A DOTA-Te-PSMA compound and its application

Abstract

The present invention provides a DOTA-Te-PSMA compound and its application, belonging to the field of biomedicine technology, and its structure is shown in Formula I: Formula I. It can be used as a precursor compound of a PSMA targeting tracer or a precursor compound of a PSMA targeting therapeutic drug.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedicine, and in particular to a DOTA-Te-PSMA compound and application thereof. Background Art

[0002] Prostate cancer is one of the diseases that affect the health of adult men. In 2020, 380,000 people died of prostate cancer worldwide, and the trend is increasing every year, which has seriously threatened men's health. The main method for detecting prostate cancer is to measure PSA (prostate specific antigen) in plasma, but some false positive results may occur, such as prostate hyperplasia and prostatitis, which can also cause PSA to increase. In order to further confirm the results, a puncture biopsy is required, which undoubtedly brings many inconveniences to patients. The development of imaging technology has provided a non-invasive visualization method for the diagnosis of prostate cancer. In recent years, nuclear medicine has played an important role in the diagnosis of prostate cancer. Nuclear medicine uses targeted ligands to carry radionuclides to target tissues and organs for imaging and treatment. Compared with CT and MRI imaging, nuclear medicine detection has high sensitivity and is very helpful for early diagnosis and treatment monitoring of diseases, especially tumors. For prostate cancer, 11C acetic acid and 18F choline are commonly used in clinical PET / CT examinations, but these two probes cannot truly reflect the true situation of the tumor. Therefore, it is necessary to find a prostate cancer biomarker to truly reflect the occurrence and development of the tumor. Prostate-specific membrane antigen (PSMA) is a membrane protein that is selectively and highly expressed on the surface of prostate cancer cells. Normal prostate cancer expresses less, which makes PSMA have great advantages in diagnosing prostate cancer.

[0003] PSMA is highly expressed in prostate cancer and its metastases, and its expression level is closely related to the occurrence and development of tumors and treatment prognosis. Studies have shown that PSMA is highly expressed on the surface of 90% of prostate cancer cells, making PSMA an ideal biomarker for high sensitivity and high specificity for the integrated diagnosis and treatment of prostate cancer and its metastases.

[0004] There is a certain amount of expression in the salivary glands and kidneys.

[0005] At present, radionuclide-labeled PSMA molecular probes still have some shortcomings, such as: affinity needs to be improved, high uptake in non-target tissues and organs, certain toxic side effects, short plasma half-life and poor therapeutic effect. Summary of the invention

[0006] The object of the present invention is to provide a DOTA-Te-PSMA compound and its application, so as to solve the technical problems in the prior art that the affinity of PSMA molecular probe needs to be improved, the uptake of non-target tissues and organs is high, there are certain toxic and side effects, the plasma half-life is short and the therapeutic effect is poor.

[0007] A DOTA-Te-PSMA compound or a salt thereof, whose structure is shown in Formula I:

[0008]

[0009] Formula I. can be used as a precursor compound of a PSMA-targeted tracer or a precursor compound of a PSMA-targeted therapeutic drug.

[0010] The second object of the present invention is to protect a radiolabeled ligand comprising a radionuclide and a DOTA-Te-PSMA compound or a salt thereof.

[0011] Furthermore, the radionuclide is selected from 68 Ga, 177 Lu, 99m Tc, 111 In, 67 Ga, 86 Y. 90 Y. 161 Tb, 186 Re, 188 Re, 64 Cu, 67 Cu, 211 At 225 Ac, 18 F. 1123 I. 124 I or 125 At least one of I; preferably 68 Ga, 177 Lu, 99m Tc, 111I n. 64 Cu, 18 F or 225 At least one of Ac; more preferably 68 Ga, 177 Lu or 225 At least one of Ac.

[0012] The radiolabeled complex comprises a radionuclide and a DOTA-Te-PSMA compound or a salt thereof. The radiolabeled complex has good pharmacokinetics in vivo and a very high T / NT ratio one hour after intravenous injection. It also has the advantages of high affinity for prostate-specific membrane antigen and low renal uptake.

[0013] Further, the radiolabeled complex is 68 Ga-DOTA-Te-PSMA compound or a salt thereof, the 68 The structure of Ga-DOTA-Te-PSMA is:

[0014]

[0015] Further, the radiolabeled complex is 177 Lu-DOTA-Te-PSMA compound or a salt thereof, the 177 The structure of Lu-DOTA-Te-PSMA is:

[0016]

[0017] The third object of the present invention is to protect a pharmaceutical composition comprising: (a) the DOTA-Te-PSMA compound or its salt, or the radiolabeled complex; and (b) a pharmaceutically acceptable carrier and / or excipient.

