Use of il-15 protein complex in combination with bacillus calmette-guérin for treating non-muscle invasive bladder cancer

Abstract

Provided is use of an IL-15 protein complex in combination with Bacillus Calmette-Guérin for treating non-muscle invasive bladder cancer. Specifically, provided is use of an IL-15 protein complex in combination with Bacillus Calmette-Guérin in the preparation of a drug for treating cancers, including but not limited to, non-muscle invasive bladder cancer.

Description

Use of IL-15 protein complex in combination with BCG for the treatment of non-muscle-invasive bladder cancer.

[0001] This application claims priority to Chinese patent application CN202510108198.3, filed on January 23, 2025, and Chinese patent application CN202512045227.9, filed on December 31, 2025. Technical Field

[0002] This disclosure pertains to the field of biomedicine and specifically relates to the use of an IL-15 protein complex, or an IL-15 protein complex in combination with BCG, for the treatment of non-muscle-invasive bladder cancer. Background Technology

[0003] The statements herein are provided only as background information in connection with this disclosure and do not necessarily constitute prior art.

[0004] Interleukin-15 (IL-15) is a cytokine of approximately 12-14 kDa that plays a role in the body's normal immune response, such as promoting the proliferation of T cells, B cells, and natural killer (NK) cells. IL-15 exerts its biological activity by binding to its receptor. The IL-15 receptor consists of three receptor subunits: IL-15 receptor α (IL-15Rα), IL-2 receptor β (IL-2Rβ), and γc. IL-15Rα contains a Sushi domain, which binds to IL-15 and is essential for the biological function of bound IL-15. Recent studies have found that the formation of a complex between IL-15 and its receptor IL-15Rα significantly enhances the biological activity of IL-15. WO2016095642A1 discloses an IL-15 protein complex composed of an IL-15 polypeptide and IL-15Rα / Fc. It introduces a disulfide bond between IL-15 and IL-15Rα, which can improve molecular stability and biological activity, and also simplify the preparation process.

[0005] Urothelial carcinoma (UC) mainly includes malignant tumors of the transitional epithelium of the renal pelvis, ureter, and bladder, with bladder cancer accounting for approximately 90%. In 2020, there were approximately 570,000 new cases of bladder cancer and approximately 210,000 deaths worldwide, ranking 12th and 14th respectively among all malignant tumors (Sung H, et al. CA: a cancer journal for clinicians, 2021, 71(3):209–249). UC can be classified according to the degree of tumor invasion into non-muscle-invasive urothelial carcinoma (NMIUC), muscle-invasive urothelial carcinoma (MIUC), and metastatic urothelial carcinoma (mUC). Among newly diagnosed UC patients, approximately 75% are in the NMIUC stage, approximately 20% are in the MIUC stage, and approximately 5% have already developed distant metastases (Sanli O, et al. Nature reviews. Disease primers, 2017, 3:17022; Patel VG, et al. CA: a cancer journal for clinicians, 2020, 70(5):404–423). Non-muscle-invasive bladder cancer (NMIBC) refers to malignant bladder tumors confined to the bladder mucosa (Tis, Ta) and lamina propria (T1), without invasion of the muscle layer; formerly known as superficial bladder cancer. Approximately 75% of patients are diagnosed with NMIBC, of ​​which Ta accounts for 70%, T1 for 20%, and Tis for 10%. Although both Ta and T1 stages belong to NMIBC, their biological characteristics are significantly different; due to the rich blood vessels and lymphatic vessels in the lamina propria, T1 stage is prone to spread. Transurethral resection of bladder tumor (TURBT) is the standard treatment for non-minimally invasive bladder cancer (NMIBC) and an important diagnostic method. Due to its advantages of minimal trauma, less bleeding, and rapid postoperative recovery, it is the preferred treatment for NMIBC. The pathological type, classification, and stage of bladder tumors are determined based on the pathological results after TURBT. However, NMIBC has a high recurrence rate after TURBT, with up to 45% of patients experiencing tumor recurrence within one year after TURBT alone, and 6%–17% of patients experiencing tumor progression (Chang SS, et al. The Journal of Urology, 2016, 196(4):1021–1029). For high-risk NMIBC patients, postoperative bladder instillation with BCG is recommended to prevent recurrence and progression. However, there is still an urgent need in clinical practice for more effective treatment options to improve the current treatment status of NMIBC. Summary of the Invention

[0006] This disclosure provides the use and methods of treating non-muscle invasive bladder cancer (NMIBC) with the IL-15 protein complex.

[0007] In some implementations, this disclosure provides for any of the following uses:

[0008] (1) Use of IL-15 protein complex in the preparation of drugs for the treatment of non-muscle-invasive bladder cancer;

[0009] (2) An IL-15 protein complex for the treatment of non-muscle-invasive bladder cancer, wherein the IL-15 protein complex is administered to a subject;

[0010] (3) A pharmaceutical composition, kit or article for treating non-muscle-invasive bladder cancer, wherein the pharmaceutical composition, kit or article comprises an IL-15 protein complex.

[0011] (4) Use of a pharmaceutical composition, kit, or article in the preparation of a medicament for treating non-muscle-invasive bladder cancer, wherein the pharmaceutical composition, kit, or article comprises an IL-15 protein complex.

[0012] In some implementations, this disclosure provides a method as shown in any of the following:

[0013] (1) Methods of treating non-muscle-invasive bladder cancer, including administering a therapeutically effective amount of IL-15 protein complex to subjects in need;

[0014] (2) A method of treating non-muscle-invasive bladder cancer, comprising administering a pharmaceutical composition, kit, or article to a subject in need, wherein the pharmaceutical composition, kit, or article contains an IL-15 protein complex.

[0015] In some implementations, the non-muscle-invasive bladder cancer is high-risk NMIBC.

[0016] In some implementations, the non-muscle-invasive bladder cancer is NMIBC that has not previously received BCG treatment.

[0017] In some implementations, the non-muscle-invasive bladder cancer is NMIBC that has not responded to previous BCG.

[0018] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS).

[0019] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS).

[0020] In some implementations, the non-muscle-invasive bladder cancer is with or without Ta or T1.

[0021] In some implementations, the non-muscle-invasive bladder cancer is associated with Ta or T1.

[0022] In some implementations, the non-muscle-invasive bladder cancer is without Ta or T1.

[0023] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment, or a high-risk NMIBC that has not previously responded to BCG.

[0024] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment, or a high-risk NMIBC that has not responded to previous BCG treatment.

[0025] In some implementations, the non-muscle-invasive bladder cancer is high-risk NMIBC that has not previously received BCG treatment, carcinoma in situ (CIS) that has not responded to previous BCG treatment (with or without Ta or T1), or high-grade Ta or T1 that has not responded to previous BCG treatment (without CIS).

[0026] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment.

[0027] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not responded to previous BCG.

[0028] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS) that has not responded to previous BCG (with or without Ta or T1).

[0029] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS) that has previously been unresponsive to BCG.

[0030] In some implementations, the non-muscle-invasive bladder cancer is defined as a previous unresponsive BCG patient with or without Ta or T1.

[0031] In some implementations, the non-muscle-invasive bladder cancer is Ta or T1 (without CIS) that has not responded to previous BCG.

[0032] In some implementations, the non-muscle-invasive bladder cancer is Ta or T1, which has previously been unresponsive to BCG.

[0033] In some embodiments, the non-muscle-invasive bladder cancer is persistent / recurrent CIS or combined with Ta / T1 within 12 months of adequate BCG treatment. In some embodiments, the non-muscle-invasive bladder cancer is high-grade Ta / T1 recurrence within 6 months of adequate BCG treatment. In some embodiments, the non-muscle-invasive bladder cancer is high-grade T1 present on the first assessment after BCG induction instillation.

[0034] In some implementations, adequate BCG treatment is defined as completing 5 out of 6 initial induction perfusions and 2 out of 3 maintenance perfusions; or completing 5 out of 6 initial induction perfusions and 2 out of 6 re-induction perfusions; if BCG is used irregularly, the total number of uses must be ≥ 6.

[0035] In some embodiments, the non-muscle-invasive bladder cancer is defined as cystoscopy within 6 weeks prior to the first dose showing no resectable lesions, or residual lesions consisting only of CIS. In some embodiments, the non-muscle-invasive bladder cancer is defined as bladder cancer for which the patient is unsuitable for or unwilling to undergo radical cystectomy.

[0036] In some embodiments, the non-muscle-invasive bladder cancer is defined as BCG-unresponsive bladder cancer that is found to be recurrent or persistent CIS or high-grade Ta by cystoscopy before the first bladder instillation 3 months after the first induction instillation. In some embodiments, the non-muscle-invasive bladder cancer is defined as BCG-untreated bladder cancer that is found to be recurrent or persistent CIS or high-grade Ta or T1 (without pathological progression) by cystoscopy before the first bladder instillation 3 months after the first induction instillation.

[0037] This disclosure provides the use and method of using IL-15 protein complex in combination with BCG for the treatment of non-muscle invasive bladder cancer (NMIBC).

[0038] In some implementations, this disclosure provides for any of the following uses:

[0039] (1) Use of IL-15 protein complex in combination with BCG in the preparation of drugs for the treatment of non-muscle-invasive bladder cancer;

[0040] (2) Use of IL-15 protein complex and BCG in the preparation of drugs for the treatment of non-muscle-invasive bladder cancer;

[0041] (3) IL-15 protein complex and BCG vaccine are used to treat non-muscle-invasive bladder cancer;

[0042] (4) The IL-15 protein complex was used to treat subjects with non-muscle-invasive bladder cancer, wherein the subjects were also given BCG.

[0043] (5) BCG is used to treat subjects with non-muscle-invasive bladder cancer, wherein the subjects are also given IL-15 protein complex.

