STING-targeted precursor compound, nuclide marker, preparation method and application of nuclide marker, pharmaceutical composition and application of pharmaceutical composition

Abstract

The invention relates to the technical field of radiopharmaceuticals and medical imaging, in particular to an STING-targeted precursor compound, a nuclide marker, a preparation method and application of the STING-targeted precursor compound, a nuclide marker, a pharmaceutical composition and application of the pharmaceutical composition. The STING targeting precursor compound, the pharmaceutically acceptable form of the STING targeting precursor compound, the nuclide marker of the STING targeting precursor compound and the pharmaceutically acceptable form of the STING targeting precursor compound have excellent in-vivo biological performance, can have high specific uptake in tumors or inflammations with high expression of interferon stimulating factors STING, has a high target-to-non-target ratio, and can be used for preparing the target-to-non-target tumor marker of the STING targeting precursor compound and the nuclide marker of the STING targeting precursor compound and the pharmaceutically acceptable form of the STING targeting precursor compound and the nuclide marker of the STING targeting precursor compound. And the non-specific background is low, and unnecessary radioactive injury can be reduced by lower non-target visceral organ uptake, so that the medication safety is high.

Description

A STING-targeting precursor compound, a radionuclide marker, its preparation method and application, and a pharmaceutical composition and its application. Technical Field

[0001] This invention relates to the fields of radiopharmaceuticals and medical imaging technology, specifically to a STING-targeting precursor compound, a radionuclide marker, its preparation method, and its application. Background Technology

[0002] Stimulator of interferon genes (STING) is an important adaptor protein mainly located on the endoplasmic reticulum membrane. When abnormal DNA from bacteria, tumor cells, or other sources enters the host body, it is sensed by the intracellular nucleic acid sensor cGAS and activated, inducing the production of type I interferon and various pro-inflammatory cytokines.

[0003] Studies have shown that the STING pathway plays a crucial role in anti-tumor immunity and inflammatory responses. Besides directly mediating tumor cell killing, STING activation can induce the production of type I interferon, enhance the antigen-presenting capacity of dendritic cells and natural killer cells, thereby promoting tumor-specific T cell responses, initiating acquired immune responses, and ultimately mediating tumor cell clearance and prolonging patient survival. Furthermore, STING also plays a key role in the regulation of inflammatory responses and is considered an important marker of early inflammation. Short-term STING activation helps enhance the anti-infection capabilities of innate immune cells and accelerate pathogen clearance. However, chronic or excessive activation of STING may lead to persistent inflammation and tissue damage, increasing the risk of tumorigenesis. For example, persistent STING signaling may induce the accumulation of immunosuppressive cells, weakening anti-tumor immune responses. Therefore, the STING pathway has a dual role in tumor immunotherapy, and its targeted regulation strategy needs to be precisely designed based on specific tumor types and patient immune status to optimize treatment efficacy and reduce potential side effects.

[0004] Traditional detection methods, such as immunohistochemistry (IHC), are susceptible to tumor heterogeneity and are insufficient for assessing overall STING levels. Positron emission tomography (PET), however, offers higher sensitivity and spatial resolution and allows for real-time quantitative analysis, potentially overcoming the limitations of current STING protein detection methods. Current molecular imaging probes targeting STING proteins primarily focus on the development of small-molecule agonists and inhibitors, such as […]. 18 F]F-DABI, [ 18 F]F-CRIn, [ 18F]FBTA and other probes have demonstrated good STING protein targeting performance, confirming the feasibility of visualizing STING protein expression in vivo. However, PET imaging results show that the above probes exhibit high levels of non-specific uptake in the liver, intestines, and gallbladder, which limits their clinical application to some extent. Summary of the Invention

[0005] Therefore, the present invention aims to provide a STING-targeting precursor compound, a radionuclide marker, a method for preparing the same and its application, a pharmaceutical composition, and its application. The STING receptor-targeting molecular compound provided by the present invention exhibits high specific uptake in tumors or inflammations with high expression of the interferon-stimulating factor STING, a high target-to-non-target ratio, and low non-specific background.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: The present invention provides a STING targeting precursor compound having the structure shown in Formula I, Formula II, or Formula III: Wherein, R1 includes -OH or -NH2; R2 and R3 independently include -H, -OH, -NH2, -CH3, -CH2OH, -CH(CH3)OH, -CH2CH(CH3)2, -CH(CH3)2, -CH(CH3)CH2CH3 or any one of the following structures: R4 is a labeling group, including any of the following structures: L1 includes any of the following structures: Either end of L1 is connected to A1; L2 and L3 independently include any of the following structures: The -NH- terminal of L2 is connected to A2, and the -NH- terminal of L3 is connected to A3; A1, A2, and A3 independently include formula A a Formula A b Or it may not exist; the formula A is not mentioned. a Includes one or any combination of the following structures: The -NH- end in formula Aa is connected to R4; the formula A b Includes any of the following structures: Formula A b The acid end in the middle is connected to L1, L2 or L3, formula A bThe other end is connected to R4; A b In line -1, the C=O end of Aa is connected to either end of L1, and the other end of Aa is connected to R4; A b In line -2, one end of L1 is connected to the C=O end of Aa, and the other end of L1 is connected to R4; A b In equation -3, either end of L1 is connected to squaric acid, and the other end of L1 is connected to R4; j, r, x, y, n, t, q, and m are independent integers between 1 and 5; the formula A b L1 in equation A is the same as L1 in equation I. b A in a With the above formula A a Same; the pharmaceutically acceptable forms include one or more of the following: salt, stereoisomer, racemate, hydrate, and solvate.

[0007] This invention also provides a method for preparing the STING targeted precursor compound described above, comprising the following steps: coupling a cyclic peptide compound with an R4 active compound to obtain the STING targeted precursor compound; wherein the cyclic peptide compound has any one of the following structures: The structure of the R4 active compound includes any one of the following structures: .

[0008] This invention also provides a method for preparing the STING targeted precursor compound described in the above technical solution, wherein A1, A2, and A3 are all of formula A b The preparation method includes the following steps: mixing a cyclic peptide compound with A b The -R4 derivative undergoes a coupling reaction to obtain the STING-targeting precursor compound; the cyclic peptide compound has any one of the following structures: The A b -R4 derivatives include any of the following structures: .

[0009] The present invention also provides pharmaceutically acceptable forms of the STING targeted precursor compounds described in the above technical solutions, wherein the pharmaceutically acceptable forms include one or more of salts, stereoisomers, racemates, hydrates, and solvates.

