Treatment of nasopharyngeal cancer with EGFR-targeted antibody conjugates

Abstract

Relates to treatment of nasopharyngeal carcinoma by using an EGFR-targeted antibody conjugate, and particularly finds that the antibody drug conjugate MYK-3 can effectively treat EGFR-positive and HER2-negative advanced gastric cancer, recurrent metastatic nasopharyngeal carcinoma and recurrent or metastatic head and neck squamous cell carcinoma in clinic in a mode of administration once every three weeks at 2.3 mg / kg. Cancers such as EGFR positive advanced biliary adenocarcinoma and EGFR positive advanced non-small cell lung cancer; and compared with the lower dosage of 2.0 mg / kg, when 2.3 mg / kg of MYK-3 is clinically used, the tumor inhibiting or delaying effect of a patient is good, and the adverse reaction of the medicine is safe and controllable.

Description

Treatment of nasopharyngeal carcinoma with an antibody conjugate targeting EGFR Technical Field

[0001] The present invention relates to the field of medicinal chemistry, in particular, to the application of antibody-drug conjugates, and more particularly, to the treatment of nasopharyngeal carcinoma with an antibody conjugate targeting EGFR. Background Art

[0002] Epidermal Growth Factor Receptor (EGFR, also known as HER1, c-ErbB1) is a cell surface receptor of the epidermal growth factor family. It is a transmembrane glycoprotein composed of 1186 amino acid residues and a molecular weight of 170kD. EGFR belongs to the ErbB subfamily of type I tyrosine kinase receptors (ErbB 1-4) and has tyrosine kinase activity. EGFR is stably expressed in many epithelial tissues, including the skin and hair follicles. Abnormal expression of EGFR or activation due to receptor mutation can lead to carcinogenesis. Many solid tumors have been found to overexpress EGFR, such as colorectal cancer, head and neck cancer, lung cancer, ovarian cancer, cervical cancer, bladder cancer, and esophageal cancer. Growth factors such as transforming growth factor α and epidermal growth factor are endogenous ligands for EGFR. These ligands bind to the EGFR, activating the receptor's intracellular tyrosine kinase activity and initiating multiple downstream signal transduction pathways, thereby regulating normal cell growth and differentiation, increasing tumor cell invasiveness, promoting angiogenesis, and inhibiting tumor cell apoptosis. The overexpression of the EGFR in tumors and its important role in tumor cell growth and differentiation make the EGFR a promising target for tumor therapy.

[0003] Antibody-drug conjugates (ADCs) are a new class of biopharmaceuticals composed of a monoclonal antibody (mAb) targeting a specific antigen and a small molecule drug (payload) with potent cytotoxicity, coupled via a linker. ADCs specifically recognize and guide the small molecule drug to cancer cell targets through the antibody, where it is internalized and releases the cytotoxic drug, resulting in specific cancer cell killing. Since its introduction, ADCs have undergone continuous innovation and optimization, achieving success in cancer treatment.

[0004] Currently, anti-EGFR antibody-drug conjugates are being continuously developed, such as the anti-EGFR antibody-drug conjugate MYK-3 described in the authorized patent CN106999606B. However, the clinical dosage of the anti-EGFR antibody-drug conjugate MYK-3 has not been thoroughly studied and still requires exploration and resolution.

[0005] Summary of the Invention

[0006] Through extensive experiments and creative work, the inventors of this application have discovered that the antibody-drug conjugate MYK-3 can effectively treat EGFR-positive, HER2-negative advanced gastric cancer, recurrent and metastatic nasopharyngeal carcinoma, recurrent or metastatic head and neck squamous cell carcinoma, EGFR-positive advanced biliary adenocarcinoma, and EGFR-positive advanced non-small cell lung cancer in clinical practice at a dose of 2.3 mg / kg once every three weeks. Compared with a lower dose of 2.0 mg / kg, the inventors found that when a 2.3 mg / kg dose of MYK-3 was used clinically, patients had good tumor suppression or delay effects, and the adverse reactions of the drug were safe and controllable.

[0007] To this end, in one aspect of the present invention, the present invention provides an antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, for use in treating diseases associated with epidermal growth factor receptor (EGFR);

[0008] The antibody drug conjugate has the structure shown in Formula I, Ab-(LD) p Formula I

[0009] in:

[0010] Ab represents an anti-epidermal growth factor receptor antibody, wherein the anti-epidermal growth factor receptor antibody comprises a heavy chain and a light chain, wherein the heavy chain variable region CDR1, CDR2, and CDR3 respectively comprise the sequences shown in SEQ ID NO: 5, SEQ ID NO: 6, and SEQ ID NO: 7, or mutants thereof, and the light chain variable region CDR1, CDR2, and CDR3 respectively comprise the sequences shown in SEQ ID NO: 12, SEQ ID NO: 13, and SEQ ID NO: 14, or mutants thereof,

[0011] L represents a linker, and the linker is 6-maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (MC-vc-PAB),

[0012] D represents a cytotoxic agent, wherein the cytotoxic agent is MMAE,

[0013] p is any number selected from 1-8 (e.g., 1, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, 20.5, 21.5, 22.5, 23.5, 24.5, 25.5, 26.5, 27.5, 28.5, 29.5, 30.5, 31.5, 32.5, 33.5, 34.5, 35.5, 36.5, 37.5, 38.5, 39.5, 40.5, 41.5, 42.5, 43.5, 44.5, 45.5, 46.5, 47.5, 48.5, 49.5, 50.5, 51.5, 52.5, 53.5, 54.5, 55.5, 56.5, 57.5, 58.5, 59.5, 60.5, 61.5, 62.5, 63.5, 64.5, 65.5, 66.5, 67.5, 68.5, 69.5, 70.5, 71.5, 72.5

[0014] Wherein, the total dosage of the antibody-drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof every three weeks is 2.1-2.4 mg / kg.

