Polypeptide coupling compound as well as preparation method and application thereof

Abstract

The invention provides a polypeptide coupling compound as well as a preparation method and application thereof, and aims at developing a series of polypeptide coupling compounds and polypeptide coupling medicines containing the polypeptide coupling compounds aiming at polypeptide amino terminals aiming at the problems of poor plasma stability, low and insufficient release rate and the like of the polypeptide coupling medicines. The compound can be effectively used for treating and / or preventing diseases.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, and in particular relates to a polypeptide conjugate compound, the resulting polypeptide conjugate drug, and its uses. Background Technology

[0002] Cancer remains a leading cause of death worldwide. Most existing anti-tumor chemotherapy drugs suffer from drawbacks such as poor solubility, significant toxicity, and the development of drug resistance, resulting in unsatisfactory treatment outcomes. Peptide-conjugate drugs (PDCs), however, overcome the shortcomings of conventional chemotherapy drugs due to their selectivity for both autologous and tumor cells, and have become a new focus of anti-tumor drug research in recent years.

[0003] PDC comprises three components: a homing peptide, a linker, and a payload. All three components synergistically deliver chemotherapeutic drugs by targeting receptors on tumor cells, thus amplifying the therapeutic effect. Peptides offer better tissue penetration, lower manufacturing costs, and higher potency, activity, selectivity, and specificity. Furthermore, chemical modifications to peptides can improve the solubility (including water and lipid solubility) of peptide-conjugated drugs compared to the original payload.

[0004] The development of peptide-conjugated drugs faces numerous challenges and problems. Peptide molecules are easily affected by various factors in vivo, such as enzymatic hydrolysis, oxidation, and polymerization, leading to loss of activity or toxicity. Linkers, which act as bridges between peptides and drug molecules, suffer from poor plasma stability, low release rates, and insufficient pharmacokinetic properties. Therefore, this research aims to design and synthesize corresponding peptide-conjugated drugs targeting the amino functional groups in amino acids. Through interdisciplinary collaboration and technological innovation, a series of peptide-conjugated drugs with high stability, high release rates, high antitumor activity, and high solubility have been designed and synthesized. Summary of the Invention

[0005] This invention provides a polypeptide conjugate compound, its preparation method, and its uses. Addressing the problems of poor plasma stability, low release rate, and insufficient release of polypeptide conjugate drugs, this invention develops a series of polypeptide conjugate compounds targeting the amino terminus of polypeptides, as well as polypeptide conjugate drugs containing these compounds, which can be effectively used in the treatment and / or prevention of diseases.

[0006] To achieve the above objectives, the present invention provides a polypeptide conjugate, or a stereoisomer thereof, a pharmaceutically acceptable salt thereof, or a solvate thereof, having the structural formula shown in Formula (II):

[0007]

[0008] P is a transmembrane peptide or a targeting peptide, and is any one of NGR, RGD, iNGR, iRGD, c(RGDfC), HN-1, CHN-1, or SSTR-1;

[0009] D is any one of irinotecan, irinotecan hydrochloride, ixenonotecan derivatives, camptothecin, 7-ethyl-10-hydroxycamptothecin, or 10,11-methylenedioxycamptothecin containing a substituent at the 7-position; when D is selected from 10,11-methylenedioxycamptothecin containing a substituent at the 7-position, the substituent at the 7-position is selected from a substituted or unsubstituted pyridine ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrazole ring, a substituted or unsubstituted... The substituted oxazole ring, substituted or unsubstituted triazole methyl aminomethyl ring, wherein the substituent in the substituted pyridine ring, substituted furan ring, substituted thiophene ring, substituted pyrazole ring, substituted oxazole ring, or substituted triazole methyl aminomethyl ring is selected from trifluoromethyl, trifluoromethoxy, substituted or unsubstituted alkyl, substituted or unsubstituted ester, substituted or unsubstituted aryl, substituted or unsubstituted pyrrolidinyl, or substituted or unsubstituted piperidinyl.

