WO2023039249A1

WO2023039249A1 - Combination therapy

Info

Publication number: WO2023039249A1
Application number: PCT/US2022/043226
Authority: WO
Inventors: Michael H. KAGEY; Cynthia SIRARD; Yong BEN
Original assignee: BeiGene Switzerland GmbH; Leap Therapeutics Inc
Current assignee: BeiGene Switzerland GmbH; Leap Therapeutics Inc
Priority date: 2021-09-10
Filing date: 2022-09-12
Publication date: 2023-03-16
Anticipated expiration: 2024-03-10
Also published as: JP2024533439A; EP4398889A1

Abstract

The invention relates to methods of treating esophagogastic cancer in a subject in need thereof. The method comprising administering an effective amount of a combination of a DKK1 antibody, tislelizumab and one or more chemotherapeutic agents to the subject, wherein the subject either has a DKK-1 H-score of 35 or more or a DKK1 Tumor Percentage Score (TPS) of 20% or more and has not received prior systemic therapy for the esophagogastric cancer, or has a CPS of less than 5. The present invention also provides a pharmaceutical composition and a kit comprising a combination of a DKK1 antibody, tislelizumab and one or more chemotherapeutic agents.

Description

COMBINATION THERAPY

RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/242896 filed on September 10, 2021. US Provisional Application No. 63/300155 filed on January 17, 2022, US Provisional Application No. 63/301364 filed on January 20, 2022 and U.S. Provisional Application No. 63/403621 filed on September 2, 2022. The entire teachings of the above applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] Cancer is a cellular disorder characterized by uncontrolled or disregulated cellular proliferation, decreased cellular differentiation, inappropriate ability to invade surrounding tissue, and/or ability to establish new growth at ectopic sites. Depending on the specific cancer involved, the treatment for cancer may involve surgery, radiotherapy, chemotherapy, immunotherapy or a combination of these treatments. It is estimated that in 2020 in the United States 1,806,590 new cases of cancer will be diagnosed and 606,520 people will die from cancer. As such, despite significant advancements in the treatment of cancer, there is a continuing need for new and improved treatments for patients with cancer.

SUMMARY OF THE INVENTION

[0003] The invention described herein relates to a method of treating an esophagogastric cancer in a subject in need of treatment. In a first embodiment, the method comprises administering to the subject suffering from esophagogastric cancer an effective amount of the combination of a DKK1 antibody, or antigen binding-fragment thereof; tislelizumab; and one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing, wherein the subject is determined to have a DKK-1 H-score of 35 or more or a DKK1 Tumor Percentage Score (TPS) of 20% or more. In a particular aspect, the subject is determined to have a Combined Positive Score (CPS) of less than 5 for PD-L1.

[0004] In a second embodiment, the method comprises administering to the subject suffering from esophagogastric cancer an effective amount of the combination of a DKK1 antibody, or antigen binding-fragment thereof; tislelizumab; and one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing, wherein the subject is determined to have Combined Positive Score (CPS) of less than 5 for PD-L1. In a particular aspect, the subject is determined to have a DKK-1 H-score of 35 or more or a DKK1 Tumor Percentage Score of 20% or more.

[0005] In a first aspect of the first or second embodiment or any particular aspect thereof, the subject has not received prior systemic therapy for the esophagogastric cancer. [0006] In a second aspect of the first or second embodiment or any particular aspect thereof, the subject has received only one prior systemic therapy for the esophagogastric cancer.

[0007] In a third aspect of the first or second embodiment, any particular aspect thereof or the first and second aspects thereof the esophagogastric cancer is gastric cancer.

[0008] In a fourth aspect of the first or second embodiment, any particular aspect thereof or the first and second aspects thereof the esophagogastric cancer is gastroesophageal junction cancer.

[0009] In a fifth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third or fourth aspect thereof the cancer is an adenocarcinoma.

[0010] In a sixth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth or fifth aspect thereof the cancer is metastatic.

[0011] In a seventh aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth or sixth aspect thereof the cancer is advanced. [0012] In an eighth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth or seventh aspect thereof the subject has received neoadjuvant therapy prior to administering an effective amount of the combination.

[0013] In a ninth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh or eighth aspect thereof the effective amount of the combination is administered in the course of one or more 21 -day cycles.

[0014] In tenth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth aspect thereof the effective amount of the combination is administered in the course of one or more 21 -day cycles, wherein 300 mg of the DKK1 antibody, or antigen binding-fragment thereof is administered on day 1 and day 15 of the 21 -day cycle. [0015] In eleventh aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth aspect thereof the effective amount of the combination is administered in the course of one or more 21 -day cycles, wherein 200 mg of tislelizumab is administered on day 1 of the 21 -day cycle.

[0016] In a twelfth aspect aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth or eleventh aspect thereof the one or more chemotherapeutic agents is selected from: 5-FU (fluorouracil), leucovorin (folinic acid); Capecitabine; Carboplatin; Cisplatin; Docetaxel; Epirubicin; Irinotecan; Oxaliplatin; Paclitaxel; andTrifluridine and Tipiracil.

[0017] In a thirteenth aspect aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh or twelfth aspect thereof the one or more chemotherapeutics agent is a combination selected from: Oxaliplatin, 5-FU and leucovorin (FOLFOX); oxaliplatin and capecitabine (CAPOX); 5-FU, leucovorin, oxaliplatin, and docetaxel (FLOT); Docetaxel and 5-FU; Docetaxel and capecitabine; paclitaxel and 5-FU; paclitaxel and capecitabine; Cisplatin and 5-FU; cisplatin and capecitabine; Paclitaxel and carboplatin; Irinotecan, 5-FU and leucovorin (FOLFIRI); Paclitaxel and cisplatin; paclitaxel and carboplatin; Docetaxel and cisplatin; Epirubicin, cisplatin and 5-FU, Epirubicin, oxaliplatin and 5-FU; Epirubicin, cisplatin and capecitabine; Epirubicin, oxaliplatin and capecitabine; Docetaxel, 5-FU, and cisplatin; Docetaxel, 5-FU, and carboplatin; Docetaxel, 5-FU, and oxaliplatin.

[0018] In a fourteenth aspect aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth or thirteenth aspect thereof the one or more chemotherapeutics agent is a combination of oxaliplatin and capecitabine (CAPOX). In a paricular aspect, the capecitabine is orally administered at 1000 mg/m2 twice daily on days 1-15 of each 21 day cycle and the oxaliplatin is administered at 130 mg/m2 on day 1 of each 21-day cycle.

[0019] It is understood that in any embodiment or aspect described herein that the effective amount of the combination is administered in the course of one or more 21-day cycles or one or more 14-day cycles in some instances. In other words, the 21-day cycle can be repeated.

[0020] In a fifteenth aspect aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth or fourteenth aspect thereof the DKK1 antibody, or antigen binding-fragment thereof, comprises a light chain variable region (LCVR) and a heavy chain variable region (HCVR), wherein the LCVR comprises complementarity determining regions (CDRs) LCDR1, LCDR2, and LCDR3 and the HCVR comprises CDRs HCDR1, HCDR2 and HCDR3, wherein LCDR1 has the amino sequence of SEQ ID NO: 1, LCDR2 has the amino sequence of SEQ ID NO:2, LCDR3 has the amino sequence of SEQ ID NO:3, HCDR1 has the amino sequence of SEQ ID NON, HCDR2 has the amino sequence of SEQ ID NO:5, and an HCDR3 has the amino sequence of SEQ ID NO:6. In a particular aspect of the fifteenth aspect, the LCVR comprises the amino acid sequence of SEQ ID NO: 7 and the HCVR comprises the amino acid sequence of SEQ ID NO: 8. In a further particular aspect, the LCVR and HCVR comprise amino acid sequences selected from the group consisting of: (i) a LCVR comprising the amino acid sequence of SEQ ID NO: 9 and a HCVR comprising the amino acid sequence of SEQ ID NO: 10; (ii) a LCVR comprising the amino acid sequence of SEQ ID NO: 11 and a HCVR comprising the amino acid sequence of SEQ ID NO: 12; (iii) a LCVR comprising the amino acid sequence of SEQ ID NO: 13 and a HCVR comprising the amino acid sequence of SEQ ID NO: 10; (iv) a LCVR comprising the amino acid sequence of SEQ ID NO: 14 and a HCVR comprising the amino acid sequence of SEQ ID NO: 10. In yet another particular apect of the fifteenth aspect, the LCVR comprises the amino acid sequence of SEQ ID NO: 11 and the HCVR comprises the amino acid sequence of SEQ ID NO: 12.

[0021] In a sixteenth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth aspect thereof, the DKK1 antibody comprises a heavy chain and a light chain amino acid sequence selected from the group consisting of a) a heavy chain comprising the amino acid sequence of SEQ ID NO: 19 and light chain comprising the amino acid sequence of SEQ ID NO: 16, b) a heavy chain comprising the amino acid sequence of SEQ ID NO: 17 and a light chain comprising the amino acid sequence of SEQ ID NO: 18, c) a heavy chain comprising the amino acid sequence of SEQ ID NO: 19 and a light chain comprising the amino acid sequence of SEQ ID NO: 20, and d) a heavy chain comprising the amino acid sequence of SEQ ID NO: 19 and a light chain comprising the amino acid sequence of SEQ ID NO: 21.

[0022] In a seventeenth aspect aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth or fifteenth aspect thereof the DKK1 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 17 and a light chain comprising the amino acid sequence of SEQ ID NO: 18.

[0023] In an eighteenth aspect of the first or second embodiment, any particular aspect thereof or the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth or seventeenth aspect thereof the DKK1 antibody comprises DKN-01.

[0024] The method of any of the embodiments or aspects described herein (numbered or otherwise) wherein the subject is a human.

[0025] In a third embodiment, the invention relates to a pharmaceutical composition comprising: a DKK1 antibody, or antigen binding-fragment thereof; tislelizumab; and one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. l is a graph showing best overall response in the response evaluable (RE) mITT patient population (21 patients) rated by the DKK1 expression (first cutoff of data).

[0027] FIG. 2 shows the results depicted as durable response by DKK1 expression (25 patients; first cutoff of data).

[0028] FIG. 3 shows the results of duration on trial by DKK1 expression (25 patients; first cutoff of data).

[0029] FIG. 4 is a graph showing that tumoral DKK1 expression predicts response to DKN-01 Therapy (first cutoff of data).

[0030] FIG. 5 is a graph showing best overall response by PD-L1 and DKK1 expression (first cutoff of data).

[0031] FIG. 6 is a graph showing that durable response in the trial is independent of PD-L1 expression (first cutoff of data).

[0032] FIG. 7 is a plot showing that PD-L1 expression and DKK1 expression are not correlated in mITT population of 19 patients.

