Methods for treating cancer and pharmaceutical compositions thereof

Abstract

To provide a method for treating the target cancer. [Solution] A method for treating a target cancer, comprising administering a bispecific antibody having binding specificity to EGFR and HER3 and a therapeutic agent to the target, wherein the therapeutic agent includes a tyrosine kinase inhibitor (TKI), an alkylating agent, an antimetabolite, a microtubule inhibitor, an anti-cancer antibiotic, a topoisomerase inhibitor, a chemoprotective agent, or a combination thereof.

Description

[Technical Field]

[0001] Cross-references to related applications This application claims the benefit as of the filing date of U.S. Provisional Application Ser. No. 63 / 251,664, filed on 3 October 2021 under 35 U.S.C. 119(e), the full disclosure of which is incorporated herein by reference.

[0002] This application relates to combination therapies useful for the treatment of cancer. In particular, this application relates to combination therapies comprising bispecific antibodies that specifically bind to human EGFR and HER3, and chemotherapeutic agents including tyrosine kinase inhibitors. [Background technology]

[0003] Unless otherwise stated herein, the substances described in this section are not prior art to the claims of this application, nor are they deemed prior art by their inclusion in this section.

[0004] The human epidermal growth factor receptor family comprises four receptor tyrosine kinases (EGFR / HER1, HER2, HER3, and HER4). EGFR has been extensively studied for its role in gene expression, cell proliferation, adhesion, angiogenesis, apoptosis, and tumor metastasis. EGFR is overexpressed in over 90% of head and neck squamous cell carcinomas (HNSCC). High levels of EGFR mutations are observed in non-small cell lung cancer (NSCLC). While both EGFR and HER3 are frequently upregulated and / or mutated in various tumors, HER3 is a member of the EGFR family whose catalytic activity in the heterodimer complex formed by the kinase domains of EGFR, HER3, and HER2 is impaired. Cancer-associated HER3 mutations enhance the allosteric activator function of HER3 by reusing local interactions at the dimerization surface.

[0005] In patients with HNSCC, standard treatments such as postoperative radiotherapy combined with cisplatin-based chemotherapy improve local control and disease-free survival. However, overall survival remains at approximately 50%.

[0006] Several tyrosine kinase inhibitors (TKIs) have been developed as targeted chemotherapy that inhibits receptor tyrosine kinase activity in human cancer cells. TKIs may be used as monotherapy targeting the intracellular kinase domain of EGFR signaling. For example, gefitinib (IRESSA®, AstraZeneca) is approved for the treatment of NSCLC with EGFR exon 19 deletion (exon19del) or exon 21 (L858R) substitution mutations. The clinical benefit of TKI treatment, either as monotherapy or in combination with radiotherapy, appears to be limited to 10-15% of HNSCC patients. In HNSCC patients, the combination of EGFR-TKI targeted chemotherapy and standard chemotherapy is under investigation (Rebuzzie et al., 2019). Each of these approaches appears to have limitations. For example, the therapeutic dose in combination chemotherapy may show significant toxicity due to its nonspecific mechanism of action, limiting the effectiveness of the treatment plan.

[0007] While targeted chemotherapy (such as TKIs) or targeted immunotherapy shows initial efficacy, it does not lead to sustained control of cancer (Wu et al., 2020). In the case of targeted immunotherapy, cetuximab (ERBITUX®), a monoclonal antibody (mAb) that targets the extracellular domain of EGFR, is approved for the clinical indications of HNSCC, namely relapsed or metastatic HNSCC that has progressed after platinum-based therapy, locally or regionally advanced HNSCC in combination with radiotherapy, end-stage HNSCC in combination with chemotherapy, and as monotherapy for relapsed local lesions or metastatic HNSCC in combination with fluorouracil and platinum-based therapy. However, the response rate of cetuximab is limited to about 20% in HNSCC patients with high EGFR amplification and is independent of human papillomavirus (HPV) status. Adding cetuximab to platinum-based chemoradiotherapy (CRT) does not lead to improved prognosis. Furthermore, the addition of cetuximab to carboplatin / paclitaxel chemotherapy or high-dose radiotherapy did not provide any survival benefit for unresectable stage III non-small cell lung cancer (NSCLC), another cancer subtype exhibiting high EGFR expression and mutation rates.

[0008] EGFR-targeted monotherapy using either mAbs or TKIs results in relatively low response rates, and patients often develop resistance (Chong et al., 2013; Lim et al., 2018). Less than 5% of HNSCCs carry EGFR mutations, which may explain the limited efficacy. Furthermore, multiple extracellular receptors and downstream signaling pathways act as surrogates, and persistently activated oncogenic signaling allows cancer to tolerate resistance to EGFR inhibitor monotherapy. [Overview of the Initiative]

[0009] The following summary is illustrative and not intended to be limiting in any sense. Further embodiments, features, and characteristics beyond those described above will become apparent by referring to the drawings and the detailed description below.

[0010] In one embodiment, the present application provides a method for treating a target cancer. The method may be a combination therapy comprising at least one antibody. In one embodiment, the method comprises administering the antibody and the therapeutic agent to the subject.

[0011] The antibody described above may be a bispecific antibody. In one embodiment, the antibody has binding specificity to EGFR and HER3. In one embodiment, the antibody includes three complementarity-determining regions (CDRs) of SEQ ID NO: 1, three CDRs of SEQ ID NO: 2, or three CDRs of SEQ ID NO: 4.

[0012] In one embodiment, the antibody includes a heavy chain variable region (VH) having an amino acid sequence with at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, and 99% sequence identity with SEQ ID NO: 1. In one embodiment, the antibody includes a heavy chain scFv domain having an amino acid sequence with at least 98% sequence identity with SEQ ID NO: 2. In one embodiment, the antibody includes a light chain variable region (VL) having an amino acid sequence with at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, and 99% sequence identity with SEQ ID NO: 4.

[0013] In one embodiment, the antibody has a heavy chain and a light chain. In one embodiment, the heavy chain contains an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, and 99% sequence identity with respect to SEQ ID NO: 3. In one embodiment, the light chain contains an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, and 99% sequence identity with respect to SEQ ID NO: 5.

[0014] The above therapeutic agent may be any cancer treatment agent or a combination of such agents. In one embodiment, the therapeutic agent may be a tyrosine kinase inhibitor (TKI), alkylating agent, antimetabolites, microtubule inhibitors, anti-cancer antibiotics, topoisomerase inhibitors, chemoprotective substances, or a combination thereof. In one embodiment, the therapeutic agent may be osimertinib, paclitaxel, docetaxel, irinotecan, carboplatin, pemetrexed, cisplatin, or a combination thereof.

[0015] In one embodiment, the tyrosine kinase inhibitor (TKI) includes erlotinib, gefitinib, icotinib, AZD3759, sapatinib, afatinib, dacomitinib, delatinib, poditinib, tarlox-TKI, osimertinib, nazartinib, olmutinib, rosiletinib, nacotinib, lazartinib, EAI045, CLN081, AZ5104, mobocertinib, its derivatives, or combinations thereof.

[0016] In one embodiment, the method for treating the above cancer uses a combination therapy comprising a bispecific antibody and osimertinib. In one embodiment, the antibody may be administered by intravenous infusion at least once a week (QW), twice a week or every other week (Q2W), every three weeks (Q3W), or every three weeks on days 1 and 8 (D1D8Q3W) at doses of, for example, 6 mg / kg, 9 mg / kg, 12 mg / kg, 14 mg / kg, 16 mg / kg, or 21 mg / kg. In one embodiment, if an acute fluid reaction during the initial administration within 120 ± 10 minutes after the first intravenous infusion is acceptable, subsequent infusions may be completed within 60 to 120 minutes. In one embodiment, the antibody and the therapeutic agent may be used on the same day, and the infusion of the therapeutic agent may be continued even after the infusion of the antibody is completed. In one embodiment, osimertinib is administered in doses of at least about 40 mg / kg, about 80 mg / kg, about 120 mg / kg, about 160 mg / kg, or about 180 mg / kg.

[0017] In one embodiment, the alkylating agent includes busulfan, cyclophosphamide, temozolomide, carboplatin, cisplatin, or a combination thereof.

[0018] In one embodiment, the method uses a combination comprising a bispecific antibody and carboplatin. In one embodiment, carboplatin is administered at a dose of from about 100 mg / m 2 to about 500 mg / m 2 . In one embodiment, carboplatin is administered at a dose of at least about 200 mg / m 2 , about 250 mg / m 2 , about 300 mg / m 2 , about 360 mg / m 2 , about 400 mg / m 2 , or at a dose of AUC about 5 mg / ml / min, AUC about 6 mg / ml / min, AUC about 7 mg / ml / min. In one embodiment, carboplatin is administered at a dose of AUC about 5 mg / ml / min.

[0019] In one embodiment, the method uses a combination comprising a bispecific antibody and cisplatin. In one embodiment, cisplatin is administered at a dose of from about 10 mg / m 2 to about 180 mg / m 2 . In one embodiment, cisplatin is administered at a dose of at least about 15 mg / m 2 , about 20 mg / m 2 , about 30 mg / m 2 , about 50 mg / m 2 , about 75 mg / m 2 , about 100 mg / m 2 , or about 120 mg / m 2 . In one embodiment, cisplatin is administered at a dose of 100 mg / m 2 , Q3W. In one embodiment, the method further includes the step of determining the dose toxicity after the first infusion or the first treatment course. If the toxicity of the above dose is too strong, the above dose may be reduced to 80%.

[0020] In one embodiment, the antimetabolite may include 6-mercaptopurine, fludarabine, 5-fluorouracil, gemcitabine, cytarabine, pemetrexed, methotrexate, its derivatives, or combinations thereof.

[0021] In one embodiment, the above method uses a combination of a bispecific antibody and pemetrexed. In one embodiment, the pemetrexed dose is approximately 150 mg / m². 2 From approximately 800 mg / m² 2 It is administered in the following dose. In one embodiment, pemetrexed is at least about 250 mg / m². 2 , about 500 mg / m 2 , or approximately 750 mg / m² 2 It is administered in the following dose. In one embodiment, pemetrexed is approximately 500 mg / m². 2 It is administered in the following dose. In one embodiment, the method further includes a step of determining the dose toxicity after the initial infusion or the first course of treatment. If the toxicity of the above dose is too high, the dose is reduced by 80%.

[0022] In one embodiment, the present application uses a combination therapy comprising a bispecific antibody and a combination of pemetrexed and cisplatin. In one embodiment, the antibody may be administered by intravenous infusion at least once weekly (QW). In one embodiment, the administration of pemetrexed and cisplatin (AP) may be in accordance with the drug information and standard usage, or may be administered immediately after the completion of the administration of the antibody.

[0023] In one embodiment, the microtubule inhibitor includes docetaxel, eribulin, ixabepyrone, paclitaxel, vinblastine, its derivatives, or combinations thereof.

[0024] In one embodiment, the above method uses a combination therapy comprising a bispecific antibody and paclitaxel. In one embodiment, the antibody may be administered by once-weekly (QW) intravenous infusion. In one embodiment, the amount of paclitaxel is approximately 20 mg / m². 2From approximately 200 mg / m² 2 It may be administered in doses of at least about 40 mg / m². In one embodiment, paclitaxel is administered at at least about 40 mg / m². 2 , about 80 mg / m 2 , about 135 mg / m 2 , or approximately 175 mg / m² 2 It is administered in the following dose. In one embodiment, the dose of paclitaxel is 80 mg / m². 2 QW is also acceptable.

