Compound targeting prostate specific membrane antigen, and preparation method therefor and use thereof

Abstract

Provided is a compound targeting a prostate specific membrane antigen (PSMA). The compound has a structure as represented by formula (I), wherein R1 is a compound targeting a prostate specific membrane antigen; L1 is -(X)n-(CH 2)m-(Y)q-, wherein X and Y are independently selected from lysine, glutamic acid or a derivative structure containing lysine and glutamic acid, n is an integer from 0 to 12, m is an integer from 0 to 60, q is an integer from 0 to 12, and each CH2 can be individually replaced with -O-, -NH(CO)- or -(CO)-NH-; L2 is -(CH2)p-, wherein p is an integer from 0 to 30, each CH2 can be individually replaced with -O-, -NH(CO)-, or -(CO)-NH-; and R2 is a nuclide chelating group. Further provided is a radioactive marker on the basis of the structure of the compound. The compound and the radioactive marker have a suitable blood circulation time and relatively high tumor assimilation and retention time, and are suitable for use in nuclide treatment and imaging of tumors with high expression of PSMA.

Description

A prostate-specific membrane antigen targeting compound and its preparation method and application Technical Field

[0001] The present invention relates to the fields of nuclear medicine and molecular imaging, and in particular to a prostate-specific membrane antigen targeting compound and its preparation, labeling and application. Background Art

[0002] Prostate cancer is the second most common cancer among men worldwide and the sixth most common cancer among men in China. Over the past decade, the incidence of prostate cancer in China has rapidly increased, with an average annual growth rate of 12.07%. Described as a "silent killer," prostate cancer is difficult to detect in its early stages, with approximately two-thirds of patients already in the advanced stages by the time of diagnosis. Prostate-specific membrane antigen (PSMA) expression in prostate cancer cells is 100 to 1,000 times higher than in normal cells, and is even higher in advanced cancer and in cancer cells receiving anti-androgen therapy. These characteristics make PSMA an ideal target for the diagnosis and treatment of prostate cancer.

[0003] In December 2020, the U.S. Food and Drug Administration approved gallium-68 labeled PSMA-11 (68Ga-PSMA-11), the first PET imaging diagnostic agent for PSMA-positive lesions in prostate cancer patients. Subsequently, 177-Lu labeled PSMA617 began to be used in the treatment of PSMA-positive lesions. As a small molecule drug, 177 Lu-PSMA617 is eluted from the blood too quickly. This metabolic characteristic results in a low uptake dose at the tumor site and a short retention time. About 30% of patients 177 Lu-PSMA617 treatment did not respond. In order to increase the dose delivered to the tumor, a study was conducted by linking maleimide-modified truncated Evans blue to PSMA containing thiol groups ( 177 Lu-EB-PSMA617) significantly prolonged the circulation half-life of PSMA-targeted probes by binding to albumin in the blood. Although this modification strategy increased the tumor uptake dose and prolonged tumor retention time, subsequent studies have found new problems. 177 Among patients treated with Lu-EB-PSMA617 (3.52±0.58GBq), 37.5% of patients developed grade 3-4 anemia, 12.5% ​​of patients developed leukopenia, and 37.5% of patients developed thrombocytopenia (Journal of Nuclear Medicine December 2020, 61(12): 1772-1778). 177The long blood half-life of Lu-EB-PSMA617 leads to hemotoxicity and bone marrow suppression, particularly in patients with prostate cancer who have a heavy burden of bone metastases and critical bone marrow function. Such severe side effects significantly diminish the clinical value of targeted drugs. These studies have led to the understanding that the optimal blood circulation half-life for targeted probes used in cancer therapy is not necessarily the longest possible, but rather a reasonable blood circulation time while ensuring high tumor uptake.

[0004] Therefore, it is necessary to further optimize the PSMA-targeted probe to adjust the blood circulation time to an appropriate range while ensuring higher tumor uptake, meet the needs of radionuclide therapy, and achieve maximum therapeutic benefits.

[0005] Summary of the Invention

[0006] Based on the above background, the primary purpose of the present invention is to develop a prostate-specific membrane antigen targeting compound with high tumor uptake and suitable blood circulation time, which can overcome the existing small molecule 177 The defects of Lu-PSMA617 being too fast to be metabolized and too short to be retained in target organs can also be avoided. 177 Unlike Lu-EB-PSMA617, which causes blood toxicity and bone marrow suppression due to its long blood half-life, this improves the diagnostic and therapeutic effects of targeted PSMA radionuclides, making it truly valuable and potential for clinical promotion and application.

[0007] Another object of the present invention is to provide a radiolabeled prostate-specific membrane antigen targeting complex that also has high tumor uptake and suitable blood circulation time, and can combine the advantages of high tumor treatment effect and low side effects.

[0008] Another object of the present invention is to provide a method for preparing the radiolabeled prostate-specific membrane antigen targeting complex.

[0009] Another object of the present invention is to provide the use of the complex in targeted radionuclide imaging and treatment of prostate cancer.

[0010] The technical solutions for achieving the above primary purpose of the present invention include the following two aspects: ligand synthesis and radioactive labeling.

