Synthetic small molecule derivatives to enhance Anti-tumor immunity

Abstract

Aspects of the disclosure relate to compositions and methods for modulating the immune response of a subject. The disclosure is based, in part, on compositions comprising one or more compounds that promotes interferon, e.g., interferon gamma (IFNγ), response in the gut microbiome of a subject and / or enhance CDS T-cell activity in a subject and / or enhances the anti-tumor effects of certain immune checkpoint inhibitor ( ICI) therapies and chemotherapeutic agents. In some embodiments, the compositions are useful for treating a subject having cancer.

Description

SYNTHETIC SMALL MOLECULE DERIVATIVES TO ENHANCE ANTI-TUMOR IMMUNITY FIELD

[0001] The disclosure is directed to compositions and methods for modulating the immune response of a subject using same. BACKGROUND

[0002] Lung cancer remains the leading cause of cancer death among people in the United States. Immune checkpoint inhibitors (ICI) and chemotherapeutic agents are commonly used to treat cancer. With ICI treatment, only a small percentage of patients experience a complete response, while chemotherapeutic agent indiscriminately target rapidly proliferating cells, which can result in patient toxicities and morbidities. Accordingly, there is an urgent unmet need in the clinic to improve the effect of ICI treatment and chemotherapeutic agents to increase response rates to ICI treatment and reduce the amount of chemotherapeutic agent required to treat cancer patients.

[0003] International (PCT) Patent Application No. PCT / US23 / 31871 discloses a small molecule metabolite, Bac430, from Bacteroides that promotes interferon gamma (IFNγ) in a subject and enhanced anti-tumor effects when administered with an immune checkpoint inhibitor (IC). However, due to the limited water-solubility of Bac430 there is a need for alternative small molecules that can demonstrate improved water-solubility and / or enhanced bioavailability. SUMMARY

[0004] The disclosure provides compositions comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing:wherein: X is selected from O, S, or NH; R1is selected from H, C1-10alkyl, -(CH2CH2O)nCH3, and -(CH2CH2O)nH; R2is selected from H, -(CH2)r-CH3, -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3- CH3, -(CH2)r-(CH)(OR3)-(CH)r1-CH3, -(CH2)r-Q,, ,, , ,, and ; Q is selected from OH, OR3, NR32, SR3, Se, C(O)OH; C(O)NR32, C(O)OR3; NH3, and NH-C(NH2)NH2; each Rxis independently selected from -OH, -SH, -NR32, C1-10alkyl, -OC1-10alkyl, -(CH2CH2O)nCH3, and -(CH2CH2O)nH; each R3is independently H or C1-10alkyl; each n is independently an integer from 1 to 30; m is 0, 1, 2, 3, 4, or 5; q is 0, 1, 2, 3, or 4; t is 0, 1, 2, or 3; each of r, r1, r2, and r3 are independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and R4is hydrogen or methyl, with the provisos that in Formula (I) and Formula (II), when R2is, ydrogen, m is 0, and r is 1, then X-R1 is not O-H and in Formula (I) and Formula (II) when R2is -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3- CH3, r1 is 1, r2 is 0, r3 is 0, and R4is hydrogen, then X-R1is not O-H.

[0005] The disclosure further provides the use in the manufacture of a medicament for increasing interferon gamma (IFNγ) secretion in a subject of a composition according to the disclosure.

[0006] The disclosure further provides the us in the manufacture of a medicament for treating cancer of a composition according to the disclosure.

[0007] The disclosure further provides methods for increasing interferon gamma (IFNγ) secretion in a subject, the methods comprising administering to the subject a composition according to the disclosure.

[0008] The disclosure further provides methods for enhancing CD8 T-cell activation in a subject, the methods comprising administering to the subject a composition according to the disclosure.

[0009] The disclosure further provides methods for treating, ameliorating, or preventing cancer in a subject, the methods comprising administering to the subject a composition according to the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG.1A is an experimental schematic for how synthetic compound Bac430 in the cis or trans configuration, and a saturated analogue control, were assayed for IFNγ stimulation.

[0011] FIG.1B provides representative results for IFNγ stimulation from primary splenic CD8+ T cells by cis-Bac430, trans-Bac430, and sat-Bac430 at a concentration range between 0.01 mM and 1 mM. P values calculated using Mann-Whitney U test compared to unstimulated negative control and PMA / Ionomycin-stimulated positive control. DMSO was used as a solvent vehicle control.

[0012] FIG.1 C provides representative results for the percent of live CD8+ T cells from the bioassay for IFNγ stimulation by cis-Bac430, trans-Bac430, and sat-Bac430 at a concentration range between 0.01 mM and 1 mM. P values calculated using Mann-Whitney U test compared to unstimulated negative control and PMA / Ionomycin-stimulated positive control.

[0013] FIG.2A shows a schematic for bi-local intratumoral injection experiment. SPF C57BL / 6 mice (n=4-7 / group) were injected in both left and right flanks with 106LLC cells at day 0. At day 7, tumors were injected every three days with either cis-Bac430 or sat-Bac430 (2.15 mg / kg) or DMSO alone at the same time as anti-PD-1 treatment or saline control for a total of four treatments. At day 21, tumors were measured and resected for immunological profiling by flow cytometry.

[0014] FIG.2B is a growth curve of left flank Lewis Lung Carcinoma (LLC) subcutaneous allograft tumors that did not receive an intratumoral injection of cis-Bac430 (2.15 mg / kg) orDMSO solvent vehicle alone. Each point represents tumor volume mean ± SEM (n=4-7 mice / group). At day 21, P values are calculated by Mann-Whitney U test.

[0015] FIG.2C is a growth curve of left flank LLC subcutaneous allograft tumors that did not receive an intratumoral injection of sat-Bac430 (2.15 mg / kg) or DMSO alone. Each point represents tumor volume mean ± SEM (n=4-7 mice / group). At day 21, P values are calculated by Mann-Whitney U test.

[0016] FIG.2D is a growth curve of right flank LLC subcutaneous allograft tumors that did directly receive an intratumoral injection of either cis-Bac430 (2.15 mg / kg) or DMSO alone at the same time as anti-PD-1 treatment or saline control. Each point represents tumor volume mean ± SEM (n=4-7 mice / group). At day 21, P values are calculated by Mann-Whitney U test.

[0017] FIG.2E is a growth curve of right flank LLC subcutaneous allograft tumors that did directly receive an intratumoral injection of either sat-Bac430 (2.15 mg / kg) or DMSO alone at the same time as anti-PD-1 treatment or saline control. Each point represents tumor volume mean ± SEM (n=4-7 mice / group). At day 21, P values are calculated by Mann-Whitney U test.

[0018] FIG.2F is a combined growth curve of LLC subcutaneous allograft tumors receiving intratumoral injection of either cis-Bac430 (2.15 mg / kg) or DMSO alone at the same time as anti-PD-1 treatment or saline control. Each point represents tumor volume mean ± SEM (n=4-7 mice / group). At day 21, P values are calculated by Mann-Whitney U test.

[0019] FIG.2G is a combined growth curve of LLC subcutaneous allograft tumors receiving intratumoral injection of either sat-Bac430 (2.15 mg / kg) or DMSO alone at the same time as anti-PD-1 treatment or saline control. Each point represents tumor volume mean ± SEM (n=4-7 mice / group). At day 21, P values are calculated by Mann-Whitney U test.

[0020] FIG.2H provides representative results showing mean ± SD of intratumoral IFNγ+ CD8+ frequency at endpoint for combined left and right flank LLC subcutaneous tumors in mice treated with an anti-PD-1 monoclonal antibody or saline control that received intratumoral injections in the right flank of either cis-Bac430, sat-Bac430 or DMSO (n=4-7 mice / group with two tumors per mouse). P values are calculated by Mann-Whitney U test.

[0021] FIG.3A is an experimental schematic for how synthetic compound cis-Bac430 and a compound of the disclosure, Bac419, were assayed for IFNγ stimulation.

[0022] FIG.3B provides representative results for the percent of total live cells from the bioassay for IFNγ stimulation by cis-Bac430 and cis-Bac419 at a concentration range between 0.01-0.25 mM. DMSO was used as a solvent vehicle control.

[0023] FIG.3C provides representative results for the percent of live CD8+ T cells from the bioassay for IFNγ stimulation by cis-Bac430 and cis-Bac419 at a concentration range between 0.01 mM and 1 mM. DMSO was used as a solvent vehicle control.

[0024] FIG.3D provides results for IFNγ stimulation from primary splenic CD8+ T cells by cis-Bac429 and cis-Bac419 at a concentration range between 0.01-0.25 mM. P values were calculated using multiple t tests with Sidak-Bonferroni multiple comparisons. DMSO was used as a solvent vehicle control.

[0025] FIG.4A provides results for IFNγ stimulation from primary human PMBC CD8+ T cells by cis-Bac419 at a concentration range between 0.01-1.0 mM. P values were calculated using multiple t tests with Sidak-Bonferroni multiple comparisons correction compared to unstimulated negative control and PMA / Ionomycin- stimulated positive control. DMSO was used as a solvent vehicle control.

[0026] FIG.4B provides the percent of live CD8+ T cells from the bioassay for IFNγ stimulation by cis-Bac419 at a concentration range between 0.01-1 mM. P values were calculated using multiple t tests with Sidak-Bonferroni multiple comparisons correction compared to unstimulated negative control and PMA / Ionomycin- stimulated positive control.

[0027] FIG.4C provides the percent of total live cells from the bioassay for IFNγ stimulation by cis-Bac419 at a concentration range between 0.01-1 mM. P values were calculated using multiple t tests with Sidak-Bonferroni multiple comparisons correction compared to unstimulated negative control and PMA / Ionomycin- stimulated positive control.

[0028] FIG.5A provides an experimental schematic for orthotopic implantation of Lewis Lung Carcinoma (LLC) tumor cells in the lung and treatment with anti-PD-1 or isotype control with concurrent treatment with nanoparticles containing cis-Bac419 or saline vehicle control.

[0029] FIG.5B provides the Kaplan-Meier survival curve for mice from each treatment group.

[0030] FIG.5C provides the mean ± SD of total body bioluminescent signal (photons / sec) from weeks 0 to 3 post-LLC implantation.

[0031] FIG.5D provides the mean ± SD of chest region bioluminescent signal (photons / sec) from weeks 0 to 3 post-LLC implantation.

[0032] FIG.5E provides the mean ± SD of endpoint tumor nodule quantification.

