Use of a prostate-specific membrane antigen targeting compound

Abstract

The present application provides a prostate-specific membrane antigen targeting compound or a pharmaceutically acceptable salt thereof as shown in formula (II-1) in the preparation of a human or mammalian PSMA high expression tumor nuclide treatment or imaging drug.

Description

[0001] This application is a divisional application of Chinese patent application No. 2022800032950, ​​filed on February 27, 2022, entitled "A prostate-specific membrane antigen targeting compound and its preparation method and application". Technical Field

[0002] This invention relates to the field of nuclear medicine and molecular imaging, specifically to a prostate-specific membrane antigen-targeting compound and its preparation, labeling, and application. Background Technology

[0003] Prostate-specific membrane antigen (PSMA) is expressed 100 to 1000 times more in prostate cancer cells than in normal cells, and its expression is even higher in advanced cancer and cancer cells treated with anti-androgen therapy. These characteristics make PSMA an ideal target for targeted diagnosis and treatment of prostate cancer.

[0004] In December 2020, the U.S. Food and Drug Administration (FDA) 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 trials for 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 low uptake and short retention time at the tumor site, with approximately 30% of patients experiencing adverse reactions. 177 Lu-PSMA617 treatment was unresponsive. To increase the dose delivered to the tumor, studies have explored linking maleimide-modified truncated Evanslan with thiol-containing PSMA. 177 Lu-EB-PSMA617, by binding to albumin in the blood, significantly prolonged the circulating half-life of the PSMA-targeting probe. While this modification strategy increased tumor uptake and prolonged tumor retention time, subsequent studies revealed new problems. 177 Among patients treated with Lu-EB-PSMA617 (3.52±0.58 GBq), 37.5% developed grade 3-4 anemia, 12.5% ​​developed leukopenia, and 37.5% developed thrombocytopenia (Journal of Nuclear Medicine December 2020, 61(12): 1772-1778). This indicates... 177The excessively long blood half-life of Lu-EB-PSMA617 leads to hematologic toxicity and bone marrow suppression, particularly severe in patients with prostate cancer and significant bone metastasis burden, whose bone marrow function is borderline. Such severe side effects significantly diminish the clinical value of targeted therapies. These studies have revealed that a longer circulating half-life for targeted probes used in cancer treatment is not necessarily better; rather, the goal is to maintain a reasonable blood circulation time while ensuring high tumor uptake.

[0005] Therefore, it is necessary to further optimize PSMA-targeting probes to adjust the blood circulation time to an appropriate range while meeting the high uptake requirements of tumors, so as to meet the needs of radionuclide therapy and achieve maximum therapeutic benefits. Summary of the Invention

[0006] Against this background, the primary objective of this invention is to develop a prostate-specific membrane antigen-targeting compound that exhibits high tumor uptake and suitable blood circulation time, thereby overcoming the limitations of existing small molecule compounds. 177 Lu-PSMA617 suffers from drawbacks such as rapid metabolism and short target organ retention time, while also avoiding issues like... 177 Like Lu-EB-PSMA617, which suffers from hematologic toxicity and bone marrow suppression due to its excessively long blood half-life, this approach aims to improve the efficacy of targeted PSMA radionuclide therapy, thereby making it truly valuable and potential for widespread clinical application.

[0007] Another objective of this invention is to provide a radiolabeled prostate-specific membrane antigen targeting complex that also has high tumor uptake and suitable blood circulation time, thus combining the advantages of high tumor therapeutic efficacy 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 application of the aforementioned complex in targeted prostate cancer radionuclide imaging and treatment.

[0010] The technical solutions for achieving the primary objective of this invention include the following two aspects: ligand synthesis and radiolabeling.

[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 which is shown in formula (I) below;

[0012]

[0013] in:

[0014] L1 is -(X) n -(CH2)m -(Y) q - where 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 derivatives 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), and each CH2 can be individually replaced by -O-, -NH(CO)- or -(CO)-NH-;

[0015] L2 is -(CH2) p - where p is an integer from 0 to 30 (preferably an integer from 0 to 12), wherein each CH2 group may be individually replaced by -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:

[0017]

[0018] R2 is a radionuclide chelating group, selected from any of the following structures:

[0019]

[0020] In the present invention, R1 in formula (I) is preferably selected from:

[0021]

[0022] In a preferred embodiment of the present invention, R1 in formula (I) is R2 is That is, the structure of the compound is shown in formula (II):