[0011] In a first aspect, the present invention provides a prostate-specific membrane antigen-targeting compound with high tumor uptake and suitable blood circulation time, the structure of the compound is shown in the following formula (I);

[0012]

[0013] in:

[0014] L1 is -(X) n-(CH2) m -(Y) q -, wherein n is an integer from 0 to 12 (preferably an integer from 0 to 6), X and Y are independently selected from lysine, glutamic acid or a derivative structure containing lysine and glutamic acid, m is an integer from 0 to 60 (preferably an integer from 0 to 30), q is an integer from 0 to 12 (preferably an integer from 0 to 6), wherein each CH2 can be independently replaced by -O-, -NH(CO)- or -(CO)-NH-;

[0015] L2 is -(CH2) p -, wherein p is an integer from 0 to 30 (preferably an integer from 0 to 12), wherein each CH2 can be individually replaced with -O-, -NH(CO)- or -(CO)-NH-, provided that no two adjacent CH2 groups are replaced;

[0016] R1 is derived from a prostate-specific membrane antigen-targeting compound, and its structure may include any of the following structures: or

[0017] R2 is a nuclide chelating group selected from any of the following structures:

[0018]

[0019] In the scheme of the present invention, R1 in the formula (I) is preferably selected from:

[0020] or

[0021] In a preferred embodiment of the present invention, R1 in the formula (I) is R2 is That is, the compound structure is shown in the following formula (II):

[0022] Wherein L1 is preferably selected from:

[0023] -Lys-(CO)-CH2CH2-(CO)-NH-CH2-(CO)-,

[0024] -Lys-(CO)-CH2CH2-(OCH2CH2)-(CO)-NH-CH2-(CO)-,

[0025] -Lys-(CO)-CH2CH2-(OCH2CH2)2-(CO)-NH-CH2-(CO)-,

[0026] -Lys-(CO)-CH2CH2-(OCH2CH2)4-(CO)-NH-CH2-(CO)-, -(CO)-CH2CH2-(CO)-Lys-,

[0027] -(CO)-CH2CH2-(OCH2CH2)-(CO)-Lys-, -(CO)-CH2CH2-(OCH2CH2)2-(CO)-Lys-,

[0028] -(CO)-CH2CH2-(OCH2CH2)4-Lys-, -Lys-(CO)-CH2-(CO)-NH-CH2-(CO)-,

[0029] -Lys-(CO)-CH2-(OCH2CH2)-O-CH2(CO)-NH-CH2-(CO)-,

[0030] -Lys-(CO)-CH2-(OCH2CH2)3-O-CH2(CO)-NH-CH2-(CO)-, -(CO)-CH2-(CO)-Lys-, or

[0031] -(CO)-(OCH2CH2)-O-CH2(CO)-Lys-, -(CO)-CH2-(OCH2CH2)3-O-CH2(CO)-Lys-.

[0032] In a further preferred embodiment of the present invention, the compound structure is shown in the following formula (II-1):

[0033]

[0034] In a preferred embodiment of the present invention, the compound structure may also be any one of the following formulas (II-2) to (II-8):

[0035]

[0036]

[0037] or

[0038]

[0039] On this basis, the present invention further provides a method for preparing the compound represented by formula (II-1), comprising the following steps:

[0040] 4,4'-diamino-3,3'-dimethylbiphenyl is unilaterally introduced with Boc protection, and then reacted with 4,6-diamino-5-hydroxy-1,3-naphthalene disulfonic acid to prepare a truncated Evans blue derivative; the Boc protection is removed, and then an amide condensation reaction occurs with Nα-Fmoc-Nε-Boc-L-lysine; the Boc protecting group is then removed under the action of TFA; then it reacts with COOH-PEG2-COOH; then it reacts with PSMA-617 in the presence of EDC and NHS; then the Fmoc protection is removed using piperazine; and finally it reacts with DOTA-NHS to obtain a compound with the structure shown in the following formula (II-1).

[0041] The preferred method of preparing the compound represented by formula (II-1) of the present invention specifically comprises the following steps:

[0042] 4,4'-diamino-3,3'-dimethylbiphenyl (Compound 1) is reacted with di-tert-butyl dicarbonate to obtain Compound 2; Compound 2 is reacted with 4,6-diamino-5-hydroxy-1,3-naphthalene disulfonic acid and sodium nitrite to obtain a truncated Evans blue derivative (Compound 3); Compound 3 is deprotected from Boc to obtain Compound 4; Compound 4 is condensed with Nα-Fmoc-Nε-Boc-L-lysine in the presence of HATU and DIPEA to obtain Compound 5; Compound 5 is dissolved in trifluoroacetic acid solution to remove the protecting group to obtain Compound 6; Compound 6 is dissolved in N,N-dimethylformamide and reacted with COOH-PEG2-COOH in the presence of HATU to obtain Compound 7; Compound 6 is then reacted with PSMA-617 in the presence of EDC and NHS to obtain Compound 8; Fmoc protection is then removed using piperazine to obtain Compound 9; and finally, it is reacted with DOTA-NHS to obtain Compound 10 having the structure shown in the following formula (II-1).