[0025] In one embodiment, the antibody and paclitaxel may be used on the same day. In one embodiment, after antibody infusion, paclitaxel may be pre-treated and injected within 3 hours. In one embodiment, the method may further include a step of determining the dose toxicity after the initial infusion. If the toxicity of the dose is too high, the dose is reduced to 80%.

[0026] In one embodiment, the present application provides a method for treating cancer using a combination therapy comprising a bispecific antibody and a combination of paclitaxel and cisplatin. In one embodiment, the antibody may be administered by intravenous infusion at least once weekly (QW). In one embodiment, the administration of paclitaxel and cisplatin (TP) may be in accordance with the drug information and standard usage, or may be administered immediately after the completion of the administration of the antibody.

[0027] In one embodiment, the above method may use a combination of a bispecific antibody and docetaxel. In one embodiment, docetaxel is administered at a dose of at least about 35 mg / m2, D1D8D215Q3W. In one embodiment, the above method further includes a step of determining the dose toxicity after the initial infusion. If the toxicity of the above dose is too high, the dose is reduced to 80%.

[0028] In one embodiment, the anti-cancer antibiotic includes dactinomycin, bleomycin, daunorubicin, doxorubicin, its derivatives, or combinations thereof.

[0029] In one embodiment, the topoisomerase inhibitor includes etoposide, irinotecan, topotecan, derivatives thereof, or combinations thereof.

[0030] In one embodiment, the above method may use a combination of a bispecific antibody and irinotecan. In one embodiment, the antibody is administered by intravenous infusion every two weeks (Q2W). In one embodiment, the irinotecan dose is approximately 50 mg / m². 2 From approximately 250 mg / m² 2 It may be administered in doses of at least about 80 mg / m². In one embodiment, irinotecan is administered at at least about 80 mg / m². 2 , 130 mg / m² 2 , 150 mg / m² 2 , 180 mg / m² 2 , 200 mg / m² 2 , or 220 mg / m² 2 It may be administered in the following dose. In one embodiment, the dose of irinotecan is 180 mg / m². 2 Q2W may also be used, and the method of infusion may be as described in the drug information sheet. In one embodiment, the antibody and irinotecan may be used on the same day, and irinotecan may be injected after the antibody infusion.

[0031] In one embodiment, the chemical protective agent includes leucovorin or a derivative thereof.

[0032] In one embodiment, the antibody may be combined with one or more therapeutic agents when treating cancer. In one embodiment, the antibody may be combined with a standard combination of chemotherapy. In one embodiment, the therapeutic agent or combination of therapeutic agents is administered according to established doses, regimens, or methodologies in cancer treatment.

[0033] The above-mentioned antibody and therapeutic agent may be administered simultaneously, or they may be administered sequentially as a single treatment session.

[0034] In one embodiment, the antibody and the therapeutic agent may be administered separately to the subject in alternating treatment sessions. In one embodiment, the antibody and the therapeutic agent are administered simultaneously and sequentially. In one embodiment, the antibody is administered at a different time than the therapeutic agent.

[0035] In one embodiment, the antibody may be administered in the first treatment session, and the therapeutic agent may be administered in the second treatment session. In one embodiment, the duration of the first treatment session may be about 7 to about 728 days. In one embodiment, the duration of the second treatment session may be about 1 to about 728 days. In one embodiment, the interval between the first treatment session and the second treatment session may be about 7 to about 21 days.

[0036] In one embodiment, the antibody may be administered once a week (Q1W), every two weeks (Q2W), every three weeks (Q3W), or on day 1 and day 8 every three weeks (D1D8Q3W).

[0037] The above antibodies are available in fixed dose, mg / kg dose, or mg / m² dose. 2 It may be administered in doses. In one embodiment, the antibody is administered in doses ranging from about 0.1 mg / kg to about 50 mg / kg. In one embodiment, the antibody is administered in doses of at least about 0.3 mg / kg, about 1.2 mg / kg, about 3.0 mg / kg, about 6.0 mg / kg, about 9.0 mg / kg, about 12.0 mg / kg, about 16.0 mg / kg, about 21.0 mg / kg, or about 28.0 mg / kg.

[0038] The above-mentioned therapeutic agents may be administered according to the drug information sheet and standard usage or dosage regimen. In one embodiment, the above-mentioned therapeutic agents may be administered in doses ranging from approximately 6.0 mg / kg to approximately 28.0 mg / kg.

[0039] In one embodiment, the present application provides a therapeutic composition for treating a subject having cancer. The therapeutic composition may include a combination of antibodies and therapeutic agents disclosed herein.

[0040] The antibody described above may be a bispecific antibody having binding specificity to both EGFR and HER3. In one embodiment, the antibody comprises three complementarity-determining regions (CDRs) of SEQ ID NO: 1, three CDRs of SEQ ID NO: 2, or three CDRs of SEQ ID NO: 4.

[0041] In one embodiment, the therapeutic agent may be any therapeutic agent or combination disclosed herein, such as osimertinib, carboplatin, cisplatin, pemetrexed, paclitaxel, its derivatives, or combinations thereof.

[0042] In one embodiment, both or either of the antibody and the therapeutic agent are in the form of a pharmaceutical formulation administered simultaneously, sequentially, or concurrently.

[0043] In one embodiment, the application further provides a kit comprising a first container, a second container, and an accompanying document. The first container comprises at least one dose of a first therapeutic composition comprising an antibody, the second container comprises at least one dose of a second therapeutic composition comprising a therapeutic agent, and the accompanying document comprises instructions for treating a target cancer using the first and second therapeutic compositions.

[0044] In one embodiment, the above instructions may state that the first therapeutic composition and the second therapeutic composition are intended for use in treating subjects having cancer that is positive for EGFR expression testing.

[0045] The above cancers may also be solid tumors. Specifically, the above cancers are lung adenocarcinoma, head and neck squamous cell carcinoma, rectal cancer, colon cancer, lung squamous cell carcinoma, thyroid cancer, bladder cancer, melanoma, cervical cancer, prostate cancer, breast cancer, uterine / endometrial cancer, pancreatic cancer, ovarian cancer, or papillary renal cancer.

[0046] In one embodiment, cancer includes solid tumors that are positive for EGFR expression testing and is selected from the group consisting of lung adenocarcinoma, head and neck squamous cell carcinoma, rectal cancer, colon cancer, lung squamous cell carcinoma, thyroid cancer, bladder cancer, melanoma, cervical cancer, prostate cancer, breast cancer, uterine / endometrial cancer, pancreatic cancer, ovarian cancer, and papillary renal cancer.

[0047] In one embodiment, the cancer is a progressive or metastatic solid tumor. [Brief explanation of the drawing]

[0048] The aforementioned and other features of this disclosure will become more fully apparent from the following description and the accompanying claims, which will be considered in conjunction with the accompanying drawings. It should be understood that these drawings depict only a few embodiments configured in accordance with this disclosure and are therefore not intended to limit its scope. This disclosure is described with further specificity and detail through the use of the accompanying drawings. [Figure 1] Figure 1 shows the efficacy of combination therapy based on representative bispecific antibody SI-B001 and osimertinib (Osi) when HCC827-936 tumor cell xenografts were treated in nude mice. Tumor volume was measured as the mean for each treatment (3 dose regimens) and the control group, and the standard error is shown (1a). Body weight curves during treatment are shown (1b). In addition, EGFR and HER3 expression in HCC827-936 cell-derived tumors was detected by flow cytometry fluorescence sorting (FACS) (1c). [Figure 2] Figure 2 shows the efficacy of SI-B001 and osimertinib (Osi)-based combination therapy when NCI-H1975 tumor cell xenografts were treated in nude mice. Tumor volume was measured as the mean value for each treatment (3 dose regimens) and the control group, with the standard error shown (2a). Body weight curves during treatment are shown (2b). In addition, EGFR and HER3 expression in NCI-H1975 cell-derived tumors was detected by FACS (2c). [Figure 3]Figure 3 shows the efficacy of SI-B001 and CarboTaxol (paclitaxel and carboplatin) combination therapy when Fadu tumor cell xenografts were treated in nude mice. Tumor volume was measured as the mean value for each treatment (3 dose regimens) and the control group, with the standard error shown (3a). The body weight curve during treatment is shown (3b). In addition, EGFR and HER3 expression in Fadu cell-derived tumors was detected by FACS (3c). [Figure 4] Figure 4 shows the measurements of tumor volume and tumor growth suppression rates for SI-B001 + chemotherapy compared to (4a) SI-B001 or chemotherapy alone, (4b) cetuximab + chemotherapy, and (4c) SI-B001 alone, cetuximab alone, or cetuximab + chemotherapy. [Figure 5] Figure 5 shows the effects of SI-B001 and cisplatin / pemetrexed-based combination therapy when nude mice were treated with HCC827 tumor cell xenografts. Tumor volume was measured as the mean for each treatment (3 dose regimens) and the control group, with the standard error shown (5a). The body weight curve during treatment is shown (5b). [Figure 6] Figure 6 shows the comparative superiority of combination therapies of SI-B100, TKIs, and chemotherapy agents for treating human tumor mouse xenograft models, as measured tumor growth rates affected by (6a) cetuximab and osimertinib alone or in combination, (6b) SI-B001 low dose and osimertinib alone or in combination, (6c) SI-B001 medium dose and osimertinib alone or in combination, (6d) SI-B001 high dose and osimertinib alone or in combination, (6e) cetuximab and chemotherapy alone or in combination, (6f) SI-B001 low dose and chemotherapy alone or in combination, (6g) SI-B001 medium dose and chemotherapy alone or in combination, and (6h) SI-B001 high dose and chemotherapy alone or in combination. [Figure 7] Figure 7 shows waterfall plots of tumor response in patients treated with (7a) SI-B001 + AP / TP or docetaxel, (7b) SI-B001 + paclitaxel, and (7c) SI-B001 + irinotecan. [Modes for carrying out the invention]

[0049] In the following detailed description, reference is made to the accompanying drawings which constitute part of this specification. In the drawings, unless otherwise indicated in the context, similar reference numerals generally identify similar components. The exemplary embodiments described in the detailed description, drawings and claims are not limiting. Other embodiments may be utilized and other modifications made without departing from the spirit or scope of the subject matter presented herein. As typically described herein and illustrated in the figures, aspects of this disclosure can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are expressly intended herein.

[0050] This disclosure typically relates to methods, compositions, and kits for treating cancer using combination therapies that include antibodies and additional therapeutic agents.

[0051] Anti-EGFR / HER3 antibody therapy (SI-B001) SI-B001 is a bispecific tetravalent anti-EGFR / HER3 monoclonal antibody (also known as SI-1X6.4 in U.S. Patent No. 10,919,977B2, which is incorporated herein by reference in its entirety). Upon administration, SI-B001 simultaneously binds to EGFR and HER3 on cancer cells, inhibiting receptor phosphorylation and oncogenic signaling. In short, SI-B001 encompasses binding to both EGFR and HER3 in a single therapeutic antibody.

