BTLA-binding (CD272) antibodies for modulating immune response and treating disease

Abstract

To provide novel anti-BTLA antibodies, pharmaceutical compositions comprising such antibodies, and therapeutic methods of using such antibodies and pharmaceutical compositions for the treatment of diseases such as cancer or autoimmune disease.SOLUTION: Provided are antibodies comprising a heavy chain variable region comprising a specific amino acid sequence and a light chain variable region comprising another specific amino acid sequence, pharmaceutical compositions comprising the antibodies, and therapeutic methods of using the antibodies and pharmaceutical compositions for the treatment of diseases such as cancer or autoimmune disease.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 827,744, filed April 1, 2019, which is incorporated by reference herein in its entirety.

[0002] The present disclosure relates to novel anti-BTLA antibodies and pharmaceutical compositions comprising such antibodies for use in modulating immune responses and treating diseases such as cancer or autoimmune diseases. [Background technology]

[0003] The treatment of diseases that induces, enhances, or suppresses immune responses is called immunotherapy.Immunotherapy has been demonstrated to increase the effectiveness of cancer treatment.Generally, the tumor microenvironment allows cancer cells to escape detection by the immune system, for example, by upregulating immune inhibitory proteins (e.g., PDL1, HVEM) expressed by tumor cells themselves.Leukocytes express specific receptors for these inhibitory proteins (e.g., PD1 for PDL1 and BTLA for HVEM) (also known as immune checkpoint receptors), and tumor cells can bind immune checkpoint receptors to suppress the immune response against themselves.

[0004] The success of many immunotherapies in cancer treatment is based on the use of immunomodulatory antibodies targeting the immune checkpoints CTLA-4 and PD-1 / PD-L1. However, most FDA-approved antibodies that block immune checkpoint pairs are effective in only approximately 20% of cancer patients. The treatment is highly effective and durable in responders. However, for the remaining 80% of cancer patients who are non-responders, new immunotherapies targeting other immune checkpoints are needed.

[0005] BTLA (B and T lymphocyte attenuator) is a transmembrane protein whose expression is induced during T cell activation. BTLA is also expressed on B cells and dendritic cells. Similar to PD-1 and CTLA-4, BTLA interacts with the B7 homolog, B7H4. However, unlike PD-1 and CTLA-4, BTLA also interacts with tumor necrosis family receptors. One such receptor is tumor necrosis factor (receptor) superfamily member 14 (TNFRSF14), also known as herpesvirus entry mediator (HVEM). HVEM is a receptor for HSV glycoprotein D, which is involved in viral entry, and is expressed on hematopoietic cells, including B and T cells, as well as non-hematopoietic cells (parenchymal cells). In addition, HVEM is expressed on various hematopoietic and solid tumors. BTLA-HVEM interaction downregulates T cell responses, such as CD8+ T cell responses. It has been found that the upregulation of BTLA and / or HVEM is a mechanism used by tumor cells to evade immune recognition and destruction.For example, BTLA and HVEM are highly expressed in B-cell chronic lymphocytic leukemia and gastric cancer; and BTLA expression is also upregulated in the cytotoxic CD8+ T cells in the peripheral blood of patients with Hodgkin's lymphoma, B-cell non-Hodgkin's lymphoma and some T-cell non-Hodgkin's lymphoma, and hepatocellular carcinoma.In addition, the absence of HVEM-BTLA signaling leads to an excessive immune response, leading to dysregulated inflammation and autoimmune disease.Therefore, the regulation of BTLA signaling can be a target for both cancer and autoimmune disease. Summary of the Invention

[0006] In one aspect, the invention relates to novel anti-BTLA antibodies. In some embodiments, the anti-BTLA antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:1 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:2. In some embodiments, the anti-BTLA antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:3 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:4. In some embodiments, the anti-BTLA antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:5 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:6. In some embodiments, the anti-BTLA antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8. In some embodiments, the anti-BTLA antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:9 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:10. In some embodiments, the anti-BTLA antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:11 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:12. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 13 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 17 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 18. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 22. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 23 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 24. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 26.In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:27 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:28. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:29 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:30. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:31 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:32. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:33 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:34. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:36. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:37 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:38. In some embodiments, an anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:39 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:40. In some embodiments, the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:41 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:42.

[0007] In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 47, a vhCDR2 comprising SEQ ID NO: 48, a vhCDR3 comprising SEQ ID NO: 49, a vlCDR1 comprising SEQ ID NO: 50, a vlCDR2 comprising SEQ ID NO: 51, and a vlCDR3 comprising SEQ ID NO: 52. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 53, a vhCDR2 comprising SEQ ID NO: 54, a vhCDR3 comprising SEQ ID NO: 55, a vlCDR1 comprising SEQ ID NO: 56, a vlCDR2 comprising SEQ ID NO: 57, and a vlCDR3 comprising SEQ ID NO: 58. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 59, a vhCDR2 comprising SEQ ID NO: 60, a vhCDR3 comprising SEQ ID NO: 61, a vlCDR1 comprising SEQ ID NO: 62, a vlCDR2 comprising SEQ ID NO: 63, and a vlCDR3 comprising SEQ ID NO: 64. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 65, a vhCDR2 comprising SEQ ID NO: 66, a vhCDR3 comprising SEQ ID NO: 67, a vlCDR1 comprising SEQ ID NO: 68, a vlCDR2 comprising SEQ ID NO: 69, and a vlCDR3 comprising SEQ ID NO: 70. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 71, a vhCDR2 comprising SEQ ID NO: 72, a vhCDR3 comprising SEQ ID NO: 73, a vlCDR1 comprising SEQ ID NO: 74, a vlCDR2 comprising SEQ ID NO: 75, and a vlCDR3 comprising SEQ ID NO: 76. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 77, a vhCDR2 comprising SEQ ID NO: 78, a vhCDR3 comprising SEQ ID NO: 79, a vlCDR1 comprising SEQ ID NO: 80, a vlCDR2 comprising SEQ ID NO: 81, and a vlCDR3 comprising SEQ ID NO: 82. In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 83, a vhCDR2 comprising SEQ ID NO: 84, a vhCDR3 comprising SEQ ID NO: 85, a vlCDR1 comprising SEQ ID NO: 86, a vlCDR2 comprising SEQ ID NO: 87, and a vlCDR3 comprising SEQ ID NO: 88. In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 89, a vhCDR2 comprising SEQ ID NO: 90, a vhCDR3 comprising SEQ ID NO: 91, a vlCDR1 comprising SEQ ID NO: 92, a vlCDR2 comprising SEQ ID NO: 93, and a vlCDR3 comprising SEQ ID NO: 94.In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 95, a vhCDR2 comprising SEQ ID NO: 96, a vhCDR3 comprising SEQ ID NO: 97, a vlCDR1 comprising SEQ ID NO: 98, a vlCDR2 comprising SEQ ID NO: 99, and a vlCDR3 comprising SEQ ID NO: 100. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and a vlCDR3 comprising SEQ ID NO: 106. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 107, a vhCDR2 comprising SEQ ID NO: 108, a vhCDR3 comprising SEQ ID NO: 109, a vlCDR1 comprising SEQ ID NO: 110, a vlCDR2 comprising SEQ ID NO: 111, and a vlCDR3 comprising SEQ ID NO: 112. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 113, a vhCDR2 comprising SEQ ID NO: 114, a vhCDR3 comprising SEQ ID NO: 115, a vlCDR1 comprising SEQ ID NO: 116, a vlCDR2 comprising SEQ ID NO: 117, and a vlCDR3 comprising SEQ ID NO: 118. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 119, a vhCDR2 comprising SEQ ID NO: 120, a vhCDR3 comprising SEQ ID NO: 121, a vlCDR1 comprising SEQ ID NO: 122, a vlCDR2 comprising SEQ ID NO: 123, and a vlCDR3 comprising SEQ ID NO: 124. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 125, a vhCDR2 comprising SEQ ID NO: 126, a vhCDR3 comprising SEQ ID NO: 127, a vlCDR1 comprising SEQ ID NO: 128, a vlCDR2 comprising SEQ ID NO: 129, and a vlCDR3 comprising SEQ ID NO: 130. In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 131, a vhCDR2 comprising SEQ ID NO: 132, a vhCDR3 comprising SEQ ID NO: 133, a vlCDR1 comprising SEQ ID NO: 134, a vlCDR2 comprising SEQ ID NO: 135, and a vlCDR3 comprising SEQ ID NO: 136.In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO: 142. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 143, a vhCDR2 comprising SEQ ID NO: 144, a vhCDR3 comprising SEQ ID NO: 145, a vlCDR1 comprising SEQ ID NO: 146, a vlCDR2 comprising SEQ ID NO: 147, and a vlCDR3 comprising SEQ ID NO: 148. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO: 154. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 155, a vhCDR2 comprising SEQ ID NO: 156, a vhCDR3 comprising SEQ ID NO: 157, a vlCDR1 comprising SEQ ID NO: 158, a vlCDR2 comprising SEQ ID NO: 159, and a vlCDR3 comprising SEQ ID NO: 160. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 161, a vhCDR2 comprising SEQ ID NO: 162, a vhCDR3 comprising SEQ ID NO: 163, a vlCDR1 comprising SEQ ID NO: 164, a vlCDR2 comprising SEQ ID NO: 165, and a vlCDR3 comprising SEQ ID NO: 166. In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 167, a vhCDR2 comprising SEQ ID NO: 168, a vhCDR3 comprising SEQ ID NO: 169, a vlCDR1 comprising SEQ ID NO: 170, a vlCDR2 comprising SEQ ID NO: 171, and a vlCDR3 comprising SEQ ID NO: 172.

[0008] In some embodiments, the anti-BTLA antibodies described herein bind to human and / or cynomolgus monkey BTLA.

[0009] In some embodiments, anti-BTLA antibodies act as BTLA antagonists, blocking BTLA binding to HVEM and HVEM-mediated inhibition of T cell function. Examples of such antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:22; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:31 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:32; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:36; a vhCDR1 comprising SEQ ID NO:107, a vhCDR2 comprising SEQ ID NO:108, a vhCDR3 comprising SEQ ID NO:109, a vlCDR1 comprising SEQ ID NO:110, a vlCDR2 comprising SEQ ID NO:111, and and vlCDR3 comprising SEQ ID NO: 112; vhCDR1 comprising SEQ ID NO: 137, vhCDR2 comprising SEQ ID NO: 138, vhCDR3 comprising SEQ ID NO: 139, vlCDR1 comprising SEQ ID NO: 140, vlCDR2 comprising SEQ ID NO: 141, and vlCDR3 comprising SEQ ID NO: 142; or antibodies containing vhCDR1 comprising SEQ ID NO: 149, vhCDR2 comprising SEQ ID NO: 150, vhCDR3 comprising SEQ ID NO: 151, vlCDR1 comprising SEQ ID NO: 152, vlCDR2 comprising SEQ ID NO: 153, and vlCDR3 comprising SEQ ID NO: 154.