[0015] In another aspect of the present invention, the present invention also provides a method for treating a disease associated with epidermal growth factor receptor (EGFR), comprising administering to a subject an antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof;

[0016] The antibody drug conjugate has the structure shown in Formula I, Ab-(LD) p Formula I

[0017] in:

[0018] Ab represents an anti-epidermal growth factor receptor antibody, wherein the anti-epidermal growth factor receptor antibody comprises a heavy chain and a light chain, wherein the heavy chain variable region CDR1, CDR2, and CDR3 respectively comprise the sequences shown in SEQ ID NO: 5, SEQ ID NO: 6, and SEQ ID NO: 7, or mutants thereof, and the light chain variable region CDR1, CDR2, and CDR3 respectively comprise the sequences shown in SEQ ID NO: 12, SEQ ID NO: 13, and SEQ ID NO: 14, or mutants thereof,

[0019] L represents a linker, and the linker is 6-maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (MC-vc-PAB),

[0020] D represents a cytotoxic agent, wherein the cytotoxic agent is MMAE,

[0021] p is any number selected from 1-8 (e.g., 1, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, 20.5, 21.5, 22.5, 23.5, 24.5, 25.5, 26.5, 27.5, 28.5, 29.5, 30.5, 31.5, 32.5, 33.5, 34.5, 35.5, 36.5, 37.5, 38.5, 39.5, 40.5, 41.5, 42.5, 43.5, 44.5, 45.5, 46.5, 47.5, 48.5, 49.5, 50.5, 51.5, 52.5, 53.5, 54.5, 55.5, 56.5, 57.5, 58.5, 59.5, 60.5, 61.5, 62.5, 63.5, 64.5, 65.5, 66.5, 67.5, 68.5, 69.5, 70.5, 71.5, 72.5

[0022] Wherein, the total dosage of the antibody-drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof every three weeks is 2.1-2.4 mg / kg.

[0023] In Formula I, LD represents that the linker and the cytotoxic agent are covalently linked to form an LD molecule; Ab-(LD) p represents p LD molecules coupled to Ab via covalent bonds.

[0024] In the present invention, the drug-antibody ratio (DAR) refers to the number of drug molecules (or cytotoxic agents) coupled to the antibody (e.g., p in Formula I). ​​The number of drug molecules contained in the antibody-drug conjugates described herein can be an integer or a decimal. Whether it is an integer or a decimal, it refers to the average number of drug molecules coupled to each antibody. "p is any value selected from 1-8", which means that p can be any integer selected from 1-8 (including endpoints 1 and 8), or any decimal selected from 1-8, such as 4.1. At the same time, it will be understood by those skilled in the art that even if the same preparation method is used, the DAR values ​​of the antibody-drug conjugates prepared in different batches are not necessarily exactly the same, for example, they can float within a range of no more than 0.5.

[0025] The drug-antibody ratio (DAR) can be determined by conventional means such as mass spectrometry, ELISA assays, HIC, and HPLC. The quantitative distribution of ADCs in terms of p can also be determined. In some cases, separation, purification, and validation of homogenous ADCs with a certain p value from ADCs with other drug loads can be achieved by means such as HIC, reverse-phase HPLC, or electrophoresis.

[0026] The structural formula of MC-vc-PAB is shown below:

[0027] The structural formula of MMAE is shown below:

[0028] In Formula I, LD is MC-vc-PAB-MMAE, and its structural formula is shown below:

[0029] When the above-mentioned LD, i.e., MC-vc-PAB-MMAE, is covalently coupled to the Ab, it is formed by coupling the succinimide at the end of the LD with the thiol group in the antibody. The structural formula of the formed ADC is as follows:

[0030] In the ADC formed above, the antibody Ab is linked to the carbon atom of the succinimide at the end of LD via -S-. This -S- is not a thiol group introduced into the Ab, but rather a thiol group contained in the antibody itself after the antibody Ab is reduced to open the disulfide bond.

[0031] In some embodiments, the total dose of the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof, administered every three weeks is 2.2-2.4 mg / kg.

[0032] In some embodiments, the total dose of the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof, administered every three weeks is 2.3 mg / kg.

[0033] It should be noted that "every three weeks" means that 3 weeks is one treatment cycle, and "the total dosage every three weeks" means the total dosage within this treatment cycle (i.e., every three weeks). For example, if the total dosage every three weeks is 2.3 mg / kg, the dosage regimen can be a single high-dose but low-frequency administration (e.g., a single dosage of 2.3 mg / kg, and a dosage frequency of once every three weeks); or a single low-dose but high-frequency administration (e.g., a single dosage of 0.77 mg / kg, and a dosage frequency of once every 7 days, i.e., once a week). As for the specific number of treatment cycles, for example, it can be at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, at least 20, at least 21, at least 22, at least 23, at least 24, at least 25, at least 26, at least 27, at least 28, at least 29, at least 30, at least 31, at least 32, at least 33, at least 34, at least 35, at least 36, at least 37, at least 38, at least 39, or at least 40, or even more. In some embodiments, the specific number of treatment cycles is set or selected based on the principle of continuing treatment until disease progression. In addition, those skilled in the art will appreciate that the dosage may fluctuate slightly within a range of no more than 0.05 mg / kg above or below the dosage.

[0034] In some embodiments, the single dose of the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate thereof, is 2.1-2.4 mg / kg (preferably 2.2-2.4 mg / kg, more preferably 2.3 mg / kg), and the administration frequency is once every three weeks. In some embodiments, administration is performed on the first day of every three weeks.

[0035] In some embodiments, the single administration dose of the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is 0.7-1.4 mg / kg (e.g., 0.7-1.1 mg / kg, specifically 0.77 mg / kg or 1.1 mg / kg), and the administration frequency is once every 7-10 days.

[0036] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is administered by intravenous drip (also known as intravenous administration, intravenous injection, etc.).

[0037] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is administered to a human.

[0038] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is administered to a patient suffering from a disease associated with epidermal growth factor receptor (EGFR).

[0039] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof is administered to a patient who has previously received anti-EGFR drug treatment. Preferably, the anti-EGFR drug is an anti-EGFR antibody.

[0040] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is administered to a patient who overexpresses EGFR.

[0041] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is administered to patients with recurrent metastatic nasopharyngeal carcinoma (NPC) who have previously received at least one line of platinum-containing regimen and PD-1 / PD-L1 inhibitor systemic treatment, or who have relapsed or are intolerant to the treatment.

[0042] In some embodiments, the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof, is administered to patients with recurrent metastatic nasopharyngeal carcinoma (NPC) who have previously received at least two lines of systemic chemotherapy and failed PD-1 / PD-L1 therapy. In some embodiments, the chemotherapy regimen previously received at least two lines of systemic chemotherapy must include at least a platinum-containing regimen, gemcitabine, and a taxane / capecitabine.

[0043] In some embodiments, the subject is a human.

[0044] In some embodiments, the subject is a patient suffering from a disease associated with epidermal growth factor receptor (EGFR).

[0045] In some embodiments, the subject is a patient who has previously received anti-EGFR drug treatment. Preferably, the anti-EGFR drug is an anti-EGFR antibody.

[0046] In some embodiments, the subject is a patient who overexpresses EGFR.

[0047] In some embodiments, the subject is a patient with recurrent metastatic nasopharyngeal carcinoma (NPC) who has progressed during or relapsed after or is intolerant to at least one first-line platinum-containing regimen and PD-1 / PD-L1 inhibitor systemic treatment.