[0023]

[0024] L1 is preferentially selected from:

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

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

[0027] -Lys-(CO)-CH2CH2-(OCH2CH2)2-(CO)-NH-CH2-(CO)-,

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

[0029] -(CO)-CH2CH2-(OCH2CH2)-(CO)-Lys-, -(CO)-CH2CH2-(OCH2CH2)2-(CO)-Lys-,

[0030] -(CO)-CH2CH2-(OCH2CH2)4-Lys-, -Lys-(CO)-CH2-(CO)-NH-CH2-(CO)-,

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

[0032] -Lys-(CO)-CH2-(OCH2CH2)3-O-CH2(CO)-NH-CH2-(CO)-, -(CO)-CH2-(CO)-Lys-, or

[0033] -(CO)-(OCH2CH2)-O-CH2(CO)-Lys-, -(CO)-CH2-(OCH2CH2)3-O-CH2(CO)-Lys-.

[0034] In a further preferred embodiment of the present invention, the compound structure is shown in formula (II-1):

[0035]

[0036] 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):

[0037]

[0038]

[0039]

[0040]

[0041] or

[0042]

[0043] Based on this, the present invention further provides a method for preparing the compound shown in formula (II-1), comprising the following steps:

[0044] 4,4′-diamino-3,3′-dimethylbiphenyl was unilaterally protected with Boc, and then reacted with 4,6-diamino-5-hydroxy-1,3-naphthalenedisulfonic acid to prepare a truncated Evans blue derivative. After removing the Boc protection, it underwent an amide condensation reaction with Nα-Fmoc-Nε-Boc-L-lysine. The Boc protecting group was then removed under TFA. Next, it reacted with COOH-PEG2-COOH. Then, it reacted with PSMA-617 in the presence of EDC and NHS. Fmoc protection was then removed using piperazine. Finally, it reacted with DOTA-NHS to obtain the compound with the structure shown in formula (II-1).

[0045] The preferred method for preparing the compound of formula (II-1) of the present invention specifically includes the following steps:

[0046] 4,4′-diamino-3,3'-dimethylbiphenyl (compound 1) was reacted with di-tert-butyl dicarbonate to give compound 2; compound 2 was reacted with 4,6-diamino-5-hydroxy-1,3-naphthalenedisulfonic acid and sodium nitrite to prepare a truncated Evans blue derivative (compound 3); compound 3 was deprotected from Boc to give compound 4; compound 4 was condensed with Nα-Fmoc-Nε-Boc-L-lysine in the presence of HATU and DIPEA to give compound 5; compound 5 was dissolved in trifluoroacetic acid solution to remove the protecting group to give compound 6; compound 6 was dissolved in N,N-dimethylformamide and reacted with COOH-PEG2-COOH in the presence of HATU to give compound 7; then reacted with PSMA-617 in the presence of EDC and NHS to give compound 8; then Fmoc protection was removed with piperazine to give compound 9; finally reacted with DOTA-NHS to give compound 10 with the structure shown in formula (II-1).

[0047] The specific synthetic route for the above steps is as follows:

[0048]

[0049] The preparation methods of other compounds in this invention are similar to those of compound 10, and can be basically carried out based on existing conventional methods and with reference to the synthetic route of compound 10.

[0050] 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) described in the present invention as a ligand. The radiolabeled complex can serve as a novel tumor radiodiagnostic and therapeutic probe, that is, it can be used as a radionuclide diagnostic probe or a radionuclide therapeutic probe. The radionuclide can be selected... 177 Lu、 90 Y、18 F, 64 Cu、 68 Ga、 62 Cu、 67 Cu、 86 Y、 89 Zr、 99m rc、 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; preferred 68 Ga、 177 Lu or 90 Y.

[0051] The preferred complex of the present invention has the structure shown in formula (III):

[0052]

[0053] in,

[0054] L1 is -(X) n -(CH2) m -(Y) q - where 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 derivatives 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), and each CH2 can be individually replaced by -O-, -NH(CO)- or -(CO)-NH-;

[0055] L2 is -(CH2) p - where p is an integer from 0 to 30 (preferably an integer from 0 to 12), wherein each CH2 group may be individually replaced by -O-, -NH(CO)- or -(CO)-NH-, provided that no two adjacent CH2 groups are replaced;

[0056] R1 is a type of... or The structure of the prostate-specific membrane antigen-targeting compound is preferably selected from:

[0057]

[0058]

[0059] or

[0060]

[0061] M is a radioactive nuclide selected from... 68 Ga、 177 Lu or 90 Any one of Y.