[0010] The present invention also provides a STING-targeted nuclide marker having the structure shown in Formula IV, Formula V or Formula VI: The R1~R3, L1~L3, and A1~A3 in Formulas IV, V, and VI are the same as the R1~R3, L1~L3, and A1~A3 in the STING targeted precursor compound described in the above technical solution. R5 is obtained by radionuclide labeling of R4 in the STING targeted precursor compound. The radionuclides include... 18 F, 43 Sc、 44 Sc、 47 Sc、 51 Cr 55 Co、 57 Co、 62 Cu、 64 Cu、 67 Cu、 67 Ga、 68 Ga、 72 As、 72 Se、 89 Zr、 86 Y、 89 Sr, 86 Y、 90 Y、 97 Ru、 99m Tc, 105 Rh、 101m Rh、 109 Pd, 111 In、 123 I, 124 I, 125 I, 131 I, 119 Sb、 128 Ba、 139 La、 140 La、 142 Pr、 149 Pm, 149 Tb, 151 Tb, 151 Eu、 153 Eu、 169 Eu、 153 Sm、 152 Gd, 153 Gd, 157 Gd, 159 Gd, 161 Tb, 165 Dy、 166 Ho、 169 Er、 175 Yb、 177 Lu、 186 Re、 188 Re、 197 Hg, 198 Au、 201 Tl、203 Pb, 211 At、 212 Pb, 212 Bi、 213 Bi、 223 Ra、 227 Th and 225 At least one of Ac.

[0011] The present invention also provides a method for preparing the STING-targeted radionuclide marker described in the above technical solution, comprising the following steps: coordinating the STING-targeting substance with a radionuclide to obtain the STING-targeted radionuclide marker; wherein the STING-targeting substance is the STING-targeting precursor compound described in the above technical solution and / or a pharmaceutically acceptable form of the STING-targeting precursor compound described in the above technical solution.

[0012] The present invention also provides pharmaceutically acceptable forms of the STING targeted radionuclide markers described above, wherein the pharmaceutically acceptable forms include salts, stereoisomers, racemates, hydrates, and solvates.

[0013] The present invention also provides a pharmaceutical composition comprising an active ingredient and a pharmaceutically acceptable excipient; the active ingredient comprising at least one of the following: the STING-targeting prodrug compound described in the above-described technical solution, the pharmaceutically acceptable form of the STING-targeting prodrug compound described in the above-described technical solution, the STING-targeting radionuclide marker described in the above-described technical solution, and the pharmaceutically acceptable form of the STING-targeting radionuclide marker described in the above-described technical solution.

[0014] Preferably, the pharmaceutical composition further includes a STING agonist and / or an immune checkpoint inhibitor.

[0015] The present invention also provides the STING-targeting precursor compound described in the above-described technical solutions, a pharmaceutically acceptable form of the STING-targeting precursor compound described in the above-described technical solutions, the STING-targeting radionuclide marker described in the above-described technical solutions, a pharmaceutically acceptable form of the STING-targeting radionuclide marker described in the above-described technical solutions, and the use of the pharmaceutical composition described in the above-described technical solutions in the preparation of therapeutic drugs or diagnostic reagents for STING-mediated diseases.

[0016] The STING-targeting compound provided by this invention consists of a cyclic peptide main structure (targeting group), linkers (L1-A1, L2-A2, or L3-A3), and a coordinating group (R4) linked in a specific chemical form. This invention uses an interferon-stimulating factor-targeting cyclic peptide as the main structure. Compared to linear peptides, cyclic peptides have higher conformational rigidity, making them more stable when binding to the receptor STING, thereby improving target affinity and selectivity. Based on this, various amino acids are introduced for site-specific modification between the targeting group and the coordinating group, and alkyl chains, polyethylene glycol, and other linkers are introduced. Through site-specific modification of amino acids and different linkers, structural modification and optimization can be carried out, which can regulate the physicochemical properties of STING targeted precursor compounds and STING targeted radionuclide markers (probes), such as lipophilicity, in vivo distribution, charge, and spatial configuration. This improves the in vivo pharmacokinetic properties of STING targeted precursor compounds and STING targeted radionuclide markers, accelerates the clearance rate of STING targeted precursor compounds and STING targeted radionuclide markers in non-target tissues, increases the target / non-target ratio, enhances the affinity between ligands and receptors, and improves the uptake of the labeled complex at the disease site, resulting in clearer imaging. By improving imaging quality, better diagnostic results are achieved. The STING targeted precursor compounds and STING targeted radionuclide markers provided by this invention, in addition to having the immunomodulatory and therapeutic effects of STING targeting, can also visualize the STING expression level through medical imaging methods and achieve targeted therapy of lesions through radionuclides, with a wide range of applications.

[0017] The STING targeted precursor compound provided by this invention has a ligand R4 that features strong labeling ability, short labeling time, and high labeling yield. R4 chelates with the radionuclide to form STING targeted radionuclide markers (targeted radionuclide probes, molecular imaging probes). STING targeted radionuclide markers have the characteristics of high affinity, high specificity, good stability, high sensitivity, excellent pharmacokinetic properties, high lesion uptake, and high target / non-target ratio. They can be used for labeling various diagnostic and therapeutic radionuclides and can also be used to construct diagnostic and therapeutic platforms based on diagnostic and therapeutic radionuclide pairs. They have great application prospects in the preparation of therapeutic drugs and / or diagnostic reagents for STING protein-mediated diseases, which is conducive to the application and clinical promotion of radionuclide-labeled probes.

[0018] The STING-targeting prodrugs and their pharmaceutically acceptable forms, as well as the STING-targeting radionuclide markers and their pharmaceutically acceptable forms, provided by this invention, all exhibit excellent in vivo biological properties. They demonstrate high specific uptake in tumors or inflammations with high expression of the interferon-stimulating factor STING, a high target-to-non-target ratio, low non-specific background, and reduced uptake in non-target organs, thus minimizing unnecessary radiation damage. The prodrugs and radionuclide markers provided by this invention not only possess excellent in vivo pharmacokinetic properties but also maintain tumor selective targeting, potentially providing comprehensive and accurate imaging evidence for the precise diagnosis and treatment of STING-related immunotherapies; they can also be combined with therapeutic radionuclides such as... 177 Lu has a wide range of applications in radionuclide therapy, as well as in tumor immunotherapy using STING-targeted radionuclide markers in combination with STING agonists and other immune checkpoint inhibitors. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 shows the mass spectrum of FND-001; Figure 2 shows the mass spectrum of FND-201; Figure 3 shows the mass spectrum of FTD-001; Figure 4 shows the mass spectrum of FTN-001; Figure 5 shows the mass spectrum of FTD-303; Figure 6 shows the mass spectrum of FTN-302; Figure 7 shows the HPLC identification spectra of FND-001, FND-201, FTD-001, and FTD-303; Figure 8 shows the HPLC identification spectra of FTN-001 and FTN-302; Figure 9 shows... 68 Ga]Ga-FND-001 and [ 68 The HPLC identification chromatogram of Ga]Ga-FND-201; Figure 10 shows [ 68 Ga]Ga-FTD-001 and [ 68 The HPLC identification chromatogram of Ga-FTD-303 is shown in Figure 11. 18 F]AlF-FTN-001 and [ 18 HPLC identification chromatogram of F]AlF-FTN-302; Figure 12 shows [ 68 Figure 13 shows the in vitro stability test results of Ga-FND-001; 68 Figure 14 shows the in vitro stability test results of Ga-FND-201; 68Figure 15 shows the in vitro stability test results of Ga-FTD-001; 68 Figure 16 shows the in vitro stability test results of Ga-FTD-303; 18 Figure 17 shows the in vitro stability test results of F]AlF-FTN-001; 18 Figure 18 shows the in vitro stability test results of [F]AlF-FTN-302; 68 Uptake and inhibition assays of Ga-FTD-001 in Raw 264.7 cells and IC50 assays 50 Data; Figure 19 shows [ 68 Uptake and inhibition assays of Ga-FTD-303 in Raw 264.7 cells and IC50 assays 50 Data; Figure 20 shows [ 18 F]AlF-FTN-001 and [ 18 [F]AlF-FTN-302 uptake and inhibition experiments in Raw 264.7 cells; Figure 21 shows [ 68 Protein binding data for Ga-FTD-303; Figure 22 shows [ 68 Ga]Ga-FTD-001 and [ 68 Ga-FTD-303 microPET imaging in a B16F10 tumor-bearing mouse model, with uptake data from major organs; Figure 23 shows [Ga-FTD-303]. 68 Ga]Ga-FTD-001 and [ 68 Ga]Ga-FTD-303 biodistribution, target / non-target ratio, and hematogenous uptake-time clearance curve in a B16F10 tumor-bearing mouse model 60 min after injection; Figure 24 shows [Ga-FTD-303 biodistribution, target / non-target ratio, and hematogenous uptake-time clearance curve; 18 F]AlF-FTN-001 and [ 18 Biodistribution of F]AlF-FTN-302 in B16F10 tumor-bearing mouse model 60 min after injection, and target / non-target ratio. Detailed Implementation