[0044] (6) A pharmaceutical composition, kit, or article for treating non-muscle-invasive bladder cancer, wherein the pharmaceutical composition, kit, or article comprises an IL-15 protein complex and BCG.

[0045] (7) Use of a pharmaceutical composition, kit, or article in the preparation of a medicament for treating non-muscle-invasive bladder cancer, wherein the pharmaceutical composition, kit, or article comprises an IL-15 protein complex and BCG.

[0046] In some implementations, this disclosure provides a method as shown in any of the following:

[0047] (1) Methods of treating non-muscle-invasive bladder cancer, including administering therapeutically effective amounts of IL-15 protein complex and BCG to subjects in need;

[0048] (2) A method of treating non-muscle-invasive bladder cancer, comprising administering a pharmaceutical composition, kit, or article to a subject in need, wherein the pharmaceutical composition, kit, or article comprises an IL-15 protein complex and BCG.

[0049] In some implementations, this disclosure provides a product represented by any of the following:

[0050] (1) A pharmaceutical composition comprising an IL-15 protein complex and BCG vaccine;

[0051] (2) A kit containing an IL-15 protein complex and BCG vaccine;

[0052] (3) Products containing IL-15 protein complex and BCG vaccine.

[0053] In some embodiments, the kit or article also includes one or more containers, each independently containing the IL-15 protein complex and BCG vaccine.

[0054] In some embodiments, the IL-15 protein complex and BCG vaccine in the pharmaceutical composition are present in individually packaged form.

[0055] In some implementations, the non-muscle-invasive bladder cancer is NMIBC that has not previously received BCG treatment.

[0056] In some implementations, the non-muscle-invasive bladder cancer is high-risk NMIBC.

[0057] In some implementations, the non-muscle-invasive bladder cancer is NMIBC that has not responded to previous BCG.

[0058] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS).

[0059] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS).

[0060] In some implementations, the non-muscle-invasive bladder cancer is with or without Ta or T1.

[0061] In some implementations, the non-muscle-invasive bladder cancer is associated with Ta or T1.

[0062] In some implementations, the non-muscle-invasive bladder cancer is without Ta or T1.

[0063] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment, or a high-risk NMIBC that has not previously responded to BCG.

[0064] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment, or a high-risk NMIBC that has not responded to previous BCG treatment.

[0065] In some implementations, the non-muscle-invasive bladder cancer is high-risk NMIBC that has not previously received BCG treatment, carcinoma in situ (CIS) that has not responded to previous BCG treatment (with or without Ta or T1), or high-grade Ta or T1 that has not responded to previous BCG treatment (without CIS).

[0066] In some implementations, the non-muscle-invasive bladder cancer is high-risk NMIBC that has not previously received BCG treatment, carcinoma in situ (CIS) that has not responded to previous BCG treatment and may or may not have Ta or T1, or high-grade Ta or T1 that has not responded to previous BCG treatment and does not have CIS.

[0067] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment.

[0068] In some implementations, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not responded to previous BCG.

[0069] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS) that has not responded to previous BCG (with or without Ta or T1).

[0070] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS) that has not responded to previous BCG treatment and may or may not be accompanied by Ta or T1.

[0071] In some implementations, the non-muscle-invasive bladder cancer is carcinoma in situ (CIS) that has previously been unresponsive to BCG.

[0072] In some implementations, the non-muscle-invasive bladder cancer is defined as a previous unresponsive BCG patient with or without Ta or T1.

[0073] In some implementations, the non-muscle-invasive bladder cancer is Ta or T1 (without CIS) that has not responded to previous BCG.

[0074] In some implementations, the non-muscle-invasive bladder cancer is Ta or T1, which is unresponsive to previous BCG treatment and does not have CIS.

[0075] In some implementations, the non-muscle-invasive bladder cancer is Ta or T1, which has previously been unresponsive to BCG.

[0076] In some embodiments, the non-muscle-invasive bladder cancer is persistent / recurrent CIS or combined with Ta / T1 within 12 months of adequate BCG treatment. In some embodiments, the non-muscle-invasive bladder cancer is high-grade Ta / T1 recurrence within 6 months of adequate BCG treatment. In some embodiments, the non-muscle-invasive bladder cancer is high-grade T1 present on the first assessment after BCG induction instillation.

[0077] In some implementations, adequate BCG treatment is defined as completing 5 out of 6 initial induction perfusions and 2 out of 3 maintenance perfusions; or completing 5 out of 6 initial induction perfusions and 2 out of 6 re-induction perfusions; if BCG is used irregularly, the total number of uses must be ≥ 6.

[0078] In some embodiments, the non-muscle-invasive bladder cancer is defined as cystoscopy within 6 weeks prior to the first dose showing no resectable lesions, or residual lesions consisting only of CIS. In some embodiments, the non-muscle-invasive bladder cancer is defined as bladder cancer for which the patient is unsuitable for or unwilling to undergo radical cystectomy.

[0079] In some embodiments, the non-muscle-invasive bladder cancer is defined as BCG-unresponsive bladder cancer that is found to be recurrent or persistent CIS or high-grade Ta by cystoscopy before the first bladder instillation 3 months after the first induction instillation. In some embodiments, the non-muscle-invasive bladder cancer is defined as BCG-untreated bladder cancer that is found to be recurrent or persistent CIS or high-grade Ta or T1 (without pathological progression) by cystoscopy before the first bladder instillation 3 months after the first induction instillation.

[0080] In some implementations, the subjects are selected based on one or more of the following criteria:

[0081] 1) Previous pathological tissue biopsy diagnosis was high-risk NMIBC;

[0082] 2) No resectable lesions were found during cystoscopy within 6 weeks prior to the first dose, or the only remaining lesion was CIS; for T1 subjects, if the pathological examination of the resected tissue after the last transurethral resection of bladder tumor (TURBT) did not show the muscle layer, a second TURBT must be performed and the pathological examination must confirm that the muscle layer tissue is included.

[0083] 3) Unsuitable for or unwilling to undergo radical cystectomy;

[0084] 4) Subjects must meet one of the following conditions:

[0085] i. High-risk NMIBC who have not previously received BCG treatment;

[0086] ii. CIS±Ta / T1 with no response to previous BCG treatment*;

[0087] iii. High-grade Ta or T1 (without CIS) that has not responded to previous BCG treatment*;

[0088] "No response to BCG treatment*" is defined as meeting any of the following conditions:

[0089] ①BCG adequate treatment for persistent / recurrent CIS or combined Ta / T1 within 12 months;

[0090] ② High-grade Ta / T1 recurrence within 6 months of adequate BCG treatment;

[0091] ③ A high-grade T1 was observed in the initial assessment after BCG-induced perfusion;

[0092] The above definition of "adequate BCG treatment" is: completing 5 out of 6 initial induction perfusions and 2 out of 3 maintenance perfusions; or completing 5 out of 6 initial induction perfusions and 2 out of 6 re-induction perfusions; if BCG is used irregularly, the total number of uses must be ≥ 6.

[0093] BCG vaccine

[0094] In some embodiments, the dosage of BCG vaccine as described in any of the preceding embodiments is 10 mg to 300 mg. In some embodiments, the dosage of BCG vaccine is 30 mg to 200 mg. In some embodiments, the dosage of BCG vaccine is 60 mg to 150 mg. In some embodiments, the dosage of BCG vaccine is 90 mg to 150 mg. In some embodiments, the dosage of BCG vaccine is 100 mg to 150 mg. In some embodiments, the dosage of BCG vaccine is 95 mg to 145 mg. In some embodiments, the dosage of BCG vaccine is 110 mg to 130 mg. In some embodiments, the dosage of BCG vaccine is 115 mg to 125 mg. In some embodiments, the dosage of the BCG vaccine is about 10 mg, about 15 mg, about 20 mg, about 25 mg, about 30 mg, about 35 mg, about 40 mg, about 45 mg, about 50 mg, about 55 mg, about 60 mg, about 65 mg, about 70 mg, about 75 mg, about 80 mg, about 85 mg, about 90 mg, about 95 mg, about 100 mg, about 105 mg, about 110 mg, about 115 mg, about 120 mg, about 125 mg, about 130 mg, about 135 mg, about 140 mg, about 145 mg, about 150 mg, about 1... 55mg, approximately 160mg, approximately 165mg, approximately 170mg, approximately 175mg, approximately 180mg, approximately 185mg, approximately 190mg, approximately 195mg, approximately 200mg, approximately 205mg, approximately 210mg, approximately 215mg, approximately 220mg, approximately 225mg, approximately 230mg, approximately 235mg, approximately 240mg, approximately 245mg, approximately 250mg, approximately 255mg, approximately 260mg, approximately 265mg, approximately 270mg, approximately 275mg, approximately 280mg, approximately 285mg, approximately 290mg, approximately 295mg, or approximately 300mg.In some embodiments, the dosage of the BCG vaccine is 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 100 mg, 105 mg, 110 mg, 115 mg, 120 mg, 125 mg, 130 mg, 135 mg, 140 mg, 145 mg, 150 mg, 155 mg, 160 mg, etc. mg, 165mg, 170mg, 175mg, 180mg, 185mg, 190mg, 195mg, 200mg, 205mg, 210mg, 215mg, 220mg, 225mg, 230mg, 235mg, 240mg, 245mg, 250mg, 255mg, 260mg, 265mg, 270mg, 275mg, 280mg, 285mg, 290mg, 295mg, or 300mg, or any range between these values. In some embodiments, the BCG dose is about 120mg.

[0095] In some embodiments, the BCG vaccine is administered once daily, once every two days, once every three days, once every four days, once every five days, once every six days, once weekly, once every two weeks, once every three weeks, once every four weeks, once every five weeks, or once every six weeks. In some embodiments, the BCG vaccine is administered once weekly.

[0096] In some embodiments, the dosage of BCG vaccine as described in any of the preceding embodiments is about 120 mg, administered once weekly.

