g., cyclic di-GMP) can bind to and activate PRRs, particularly STING. In some embodiments, expression of one or more PRRs can be induced by other means not explicitly described herein.

[0110] In some embodiments, the methods of inducing expression of a PRR (e.g., STING) disclosed herein include administering to a subject suffering from a microbial infection, e.g., a bacterial infection, an effective amount of a compound of formula (I) or a pharma- ceutical acceptable salt thereof.

[0111] In some embodiments, the bacteria is a gram-negative or gram-positive bacteria. Examples of bacteria include Listeria (e.g., Listeria monocytogenes), Francisella (e.g., Francisella tularensis), Mycobacteria (e.g., Mycobacteria tuberculosis), Brucella (e.g., Brucella abortis), Streptococcus (e.g., Group B Streptococcus), Legionella (e.g., Legionella pneumophila), Escherichia coli (e.g., Escherichia coli), Pseudomonas (e.g., Psuedomonas aeruginosa), Salmonella (e.g., Salmonella typhi), and the like. typhi), Shigella (e.g., Shigella flexneri), Campylobacter (e.g., Campylobacter jejuni), Clostridium (e.g., Clostrodium botulinum), Enterococcus (e.g., Enterococcus faecalis), Vibrio (e.g., Vibrio cholera), Yersinia (e.g., Yersinia pestis), Staphylococcus (e.g., Staphylococcus aureus), or other genera, species, subtypes, or variants thereof.

[0112] In some embodiments, the methods of inducing expression of a PRR (e.g., STING) in a subject suffering from a bacterial infection disclosed herein result in increased PRR expression (e.g., STING expression), hi some embodiments, expression of a PRR (e.g., STING) is induced by a factor of about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2, about 2.5, about 3, about 4, about 5, about 7.5, about 10, about 15, about 20, about 25, about 30, about 40, about 50, about 75, about 100, about 150, about 200, about 250, about 500, about 1000, about 1500, about 2500, about 5000, about 10,000, or more. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 5 minutes of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 1.5 hours, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 10 hours, about 12 hours or more of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof to a subject.

[0113] Cancer Treatment Many patients with advanced solid tumors exhibit a spontaneous T cell inflammatory tumor microenvironment that predicts prognosis and clinical response to immunotherapy. Recent findings suggest that the cytosolic DNA sensing STING pathway is a key innate immune sensing mechanism that drives type I IFN production in the context of tumors. Knowledge of this pathway is driving the further development of novel immunotherapeutic strategies.

[0114] In early stage colorectal cancer, the presence of activated CD8+ T cells within the tumor microenvironment is predictive of a favorable outcome. Patients with other solid tumor histologies also appear to have naturally occurring T cell infiltrates that may have similar positive prognostic value. These include breast cancer, renal cell carcinoma, melanoma, ovarian cancer, and gastrointestinal tumors. The T cell infiltrates are thought to contain tumor antigen-specific T cells that are naturally activated in response to the growing tumor, possibly by immunological surveillance mechanisms. This attempt at a host immune response is thought to delay tumor progression, even if it does not completely eliminate the tumor, thus resulting in improved clinical outcomes. Furthermore, innate immune mechanisms can generate adaptive T cell responses against tumor antigens even in the absence of exogenous infection. In this regard, human cancer gene expression profiling studies provide a link between type I IFN signatures, T cell infiltration, and clinical outcome. Thus, the innate immune sensing pathway that induces type I IFN production may represent an essential intermediate mechanistic step. In gene expression profiling of melanomas, two major subsets of the tumor microenvironment have been found, with the presence or absence of a transcriptional profile indicative of a T cell infiltrate. Indeed, CD8+ T cells, macrophages, and some B cells and plasma cells in these lesions in melanoma metastases resemble the phenotype described in early colon cancer and other tumors where activated T cells were associated with a favorable prognosis. CD8+ T cells were required for the elevation of all immunological factors within the tumor microenvironment. Studies have shown that IFN production is required for optimal T cell priming against tumor antigens. There are many PRRs that induce IFN-β production by host DCs in response to growing tumors in vivo, including STING. STING is an adaptor protein that is activated by cyclic dinucleotides generated by cyclic GMP-AMP synthase (cGAS), and it is activated directly by cytosolic DNA. In the presence of these cyclic dinucleotides and / or DNA, STING translocates from the endoplasmic reticulum to various perinuclear compartments.For example, palmitoylation of STING in the Golgi apparatus has been shown to be essential for STING activation (Mukai, K. et al(2016) Nat Commun doi:10.1038 / ncomms11932).

[0115] Activated STING forms aggregates and activates TBK1, which in turn phosphorylates interferon regulatory factor 3 (IRF3), which directly contributes to type I IFN gene transcription. This pathway has also been implicated in DNA virus sensing and in certain autoimmune models. Furthermore, activating mutations in STING have recently been identified in human patients with vasculitis / pulmonary inflammatory syndromes characterized by increased type I IFN production. Mechanistic studies using mouse transplantable tumor models have shown that STING- and IRF3-knockout mice exhibit defective spontaneous T cell priming to tumor antigens in vivo, precluding the rejection of immunogenic tumors. Similarly, tumor-derived DNA was found in the cytosol of a major population of tumor-infiltrating DCs, which was associated with STING pathway activation and IFN-β production. Thus, the host STING pathway appears to be a critical innate immune sensing pathway that detects the presence of tumors and drives DC activation and subsequent T cell priming to tumor-associated antigens in vivo. A functional role for the STING pathway in vivo has also been reported in other mouse tumor systems. Induced glioma models have been shown to result in the induction of type I IFN gene signatures as part of the host response. This induction was significantly reduced in STING-knockout mice, leading to stronger tumor growth and shorter mouse survival. Exogenous delivery of cyclic dinucleotides as STING agonists exerted therapeutic effects in vivo. The crucial role of host type I IFN and host STING pathways was also confirmed in B16.OVA and EL4.OVA models in response to cryoablation. Interestingly, host STING was also required for maximal production of anti-DNA antibodies, thus resembling the mechanisms involved in the Bm12 mouse model of lupus erythematosus. Thus, the antitumor immune response induced in part by tumor DNA overlaps with mechanisms involved in autoimmunity driven by extracellular DNA. A role for STING has also been investigated in an induced colon cancer model. It appears that the ability of cancers to support STING pathway activation in individual patients may be linked to the spontaneous development of a T cell inflammatory tumor microenvironment.Since this phenotype is associated with improved prognosis for patients with early cancer and also with clinical response to immunotherapy in the metastatic setting, failure to activate STING represents an early functional block and may therefore have prognostic / predictive value as a biomarker in itself. Second, strategies to activate or mimic the output of the host STING pathway should have immunotherapeutic potential in the clinic. As non-T cell inflammatory tumors appear to have no signs of type I IFN transcriptional signatures, strategies to promote robust innate signaling through APCs in the tumor microenvironment may facilitate improved cross-priming of tumor antigen-specific CD8+ T cells and even increase chemokine production for subsequent oncolytic activity.

[0116] Recognition of nucleic acid ligands by PRRs such as cGAS, RIG-I, and / STING triggers a series of downstream signaling events that can stimulate the production of type I interferons (e.g., IFN-α or IFN-β) and thus lead to apoptosis in susceptible cells. Recently, a link between the induction of PRR expression and a number of cancers has been discovered. For example, RIG-I expression has been shown to be significantly reduced in hepatocellular carcinoma, and patients exhibiting low RIG-I expression in tumors had shorter survival times and poorer responses to IFN-α therapy (Hou, J. et al, Cancer Cell (2014) 25:49-63). Thus, it has been suggested that the level of RIG-I expression may be useful as a biomarker for predicting prognosis and response to immunotherapy. In other cases, induction of RIG-I expression has been shown to induce immunogenic cell death in pancreatic, prostate, breast, skin, and lung cancer cells (Duewell, P. et al, Cell Death Differ(2014) 21:1825-1837; Besch, R. et al, J Clin Invest(2009) 119:2399-2411; Kaneda, Y. Oncoimmunology(2013) 2:e23566; Li, XY et al, Mol Cell Oncol(2014) 1:e968016), highlighting new approaches in immune-mediated cancer therapy.

