Pharmaceutical composition comprising Anti-CTLA4 and Anti-PD1 antibodies, and therapeutic use thereof

Abstract

The present invention relates to use of a combination of anti-CTLA4 and anti-PD1 antibodies for treating limited-stage small cell lung cancer, in particular for the consolidation therapy of limited-stage small cell lung cancer after radiotherapy or chemotherapy.

Description

Pharmaceutical compositions comprising mixed antibodies against anti-CTLA4 and anti-PD1 and their therapeutic uses

[0001] This application claims priority to Chinese Patent Application No. CN202510072150.1, filed on January 16, 2025, entitled "Pharmaceutical Composition Containing Mixed Antibodies Against CTLA4 and AntiPD1 and Its Therapeutic Use Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to immunotherapy for cancer, particularly small cell lung cancer. More specifically, this disclosure relates to the use of pharmaceutical compositions comprising a mixture of anti-CTLA4 and anti-PD1 antibodies for the treatment of limited-stage small cell lung cancer. Background Technology

[0003] Lung cancer is one of the leading causes of cancer-related deaths worldwide. The 2024 Global Cancer Statistics report shows that in 2022, there were nearly 2.5 million new cases of lung cancer globally (accounting for 12.4% of all cancers worldwide), and approximately 1.8 million new deaths (18.7%). Small cell lung cancer (SCLC) accounts for approximately 13-17% of all lung cancers (data from CSCO 2025), with about 250,000 patients diagnosed with SCLC globally each year, and nearly 200,000 dying from it. In 2022, my country had approximately 1.0606 million new cases of lung cancer, ranking first among malignant tumors and accounting for about 22.0% of all malignant tumors, seriously threatening human health.

[0004] Based on progression, SCLC is divided into limited-stage (LS) and extensive-stage (ES). LS-SCLC refers to tumors confined to one side of the pleural cavity and can be included in a single radiotherapy field, while ES-SCLC refers to tumors that extend beyond one side of the pleural cavity and include malignant pleural effusion, pericardial effusion, or hematogenous metastases. At diagnosis, LS-SCLC accounts for approximately 30% of all SCLC cases.

[0005] Extensive-stage small cell lung cancer (ES-SCLC) is sensitive to chemotherapy, with an objective response rate as high as 40-70%. However, the duration of remission is short, with a median progression-free survival (PFS) of <6 months, median overall survival (mOS) of <12 months, and a five-year survival rate of less than 6%, indicating a very poor prognosis. Although combining immunotherapy with chemotherapy can prolong overall survival in ES-SCLC, the efficacy remains unsatisfactory. Currently, immunosuppressants available in China for first-line treatment of ES-SCLC include atezolizumab, durvalumab, slulimab, adebelimab, toripalimab, and tislelizumab.

[0006] A very small percentage of patients with very early-stage LS-SCLC (T1-2N0) have the opportunity to undergo surgical treatment. Besides surgery, CRT (chemoradiotherapy) is the standard treatment for LS-SCLC. CRT includes cCRT (concurrent chemoradiotherapy) and sCRT (sequential chemoradiotherapy), which refers to chemotherapy with cisplatin or carboplatin and etoposide combined with thoracic radiotherapy simultaneously or sequentially. For 30 years, although researchers have been continuously exploring new chemotherapy regimens (such as the CEV regimen) and radiotherapy regimens (such as optimal thoracic radiotherapy doses and fractionation patterns), the treatment modality of CRT has remained unchanged. However, although the response rate of LS-SCLC patients treated with cCRT is as high as 90%, the remission period is short, and most patients eventually experience disease progression. The median progression-free survival (mPFS) is only 10–15 months, and the median overall survival (mOS) is 15–30 months. There is a huge unmet clinical need for the treatment of LS-SCLC, and there is an urgent need to explore more effective treatment strategies to enable more patients to achieve long-term survival. Multiple studies have explored post-CRT immune consolidation therapy and CRT combined with immunotherapy, with data suggesting that new treatment modalities may prolong overall survival (OS). The ADRIATIC study was the first phase 3 trial to conduct post-cCRT immune consolidation therapy in LS-SCLC patients. This study was the first to demonstrate that durvalumab (a PD-L1 inhibitor) consolidation therapy after completing cCRT significantly improved PFS and OS in LS-SCLC, with a favorable safety profile. Similar to ADRIATIC, several clinical studies of PD-L1 / PD-1 immunosuppressants for consolidation therapy are also underway.

[0007] ZPML265 is a mixed antibody drug formulation belonging to the category of dual-target immunotherapy. It consists of a recombinant humanized IgG1 monoclonal antibody targeting human CTLA4 and a recombinant humanized IgG4 monoclonal antibody targeting human PD1. These two different antibodies are produced by a single host cell. This mixed antibody can simultaneously and specifically bind to CTLA4 and PD1, thereby blocking two immune checkpoint signaling pathways: CTLA-4 and B7-1 / B7-2, and PD-1 and PD-L1. This relieves the inhibitory effect of these two pathways on T lymphocytes, restoring their functional activity and anti-tumor immune response, thus enabling the body to fight and kill tumors.