[0052] Antibody-based immunotherapy inhibits cancer cell proliferation by means of inhibiting the binding of growth factors to receptors, blocking homodimeric and heterodimeric signaling states on the cell surface, and promoting internalization and degradation. Meanwhile, small molecules such as tyrosine kinase inhibitors (TKIs) inhibit cytoplasmic kinase activity induced by oncogenic signaling from one or more EGFR family members. All solid cancer cells are inherently heterogeneous; that is, even the state of EGFR mutations and aberrations in the same patient's cancer can vary from time to time. Combination therapies combining antibodies and additional therapeutic agents disclosed herein offer significant technical advantages, such as increasing the therapeutic effect on heterogeneous tumor cells at different stages of tumor progression, reducing the incidence of recurrence, or both. In one embodiment, SI-B001, used in combination with a TKI, combines antibody-based inhibition of EGFR family member(s)-mediated oncogenic signaling with inhibition of cytoplasmic signaling by an EGFR TKI by attacking the vertical pathway of EGFR oncogenic signaling.

[0053] SI-B001 combination therapy In some embodiments, the Disclosure provides a method for treating cancer in patients in need. The cancer may be, but is not limited to, a solid tumor, soft tissue sarcoma, squamous cell carcinoma, head and neck squamous cell carcinoma (HNSCC), non-small cell lung cancer (NSCLC), esophageal squamous cell carcinoma (ESCC), or EGFR-expressing cancer. The method may include administering an effective dose of SI-B001 to the patient in combination with one or more standard treatments, additional therapeutic agents, or a combination thereof.

[0054] Standard treatments for HNSCC, NSCLC, and ESCC, but not limited to these, are well known to those skilled in the art and include surgery, radiotherapy, chemotherapy, photodynamic therapy, targeted therapy, or targeted immunotherapy, or combinations thereof. In some embodiments, the standard treatment is carboplatin (PARAPLATIN®, BMS), cisplatin (PLANTINOL®, BMS), docetaxel (TAXOTERE®, Sanofi-Aventis), irinotecan (CAMPTOSAR®, Pfizer), pemetrexed disodium (ALIMTA®, Eli The chemotherapy regimen is selected from those using Lilly, afatinib dimaleate, alectinib (ALECENZA®, Genentech), bleomycin, brigatinib, ceritinib (ZYKADIA®, Novartis), crizotinib (XALKORI®, Pfizer), dabrafenib, doxorubicin hydrochloride, etoposide, everolimus, 5-fluorouracil, gemcitabine hydrochloride, hydroxyurea, mechloretamine hydrochloride, methotrexate, sunitinib, trametinib, vinorelbine tartrate (NAVELBINE®, Pierre Fabre), topotecan hydrochloride, derivatives, or combinations thereof.

[0055] In some embodiments, additional therapeutic agents may be tyrosine kinase inhibitors for targeted chemotherapy, including, for example, erlotinib, gefitinib, icotinib, AZD3759, sapatinib, afatinib, dacomitinib, delatinib, poziotinib, nazartinib, olmutinib, rosiletinib, nacotinib, lazartinib, EAI045, CLN081, AZ5104, mobocertinib, or derivatives thereof. In some embodiments, the additional therapeutic agent is osimertinib (TAGRISSO®, AstraZeneca), a third-generation irreversible EGFR inhibitor designed to target mutant and abnormally expressed EGFR without affecting wild-type EGFR. Osimertinib is well-tolerated in patients with advanced or metastatic NSCLC.

[0056] In some embodiments, additional therapeutic agents may be, for example, cetuximab (anti-EGFR antibody, ERBITUX®, Lilly), nivolumab (anti-PD1 antibody, OPDIVO®, BMS), pembrolizumab (anti-PD1 antibody, KEYTRUDA®, Merck), semiprimab (anti-PD1 antibody, LIBTAYO®, Regeneron), atezolizumab (anti-PD-L1 antibody, TECENTRIQ®, Roche), durvalumab (anti-PD-L1 antibody, IMFINZI®, AstraZeneca), bevacizumab (anti-VEGF antibody, AVASTIN®, Roche), or monoclonal antibodies for targeted immunotherapy, including biosimilars thereof.

[0057] In some embodiments, SI-B001 is administered to patients as a first-line monotherapy for HNSCC, NSCLC, and ESCC. In other embodiments, SI-B001 is administered to patients as a first-line treatment in combination with standard treatments for HNSCC, NSCLC, and ESCC, including surgery, radiotherapy, chemotherapy, photodynamic therapy, or targeted immunotherapy, or a combination thereof.

[0058] In some embodiments, SI-B001 is administered as first-line treatment to lung cancer patients in combination with standard chemotherapy or docetaxel (TAXOTERE®, Sanofi-Aventis), including but not limited to NSCLC and recurrent and metastatic non-small cell lung cancer. In other embodiments, SI-B001 is administered as first-line treatment to head and neck cancer patients in combination with standard chemotherapy or paclitaxel (TAXOL®, BMS, ABRAXANE®, Abraxis), including but not limited to HNSCC and recurrent and metastatic HNSCC. In yet another embodiment, SI-B001 is administered as first-line treatment to esophageal cancer patients in combination with standard chemotherapy or irinotecan (CAMPTOSAR®, Pfizer), including but not limited to ESCC and recurrent and metastatic ESCC.

[0059] In some embodiments, when standard treatment fails, such as when surgery fails to remove all cancerous tissue or when the cancer is partially resistant to chemotherapy or immunotherapy, second-line treatments may be used, including well-known second-line treatments for treating HNSCC, NSCLC, and ESCC. Accordingly, in some embodiments, the Disclosure provides a method for treating HNSCC, NSCLC, and ESCC in patients whose cancer is resistant to first-line treatment, the method optionally including administering SI-B001 in combination with second-line treatment.

[0060] In some embodiments, the Disclosure provides a method for treating cancer, comprising administering SI-B001 as a second-line treatment. In some embodiments, the Disclosure provides a method for treating resistant cancer, comprising administering SI-B001 in combination with another second-line treatment or a second-line treatment of standard treatment for HNSCC (ClinicalTrials.gov ID: NCT05054439, S206), NSCLC (ClinicalTrials.gov ID: NCT05020457, S201), and ESCC (ClinicalTrials.gov ID: NCT05022654, S207, incorporated herein as a whole). In some embodiments, the second-line treatment may be chemotherapy. For example, SI-B001 is administered to patients with HNSCC, NSCLC, and ESCC as second-line therapy in combination with standard chemotherapy or paclitaxel in the treatment of HNSCC, NSCLC, and ESCC, including but not limited to relapsed, recurrent, and / or metastatic HNSCC, NSCLC, and ESCC. In some embodiments, the second-line therapy may be targeted therapy. For example, SI-B001 is administered to patients with HNSCC, NSCLC, and ESCC as second-line therapy in combination with standard chemotherapy or osimertinib in the treatment of cancers such as HNSCC, NSCLC, and ESCC, including but not limited to relapsed, recurrent, and / or metastatic HNSCC, NSCLC, and ESCC.

[0061] In some embodiments, if primary or secondary standard treatment fails, for example, if chemotherapy continues to fail and remission occurs, a third-line treatment is administered to the patient. In some embodiments, the Disclosure provides a method for treating HNSCC (ClinicalTrials.gov ID: NCT05054439, S206), NSCLC (ClinicalTrials.gov ID: NCT05020457, S201), and ESCC (ClinicalTrials.gov ID: NCT05022654, S207) that are resistant to both primary and secondary treatments, comprising administering SI-B001 as a third-line treatment for HNSCC, NSCLC, and ESCC. In some embodiments, the Disclosure provides a method for treating HNSCC, NSCLC, and ESCC that are resistant to both primary and secondary treatments, comprising administering SI-B001 in combination with another third-line treatment or third-line standard treatment for HNSCC, NSCLC, and ESCC.

[0062] In some embodiments, SI-B001 is administered as a sensitizer for the treatment of HNSCC, NSCLC, and ESCC in patients who require it. Without being constrained by any theory, SI-B001 is considered to enhance the effectiveness of standard, first-line, second-line, or tertiary treatments for HNSCC, NSCLC, and ESCC. In some embodiments, this disclosure provides a method for treating HNSCC, NSCLC, and ESCC in patients who require it, comprising administering SI-B001 to the patient before administering one or more standard, first-line, second-line, or tertiary treatments. In some embodiments, administration of SI-B001 results in a more effective treatment of HNSCC, NSCLC, and ESCC compared to treatment without administration of SI-B001. In some embodiments, the Disclosure provides a method for treating HNSCC, NSCLC, and ESCC in patients in need, comprising administering SI-B001 to the patient after administration of one or more standard treatments, first-line treatments, second-line treatments, or tertiary treatments.

[0063] Those skilled in the art will understand the amounts and dosage regimens for administering such additional therapeutic agents for the treatment of HNSCC, NSCLC, and ESCC. Table 1 summarizes, as an example, the administration of exemplary therapeutic agents suitable for the treatment of HNSCC, NSCLC, and ESCC.

[0064] The term "pharmaceutical formulation" refers to the process by which different chemical substances, including stable and patient-acceptable pharmaceutically active compounds, are combined to produce the final drug in dose form. In the case of orally administered drugs, the active pharmaceutical compound is incorporated into a non-toxic carrier, adjuvant, or vehicle that does not impair the pharmacological activity of the formulated compound. The formulated pharmaceutical compound is compatible with these other substances in a way that does not cause harm, whether directly or indirectly. Examples of pharmaceutically acceptable carriers, adjuvants, or vehicles that may be used in the compositions of this disclosure include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins such as human serum albumin, buffering substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulosic substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene block polymers, salts or electrolytes such as polyethylene glycol, and lanolin.

[0065] The compositions of this disclosure may be administered orally, parenterally, by inhalation spray, topically (as a powder, ointment, or drop), rectally, nasally, buccally, vaginally, intravesically, or via an implanted reservoir. In this specification, the term “parenterally” includes methods of injection or infusion subcutaneously, intravenously, intramuscularly, intra-articularly, intra-articularly, intra-articularly, intra-articularly, intra-sternally, intrathecally, intrahepatically, intra-lesionally, and intracranially. Preferably, the compositions are administered orally, intraperitoneally, or intravenously. The sterile injection forms of the compositions of this disclosure may be aqueous or oily suspensions. These suspensions may be formulated according to art-known techniques using appropriate dispersants or wetting and suspending agents. The sterile injection preparations may also be sterile injection solutions or suspensions in non-toxic, parenterally acceptable diluents or solvents, such as a solution in 1,3-butanediol. Acceptable vehicles and solvents that may be employed include water, Ringer's solution, and isotonic sodium chloride solution. Furthermore, sterile fixatives are conventionally used as solvents or suspension media.

[0066] It should be understood that the specific dose and treatment regimen for any given patient will depend on a variety of factors, including the activity of the particular compound used, age, weight, general health, sex, diet, administration time, excretion rate, drug combination, and the judgment of the treating physician and the severity of the disease being treated. The amount of the compound of this disclosure in the composition will also depend on the compound in the composition.