[0043] The synthetic route of the above-mentioned specific steps is as follows:

[0044]

[0045] The preparation methods of other compounds in the scheme of the present invention are similar to the preparation method of compound 10, and can basically be prepared based on existing conventional means with reference to the synthetic route of compound 10.

[0046] On the other hand, the present invention further provides a radiolabeled complex, which is a complex obtained by labeling a radionuclide with the compound of formula (I) of the present invention as a ligand. The radiolabeled complex can be used as a new type of tumor radiotherapy probe, that is, as a radionuclide diagnostic probe or a radionuclide therapeutic probe. The nuclide can be selected 177 Lu, 90 Y.18 F. 64 Cu, 68 Ga, 62 Cu, 67 Cu, 86 Y. 89 Zr, 99m Tc, 89 Sr, 153 Sm, 149 Tb, 161 Tb, 186 Re、 188 Re、 212 Pb, 213 Bi, 223 Ra, 225 Ac, 226 Th, 227 Th, 131 I. 211 At or 111 Any one of In; preferably 68 Ga, 177 Lu or 90 Y.

[0047] The preferred complex of the present invention has a structure as shown in the following formula (III):

[0048]

[0049] in,

[0050] L1 is -(X) n -(CH2) m -(Y) q -, wherein n is an integer from 0 to 12 (preferably an integer from 0 to 6), X and Y are independently selected from lysine, glutamic acid or a derivative structure containing lysine and glutamic acid, m is an integer from 0 to 60 (preferably an integer from 0 to 30), q is an integer from 0 to 12 (preferably an integer from 0 to 6), wherein each CH2 can be independently replaced with -O-, -NH(CO)- or -(CO)-NH-;

[0051] L2 is -(CH2) p -, wherein p is an integer from 0 to 30 (preferably an integer from 0 to 12), wherein each CH2 can be individually replaced with -O-, -NH(CO)- or -(CO)-NH-, provided that no two adjacent CH2 groups are replaced;

[0052] R1 is a or The structure of the prostate-specific membrane antigen targeting compound is preferably selected from:

[0053] or

[0054] M is a radionuclide selected from 68 Ga, 177 Lu or 90 Any one of Y.

[0055] The radiolabeled complex of the present invention can be prepared by reacting a compound containing a radionuclide with the compound of formula (I) of the present invention according to various existing labeling methods; the preferred labeling method of the present invention is the following wet method or freeze-drying method:

[0056] The wet labeling method comprises: dissolving an appropriate amount of the compound of formula (I) of the present invention in a buffer solution or deionized water; adding a radionuclide solution to the resulting solution, and reacting in a closed manner for 5-40 minutes to generate a radionuclide-labeled complex;

[0057] Alternatively, the freeze-drying labeling scheme comprises: dissolving an appropriate amount of the compound of formula (I) of the present invention in a buffer solution or deionized water; the resulting solution is sterile filtered, divided into containers, and sealed with a stopper after freeze drying to obtain a freeze-dried medicine box; adding an appropriate amount of acetic acid solution or buffer solution to the freeze-dried medicine box to dissolve, and then adding the corresponding radionuclide solution, and reacting in a closed manner for 5-40 minutes to generate a radionuclide-labeled complex. Wherein, the subpackaging container is preferably a freezing tube or a controlled antibiotic bottle. It is also possible to choose to add excipients to the medicine box according to the molding of the freeze-dried powder of the medicine box, such as mannitol, ascorbic acid, etc., and by adjusting the dosage of the compound of formula (I) and the excipient according to the present invention, the medicine box molding is optimized.

[0058] The products obtained from the wet labeling scheme and the freeze-drying labeling scheme can be further prepared into injection solutions through conventional treatment (such as chromatographic separation and purification, solvent removal by rotary evaporation, dissolution of the residue with PBS, water or saline, sterile filtration, etc.).

[0059] In a preferred embodiment of the present invention, compound 10 represented by formula (II-1) is used as a ligand, and the preferred preparation method of radiolabeled compound 10 is a wet labeling method, comprising the following steps: dissolving compound 10 in a buffer solution or deionized water; adding fresh radioactive solution thereto, reacting in a sealed manner at 37-90°C for 5-40 minutes, and cooling; diluting the reaction solution with water, separating and purifying it on a Sep-Pak C18 chromatographic column, rinsing the chromatographic column with a buffer solution or water to remove unreacted radioactive ions, eluting it with a hydrochloric acid ethanol solution or an ethanol solution, and then diluting it with physiological saline or PBS and sterile filtering to obtain an injection of a radiolabeled complex having a structure as described in formula (IV); wherein the radionuclide M is 68Ga, 177 Lu or 90 Y et al.

[0060] Another preferred preparation method of the radiolabeled compound 10 of the present invention is a lyophilization labeling method, comprising: dissolving compound 10 and other necessary reagents in a buffer solution, sterile filtering the resulting solution, and then packaging it into cryopreservation tubes, freeze-drying, and sealing to obtain a lyophilized drug box; adding an appropriate amount of buffer solution to dissolve the solution, then adding a freshly prepared radioactive solution, sealing and reacting at 37-120°C for 5-40 minutes, and cooling; diluting the reaction solution with water, and then separating and purifying it on a Sep-Pak C18 column, rinsing the column with buffer or water to remove unreacted radioactive ions, eluting with a hydrochloric acid ethanol solution or an ethanol solution, and then diluting it with physiological saline or PBS and sterile filtering to obtain an injection of a radiolabeled complex with a structure as shown in formula (IV); wherein the radionuclide M is 68 Ga, 177 Lu or 90 Y et al.