[0008] Currently, only the ADRIATIC study has yielded positive results in consolidation therapy after cCRT in LS-SCLC patients, and it was approved by the National Medical Products Administration on June 4, 2025. Other similar studies have not yet obtained final results. Clinically, there is a need for more and better immunotherapies for consolidation therapy after radiotherapy and chemotherapy in LS-SCLC patients, thereby prolonging their survival.

[0009] Invention Overview

[0010] The technical problem to be solved by this disclosure is to provide an immunotherapy to fill the international clinical gap in the lack of dual immunotherapy drugs for consolidation therapy after radiotherapy and chemotherapy in patients with limited-stage small cell lung cancer, thereby addressing the clinical need for such patients with short survival after radiotherapy and chemotherapy.

[0011] This disclosure provides the use of a mixed antibody containing effective amounts of anti-CTLA4 and anti-PD1 in the preparation of a pharmaceutical composition for the treatment of limited-stage small cell lung cancer.

[0012] Furthermore, this disclosure also provides a method for treating limited-stage small cell lung cancer, the method comprising administering a subject a pharmaceutical composition, said pharmaceutical composition being the aforementioned mixed antibody containing an effective amount of anti-CTLA4 and anti-PD1.

[0013] In some implementations, the treatment of limited-stage small cell lung cancer is consolidation therapy following chemoradiotherapy, such as consolidation therapy following concurrent chemoradiotherapy or sequential chemoradiotherapy.

[0014] In some embodiments, the mixed antibody is produced by a single host cell containing nucleic acids encoding two different antibodies, anti-CTLA4 and anti-PD1. The sequences of the anti-CTLA4 antibody heavy chains HCDR1, HCDR2, and HCDR3 are shown in SEQ ID NO: 1, 2, and 3, respectively; the sequences of the anti-CTLA4 antibody light chains LCDR1, LCDR2, and LCDR3 are shown in SEQ ID NO: 4, 5, and 6, respectively; the sequences of the anti-PD1 antibody heavy chains HCDR1, HCDR2, and HCDR3 are shown in SEQ ID NO: 9, 10, and 11, respectively; and the sequences of the anti-PD1 antibody light chains LCDR1, LCDR2, and LCDR3 are shown in SEQ ID NO: 12, 13, and 14, respectively.

[0015] In some embodiments, the heavy chain variable region sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 7, the light chain variable region sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 8, the heavy chain variable region sequence of the anti-PD1 antibody is shown in SEQ ID NO: 15, and the light chain variable region sequence of the anti-PD1 antibody is shown in SEQ ID NO: 16.

[0016] In some embodiments, the heavy chain sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 17, the light chain sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 18, the heavy chain sequence of the anti-PD1 antibody is shown in SEQ ID NO: 19, and the light chain sequence of the anti-PD1 antibody is shown in SEQ ID NO: 20.

[0017] In some implementations, the mixed antibody is administered at a dose of 5 mg / kg every three weeks, via intravenous infusion on day 1, with a treatment cycle of 21 days.

[0018] The results of a Phase I clinical trial of the disclosed mixed antibody as a monotherapy showed definite efficacy and good safety in 26 enrolled patients with small cell lung cancer. Furthermore, preliminary clinical studies of the mixed antibody combined with chemotherapy in small cell lung cancer have also demonstrated synergistic anti-tumor effects and superior clinical efficacy. Therefore, the mixed antibody provided in this disclosure is expected to have manageable safety and good patient compliance for the medical treatment of limited-stage small cell lung cancer, and can largely fill the international gap of no approved dual-target immunotherapy drugs for limited-stage small cell lung cancer, addressing an unmet urgent clinical need. Detailed Implementation

[0019] the term

[0020] All publications, patents and patent applications mentioned in this specification are incorporated herein by reference as if specifically and individually indicated that each individual publication, patent or patent application is incorporated by reference.

[0021] Before this disclosure is described in detail below, it should be understood that this disclosure is not limited to the specific methodologies, procedures, and reagents described herein, as these can vary. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0022] Some embodiments disclosed herein include numerical ranges, and certain aspects of this disclosure may be described using ranges. Unless otherwise stated, it should be understood that numerical ranges or descriptions using ranges are for purposes of brevity and convenience only and should not be considered as a strict limitation of the scope of this disclosure. Therefore, descriptions using ranges should be considered as specifically disclosing all possible subranges and all possible specific numerical points within those ranges, as these subranges and numerical points have been explicitly stated herein. The above principles apply equally regardless of the breadth of the numerical values ​​described. When a range description is used, the range includes the endpoints of the range.

[0023] When referring to measurable values ​​such as quantities, temporary durations, etc., the term “about” means a variation of ±20%, or in some cases ±10%, or in some cases ±5%, or in some cases ±1%, or in some cases ±0.1% of the specified value.

[0024] The three-letter and single-letter codes for amino acids used in this article are as described in J. Biol. Chem, 243, p3558 (1968).

[0025] As used in this article, the term "antibody" typically refers to a Y-type tetrameric protein comprising two heavy (H) polypeptide chains (HC) and two light (L) polypeptide chains (LC) held together by covalent disulfide bonds and non-covalent interactions. Natural IgG antibodies possess this structure. Each light chain contains a variable domain (VL) and a constant domain (CL). Each heavy chain contains a variable domain (VH) and a constant domain (CH).