[0033] FIG.5F provides the mean ± SD of intratumoral IFNγ+ CD8+ frequency at endpoint for orthotopic lung tumors in mice treated with an anti-PD-1 monoclonal antibody or isotype control that received intravenous injections tail vein injections of either cis-Bac419 or saline vehicle. DETAILED DESCRIPTION

[0034] The disclosure relates, in various aspects, to compositions and methods for modulating the immune response of a subject. For example, aspects of the disclosure are based, at least in part, on compositions comprising a compound that promotes interferon, e.g., interferon gamma (IFNγ) response in the gut microbiome of a subject. As another example, aspects of the disclosure are based, at least in part, on compositions comprising a compound that activates the CD8 T-cell activity of a subject. The compositions of the disclosure can provide one or more advantages including, but not limited to, increased solubility in water relative to cisBac430 and / or increased activity relative to cisBac430.

[0035] As described in International (PCT) Patent Application No. PCT / US23 / 31871, it has been observed that non-small cell lung cancer (NSCLC) patients that respond (R) to immune checkpoint blockade (ICB) have a different microbial community structure than non- responders (NR) pre-treatment. Pooled R microbiota transplantation into gnotobiotic xenograft mice decreased tumor growth compared to NR colonized mice following anti-PD-1 therapy, and this decrease was associated with enrichment of the Bacteroides genus. International (PCT) Patent Application No. PCT / US23 / 31871 is herein incorporated by reference in the entirety. As described in PCT Patent Application No. PCT / US23 / 31871 preliminary active metabolite identification studies used stimulatory Bacteroides isolate M2H3 based on its strong effect on IFNγ production. Targeted tandem MS analysis of the major molecular feature in the active fraction followed by database searches (1) suggested that these chemical entities are N-acyl amides (2), featuring a phenylalanine residue coupled with a monounsaturated C18fatty acid chain (18 carbons in length). The configuration of the phenylalanine moiety was established as S based upon chemical degradation and chiral functionalization (Marfey’s analysis) (3), and the double bond position of the lipid was established as ω-7 (vaccenic acid) using an olefin cross metathesis approach (4) coupled with metabolomics. The cis and trans geometric isomers of the proposed N-acyl amides, cis- Bac430 and trans-Bac430, respectively, were synthesized and it was confirmed that these were the major and minor metabolites in the active fraction by comparative UPLC-QTOF-MS and co-injection studies:

[0036] Both synthetic cis- and trans-Bac430 were tested for bioactivity using primary splenic CD8+ T cells in a heterogenous mixture of splenocytes (FIG.1A). To further test the structural specificity, a saturated analogue of Bac429 (sat-Bac429) lacking the double bond at the ω-7 position was also designed and synthesized. Cis-Bac429 alone robustly stimulated IFNγ from primary murine splenic CD8+ T cells in a dose-dependent manner (FIG.1B). Neither trans-Bac429 nor sat-Bac429, when used alone, exhibited stimulatory effects on the CD8+ T cells, indicating structural specificity is required for this phenotype. However, it was found that at some concentrations of Bac430, including trans-Bac430 in combination with cis-Bac430 provided a synergistic effect with respect to the bioactivity for increasing IFNγ secretion. For example, at Bac430 concentrations of 0.10 mM and 0.25 mM, an increase in IFNγ stimulation was demonstrated for the mixture of cis / trans-Bac430, relative to the amount of IFNγ stimulation observed for cis-430 alone and trans-430 alone. Additionally, no toxicity of CD8+ T cells was observed following cis-Bac430, trans-Bac430, or sat-Bac430 exposure, even at high concentrations (~1 mM) (FIG.1C).

[0037] Given that cis-Bac430 reflects the stimulatory phenotype of the Bacteroides isolate, the anti-tumor effect of cis-Bac430 was assessed in combination with anti-PD-1 in vivo. SPF mice were implanted with two separate LLC tumors on the left and right flanks, with the goal of assessing both the direct and systemic anti-tumor synergy of cis-Bac430 with anti-PD-1. In this bilateral model, only the right flank tumor was injected intratumorally (FIG.2A). Mice were injected intratumorally with a microdose of cis-Bac430 (2.15 mg / kg), which given the in vitro active concentration of ~0.1 mM, would only enable an active concentration of Bac430 in the local right flank tumor. Only mice receiving intratumoral cis- Bac430 in combination with anti-PD-1 showed smaller tumor volume at endpoint, and the effect was seen in both the injected and non-injected tumor sites compared to sat-Bac430 treated with anti-PD-1 or DMSO, sat-Bac430 or cis-Bac430 injection alone (FIG.2B-G). Cis-Bac430-treated mice combined with anti-PD-1 also showed increased frequency of tumor infiltrating cytotoxic IFNγ+ CD8+ T cells in both injected and non-injected tumors (Fig.2H).

[0038] The disclosure provides a composition comprising a compound having a structure according to Formula (I), Formula (II), a pharmaceutically acceptable salt of Formula (I) or Formula (II), or a combination of any of the foregoing:from -OH, -SH, -NR32, C1-10alkyl, -OC1-10alkyl, -(CH2CH2O)nCH3, and -(CH2CH2O)nH; each R3is independently H or C1-10alkyl; each n is independently an integer from 1 to 30; m is 0, 1, 2, 3, 4, or 5; q is 0, 1, 2, 3, or 4; t is 0, 1, 2, or 3; each of r, r1, r2, and r3 are independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and R4is selected from hydrogen and methyl, with the provisos that in Formula (I) and Formula (II) when R2ishydrogen, then X-R1 is not O-H and in Formula (I) and Formula (II) when R2is - (CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3, r1 is 1, r2 is 0, r3 is 0,and R4is hydrogen, then X-R1is not O-H.

[0039] In some cases, in Formula (I) and Formula (II), when X is O, R4is H or methyl, and R1is H or C1-6alkyl, then R2is not -(CH2)r-CH3 where r is 0. In some cases, in Formula (I) and Formula (II), when X is O, R4is H or methyl, and R1is H or C1-6alkyl, then R2is notases, in Formula (I) and Formula (II), when X is O, R4is H or methyl, and R1is H or C1-6alkyl, then R2is not H. In some cases, in Formula (I) and Formula (II), when X is O, R4is H or methyl, and R1is H or C1-6alkyl, then R2is notsome cases, in Formula (I) and Formula (II), when X is O, R4is H or methyl, and R1is H or C1-6alkyl, then R2is not -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3 where (a) r1 is1, r2 is 0, and r3 is 0, or (b) r1 is 0, r2 is 0, and r3 is 0. In some cases, in Formula (I) and Formula (II), when X is O, R4is H or methyl, and R1is H or C1-6alkyl, then R2is not -(CH2)r-Q where (a) r is 1, Q is SR3, and R3is H, (b) r is 1 or 2, and Q is C(O)OH, (c) r is 4, Q is NR32, and both R3are H, (d) r is 2, Q is SR3, and R3is C1alkyl, (e) r is 1 or 2, Q is C(O)NR32, and both R3are H, (f) r is 3 and Q is NH-C(NH2)NH2, (g) r is 1 and Q is OH, or (h) r is 1, Q is OR3, and r3is C1alkyl.

[0040] As used herein a “compound(s) having a structure according to Formula,” “compound(s) according to Formula,” and “compound(s) of Formula” are used interchangeably. As used herein, “compound(s) having a structure according to Formula,”“compound(s) according to Formula,” and “compound(s) of Formula” encompass pharmaceutical salts of the referenced compound. In structures shown herein, hydrogen atoms may be shown where necessary for clarity. Any hydrogen atom not shown can be considered implied where necessary to provide a full valence shell for, e.g., a central carbon atom.

[0041] As used herein, “independently selected from” means that the indicated groups can be the same or different, unless indicated otherwise. For example, where two R groups are present and “independently selected from x, y, and z,” both R groups can be the same (e.g., x) or the R groups can be different (e.g., one R is x, and one R is y). As another example, where three R groups are present and “independently selected from x, y, and z,” all R groups can be the same (e.g., x), all R groups can be different (e.g., x, y, and z), or two R groups can be the same and one R group can be different (e.g., x, x, and z).

[0042] The phrase "pharmaceutically acceptable salt" as used herein refers to a salt of the administered compounds prepared from pharmaceutically acceptable non-toxic acids or bases, including inorganic acids or bases, organic acids or bases, solvates, hydrates, or clathrates thereof.

[0043] Suitable pharmaceutically acceptable acid addition salts may be prepared from an inorganic acid or from an organic acid. Examples of inorganic acids include hydrochloric, hydrobromic, hydriodic, nitric, carbonic, sulfuric (including sulfate and hydrogen sulfate), and phosphoric acids (including hydrogen phosphate and dihydrogen phosphate). Appropriate organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, examples of which include formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucuronic, maleic, malonic, saccharin, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, 4-hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethanesulfonic, benzenesulfonic, pantothenic, trifluoromethanesulfonic, 2- hydroxyethanesulfonic, p-toluenesulfonic, sulfanilic, cyclohexylaminosulfonic, stearic, alginic, β-hydroxybutyric, salicylic, galactaric and galacturonic acid.

[0044] Suitable pharmaceutically acceptable base addition salts of compounds described herein include, for example, ammonium salts, metallic salts including alkali metal, alkaline earth metal and transition metal salts such as, for example, calcium, magnesium, potassium, sodium, and zinc salts. Pharmaceutically acceptable base addition salts also include organic salts made from basic amines such as, for example, N,N'-dibenzylethylene-diamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine)and procaine. All of these salts may be prepared from the corresponding compound by reacting, for example, the appropriate acid or base with the compound.

[0045] Unless otherwise indicated, structures depicted herein include all enantiomeric and / or diastereomeric forms of the structure. For example, the (R) and (S) configurations for each asymmetric center are included, unless specified otherwise. The compounds of the disclosure include stereoisomers. “Stereoisomers” refer to compounds that differ in the chirality of one or more stereocenters. The compounds of the disclosure can exist as a single stereoisomer, or as a mixture of stereoisomers. Stereochemistry of the compounds herein indicate a relative stereochemistry, not absolute, unless indicated otherwise. As used herein, a single stereoisomer, diastereomer, or enantiomer refers to a compound that is more than 50% of the indicated stereoisomer, diastereomer, or enantiomer, for example, more than 75%, more than 90%, or more than 95% of the indicated stereoisomer, diastereomer, or enantiomer. The compounds of the disclosure can be optically pure. As used herein, “optically pure” refers to the predominant presence of one enantiomer of a compound if multiple stereochemical configurations can exist (e.g., at least 99% enantiomeric excess). The compounds of the disclosure can be racemic. The compounds of the disclosure can have an S configuration at the stereocenter indicated with a * in Formula (I), Formula (II), Formula (III), and Formula (IV). The compounds of the disclosure can have an R configuration at the stereocenter indicated with a * in Formula (I), Formula (II), Formula (III), and Formula (IV).