[0010] In some embodiments, anti-BTLA antibodies act as BTLA agonists, suppressing pro-inflammatory immune cell function. Examples of such antibodies include a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 26; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 29 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 30; a vhCDR1 comprising SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and and vlCDR3 comprising SEQ ID NO: 106; vhCDR1 comprising SEQ ID NO: 119, vhCDR2 comprising SEQ ID NO: 120, vhCDR3 comprising SEQ ID NO: 121, vlCDR1 comprising SEQ ID NO: 122, vlCDR2 comprising SEQ ID NO: 123, and vlCDR3 comprising SEQ ID NO: 124; or vhCDR1 comprising SEQ ID NO: 131, vhCDR2 comprising SEQ ID NO: 132, vhCDR3 comprising SEQ ID NO: 133, vlCDR1 comprising SEQ ID NO: 134, vlCDR2 comprising SEQ ID NO: 135, and vlCDR3 comprising SEQ ID NO: 136.

[0011] In some embodiments, the anti-BTLA antibodies described herein comprise a constant region having an amino acid sequence at least 90% identical to that of human IgG. In some embodiments, the IgG is selected from IgG1, IgG2, IgG3, or IgG4. In some embodiments, the IgG is IgG2.

[0012] In another aspect, the invention relates to nucleic acid compositions encoding any one of the anti-BTLA antibodies described herein. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 185 and a second nucleic acid comprising SEQ ID NO: 186. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 187 and a second nucleic acid comprising SEQ ID NO: 188. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 189 and a second nucleic acid comprising SEQ ID NO: 190. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 191 and a second nucleic acid comprising SEQ ID NO: 192. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 193 and a second nucleic acid comprising SEQ ID NO: 194. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 195 and a second nucleic acid comprising SEQ ID NO: 196. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 197 and a second nucleic acid comprising SEQ ID NO: 198. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 199 and a second nucleic acid comprising SEQ ID NO: 200. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:201 and a second nucleic acid comprising SEQ ID NO:202. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:203 and a second nucleic acid comprising SEQ ID NO:204. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:205 and a second nucleic acid comprising SEQ ID NO:206. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:207 and a second nucleic acid comprising SEQ ID NO:208. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:209 and a second nucleic acid comprising SEQ ID NO:210. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:211 and a second nucleic acid comprising SEQ ID NO:212. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:213 and a second nucleic acid comprising SEQ ID NO:214. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO:215 and a second nucleic acid comprising SEQ ID NO:216.In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 217 and a second nucleic acid comprising SEQ ID NO: 218. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 219 and a second nucleic acid comprising SEQ ID NO: 220. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 221 and a second nucleic acid comprising SEQ ID NO: 222. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 223 and a second nucleic acid comprising SEQ ID NO: 224. In some embodiments, the nucleic acid composition includes a first nucleic acid comprising SEQ ID NO: 225 and a second nucleic acid comprising SEQ ID NO: 226.

[0013] Another aspect of the present invention relates to an expression vector composition comprising any one of the nucleic acid compositions described herein. In some embodiments, the first nucleic acid is contained in a first expression vector and the second nucleic acid is contained in a second expression vector. In some other embodiments, the first nucleic acid and the second nucleic acid are contained in a single expression vector.

[0014] Another aspect of the invention relates to a host cell containing any one of the expression vectors described herein. Also provided is a method of making an anti-BTLA antibody, comprising culturing a host cell under conditions in which the antibody is expressed, and recovering the antibody.

[0015] In another aspect, the invention relates to a composition comprising any one of the anti-BTLA antibodies described herein and a pharmaceutically acceptable carrier or diluent.

[0016] Also described are methods for modulating an immune response in a subject, the methods comprising administering to the subject an effective amount of any one of the anti-BTLA antibodies described herein, or any one of the compositions described herein. In some embodiments, the methods stimulate an immune response in the subject, and the methods comprise administering to the subject an effective amount of an anti-BTLA antibody that acts as a BTLA antagonist, or a pharmaceutical composition thereof. In some embodiments, the methods suppress an immune response in the subject, and the methods comprise administering to the subject an effective amount of an anti-BTLA antibody that acts as a BTLA agonist, or a pharmaceutical composition thereof.

[0017] In some embodiments, the method stimulates an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody, wherein the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 22; and / or a vhCDR1 comprising SEQ ID NO: 107, a vhCDR2 comprising SEQ ID NO: 108, a vhCDR3 comprising SEQ ID NO: 109, a vlCDR1 comprising SEQ ID NO: 110, a vlCDR2 comprising SEQ ID NO: 111, and a vlCDR3 comprising SEQ ID NO: 112.

[0018] In some embodiments, a method stimulates an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody, wherein the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 31 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 32; and / or a vhCDR1 comprising SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO: 142.

[0019] In some embodiments, the method stimulates an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody, wherein the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 36; and / or a vhCDR1 comprising SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO: 154.

[0020] In some embodiments, a method suppresses an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody, wherein the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20; and / or a vhCDR1 comprising SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and a vlCDR3 comprising SEQ ID NO: 106.

[0021] In some embodiments, a method suppresses an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody, wherein the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 26; and / or a vhCDR1 comprising SEQ ID NO: 119, a vhCDR2 comprising SEQ ID NO: 120, a vhCDR3 comprising SEQ ID NO: 121, a vlCDR1 comprising SEQ ID NO: 122, a vlCDR2 comprising SEQ ID NO: 123, and a vlCDR3 comprising SEQ ID NO: 124.

[0022] In some embodiments, a method suppresses an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody, wherein the anti-BTLA antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:29 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:30; and / or a vhCDR1 comprising SEQ ID NO:131, a vhCDR2 comprising SEQ ID NO:132, a vhCDR3 comprising SEQ ID NO:133, a vlCDR1 comprising SEQ ID NO:134, a vlCDR2 comprising SEQ ID NO:135, and a vlCDR3 comprising SEQ ID NO:136.

[0023] In another aspect, the present invention relates to a method of treating cancer in a subject, comprising administering to the subject an effective amount of an anti-BTLA antibody, or composition thereof, described herein, wherein the anti-BTLA antibody acts as a BTLA antagonist. In some embodiments, the cancer being treated upregulates HVEM compared to corresponding non-cancerous tissue. In some embodiments, the subject being treated expresses high levels of BTLA on T cells. The cancer being treated may be gastric cancer. In some embodiments, the anti-BTLA antibody is used in combination with one or more additional therapeutic agents to treat the cancer. In some embodiments, such anti-cancer therapeutic agents are other immune checkpoint inhibitors, such as ipilimumab, nivolumab, pembrolizumab, avelumab, durvalumab, and atezolizumab.

[0024] In another aspect, the invention relates to a method of treating an autoimmune disease in a subject, comprising administering to the subject an effective amount of an anti-BTLA antibody, or composition thereof, described herein, wherein the anti-BTLA antibody acts as a BTLA agonist. In some embodiments, the subject being treated expresses low levels of HVEM on autoreactive T cells present at the site of autoimmune disease development. In some embodiments, the autoimmune disease is multiple sclerosis.

[0025] The present invention can be more fully understood from the following detailed description read in conjunction with the accompanying drawings, the following figures of which are included in the drawings: [Brief explanation of the drawings]

[0026] [Figure 1] Figure 1 shows the binding of anti-BTLA antibody 13-F7A to human BTLA by ELISA. Anti-BTLA antibodies 4C7 and 8D5 were used as controls. Human IgG was used as a negative control. Relative light units (RLU) were calculated. [Figure 2A] Figures 2A-2C are histograms showing the binding of anti-BTLA antibody 13-F7A to BTLA by FACS analysis. Figure 2A shows the binding of 13-F7A to human BTLA expressed in HEK-293 cells. Antibody concentrations of 10 μg / ml and 1 μg / ml were tested, along with a secondary antibody-only control. [Figure 2B] Figures 2A-2C are histograms showing the binding of anti-BTLA antibody 13-F7A to BTLA by FACS analysis. Figure 2B shows the binding of 13-F7A to cynomolgus monkey BTLA expressed in HEK-293 cells. Antibody concentrations of 10 μg / ml and 1 μg / ml were tested, along with a secondary antibody-only control. [Figure 2C] Figures 2A-2C are histograms showing binding of anti-BTLA antibody 13-F7A to BTLA by FACS analysis. Figure 2C is a negative control showing binding of 13-F7A to HEK-293 cells. Antibodies at 10 μg / ml and 1 μg / ml were tested, along with a secondary antibody-only control. [Figure 3] Figure 3 shows that anti-BTLA antibody 13-F7A inhibits human BTLA / HVEM interaction by ELISA. Anti-BTLA antibodies 4C7 and 8D5 and human IgG were used as controls. [Figure 4] Figure 4 shows the binding affinity of anti-BTLA antibody 13-F7A to human BTLA as measured by Bio-Layer Interferometry. 13-F7A was immobilized on a biosensor chip and tested with recombinant human BTLA at 166.7, 55.6, 18.5, and 6.17 nM. The measured dissociation constant, K, is 5.4 x 10E-9 M. [Figure 5A]Figures 5A-5F show dose-response curves for SEB-stimulated IL-2 secretion by primary T cells in the presence of anti-BTLA antibodies. Human IgG2 and IgG4 were used as controls. Figures 5A-5C show the anti-BTLA antibodies 16-I20A, 15-C19A, and 16-H16A and their antagonistic effects on T cell function. [Figure 5B] Figures 5A-5F show dose-response curves for SEB-stimulated IL-2 secretion by primary T cells in the presence of anti-BTLA antibodies. Human IgG2 and IgG4 were used as controls. Figures 5A-5C show the anti-BTLA antibodies 16-I20A, 15-C19A, and 16-H16A and their antagonistic effects on T cell function. [Figure 5C] Figures 5A-5F show dose-response curves for SEB-stimulated IL-2 secretion by primary T cells in the presence of anti-BTLA antibodies. Human IgG2 and IgG4 were used as controls. Figures 5A-5C show the anti-BTLA antibodies 16-I20A, 15-C19A, and 16-H16A and their antagonistic effects on T cell function. [Figure 5D] Figures 5A-5F show dose-response curves for SEB-stimulated IL-2 secretion by primary T cells in the presence of anti-BTLA antibodies. Human IgG2 and IgG4 were used as controls. Figures 5D-5F show the anti-BTLA antibodies 12-I8A, 8-M23A, and 13-F7A and their agonistic effects on T cell function. [Figure 5E] Figures 5A-5F show dose-response curves for SEB-stimulated IL-2 secretion by primary T cells in the presence of anti-BTLA antibodies. Human IgG2 and IgG4 were used as controls. Figures 5D-5F show the anti-BTLA antibodies 12-I8A, 8-M23A, and 13-F7A and their agonistic effects on T cell function. [Figure 5F] Figures 5A-5F show dose-response curves for SEB-stimulated IL-2 secretion by primary T cells in the presence of anti-BTLA antibodies. Human IgG2 and IgG4 were used as controls. Figures 5D-5F show the anti-BTLA antibodies 12-I8A, 8-M23A, and 13-F7A and their agonistic effects on T cell function. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present disclosure provides novel anti-BTLA antibodies. The anti-BTLA antibodies described herein bind to human and / or cynomolgus monkey BTLA. In some embodiments, the anti-BTLA antibodies bind to human and / or cynomolgus monkey BTLA with high affinity. In some embodiments, the anti-BTLA antibodies act as functional BTLA antagonists; upon binding to BTLA, they block the interaction between BTLA and HVEM and block HVEM-mediated suppression of T cell function. In some embodiments, the anti-BTLA antibodies act as functional BTLA agonists; upon binding to BTLA, they suppress T cell function. Methods of using the antibodies to modulate immune responses in subjects, for example, to treat cancer or autoimmune diseases, are also provided herein. Additionally, nucleic acids encoding these antibodies, as well as host cells containing such nucleic acids, are described herein.