[0021] This invention provides a STING-targeting precursor compound having the structure shown in Formula I, Formula II, or Formula III: Wherein, R1, R2, and R3 are amino acid residues, and L1, L2, L3, A1, A2, and A3 are linking groups; R1 includes -OH or -NH2; R2 and R3 independently include -H, -OH, -NH2, -CH3, -CH2OH, -CH(CH3)OH, -CH2CH(CH3)2, -CH(CH3)2, -CH(CH3)CH2CH3, or any one of the following structures: R4 is a labeling group, including any of the following structures: L1 includes any of the following structures: Either end of L1 is connected to A1; L2 and L3 independently include any of the following structures: The -NH- terminal of L2 is connected to A2, and the -NH- terminal of L3 is connected to A3; A1, A2, and A3 independently include formula A a Formula A b Or it may not exist; the formula A is not mentioned. a Includes one or any combination of the following structures: The -NH- end in formula Aa is connected to R4; the formula A b Includes any of the following structures: Formula A b The acid end in the middle is connected to L1, L2 or L3, formula A b The other end is connected to R4; A b In line -1, the C=O end of Aa is connected to either end of L1, and the other end of Aa is connected to R4; A b In line -2, one end of L1 is connected to the C=O end of Aa, and the other end of L1 is connected to R4; A b In equation -3, either end of L1 is connected to squaric acid, and the other end of L1 is connected to R4; j, r, x, y, n, t, q, and m are independent integers between 1 and 5; the formula A b L1 in equation A is the same as L1 in equation I. b A in a With the above formula A a Same; the pharmaceutically acceptable forms include one or more of the following: salt, stereoisomer, racemate, hydrate, and solvate.

[0022] In this invention, the STING-targeting precursor compound may include any of the following structures: FSD-002; FND-001; FND-201; FTD-001; FTD-301; FTD-303; FTD-304; FTD-305; FTN-001; FTN-302.

[0023] Table 1 STING-targeted precursor compounds

[0024] This invention uses an interferon-stimulating factor-targeting cyclic peptide as the main structure, and further modifies and optimizes the structure, followed by radionuclide labeling, to obtain a molecular imaging probe with excellent performance and suitable in vivo pharmacokinetic properties. The STING-targeting prodrug compound provided by this invention has ligands with strong labeling ability, short labeling time, and high labeling yield, which is beneficial for commercial application and clinical promotion.

[0025] This invention also provides a method for preparing the STING targeted precursor compound described in the above technical solution (hereinafter referred to as Method 1), comprising the following steps: coupling a cyclic peptide compound with an R4 active compound to obtain the STING targeted precursor compound; the cyclic peptide compound having any one of the following structures: The structure of the R4 active compound includes any one of the following structures: .

[0026] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0027] In this invention, the molar ratio of the cyclic peptide compound to the R4 active compound can be 1:0.5~20, or 1:1~5, specifically 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, or 1:20. This invention does not have a specific limitation on the source of the cyclic peptide compound; commercially available products well known to those skilled in the art or methods for preparing cyclic peptide compounds well known to those skilled in the art can be used. The R4 active compound used in this invention has an activated ester group, an anhydride group, or an isothiocyanate group.

[0028] In this invention, the coupling reaction is carried out in the presence of an organic base and an organic solvent. Specifically, the cyclic peptide compound, the R4 active compound, the organic base, and the organic solvent are mixed to carry out the coupling reaction.

[0029] In this invention, the organic base may include N,N-diisopropylethylamine (DIPEA) and / or triethylamine (TEA). In this invention, the molar ratio of the cyclic peptide compound to the organic base may be 1:0.5~20, or 1:1.5~5, specifically 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, or 1:20.

[0030] In this invention, the organic solvent may include one or more of amide solvents, dimethyl sulfoxide, and lower alcohols, specifically one or more of N,N-dimethylformamide, dimethyl sulfoxide, and ethanol. This application does not have a specific limitation on the amount of the organic solvent used, as long as it is sufficient to ensure the smooth progress of the coupling reaction. Specifically, it may be 5-100 mg / mL, or 10-50 mg / mL, specifically 5 mg / mL, 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 60 mg / mL, 70 mg / mL, 80 mg / mL, 90 mg / mL, or 100 mg / mL.

[0031] In this invention, the temperature of the coupling reaction can be 10~100℃, or 20~50℃, specifically 10℃, 20℃, 25℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃ or 100℃; the time of the coupling reaction can be 10min~24h, or 2~10h, specifically 10min, 0.5h, 1h, 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h or 24h.

[0032] After completing the coupling reaction, the present invention may further include: adding acid to the reaction solution obtained from the coupling reaction to neutralize it to a pH of 7.4, and then performing high-performance liquid chromatography purification to obtain the STING targeted precursor compound. In the present invention, the acid may include dilute hydrochloric acid, and the concentration of the dilute hydrochloric acid may be 0.01~1 mol / L, or 0.05~0.5 mol / L, or further 0.1~0.3 mol / L, specifically 0.1 mol / L or 0.2 mol / L. In this invention, the conditions for high-performance liquid chromatography (HPLC) purification may include: a semi-preparative C18 reversed-phase column; a mobile phase system comprising mobile phase A and mobile phase B, wherein mobile phase A may be 0.1 vol% trifluoroacetic acid-acetonitrile, and mobile phase B may be 0.1 vol% trifluoroacetic acid-water; the elution method is gradient elution; the gradient elution program includes: 0-30 min, wherein the volume fraction of mobile phase B linearly decreases from 95% to 5%; the mobile phase flow rate is 3-10 mL / min, and may also be 4-8 min, and may further be 5-6 min; the HPLC purification may include semi-preparative HPLC purification.