[0062] The radiolabeled complex of the present invention can be prepared by combining 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 lyophilization method:

[0063] The wet labeling scheme includes: dissolving an appropriate amount of the compound of formula (I) described in this invention in a buffer solution or deionized water; adding a radioactive nuclide solution to the resulting solution, and reacting in a sealed container for 5-40 minutes to generate a radioactive nuclide-labeled complex;

[0064] Alternatively, the lyophilization labeling scheme includes: dissolving an appropriate amount of the compound of formula (I) described in this invention in a buffer solution or deionized water; sterilizing the resulting solution, dispensing it into containers, lyophilizing it, and then sealing it to obtain a lyophilized medicine box; adding an appropriate amount of acetic acid solution or buffer solution to the lyophilized medicine box to dissolve it, then adding the corresponding radionuclide solution, and reacting in a sealed container for 5-40 minutes to generate a radionuclide-labeled complex. The dispensing container is preferably a cryovial or a controlled antibiotic vial. Excipients, such as mannitol or ascorbic acid, can be added to the medicine box depending on the lyophilization powder forming process, and the optimal forming of the medicine box can be achieved by adjusting the amount of the compound of formula (I) described in this invention and the excipients.

[0065] The products obtained by the wet labeling scheme and the lyophilized labeling scheme can be further processed into injection solutions by conventional methods (such as chromatographic separation and purification, rotary evaporation to remove solvent, dissolving the residue with PBS, water or physiological saline, sterile filtration, etc.).

[0066] In a preferred embodiment of the present invention, compound 10, as shown in formula (II-1), is used as the ligand. The preferred method for preparing the 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, reacting at 37-90°C for 5-40 minutes in a sealed environment, and then cooling; diluting the reaction solution with water and purifying it using a Sep-Pak C18 column; rinsing the column with buffer or water to remove unreacted radioactive ions; rinsing with hydrochloric acid-ethanol solution or ethanol solution; and then diluting with physiological saline or PBS and sterile filtering to obtain an injection solution of the radiolabeled complex with the structure described in formula (IV); wherein the radionuclide M is... 68 Ga、 177 Lu or 90 Y et al.

[0067] Another preferred method for preparing the radiolabeled compound 10 of this invention is the lyophilization labeling method, comprising: dissolving compound 10 and other necessary reagents in a buffer solution; sterile filtering the resulting solution and dispensing it into cryovials; lyophilizing and sealing the cryovials to obtain a lyophilized drug case; adding an appropriate amount of buffer solution to the lyophilized drug case to dissolve the compound, then adding a freshly prepared radioactive solution, reacting at 37-120℃ for 5-40 min under sealed conditions, and cooling; diluting the reaction solution with water and purifying it using a Sep-Pak C18 chromatographic column; rinsing the column with buffer solution or water to remove unreacted radioactive ions; rinsing with hydrochloric acid-ethanol solution or ethanol solution; and then diluting with physiological saline or PBS and sterilely filtering to obtain an injection solution of the radiolabeled complex with the structure shown in formula (IV); wherein the radionuclide M is... 68 Ga、 177 Lu or 90 Y et al.

[0068]

[0069] The other chemical substances used in the above synthesis steps are commercially available products.

[0070] The buffer solution is a substance that stabilizes the pH of the reaction solution, and may be acetate, lactate, tartrate, malate, maleate, succinate, ascorbate, carbonate, phosphate, or mixtures thereof.

[0071] In another aspect, the present invention also provides the use of the compound of formula (I) or a pharmaceutically acceptable salt thereof in the preparation of radionuclide therapeutic or imaging drugs for mammalian tumors with high PSMA expression.

[0072] The present invention also provides the application of the radiolabeled complex of formula (III) in radionuclide therapy and imaging of mammalian PSMA-overexpressing tumors.

[0073] In a preferred application of the present invention, the complex is prepared as an injection and administered intravenously to human patients or mammals with PSMA-overexpressing tumors.