[0026] Five main classes of antibodies are known in this art: IgA, IgD, IgE, IgG, and IgM, with their corresponding heavy chain constant domains designated α, δ, ε, γ, and μ, respectively. IgG and IgA can be further subdivided into different subclasses; for example, IgG can be divided into IgG1, IgG2, IgG3, and IgG4, and IgA into IgA1 and IgA2. The light chain of antibodies from any vertebrate species can be assigned to one of two distinctly different types based on the amino acid sequence of its constant domain, termed κ and λ.

[0027] The term "variable region" or "variable domain" indicates a significant change in the amino acid composition from one antibody to another and is primarily responsible for antigen recognition and binding. The variable region of each light / heavy chain pair forms the antibody binding site, giving the complete IgG antibody two binding sites (i.e., it is bivalent). The variable region (VH) of the heavy chain and the variable region (VL) of the light chain each contain three regions with extreme variability, called hypervariable regions (HVR), or more commonly, complementarity-determining regions (CDR). Each VH and VL has four framework regions (FR), denoted as FR1, FR2, FR3, and FR4, respectively. Therefore, the CDR and FR sequences typically appear in the following sequence of the heavy chain variable domain (VH) (or light chain variable domain (VL)): FR1-HCDR1(LCDR1)-FR2-HCDR2(LCDR2)-FR3-HCDR3(LCDR3)-FR4.

[0028] In a broad sense, the types of "antibodies" can include polyclonal antibodies, monoclonal antibodies, chimeric antibodies, humanized antibodies and primate-derived antibodies, CDR transplantation antibodies, human antibodies (including recombinant human antibodies), recombinant antibodies, intracellular antibodies, multispecific antibodies, bispecific antibodies, single-chain antibodies, monovalent antibodies, multivalent antibodies, single-domain antibodies, nanobodies, synthetic antibodies (including mutant proteins and their variants), and so on.

[0029] The term "monoclonal antibody" (or "mAb") refers to a substantially homogeneous antibody produced from a single cell clone that targets only a specific antigenic epitope. Monoclonal antibodies can be prepared using a variety of techniques known in the art, including hybridoma technology, recombinant technology, phage display technology, transgenic animals, synthetic technology, or combinations of the above.

[0030] It should be noted that the division of the CDR and FR in the antibody variable region of this disclosure is determined according to the Kabat definition. Other nomenclature and numbering systems, such as Chothia, IMGT, or AHo, are also known to those skilled in the art. Therefore, humanized antibodies based on the antibody sequence of this disclosure that contain one or more CDRs derived from any nomenclature system are explicitly kept within the scope of this disclosure.

[0031] The term "antigen" refers to a substance that is recognized and specifically bound by an antibody or antibody-binding fragment. In a broad sense, an antigen can include any immunogenic fragment or determinant of a selected target, including single epitopes, multiple epitopes, single domains, multiple domains, or complete extracellular domains (ECDs) or proteins.

[0032] The terms “polypeptide,” “peptide,” and “protein” are used interchangeably herein to refer to polymers of amino acids of any length. Polymers can be linear, cyclic, or branched, and can contain modified amino acids, particularly conserved modified amino acids, and can be interrupted by non-amino acid molecules. The term also includes, for example, amino acid polymers that have been modified by glycosylation, esterification, acetylation, phosphorylation, methylation, etc.

[0033] As used herein, the term "mixed antibody" refers to a limited number of major antibody species produced from a host cell (optionally from a single host cell line) that has been transfected with DNA encoding at least two different antibodies (optionally full-length primate IgG antibodies) with different binding specificities. Optionally, no more than two, three, four, five, six, seven, eight, nine, or ten species are included. In some embodiments, DNA encoding at least two different heavy chains (HC) and at least two different light chains (LC) can be introduced into the same host cell; for example, the host cell can be transfected with DNA encoding at least two, but no more than four, different antibodies with different binding specificities. In some embodiments, the sequences of all transfected DNA encoding HC and LC can be mutated to alter the amino acid sequences of the antibodies, making non-homologous HC / LC pairing unfavorable and highly favorable for homologous HC / LC pairing. In the case of introducing two different HCs into the host cell, one or both of the two different HCs can optionally be altered to unfavor the formation of heterodimers. In some embodiments, only one heavy chain is altered to prevent heterodimer formation. In some embodiments, when DNA encoding only two different antibodies is introduced into a host cell, only one of the antibodies encoded by said DNA contains one or more partner body orientation modifications that favor homologous HC / LC pairing, while the other antibody does not contain such modifications. In some embodiments, the host cell produces only two major antibody species, where each HC primarily pairs with its homologous LC, and most antibodies are tetramers containing two heavy chains with the same amino acid sequence and two light chains with the same amino acid sequence (see PCT / US2017 / 030676).

[0034] The term "pharmaceutical composition" refers to a formulation or combination of formulations containing one, two, or more active ingredients, wherein the active ingredients contained herein are present in a biologically effective form and do not contain any additional ingredients that would have unacceptable toxicity to a subject administering the formulation. When a "pharmaceutical composition" exists as a combination of individual formulations containing two or more different active ingredients, it can be administered simultaneously, sequentially, separately, or at intervals, with the aim of exerting the biological activity of multiple active ingredients together for the treatment of a disease.