[0048] In some embodiments, the subject is a patient with recurrent metastatic nasopharyngeal carcinoma (NPC) who has previously received at least two lines of systemic chemotherapy and failed PD-1 / PD-L1 therapy. In some embodiments, the chemotherapy regimen previously received at least two lines of systemic chemotherapy must include at least a platinum-containing regimen, gemcitabine, and taxanes / capecitabine.

[0049] In some embodiments, the taxanes include paclitaxel, docetaxel, nab-paclitaxel, and liposomal paclitaxel.

[0050] In some embodiments, the platinum-containing regimen includes cisplatin, carboplatin, nedaplatin, and the like.

[0051] In some embodiments, the platinum-containing regimen includes, but is not limited to, the following treatment regimens:

[0052] Cisplatin plus gemcitabine (preferred); or

[0053] Platinum (cisplatin or carboplatin, etc.) + taxane (such as docetaxel or paclitaxel, etc.); or

[0054] Platinum + EGFR monoclonal antibody (such as cetuximab or nimotuzumab).

[0055] In some embodiments, the disease associated with epidermal growth factor receptor (EGFR) is cancer.

[0056] In some embodiments, the cancer is selected from nasopharyngeal cancer, head and neck squamous cell carcinoma, biliary tract cancer, esophageal cancer, duodenal cancer, colorectal cancer, colon cancer, rectal cancer, head and neck cancer, lung cancer (such as non-small cell lung cancer), ovarian cancer, cervical cancer, bladder cancer, esophageal cancer, breast cancer, kidney cancer, prostate cancer, gastric cancer, pancreatic cancer, and brain glioma.

[0057] In some embodiments, the cancer is selected from nasopharyngeal carcinoma, head and neck squamous cell carcinoma, non-small cell lung cancer, biliary tract cancer, gastric cancer, esophageal cancer, and duodenal cancer.

[0058] In some embodiments, the cancer is nasopharyngeal carcinoma.

[0059] In some embodiments, the cancer is an advanced heavily pretreated solid tumor.

[0060] In some embodiments, the cancer is an EGFR-positive advanced solid tumor that has recurred or metastasized after multiple previous tumor-related treatments.

[0061] In some embodiments, the cancer is selected from EGFR-positive, HER2-negative advanced gastric cancer, recurrent metastatic nasopharyngeal carcinoma, recurrent or metastatic head and neck squamous cell carcinoma, EGFR-positive advanced biliary tract adenocarcinoma, EGFR-positive advanced non-small cell lung cancer, etc., wherein "EGFR-positive" refers to overexpression of EGFR, and "HER2-negative" refers to no overexpression of HER2.

[0062] In some embodiments, the cancer is recurrent metastatic nasopharyngeal carcinoma.

[0063] In some embodiments, p is any number selected from 2-6.

[0064] In some embodiments, p is any number selected from 3-5.

[0065] In some embodiments, the FR1, FR2, FR3, and FR4 regions of the heavy chain variable region of the anti-EGFR antibody comprise the sequences shown in SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, and SEQ ID NO: 11, respectively, or mutants thereof.

[0066] In some embodiments, the FR1, FR2, FR3, and FR4 regions of the anti-EGFR antibody light chain variable region comprise the sequences shown in SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, and SEQ ID NO: 18, or mutants thereof, respectively.

[0067] In some embodiments, the heavy chain constant region of the anti-EGFR antibody is selected from human IgG, IgM, IgA, IgD, IgE constant regions or mutants of the above constant regions.

[0068] In some embodiments, the IgG is selected from IgG1, IgG2, IgG3, and IgG4.

[0069] In some embodiments, the light chain constant region of the anti-epidermal growth factor receptor antibody is a human lambda constant region, a kappa constant region, or a mutant of the above constant regions.

[0070] In some embodiments, the sequence of the heavy chain variable region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 1, or comprises a sequence having an identity greater than 70%, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% to the sequence shown in SEQ ID NO: 1.

[0071] In some embodiments, the sequence of the heavy chain variable region of the anti-EGFR antibody is as shown in SEQ ID NO: 1.

[0072] In some embodiments, the sequence of the light chain variable region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 2, or comprises a sequence having an identity greater than 70%, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% to the sequence shown in SEQ ID NO: 2.

[0073] In some embodiments, the sequence of the light chain variable region of the anti-epidermal growth factor receptor antibody is shown in SEQ ID NO: 2.

[0074] In some embodiments, the sequence of the heavy chain constant region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 3, or comprises a sequence having an identity greater than 70%, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% to the sequence shown in SEQ ID NO: 3.

[0075] In some embodiments, the sequence of the heavy chain constant region of the anti-EGFR antibody is as shown in SEQ ID NO:3.

[0076] In some embodiments, the sequence of the light chain constant region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 4, or comprises a sequence having an identity greater than 70%, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% to the sequence shown in SEQ ID NO: 4.

[0077] In some embodiments, the sequence of the light chain constant region of the anti-epidermal growth factor receptor antibody is shown in SEQ ID NO:4. Beneficial effects

[0078] The purpose of this invention is to determine the clinical dosage and indications for MYK-3. Through Phase I / II clinical studies, the inventors found that MYK-3, at a dose of 2.3 mg / kg once every three weeks, can treat EGFR-positive, HER2-negative advanced gastric cancer, recurrent and metastatic nasopharyngeal carcinoma, recurrent or metastatic head and neck squamous cell carcinoma, EGFR-positive advanced biliary adenocarcinoma, and EGFR-positive advanced non-small cell lung cancer. MYK-3 demonstrated significant therapeutic efficacy across an extended range of recurrent and metastatic nasopharyngeal carcinoma. Comparing MYK-3 doses with 2.0 mg / kg and 2.5 mg / kg, the inventors found that the clinical use of 2.3 mg / kg of MYK-3 resulted in a significant tumor suppression or delay effect, with safe and manageable adverse drug reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1: HIC-HPLC profile of drug / antibody ratio determination of antibody drug conjugates.

[0080] Figure 2: In vitro cell activity assay of monoclonal antibodies and antibody-drug conjugates, where ○ represents BA03 monoclonal antibody,

[0081] ▲Represents MYK-3 antibody-drug conjugate.

[0082] Figure 3: Growth inhibitory activity of MYK-3 on colon cancer cell HT-29, where ○ represents BA03 monoclonal antibody and ▲ represents MYK-3 antibody-drug conjugate.