[0028] To facilitate understanding of the present invention, several terms and phrases are defined below.

[0029] As used herein, each of the following terms has the meaning associated with it in this section.

[0030] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0031] As used herein, when referring to a measurable value, for example, an amount, a temporal duration, etc., "about" is meant to encompass variations of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and even more preferably ±0.1% from the specified value, as such variations are appropriate for practicing the disclosed methods.

[0032] As used herein, "ablation" refers to a reduction or elimination of activity. Thus, for example, "ablation of FcγR binding" means that an Fc region amino acid variant has less than 50% of the starting binding compared to an Fc region not containing the particular variant, preferably less than 70-80-90-95-98% loss of activity, and generally means that the activity is below the level of detectable binding in a Biacore assay.

[0033] As used herein, "ADCC" or "antibody-dependent cell-mediated cytotoxicity" refers to a cell-mediated reaction in which nonspecific cytotoxic cells expressing FcγR recognize bound antibody on target cells and subsequently cause lysis of the target cells. ADCC correlates with binding to FcγRIIIa; increased binding to FcγRIIIa leads to increased ADCC activity. As discussed herein, many embodiments of the present invention ablate ADCC activity altogether.

[0034] As used herein, "ADCP" or "antibody-dependent cell-mediated phagocytosis" refers to a cell-mediated reaction in which nonspecific cytotoxic cells expressing FcγR recognize bound antibody on target cells and subsequently cause phagocytosis of the target cells.

[0035] As used herein, "antigen-binding domain" or "ABD" refers to a set of six complementarity-determining regions (CDRs) that, when present as part of a polypeptide sequence, specifically bind to a target antigen as discussed herein. Thus, an "antigen-binding domain" binds to a target antigen as outlined herein. As known in the art, these CDRs generally exist as a first set of variable heavy chain CDRs (vhCDRs or VHCDRs or CDR-HC) and a second set of variable light chain CDRs (vlCDRs or VLCDRs or CDR-LC), each comprising three CDRs: vhCDR1, vhCDR2, and vhCDR3 for the heavy chain and vlCDR1, vlCDR2, and vlCDR3 for the light chain. The CDRs are present in the variable heavy chain and variable light chain domains, respectively, and together form an Fv region. Thus, in some cases, the six CDRs of an antigen-binding domain are contributed by the variable heavy chain and the variable light chain. In the "Fab" format, the set of six CDRs is contributed by two different polypeptide sequences: a variable heavy domain (vh or VH; containing vhCDR1, vhCDR2, and vhCDR3) and a variable light domain (vl or VL; containing vlCDR1, vlCDR2, and vlCDR3), with the C-terminus of the vh domain attached to the N-terminus of the CH1 domain of the heavy chain and the C-terminus of the vl domain attached to the N-terminus of the constant light domain (thus forming the light chain). In the scFv format, the VH and VL domains are generally covalently linked into a single polypeptide sequence by the use of a linker as outlined herein, which (starting from the N-terminus) can be either vh-linker-vl or vl-linker-vh, with the former generally preferred (optionally including a domain linker on each side, depending on the format used). As is understood in the art, the CDRs are separated by framework regions in each variable heavy and variable light chain domain: for the light chain variable region, these are FR1-vlCDR1-FR2-vlCDR2-FR3-vlCDR3-FR4, and for the heavy chain variable region, these are FR1-vhCDR1-FR2-vhCDR2-FR3-vhCDR3-FR4, and the framework regions show a high degree of identity to human germline sequences.Antigen-binding domains of the present invention include Fab, Fv and scFv.

[0036] As used herein, "linker" refers to a linker used in scFv and / or other antibody structures. Generally, several suitable scFv linkers exist that can be used, including traditional peptide bonds and those produced by recombinant techniques. Linker peptides may primarily contain the following amino acid residues: Gly, Ser, Ala, or Thr. The linker peptide should be of an appropriate length to link the two molecules so that they assume the correct conformation relative to each other and retain the desired activity. In one embodiment, the linker is about 1 to 50 amino acids in length, preferably about 1 to 30 amino acids in length. In one embodiment, linkers of 1 to 20 amino acids in length may be used, with about 5 to about 10 amino acids finding use in some embodiments. Useful linkers include glycine-serine polymers, including, for example, (GS), (GSGGS), (GGGGS), and (GGGS), where n is an integer of at least 1 (generally 3 to 4), glycine-alanine polymers, alanine-serine polymers, and other flexible linkers. Alternatively, various nonproteinaceous polymers may find use as linkers, including, but not limited to, polyethylene glycol (PEG), polypropylene glycol, polyoxyalkylenes, or copolymers of polyethylene glycol and polypropylene glycol. Other linker sequences may include any length of a CL / CH1 domain of any sequence (but not all residues of the CL / CH1 domain); for example, the first 5-12 amino acid residues of the CL / CH1 domain. Linkers may be derived from immunoglobulin light chains, such as Cκ or Cλ. Linkers may be derived from any isotype of immunoglobulin heavy chain, including, for example, Cγ1, Cγ2, Cγ3, Cγ4, Cα1, Cα2, Cδ, Cε, and Cμ. Linker sequences may also be derived from other proteins, such as Ig-like proteins (e.g., TCR, FcR, KIR), sequences derived from the hinge region, and other naturally occurring sequences of other proteins. In some embodiments, the linker is a "domain linker" used to link any two domains outlined together herein.While any suitable linker can be used, many embodiments utilize glycine-serine polymers including, for example, (GS)n, (GSGGS)n, (GGGGS)n, and (GGGS)n, where n is an integer of at least 1 (generally 3 to 4 to 5), as well as any peptide sequence of sufficient length and flexibility to allow each domain to retain its biological function and to allow recombinant joining of the two domains.

[0037] The term "antibody" is used in the broadest sense and includes, for example, intact immunoglobulins or antigen-binding portions. Antigen-binding portions can be produced by recombinant DNA techniques or by enzymatic or chemical cleavage of intact antibodies. Thus, the term antibody includes traditional tetrameric antibodies of two heavy chains and two light chains as well as antigen-binding fragments, such as Fv, Fab, and scFv. In some cases, the present invention provides bispecific antibodies comprising at least one antigen-binding domain as outlined herein.

[0038] As used herein, "modification" refers to an amino acid substitution, insertion, and / or deletion in a polypeptide sequence or an alteration to a moiety chemically linked to a protein. For example, a modification may be an altered carbohydrate or PEG structure attached to a protein. As used herein, an "amino acid modification" refers to an amino acid substitution, insertion, and / or deletion in a polypeptide sequence. For clarity, unless otherwise noted, amino acid modifications always refer to amino acids encoded by or encoded by DNA (e.g., the 20 amino acids for which codons exist in DNA and RNA).

[0039] As used herein, an "amino acid substitution" or "substitution" refers to the replacement of an amino acid with a different amino acid at a particular position in a parent polypeptide sequence. In particular, in some embodiments, the substitution is for an amino acid that is not naturally occurring at the particular position, either in the organism or in any organism. For example, the substitution M252Y refers to a variant polypeptide, in this case an Fc variant in which methionine at position 252 has been replaced with tyrosine. For clarity, a protein that has been engineered to change the nucleic acid coding sequence but not the starting amino acid (e.g., exchanging CGG (which encodes arginine) for CGA (which still encodes arginine) to increase expression levels in the host organism) is not an "amino acid substitution"; in other words, if the protein has the same amino acid at the particular position where it starts, a new gene will be created that encodes the same protein, but this is not an amino acid substitution.

[0040] As used herein, "variant protein" or "protein variant" or "variant" refers to a protein that differs from that of a parent protein by virtue of at least one amino acid modification. The protein variant may refer to the protein itself, a composition comprising the protein, or the amino acid sequence encoding it. Preferably, the protein variant has at least one amino acid modification compared to the parent protein, e.g., about 1 to about 70 amino acid modifications, preferably about 1 to about 5 amino acid modifications, compared to the parent. As described below, in some embodiments, the parent polypeptide, e.g., the Fc parent polypeptide, is an Fc region from a human wild-type sequence, e.g., IgG1, IgG2, IgG3, or IgG4. The protein variant sequence herein preferably has at least about 80% identity, most preferably at least about 90% identity, and more preferably at least about 95%-98%-99% identity to the parent protein sequence. The variant protein may refer to the variant protein itself, a composition comprising the protein variant, or the DNA sequence encoding it.

[0041] Thus, as used herein, "antibody variant" or "variant antibody" refers to an antibody that differs from a parent antibody by virtue of at least one amino acid modification; as used herein, "IgG variant" or "variant IgG" refers to an antibody that differs from a parent IgG (again, often a human IgG sequence) by virtue of at least one amino acid modification; and as used herein, "immunoglobulin variant" or "variant immunoglobulin" refers to an immunoglobulin sequence that differs from that of a parent immunoglobulin sequence by virtue of at least one amino acid modification. As used herein, "Fc variant" or "variant Fc" refers to a protein comprising an amino acid modification in the Fc domain. Fc variants of the present invention are defined according to the amino acid modifications that comprise them. Thus, for example, M252Y or 252Y is an Fc variant having a substituted tyrosine at position 252 relative to the parent Fc polypeptide (where numbering is according to the EU index). Similarly, M252Y / S254T / T256E defines an Fc variant having the substitutions M252Y, S254T, and T256E relative to the parent Fc polypeptide. The identity of the wild-type amino acids may not be specified, in which case the variant is referred to as 252Y / 254T / 256E. It is noted that the substitutions may be provided in any order, i.e., for example, 252Y / 254T / 256E is the same Fc variant as 254T / 252Y / 256E, etc. For all positions discussed herein with respect to antibodies, unless otherwise noted, amino acid position numbering is according to Kabat for variable region numbering and according to the EU index for constant regions, including the Fc region. The EU index, or EU index as in the Kabat or EU numbering scheme, refers to the EU antibody numbering (Edelman et al., 1969, Proc Natl Acad Sci USA 63:78-85, incorporated herein by reference in its entirety). Modifications may be additions, deletions, or substitutions. Substitutions may include natural amino acids, and in some cases, synthetic amino acids.

[0042] As used herein, "protein" means at least two covalently attached amino acids, including proteins, polypeptides, oligopeptides, and peptides. Peptidyl groups can contain natural amino acids and peptide bonds.

[0043] As used herein, "Fab" or "Fab region" refers to a polypeptide comprising the VH, CH1, VL, and CL immunoglobulin domains. Fab may refer to this region in isolation or in the context of a full-length antibody, antibody fragment, or Fab fusion protein. As used herein, "Fv" or "Fv fragment" or "Fv region" refers to a polypeptide comprising the VL and VH domains of a single antigen binding domain (ABD). As will be appreciated by those skilled in the art, these are generally composed of two chains or can be combined (generally with a linker as discussed herein) to form an scFv.