[0117] STING is recognized as a key adaptor protein in the cGAS-STING-IFN cascade, but has also been reported to be a sensor for DNA. A role for STING in stimulating innate immunity in response to cancer has also been confirmed. Recent studies have revealed the presence of tumor-derived DNA in the cytosol of certain antigen-presenting cells, such as tumor-infiltrating dendritic cells, likely arising through tumor cell stress or cell death. This tumor-derived DNA is known to trigger the production of cyclic nucleotides that have been shown to activate STING, leading to cGAS activation and, consequently, the production of associated type 1 interferons (Woo, SR et al, Immunity(2014) 41:830-842). Stimulation of STING and the resulting downstream signaling pathways also appear to contribute to the recruitment of effector T cells to the inflamed tumor microenvironment (Woo, SR Trends in Immunol(2015) 36:250-256). STING activation in the tumor microenvironment can induce adaptive immune responses that result in antitumor activity. Thus, in tumors that are STING deficient, the compounds described herein may still have anti-tumor activity through activation of antigen-presenting cells and dendritic cells (APCs and DCs) and induction of adaptive immune responses.

[0118] In some embodiments, the method of inducing expression of a PRR (e.g., a PRR described herein) comprises administering to a subject suffering from cancer an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the method of inducing expression of STING disclosed herein comprises administering to a subject suffering from cancer a compound of formula (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the method of inducing expression of RIG-I disclosed herein comprises administering to a subject suffering from cancer a compound of formula (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the method of inducing expression of NOD2 disclosed herein comprises administering to a subject suffering from cancer a compound of formula (I) or a pharmaceutically acceptable salt thereof. In some embodiments, the cancer is selected from cancer of the breast, bone, brain, cervix, colon, gastrointestinal tract, eye, gallbladder, lymph nodes, blood, lung, liver, skin, oral cavity, prostate, ovary, penis, pancreas, uterus, testes, stomach, thymus, thyroid, or other body parts. In some embodiments, the cancer comprises a solid tumor (e.g., carcinoma, sarcoma, or lymphoma). In some embodiments, the cancer is hepatocellular carcinoma or other liver cancer. In some embodiments, the cancer is leukemia or other blood cancer. In some embodiments, the cancer comprises breast cancer, renal cell carcinoma, colon cancer, melanoma, ovarian cancer, head and neck squamous cell carcinoma, pancreatic cancer, prostate cancer, lung cancer, brain cancer, thyroid cancer, renal cancer, testicular cancer, gastric cancer, urothelial cancer, skin cancer, cervical cancer, endometrial cancer, liver cancer, lung cancer, lymphoma, or gastrointestinal stromal cancer, and solid tumors. In some embodiments, cancer cells (eg, tumor cells) contain specific cancer-associated antigens that elicit a T cell-mediated anti-tumor response.

[0119] In some embodiments, the methods of inducing expression of a PRR (e.g., STING, RIG-I, MDA5, LGP2) in a subject suffering from cancer disclosed herein result in increased PRR expression (e.g., expression of STING). In some embodiments, expression of a PRR (e.g., STING) is induced by a factor of about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2, about 2.5, about 3, about 4, about 5, about 7.5, about 10, about 15, about 20, about 25, about 30, about 40, about 50, about 75, about 100, about 150, about 200, about 250, about 500, about 1000, about 1500, about 2500, about 5000, about 10,000, or more. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 5 minutes of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 5 minutes of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 1.5 hours, 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 10 hours, about 12 hours or more after administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof. It has been recognized that activation of STING by compounds can lead to the induction of expression of other PRRs, such as RIG-I, MDA5, and NOD2, which can further amplify IFN production in the tumor microenvironment and stimulate T cells for enhanced antitumor activity.

[0120] In some embodiments, the methods of inducing expression of a PRR (e.g., STING) in a subject suffering from cancer disclosed herein result in an increase in PRR expression (e.g., expression of STING). In some embodiments, expression of a PRR (e.g., STING) is induced by a factor of about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2, about 2.5, about 3, about 4, about 5, about 7.5, about 10, about 15, about 20, about 25, about 30, about 40, about 50, about 75, about 100, about 150, about 200, about 250, about 500, about 1000, about 1500, about 2500, about 5000, about 10,000, or more. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 5 minutes of administration of a compound of Formula (I) or a pharma- ceutically acceptable salt or stereoisomer thereof. In some embodiments, induction of expression of a PRR (e.g., STING) occurs within about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 1.5 hours, 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 10 hours, about 12 hours or more after administration of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof.

[0121] Pharmaceutical Compositions Although it is possible to administer the compounds of the present disclosure (e.g., compounds of formula (I)) alone, it is preferable to administer the compounds as pharmaceutical compositions or preparations, in which the compounds are combined with one or more pharma- ceutically acceptable diluents, excipients or carriers. The compounds according to the present invention can be formulated for administration in any convenient manner for use in human or veterinary medicine. In certain embodiments, the compounds included in the pharmaceutical preparations can be active themselves or can be, for example, prodrugs that can be converted to active compounds in physiological conditions. Regardless of the route of administration selected, the compounds of the present disclosure, available in a suitable hydrated form, and / or the pharmaceutical compositions of the present disclosure, are formulated into pharma- ceutically acceptable dosage forms, as described below, or by other conventional methods known to those skilled in the art.

[0122] The amount and concentration of the compound of the present disclosure (e.g., compound of formula (I)) in the pharmaceutical composition and the amount of the pharmaceutical composition administered to the subject can be selected based on clinically relevant factors such as the medically relevant characteristics of the subject (e.g., age, weight, sex, other medical conditions, etc.), the solubility of the compound in the pharmaceutical composition, the potency and activity of the compound, and the mode of administration of the pharmaceutical composition. For further information on routes and methods of administration, see Chapter 25.3 in Volume 5 of Comprehensive Medicinal Chemistry (Corwin Hansch; Chairman of Editorial Board), Pergamon Press 1990.

[0123] Thus, another aspect of the present disclosure provides pharma- ceutically acceptable compositions comprising a therapeutically or prophylactically effective amount of a compound described herein (e.g., a compound of formula (I)) formulated together with one or more pharma- ceutically acceptable carriers (additives) and / or diluents. As described in detail below, the pharmaceutical compositions of the present disclosure can be specially formulated for oral, intratumoral, or parenteral administration, e.g., as a sterile solution or suspension, e.g., suitable for subcutaneous, intramuscular, or intravenous injection, in solid or liquid form. However, in certain embodiments, the compounds of the present invention can be simply dissolved or suspended in sterile water. In certain embodiments, the pharmaceutical formulations are non-pyrogenic, i.e., do not elevate the patient's body temperature.

[0124] As used herein, the expressions "systemic administration," "administered systemically," "peripheral administration," and "administered peripherally" refer to administration of a compound other than directly into the central nervous system whereby the compound enters the patient's system and is therefore subject to metabolism and other similar processes, e.g., subcutaneous administration.

[0125] The expression "pharmacologically acceptable" is employed herein to refer to those compounds, materials, compositions, and / or dosage forms that are suitable for use in contact with the tissues of human beings and animals, within the scope of sound medical judgment, without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio.

[0126] As used herein, the phrase "pharmacologically acceptable carrier" refers to a pharma- ceutically acceptable material, composition, or vehicle, such as a liquid or solid filler, diluent, stabilizer, excipient, solvent, or encapsulating material, that is involved in carrying or transporting the subject antagonist from one organ or part of the body to another. Each carrier must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the patient. Some examples of materials which can serve as pharma- ceutically acceptable carriers include, but are not limited to, (1) sugars, such as lactose, glucose, and sucrose; (2) starches, such as corn starch and potato starch; (3) cellulose and its derivatives, such as sodium carboxymethylcellulose, ethylcellulose, and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter and suppository wax; (9) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; and (10) propylene glycol. (11) polyols, such as glycerin, sorbitol, mannitol, polyethylene glycol, (12) esters, such as ethyl oleate and ethyl laurate, (13) agar, (14) buffers, such as magnesium hydroxide and aluminum hydroxide, (15) alginic acid, (16) ascorbic acid, (17) pyrogen-free water, (18) isotonic saline, (19) Ringer's solution, (20) ethyl alcohol, (21) phosphate buffers, (22) cyclodextrins, such as Captisol®, and (23) other non-toxic compatible substances, such as antioxidants and antimicrobials employed in pharmaceutical formulations.

[0127] As mentioned above, certain embodiments of the compounds described herein may contain a basic functional group, such as an amine, and therefore may form pharma- ceutically acceptable salts with a pharma- ceutically acceptable acid. The term "pharma-ceutically acceptable salts" in this respect refers to the relatively non-toxic inorganic and organic acid addition salts of the compounds of the present disclosure. These salts may be prepared in situ during the final isolation and purification of the compounds of the present disclosure, or by separately reacting the purified compounds of the present disclosure in free base form with a suitable organic or inorganic acid and isolating the salt thus formed. Representative salts include hydrobromide, hydrochloride, sulfate, bisulfate, phosphate, nitrate, acetate, valerate, oleate, palmitate, stearate, laurate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, naphthylate, mesylate, glucoheptonate, lactobionate, and laurylsulfonate salts, and the like (see, e.g., Berge et al. (1977) "Pharmaceutical Salts", J. Pharm. Sci. 66:1-19).