[0061]

[0062] Other chemical substances used in the above synthesis steps are commercially available products.

[0063] The buffer solution is a substance that stabilizes the pH value of the reaction solution, and can be acetate, lactate, tartrate, malate, maleate, succinate, ascorbate, carbonate and phosphate, as well as mixtures thereof.

[0064] In another aspect, the present invention also provides the use of the compound represented by formula (I) or a pharmaceutically acceptable salt thereof in the preparation of a radionuclide therapy or imaging drug for PSMA-highly expressed tumors in mammals.

[0065] The present invention also provides the use of a radiolabeled complex represented by formula (III) in radionuclide therapy and imaging of PSMA-highly expressed tumors in mammals.

[0066] In the preferred application of the present invention, the complex is prepared into an injection and administered by intravenous injection to human patients or mammals with PSMA-highly expressed tumors.

[0067] The present invention provides a prostate-specific membrane antigen-targeting compound with high tumor uptake and suitable blood circulation time, as well as a radionuclide-labeled complex thereof. Methods for preparing and labeling such a compound are also provided. Biological test results demonstrate that the compound exhibits a suitable blood circulation half-life, high tumor uptake, and high retention time. These superior properties are not currently possessed by other PSMA-targeting agents, making it suitable for radionuclide therapy and imaging of PSMA-highly expressing tumors. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 shows the tumor uptake results of different drugs in a mouse prostate cancer subcutaneous xenograft model 24 hours after injection.

[0069] Figure 2 shows the results of injection of the compound of Example 31 into normal mice. 177 Lu-PSMA and 177 Comparison of blood uptake of Lu-EB-PSMA at different time points after 617.

[0070] FIG3 shows the tissue distribution results of the compound of Example 31 24 hours after injection into a subcutaneous xenograft tumor model of prostate cancer mice.

[0071] Figure 4 shows the injection of a subcutaneous xenograft tumor model in prostate cancer mice. 177 Tissue distribution results of Lu-EB-PSMA 617 24 hours after administration.

[0072] FIG5 is a SPECT-CT image of normal mice at different time points after injection of the compound of Example 31.

[0073] Figure 6 is an example of injection in normal mice 177 SPECT-CT images at different time points after Lu-labeled compound II-2.

[0074] Figure 7 is a normal mouse injected 177 Blood uptake results of Lu-labeled compound II-2 at different time points.

[0075] FIG8 is a mass spectrum of compound 10 prepared in Example 1.

[0076] FIG9 is a mass spectrum of compound II-3 prepared in Example 3.

[0077] FIG10 is a HPLC chromatogram of compound 5 prepared in Example 1.

[0078] FIG11 is a HPLC chromatogram of compound 6 prepared in Example 1.

[0079] FIG12 is a HPLC chromatogram of compound 7 prepared in Example 1.

[0080] FIG13 is a HPLC chromatogram of compound 8 prepared in Example 1.

[0081] FIG14 is a HPLC chromatogram of compound 9 prepared in Example 1.

[0082] FIG15 is a HPLC chromatogram of compound 10 prepared in Example 1. DETAILED DESCRIPTION

[0083] The technical solution of the present invention is further illustrated and described below through specific implementation methods in conjunction with the accompanying drawings.

[0084] Example 1: Preparation of compound 10 of formula (II-1)

[0085] Synthesis of compound 2:

[0086] In a 100 mL flask, 4,4'-diamino-3,3'-dimethylbiphenyl (Compound 11) (2.12 g, 10.0 mmol), di-tert-butyl dicarbonate (2.2 g, 10.0 mmol), N,N-diisopropylethylamine (1.3 g, 10.0 mmol), and 20 mL of dichloromethane were added, and the mixture was stirred at room temperature overnight. The reaction was monitored by HPLC to completion (rt was 10.13 minutes), and the solvent was removed by distillation under reduced pressure to obtain a crude product, which was purified by silica gel column (petroleum ether / ethyl acetate = 5:1) to obtain Compound 2 as a white solid in a yield of 59%.

[0087] Synthesis of compound 3:

[0088] Compound 2 (0.31 g, 1.0 mmol) and 4 mL of acetonitrile were placed in a 50 mL flask, cooled on ice, and 1.5 mL of 2M hydrochloric acid was added dropwise. The mixture was allowed to react for 15 minutes. Sodium nitrite (0.068 g, 1.0 mmol) was dissolved in 2 mL of water and added dropwise to the reaction flask again. The mixture was allowed to react for half an hour, which served as Solution A. In a separate 50 mL flask, 4,6-diamino-5-hydroxy-1,3-naphthalenedisulfonic acid (0.33 g, 1.0 mmol), sodium carbonate (0.105 g, 1.0 mmol), and 5 mL of water were added. The mixture was cooled on ice, and Solution A was slowly added dropwise to Solution B. The reaction was stirred on ice for 2 hours. Pure Compound 3 was obtained by reverse-phase column chromatography and freeze-drying in a 47% yield.