[0044] As used herein, "amino acid" and "amino acid identity" refer to one of the 20 naturally occurring amino acids encoded by or encoded in DNA and RNA.

[0045] As used herein, "effector function" refers to a biochemical event that results from the interaction of an antibody Fc region with an Fc receptor or ligand. Effector functions include, but are not limited to, ADCC, ADCP, and CDC.

[0046] As used herein, "Fc gamma receptor," "FcγR," or "Fc gamma R" refers to any member of a family of proteins that bind to the Fc region of an IgG antibody and are encoded by the FcγR gene. In humans, this family includes, but is not limited to, FcγRI (CD64), which includes the isoforms FcγRIa, FcγRIb, and FcγRIc; FcγRII (CD32), which includes the isoforms FcγRIIa (allotypes H131 and R131), FcγRIIb (FcγRIIb-1 and FcγRIIb-2), and FcγRIIc; and FcγRIII (CD16), which includes the isoforms FcγRIIIa (allotypes V158 and F158) and FcγRIIIb (allotypes FcγRIIb-NA1 and FcγRIIb-NA2) (Jefferis et al., 2002, Immunol Lett 82:57-65, incorporated by reference in its entirety), as well as any undiscovered human FcγR or FcγR isoform or allotype. In some cases, as outlined herein, binding to one or more FcγR receptors is reduced or ablated, for example, reduced binding to FcγRIIIa reduces ADCC, and in some cases, reduced binding to FcγRIIIa and FcγRIIb is desired.

[0047] As used herein, "FcRn" or "neonatal Fc receptor" refers to a protein that binds to the Fc region of an IgG antibody and is at least partially encoded by the FcRn gene. FcRn can be derived from any organism, including, but not limited to, humans, mice, rats, rabbits, and monkeys. As is known in the art, a functional FcRn protein often comprises two polypeptides, referred to as a heavy chain and a light chain. The light chain is beta-2-microglobulin, and the heavy chain is encoded by the FcRn gene. Unless otherwise noted herein, FcRn or FcRn protein refers to the complex of the FcRn heavy chain and beta-2-microglobulin.

[0048] As used herein, "parent polypeptide" refers to a starting polypeptide that is subsequently modified to generate a variant. A parent polypeptide may be a naturally occurring polypeptide, or a variant or engineered version of a naturally occurring polypeptide. A parent polypeptide may refer to the polypeptide itself, a composition comprising the parent polypeptide, or the amino acid sequence that encodes it. Thus, as used herein, a "parent immunoglobulin" refers to an unmodified immunoglobulin polypeptide that is modified to generate a variant, and a "parent antibody" as used herein refers to an unmodified antibody that is modified to generate a variant antibody. It should be noted that "parent antibody" includes known commercially available recombinantly produced antibodies, as outlined below.

[0049] As used herein, "heavy chain constant region" generally refers to the CH1-hinge-CH2-CH3 portion of an antibody derived from human IgG1, IgG2, or IgG4.

[0050] As used herein, "target antigen" refers to the molecule that is specifically bound by the variable region of a given antibody. In the present case, the target antigen is the BTLA protein.

[0051] As used herein, "target cell" means a cell that expresses a target antigen.

[0052] As used herein, "variable region" refers to a region of an immunoglobulin that comprises one or more Ig domains substantially encoded by any of the V.kappa, V.lambda, and / or VH genes that make up the kappa, lambda, and heavy chain immunoglobulin loci, respectively.

[0053] As used herein, "wild-type or WT" refers to an amino acid or nucleotide sequence found in nature, including allelic variations. A WT protein has an amino acid or nucleotide sequence that has not been intentionally modified.

[0054] As used herein, "position" means a location in the sequence of a protein. Positions may be numbered consecutively or according to an established format, such as the EU index for antibody numbering.

[0055] As used herein, "residue" refers to a position in a protein and its associated amino acid identity. For example, asparagine 297 (also referred to as Asn297 or N297) is the residue at position 297 in the human antibody IgG1.

[0056] The antibodies of the present invention are generally recombinant, meaning that the antibody is produced using recombinant nucleic acid techniques in an exogenous host cell.

[0057] With respect to protein sequences, "percent (%) amino acid sequence identity" is defined as the percentage of amino acid residues in a candidate sequence that are identical to those in a particular (parent) sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, without considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be accomplished in a variety of ways within the skill of those in the art, using publicly available computer software, such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms necessary to achieve maximum alignment over the entire length of the sequences being compared. One particular program is the ALIGN-2 program outlined in paragraphs

[0279] to

[0280] of U.S. Patent Application Publication No. 20160244525, incorporated herein by reference. Another approximate alignment for nucleic acid sequences is provided by the local homology algorithm of Smith and Waterman, Advances in Applied Mathematics, 2:482-489 (1981). This algorithm can be applied to amino acid sequences using a scoring matrix developed by Dayhoff, Atlas of Protein Sequences and Structure, MO Dayhoff ed., 5 suppl. 3:353-358, National Biomedical Research Foundation, Washington, DC, USA, and standardized by Gribskov, Nucl. Acids Res. 14(6):6745-6763 (1986).

[0058] An exemplary implementation of this algorithm for determining the percent identity of a sequence is provided in the "BestFit" utility application by Genetics Computer Group (Madison, WI). Default parameters for this method are described in the Wisconsin Sequence Analysis Package Program Manual, Version 8 (1995) (available from Genetics Computer Group, Madison, WI). Another method for establishing percent identity in the context of the present invention is to use the MPSRCH package, a program developed by John F. Collins and Shane S. Sturrok, distributed by IntelliGenetics, Inc. (Mountain View, CA), and copyrighted by the University of Edinburgh. From this package suite, the Smith-Waterman algorithm may be employed, with default parameters used for the scoring table (e.g., gap open penalty 12, gap extension penalty 1, and gap 6). From the data generated, the "match" value reflects "sequence identity." Other programs suitable for calculating the percent identity or similarity between sequences are generally known in the art, for example, another alignment program is BLAST, used with default parameters. For example, BLASTN and BLASTP can be used with the following default parameters: genetic code = standard; filter = none; strand = both; cutoff = 60; expectation = 10; matrix = BLOSUM62; description = 50 sequences; sorting = high score; database = non-redundant, GenBank + EMBL + DDBJ + PDB + GenBank CDS translation + Swiss protein + Spupdate + PIR. Details of these programs can be found at the internet address located by typing http: / / in front of blast.ncbi.nlm.nih.gov / Blast.cgi.

[0059] The degree of identity between an amino acid sequence of the present invention ("invention sequence") and a parent amino acid sequence is calculated as the number of perfect matches in an alignment of the two sequences, divided by the length of the "invention sequence" or the length of the parent sequence, whichever is shortest. The result is expressed as percent identity.

[0060] In some embodiments, two or more amino acid sequences are at least 50%, 60%, 70%, 80%, or 90% identical, hi some embodiments, two or more amino acid sequences are at least 95%, 97%, 98%, 99%, or even 100% identical.

[0061] "Specific binding" or "specifically binds" or "specific" for a particular antigen or epitope means binding that is measurably different from non-specific interactions. Specific binding can be measured, for example, by determining the binding of a molecule compared to the binding of a control molecule, which is generally a molecule of similar structure that does not have binding activity. For example, specific binding can be determined by competition with a control molecule that is similar to the target.

[0062] As used herein, the term "Kassoc" or "Ka" is intended to refer to the association rate of a particular antibody-antigen interaction, while the term "Kdis" or "Kd" is intended to refer to the dissociation rate of a particular antibody-antigen interaction. D " is intended to refer to the dissociation constant, which is obtained from the ratio of Kd to Ka (i.e., Kd / Ka) and is expressed as a molar concentration (M). D Values ​​can be determined using methods well established in the art. In some embodiments, the K D A method for determining the K of an antibody is by using surface plasmon resonance, for example, by using a biosensor system, such as a BIACORE® system. Dis determined by Bio-Layer Interferometry. In some embodiments, K D The value is measured at immobilization. D The K value is measured on an immobilized antibody (e.g., a parent murine antibody, a chimeric antibody, or a humanized antibody variant). In certain embodiments, D The K value is measured in bivalent binding mode. D The values ​​are determined in monovalent binding mode.

[0063] "Disease" includes a state of health in an animal, including a human, in which the animal is unable to maintain homeostasis and the animal's health continues to deteriorate if the disease is not remitted.

[0064] In contrast, a "disorder" in an animal, including a human, includes a state of health in which the animal is able to maintain homeostasis, but in which the animal's state of health is less favorable than in the absence of the disorder. If left untreated, the disorder does not necessarily cause a further decrease in the animal's state of health.

[0065] The terms "treatment," "treating," "treat," and the like refer to obtaining a desired pharmacological and / or physiological effect. The effect may be prophylactic, in terms of completely or partially preventing or reducing the likelihood of a disease or its symptoms, and / or therapeutic, in terms of partially or completely curing the disease and / or side effects that may result from the disease. As used herein, "treatment" encompasses any treatment of disease in mammals, particularly humans, and includes: (a) preventing the disease from occurring in a subject who may be predisposed to the disease but has not yet been diagnosed as having it; (b) inhibiting the disease, i.e., halting its development or progression; and (c) mitigating the disease, i.e., causing regression of the disease and / or alleviating one or more disease symptoms. "Treatment" is also meant to encompass the delivery of an agent to provide a pharmacological effect even in the absence of a disease or condition. For example, "treatment" encompasses the delivery of a composition capable of eliciting an immune response or conferring immunity (e.g., in the case of a vaccine) in the absence of a disease state.

[0066] As used herein, the term "mammal" refers to any mammal, including, but not limited to, rodent mammals, e.g., mice and hamsters, and logomorpha mammals, e.g., rabbits. In some embodiments, the mammal is from the carnivora order, including felines (cats) and canines (dogs). In some embodiments, the mammal is from the artiodactyla order, including bovines (cattle) and porcines (pigs), or perissodactyla order, including equines (horses). Most preferably, the mammal is from the order Primates, Ceboids, or Simoids (monkeys), or from the order Anthropoids (humans and apes). In some embodiments, the mammal is a human. In some embodiments, the mammal is a cynomolgus monkey.

[0067] As used herein, the term "regression" and its derivatives do not necessarily mean 100% or complete regression. Rather, there are various degrees of regression that one of skill in the art recognizes as having potential benefit or therapeutic effect. In this regard, the disclosed methods can provide any amount of any level of regression of cancer in a mammal. Furthermore, the regression provided by the methods of the present invention can include regression of one or more conditions or symptoms of a disease, e.g., cancer. Also, for purposes of this specification, "regression" can encompass delaying the onset of the disease, delaying the onset of symptoms, and / or delaying the onset of the condition. With respect to progressive diseases and disorders, "regression" can encompass a slowing of the progression of the disease or disorder, a slowing of the progression of symptoms of the disease or disorder, and / or a slowing of the progression of the condition.