[0074] This invention provides a prostate-specific membrane antigen (PSMA) targeting compound with high tumor uptake and suitable blood circulation time, as well as its radionuclide-labeled complex, and provides methods for preparing and labeling this compound. Biological assays show that it has a suitable blood circulation half-life, high tumor uptake, and retention time. These superior properties are not found in other PSMA-targeting agents, making it suitable for radionuclide therapy and imaging of PSMA-overexpressing tumors. Attached Figure Description

[0075] Figure 1 This reflects the tumor uptake results 24 hours after injection of different drugs into a mouse model of subcutaneous prostate cancer xenografts.

[0076] Figure 2 This is demonstrated by injecting compound 31 of Example into normal mice. 177 Lu-PSMA and 177 Comparison of blood uptake at different time points after Lu-EB-PSMA 617.

[0077] Figure 3 This reflects the tissue distribution results 24 hours after injection of compound 31 in a mouse subcutaneous xenograft model of prostate cancer.

[0078] Figure 4 This is demonstrated by injection into a mouse subcutaneous xenograft model of prostate cancer. 177 Tissue distribution results of Lu-EB-PSMA 617 24 hours later.

[0079] Figure 5 These are SPECT-CT images taken at different time points after normal mice were injected with the compound of Example 31.

[0080] Figure 6 In a normal mouse injection example 177 SPECT-CT images at different time points after Lu-labeled compound II-2.

[0081] Figure 7 Injected into normal mice 177 Blood uptake results at different time points after Lu-labeled compound II-2.

[0082] Figure 8 This is the mass spectrum of compound 10 prepared in Example 1.

[0083] Figure 9This is the mass spectrum of compound II-3 prepared in Example 3.

[0084] Figure 10 This is the HPLC chromatogram of compound 5 prepared in Example 1.

[0085] Figure 11 This is the HPLC chromatogram of compound 6 prepared in Example 1.

[0086] Figure 12 This is the HPLC chromatogram of compound 7 prepared in Example 1.

[0087] Figure 13 This is the HPLC chromatogram of compound 8 prepared in Example 1.

[0088] Figure 14 This is the HPLC chromatogram of compound 9 prepared in Example 1.

[0089] Figure 15 This is the HPLC chromatogram of compound 10 prepared in Example 1. Detailed Implementation

[0090] The technical solution of the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings.

[0091] Example 1: Preparation of compound 10 of formula (II-1)

[0092] Synthesis of compound 2:

[0093] In a 100 mL flask, 4,4′-diamino-3,3'-dimethylbiphenyl (compound 11) (2.12 g, 10.0 mmol), ditert-butyl dicarbonate (2.2 g, 10.0 mmol), and N,N-diisopropylethylamine (1.3 g, 10.0 mmol) were added, and the mixture was stirred overnight at room temperature. The reaction was monitored by HPLC (rt = 10.13 min). The solvent was removed by vacuum distillation to obtain the crude product, which was purified by silica gel column chromatography (petroleum ether / ethyl acetate = 5:1) to give compound 2 as a white solid, with a yield of 59%.

[0094] Synthesis of compound 3:

[0095] In a 50 mL flask, compound 2 (0.31 g, 1.0 mmol) and 4 mL of acetonitrile were added separately. The mixture was kept in an ice bath. 1.5 mL of 2M hydrochloric acid was added dropwise to the reaction flask, and the reaction was allowed to proceed for 15 min. Sodium nitrite (0.068 g, 1.0 mmol) dissolved in 2 mL of water was added dropwise to the reaction flask, and the reaction was allowed to proceed for another 30 minutes. This solution, known as solution A, was prepared separately. In another 50 mL reaction 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 kept in an ice bath. Solution A was slowly added dropwise to solution B, and the reaction was stirred in an ice bath for 2 hours. The mixture was then subjected to reverse-phase column chromatography and freeze-dried to obtain pure compound 3 in 47% yield.

[0096] Synthesis of compound 4:

[0097] Compound 3 (0.52 g, 1.0 mmol) was dissolved in trifluoroacetic acid under ice bath conditions. The system was heated to room temperature and reacted for 2 h. After the reaction was completed, the solvent was removed by vacuum distillation to obtain the crude product. The crude product was subjected to reverse-phase column chromatography and freeze-dried to obtain pure compound 4 in 73% yield.

[0098] Synthesis of compound 5:

[0099] 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), and N,N-diisopropylethylamine (0.26 g, 2.0 mmol), along with 10 mL of N,N-dimethylformamide, were added to a 100 mL flask. The reaction mixture was stirred until complete, and the solvent was removed by vacuum distillation to obtain the crude product. The crude product was subjected to reverse-phase column chromatography and freeze-dried to give pure compound 5 in 57% yield.