[0097] In some embodiments, the BCG vaccine, as described in any of the preceding embodiments, is administered via systemic, intravenous, subcutaneous, intramuscular, bladder administration (e.g., bladder irrigation, bladder infusion, intravesical administration, or receiving the drug via a catheter placed in the bladder), or infusion. In some embodiments, the BCG vaccine is formulated in a pharmaceutically acceptable buffer such as normal saline. In some embodiments, the BCG vaccine is administered by infusion into the bladder. In some embodiments, the BCG vaccine provides a continuous, maintenance level of the composition infused into the bladder within the patient.

[0098] In some embodiments, the BCG vaccine is administered via bladder instillation, intravenous injection, subcutaneous injection, or intramuscular injection, as described in any of the preceding embodiments. In some embodiments, the BCG vaccine is administered via bladder instillation.

[0099] In some embodiments, the BCG administration cycle, as described in any of the preceding embodiments, is 1 week (7 days), 2 weeks (14 days), 3 weeks (21 days), 4 weeks (28 days), 5 weeks (35 days), 6 weeks (42 days), 7 weeks (49 days), 8 weeks (56 days), 9 weeks (63 days), 10 weeks (70 days), 11 weeks (77 days), or 12 weeks (84 days). In some embodiments, the BCG administration cycle is 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, or 10 months. In some embodiments, the BCG administration cycle is 6 weeks. In some embodiments, the BCG administration cycle is 3 months.

[0100] In some embodiments, the BCG vaccine as described in any of the preceding embodiments is administered over a period of 6 weeks, with a dose of approximately 120 mg, and at a frequency of once weekly.

[0101] In some embodiments, the BCG vaccine administration period, as described in any of the preceding embodiments, is 3 months, with a dose of approximately 120 mg administered once weekly for the first 3 weeks.

[0102] In some embodiments, the BCG vaccine administration period, as described in any of the preceding embodiments, is 3 months, with a dose of approximately 120 mg administered once weekly for the first 6 weeks.

[0103] In some implementations, subjects receive cycles of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 dosing cycles. In some implementations, subjects receive a cycle of 1 dosing cycle. In some implementations, subjects receive a cycle of 4 dosing cycles. In some implementations, subjects receive a cycle of 5 dosing cycles.

[0104] In some embodiments, the BCG vaccine is administered at a dose of approximately 120 mg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months following the first dose.

[0105] In some embodiments, the BCG vaccine is administered at a dose of about 120 mg once a week for the first 6 weeks, the first 6 weeks after 3 months from the first administration, and the first 3 weeks after 6, 12, 18, and 24 months from the first administration. In some embodiments, the BCG vaccine is administered at a dose of 120 mg once a week for the first 6 weeks, the first 6 weeks after 3 months from the first administration, and the first 3 weeks after 6, 12, 18, and 24 months from the first administration.

[0106] <IL-15 protein complex>

[0107] In some embodiments, the IL-15 protein complex as described above comprises soluble fusion protein (I) and soluble fusion protein (II);

[0108] where the soluble fusion protein (I) comprises an IL-15 polypeptide or a functional fragment thereof, and the soluble fusion protein (II) comprises an IL-15Rα polypeptide or a functional fragment thereof;

[0109] One or more amino acid sites on the soluble fusion protein (I) or the soluble fusion protein (II) are mutated to Cys, and the Cys mutated at the corresponding amino acid site on the soluble fusion protein (II) or the soluble fusion protein (I) pairs to form a disulfide bond.

[0110] In some embodiments, for the IL-15 protein complex as described in any one of the above, the soluble fusion protein (II) further comprises an Fc fragment or a mutant thereof. In some embodiments, the soluble fusion protein (II) consists of an IL-15Rα polypeptide or a functional fragment thereof linked to the N-terminus of the Fc fragment. In some embodiments, the Fc fragment comprises the amino acid sequence shown in SEQ ID NO:1.

[0111] In some embodiments, for the IL-15 protein complex as described in any one of the above, the sequence of the soluble fusion protein (I) comprises the amino acid sequence shown in SEQ ID NO:2.

[0112] In some embodiments, for the IL-15 protein complex as described in any one of the above, the amino acid Cys mutation site occurs at L45, Q48, V49, L52, E53, C88, or E89 on the IL-15 polypeptide or a functional fragment thereof; preferably at L52, E53, or E89; more preferably L52.

[0113] In some embodiments, such as the IL-15 protein complex described in any of the preceding embodiments, the amino acid Cys mutation site occurs at K34, L42, A37, G38 or S40 on the IL-15Rα polypeptide or a functional fragment thereof; preferably at A37, G38 or S40; more preferably at S40.

[0114] In some embodiments, such as the IL-15 protein complex described in any of the preceding embodiments, the soluble fusion protein (Π) comprises an amino acid sequence as shown in SEQ ID NO:5, 3, 4 or 6.

[0115] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is selected from a combination of a soluble fusion protein (I) and a soluble fusion protein (II) as shown in any of the following:

[0116] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is a combination of IL-15(L52C) (SEQ ID NO:2) soluble fusion protein (I) and IL-15Rα-Sushi+(S40C)-Fc (SEQ ID NO:5) soluble fusion protein (II).

[0117] In some embodiments, the preparation of the IL-15 protein complex as described in any of the preceding embodiments can be referenced to WO2016095642A1 and WO2019019998A1. The relevant contents of the sequences, preparation methods and compositions in WO2016095642A1 and WO2019019998A1 are incorporated herein by reference.

[0118] In some embodiments, the dosage of the IL-15 protein complex, as described in any of the preceding embodiments, is from 50 μg to 2000 μg. In some embodiments, the dosage of the IL-15 protein complex is from 150 μg to 800 μg. In some embodiments, the dosage of the IL-15 protein complex is from 100 μg to 700 μg. In some embodiments, the dosage of the IL-15 protein complex is from 150 μg to 650 μg. In some embodiments, the dosage of the IL-15 protein complex is from 200 μg to 600 μg. In some embodiments, the dosage of the IL-15 protein complex is from 150 μg to 250 μg. In some embodiments, the dosage of the IL-15 protein complex is from 180 μg to 220 μg. In some embodiments, the dosage of the IL-15 protein complex is from 300 μg to 500 μg. In some embodiments, the dosage of the IL-15 protein complex is 350 μg to 450 μg. In some embodiments, the dosage of the IL-15 protein complex is 400 μg to 800 μg. In some embodiments, the dosage of the IL-15 protein complex is 450 μg to 750 μg. In some embodiments, the dosage of the IL-15 protein complex is 500 μg to 700 μg. In some embodiments, the dosage of the IL-15 protein complex is 550 μg to 650 μg. In some embodiments, the dosage of the IL-15 protein complex is about 50 μg, about 100 μg, about 150 μg, about 200 μg, about 225 μg, about 250 μg, about 275 μg, about 300 μg, about 325 μg, about 350 μg, about 375 μg, about 400 μg, about 425 μg, about 450 μg, about 475 μg, about 500 μg, about 525 μg, about 550 μg, about 575 μg, about 600 μg, about 625 μg, about 650 μg, about 675 μg, about 700 μg, about 725 μg, about 750 μg. μg, approximately 775μg, approximately 800μg, approximately 850μg, approximately 900μg, approximately 950μg, approximately 1000μg, approximately 1050μg, approximately 1100μg, approximately 1150μg, approximately 1200μg, approximately 1250μg, approximately 1300μg, approximately 1350μg, approximately 1400μg, approximately 1450μg, approximately 1500μg, approximately 1550μg, approximately 1600μg, approximately 1650μg, approximately 1700μg, approximately 1750μg, approximately 1800μg, approximately 1850μg, approximately 1900μg, approximately 1950μg, or approximately 2000μg.In some embodiments, the dosage of the IL-15 protein complex is 50 μg, 100 μg, 150 μg, 200 μg, 225 μg, 250 μg, 275 μg, 300 μg, 325 μg, 350 μg, 375 μg, 400 μg, 425 μg, 450 μg, 475 μg, 500 μg, 525 μg, 550 μg, 575 μg, 600 μg, 625 μg, 650 μg, 675 μg, 700 μg, 725 μg, 750 μg, and 775 μg. The dosage of the IL-15 protein complex is approximately 200 μg, or 800 μg, 850 μg, 900 μg, 950 μg, 1000 μg, 1050 μg, 1100 μg, 1150 μg, 1200 μg, 1250 μg, 1300 μg, 1350 μg, 1400 μg, 1450 μg, 1500 μg, 1550 μg, 1600 μg, 1650 μg, 1700 μg, 1750 μg, 1800 μg, 1850 μg, 1900 μg, 1950 μg, or 2000 μg, or any range between these values. In some embodiments, the dosage of the IL-15 protein complex is approximately 200 μg. In some embodiments, the dosage of the IL-15 protein complex is approximately 400 μg. In some embodiments, the dosage of the IL-15 protein complex is about 600 μg. In some embodiments, the dosage of the IL-15 protein complex is 200 μg. In some embodiments, the dosage of the IL-15 protein complex is 400 μg. In some embodiments, the dosage of the IL-15 protein complex is 600 μg.

[0119] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is administered once daily, once every two days, once every three days, once every four days, once every five days, once every six days, once weekly, once every two weeks, once every three weeks, once every four weeks, once every five weeks, or once every six weeks. In some embodiments, the IL-15 protein complex is administered once weekly.

[0120] In some embodiments, the dosage of the IL-15 protein complex, as described in any of the preceding embodiments, is about 200 μg, administered once weekly. In some embodiments, the dosage of the IL-15 protein complex is about 400 μg, administered once weekly. In some embodiments, the dosage of the IL-15 protein complex is about 600 μg, administered once weekly. In some embodiments, the dosage of the IL-15 protein complex is 200 μg, administered once weekly. In some embodiments, the dosage of the IL-15 protein complex is 400 μg, administered once weekly. In some embodiments, the dosage of the IL-15 protein complex is 600 μg, administered once weekly.