[0033] FIG. 8 is a graph showing best overall response in the response evaluable (RE) mITT patient population (21 patients; second cutoff of data).

[0034] FIG. 9 is a graph showing best overall response by PD-L1 and DKK1 expression in mITT population (21 patients; second cutoff of data). [0035] FIG. 10 shows the results depicted as durable response by DKK1 expression in mITT population (21 patients; second cutoff of data).

[0036] FIG. 11 is a graph showing the duration of response (responders 15; second cutoff of data).

[0037] FIG. 12 is a graph showing progression free survival (ITT, N=25; second cutoff of data).

[0038] FIG. 13 is an analysis showing that patient response in Part A is associated with elevated DKK1 expression. DKK1 expression was measured by RNAscope. Using either an H-score cutoff of ≥35 or a DKK1 Percent Positive (i.e., TPS) cutoff of ≥20% provides a similar result. ORR not correlated to PD-L1 CPS high ( ≥5).

[0039] FIG. 14 is a plot comparing DKK1 H-score and DKK1 TPS for Part A tumor specimens. There is a significant Spearman correlation between DKK1 H-score and DKK1 TPS. The concordance between DKK1 high and low binning using an H-score cutoff of 35 or greater and a TPS cutoff of 20% or greater is 96%.

[0040] FIG. 15 shows the Best Overall Response based on DKK1 Expression for response evaluable mITT population (third cutoff of data).

[0041] FIG. 16 shows the results depicted as durability of clinical benefit (mITT, N=21; third cutoff of data).

[0042] FIG. 17 is a graph showing best overall response by PD-L1 and DKK1 expression in mITT population (21 patients, third cutoff of data).

[0043] FIG. 18 shows Progression-free Survival (PFS) by DKK1 Expression (ITT, N=25, third cutoff of data).

[0044] FIG. 19 shows Progression-free Survival by PD-L1 Expression (ITT, N=25, third cutoff of data).

[0045] FIG. 20 shows Overall Survival by DKK1 Expression (ITT, N=25, third cutoff of data).

[0046] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0047] A description of example embodiments of the invention follows.

[0048] The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.

[0049] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

TYPES OF ESOPHAGOGASTRIC CANCER

[0050] Esophagogastric cancer as used herein refers to esophageal cancer and gastric (stomach) cancer (GC).

[0051] “Esophageal cancer” (EC) as used herein refers to cancer of the esophagus as well as the gastro-esophageal junction (GEJ). As commonly used in the art, esophageal cancer comprises esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Generally, ESCC refers to cancer that originates in squamous cells, which cells line the esophagus in approximately upper 2/3 of the organ. EAC refers to cancer that originates in gland cells, which replace an area of squamous cells (e.g., in Barrett’s esophagus), typically in the lower 1/3 of the esophagus. As such, esophageal adenocarcinoma as used herein refers to adenocarcinoma of the esophagus as well as the gastro-esophageal junction.

[0052] In one embodiment, the esophagogastric cancer is esophageal cancer. In one aspect, the esophageal cancer is locally advanced or metastatic. In another aspect, the locally advanced or metastatic esophageal cancer is inoperable. In another aspect, the esophageal cancer is an adenocarcinoma. In another embodiment, the subject being treated for the locally advanced or metastatic esophageal cancer has not had prior systemic therapy for the esophageal cancer. In a specific aspect, the subject has not had prior systemic therapy, but has received neoadjuvant or adjuvant therapy.

[0053] In one embodiment, the esophagogastric cancer is locally advanced or metastatic GEJ cancer. In one aspect, the locally advanced or metastatic GEJ cancer is inoperable. In another aspect, the GEJ cancer is an adenocarcinoma. In another embodiment, the subject being treated for the locally advanced or metastatic GEJ cancer has not had prior systemic therapy for the GEJ cancer. In a specific aspect, the subject has not had prior systemic therapy, but has received neoadjuvant or adjuvant therapy. In a further embodiment, the subject being treated for locally advanced or metastatic esophagogastric cancer (e.g., GEJ cancer or gastric cancer) has a CPS of less than 5. In a specific aspect, the CPS is a vCPS (visual CPS) and is less than 5.

[0054] As used herein, “gastric cancer” or GC refers to cancer of the stomach. A specific type of gastric cancer is “gastric adenocarcinoma.”

[0055] An adenocarcinoma is a type of cancerous tumor that is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or both.

[0056] Gastric cancer is a leading cause of cancer-related death in the world, and it remains difficult to cure, primarily because most patients present with advanced disease. The stomach begins at the gastroesophageal junction and ends at the duodenum. Histologically, the 90-95% of gastric malignancies are adenocarcinoma. Curative therapy involves surgical resection, most commonly a total or subtotal gastrectomy, with an accompanying lymphadenectomy. The overall 5-year survival rate of patients with resectable gastric cancer ranges from 10% to 30%.

[0057] In one embodiment, the gastric cancer is locally advanced or metastatic gastric cancer. In one aspect, the locally advanced or metastatic gastric cancer is inoperable. In another aspect, the gastric cancer is an adenocarcinoma. In another embodiment, the subject being treated for the locally advanced or metastatic gastric cancer has not had prior systemic therapy for the gastric cancer. In a specific aspect, the subject has not had prior systemic therapy, but has received neoadjuvant or adjuvant therapy.

[0058] Neoadjuvant therapy encompasses all treatments that are administered before the primary cancer treatment, whereas adjuvant therapy describes regimens administered after the primary treatment. In the case of esophagogastic cancer (e.g., gastric cancer or GEJ cancer), neoadjuvant therapy typically includes a combination of chemotherapy and radiation therapy and is administered to patients who are surgical candidates for primary resection. Neoadjuvant therapy is administered in advance of primary resection to reduce overall tumor burden and for ease of tumor removal. Adjuvant therapy is then administered after primary resection to reduce risk of recurrence. Both neoadjuvant and adjuvant therapy can be utilized as adjuncts to primary surgical resection.

[0059] PD-L1 protein expression in viable cancer and immune cells determined by immunohistochemistry (IHC) is correlated with a therapeutic effect of immune checkpoint inhibitors, and is thus considered an important biomarker in deciding whether to treat a patient with anti-PD-l/ PD-L1 inhibitors. As used herein, CPS (Combined Positive Score) is the number value obtained using a scoring method to evaluate the expression level of programmed death ligand 1 (PD-L1) on tumor cells and tumor associated immune cells for patients being considered for Immune Checkpoint Inhibitor (ICI) therapy. CPS is the ratio of the number of all PD-L1 expressing cells (tumor cells, lymphocytes, macrophages) to the number of all tumor cells. vCPS, visually estimated Combined Positive Score, is a type of CPS and is based on a visual estimation of PD-L1 expression on tumor and immune cells. In a further embodiment, the subject being treated for locally advanced or metastatic esophagogastric cancer (e.g., GEJ cancer or gastric cancer) has a CPS of less than 5. In a specific aspect, the CPS is a vCPS (visual CPS) and is less than 5. The methodologies are summarized below. Those of skill in the art would consider the analysis by CPS and vCPS interchangeable.

[0060] In a further embodiment, the subject’s tumor (subject suffering from esophagogastric cancer) has increased levels of DKK1 expression, as determined by one or more of the various standard mRNA or protein detection methods known in the art, e.g., in situ hybridization, immunohistochemistry, qPCR, RNA-Seq and NanoString.

[0061] H-score and % Positive Values (also referred to herein as DKK1 Tumor Percentage Score (TPS)

[0062] The level of expression of a gene product of interest, e.g., the expression of DKK1, can be evaluated by methods of immunohistochemistry or in situ hybridization techniques. Convenient semiquantitative measures of the level of expression are computing % positive value (% of tumor cells stained by DKK-1 RNA detecting reagent) or assigning an “H-score” (or “histo” score) to tumor samples. For H-score, a staining intensity (0, 1+, 2+, or 3+) is determined for each cell in a fixed field. For in situ hybridization techniques the number of dots for each cell can be determined where 0 is no detected dots per cell, 1+ is 1-3 dots per cell, 2+ is 4-9 dots per cell and 3+ is 10+ dots per cell. The H-score may then be based on a predominant staining intensity (or dot number per cell), or more complexly, can include the sum of individual percentages for each intensity (or dot number per cell) level seen. By one method, the percentage of cells at each staining intensity (or dot number per cell) level is calculated, and finally, an H-score is assigned using the following formula:

H-score = [1 × (% cells 1+) + 2 x (% cells 2+) + 3 x (% cells 3+)]

[0063] The final H-score, ranging from 0 to 300, gives more relative weight to higher- intensity or amount of staining (e.g., dots per cell) in any given tumor sample. The sample can then be considered positive or negative on the basis of a specific discriminatory threshold. See, for example, Hirsch FR, Varella-Garcia M, Bunn PA Jr, et al. Epidermal growth factor receptor in non-small-cell lung carcinomas: Correlation between gene copy number and protein expression and impact on prognosis. J Clin Oncol 21 :3798-3807, 2003; and John T, Liu G, Tsao M-S: Overview of molecular testing in non-small-cell lung cancer: Mutational analysis, gene copy number, protein expression and other biomarkers of EGFR for the prediction of response to tyrosine kinase inhibitors. Oncogene 28:S14-S23, 2009.

[0064] In various embodiments, an H-score (e.g., a predetermined value of the H-score) can be from 0 to 300, for example, 20 to 100, or 20 to 50. Example of predetermined values of H-score are: 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100. In alternative example embodiments, predetermined values of H-score are: 10 or greater, 20 or greater, 30 or greater, 40 or greater, 50 or greater, 60 or greater, 70 of greater, 80 or greater, or 90 or greater. In certain embodiments, the predetermined value of H-score is: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,

28, 29, 30, 31, 32, 33, 34, 35, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,

51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74,

75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98,

99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,

135, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151,

152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169,

170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205,

206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,

224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 235, 236, 237, 238, 239, 240,

241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258,

259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276,

277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294,

295, 296, 297, 298, 299, or 300.

[0065] In alternative embodiments, the measure of DKK1 expression can be a value of the fraction of tumor cells that stain positive for DKK1 (% positive). First a staining amount (0, 1+, 2+, or 3+), based on number of dots in the cell, is determined for each tumor cell in a fixed field. After all neoplastic cells were assigned as “positive,” (detecting at least one single staining dot for RNAscope in situ hybridization), the percentage of positive tumor cells is determined by adding up the total neoplastic cells with staining and dividing by the total number of neoplastic cells. % Positive can range from 0 to 100. % Positive is also referred to herein as Tumor Percentage Score (TPS).