[0033] In this invention, when A1, A2, and A3 are all of formula A b The preparation method (referred to as method 2) includes the following steps: mixing the cyclic peptide compound with A b The -R4 derivative was coupled to obtain the STING targeting precursor compound; the cyclic peptide compound was the same as in method 1; the A b -R4 derivatives include any of the following structures: .

[0034] In this invention, the molar ratio of the cyclic peptide compound to the R4 active compound can be 1:0.5~20, or 1:1~5, specifically 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18 or 1:20.

[0035] In this invention, the coupling reaction can be carried out in the presence of a solvent. Specifically, the cyclic peptide compound and A are... b The -R4 derivative is mixed with a solvent to carry out a coupling reaction. In this invention, the solvent may include a phosphate buffer solution with a pH value of 7.4-7.8 or 7.4-7.6; the concentration of the phosphate buffer solution may be 0.01-0.05 mol / L, 0.02-0.04 mol / L, or even 0.03 mol / L.

[0036] In this invention, the temperature and time of the coupling reaction are the same as in method 2, and will not be repeated here.

[0037] After completing the coupling reaction, the present invention may further include: purifying the reaction solution obtained from the coupling reaction by high-performance liquid chromatography (HPLC) to obtain the STING targeted precursor compound. In this invention, the HPLC purification conditions are the same as in Method 1, and will not be repeated here.

[0038] This invention also provides pharmaceutically acceptable forms of the STING targeted precursor compounds described above. These pharmaceutically acceptable forms may include salts, stereoisomers, racemates, hydrates, and solvates. In this invention, the salts may include trifluoroacetate, phosphate, hydrochloride, ammonium salt, formate, acetate, potassium salt, or sodium salt. This invention does not specifically limit the preparation method of the pharmaceutically acceptable forms of the STING targeted precursor compounds; any preparation method well-known to those skilled in the art for each pharmaceutically acceptable form may be used.

[0039] The present invention also provides a STING-targeted nuclide marker having the structure shown in Formula IV, Formula V or Formula VI: R1~R3, L1~L3 and A1~A3 in Formulas IV, V and VI are the same as R1~R3, L1~L3 and A1~A3 in the STING targeting precursor compound described in the above technical solution, and R5 is obtained by radionuclide labeling of R4 in the STING targeting precursor compound.

[0040] In this invention, the nuclide includes 18 F, 43 Sc、 44 Sc、 47 Sc、 51 Cr 55 Co、 57 Co、 62 Cu、 64 Cu、 67 Cu、 67 Ga、 68 Ga、 72 As、 72 Se、 89 Zr、 86 Y、 89 Sr, 86 Y、 90 Y、 97 Ru、 99m Tc, 105 Rh、 101m Rh、 109 Pd, 111 In、 123 I, 124 I,125 I, 131 I, 119 Sb、 128 Ba、 139 La、 140 La、 142 Pr、 149 Pm, 149 Tb, 151 Tb, 151 Eu、 153 Eu、 169 Eu、 153 Sm、 152 Gd, 153 Gd, 157 Gd, 159 Gd, 161 Tb, 165 Dy、 166 Ho、 169 Er、 175 Yb、 177 Lu、 186 Re、 188 Re、 197 Hg, 198 Au、 201 Tl、 203 Pb, 211 At、 212 Pb, 212 Bi、 213 Bi、 223 Ra、 227 Th and 225 At least one of Ac.

[0041] The STING-targeting precursor compounds provided by this invention feature innovative molecular structures achieved through site-specific amino acid modification and linker regulation; and STING-targeting radionuclide markers are obtained through radionuclide labeling. In addition to their STING-targeting immunomodulatory and therapeutic effects, these precursor compounds and radionuclide markers can also visualize STING expression levels using medical imaging techniques and enable targeted therapy of lesions via radionuclides.

[0042] The STING targeted radionuclide markers provided by this invention introduce various amino acids, alkyl chains, polyethylene glycol, and other linkers between the targeting group and the coordinating group to regulate the physicochemical properties of the probe (lipid solubility, in vivo distribution, charge, and spatial configuration), thereby improving the in vivo pharmacokinetic properties of the marker. This includes accelerating the clearance rate of the marker in non-target tissues, increasing the target / non-target ratio, enhancing the affinity between the ligand and the receptor, and improving the uptake of the marker at the disease site, resulting in clearer imaging. By improving imaging quality, better diagnostic results are achieved, effectively expanding the application scope of STING targeted markers.

[0043] The STING-targeting precursor compounds and their radionuclide markers provided by this invention exhibit excellent in vivo biological properties. They demonstrate high specific uptake in tumors or inflammations with high expression of the interferon-stimulating factor STING, a high target-to-non-target ratio, low non-specific background, and reduced uptake in non-target organs, thus minimizing unnecessary radiation damage. They have wide applications, including not only for the diagnosis of tumors or inflammations but also for use in combination with therapeutic radionuclides such as... 177 Lu can be used for radionuclide therapy, or radionuclides can be used in combination with STING agonists and other immune checkpoint inhibitors for tumor immunotherapy.

[0044] The present invention also provides a method for preparing the STING-targeted radionuclide marker described in the above technical solution, comprising the following steps: coordinating the STING-targeting substance with a radionuclide to obtain the STING-targeted radionuclide marker; wherein the STING-targeting substance is the STING-targeting precursor compound described in the above technical solution and / or the pharmaceutically acceptable form of the STING-targeting precursor compound described in the above technical solution.

[0045] In this invention, the STING targeted radionuclide label can be prepared using a wet labeling method or a freeze-drying labeling method.

[0046] In this invention, the wet labeling method includes the following steps: dissolving the STING target substance in a solvent to obtain a STING target substance solution, mixing the STING target substance solution with a radionuclide solution, and performing a coordination reaction to obtain a STING target radionuclide label solution.

[0047] In this invention, the solvent includes an acetate solution, specifically an aqueous solution of sodium acetate and / or an aqueous solution of ammonium acetate; the concentration of the acetate solution can be 0.1~2 mol / L, or 0.5~1.5 mol / L, or even 1 mol / L. In this invention, the solvent in the radionuclide solution can include hydrochloric acid, the concentration of which can be 0.01~1 mol / L, or 0.05~0.5 mol / L, or even 0.1~0.3 mol / L, or specifically 0.1 mol / L or 0.2 mol / L.

[0048] In this invention, the ratio of the mass of the STING target material to the radioactivity of the nuclide can be 1µg:0.037~1GBq, or 1µg:0.1~0.5GBq, specifically 1µg:0.037GBq, 1µg:0.05GBq, 1µg:0.1GBq, 1µg:0.2GBq, 1µg:0.3GBq, 1µg:0.4GBq, 1µg:0.5GBq, 1µg:0.6GBq, 1µg:0.7GBq, 1µg:0.8GBq, 1µg:0.9GBq, or 1µg:1GBq.