[0010] B is -(CH2) n -、-(CH2CH2O) n -、-(CH2) n -SS-(CH2) n - A C3-C8 carbocyclic group or phenyl group, wherein n is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11; C is -(AA). n - where AA is an amino acid or polypeptide, and n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or AA is independently selected from the group consisting of the following amino acid or peptide sequences: Val-Cit, Val-Ala, Val-Lys, Phe-Lys, Lys-Lys, Ala-Lys, Phe-Cit, Leu-Cit, Ile-Cit, Tr p, Lys, Cit, Phe-Ala, Phe-Phe-Lys, D-Phe-Phe-Lys, Gly-Phe-Lys, Leu-Ala-Leu, Ile-Ala-Leu, Va l-Ala-Val, Ala-Leu-Ala-Leu, β-Ala-Leu-Ala-Leu and Gly-Phe-Leu-Gly, Gly-Gly-Phe-Gly; m is selected from 0 or 1.

[0011] Preferably, P is a transmembrane peptide or a targeting peptide, selected from any of the following groups:

[0012]

[0013]

[0014] Preferably, the polypeptide conjugate, or its stereoisomer, its pharmaceutically acceptable salt, or its solvate are selected from any one of the following groups:

[0015]

[0016]

[0017]

[0018] The present invention also provides a polypeptide-conjugated drug, which is prepared by using the polypeptide-conjugated compound described in the above technical solution, or its stereoisomer, pharmaceutically acceptable salt, or solvate thereof.

[0019] The present invention also provides the use of the polypeptide conjugate compound according to the above technical solution, or its stereoisomer, pharmaceutically acceptable salt, or solvate thereof in the preparation for the diagnosis, prevention or treatment of a disease or condition or the reduction of the severity of said disease or condition.

[0020] Preferably, the disease or condition is cancer, selected from at least one of the following: breast cancer, squamous cell carcinoma, lung cancer, peritoneal cancer, liver cancer, gastric cancer, gastrointestinal cancer, endometrial cancer, glioblastoma, cervical cancer, ovarian cancer, bladder cancer, urethral cancer, hepatocellular carcinoma, intestinal cancer, colon cancer, rectal cancer, colorectal cancer, endometrial cancer, uterine cancer, salivary gland cancer, kidney cancer, prostate cancer, vulvar cancer, thyroid cancer, anal cancer, penile cancer, melanoma, multiple myeloma, lymphoma, lymphoid tumor, brain cancer, gallbladder cancer, esophageal cancer, bile duct cancer, head and neck cancer, and related metastatic tumors.

[0021] Preferably, the disease or symptom is an infectious disease, selected from at least one of the following groups: respiratory infectious diseases, digestive infectious diseases, contact infectious diseases, vector-borne infectious diseases, and blood or body fluid infectious diseases.

[0022] Preferably, the lung cancer is adenocarcinoma, squamous cell carcinoma, small cell lung cancer, or non-small cell lung cancer; the breast cancer is HER2-positive breast cancer; the lymphoma is B-cell lymphoma; and the squamous cell carcinoma is epithelial squamous cell carcinoma or oral squamous cell carcinoma. Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0023] This invention develops a series of peptide-conjugated drugs targeting the amino terminus of peptides, exhibiting good plasma stability, in vivo and in vitro antitumor activity, and good safety. Furthermore, it utilizes...

[0024] Further bioactivity evaluations were conducted on its plasma stability, in vitro antitumor activity, in vivo antitumor activity, and safety, confirming its effectiveness in the treatment and / or prevention of diseases. Attached Figure Description

[0025] Figure 1 The accompanying drawings for the abstract of this invention provide a flowchart for the design and synthesis of peptide-conjugated drugs.

[0026] Figure 2 The release of drug molecule 10,11-methylenedioxycamptothecin (FL118) from compound a2 provided in the embodiments of the present invention is shown in (A) curve of FL118 release from compound a2 under the action of DTT; (B) curve of FL118 release from a2 without the addition of DTT.

[0027] Figure 3 The in vivo antitumor activity studies of compounds a1 and a2 provided in the embodiments of the present invention include: (A) changes in tumor volume in the control group, irinotecan (CPT-11) group, FL118 group, a1 group and a2 group after intravenous administration in the NCI-H446 xenograft model, **P<0.01 vs control group, nsP>0.05; (B) changes in body weight of nude mice in each treatment group; (C, D) tumor images after treatment; Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: Synthesis of Targeted Peptides

[0030] The template peptides and active peptides (NGR, RGD, iNGR, iRGD, c(RGDfC), SSTR, HN-1, and CHN-1) used in this study were all manually synthesized using the standard Fmoc solid-phase peptide synthesis (Fmoc-SPPS) method.