[0046] In general, the compounds having a structure according to Formula (I), Formula (II), Formula (III), and Formula (IV), can have a ClogP value that is no greater than the ClogP value for Bac430. Thus, the compounds of the disclosure can have a ClogP value of 8.80 or less. The Clog P value is the partition coefficient for a given compound and represents the distribution of the compound between octanol and water. As the ClogP value decreases, the solubility in water of the compound increases. Methods of determining ClogP values are known in the art. Unless specified otherwise, ClogP values provided herein are values predicted by the ChemDraw program. The compounds of the disclosure can have a ClogP of 8.80 or less, 8.50 or less, 8.30 or less, 8.15 or less, 8.00 or less, 7.80 or less, 7.50 or less, 7.30 or less, 7.00 or less, 6.80 or less, 6.50 or less, 6.40 or less, 6.20 or less, 6.00 or less, 5.80 or less, 5.75 or less, 5.60 or less, 5.50 or less, 5.30 or less, 5.00 or less, 4.80 or less, 4.50 or less, 4.30 or less, or 4.00 or less. The compounds of the disclosure can have a ClogP of 6.50 or less, 6.40 or less, 6.20 or less, 6.00 or less, 5.80 or less, 5.75 or less, 5.60 or less, 5.50 or less, 5.30 or less, 5.00 or less, 4.80 or less, 4.50 or less, 4.30 or less, or 4.00 or less.

[0047] The compositions of the disclosure can include a compound having a structure according to Formula (I) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can include a mixture of a compound of Formula (I) or a pharmaceutically acceptable salt thereof and a compound of Formula (II) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can include a compound having a structure according to Formula (III) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can include a compound having a structure according to Formula (IV) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can include a mixture of a compound of Formula (III) or a pharmaceutically acceptable salt thereof and a compound of Formula (IIV) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can include a combination of two or more compounds having a structure according to Formula (I), Formula (II), Formula (III), and Formula (IV).

[0048] In the compounds of Formula (I), Formula (II), Formula (III), and Formula (IV), X can generally be O, S, or NH. X can be O or NH. X can be O. X can be NH. X can be S.

[0049] In general, R1can be H, C1-10alkyl, -(CH2CH2O)nCH3, or -(CH2CH2O)nH, wherein n can be an integer from 1 to 30. R1can be H. R1can be C1-10alkyl, for example, C1-8alkyl, C1- 6alkyl, C1-4alkyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, or t-butyl. R1can be methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, or t-butyl. R1can be methyl, ethyl, n-propyl, n-butyl, or t-butyl. R1can be -(CH2CH2O)nCH3 wherein n is an integer from 1-30, for example, 1-25, 1-20, 1 to 15, 1-10, 1-8, 2-6, 3-4, 1, 2, 3, 4, 5, or 6. R1can be -(CH2CH2O)nCH3 wherein n is an integer from 1 to 6. R1can be -(CH2CH2O)nH wherein n is an integer from 1-30, for example, 1-25, 1-20, 1 to 15, 1-10, 1-8, 2-6, 3-4, 1, 2, 3, 4, 5, or 6. R1can be -(CH2CH2O)nH wherein n is an integer from 1 to 6.

[0050] The amide, ester, and thioester forms of Formula (I), Formula (II), Formula (III), and Formula (IV), where X is NH, O, or S and R1is not H can be used to increase water solubility of the compound by selecting an R1group that is hydrophilic. Advantageously, the R1group can be selected such that upon administration the compounds convert in situ to the carboxylic acid form, wherein X is O and R1is H, thereby increasing the lipophilicity of the compound and increasing bioavailability. Without intending to be bound by theory, it is believed that the carboxylic acid form of the compounds of Formula (I), Formula (II), Formula (III), and Formula (IV), wherein X is O and R1is H, is the metabolically stable form and the ester and thioester forms of the compounds, where X is O or S and R1is not H, are not metabolically stable such that upon administration the ester and thioester groups will be cleaved / hydrolyzed to provide the acid form of the compound.

[0051] As used herein, the term “alkyl” refers to straight chained and branched saturated hydrocarbon groups containing one to thirty carbon atoms, for example, one to twenty carbon atoms, or one to ten carbon atoms. The term Cnmeans the alkyl group has “n” carbon atoms. For example, C6alkyl refers to an alkyl group that has 6 carbon atoms. C1-7alkyl refers to an alkyl group having a number of carbon atoms encompassing the entire range (i.e., 1 to 6 carbon atoms), as well as all subgroups (e.g., 1-5, 2-5, 3-6, 1, 2, 3, 4, 5, and 6 carbon atoms). Nonlimiting examples of alkyl groups include, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl (2-methylpropyl), and t-butyl (1,1-dimethylethyl). Unless otherwise indicated, an alkyl group can be an unsubstituted alkyl group or a substituted alkyl group.

[0052] As used herein, a “substituted” functional group is a functional, group having at least one hydrogen radical that is substituted with a non-hydrogen radical (i.e., a substituent). Examples of non-hydrogen radicals (or substituents) include, but are not limited to, alkyl, cycloalkyl, alkenyl, cycloalkyl, alkynyl, ether, aryl, heteroaryl, heterocycle, hydroxyl, oxy (or oxo), alkoxyl, ester, thioester, acyl, carboxyl, cyano, nitro, amino, sulfhydryl, and halo. When a substituted alkyl group includes more than one non-hydrogen radical, the substituents can be bound to the same carbon or different carbon atoms.

[0053] R2is generally selected from H, -(CH2)r-CH3, -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3,2, 3, 4, 5, 6, 7, 8, 9, or 10. R2can be selected to adjust the water-solubility and / or bioavailability of the compounds of Formula (I) and Formula (II).

[0054] R2can be selected fr (CH2)r-(CH)(OR3)-(CH2)r1-CH3,R2can be -(CH2)r-CH3, and r can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8; or 0, 1, 2, 3, or 4. R2can be -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3, wherein r1 is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 0, 1, 2, 3, or 4; r2 can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 0, 1, 2, 3, or 4; and r3 can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 0, 1, 2, 3, or 4. The values for each of r1, r2, and r3 can be the same or different. For example, each of r1, r2, and r3 can be 1. As another example, r1 can be 0, r2 can be 1, and r3 can be 2. As another example, r1 can be 1 and r2 and r3 can be 1. R2can be -(CH2)r-(CH2)(OR3)- (CH2)r1-CH3, wherein r can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 0, 1, 2, 3, or 4; and r1 can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 0, 1, 2, 3, or 4. The values for each of r and r1 can be the same or different. For example, r and r1 can be 0. As another example, r can be 1 and r1 can be 0.

[0055] R2

[0056] R2can be selected from, , ,

[0057] R2can be , for example, , ,, , , , can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 1, 2, 3, or 4.

[0058] R2le,

[0059] R2can be , for example, ,

[0060] R2can beein r can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 1, 2, 3, or 4. r can be 1.

[0061] R2can bewherein r can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 1, 2, 3, or 4.

[0062] R2can beein r can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 1, 2, 3, or 4.

[0063] R2can be -(CH2)r-Q, wherein Q can be selected from -OH, -OR3, -NR32, -SR3, -Se, -C(O)OH; -C(O)NR32, -C(O)OR3; -NH3, and -NH-C(NH2)NH2 and r can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8, or 1, 2, 3, or 4. Q can be selected from -OH, -OR3, -NR32, -SR3, -Se, -C(O)OH, -C(O)NR32, and -C(O)OR3. Q can be selected from - OH, -NH2, -SH, -SCH3, -Se, -C(O)(OH), and -C(O)NH2. R2can be -(CH2)r-Q , wherein Q is NR32, R3is H, and r is 4.

[0064] In general, as the hydrophilicity of R2increases, the water-solubility of the compound increases.

[0065] In general, each Rxcan be independently selected from -OH, -SH, -NR32, C1-10alkyl, -OC1-10alkyl, -(CH2CH2O)nCH3, and -(CH2CH2O)nH, wherein each n is independently an integer from 1-30, for example, from 1-25, 1-20, 1-15, 1-10, 1-8, 2-6, 2-4, 1, 2, 3, 4, 5, or 6. Each Rxcan be independently selected from -OH, -NR32, -C1-4alkyl, -(CH2CH2O)nCH3, and -(CH2CH2O)nH, wherein each n is independently an integer from 1-30, for example, from 1- 25, 1-20, 1-15, 1-10, 1-8, 2-6, 2-4, 1, 2, 3, 4, 5, or 6. One or more Rxcan be -OH. One or more Rxcan be -NR32, for example, -NH2 or -N(C1-4alkyl)2. Rxcan be -SH. Rxcan be C1- 10alkyl, for example, C1-8alkyl, C1-6alkyl, C1-4alkyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, s- butyl, or t-butyl. One or more Rxcan be methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, or t- butyl. One or more Rxcan be methyl, ethyl, n-propyl, n-butyl, or t-butyl. One or more Rxcan be -(CH2CH2O)nCH3 wherein n is an integer from 1-30, for example, 1-25, 1-20, 1 to 15, 1- 10, 1-8, 2-6, 3-4, 1, 2, 3, 4, 5, or 6. One or more Rxcan be -(CH2CH2O)nCH3 wherein n is an integer from 1 to 6. One or more Rxcan be -(CH2CH2O)nH wherein n is an integer from 1-30, for example, 1-25, 1-20, 1 to 15, 1-10, 1-8, 2-6, 3-4, 1, 2, 3, 4, 5, or 6. One or more Rxcan be -(CH2CH2O)nH wherein n is an integer from 1 to 6. Where more than one Rxis present in a structure, each Rxcan be the same or different. For example, when two Rxare present, one Rxcan be -OH and one Rxcan be C1-4alkyl.