[0067] Compounds and compositions obtained by the methods disclosed herein may be administered in any amount and via any route of administration that is effective in treating cancer, including those disclosed herein. The exact required dose may vary depending on the subject, depending on the species, age, and general condition, the severity of the cancer, the drug, and the mode of administration. The compounds and compositions disclosed herein are preferably formulated in uniform doses that facilitate the administration of physically discontinuous units of the drug appropriate for the patient being treated. However, it will be understood that the total daily dose of the compounds and compositions disclosed herein will be determined by the healthcare professional in charge, within the scope of professional medical judgment. The specific effective dose level for any particular patient or organism depends on a variety of factors, including the cancer being treated and its severity, the activity of the particular compound employed, the particular composition employed, the patient's age, weight, general health, sex, and diet, the timing of administration, route of administration, and excretion rate of the particular compound employed, the duration of treatment, drugs used in combination with or concurrently with the particular compound employed, and similar factors well known in the medical field.

[0068] Injectable preparations for sterile injection, such as aqueous or oily suspensions, may be formulated according to known techniques using appropriate dispersants or wetting and suspending agents. Sterile injectable preparations may also be sterile injectable solutions, suspensions, or emulsions in non-toxic, parenterally acceptable diluents or solvents, such as a solution in 1,3-butanediol. Acceptable vehicles and solvents that may be employed include water, Ringer's solution, and isotonic sodium chloride solution. Injectable preparations may be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating a sterilizer in the form of a sterile solid composition that can be dissolved or dispersed in sterile water or other sterile injectable media before use.

[0069] The kits of this disclosure are particularly suitable for different dose forms, such as oral and parenteral administration, administration of separate compositions at different dose intervals, or titration of separate compositions against each other. To assist compliance, the kits may typically include instructions regarding administration and may provide memory aids.

[0070] In this specification, the terms "a," "an," and "the" are defined to mean "one or more," and include the plural, unless otherwise inappropriate to the context.

[0071] The terms “polypeptide,” “peptide,” and “protein” are defined herein as meaning biomolecules consisting of interchangeable and peptide-linked amino acids.

[0072] The terms “antigen,” “antigenic site,” and “epitope” refer to entities or fragments thereof that can induce an immune response in living organisms, particularly animals, and more specifically mammals, including humans. These terms include immunogens and their regions that bear antigenicity or antigenic determinants.

[0073] The term "antibody" is used in its broadest sense and particularly includes single monoclonal antibodies (including agonist and antagonist antibodies), antibody compositions having polyepitope specificity, and antibody fragments (e.g., Fab, F(ab')2, and Fv) insofar as they exhibit desired biological activity. In some embodiments, the antibody may be a monoclonal antibody, a polyclonal antibody, a chimeric antibody, a single-chain antibody, a bispecific or bieffective antibody, a human antibody and a humanized antibody, and their active fragments. Examples of active fragments of molecules that bind to known antigens include Fab, F(ab')2, scFv, and Fv fragments, which include products of the Fab immunoglobulin expression library, and epitope-binding fragments of any of the antibodies and fragments described above. In some embodiments, the antibody may include an immunoglobulin molecule and a molecule containing an immunologically active site of the immunoglobulin molecule, i.e., a binding site that can bind to an antigen, antigen site, or epitope. Immunoglobulins may be any type (IgG, IgM, IgD, IgE, IgA, and IgY) or class (IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2) or subclass of immunoglobulin molecules. In one embodiment, the antibody may be the whole antibody or any antigen-binding fragment derived from the whole antibody.

[0074] A typical antibody refers to a heterotetrameric protein that typically contains two heavy chains (H chains) and two light chains (L chains). Each heavy chain contains a heavy chain variable domain (abbreviated as VH) and a heavy chain constant domain. Each light chain contains a light chain variable domain (abbreviated as VL) and a light chain constant domain. The "light chain" of any vertebrate species antibody (immunoglobulin) can be assigned to one of two distinct types called κ (kappa) and λ (lambda) based on the amino acid sequence of its constant domain. The VH and VL regions can be further subdivided into the hypervariable complementarity-determining region (CDR) domain and a more conserved region called the framework region (FR). Each variable domain (either VH or VL) typically consists of three CDRs and four FRs, arranged in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4, from the amino terminus to the carboxyl terminus. Within the variable regions of the light and heavy chains are binding regions that interact with the antigen.

[0075] In this specification, the term “monoclonal antibody” refers to an antibody obtained from a substantially homogeneous population of antibodies, that is, an antibody in which the individual antibodies constituting the population are identical, except for any spontaneously occurring variations that may be present in small amounts. Monoclonal antibodies are highly specific and act on one antigen site as a monoclonal monospecific antibody, or on more than one antigen site as a monoclonal multispecific antibody. Furthermore, in contrast to conventional (polyclonal) antibody preparations, which typically contain different antibodies that act on different determinants (epitopes), each monoclonal antibody acts on a single determinant on an antigen. In addition to its specificity, monoclonal antibodies have the advantage of being synthesized by hybridoma culture without contamination by other immunoglobulins. The modifier “monoclonal” indicates the characteristic of the antibody being obtained from a substantially homogeneous population of antibodies and should not be interpreted as requiring antibody production by any method. For example, monoclonal antibodies used in accordance with this disclosure may be prepared by the hybridoma method first described in Kohler & Milstein, Nature, 256:495 (1975), or by the recombinant DNA method (see, for example, U.S. Patent No. 4,816,567).

[0076] Monoclonal antibodies may include "chimeric" antibodies (immunoglobulins) in which, insofar as they exhibit the desired biological activity, a portion of the heavy chain and / or light chain is identical or homologous to the corresponding sequence of an antibody from a particular species or belonging to a particular antibody class or subclass, while the rest of the chain is identical or homologous to the corresponding sequence of an antibody from a different species or belonging to a different antibody class or subclass, and fragments of such antibodies (US Pat. No. 4,816,567, and Morrison et al., Proc. Natl. Acad. Sci. USA, 81:6851-6855

[1984] ). Monoclonal antibodies can be produced using a variety of methods, including mouse hybridoma or phage display (see review in Siegel. Transfus. Clin. Biol. Biol. 9:15-22 (2002)), or direct molecular cloning of antibodies from primary B cells (see Tiller. New Biotechnol. 28:453-7 (2011)). In this disclosure, antibodies were produced by combining methods of immunizing rabbits, mice, or llamas with subsequent strategies such as hybridoma or display. Rabbits are known to produce antibodies with high affinity, diversity, and specificity (Weber et al. Exp. Mol. Med. 49:e305). In addition to B cell culture after rabbit immunization, common strategies for antibody production and discovery include immunization of other animals (e.g., mice, llamas) followed by display on hybridomas and / or phages, yeast, or mammalian cells, or display using synthetic variable gene libraries. This general method for antibody discovery is similar to that described in Seeber et al. PLOS One. 9:e86184 (2014).

[0077] The term “antigen-binding or epitope-binding site or fragment” refers to a fragment of an antibody that can bind to an antigen. These fragments may have antigen-binding function and additional functions of an intact antibody. Examples of binding fragments include, but are not limited to, single-chain Fv fragments (scFv) consisting of the VL and VH domains of a single arm of an antibody linked to a single polypeptide chain by a synthetic linker, or Fab fragments, which are monovalent fragments consisting of the VL, constant light chain (CL), VH, and constant heavy chain 1 (CH1) domains. Antibody fragments may also be smaller subfragments, and may consist of domains as small as a single CDR domain, a CDR3 region from either the VL and / or VH domain (see, e.g., Beiboer et al., Biol. 296:833-49 (2000)). Antibody fragments are manufactured using conventional methods known to those skilled in the art. Antibody fragments can be screened for usefulness using the same techniques employed for intact antibodies.

[0078] "Antigen or epitope-binding fragments" can be obtained from the antibodies of this disclosure by several known techniques. For example, purified monoclonal antibodies can be cleaved with an enzyme such as pepsin and subjected to HPLC gel filtration. A suitable fraction containing the Fab fragment can then be collected and concentrated by membrane filtration or the like. For further descriptions of general techniques for isolating active fragments of antibodies, see, for example, Khaw, BA et al. J. Nucl. Med. 23:1011-1019 (1982) and Rousseaux et al. Methods Enzymology, 121:663-69, Academic Press, 1986.

[0079] When an antibody is digested with papain, two identical antigen-binding fragments called "Fab" fragments, each having a single antigen-binding site, and the remaining "Fc" fragment, whose name reflects its ability to easily crystallize. Pepsin treatment yields an F(ab')2 fragment having two antigen-binding sites and capable of crosslinking antigens. The Fab fragment may contain a constant domain of the light chain and a first constant domain (CH1) of the heavy chain. The Fab' fragment differs from the Fab fragment by the addition of several residues at the carboxyl terminus of the heavy chain CH1 domain, which contains one or more cysteines from the antibody hinge region. Fab'-SH is the herein designation for Fab' in which the cysteine ​​residues of the constant domain have free thiol groups. The F(ab')2 antibody fragment was originally produced as a pair of Fab' fragments with hinge cysteines between them. Other chemical bindings of antibody fragments are also known.

[0080] "Fv" refers to the minimal antibody fragment containing a complete antigen recognition and binding site. This region consists of a dimer in which one heavy chain variable domain and one light chain variable domain are tightly non-covalently bonded. In this configuration, the three CDRs of each variable domain interact to define the antigen-binding site on the surface of the VH-VL dimer. Overall, six CDRs confer antigen-binding specificity to the antibody. However, even a single variable domain (or half of an Fv containing only three antigen-specific CDRs) has the ability to recognize and bind to the antigen, albeit with lower affinity than the entire binding site.

[0081] Immunoglobulins can be classified into various classes based on the amino acid sequence of their heavy chain constant domains. There are five main classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM. Some of these may be further divided into subclasses (isotypes), such as IgG-1, IgG-2, IgG-3, and IgG-4, and IgA-1 and IgA-2. The heavy chain constant domains corresponding to different classes of immunoglobulins are called α, delta, epsilon, γ, and μ, respectively. The subunit structures and three-dimensional structures of different classes of immunoglobulins are well known.

[0082] "Polyvalent" antibodies bind to multiple sites on a single target, and depending on the number of binding sites, they may exhibit higher functional affinity and binding activity than monomers. All antibodies are polyvalent; for example, IgG is bivalent and IgM is decavalent.

[0083] The "homology" between two sequences is determined by sequence identity. If the two sequences being compared are of different lengths, sequence identity is preferably related to the proportion of nucleotide residues in the shorter sequence that are identical to those in the longer sequence. Sequence identity can be determined conventionally using a computer program. Any discrepancies that appear in the comparison between a given sequence and the sequences described above in this disclosure may be caused, for example, by additions, deletions, substitutions, insertions, or recombinations.

[0084] The term "targeted chemotherapy" refers to molecularly targeted therapies for treating cancer, as well as other medical treatments such as drug therapy, hormone therapy, and cytotoxic chemotherapy. The first-in-class drug of targeted therapy or targeted chemotherapy is imatinib (GLEEVEC®, Novartis), an anti-cancer tyrosine kinase inhibitor (TKI). This class of TKIs has significantly improved treatment outcomes for chronic myeloid leukemia, Philadelphia chromosome-positive acute lymphoblastic leukemia, certain gastrointestinal stromal tumors, eosinophilic syndrome, chronic eosinophilic leukemia, systemic mastocytosis, myelodysplastic syndrome, and dermatofibrosarcoma protuberance. TKIs have also been used to treat other diseases such as idiopathic pulmonary fibrosis.