[0035] The term “pharmaceutical carrier” or “pharmaceuticalally acceptable carrier” refers to a diluent, adjuvant (e.g., Freund’s adjuvant (complete and incomplete)), excipient, or medium that is administered with a therapeutic agent.

[0036] The term "effective dose" refers to a dose of a pharmaceutical preparation containing the active ingredient of this disclosure that, when administered to a patient in a single or multiple doses, produces the intended effect in the treated patient. The effective dose can be readily determined by an attending physician skilled in the art by considering a variety of factors, such as: racial differences; weight, age, and health status; the specific disease involved; the severity of the disease; the individual patient's response; the specific antibody administered; the administration modality; the bioavailability characteristics of the administered preparation; the chosen dosing regimen; and the use of any concomitant therapies.

[0037] The terms “host cell,” “host cell line,” and “host cell culture” are used interchangeably and refer to cells in which exogenous nucleic acids have been introduced, including the progeny of such cells. Host cells include “transformers” and “transformed cells,” which include the primary transformed cells and their progeny, regardless of the number of passages. Progeny may not be identical to the parent cells in terms of nucleic acid content and may contain mutations. This document includes mutant progeny that have the same function or biological activity as those screened or selected in the initially transformed cells.

[0038] As used in this article, "transfection" refers to the introduction of exogenous nucleic acids into eukaryotic cells. Transfection can be achieved through various techniques known in the art, including electroporation, microinjection, and liposome fusion.

[0039] The terms "nucleic acid molecule encoding," "encoding DNA sequence," and "encoding DNA" refer to the sequence of deoxyribonucleotides along a deoxyribonucleic acid (DNA) chain. This sequence of deoxyribonucleotides determines the sequence of amino acids along a polypeptide (protein) chain. Therefore, a nucleic acid sequence encodes an amino acid sequence.

[0040] Methods for producing and purifying antibodies and antigen-binding fragments are well-known and available in the prior art, such as in Cold Spring Harbor's Guide to Antibody Laboratory Techniques, Chapters 5-8 and 15. The engineered antibodies or antigen-binding fragments disclosed herein can be prepared and purified using conventional methods. For example, cDNA sequences encoding heavy and light chains can be cloned and recombined into expression vectors. Recombinant immunoglobulin expression vectors can be stably transfected into CHO cells. Stable clones are obtained by expressing antibodies that specifically bind to human antigens. Positive clones are scaled up in serum-free medium in a bioreactor to produce antibodies. Culture media secreted with antibodies can be purified and collected using conventional techniques. Antibodies can be concentrated by filtration using conventional methods. Soluble mixtures and polymers can also be removed using conventional methods, such as molecular sieving and ion exchange.

[0041] As used herein, the terms “individual” or “subject” refer to any animal, such as a mammal or marsupial. Individuals disclosed herein include, but are not limited to, humans, non-human primates (such as cynomolgus monkeys or rhesus monkeys or other types of macaques), mice, pigs, horses, donkeys, cattle, sheep, rats, and any kind of poultry.

[0042] As used herein, the terms “disease,” “symptom,” or “disorder,” etc., refer to any alteration or dysregulation that impairs or interferes with the normal function of cells, tissues, or organs. For example, “disease” includes, but is not limited to: tumors, pathogen infections, autoimmune diseases, T-cell dysfunction disorders, or deficiencies in immune tolerance (such as transplant rejection).

[0043] As used in this article, the term "tumor" refers to a disease characterized by the pathological proliferation of cells or tissues, and their subsequent migration or invasion into other tissues or organs. Tumor growth is typically uncontrolled and progressive, neither inducing nor inhibiting the proliferation of normal cells. Tumors include "cancer," which broadly refers to all malignant tumors.

[0044] As used in this article, the term "treatment" refers to a clinical intervention in an attempt to alter an individual's or treat a disease caused by cells, which can be preventative or intervention in a clinicopathological process. Treatment effects include, but are not limited to, preventing the onset or recurrence of disease, alleviating symptoms, reducing any direct or indirect pathological consequences of the disease, preventing metastasis, slowing the rate of disease progression, improving or alleviating the condition, and alleviating or improving prognosis.

[0045] As used herein, the term "combination" refers to a treatment regimen that provides at least two or more different therapies to achieve a specified therapeutic effect. These therapies can be physical, such as radiation therapy, or chemical, such as administering a drug to the subject, including combination drugs. "Combination drugs" refers to a combination of two or more pharmaceutical preparations, each containing an active ingredient, that are administered to a subject in combination. The active ingredients may be mixed together to form a single dosing unit or may be administered separately as independent dosing units; during administration, the different pharmaceutical preparations may be administered substantially synchronously, simultaneously, or sequentially.

[0046] Overall survival (OS) refers to the time from randomization (or commencement of study treatment) to death from any cause. For subjects still alive at the data analysis cutoff date, their OS data will be censored at that cutoff date; for subjects lost to follow-up, their survival status will be censored on the last confirmed date.