[0031] Example 2 Preparation of peptide-cytotoxin conjugate (PDC)

[0032] 1. Preparation of compound FL118-NGR(a1):

[0033]

[0034] Add resin peptide RGD (0.1 g, 0.063 mmol), compound FL118-C4-COOH (84.8 mg, 0.13 mmol), and HATU (96 mg, 0.063 mmol) to a 100 mL solid-phase reaction tube.

[0035] 0.26 mmol), DIPEA (65 mg, 0.52 mmol), and DMF (20 mL) were added. After reacting at room temperature for 12 h, the resin was washed three times with DMF and dried. Finally, the resin was cut with 10 mL of TFA:Tips:H2O (90%:5%:5%) at room temperature for 3 h, washed with DCM, and the solvent was removed from the filtrate under reduced pressure. 50 mL of ice-cold diethyl ether was added to the residue, and the precipitate was obtained by centrifugation and purified by preparative liquid chromatography (RP-HPLC). Mobile phase A: 0.05% TFA in pure water, mobile phase B: 0.05% TFA in acetonitrile. Absorbance: 254 nm and 365 nm. Preparative mobile phase gradient method: flow rate 6 mL / min, 0-20 min, A = 90%-60%; 20-50 min, A = 60%-40%. The collected liquid was freeze-dried at -80℃, yielding 6.3 mg of a pale yellow solid, with a yield of 60% and an HPLC purity of 97.2%. The mobile phase gradient method was used for analysis: flow rate 1 mL / min, 0–30 min, A = 90%–30%. Freeze-drying yielded 10 mg of a white solid FL118-NGR, with a yield of 20.5%. 1 HNMR(400MHz,CD3OD)δ8.25(s,1H),7.36(s,1H),7.24(s,1H),7.17(s,1H),6.21(s,2H),5.59(d,J=16.7Hz,1H),5.43(d, J=16.6Hz,1H),5.00(d,J=5.1Hz,2H),4.59(t,J=5.9Hz,1H),4.23(dd,J=9.9,4.4Hz,1H),3.75-3.55(m,2H),3.16-3.08( m,2H),3.02-2.93(m,2H),2.77(t,J=5.4Hz,2H),2.64(d,J=6.5Hz,2H),2.29-2.15(m,2H),1.86(dt,J=9.3,4.6Hz,1H),1 .70(dd,J=9.5,4.5Hz,1H),1.56(d,J=7.5Hz,2H),1.36-1.27(m,2H),1.05(t,J=7.3Hz,3H).ESI-MS(m / z):410.28[M+2H] 2+ 819.48 [M+H] 1+ Rt 4.073min, purity 98.7%.

[0036] 2. Synthesis of compound FL118-SS-NGR(a2):

[0037]

[0038] Using NGR resin peptide NGR (0.2 g, 0.13 mmol) and compound FL118-SS-COOH (170 mg, 0.26 mmol) as raw materials, the synthesis and purification method of Example 24 (compound FL118-NGR) was followed to obtain a white solid FL118-SS-NGR (15 mg), yield: 5%. 1 HNMR (400MHz, CD3OD) δ8.29(s,1H),7.36(s,1H),7.25(d,J=6.3Hz,2H),6.21(d,J=4.3Hz,2H),5.63(d,J=16.7Hz,1H),5.45(d,J=16.7Hz,1H),5.07(d ,J=11.7Hz,2H),4.60(t,J=6.0Hz,1H),4.48-4.35(m,3H),4.19(q,J=6.1Hz ,2H),3.94(d,J=17.0Hz,1H),3.79(d,J=17.0Hz,1H),3.18(td,J=7.2,1.8H z,2H),3.01(t,J=6.3Hz,2H),2.88(td,J=6.3,2.1Hz,2H),2.79(dd,J=7.9, 6.0Hz,2H),2.55(ddd,J=20.5,7.5,5.3Hz,4H),2.22(dd,J=14.9,7.4Hz,2H ),2.03(s,1H),1.97-1.87(m,1H),1.78(dd,J=9.6,5.0Hz,1H),1.63(t,J=8 .7Hz,2H),1.28(s,1H),1.05(t,J=7.4Hz,3H).ESI-MS(m / z):500.22[M+2H] 2+ 1000.45[M+H] 1+ Rt 12.407min, purity 99.3%.