[0085] The term "EGFR-TKI" refers to TKI drugs that inhibit tyrosine kinase activity in the EGFR signaling pathway. Tyrosine kinases are enzymes that activate many proteins through signaling cascades, including signaling via EGFR family members. TKIs are also known as "tyrosine phosphorylation inhibitors" and can be distinguished from protein kinases that phosphorylate serine or threonine residues, and from those of the EGFR kinase domain and insulin receptor. Proteins are activated by the addition of a phosphate group (phosphorylation). Three generations of EGFR-TKIs have been developed as targeted chemotherapy for treating cancers with EGFR mutations, and these are classified based on their mechanism of action and clinical benefit (Sullivan and Planchard, 2017).

[0086] The term "Bliss independence score" refers to the Bliss independence model, which is widely used to analyze drug combination data when screening potential drug combinations. This method compares the observed combination response (YO) with the predicted combination response (YP), and is based on the assumption that there are no effects from drug interactions. Suppose two drugs A and B both suppress tumor growth: Drug A at dose a suppresses tumor growth Y a It suppresses % and drug B at dose b is Y of tumor growthb It suppresses %. When two drugs act independently, the combined inhibition rate Y is calculated using the perfect additivity of probability theory. ab,P It can be predicted: Y ab,P = Y a + Y b -Y a x Y b

[0087] This disclosure may be more readily understood by referring to the following detailed descriptions of the specific embodiments and examples contained herein. While this disclosure has been described with reference to certain details of its specific embodiments, such details are not intended to be considered limitations on the scope of this disclosure. Indeed, various modifications of this disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description and the accompanying drawings. Such modifications are intended to be included in the accompanying claims. [Examples]

[0088] Example 1. Xenograft model of human cancer Xenotransplantation of human cancer cells into immunodeficient mice is a standard model used in preclinical oncology research and trials of anticancer drug therapies. Typically, human cancer cell lines are injected subcutaneously into mice. The control group receives no drug, while one or more groups of mice receive the drug or a combination of drugs. The main outcome parameter is drug-induced growth inhibition, and tumor size is measured over time, often externally using calipers. After the tumor reaches a certain size, the mice are euthanized. The effect of the drug on the tumor is further analyzed at the tissue or molecular level (e.g., DNA, protein). The primary outcome parameter of xenotransplantation models for testing drug efficacy is the growth of the treated tumor compared to the control. Typically, xenotransplanted tumors grow to 100 mm in a few weeks. 3 (Diameter 6 mm) to 1000 mm 3It grows up to 12 mm in diameter. In contrast to exponential growth in (2D) in vitro experiments, the growth rate often decreases as the tumor size increases. The tumor growth inhibitory effect varies depending on the drug and transplanted cell line. The effects of therapeutic agents can be direct on tumor cells, indirect through the microenvironment such as inhibition of angiogenesis, or both.

[0089] The safety and efficacy of SI-B001 monotherapy and combination therapy with standard treatment, chemotherapy, and / or TKI-based targeted therapy were evaluated using xenograft models of HNSCC and NSCLC. Experimental animals used were Balb / c-nu mice, female, aged 5-7 weeks, and weighing 17-21 g.

[0090] To establish a xenotransplant model for HNSCC, human head and neck cancer cells, FaDu cells, were transplanted into mice. FaDu is a cell line isolated from hypopharyngeal tumors of squamous cell carcinoma patients and expresses wild-type EGFR (ATCC).

[0091] To establish a xenograft model for NSCLC, two expressing lung cancer cell lines were used. The human lung adenocarcinoma cell line HCC827_936 was obtained clonally from the HCC827 cell line (ATCC) isolated from patient NSCLC tissue. HCC827_936 cells express EGFR mutations in exon 19del and exon 20ins. The other lung cancer cell line, NCI-H1975 cells (ATCC), expresses the EGFR L858R / T790M double mutation.

[0092] Each of the three human cancer cell lines was cultured in RPMI1640 medium containing 10% fetal bovine serum, harvested during the exponential growth phase, resuspended in PBS to an appropriate concentration, and then used for subcutaneous tumor transplantation in mice.

[0093] Example 2. Combination therapy with SI-B001 and osimertinib in the HCC827_936 model To evaluate the antitumor efficacy and safety of the experimental drug SI-B001 in combination with osimertinib, 40 female nude mice were given 5 × 10⁶ doses. 6Individual HCC827_936 cells were subcutaneously transplanted, and the cells were resuspended in PBS (0.1 ml / mouse). The tumors had an average volume of approximately 163 mm². 3 Once the tumors had grown, the mice were randomly divided into groups according to tumor size and body weight to establish an HCC827_936 xenograft model.

[0094] Saline solution and SI-B001 were administered weekly by intravenous infusion. SI-B001 was given in three different dose regimens: 9 mg / kg, 16 mg / kg, and 28 mg / kg. DMSO and osimertinib were administered once weekly by oral administration. Osimertinib was given in a fixed dose regimen of 96 mg / kg (Table 2).

[0095] Tumor volume (mm 3 V = 1 / 2 × (a × b) 2 Here, a represents the major axis and b represents the minor axis. Relative tumor volume (RTV), RTV = Vt / V0, where V0 is the tumor volume at time 0 and Vt is the tumor volume after treatment at time t. The T / C value (%) is an indicator of the tumor response to treatment and is the most commonly used evaluation index. T / C % = T RTV / C RTV × 100%, here T RTV This refers to the mean RTV of the treatment group, and C RTV This is the mean RTV of the control group. The T / C value (%) is also expressed as T / C% = T TW / C TW It can also be calculated as × 100%, where TTW is the average tumor weight at the end of the treatment group experiment, and C TW This represents the average tumor weight at the end of the control group experiment. The relative tumor suppression rate (tumor growth inhibition rate, TGI) is one of the indicators showing the tumor response to treatment, and TGI% = 100% - T / C%.

[0096] The mean tumor volume of mice in the vehicle control group was 720.68 mm² on day 31. 3 In the control group receiving osimertinib monotherapy, the mean tumor volume was 344.53 mm on day 31. 3The TGI (%) was 54.89% (p=0.262). The mean tumor volume at day 31 for SI-B001 monotherapy, in dose groups of 9 / 16 / 28 mg / kg / mouse, was 789.65 mm², respectively. 3 , 601.42 mm 3 , and 203.92 mm 3 The TGI (%) was -10.71%, 24.64%, and 73.20%, respectively (compared to the vehicle control group, p=0.783, p=0.654, and p=0.123). In each dose group (9 / 16 / 28+96 mg / kg / mouse), the combination of SI-B001 and osimertinib resulted in a mean tumor volume of 46.79 mm at day 31. 3 7.75 mm 3 , 0 mm 3 The TGI% was 93.74%, 99.07%, and 100.00% (compared to SI-B001 monotherapy at the corresponding dose levels, p=0.002, p=0.012, and p=0.268; compared to osimertinib monotherapy, p=0.007, p=0.036, and p=0.044), indicating that the antitumor effect was superior to that of SI-B001 monotherapy and osimertinib monotherapy. In summary, the overall dose group of the combination of SI-B001 and osimertinib showed a significantly higher antitumor effect (Figure 1a, Table 3). The antitumor effect was superior to that of SI-B001 monotherapy and osimertinib monotherapy, demonstrating a significant synergistic antitumor effect with the combination therapy. Furthermore, the level of tumor suppression was positively correlated with increasing doses of SI-B001.

[0097] The body weight of the mice was measured throughout the experiment (Figure 1b). In vehicle group #1, two mice died before D31, with a mortality rate of 40%. In the SI-B001 monotherapy low-dose group #3, one mouse died before D31, with a mortality rate of 20%. In the SI-B001 monotherapy medium-dose group #4, three mice died before D31, with a mortality rate of 60%. In the SI-B001 monotherapy high-dose group #5, three mice died before D31, with a mortality rate of 60%. In the osimertinib monotherapy group #2, three mice died before D31, with a mortality rate of 60%. In the SI-B001 low-dose group of combination therapy #6, no mice died before D31. In the other two combination therapy groups #7 and #8, three mice died before D31, with a mortality rate of 60%. Regarding the number of deaths, no clear trends were observed between the groups. This indicates that there is no significant toxicity when SI-B001 and osimertinib are used in combination.

[0098] To identify tumor tissue targets in tumor-carrying mice at the end of the experiment, tumor tissue was collected after euthanasia of the mice, and the characteristics of EGFR and HER3 expression in the tumor tissue were examined using flow cytometry fluorescence sorting (FACS) analysis (Figure 1c).

[0099] In this example, the treatment plan for HNSCC demonstrates the efficacy of SI-B001 in combination with osimertinib in dose-escalation in an HCC827_936-derived xenograft model. The results showed that osimertinib could achieve some degree of cancer control, but mice treated with this TKI ultimately relapsed. On the other hand, combining two of the three sub-therapeutic doses of SI-B001 tested achieved sustained control. Combining osimertinib with SI-B001 at a dose that achieved disease stabilization also achieved sustained control. By day 31, a significant difference (p<0.05) in tumor volume was observed between the combination with osimertinib (the TKI) and all three combinations including SI-B001 (Table 3).

[0100] These results demonstrate that the combination of SI-B001 with TKIs can achieve significantly advantageous therapeutic efficacy, providing support for human clinical trials (Table 1).

[0101] Example 3. Combination therapy with SI-B001 and osimertinib in the NCI-H1975 model. To evaluate the antitumor efficacy and safety of the experimental drug SI-B001 in combination with osimertinib, 80 female nude mice were given 5 × 10⁶ doses. 6 NCI-H1975 cells were subcutaneously transplanted, and the cells were resuspended in PBS (0.1 ml / mouse). The tumors had an average volume of approximately 170 mm². 3 Once the tumors had grown, the mice were randomly divided into groups according to tumor size and body weight to establish a human head and neck squamous cell carcinoma cell NCI-H1975 xenograft model.

[0102] Saline solution and SI-B001 were administered once weekly by intravenous infusion. SI-B001 was given in three different dose regimens: 9 mg / kg, 16 mg / kg, and 28 mg / kg. DMSO and osimertinib were administered orally once weekly. Osimertinib was given in a fixed dose regimen of 96 mg / kg (Table 4).

[0103] Tumor volume (mm 3 V = 1 / 2 × (a × b) 2 Here, a represents the major axis and b represents the minor axis. Relative tumor volume (RTV), RTV = Vt / V0, where V0 is the tumor volume at time 0 and Vt is the tumor volume after treatment at time t. The T / C value (%) is an indicator of the tumor response to treatment and is the most commonly used evaluation index. T / C % = T RTV / C RTV × 100%, here T RTV This refers to the mean RTV of the treatment group, and C RTV This is the mean RTV of the control group. The T / C value (%) is also expressed as T / C% = T TW / C TW It can also be calculated as × 100%, where TTW is the average tumor weight at the end of the treatment group experiment, and C TWThis represents the average tumor weight at the end of the control group experiment. The relative tumor suppression rate (tumor growth inhibition rate, TGI) is one of the indicators showing the tumor response to treatment, and TGI% = 100% - T / C%.