[0089] Synthesis of compound 4:

[0090] Compound 3 (0.52 g, 1.0 mmol) was dissolved in trifluoroacetic acid in an ice bath and the system was heated to room temperature for 2 h. After the reaction, the solvent was removed by distillation under reduced pressure to obtain a crude product. The crude product was purified by reverse phase column chromatography and freeze-dried to obtain pure compound 4 with a yield of 73%.

[0091] Synthesis of compound 5:

[0092] In a 100 mL flask, compound 4 (0.54 g, 1.0 mmol), Nα-Fmoc-Nε-Boc-L-lysine (0.46 g, 1.0 mmol), HATU (0.38 g, 1.0 mmol), N,N-diisopropylethylamine (0.26 g, 2.0 mmol), and 10 mL of N,N-dimethylformamide were added. The reaction mixture was stirred until the reaction was complete, and the solvent was removed by distillation under reduced pressure to obtain a crude product. The crude product was purified by reverse phase column chromatography and freeze-dried to obtain pure compound 5 in a 57% yield.

[0093] Synthesis of compound 6:

[0094] Compound 5 was deprotected from tert-butyl ester and Boc using thioanisole: 1,2-ethanedithiol: anisole: TFA (5:3:2:90) at room temperature to afford compound 6. After the reaction, TFA was removed by argon flow, and the compound was dissolved in 10 mL of N,N-dimethylformamide and set aside.

[0095] Synthesis of compound 7:

[0096] To compound 6 in N,N-dimethylformamide were added COOH-PEG2-COOH (0.23 g, 1.10 mmol), HATU (0.38 g, 1.0 mmol), and N,N-diisopropylethylamine (0.39 g, 3.0 mmol), respectively. The mixture was stirred at room temperature overnight. The reaction was monitored for completion by HPLC (rt = 10.84 min). The solvent was removed by distillation under reduced pressure to obtain a crude product. The crude product was purified by reverse phase column chromatography and freeze-dried to obtain pure compound 7 with a two-step yield of 50%.

[0097] Synthesis of compound 8:

[0098] In a 50 mL flask, compound 7 (0.21 g, 0.2 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.04 g, 0.2 mmol), NHS (0.02 g, 0.2 mmol), and 10 mL of N,N-dimethylformamide were added. After 4 h of reaction, N,N-diisopropylethylamine (0.06 g, 0.5 mmol) and PSMA-617 (0.13 g, 0.2 mmol) were added. The reaction mixture was stirred and the reaction was monitored for completion by HPLC (RT: 12.16 min). The solvent was removed by distillation under reduced pressure to obtain a crude product. The crude product was purified by reverse phase column chromatography and freeze-dried to obtain pure compound 8 in a 59% yield.

[0099] Synthesis of compound 9:

[0100] In a 25 mL flask, compound 8 (0.16 g, 0.1 mmol) and piperidine (0.08 g, 10.0 mmol) were added to 5 mL of DMF. The deprotection process was monitored by HPLC until the reaction was complete (rt = 10.47 min), and the solvent was removed by vacuum distillation to obtain a crude product. The crude product was purified by reverse phase column chromatography and freeze-dried to obtain pure compound 9 in a 63% yield.

[0101] Synthesis of compound 10:

[0102] In a 25 mL flask, compound 9 (0.13 g, 0.1 mmol), DOTA-NHS (0.05 g, 0.1 mmol) and N, N-diisopropylethylamine (0.04 g, 0.3 mmol) were added to 5 mL of N, N-dimethylformamide. The reaction system was stirred at room temperature and monitored by HPLC until the reaction was complete (rt was 11.35 minutes). The solvent was removed by vacuum distillation to obtain a crude product. The crude product was subjected to reverse phase column chromatography and freeze-dried to obtain pure compound 10 with a yield of 61%. For the characterization of its structure, see Figure 8.

[0103] The synthetic route of the above steps is as follows:

[0104]

[0105]

[0106] Examples 2-6

[0107] The structures of the compounds of Examples 2-6 are shown in Formula (II-2) to Formula (II-6), and their preparation methods can refer to Example 1. For example, in the preparation of Formula (II-2) and Formula (II-3), the COOH-PEG2-COOH reacted with compound 6 in Example 1 is replaced with COOH-PEG4-COOH, malonic acid or other suitable compounds; in the preparation of Formula (II-4) to Formula (II-6), the Nα-Fmoc-Nε-Boc-L-lysine reacted with compound 4 in Example 1 is replaced with Boc glycine, and the PSMA-617 reacted with compound 7 in Example 1 is replaced with PSMA-617-(Fmoc)Lys- to obtain the following corresponding structures:

[0108]

[0109]

[0110] or

[0111]

[0112] For the characterization of the structure of the above compound II-3, see Figure 9.