[0066] In the compounds of the disclosure, m, q, and t represent the number of Rxgroups that can be present on a given ring structure. In general, m can be 0, 1, 2, 3, 4, or 5, q can be 0, 1, 2, 3, or 4, and t can be 0, 1, 2, or 3. m can be 0, 1, 2, 3, or 4, or 0, 1, 2, or 3. m can be 0. m can be 1. m can be 2. m can be 3. m can be 4. m can be 5. q can be 0, 1, 2, or 3, or 0, 1, or 2. q can be 0. q can be 1. q can be 2. q can be 3. q can be 4. t can be 0, 1, or 2. t can be 0. t can be 1. t can be 2. t can be 3.

[0067] In general, each R3can independently be H or C1-10alkyl. Each R3can independently be H or C1-4alkyl. R3can be H. R3can be C1-10alkyl, for example, C1-8alkyl, C1-6alkyl, C1-4alkyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, or t-butyl. R3can be methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, or t-butyl. R3can be methyl, ethyl, n-propyl, n-butyl, or t-butyl. Where two or more R3are present in the same compound, each R3can be the same or different. For example, when two R3are present, both R3can be H. As anotherexample, when two R3are present, one R3can be H and one R3can be C1-10alkyl. Each R3can independently be H. Each R3can independently be C1-4alkyl.

[0068] R4can be H or methyl. Without intending to be bound by theory, it is believed that when R4is methyl, the stability of the compounds to enzymatic cleavage can be increased relative to an otherwise identical compound wherein R4is hydrogen. In particular, without intending to be bound by theory, it is believed that the presence the methyl group in the R4position interferes with enzymatic cleavage of the amide bond, rate limiting the degradation by serum proteases.

[0069] Further, without intending to be bound by theory, it is believed that the presence of the CF3 group in compounds having a structure according to Formula (III) or Formula (IV) improves the stability of the compounds to enzymatic cleavage relative to an otherwise identical compound having a structure according to Formula (I) or Formula (II). In particular, without intending to be bound by theory, it is believed that the presence the CF3 group in compounds having a structure according to Formula (III) or Formula (IV) hinders enzymatic cleavage at what would be an amide bond in compounds having a structure according to Formula (I) or Formula (II), rate limiting the degradation by serum proteases.

[0070] The composition can include a compound having a structure selected from the group of:combination of the foregoing.

[0071] The composition can include a compound having a structure selected from the group of:and a combination of the foregoing.

[0072] The composition can include a compound having a structure selected from theand a combination of the foregoing.

[0073] The composition can include a compound having a structure selected from the group of:and a combination of the foregoing.

[0074] The composition can be an aqueous composition, wherein the compound of the disclosure is solubilized in water and / or a water-containing solvent. Compounds of the disclosure that are not intrinsically water-soluble, can be pre-dissolved in a suitable solvent, including but not limited to, for example, dimethyl sulfoxide (DMSO), formic acid, alcohols such as ethanol or hexafluoroisopropanol (HFIP), and / or oils such as castor oil or Cremophor ( a non-ionic solubilizer and emulsifier that is made by reacting ethylene oxide with castor oil), and then diluted with water to prepare an aqueous composition.

[0075] The composition can further comprise a carrier. In general, the carrier can be any substance that does not react with the compounds having a structure according to Formula (I), Formula (II), or pharmaceutically acceptable salts thereof. The carrier can be a pharmaceutically acceptable excipient.

[0076] The phrase “pharmaceutically acceptable” is employed herein to refer to those ligands, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio. Compositions described herein can be administered in various forms, depending on the disorder to be treated and the age, condition, and body weight of the patient, as is well known in the art. For example, where the compositions are to be administered orally, they may be formulated as tablets, coated tablets, capsules, granules, powders, suspensions, solutions, slurries, syrups, juices, or emulsions; or for parenteral administration, they may be formulated as injections (intravenous, intramuscular, or subcutaneous), drop infusion preparations, or suppositories. These compositions can be prepared by conventional means in conjunction with the methods described herein, and, if desired, the active ingredient may be mixed with any conventional additive or excipient, such as a binder, a disintegrating agent, a lubricant, acorrigent, a solubilizing agent, a suspension aid, an emulsifying agent, or a coating agent. In embodiments, the composition is an oral composition. In some cases, the oral composition is a tablet, capsule, or suspension. In embodiments, the composition is an injectable composition. For tablets and capsules, an active ingredient, such as the compositions including a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV) may be combined with binders, lubricants, disintegrants, and / or colorants. Examples of binders include, but are not limited to, starch, gelatin, natural sugars, natural and synthetic gums such as acacia, tragacanth and sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, and the like. Examples of disintegrants include, but are not limited to, starch, methyl cellulose, agar, bentonite, xanthan gum, and the like. Liquid formulations may include carriers such as saline, sterile water, Ringer’s solution, buffered saline, dextrose solution, maltodextrin solution, glycerol, or ethanol.

[0077] The phrase “pharmaceutically acceptable excipient” as used herein means a pharmaceutically acceptable material, composition, or vehicle, such as a liquid or solid filler, diluent, excipient, solvent, or encapsulating material. As used herein the language “pharmaceutically acceptable excipient” includes buffers, sterile water for injection, solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. Each excipient must be “acceptable” in the sense of being compatible with the other ingredients of the composition and not injurious to the patient. Some examples of materials which can serve as pharmaceutically acceptable excipients include: (1) sugars, such as lactose, glucose, and sucrose; (2) starches, such as corn starch, potato starch, and substituted or unsubstituted cyclodextrins (α-, β-, or γ-cyclodextrins); (3) cellulose, and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, cellulose acetate, hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose acetate succinate (HPMCAS); (4) polymers such as polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate (PVP / VA); (5) surfactants such as sodium lauryl sulfate, polysorbates (Tween), polyoxyethylene stearates (Myri), polyoxyethylene alkyl ethers (Brij), polyethylene glycol, polyvinyl acetate and polyvinylcaprolactame-based graft copolymer (Soluplus), D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS); (6) gelatin; (7) talc; (8) excipients such as cocoa butter and suppository waxes; (9) lipids such as Captex, Capmul and Cremophore; (10) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; (11) glycols, such as propylene glycol; (12) polyols, such as glycerin, sorbitol, mannitol, and polyethylene glycol; (13) esters, such as ethyl oleate and ethyl laurate; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid;(16) pyrogen-freewater; (17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxic compatible substances employed in pharmaceutical compositions. In certain embodiments, pharmaceutical compositions provided herein are non-pyrogenic, i.e., do not induce significant temperature elevations when administered to a patient.

[0078] The compositions of the disclosure can comprise at least one pharmaceutically acceptable excipient and a compound of Formula (I) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can comprise at least one pharmaceutically acceptable excipient, a compound of Formula (I) or a pharmaceutically acceptable salt thereof, and a compound of Formula (II) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can comprise at least one pharmaceutically acceptable excipient and a compound of Formula (III) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure can comprise at least one pharmaceutically acceptable excipient and a compound of Formula (IV) or a pharmaceutically acceptable salt thereof. The compositions or the disclosure consist essentially of at least one pharmaceutically acceptable excipient and a compound of Formula (I) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist essentially of at least one pharmaceutically acceptable excipient, a compound of Formula (I) or a pharmaceutically acceptable salt thereof, and a compound of Formula (II) or a pharmaceutically acceptable salt thereof. The compositions or the disclosure consist essentially of at least one pharmaceutically acceptable excipient and a compound of Formula (III) or a pharmaceutically acceptable salt thereof. The compositions or the disclosure consist essentially of at least one pharmaceutically acceptable excipient and a compound of Formula (IV) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist essentially of at least one pharmaceutically acceptable excipient, a compound of Formula (III) or a pharmaceutically acceptable salt thereof, and a compound of Formula (IV) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist of at least one pharmaceutically acceptable excipient and a compound of Formula (I) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist of at least one pharmaceutically acceptable excipient, a compound of Formula (I) or a pharmaceutically acceptable salt thereof, and a compound of Formula (II) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist of at least one pharmaceutically acceptable excipient and a compound of Formula (III) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist of at least one pharmaceutically acceptable excipient and a compound of Formula (IV) or a pharmaceutically acceptable salt thereof. The compositions of the disclosure consist of atleast one pharmaceutically acceptable excipient, a compound of Formula (III) or a pharmaceutically acceptable salt thereof, and a compound of Formula (IV) or a pharmaceutically acceptable salt thereof.

[0079] The compositions of the disclosure can be formulated for administration to a mammal. The compositions of the disclosure can be cell-free. The compositions of the disclosure can be free of any additional biologically active ingredient. As used herein, “free of any additional biologically active ingredient” means that the compositions of the disclosure include less than 2 wt.% of a biologically active ingredient other than the compounds having a structure according to Formula (I), Formula (II), Formula (III), Formula (IV), and pharmaceutically acceptable salts of any of the foregoing, based on the total weight of the composition, for example, less than 1 wt.% or less than 0.5 wt.%. The compositions of the disclosure can be free of any additional biologically active ingredient that elicits a measurable immunomodulatory effect in a mammal, such as but not limited to increasing or promoting IFNγ secretion in the mammal. The compositions of the disclosure can be free of any additional biologically active ingredient in an amount sufficient to elicit a measurable immunomodulatory effect in a mammal, such as but not limited to increasing or promoting IFNγ secretion in the mammal.

[0080] The compounds having a structure according to Formula (I), Formula (II), Formula (III), and Formula (IV) can be used to modulate the immune response in a subject in need thereof, for example, increasing interferon (IFN) secretion in a subject and / or enhancing CD8 T-cell activation in a subject. Accordingly, the disclosure provides a method for increasing interferon (IFN) secretion in a subject. The method comprises administering to the subject a composition of the disclosure. The method can include administering a composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), and Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), and Formula (IV), or a combination of the foregoing. Methods for measuring IFN production in a subject are well known in the art. Optionally, the composition of the disclosure mediates at least about a 10%, at least about a 20%, at least about a 30%, at least about a 40%, at least about a 50%, at least about a 60%, at least about a 70%, at least about an 80%, or at least about a 90% increase in IFN production in a subject (e.g., as detected in a biological sample from the subject) in a clinically relevant timeframe. The level of IFN production is compared to, e.g., the level of IFN production observed in the subject prior to administration of the composition or compared to a biologically matched control population which is not administered the composition. In various aspects, after the administration of the composition, interferon, e.g., interferon gamma (IFNγ), secretion is increased in the subject relative to IFNγ secretion before the administration.