[0104] The mean tumor volume of mice in the vehicle control group was 2316.19 mm² on day 25. 3 In the control group receiving osimertinib monotherapy, the mean tumor volume was 75.02 mm on day 25. 3 The TGI (%) was 95.35% (p=0.030). The mean tumor volume at day 25 for SI-B001 monotherapy, in dose groups of 9 / 16 / 28 mg / kg / mouse, was 253.83 mm², respectively. 3 173.94 mm 3 , and 186.08 mm 3 The TGI (%) was 81.79%, 86.85%, and 84.80%, respectively (p=0.027, p=0.021, p=0.021). In each dose group (9 / 16 / 28+96 mg / kg / mouse), the combination of SI-B001 and osimertinib resulted in a mean tumor volume of 49.36 mm at day 25. 3 9.75 mm 3 8.68 mm 3 The TGI% was 97.77%, 99.41%, and 99.54% (compared to SI-B001 monotherapy at the corresponding dose levels, p=0.243, p=0.409, and p=0.399; compared to osimertinib monotherapy, p=0.633, p=0.096, and p=0.092), indicating that the antitumor effect was superior to that of SI-B001 monotherapy and osimertinib monotherapy (Figure 2a, Table 5). In summary, the overall dose group of SI-B001 and osimertinib combination therapy showed significantly higher antitumor effects. The antitumor effect was superior to that of SI-B001 monotherapy and osimertinib monotherapy, demonstrating a significant synergistic antitumor effect. Furthermore, the level of tumor suppression was positively correlated with increasing doses of SI-B001.

[0105] The body weight of the mice was measured throughout the experiment (Figure 2b). In vehicle group #1, one mouse died before D25, and the mortality rate was 20%. In SI-B001 monotherapy groups #3, #4, and #5, two mice died before D25, and the mortality rate was 40%. In osimertinib monotherapy group #2, no mice died before D25. In combination therapy groups #6, #7, and #9, there were no, one, and one mouse deaths before D25, respectively. No significant differences were observed in body weight loss during the experiment among all surviving mice in all groups. No clear trends were observed in the number of deaths among the groups. This indicates that there is no significant toxicity when SI-B001 and osimertinib are used in combination.

[0106] To identify tumor tissue targets in tumor-carrying mice at the end of the experiment, tumor tissue was collected after euthanasia, and the characteristics of EGFR and HER3 expression in the tumor tissue were examined using FACS analysis (Figure 2c).

[0107] In this example, SI-B001 (EGFR-HER3 bispecific antibody) in combination with osimertinib showed increased drug activity when administered in combination to treat the lung cancer cell line NCI-H1975 as a tumor xenograft transplanted into Balb / c-nu mice. In this model, monotherapy with osimertinib and SI-B001 maintained a relatively stable disease state as measured by tumor volume. On the other hand, combining osimertinib with any of the three therapeutic doses of SI-B001 tested significantly enhanced tumor control by the last evaluable time point (p<0.05) (Table 5). This evidence supports clinical trials suggesting that the therapeutic capacity of SI-B001 in patients may be enhanced when used in combination with osimertinib (Table 1).

[0108] Example 4. Combination therapy of SI-B001 and CarboTaxol (paclitaxel and carboplatin) in the Fadu model To evaluate the antitumor efficacy and safety of the experimental drug SI-B001 in combination with paclitaxel and carboplatin, 80 female nude mice were given 5 × 10⁶ doses. 6FaDu cells were subcutaneously implanted, and the cells were resuspended in PBS (0.1 ml / mouse). When the tumors grew to an average volume of approximately 230 mm 3 , they were randomly grouped according to the tumor size and mouse body weight, and a FaDu xenograft model of human head and neck squamous cell carcinoma was established.

[0109] Normal saline (vehicle control), cetuximab, SI-B001, paclitaxel, and carboplatin were administered by intravenous infusion once a week. SI-B001 was given at three dose regimens of 6 mg / kg, 9 mg / kg, and 12 mg / kg. Cetuximab was given at 10.5 mg / kg on day 0 and then 6.5 mg / kg three times a week. Paclitaxel and carboplatin were given at fixed dose regimens of 20.6 mg / kg and 28 mg / kg, respectively (Figure 3a, Table 6).

[0110] Tumor volume (mm 3 ) V = 1 / 2 × (a×b) 2 , where a represents the long diameter and b represents the short diameter. Relative tumor volume (RTV), RTV = Vt / V0, where V0 is the tumor volume at time 0 and Vt is the tumor volume after treatment at time t. The T / C value (%) is an indicator of the tumor response to treatment and is the most commonly used evaluation indicator. T / C % = T RTV / C RTV × 100%, where T RTV is the mean RTV of the treatment group, and C RTV is the mean RTV of the control group. The T / C value (%) can also be calculated as T / C% = T TW / C TW × 100%, where TTW is the mean tumor weight at the end of the experiment in the treatment group, and C TW is the mean tumor weight at the end of the experiment in the control group. The relative tumor inhibition rate (tumor growth inhibition rate, TGI) is one of the indicators showing the tumor response to treatment, and TGI% = 100% - T / C%.

[0111] SI-B001 vs. Chemotherapy vs. SI-B001 + Chemotherapy All dose groups of SI-B001 monotherapy (6, 9, and 12 mg / kg doses) showed significant antitumor effects, with TGI rates of 96.76%, 97.9%, and 98.8%, respectively. The control chemotherapy regimen of paclitaxel + carboplatin showed good antitumor effects, with a TGI rate of 56.16%. All dose groups of SI-B001 + paclitaxel + carboplatin (6, 9, 12 + 20.6 + 28 mg / kg) were significantly more effective than the control chemotherapy group and the SI-B001 monotherapy group, with TGI rates of 99.2%, 99.23%, and 99.38%, respectively. This indicates that the combination of SI-B001 + paclitaxel + carboplatin has a synergistic antitumor effect in the human head and neck squamous epithelium FaDu xenograft model (Figure 4a).

[0112] SI-B001 + chemotherapy vs. cetuximab + chemotherapy All dose groups of SI-B001 monotherapy (6, 9, and 12 mg / kg doses) showed significant antitumor effects, with TGIs of 96.76%, 97.9%, and 98.8%, respectively. The control group, cetuximab monotherapy, had a TGI of 74.27%, which was significantly weaker than the SI-B001 monotherapy groups. The control group, cetuximab + paclitaxel + carboplatin combination therapy, showed good antitumor effects with a TGI of 79.98%, but was significantly weaker than all SI-B001 monotherapy groups (96.76%, 97.9%, and 98.8%) and the SI-B001 chemotherapy combination groups (99.2%, 99.23%, and 99.38%) (Figures 4b, 4c).

[0113] The body weight of the mice was measured throughout the experiment. There were no mouse deaths or significant weight loss in any of the SI-B001 monotherapy groups (Figure 3b). This indicates that SI-B001 monotherapy has low toxicity and good safety. In the paclitaxel + carboplatin chemotherapy group, four mice died before the end of the experiment, with a mortality rate of 80%, and three of these mice showed severe weight loss (≥20%) before death. The body weight of the mice in the paclitaxel + carboplatin chemotherapy group fluctuated significantly. This indicates that paclitaxel + carboplatin chemotherapy is more toxic and less safe than SI-B001 monotherapy. There were no mouse deaths or significant weight loss in the SI-B001 + chemotherapy combination group and the cetuximab + chemotherapy combination group. This indicates that both SI-B001 + chemotherapy and cetuximab + chemotherapy are well-tolerated and safe.

[0114] To identify tumor tissue targets in tumor-carrying mice at the end of the experiment, tumor tissue was collected after euthanasia, and the characteristics of EGFR and HER3 expression in the tumor tissue were examined using FACS analysis (Figure 3c).

[0115] In summary, SI-B001 (EGFR-HER3 bispecific antibody) in combination with CarboTaxol (paclitaxel and carboplatin) showed increased drug activity in the treatment of head and neck squamous epithelial FaDu cell lines as tumor xenografts transplanted into Balb / c-nu mice. In this model, CarboTaxol (paclitaxel and carboplatin) could slow the tumor growth rate but could not achieve tumor regression. On the other hand, when combined with any of the three therapeutic doses of SI-B001 tested, tumor regression was controllable (Figure 3a). At day 17, when all animals were evaluable for tumor volume, a significant difference in tumor volume (p<0.05) was evident among all three combinations of CarboTaxol (paclitaxel and carboplatin) and SI-B001 (Table 7). Based on this evidence, the combination of SI-B001 can achieve improved therapeutic capacity when used in combination with chemotherapy.

[0116] Example 5. SI-B001 and Cis / Pem combination therapy in the HCC827 model To evaluate the antitumor effect and safety of the experimental drug SI-B001 in combination with Cis / Pem, 40 female nude mice were given 5 × 10⁶ doses. 6 Individual HCC827_936 cells were subcutaneously transplanted, and the cells were resuspended in PBS (0.1 ml / mouse). The tumors had an average volume of approximately 163 mm². 3 Once the tumors had grown, the mice were randomly divided into groups according to tumor size and body weight to establish a xenograft model of human head and neck squamous cell carcinoma cells (HCC827_936).

[0117] Saline (vehicle control), SI-B001, cisplatin, and pemetrexed were administered weekly by intravenous infusion. SI-B001 was administered in three different dose regimens: 9 mg / kg, 16 mg / kg, and 28 mg / kg. Cisplatin and pemetrexed were administered at 7.72 mg / kg and 51.48 mg / kg when used in combination with cetuximab or SI-B001, and at 3.86 mg / kg and 25.74 mg / kg when administered alone (Figure 5a, Table 8).

[0118] Tumor volume (mm 3 V = 1 / 2 × (a × b) 2 Here, a represents the major axis and b represents the minor axis. Relative tumor volume (RTV), RTV = Vt / V0, where V0 is the tumor volume at time 0 and Vt is the tumor volume after treatment at time t. The T / C value (%) is an indicator of the tumor response to treatment and is the most commonly used evaluation index. T / C % = T RTV / C RTV × 100%, here T RTV This refers to the mean RTV of the treatment group, and C RTV This is the mean RTV of the control group. The T / C value (%) is also expressed as T / C% = T TW / C TW It can also be calculated as × 100%, where TTW is the average tumor weight at the end of the treatment group experiment, and C TWThis represents the average tumor weight at the end of the control group experiment. The relative tumor suppression rate (tumor growth inhibition rate, TGI) is one of the indicators showing the tumor response to treatment, and TGI% = 100% - T / C%.

[0119] The mean tumor volume of mice in the vehicle control group was 765.1 mm² on day 24. 3 The mean tumor volume in the control Cis / Pem group was 603.1 mm² on day 24. 3 The TGI (%) was 21.2% (p=0.473). The mean tumor volume at day 24 for SI-B001 monotherapy, in dose groups of 9 / 16 / 28 mg / kg / mouse, was 682 mm², respectively. 3 588.1 mm 3 , and 205.7 mm 3 The TGI (%) was 10.8%, 23.1%, and 73.1%, respectively (compared to the vehicle control group, p=0.562, p=0.198, and p=0.007). In each dose group, the combination of SI-B001 and Cis / Pem (9 / 16 / 28 + 3.86 + 25.74 mg / kg / week) resulted in a mean tumor volume of 337.7 mm² at day 24. 3 335.6 mm 3 , 241.8 mm 3 The TGI% was 55.9%, 56.1%, and 68.4% (compared to SI-B001 monotherapy at the corresponding dose levels, p=0.032, p=0.030, and p=0.652; compared to Cis / Pem, p=0.297, p=0.321, and p=0.222). The antitumor effect was superior to the corresponding SI-B001 monotherapy and to Cis / Pem monotherapy, except for the high dose of SI-B001.