[0113] Example 7-30:

[0114] Referring to the preparation methods of Examples 1-6, the compound expressed by the following formula (I) was prepared:

[0115]

[0116]

[0117]

[0118]

[0119] Example 31. Preparation of a Lu-177 labeled complex:

[0120] Wet method: about 18.5~1850MBq 177 LuCl3 sodium acetate solution was added to a centrifuge tube containing 0.5 mL of acetic acid-acetate solution (1.0 g / L) of compound 10 from Example 1 and reacted at 90°C for 20 min. A C18 separation column was first slowly eluted with 10 mL of anhydrous ethanol and then with 10 mL of water. The labeled solution was diluted with 10 mL of water and loaded onto the separation column. Unlabeled 177 Lu ions were then washed with 0.3 mL of 10 mM HCl in ethanol to obtain 177 The eluent was diluted with saline and sterile filtered to obtain the 177 Injection of Lu-labeled complexes.

[0121] Lyophilization: About 18.5~1850MBq 177 LuCl3 sodium acetate solution was added to the freeze-dried drug box containing compound 10 of Example 1, mixed and reacted at 90°C for 20 minutes. A C18 separation column was taken and slowly eluted with 10 mL of anhydrous ethanol, then with 10 mL of water. The labeled solution was diluted with 10 mL of water and loaded onto the separation column. Unlabeled 177 Lu ions were then washed with 0.3 mL of 10 mM HCl in ethanol to obtain 177 Lu labeled complex eluent. The eluent is diluted with physiological saline and sterile filtered to obtain 177 Injection of Lu-labeled complexes.

[0122] Experimental example. Analysis and application effect

[0123] 1. HPLC analysis and identification

[0124] The HPLC system was as follows: a SHIMADZULC-20A C18 column (YMC, 3 μm, 4.6 × 150 mm) was used for analysis. Detection wavelength was 254 nm, flow rate was 1 mL / min, and elution gradient was as follows: 0-3 min: 10% acetonitrile and 90% water (50 mM ammonium acetate) maintained constant; 3-16 min: increased to 90% acetonitrile and 10% water (50 mM ammonium acetate); 16-18 min: maintained at 90% acetonitrile and 10% water (50 mM ammonium acetate); 18-20 min: decreased to 10% acetonitrile and 90% water (50 mM ammonium acetate); 20-22 min: maintained at 10% acetonitrile and 90% water (50 mM ammonium acetate).

[0125] The above system was used to identify and analyze Compound 5, Compound 6, Compound 7, Compound 8, Compound 9, and Compound 10 in Example 1. The identification and analysis results are shown in Figures 10, 11, 12, 13, 14, and 15, respectively.

[0126] The radiolabeled probe prepared in Example 31 was used as an experimental agent, and its performance determination experiment was described as follows:

[0127] 2. 177 Lu-labeled complex uptake experiment in a subcutaneous transplanted tumor model of prostate cancer in mice

[0128] The compound of Example 31 or other existing radioactive probes targeting PSMA were injected into a subcutaneous xenograft model of prostate cancer in mice, and the tumor uptake and tissue distribution results were compared. The specific protocol is as follows:

[0129] The prostate cancer subcutaneous transplanted tumor model (22RV1) in mice was randomly divided into three groups: experimental group, control group A and control group B, with 3 mice in each group.

[0130] Prepared according to the method of Example 31 with a purity greater than 95% 177 Lu complex, which is 177 The Lu-labeled compound 10 of Example 1 was used as the drug in the experimental group of this experiment and was designated as drug B.

[0131] Prepared by existing methods with a purity greater than 95% 177 Lu-PSMA 617, used as the drug for the control group A of this experiment, is denoted as drug A.

[0132] According to the method of Example 8 in WO2019 / 165200, 177Lu-EB-PSMA 617 with a purity greater than 95% was prepared and used as the drug for the control group B of this experiment, recorded as drug C.

[0133] The experimental, control A, and control B groups were injected via the tail vein with 5 MBq of drug B, drug A, and drug C, respectively. Twenty-four hours after injection, mice in each group were sacrificed and tumor tissue, blood, or other tissues were dissected and weighed. Radioactivity counts in the experimental, control A, and control B samples were measured using a gamma counter. The data were background-subtracted, decay-time-corrected, and averaged. Data are expressed as the percentage of the injected dose per gram of tissue (%ID / g). The results are shown in Figures 1, 3, and 4.

[0134] As can be seen from Figure 1, the embodiment 31 of the present invention 177 The tumor uptake of Lu complex (B) was 23.46±0.63% ID / g at 24h after injection, which was much higher than that of control group A. 177 The tumor uptake of Lu-PSMA 617 (A) was 7.60±1.22% ID / g, which was lower than that of the control group B. 177 Tumor uptake of Lu-EB-PSMA 617 (C) (48.97 ± 7.77% ID / g).

[0135] Figures 3 and 4 are respectively the experimental group injected with Example 31 of the present invention 177 Lu complex (B) and control group B were injected 177 The distribution of Lu-EB-PSMA 617 (C) in major tissues after 24 hours can be observed. 177 The renal uptake of Lu complexes at 24 h after injection (Figure 3) was much lower than 177 Lu-EB-PSMA 617 group (Figure 4).