[0068] An "effective amount" or "therapeutically effective amount" of a composition includes an amount of the composition sufficient to provide a beneficial effect to a subject to which the composition is administered. An "effective amount" of a delivery vehicle includes an amount sufficient to effectively bind with or deliver the composition.

[0069] "Individual" or "host" or "subject" or "patient" means any mammalian subject for whom diagnosis, treatment, or therapy is desired, particularly humans. Other subjects may include cynomolgus monkeys, cows, dogs, cats, guinea pigs, rabbits, rats, mice, horses, etc.

[0070] The term "in combination" as used herein refers to, for example, the administration of a first treatment during the entire course of administration of a second treatment; the administration of a first treatment over a period that overlaps with the administration of a second treatment, for example, the administration of a first treatment begins before the administration of a second treatment and ends before the administration of the second treatment; the administration of a second treatment begins before the administration of a first treatment and ends before the administration of the first treatment; the administration of a first treatment begins before the administration of a second treatment and ends before the administration of the first treatment; the administration of a second treatment begins before the administration of a first treatment and ends before the administration of the first treatment. Thus, "in combination" can also refer to a regimen involving the administration of two or more treatments. As used herein, "in combination" also refers to the administration of two or more treatments, which can be administered in the same or different formulations, by the same or different routes, and in the same or different dosage forms.

[0071] "Encoding" includes the inherent property of, and the biological properties resulting from, a specific sequence of nucleotides in a polynucleotide, e.g., a gene, cDNA, or mRNA, to serve as a template for the synthesis of other polymers and macromolecules in biological processes, having either a defined sequence of nucleotides (i.e., rRNA, tRNA, and mRNA) or a defined sequence of amino acids. Thus, for example, a gene encodes a protein when transcription and translation of mRNA corresponding to that gene produces that protein in a cell or other biological system. Both the coding strand, whose nucleotide sequence is identical to the mRNA sequence and is usually provided in a sequence listing, and the non-coding strand, which is used as a template for transcription of the gene or cDNA, can be referred to as encoding the protein or other product of that gene or cDNA.

[0072] The term "nucleic acid" includes RNA or DNA molecules having multiple nucleotides in any form, including single-stranded, double-stranded, oligonucleotide, or polynucleotide. The term "nucleotide sequence" includes the ordering of nucleotides in an oligonucleotide or polynucleotide in the single-stranded form of a nucleic acid.

[0073] "Nucleic acid construct" means a nucleic acid sequence comprising one or more functional units assembled together that are not found together in nature. Examples include circular, linear, double-stranded, extrachromosomal DNA molecules (plasmids), cosmids (plasmids containing COS sequences from lambda phage), viral genomes, etc., that contain non-naturally occurring nucleic acid sequences.

[0074] As used herein, the term "operably linked" includes a polynucleotide in a functional relationship with a second polynucleotide, e.g., a single-stranded or double-stranded nucleic acid segment, comprising two polynucleotides arranged within the nucleic acid segment such that at least one of the two polynucleotides can exert its characterized physiological effect on the other. For example, a promoter operably linked to the coding region of a gene can promote transcription of the coding region. When indicating operably linked, the specified order is not important. For example, the phrases "a promoter operably linked to a nucleotide sequence" and "a nucleotide sequence operably linked to a promoter" are used interchangeably herein and are considered equivalent. In some cases, a nucleic acid encoding a desired protein further includes a promoter / regulatory sequence, which is located at the 5' end of the desired protein-coding sequence, such that it drives expression of the desired protein in a cell.

[0075] The terms "oligonucleotide," "polynucleotide," and "nucleic acid molecule," used interchangeably herein, refer to polymeric forms of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. Thus, the term includes, but is not limited to, single-stranded, double-stranded, or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids, or polymers containing purine and pyrimidine bases, or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases. The backbone of a polynucleotide may contain sugars and phosphate groups (typically found in RNA or DNA), or modified or substituted sugar or phosphate groups.

[0076] The term "recombinant" as applied to a polynucleotide means that the polynucleotide is the product of various combinations of cloning, restriction, or ligation steps, and other procedures that result in constructs that are separate and / or different from polynucleotides found in nature. The term includes progeny copies of the original polynucleotide construct and the original viral construct, respectively.

[0077] As used herein, the term "promoter" includes a DNA sequence operably linked to a nucleic acid sequence to be transcribed, such as a nucleic acid sequence encoding a desired molecule. A promoter is generally positioned upstream of the nucleic acid sequence to be transcribed and provides sites for specific binding by RNA polymerase and other transcription factors.

[0078] A "vector" is capable of transferring a gene sequence into a target cell. Typically, "vector construct," "expression vector," and "gene transfer vector" refer to any nucleic acid construct capable of directing the expression of a gene of interest, which can transfer a gene sequence into a target cell, which can be achieved by genomic integration of all or part of the vector or transient or genetic maintenance of the vector as an extrachromosomal element. Thus, this term includes cloning and expression vehicles as well as integrating vectors.

[0079] The term "control element" as used herein includes nucleotide sequences that control some aspects of the expression of a nucleic acid sequence. Examples of control elements include enhancers, internal ribosome entry sites (IRES), introns, replication origins, polyadenylation signals (pA), promoters, enhancers, transcription termination sequences, and upstream regulatory domains, which contribute to the replication, transcription, and / or post-transcriptional processing of nucleic acid sequences. In this case, control elements may also include cis-regulatory DNA elements and transposable elements (TEs). Those skilled in the art can use routine experimentation to select these and other control elements for use in expression constructs. Expression constructs can be produced using genetic recombinant approaches or synthetically using well-known methodologies.

[0080] A "control element" or "control sequence" is a nucleotide sequence involved in a molecular interaction that contributes to the functional control of a polynucleotide, including replication, duplication, transcription, splicing, translation, or degradation of the polynucleotide. Regulation may affect the frequency, rate, or specificity of the process and may be enhancing or inhibitory in nature. Control elements known in the art include, for example, transcriptional regulatory sequences such as promoters and enhancers. A promoter is a DNA region that, under certain conditions, is capable of binding RNA polymerase and initiating transcription of a coding region that is usually located downstream (3' direction) from the promoter.

[0081] As used herein, the description of an amino acid residue as being "phosphorylated" means that a phosphate group is ester-linked to the side chain of the amino acid residue. Exemplary amino acid residues that can be phosphorylated include serine (Ser), threonine (Thr), and tyrosine (Tyr).

[0082] As used herein, the term "pharmaceutical composition" refers to a combination of an active agent and a carrier (inert or active) making the composition particularly suitable for diagnostic or therapeutic use in vivo or ex vivo.

[0083] As used herein, the term "pharmaceutically acceptable carrier" refers to any standard pharmaceutical carrier, such as phosphate buffered saline, water, emulsions (e.g., oil / water or water / oil emulsions), and various types of wetting agents. The composition may also contain stabilizers and preservatives. For examples of carriers, stabilizers, and adjuvants, see, for example, Martin, Remington's Pharmaceutical Sciences, 15th Ed., Mack Publ. Co., Easton, PA

[1975] .

[0084] Throughout the description, when compositions are described as "having," "including," or "comprising" certain components, or processes and methods are described as "having," "including," or "comprising" certain steps, this also contemplates the existence of compositions of the invention that consist essentially of or consist of the referenced components, and the existence of processes and methods according to the invention that consist essentially of or consist of the referenced processing steps.

[0085] As a general matter, compositions specifying percentages are by weight unless otherwise specified. Further, if a variable is not accompanied by a definition, the variable's prior definition takes precedence.

[0086] Various aspects of the invention are described in the following sections; however, an aspect of the invention described in one particular section is not limited to any particular section.

[0087] I. Antibodies The present disclosure provides novel anti-BTLA antibodies. Such antibodies are capable of binding to human and / or cynomolgus monkey BTLA. Table 1 lists peptide sequences of heavy and light chain variable regions capable of binding to human and / or cynomolgus monkey BTLA in the combinations shown in Table 1. In some embodiments, the heavy and light chain variable regions are arranged in a Fab format. In some embodiments, the heavy and light chain variable regions are fused together to form an scFv.

[0088] [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4] [Table 1-5] [Table 1-6] [Table 1-7] [Table 1-8]

[0089] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:1 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:2.

[0090] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO:47, a vhCDR2 comprising SEQ ID NO:48, a vhCDR3 comprising SEQ ID NO:49, a vlCDR1 comprising SEQ ID NO:50, a vlCDR2 comprising SEQ ID NO:51, and a vlCDR3 comprising SEQ ID NO:52. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0091] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:3 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:4.

[0092] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 53, a vhCDR2 comprising SEQ ID NO: 54, a vhCDR3 comprising SEQ ID NO: 55, a vlCDR1 comprising SEQ ID NO: 56, a vlCDR2 comprising SEQ ID NO: 57, and a vlCDR3 comprising SEQ ID NO: 58. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus monkey BTLA.

[0093] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:5 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:6.

[0094] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO:59, a vhCDR2 comprising SEQ ID NO:60, a vhCDR3 comprising SEQ ID NO:61, a vlCDR1 comprising SEQ ID NO:62, a vlCDR2 comprising SEQ ID NO:63, and a vlCDR3 comprising SEQ ID NO:64. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0095] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:7 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:8.

[0096] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 65, a vhCDR2 comprising SEQ ID NO: 66, a vhCDR3 comprising SEQ ID NO: 67, a vlCDR1 comprising SEQ ID NO: 68, a vlCDR2 comprising SEQ ID NO: 69, and a vlCDR3 comprising SEQ ID NO: 70. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus monkey BTLA.

[0097] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:9 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:10.

[0098] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 71, a vhCDR2 comprising SEQ ID NO: 72, a vhCDR3 comprising SEQ ID NO: 73, a vlCDR1 comprising SEQ ID NO: 74, a vlCDR2 comprising SEQ ID NO: 75, and a vlCDR3 comprising SEQ ID NO: 76. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0099] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 11 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 12.

[0100] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 77, a vhCDR2 comprising SEQ ID NO: 78, a vhCDR3 comprising SEQ ID NO: 79, a vlCDR1 comprising SEQ ID NO: 80, a vlCDR2 comprising SEQ ID NO: 81, and a vlCDR3 comprising SEQ ID NO: 82. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0101] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 13 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 14.

[0102] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 83, a vhCDR2 comprising SEQ ID NO: 84, a vhCDR3 comprising SEQ ID NO: 85, a vlCDR1 comprising SEQ ID NO: 86, a vlCDR2 comprising SEQ ID NO: 87, and a vlCDR3 comprising SEQ ID NO: 88. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0103] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 15 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 16.

[0104] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 89, a vhCDR2 comprising SEQ ID NO: 90, a vhCDR3 comprising SEQ ID NO: 91, a vlCDR1 comprising SEQ ID NO: 92, a vlCDR2 comprising SEQ ID NO: 93, and a vlCDR3 comprising SEQ ID NO: 94. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0105] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 17 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 18.

[0106] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 95, a vhCDR2 comprising SEQ ID NO: 96, a vhCDR3 comprising SEQ ID NO: 97, a vlCDR1 comprising SEQ ID NO: 98, a vlCDR2 comprising SEQ ID NO: 99, and a vlCDR3 comprising SEQ ID NO: 100. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0107] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 19 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:20.