[0047] Progression-free survival (PFS) refers to the time a subject spends from the start of study treatment until the first recorded objective imaging assessment of disease progression or death from any cause (whichever occurs first).

[0048] The objective response rate (ORR) is defined as the proportion of patients whose tumor volume shrinks by 30% (typically) and is maintained for the minimum required duration. It is a short-term efficacy indicator and includes cases of complete response (CR) and partial response (PR). According to RECIST v1.1, for subjects who are initially assessed as CR or PR, repeat imaging assessments must be performed within a specific time window after the initial response assessment (e.g., 4–8 weeks, or as specified in the study protocol) to confirm the response status.

[0049] Disease control rate (DCR) refers to the sum of the proportion of subjects who achieve complete remission (CR), partial remission (PR), or stable disease (SD) with the best confirmed overall efficacy within a pre-specified evaluation period.

[0050] Complete remission (CR): All target lesions disappear and any pathological lymph nodes must shrink to a short axis <10mm.

[0051] Partial remission (PR): The total diameter of the target lesions is reduced by at least 30% compared to the total diameter at baseline.

[0052] Disease progression (PD): The sum of the diameters of all target lesions during the entire trial study is used as a reference (if the baseline value is the minimum, then the baseline value is used as a reference), and the sum of their diameters increases by at least 20% in relative terms and by at least 5 mm in absolute terms; or one or more new lesions appear.

[0053] Disease stability (SD): The shrinkage of the target lesion did not meet the PR criteria, and its increase did not meet the PD criteria. The minimum value of the sum of the diameters of the target lesions was used as a reference during the study period.

[0054] Duration of remission (DOR) is defined as the time from the date of initial assessment of CR or PR (whichever occurred first) to the date of initial assessment of disease progression or death from any cause (whichever occurred first).

[0055] Treatment-associated adverse events (TEAEs) refer to adverse events that occur during treatment.

[0056] Treatment-related adverse events (TRAEs) are adverse events that, according to investigator assessment, are likely to be causally related to the investigational drug.

[0057] Serious adverse events (SAEs) refer to adverse medical events that occur after treatment with an investigational drug and result in death, life-threatening events, hospitalization or prolonged hospitalization, persistent or significant loss of function, or congenital abnormalities / birth defects.

[0058] Consolidation therapy refers to a treatment approach where, after initial treatment, patients undergo long-term, stable treatment to maintain the therapeutic effect and prevent disease recurrence or other complications.

[0059] Example

[0060] The present disclosure is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the disclosure.

[0061] Example 1: Obtaining the mixed antibody ZPML265 and anti-PD1 antibody ZPML264

[0062] A hybrid antibody was prepared from a single host cell line (see PCT / US2017 / 030676). This hybrid antibody contained two active components: a recombinant humanized IgG1 monoclonal antibody targeting human CTLA4 and a recombinant humanized IgG4 monoclonal antibody targeting human PD1. This hybrid antibody could simultaneously and specifically bind to both human CTLA4 and PD1. After simultaneous expression of the two antibodies in a single host cell line, they were collected, purified, and combined with a pharmaceutically acceptable vector to form a single hybrid antibody drug formulation, ZPML265.

[0063] ZPML264 injection contains only one active ingredient, namely the recombinant humanized IgG4 monoclonal antibody targeting human PD1 found only in ZPML265 (anti-PD1 antibody in Table 1). After expressing this antibody in a host cell line, it is collected, purified, and combined with a pharmaceutically acceptable carrier to form the drug formulation ZPML264.

[0064] The amino acid sequences of the anti-CTLA4 antibody and anti-PD1 antibody contained in ZPML265 and ZPML264 are shown in Table 1 below.

[0065] Table 1. Amino acid sequences of each component in the mixed antibody ZPML265 and anti-PD1 antibody ZPML264

[0066] Example 2: Efficacy and safety of ZPML265 monotherapy for extensive-stage small cell lung cancer

[0067] Administration:

[0068] In a Phase I clinical trial conducted in China, 26 patients with pathologically confirmed extensive-stage small cell lung cancer were enrolled. Patients were 18 years of age or older, had an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1, expected survival of ≥3 months, and functional levels of major organs prior to first use of the investigational drug.

[0069] 1) Absolute neutrophil count ≥1.5×10 9 / L;

[0070] 2) Platelets ≥75×10 9 / L;

[0071] 3) Hemoglobin ≥ 90 g / L;

[0072] 4) Serum albumin ≥30g / L;

[0073] 5) Alanine aminotransferase (AST) and aspartate aminotransferase (ALT) ≤2.5×Upper limit of normal (ULN) (≤5×ULN is allowed for patients with liver cancer or liver metastasis);

[0074] 6) Total bilirubin ≤1.5×ULN (≤3×ULN is allowed for those with Gilbert's syndrome);

[0075] 7) International Normalized Ratio (INR) ≤ 1.5; Activated Partial Thromboplastin Time (APTT) ≤ 1.5 × ULN;

[0076] 8) Serum creatinine ≤ 1.5 × ULN. If the subject's creatinine level > 1.5 × ULN, then the creatinine clearance rate (CrCl) must be ≥ 50 mL / min (calculated according to the Cockcroft-Gault formula).