[0136] 3. 177 Experiments of Lu-labeled complexes in normal mice

[0137] Normal mice were randomly divided into experimental group 1, experimental group 2, control group A and control group B, with 3 mice in each group.

[0138] Prepared according to the method of Example 31 with a purity greater than 95% 177 Lu complex, which is 177 Lu-labeled compound 10 from Example 1 was used as drug B in experimental group 1 of this experiment.

[0139] Referring to the method of Example 31, compound 10 was replaced by compound II-2 of Example 2 to prepare 177 Lu-labeled compound II-2 was used as drug D in experimental group 2 of this experiment.

[0140] Prepared by existing methods with a purity greater than 95% 177Lu-PSMA 617, used as the drug for the control group A of this experiment, is denoted as drug A.

[0141] 177Lu-EB-PSMA 617 with a purity greater than 95% was prepared according to the method of Example 8 in WO2019 / 165200 and used as the drug for the control group B of this experiment, recorded as drug C.

[0142] Experimental Group 1, Experimental Group 2, Control Group A, and Control Group B were injected via the tail vein with 5 MBq of Drug B, Drug D, Drug A, and Drug C, respectively. Blood uptake was measured 1 hour, 4 hours, and 24 hours after injection, and the results are shown in Figures 2 and 7. SPECT-CT imaging was performed 1 hour, 4 hours, 24 hours, and 48 hours after injection, and the results are shown in Figures 5 and 6.

[0143] As shown in Figure 2, at all the time points tested (1 hour, 4 hours and 24 hours), the 177 The uptake of Lu complex (B) in blood is higher than 177 Lu-PSMA 617(A) group but much lower than 177 Lu-EB-PSMA 617 (C) group. From the comparison between Figure 7 and Figure 2, it can be seen that at all the time points tested (1 hour, 4 hours and 24 hours), 177 The uptake of Lu-labeled compound II-2 in the blood was much lower than 177 Lu-EB-PSMA 617 (C) group.

[0144] Figures 5 and 6 are injection examples 31 177 Lu complexes and 177 SPECT-CT imaging of normal mice with Lu-labeled compound II-2.

[0145] In summary, compared with existing PSMA-targeted probes, the prostate-specific membrane antigen-targeted compound provided by the present invention not only has higher tumor uptake, but more importantly, has a suitable blood circulation time. Therefore, when treating prostate cancer, the radionuclide-labeled prostate-specific membrane antigen-targeted compound of the present invention can not only meet the treatment needs in terms of blood uptake and tumor uptake, but also has greatly reduced blood toxicity and bone marrow suppression risks. It has higher clinical application value and is expected to be used in radionuclide therapy and imaging of prostate cancer.

[0146] Although the present invention has been described in detail above using general explanations, specific embodiments, and experiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A prostate-specific membrane antigen targeting compound or a pharmaceutically acceptable salt thereof, characterized in that: Its molecular structure is composed of a linking group L 1 and L 2 which connects the truncated Evans blue, the PSMA targeting compound and the radionuclide chelating group together, and its structure is shown in the following formula (I) wherein: L 1 is -(X) n -(CH 2 ) m -(Y) q -, where n is an integer from 0 to 12 (preferably an integer from 0 - 6), X and Y are independently selected from lysine, glutamic acid or a derivative structure containing lysine and glutamic acid, m is an integer from 0 to 60 (preferably an integer from 0 - 30), q is an integer from 0 to 12 (preferably an integer from 0 - 6), and each CH 2 can be independently replaced by -O-, -NH(CO)- or -(CO)-NH-; L 2 is -(CH 2 ) p -, where p is an integer from 0 to 30 (preferably an integer from 0 - 12), and where each CH 2 can be independently replaced by -O-, -NH(CO)- or -(CO)-NH-, provided that no two adjacent CH 2 groups are replaced; R 1 from a prostate-specific membrane antigen-targeting compound, which is a compound structure comprising any one of the following structures: Or R 2 is a nuclide chelating group and is selected from any one of the following structures:

2. The compound according to claim 1, characterized in that: R in the formula (I) 1 selected from: Or 3. The compound according to claim 1, characterized in that: R in the formula (I) 1 is that is, the structure of the compound is as shown in the following formula (II): L in the formula (II) 1 Selected from: -Lys-(CO)-CH 2 CH 2 -(CO)-NH-CH 2 -(CO)-、-Lys-(CO)-CH 2 CH 2 -(OCH 2 CH 2 )-(CO)-NH-CH 2 -(CO)-、-Lys-(CO)-CH 2 CH 2 -(OCH 2 CH 2 ) 2 -(CO)-NH-CH 2 -(CO)-、-Lys-(CO)-CH 2 CH 2 -(OCH 2 CH 2 ) 4 -(CO)-NH-CH 2 -(CO)-、-(CO)-CH 2 CH 2 -(CO)-Lys-、-(CO)-CH 2 CH 2 -(OCH 2 CH 2 )-(CO)-Lys-、-(CO)-CH 2 CH 2 -(OCH 2 CH 2 ) 2 -(CO)-Lys-、 -(CO)-CH 2 CH 2 -(OCH 2 CH 2 ) 4 -Lys-、-Lys-(CO)-CH 2 -(CO)-NH-CH 2 -(CO)-、-Lys-(CO)-CH 2 -(OCH 2 CH 2 )-O-CH 2 (CO)-NH-CH 2 -(CO)-、-Lys-(CO)-CH 2 -(OCH 2 CH 2 ) 3 -O-CH 2 (CO)-NH-CH 2 -(CO)-, -(CO)-CH 2 -(CO)-Lys-, or -(CO)-(OCH 2 CH 2 )-O-CH 2 (CO)-Lys-, -(CO)-CH 2 -(OCH 2 CH 2 ) 3 -O-CH 2 (CO)-Lys-.