[0100] Synthesis of compound 6:

[0101] Compound 5 was deprotected from tert-butyl ester and Boc protection using a reaction mixture of thioanisole:1,2-ethanedithiol:anisole:TFA (5:3:2:90) at room temperature to give compound 6. After the reaction was complete, TFA was removed by an argon stream, and the compound was then dissolved in 10 mL of N,N-dimethylformamide for later use.

[0102] Synthesis of compound 7:

[0103] To the N,N-dimethylformamide of compound 6, COOH-PEG2-COOH (0.23 g, 110 mmol), HATU (0.38 g, 1.0 mmol), and N,N-diisopropylethylamine (0.39 g, 3.0 mmol) were added, respectively. The mixture was stirred overnight at room temperature, and the reaction was monitored by HPLC (rt = 10.84 min). The solvent was removed by vacuum distillation to obtain the crude product. The crude product was subjected to reverse-phase column chromatography and freeze-dried to obtain pure compound 7, with a two-step yield of 50%.

[0104] Synthesis of compound 8:

[0105] 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 to a 50 mL flask. After reacting for 4 h, N,N-diisopropylethylamine (0.06 g, 0.5 mmol) and PSMA-617 (0.13 g, 0.2 mmol) were added, and the reaction mixture was stirred. The reaction was monitored by HPLC (rt = 12.16 min). The solvent was removed by vacuum distillation to obtain the crude product. The crude product was subjected to reverse-phase column chromatography and freeze-dried to obtain pure compound 8 in 59% yield.

[0106] Synthesis of compound 9:

[0107] Compound 8 (0.16 g, 0.1 mmol) and piperidine (0.08 g, 10.0 mmol) were added to 5 mL of DMF in a 25 mL flask. The deprotection process was monitored by HPLC until the reaction was complete (rt = 10.47 min). The solvent was removed by vacuum distillation to obtain the crude product. The crude product was subjected to reverse-phase column chromatography and freeze-dried to obtain pure compound 9 in 63% yield.

[0108] Synthesis of compound 10:

[0109] 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 sequentially to 5 mL of N,N-dimethylformamide in a 25 mL flask. The reaction mixture was stirred at room temperature and monitored by HPLC until the reaction was complete (rt = 11.35 min). The solvent was removed by vacuum distillation to obtain the crude product. The crude product was subjected to reverse-phase column chromatography and freeze-dried to obtain pure compound 10 in 61% yield. Characterization of its structure is described in [reference needed]. Figure 8 .

[0110] The synthesis route for the above steps is as follows:

[0111]

[0112]

[0113] Examples 2-6

[0114] The structures of the compounds in Examples 2-6 are shown in Formulas (II-2) to (II-6). Their preparation methods can all refer to Example 1. For example, in the preparation of Formulas (II-2) and (II-3), the COOH-PEG2-COOH reacting with compound 6 in Example 1 is replaced with COOH-PEG4-COOH, malonic acid, or other suitable compounds; in the preparation of Formulas (II-4) to (II-6), the Nα-Fmoc-Nε-Boc-L-lysine reacting with compound 4 in Example 1 is replaced with Boc glycine, and the PSMA-617 reacting with compound 7 in Example 1 is replaced with PSMA-617-(Fmoc)Lys-, resulting in the following corresponding structures:

[0115]

[0116]

[0117]

[0118]

[0119] or

[0120]

[0121] For characterization of the structure of the above compound II-3, please refer to [link to relevant documentation]. Figure 9 .

[0122] Examples 7-30:

[0123] Compounds expressed by formula (I) were prepared according to the preparation methods described in Examples 1-6:

[0124]

[0125]

[0126]

[0127]

[0128] Example 31. Preparation of a Lu-177 labeled complex:

[0129] Wet method: Approximately 18.5–1850 MBq 177LuCl3 sodium acetate solution was added to centrifuge tubes containing 0.5 mL of acetic acid-acetate solution (1.0 g / L) of compound 10 from Example 1, and the mixture was incubated at 90 °C for 20 min. A C18 separation column was taken and slowly rinsed with 10 mL of anhydrous ethanol, followed by 10 mL of water. The labeled solution was diluted with 10 mL of water and loaded onto the separation column. Unlabeled components were first removed with 10 mL of water. 177 Lu ions were obtained by rinsing with 0.3 mL of 10 mM HCl in ethanol. 177 Lu-labeled complexes. The eluent was diluted with physiological saline and then sterile filtered to obtain... 177 Injection of Lu-labeled complexes.