[0128] In other cases, the compounds of the present disclosure may contain one or more acidic functional groups, and thus may form pharma- ceutically acceptable salts with pharma- ceutically acceptable bases. In these cases, the term "pharma-ceutically acceptable salts" refers to the relatively non-toxic inorganic and organic base addition salts of the compounds of the present disclosure (e.g., compounds of formula (I)). These salts can also be prepared in situ during the final isolation and purification of the compounds, or by separately reacting the purified compounds in their free acid form with a suitable base, such as a hydroxide, carbonate, or bicarbonate of a pharma-ceutically acceptable metal cation, with ammonia, or with a pharma-ceutically acceptable organic primary, secondary, or tertiary amine. Representative alkali or alkaline earth salts include lithium, sodium, potassium, calcium, magnesium, and aluminum salts. Representative organic amines useful for the formation of base addition salts include ethylamine, diethylamine, ethylenediamine, ethanolamine, diethanolamine, piperazine, and the like (see, e.g., Berge et al., supra).

[0129] Wetting agents, emulsifiers, and lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, release agents, coating agents, sweeteners, flavorings and fragrances, preservatives, and antioxidants can also be present in the composition. Examples of pharma-ceutically acceptable antioxidants include (1) water-soluble antioxidants such as ascorbic acid, cysteine ​​hydrochloride, sodium bisulfate, sodium metabisulfite, and sodium sulfite, (2) oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, and α-tocopherol, and (3) metal chelating agents such as citric acid, ethylenediaminetetraacetic acid (EDTA), sorbitol, tartaric acid, and phosphoric acid.

[0130] Pharmaceutically acceptable carriers, as well as wetting agents, emulsifiers, lubricants, colorants, release agents, coating agents, sweeteners, flavoring agents, perfumes, preservatives, antioxidants, and other additional ingredients, may be present in amounts of about 0.001% to 99% of the compositions described herein. For example, the pharma- ceutically acceptable carriers, as well as wetting agents, emulsifiers, lubricants, colorants, release agents, coating agents, sweeteners, flavoring agents, fragrances, preservatives, antioxidants, and other additional ingredients, may be present from about 0.005%, about 0.01%, about 0.05%, about 0.1%, about 0.25%, about 0.5%, about 0.75%, about 1%, about 1.5%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 85%, about 90%, about 95%, or about 99% of the compositions described herein.

[0131] The pharmaceutical compositions of the present disclosure may be in a form suitable for oral administration, for example, a liquid or solid oral dosage form. In some embodiments, the liquid dosage form includes a suspension, a solution, a lozenge, an emulsion, a drink, an elixir, or a syrup. In some embodiments, the solid dosage form includes a capsule, a tablet, a powder, a dragee, or a powder. The pharmaceutical composition may be in a unit dosage form suitable for single administration of a precise dosage. In addition to the compound described herein (e.g., a compound of Formula (I)) or a pharma-ceutically acceptable salt thereof, the pharmaceutical composition may include a pharma-ceutically acceptable carrier, and may optionally further include one or more pharma-ceutically acceptable excipients, such as, for example, a stabilizer (e.g., a binder, e.g., a polymer, e.g., a suspending agent, a diluent, a binder, and a lubricant.

[0132] In some embodiments, the compositions described herein comprise a liquid dosage form for oral administration, such as a solution or suspension. In other embodiments, the compositions described herein comprise a solid dosage form for oral administration that can be directly compressed into a tablet. In addition, the tablet may comprise other medicinal or pharmaceutical agents, carriers, and / or adjuvants. Exemplary pharmaceutical compositions include, for example, compressed tablets (e.g., direct compressed tablets) comprising a compound of the present disclosure (e.g., a compound of formula (I)) or a pharma- ceutically acceptable salt thereof.

[0133] Formulations of the present disclosure include those suitable for parenteral administration. The formulations may be conveniently provided in unit dosage form and may be prepared by methods well known in the pharmaceutical art. The amount of active ingredient that may be combined with a carrier material to produce a single dosage form will vary depending on the host being treated, the particular mode of administration. The amount of active ingredient that may be combined with a carrier material to produce a single dosage form will generally be that amount of compound that produces a therapeutic effect. Generally, out of one hundred percent, this amount will range from about 1 percent to about 99 percent of the active ingredient, preferably from about 5 percent to about 70 percent, and most preferably from about 10 percent to about 30 percent. Pharmaceutical compositions of the present disclosure suitable for parenteral administration include a compound of the present disclosure in combination with one or more pharma- ceutically acceptable sterile isotonic aqueous or non-aqueous solutions, dispersions, suspensions or emulsions, which may contain antioxidants, buffers, bacteriostats, solutes that render the formulation isotonic with the blood of the intended recipient, or suspending or thickening agents, or sterile dispersions that can be reconstituted into sterile injectable solutions or injectable dispersions prior to use.

[0134] Examples of suitable aqueous and non-aqueous carriers that can be used in the pharmaceutical compositions of the present disclosure include water, ethanol, polyhydric alcohols (such as glycerol, propylene glycol, polyethylene glycol, etc.) and suitable mixtures thereof, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate.Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by maintaining the required particle size in the case of dispersions, and by the use of surfactants.

[0135] These compositions may contain auxiliary agents such as preservatives, wetting agents, emulsifying agents, and dispersing agents. Prevention of microbial action can be ensured by including various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents in the composition, such as sugars, sodium chloride, and the like. Furthermore, prolonged absorption of the injectable pharmaceutical form can be brought about by including agents that delay absorption, such as aluminum monostearate and gelatin.

[0136] In some cases, in order to prolong the effect of the disclosed compound (e.g., compound of formula (I)), it may be desirable to delay the absorption of the drug from subcutaneous, intraperitoneal or intramuscular injection. This can be accomplished by using a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends on its rate of dissolution, which in turn can depend on crystal size and crystalline form. Alternatively, delayed absorption of the disclosed compound from a parenterally administered form can be accomplished by dissolving or suspending the compound in an oil vehicle.

[0137] In some embodiments, it may be advantageous to administer the compounds of the present disclosure (e.g., compounds of formula (I)) in a sustained manner. It will be apparent that formulations that provide sustained absorption characteristics may be used. In certain embodiments, sustained absorption can be achieved by combining the compounds of the present disclosure with other pharma- ceutically acceptable ingredients, diluents, or carriers that delay the release characteristics of the compounds of the present disclosure into the systemic circulation.

[0138] Route of administration The compounds and compositions used in the methods described herein can be administered to a subject in a variety of forms depending on the route of administration selected, as will be appreciated by those skilled in the art. Exemplary routes of administration for the compositions used in the methods described herein include topical, enteral, or parenteral administration. Topical administration includes, but is not limited to, transdermal, inhalation, enemas, eye drops, ear drops, and administration through internal mucous membranes. Enteral administration includes oral, rectal, vaginal, and tube feeding. Parenteral administration includes intravenous, arterial, intracapsular, intraorbital, intracardiac, intradermal, intratracheal, subcuticular, intraarticular, subcapsular, subarachnoid, intraspinal, epidural, intraosseous, intraperitoneal, subcutaneous, intramuscular, transepithelial, intranasal, intrapulmonary, intrathecal, intrarectal, and topical administration forms. Parenteral administration can be by continuous infusion over a selected period of time. In certain embodiments of the present disclosure, the composition described herein comprising the compound of formula (I) is administered orally. In other embodiments of the present disclosure, the composition described herein comprising the compound of formula (I) is administered parenterally (e.g., intraperitoneally). It has been found that for the treatment of solid tumors, direct injection of the compound into the tumor can also be performed (e.g., intratumoral administration). It has been found that for the treatment of solid tumors, direct injection of the compound into the tumor can also be performed (e.g., intratumoral administration).

[0139] For intravenous, intraperitoneal, or intrathecal delivery or direct injection (e.g., intratumor), the composition must be sterile and fluid to the extent that the composition can be delivered by syringe. In addition to water, the carrier can be isotonic buffered saline, ethanol, polyol (e.g., glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. Proper fluidity can be maintained, for example, by the use of a coating agent such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. In many cases, it is preferable to include an isotonic agent in the composition, for example, sugar, polyalcohol such as mannitol or sorbitol, and sodium chloride. Prolonged absorption of an injectable composition can be brought about by including in the composition an agent that delays absorption, for example, aluminum monostearate or gelatin.