[0081] The disclosure further provides a method for treating, ameliorating, or preventing cancer in a subject, the method comprising administering to the subject a composition of the disclosure, for example a composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), and Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), and Formula (IV), or a combination of the foregoing. In general, the composition can be any composition described herein, including any pharmaceutically acceptable carrier or excipients.

[0082] The cancer can be one selected from the group consisting of acute lymphocytic cancer, acute myeloid leukemia, alveolar rhabdomyosarcoma, bone cancer, brain cancer (e.g., glioma), breast cancer (e.g., triple negative breast cancer), cancer of the anus, anal canal, or anorectum, cancer of the eye, cancer of the intrahepatic bile duct, cancer of the joints, cancer of the head, neck, gallbladder, or pleura, cancer of the nose, nasal cavity, or middle ear, cancer of the oral cavity, cancer of the vulva, chronic lymphocytic leukemia, chronic myeloid cancer, colon cancer, esophageal cancer, cervical cancer, gastrointestinal cancer (e.g., gastrointestinal carcinoid tumor), Hodgkin lymphoma, endometrial or hepatocellular carcinoma, hypopharynx cancer, kidney cancer, larynx cancer, liver cancer, lung cancer (e.g., non-small cell lung cancer, bronchioloalveolar carcinoma), malignant mesothelioma, melanoma, multiple myeloma, nasopharynx cancer, non-Hodgkin lymphoma, ovarian cancer, pancreatic cancer, peritoneum, omentum, and mesentery cancer, pharynx cancer, prostate cancer, rectal cancer, renal cancer (e.g., renal cell carcinoma (RCC)), small intestine cancer, soft tissue cancer, stomach cancer, testicular cancer, thyroid cancer, ureter cancer, urinary bladder cancer, and a combination of the foregoing. In particular aspects, the cancer is non-small cell lung cancer (NSCLC). In various aspects, the subject has a solid tumor.

[0083] The administration of the composition including a compound having a structure according to Formula (I), Formula (II), a pharmaceutically acceptable salt of Formula (I) or Formula (II), or a combination of the foregoing can enhance the anti-tumor effects of an immune checkpoint inhibitor (ICI) therapy, for example anti-PD-1 antibodies. An “immune checkpoint inhibitor” or “ICI” is any agent (e.g., compound or molecule) that that decreases, blocks, inhibits, abrogates, or interferes with the function of a protein of an immune checkpoint pathway. Proteins of the immune checkpoint pathway regulate immune responses and, in some instances, prevent T cells from attacking cancer cells. In various aspects, the protein of the immune checkpoint pathway is, for example, CTLA-4, PD-1, PD- L1, PD-L2, B7-H3, B7-H4, TIGIT, VISTA, LAG3, CD112 TIM3, BTLA, or co-stimulatory receptor ICOS, OX40, 41BB, or GITR. In various aspects, the ICI is a small molecule, an inhibitory nucleic acid, or an inhibitor polypeptide. In various aspects, the ICI is an antibody,antigen-binding antibody fragment, or an antibody protein product, that binds to and inhibits the function of the protein of the immune checkpoint pathway. Suitable ICIs which are antibodies, antigen-binding antibody fragments, or an antibody protein products are known in the art and include, but are not limited to, ipilimumab (CTLA-4; Bristol Meyers Squibb), nivolumab (PD-1; Bristol Meyers Squibb), pembrolizumab (PD-1; Merck), atezolizumab (PD- L1; Genentech), avelumab (PD-L1; Merck), and durvalumab (PD-L1; Medimmune) (Wei et al., Cancer Discovery 8: 1069-1086 (2018)). Other examples of ICIs include, but are not limited to, IMP321 (LAG3: Immuntep); BMS-986016 (LAG3; Bristol Meyers Squibb); IPH2101 (KIR; Innate Pharma); tremelimumab (CTLA-4; Medimmune); pidilizumab (PD-1; Medivation); MPDL3280A (PD-L1; Roche); MEDI4736 (PD-L1; AstraZeneca); MSB0010718C (PD-L1; EMD Serono); AUNP12 (PD-1; Aurigene); MGA271 (B7-H3: MacroGenics); and TSR-022 (TIM3; Tesaro).

[0084] The disclosure further provides a method of treating a subject in need thereof by administering a composition of the disclosure and further administering one or more ICI to the subject, such as any of the ICIs, or combinations thereof, described herein. The composition of the disclosure can be administered to the subject prior to administration of the ICI. The composition of the disclosure is administered to the subject after administration of the ICI. The composition of the disclosure can be administered to the subject at about the same time or concurrently with the ICI. The composition of the disclosure can be co- administered to the subject with the ICI. The composition of the disclosure can be co- formulated with the ICI.

[0085] In various instances, the one or more ICI comprises a PD-1 inhibitor. "Programmed Death-1" (PD-1), also known as cluster of differentiation 279 (CD279), refers to an immunoinhibitory receptor belonging to the CD28 family. PD-1 is expressed on previously activated T cells in vivo, and binds to two ligands, PD-L1 and PD-L2. The human PD-1 sequence can be found under GenBank Accession No. U64863. For example, the PD-1 inhibitor may bind to and inhibit the function of PD-1, e.g., an anti-PD-1 antibody, antigen binding antibody fragment, or an antibody-like molecule. In various aspects, the PD-1 inhibitor is durvalumab, atezolizumab, or avelumab. In various aspects, the ICI is a PD-L2 inhibitor. For example, the PD-L2 inhibitor binds to and inhibits the function of PD-L2, e.g., an anti-PD-L2 antibody, antigen binding antibody fragment, or an antibody-like molecule. Examples of PD-1 and PD-L1 inhibitors are described in, e.g., U.S. Patent Nos.7,488,802; 7,943,743; 8,008,449; 8,168,757; 8,217,149: and PCT Patent Publication Nos. WO03042402, WO2008156712, WO2010089411, WO2010036959, WO2011066342, WO2011159877, WO2011082400, and WO2011161699; which are incorporated by reference herein in their entireties. The composition of the disclosure can be administeredwith a PD-1 inhibitor. The composition of the disclosure can be administered with a PD-L1 inhibitor. The composition of the disclosure can be administered with a PD-L2 inhibitor. The composition of the disclosure can be administered with a PD-1 inhibitor and a second ICI selected from the ICI described herein.

[0086] The disclosure further provides a method for enhancing CD8 T-cell activation in a subject. The method comprises administering to the subject a composition of the disclosure. The method can include administering a composition comprising a compound having a structure according to Formula (I), Formula (II), a pharmaceutically acceptable salt of Formula (I) or Formula (II), or a combination of the foregoing. Methods for measuring enhanced CD8 T-call activation in a subject are well known in the art. Optionally, the composition of the disclosure mediates at least about a 10%, at least about a 20%, at least about a 30%, at least about a 40%, at least about a 50%, at least about a 60%, at least about a 70%, at least about an 80%, or at least about a 90% increase in CD8 T-cell activation in a subject (e.g., as detected in a biological sample from the subject) in a clinically relevant timeframe. The level CD8 T-cell activation is compared to, e.g., the level of IFN production observed in the subject prior to administration of the composition or compared to a biologically matched control population which is not administered the composition. In various aspects, after the administration of the composition, CD8 T-cell activation is increased in the subject relative to CD8 T-cell activation before the administration.

[0087] The administration of the composition including a compound having a structure according to Formula (I), Formula (II), Formula (III), and Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), and Formula (IV), or a combination of the foregoing can enhance an immunogenic effect of a chemotherapeutic agent, for example, where the chemotherapeutic agent provides an upregulation of co-stimulatory signals and / or other pro-survival genes in immune cells; and / or wherein cell death signals caused by the chemotherapeutic agent results in T cell driven immunity against the antigens from dying cells, to improve responses to chemotherapeutic agents. Common chemotherapeutics include, but are not limited to, adriamycin, asparaginase, bleomycin, busulphan, cisplatin, carboplatin, carmustine, capecitabine, chlorambucil, cytarabine, cyclophosphamide, camptothecin, dacarbazine, dactinomycin, daunorubicin, dexrazoxane, docetaxel, doxorubicin, etoposide, floxuridine, fludarabine, fluorouracil, gemcitabine, hydroxyurea, idarubicin, ifosfamide, irinotecan, lomustine, mechlorethamine, mercaptopurine, meplhalan, methotrexate, mitomycin, mitotane, mitoxantrone, nitrosurea, paclitaxel, pamidronate, pentostatin, plicamycin, procarbazine, rituximab, streptozocin, teniposide, thioguanine, thiotepa, vinblastine, vincristine, vinorelbine, taxol, transplatinum, 5- fluorouracil, and the like.

[0088] The disclosure further provides a method of treating a subject in need thereof by administering a composition of the disclosure and further administering one or more chemotherapeutic agents to the subject, such as any of the chemotherapeutic agents, or combinations thereof, described herein. The composition of the disclosure can be administered to the subject prior to administration of the chemotherapeutic agent. The composition of the disclosure is administered to the subject after administration of the chemotherapeutic agent. The composition of the disclosure can be administered to the subject at about the same time or concurrently with the chemotherapeutic agent. The composition of the disclosure can be co-administered to the subject with the chemotherapeutic agent. The composition of the disclosure can be co-formulated with the chemotherapeutic agent.

[0089] The term “treat,” as well as words related thereto, do not necessarily imply 100% or complete treatment or remission. Rather, there are varying degrees of treatment of which one of ordinary skill in the art recognizes as having a potential benefit or therapeutic effect. In this respect, the methods of treating a disease of the present disclosure can provide any amount or any level of treatment. Furthermore, the treatment provided by the method may include treatment of one or more conditions or symptoms or signs of the disease being treated. For instance, the treatment method of the disclosure may inhibit one or more symptoms of the disease. Also, the treatment provided by the methods of the present disclosure may encompass slowing the progression of the disease. For example, the methods can treat cancer by virtue of enhancing the T cell activity or an immune response against the cancer, thereby reducing tumor or cancer growth, reducing metastasis of tumor cells, increasing cell death of tumor or cancer cells, and the like. Examples of a therapeutic response include (but are not limited to) one or more of the following improvements in the disease: (1) a reduction in the number of neoplastic cells; (2) an increase in neoplastic cell death; (3) inhibition of neoplastic cell survival; (4) inhibition (i.e., slowing to some extent, preferably halting) of tumor growth or appearance of new lesions; (5) decrease in tumor size or burden; (6) absence of clinically detectable disease, (7) decrease in levels of cancer markers; (8) an increased patient survival rate; and / or (9) some relief from one or more symptoms associated with the disease or condition (e.g., pain). For example, the efficacy of treatment may be determined by detecting of a change in tumor mass and / or volume after treatment. The size of a tumor may be compared to the initial size and dimensions as measured by CT, PET, mammogram, ultrasound, or palpation, as well as by caliper measurement or pathological examination of the tumor after biopsy or surgical resection. Response may be characterized quantitatively using, e.g., percentage change in tumor volume (e.g., the method of the disclosure results in a reduction of tumor volume by at least10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90%). Alternatively, tumor response or cancer response may be characterized in a qualitative fashion like "pathological complete response" (pCR), "clinical complete remission" (cCR), "clinical partial remission" (cPR), "clinical stable disease" (cSD), "clinical progressive disease" (cPD), or other qualitative criteria. In addition, treatment efficacy also can be characterized in terms of responsiveness to other immunotherapy treatment or chemotherapy. In various aspects, the methods of the disclosure further comprise monitoring treatment in the subject.