[0066] In various embodiments, % Positive value, (e.g., a predetermined value of % positive) can be from 15% to 50%, for example from 20% to 40%, or 20% to 25%. Example predetermined values of % Positive or TPS are: 15% or greater, 20% or greater, 25% or greater, 30% or greater, 35% or greater, 40% or greater, 45% or greater, or 50% of greater. In certain embodiments, the predertmined value of % positive or TPS is: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,

30, 31, 32, 33, 34, 35, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,

53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,

77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or

100%.

[0067] RNAscope Analysis

[0068] One of the methods of computing an H-score of a sample is an RNAscope® in situ hybridization technique developed by and commercially available from Advanced Cell Diagnostics, Inc., as described, for example, at the URL https://acdbio.com/ and from Flagship Biosciences, Broomfield, CO. This technique relies on an optical signal from a hybridization probe cognate to the mRNA of interest. The signal can be detected either by a bright-field or epifluorescent microscopy. The technique permits detection of a single molecule. See, for example, RNAscope: A Novel In Situ RNA Analysis Platform for Formalin-Fixed Paraffin-Embedded Tissues. Wang F., Flanagan J, Su N, Wang LC, Bui S, Nielson A, Wu X, Vo HT, Ma XJ, Luo Y (2012). J of Mol Diagnostics, 14(l):22-29.

DKK1 AND DKK1 ANTIBODIES

[0069] Dickkopf-1 (DKK1) is a secreted modulator of Wnt signaling pathways, which influences a number of biological processes such as stem cell maintenance, cell fate decisions, cell proliferation, survival, migration and polarity determination during development and adult tissue homeostasis. DKK1 has been most extensively characterized as an inhibitor of canonical Wnt/beta-catenin dependent signaling and this has been associated with contributing to an immune suppressive tumor microenvironment. DKK1 has also been implicated in promoting tumor growth and metastasis through activation of noncanonical (beta-catenin independent Wnt signaling) and PI3K/AKT signaling pathways. DKK1 also regulates bone homeostasis during development and in adult organisms. DKK1 inhibits osteoblastogenesis, or the differentiation of mesechymal stem cells to osteoblasts (OB), a process promoted by Wnt signaling. As a result, the OB (bone formation)/osteoclast (OC) (bone resorption) equilibrium is shifted toward increased bone resorption, eventually resulting in osteolytic lesions. Certain tumors are associated with the development of osteolytic bone disease mediated by increased OC bone resorption and impaired OB bone formation.

[0070] In a further embodiment, the esophagogastric cancer has increased levels of DKK1 expression, as determined by one or more of the various standard mRNA or protein detection methods known in the art, e.g., in situ hybridzidation or immunohistochemistry. [0071] DKK1 antibodies have been described previously (see, e.g., U.S. Patent Nos. 8,148,498, incorporated by reference herein in its entirety). The present DKK1 antibodies of the disclosure are therapeutically useful DKK1 antagonists possessing a number of desirable properties. For example, the DKK1 antibodies reduce DKK1 mediated inhibition of alkaline phosphatase, a marker or osteoblast activity, as well as treat various types of cancer (e.g., non-small cell lung cancer).

[0072] A full-length antibody as it exists naturally is an immunoglobulin molecule comprising 2 heavy (H) chains and 2 light (L) chains interconnected by disulfide bonds. The amino terminal portion of each chain includes a variable region of about 100-110 amino acids primarily responsible for antigen recognition via the complementarity determining regions (CDRs) contained therein. The carboxy-terminal portion of each chain defines a constant region primarily responsible for effector function.

[0073] The CDRs are interspersed with regions that are more conserved, termed framework regions ("FR"). Each light chain variable region (LCVR) and heavy chain variable region (HCVR) is composed of 3 CDRs and 4 FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The 3 CDRs of the light chain are referred to as "LCDR1, LCDR2, and LCDR3" and the 3 CDRs of the heavy chain are referred to as "HCDR1, HCDR2, and HCDR3." The CDRs contain most of the residues which form specific interactions with the antigen. The numbering and positioning of CDR amino acid residues within the LCVR and HCVR regions is in accordance with the well-known Kabat numbering convention.

[0074] Light chains are classified as kappa or lambda, and are characterized by a particular constant region as known in the art. Heavy chains are classified as gamma, mu, alpha, delta, or epsilon, and define the isotype of an antibody as IgG, IgM, IgA, IgD, or IgE, respectively. IgG antibodies can be further divided into subclasses, e.g., IgGl, IgG2, IgG3, IgG4. Each heavy chain type is characterized by a particular constant region with a sequence well known in the art.

[0075] As used herein, the term "monoclonal antibody" (Mab) refers to an antibody that is derived from a single copy or clone including, for example, any eukaryotic, prokaryotic, or phage clone, and not the method by which it is produced. Mabs of the present invention preferably exist in a homogeneous or substantially homogeneous population. Complete Mabs contain 2 heavy chains and 2 light chains.

[0076] Unless specified otherwise, the term “DKK1 antibody” encompasses both a full- length antibody as well as an antigen binding-fragment of the DKK1 antibody.

[0077] "Antigen-binding fragments" of such monoclonal antibodies include, for example, Fab fragments, Fab' fragments, F(ab')2 fragments, and single chain Fv fragments as well as bispecific and/or multivalent antibodies that may utilize the DKK1 antibody CDRs. Monoclonal antibodies and antigen-binding fragments thereof can be produced, for example, by recombinant technologies, phage display technologies, synthetic technologies, e.g., CDR-grafting, or combinations of such technologies, or other technologies known in the art. For example, mice can be immunized with human DKK1 or fragments thereof, the resulting antibodies can be recovered and purified, and determination of whether they possess binding and functional properties similar to or the same as the antibody compounds disclosed herein can be assessed by the methods known in the art. Antigen-binding fragments can also be prepared by conventional methods. Methods for producing and purifying antibodies and antigen-binding fragments are well known in the art and can be found, for example, in Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., chapters 5-8 and 15, ISBN 0- 87969-314-2.

[0078] Monoclonal DKK1 antibodies disclosed herein are engineered to comprise framework regions that are substantially human or fully human surrounding CDRs derived from a non-human antibody. "Antigen-binding fragments" of such human engineered antibodies include, for example, Fab fragments, Fab' fragments, F(ab')2 fragments, and single chain Fv fragments. "Framework region" or "framework sequence" refers to any one of framework regions 1 to 4. Human engineered antibodies and antigen-binding fragments thereof encompassed by the antibodies disclosed herein include molecules wherein any one or more of framework regions 1 to 4 is substantially or fully human, i.e., wherein any of the possible combinations of individual substantially or fully human framework regions 1 to 4, is present. For example, this includes molecules in which framework region 1 and framework region 2, framework region 1 and framework region 3, framework region 1, 2, and 3, etc., are substantially or fully human. Substantially human frameworks are those that have at least about 80% sequence identity to a known human germline framework sequence. Preferably, the substantially human frameworks have at least about 85%, about 90%, about 95%, or about 99% sequence identity to a known human germline framework sequence.

[0079] Human engineered antibodies in addition to those disclosed herein exhibiting similar functional properties can be generated using several different methods. The specific antibody compounds disclosed herein can be used as templates or parent antibody compounds to prepare additional antibody compounds. In one approach, the parent antibody compound CDRs are grafted into a human framework that has a high sequence identity with the parent antibody compound framework. The sequence identity of the new framework will generally be at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 99% identical to the sequence of the corresponding framework in the parent antibody compound. This grafting may result in a reduction in binding affinity compared to that of the parent antibody. If this is the case, the framework can be back-mutated to the parent framework at certain positions based on specific criteria disclosed by Queen et al. (1991) Proc. Natl. Acad. Sci. USA 88:2869. Additional references describing methods useful in humanizing mouse antibodies include U.S. Pat. Nos.

4,816,397; 5,225,539, and 5,693,761; computer programs ABMOD and ENCAD as described in Levitt (1983) J. Mol. Biol. 168:595-620; and the method of Winter and co- workers (Jones et al. (1986) Nature 321 :522-525; Riechmann et al. (1988) Nature 332:323- 327; and Verhoeyen et al. (1988) Science 239:1534-1536). Methods for identifying residues to consider for back-mutation are known in the art (see, e.g., U.S. Patent No. 8,148,498).

[0080] The DKK1 antibody administered in the method of treatment described herein comprises a light chain variable region (LCVR) and a heavy chain variable region (HCVR), wherein the LCVR comprises complementarity determining regions (CDRs) LCDR1, LCDR2, and LCDR3 and the HCVR comprises CDRs HCDR1, HCDR2 and HCDR3. [0081] In one embodiment, the DKK1 antibody comprises a LCDR1 having the amino sequence of SEQ ID NO: 1, LCDR2 having the amino sequence of SEQ ID NO:2, LCDR3 having the amino sequence of SEQ ID NO:3, HCDR1 having the amino sequence of SEQ ID NO:4, HCDR2 having the amino sequence of SEQ ID NO:5, and HCDR3 having the amino sequence of SEQ ID NO:6.

[0082] In another embodiment, the DKK1 antibody comprises a LCVR having the amino acid sequence of SEQ ID NO: 7 and a HCVR having the amino acid sequence of SEQ ID NO: 8. In a particular embodiment, the LCVR comprises the amino acid sequence of SEQ ID NO: 11 and the HCVR comprises the amino acid sequence of SEQ ID NO: 12. [0083] In further embodiments, the DKK1 antibody comprises a heavy chain (HC) having the amino acid sequence of SEQ ID NO: 17 and a light chain (LC) having the amino acid sequence of SEQ ID NO: 18. The DKK1 antibody or antigen binding-fragment thereof comprising the HC and LC amino acid sequence of SEQ ID NO: 17 and SEQ ID NO: 18, respectively, is referred to herein as DKN-01. In particular, DKN-01 has the molecular/empirical formula C₆₃₉₄ H₉₈₁₀ N₁₆₉₈ O₂₀₁₂ S₄₂ and a molecular weight of 144015 Daltons (intact).

[0084] In certain embodiments, the DKK1 antibody disclosed herein is an IgG₄ antibody with a neutralizing activity against human DKK1 comprising the sequence set forth in SEQ ID NO: 22, or a fragment thereof. For example, canonical Wnt signaling is important for osteoblast differentiation and activity. Wnt-3a combined with BMP-4 induces multipotent mouse C2C12 cells to differentiate into osteoblasts with a measurable endpoint of alkaline phosphatase ("AP"), a marker of osteoblast activity. DKK1, an inhibitor of canonical Wnt signaling, inhibits the differentiation and production of AP. Neutralizing DKK1 antibodies prevent DKK1-mediated inhibition of AP. Antibodies which block DKK1 inhibitory activity prevent the loss of AP activity (see U.S. Patent No. 8,148,498). In a particular embodiment, the DKK1 antibody possessing neutralizing activity is DKN- 01, which is an IgG4 antibody.