[0039] In the synthesis step 10 of compound Example 3, NGR is replaced with RGD, CNGRC, iNGR, iRGD, CHN-1 or SSTR-1, and the experimental operation is the same, to obtain the above-mentioned PDCs compounds, namely compounds (a3-a11, a14 and a16).

[0040] 3. Preparation of compound FL118-SS-RGD(a3):

[0041]

[0042] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were FL118-SS-COOH and RGD, yielding 16 mg of a white solid, with a yield of 5.2%. ESI-MS (m / z): 500.72 [M+2H] 2+ 1001.44[M+H] 1+ Rt13.5min, purity96.27%.

[0043] 4. Preparation of compound CPT-11-SS-RGD(a4):

[0044]

[0045] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were CPT-11-FL118-SS-COOH and RGD, yielding 12 mg of a white solid, with a yield of 4.5%. ESI-MS (m / z): 597.63 [M+2H] 2+ 1194.45 [M+H] 1+ .Rt 16.3min, purity 97.22%.

[0046] 5. Preparation of compound 10,11-methylenedioxy-7-(3-furan)camptothecin-SS-RGD(a5):

[0047]

[0048] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were 10,11-methylenedioxy-7-(3-furan)camptothecin-SS-COOH and RGD, yielding 13 mg of a white solid, with a yield of 5.5%. ESI-MS (m / z): 533.43 [M+2H] 2+ 1066.28 [M+H] 1+ .Rt 17.4min, purity 98.16%.

[0049] 6. Preparation of compound 10,11-methylenedioxy-7-(3-thiophene)camptothecin-SS-RGD(a6):

[0050]

[0051] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were 10,11-methylenedioxy-7-(3-thiophene)camptothecin-SS-COOH and RGD, yielding 18 mg of a white solid, with a yield of 6.5%. ESI-MS (m / z): 541.26 [M+2H] 2+ 1082.26 [M+H] 1+ .Rt 17.8min,purity 96.68%.

[0052] 7. Preparation of compound 10,11-methylenedioxy-7-(1-(3-methylbenzyl)-1H-1,2,3-triazol-4-yl)methyl)amino)methyl)camptothecin-SS-RGD(a7):

[0053]

[0054] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were 10,11-methylenedioxy-7-(1-(3-methylbenzyl)-1H-1,2,3-triazol-4-yl)methyl)amino)methyl)camptothecin-SS-COOH and RGD, yielding 14 mg of a white solid, with a yield of 4.6%. ESI-MS (m / z): 607.64 [M+2H] 2+ 1214.39 [M+H] 1+ Rt15.6min, purity 96.27%.

[0055] 8. Preparation of compound 10,11-methylenedioxy-7-(1-(3-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)amino)methyl)camptothecin-SS-RGD(a8):

[0056]

[0057] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were 10,11-methylenedioxy-7-(1-(3-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)amino)methyl)camptothecin-SS-COOH and RGD, yielding 17 mg of a white solid, with a yield of 6.2%. ESI-MS (m / z): 609.36 [M+2H] 2+ 1218.37 [M+H] 1+ Rt15.3min, purity 96.27%.

[0058] 9. Preparation of compound FL118-SS-CNGRC(a9):

[0059]

[0060] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were FL118-SS-COOH and CNGRC, yielding 41.2 mg of a white solid, with a yield of 4.63%. ESI-MS (m / z): 602.73 [M+2H] 2+ 1204.43 [M+H] 1+ .Rt 15.1min, purity 98.47%.

[0061] 10. Preparation of compound FL118-SS-iNGR(a10):

[0062]

[0063] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were FL118-SS-COOH and iNGR, yielding 31.2 mg of a white solid, with a yield of 4.25%. ESI-MS (m / z): 543.95 [M+3H] 3+ 815.39 [M+2H] 2+ .Rt 14.3min,purity 96.976%.