[0140] The choice of route of administration will depend on whether a local or systemic effect is to be achieved. For example, for local action, the composition can be formulated for topical administration and administered directly to the site where the action is desired. For systemic, long-term action, the composition can be formulated for enteral administration and administered via the digestive tract. For systemic, immediate and / or short-term action, the composition can be formulated for parenteral administration and administered by a route other than via the digestive tract.

[0141] Dosage The compositions of the present disclosure are formulated into acceptable dosage forms by conventional methods known to those skilled in the art. The actual dosage level of the active ingredient (e.g., compound of formula (I)) in the compositions of the present disclosure may be varied to obtain an amount of the active ingredient effective to achieve the desired therapeutic response for a particular subject, composition, and mode of administration without being toxic to the patient. The dosage level selected will depend on a variety of pharmacokinetic factors, including the activity of the particular composition of the present disclosure employed, the route of administration, the time of administration, the rate of absorption of the particular drug employed, the duration of treatment, other drugs, substances, and / or materials used in conjunction with the particular composition employed, the age, sex, weight, condition, general health and previous medical history of the subject being treated, and similar factors well known in the medical field. A physician or veterinarian skilled in the art can easily determine and prescribe the effective amount of the composition required. For example, the physician or veterinarian can begin administering the substance of the present disclosure employed in the composition at a level lower than that required to achieve the desired therapeutic effect and gradually increase the dosage until the desired effect is achieved. Generally, the suitable daily dose of the composition of the present disclosure will be the amount of the substance that is the lowest dose effective to produce a therapeutic effect.Such effective amount will generally depend on the factors mentioned above.Preferably, the effective daily dose of the therapeutic composition can be administered as 2, 3, 4, 5, 6 or more partial doses that are administered separately at appropriate intervals throughout the day, optionally in unit dosage form.

[0142] Preferred therapeutic dosage levels are from about 0.1 mg / kg to about 1000 mg / kg (e.g., about 0.2 mg / kg, 0.5 mg / kg, 1.0 mg / kg, 1.5 mg / kg, 2 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 10 mg / kg, 15 mg / kg, 20 mg / kg, 25 mg / kg, 30 mg / kg, 35 mg / kg, 40 mg / kg, 45 mg / kg, 50 mg / kg, 55 mg / kg, 60 mg / kg, 70 mg / kg, 75 mg / kg, 80 mg / kg, 85 mg / kg, 90 mg / kg, 95 mg / kg, 100 mg / kg, 100 mg / kg, 110 mg / kg, 120 mg / kg, 130 mg / kg, 140 mg / kg, 150 mg / kg, 160 mg / kg, 170 mg / kg, 180 mg / kg, 190 mg / kg, 210 mg / kg, 220 mg / kg, 230 mg / kg, 240 mg / kg, 250 mg / kg, 260 mg / kg, 270 mg / kg, 280 mg / kg, 290 mg / kg, 300 mg / kg, 310 mg / kg, 320 mg / kg, 330 mg / kg, 340 mg / kg, 350 mg / kg, 360 mg / kg, 370 mg / kg, 380 mg / kg, 390 mg / kg, 400 mg / kg, 410 mg / kg, 420 mg / kg, 430 mg / kg, 440 mg / kg, 450 mg / kg, 460 mg / kg, 470 mg / kg, g / kg, 40mg / kg, 45mg / kg, 50mg / kg, 60mg / kg, 70mg / kg, 80mg / kg, 90mg / kg, 100mg / kg, 125mg / kg, 150mg / kg, 175mg / kg, 200mg / kg, 250mg / kg, 300mg / kg, 350mg / kg, 400mg / kg, 450mg / kg, 500mg / kg, 600mg / kg, 700mg / kg, 800mg / kg, 900mg / kg, or 1000mg / kg). Preferred prophylactic dosage levels are from about 0.1 mg / kg to about 1000 mg / kg (e.g., about 0.2 mg / kg, 0.5 mg / kg, 1.0 mg / kg, 1.5 mg / kg, 2 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 10 mg / kg, 15 mg / kg, 20 mg / kg, 25 mg / kg, 30 mg / kg, 35 mg / kg, 40 mg / kg, 45 mg / kg, 50 mg / kg, 60 mg / kg, 70 mg / kg, 80 mg / kg, 90 mg / kg, 100 mg / kg, 110 mg / kg, 120 mg / kg, 130 mg / kg, 140 mg / kg, 150 mg / kg, 160 mg / kg, 170 mg / kg, 180 mg / kg, 190 mg / kg, 210 mg / kg, 220 mg / kg, 230 mg / kg, 240 mg / kg, 250 mg / kg, 260 mg / kg, 270 mg / kg, 280 mg / kg, 290 mg / kg, 300 mg / kg, 350 mg / kg, 360 mg / kg, 370 mg / kg, 380 mg / kg, 390 mg / kg, 400 mg / kg, 410 mg / kg, 420 mg / kg, 430 mg / kg, 440 mg / kg, 450 mg / kg, 450 mg / kg, 460 mg / kg, 470 mg / kg, 480 mg / kg, 490 mg / kg, 500 mg / kg, 510 mg / kg, 520 mg / kg, 530 mg / kg, 540 mg / kg, 55 g / kg, 50 mg / kg, 60 mg / kg, 70 mg / kg, 80 mg / kg, 90 mg / kg, 100 mg / kg, 125 mg / kg, 150 mg / kg, 175 mg / kg, 200 mg / kg, 250 mg / kg, 300 mg / kg, 350 mg / kg, 400 mg / kg, 450 mg / kg, 500 mg / kg, 600 mg / kg, 700 mg / kg, 800 mg / kg, 900 mg / kg, or 1000 mg / kg). Doses can also be titrated (e.g., doses can be increased incrementally until signs of toxicity, such as headache, diarrhea, or nausea, appear).

[0143] The frequency of treatment can also vary. The subject can be treated once or more times a day (e.g., 1, 2, 3, 4 or more times) or every so many hours (e.g., about every 2, 4, 6, 8, 12, or 24 hours). The composition can be administered once or twice per 24 hours. The time course of treatment can be of varying duration, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more days, 2 weeks, 1 month, 2 months, 4 months, 6 months, 8 months, 10 months, or more than 1 year. For example, treatment can be twice daily for 3 days, twice daily for 7 days, twice daily for 10 days. The treatment cycle can be repeated at regular intervals, for example, weekly, bimonthly, or monthly, and the treatment cycles are separated by periods when no treatment is given. The treatment can be a single treatment, or can continue for the life of the subject (e.g., for many years).

[0144] Patient Selection and Monitoring The methods of the disclosure described herein require administration of a compound of formula (I) or a pharma- ceutically acceptable salt thereof to a subject to activate PRRs for the production of IFN, ISG and cytokines or to further induce expression of PRRs (e.g., RIG-I, STING, etc.). In some embodiments, the subject is suffering from or diagnosed with a condition, e.g., a proliferative disease, e.g., cancer. Thus, a patient and / or subject can be selected for treatment with a compound of formula (I) or a pharma- ceutically acceptable salt thereof by first assessing the patient and / or subject to determine whether the subject is infected with a proliferative disease, e.g., cancer. A subject can be assessed as being infected with a proliferative disease (e.g., cancer) using methods known in the art. For example, the subject can be monitored after administration of a compound described herein (e.g., a compound of formula (I)) or a pharma- ceutically acceptable salt thereof.

[0145] In some embodiments, the subject is a mammal. In some embodiments, the subject is a human. In some embodiments, the subject is an adult. In some embodiments, the subject is suffering from a proliferative disease, e.g., cancer. In some embodiments, the subject is suffering from cancer of the breast, bone, brain, cervix, colon, gastrointestinal tract, eye, gallbladder, lymph nodes, blood, lung, liver, skin, oral cavity, prostate, ovary, penis, pancreas, uterus, testes, stomach, thymus, thyroid, or other body parts. In some embodiments, the subject is suffering from cancer, including solid tumors (e.g., carcinoma, sarcoma, or lymphoma). In some embodiments, the subject is suffering from hepatocellular carcinoma or other liver cancer. In some embodiments, the subject is suffering from leukemia or other blood cancer. In some embodiments, the subject is suffering from breast cancer, renal cell carcinoma, colon cancer, melanoma, ovarian cancer, head and neck squamous cell carcinoma, pancreatic cancer, prostate cancer, lung cancer, brain cancer, or gastrointestinal stromal cancer. In some embodiments, the subject has cancer cells (eg, tumor cells) that contain a specific cancer-associated antigen that elicits a T cell response.