[0085] The DKK1 antibodies disclosed herein possess high affinity (Kd) to DKK1 (e.g., human DKK1, SEQ ID NO: 22), as described in U.S. Patent No. 8,148,498. For example, the present DKK1 antibodies possess a Kd of between 0.5xl0'¹² M and 3.0xl0^-11 M, at 37 °C.

[0086] TISLELIZUMAB

[0087] Tislelizumab (also referred to as BGB-A317) is a humanized IgG4 anti-PD-1 monoclonal antibody (mAb) with high affinity and specificity for PD-1 that was engineered to minimize binding to FcγR on macrophages to greatly reduce antibodydependent phagocytosis, a potential mechanism of T-cell clearance and resistance to anti-PD-1 therapy.

[0088] Tislelizumab was designed to bind to PD-1, a cell surface receptor that plays an important role in allowing tumor cells to evade the immune system. Many types of cancer cells have hijacked the PD-L1 expression system that normally exists in healthy cells. By expressing PD-L1, cancer cells can interact with PD-1 expressing cytotoxic T-lymphocytes, or CTLs and protect themselves from being killed by these CTLs. Tislelizumab can potentially restore the ability of CTLs to kill cancer cells by binding to PD-1, without activating the receptor, thereby preventing PD-L1 from engaging PD-1.

[0089] The tislelizumab administered in the method of treatment described herein comprises a light chain variable region (LCVR) and a heavy chain variable region (HCVR), wherein the LCVR comprises complementarity determining regions (CDRs) LCDR1, LCDR2, and LCDR3 and the HCVR comprises CDRs HCDR1, HCDR2 and HCDR3, [0090] In one embodiment, tislelizumab comprises a heavy chain (HC) having the amino acid sequence of SEQ ID NO: 23 and a light chain (LC) having the amino acid sequence of SEQ ID NO: 24. In particular, tislelizumab has the molecular/empirical formula C64io H9916 N1698-86 O2009 S40 and a molecular weight of 144024.0108 Daltons.

[0091] In another embodiment, tislelizumab comprises a HCDR1 having the amino sequence of SEQ ID NO:25, HCDR2 having the amino sequence of SEQ ID NO:26, HCDR3 having the amino sequence of SEQ ID NO:27, LCDR1 having the amino sequence of SEQ ID NO:28, LCDR2 having the amino sequence of SEQ ID NO:29, and LCDR3 having the amino sequence of SEQ ID NO:30.

[0092] The amino acid sequence and other relevant information relating to tislelizumab can be found in US Patent No. 8,735,553, the entire contents of which is hereby incorporated by reference.

SEQUENCES

[0093] The following are sequences of the DKN-01 antibody that can be employed in the practice of the various example embodiments described herein.

The following are sequences of the tislelizumab that can be employed in the practice of the various example embodiments described herein. [00138] The following are sequences of the tislelizumab that can be employed in the practice of the various example embodiments described herein.

CHEMOTHERAPEUTIC AGENTS

[00155] Many different kinds of chemotherapy or chemo drugs are used to treat cancer - either alone or in combination with other drugs or treatments. These drugs are very different in their chemical composition (what they are made of), how they are prescribed and given, how useful they are in treating certain types of cancer, and the side effects they might have. [00156] Not all medicines and drugs to treat cancer work the same way. Other drugs to treat cancer, such as targeted therapy, hormone therapy, and immunotherapy work differently than traditional or standard chemotherapeutic agents. The chemotherapeutic agents used in the method of treatment described herein are traditional or standard chemotherapeutics agents and are not targeted therapy, hormone therapy or immunotherapy (e.g., biologies).

[00157] Chemotherapy drugs can target cells at different phases of the cell cycle. Chemotherapy drugs can be grouped by how they work, their chemical structure, and their relationships to other drugs. Some drugs work in more than one way, and may belong to more than one group.

[00158] Alkylating agents keep the cell from proliferating by damaging its DNA. Examples of alkylating agents for use as the at least one chemotherapeutic agent of the method described herein include: Altretamine; Bendamustine; Busulfan; Carboplatin;

Carmustine; Chlorambucil; Cisplatin; Cyclophosphamide; Dacarbazine; Ifosfamide; Lomustine; Mechlorethamine; Melphalan; Oxaliplatin; Temozolomide;Thiotepa; and Trabectedin.

[00159] Antimetabolites interfere with DNA and RNA by acting as a substitute for the normal building blocks of RNA and DNA. When this happens, the DNA cannot make copies of itself, and a cell cannot divide. Examples of antimetabolites for use as the at least one chemotherapeutic agent of the method described herein include withouth limitation: Azacitidine; 5-fluorouracil (5-FU); 6-mercaptopurine (6-MP); Capecitabine; Cladribine; Clofarabine; Cytarabine (Ara-C); Decitabine; Floxuridine; Fludarabine; Gemcitabine, Hydroxyurea; Methotrexate; Nelarabine; Pemetrexed; Pentostatin; Pralatrexate;

Thioguanine; and Trifluridine/tipiracil combination.

[00160] Anthracyclines are anti-tumor antibiotics that interfere with enzymes involved in copying DNA during the cell cycle. They bind with DNA so it cannot make copies of itself, and a cell cannot divide. Examples of anthracyclines for use as the at least one chemotherapeutic agent of the method described herein include without limitation: Daunorubicin; Doxorubicin, Doxorubicin liposomal; Epirubicin; Idarubicin; and Valrubicin.

Anti-tumor antibiotics that are not anthracyclines include without limitation: Bleomycin; Dactinomycin; Mitomycin-C; and Mitoxantrone. [00161] Topoisomerase inhibitors are drugs that interfere with enzymes called topoisomerases. Topoisomerase I inhibitors (also called camptothecins) include without limitation: Irinotecan; Irinotecan liposomal; and Topotecan. Topoisomerase II inhibitors (also called epipoclophyllotoxins) include without limitation: Etoposide (VP-16);

Mitoxantrone (also acts as an anti-tumor antibiotic): and Teniposide.

[00162] Mitotic inhibitors include taxanes and vinca alkaloids. Taxanes include without limitation: Cabazitaxel; Docetaxel; Nab-paclitaxel; and Paclitaxel. Vinca alkaloids include without limitation: Vinblastine; Vincristine; Vincristine liposomal; and Vinorelbine.

[00163] Some chemotherapy drugs do not fit well into any of the listed categories. Examples include: All-trans-retinoic acid; Arsenic trioxide; Asparaginase; Eribulin; Hydroxyurea; Ixabepilone; Mitotane; Omacetaxine; Pegaspargase; Procarbazine; Romidepsin; and Vorinostat.

[00164] In a specific embodiment, chemotherapeutic agents that can be used to treat esophagogastric cancer include: 5-FU (fluorouracil), often given along with leucovorin (folinic acid); Capecitabine; Carboplatin; Cisplatin; Docetaxel; Epirubicin; Irinotecan; Oxaliplatin; Paclitaxel; and Trifluridine and Tipiracil, a combination drug in pill form.

[00165] In a particular embodiment, a combination of chemotherapeutic agents are administered in accordance with the method described herein. Such combinations include: Oxaliplatin plus 5-FU/leucovorin (FOLFOX); oxaliplatin plus capecitabine (CAPOX, also referred to herein as XELOX); FLOT (5-FU/leucovorin, oxaliplatin, and docetaxel);

Docetaxel or paclitaxel plus either 5-FU or capecitabine; Cisplatin plus either 5-FU or capecitabine; Paclitaxel and carboplatin; Irinotecan plus 5-FU/leucovorin (FOLFIRI); Paclitaxel plus either cisplatin or carboplatin; Docetaxel plus cisplatin; Epirubicin, either cisplatin or oxaliplatin, and either 5-FU or capecitabine; and Docetaxel, 5-FU, and either cisplatin, carboplatin, or oxaliplatin.

[00166] In a specific embodiment, the one of more second therapeutics agents for use in the method of treating esophagogastric cancer is C APOX, FOLFOX, FLOT or FOLFIRI. In a very specific ebmodiment, the one of more second therapeutic agents for use in the method of treating esophagogastric cancer is CAPOX.

ADMINISTRATION AND DOSING

Modes of Administration [00167] The DKK1 antibody and tislelizumab and the one or more chemotherapeutic agents used in the combination described herein (i.e., the components of the combination therapy) can be formulated separately or in combination, and can be co-administered either separately or toghether, for parenteral, oral, transdermal, sublingual, buccal, rectal, intranasal, intrabronchial or intrapulmonary administration.

[00168] For parenteral administration, one or more of the components of the combination therapy (e.g., DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) for use in the methods or compositions of the invention can be formulated for injection or infusion, for example, intravenous, intramuscular or subcutaneous injection or infusion, or for administration in a bolus dose and/or infusion (e.g., continuous infusion). Suspensions, solutions or emulsions in an oily or aqueous vehicle, optionally containing other formulatory agents such as suspending, stabilizing and/or dispersing agents can be used.

[00169] For oral administration one or more of the components of the combination therapy (e.g., DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) can be in the form of tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., polyvinylpyrrolidone or hydroxypropylmethylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrates (e.g., sodium starch glycollate); or wetting agents (e.g., sodium lauryl sulphate). If desired, the tablets can be coated using suitable methods. Liquid preparation for oral administration can be in the form of solutions, syrups or suspensions. The liquid preparations can be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agent (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters or ethyl alcohol); and preservatives (e.g., methyl or propyl p-hydroxy benzoates or sorbic acid).

[00170] For buccal administration, one or more of the components of the combination therapy (e.g., DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) for use in the methods or compositions of the invention can be in the form of tablets or lozenges formulated in a conventional manner.

[00171] For rectal administration, one or more of the components of the combination therapy (e.g., DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) for use in the methods or compositions of the invention can be in the form of suppositories. [00172] For sublingual administration, tablets can be formulated in conventional manner. [00173] For intranasal, intrabronchial or intrapulmonary administration, conventional formulations can be employed.

[00174] Further, one or more of the components of the combination therapy (e.g., DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) for use in the methods or compositions of the invention can be formulated in a sustained release preparation. For example, the one or more of the components can be formulated with a suitable polymer or hydrophobic material which provides sustained and/or controlled release properties to the active agent compound. As such, one or more components of the combination therapy for use in the method of the invention can be administered in the form of microparticles, for example, by injection or in the form of wafers or discs by implantation. Various methods of formulating controlled release drug preparations are known in the art.

[00175] Administration of one or more components of the combination therapy, or a pharmaceutically acceptable salt thereof, or a composition comprising one or more components of the combination therapy (or pharmaceutical salt thereof) of the invention useful to practice the methods described herein, can be continuous, hourly, four times daily, three time daily, twice daily, once daily, once every other day, twice weekly, once weekly, once every two weeks, once a month, or once every two months, or longer, or some other intermittent dosing regimen.