[0077] 9) Left ventricular ejection fraction (LVEF) > 50%.

[0078] Dosage regimen: ZPML265 is administered at a dose of 5 mg / kg every three weeks via intravenous infusion.

[0079] Validity results:

[0080] Efficacy data from ZPML265 monotherapy in 26 patients with extensive-stage small cell lung cancer (SCLC): The confirmed objective response rate (ORR) was 23.1%, and the disease control rate (DCR) was 34.6%. Among 12 patients with SCLC who had received ≥1 line of prior therapy and had not received immunotherapy, 3 achieved partial response (PR) and 2 achieved stable disease (SD). The confirmed ORR was 25.0%, and the confirmed DCR was 41.7%. Among 11 patients with SCLC who had received ≥1 line of prior therapy and had received immunotherapy, 2 achieved PR and 1 achieved SD. The confirmed ORR was 18.2%, and the confirmed DCR was 27.3%. As of September 23, 2022, the median overall survival (OS) for patients with advanced SCLC treated with ZPML265 monotherapy was 9.3 months. This study demonstrates the promising therapeutic efficacy of ZPML265 monotherapy in the treatment of SCLC.

[0081] Safety results:

[0082] Safety data were pooled from 666 patients treated with ZPML265. (615 (92.3%) patients experienced TEAEs, and 493 (74.0%) patients experienced ZPML265-related TEAEs. ≥ Grade 3 TEAEs and SAEs were reported in 225 (33.8%) and 180 (27.0%) patients, respectively, and ZPML265-related ≥ Grade 3 TEAEs and ZPML265-related SAEs were reported in 119 (17.9%) and 85 (12.8%) patients, respectively.

[0083] Among them, the incidence of TRAE ≥10% included: rash 119 (17.9%) cases, hypothyroidism 99 (14.9%) cases, hyperthyroidism 80 (12.0%) cases, pruritus 78 (11.7%) cases, elevated aspartate aminotransferase 76 (11.4%) cases, and elevated alanine aminotransferase 69 (10.4%) cases.

[0084] The incidence of TRAE grade ≥3 was 17.9%. TRAEs with an incidence of ≥1% included 14 cases (2.1%) of anemia, 8 cases (1.2%) of immune-mediated lung disease, elevated lipase and elevated aspartate aminotransferase, and 7 cases (1.1%) of elevated gamma-glutamyl transferase and decreased platelet count.

[0085] In contrast to ZPML265 monotherapy, another meta-analysis that summarized 2,664 cases of nivolumab combined with ipilimumab showed that the overall incidence of treatment-related serious adverse events was 29.6%, and the incidence of ≥ grade 3 TRAEs was 39.9%, which was higher than the relevant data for ZPML265 monotherapy.

[0086] Based on existing data, the treatment is safe and no new safety signals have been found compared with other immunotherapy drugs.

[0087] in conclusion:

[0088] Overall, ZPML265 monotherapy showed promising efficacy in treating extensive-stage small cell lung cancer. In terms of safety, the incidence of TRAE was similar to that of anti-PD-(L)1 monotherapy and lower than that of dual immunotherapy with nivolumab and ipilimumab. In other words, while ensuring drug efficacy, its safety profile is superior to existing clinical protocols.

[0089] Example 3: A Phase II clinical study evaluating ZPML265 in combination with carboplatin and etoposide as first-line treatment for extensive-stage small cell lung cancer.

[0090] In a phase II clinical trial of ZPML265 in combination with carboplatin and etoposide as first-line treatment for extensive-stage small cell lung cancer, patients with histologically or cytologically confirmed extensive-stage small cell lung cancer were enrolled. Patients were ≥18 years and ≤75 years old, regardless of gender. Their ECOG performance status score was 0-1. Expected survival was ≥12 weeks. Prior to first use of the investigational drug, the functional levels of vital organs must meet the following requirements:

[0091] 1) Complete blood count (without blood transfusion or use of hematopoietic stimulating factor drugs within 14 days prior to laboratory test): White blood cell count ≥ 3.0 × 10⁻⁶ 9 / L; absolute neutrophil count ≥1.5×10 9 / L; Platelets ≥100×10 9 / L; Hemoglobin ≥90g / L;

[0092] 2) Liver function: For subjects without liver metastases, aspartate aminotransferase ≤2.5×ULN; alanine aminotransferase ≤2.5×ULN; for subjects with liver metastases, ALT and AST <5×ULN; serum total bilirubin ≤1.5×ULN (for Gilbert's syndrome, total bilirubin ≤3.0mg / dL).

[0093] 3) Renal function: serum creatinine ≤1.5×ULN or creatinine clearance ≥50mL / min;

[0094] 4) Coagulation function: International Normalized Ratio ≤ 1.5 × ULN, Activated Partial Thromboplastin Time ≤ 1.5 × ULN (only applicable to patients who are not currently receiving anticoagulation therapy; patients currently receiving anticoagulation therapy should receive a stable dose of anticoagulant therapy);

[0095] 5) Other: Lipase ≤ 1.5 × ULN (if lipase > 1.5 × ULN, patients without clinical or imaging evidence of pancreatitis can be enrolled); amylase ≤ 1.5 × ULN (if amylase > 1.5 × ULN, patients without clinical or imaging evidence of pancreatitis can be enrolled); alkaline phosphatase ≤ 2.5 × ULN, for subjects with liver or bone metastases, ALP ≤ 5 × ULN.