[0121] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is administered via systemic, intravenous, subcutaneous, intramuscular, bladder administration (e.g., bladder instillation, bladder drip, intravesical administration, or receiving the drug via a catheter placed in the bladder), or infusion. In some embodiments, the IL-15 protein complex is formulated in a pharmaceutically acceptable buffer such as normal saline. In some embodiments, the IL-15 protein complex is administered by infusion into the bladder. In some embodiments, the IL-15 protein complex provides a continuous, maintenance level of the composition via infusion into the bladder within the patient.

[0122] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is administered via bladder instillation, intravenous injection, subcutaneous injection, or intramuscular injection. In some embodiments, the IL-15 protein complex is administered via bladder instillation.

[0123] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is diluted 1 to 1000 times. In some embodiments, the IL-15 protein complex is diluted 5 to 100 times. In some embodiments, the IL-15 protein complex is diluted 30 to 80 times. In some embodiments, the IL-15 protein complex is diluted 40 to 60 times. In some embodiments, the IL-15 protein complex is diluted 45 to 55 times. In some embodiments, the IL-15 protein complex is diluted by about 1x, about 5x, about 10x, about 15x, about 20x, about 25x, about 30x, about 35x, about 40x, about 45x, about 50x, about 55x, about 60x, about 65x, about 70x, about 75x, about 80x, about 85x, about 90x, about 95x, about 100x, about 150x, about 200x, about 250x, about 300x, about 350x, about 400x, about 450x, about 500x, about 550x, about 600x, about 650x, about 700x, about 750x, about 800x, about 850x, about 900x, about 950x, or about 1000x. In some embodiments, the IL-15 protein complex is diluted at 1x, 5x, 10x, 15x, 20x, 25x, 30x, 35x, 40x, 45x, 50x, 55x, 60x, 65x, 70x, 75x, 80x, 85x, 90x, 95x, 100x, 150x, 200x, 250x, 300x, 350x, 400x, 450x, 500x, 550x, 600x, 650x, 700x, 750x, 800x, 850x, 900x, 950x, or 1000x, or any range between these values. In some embodiments, the IL-15 protein complex is diluted at approximately 50x. In some embodiments, the IL-15 protein complex is diluted at 50x.

[0124] In some embodiments, the dosing cycle of the IL-15 protein complex, as described in any of the preceding embodiments, is 1 week (7 days), 2 weeks (14 days), 3 weeks (21 days), 4 weeks (28 days), 5 weeks (35 days), 6 weeks (42 days), 7 weeks (49 days), 8 weeks (56 days), 9 weeks (63 days), 10 weeks (70 days), 11 weeks (77 days), or 12 weeks (84 days). In some embodiments, the dosing cycle of the IL-15 protein complex is 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, or 10 months. In some embodiments, the dosing cycle of the IL-15 protein complex is 6 weeks. In some embodiments, the dosing cycle of the IL-15 protein complex is 3 months.

[0125] In some embodiments, the IL-15 protein complex described in any of the preceding embodiments is administered for 6 weeks at a dose of approximately 200 μg once weekly. In some embodiments, the IL-15 protein complex is administered for 6 weeks at a dose of approximately 400 μg once weekly. In some embodiments, the IL-15 protein complex is administered for 6 weeks at a dose of approximately 600 μg once weekly. In some embodiments, the IL-15 protein complex is administered for 6 weeks at a dose of 200 μg once weekly. In some embodiments, the IL-15 protein complex is administered for 6 weeks at a dose of 400 μg once weekly. In some embodiments, the IL-15 protein complex is administered for 6 weeks at a dose of 600 μg once weekly.

[0126] In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of approximately 200 μg for the first 3 weeks, administered once weekly. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of approximately 400 μg for the first 3 weeks, administered once weekly. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of approximately 600 μg for the first 3 weeks, administered once weekly. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of 200 μg for the first 3 weeks, administered once weekly. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of 400 μg for the first 3 weeks, administered once weekly. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of 600 μg for the first 3 weeks, administered once weekly.

[0127] In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of approximately 200 μg once weekly for the first 6 weeks. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of approximately 400 μg once weekly for the first 6 weeks. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of approximately 600 μg once weekly for the first 6 weeks. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of 200 μg once weekly for the first 6 weeks. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of 400 μg once weekly for the first 6 weeks. In some embodiments, the IL-15 protein complex is administered for 3 months, with a dose of 600 μg once weekly for the first 6 weeks.

[0128] In some implementations, subjects receive cycles of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 dosing cycles. In some implementations, subjects receive a cycle of 1 dosing cycle. In some implementations, subjects receive a cycle of 4 dosing cycles. In some implementations, subjects receive a cycle of 5 dosing cycles.

[0129] In some embodiments, the IL-15 protein complex is administered at a dose of about 200 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of about 400 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of about 600 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of 200 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of 400 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months from the first dose. In some embodiments, the IL-15 protein complex is administered at a dose of 600 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months from the first dose.

[0130] In some embodiments, the IL-15 protein complex is administered at a dose of about 200 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of initial administration, and the first 3 weeks after 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of about 400 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of initial administration, and the first 3 weeks after 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of about 600 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of initial administration, and the first 3 weeks after 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of 200 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of initial administration, and the first 3 weeks after 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of 400 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of initial administration, and the first 3 weeks after 6, 12, 18, and 24 months of initial administration. In some embodiments, the IL-15 protein complex is administered at a dose of 600 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of initial administration, and the first 3 weeks after 6, 12, 18, and 24 months of initial administration.

[0131] <Dosage Regimen>

[0132] In some implementations, the IL-15 protein complex and BCG are administered simultaneously, separately, or sequentially.

[0133] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0134] (a) The dosage of the IL-15 protein complex is from 50 μg to 2000 μg, preferably from 150 μg to 800 μg, more preferably about 200 μg, about 400 μg or about 600 μg; most preferably about 600 μg; and / or

[0135] The IL-15 protein complex is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once weekly, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once weekly.

[0136] and

[0137] (b) The dosage of the BCG vaccine is from 10 mg to 300 mg, preferably from 100 mg to 150 mg, more preferably about 120 mg; and / or

[0138] The BCG vaccine is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once a week, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once a week.

[0139] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0140] (a) The dosage of the IL-15 protein complex is from 50 μg to 2000 μg; and / or

[0141] The IL-15 protein complex is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once weekly, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks.

[0142] and

[0143] (b) The dosage of the BCG vaccine is from 10 mg to 300 mg; and / or

[0144] The BCG vaccine is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once a week, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks.

[0145] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0146] (a) The dosage of the IL-15 protein complex is from 150 μg to 800 μg; and / or

[0147] The IL-15 protein complex is administered once a week;

[0148] and

[0149] (b) The dosage of the BCG vaccine is 100 mg to 150 mg; and / or

[0150] The BCG vaccine is administered once a week.

[0151] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0152] (a) The dosage of the IL-15 protein complex is about 200 μg, about 400 μg, or about 600 μg; and / or

[0153] The IL-15 protein complex is administered once a week;

[0154] and

[0155] (b) The dosage of the BCG vaccine is approximately 120 mg; and / or

[0156] The BCG vaccine is administered once a week.

[0157] In some implementations, the dosing regimen for the IL-15 protein complex combined with BCG, as described in any of the preceding embodiments, is as follows:

[0158] (a) The dosage of the IL-15 protein complex is approximately 600 μg, administered once weekly; and

[0159] (b) The dosage of the BCG vaccine is approximately 120 mg, administered once a week.

[0160] In some implementations, the dosing regimen for the IL-15 protein complex combined with BCG, as described in any of the preceding embodiments, is as follows:

[0161] (a) The dosage of the IL-15 protein complex is 600 μg, administered once weekly; and

[0162] (b) The dosage of BCG vaccine is 120 mg, administered once a week.

[0163] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0164] (a) The IL-15 protein complex was administered at a dose of about 200 μg, about 400 μg, or about 600 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months from the first dose; and

[0165] (b) The BCG vaccine was administered at a dose of approximately 120 mg once a week for the first 6 weeks and for the first 3 weeks after the first dose at 3, 6, 12, 18 and 24 months.

[0166] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0167] (a) The IL-15 protein complex was administered at a dose of approximately 600 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months from the first dose; and

[0168] (b) The BCG vaccine was administered at a dose of approximately 120 mg once a week for the first 6 weeks and for the first 3 weeks after the first dose at 3, 6, 12, 18 and 24 months.

[0169] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0170] (a) The IL-15 protein complex was administered at a dose of 600 μg once weekly for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18, and 24 months from the first dose; and

[0171] (b) The BCG vaccine was administered at a dose of 120 mg once a week for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18 and 24 months from the first dose.

[0172] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0173] (a) The IL-15 protein complex was administered at a dose of about 200 μg, about 400 μg, or about 600 μg once weekly for the first 6 weeks, the first 6 weeks after 3 months of first administration, and the first 3 weeks after 6, 12, 18, and 24 months of first administration; and

[0174] (b) The BCG vaccine was administered at a dose of about 120 mg once a week for the first 6 weeks and the first 6 weeks after 3 months from the first dose, and the first 3 weeks after 6, 12, 18 and 24 months from the first dose.

[0175] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0176] (a) The IL-15 protein complex was administered at a dose of approximately 600 μg once weekly for the first 6 weeks, and for the first 6 weeks after 3 months of initial administration, and for the first 3 weeks after 6, 12, 18, and 24 months of initial administration; and

[0177] (b) The BCG vaccine was administered at a dose of about 120 mg once a week for the first 6 weeks and the first 6 weeks after 3 months from the first dose, and the first 3 weeks after 6, 12, 18 and 24 months from the first dose.