[0049] In this invention, the temperature of the coordination reaction can be 20~150℃, or 80~100℃, specifically 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃ or 150℃; the time of the coordination reaction can be 10~30min, or 15~25min, specifically 20min.

[0050] After completing the coordination reaction, the present invention may further include: sampling the reaction solution obtained from the coordination reaction for HPLC analysis and identification; if the radiochemical purity is greater than 95%, no purification is required, and PBS or physiological saline can be added to dilute it to the required concentration of STING targeted radionuclide label solution; if the radiochemical purity is less than 95%, purification is performed to obtain the STING targeted radionuclide label solution. In the present invention, the purification may include C18 column purification, specifically Sep-Pak C18 separation column purification; the C18 column is activated sequentially with anhydrous ethanol and water before use; the C18 column purification includes first rinsing with water to remove unreacted radionuclides, then eluting with anhydrous ethanol, removing the ethanol from the resulting eluent to obtain the STING targeted radionuclide label solution; the ethanol removal method includes removing ethanol with a nitrogen gas flow.

[0051] In this invention, the lyophilization labeling method includes the following steps: dissolving the STING targeting substance in a solvent to obtain a STING targeting substance solution; dispensing the STING targeting substance solution into a lyophilization container, freezing-drying it, and then sealing it to obtain a lyophilized kit; adding a solvent to the lyophilized kit to dissolve the substance, then adding a radionuclide solution to perform a coordination reaction to obtain a STING targeting radionuclide labeled solution. In this invention, the preparation conditions for the lyophilization labeling method are the same as those for the wet labeling method, and will not be repeated here.

[0052] The present invention may add pharmaceutically acceptable excipients to the radionuclide-labeled probe solution obtained by the wet labeling method or the lyophilized kit as needed; the pharmaceutically acceptable excipients may include at least one of excipients, antioxidants, binders, buffers, colorants, diluents, disintegrants, emulsifiers, flavoring agents, flow aids, lubricants, preservatives, stabilizers, surfactants, tablets, and wetting agents; the present invention does not have a special limitation on the types of the above-mentioned pharmaceutically acceptable excipients, and pharmaceutically acceptable excipients well known to those skilled in the art can be used.

[0053] This invention also provides pharmaceutically acceptable forms of the STING targeted radionuclide markers described above. These pharmaceutically acceptable forms may include salts, stereoisomers, racemates, hydrates, and solvates. In this invention, the salts may include trifluoroacetate, phosphate, hydrochloride, ammonium salt, formate, acetate, potassium salt, or sodium salt. This invention does not specifically limit the preparation method of the pharmaceutically acceptable forms of the STING targeted radionuclide markers; any preparation method well-known to those skilled in the art for each pharmaceutically acceptable form may be used.

[0054] The present invention also provides a pharmaceutical composition comprising an active ingredient and a pharmaceutically acceptable excipient; the active ingredient comprising at least one of the following: the STING-targeting prodrug compound described in the above-described technical solution, a pharmaceutically acceptable form of the STING-targeting prodrug compound described in the above-described technical solution, the STING-targeting radionuclide marker described in the above-described technical solution, and a pharmaceutically acceptable form of the STING-targeting radionuclide marker described in the above-described technical solution.

[0055] In this invention, the pharmaceutical composition may further include a STING agonist and / or an immune checkpoint inhibitor. In this invention, the STING agonist may include one or more of diABZIs, MSA-2, SR-717, and ADU-S100. In this invention, the immune checkpoint inhibitor may include a PD-L1 inhibitor and / or a CTLA-4 inhibitor.

[0056] The present invention does not have a specific limitation on the mass percentage of the active component in the pharmaceutical composition; any content is acceptable.

[0057] In this invention, the pharmaceutically acceptable excipients may include at least one of the following: excipients, antioxidants, binders, buffers, colorants, diluents, disintegrants, emulsifiers, flavoring agents, glidants, lubricants, preservatives, stabilizers, surfactants, tableting agents, and wetting agents. This invention does not have any particular limitation on the types of the above-mentioned pharmaceutically acceptable excipients, and any pharmaceutically acceptable excipients well known to those skilled in the art may be used.

[0058] There are no particular limitations on the pharmaceutically acceptable excipients mentioned above. Any pharmaceutically acceptable excipients well known to those skilled in the art can be used. Specifically, they may include at least one of the following: excipients, antioxidants, binders, buffers, colorants, diluents, disintegrants, emulsifiers, flavoring agents, glidants, lubricants, preservatives, stabilizers, surfactants, tableting agents, and wetting agents.

[0059] This invention also provides the application of the STING-targeting prodrug compound described in the above-mentioned technical solutions, the pharmaceutically acceptable form of the STING-targeting prodrug compound described in the above-mentioned technical solutions, the STING-targeting radionuclide marker described in the above-mentioned technical solutions, and the pharmaceutically acceptable form of the STING-targeting radionuclide marker described in the above-mentioned technical solutions in the preparation of therapeutic drugs or diagnostic reagents for STING-mediated diseases. In this invention, the STING-mediated diseases include at least one of tumors and their metastases and inflammation; the tumors may include at least one of prostate cancer, breast cancer, ovarian cancer, liver cancer, lung cancer, colorectal cancer, bone sarcoma, connective tissue sarcoma, renal cell carcinoma, gastric cancer, pancreatic cancer, nasopharyngeal carcinoma, head and neck cancer, neuroendocrine tumors, skin melanoma, and bone metastases; the STING-mediated diseases may be STING-mediated diseases in humans or animals.

[0060] In this invention, the diagnostic reagent may be administered via intravenous injection.

[0061] The STING targeted precursor compounds and their pharmaceutically acceptable forms, as well as the STING targeted precursor compound radionuclide markers and their pharmaceutically acceptable forms, provided by this invention, all possess excellent in vivo biological properties. They exhibit high specific uptake in tumors or inflammations with high expression of interferon-stimulating factor STING, a high target-to-non-target ratio, and low non-specific background. The low uptake in non-target organs can reduce unnecessary radiation damage, and the drugs have high safety profiles. They can be applied to assess the expression level of interferon-stimulating factor at tumor sites or for targeted therapy.

[0062] To further illustrate the present invention, the following detailed descriptions, in conjunction with embodiments, provide a STING-targeting precursor compound, a radionuclide marker, its preparation method and application, and a pharmaceutical composition and its application, but these should not be construed as limiting the scope of protection of the present invention.

[0063] The following examples illustrate the preparation of the STING targeted precursor compound using the following raw material structural formula: DOTA-NHS: Cyclic peptide FN: Nota-NHS: Cyclic peptide FT: Cyclic peptide FN-2: F1-DOTA: F2-NOTA: .