[0064] 11. Preparation of compound FL118-SS-iRGD(a11):

[0065]

[0066] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were FL118-SS-COOH and iRGD, yielding 23.2 mg of a white solid, with a yield of 3.43%. ESI-MS (m / z): 544.26 [M+3H] 3+ 816.34[M+2H] 2+ Rt 17.1min, purity 96.494%.

[0067] 12. Preparation of compound SN38-HN-1(a12):

[0068]

[0069] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were SN38-C4-COOH and HN-1, yielding 14 mg of a white solid, with a yield of 6.3%. ESI-MS (m / z): 1780.91 [M+H] +.Rt 16.342min, purity 97.2%.

[0070] 13. Preparation of compound SN38-PABC-AV-C4-HN-1(a13):

[0071]

[0072] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were SN38-PABC-AV-C4-COOH and HN-1, yielding a white solid SN38-PABC-AV-C4-HN-1 (15 mg), with a yield of 6.3%. ESI-MS (m / z): 2204.06 [M+H] + Rt 18.4min, purity 97.3%.

[0073] 14. Preparation of compound SN38-SS-CHN-1(a14):

[0074]

[0075] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were SN38-C4-COOH and CHN-1, yielding 13.4 mg of a white solid, with a yield of 2.69%. ESI-MS (m / z): 2063.90 [M+H] + Rt 15.3 min, purity 98.426%. 15. Preparation of compound SN38-PABC-Cit-V-C4-CHN-1(a15):

[0076]

[0077] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were SN38-PABC-Cit-V-C4-COOH and CHN-1, yielding 14.2 mg of a white solid, with a yield of 6.22%. ESI-MS (m / z): 2304.08 [M+H + Rt16.6min, purity98.4%.

[0078] 16. Preparation of compound SN38-SS-SSTR-1(a16):

[0079]

[0080] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were SN38-SS-COOH and SSTR-1, yielding 18.5 mg of a white solid, with a yield of 5.23%. ESI-MS (m / z): 1691.67 [M+H] + Rt 16.6 min, purity 99.437%. 17. Preparation of compound SN38-PABC-AV-C4-SSTR-1(a17):

[0081]

[0082] The preparation was carried out using the same method as step 1 in Example 2, except that the starting materials were SN38-PABC-AV-C4-COOH and SSTR-1, yielding 17.4 mg of a white solid, with a yield of 4.29%. ESI-MS (m / z): 1816.73 [M+H] + Rt16.6min, purity99.8%.

[0083] 18. Preparation of compound SN38-PABC-Cit-V-C4-SSTR-1(a18):

[0084]

[0085] The preparation was carried out using the same method as step 1 in Example 2, except that the original...

[0086] The feedstock was SN38-PABC-Cit-V-C4-COOH and SSTR-1, yielding 19.1 mg of a white solid, yield: 5.13%. ESI-MS (m / z): 1931.77 [M+H] + Rt 16.6min, purity 97.8%.

[0087] Example 3: Design and synthesis process of peptide-conjugated drugs:

[0088] The linker for connecting small drug molecules was condensed with an NGR resin peptide under the action of HATU and DIPEA to obtain the corresponding compound. Finally, the compound was cleaved for three hours with 90% TFA, 5% triisopropylsilane, and 5% water, precipitated with diethyl ether, and purified by liquid chromatography to obtain the target PDC compound (see attached). Figure 1 ).

[0089] Example 4: Solubility Study of PDC Compounds

[0090] Solubility plays a crucial role in pharmaceutical formulation research. Therefore, we further tested the solubility of compounds a1-a18 in water and ethanol solutions. The compounds were dissolved in water and ethanol, respectively, to form supersaturated solutions. After filtration, the solutions were analyzed by HPLC. The results are shown in Table 1. a1 is readily soluble in water (50.0 mg / mL) and in ethanol (0.31 mg / mL); a2-18 is readily soluble in water (9.7-38.4 mg / mL) and in ethanol (0.36 mg / mL). These results indicate that the PDC compounds exhibit good solubility in water and ethanol, significantly improving the solubility of the parent cores FL118 and SN38 in both solutions. This provides guidance for subsequent formulation research, structural modification, and design of the compounds.