[0090] The subject of the methods described herein is a mammal, including, but not limited to, mammals of the order Rodentia, such as mice and hamsters, and mammals of the order Logomorpha, such as rabbits, mammals from the order Carnivora, including Felines (cats) and Canines (dogs), mammals from the order Artiodactyla, including Bovines (cows) and Swines (pigs) or of the order Perssodactyla, including Equines (horses). The mammals can be of the order Primates, Ceboids, or Simoids (monkeys) or of the order Anthropoids (humans and apes). The mammal can be a human, optionally a human suffering from or suspected of suffering from cancer.

[0091] Actual dosage levels of the compound of Formula (I), compound of Formula (II), and / or pharmaceutically acceptable salts thereof in the compositions of the disclosure may be varied so as to obtain a “therapeutically effective amount,” which is an amount of the active ingredient effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient. The amount of the compound of Formula (I), compound of Formula (II), and / or pharmaceutically acceptable salts thereof administered to a subject in need thereof is an amount effective to achieve a desired biological effect in a clinically relevant time period. For instance, a dose of the compound of Formula (I), compound of Formula (II), and / or pharmaceutically acceptable salts thereof administered to the subject can be on the nano-, micro-, or milli-molar scale. A dose of the compound of Formula (I), compound of Formula (II), and / or pharmaceutically acceptable salts thereof administered to the subject can be on the nano- or micro-molar scale. The compound of Formula (I), compound of Formula (II), and / or pharmaceutically acceptable salts thereof can be administered at a concentration in a range of about 5 to about 100 µM, about 10 to about 50 µM, about 10 to about 30 µM, about 15 to about 25 µM, or about 50-100 µM. The concentration of the compound of Formula (I), compound of Formula (II), and / or pharmaceutically acceptable salts thereof in the compositions of the disclosure will vary depending on several factors, including the dosage of the compound to be administered, the pharmacokinetic characteristics of the compounds, and the route of administration. Typical dose ranges can include from about 1 mg / Kg to about 100 mg / Kg ofbody weight per day, and can be given in divided doses, e.g., with each cycle of anti-PD-1 therapy. The dosage will be a therapeutically effective amount depending on several factors including the overall health of a patient, the composition, and the route of administration.

[0092] In general, the compositions of the disclosure can be administered using any suitable route of administration. Routes of administration of the compositions of the disclosure can include inhalational, oral, nasal, rectal, parenteral, sublingual, transdermal, transmucosal (e.g., sublingual, lingual, (trans)buccal, (trans)urethral, vaginal (e.g., trans- and perivaginally), (intra)nasal, and (trans)rectal), intravesical, intrapulmonary, intraduodenal, intragastrical, intrathecal, epidural, intrapleural, intraperitoneal, subcutaneous, intramuscular, intradermal, intra-arterial, intravenous, intrabronchial, inhalation, and topical administration. The administration can comprise oral or parenteral administration. The administration can comprise oral administration. The administration can comprise parenteral administration. The administration can comprise intratumoral injection.

[0093] It is to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. As used in the specification and claims, the term “comprising” can include the aspects of “consisting of” and “consisting essentially of.” Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong.

[0094] Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range as well as any ranges therebetween. As used herein, the indefinite articles “a,” “an,” and the corresponding definite article “the” mean “at least one” or “one or more,” unless otherwise specified. It is also understood that the various features disclosed in the specification and the drawings can be used in any and all combinations.

[0095] The term “about” is used according to its ordinary meaning, for example, to mean approximately or around. In one embodiment, the term “about” means ±10% of a stated value or range of values. In another embodiment, the term “about” means ±5% of a stated value or range of values. A value or range described in combination with the term “about” expressly includes the specific value and / or range as well (e.g., for a value described as “about 40,” “40” is also expressly contemplated).EXAMPLES Example 1: Preparation of Compounds of the Disclosure

[0096] Compounds of the disclosure can be prepared according to the following scheme.In the foregoing scheme, PPh3 is triphenyl phosphate, MeCN is acetonitrile, KHMDS is potassium bis(trimethylsilyl)amide, THF is tetrahydrofuran, EDC is 1-ethyl-3- (dimethylaminopropyl) carbodiimide hydrochloride, and HOBt is hydroxybenzotriazole.Example 2: Preparation of Compounds of the Disclosure

[0097] Compounds of the disclosure can be prepared according to the following scheme.In the foregoing scheme, EDC is 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride, HOBt is hydroxybenzotriazole, and THF is tetrahydrofuran.Example 3: Preparation of Compounds of the Disclosure

[0098] cis-Bac419 can be prepared according to the following scheme.In the foregoing scheme, PPh3 is triphenyl phosphate, MeCN is acetonitrile, KHMDS is potassium bis(trimethylsilyl)amide, THF is tetrahydrofuran, EDC is 1-ethyl-3- (dimethylaminopropyl) carbodiimide hydrochloride, and DMAP is N,N-dimethylpyridin-4- amine. Example 4: Preparation of Compounds of the Disclosure

[0099] Compounds of the disclosure can be prepared according to the following scheme.In the foregoing scheme, THF is tetrahydrofuran.Example 5: Preparation of Compounds of the Disclosure

[0100] Compounds of the disclosure can be prepared according to the following scheme.In the foregoing scheme, MeCN is acetonitrile. Example 6: IFNγ Stimulation by a Compound of the Disclosure

[0101] Cis-Bac419 was prepared and the ClogP value was calculated to be 6.40, which is a significant reduction from cis-Bac430 ClogP value of 8.80.The cis-Bac419 derivative was fully dissolved in sterile saline without the addition of DMSO, while cis-Bac430 requires 100% DMSO as a cosolvent to dissolve. For the tests provided herein, both cis-Bac430 and cis-Bac419 were dissolved to a concentration of 10 mM in 100% DMSO.

[0102] Both synthetic cis-Bac430 and Bac419 were tested for bioactivity using primary mouse splenic CD8+ T cells in a heterogenous mixture of splenocytes (Fig.3A-B). Briefly, Primary CD8+ T cells were obtained by harvesting fresh spleens from WT SPF C57BL / 6 mice followed by homogenization by the gentle MACS dissociator (Miltenyi Biotec). Dissociated splenocytes were then centrifuged at 300 g for 5 minutes before beingresuspended in RPMI. These cells were then plated in 0.5 mL of RPMI with 1x Brefeldin A solution (Biolegend) in 24 well tissue culture plates, followed by addition of the appropriate volume of 10 mM cis-Bac430 or cis-Bac419 to reach concentrations of 0.01, 0.1, 0.25 mM. For human donors, unidentified buffy coat samples from 5 separate healthy donors were obtained from Life South under IRB201400101. PMBCs were isolated using a Percoll density gradient as previously described. Human lymphocyte cells were plated in 0.5 mL of RPMI with 1x Brefeldin A solution (Biolegend) in 24 well tissue culture plates, followed by addition of the appropriate volume of 10 mM 10 mM cis-Bac430 or cis-Bac419 to reach concentrations of 0.01, 0.1, 1 mM. Cell Stimulation Cocktail, 500x (PMA / Ionomycin) (2 µL / mL) (Invitrogen ebioscience) was added to cells as a positive control for stimulation of IFNγ. To quantify IFNγ produced by CD8+ T cells, these cells were incubated for 5 hours prior to harvesting and staining. After incubation, each well was pelleted by centrifugation, and the cell pellet was washed twice and resuspended in cold cell staining buffer (Biolegend). LIVE / DEAD Fixable Violet Dead Cell Stain Kit (Thermo Fisher) was added to pelleted cells and stained for 15 minutes at 4 °C. Cells were then stained with CD8 PE (Biolegend, clone 53-6.7). Following cell surface marker staining, cells were washed in staining buffer as before and then permeabilized and fixed using a fixation / permeabilization kit (BD Biosciences). Following permeabilization, for IFNγ production, cells were stained with IFNγ PE-Cy7 (Biolegend, clone XMG1.2). Flow cytometry was performed on a BD LSR Fortessa flow cytometer and analyzed using FlowJo software version 10.6.1.

[0103] Both cis-Bac430 and cis-Bac419 were found to robustly stimulate IFNγ production from CD8+ T cells in a dose dependent manner, with cis-Bac419 outperforming cis-Bac430 at the 0.25 mM dose. (Fig.3C). Additionally, no deleterious effect on viability of CD8+ T cells was observed following cis-Bac430 or cis-Bac419 exposure, even at high concentrations (Fig.3D).

[0104] Synthetic cis-Bac419 was tested for bioactivity using primary healthy human donor blood CD8+ T cells (n=2 healthy human donors) in a heterogenous mixture of blood mononuclear lymphocytes. cis-Bac419 stimulated IFNγ from primary human PBMC CD8+ T cells in a dose-dependent manner with no reduction in viability (Fig.4A-B), suggesting a conserved effect in human immune cells.