Combination Therapy

[00176] As used herein, “coadministration”, "in combination with" or "in conjunction with" refers to administration of one treatment modality in addition to at least one other treatment modality. As such, "in combination with" or "in conjunction with" refers to administration of one treatment modality before, during, or after administration of at least one other treatment modality to the individual. In a particular embodiment, coadministration includes receiving the DKN-01 antibody and the tislelizumab together in the same or different IV lines with their individual formulations.

[00177] The DKK1 antibody disclosed herein can be used for treating esophagogastric cancer in combination with tislelizumab and one or more chemotherapeutic agents. Such combination administration can be by means of a single dosage form which includes a DKK1 antibody, tislelizumab and one or more chemotherapeutic agents, such single dosage form including a tablet, capsule, spray, inhalation powder, injectable liquid or the like. Alternatively, combination administration can be by means of administration of different dosage forms, with one dosage form containing a DKK1 antibody, another dosage form including tislelizumab and yet another dosage form including the one more chemotherapeutic agents (if more than one chemotherapeutic agent is use it is understood that these agents can be administered using the same or different dosage forms).

[00178] The components of the combination therapy can be administered in any order. For example, tislelizumab can be administered before, simultaneously with, or after the administration of a DKK1 antibody and before, simultaneously with, or after the administration of the one or more chemotherapeutic agents. Accordingly, the components of the combination therapy can be administered together in a single formulation or can be administered in separate formulations, e.g., either simultaneously or sequentially, or both. For example, if a DKK1 antibody and tislelizumab are administered sequentially in separate compositions, the DKK1 antibody can be administered before or after tislelizumab. The duration of time between the administration of the components of the combination therapy will be easily determined by the administering physician.

[00179] Further, the components of the combination therapy may or may not be administered on similar dosing schedules. For example, the DKK1 antibody and tislelizumab may have different half-lives and/or act on different time-scales such that the DKK1 antibody is administered with greater frequency than tislelizumab or vice-versa. For example, the DKK1 antibody and tislelizumab can be administered together (e.g., in a single dosage or sequentially) on one day, followed by administration of only the one or more chemotherapeutic agents a set number of days later. The number of days in between administration of components of the combination therapy can be appropriately determined according to the safety and pharmacodynamics of each drug.

[00180] In a particular embodiment, the treatment period for the combination treatment is a 21 -Day cycle which can be repeated until the patient is determined to not be gaining any clinical benefit from the combination therapy. For example, the patient can undergo from about one cycle to about 30 cycles of treatment (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 7, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30).

[00181] As used herein, an “effective amount” refers to an amount of the combination of therapeutic agents that is therapeutically or prophylactically sufficient to treat the target disorder. An effective amount will depend on the age, gender, and weight of the patient, the current medical condition of the patient, and the nature of the esophagogastric cancer being treated. Those of skill in the art will be able to determine appropriate dosages depending on these and other factors.

[00182] Suitable doses per administration for a DKK1 antibody include doses of about or greater than about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 100 mg, about 200 mg, about 300 mg, about 400 mg, about 500 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, about 750 mg, about 775 mg, about 800 mg, about 825 mg, about 850 mg, about 875 mg, about 900 mg, about 925 mg, about 950 mg, about 975 mg, about 1000 mg, about 1025 mg, about 1050 mg, about

1075 mg, about 1100 mg, about 1125 mg, about 1150 mg, about 1175 mg, about 1200 mg, about 1225 mg, about 1250 mg, about 1275 mg, about 1300 mg, about 1325 mg, about 1350 mg, about 1375 mg, about 1400 mg, about 1425 mg, about 1450 mg, about 1475 mg, about 1500 mg, about 1525 mg, about 1550 mg, about 1575 mg, about 1600 mg, about 1625 mg, about 1650 mg, about 1675 mg, about 1700 mg, about 1725 mg, about 1750 mg, about 1775 mg, about 1800 mg, about 1825 mg, about 1850 mg, about 1875 mg, about 1900 mg, about 1925 mg, about 1950 mg, about 1975 mg, about 2000 mg, about 2025 mg, about 2050 mg, about 2075 mg, about 2100 mg, about 2125 mg, about 2150 mg, about 2175 mg, about 2200 mg, about 2225 mg, about 2250 mg, about 2275 mg, about 2300 mg, about 2325 mg, about 2350 mg, about 2375 mg, about 2400 mg, about 2425 mg, about 2450 mg, about 2475 mg, about 2500 mg, about 2525 mg, about 2550 mg, about 2575 mg, about 2600 mg, or about 3,000 mg. Each suitable dose can be administered over a period time deemed appropriate by a skilled practitioner. For example, each suitable dose can be administered over a period of about 30 minutes and up to about 1 hour, about 2 hours, about 3, hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, or about 8 hours. In a specific embodiment, a suitable does for the DKK1 antibody (e.g., DKN-01) can from about 50 mg to about 300 mg (such as 50 mg, 75 mg, 100 mg, 125 mg, 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, 275 mg or 300 mg). The selected dose can be administered intravenously over a period of about 30 minutes to about 2 hours. In a particular embodiment, a suitable dose for DKK1 antibody can be about 300 mg administered over a period of about 30 minutes and up to about 2 hours. Another suitable dose for the DKK1 antibody can be about 600 mg administered over a period of about 30 minutes and up to about 2 hours. Administration of these doses over the recited period of time can be accomplished using an intravenous route. For example, the DKK1 antibody (e.g., DKN-01) can be dosed on Days 1 and 15 of a 21 -day cycle and then repeated for every additional cycle.

[00183] Suitable doses per administration for tislelizumab can be determined based on the recommended dosing known for treatment. For example, a suitable dose per administration of tislelizumab is from about 20 mg to about 2000 mg intravenously. Such as from about 100 to 300 mg, for example about 200 mg. The administration can be over the necessary period of time to deliver the desired dose in a safe and effective manner. In some instances, the time is at least a 30 minute period, a 60 minute period, a 2 hour period, a 3 hour period etc. This administration can be repeated every three weeks (21 days). In a particular embodiment, a suitable dose per administration is about 200 mg using an intravenous route. This dose can be repeated every three weeks.

[00184] An effective amount can be achieved in the methods of the invention by coadministering the combination of an intitial amount of DKK1 antibody (or a pharmaceutically acceptable salt, hydrate or solvate thereof), an initial amount of tislelizumab and an initial amount of one or more chemotherapeutic agents. It is understood that the administration of the amount of chemotherapeutic agents can vary if more than one chemotherapeutic agent is included. In one embodiment, the components of the combination (e.g., a DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) are each administered in a respective effective amount (e.g., each in an amount which would be therapeutically effective if administered alone). In another embodiment, the components of the combination (e.g., a DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) are each administered in an amount which alone does not provide a therapeutic effect (a sub-therapeutic dose). In yet another embodiment, one or two components of the combination can be administered in an effective amount, while the remaining component is administered in a sub-therapeutic dose. For example, the DKK1 antibody can be administered in a sub-therapeutic dose, tislelizumab can be administered in an effective amount and the one or more therapeutic agents can be administered each at its effective amount. In yet another embodiment, the DKK1 antibody is DKN-01 and is administered at 300 mg, tislelizumab is administered at 200 mg, the one or more chemotherapeutic agents are oxaliplatin and capecitabine and are administered at 130 mg/m² and 1000 mg/m². In another embodiment, the DKK1 antibody is DKN-01 and is administered at 600 mg and tislelizumab is administered at 200 mg. [00185] In a specific embodiment DKN-01 is administered on Days 1 and 15 of a 21 -day cycle by IV infusion at about 300 mg, tislelizumab is administered on Day 1 of a 21-day cyles at about 200 mg by IV infusion, capecitabine is administered orally on Days 1-15 of a 21-day cycle, twice a day at about 1000 mg/m² and oxaliplatin is administered on Day 1 of a 21-day cycle by IV infusion at about 130 mg/m2.

[00186] In a further specific embodiment DKN-01 is administered on Days 1 and 15 of a 21-day cycle by IV infusion at about 600 mg, tislelizumab is administered on Day 1 of a 21-day cyles at about 200 mg by IV infusion, capecitabine is administered orally on Days 1-15 of a 21-day cycle, twice a day at about 1000 mg/m² and oxaliplatin is administered on Day 1 of a 21-day cycle by IV infusion at about 130 mg/m2.

[00187] As used herein, the term “subject” refers to a mammal, preferably a human, but can also mean an animal in need of veterinary treatment, e.g., companion animals (e.g., dogs, cats, and the like), farm animals (e.g., cows, sheep, pigs, horses, and the like) and laboratory animals (e.g., rats, mice, guinea pigs, and the like).

[00188] As used herein “treating” includes achieving, partially or substantially, delaying, inhibiting or preventing the progression of clinical indications related to the esophagogastric cancer. For example, “treating” includes reduction in tumor growth, or prevention of further growth, as detected by standard imaging methods known in the art, including, for example, computed tomography (CT) scan, magnetic resonance imaging (MRI), chest x-ray, and CT/positron emission tomography (CT/PET) scans, and evaluated according to guidelines and methods known in the art. For example, responses to treatment can be evaluted through the Response Evaluation Criteria in Solid Tumors (RECIST) (Revised RECIST Guideline version 1.1; see Eisenhauer et al., Eur.. J. Cancer 45(2):228- 47, 2009). Thus, in some embodiments, “treating” refers to a Complete Response (CR), which is defined according to the RECIST guideline as the disappearance of all target lesions, or a Partial Response (PR), which is defined as at least a 30% decrease in the sum of diameter of target lesions, taking as reference the baseline sum diameters. Other means for evaluating tumor response to treatment include evaluation of tumor markers and evaluation of performance status (e.g., assessment of creatinine clearance; see Cockcroft and Gault, Nephron. 16:31-41, 1976).

[00189] An "objective response" refers to a measurable response, including complete response (CR) or partial response (PR). In some embodiments, the term "objective response rate" (ORR) refers to the sum of complete response (CR) rate and partial response (PR) rate.

[00190] "Complete response" or "CR," as used herein, means the disappearance of all signs of cancer (e.g., disappearance of all target lesions) in response to treatment. This does not always mean the cancer has been cured.

[00191] As used herein, "partial response" or "PR" refers to a decrease in the size of one or more tumors or lesions, or in the extent of cancer in the body, in response to treatment.

[00192] For example, in some embodiments, PR refers to at least a 30% decrease in the sum of the longest diameters (SLD) of target lesions, taking as reference the baseline SLD.

[00193] As used herein, "progressive disease" or "PD" refers to at least a 20% increase in the SLD of target lesions, taking as reference the smallest SLD recorded since the treatment started or the presence of one or more new lesions.