[0130] Freeze-drying method: approximately 18.5–1850 MBq 177 LuCl3 sodium acetate solution was added to the lyophilized kit containing compound 10 from Example 1, mixed well, and reacted at 90°C for 20 min. A C18 separation column was taken, first slowly rinsed with 10 mL of anhydrous ethanol, then rinsed with 10 mL of water. The labeled solution was diluted with 10 mL of water and loaded onto the separation column. Unlabeled components were first removed with 10 mL of water. 177 Lu ions were obtained by rinsing with 0.3 mL of 10 mM HCl in ethanol. 177 The Lu-labeled complex eluent was obtained by diluting the eluent with physiological saline and then sterile filtering. 177 Injection of Lu-labeled complexes.

[0131] Experimental Example. Analysis and Application Effects

[0132] 1. HPLC analysis and identification

[0133] The HPLC system was as follows: SHIMADZULC-20A; C18 column (YMC, 3μm, 4.6×150mm) was used for analysis. Detection wavelength was 254nm, flow rate was 1mL / min, and the elution gradient was as follows: 0–3 min: 10% acetonitrile and 90% water (50mM ammonium acetate) remained constant; 3–16 min: increased to 90% acetonitrile and 10% water (50mM ammonium acetate); 16–18 min: maintained at 90% acetonitrile and 10% water (50mM ammonium acetate); 18–20 min: decreased to 10% acetonitrile and 90% water (50mM ammonium acetate); 20–22 min: maintained at 10% acetonitrile and 90% water (50mM ammonium acetate).

[0134] Compounds 5, 6, 7, 8, 9, and 10 from Example 1 were identified and analyzed using the above-described system. The identification and analysis results are as follows: Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 and Figure 15 As shown.

[0135] The following describes the performance determination experiments using the radiolabeled probe prepared in Example 31 as the experimental reagent:

[0136] 2. 177 Uptake of Lu-labeled complexes in a mouse subcutaneous xenograft model of prostate cancer

[0137] In a mouse model of subcutaneous prostate cancer xenografts, the compound of Example 31 or other existing radioactive probes targeting PSMA were injected, and tumor uptake and tissue distribution results were compared. The specific protocol is as follows:

[0138] The mouse subcutaneous xenograft model of prostate cancer (22RV1) was randomly divided into 3 groups: experimental group, control group A and control group B, with 3 mice in each group.

[0139] Prepare a product with a purity greater than 95% according to the method in Example 31. 177 Lu complex, which is 177 Compound 10 of Example 1, labeled with Lu, is used as the drug in the experimental group of this experiment and is designated as drug B.

[0140] Prepare a product with a purity greater than 95% using existing methods. 177 Lu-PSMA 617, used as the control group A in this experiment, is denoted as drug A.

[0141] 177Lu-EB-PSMA617 with a purity greater than 95% was prepared according to the method in Example 8 of WO2019 / 165200 and used as the drug in control group B of this experiment, denoted as drug C.

[0142] The experimental group, control group A, and control group B were injected intravenously with 5 MBq of drugs B, A, and C, respectively. Twenty-four hours after injection, mice in each group were sacrificed, and tumor tissue, blood, or other tissues were obtained and weighed. The radioactivity counts of the samples from the experimental group, control group A, and control group B were measured using a gamma counter. The measured data were adjusted for background and decay time, and then averaged. Data are expressed as the percentage of the injected dose taken up per gram of tissue (%ID / g). Results are shown in [Figure number missing]. Figure 1 , Figure 3 and Figure 4 .

[0143] Depend on Figure 1 As can be seen, in embodiment 31 of the present invention 177 The Lu complex (B) showed tumor uptake of 23.46 ± 0.63% ID / g 24 hours after injection, significantly higher than that of the control group A. 177Tumor uptake of Lu-PSMA 617(A) (7.60±1.22% ID / g) was lower than that of control group B. 177 Tumor uptake of Lu-EB-PSMA617(C) (48.97±7.77% ID / g).