[0146] In some embodiments, the subject is treatment naive. In some embodiments, the subject has previously been treated for a proliferative disease (e.g., cancer). In some embodiments, the subject is relapsing.

[0147] Combination therapy The compounds described herein can be used in combination with other known therapies. As used herein, "in combination" means that two (or more) different therapies are delivered to a subject while the subject is suffering from a disorder, for example, two or more therapies are delivered after the subject is diagnosed with a disorder, but before the disorder is cured or eliminated, or before the treatments are discontinued for other reasons. In some embodiments, the delivery of one treatment is still occurring when the delivery of the second begins, so there is an overlap in terms of administration. This is sometimes referred to herein as "simultaneous" or "co-delivery." In other embodiments, the delivery of one treatment ends before the delivery of the other treatment begins. In some embodiments in either case, the treatments are more effective because of the combined administration. For example, the second treatment is more effective, e.g., an equivalent effect is seen with less of the second treatment, or the second treatment reduces symptoms to a greater extent than would be seen if the second treatment was administered without the first treatment, or a similar situation is seen with the first treatment. In some embodiments, the delivery is such that the relief of symptoms, or other parameters associated with the disorder, is greater than would be seen with one treatment delivered in the absence of the other parameter. The effects of the two treatments can be partially additive, wholly additive, or greater than additive. Delivery can be such that the effect of the first treatment delivered is still detectable when the second treatment is delivered.

[0148] The compounds described herein and the at least one additional therapeutic agent can be administered simultaneously, in the same composition or in separate compositions, or sequentially. For sequential administration, the compounds described herein can be administered first and the additional agent can be administered second, or the order of administration can be reversed.

[0149] In some embodiments, the combination of a compound of Formula (I) or a pharma- ceutically acceptable salt thereof with an additional agent has a synergistic or additive effect. In some embodiments, the term "additive" refers to a result in which, when two agents are used together, the combination of agents acts in a manner equal to, but not greater than, the sum of the individual activity of each agent.

[0150] In some embodiments, the term "additive" refers to a result in which, when two drugs are used together, the combination of drugs acts in a manner equal to, but not greater than, the sum of the individual activities of each drug. In some embodiments, the term "synergistic" or "synergistic" refers to a result in which, when two drugs are used together, the combination of drugs requires a lower concentration of each individual drug than is necessary to be effective in the absence of the other drug. In some embodiments, a synergistic effect results in a lower minimum inhibitory concentration of one or both drugs, thereby making the effect greater than an additive effect. A synergistic effect is greater than an additive effect. In some embodiments, drugs in the compositions herein may exhibit synergistic effects, where the activity at a particular concentration is at least about 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 5, 10, 12, 15, 20, 25, 50, or 100 times greater than the activity of either drug alone.

[0151] For example, any of the methods described herein may further comprise administering a therapeutically effective amount of an additional agent. Exemplary additional pharmaceutical agents include, but are not limited to, antiproliferative agents, anticancer agents, antidiabetic agents, anti-inflammatory agents, immunosuppressants, and pain relieving agents. Pharmaceutical agents include drug compounds (e.g., compounds approved by the U.S. Food and Drug Administration as defined in the Code of Federal Regulations (CFR)), peptides, proteins, carbohydrates, monosaccharides, oligosaccharides, polysaccharides, nucleoproteins, mucoproteins, lipoproteins, synthetic polypeptides or proteins, small molecules bound to proteins, glycoproteins, steroids, nucleic acids, DNA, RNA, nucleotides, nucleosides, oligonucleotides, antisense oligonucleotides, lipids, hormones, vitamins, and cells. In some embodiments, the additional agent is an anticancer agent, such as an alkylating agent (e.g., cyclophosphamide).

[0152] In one embodiment, the additional agent is an immuno-oncology agent, e.g., an agent that activates the immune system, e.g., enables it to recognize and destroy cancer cells. An exemplary immuno-oncology compound is a compound that inhibits immune checkpoint blockade pathways. In one embodiment, the compound is an antibody, such as a PD-1 antibody or a PD-L1 antibody or a co-stimulatory antibody. In some embodiments, the compound is an anti-CTLA4 antibody. In another embodiment, the agent is a cell-based agent, such as a CAR-t therapy. EXAMPLES

[0153] The present disclosure is further illustrated by the following examples and synthesis diagrams, which should not be interpreted as limiting the scope or spirit of the present disclosure to the specific procedures described herein. It should be understood that the examples are provided to illustrate certain embodiments, and are in no way intended to limit the scope of the present disclosure. It should also be understood that there are various other embodiments, modifications and equivalents that may be envisioned by those skilled in the art without departing from the spirit of the present disclosure and / or the scope of the appended claims.

[0154] Abbreviations used in the examples below and elsewhere in this specification are as follows:

[0155] 3H-BD: Iyer-Beaucage reagent Ac: Acetyl DCA: dichloroacetic acid DCC: N,N'-dicyclohexylcarbodiimide DCM: dichloromethane DMAP: 4-dimethylaminopyridine DMT: Dimethoxytrityl EtOAc: ethyl acetate ETT: 5-(ethylthio)-1H-tetrazole h: time IPA: Isopropyl alcohol LCMS: Liquid chromatography-mass spectrometry MeOH: Methanol MSNT: 1-mesitylene-2-sulfonyl-3-nitro-1,2,4-triazole PTSA: p-Toluenesulfonic acid Py: Pyridine rt: room temperature TBHP: tert-butyl hydroperoxide TEA: Triethylamine THF: tetrahydrofuran TLC: thin layer chromatography.

[0156] [Example 1] Synthesis of Exemplary Compounds of the Disclosure

[0157] [ka]

[0158] Synthesis of allyl ((2R,3R,4R,5R)-5-(6-benzamido-9H-purin-9-yl)-4-fluoro-2-(hydroxymethyl)tetrahydrofuran-3-yl)(2-cyanoethyl)phosphate (C)

[0159] [ka]

[0160] Phase 1 5′O-DMT-2′F-3′ phosphoramidite-dA (15.0 g, 17.12 mmol) was coevaporated with dry acetonitrile (2×100 mL) and dried under high vacuum for 1 h. The residue in the flask was flushed with argon. Acetonitrile (150 mL, dry) was added to the residue under argon. Allyl alcohol (Aldrich, 99%) (2.32 mL, 34.24 mmol) was added to the solution followed by ETT (2.22 g, 17.12 mmol) in acetonitrile (20 mL). The reaction mixture was stirred at room temperature under argon for 2.5 h. TLC analysis (98:2 DCM:MeOH, multiple times) indicated the reaction was complete. It was then cooled to 0-5 °C in an ice-water bath. tert-Butyl hydroperoxide (TBHP, 5-6M solution in nonane, 2.0 equiv.) was added dropwise to the reaction mixture at 0-5°C (ice-water bath). The mixture was warmed to room temperature and stirred at room temperature for an additional 30 min. Excess TBHP was quenched by cooling the solution and then adding saturated thiosulfate solution (10 mL). The reaction mixture was warmed to room temperature and the solvent was evaporated under reduced pressure to remove acetonitrile. The reaction mixture was partitioned between DCM (150 mL) and water (100 mL). The organic layer was separated and the aqueous layer was extracted with DCM (50 mL). The combined organic layers were dried over Na2SO4 and filtered to remove Na2SO4 salts.

[0161] Step 2: Detritylation A solution of crude DMT-N-bz-3′-O-allyl-2′-FdA obtained above in DCM (200 mL) was cooled in an ice-water bath. Paratoluenesulfonic acid (PTSA) (10.0 g) was dissolved in MeOH (60 mL) and diluted with DCM (140 mL) to prepare a solution of 5% PTSA in DCM:MeOH (7:3, 200 mL) and added to DMT-N-bz-3′-O-allyl-2′-FdA. This was stirred at 0-5 °C for approximately 30 min and the reaction was checked for completion by TLC (95:5 DCM:MeOH, Rf = 0.2). Once DMT deprotection was complete, water (100 mL) was added and the reaction was allowed to warm to room temperature while stirring for 15 min. The mixture was transferred to a separatory funnel and the layers were separated. The aqueous layer was extracted with DCM (25 mL) and the combined organic layers were washed with aqueous NaHCO3 (5%, 2 x 100 mL). The organic layers were then washed with saturated brine (100 mL) and dried over Na2SO4. After filtering the salts, the solution was concentrated under reduced pressure to give the crude product, which was dried under high vacuum to give a foamy solid. The crude product was dissolved in DCM (30 mL) and added to t-butyl methyl ether (180 mL) to give a white precipitate, which was filtered off. After the first filtration, the product was triturated with t-butyl methyl ether (150 mL) and filtered to give a white solid, which was dried under high vacuum overnight to give 9.3 g (99% yield) of pure product C as a white solid.