[00194] As used herein, "progression free survival" or "PFS" refers to the length of time during and after treatment during which the disease being treated (e.g., cancer) does not get worse. Progression-free survival may include the amount of time patients have experienced a complete response or a partial response, as well as the amount of time patients have experienced stable disease.

[00195] As used herein, "overall response rate" (ORR) refers to the sum of complete response (CR) rate and partial response (PR) rate.

[00196] As used herein, "overall survival" refers to the percentage of individuals in a group who are likely to be alive after a particular duration of time.

[00197] " Sustained response" refers to the sustained effect on reducing tumor growth after cessation of a treatment. For example, the tumor size may be the same size or smaller as compared to the size at the beginning of the medicament administration phase. In some embodiments, the sustained response has a duration of at least the same as the treatment duration, at least 1.5x, 2x, 2.5x, or 3x length of the treatment duration, or longer.

[00198] "Duration of Response" for purposes of the present invention means the time from documentation of tumor model growth inhibition due to drug treatment to the time of acquisition of a restored growth rate similar to pretreatment growth rate.

[00199] Pharmaceutical Composition [00200] The components of the combination therapy (e.g., the DKK1 antibody, tiselizumab and one or more chemotherapeutic agents) can be incorporated into pharmaceutical compositions suitable for administration. Such compositions typically comprise the DKK1 antibody, or tislelizumab and one or more chemotherapeutic agents, separate or together in any combination, and a pharmaceutically acceptable carrier. As used herein the language "pharmaceutically acceptable carrier" is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the compositions is contemplated.

[00201] A pharmaceutical composition of the invention is formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral, e.g., intravenous, intradermal, subcutaneous, oral (e.g., inhalation), transdermal (topical), transmucosal, and rectal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

[00202] Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EL(TM) (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). In all cases, the composition must be sterile and should be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.

[00203] Sterile injectable solutions can be prepared by incorporating the combination (e.g., a DKK1 antibody, tislelizumab and one or more chemotherapeutic agents) in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

[00204] Oral compositions generally include an inert diluent or an edible carrier. They can be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules. Oral compositions can also be prepared using a fluid carrier for use as a mouthwash, wherein the compound in the fluid carrier is applied orally and swished and expectorated or swallowed. Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring. [00205] For administration by inhalation, the compounds are delivered in the form of an aerosol spray from pressured container or dispenser which contains a suitable propellant, e.g., a gas such as carbon dioxide, or a nebulizer.

[00206] Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid- derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories.

[00207] For transdermal administration, the active compounds are formulated into ointments, salves, gels, or creams as generally known in the art.

[00208] The compounds can also be prepared in the form of suppositories (e.g., with conventional suppository bases such as cocoa butter and other glycerides) or retention enemas for rectal delivery.

[00209] In one embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially from Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in U.S. Pat. No. 4,522,811.

[00210] It is especially advantageous to formulate oral or parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and the limitations inherent in the art of compounding such an active compound for the treatment of individuals.

[00211] EXEMPLIFICATION SECTION

[00212] Description of Overall Study Design: The DisTinGuish Study (NCT04363801) is a Phase 2a nonrandomized, open-label, multicenter study to be conducted concurrently in 2 Parts (Parts A and B). Approximately 72 patients aged 18 years or older with inoperable, histologically confirmed locally advanced or metastatic G/GEJ adenocarcinoma with measurable disease (RECIST vl.l) requiring therapy will be enrolled in the study. Both parts are designed to evaluate safety, tolerability, and efficacy of the combination therapy of intravenous (IV) DKN-01 and tislelizumab ± CAPOX in G/GEJ adenocarcinoma patients. Treatment continues in repeating 21 -day cycles until patient meets criteria for discontinuation or is no longer deriving clinical benefit. Parts A and B will be enrolled concurrently. Two doses of DKN-01 will be evaluated in Part B (Part Bl and Part B2).

[00213] Part A (First Line Treatment) patients will receive IV DKN-01 (300 mg) on Days 1 and 15, IV tislelizumab (200 mg) on Day 1, IV oxaliplatin (130 mg/m2) on Day 1, and oral capecitabine (1000 mg/m2 twice daily [BID]) on Days 1-15 of each 21-day cycle. Part A is restricted to patients who have not had prior systemic therapy for locally advanced or metastatic disease. Patients may have received prior neoadjuvant or adjuvant therapy as long as it was completed without disease recurrence for at least 6 months.

[00214] Part Bl (Second Line Treatment) patients will receive IV DKN-01 (300 mg) on Days 1 and 15 and IV tislelizumab (200 mg) on Day 1 of each 21-day cycle. Patients enrolled in Part B are required to have DKK1-high (H-score ≥ 35) G/GEJ adenocarcinoma (pre-screen biopsy) and may have had only 1 prior systemic therapy for locally advanced/metastatic disease (platinum + fluoropyrimidine-based therapy; ±HER2 therapy if applicable). Patients may have received prior neoadjuvant or adjuvant therapy.

[00215] Part B2 (Second Line Treatment) patients will receive IV DKN-01 (600 mg) on Days 1 and 15 and IV tislelizumab (200 mg) on Day 1 of each 21-day cycle.

[00216] Patients enrolled in Part B are required to have DKK1-high (H-score ≥ 35) G/GEJ adenocarcinoma (pre-screen biopsy) and must have had only 1 prior systemic therapy for locally advanced/metastatic disease (platinum + fluoropyrimidine-based therapy; ±HER2 therapy if applicable). Patients may have received prior neoadjuvant or adjuvant therapy. [00217] PART A: Details of Study and Results

Design: Phase 2a study of DKN-01 + tislelizumab + capecitabine/oxaliplatin (CAPOX/XELOX) in advanced GEA (Gastroesophageal Adenocarcinoma) patients Tumoral DKK1 mRNA expression: assessed by a chromogenic in situ hybridization RNAscope assay and assigned an H-score (0-300) (Flagship Biosciences, Broomfield, CO; Advanced Cell Diagnostics, Newark, CA)

Primary efficacy endpoint: objective response rate (ORR)

Secondary efficacy endpoints: duration of response (DoR), disease control rate (DCR), progression- free survival (PFS) and overall survival (OS)

Analysis population: modified intent to treat (mITT) population (completed > 1 dose DKN-01)

Analysis by DKK1 expression: comparison between DKK1- high (H-score ≥35) and DKK 1 -1 ow group s

[00218] Graphical Depiction of Part A shown in Table 1 below:

TABLE 1

[00219] The breakdown of patients in Part A as of the second data cutoff is as shown below in Table 2:

TABLE 2

[00220] The breakdown of patients in Part A as of the third data cutoff is as shown below in Table 3:

TABLE 3

[00221] The breakdown of patients in Part B as of the second data cutoff is as shown below in Table 4:

TABLE 4

[00222] DEMOGRAPHIC ANC CLINCAL CHARACTERISTICS:

Table 5: As of the first data cutoff:

TABLE 5

[00223] Table 6: As of the second data cutoff for both Parts A and B (B1 and B2) TABLE 6

Disposition & Exposure

[00224] Table 7: As of the third data cutoff for Part A

TABLE 7:

Disposition and Exposure

[00225] DETERMINATION OF DKK1 EXPRESSION:

DKK1 Expression was determined using RNAscope and digital pathology as follows: Tumor specimens were stained for DKK1 expression and quantified using a digital image analysis algorithm (Flagship Biosciences (Broomfield, CO). An H-score was calculated by determining the percentage of tumor cells expressing low (1-3 dots per cell), medium (4-9 dots per cell) and high (10+ dots per cell) levels of DKK1 with the following formula. H- score = (%low)+2*(%medium)+3*(%high) . H-score range: 0 to 300. For one tumor specimen the H-score was determined by manual pathology and not the digital image analysis algorithm.

[00226] The DKK1 expression level is correlated with cancer type in Table 8 below for Part A of the Study as of the first data cutoff.

TABLE 8:

[00227] The DKK1 expression level is correlated with cancer type in Table 9 below for Part B of the Study (as of the second data cutoff). TABLE 9:

[00228] SUMMARY OF PATIENT DATA TABLE 10:

RESULTS:

[00229] Based on data available at the first data cutoff, all response evaluable DKK1- high (H-score ≥35) GC/GEJ had Partial Response, results are summarized as follows and shown in the table below: the mITT (modified Intention-to-Treat) population included 22 patients; the response evaluable (RE) mITT population was 21 patients; ORR (Objective Response Rate assessed with RECIST vl. l) in mITT was 68.2% (15 PR, 6 SD, 1 NE) and DCR (Disease Control Rate (patients with a CR, PR or SD)) was 95.5%; DKK1-high mITT ORR was 90%; and DKK1-low mITT ORR was 55.6%. Best Overall Response based on DKK1 Expression for response evaluable mITT population is shown in FIG. 1 and supported by the data in Table 11..

TABLE 11:

[00230] Based on data available at the second data cutoff, the Best Overall Response based on DKK1 Expression for response evaluable mITT population is shown in FIG. 8 and supported by the data in Table 12 below:

TABLE 12:

[00231] From the above table it can be seen that the mITT (modified Intention-to-Treat) population included 22 patients; the response evaluable (RE) mITT population was 21 patients; ORR (Objective Response Rate assessed with RECIST vl.l) in mITT was 68% including one complete response (CR) and 14 partial responses (PR); DKK1-high mITT ORR was 90%; and DKK1-low mITT ORR was 56%.

Based on data available at the third data cutoff, the Best Overall Response based on DKK1 Expression for response evaluable mITT population is shown in FIG. 15 and supported by the data Table 13 below. TABLE 13:

[00232] FIG. 2 shows the results depicted as durable response by DKK1 expression based on data available as of the first data cutoff.

[00233] FIG. 10 shows the results depicted as durability of clinical benefit (mITT, N=21) based on data available as of the second data cutoff (note addition of CR as compared to FIG. 2).

[00234] FIG. 16 shows the results depicted as durability of clinical benefit (mITT, N=21) based on data available as of the third data cutoff.

[00235] FIG. 3 shows the results of duration on trial by DKK1 expression based on data available as of the first data cutoff.

[00236] FIG. 4 is a graph showing that tumoral DKK1 expression predicts response to DKN-01 Therapy.