[0178] In some embodiments, the dosing regimen of the IL-15 protein complex in combination with BCG is as follows:

[0179] (a) The IL-15 protein complex was administered at a dose of 600 μg once weekly for the first 6 weeks, and for the first 6 weeks after 3 months from the first dose, and for the first 3 weeks after 6, 12, 18, and 24 months from the first dose; and

[0180] (b) The BCG vaccine was administered at a dose of 120 mg once a week for the first 6 weeks and for the first 6 weeks after 3 months from the first dose, and for the first 3 weeks after 6, 12, 18 and 24 months from the first dose.

[0181] In some implementations, the dosing regimen of the IL-15 protein complex, or the IL-15 protein complex combined with BCG for the treatment of non-muscle-invasive bladder cancer, as described in any of the preceding embodiments, has good safety and antitumor activity. Attached Figure Description

[0182] Figure 1: Schematic diagram of the structure of protein complexes numbered 1, 2, 3, and 4.

[0183] the term

[0184] To facilitate understanding of this disclosure, certain technical and scientific terms are specifically defined below. Unless otherwise expressly defined herein, all other technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0185] The singular forms “a,” “an,” and “the” used in this disclosure include plural references unless the context clearly indicates otherwise.

[0186] Unless the context clearly requires otherwise, the words “comprising,” “having,” “including,” etc., in the patent specification and claims should be understood as “including but not limited to,” rather than as exclusive or exhaustive.

[0187] "Optional" or "optionally" means that the event or circumstances described below may, but do not have to, occur, including the circumstances in which the event or circumstances may or may not occur.

[0188] The term “and / or”, such as “X and / or Y”, should be understood to mean “X and Y” or “X or Y” and should be used to provide clear support for both meanings or either meaning.

[0189] Those skilled in the art will understand that when used as a reference range, cutoff value, or specific value, "about" can mean within one or more standard deviations. Alternatively, "about" can mean a range with a difference of up to 20% (i.e., ±20%). Since many of the values ​​used herein were determined experimentally, those skilled in the art will understand that such determinations can vary between different experiments and are generally true across experiments. Due to this inherent variability, the values ​​used herein should not be unduly restricted. Therefore, the term "about" is used to cover variations of ±20%, ±10%, ±5%, ±1%, ±0.5%, or ±0.1% or less from a specified value.

[0190] Although this disclosure provides content ranges or content values, those skilled in the art will understand that the content ranges or content values ​​cover the acceptable range of error for the specific values ​​measured.

[0191] The three-letter and single-letter codes for amino acids used in this disclosure are as described in J. Biol. Chem., 243, p3558 (1968).

[0192] The term "amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimics that function in a manner similar to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those that are subsequently modified, such as hydroxyproline, γ-carboxyglutamic acid, and O-phosphoserine. Amino acid analogs are compounds that have the same basic chemical structure as naturally occurring amino acids (i.e., the α-carbon bound to hydrogen, carboxyl, amino, and R groups), such as homoserine, ortholeucine, methionine sulfoxide, and methionine methylsulfonium. These analogs have modified R groups (e.g., ortholeucine) or modified peptide backbones but retain the same basic chemical structure as naturally occurring amino acids. Amino acid mimics are chemical compounds that have a structure different from the general chemical structure of amino acids but function in a manner similar to naturally occurring amino acids.

[0193] The term "antibody" is used in the broadest sense and encompasses a wide range of antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies; monospecific antibodies, multispecific antibodies (e.g., bispecific antibodies); full-length antibodies and antigen-binding fragments (or antigen-binding portions), as long as they exhibit the desired antigen-binding activity. "Natural antibody" refers to a naturally occurring immunoglobulin molecule. For example, a natural IgG antibody is a heterotetraglycoprotein of approximately 150,000 Daltons, composed of two identical light chains and two identical heavy chains bound by disulfide bonds. From the N to C terminus, each heavy chain has a variable region (VH), also called a variable heavy domain or heavy chain variable region, followed by a heavy chain constant region. The IgG heavy chain constant region (CH) typically contains three constant domains (CH1, CH2, and CH3); similarly, from the N to C terminus, each light chain has a variable region (VL), also called a variable light domain or light chain variable domain, followed by a constant light domain (light chain constant region, CL).

[0194] The term "variable region" or "variable domain" refers to the domain in the antibody heavy or light chain involved in antibody-antigen binding. In this paper, the antibody heavy chain variable region (VH) and light chain variable region (VL) each contain four conserved frame regions (FRs) and three complementarity-determining regions (CDRs). The term "complementarity-determining region" or "CDR" refers to the region within the variable domain that primarily facilitates antigen binding; "frame" or "FR" refers to the variable domain residues other than the CDR residues. The VH contains three CDR regions: HCDR1, HCDR2, and HCDR3; the VL contains three CDR regions: LCDR1, LCDR2, and LCDR3. Each VH and VL consists of three CDRs and four FRs arranged in the following order from the amino terminus (also called the N-terminus) to the carboxyl terminus (also called the C-terminus): FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. A single VH or VL may be sufficient to confer antigen-binding specificity.

[0195] The amino acid sequence boundaries of CDRs can be determined using various well-known schemes, such as the "Kabat" numbering rule, the "Chothia" numbering rule, the "ABM" numbering rule, the "contact" numbering rule, and the ImMunoGenTics (IMGT) numbering rule. The correspondence between various numbering systems is well known to those skilled in the art and is exemplified as shown in Table 1 below.

[0196] Table 1. Relationship between CDR numbering systems

[0197] Unless otherwise stated, the variable regions and CDR sequences in this disclosure embodiment are subject to the "Kabat" numbering rule.

[0198] The term "monoclonal antibody" refers to a group of substantially homogeneous antibodies, meaning that the antibody molecules contained in this group have the same amino acid sequence, except for the possible small number of naturally occurring mutations. In contrast, polyclonal antibody formulations typically contain multiple different antibodies with different amino acid sequences in their variable structural domains, and they generally specifically target different epitopes. "Monoclonal" indicates the characteristic of an antibody obtained from a substantially homogeneous group of antibodies and should not be construed as requiring the antibody to be produced by any particular method. In some embodiments, the antibodies provided in this disclosure are monoclonal antibodies.

[0199] The antibodies disclosed herein may be derived from animals (such as antibodies from mice, birds, rabbits, camels, monkeys, etc.), chimeric antibodies, or humanized antibodies.

[0200] The term "chimeric" antibody refers to an antibody in which a portion of the heavy and / or light chain is derived from a specific source or species, while the remaining portion of the heavy and / or light chain is derived from another different source or species.

[0201] The term "humanized" antibody refers to an antibody that retains the reactivity of a non-human antibody while exhibiting lower immunogenicity in humans. For example, this can be achieved by retaining the non-human CDR region and replacing the rest of the antibody with its human counterpart (i.e., the frame region portion of the constant region and the variable region).

[0202] The term "affinity" refers to the overall strength of the non-covalent interaction between a single binding site of a molecule (e.g., an antibody) and its binding ligand (e.g., an antigen). Unless otherwise specified, as used herein, binding "affinity" refers to internal binding affinity, which reflects a 1:1 interaction between members of a binding pair (e.g., antibody and antigen). The affinity of molecule X for its ligand Y can typically be represented by the dissociation constant (KD). Affinity can be measured using conventional methods known in the art.

[0203] The term "antigen" refers to a molecule or molecular moiety that can be bound by a selective binder of an antigen-binding protein (such as an antibody). An antigen may have one or more epitopes that can interact with different antigen-binding proteins (such as antibodies).

[0204] The term "epitope" refers to a region on an antigen that can specifically bind to an antibody or its antigen-binding fragment. Epitopes can be formed from consecutive amino acids (linear epitopes) or contain non-consecutive amino acids (conformal epitopes), for example, due to the folding of the antigen (i.e., tertiary folding of the antigen as a protein), which allows non-consecutive amino acids to be spatially close. The difference between conformational and linear epitopes is that antibody binding to a conformational epitope is lost in the presence of a denaturing solvent. An epitope contains at least 3, at least 4, at least 5, at least 6, at least 7, or 8-10 amino acids in a unique spatial conformation. Screening for antibodies that bind to a specific epitope (i.e., those that bind the same epitope) can be performed using methods routine in the art, such as, but not limited to, alanine scanning, Western blotting, peptide cleavage analysis, epitope excision, epitope extraction, chemical modification of the antigen, and cross-blocking.

[0205] The terms "capable of specific binding," "specific binding," or "binding" refer to the ability of an antibody to bind to a specific antigen or epitope with a higher affinity than other antigens or epitopes. Typically, antibodies bind at an affinity of approximately 1 × 10⁻⁶. -7 An equilibrium dissociation constant (KD) of M or less binds to an antigen or epitope. In some embodiments, the KD of antibody binding to an antigen is 10% or less (e.g., 1%) of the KD of the antibody binding to a nonspecific antigen (e.g., BSA, casein). KD can be measured using known methods, such as by FACS or surface plasmon resonance assays. However, antibodies that specifically bind to an antigen or an epitope within an antigen may be cross-reactive to other related antigens, for example, to corresponding antigens from other species (homologous), such as humans or monkeys, such as the cynomolgus (cyno), the chimpanzee (chimp), or the common marmoset (marmoset).

[0206] The term "protein complex" or "complex protein" refers to a protein composed of two different monomeric proteins. In this disclosure, the "monomeric proteins" (i.e., soluble fusion protein (I) and soluble fusion protein (II)) constituting the protein complex can be either fusion proteins or non-fusion proteins.