[0083] Figure 4: Growth inhibitory activity of MYK-3 on brain glioma cancer cell line U87-MG, where ○ represents BA03 monoclonal antibody and ▲ represents MYK-3 antibody-drug conjugate.

[0084] Figure 5: Growth inhibitory activity of MYK-3 on lung cancer A549 cells, where ○ represents BA03 monoclonal antibody and ▲ represents MYK-3 antibody-drug conjugate.

[0085] Figure 6: Growth inhibitory activity of MYK-3 against KRAS mutant colon cancer cells LoVo, where ◇ represents Erbitux monoclonal antibody and ▲ represents MYK-3 antibody-drug conjugate. DETAILED DESCRIPTION

[0086] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be obtained commercially.

[0087] Unless otherwise indicated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, terms and laboratory procedures related to protein and nucleic acid chemistry, molecular biology, cell and tissue culture, microbiology, and immunology used herein are those widely used in the respective fields and are standard procedures. To facilitate a better understanding of the present invention, definitions and explanations of relevant terms are provided below.

[0088] In the present invention, unless otherwise stated, any numerical range should be understood to include any value or any sub-range within the range.

[0089] In the present invention, the term "antibody" refers to an immunoglobulin molecule that is usually composed of two pairs of identical polypeptide chains, each pair having a "light" (L) chain and a "heavy" (H) chain. The light chains of antibodies can be divided into two types: κ and λ. Heavy chains can be divided into five types: μ, δ, γ, α or ε. Depending on the heavy chain, antibodies can be divided into five types: IgM, IgD, IgG, IgA and IgE. Within the light chain and heavy chain, the variable region and the constant region are connected by a "J" region of about 12 or more amino acids, and the heavy chain also contains a "D" region of about 3 or more amino acids. Each heavy chain consists of a heavy chain variable region (V H ) and heavy chain constant region (C H ). The heavy chain constant region consists of three domains (C H 1. C H 2 and C H 3). Each light chain consists of a light chain variable region (V L ) and the light chain constant region (C L ). The light chain constant region consists of a domain C L The constant regions of antibodies mediate the binding of immunoglobulins to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the C1q component of the complement system. H and V L The V domain can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDRs), interspersed with regions that are more conserved, termed framework regions (FRs). H and V L It consists of three CDRs and four FRs arranged from amino terminus to carboxyl terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The variable region (V H and V L ) respectively form the antibody binding site. The assignment of amino acids to each region or domain follows the Kabat Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987 and 1991)), or the definitions of Chothia & Lesk (1987) J. Mol. Biol. 196:901-917; Chothia et al. (1989) Nature 342:878-883.

[0090] The antibodies of the present invention can be prepared by various methods known in the art, such as by genetic engineering recombinant technology. For example, DNA molecules encoding the heavy and light chain genes of the antibodies of the present invention can be obtained by chemical synthesis or PCR amplification. The resulting DNA molecules are inserted into expression vectors and then transfected into host cells. The transfected host cells are then cultured under specific conditions to express the antibodies of the present invention.

[0091] In the present invention, algorithms used to determine percentage sequence homology and sequence similarity are, for example, BLAST and BLAST 2.0 algorithms, which are described in Altschul et al. (1977) Nucl. Acid. Res. 25:3389-3402 and Altschul et al. (1990) J. Mol. Biol. 215:403-410, respectively. BLAST and BLAST 2.0 can be used to determine percentage amino acid sequence homology of the present invention using, for example, parameters described in the literature or using default parameters. Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (NCBI).

[0092] In the present invention, the amino acid sequence having at least 70% sequence identity to the amino acid sequence includes polypeptide sequences that are substantially identical to the amino acid sequence, for example, those sequences that contain at least 70% sequence identity, preferably at least 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more sequence identity, when compared to the polypeptide sequence of the present invention using the methods described herein (e.g., BLAST analysis using standard parameters).

[0093] In the present invention, a mutant of an amino acid sequence refers to a sequence having greater than 70% homology to the amino acid sequence, such as greater than 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, such as a sequence having 3, 2, or 1 amino acid substitutions, deletions, or additions. Preferably, the number of amino acids substituted, added, or deleted does not exceed 3. More preferably, the number of amino acids substituted, added, or deleted does not exceed 2. Most preferably, the number of amino acids substituted, added, or deleted does not exceed 1.

[0094] "Substitution" variants are variants in which at least one amino acid residue in the native sequence has been removed and a different amino acid has been inserted in the same position. The substitutions can be single, in which only one amino acid is substituted in the molecule, or multiple, in which two or more amino acids are substituted in the same molecule. Multiple substitutions can be located at consecutive sites. Likewise, one amino acid can be substituted by multiple residues, in which case such variants include both substitutions and insertions. "Insertion" (or "addition") variants are variants in which one or more amino acids are inserted adjacent to an amino acid at a specific position in a native sequence. Adjacent to an amino acid means linked to the α-carboxyl or α-amino functional group of the amino acid. "Deletion" variants are variants in which one or more amino acids in the native amino acid sequence have been removed. Typically, deletion variants have one or two amino acids deleted in a specific region of the molecule.

[0095] In the present invention, EGFR overexpression refers to an increase in the expression level of EGFR compared with the expression level of EGFR on the surface of normal epithelial cells; it can be specifically divided into high expression, moderate expression and low expression. For example, DiFi cells are a cell line with high EGFR expression, LoVo cells are a cell line with moderate EGFR expression, and HT-29 cells are a cell line with low EGFR expression (Wild, R., et al., Mol. Cancer Rher 2006:5(1), p104-113, Cetuximab preclinical antitumor activity (monotherapy and combination based) is not predicted by relative total or activated epidermal growth factor receptor tumor expression levels).

[0096] In the present invention, the KRAS gene and the K-RAS gene have the same meaning. KRAS is a member of the RAS gene family that encodes the K-ras protein, which is associated with the development, proliferation, migration, spread, and angiogenesis of various tumors. Common mutation sites are codons 12 and 13 of exon 2 and codon 61 of exon 3 of the K-RAS gene. Seven mutation hotspots exist: G12C, G12R, G12S, G12V, G12D, G12A, and G13V / D. These seven mutations account for over 90% of all tumors. In one embodiment of the present invention, the tumor is a KRAS gene mutation associated with EGFR overexpression.

[0097] In the present invention, the 20 conventional amino acids and their abbreviations follow conventional usage. See Immunology—A Synthesis (2nd edition, ES Golub and DR Gren, Eds., Sinauer Associates, Sunderland, Mass. (1991)), which is incorporated herein by reference.