[0120] In summary, SI-B001 combined with Cis / Pem exhibits overall high antitumor efficacy (Figure 5a, Table 9). The antitumor effect was superior to that of SI-B001 monotherapy and Cis / Pem monotherapy, demonstrating a synergistic antitumor effect. Furthermore, the level of tumor suppression was positively correlated with increasing doses of SI-B001.

[0121] To evaluate safety issues, mouse body weight was measured throughout the experiment (Figure 5b). In vehicle group #1, one mouse died before D24, with a mortality rate of 20%. In the SI-B001 monotherapy low-dose group #3, one mouse died before D24, with a mortality rate of 20%. In the SI-B001 monotherapy medium-dose group #4, two mice died before D24, with a mortality rate of 40%. In the SI-B001 monotherapy high-dose group #5, two mice died before D24, with a mortality rate of 40%. In the Cis / Pem group #2, three mice died by D24, with a mortality rate of 60%. In the SI-B001 low-dose and high-dose combination groups #6 and #8, two mice died before D24, with a mortality rate of 40%. In group #7, which received a moderate dose of SI-B001 in combination, one mouse died before D24, resulting in a mortality rate of 20%. No clear trend in the number of deaths was observed between the groups. This indicates that there is no significant toxicity when SI-B001 and Cis / Pem are used in combination.

[0122] SI-B001, when administered in combination with Cis / Pem, shows increased drug activity when used to treat lung cancer-derived HCC827 cell lines as tumor xenografts transplanted into Balb / c-nu mice. In this model, Cis / Pem can slow tumor growth rate at an evaluable early stage, but ultimately does not control tumor growth. As a monotherapy, SI-B001 showed dose-dependent control of tumor growth. High control can be achieved when Cis / Pem is combined with SI-B001 at subthermal doses.

[0123] Based on this evidence, the combination of SI-B001 with chemotherapy can achieve improved therapeutic efficacy.

[0124] Example 6: Synergistic effect of SI-B001 and TKI or chemotherapy in combination therapy According to the definition of Bliss, a combination therapy is synergistic if the Bliss independence score is greater than 0. The Bliss definition of synergy was applied to tumor volume data measured over 31 days in an HCC827 xenograft Balb / c-nu mouse model. In this model, mice were treated with cetuximab, SI-B001 low dose (9 mg / kg), SI-B001 medium dose (16 mg / kg), SI-B001 high dose (28 mg / kg), platinum-based dual chemotherapy (cisplatin and pemetrexed), third-generation TKI (osimertinib), and combinations thereof. Cetuximab, chemotherapy, and osimertinib were administered at clinically equivalent doses (Table 9).

[0125] Tumor growth rates in each treatment group were calculated using a linear mixed model and the same assumptions as defined in Demidenko, 2019. Comparisons of tumor growth with combination therapy versus individual drugs are shown in Figures 6a-6h. Both cetuximab and SI-B001 showed significant synergistic effects when combined with osimertinib (Table 10). The synergistic effect of SI-B001 and osimertinib increased with increasing doses of SI-B001 and was stronger than the synergistic effect of cetuximab and osimertinib. The combination of high-dose SI-B001 and osimertinib showed the best overall efficacy. When cetuximab and SI-B001 were combined with chemotherapy, all showed significant synergistic effects except for high-dose SI-B001 (Table 11). The combination of medium-dose SI-B001 and chemotherapy showed the best overall efficacy.

[0126] These results demonstrate that SI-B001 can achieve high therapeutic efficacy when used in combination with TKIs, supporting the findings from human clinical trials (Table 1).

[0127] Example 7: Clinical trial of SI-B001 in combination with chemotherapy as a therapeutic agent for solid tumors. SI-B001, used in combination with chemotherapy, has been tested in clinical trials in NSCLC, HNSCC, and ESCC (Table 1, S201, S206, and S207, respectively).

[0128] In the S201 trial, SI-B001 was used in combination with AP (Cis / Pem, cisplatin + pemetrexed) or TP (CarboTaxol, carboplatin + paclitaxel) for second-line NSCLC patients who had received only anti-PD-1 / L1 monotherapy as first-line treatment, and with docetaxel for second / third-line NSCLC patients who had received both platinum-based chemotherapy and anti-PD-1 / L1 therapy. According to a preliminary report, 91% of the 46 enrolled patients were male, with a median age of 62.5 years (range 33–76 years). Of the 46 patients, one received SI-B001 + AP / TP therapy, and 45 received SI-B001 + docetaxel therapy, with a median number of prior treatment lines of two. Of the 46 patients, 27 were eligible for efficacy evaluation (at least one tumor assessment after baseline), and 14 of these were still undergoing treatment. The overall response rate (ORR) was 33.3% (95% confidence interval, 16.5 to 54.0), and the disease control rate (DCR) was 81.5% (95% confidence interval, 61.9 to 93.7). Figure 7a shows the tumor response in a waterfall plot. The efficacy of SI-B001 in combination with chemotherapy in this indication demonstrated a potential benefit in this patient population compared to chemotherapy alone (Schuette et al., 2005).

[0129] The S206 trial involved the use of SI-B001 in combination with paclitaxel in second- or third-line HNSCC patients resistant to prior chemotherapy and anti-PD-1 / L1 therapy. Preliminary reports indicated that 87% of the 23 enrolled patients were male, with a median age of 56 years (range 36–75 years). All patients had received one line of prior chemotherapy plus immunotherapy. Of the 23 patients, 9 were eligible for efficacy evaluation (at least one tumor assessment after baseline), and 2 were still undergoing treatment. The overall response rate (ORR) was 55.6% (95% confidence interval, 21.2–86.3), and the disease control rate (DCR) was 88.9% (95% confidence interval, 51.8–99.7). Figure 7b shows the tumor response in a waterfall plot. Compared to past data on cetuximab plus chemotherapy (Issa et al., 2021), the improved response rate with SI-B001 plus paclitaxel treatment appears to be a trend toward greater clinical utility in this patient population.

[0130] The S207 trial involved SI-B001 in combination with irinotecan in second-line ESCC patients resistant to frontline platinum-based chemotherapy and anti-PD-1 / L1 therapy. Preliminary reports indicated that 90% of the 21 enrolled patients were male, with a median age of 58 years (range, 48–70 years). Of these 21 patients, 15 were eligible for efficacy evaluation (at least one tumor assessment after baseline), and 6 were still receiving treatment. The overall response rate (ORR) was 33.3% (95% confidence interval, 11.8–61.6), and the disease control rate (DCR) was 80.0% (95% confidence interval, 51.9–95.7). Tumor response is shown in a waterfall plot (Figure 7c). Based on preliminary data, the efficacy of SI-B001 + irinotecan may be better than that of irinotecan alone or in combination with other chemotherapy in patients with previously treated ESCC (Burkart et al., 2007).

[0131] In summary, SI-B001, when used in combination with chemotherapy, was well-tolerated in all three trials. No treatment-related deaths were observed. Therefore, the efficacy and safety data support further development of SI-B001 in these indications.

[0132] reference: Robichaux JP, Le X, Vijayan RSK, et al. Structure-based classification predicts drug response in EGFR-mutant NSCLC. Nature. 2021 Sep;597(7878):732-737. Wu L, Ke L, Zhang Z, Yu J, Meng X. Development of EGFR TKIs and Options to Manage Resistance of Third-Generation EGFR TKI Osimertinib: Conventional Ways and Immune Checkpoint Inhibitors. Front Oncol. 2020 Dec 18;10:602762. Rebuzzi SE, Alfieri R, La Monica S, Minari R, Petronini PG, Tiseo M. Combination of EGFR-TKIs and chemotherapy in advanced EGFR mutated NSCLC:Review of the literature and future perspectives. Crit Rev Oncol Hematol. 2020 Feb;146:102820. Demidenko, E., & Miller, TW(2019). Statistical determination of synergy based on Bliss definition of drugs independence. PLoS One, 14(11), e0224137. Chong CR, Janne PA. The quest to overcome resistance to EGFR-targeted therapies in cancer. Nat Med 2013;19:1389-400. Lim SM, Syn NL, Cho BC, et al. Acquired resistance to EGFR targeted therapy in non-small cell lung cancer:Mechanisms and therapeutic strategies. Cancer Treat Rev 2018;65:1-10. Sullivan, I and Planchard, D.(2017) Next-generation EGFR tyrosine kinase inhibitors for treating EGFR-mutant lung cancer beyond first line. Front. Med. 3:76. Schuette, W., Nagel, S., Blankenburg, T., et al.(2005). Phase III study of second-line chemotherapy for advanced non-small-cell lung cancer with weekly compared with 3-weekly docetaxel. Journal of Clinical Oncology, 23(33), 8389-8395. Issa, M., Klamer, B., Karivedu, V., et al. (2021). Use of cetuximab added to weekly chemotherapy to improve progression-free survival in patients with recurrent metastatic head and neck squamous cell carcinoma after progression on immune checkpoint inhibitors. Journal of Clinical Oncology > List of Issues > Volume 39, Issue 15_suppl. Burkart, C., Bokemeyer, C., Klump, B., et al. (2007). A phase II trial of weekly irinotecan in cisplatin-refractory esophageal cancer. Anticancer research, 27(4C), 2845-2848.

[0133] table

[0134] [Table 1] Exemplary indications for human cancer: 201 Patients with locally advanced or metastatic EGFR wild-type ALK wild-type NSCLC who have experienced disease progression or intolerance to first-line therapy containing anti-PD-1 / L1 antibodies or retrospective therapy containing anti-PD-1 / L1 antibodies. 206 Patients with relapsed or metastatic HNSCC (non-nasopharyngeal) that has progressed or is intolerant to prior treatment with platinum-based chemotherapy or non-platinum-based anti-PD-1 / L1 monoclonal antibodies (who have previously received up to two lines of systemic therapy). 207 Patients with relapsed or metastatic ESCC whose disease has progressed or become intolerant to anti-PD-1 / L1 monoclonal antibodies, with or without chemotherapy.

[0135] [Table 2] Note: The administered volume was 10 ml / kg per mouse. Tumor volume was assessed twice a week.

[0136] [Table 3]

[0137] [Table 4] Note: The administered volume was 10 ml / kg per mouse. Tumor volume was assessed twice a week.

[0138] [Table 5]

[0139] [Table 6] Note: The administration volume was 10 ml / kg per mouse. The cetuximab dose "10.5-6.5×3" indicates that 10.5 mg / kg was administered on day 0, followed by 6.5 mg / kg three times a week thereafter. Pac stands for paclitaxel, and Car stands for carboplatin. Tumor volume was assessed twice a week.

[0140] [Table 7]

[0141] [Table 8] Note: The dose is 10 ml / kg per mouse. Pem stands for pemetrexed, and Cis stands for cisplatin. Tumor volume is assessed twice a week.