[0207] The term "fusion protein" refers to a protein product obtained by linking the coding regions of two or more genes using gene recombination methods, chemical methods, or other suitable methods, and expressing the recombinant protein under the control of the same regulatory sequence. In some embodiments, the soluble fusion protein (I) is a monomeric protein obtained by fusing or non-fusion expressing IL-15 or a variant thereof with a bioactive polypeptide such as an Fc fragment; the soluble fusion protein (II) is a monomeric protein obtained by fusing or non-fusion expressing IL-15Rα or a variant thereof with a bioactive polypeptide such as an Fc fragment. In the fusion proteins disclosed herein, the coding regions of two or more genes may be fused at one or more positions by sequences encoding peptide linkers. Peptide linkers may also be used to construct the fusion proteins of this disclosure.

[0208] The term "combination" is a route of administration that refers to the administration of at least one dose of an IL-15 protein complex and at least one dose of BCG within a specified time period, wherein both drugs exhibit pharmacological effects. The time period can be within a dosing cycle, such as within 6 months, 3 months, 1 month, 4 weeks, 3 weeks, 2 weeks, 1 week, within 24 hours, within 12 hours, or within 8 hours. The IL-15 protein complex and BCG can be administered simultaneously or sequentially. This period includes treatments in which the IL-15 protein complex and BCG are administered via the same or different routes of administration. The routes of administration for combination as described in this disclosure are selected from simultaneous administration, independently formulated and co-administered, or independently formulated and sequentially administered.

[0209] "Pharmaceutical composition" means a mixture containing one or more antibodies described herein or their physiologically / pharmacologically acceptable salts or prodrugs, along with other chemical components, such as physiologically / pharmacologically acceptable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration to a living organism, thereby promoting the absorption of the active ingredient and the exertment of its biological activity.

[0210] "Pharmaceutically acceptable carriers" or "pharmaceutically acceptable excipients" include any material that, when combined with an active ingredient, allows the ingredient to retain its biological activity and does not react with the subject's immune system. Examples include, but are not limited to, any standard pharmaceutical carrier, such as phosphate-buffered saline solutions, water, emulsions such as oil / water emulsions, and various types of wetting agents. In some embodiments, the diluent for aerosol or parenteral administration is phosphate-buffered saline (PBS) or physiological (0.9%) saline. Compositions containing such carriers are formulated using well-known conventional methods.

[0211] "Administration," "giving," and "treatment," when applied to animals, humans, experimental subjects, cells, tissues, organs, or biological fluids, refer to the contact of an exogenous drug, therapeutic agent, diagnostic agent, or composition with the animal, human, subject, cell, tissue, organ, or biological fluid. "Administration," "giving," and "treatment" can refer to, for example, therapeutic, pharmacokinetic, diagnostic, research, and experimental methods. Cellular treatment includes contact between a reagent and cells, as well as contact between a reagent and a fluid, wherein the fluid is in contact with the cells. "Administration," "giving," and "treatment" also mean, by means of a reagent, diagnostic agent, conjugate composition, or by means of another cell in vitro and ex vivo, such as cells. "Treatment," when applied to humans, veterinary, or research subjects, refers to therapeutic treatment, preventative or prophylactic measures, research, and diagnostic applications.

[0212] "Treatment" means administering an oral or topical therapeutic agent, such as a pharmaceutical composition comprising any of the substances disclosed herein, to a patient who has symptoms of one or more diseases, and the therapeutic agent is known to have a therapeutic effect on these symptoms. Typically, a therapeutic agent is administered in a treated patient or population in an amount that effectively relieves symptoms of one or more diseases, in order to induce the regression of such symptoms or inhibit their progression to any clinically measurable degree. The amount of a therapeutic agent that effectively relieves any specific disease symptom (also referred to as a "therapeuticly effective amount") can vary depending on a variety of factors, such as the patient's disease state, age, and weight, and the drug's ability to produce the desired therapeutic effect in the patient. Whether the disease symptoms have been relieved can be evaluated using any clinical test method commonly used by a physician or other healthcare professional to assess the severity or progression of the symptoms. Although the embodiments disclosed herein (e.g., treatment methods or products) may be ineffective in alleviating symptoms of each target disease, they should reduce symptoms of the target disease in a statistically significant number of patients, as determined by any statistical test known in the art, such as the Student t-test, chi-square test, U-test according to Mann and Whitney, Kruskal-Wallis test (H-test), Jonckheere-Terpstra test, and Wilcoxon test.

[0213] "Effective amount" includes an amount sufficient to improve or prevent the symptoms or condition of a medical condition. Effective amount also means an amount sufficient to allow or facilitate a diagnosis. The effective amount used on a subject may vary depending on factors such as the condition to be treated, the subject's overall health, the route and dosage of administration, and the severity of side effects. Effective amount may be the maximum dose or administration regimen that avoids significant side effects or toxicity. Subjects disclosed herein may be animal or human subjects.

[0214] The most commonly used staging system for bladder cancer is the American Joint Committee on Cancer (AJCC) TNM system. The components of the TNM staging system include: the size of the primary tumor and its progression to surrounding tissues (T); the presence and extent of metastasis to associated lymph nodes (N); and the presence or absence of distant metastasis (M). These three elements are followed by letters or numbers to indicate their respective degree of progression.

[0215] In non-muscle-invasive bladder cancer, stage "Ta" is non-invasive papillary carcinoma, which has not invaded the connective tissue or deep muscle layer of the bladder wall. Stage "Tis" is flat carcinoma, also known as carcinoma in situ (CIS), which has not invaded the connective tissue or deep muscle layer of the bladder wall. In stage "T1", cancer cells have grown into the connective tissue layer but have not yet reached the muscle layer of the bladder wall.

[0216] Disease-free survival (DFS) is defined as the period from first-time drug use to tumor progression, cystectomy, or death. In some implementations, tumor progression refers to recurrent CIS, T1, high-grade Ta, or higher TNM stage.

[0217] Dose-limiting toxicity (DLT) is defined as any of the following events related to the study drug IL-15 protein complex that occur during the DLT observation period (the first 3 weeks of the induction perfusion period) (grading criteria refer to NCI CTCAE 5.0):

[0218] 1) Hematological toxicity:

[0219] - Grade 4 neutrophil count decrease lasting >5 days (after symptomatic treatment);

[0220] - Grade 3 or higher febrile neutropenia;

[0221] -4 level anemia;

[0222] -4 grade platelet count decrease;

[0223] -Grade 3 platelet count decrease lasting >7 days;

[0224] Grade -3 decreased platelet count with significant clinical bleeding symptoms;

[0225] -4 grade lymphocyte count decrease lasting ≥14 days.

[0226] 2) Hepatotoxicity:

[0227] -4 grade ALT or AST elevation;

[0228] -3 grade ALT or AST elevation accompanied by ≥2 grade TBIL elevation;

[0229] - If the subject has no liver metastases, ALT or AST > 5 times the upper limit of normal (ULN) for > 3 days;

[0230] - If the subject has liver metastases, if the baseline ALT or AST level is ≤3 times the ULN, or if ALT or AST is >5 times the ULN for more than 3 days;

[0231] - If the subject has liver metastases, if the baseline ALT or AST level is >3 times the ULN, or if ALT or AST is >8 times the ULN for >3 days.

[0232] 3) Urinary tract-related adverse reactions:

[0233] - Bladder perforation or urinary fistula;

[0234] - Grade 3 or higher bladder spasm, cystitis, hematuria, urinary retention, urinary tract pain, urinary incontinence that persist for more than 7 days after symptomatic treatment.

[0235] 4) Other non-hematologic toxicities:

[0236] - Other non-hematologic toxicities of grade ≥3, excluding: grade 3 fatigue lasting <7 days; grade 3 nausea, vomiting, diarrhea, and loss of appetite that can be relieved to grade ≤2 within 3 days after symptomatic treatment; grade ≥3 rash without symptomatic treatment with glucocorticoids or anti-inflammatory drugs; or abnormal laboratory test indicators without clinical symptoms or signs (including grade ≥3 alkaline phosphatase elevation and hyperuricemia, etc.).

[0237] 5) The subject discontinued treatment during the DLT observation period due to drug-related toxicity.

[0238] In addition, if the investigational drug cannot be administered normally due to related toxicity (dosing delay >7 days), or if any of the above serious toxic events occur after the DLT observation period, the sponsor and the investigator will discuss together whether to classify it as a DLT event.

[0239] Details of one or more embodiments of this disclosure are set forth in the foregoing description. While any methods and materials similar to or the same as those described herein may be used to implement or test this disclosure, preferred methods and materials are described below. Other features, objects, and advantages of this disclosure will be apparent from the description and claims. In the description and claims, the singular form includes plural references unless the context clearly indicates otherwise. Unless otherwise defined, all technical and scientific terms used herein have their general meaning as understood by one of ordinary skill in the art to which this disclosure pertains. All patents and publications referenced in the description are incorporated herein by reference. The following embodiments are presented to illustrate preferred embodiments of this disclosure more fully. These embodiments should not be construed in any way as limiting the scope of this disclosure, which is defined by the claims. Detailed Implementation

[0240] The present disclosure is further described below with reference to embodiments, but these embodiments are not intended to limit the scope of the invention.

[0241] Experimental methods not specifying specific conditions in the examples or test cases disclosed herein are generally performed under standard conditions or as recommended by the raw material or product manufacturer. Reagents not specifying their source are commercially available, standard reagents.

[0242] Example 1: A Phase I / II clinical study of dose escalation and dose expansion of injectable IL-15 protein complex monotherapy or in combination with BCG intravesical instillation for the treatment of non-muscle-invasive bladder cancer.

[0243] 1. Drug Information

[0244] IL-15 protein complex: The structural diagram is shown in Figure 1, number 3, and it consists of soluble fusion protein (I) (SEQ ID NO:2) and soluble fusion protein (Π) (SEQ ID NO:5). Dosage form: Lyophilized powder for injection. Strength: 1 mg / vial. Route of administration: Bladder instillation.