[0098] In the present invention, less than the theoretical maximum number of drug moieties is coupled to the antibody in the coupling reaction. Generally speaking, antibodies do not contain many free and reactive cysteine ​​thiol groups to which drug moieties can be attached; in fact, most cysteine ​​thiol groups in antibodies exist as disulfide bridges. In certain embodiments, antibodies can be reduced under partial or full reducing conditions with a reducing agent such as dithiothreitol (DTT) or tricarbonylethylphosphine (TCEP) to generate reactive cysteine ​​thiol groups.

[0099] In the present invention, the term "pharmaceutically acceptable salt" refers to (i) a salt formed by an acidic functional group present in the conjugate provided by the present invention and a suitable inorganic or organic cation (base), and includes, but is not limited to, alkali metal salts, such as sodium salts, potassium salts, lithium salts, etc.; alkaline earth metal salts, such as calcium salts, magnesium salts, etc.; other metal salts, such as aluminum salts, iron salts, zinc salts, copper salts, nickel salts, cobalt salts, etc.; inorganic base salts, such as ammonium salts; organic base salts, such as tert-octylamine salts, dibenzylamine salts, morpholine salts, glucosamine salts, phenylglycine alkyl ester salts, ethylenediamine salts, N-methylglucosamine salts, guanidine salts, diethylamine salts, triethylamine salts, dicyclohexylamine salts, N,N'-dibenzylethylenediamine salts, chloroprocaine salts, procaine salts, diethanolamine salts, N-benzyl-phenethylamine salts, piperazine salts, tetramethylamine salts, and tris(hydroxymethyl)aminomethane salts. and (ii) salts formed between the basic functional groups present in the conjugates provided by the present invention and appropriate inorganic or organic anions (acids), including but not limited to hydrohalides, such as hydrofluorides, hydrochlorides, hydrobromides, and hydroiodides; inorganic acid salts, such as nitrates, perchlorates, sulfates, and phosphates; lower alkanesulfonates, such as methanesulfonates, trifluoromethanesulfonates, and ethanesulfonates; arylsulfonates, such as benzenesulfonates and p-toluenesulfonates; organic acid salts, such as acetates, malates, fumarates, succinates, citrates, tartrates, oxalates, and maleates; and amino acid salts, such as glycine, trimethylglycine, arginine, ornithine, glutamate, and aspartate.

[0100] Pharmaceutically acceptable salts can be obtained using standard procedures well known in the art, for example, by reacting a sufficient amount of a basic substance with a suitable acid to provide a pharmaceutically acceptable anion, or by reacting a sufficient amount of an acidic substance with a suitable base to provide a pharmaceutically acceptable cation.

[0101] In the present invention, solvates refer to forms of the antibody-drug conjugates of the present invention that form complexes in solid or liquid form by coordination with solvent molecules. Hydrates are a specific form of solvates that have coordinated water molecules. In the present invention, hydrates are preferred solvates.

[0102] As used herein, the term "treat" generally refers to obtaining a desired pharmacological and / or physiological effect. This effect can be prophylactic, in terms of completely or partially preventing a disease or its symptoms; and / or therapeutic, in terms of partially or completely stabilizing or curing a disease and / or causing side effects due to the disease. As used herein, "treat" encompasses any treatment of a disease in a patient, including: (a) preventing the onset of a disease or symptom in a patient who is susceptible to the disease or symptom but has not yet been diagnosed with the disease; (b) suppressing the symptoms of a disease, i.e., arresting its development; or (c) alleviating the symptoms of a disease, i.e., causing the disease or symptom to regress.

[0103] In the present invention, the term "subject" refers to a vertebrate. In certain embodiments, the vertebrate refers to a mammal. Mammals include, but are not limited to, livestock (such as cattle), pets (such as cats, dogs, and horses), primates, mice, and rats. In certain embodiments, the mammal refers to a human.

[0104] The antibody BA03 in the present invention is the BA03 in Chinese invention patent application CN 103772504A. Its preparation method is described in Example 3 of the patent application. The sequences of the various parts of the antibody are as follows:

[0105] The heavy chain variable region sequence is:

[0106] The underlined parts are CDR1 (SEQ ID NO: 5), CDR2 (SEQ ID NO: 6), and CDR3 (SEQ ID NO: 7);

[0107] The ununderlined parts are FR1 (SEQ ID NO: 8), FR2 (SEQ ID NO: 9), FR3 (SEQ ID NO: 10), and FR4 (SEQ ID NO: 11).

[0108] The light chain variable region sequence is:

[0109] The underlined parts are CDR1 (SEQ ID NO: 12), CDR2 (SEQ ID NO: 13), and CDR3 (SEQ ID NO: 14);

[0110] The ununderlined parts are FR1 (SEQ ID NO: 15), FR2 (SEQ ID NO: 16), FR3 (SEQ ID NO: 17), and FR4 (SEQ ID NO: 18).

[0111] The heavy chain constant region sequence is:

[0112] The light chain constant region sequence is:

[0113] The present invention will be further explained below with reference to specific examples, but these examples are not intended to limit the scope of the present invention.

[0114] Example 1: Preparation of Antibody Drug Conjugates

[0115] Take 10 mg of BA03 antibody and replace it with reducing buffer (25mM sodium borate, pH8.0, 25mM NaCl, 5mM EDTA) using a 15mL 30KD ultrafiltration device, and replace it three times in total; the final volume is about 1mL, transfer it to a new Eppendorf centrifuge tube (weighed), and weigh it; detect the protein concentration and calculate the total protein amount. Add 2.5 times the molar number of DTT to the antibody, incubate at room temperature for 2 hours, and mix continuously; use a 15mL 30KD ultrafiltration device to replace it with coupling buffer (50mM Tris, pH7.2, 150mM NaCl, 5mM EDTA) and replace it three times in total. Take the concentrate, determine the protein concentration by A280, weigh it, and calculate the total protein amount; take 10μL sample and determine the number of free thiol groups by Ellman's method;

[0116] The molar concentration of free thiol groups was calculated using the following formula:

[0117] b: Light path length of the cuvette (usually 1 cm).

[0118] The number of moles of free thiol groups was calculated based on the molar concentration of free thiol groups and the total volume of protein solution.

[0119] To the reduced antibody, add 1.1 times the molar number of free sulfhydryl groups of vc-MMAE (purchased from Shanghai Haoyuan Chemical Technology Co., Ltd., Catalog No. HY-15575) (dissolved in DMSO). Mix thoroughly and react at room temperature for 2 hours with intermittent mixing. Add 20 times the molar number of vc-MMAE to the reaction system, mix thoroughly, and let it stand for 5 minutes. Use a 15 mL 30KD ultrafiltration device to replace the conjugate storage solution (20 mM sodium citrate, 0.3% NaCl, 5% trehalose, 0.05% Tween-80, pH 6.0). Replace three times to obtain the antibody-drug conjugate MYK-3. Samples were stored at 4°C.