4. The compound according to claim 3, characterized in that: The structure of the said compound is shown as the following formula (II-1):

5. The compound according to claim 3, characterized in that: The structure of the said compound is any one of the following formulas (II-2) to (II-8): or 6. A method for preparing a prostate-specific membrane antigen targeting compound, characterized in that: comprising the following steps: The 4,4'-diamino-3,3'-dimethylbiphenyl was introduced with Boc protection unilaterally, and then reacted with 4,6-diamino-5-hydroxy-1,3-naphthalenedisulfonic acid to prepare a truncated Evans blue derivative; the Boc protection was removed, and then an amide condensation reaction was carried out with Nα-Fmoc-Nε-Boc-L-lysine; then the Boc was removed under the action of TFA; then it reacted with COOH-PEG 2 -COOH for an amide condensation reaction; then it reacted with PSMA-617 in the presence of EDC and NHS; then the Fmoc protection was removed using piperazine; finally, it reacted with DOTA-NHS to obtain a compound with the structure shown in the following formula (II-1):

7. A radioactively labeled prostate-specific membrane antigen targeting compound, which is a complex obtained by labeling a radionuclide with the compound of formula (I) as claimed in claim 1; the radionuclide is preferably 177 Lu, 90 Y, 18 F, 64 Cu, 68 Ga, 62 Cu, 67 Cu, 86 Y, 89 Zr, 99m Tc, 89 Sr, 153 Sm, 149 Tb, 161 Tb, 186 Re, 188 Re, 212 Pb, 213 Bi, 223 Ra, 225 Ac, 226 Th, 227 Th, 131 I, 211 At or 111 In; a further preferred radionuclide is 68 Ga, 177 Lu or 90 Y.

8. A radioactively labeled prostate-specific membrane antigen targeting compound, the structure of which is shown as the following formula (III): wherein, L 1 is -(X) n -(CH 2 ) m -(Y) q -, where n is an integer from 0 to 12 (preferably an integer from 0 - 6), X and Y are independently selected from lysine, glutamic acid or a derivative structure containing lysine and glutamic acid, m is an integer from 0 to 60 (preferably an integer from 0 - 30), q is an integer from 0 to 12 (preferably an integer from 0 - 6), where each CH 2 can be independently replaced by -O-, -NH(CO)- or -(CO)-NH-; L 2 is -(CH 2 ) p -, where p is an integer from 0 to 30 (preferably an integer from 0 - 12), and where each CH 2 may be independently replaced by -O-, -NH(CO)- or -(CO)-NH-, provided that no two adjacent CH 2 groups are replaced; R 1 includes Or The structure of the prostate-specific membrane antigen targeting compound of the structure is preferably selected from: Or M is a radionuclide selected from 68 Ga, 177 Lu or 90 any one of Y.

9. A method for preparing a radioactively labeled prostate-specific membrane antigen targeting compound, comprising the following steps: Dissolve the compound of formula (I) according to claim 1 in a buffer solution or deionized water; Add a radionuclide solution to the obtained solution, and react in a closed system for 5 - 40 min to generate a radionuclide-labeled complex; or comprising the following steps: Dissolve the compound of formula (I) according to claim 1 in a buffer solution or deionized water; After filtering the obtained solution aseptically, dispense it into containers, freeze-dry it and then stopper and seal it to obtain a freeze-dried drug kit; Add an appropriate amount of acetic acid solution or buffer to dissolve the freeze-dried drug kit, and then add the corresponding radionuclide solution, and react in a closed system for 5 - 40 min to generate a radionuclide-labeled complex.

10. A pharmaceutical composition, which comprises the compound according to any one of claims 1 - 8 and a pharmaceutically acceptable carrier.

11. According to the composition of claim 10, characterized in that: The said pharmaceutically acceptable carrier is selected from binders, buffers, colorants, diluents, disintegrants, emulsifiers, flavoring agents, glidants, lubricants, preservatives, stabilizers, surfactants, tabletting agents or wetting agents, or a combination thereof.

12. A method for treating or diagnosing prostate cancer in a mammal, which comprises administering to the mammal a therapeutically effective amount of the compound according to any one of claims 1 - 8, optionally in combination with one or more other active ingredients.

13. According to the method of claim 11, characterized in that: The said one or more other active ingredients are selected from one or more other therapeutic compounds; The said other therapeutic compounds are further preferably anti-cancer therapeutic compounds, more preferably doxorubicin, paclitaxel, docetaxel, cisplatin, camptothecin, temozolomide, bevacizumab, trastuzumab or cetuximab or a combination thereof.

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