[0064] Example 1: Preparation of FND-001: DOTA-NHS, cyclic peptide FN, and N,N-diisopropylethylamine (DIPEA) were mixed in N,N-dimethylformamide at a molar ratio of 1:1:2. The resulting mixture (cyclic peptide FN concentration of 20 mg / mL) was reacted at room temperature for 4 h. 0.1 mol / L dilute hydrochloric acid was added to neutralize to pH 7.4. The mixture was then purified by semi-preparative HPLC. The target solution was collected and lyophilized to obtain FND-001. Semi-preparative HPLC purification conditions: The chromatographic column was a semi-preparative C18 reversed-phase column (4.6 × 250 mm, Thermo Fisher Scientific); mobile phase A was 0.1 vol% trifluoroacetic acid-acetonitrile; mobile phase B was 0.1 vol% trifluoroacetic acid-water; gradient elution program: 0–30 min; the volume fraction of mobile phase B linearly decreased from 95% to 5%; mobile phase flow rate was 3 mL / min.

[0065] The mass spectrum of FND-001 is shown in Figure 1. The theoretical molecular weight is 1866.83, and the measured mass-to-charge ratio is [M+H]. + The value is 1867.2513, [M+2H]. + The value is 934.1236.

[0066] Example 2: Preparation of FND-201: The only difference from the preparation method of FND-001 is that the cyclic peptide FN is replaced with the cyclic peptide FN-2, resulting in FND-201. The mass spectrum of FND-201 is shown in Figure 2. The theoretical molecular weight is 2011.90, and the measured mass-to-charge ratio is [M+2H]. + It is 1006.6610.

[0067] Example 3: Preparation of FTD-001: The only difference from the preparation method of FND-001 is that the cyclic peptide FN is replaced with the cyclic peptide FT to obtain FTD-001. The mass spectrum of FTD-001 is shown in Figure 3. The theoretical molecular weight is 1764.78, and the measured mass-to-charge ratio is [M+2H]. + It is 883.1898.

[0068] Example 4: Preparation of FTN-001: The only difference from the preparation method of FTD-001 is that DOTA-NHS is replaced with NOTA-NHS to obtain FTN-001. The mass spectrum of FTN-001 is shown in Figure 4. The theoretical molecular weight is 1664.77, and the measured mass-to-charge ratio is [M+2H]. + The value is 832.5264.

[0069] Example 5: Preparation of FTD-303: F1-DOTA and cyclic peptide FT were mixed with phosphate buffer (pH=9.0) at a molar ratio of 1:1. The resulting mixture was reacted at room temperature for 4 h. The resulting reaction solution was purified by semi-preparative high-performance liquid chromatography (HPLC), and the target fraction was collected and lyophilized to obtain FTD-303. The mass spectrum of FTD-303 is shown in Figure 5. The theoretical molecular weight is 2376.0027, and the mass-to-charge ratio [M+2H] was measured. + The value is 1188.7721, [M+3H] + The value is 792.8442.

[0070] Example 6: Preparation of FTN-302: The only difference from the preparation method of FTD-303 is that F1-DOTA is replaced with F2-NOTA to obtain FTN-302. The mass spectrum of FTN-302 is shown in Figure 6. The theoretical molecular weight is 2144.90, and the measured mass-to-charge ratio is [M+2H]. + The value is 1073.7062.

[0071] The HPLC chromatograms of FND-001, FND-201, FTD-001 and FTD-303 are shown in Figure 7, and the HPLC chromatograms of FTN-001 and FTN-302 are shown in Figure 8. It can be seen that the chemical purity of the above results is greater than 93%.

[0072] Example 7: STING Targeting 68 Ga nuclide markers ([ 68 Ga]Ga-FND-001、[ 68 Ga]Ga-FND-201、[ 68 Ga]Ga-FTD-001, [ 68 Preparation of Ga-FTD-303 (Ga) using a wet labeling method: at an activity of 1.11 GBq 68 4 mL of acetate-acetate solution was added to 1 mL of GaCl3 hydrochloric acid solution (eluted from the germanium-gallium generator) to adjust the pH of the system to 4.0. Then, 50 µg of the STING targeting precursor compound (FND-001, FND-201, FTD-001, or FTD-303) was added and mixed thoroughly. The mixture was reacted at 90 °C for 15 min. The resulting reaction solution was cooled to room temperature, and a sample was taken for HPLC analysis. If the radiochemical purity was greater than 95%, no further purification was required. The solution was diluted with physiological saline or water for injection and sterile filtered to obtain the STING targeting precursor. 68Ga radionuclide-labeled injection solution. When the radiochemical purity is below 95%, purification is required. The purification steps are as follows: First, activate and rinse the Sep-Pak C18 separation column sequentially with 10 mL of anhydrous ethanol and then 10 mL of water. After diluting and cooling the reaction solution with 5 mL of pure water, load the sample onto the activated C18 column. Wash the C18 column with pure water until unreacted substances are removed. 68 Ga ions were then elute with anhydrous ethanol to obtain an ethanol eluent. The ethanol was removed from the eluent using a nitrogen gas stream. After dilution with physiological saline, the eluent was sterilely filtered to obtain the STING targeted solution. 68 Ga nuclide-labeled injection solution.

[0073] Lyophilization labeling method: Mix 1 mL of 0.25 M sodium acetate with 1.11 GBq of... 68 GaCl3 hydrochloric acid solution (rinsed from the germanium-gallium generator, 4 mL) was added to a lyophilized kit containing 50 µg of STING targeted precursor compound (FND-001, FND-201, FTD-001 or FTD-303), mixed thoroughly, and reacted at room temperature to 90 °C for 15 min. The resulting reaction solution was then post-processed according to the wet labeling method to obtain the STING targeted radionuclide label injection solution.

[0074] Example 8: STING Targeting 18 F radionuclide markers ([ 18 F]AlF-FTN-001、[ 18 The preparation of F]AlF-FTN-302 will be derived from cyclotron-produced... 18 Solution F was trapped on a pre-activated QMA column. Subsequently, it was washed with physiological saline, and the fraction with the highest activity was collected. 18 Solution F. At an activity of 1.85 GBq. 18 Add 50 μL of acetic acid-acetate solution to solution F to adjust the pH of the system to 4.0. Then add 2 mmol / L aluminum chloride solution and 100 µg of STING targeting precursor compound (FTN-001 or FTN-302), mix well, and react at 100 °C for 30 min. Post-process the resulting reaction solution according to Example 7 to obtain STING targeting... 18 F radionuclide labeling injection solution.

[0075] [ 68 Ga]Ga-FND-001、[ 68 Ga]Ga-FND-201、[ 68 Ga]Ga-FTD-001, [ 68 Ga]Ga-FTD-303, [ 18 F]AlF-FTN-001 and [ 18The HPLC analysis and identification results of F]AlF-FTN-302 are shown in Figures 9-11. HPLC analysis and identification conditions: The chromatographic column was a reversed-phase C18 analytical column (4.6×250 mm), mobile phase A was 0.1 vol% TFA-acetonitrile, mobile phase B was 0.1 vol% TFA-water, gradient elution program: 0~20 min: the volume fraction of mobile phase A increased linearly from 20% to 95%; the mobile phase flow rate was 1 mL / min. The retention times of the STING targeted radionuclide label were 10.76 min ([ 68 Ga]Ga-FND-001), 10.79min ([ 68 Ga]Ga-FND-201), 10.78min ([ 68 Ga]Ga-FTD-001), 10.95min ([ 68 Ga]Ga-FTD-303), 11.41min ([ 18 F]AlF-FTN-001) and 14.10min ([ 18 (F]AlF-FTN-302), the radiochemical purity of each STING-targeted nuclide marker is greater than 95%.