[0120] Determination of drug / antibody ratio:

[0121] The prepared antibody-drug conjugate MYK-3 was analyzed by HIC-HPLC (Jun Ouyang, Drug-To-Antibody (DAR) Ratio and Drug Distribution by Hydrophobic Interaction Chromatography and Reverse Phase High Performance Chromatography, Laurent Ducry (ed.), Antibody Drug Conjugates, Chapter 17, Methods in Molecular Biology, Vol 1045, p275-283) to determine the drug / antibody ratio (DAR), as shown in Figure 1. The average drug loading DAR was calculated based on the peak area of ​​the chromatogram to be 4.1.

[0122] Example 2: Determination of in vitro cell activity of antibody drug conjugate MYK-3

[0123] Cell viability assay:

[0124] After 3-4 generations of cell passage, the revived cell line was first poured out of the culture medium, rinsed with 5 mL DPBS, and then digested with 3 mL trypsin, resuspended with culture medium, centrifuged, discarded the supernatant, resuspended with culture medium again, and 0.5 mL was taken out for counting with a cell counter. Plated on a 96-well cell culture plate (DiFi cells at 10,000 cells / well, HT-29 cells at 5,000 cells / well, A549 cells at 2,000 cells / well, U87-MG cells at 3,000 cells / well, LoVo cells at 4,000 cells / well), cultured for 24 hours, and then serially diluted monoclonal antibody BA03 and antibody drug conjugate MYK-3 were added and incubated for 72 hours. After that, 20 μL CCK8 colorimetric reagent was added to each well, and OD450-650 was detected with a microplate reader at a wavelength of 450-650 nm, and four-parameter fitting was performed.

[0125] In vitro cell activity test results:

[0126] The following cell lines were purchased from the Shanghai Institute of Cell Biology, Chinese Academy of Sciences.

[0127] Activity in DiFi cells (human colorectal cancer cells) with high EGFR expression: MYK-3 has significantly higher cell growth inhibitory activity than monoclonal antibody BA03, EC 50 The EC of BA03 was reduced by about 10 times. 50 The EC of MYK-3 is 51.9 ng / mL. 50 is 5.1 ng / mL), as shown in Figure 2.

[0128] Activity in other tumor cells with moderate and low EGFR expression: MYK-3 also showed significant cell growth inhibitory activity compared to the monoclonal antibody itself against cancer cells with moderate and low EGFR expression (human colon cancer cell HT29, human lung cancer cell A549, and human brain astroglioma cell U87-MG) (as shown in Figures 3, 4, and 5). The EC of HT-29 was 50 is 611 ng / mL, the EC of A549 50 is 28.3 μg / mL, and the EC of U87-MG 50 It is 5.3μg / mL.

[0129] In addition, we also tested the activity of MYK-3 in KRAS mutant colorectal cancer cells LoVo (Dunn EF, Ilda M, Myers RA, Hintz KA, Campbell DA, Armstrong EA, Li C and Wheeler DL. Dasatinib sensitizes KRAS mutant colorectal tumors to cetruximab. Oncogene 2011; 30: 561-574) with moderate EGFR expression and found that MYK-3 showed significant tumor growth inhibitory activity against KRAS mutant colorectal cancer cells LoVo (as shown in Figure 6, EC 50 3.2 μg / mL), while BA03 alone had almost no inhibitory activity against this cell line.

[0130] Example 3: Clinical trial of antibody drug conjugate MYK-3

[0131] The results of this trial are derived from the results of the Phase I clinical trial and the ongoing Phase II expansion.

[0132] 1) Phase I clinical trial

[0133] Research Methodology:

[0134] In the 3+3 designed Phase Ia dose escalation phase of the clinical trial, patients with locally advanced or metastatic solid tumors who failed standard treatment or were unable to obtain standard treatment received MYK-3 once every 3 weeks (Q3W) for up to 8 cycles of treatment. The starting dose of MYK-3 was 0.1 mg / kg, followed by 0.3, 0.6, 1.0, 1.5, 2.0, 2.5 and 3.0 mg / kg. The Phase Ib clinical study included expansion cohorts of advanced or metastatic CRC (colorectal cancer), SCCHN (squamous cell carcinoma of the head and neck), and NPC (nasopharyngeal carcinoma) that had progressed on multiple previous treatments and were treated with 2.5 mg / kg Q3W. Observations included AEs (adverse events), DLTs (dose-limiting toxicity), and anti-tumor activity evaluated every two cycles.

[0135] result:

[0136] A total of 22 patients were enrolled in Phase Ia without EGFR positivity prescreening; a total of 39 patients with CRC (12), SCCHN (13), and NPC (14) were enrolled in Phase Ib after EGFR IHC prescreening. The median age of patients in Phase Ia and Phase Ib was 54.5 and 50.4 years, respectively, and the median number of previous therapies was 3 (1, 8) and 2 (1, 6), respectively. The dose of Ph Ib was 2.5 mg / kg. In Phase I, common TRAEs (treatment-related adverse events) occurring in ≥20% of patients were rash, increased aspartate aminotransferase (39%); alopecia (33%); decreased appetite (31%); increased alanine aminotransferase (30%); pruritus (28%); decreased white blood cell count (25%); myalgia (23%); fever (21%); decreased neutrophil count and fatigue (20%). The most common TRAEs were grade ≥3, reported in 19 patients (31%). All grade 3 or higher AEs occurred in the 2.5 mg / kg cohort. Among the 19 patients who underwent tumor assessment in Phase Ia, the ORR (objective response rate) was 5% (1 / 19) and the DCR (disease control rate) was 32% (6 / 19). Among the 27 efficacy-evaluable patients in Phase Ib, the BOR (best overall response) was 8 confirmed PRs (partial tumor responses) and 12 SDs (stable disease), with an ORR of 29.6% and a DCR of 74%. The ORR for patients with SCCHN was 40% and the DCR was 100%. The ORR for patients with NPC was 44% and the DCR was 89%. The ORR for patients with CRC was 0% and the DCR was 25%.