[0096] Dosage regimen:

[0097] ZPML265 is administered at a dose of 5 mg / kg every three weeks via intravenous infusion (IV).

[0098] Carboplatin was administered intravenously on day 1 at a target AUC of 5 mg / min / mL, and etoposide was administered at a dose of 100 mg / mL. 2 The medication is administered intravenously on days 1, 2, and 3, with each cycle lasting 21 days. 4-6 cycles are administered.

[0099] Validity results:

[0100] ZPML265 monotherapy combined with chemotherapy was used to treat 40 patients with extensive-stage small cell lung cancer. The efficacy analysis was based on 39 evaluable patients. As of April 28, 2023, the confirmed tumor response was as follows: ORR was 89.7% (35 / 39), 35 patients (89.7%) achieved PR, 3 patients (7.7%) achieved SD, 1 patient (2.6%) achieved PD, the overall DCR was 97.4% (38 / 39), the 3-month PFS rate was 94.8%, and the median PFS was 5.7 months (95% confidence interval: 5.4-8.3 months).

[0101] Currently, the ORR of ZPML265 combined with chemotherapy is superior to that of PD-(L)1 inhibitors plus chemotherapy in similar studies (atezolizumab combined with chemotherapy ORR: 60.2%, durvalumab combined with chemotherapy ORR: 68%).

[0102] Safety results:

[0103] All 40 subjects received at least one dose of ZPML265. As of January 16, 2023, the median duration of ZPML265 treatment was 25.64 weeks (range: 3.0–38.9 weeks). At least one treatment-associated adverse event (TEAE) occurred in all 40 subjects included in the safety analysis set, with 85% of patients experiencing ZPML265-related adverse events. The adverse events that occurred in ≥30% of patients were anemia (50%), decreased platelet count (40%), decreased neutrophil count (32.5%), decreased white blood cell count (37.5%), nausea (32.5%), and fatigue (30%). Of these, 16 patients (40%) experienced grade ≥3 TEAEs, with decreased neutrophil count (20.0%) and decreased platelet count (10.0%) occurring in ≥10% of cases. No fatal TEAEs were reported.

[0104] No TEAEs leading to permanent discontinuation of ZPML265 or chemotherapy occurred.

[0105] Safety data are comparable to those of single-target immunotherapy combined with chemotherapy. The most common adverse event was hematologic toxicity, a common toxicity associated with the chemotherapy drugs etoposide and carboplatin. The incidence of grade 3-4 events was 90%, similar to the incidence of slulimab in the ASTRUM-005 study (82.5%).

[0106] in conclusion:

[0107] Overall, ZPML265 combined with chemotherapy as first-line treatment for extensive-stage small cell lung cancer showed promising therapeutic effects. In terms of safety, the incidence of grade 3-4 TRAEs was similar to that of anti-PD-(L)1 monotherapy, meaning that the safety profile was comparable to existing clinical protocols while ensuring drug efficacy.

[0108] Example 4: A Phase III clinical study evaluating ZPML265 as consolidation therapy after chemoradiotherapy in patients with limited-stage small cell lung cancer.

[0109] The ZPML265 phase III clinical trial, designed as consolidation therapy after chemoradiotherapy for patients with limited-stage small cell lung cancer (LS-SCLC), enrolled pathologically confirmed LS-SCLC (stages I-III SCLC [any T, any N, M0], according to the American Joint Committee on Cancer Staging Manual [AJCC 8th edition] criteria), meaning the patient's lesions could be contained within the radical radiotherapy field. Patients meeting the AJCC 8th edition TNM staging criteria of stage I or II were required to be medically inadmissible for surgery (as determined by the investigator) or refuse surgery to be enrolled.

[0110] Patients should be 18-75 years old, regardless of gender. ECOG performance status score should be 0-1. Expected survival should be ≥12 weeks. Patients must achieve complete remission (CR), partial remission (PR), or stable disease (SD) after receiving curative platinum-based cCRT or sCRT, and must not experience disease progression (PD). The functional levels of vital organs must meet the following requirements before the first use of the investigational drug (Note: No blood components or hematopoietic growth factors may be used to interfere with the following indicators within 7 days prior to the screening laboratory tests):

[0111] a) Absolute neutrophil count (ANC) ≥ 1.5 × 10⁻⁶ 9 / L;

[0112] b) Platelet count ≥100×10 9 / L;

[0113] c) Hemoglobin ≥ 90 g / L;

[0114] d) Bilirubin ≤ 1.5 × upper limit of normal (ULN), alanine aminotransferase (ALT) ≤ 2.5 × ULN, aspartate aminotransferase (AST) ≤ 2.5 × ULN;

[0115] e) Creatinine clearance ≥ 40 mL / min (Cockcroft-Gault formula);

[0116] f) Activated partial thromboplastin time (APTT) / partial thromboplastin time (PTT) ≤ 1.5 × ULN, International Normalized Ratio (INR) ≤ 1.5 (acceptable if stable doses of anticoagulation therapy such as low molecular weight heparin or warfarin are used, and the INR is within the expected therapeutic range of the anticoagulant).