[0018] The fourth object of the present invention is to protect a kit comprising the DOTA-Te-PSMA compound or its salt, or the radiolabeled complex, or the pharmaceutical composition.

[0019] The fifth object of the present invention is to protect the use of the DOTA-Te-PSMA compound or its salt, or the radiolabeled complex, or the pharmaceutical composition, or the kit in the preparation of a product for detecting and / or detecting cells and / or tissues expressing prostate-specific membrane antigen.

[0020] Furthermore, the cells and / or tissues expressing prostate-specific membrane antigen include prostate cancer, pre-metastatic prostate cancer, colon cancer, breast cancer, kidney cancer or bladder cancer.

[0021] Furthermore, the product comprises a diagnostic tracer and / or a therapeutic agent.

[0022] Furthermore, the diagnostic tracer is used for positron emission tomography, electronic computed tomography, positron emission computed tomography, single photon emission tomography or single electron emission computed tomography.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The DOTA-Te-PSMA compound or its salt, radiolabeled complex, pharmaceutical composition or kit described in the present invention has advantages such as high affinity, high T / NT value and rapid renal clearance in the diagnosis, treatment, metastasis and staging of prostate cancer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the mass spectrum of DOTA-Te-PSMA.

[0026] Figure 2 This is the UV spectrum of DOTA-Te-PSMA.

[0027] Figure 3 for 68 Radio-HPLC spectrum of Ga-DOTA-Te-PSMA.

[0028] Figure 4 for 177 Radio-HPLC spectrum of Lu-DOTA-Te-PSMA.

[0029] Figure 5 for 68 PET / CT images of Ga-DOTA-Te-PSMA on PC3-PIP model.

[0030] Figure 6 for 68 PET / CT images of Ga-PSMA11 on PC3-PIP model.

[0031] Figure 7 for 177 SPETCT / CT images of Lu-DOTA-Te-PSMA on PC3-PIP model.

[0032] Figure 8 for 177 SPETCT / CT images of Lu-PSMA617 on PC3-PIP model.

[0033] Fig. 9 for 68 In vitro stability data of Ga-DOTA-Te-PSMA.

[0034] Fig.10 for 68 Ga-DOTA-Te-PSMA uptake data into PC3-PIP cells.

[0035] Fig.11 for 68 In vivo distribution data of Ga-DOTA-Te-PSMA in the PC3-PIP model. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0037] Example 1

[0038] This example discloses the synthesis of DOTA-Te-PSMA

[0039] Take 2 mmol of tert-butyl protected 2PSMA-PEG4-NH2 as the starting material, dissolve it with 2.2 mmol of DOTA-glycine in an appropriate amount of DMF, slowly add 3.0 mmol of HATU and 3.0 mmol of HOBT at 0°C, add an appropriate amount of DIPEA as a catalyst, react at room temperature overnight, monitor by TLC spot plate, purify by silica gel column after the reaction is complete, and de-tert-butyl protect the product with 95% trifluoroacetic acid to obtain a crude product.

[0040] The obtained crude product was separated and purified by preparative RP-HPLC, and the purified product was analyzed by analytical HPLC and MS. Figure 1 , HPLC chart see Figure 2 .

[0041] Example 2

[0042] This embodiment discloses 68 Preparation of Ga-DOTA-Te-PSMA

[0043] Using DOTA-Te-PSMA compound as precursor, prepare DOTA-Te-PSMA into a 1 μg / μl solution for standby use. Take 25 μl of the above precursor solution and add it to 37 MBq to 1000 MBq of 68 GaCl3 solution, and adjust pH to 4-5 with 0.25M sodium acetate buffer, react at 90℃ for 15min. Add 5ml of saline to the reaction solution and pass it through a C18 light column. Use 20ml of saline to wash the remaining 68 GaCl3. Elute the product in the C18 column with 2 ml of 50% ethanol solution, pass through a 0.22um sterile filter membrane, and finally dilute the ethanol concentration to less than 10%. Radiochemical purity> 98%, such as Figure 3 shown.

[0044] Example 3

[0045] This embodiment discloses 177 Preparation of Lu-DOTA-Te-PSMA

[0046] Using DOTA-Te-PSMA compound as precursor, prepare DOTA-Te-PSMA into a 1 μg / μl solution for standby use. Take 25 μl of the above precursor solution and add it to 37 MBq to 1000 MBq of 177 LuCl3 solution, and adjust pH to 4-5 with 0.25M sodium acetate buffer, react at 90℃ for 15min. Add 5ml of saline to the reaction solution and pass it through a C18 light column. Use 20ml of saline to wash the remaining 177 LuCl3. Elute the product in the C18 column with 2 ml of 50% ethanol solution, pass through a 0.22um sterile filter membrane, and finally dilute the ethanol concentration to less than 10%. Radiochemical purity> 98%, such as Figure 4 shown.