[0137] in conclusion:

[0138] Compared to FDA-approved monoclonal antibodies targeting EGFR (including cetuximab and panitumumab), the frequency of rash, itching, and other skin toxic reactions during MYK-3 treatment is lower than that of cetuximab and panitumumab. MYK-3 has shown manageable safety and encouraging anti-tumor activity in Phase I clinical studies, and has encouraging anti-tumor activity in patients with EGFR-positive advanced solid tumors (including NPC and SCCHN) that have relapsed or metastasized after multiple previous tumor-related therapies, which will be further studied in Phase II studies. Based on the safety data of patients in the Phase Ia dose escalation phase and the Ib dose expansion phase, it is expected that the safety and tolerability of MYK-3 at a dose of 2.0 mg / kg will be improved relative to the 2.5 mg / kg dose, so 2.0 mg / kg and 2.3 mg / kg will be further explored as possible clinical recommended doses of MYK-3 in Phase II studies.

[0139] 2) Phase II clinical trials

[0140] Research Methodology:

[0141] The ongoing Phase II extension study is investigating the efficacy of MYK-3 in the treatment of recurrent metastatic nasopharyngeal carcinoma. Patients receive MYK-3 every 3 weeks (Q3W) at doses of 2.0 mg / kg and 2.3 mg / kg.

[0142] Test description:

[0143] A clinical trial evaluating the potential efficacy and safety of MYK-3 in subjects with recurrent metastatic nasopharyngeal carcinoma (NPC).

[0144] Study population:

[0145] The study consists of two parts: Part A (an exploratory Phase IIa study to confirm the effectiveness of MYK-3 in NPC subjects who are eligible for second-line or higher-level treatment) and Part B (a confirmatory Phase IIb study in NPC subjects who are eligible for third-line or higher-level treatment).

[0146] All subjects were patients with recurrent and metastatic nasopharyngeal carcinoma who were inoperable and unsuitable for radiotherapy and had the following characteristics: (1) Part A: patients who had relapsed after initial surgery and radiotherapy and were not suitable for further surgery or radiotherapy, and had previously received at least first-line platinum-containing regimens and PD-1 / PD-L1 inhibitor systemic treatment, or had relapsed or were intolerant to treatment; (2) Part B: patients who had previously received at least two lines of systemic chemotherapy and failed PD-1 / PD-L1 treatment, and their previous chemotherapy regimens must have included at least platinum-containing regimens, gemcitabine, and taxanes / capecitabine (platinum-containing regimens include cisplatin, carboplatin, and nedaplatin; taxanes include paclitaxel, docetaxel, albumin-paclitaxel, and liposome-containing paclitaxel); (3) patients with advanced, incurable metastatic tumors, for whom participation in a clinical trial was an appropriate treatment option; (4) patients met all inclusion criteria and did not meet any exclusion criteria. Platinum-containing regimens include cisplatin, carboplatin, and nedaplatin.

[0147] Study Design:

[0148] This Phase II study consists of Part A and Part B.

[0149] The exploratory phase, Part A, will evaluate the safety and PK characteristics of MYK-3 in subjects eligible for second-line or higher-level treatment to determine the optimal dose and tolerability. The ORR, as assessed by an independent review committee (IRC), according to RECIST v1.1, will be used to confirm MYK-3's futility versus anti-tumor activity. If the safety and anti-tumor efficacy of MYK-3 are sufficiently demonstrated in Part A based on the documented ORR, the phase B phase will proceed.

[0150] Part B is a randomized, controlled clinical study comparing the efficacy and safety of MYK-3 injection versus capecitabine / docetaxel in patients with recurrent metastatic nasopharyngeal carcinoma who have previously received at least two lines of systemic chemotherapy and PD-1 / PD-L1 inhibitors. The study utilizes a randomized, stratified approach based on the presence of liver metastases (presence vs. absence) and Eastern Cooperative Oncology Group performance status (ECOG PS) (0 vs. 1). Participants in the experimental group will receive MYK-3. Participants in the control group who have not previously received capecitabine will receive capecitabine first. Participants who have previously received capecitabine will receive either capecitabine or docetaxel at the investigator's discretion.

[0151] Based on the completed first-in-human trial data and subsequent efficacy, safety, PK and other analyses, the Phase Ia dose-escalation phase showed that the MTD was 2.5 mg / kg, and the Phase Ib expansion phase showed that this dose level achieved good efficacy in the head and neck squamous cell carcinoma cohort and the nasopharyngeal carcinoma cohort. Taking into account the risk-benefit and evaluation of the optimal dose for further development, this Phase II study selected the dose level before the MTD of 2.0 mg / kg and the intermediate dose of 2.3 mg / kg as the doses for further exploration in Part A of this trial.

[0152] Part A: Subjects will receive 2.0 mg / kg or 2.3 mg / kg of MYK-3 intravenously on the first day of every 3 weeks (Q3W, 3 weeks as a treatment cycle).

[0153] Part B: Subjects in the experimental group will receive 2.3 mg / kg of MYK-3 intravenously on the first day of every 3 weeks (Q3W, 3 weeks as a treatment cycle). Subjects in the control group will receive 1000 mg / m2 of MYK-3 intravenously on days 1-14 of every 3 weeks (Q3W, 3 weeks as a treatment cycle) at the investigator's option. 2 Capecitabine was administered orally twice a day (if the first dose of capecitabine was on the evening of D1, it was administered orally until the morning of D15), or 75 mg / m2 on the first day of every 3 weeks (Q3W, 3 weeks as a treatment cycle) 2 Docetaxel was administered intravenously.

[0154] Based on comprehensive data on long-term drug safety, efficacy, and PK from Part A and Phase I trials, the SMC (Safety Monitoring Committee) ultimately determined that the recommended dose of MYK-3 for Part B is 2.3 mg / kg.

[0155] Test results:

[0156] The test results are shown in Tables 1, 2 and 3 below.

[0157] Table 1: Efficacy of MYK-3 in subjects with recurrent metastatic nasopharyngeal carcinoma (NPC)

[0158] Table 2: EGFR IHC statistical results in enrolled subjects with recurrent and metastatic nasopharyngeal carcinoma (NPC)

[0159] Note: EGFR IHC was not performed in 2 patients in groups 2.0 and 2.3 respectively.

[0160] Table 3: Summary of adverse reactions of MYK-3 in patients with recurrent or metastatic nasopharyngeal carcinoma

[0161] in conclusion:

[0162] An exploratory Phase IIa study of MYK-3 demonstrated significant anti-tumor activity in subjects with recurrent metastatic nasopharyngeal carcinoma (NPC) after multiple prior cancer-related therapies, with objective responses of 39.3% and 55.2% at doses of 2.0 mg / kg and 2.3 mg / kg, respectively, offering new hope for this population currently lacking effective treatment options. Based on the superior efficacy of the 2.3 mg / kg dose group compared to the 2.0 mg / kg dose group, as well as its favorable safety and tolerability profile, the 2.3 mg / kg dose was ultimately selected as the MYK-3 dose for the treatment of recurrent metastatic NPC.