[0091] Table 1. Solubility of compounds a1-a18 in water and ethanol solutions.

[0092]

[0093]

[0094] Example 5: In vitro antitumor activity assay of PDC compounds a1-a18:

[0095] Preparation of compound a1-a18 solution: Dissolve 1 mg of the compound in 2 mL of deionized water to prepare a 0.5 mg / mL solution, and sonicate at 40 °C for 30 min. The IC50 of compound a1-a18 against six cell lines—human non-small cell lung cancer A549, small cell lung cancer NCI-H446, human non-small cell lung cancer H1975, human non-small cell lung cancer HCC827, human pancreatic cancer cells PANC-1, and human metastatic pancreatic adenocarcinoma cells ASPC-1—was determined using the SRB method. 50 Table 2 shows the cytotoxicity results of the compounds on six cell lines. All target compounds a1-a18 exhibited good cytotoxic activity, with IC50 values... 50 The cytotoxicity values ​​ranged from 118.52 nM to 0.065 nM, with most compounds exhibiting superior cytotoxic activity compared to the parent compound, camptothecin derivatives. Several of these compounds showed strong cytotoxicity against the tested tumor cells.

[0096] Table 2: Cytotoxic activity of the compounds against six cancer cell lines a

[0097]

[0098]

[0099] a SRB assay: Cells were incubated with the specified compound for 72 hours (mean ± SD, n = 3). bIC 50 : The concentration that inhibits cell growth by 50%.

[0100] -: Not tested.

[0101] The following discussion uses compounds a1 and a2 as examples to explore the relevant activities of PDC compounds.

[0102] Example 6: In vitro reducing release and stability study of compound a2:

[0103] Compound a2 is a PDC compound containing disulfide bonds as linkers. These disulfide bonds can be cleaved by reducing agents such as dithiothreitol (DTT) or glutathione (GSH), releasing 10,11-methylenedioxy-camptothecin. Therefore, we investigated whether compound a2 can release 10,11-methylenedioxy-camptothecin. This experiment used DTT as the reducing agent and employed HPLC analysis. The results are attached. Figure 2 As shown, a2 was stable in PBS solution without DTT, releasing almost no FL118 within 10 h. In contrast, a2 was unstable in PBS solution with 10 mM DTT; after 15 min, the release of 10,11-methylenedioxy-camptothecin was 64.37%, and complete release was achieved after 3 h. These results indicate that compound a2 is stable under normal physiological conditions, but the disulfide bonds can be cleaved under the influence of a reducing agent (DTT), increasing the rate of release of the cytotoxic molecule 10,11-methylenedioxy-camptothecin.

[0104] Example 7: In vivo antitumor activity assay of PDC compounds a1 and a2:

[0105] To verify the antitumor activity of compounds a1 and a2 in vivo, an NCI-H446 xenograft model was established. The tumor volume was increased to 100 mm². 3 Subsequently, the mice were divided into five groups: a solvent control group, an irinotecan (CPT-11) and 10,11-methylenedioxycamptothecin (FL118) positive control group, and groups a1 and a2 (see attached table). Figure 3 a1 was administered via tail vein injection at a dose of 4.17 mg / kg (equivalent to 2 mg / kg for FL118); a2 was administered via tail vein injection at a dose of 5.01 mg / kg (equivalent to 2 mg / kg for FL118); FL118 and CPT-11 were administered via tail vein injection at doses of 2 mg / kg and 100 mg / kg, respectively; all were administered twice weekly for a total of 4 weeks. Experimental results are as follows: Figure 1As shown, a2 significantly inhibited tumor growth with a tumor inhibition rate of 56.66%, which was slightly lower than that of the positive control drug irinotecan (65.24%) and higher than that of FL118 (33.14%), while the tumor inhibition rate of a1 was only 16.57%.