[0108] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and a vlCDR3 comprising SEQ ID NO: 106. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0109] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:21 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:22.

[0110] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 107, a vhCDR2 comprising SEQ ID NO: 108, a vhCDR3 comprising SEQ ID NO: 109, a vlCDR1 comprising SEQ ID NO: 110, a vlCDR2 comprising SEQ ID NO: 111, and a vlCDR3 comprising SEQ ID NO: 112. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0111] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:23 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:24.

[0112] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 113, a vhCDR2 comprising SEQ ID NO: 114, a vhCDR3 comprising SEQ ID NO: 115, a vlCDR1 comprising SEQ ID NO: 116, a vlCDR2 comprising SEQ ID NO: 117, and a vlCDR3 comprising SEQ ID NO: 118. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus monkey BTLA.

[0113] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:25 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:26.

[0114] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 119, a vhCDR2 comprising SEQ ID NO: 120, a vhCDR3 comprising SEQ ID NO: 121, a vlCDR1 comprising SEQ ID NO: 122, a vlCDR2 comprising SEQ ID NO: 123, and a vlCDR3 comprising SEQ ID NO: 124. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0115] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:27 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:28.

[0116] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 125, a vhCDR2 comprising SEQ ID NO: 126, a vhCDR3 comprising SEQ ID NO: 127, a vlCDR1 comprising SEQ ID NO: 128, a vlCDR2 comprising SEQ ID NO: 129, and a vlCDR3 comprising SEQ ID NO: 130. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus monkey BTLA.

[0117] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:29 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:30.

[0118] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 131, a vhCDR2 comprising SEQ ID NO: 132, a vhCDR3 comprising SEQ ID NO: 133, a vlCDR1 comprising SEQ ID NO: 134, a vlCDR2 comprising SEQ ID NO: 135, and a vlCDR3 comprising SEQ ID NO: 136. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0119] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 31 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 32.

[0120] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO: 142. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0121] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 33 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 34.

[0122] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 143, a vhCDR2 comprising SEQ ID NO: 144, a vhCDR3 comprising SEQ ID NO: 145, a vlCDR1 comprising SEQ ID NO: 146, a vlCDR2 comprising SEQ ID NO: 147, and a vlCDR3 comprising SEQ ID NO: 148. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus monkey BTLA.

[0123] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 35 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 36.

[0124] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO: 154. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0125] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 37 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 38.

[0126] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 155, a vhCDR2 comprising SEQ ID NO: 156, a vhCDR3 comprising SEQ ID NO: 157, a vlCDR1 comprising SEQ ID NO: 158, a vlCDR2 comprising SEQ ID NO: 159, and a vlCDR3 comprising SEQ ID NO: 160. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0127] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 39 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 40.

[0128] In some embodiments, the anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 161, a vhCDR2 comprising SEQ ID NO: 162, a vhCDR3 comprising SEQ ID NO: 163, a vlCDR1 comprising SEQ ID NO: 164, a vlCDR2 comprising SEQ ID NO: 165, and a vlCDR3 comprising SEQ ID NO: 166. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0129] In some embodiments, an anti-BTLA antibody of the present disclosure includes a heavy chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:41 and a light chain variable region having an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:42.

[0130] In some embodiments, an anti-BTLA antibody comprises a vhCDR1 comprising SEQ ID NO: 167, a vhCDR2 comprising SEQ ID NO: 168, a vhCDR3 comprising SEQ ID NO: 169, a vlCDR1 comprising SEQ ID NO: 170, a vlCDR2 comprising SEQ ID NO: 171, and a vlCDR3 comprising SEQ ID NO: 172. In some embodiments, one or more of such six CDRs have one, two, three, four, or five amino acid modifications. In further embodiments, a single CDR contains one or two amino acid substitutions, and the modified anti-BTLA antibody retains binding to human and / or cynomolgus BTLA.

[0131] In addition to the sequence variants described herein in the heavy and light chain variable regions and / or CDRs, changes can be made in the framework regions of the heavy and / or light chain variable regions. In some embodiments, variants in the framework regions (e.g., excluding the CDRs) retain at least about 80, 85, 90, or 95% identity with the germline sequence. Table 2 lists germline gene alleles that encode the anti-BTLA antibodies described herein. Variants can be made that retain at least about 80, 85, 90, or 95% identity with any one of the alleles of the light chain V gene, light chain J gene, heavy chain V gene, heavy chain J gene, and heavy chain D gene.

[0132] [Table 2-1] [Table 2-2]

[0133] In some embodiments, variations are made in framework regions that retain at least 80, 85, 90, or 95% identity to the germline gene sequences listed in Table 2, while the six CDRs are kept unchanged.

[0134] In some embodiments, variations are made in both the framework regions (which retain at least 80, 85, 90, or 95% identity to the germline gene sequences listed in Table 2) and the six CDRs. The CDRs may have amino acid modifications (e.g., 1, 2, 3, 4, or 5 amino acid modifications in the set of CDRs) (i.e., the CDRs may be modified, as long as the total number of changes in the set of six CDRs is less than 6 amino acid modifications, and any combination of CDRs may be altered; for example, one change may be in vlCDR1, two changes in vhCDR2, no change in vhCDR3, etc.).

[0135] One skilled in the art can design anti-BTLA antibodies according to the invention by selecting the amino acid sequences of the heavy and light chain CDRs and / or variable regions from those described herein and, if necessary, combining them with the amino acid sequences of the antibody heavy and light chain framework regions and / or constant regions. The antibody framework regions and / or constant regions (Fc domains) described in the invention can be derived from any species, e.g., human, rabbit, dog, cat, mouse, horse, or monkey.

[0136] In some embodiments, the constant region is derived from a human and includes a heavy chain constant region derived from an IgG, IgA, IgM, IgE, or IgD subtype or variant thereof, and a light chain constant region derived from a kappa or lambda subtype or variant thereof. In some embodiments, the heavy chain constant region is derived from a human IgG, including IgG1, IgG2, IgG3, and IgG4. In some embodiments, the amino acid sequence of the heavy chain constant region is at least 80%, 85%, 90%, or 95% identical to that of a human IgG1, IgG2, IgG3, or IgG4 constant region. In some other embodiments, the amino acid sequence of the constant region is at least 80%, 85%, 90%, or 95% identical to that of an antibody constant region from another mammal, such as a rabbit, dog, cat, mouse, horse, or monkey. In some embodiments, the antibody constant region includes a hinge, a CH2 domain, a CH3 domain, and optionally a CH1 domain.

[0137] In some embodiments, the antibodies described herein may be derived from a mixture of different species (e.g., forming chimeric and / or humanized antibodies). Generally, both "chimeric antibodies" and "humanized antibodies" refer to antibodies that combine regions from multiple species. For example, "chimeric antibodies" traditionally contain variable regions from mouse (or, in some cases, rat) and constant regions from human. "Humanized antibodies" generally refer to non-human antibodies that have had variable domain framework regions swapped with sequences found in human antibodies. Generally, in humanized antibodies, the entire antibody (except for the CDRs) is encoded by a polynucleotide of human origin or is identical to such an antibody except within the CDRs. CDRs (some or all of which are encoded by nucleic acids originating from a non-human organism) are grafted onto the beta-sheet framework of a human antibody variable region to create an antibody whose specificity is determined by the grafted CDRs. The production of such antibodies is described, for example, in WO92 / 11018; Jones, 1986, Nature 321:522-525; Verhoeyen et al., 1988, Science 239:1534-1536, all of which are incorporated by reference in their entireties. "Backmutation" of selected acceptor framework residues to the corresponding donor residues is often required to restore affinity lost in the initial grafted construct (US5530101; US5585089; US5693761; US5693762; US6180370; US5859205; US5821337; US6054297; US6407213, all of which are incorporated by reference in their entireties). A humanized antibody also optimally comprises at least a portion of an immunoglobulin constant region (typically that of a human immunoglobulin) and thus typically comprises a human Fc region. Humanized antibodies can also be produced using mice with genetically engineered immune systems, as described, for example, in Roque et al., 2004, Biotechnol. Prog. 20:639-654, which is incorporated by reference in its entirety.Various techniques and methods for humanizing and reshaping non-human antibodies are well known in the art (see Tsurushita & Vasquez, 2004, Humanization of Monoclonal Antibodies, Molecular Biology of B Cells, 533-545, Elsevier Science (USA), and references cited therein, all of which are incorporated by reference in their entirety). Humanization methods include, but are not limited to, those described in Jones et al., 1986, Nature 321:522-525; Riechmann et al., 1988, Nature 332:323-329; Verhoeyen et al., 1988, Science 239:1534-1536; Queen et al., 1989, Proc Natl Acad Sci, USA 86:10029-33; He et al., 1998, J. Immunol. 160: 1029-1035; Carter et al., 1992, Proc Natl Acad Sci, USA 89:4285-9; Presta et al., 1997, Cancer Res. 57(20):4593-9; Gorman et al., 1991, Proc. Natl. Acad. Sci. USA 88:4181-4185; O'Connor et al., 1998, Protein Eng 11:321-8. Other methods for reducing the immunogenicity of humanized or non-human antibody variable regions can include resurfacing techniques, for example, as described in Roguska et al., 1994, Proc. Natl. Acad. Sci. USA 91:969-973, which is incorporated by reference in its entirety.Other humanization methods may involve grafting of only a portion of the CDRs, including, but not limited to, those described in Tan et al., 2002, J. Immunol. 169:1119-1125; De Pascalis et al., 2002, J. Immunol. 169:3076-3084, all of which are incorporated by reference in their entirety.

[0138] In some embodiments, antibodies of the present invention comprise a heavy chain variable region derived from a particular human germline heavy chain immunoglobulin gene and / or a light chain variable region derived from a particular human germline light chain immunoglobulin gene. Such antibodies may contain amino acid differences compared to human germline sequences, for example, due to natural somatic mutations or deliberate introduction of site-specific mutations. However, humanized antibodies typically have an amino acid sequence at least 80% identical to that encoded by a human germline immunoglobulin gene and contain amino acid residues that distinguish the antibody from the human sequence when compared to the germline immunoglobulin amino acid sequence of another species (e.g., a murine germline sequence). In certain cases, a humanized antibody may be at least 95, 96, 97, 98, or 99% identical, or even at least 96%, 97%, 98%, or 99% identical, in amino acid sequence, to the amino acid sequence encoded by a human germline immunoglobulin gene. Typically, a humanized antibody derived from a particular human germline sequence exhibits no more than 10-20 amino acid differences from the amino acid sequence encoded by a human germline immunoglobulin gene. In certain cases, a humanized antibody may display no more than 5, or even no more than 4, 3, 2, or 1 amino acid difference from the amino acid sequence encoded by the germline immunoglobulin gene.