[00237] FIG. 5 is a graph showing best overall response by PD-L1 and DKK1 expression for study data as of the first data cutoff. Further analysis as set forth in the table below indicates that DKK1 high patients respond regardless of PD-L1 status. As shown in Table 14, activity was independent of PD-L1 expression with 79% ORR in PD-L1 low (vCPS<5) and 67% ORR PD-L1 high (vCPS≥5). There was a 100% ORR in DKK1-high, PD-L1-low patients (n=6) TABLE 14:

79% ORR in patients with PD-L1-low expression (CPS<5) 100% ORR in DKK1-high, PD-L1 low patients

67% ORR in patients with PD-L1 high expression (CPS ≥5) 75% ORR in DKK1-high, PD-L1 high patients

[00238] FIG. 9 is a graph showing best overall response by PD-L1 and DKK1 expression for study data as of the second data cutoff. Based on the data in FIG. 9, it can be seen that DKK1-high patients responded regardless of PD-L1 status (mITT): For PD-L1 -low expression (vCPS <5) 79% ORR in PD-L1-low patients and 100% ORR in DKK1-high, PD- Ll-low patients. For PD-L1 high expression (vCPS ≥ 5), 67% ORR in PD-L1 high patients and 75% ORR in DKK1-high, PD-L1 high patients.

[00239] FIG. 17 is a graph showing best overall response by PD-L1 and DKK1 expression for study data as of the third data cutoff. Based on the data in FIG. 17, it can be seen that DKK1-high patients responded regardless of PD-L1 status (mITT): For PD-L1 - low expression (vCPS <5) 79% (11/14) ORR in PD-L1-low patients and 100% (6/6) ORR in DKK1-high, PD-L1-low patients. For PD-L1 high expression (vCPS ≥ 5), 67% (4/6) ORR in PD-L1 high patients and 75% (3/4) ORR in DKK1-high, PD-L1 high patients.

[00240] FIG. 6 is a graph showing that durable response in the trial is independent of PD-L1 expression.

[00241] FIG. 7 is a plot showing that PD-L1 expression and DKK1 expression are not correlated. [00242] FIG. 11 is a graph showing the duration of response (responders, N=15). The median duration of response is 10.7 months in DKK1-high vs. 7.9 months in DKK1-low patients.

[00243] FIG. 12 is a graph showing Progression Free Survival (PFS) (ITT, N=25). The median PFS was 10.7 months: DKK1-high 11.9 months vs. DKK1-low 10.7 months. [00244] KEY FINDINGS

[00245] Twenty-five first-line patients were enrolled, and as of the first cut-off date for certain of the data provided herein, 15 patients had experienced a partial response (PR), six patients had a best response of stable disease (SD), one patient was non-evaluable for response (NE), and three patients were unable to complete a full cycle of DKN-01 therapy [non-modified ITT (mITT)]. Among the 21 patients that had RNAscope® DKK1 expression available, 12 were DKK1-high [9 PR, 1 NE, 2 non-mITT] and 9 were DKK1- low [5 PR, 4 SD], Among the 20 mITT patients that had PD-L1 expression available, 14 were PD-L1 low vCPS < 5 [11 PR, 3 SD] and 6 were PD-L1 high vCPS ≥ 5 [4 PR, 1 SD, 1 NE],

[00246] As of the second cut-off date, 1 patient had experienced a complete response (CR), 14 patients had experienced a partial response (PR), six patients had a best response of stable disease (SD), one patient was non-evaluable for response (NE) and three patients were unable to complete a full cycle of DKN-01 therapy [non-modified ITT (mITT)]. Among the 21 patients that had RNAscope® DKK1 expression available 12 were DKK1- high and 9 were DKK-1 low.

[00247] Among patients who received a full course of DKN-01 + Tislelizumab + chemotherapy treatment (based on second cutoff data and third cutoff data), the ORR was 68%, with 90% ORR in DKK1-high patients and 56% in DKK1-low patients. For advanced-stage ESCC, combination chemotherapy is typically given as first-line treatment. Treatment regimens commonly include a platinum agent (cisplatin or oxaliplatin) in combination with paclitaxel or 5-FU. The ORRs and median survival durations appear generally comparable across the various regimens. First-line chemotherapy has an ORR of 37%-58%, but the median DoR is only 4-7 months (Am. J Cancer Res 2016, 6:2345-50; BMC Cancer 2015; 15: 693; Int J Clin Oncol 2018;23: 466-72). First-line chemotherapy for advanced GC contains a platinum agent and a fluoropyrimidine. The ORR typically observed can range from approximately 25% to 75% with median DoR up to 4.8 months; median OS of approximately 9-13 months is typical (See, Lancet 2010;376:687-97; Lancet 2014;383:31-9; Int J Hematol Oncol Stem Cell Res 2016;10:212-6; Cancer Chemother Pharmacol 2008;61 :623-9; and J Clin Oncol 2008;26: 1435-42).

[00248] Within the G/GEJ adenocarcinoma cohort of a study involving Tislelizumab and chemotherpy, the ORR was 46.7% and the responses were durable (Xu et al., Clin Cancer Res 2020 (26) (17) 4542-4550). Thus, an ORR of 68.2% with 90% in DKK1-high shows an unexpected increase over baseline chemotherapy or PD1 antibody therapy in combination with chemotherapy.

[00249] In addition, response was independent of PD-L1 expression, and particularly strong in the less favorable to checkpoint inhibitor therapy, PD-L1 low (CPS < 5), population, for example based on the first cutoff data: a) Among those patients with PD-L1-low expression (vCPS < 5), the ORR was 79%, with 100% in DKK1-high patients and 57% in DKK1-low patients b) Among those patients with PD-L1-high expression (vCPS ≥ 5), the ORR was 67%, with 75% ORR in DKK1-high patients and 50% in DKK1-low patients c) DKK1 levels could not be determined in one patient; however, the patient’s PD-L1 level was determined to be low (vCPS score less than 1) and the patient achieved a partial response

[00250] Based on the second and third cutoff data, activity was also found to be independent of PD-L1 expression: a) 79% ORR in PD-L 1 -low (vCPS < 5) and 67% ORR PD-L 1 -high (vCPS ≥ 5) patients. b) 100% ORR in DKK1-high, PD-L1-low patients (n=6)

[00251] FIG. 18 shows Progression-free Survival (PFS) by DKK1 Expression (ITT, N=25). The overall progression free survival for first line patients treated with DKN-01 + Tislelizumab + CAPOX was 11.3 months which is a substantial improvement over 7.7 months for the current standard of care first-line therapy (chemotherapy + nivolumab, See OPDIVO (nivolumab) injection prescribing information, Bristol -Myers Squibb Company, August 2021). DKK1 high and DKK1 low patients had a similar median PFS of 11.3 and 12.0 months, respectively. Given that DKK1 high patients have a much poorer prognosis than DKK1 low patients, this data indicates that DKN-01 is improving the PFS for DKK1 high patients. [00252] FIG. 20 shows Overall Survival by DKK1 Expression (ITT, N=25). While the overall survival (OS) data is not yet mature, the current data indicates that there will be an improvement over the OS of 13.8 months for standard of care first-line therapy (chemotherapy + nivolumab, See OPDIVO (nivolumab) injection prescribing information, Bristol -Myers Squibb Company, August 2021) for the overall population and the DKK1 high and DKK1 low subgroups.

[00253] FIG. 19 shows Progression-free Survival by PD-L1 Expression (ITT, N=25). The PFS for vCPS-low (<5) and vCPS-high (≥5) is 10.7 and 11.6 months, respectively. Data indicates that PD-L1 expression levels are not substantially affecting PFS.

[00254] DisTinGuish Trial Part C

[00255] Part C, like Parts A and B described above, is a Phase 2 open-label multicenter study. Part C will enroll G/GEJ adenocarcinoma patients who have received no prior systemic treatment in the locally advanced/metastatic setting (first-line treatment). Part C is the open-label, randomized, controlled, 2-arm portion of the study to evaluate the efficacy and safety of tislelizumab + chemotherapy regimen (CAPOX or mFOLFOX6) +/- DKN-01 in adult patients with inoperable, histologically confirmed locally advanced or metastatic G/GEJ adenocarcinoma with measurable disease (RECIST vl.l) requiring therapy. Approximately 160 patients will be randomized in a 1 : 1 ratio to receive either DKN-01 in combination with tislelizumab and chemotherapy regimen (CAPOX or mFOLFOX6) (n=80) or tislelizumab in combination with chemotherapy regimem (CAPOX or mFOLFOX6) (n=80). Patients will be assigned to treatment using a central stratified block randomization scheme. Patients will be stratified at randomization by the following factors:

• DKK1 RNA scope tumor percentage score (TPS) (≥20% vs. <20%)

• PD-L1 immunohistochemistry Combined Positive Score (CPS) (≥5 vs <5)

[00256] Patients in both groups receviving the CAPOX chemotherapy regimen will receive tislelizumab (200 mg, IV) on Day 1 of each 21 -day cycle. The CAPOX regimen will include oxaliplatin 130 mg/m2 on Day 1 and capecitabine 1000mg/m2 BID on Days 1- 15 of each 21 -day cycle for a total of 28 doses. Patients in the experimental group will receive DKN-01 (600 mg, IV) on Day 1 of each cycle. For Cycle 1 only, an additional loading dose of DKN-01 (600 mg, IV) will be administered on day 15. Patients in the control group will not receive DKN-01 treatment. This dosing scheme is shown graphically below.

[00257] Patients in both groups receiving the mFOLFOX6 chemotherapy regimen will receive tislelizumab (400 mg, IV) every 6 weeks starting on CID 1 and continuing every third 14-day cycle (e.g., C4D1, C7D1 etc.). The mFOLFOX6 regimen will be administered every 14 days and includes leucovorin calcium (folinic acid) 400 mg/m² IV on Day 1, fluorouracil 1200 mg/m² IV/day (Days 1 and 2), and oxaliplatin 85 mg/m² IV on Day 1. Patients in the experimental group will receive DKN-01 (400 mg, IV) on Day 1 and an additional loading dose of DKN-01 (400 mg, IV) will be administered on Day 8. Patients in the control group will not receive DKN-01 treatment. This dosing scheme is shown graphically below.

[00258] Inclusion criteria for Part C includes no previous systemic therapy for inoperable, locally advanced or metastatic G/GEJ adenocarcinoma. Patients may have received prior neoadjuvant or adjuvant therapy as long as it was completed without disease recurrence for at least 6 months since last treatment.

[00259] The primary study objective of Part C is to assess whether the addition of DKN- 01 to the combination of tislelizumab + chemotherapy regimen (CAPOX or mF0LF0X6 [leucovorin calcium, fluorouracil, and oxaliplatin]) improves PFS according to the RECIST vl .1 as assessed by the investigator in patients with advanced DKK1-high G/GEJ adenocarcinoma compared to tislelizumab + chemotherapy regimen (CAPOX or mFOLFOX6) as a first-line therapy.