[0117] Dosage regimen:

[0118] • Experimental group 1: ZPML265 group

[0119] ZPML265 group: ZPML265 injection (5 mg / kg, IV) and ZPML264 mimic (the mimic is an excipient without the active ingredient ZPML264, IV), administered on day 1 of each cycle. Each cycle is 21 days, i.e., Q3W.

[0120] • Experimental group 2: ZPML264 group

[0121] ZPML264 group: ZPML264 injection (200 mg, [3 mg / kg if body weight < 40 kg], IV) and ZPML265 mimic (the mimic is an excipient without the active ingredient ZPML265, IV), administered on day 1 of each cycle. Each cycle is 21 days, i.e., Q3W.

[0122] All subjects were treated until they met the criteria for termination of treatment.

[0123] The embodiments described above are merely exemplary, and any person skilled in the art will recognize or be able to identify numerous equivalents of specific compounds, materials, and operations without the need for extraordinary experimentation. All such equivalents are within the scope of this disclosure and are encompassed by the claims.

Claims

1. Use of a mixed antibody containing effective amounts of anti-CTLA4 and anti-PD1 in the preparation of a pharmaceutical composition for the treatment of limited-stage small cell lung cancer, wherein the mixed antibody is produced by a single host cell containing nucleic acids encoding both anti-CTLA4 and anti-PD1 antibodies, wherein, The sequences of the anti-CTLA4 antibody heavy chains HCDR1, HCDR2, and HCDR3 are shown in SEQ ID NO: 1, 2, and 3, respectively; the sequences of the anti-CTLA4 antibody light chains LCDR1, LCDR2, and LCDR3 are shown in SEQ ID NO: 4, 5, and 6, respectively; the sequences of the anti-PD1 antibody heavy chains HCDR1, HCDR2, and HCDR3 are shown in SEQ ID NO: 9, 10, and 11, respectively; and the sequences of the anti-PD1 antibody light chains LCDR1, LCDR2, and LCDR3 are shown in SEQ ID NO: 12, 13, and 14, respectively.

2. The use as described in claim 1, wherein, The heavy chain variable region sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 7, the light chain variable region sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 8, the heavy chain variable region sequence of the anti-PD1 antibody is shown in SEQ ID NO: 15, and the light chain variable region sequence of the anti-PD1 antibody is shown in SEQ ID NO:

16.

3. The use as described in claim 1, wherein, The heavy chain sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 17, the light chain sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 18, the heavy chain sequence of the anti-PD1 antibody is shown in SEQ ID NO: 19, and the light chain sequence of the anti-PD1 antibody is shown in SEQ ID NO:

20.

4. The use as described in any one of claims 1-3, wherein the treatment of limited-stage small cell lung cancer is consolidation therapy following radiotherapy and chemotherapy.

5. The use as described in any one of claims 1-3, wherein, The dosage of the mixed antibody is 5 mg / kg, administered once every three weeks, via intravenous infusion on day 1, with a cycle of 21 days.

6. A method for treating limited-stage small cell lung cancer, the method comprising administering to a subject a mixed antibody containing an effective amount of anti-CTLA4 and anti-PD1, said mixed antibody being produced by a single host cell containing nucleic acids encoding both anti-CTLA4 and anti-PD1 antibodies, wherein, The sequences of the anti-CTLA4 antibody heavy chains HCDR1, HCDR2, and HCDR3 are shown in SEQ ID NO: 1, 2, and 3, respectively; the sequences of the anti-CTLA4 antibody light chains LCDR1, LCDR2, and LCDR3 are shown in SEQ ID NO: 4, 5, and 6, respectively; the sequences of the anti-PD1 antibody heavy chains HCDR1, HCDR2, and HCDR3 are shown in SEQ ID NO: 9, 10, and 11, respectively; and the sequences of the anti-PD1 antibody light chains LCDR1, LCDR2, and LCDR3 are shown in SEQ ID NO: 12, 13, and 14, respectively.

7. The method of claim 6, wherein, The heavy chain variable region sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 7, the light chain variable region sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 8, the heavy chain variable region sequence of the anti-PD1 antibody is shown in SEQ ID NO: 15, and the light chain variable region sequence of the anti-PD1 antibody is shown in SEQ ID NO:

16.

8. The method of claim 6, wherein, The heavy chain sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 17, the light chain sequence of the anti-CTLA4 antibody is shown in SEQ ID NO: 18, the heavy chain sequence of the anti-PD1 antibody is shown in SEQ ID NO: 19, and the light chain sequence of the anti-PD1 antibody is shown in SEQ ID NO:

20.

9. The method according to any one of claims 6-8, wherein the treatment of limited-stage small cell lung cancer is consolidation therapy after radiotherapy and chemotherapy.

10. The method according to any one of claims 6-8, wherein, The dosage of the mixed antibody is 5 mg / kg, administered once every three weeks, via intravenous infusion on day 1, with a cycle of 21 days.

Images