[0139] In some embodiments, the antibodies of the present disclosure are humanized and affinity matured as known in the art. Structure-based methods may be used for humanization and affinity maturation, for example, as described in U.S. Patent No. 7,657,380. Selection-based methods may be used to humanize and / or affinity mature antibody variable regions, including, but not limited to, those described in Wu et al., 1999, J. Mol. Biol. 294:151-162; Baca et al., 1997, J. Biol. Chem. 272(16):10678-10684; Rosok et al., 1996, J. Biol. Chem. 271(37): 22611-22618; Rader et al., 1998, Proc. Natl. Acad. Sci. USA 95: 8910-8915; Krauss et al., 2003, Protein Engineering 16(10):753-759, all of which are incorporated by reference in their entireties.

[0140] II. Antibody Characteristics In some embodiments, the anti-BTLA antibodies described herein bind to human and / or cynomolgus monkey BTLA. In some embodiments, the binding of the anti-BTLA antibodies to human and / or cynomolgus monkey BTLA is measured by ELISA, e.g., the exemplary assay described in Example 1. In such embodiments, the antibodies described herein exhibit an EC50, as measured by such an assay, which may be in the 0.1-20 nM range. In some embodiments, the binding of the anti-BTLA antibodies to human and / or cynomolgus monkey BTLA is measured by FACS, e.g., the exemplary assay described in Example 2. In such embodiments, the antibodies described herein exhibit an EC50, as measured by FACS, which is in the 0.1-20 nM range. In further embodiments, the EC50 of the antibodies described herein is in the range of about 0.1-30, 1-28, 2-26, 3-24, 4-22, 5-20, 6-18, 7-16, 8-14, or 9-12 nM, as measured by either ELISA or FACS.

[0141] In some embodiments, the anti-BTLA antibodies described herein bind with high affinity to human and / or cynomolgus monkey BTLA. D The K value can be measured with immobilized antigen or immobilized antibody. D Values ​​can also be measured in monovalent or bivalent binding modes. For example, the K between an antibody and human BTLA as measured by Bio-Layer interferometry. D The value is 1 x 10 -6 M or less, 5×10 -7 M or less, 2.5×10 -7 M or less, 1×10 -7 M or less, 5×10 -8 M or less, 1×10 -8 M or less, 1×10 -9 M or less, or 1 x 10 -10 The K between the antibody and cynomolgus monkey BTLA can be ≤ M. D The value is 1 x 10 -6 M or less, 5×10 -7M or less, 2.5×10 -7 M or less, 1×10 -7 M or less, 5×10 -8 M or less, 2.5×10 -8 M or less, 1×10 -8 M or less, 5×10 -9 M or less, 1×10 -9 M or less, 5×10 -10 M or less, or 1 x 10 -10 In some embodiments, the K between the antibody and human BTLA can be equal to or less than 1 M. D Values ​​will be in the range of 0.1 nM-1 μM, 0.25 nM-500 nM, 0.5 nM-250 nM, 1 nM-100 nM, or 2 nM-50 nM. In some embodiments, the K between the antibody and cynomolgus BTLA D Values ​​can be in the range of 0.1 nM-1 μM, 0.25 nM-500 nM, 0.5 nM-250 nM, 1 nM-100 nM, or 2 nM-50 nM.

[0142] The binding affinities of the anti-BTLA antibodies described herein are compared to the BTLA monoclonal antibody 4C7, described in U.S. Patent No. 8,563,694. In some embodiments, the anti-BTLA antibodies described herein have a higher binding affinity for human BTLA than 4C7. In some embodiments, the anti-BTLA antibodies described herein have a higher binding affinity for cynomolgus monkey BTLA than 4C7. Table 7 shows exemplary K of some of the antibody clones, as well as 4C7. D

[0013] One advantage of having a higher binding affinity than 4C7 is that the antibodies described herein may be more effective at modulating immune responses and / or participating in anti-tumor immune responses. Another advantage of having a higher binding affinity for cynomolgus monkey BTLA than 4C7 is that preclinical monkey studies (e.g., pharmacokinetics, pharmacodynamics, safety, and toxicity studies) derived from these antibodies may have greater predictive power than studies using 4C7.

[0143] In some embodiments, the anti-BTLA antibodies exhibit low immunogenicity when administered to a human subject. These antibodies may contain an Fc domain derived from human IgG1, human IgG2, or human IgG3. In some embodiments, these antibodies are humanized using framework regions derived from human immunoglobulins.

[0144] The effect of anti-BTLA antibodies on T cell function can be assayed using a variety of methods known in the art and described herein, including, for example, the method described in Example 5. Thus, anti-BTLA antibodies can act as BTLA antagonists or BTLA agonists.

[0145] In some embodiments, the described anti-BTLA antibodies act as BTLA antagonists, blocking the interaction of BTLA with HVEM and HVEM-mediated suppression of T cell function. As a result, such anti-BTLA antibodies stimulate an immune response. Examples of such anti-BTLA antibodies include those comprising a heavy chain variable region comprising an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:21, and a heavy chain variable region comprising an amino acid sequence at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:22. light chain variable regions comprising amino acid sequences that are identical (88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the respective CDR1s of the same nucleotide sequence; and / or antibodies that contain a vhCDR1 comprising SEQ ID NO: 107, a vhCDR2 comprising SEQ ID NO: 108, a vhCDR3 comprising SEQ ID NO: 109, a vlCDR1 comprising SEQ ID NO: 110, a vlCDR2 comprising SEQ ID NO: 111, and a vlCDR3 comprising SEQ ID NO: 112. Alternatively, such anti-BTLA antibodies that act as antagonists may include a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:31, and a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:32. a light chain variable region comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the CDR1 of SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO: 142.Alternatively, such anti-BTLA antibodies that act as antagonists may include a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:35, and a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:36. a light chain variable region comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the CDR1 of SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO: 154.

[0146] In some other embodiments, the anti-BTLA antibodies described herein act as BTLA agonists and suppress immune cell function, including pro-inflammatory T cell function. As a result, such anti-BTLA antibodies suppress the immune response. For example, such anti-BTLA antibodies include a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 19, and a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 20. a light chain variable region comprising an amino acid sequence that is 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the CDR1 of SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and a vlCDR3 comprising SEQ ID NO: 106. Alternatively, such an anti-BTLA antibody may comprise a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:25, and a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:26. a light chain variable region comprising an amino acid sequence that is 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the CDR1 of SEQ ID NO: 119, a vhCDR2 comprising SEQ ID NO: 120, a vhCDR3 comprising SEQ ID NO: 121, a vlCDR1 comprising SEQ ID NO: 122, a vlCDR2 comprising SEQ ID NO: 123, and a vlCDR3 comprising SEQ ID NO: 124.Alternatively, such anti-BTLA antibodies that act as agonists may include a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 29, and a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 30. a light chain variable region comprising an amino acid sequence that is identical to the CDR1 of SEQ ID NO: 131, a vhCDR2 comprising SEQ ID NO: 132, a vhCDR3 comprising SEQ ID NO: 133, a vlCDR1 comprising SEQ ID NO: 134, a vlCDR2 comprising SEQ ID NO: 135, and a vlCDR3 comprising SEQ ID NO: 136.

[0147] III. Nucleic Acids of the Invention Nucleic acids encoding the anti-BTLA antibodies described herein are also provided, as well as expression vectors containing such nucleic acids and host cells transformed with such nucleic acids and / or expression vectors. As will be understood by those skilled in the art, the protein sequences set forth herein can be encoded by any number of nucleic acid sequences possible due to the degeneracy of the genetic code. Table 3 provides exemplary nucleic acids encoding the heavy and light chain variable regions of the antibodies described herein.

[0148] [Table 3-1] [Table 3-2] [Table 3-3] [Table 3-4] [Table 3-5] [Table 3-6] [Table 3-7] [Table 3-8] [Table 3-9] [Table 3-10] [Table 3-11]

[0149] Nucleic acid compositions encoding anti-BTLA antibodies and / or BTLA-binding domains are also provided. As will be understood by those skilled in the art, in the case of an antigen-binding domain, the nucleic acid composition generally comprises a first nucleic acid encoding a heavy chain variable region and a second nucleic acid encoding a light chain variable region. In the case of an scFv, a single nucleic acid encoding the heavy chain variable region and the light chain variable region, separated by a linker as described herein, can be produced. In the case of a traditional antibody, the nucleic acid composition generally comprises a first nucleic acid encoding a heavy chain and a second nucleic acid encoding a light chain, which, upon expression in a cell, spontaneously assembles into a "traditional" tetrameric format of two heavy chains and two light chains.

[0150] As is known in the art, nucleic acids encoding the components of the present invention can be incorporated into an expression vector and used to produce the antibodies of the present invention, depending on the host cell. These two nucleic acids can be incorporated into a single expression vector or into two different expression vectors. Generally, the nucleic acid can be operably linked to any number of control elements in the expression vector (promoter, origin of replication, selectable marker, ribosome binding site, inducer, etc.). The expression vector can be an extrachromosomal or integrating vector.

[0151] The nucleic acids and / or expression vectors of the present invention can be introduced into any type of host cell known in the art, including mammalian, bacterial, yeast, insect, and fungal cells. After transfection, single-cell clones can be isolated for cell bank generation using methods known in the art, such as limiting dilution, ELISA, FACS, microscopy, or Clonepix. Clones can be cultured under conditions appropriate for scale-up in bioreactors and maintaining antibody expression. Antibodies can be isolated and purified using methods known in the art, including centrifugation, depth filtration, cell lysis, homogenization, freeze-thaw, affinity purification, gel filtration, ion exchange chromatography, hydrophobic interaction exchange chromatography, and mixed-mode chromatography.

[0152] IV. Therapeutic application The present disclosure provides a method for modulating an immune response in a subject, the method comprising administering to the subject an effective amount of an anti-BTLA antibody described herein, or a pharmaceutical composition containing an anti-BTLA antibody.

[0153] In some embodiments, methods of modulating an immune response encompassed by the present disclosure include stimulating an immune response in a subject, and in further embodiments, such methods include administering to the subject an effective amount of an anti-BTLA antibody that acts as a BTLA antagonist, or by administering a pharmaceutical composition containing an antagonistic anti-BTLA antibody.

[0154] In some embodiments, methods encompassed by the disclosure include, for example, a method for producing a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:21, and at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:22. 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to a BTLA antibody; and / or a vhCDR1 comprising SEQ ID NO: 107, a vhCDR2 comprising SEQ ID NO: 108, a vhCDR3 comprising SEQ ID NO: 109, a vlCDR1 comprising SEQ ID NO: 110, a vlCDR2 comprising SEQ ID NO: 111, and a vlCDR3 comprising SEQ ID NO: 112.

[0155] In some embodiments, the methods described herein involve, for example, producing a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 31, and at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 32. an immune response in a subject is stimulated by administering an anti-BTLA antibody comprising a light chain variable region comprising an amino acid sequence that is (90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to the target polypeptide; and / or a vhCDR1 comprising SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO: 142.

[0156] In some embodiments, the methods described herein involve, for example, a method for producing a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 35, and at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 36. an immune response in a subject is stimulated by administering an anti-BTLA antibody comprising a light chain variable region comprising an amino acid sequence that is (90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to the target polypeptide; and / or a vhCDR1 comprising SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO: 154.