[0144] Figure 3 and Figure 4 The experimental groups were injected with the product of Example 31 of the present invention. 177 Lu complex (B) and control group B were injected 177 The distribution of major tissues after 24 hours of Lu-EB-PSMA617(C) treatment can be observed, as in Example 31 of this invention. 177 Renal uptake of Lu complex 24 hours after injection ( Figure 3 ) far below 177 Lu-EB-PSMA617 group ( Figure 4 ).

[0145] 3. 177 Experiments with Lu-labeled complexes in normal mice

[0146] 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.

[0147] Prepare a product with a purity greater than 95% according to the method in Example 31. 177 Lu complex, which is 177 Compound 10 of Example 1, labeled with Lu, was used as drug B in experimental group one of this experiment.

[0148] Following the method of Example 31, compound 10 was replaced with compound II-2 from Example 2 to prepare the following product: 177 The Lu-labeled compound II-2 was used as drug D in experimental group two of this experiment.

[0149] Prepare a product with a purity greater than 95% using existing methods. 177 Lu-PSMA 617, used as the control group A in this experiment, is denoted as drug A.

[0150] 177Lu-EB-PSMA617 with a purity greater than 95% was prepared according to the method in Example 8 of WO2019 / 165200 and used as the drug in control group B of this experiment, denoted as drug C.

[0151] Experimental Group 1, Experimental Group 2, Control Group A, and Control Group B were administered 5 MBq of drug B, drug D, drug A, and drug C via tail vein injection, respectively. Blood uptake was measured 1 hour, 4 hours, and 24 hours after injection. Results are shown below. Figure 2 and Figure 7SPECT-CT imaging was performed 1 hour, 4 hours, 24 hours, and 48 hours after injection. The results are shown in the table below. Figure 5 and Figure 6 .

[0152] Depend on Figure 2 As can be seen, at all test time points (1 hour, 4 hours, and 24 hours), the performance of Embodiment 31 of the present invention... 177 The uptake of Lu complex (B) in the blood is higher than 177 Lu-PSMA617(A) group, but much lower than 177 Lu-EB-PSMA617(C) group. From Figure 7 and Figure 2 The comparison shows that at all test time points (1 hour, 4 hours, and 24 hours), 177 The uptake of Lu-labeled compound II-2 in the blood is far lower than 177 Lu-EB-PSMA 617(C) group.

[0153] Figure 5 and Figure 6 Injection Example 31 177 Lu complexes and 177 SPECT-CT images of normal mice with Lu-labeled compound II-2.

[0154] In summary, compared with existing PSMA-targeting probes, the prostate-specific membrane antigen-targeting compound provided by this invention not only has higher tumor uptake but, more importantly, a suitable blood circulation time. This allows the radionuclide-labeled prostate-specific membrane antigen-targeting compound of this invention to meet the treatment needs in terms of blood uptake and tumor uptake when treating prostate cancer, while significantly reducing the risks of blood toxicity and bone marrow suppression. It has higher clinical application value and is expected to be applied to radionuclide therapy and imaging of prostate cancer.

[0155] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. The use of a prostate-specific membrane antigen-targeting compound or a pharmaceutically usable salt thereof in the preparation of a radionuclide therapy or imaging drug for mammalian prostate cancer, characterized in that, The structure of the prostate-specific membrane antigen-targeting compound is shown in formula (II-1): Equation (II-1).

2. The application of a radiolabeled prostate-specific membrane antigen-targeting compound in the preparation of radionuclide therapy and imaging drugs for mammalian prostate cancer, characterized in that, The radiolabeled prostate-specific membrane antigen-targeting compound is a complex obtained by labeling a radionuclide with the compound shown in formula (II-1) as a ligand; Equation (II-1).

3. The application according to claim 2, characterized in that, The radionuclides mentioned are selected from 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.

4. The application according to claim 3, characterized in that, The radionuclides mentioned are selected from 68 Ga、 177 Lu or 90 Y.

5. The application according to any one of claims 2-4, characterized in that, The complex is prepared into an injection and administered via intravenous injection.

6. The application according to claim 5, characterized in that: The therapeutically effective amount of the compound is combined with one or more other active ingredients; the one or more other active ingredients are selected from one or more other therapeutic compounds; the other therapeutic compounds are selected from anticancer therapeutic compounds, which are selected from doxorubicin, paclitaxel, docetaxel, cisplatin, camptothecin, temozolomide, bevacizumab, trastuzumab, cetuximab, or combinations thereof.

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