[0245] Specifically, the IL-15 protein complex for injection appears as a white to off-white lumps or powder, and the reconstituted liquid should be clear or opalescent. The IL-15 protein complex is reconstituted with 1.1 mL of sterile water for injection, and the corresponding dosage is injected into 50 mL of 0.9% sodium chloride solution for bladder instillation.

[0246] Bacille Calmette Guerin (BCG): Dosage form: lyophilized powder for injection. Strength: 60mg / vial. Route of administration: bladder instillation.

[0247] 2. Study population

[0248] 2.1 Selection Criteria

[0249] Participants must meet all of the following criteria to be eligible for this study:

[0250] 1) Voluntarily participate in this clinical study, understand the study procedures, and be able to sign an informed consent form in writing.

[0251] 2) Age ≥ 18 years old, gender not limited.

[0252] 3) Eastern Cooperative Oncology Group (ECOG) performance status score ≤2.

[0253] 4) Expected survival time ≥ 2 years.

[0254] 5) Previous pathological tissue biopsy diagnosis was high-risk NMIBC.

[0255] 6) No resectable lesions were found during cystoscopy within 6 weeks prior to the first dose, or the only remaining lesion was CIS; for T1 subjects, if the pathological examination of the resected tissue after the last transurethral resection of bladder tumor (TURBT) did not show the muscle layer, a second TURBT must be performed and the pathological examination must confirm that the muscle layer tissue was included.

[0256] 7) Unsuitable for or unwilling to undergo radical cystectomy.

[0257] 8) Subjects in the Phase II dose expansion phase must meet one of the following conditions:

[0258] Cohort 1: High-risk NMIBC who have not previously received BCG treatment;

[0259] Cohort 2: CIS±Ta / T1 in patients who had not responded to previous BCG treatment*;

[0260] Cohort 3: High-grade Ta or T1 (without CIS) who have not responded to previous BCG treatment*.

[0261] The term "no response to BCG treatment*" is defined as meeting any of the following conditions: ①. Persistent / recurrent CIS or combined Ta / T1 within 12 months of adequate BCG treatment; ②. Recurrence of high-grade Ta / T1 within 6 months of adequate BCG treatment; ③. High-grade T1 is observed on the first assessment after BCG induction perfusion. "Adequate BCG treatment" as described above includes: 5 out of 6 initial induction perfusions and 2 out of 3 maintenance perfusions; or 5 out of 6 initial induction perfusions and 2 out of 6 re-induction perfusions. If BCG is used irregularly, the total number of treatments must be ≥6.

[0262] 9) As defined by the following laboratory test results, there is adequate hematological and end-organ function:

[0263] - Complete blood count (no blood transfusions or blood products administered within 14 days prior to the blood count, and no G-CSF or other hematopoietic stimulating factors used for correction): Absolute neutrophil count (ANC) ≥ 1.0 × 10⁻⁶ 9 / L; Platelet count (PLT) ≥100×10 9 / L; Hemoglobin (Hb) ≥80g / L;

[0264] - Liver function tests: Total bilirubin (TBIL) ≤ 2 × ULN; serum transaminase ALT and / or AST ≤ 3 × ULN;

[0265] - Kidney function test: Serum creatinine (Cr) ≤ 1.5 × ULN;

[0266] - Electrocardiogram (ECG): Normal QTc interval (males ≤450ms, females ≤470ms). QTc interval is corrected using the Fridricilia formula (Fridericia formula: QTc = QT / (RR)). 0.33 ));

[0267] - Echocardiography: Left ventricular ejection fraction (LVEF) ≥ 50%;

[0268] - Coagulation function test: APTT≤1.5×ULN, and INR or PT≤1.5×ULN.

[0269] 10) Contraception should be used during the study treatment period and for 6 months after the end of the study treatment period. Female subjects of childbearing age or male subjects whose partners are female of childbearing age should use highly effective contraception. Female subjects of childbearing age must have a negative serum HCG test within 7 days before the first dose and must not be breastfeeding.

[0270] 3. Research Design

[0271] 3.1 Phase I Study

[0272] Phase I studies mainly consist of two phases: Phase Ia and Phase Ib. Phase Ia is the dose escalation phase for IL-15 protein complex monotherapy, aiming to evaluate the safety and tolerability of IL-15 protein complex monotherapy. Phase Ib is the dose exploration phase for IL-15 protein complex in combination with BCG, aiming to evaluate the safety and tolerability of IL-15 protein complex in combination therapy and to determine the RP2D of IL-15 protein complex in combination therapy.

[0273] 3.1.1 Phase Ia: Dosage escalation phase of IL-15 protein complex monotherapy

[0274] The IL-15 protein complex will be administered in three pre-set dose groups: 200 μg, 400 μg, and 600 μg via bladder instillation. The dosing cycle includes an induction instillation period of 6 times (once a week for 6 consecutive weeks) and a maintenance instillation period of 15 times (once a week for 3 weeks before the first induction instillation at 3, 6, 12, 18, and 24 months, for a total of 3 times a month).

[0275] For BCG-unresponsive subjects, if a subject is found to have recurrent or persistent CIS or high-grade Ta by cystoscopy before the first bladder instillation 3 months after the first induction instillation, or if a subject is found to have recurrent or persistent CIS or high-grade Ta or T1 (without pathological progression) by cystoscopy before the first bladder instillation 3 months after the first induction instillation, then 3 additional instillations (once a week) should be added after completing the routine 3 instillations this month as re-induction instillations.

[0276] This study will employ a "3+3" dose escalation principle, with the DLT observation period being the first 3 weeks of the induction perfusion phase. Considering the possibility that the initial dose of 200 μg might be too low and result in no therapeutic benefit for the subjects, only one subject will be enrolled using a rapid titration method. If no DLT event occurs in this subject during the DLT observation period, the next dose will be escalated. If a DLT event occurs, the rapid titration will be switched to a "3+3" dose escalation pattern for dose exploration.

[0277] 3.1.2 Phase Ib: Dosage Exploration Phase of IL-15 Protein Complex Combined with BCG

[0278] Based on the safety, tolerability, drug concentration / PD, and preliminary efficacy data from Phase Ia, the investigator and sponsor will jointly determine the exploratory dose of IL-15 protein complex for co-administration with BCG. BCG will be administered at a fixed dose (120 mg). The highest dose of IL-15 protein complex during the monotherapy dose escalation phase will be prioritized for co-administration exploration. The co-administration cycle will be the same as in Phase Ia. Each dose group will enroll 3-6 subjects, with the observation period being 3 weeks (21 days) before the induction perfusion phase. After all subjects in the dose group have completed at least 3 weeks (21 days) of treatment, if ≤1 / 6 of the subjects in the highest dose group experience DLT, the study will proceed to Phase II. If ≥2 / 6 of the subjects in the highest dose group experience DLT, the IL-15 protein complex will be reduced to the second-highest dose group for co-administration exploration. If ≤1 / 6 of the subjects in the current dose group experience DLT, the study will proceed to Phase II. If ≥2 / 6 of the subjects in the current dose group experience DLT, the investigator and sponsor will jointly determine whether to increase the exploration of a lower dose of IL-15 protein complex. The dosing cycle and specific dosing schedule (including re-induction perfusion) are the same as in phase Ia.

[0279] 3.2 Phase II Study

[0280] The Phase II study aims to further evaluate the safety and tolerability of the IL-15 protein complex combination therapy and to assess the preliminary efficacy of the two-drug combination therapy for NMIBC. Based on prior treatment history, NMIBC risk stratification, and pathological type, this phase of the study will enroll the following three groups of participants:

[0281] 1) Cohort 1: High-risk NMIBC who have not previously received BCG treatment;

[0282] 2) Cohort 2: Carcinoma in situ (CIS) with or without Ta or T1, which had previously been unresponsive to BCG.

[0283] 3) Queue 3: Ta or T1 who have previously not responded to BCG (without CIS);

[0284] The dosage used was determined in Phase I, and the dosing cycle and specific dosing schedule (including re-induction perfusion) were the same as in Phase Ib.

[0285] 4. Administration method

[0286] The IL-15 protein complex was administered at doses of 200 μg, 400 μg, and 600 μg, either alone or in combination with 120 mg BCG, dissolved in 50 mL of normal saline. Bladder instillation was performed over at least 2 hours. The first 6 weeks constituted the induction instillation period, with instillation once weekly for a total of 6 weeks. This was followed by a maintenance instillation period, with instillation once weekly (i.e., 3 times per month for a total of 15 times) for the first 3 weeks following the initial induction instillation at 3, 6, 12, 18, and 24 months.

[0287] Re-induction instillation (high risk): For BCG-unresponsive subjects, if cystoscopy reveals recurrent or persistent CIS or high-grade Ta 3 months after the first induction instillation and before the first bladder instillation, or for BCG-untreated subjects, if cystoscopy reveals recurrent or persistent CIS or high-grade Ta or T1 (without pathological progression) 3 months after the first induction instillation and before the first bladder instillation, then 3 additional instillations (once a week) should be added after completing the routine 3 instillations this month as re-induction therapy.

[0288] The study may proceed as follows: treatment administration continues until the prescribed treatment period is completed; disease relapses or persists; study treatment is withdrawn voluntarily; toxicity is intolerable; death occurs; loss to follow-up occurs; or the investigator deems it necessary to withdraw from the study.

[0289] 5. Evaluation Indicators

[0290] 5.1 Safety Evaluation

[0291] Safety assessment includes collecting AE / SAE data, laboratory tests, vital signs and physical examination, 12-lead ECG, and echocardiography.

[0292] The primary endpoints were dose-limiting toxicity (DLT), maximum tolerated dose (MTD), and recommended phase 2 dose (RP2D) for phase Ia and phase Ib studies.

[0293] As of September 2024, a total of 84 subjects were enrolled (n=8 in phase Ia; n=6 in phase Ib; n=29, 17, and 24 in phase II cohorts 1, 2, and 3, respectively).