[0047] Example 4

[0048] This embodiment discloses 68 PET / CT imaging of Ga-DOTA-Te-PSMA

[0049] Take 100μci 68 Ga-DOTA-Te-PSMA was injected into PC3-PIP tumor-bearing mice with high PSMA expression via the tail vein. PET / CT imaging was performed 0.5h, 1h, 2h, and 5h after injection. The results are shown in Figure 5 shown.

[0050] Example 5

[0051] This embodiment discloses 68 PET / CT imaging of Ga-PSMA11

[0052] Take 100μci 68 Ga-PSMA11 was injected into PC3-PIP tumor-bearing mice with high PSMA expression via the tail vein. PET / CT imaging was performed 0.5h, 1h, 2h, and 5h after injection. The results are shown in Figure 6 shown.

[0053] Embodiment 6: 177 SPETCT / CT imaging of Lu-DOTA-Te-PSMA

[0054] Take 200μci 177 Lu-DOTA-Te-PSMA was injected into PC3-PIP tumor-bearing mice with high PSMA expression via the tail vein. SPETCT / CT imaging was performed 6h, 24h, and 48h after injection. The results are as follows: Figure 7 shown.

[0055] Example 7

[0056] This embodiment discloses 177 SPETCT / CT imaging of Lu-PSMA617

[0057] Take 200μci 177 Lu-PSMA617 was injected into PC3-PIP tumor-bearing mice with high PSMA expression via the tail vein. SPETCT / CT imaging was performed 6h, 24h, and 48h after injection. The results are as follows: Figure 8 shown.

[0058] Example 8

[0059] This embodiment discloses 68 In vitro stability of Ga-DOTA-Te-PSMA

[0060] Take 1mci 68 Ga-DOTA-Te-PSMA was added with 1 ml of PBS solution and placed at 37°C. Samples were taken at 0.5 h, 1 h, and 2 h, and the radiochemical purity was measured by Radio-HPLC.

[0061] Take 1mci 68 Ga-DOTA-Te-PSMA was added to 1 ml of 10% FBS solution and placed at 37°C. Samples were taken at 0.5 h, 1 h, and 2 h, and the radiochemical purity was measured by Radio-HPLC. The data obtained are shown in Fig. 9 .

[0062] Example 9

[0063] This embodiment discloses 68 Cellular uptake of Ga-DOTA-Te-PSMA

[0064] PC3-PIP cells were cultured in 1640 medium containing 10% FBS. After the cells grew to 70-80%, they were digested with trypsin and inoculated into 24-well plates (about 1.5*10 5 Cell / well), and cultured overnight at 37°C, 5% CO2. The next day, the cells were starved with pure culture medium 1640, and then about 50ul / 1μCi / well of radiolabeled product was added. The cells were placed in an incubator and cultured for 30, 60 and 120min, and the cell uptake value at each time point was measured using a γ counter (n≥3). The data obtained are shown in Fig.10 Or Table 1.

[0065] Table 1

[0066] Ingest Internalization Blocking uptake 30min 31.47±6.32 11.48±0.33 60min 31.18±5.96 14.07±2.91 0.90801±0.19 120min 29.57±7.06 14.40±3.27

[0067] Example 10

[0068] This embodiment discloses 68Distribution of Ga-DOTA-Te-PSMA in vivo

[0069] Take 50μci 68 Ga-DOTA-Te-PSMA was injected into PC3-PIP tumor-bearing mice with high PSMA expression via the tail vein. The mice were killed by dislocating the neck after 30 minutes, 60 minutes, and 120 minutes. The heart, blood, lung, liver, stomach, spleen, kidney, muscle, small intestine, bone, salivary gland, pancreas and tumor of the mice were immediately collected for gamma counting. The percentage of injected dose per gram of tissue (%ID / g) was calculated. The data obtained are shown in Fig.11 Or Table 2.