[0162] Synthesis of allyl((2R,3R,4R,5R)-5-(6-benzamido-9H-purin-9-yl)-2-((((2-cyanoethoxy)(((2R,3S,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-fluoro-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)phosphorothioyl)oxy)methyl)-4-fluorotetrahydrofuran-3-yl)(2-cyanoethyl)phosphate (F)

[0163] [ka]

[0164] Step 1: Coupling reaction for the synthesis of phosphorothioate dimers A mixture of C (1.09 g, 2.0 mmol) and E (1.5 g, 2.0 mmol) was coevaporated with anhydrous acetonitrile (2×40 mL) and dried under high vacuum for 1 h. Argon was flushed into the round-bottom flask and anhydrous acetonitrile (40 mL) was added to the reaction mixture. ETT (260 mg, 2.0 mmol) in acetonitrile (2.0 mL) was added to the mixture of C and E under argon. The mixture was stirred at room temperature under argon for 2 h. TLC analysis (95:5 DCM:MeOH, Rf=0.5) indicated the reaction was complete. Deoxygenated water was added to the reaction mixture (72 μL, 2 equivalents relative to E).

[0165] Step 2: Sulfurization In a silanization flask, Ayer-Beucage reagent (3H-BD) (800 mg, 4.0 mmol) was dissolved in acetonitrile (10.0 mL). The reaction mixture of C and E from above was added to the solution of sulfurization reagent (3H-BD) under argon and stirred at room temperature for 45 min to complete the sulfurization reaction. Methanol (10 mL) was added to the reaction mixture, which was stirred for 30 min and then concentrated to dryness under reduced pressure. The dry residue was dissolved in DCM (50 mL) and washed with water (50 mL). The DCM layer was collected, dried over Na2SO4, and filtered.

[0166] Step 3: Detritylation Anhydrous DCM solution (50 mL) was cooled to approximately 0°C in a round bottom flask. PTSA (2.5 g) was dissolved in methanol (15 mL) and diluted with DCM (35 mL) to prepare a 5% solution of PTSA in DCM:MeOH (7:3, 50 mL), which was added to the DCM reaction mixture and stirred in an ice-water bath for 15-20 min. The progress of the reaction was monitored by TLC (95:5 DCM:MeOH, Rf=0.15). Water (50 mL) was added and mixed for an additional 15 min. The mixture was transferred to a separatory funnel, the aqueous layer was separated, and the organic layer was collected. The aqueous layer was extracted with DCM (25.0 mL). The combined organic layers were washed with 5% NaHCO3 solution (2 x 50 mL) until the pH of the aqueous layer was >7.0. The organic layer was then washed with saturated brine, dried over Na2SO4, filtered and concentrated under reduced pressure to give the crude product, which was dried under high vacuum. The crude product was purified by combiflash silica gel column chromatography with 0-5% MeOH / DCM to give 550 mg of the desired product F as an off-white solid.

[0167] Synthesis of (2S,3S,4S,5S)-5-(6-benzamido-9H-purin-9-yl)-2-((((2-cyanoethoxy)(((2S,3R,4S,5S)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-fluoro-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)phosphorothioyl)oxy)methyl)-4-fluorotetrahydrofuran-3-yl(2-cyanoethyl)hydrogen phosphate (G)

[0168] [ka]

[0169] To a solution of the 3′-allyl protected dimer (500 mg, 0.565 mmol) in acetone (10 mL) was added sodium iodide (810 mg, 5.41 mmol) and the resulting solution was stirred at 60° C. for 1 h. TLC analysis (80:20 DCM:MeOH, Rf=0.15) indicated the reaction was complete. The reaction mixture was cooled to room temperature. DCM (10 mL) was added to the suspension to precipitate the product. The product was collected by centrifugation, triturated with DCM (25 mL), and then centrifuged a second time to give the product. The product was dried under high vacuum to give an off-white solid. This solid was triturated with 20% MeOH / DCM:t-butyl methyl ether (1:1, 25 mL), collected by centrifugation, and dried under high vacuum to give 500 mg of the product as an off-white solid.

[0170] Synthesis of (H)

[0171] [ka]

[0172] Dinucleotide G (500 mg, 0.565 mmol) was coevaporated with anhydrous pyridine (20 mL x 2), dried in vacuum, flushed with argon (3 x 3), and dissolved in anhydrous pyridine (20 mL). 1-Mesitylene-2-sulfonyl-3-nitro-1,2,4-triazole (MSNT) (0.838 g, 2.82 mmol) was added to the solution of G at room temperature. The resulting mixture was stirred at room temperature for 1.5 h. The reaction progress was monitored by TLC analysis (90:10 DCM:MeOH), which showed the cyclization to be complete after 1.5 h. Toluene (20 mL) was added to the reaction mixture. The solvent was evaporated under reduced pressure to give the crude product. The resulting mixture was dissolved in 25% IPA / DCM (50 mL) and washed with water (50 mL). The aqueous layer was extracted with 25% IPA / DCM (50 mL) and the combined organic layers were washed with saturated aqueous NaHCO3 (10 mL) and brine (10 mL). The organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure to give the crude product. The crude product was dissolved in 10% MeOH / DCM (5 mL) and precipitated by addition to t-butyl methyl ether (10 mL) (to remove colored impurities). The precipitate was collected by centrifugation. The product was triturated with DCM:t-butyl methyl ether (1:1, 15 mL) and the product was collected by centrifugation to give a light yellow product. The crude product was purified by combiflash silica gel column chromatography (gradient 0-10% MeOH / DCM) to give 80 mg of product H as an off-white solid.

[0173] Synthesis of 4-(iodomethyl)phenyl 4-(decyloxy)benzoate (I)

[0174] [ka]

[0175] Phase 1 To a suspension of the benzoic acid derivative (10 g, 0.054 mol) in toluene in a 250 mL one-neck flask, thionyl chloride (7.8 mL) was added slowly and stirred at room temperature for 15 min, then heated in an oil bath at 80-85 °C to obtain a clear solution, which was maintained for about 3 h. The reaction mixture was cooled to room temperature and excess thionyl chloride was removed under reduced pressure. Toluene was concentrated using a rotary evaporator at 40-45 °C. It was then coevaporated twice with ethyl acetate (25 mL). The residue was taken up in ethyl acetate (15 mL). 4-Hydroxybenzyl alcohol (4.5 g, 0.054 mol) was suspended in ethyl acetate (25 mL) and cooled in an ice bath. TEA (5.5 mL) was added with stirring, followed by a solution of the acid chloride in ethyl acetate with stirring. A suspension was formed, which was stirred overnight. The insoluble solids were removed by filtration and the filtrate was transferred to a separatory funnel. The filtrate was diluted with ethyl acetate (200 mL), washed with water (50 mL), and the organic layer was washed with brine (50 mL). Concentration after drying gave the crude product, which was taken up in 200 mL of 4:1 hexane (or heptane): EtOAc and stirred for 2 h to precipitate the product. The precipitated product was filtered and the solid was dried under high vacuum to give 9.0 g (67% yield) of the desired product.

[0176] Phase 2 To a suspension of 4-hydroxylbenzyl alcohol coupling derivative (9.0 g, 0.026 mol) in a mixture of anhydrous acetonitrile (80 mL) and anhydrous dichloromethane (30 mL) in a 250 mL one-neck flask, CsI (18.2 g, 0.078 mol) was added in one portion. To this, BF3·Et2O (8.7 mL) was added slowly and stirred overnight at room temperature in the dark (covered with aluminum foil) under argon. The reaction was found to be complete by TLC hexane:EtOAc (7:3). The product was concentrated and the reaction mixture was worked up by adding water (50 mL) and then extracted with DCM (200 mL) in a separatory funnel. The organic layer was washed with saturated sodium bicarbonate (25 mL) and then with NaHSO3 (5%, 30 mL). The organic layer was dried over anhydrous Na2SO4, filtered and concentrated to a film, which was then dried under vacuum for 2 days to give 9.6 g (85% yield) of the desired product I.