[0076] Test Example 1: In vitro stability testing of the STING targeted radionuclide markers prepared in Examples 7-8. 68 Ga]Ga-FND-001、[ 68 Ga]Ga-FND-201、[ 68 Ga]Ga-FTD-001, [ 68 Ga]Ga-FTD-303 was placed in PBS (pH=7.4) at room temperature for different times (30 min, 60 min, 120 min), and samples were analyzed by HPLC.

[0077] Will[ 68 Ga]Ga-FND-001、[ 68 Ga]Ga-FND-201、[ 68 Ga]Ga-FTD-001, [ 68 Ga]Ga-FTD-303 was co-incubated with serum at room temperature for different times (30 min, 60 min, 120 min), acetonitrile was added to remove protein, centrifuged at 12000 r / min for 5 min, and the supernatant was analyzed by HPLC.

[0078] [ 68 Ga]Ga-FND-001、[ 68 Ga]Ga-FND-201、[ 68 Ga]Ga-FTD-001, [ 68The HPLC results of stability identification of Ga-FTD-303 with PBS and in vitro serum are shown in Figures 12-15. 18 F]AlF-FTN-001 and [ 18 The HPLC results of the stability identification of F]AlF-FTN-302 with PBS and in vitro serum are shown in Figures 16 and 17. The data show that it maintains high stability (radiochemical purity >95%) in physiological saline or in vitro serum systems up to 2 hours.

[0079] Test Example 2: Determination of the lipid distribution coefficient (LogP) of the STING targeted radionuclide markers prepared in Examples 7-8. 0.1 mL of the STING targeted radionuclide marker injection solution (concentration 0.37 MBq / mL) diluted with PBS (pH=7.4) was added to a centrifuge tube containing a mixture of 0.9 mL PBS and 1 mL n-octanol. The mixture was vortexed thoroughly for 3 min, centrifuged at 12000 r / min for 5 min, and 0.1 mL of liquid was taken from both the aqueous and n-octanol phases and counted using a γ-counter. The experiment was repeated three times, and the average value was taken.

[0080] The formula for calculating LogP is: P = I 有机相 / I 水相 Among them, I 有机相 I represents the radioactivity count measured in the organic phase. 水相 The radioactivity counts measured in the aqueous phase are represented. The lipid-water distribution coefficients of each nuclide marker were calculated. The results are shown in Table 2, indicating that each STING-targeted nuclide marker exhibits hydrophilicity.

[0081] Table 2. Lipid-water distribution coefficients of STING-targeted radionuclide markers

[0082] Test Example 3: Cell and Protein Binding Assays of STING Targeted Radionuclide Markers Prepared in Examples 7-8. Raw 264.7 cells were uniformly seeded in 24-well plates and allowed to adhere overnight. At the start of the experiment, the original culture medium was aspirated and fresh serum-free medium was added. Then, approximately 74 kBq of STING targeted radionuclide marker injection solution was added to each well, and the cells were incubated at 37°C for 60 min. After the incubation time point, the culture medium was aspirated, and pre-cooled PBS was added to each well for washing twice. Then, 0.5 mL of sodium hydroxide solution at a concentration of… was added to fully lyse the cells. Finally, the cells in the wells were collected and counted using a γ-counter. In the inhibition assay, 10 µg of NNK-2 (a competitive binding compound) was added to each well 5 min in advance, and other procedures were the same as described above. At IC50… 50In the assay, different concentrations of precursors were added to each well of cells, and other procedures were the same as described above.

[0083] In the protein binding experiment, participants were divided into three groups: a control group, an inhibition group, and a binding group. Except for the control group, the other two groups received 4 µg of STING protein. The inhibition group received an additional 10 µg of NNK-2 (a competitive binding compound). Subsequently, each group received […]. 68 Ga]Ga-FTD-303 solution (74 kBq) was incubated at 37°C for 60 min. After reaching the incubation time point, the tubes were centrifuged at 12000 r / min for 15 min and washed three times with 0.2 mL of pure water. Finally, the radioactivity count in each group of ultrafiltration tubes was determined using a γ-counter.

[0084] STING-targeted radionuclide marker uptake and inhibition assays and IC50 assays in Raw 264.7 cells. 50 The data results are shown in Figures 18-20. It can be seen that, compared with the normal group, the cellular uptake value in the inhibition group was significantly decreased; 68 Ga]Ga-FTD-001 and [ 68 Ga]Ga-FTD-303 IC 50 The measured values ​​were 8.81 nM and 5.25 nM, respectively, indicating that [ 68 Ga]Ga-FTD-303 has higher affinity and specificity for STING protein.

[0085] [ 68 The protein binding data of Ga-FTD-303 are shown in Figure 21. It can be seen that in the protein binding experiment, the protein binding rate in the binding group was significantly higher than that in the inhibition group. This result directly verifies […]. 68 Ga]Ga-FTD-303 exhibits STING protein targeting specificity.

[0086] Test Example 4: STING target prepared in Example 7 68 MicroPET / CT imaging of B16F10 tumor-bearing mice labeled with Ga nuclide was performed using approximately 7-week-old male C57BL / 6 mice (weighing about 20g). B16F10 cells were subcutaneously injected into the right upper limb. Imaging was performed when the tumor reached 0.8-1.0cm in size. 9.25MBq was injected via the tail vein of the mouse. 68 Ga]Ga-FTD-001 or [ 68 Ga]Ga-FTD-303 was used to perform MicroPET imaging at different time points, and regions of interest (ROIs) were delineated in the whole-body decay-corrected images obtained from the scans, and probe distribution values ​​were calculated.

[0087] As shown in Figure 22, [ 68Ga]Ga-FTD-001 and [ 68 The Ga-FTD-303 radionuclide marker showed significant uptake at the tumor-bearing site. Different metabolic pathways were observed in mice. 68 Ga]Ga-FTD-001 is primarily metabolized via the hepatobiliary pathway. 68 Ga-FTD-303, unlike other methods, is metabolized by the kidneys, resulting in a significant improvement in overall imaging performance. In the specific blocking group, the uptake values ​​of both probes decreased at the tumor site in tumor-bearing mice due to the specific blocking effect of NNK-2. This result was verified at the in vivo level. 68 Ga]Ga-FTD-001 and [ 68 The specificity of Ga]Ga-FTD-303.