Claims

1. An antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, for treating diseases associated with epidermal growth factor receptor (EGFR); The antibody-drug conjugate has the structure shown in Formula I, Ab-(LD) p Formula I in: Ab represents an anti-epidermal growth factor receptor antibody, wherein the anti-epidermal growth factor receptor antibody comprises a heavy chain and a light chain, wherein the heavy chain variable region CDR1, CDR2, and CDR3 respectively comprise the sequences shown in SEQ ID NO: 5, SEQ ID NO: 6, and SEQ ID NO: 7, or mutants thereof, and the light chain variable region CDR1, CDR2, and CDR3 respectively comprise the sequences shown in SEQ ID NO: 12, SEQ ID NO: 13, and SEQ ID NO: 14, or mutants thereof, L represents a linker, and the linker is 6-maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (MC-vc-PAB), D represents a cytotoxic agent, wherein the cytotoxic agent is MMAE, p is any value selected from 1-8; Wherein, the total dosage of the antibody-drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof every three weeks is 2.1-2.4 mg / kg.

2. The antibody-drug conjugate according to claim 1, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The total dosage of the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof, administered every three weeks is 2.2-2.4 mg / kg; Preferably, the total dosage of the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, administered every three weeks is 2.3 mg / kg.

3. The antibody drug conjugate according to any one of claims 1 to 2, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The single dosage of the antibody drug conjugate, or its pharmaceutically acceptable salt, solvate or solvate of the salt is 2.1-2.4 mg / kg (preferably 2.2-2.4 mg / kg, more preferably 2.3 mg / kg), and the administration frequency is once every three weeks.

4. The antibody drug conjugate according to any one of claims 1 to 2, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The single dosage of the antibody-drug conjugate, or its pharmaceutically acceptable salt, solvate or solvate of the salt is 0.7-1.4 mg / kg, and the administration frequency is once every 7-10 days.

5. The antibody drug conjugate according to any one of claims 1 to 4, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The antibody-drug conjugate, or its pharmaceutically acceptable salt, solvate or solvate of the salt is administered by intravenous drip.

6. The antibody drug conjugate according to any one of claims 1 to 5, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The subject to which the antibody-drug conjugate, or a pharmaceutically acceptable salt, solvate, or solvate of the salt thereof is administered is a human; Preferably, the subject to be administered the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, is a patient suffering from a disease associated with epidermal growth factor receptor (EGFR); Preferably, the subject to whom the antibody-drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof is administered is a patient who has previously received anti-EGFR drug treatment. Preferably, the anti-EGFR drug is an anti-EGFR antibody; Preferably, the subject to which the antibody drug conjugate, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof is administered is a patient who overexpresses EGFR.

7. The antibody-drug conjugate according to claim 1 or 6, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The disease associated with epidermal growth factor receptor (EGFR) is cancer; Preferably, the cancer is selected from nasopharyngeal carcinoma, head and neck squamous cell carcinoma, biliary tract cancer, esophageal cancer, duodenal cancer, colorectal cancer, colon cancer, rectal cancer, head and neck cancer, lung cancer (such as non-small cell lung cancer), ovarian cancer, cervical cancer, bladder cancer, esophageal cancer, breast cancer, kidney cancer, prostate cancer, gastric cancer, pancreatic cancer, and brain glioma; Preferably, the cancer is selected from nasopharyngeal carcinoma, head and neck squamous cell carcinoma, non-small cell lung cancer, biliary tract cancer, gastric cancer, esophageal cancer, and duodenal cancer; Preferably, the cancer is selected from EGFR-positive, HER2-negative advanced gastric cancer, recurrent metastatic nasopharyngeal carcinoma, recurrent or metastatic head and neck squamous cell carcinoma, EGFR-positive advanced biliary adenocarcinoma, EGFR-positive advanced non-small cell lung cancer, cancer.

8. The antibody drug conjugate according to any one of claims 1 to 7, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: p is any value selected from 2-6; Preferably, p is any value selected from 3-5.

9. The antibody drug conjugate according to any one of claims 1 to 8, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The anti-epidermal growth factor receptor antibody has one or more of the following characteristics: 1) The FR1, FR2, FR3, and FR4 regions of the heavy chain variable region of the anti-epidermal growth factor receptor antibody respectively comprise the sequences shown in SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, and SEQ ID NO: 11, or mutants thereof; 2) the FR1, FR2, FR3, and FR4 regions of the anti-epidermal growth factor receptor antibody light chain variable region respectively comprise the sequences shown in SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, and SEQ ID NO: 18, or mutants thereof; 3) The heavy chain constant region of the anti-epidermal growth factor receptor antibody is selected from human IgG, IgM, IgA, IgD, IgE constant regions or mutants of the above constant regions; Preferably, the IgG is selected from IgG1, IgG2, IgG3 and IgG4; 4) The light chain constant region of the anti-epidermal growth factor receptor antibody is a human lambda constant region, a kappa constant region, or a mutant of the above constant regions.

10. The antibody drug conjugate according to any one of claims 1 to 9, or a pharmaceutically acceptable salt, solvate or solvate of the salt thereof, wherein: The anti-epidermal growth factor receptor antibody has one or more of the following characteristics: 1) The sequence of the heavy chain variable region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 1, or comprises a sequence having an identity greater than 70%, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% to the sequence shown in SEQ ID NO: 1; Preferably, the sequence of the heavy chain variable region of the anti-epidermal growth factor receptor antibody is as shown in SEQ ID NO: 1; 2) The sequence of the light chain variable region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 2, or comprises a sequence having greater than 70% homology to the sequence shown in SEQ ID NO: 2, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% homology; Preferably, the sequence of the light chain variable region of the anti-epidermal growth factor receptor antibody is as shown in SEQ ID NO: 2; 3) The sequence of the heavy chain constant region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 3, or comprises a sequence having greater than 70% homology to the sequence shown in SEQ ID NO: 3, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% homology to the sequence shown in SEQ ID NO: 3; Preferably, the sequence of the heavy chain constant region of the anti-epidermal growth factor receptor antibody is as shown in SEQ ID NO: 3; 4) The sequence of the light chain constant region of the anti-epidermal growth factor receptor antibody comprises the sequence shown in SEQ ID NO: 4, or comprises a sequence having greater than 70% homology to the sequence shown in SEQ ID NO: 4, preferably greater than 75%, 80%, 85%, 90%, 95%, or 99% homology to the sequence shown in SEQ ID NO: 4; Preferably, the sequence of the light chain constant region of the anti-epidermal growth factor receptor antibody is shown in SEQ ID NO: 4.

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