[0177] Synthesis of Example 4

[0178] [ka]

[0179] Step 1: Deprotection of cyclic phosphoromonothiodiphosphate The fully protected cyclic phosphoromonothiodiphosphate (70 mg) was dissolved in a mixture of concentrated NHOH (2.0 mL) and DCM (5.0 mL) and stirred at room temperature overnight. LC-MS analysis showed the reaction was complete. The reaction mixture was transferred to a separatory funnel and the DCM layer was removed. The aqueous layer was evaporated under reduced pressure to remove ammonia and then washed with ethyl acetate (3 x 5 mL) to completely remove the benzamide by-product. The product was isolated from the aqueous layer by lyophilization to give 60 mg as a white solid.

[0180] Phase 2: Cyclic phosphoromonothiodiphosphate (50 mg, 0.072 mmol) was dissolved in water (500 μL). A solution of I (53 mg, 0.108 mmol) in a mixture of THF:acetone (1:1, 3.5 mL) was added to the reaction mixture. The solution was stirred at room temperature for 2 days. The solvent was removed under reduced pressure. The crude product was redissolved in THF:acetone (1:1, 5.0 mL) and precipitated by addition to diethyl ether (10 mL) to remove unreacted iodo-compound. The precipitate was collected by centrifugation to give the product as an off-white solid. This was redissolved in IPA:DCM (1:1, 20 mL) and mixed with water (20 mL), which formed a single-phase solution. Saturated sodium chloride (5 mL) was added to achieve separation of the two phases. The organic layer was collected (bottom layer) and the aqueous layer was re-extracted with IPA:DCM (1:1, 2×10 mL). The combined organic layers were dried over Na2SO4. 、 Filtration and concentration under reduced pressure gave the product as an off-white solid, which was redissolved in 5% acetonitrile / water (2.0 mL) and lyophilized to give 76 mg of product 4 as an off-white solid.

[0181] [Example 2] In vitro induction of IRF and NF-κβ in THP1 cells

[0182] [Table 2]

[0183] [Example 3] Assessment of IRF and NF-KB induction THP1 dual cells grown in complete medium were treated with various concentrations of compounds of the present disclosure or DMSO control. Dual cells contain both a secreted embryonic alkaline phosphatase (SEAP) reporter gene under the control of an IFN-β minimal promoter fused to five copies of the NF-κB consensus transcription response element to measure NF-κB activity, and a Lucia reporter gene under the control of an ISG54 minimal promoter to measure IRF activity. After 20 hours of incubation, IRF activity was assessed using QUANTI-luc to measure the levels of Lucia, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from the fold change in emission / absorbance compared to DMSO-treated samples. Negative values ​​were given a basal value of 1 to plot data on a logarithmic scale to accurately depict dose response. EC 50 Got the value.

[0184] Cells grown in complete medium were treated with various concentrations of the disclosed compounds or DMSO control. The duplicated cells contain both a secreted embryonic alkaline phosphatase (SEAP) reporter gene under the control of the IFN-β minimal promoter fused to five copies of the NF-κB consensus transcription response element to measure NF-κB activity, and a Lucia reporter gene under the control of the ISG54 minimal promoter to measure IRF activity. After 20 hours of incubation, IRF activity was assessed using QUANTI-luc to measure the levels of Lucia, and NF-κB activity was determined by measuring SEAP levels at 620-655 nm. % induction was calculated from the fold change in emission / absorbance compared to DMSO-treated samples. EC was determined by curve fitting with Xlfit. 50 Get the value.

[0185] [Example 4] Testing the efficacy of compound 4 in the CT26 murine colon cancer model using female BALB / c mice mouse Female BALB / c mice (BALB / cAnNcr1, Charles River) were 8 weeks old and had a weight range of 15.1-19.7 g on study day 1. Animals were fed ad libitum water (reverse osmosis, 1 ppm Cl) and NIH 31 modified and irradiated laboratory diet consisting of 18.0% crude protein, 5.0% crude fat, and 5.0% crude fiber.

[0186] Tumor cell culture CT26 mouse colon carcinoma cells were grown in RPMI-1640 medium containing 10% fetal bovine serum, 2 mM glutamine, 100 units / mL sodium penicillin G, 100 μg / mL streptomycin sulfate, and 25 μg / mL gentamicin. Cells were cultured in tissue culture flasks in a humidified incubator at 37°C in an atmosphere of 5% CO2 and 95% air.

[0187] In vivo implantation and tumor growth On the day of transplantation, cultured CT26 cells were harvested in the logarithmic growth phase and diluted to a concentration of 3 × 10 6Each mouse was injected with 3 × 10 cells / mL in phosphate-buffered saline, pH 7.4 (PBS) into the right flank. 5 Tumor cells (0.1 mL cell suspension) were injected subcutaneously to a volume of 80–120 mm 3 Tumors were monitored as they approached the target range of 100–1200 mm. Eleven days after tumor cell implantation, on study day 1, animals were divided into three groups (n=8 / group) with individual tumor volumes ranging from 63 to 126 mm. 3 The group mean tumor volume was 105 mm 3 Tumors were measured twice a week during the study using calipers. Tumor size was calculated using the following formula:

[0188]

number

[0189] Test item An appropriate volume of sterile saline (vehicle) was added to each tube, vortexed, incubated at 37°C for 2-5 minutes, and then sonicated as needed to dissolve Compound 4. Preparation of Compound 4 provided suitable 0.2 and 0.6 mg / mL dosing solutions that provided doses of 1 and 3 mg / kg in a dosing volume of 5 mL / kg, adjusted for animal weight. Fresh vials were prepared on each dosing day.

[0190] treatment On study day 1, three groups of BALB / c mice (n=8) were dosed according to the protocol in Figure 20. Compound 4 and vehicle were administered intravenously (iv). Group 1 received vehicle on days 1, 5, 9, and 14. Groups 2 and 3 received CMD4 at 1 and 3 mg / kg, respectively, on days 1, 5, 9, and 14.

[0191] Tumor growth delay endpoint The study endpoint was a tumor volume of 2000 mm3 or day 30, whichever came first. The study was terminated on day 29. The study protocol defined a tumor growth delay assay based on median time to endpoint (TTE) in treated versus control groups. Tumors were measured twice weekly with calipers and each animal was randomly assigned to receive a 100-mg dose until its tumor reached 2000 mm 3 Upon reaching the volumetric endpoint, mice were sacrificed for tumor progression (TP). The TTE for each mouse was calculated using the following equation:

[0192]

number

[0193] On day 29, MTV(n) was defined as the median tumor volume of the n number of animals that survived to the last day and whose tumors did not reach the volume endpoint. Animals that were determined to have died from treatment-related (TR) causes were assigned a TTE value equal to the date of death. Animals that died from non-treatment-related (NTR) causes were excluded from the analysis. Treatment outcome was assessed from tumor growth delay (TGD), defined as the increase in median TTE for the treatment group compared to the control group.

[0194] TGD=TC This is expressed in days or as a percentage of the median TTE in the control group.

[0195]

number

[0196] Tumor growth inhibition (TGI) assay The study endpoint was a mean tumor volume of 2000 mm in the control group. 3 The total tumor growth inhibition (TGI) was defined as the time to tumor growth (sum of both flank tumors) or 30 days, whichever came first. The study reached the TGI endpoint on day 18. Data from the final day (day 18) when all animals remained on the study were used to determine treatment efficacy. MTV(n), the median tumor volume for n number of animals on the final day, was determined for each group. Percentage tumor growth inhibition (%TGI) was defined as the difference between the MTV of the designated control group (group 1) and the MTV of the drug-treated group, and is expressed as a percentage of the MTV of the control group.

[0197]

number

[0198] The dataset for the TGI analysis included all animals in the group, excluding those sacrificed for sample collection (ES) and those that died due to treatment-related (TR) or non-treatment-related (NTR) causes.

[0199] Criteria for regression responses Therapeutic efficacy was also determined from the number of regression responses. Treatment can induce partial regression (PR) or complete regression (CR) of tumors in animals. In a PR response, the tumor volume is 50% or less of the day 1 volume for three consecutive measurements during the study period and is greater than or equal to 13.5 mm for one or more of these three measurements. 3 In the CR response, tumor volumes were 13.5 mm for three consecutive measurements during the study. 3 Animals were scored for PR or CR events only once during the study, and only as CR if both PR and CR criteria were met. Animals with a CR response on the final day of the study were further classified as tumor-free survivors (TFS).