Claims

1. A polypeptide conjugate, or its stereoisomer, pharmaceutically acceptable salt or solvate thereof, having the structural formula shown in Formula (II): P is a transmembrane peptide or a targeting peptide, and is any one of NGR, RGD, iNGR, iRGD, c(RGDfC), HN-1, CHN-1, or SSTR-1; D is any one of irinotecan, irinotecan hydrochloride, ixenonotecan derivative, camptothecin, 7-ethyl-10-hydroxycamptothecin, 10,11-methylenedioxycamptothecin, or 10,11-methylenedioxycamptothecin containing a substituent at the 7-position; when D is selected from 10,11-methylenedioxycamptothecin containing a substituent at the 7-position, the substituent at the 7-position is selected from a substituted or unsubstituted pyridine ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted pyrazole. The ring, substituted or unsubstituted oxazole ring, substituted or unsubstituted triazole methyl aminomethyl ring, wherein the substituent in the substituted pyridine ring, substituted furan ring, substituted thiophene ring, substituted pyrazole ring, substituted oxazole ring, or substituted triazole methyl aminomethyl ring is selected from trifluoromethyl, trifluoromethoxy, substituted or unsubstituted alkyl, substituted or unsubstituted ester, substituted or unsubstituted aryl, substituted or unsubstituted pyrrolidinyl, or substituted or unsubstituted piperidinyl. B is -(CH2) n -、-(CH2CH2O) n -、-(CH2) n -SS-(CH2) n - C3-C8 carbon cycloyl or phenyl, wherein n is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11; C is -(AA) n - where AA is an amino acid or polypeptide, and n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or AA is independently selected from the group consisting of the following amino acid or peptide sequences: Val-Cit, Val-Ala, Val-Lys, Phe-Lys, Lys-Lys, Ala-Lys, Phe-Cit, Leu-Cit, Ile-Cit, Tr p, Lys, Cit, Phe-Ala, Phe-Phe-Lys, D-Phe-Phe-Lys, Gly-Phe-Lys, Leu-Ala-Leu, Ile-Ala-Leu, Va l-Ala-Val, Ala-Leu-Ala-Leu, β-Ala-Leu-Ala-Leu and Gly-Phe-Leu-Gly, Gly-Gly-Phe-Gly; m is selected from 1 or 0.

2. The polypeptide coupling compound according to claim 1, characterized in that, P is either a transmembrane peptide or a targeting peptide, selected from any of the following groups:

3. The polypeptide coupling compound according to claim 1, characterized in that, The polypeptide conjugate, or its stereoisomer, pharmaceutically acceptable salt thereof, or its solvate thereof, is selected from any one of the following groups:

4. A polypeptide-conjugated drug, characterized in that, It is prepared using the polypeptide conjugate of claim 1, or its stereoisomer, pharmaceutically acceptable salt, or solvate thereof.

5. The use of the polypeptide conjugate of claim 1, or its stereoisomers, pharmaceutically acceptable salts thereof, or its solvates in the preparation for the diagnosis, prevention or treatment of a disease or condition or the reduction of the severity of said disease or condition.

6. The use according to claim 5, characterized in that, The disease or condition described is cancer, selected from at least one of the following groups: breast cancer, squamous cell carcinoma, lung cancer, peritoneal cancer, liver cancer, gastric cancer, gastrointestinal cancer, endometrial cancer, glioblastoma, cervical cancer, ovarian cancer, bladder cancer, urethral cancer, hepatocellular carcinoma, intestinal cancer, colon cancer, rectal cancer, colorectal cancer, endometrial cancer, uterine cancer, salivary gland cancer, kidney cancer, prostate cancer, vulvar cancer, thyroid cancer, anal cancer, penile cancer, melanoma, multiple myeloma, lymphoma, lymphoid tumor, brain cancer, gallbladder cancer, esophageal cancer, bile duct cancer, head and neck cancer, and related metastatic tumors.

7. The use according to claim 5, characterized in that, The disease or symptom is an infectious disease, selected from at least one of the following groups: respiratory infectious diseases, digestive infectious diseases, contact infectious diseases, vector-borne infectious diseases, and blood-borne or body fluid infectious diseases.

8. The use according to claim 7, characterized in that, The lung cancer is adenocarcinoma, squamous cell carcinoma, small cell lung cancer, or non-small cell lung cancer; the breast cancer is HER2-positive breast cancer; the lymphoma is B-cell lymphoma; and the squamous cell carcinoma is epithelial squamous cell carcinoma or oral squamous cell carcinoma.

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