[0294] In Phase Ia, no DLT was observed with IL-15 protein complex monotherapy (200 μg, 400 μg, and 600 μg), and in Phase Ib, no MTD was reached with IL-15 protein complex (600 μg) in combination with BCG (120 mg). Therefore, in Phase II, 600 μg of IL-15 protein complex in combination with 120 mg of BCG was used.

[0295] Treatment-related adverse events (TRAEs) occurred in 4 out of 8 subjects treated with IL-15 protein complex (TRAE) (50.0%), and in 53 out of 76 subjects treated with IL-15 protein complex in combination with BCG (TRAE) (69.7%).

[0296] One grade 3 adverse event (TRAE) occurred in subjects receiving IL-15 protein complex therapy (12.5%), which was a urinary tract infection. Seven grade 3 TRAEs (9.2%) occurred in subjects receiving IL-15 protein complex therapy in combination with BCG. Among these, grade 3 TRAEs with more than one occurrence were urinary tract infection and hypertension. No grade 4 or 5 TRAEs occurred. No serious adverse events (SAEs) related to the study drug occurred.

[0297] 5.2 Evaluation of Tumor Treatment Efficacy

[0298] The evaluation of bladder cancer treatment efficacy is mainly based on cystoscopy and urine cytology examination, and CTU / MRU results may be referenced when necessary.

[0299] For individuals with CIS, CR is defined as negative cystoscopy and negative urine cytology or only indicating atypical hyperplasia; or positive cystoscopy and benign or low-grade Ta on biopsy and negative urine cytology; or negative cystoscopy, malignant cells found in urine cytology, negative random cystoscopy biopsy and / or tumor found in the upper urinary tract or prostate region of the urinary tract.

[0300] For the high-grade Ta / T1 population, DFS is defined as the progression of tumor (recurrent CIS, T1, high-grade Ta or higher TNM stage) from first-drug therapy, or the need for cystectomy, or death.

[0301] Whether disease progression was assessed at the initial evaluation (3 months after the first dose) depends on the specific circumstances: if cystoscopy at week 13 revealed a T1 or higher TNM stage, the subject was directly considered to have disease progression; if cystoscopy at week 13 revealed recurrence or persistent high-grade Ta or CIS, resection was performed followed by three additional instillations. If a subsequent examination still showed a T1, high-grade Ta, CIS, or higher TNM stage, the time of first progression was recorded as week 13.

[0302] The primary endpoints were the complete response (CR) rate in cohort 2 and the 12-month disease-free survival (DFS) rate in cohorts 1 and 3.

[0303] As of September 2024, among the evaluable participants in Cohort 2, the 3 / 6-month CR rate was 90.9% (10 / 11). In Cohorts 1 and 3, no 12-month evaluation was achieved. The 9-month DFS rate was 94.4% in Cohort 1 and 53.9% in Cohort 3.

[0304] As of October 2025, a total of 104 subjects were enrolled in the IL-15 protein complex combined with BCG therapy. Results showed that in the Phase II cohort 1+Ib group of high-risk NMIBC who had not previously received BCG therapy, the 9-month DFS rate was 93.94% and the 12-month DFS rate was 90.33%; in the Phase II cohort 3+Ib group of Ta or T1 (without CIS) who had not previously responded to BCG, the 9-month DFS rate was 67.20% and the 12-month DFS rate was 59.24%.

[0305] In summary, the IL-15 protein complex, whether used alone or in combination with BCG, demonstrates a tolerable and manageable safety profile and shows promising antitumor activity in non-muscle-invasive bladder cancer.

Claims

1. The use of IL-15 protein complex in combination with BCG in the preparation of drugs for the treatment of non-muscle-invasive bladder cancer; The IL-15 protein complex comprises a soluble fusion protein (I) and a soluble fusion protein (II); The soluble fusion protein (Π) comprises an amino acid sequence as shown in SEQ ID NO: 5, 3, 4 or 6; and The soluble fusion protein (I) comprises the amino acid sequence shown in SEQ ID NO:2; Preferably, The soluble fusion protein (Π) comprises the amino acid sequence shown in SEQ ID NO:5; and The soluble fusion protein (I) contains an amino acid sequence as shown in SEQ ID NO:

2.

2. The use according to claim 1, wherein the dosage of the IL-15 protein complex is 50 μg to 2000 μg, preferably 150 μg to 800 μg, more preferably about 200 μg, about 400 μg or about 600 μg; most preferably about 600 μg; and / or The IL-15 protein complex is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once weekly, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once weekly.

3. The use according to claim 1 or 2, wherein the dosage of BCG is 10 mg to 300 mg, preferably 100 mg to 150 mg, more preferably about 120 mg; and / or The BCG vaccine is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once a week, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once a week.

4. The use according to any one of claims 1 to 3, wherein the administration regimen of the IL-15 protein complex combined with BCG is as follows: (a) The dosage of the IL-15 protein complex is from 50 μg to 2000 μg, preferably from 150 μg to 800 μg, more preferably about 200 μg, about 400 μg or about 600 μg; most preferably about 600 μg; and / or The IL-15 protein complex is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once weekly, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once weekly. and (b) The dosage of the BCG vaccine is from 10 mg to 300 mg, preferably from 100 mg to 150 mg, more preferably about 120 mg; and / or The BCG vaccine is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once a week, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once a week.

5. The use according to claim 4, wherein the administration regimen of the IL-15 protein complex combined with BCG is as follows: (a) The IL-15 protein complex was administered at a dose of about 600 μg once a week for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18 and 24 months from the first dose. and (b) The BCG vaccine was administered at a dose of about 120 mg once a week for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18 and 24 months from the first dose. or (a) The IL-15 protein complex was administered at a dose of about 600 μg once a week for the first 6 weeks and the first 6 weeks after 3 months from the first dose, and the first 3 weeks after 6, 12, 18 and 24 months from the first dose. and (b) The BCG vaccine was administered at a dose of about 120 mg once a week for the first 6 weeks and the first 6 weeks after 3 months from the first dose, and the first 3 weeks after 6, 12, 18 and 24 months from the first dose.

6. The use according to any one of claims 1 to 5, wherein the non-muscle-invasive bladder cancer is a high-risk NMIBC; Preferably, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment, or a high-risk NMIBC that has not responded to previous BCG treatment. More preferably, the non-muscle-invasive bladder cancer is high-risk NMIBC that has not previously received BCG treatment, carcinoma in situ (CIS) that has not responded to previous BCG treatment and may or may not have Ta or T1, or high-grade Ta or T1 that has not responded to previous BCG treatment and does not have CIS.

7. A method of treating non-muscle-invasive bladder cancer, comprising administering a therapeutically effective amount of IL-15 protein complex and BCG to a subject in need; The IL-15 protein complex comprises a soluble fusion protein (I) and a soluble fusion protein (II); The soluble fusion protein (Π) comprises an amino acid sequence as shown in SEQ ID NO: 5, 3, 4 or 6; and The soluble fusion protein (I) comprises the amino acid sequence shown in SEQ ID NO:2; Preferably, The soluble fusion protein (Π) comprises the amino acid sequence shown in SEQ ID NO:5; and The soluble fusion protein (I) contains an amino acid sequence as shown in SEQ ID NO:

2.

8. The method according to claim 7, wherein the dosage of the IL-15 protein complex is 50 μg to 2000 μg, preferably 150 μg to 800 μg, more preferably about 200 μg, about 400 μg or about 600 μg; most preferably about 600 μg; and / or The IL-15 protein complex is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once weekly, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once weekly.

9. The method according to claim 7 or 8, wherein the BCG dosage is 10 mg to 300 mg, preferably 100 mg to 150 mg, more preferably about 120 mg; and / or The BCG vaccine is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once a week, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once a week.

10. The method according to any one of claims 7 to 9, wherein the administration regimen of the IL-15 protein complex combined with BCG is as follows: (a) The dosage of the IL-15 protein complex is from 50 μg to 2000 μg, preferably from 150 μg to 800 μg, more preferably about 200 μg, about 400 μg or about 600 μg; most preferably about 600 μg; and / or The IL-15 protein complex is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once weekly, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once weekly. and (b) The dosage of the BCG vaccine is from 10 mg to 300 mg, preferably from 100 mg to 150 mg, more preferably about 120 mg; and / or The BCG vaccine is administered once daily, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once a week, once every 2 weeks, once every 3 weeks, once every 4 weeks, once every 5 weeks, or once every 6 weeks; preferably once a week.

11. The method according to claim 10, wherein the administration regimen of the IL-15 protein complex combined with BCG is as follows: (a) The IL-15 protein complex was administered at a dose of about 600 μg once a week for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18 and 24 months from the first dose. and (b) The BCG vaccine was administered at a dose of about 120 mg once a week for the first 6 weeks and for the first 3 weeks after 3, 6, 12, 18 and 24 months from the first dose. or (a) The IL-15 protein complex was administered at a dose of about 600 μg once a week for the first 6 weeks and the first 6 weeks after 3 months from the first dose, and the first 3 weeks after 6, 12, 18 and 24 months from the first dose. and (b) The BCG vaccine was administered at a dose of about 120 mg once a week for the first 6 weeks and the first 6 weeks after 3 months from the first dose, and the first 3 weeks after 6, 12, 18 and 24 months from the first dose.

12. The method according to any one of claims 7 to 11, wherein the non-muscle-invasive bladder cancer is a high-risk NMIBC; Preferably, the non-muscle-invasive bladder cancer is a high-risk NMIBC that has not previously received BCG treatment, or a high-risk NMIBC that has not responded to previous BCG treatment. More preferably, the non-muscle-invasive bladder cancer is high-risk NMIBC that has not previously received BCG treatment, carcinoma in situ (CIS) that has not responded to previous BCG treatment and may or may not have Ta or T1, or high-grade Ta or T1 that has not responded to previous BCG treatment and does not have CIS.

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