[0142] [Table 9]

[0143] [Table 10]

[0144] JPEG2026086855000011.jpg47165

[0145] Sequence List >Sequence ID 1: SI-B001, a bispecific antibody heavy chain VH amino acid sequence with SI-1X6.4 CDR. QVQLKQSGPGLVQPSQSLSITCTVSGFSLT NYGVH WVRQSPGKGLEWLG VIWSGGNTDYNTPFTS RLSINKDNSKSQVFFKMNSLQSNDTAIYYCAR ALTYYDYEFAY WGQGTLVTVSS >Sequence ID 2: SI-B001, a bispecific heavy chain scFv domain amino acid sequence with SI-1x6.4 CDR. QVQLQESGGGLVKPGGSLRLSCAASGFTFS SYWMS WVRQAPGKGLEWVA NINRDGSASYYVDSVKG RFTISRDDAKNSLYLQMNSLRAEDTAVYYCAR DRGVGYFDL WGRGTLVTVSSGGGGGSGGGGSGGGGSQSALTQPASVSGSPGQSITISC TGTSSDVGGYNFVS WYQQHPGKAPKLMIY DVSDRPS GVSDRFSGSKSSGNTASLIISGLQADDEADYYC SSYGSSSTHVI FGGGTKVTVL >Sequence ID 3: SI-B001, SI-1X6.4 bispecific antibody heavy chain full-length amino acid sequence. QVQLKQSGPGLVQPSQSLSITCTVSGFSLTNYGVHWVRQSPGKGLEWLGVIWSGGNTDYNTPFTSRLSINKDNSKSQVFFKMNSLQSNDTAIYYCARALTYYDYEFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAV LQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVY TLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGGGSGGGGSQVQLQESGGGLVKPGGSLRLSCAASGFTFSSYWMSWVRQAPGKGLEWVANINRDGSASYYVDSVKGRF TISRDDAKNSLYLQMNSLRAEDTAVYYCARDRGVGYFDLWGRGTLVTVSSGGGGSGGGGSGGGGSQSALTQPASVSGSPGQSITISCTGTSSDVGGYNFVSWYQQHPGKAPKLMIYDVSDRPSGVSDRFSGSKSGNTASLIISGLQADDEADYYCSSYGSSSSTHVIFGGGTKVTVL >Sequence ID 4: SI-B001, bispecific antibody light chain VL amino acid sequence with SI-1x6.4 CDR. DILLTQSPVILSVSPGERVSFSC RASQSIGTNIH WYQQRTNGSPRLLIK YASESIS GIPSRFSGSGSGTDFTLSINSVESEDIADYYC QQNNNWPTT FGAGTKLELK >Sequence ID 5: SI-B001, SI-1x6.4 bispecific antibody light chain full-length amino acid sequence. DILLTQSPVILSVSPGERVSFSCRASQSIGTNIHWYQQRTNGSPRLLIKYASESISGIPSRFSGSGSGTDFTLSINSVESEDIADYYCQQNNNWPTTFGAGTKLELKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

Claims

1. A method for treating a target cancer, comprising administering a bispecific antibody having binding specificity to EGFR and HER3 and a therapeutic agent to the target, wherein the therapeutic agent includes a tyrosine kinase inhibitor (TKI), an alkylating agent, an antimetabolite, a microtubule inhibitor, an anti-cancer antibiotic, a topoisomerase inhibitor, a chemoprotective agent, or a combination thereof.

2. The method according to claim 1, wherein the bispecific antibody comprises three complementarity-determining regions (CDRs) of SEQ ID NO: 1, three CDRs of SEQ ID NO: 2, or three CDRs of SEQ ID NO:

4.

3. The method according to claim 1, wherein the bispecific antibody comprises a heavy chain variable region (VH) having an amino acid sequence having at least 98% sequence identity with SEQ ID NO: 1, a heavy chain scFv domain having an amino acid sequence having at least 98% sequence identity with SEQ ID NO: 2, and a light chain variable region (VL) having an amino acid sequence having at least 98% sequence identity with SEQ ID NO:

4.

4. The method according to claim 1, wherein the bispecific antibody comprises a heavy chain and a light chain, the heavy chain comprising an amino acid sequence having at least 98% sequence identity with SEQ ID NO: 3, and the light chain comprising an amino acid sequence having at least 98% sequence identity with SEQ ID NO:

5.

5. The method according to claim 1, wherein the therapeutic agent comprises osimertinib, paclitaxel, docetaxel, irinotecan, carboplatin, pemetrexed, cisplatin, or a combination thereof.

6. The method according to claim 1, wherein the bispecific antibody and the therapeutic agent are administered simultaneously or sequentially as a single treatment session.

7. The method according to claim 1, wherein the bispecific antibody and the therapeutic agent are administered separately to the subject in alternating treatment sessions.

8. The bispecific antibody is administered in the first treatment session, and the therapeutic agent is administered in the second treatment session. The antibody is administered once a week (Q1W), once every two weeks (Q2W), once every three weeks (Q3W), or once a week for two weeks every three weeks (D1D8, Q3W). The antibody is administered in a fixed dose, mg / kg dose, or mg / m² dose. 2 The method according to claim 1, administered in a specified dose.

9. The method according to claim 8, wherein the duration of the first treatment session is approximately 7 to approximately 728 days.

10. The method according to claim 8, wherein the duration of the second treatment session is approximately 1 to approximately 728 days.

11. The method according to claim 8, wherein the interval between the first treatment session and the second treatment session is about 7 to about 21 days.

12. The method according to claim 1, wherein the bispecific antibody is administered in doses of at least about 0.3 mg / kg, about 1.2 mg / kg, about 3.0 mg / kg, about 6.0 mg / kg, about 9.0 mg / kg, about 12.0 mg / kg, about 14.0 mg / kg, about 16.0 mg / kg, and about 21.0 mg / kg or about 28.0 mg / kg.

13. The method according to claim 1, wherein the therapeutic agent is administered in a dose of approximately 6.0 mg / kg to approximately 28.0 mg / kg.

14. The method according to claim 1, wherein the tyrosine kinase inhibitor (TKI) includes erlotinib, gefitinib, icotinib, AZD3759, sapatinib, afatinib, dacomitinib, delatinib, poziotinib, tarlox-TKI, osimertinib, nazartinib, olmutinib, rosiletinib, nacotinib, razertinib, EAI045, CLN081, AZ5104, mobocertinib, derivatives thereof, or combinations thereof.

15. The method according to claim 1, wherein the alkylating agent comprises busulfan, cyclophosphamide, temozolomide, carboplatin, cisplatin, or a combination thereof.

16. The method according to claim 1, wherein the antimetabolite includes 6-mercaptopurine, fludarabine, 5-fluorouracil, gemcitabine, cytarabine, pemetrexed, methotrexate, derivatives thereof, or combinations thereof.

17. The method according to claim 1, wherein the microtubule inhibitor includes docetaxel, eribulin, ixabepyrone, paclitaxel, vinblastine, derivatives thereof, or combinations thereof.

18. The method according to claim 1, wherein the anti-cancer antibiotic comprises dactinomycin, bleomycin, daunorubicin, doxorubicin, derivatives thereof, or combinations thereof.

19. The method according to claim 1, wherein the topoisomerase inhibitor comprises etoposide, irinotecan, topotecan, derivatives thereof, or combinations thereof.

20. The method according to claim 1, wherein the chemical protective agent comprises leucovorin or a derivative thereof.

21. The method according to claim 1, wherein the therapeutic agent comprises osimertinib, and the osimertinib is administered in a dose of at least about 40 mg / kg, about 80 mg / kg, about 120 mg / kg, or about 160 mg / kg.

22. The aforementioned therapeutic agent contains carboplatin, and the carboplatin is present in a dose of at least about 200 mg / m². 2 , about 250 mg / m 2 , about 300 mg / m 2 , about 360 mg / m 2 , about 400 mg / m 2 The method according to claim 1, administered in a dose with an AUC of approximately 5 mg / ml / min, approximately 6 mg / ml / min, or approximately 7 mg / ml / min.

23. The therapeutic agent includes cisplatin, and cisplatin is administered at a dose of at least about 15 mg / m 2 , about 20 mg / m 2 , about 30 mg / m 2 , about 50 mg / m 2 , about 75 mg / m 2 , about 100 mg / m 2 , or about 120 mg / m 2 , the method according to claim 1.

24. The aforementioned therapeutic agent contains pemetrexed, and the amount of pemetrexed is at least about 250 mg / m². 2 , about 500 mg / m 2 , or approximately 750 mg / m² 2 The method according to claim 1, administered in the dose of [specify dose].

25. The aforementioned therapeutic agent contains paclitaxel, and the amount of paclitaxel is at least about 40 mg / m². 2 , about 80 mg / m 2 , about 135 mg / m 2 , or approximately 175 mg / m² 2 The method according to claim 1, administered in the dose of [specify dose].

26. The aforementioned therapeutic agent contains docetaxel, and the amount of docetaxel is at least about 35 mg / m². 2 The method according to claim 1, administered in a dose of D1D8Q3W.

27. The method according to claim 1, wherein the bispecific antibody and the therapeutic agent are administered simultaneously and sequentially.

28. The method according to claim 1, wherein the bispecific antibody is administered at a time different from that of the therapeutic agent.

29. The method according to claim 1, wherein the cancer includes solid tumors that are positive for EGFR expression testing and is selected from the group consisting of lung adenocarcinoma, head and neck squamous cell carcinoma, rectal cancer, colon cancer, lung squamous cell carcinoma, thyroid cancer, bladder cancer, melanoma, cervical cancer, prostate cancer, breast cancer, uterine / endometrial cancer, pancreatic cancer, ovarian cancer, and papillary renal cancer.

30. A therapeutic composition comprising a combination of a bispecific antibody having binding specificity to EGFR and HER3 and a therapeutic agent, wherein the therapeutic agent comprises a tyrosine kinase inhibitor (TKI), an alkylating agent, an antimetabolite, a microtubule inhibitor, an anti-cancer antibiotic, a topoisomerase inhibitor, a chemoprotective agent, or a combination thereof.

31. The therapeutic composition according to claim 30, wherein the bispecific antibody comprises three complementarity-determining regions (CDRs) of SEQ ID NO: 1, three CDRs of SEQ ID NO: 2, or three CDRs of SEQ ID NO: 4, and the therapeutic agent comprises osimertinib, carboplatin, cisplatin, pemetrexed, paclitaxel, its derivatives, or a combination thereof.

32. The therapeutic composition according to claim 30, wherein the bispecific antibody and the therapeutic agent are in the form of a pharmaceutical formulation administered simultaneously, sequentially, or in parallel.

33. A kit comprising a first container, a second container, and an accompanying leaflet, The kit comprises a first container containing at least one dose of a first therapeutic composition comprising a bispecific antibody having binding specificity to EGFR and HER3, a second container containing at least one dose of a second therapeutic composition comprising a therapeutic agent, and a package insert comprising instructions for treating a target cancer using the first and second therapeutic compositions, and the therapeutic agent comprising a tyrosine kinase inhibitor (TKI), alkylating agent, antimetabolite, microtubule inhibitor, anti-cancer antibiotic, topoisomerase inhibitor, chemoprotective agent, or a combination thereof.

34. The kit according to claim 33, wherein the instructions state that the first and second therapeutic compositions are intended for use in treating subjects having cancer that is positive for EGFR expression testing.

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