[0070] Table 2

[0071] 30min 60min 120min Heart 0.83±0.22 0.34±0.12 0.09±0.02 Liver 0.57±0.07 0.39±0.09 0.21±0.03 Spleen 2.23±0.21 0.96±0.32 0.22±0.09 Lung 1.74±0.13 0.82±0.16 0.24±0.07 Kidney 58.35±2.69 28.87±3.11 4.75±2.63 Stomach 0.76±0.09 0.49±0.26 0.11±0.02 Intestine 0.86±0.15 0.42±0.21 0.09±0.01 Muscle 0.47±0.23 1.09±0.61 0.08±0.03 Bone 0.62±0.11 0.49±0.08 0.32±0.17 Salivary 0.72±0.31 0.60±0.16 0.17±0.02 Brain 0.11±0.01 0.04±0.01 0.03±0.03 Blood 2.23±0.42 0.75±0.41 1.14±1.43 Pancreas 0.77±0.12 0.38±0.07 0.13±0.02 Tumor 23.05±2.66 28.88±1.81 21.84±3.53

[0072] result:

[0073] (1) From Figure 5 It can be seen that 68 Ga-DOTA-Te-PSMA was specifically taken up in PC3-PIP tumor sites with high PSMA expression. The uptake in the kidney was low at 0.5 h and no uptake in the kidney at 1 h of imaging. The uptake in other organs was also low.

[0074] (2) From Figure 6 It can be seen that 68 Ga-PSMA11 was highly uptaken in the kidney at 0.5h, 1h, 2h, and 5h.

[0075] (3) From Figure 7 and Figure 8 It can be seen that 177 Lu-DOTA-Te-PSMA was specifically taken up in PC3-PIP tumors where PSMA was highly expressed, and the uptake was still high at 72 hours. 177 Compared with Lu-PSMA617, 177 The renal uptake of Lu-DOTA-Te-PSMA was significantly lower than 177 Lu-PSMA617.

[0076] (4) From Fig. 9 It can be seen that 68 Ga-DOTA-Te-PSMA has good stability in vitro, and the radiochemical purity is still >95% after 2 hours.

[0077] (5) From Fig.10 As shown in Table 1, 68 Ga-DOTA-Te-PSMA has a higher uptake and internalization in PC3-PIP cells with high PSMA expression, and blocking experiments also prove that DOTA-Te-PSMA targets PSMA.

[0078] (6) From Fig.11 From Table 2, we can see that 68 The uptake of Ga-DOTA-Te-PSMA in mice, where the T / NT value is >50, has a very high T / NT value.

[0079] The embodiments described above are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A DOTA-Te-PSMA compound or a salt thereof, the structure of which is shown in Formula I: Formula I.

2. A radiolabeled complex, characterized in that It comprises a radionuclide and the DOTA-Te-PSMA compound or a salt thereof as claimed in claim 1.

3. A radiolabeled complex according to claim 2, characterized in that: The radionuclide is selected from 68 Ga, 177 Lu, 99m Tc, 111 In, 67 Ga, 86 Y. 90 Y. 161 Tb, 186 Re, 188 Re, 64 Cu, 67 Cu, 211 At 225 Ac, 18 F. 123 I. 124 I or 125 At least one of I.

4. A radiolabeled complex according to claim 3, characterized in that: The radionuclide is selected from 68 Ga, 177 Lu, 99m Tc, 111I n. 64 Cu, 18 F or 225 At least one of Ac.

5. A radiolabeled complex according to claim 4, characterized in that: The radionuclide is selected from 68 Ga, 177 Lu or 225 At least one of Ac.

6. A radiolabeled complex according to any one of claims 3 to 5, characterized in that: The radiolabeled complex is 68 Ga-DOTA-Te-PSMA compound or a salt thereof, the 68 The structure of Ga-DOTA-Te-PSMA is: ； Alternatively, the radiolabeled complex is 177 Lu-DOTA-Te-PSMA compound or a salt thereof, the 177 The structure of Lu-DOTA-Te-PSMA is: 。 7. A pharmaceutical composition, characterized in that include: (a) the DOTA-Te-PSMA compound or a salt thereof according to claim 1, or the radiolabeled complex according to any one of claims 2 to 6; and (b) a pharmaceutically acceptable carrier and / or excipient.

8. Use of the DOTA-Te-PSMA compound or a salt thereof according to claim 1, or the radiolabeled complex according to any one of claims 2 to 6, or the pharmaceutical composition according to claim 7 in the preparation of a product for detecting cells and / or tissues expressing prostate-specific membrane antigen.

9. The use according to claim 8, characterized in that: The cells and / or tissues expressing prostate-specific membrane antigen include prostate cancer, colon cancer, breast cancer, kidney cancer or bladder cancer.

10. The use according to claim 8, characterized in that: The products include diagnostic tracers.

11. The use according to claim 10, characterized in that: The diagnostic tracer is used for positron emission tomography, electronic computed tomography, positron emission computed tomography, single photon emission tomography or single electron emission computed tomography.

12. A kit, characterized in that: The method comprises the DOTA-Te-PSMA compound or a salt thereof according to claim 1, or the radiolabeled complex according to any one of claims 2 to 6, or the pharmaceutical composition according to claim 7.

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