[0200] toxicity Animals were weighed once daily for the first 5 days of the study and twice weekly thereafter. Mice were observed frequently for health and any obvious signs of adverse treatment-related (TR) side effects, and significant clinical findings were recorded. Individual body weight loss was monitored by protocol, and animals with a weight loss of more than 30% at one measurement or more than 25% at three measurements were to be sacrificed as TR deaths for health reasons. If the group mean body weight recovered, dosing could be resumed in that group, but at a lower dose or less frequent dosing schedule. Acceptable toxicity was defined as a group mean BW loss of less than 20% during the study and no more than one TR death in 10 or 10% of treated animals. Dosing regimens resulting in greater toxicity were considered to exceed the maximum tolerated dose (MTD). Deaths were to be classified as TR if they were due to treatment side effects confirmed by clinical signs and / or necropsy, or could be classified as TR if they were due to unknown causes during the dosing period or within 14 days of the last dose. Deaths were classified as NTR if there was evidence that the death was related to the tumor model and not treatment-related. NTR deaths were further classified as NTRa (due to accidental or human error), NTRm (due to autopsy-confirmed tumor dissemination due to invasion or metastasis), and NTRu (due to unknown causes).

[0201] Test Design

[0202] [Table 3]

[0203] Table 1 shows the study design as of Study Day 1. The vehicle is saline.

[0204] Equivalent The disclosures of each and every patent, patent application and publication cited herein are incorporated herein in their entirety by reference. Although the present disclosure has been described above with reference to specific embodiments, it is apparent that other embodiments and modifications may be devised by those skilled in the art without departing from the true spirit and scope of the present disclosure. The appended claims are to be construed to include all such embodiments and equivalent modifications. Any patent, publication, or other disclosure that is said to be incorporated herein by reference is incorporated herein in whole or in part only to the extent that it does not conflict with existing definitions, descriptions, or other disclosures set forth in this disclosure. Thus, and to the extent necessary, the present disclosure as expressly set forth herein takes precedence over any conflicting material incorporated herein by reference.

[0205] Although the present disclosure has been shown and described with particular reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present disclosure as encompassed by the appended claims.

Claims

1. A compound of formula (I) or a pharma- ceutically acceptable salt or stereoisomer of said compound: 【Chemistry 1】 [In the formula, Z is O; B 1 is a natural purinyl nucleobase and B 2 is a natural pyrimidinyl nucleobase; or B 2 is a natural purinyl nucleobase and B 1 is a natural pyrimidinyl nucleobase; X １ and X ２ each of is O; Y １ and Y ２ each is independently O, or S; L １ and L ２ Each of is independently absent or C １ -C ６ is alkyl; R １ and R ２ each independently represents hydrogen, halo, -CN, C １ -C ２０ Alkyl or OR ７ and R ３ and R ４ is independently hydrogen or aryl, and each aryl is selected from one or more R ８ may be substituted with; R ７ is hydrogen, or C １ -C ２０ is alkyl; Each R ８ are independent, C １ -C ２０ Alkyl, O-aryl, C(O)-aryl, OC(O)-aryl, C(O)O-aryl, C(O)N(H)-aryl, N(H)C(O)-aryl, N(H) ２ C(O)-aryl, or S(O) ２ N(H)-aryl, each aryl being one or more R ９ may be substituted by; and Each R ９ are independent, C １ -C ２０ Alkyl, or O-C １ -C ２０ is alkyl.

2. The compound according to claim 1, wherein the compound is a compound of the following formula (I-a), (I-b), (I-c), or (I-d), or a pharma- ceutically acceptable salt of the compound: 【Chemistry 2】

3. B １ is a natural purinyl nucleobase, B ２ 3. The compound according to claim 1 or 2, wherein is a naturally occurring pyrimidinyl nucleobase.

4. B １ is adenyl or guanyl, B ２ The compound according to claim 1 or 2, wherein is cytosinyl, thyminyl or uracilyl.

5. B １ is adenyl, B ２ The compound according to claim 1 or 2, wherein is uracilyl.

6. R １ and R ２ each independently represents hydrogen, halo, or OR ７ The compound according to any one of claims 1 to 5,

7. R １ and R ２ The compound of any one of claims 1 to 6, wherein each of is independently halo.

8. R １ and R ２ Each of these is hydrogen or ７ The compound according to any one of claims 1 to 5, which is not

9. Y １ and Y ２ is O, and Y １ and Y ２ The compound according to any one of claims 1 to 8, wherein the other is S.

10. Y １ and Y ２ The compound according to any one of claims 1 to 8, wherein each of is independently S.

11. Y １ and Y ２ The compound according to any one of claims 1 to 8, wherein each of is independently O.

12. L １ and L ２ each of is independently absent, or C １ -C ６ The compound according to any one of claims 1 to 11, which is alkyl.

13. R ３ and R ４ each independently is hydrogen, aryl, or heteroaryl, and the aryl and heteroaryl are each independently selected from 1 to 5 R ８ The compound according to any one of claims 1 to 12, which is optionally substituted with

14. R ３ are aryl or heteroaryl, each of which is 1 to 5 R ８ may be substituted with R ４ The compound according to any one of claims 1 to 13, wherein is hydrogen.

15. R ３ There is one R ８ phenyl substituted with R ４ The compound according to any one of claims 1 to 14, wherein is hydrogen.

16. R ３ and R ４ Each of the groups independently represents one R ８ The compound according to any one of claims 1 to 13, which is phenyl substituted with

17. Y １ and Y ２ each of R ３ and R ４ The compound according to any one of claims 1 to 8, wherein each of is independently hydrogen.

18. Y ２ is O, and R ４ The compound according to any one of claims 1 to 9 and 11, wherein is hydrogen.

19. Y １ and Y ２ Each of R is independently S; ３ and R ４ Each of the groups independently represents one R ８ The compound according to any one of claims 1 to 8, which is substituted with

20. Y １ is S and R ３ There is one R ８ The compound according to any one of claims 1 to 10, substituted with

21. R ８ But 1 to 5 R ９ 21. The compound according to any one of claims 1 to 20, which is C(O)-aryl, optionally substituted by:

22. R ８ But 1 to 5 R ９ 21. The compound according to any one of claims 1 to 20, which is OC(O)-aryl, optionally substituted by:

23. R ９ is O-C １ -C １２ 23. The compound of claim 21 or 22, which is alkyl.

24. 2. The compound of claim 1, wherein the compound is selected from the table below, or a pharma- ceutically acceptable salt thereof. 【Table 1】

25. A pharmaceutical composition for treating cancer, comprising a compound according to any one of claims 1 to 24, a pharma- ceutically acceptable salt or stereoisomer of said compound.

26. 26. The pharmaceutical composition of claim 25, wherein the cancer is cancer of the breast, bone, brain, cervix, colon, digestive tract, eye, gallbladder, lymph node, blood, lung, liver, skin, oral cavity, prostate, ovary, penis, pancreas, uterus, testicle, stomach, thymus, thyroid, or other parts of the body.

27. The pharmaceutical composition of claim 26, wherein the cancer is liver cancer.

28. The pharmaceutical composition according to any one of claims 25 to 27, formulated for intratumoral administration.

29. The pharmaceutical composition according to any one of claims 25 to 27, formulated for oral administration.

30. The pharmaceutical composition according to any one of claims 25 to 27, formulated for parenteral administration.

31. 31. The pharmaceutical composition of claim 30, wherein the parenteral administration is intravenous, subcutaneous, or intramuscular.

32. 31. The pharmaceutical composition of claim 30 formulated for intraperitoneal administration.

33. The pharmaceutical composition of any one of claims 25 to 32, further comprising an additional therapeutic agent.

34. The pharmaceutical composition of any one of claims 25 to 32, administered together with an additional therapeutic agent.

35. 35. The pharmaceutical composition of claim 33 or 34, wherein the additional therapeutic agent is an anti-cancer agent.

36. 35. The pharmaceutical composition of claim 33 or 34, wherein the additional therapeutic agent is methotrexate, 5-fluorouracil, doxorubicin, vincristine, bleomycin, vinblastine, dacarbazine, toposide, cisplatin, epirubicin, or sorafenib tosylate.

37. A pharmaceutical composition for treating a microbial infection comprising a compound according to any one of claims 1 to 24, a pharma- ceutically acceptable salt or stereoisomer of said compound.

38. A pharmaceutical composition for treating a viral infection comprising a compound according to any one of claims 1 to 24, a pharma- ceutically acceptable salt or stereoisomer of said compound.

39. 39. The pharmaceutical composition of claim 38, wherein the viral infection is Hepatitis C virus, Norovirus, Junin virus, respiratory syncytial virus, or Dengue virus.

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