[0105] Accordingly, Example 6 demonstrates the use of a compound of the disclosure for increasing interferon gamma (IFNγ) secretion and stimulation of CD8+ T cells. Example 7: Systemic administration of cis-Bac419 in combination with anti-PD-1 therapy reduces orthotopic lung tumor volume and enhances anti-tumor immunity

[0106] To assess the ability of cis-Bac419 to augment anti-PD-1 therapy in non- responsive lung cancer, SPF mice were injected via tail vein with 2x106Lewis Lung Carcinoma cells expressing a luciferase reporter (LLC-luc). Two weeks post-LLC injection, mice were injected intraperitoneally with anti-PD-1 mAb (250μg; clone RMP1-14, BioXcell) or isotype control (rat IgG2a isotype control, anti-trinitrophenol clone 2A3 BioXcell) every three days for a total of 4 treatments. At the same times as anti-PD-1 treatments, mice were also injected via tail vein with 100 µL of cis-Bac419 (2.5 mg / mL) compound incorporated in DOTAP cationic lipid nanoparticles in sterile saline or sterile saline vehicle alone, for a total of 4 treatments (FIG.5A).3 weeks post-tumor implantation, mice were euthanized and lungs harvested. Pre-euthanasia, mice were injected weekly with D-luciferin (150 mg / kg, Revvity Health Sciences Inc.) and imaged using the IVIS imaging system with bioluminescence quantification. At endpoint, mice were euthanized, and lungs were inflated with PBS via the trachea prior to removal, resected and photographed. Tumor nodules were counted. A portion of tumor (at least 50 mg) was taken for processing for flow cytometry. The remaining lung tissue was paraffin-embedded for histological examination.

[0107] For resected lung tumors destined for flow cytometric analysis, the tumors were finely divided using surgical blade and kept at 4 °C in PBS buffer containing 2 mg / ml STEMxyme (a mix of collagenase / dispase, Worthington Biochemical Corp)) and 0.1 mg / ml DNase I (StemCell Technologies). Tissues were then incubated at 37 °C for 15 minutes and transferred to 25C tubes (Miltenyi Biotec) for homogenization by the gentleMACS dissociator (Miltenyi Biotec) using program mouse-imp-tumor-01. Dissociated tissue was then passed through a 70 μm cell strainer, followed by centrifugation at 300g for 5 minutes before being resuspended in RPMI. Cells from tumor were then plated in 0.5 mL of RPMI with 1x Brefeldin A solution (Biolegend) in 24 well tissue culture plates, followed by addition of PMA / Ionomycin (2 µL / mL Cell Stimulation Cocktail, eBioscience). To detect IFNγ produced by CD8+ T cells, these cells were incubated for 5 hours prior to harvesting and staining. After incubation, each well was pelleted by centrifugation, and the cell pellet was washed twice and resuspended in cold cell staining buffer (Biolegend). LIVE / DEAD Fixable Violet Dead Cell Stain Kit (Thermo Fisher) was added to pelleted cells and stained for 15 minutes at 4 °C. For the T cell cytokine panel, cells were then stained with cell surface antibodies for flow cytometry analysis: CD45 BV510 (Biolegend, clone 30-F11), CD4 BV711 (Biolegend, clone GK1.5), CD8 PE (Biolegend, clone 53-6.7), CD3 BV605 (Biolegend, clone 17A2), CD107a AF700 (Biolegend, clone 1D4B) and CCR9 APC (Thermo Fisher Scientific, clone eBioCW-1.2 (CW-1.2)). To quantify IFNγ produced by T cells, following cell surface marker staining, cells were then permeabilized and fixed using a fixation / permeabilization kit (BD Biosciences). Following permeabilization, for IFNγ production, cells were stained with IFNγPE-Cy7 (Biolegend, clone XMG1.2) for 15 minutes at 4 °C in the dark. Flow cytometry was performed on a BD LSR Fortessa flow cytometer in the UF ICBR (RRID:SCR_019119, BD Biosciences) and analyzed using FlowJo software version 10.6.1.

[0108] Kaplan-Meier survival analysis showed that mice from the anti-PD-1 plus Bac419 treatment group were the most likely to survive overall with n=7 mice surviving to endpoint, while only n=4 mice from the isotype plus saline treatment group survived (Fig.5B). Weekly bioluminescent imaging showed that isotype plus saline treated mice had the highest total and chest region bioluminescent signal at endpoint, while anti-PD-1 plus Bac419 treated mice had the lowest total and chest region bioluminescent signal at endpoint Fig.5C and 5D). Isotype plus saline treated mice had the highest number of tumor nodules in their lungs at endpoint, while anti-PD-1 plus Bac419 treated mice had the lowest number of tumor nodules. Lastly, immune flow cytometric analysis of portions of resected tumor from each group showed that mice treated with anti-PD-1 and Bac419 had the highest frequency of tumor-infiltrating IFNγ+ CD8+ T cells (Fig.5E).

[0109] Thus, Example 7 shows promising trends in survival, tumor growth prevention, and immune infiltration using compounds of the disclosure.

Claims

What is claimed is:

1. A composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing:wherein: X is selected from O, S, or NH; R1is selected from H, C1-10alkyl, -(CH2CH2O)nCH3, and -(CH2CH2O)nH; R2is selected from H, -(CH2)r-CH3, -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3, -(CH2)r- (CH)(OR3)-(CH2)r1-CH3, -(CH2)r-Q,Q is selected from OH, OR3, NR32, SR3, Se, C(O)OH; C(O)NR32, C(O)OR3; NH3, and NH-C(NH2)NH2; each Rxis independently selected from -OH, -SH, -NR32, C1-10alkyl, -OC1-10alkyl, - (CH2CH2O)nCH3, and -(CH2CH2O)nH; each R3is independently H or C1-10alkyl; each n is independently an integer from 1 to 30; m is 0, 1, 2, 3, 4, or 5; q is 0, 1, 2, 3, or 4; t is 0, 1, 2, or 3; each of r, r1, r2, and r3 are independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and R4is selected from hydrogen and methyl; with the provisos that in Formula (I) and Formula (II), when R2ism is 0, r is 1, and R4is hydrogen, then X-R1 is not O-H and in Formula (I) and Formula (II) when R2is -(CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3, r1 is 1, r2 is 0, r3 is 0, and R4is hydrogen, then X-R1is not O-H.

2. The composition of claim 1, comprising a compound having a structure according to Formula (I) or a pharmaceutically acceptable salt thereof.

3. The composition of claim 2, further comprising a compound having a structure according to Formula (II) or a pharmaceutically acceptable salt thereof.

4. The composition of any one of claims 1 to 3, comprising a compound having a structure according to Formula (III) or a pharmaceutically acceptable salt thereof.

5. The composition of any one of claims 1 to 3, comprising a compound having a structure according to Formula (IV) or a pharmaceutically acceptable salt thereof.

6. The composition of any one of claims 1 to 5, wherein X is O or NH.

7. The composition of any one of claims 1 to 6, wherein X is O.

8. The composition of any one of claims 1 to 6, wherein X is NH.

9. The composition of any one of claims 1 to 8, wherein R1is H.

10. The composition of any one of claims 1 to 8, wherein R1is C1-10alkyl, C1-4alkyl, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, or t-butyl.

11. The composition of any one of claims 1 to 8, wherein R1is -(CH2CH2O)nCH3, or -(CH2CH2O)nH.

12. The composition of any one of claims 1 to 11, wherein each n is independently an integer from 1 to 25, 1 to 20, 1 to 15, 1 to 10, 1 to 8, 2 to 6, or 3 to 4.

13. The composition of any one of claims 1 to 12, wherein R2is selected from H, - (14. The composition of any one of claims 1 to 13, wherein R2is H.

15. The composition of any one of claims 1 to 13, wherein R2is -(CH2)r-CH3, and r is 0, 1, 2, 3, 4, or 5.

16. The composition of any one of claims 1 to 13, wherein R2is - (CH2)r1(CH)((CH2)r2CH3)-(CH2)r3-CH3, wherein r1 is 0, 1, 2, 3, 4, or 5, r2 is 0, 1, 2, 3, 4, or 5, and r3 is 0, 1, 2, 3, 4, or 5.

17. The composition of any one of claims 1 to 13, wherein R2is -(CH2)r- (CH)(OR3)-(CH2)r1-CH3, wherein r is 0, 1, 2, 3, 4, or 5, and r1 is 0, 1, 2, 3, 4, or 5.

18. The composition of any one of claims 1 to 13, wherein R2is,19. The composition of any one of claims 1 to 13, wherein R2is.

20. The composition of any one of claims 1 to 12, wherein R2is selected from ,21. The composition of any one of claims 1 to 12 or 20, wherein R2is22. The composition of any one of claims 1 to 12 or 20, wherein R2is23. The composition of any one of claims 1 to 12 or 20, wherein R2is.

24. The composition of any one of claims 1 to 12 or 20, wherein R2is.

25. The composition of claim 24, wherein r is 1.

26. The composition of any one of claims 1 to 12 or 20, wherein R2is, for example, or .

27. The composition of any one of claims 1 to 12 or 20, wherein R2is.

28. The composition of any one of claims 1 to 12 or 20, wherein R2is -(CH2)r-Q.

29. The composition of claim 28, wherein r is 1, 2, 3, 4, or 5 and Q is selected from -OH, -OR3, -NR32, -SR3, -Se, -C(O)OH, -C(O)NR32, and -C(O)OR3.

30. The composition of claim 29, wherein Q is -NR32 and r is 4.

31. The composition of any one of claims 1 to 29, wherein each Rxis independently selected from -OH, -NR32, -C1-4alkyl, -OC1-4alkyl, -(CH2CH2O)nCH3, and - (CH2CH2O)nH.

32. The composition of any one of claims 1 to 31, wherein each R3is independently C1-4alkyl.

33. The composition of any one of claims 1 to 31, wherein each R3is independently H.

34. The composition of any one of claims 1 to 32, wherein m is 0, 1, 2, or 3.

35. The composition of any one of claims 1 to 34, wherein q is 0, 1, or 2.

36. The composition of any one of claims 1 to 35, wherein t is 0, 1, or 2.

37. The composition of any one of claims 1 to 36, wherein each of r, r1, r2, and r3 are independently 0, 1, 2, 3, or 4.

38. The composition of any one of claims 1 to 37, wherein R4is H.

39. The composition of any one of claims 1 to 37, wherein R4is methyl.

40. The composition of any one of claims 1 to 37, wherein the composition is an aqueous composition.

41. The composition of any one of claims 1 to 40, further comprising a pharmaceutically acceptable carrier.

42. The composition of any one of claims 1 to 41, wherein the composition comprises a compound having a structure selected from the group of:and a combination of the foregoing.

43. The composition of any one of claims 1 to 41, wherein the composition comprises a compound having a structure selected from the group of: (( ( ( ( ( ( ( (and a combination of the foregoing.