[00260] Secondary Study Objectives include: determining whether the addition of DKN- 01 to the combination of tislelizumab + chemotherapy regimen (CAPOX or mFOLFOX6) improves PFS according to RECIST vl. l as assessed by the investigator in all patients with advanced G/GEJ adenocarcinoma compared to tislelizumab + chemotherapy regimen (CAPOX or m FOLFOX6) as a first-line therapy; estimating the objective response rate (ORR) according to RECIST vl. l as assessed by the investigator, the duration of response (DoR) and oversail survival (OS) in advanced DKK1-high and overall G/GEJ adenocarcinoma patients treated with DKN-01 in combination with tislelizumab + chemotherapy regimen (CAPOX or mFOLFOx6) compared to tislelizumab + chemotherapy regimen (CAPOX or mFOLFOX6) as a first-line therapy; and assessing whether the addition of DKN-01 to the combination of tislelizumab + chemotherapy regim (CAPOX and mFOLFOX6) improves PFS and ORR according to RECIST vl. l as assessed by the investigator in patients with CPS≥5 or CPS <5 advanced DKK1-high and overall G/GEJ adenocarcinoma compared to tislelizumab + chemotherapy regimen (CAPOX or mFOLFOX6) as first-line therapy.

[00261] The complete Study Treatment Regimen for Part C is shown graphically in Table 15

TABLE 15:

Claims

CLAIMS What is claimed is:

1. A method of treating an esophagogastric cancer in a subject in need of treatment, the method comprising administering to the subject an effective amount of the combination of: a) a DKK1 antibody, or antigen binding-fragment thereof; b) tislelizumab; and c) one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing, wherein the subject is determined to have a DKK-1 H-score of 35 or more.

2. The method of Claim 1, wherein the subject is determined to have a Combined Positive Score (CPS) of less than 5 for PD-L1.

3. A method of treating an esophagogastric cancer in a subject in need of treatment, the method comprising administering to the subject an effective amount of the combination of: a) a DKK1 antibody, or antigen binding-fragment thereof; b) tislelizumab; and c) one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing, wherein the subject is determined to have a DKK1 Tumor Percentage Score (TPS) of 20% or more.

4. The method of Claim 3, wherein the subject is determined to have a Combined Positive Score (CPS) of less than 5 for PD-L1.

5. A method of treating an esophagogastric cancer in a subject in need of treatment, the method comprising administering to the subject an effective amount of the combination of a) a DKK1 antibody, or antigen binding-fragment thereof; b) tislelizumab; and c) one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing.

6. The method of claim 5, wherein wherein the subject is determined to have Combined Positive Score CPS) of less than 5 for PD-L1

7. The method of any of of Claims 1-6, wherein the subject has not received prior systemic therapy for the esophagogastric cancer.

8. The method of any one of Claims 1-6, wherein the subject has received only one prior systemic therapy for the esophagogastric cancer.

9. The method of any one of Claims 1-8, wherein the esophagogastric cancer is gastric cancer.

10. The method of any one of Claims 1-8, wherein the esophagogastric cancer is gastroesophageal junction cancer.

11. The method of any one of claims 1-10, wherein the cancer is an adenocarcinoma.

12. The method of any one of claims 1-11, wherein the cancer is metastatic.

13. The method of any one of claims 1-12, wherein the cancer is advanced.

14. The method of any one of Claims 1-13, wherein the subject has received neoadjuvant therapy prior to administering an effective amount of the combination.

15. The method of any one of Claims 1-14, wherein the effective amount of the combination is administered in the course of one or more 21 -day cycles.

16. The method of Claim 15, wherein 300 mg of the DKK1 antibody, or antigen binding-fragment thereof is administered on day 1 and day 15 of each 21 -day cycle.

17. The method of Claim 15 or 16, wherein 200 mg of tislelizumab is administered on day 1 of each 21 -day cycle.

18. The method of any one of claims 1-17, wherein the one or more chemotherapeutic agents is selected from the group consisting of: 5-FU (fluorouracil), leucovorin (folinic acid); Capecitabine; Carboplatin; Cisplatin; Docetaxel; Epirubicin; Irinotecan; Oxaliplatin; Paclitaxel; andTrifluridine and tipiracil.

19. The method of Claim 1-17 and, wherein the one or more chemotherapeutics agent is a combi cted from the group consisting of: Oxaliplatin, 5-FU and leucovorin (FOLFOX); oxaliplatin and capecitabine (CAPOX); 5-FU, leucovorin, oxaliplatin, and docetaxel (FLOT); Docetaxel and 5-FU; Docetaxel and capecitabine; paclitaxel and 5-FU; paclitaxel and capecitabine; Cisplatin and 5-FU; cisplatin and capecitabine; Paclitaxel and carboplatin; Irinotecan, 5-FU and leucovorin ( FOLFIRI ); Paclitaxel and cisplatin; placlitaxel and carboplatin;

Docetaxel and cisplatin; Epirubicin, cisplatin and 5-FU; Epirubicin, oxaliplatin and 5-FU; Epirubicin, cisplatin and capecitabine; Epirubicin, oxaliplatin and capecitabine; Docetaxel, 5-FU, and cisplatin; Docetaxel, 5-FU, and carboplatin; Docetaxel, 5-FU, and oxaliplatin,

20. The method of claim 19, wherein the combination is oxaliplatin and capecitabine (CAPOX).

21. The method of Claim 20, wherein the capecitabine is orally administered at 1000 mg/m2 twice daily on days 1-15 of each 21 -day cycle and the oxaliplatin is administered at 130 mg/m2 on day 1 of each 21-day cycle.

22. The method of any one of Claims 15-21, wherein the 21-day cycle is repeated.

23. The method of Claim 15, wherein 600 mg of the DKK1 antibody, or antigen binding-fragment thereof is administered on day 1 of each 21-day cycle and day 8 of the first 21-day cycle.

24. The method of Claim 23, wherein 200 mg of tislelizumab is administered on day 1 of each 21 -day cycle.

25. The method of Claim 23 or Claim 24, wherein the one or more chemotherapeutic agents is oxaliplatin and capecitabine (CAPOX).

26. The method of Claim 25, wherein the capecitabine is orally administered at 1000 mg/m2 twice daily on days 1-15 of each 21 day cycle and the oxaliplatin is administered 130 mg/m2 on day 1 of each 21-day cycle.

27. The method of any one of Claims 23-26, wherein the 21-day cycle is repeated.

28. The method of any one of Claims 1-14, wherein the effective amount of the combination is administered in the course of one or more 14-day cycles.

29. The method of Claim 28, wherein 400 mg of the DKK1 antibody, or antigen binding-fragment thereof is administered on on day 1 of each 14-day cycle and day 8 of the first 14-day cycle.

30. The method of Claim 28 or 29, wherein 400 mg of tislelizumab is administered on day 1 of the first 14-day cycle and then on day 1 of every third 14-day cycle.

31. The method of any one of claims 28-30, wherein the one or more chemotherapeutic agents is oxaliplatin, fluorouracil and leucovorin calcium (FOLFOX6).

32. The method of Claim 31, wherein the leucovorin calcium is administered at 400 mg/m2 on day 1 of each 14-day cycle, the fluoruracil is administered at 1200 mg/m2 on days 1 and 2 of each 14-day cycle and the oxaliplatin is administered at 85 mg/m2 on day 1 of each 14-day cycle.

33. The method of any one of Claims 28-32, wherein the 14-day cycle is repeated.

34. The method of any one of claims 1-33, wherein the DKK1 antibody, or antigen binding-fragment thereof, comprises a light chain variable region (LCVR) and a heavy chain variable region (HCVR), wherein the LCVR comprises complementarity determining regions (CDRs) LCDR1, LCDR2, and LCDR3 and the HCVR comprises CDRs HCDR1, HCDR2 and HCDR3, wherein LCDR1 has the amino sequence of SEQ ID NO: 1, LCDR2 has the amino sequence of SEQ ID NO:2, LCDR3 has the amino sequence of SEQ ID NO:3, HCDR1 has the amino sequence of SEQ ID NON, HCDR2 has the amino sequence of SEQ ID NO:5, and an HCDR3 has the amino sequence of SEQ ID NO:6.

35. The method of claim 34, wherein the LCVR comprises the amino acid sequence of SEQ ID NO: 7 and the HCVR comprises the amino acid sequence of SEQ ID NO: 8.

36. The method of claim 34 or 35, wherein the LCVR and HCVR comprise amino acid sequences selected from the group consisting of: (i) a LCVR comprising the amino acid sequence of SEQ ID NO: 9 and a HCVR comprising the amino acid sequence of SEQ ID NO: 10; (ii) a LCVR comprising the amino acid sequence of SEQ ID NO: 11 and a HCVR comprising the amino acid sequence of SEQ ID NO: 12; (iii) a LCVR comprising the amino acid sequence of SEQ ID NO: 13 and a HCVR comprising the amino acid sequence of SEQ ID NO: 10; (iv) a LCVR comprising the amino acid sequence of SEQ ID NO: 14 and a HCVR comprising the amino acid sequence of SEQ ID NO: 10.

37. The method of claim 36, wherein the LCVR comprises the amino acid sequence of SEQ ID NO: 11 and the HCVR comprises the amino acid sequence of SEQ ID NO: 12.

38. The method of claim 36, wherein the DKK1 antibody comprises a heavy chain and a light chain amino acid sequence selected from the group consisting of a) a heavy chain comprising the amino acid sequence of SEQ ID NO: 19 and light chain comprising the amino acid sequence of SEQ ID NO: 16, b) a heavy chain comprising the amino acid sequence of SEQ ID NO: 17 and a light chain comprising the amino acid sequence of SEQ ID NO: 18, c) a heavy chain comprising the amino acid sequence of SEQ ID NO: 19 and a light chain comprising the amino acid sequence of SEQ ID NO: 20, and d) a heavy chain comprising the amino acid sequence of SEQ ID NO: 19 and a light chain comprising the amino acid sequence of SEQ ID NO: 21.

39. The method of Claim 38, wherein the DKK1 antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 17 and a light chain comprising the amino acid sequence of SEQ ID NO: 18.

40. The method of any one of Claims 1-39, wherein the DKK1 antibody is DKN-01.

41. The method of any one of claims 1-40, wherein the subject is a human.

42. A pharmaceutical composition comprising: a) a DKK1 antibody, or antigen binding-fragment thereof; b) tislelizumab; and c) one or more chemotherapeutic agents or a pharmaceutically acceptable salt of any of the foregoing.

43. A kit compri sing : a) a DKK1 antibody, or antigen binding-fragment thereof; b) tislelizumab; c) one or more chemotherapeutic agents or a pharmaceutically acceptable salt thereof; and d) instructions for use.

44. The method of any one of Claims 1-8, wherein the esophagogastric cancer is esophageal squamous cell carcinoma (ESCC).

45. The method of any one of Claims 1-8, wherein the esophagogastric cancer is esophageal esophageal adenocarcinoma (EAC).