[0088] Example 5: Biodistribution Experiment of STING-Targeted Radionuclide Marker in B16F10 Tumor-Bearing Mice. Seven-week-old C57BL / 6 male mice (approximately 20g in weight) were used. B16F10 cells were subcutaneously injected into their right upper limb. When the tumor grew to 0.8–1.0 cm, the biodistribution experiment was conducted. 0.74 MBq of STING-targeted radionuclide marker was injected into the tail vein of the mice. Sixty minutes after injection, the mice were euthanized by decapitation. Blood, brain, heart, liver, lungs, kidneys, intestines, spleen, stomach, muscles, bones, and tumors (or other organs and tissues of interest) were collected. The radioactivity counts were measured, and the results were expressed as the percentage uptake dose per gram of tissue or organ (%ID / g).

[0089] As shown in Figure 23, [ 68 Ga]Ga-FTD-001 and [ 68 Ga-FTD-303 showed good uptake within tumors, similar to PET imaging results. In non-target organs, […]. 68 Ga-FTD-001 is mainly distributed in the liver and lungs, with relatively poor imaging background; 68 Ga-FTD-303 differs from others, as it is mainly distributed in the kidneys and has a relatively fast in vivo clearance rate, with a blood clearance half-life of 62.1 min and a maximum tumor-to-sarcoma ratio of 6.12±1.48, resulting in significantly improved imaging performance.

[0090] As shown in Figure 24, [ 18 F]AlF-FTN-001 and [ 18 F]AlF-FTN-302 exhibits different metabolic patterns in tumor-bearing mice, 18 F]AlF-FTN-001 is primarily cleared via the hepatobiliary route. 18 F]AlF-FTN-302 is cleared via the kidneys. Quantitative analysis shows that... 18The uptake of F]AlF-FTN-302 in tumors was significantly higher than that of [ 18 The F]AlF-FTN-001 has a lower uptake value in non-target organs such as the liver, lungs, and intestines, resulting in higher imaging contrast.

[0091] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A STING-targeting precursor compound, characterized in that, It has the structure shown in Formula I, Formula II or Formula III: Wherein, R1 includes -OH or -NH2; R2 and R3 independently include -H, -OH, -NH2, -CH3, -CH2OH, -CH(CH3)OH, -CH2CH(CH3)2, -CH(CH3)2, -CH(CH3)CH2CH3 or any one of the following structures: R4 is a labeling group, including any of the following structures: L1 includes any of the following structures: Either end of L1 is connected to A1; L2 and L3 independently include any of the following structures: The -NH- terminal of L2 is connected to A2, and the -NH- terminal of L3 is connected to A3; A1, A2, and A3 independently include formula A a Formula A b Or it may not exist; the formula A is not mentioned. a Includes one or any combination of the following structures: The -NH- end in formula Aa is connected to R4; the formula A b Includes any of the following structures: Formula A b The acid end in the middle is connected to L1, L2 or L3, formula A b The other end is connected to R4; A b In line -1, the C=O end of Aa is connected to either end of L1, and the other end of Aa is connected to R4; A b In line -2, one end of L1 is connected to the C=O end of Aa, and the other end of L1 is connected to R4; A b In equation -3, either end of L1 is connected to squaric acid, and the other end of L1 is connected to R4; j, r, x, y, n, t, q, and m are independent integers between 1 and 5; the formula A b L1 in equation A is the same as L1 in equation I. b A in a With the above formula A a Same; the pharmaceutically acceptable forms include one or more of the following: salt, stereoisomer, racemate, hydrate, and solvate.

2. The method for preparing the STING targeted precursor compound according to claim 1, characterized in that, Includes the following steps: The cyclic peptide compound was coupled with the R4 active compound to obtain the STING targeting precursor compound. The cyclic peptide compound has any one of the following structures: The structure of the R4 active compound includes any one of the following structures: 。 3. The method for preparing the STING targeted precursor compound according to claim 1, characterized in that, When A1, A2, and A3 are all expressions of equation A b The preparation method includes the following steps: mixing a cyclic peptide compound with A b The -R4 derivative undergoes a coupling reaction to obtain the STING-targeting precursor compound; the cyclic peptide compound has any one of the following structures: The A b -R4 derivatives include any of the following structures: 。 4. The pharmaceutically acceptable form of the STING targeted prodrug compound of claim 1, characterized in that, The pharmaceutically acceptable forms include one or more of the following: salt, stereoisomer, racemate, hydrate, and solvate.

5. A STING-targeted radionuclide marker, characterized in that, It has the structure shown in Formula IV, Formula V or Formula VI: The R1~R3, L1~L3, and A1~A3 in Formulas IV, V, and VI are the same as the R1~R3, L1~L3, and A1~A3 in the STING targeting precursor compound of claim 1, and R5 is obtained by radionuclide labeling of R4 in the STING targeting precursor compound; the radionuclide includes 18 F, 43 Sc、 44 Sc、 47 Sc、 51 Cr 55 Co、 57 Co、 62 Cu、 64 Cu、 67 Cu、 67 Ga、 68 Ga、 72 As、 72 Se、 89 Zr、 86 Y、 89 Sr, 86 Y、 90 Y、 97 Ru、 99m Tc, 105 Rh、 101m Rh、 109 Pd, 111 In、 123 I, 124 I, 125 I, 131 I, 119 Sb、 128 Ba、 139 La、 140 La、 142 Pr、 149 Pm, 149 Tb, 151 Tb, 151 Eu、 153 Eu、 169 Eu、 153 Sm、 152 Gd, 153 Gd, 157 Gd, 159 Gd, 161 Tb, 165 Dy、 166 Ho、 169 Er、 175 Yb、 177 Lu、 186 Re、 188 Re、 197 Hg, 198 Au、 201 Tl、 203 Pb, 211 At、 212 Pb, 212 Bi、 213 Bi、 223 Ra、 227 Th and 225 At least one of Ac.

6. The method for preparing the STING targeted radionuclide marker according to claim 5, characterized in that, Includes the following steps: The STING targeting substance is coordinated with a nuclide to obtain the STING targeting nuclide label; the STING targeting substance is a pharmaceutically acceptable form of the STING targeting precursor compound of claim 1 and / or the STING targeting precursor compound of claim 4.

7. The pharmaceutically acceptable form of the STING-targeted radionuclide marker of claim 5, characterized in that, The pharmaceutically acceptable forms include salts, stereoisomers, racemates, hydrates, and solvates.

8. A pharmaceutical composition, characterized in that, It includes an active ingredient and pharmaceutically acceptable excipients; the active ingredient includes at least one of the following: the STING targeted precursor compound of claim 1, the STING targeted precursor compound of claim 4 in a pharmaceutically acceptable form, the STING targeted radionuclide marker of claim 5, and the STING targeted radionuclide marker of claim 7 in a pharmaceutically acceptable form.

9. The pharmaceutical composition according to claim 8, characterized in that, The pharmaceutical composition also includes a STING agonist and / or an immune checkpoint inhibitor.

10. The use of the STING-targeting prodrug of claim 1, the pharmaceutically acceptable form of the STING-targeting prodrug of claim 4, the STING-targeting radionuclide marker of claim 5, the pharmaceutically acceptable form of the STING-targeting radionuclide marker of claim 7, or the pharmaceutical composition of claim 9 or 10 in the preparation of a therapeutic or diagnostic agent for STING-mediated diseases.

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