44. The composition of any one of claims 1 to 41, wherein the composition comprises a compound having a structure selected from the group of:and a combination of the foregoing.

45. The composition of any one of claims 1 to 41, wherein the composition comprises a compound having a structure selected from the group of:and a combination of the foregoing.

46. Use in the manufacture of a medicament for increasing interferon gamma (IFNγ) secretion in a subject of a composition according to any one of claims 1 to 42.

47. Use in the manufacture of a medicament for treating cancer of a composition according to any one of claim 1 to 42.

48. A method for increasing interferon gamma (IFNγ) secretion in a subject, the method comprising administering to the subject a composition according to any one of claims 1 to 42.

49. The method of claim 48, wherein the subject is a mammal, optionally a human.

50. The method of claim 48 or claim 39, wherein the administration comprises oral administration.

51. The method of claim 48 or 49, wherein the administration comprises parenteral administration.

52. The method of any one of claims 48 to 51, wherein the composition is an aqueous composition.

53. The method of any one of claims 48 to 52, wherein the subject has or is suspected of having cancer.

54. The method of claim 53, wherein the cancer is selected from acute lymphocytic cancer, acute myeloid leukemia, alveolar rhabdomyosarcoma, bone cancer, brain cancer (e.g., glioma), breast cancer (e.g., triple negative breast cancer), cancer of the anus, anal canal, or anorectum, cancer of the eye, cancer of the intrahepatic bile duct, cancer of the joints, cancer of the head, neck, gallbladder, or pleura, cancer of the nose, nasal cavity, or middle ear, cancer of the oral cavity, cancer of the vulva, chronic lymphocytic leukemia, chronic myeloid cancer, colon cancer, esophageal cancer, cervical cancer, gastrointestinal cancer (e.g., gastrointestinal carcinoid tumor), Hodgkin lymphoma, endometrial or hepatocellular carcinoma, hypopharynx cancer, kidney cancer, larynx cancer, liver cancer, lung cancer (e.g., non-small cell lung cancer, bronchioloalveolar carcinoma),malignant mesothelioma, melanoma, multiple myeloma, nasopharynx cancer, non-Hodgkin lymphoma, ovarian cancer, pancreatic cancer, peritoneum, omentum, and mesentery cancer, pharynx cancer, prostate cancer, rectal cancer, renal cancer (e.g., renal cell carcinoma (RCC)), small intestine cancer, soft tissue cancer, stomach cancer, testicular cancer, thyroid cancer, ureter cancer, urinary bladder cancer, and combinations of the foregoing.

55. The method of any one of claims 48 to 54, wherein the cancer is non-small cell lung carcinoma (NSCLC).

56. The method of any one of claims 48 to 55, further comprising administering an immune checkpoint inhibitor (ICI) to the subject.

57. The method of claim 56, wherein the ICI is administered concurrently with composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing.

58. The method of claim 56, wherein the ICI and the composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing, are administered step wise.

59. The method of any one of claims 56 to 58, wherein the ICI comprises an anti- PD-1 antibody, an anti-PD-L1 antibody, an anti-PD-L2 antibody, or a combination thereof.

60. A method for enhancing CD8 T-cell activation in a subject, the method comprising administering to the subject a composition according to any one of claims 1 to 42.

61. The method of claim 60, wherein the subject is a mammal, optionally a human.

62. The method of claim 60 or claim 51, wherein the administration comprises oral administration.

63. The method of claim 60 or 61, wherein the administration comprises parenteral administration.

64. The method of any one of claims 60 to 63, wherein the composition is an aqueous composition.

65. The method of any one of claims 60 to 64, wherein the subject has or is suspected of having cancer.

66. The method of claim 65, wherein the cancer is selected from acute lymphocytic cancer, acute myeloid leukemia, alveolar rhabdomyosarcoma, bone cancer, brain cancer (e.g., glioma), breast cancer (e.g., triple negative breast cancer), cancer of the anus, anal canal, or anorectum, cancer of the eye, cancer of the intrahepatic bile duct, cancer of the joints, cancer of the head, neck, gallbladder, or pleura, cancer of the nose, nasal cavity, or middle ear, cancer of the oral cavity, cancer of the vulva, chronic lymphocytic leukemia, chronic myeloid cancer, colon cancer, esophageal cancer, cervical cancer, gastrointestinal cancer (e.g., gastrointestinal carcinoid tumor), Hodgkin lymphoma, endometrial or hepatocellular carcinoma, hypopharynx cancer, kidney cancer, larynx cancer, liver cancer, lung cancer (e.g., non-small cell lung cancer, bronchioloalveolar carcinoma), malignant mesothelioma, melanoma, multiple myeloma, nasopharynx cancer, non-Hodgkin lymphoma, ovarian cancer, pancreatic cancer, peritoneum, omentum, and mesentery cancer, pharynx cancer, prostate cancer, rectal cancer, renal cancer (e.g., renal cell carcinoma (RCC)), small intestine cancer, soft tissue cancer, stomach cancer, testicular cancer, thyroid cancer, ureter cancer, urinary bladder cancer, and combinations of the foregoing.

67. The method of any one of claims 60 to 66, further comprising administering a chemotherapeutic agent to the subject.

68. The method of claim 67, wherein the chemotherapeutic agent is administered concurrently with composition comprising a compound having a structure according to Formula (I), Formula (II), a pharmaceutically acceptable salt of Formula (I) or Formula (II), or a combination of any of the foregoing.

69. The method of claim 67, wherein the chemotherapeutic agent and the composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing, are administered step wise.

70. The method of any one of claims 67 to 69, wherein the chemotherapeutic agent is selected from adriamycin, asparaginase, bleomycin, busulphan, cisplatin, carboplatin, carmustine, capecitabine, chlorambucil, cytarabine, cyclophosphamide, camptothecin, dacarbazine, dactinomycin, daunorubicin, dexrazoxane, docetaxel, doxorubicin, etoposide, floxuridine, fludarabine, fluorouracil, gemcitabine, hydroxyurea, idarubicin, ifosfamide, irinotecan, lomustine, mechlorethamine, mercaptopurine, meplhalan, methotrexate, mitomycin, mitotane, mitoxantrone, nitrosurea, paclitaxel, pamidronate, pentostatin, plicamycin, procarbazine, rituximab, streptozocin, teniposide, thioguanine,thiotepa, vinblastine, vincristine, vinorelbine, taxol, transplatinum, 5-fluorouracil, and a combination thereof.

71. A method for treating, ameliorating, or preventing cancer in a subject, the method comprising administering to the subject a composition according to any one of claims 1 to 42.

72. The method of claim 71, wherein the subject is a mammal, optionally a human.

73. The method of claim 71 or 72, wherein the administration comprises oral administration.

74. The method of claim 71 or 72, wherein the administration comprises parenteral administration.

75. The method of any one of claims 71 to 74, wherein the composition is an aqueous composition.

76. The method of any one of claims 71 to 75, wherein the cancer is selected from acute lymphocytic cancer, acute myeloid leukemia, alveolar rhabdomyosarcoma, bone cancer, brain cancer (e.g., glioma), breast cancer (e.g., triple negative breast cancer), cancer of the anus, anal canal, or anorectum, cancer of the eye, cancer of the intrahepatic bile duct, cancer of the joints, cancer of the head, neck, gallbladder, or pleura, cancer of the nose, nasal cavity, or middle ear, cancer of the oral cavity, cancer of the vulva, chronic lymphocytic leukemia, chronic myeloid cancer, colon cancer, esophageal cancer, cervical cancer, gastrointestinal cancer (e.g., gastrointestinal carcinoid tumor), Hodgkin lymphoma, endometrial or hepatocellular carcinoma, hypopharynx cancer, kidney cancer, larynx cancer, liver cancer, lung cancer (e.g., non-small cell lung cancer, bronchioloalveolar carcinoma), malignant mesothelioma, melanoma, multiple myeloma, nasopharynx cancer, non-Hodgkin lymphoma, ovarian cancer, pancreatic cancer, peritoneum, omentum, and mesentery cancer, pharynx cancer, prostate cancer, rectal cancer, renal cancer (e.g., renal cell carcinoma (RCC)), small intestine cancer, soft tissue cancer, stomach cancer, testicular cancer, thyroid cancer, ureter cancer, urinary bladder cancer, and combinations of the foregoing.

77. The method of any one of claims 71 to 76, wherein the cancer is non-small cell lung carcinoma (NSCLC).

78. The method of any one of claims 71 to 77, further comprising administering an immune checkpoint inhibitor (ICI), chemotherapeutic agent, or combination thereof to the subject.

79. The method of claim 78, wherein the ICI or chemotherapeutic agent is administered concurrently with composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV),a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing.

80. The method of claim 78, wherein the ICI or chemotherapeutic agent and the composition comprising a compound having a structure according to Formula (I), Formula (II), Formula (III), or Formula (IV), a pharmaceutically acceptable salt of Formula (I), Formula (II), Formula (III), or Formula (IV), or a combination of any of the foregoing, are administered step wise.

81. The method of any one of claims 78 to 80, wherein the ICI comprises an anti- PD-1 antibody, anti-PD-L1 antibody, anti-PD-L2 antibody, or a combination thereof.

82. The method of any one of claims 78 to 81, wherein after the administration of the composition, interferon gamma (IFNγ) secretion is increased in the subject relative to IFNγ secretion before the administration.

83. The method of any one of claims 78 to 82, wherein the chemotherapeutic agent is selected from adriamycin, asparaginase, bleomycin, busulphan, cisplatin, carboplatin, carmustine, capecitabine, chlorambucil, cytarabine, cyclophosphamide, camptothecin, dacarbazine, dactinomycin, daunorubicin, dexrazoxane, docetaxel, doxorubicin, etoposide, floxuridine, fludarabine, fluorouracil, gemcitabine, hydroxyurea, idarubicin, ifosfamide, irinotecan, lomustine, mechlorethamine, mercaptopurine, meplhalan, methotrexate, mitomycin, mitotane, mitoxantrone, nitrosurea, paclitaxel, pamidronate, pentostatin, plicamycin, procarbazine, rituximab, streptozocin, teniposide, thioguanine, thiotepa, vinblastine, vincristine, vinorelbine, taxol, transplatinum, 5-fluorouracil, and a combination thereof.

84. The method of any one of claims 78 to 83, wherein after the administration of the compositions, CD8 T-cell activity is increased in the subject relative to CD8 T-cell activity before the administration.

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