[0157] In some embodiments, the present disclosure provides methods for suppressing an immune response in a subject, e.g., by administering to the subject an effective amount of an anti-BTLA antibody that acts as a BTLA agonist, or by administering to the subject a pharmaceutical composition containing such an agonistic anti-BTLA antibody.

[0158] In some other embodiments, the methods described herein involve, for example, producing a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 19, and at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 20. an anti-BTLA antibody comprising a light chain variable region comprising an amino acid sequence that is identical to the CDR1 of SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and a vlCDR3 comprising SEQ ID NO: 106, thereby suppressing an immune response in a subject.

[0159] In some other embodiments, the methods described herein involve, for example, producing a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:25, and at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO:26. an anti-BTLA antibody comprising a light chain variable region comprising an amino acid sequence that is identical to the CDR1 of SEQ ID NO: 119, a vhCDR2 comprising SEQ ID NO: 120, a vhCDR3 comprising SEQ ID NO: 121, a vlCDR1 comprising SEQ ID NO: 122, a vlCDR2 comprising SEQ ID NO: 123, and a vlCDR3 comprising SEQ ID NO: 124, thereby suppressing an immune response in a subject.

[0160] In some other embodiments, the methods described herein involve, for example, producing a heavy chain variable region comprising an amino acid sequence that is at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 29, and at least 80% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) identical to SEQ ID NO: 30. an anti-BTLA antibody comprising a light chain variable region comprising an amino acid sequence that is identical to the CDR1 of SEQ ID NO: 131, a vhCDR2 comprising SEQ ID NO: 132, a vhCDR3 comprising SEQ ID NO: 133, a vlCDR1 comprising SEQ ID NO: 134, a vlCDR2 comprising SEQ ID NO: 135, and a vlCDR3 comprising SEQ ID NO: 136, thereby suppressing an immune response in a subject.

[0161] The present disclosure also provides methods for treating cancer in a subject, including administering to the subject an effective amount of an anti-BTLA antibody that acts as a BTLA antagonist, or a pharmaceutical composition containing such an anti-BTLA antibody. In some embodiments, the cancer being treated expresses HVEM and / or BTLA on the surface of cancer cells. In some embodiments, the cancer being treated upregulates HVEM and / or BTLA compared to corresponding non-cancerous tissue. In some embodiments, the subject being treated expresses HVEM and / or BTLA on T cells, e.g., CD8+ and / or CD4+ T cells. In some embodiments, the subject being treated expresses high levels of HVEM and / or BTLA on one or more types of immune cells, including CD4+ T cells, CD8+ T cells, B cells, natural killer T cells, natural killer cells, macrophages, and dendritic cells. In some embodiments, the cancer being treated uses the BTLA-HVEM pathway to downregulate T cell responses and / or evade immune recognition and destruction. In some embodiments, the cancer being treated is unresponsive to existing immunomodulatory antibodies that target other immune checkpoints, such as CTLA-4, PD-1, or PD-L1.

[0162] In some embodiments, the cancer is a solid tumor such as gastric cancer, colorectal cancer, hepatocellular carcinoma, melanoma, or esophageal squamous cell carcinoma. In some embodiments, the cancer is B-cell chronic lymphocytic leukemia, Hodgkin's lymphoma, B-cell non-Hodgkin's lymphoma, or T-cell non-Hodgkin's lymphoma.

[0163] In some other embodiments, the cancer is brain cancer, bladder cancer, breast cancer, cervical cancer, endometrial cancer, esophageal cancer, leukemia, lung cancer, liver cancer, melanoma, ovarian cancer, pancreatic cancer, prostate cancer, rectal cancer, kidney cancer, testicular cancer, or uterine cancer. In still other embodiments, the cancer is vascularized tumor, squamous cell carcinoma, adenocarcinoma, small cell carcinoma, neuroblastoma, sarcoma (e.g., angiosarcoma or chondrosarcoma), laryngeal cancer, parotid gland cancer, biliary tract cancer, thyroid cancer, acral lentiginous melanoma, actinic keratosis, acute lymphocytic leukemia, acute myeloid leukemia, adenoid cystic carcinoma, adenoma, adenosarcoma, adenosquamous carcinoma, anal canal cancer, anal cancer, anorectal cancer. cancer, astrocytic tumor, Bartholin's gland carcinoma, basal cell carcinoma, biliary tract cancer, bone cancer, bone marrow cancer, bronchial cancer, bronchial adenocarcinoma, carcinoid, bile duct carcinoma, chondosarcoma, choroid plexus papilloma / carcinoma, chronic lymphocytic leukemia, chronic myeloid leukemia, clear cell carcinoma, connective tissue cancer, cystadenoma, digestive system cancer, duodenal cancer, endocrine system cancer, endodermal sinus tumor, endometrial hyperplasia, endometrial stromal sarcoma, endometrioid adenocarcinoma, endothelial cell carcinoma, ependymal carcinoma, epithelial cell carcinoma, Ewing's sarcoma, eye and orbit cancer, female genital cancer, focal nodular hyperplasia, gallbladder cancer, gastric antrum cancer cancer, gastric fundus cancer, gastrinoma, glioblastoma, glucagonoma, cardiac cancer, hemangiblastomas, hemangioendothelioma, hemangioma, hepatocellular adenoma, hepatic adenomatosis, hepatobiliary cancer, hepatocellular carcinoma, Hodgkin's disease, ileal cancer, insulinoma, intraepithelial neoplasia, interepithelial squamous cell neoplasia, intrahepatic bile duct cancer, invasive squamous cell carcinoma, jejunal cancer, joint cancer, Kaposi's sarcoma, pelvic cancer, large cell carcinoma, colorectal cancer, leiomyosarcoma, lentigo maligna melanoma, lymphoma, male genital cancer, malignant mesothelioma, medulloblastoma, medulloepithelioma, meningeal cancer, mesothelial carcinoma, metastatic cancer, mouth cancer, mucoepidermoid carcinomacarcinoma, multiple myeloma, muscle cancer, nasal passage cancer, nervous system cancer, neuroepithelial adenocarcinoma, nodular melanoma, nonepithelial skin cancer, oat cell carcinoma, oligodendroglial carcinoma, oral cavity cancer, osteosarcoma, papillary serous adenocarcinoma, penile cancer, pharyngeal cancer, pituitary tumor, plasmacytoma, pseudosarcoma, pulmonary blastoma, rectal cancer, renal cell carcinoma, respiratory system cancer, retinoblastoma, rhabdomyosarcoma, sarcoma, serous carcinoma, sinus cancer, skin cancer, small cell carcinoma, small intestine cancer, smooth muscle carcinoma, soft tissue cancer, somatostatin-secreting tumor, spinal cancer, squamous cell carcinoma, striated muscle carcinoma, submesothelial carcinoma cancer, superficial spreading melanoma, T-cell leukemia, tongue cancer, undifferentiated carcinoma, ureteral cancer, urethral cancer, urinary bladder cancer, urinary tract cancer, cervical cancer, uterine cancer, uveal melanoma, vaginal cancer, verrucous carcinoma, vipoma, vulva cancer, well-differentiated carcinoma, or Wilms' tumor.

[0164] In some other embodiments, the cancer to be treated is a non-Hodgkin's lymphoma, such as a B-cell lymphoma or a T-cell lymphoma. In certain embodiments, the non-Hodgkin's lymphoma is a B-cell lymphoma, such as diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, follicular lymphoma, small lymphocytic lymphoma, mantle cell lymphoma, marginal zone B-cell lymphoma, extranodal marginal zone B-cell lymphoma, nodal marginal zone B-cell lymphoma, splenic marginal zone B-cell lymphoma, Burkitt's lymphoma, lymphoplasmacytic lymphoma, hairy cell leukemia, or primary central nervous system (CNS) lymphoma. In certain other embodiments, the non-Hodgkin's lymphoma is a T-cell lymphoma, e.g., precursor T-lymphoblastic lymphoma, peripheral T-cell lymphoma, cutaneous T-cell lymphoma, angioimmunoblastic T-cell lymphoma, extranodal natural killer / T-cell lymphoma, enteropathy-type T-cell lymphoma, subcutaneous panniculitis-like T-cell lymphoma, anaplastic large cell lymphoma, or peripheral T-cell lymphoma.

[0165] The present disclosure also provides a method of treating an autoimmune or inflammatory disorder in a subject, comprising administering to the subject an effective amount of an anti-BTLA antibody that acts as a BTLA agonist, or a pharmaceutical composition containing such an anti-BTLA antibody. In some embodiments, HVEM and / or BTLA are expressed at low levels in one or more types of immune cells in the treated subject, including T cells, B cells, natural killer cells, dendritic cells, endothelial cells, and macrophages. In some embodiments, HVEM and / or BTLA are expressed at low levels in the subject on autoreactive immune cells (e.g., T cells, B cells, natural killer cells, dendritic cells, endothelial cells, and macrophages) at sites where autoimmune diseases occur, such as lymph nodes and the central nervous system in subjects with multiple sclerosis, joints in subjects with rheumatoid arthritis, and the gastrointestinal tract in subjects with celiac disease. Administering anti-BTLA antibodies that act as BTLA agonists can suppress pro-inflammatory immune responses, including pro-inflammatory T cell responses, and modulate immune responses in subjects suffering from autoimmune or inflammatory disorders.

[0166] In some embodiments, the autoimmune or inflammatory disorder to be treated is multiple sclerosis, Addison's disease, amyotrophic lateral sclerosis, Crohn's disease, Cushing's syndrome, diabetes mellitus type 1, graft-versus-host disease, Graves' disease, Guillain-Barré syndrome, lupus erythematosus, psoriasis, psoriatic arthritis, rheumatoid arthritis, sarcoidosis, scleroderma, systemic lupus erythematosus, transplant rejection, or vasculitis.

[0167] In some other embodiments, the autoimmune disorders treated include, but are not limited to, acute disseminated encephalomyelitis (ADEM), agammaglobulinemia, alopecia areata, ankylosing spondylitis, antiphospholipid syndrome, antisynthetase syndrome, atopic allergy, atopic dermatitis, autoimmune aplastic anemia, autoimmune cardiomyopathy, autoimmune enteropathy, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease, autoimmune lymphoproliferative syndrome, autoimmune pancreatitis, autoimmune peripheral neuropathy, autoimmune polyendocrine syndrome, autoimmune progesterone dermatitis, autoimmune thrombocytopenic purpura, autoimmune urticaria, autoimmune uveitis, Baro's disease / Baro's concentric sclerosis, Behcet's disease, Buerger's disease, Bickerstaff brainstem encephalitis, Blau syndrome, bullous pemphigoid, cancer, Castleman's disease, celiac disease, Chagas disease, chronic inflammation chronic demyelinating polyneuropathy, chronic inflammatory demyelinating polyneuropathy, chronic obstructive pulmonary disease, chronic recurrent multifocal osteomyelitis, Churg-Strauss syndrome, cicatricial pemphigoid, Cogan's syndrome, cold agglutinin disease, complement component 2 deficiency, contact dermatitis, cranial arteritis, CREST syndrome, cutaneous leukocytoclastic vasculitis, Degos disease, Dercum's disease, dermatitis herpetiformis, dermatomyositis, diffuse cutaneous systemic sclerosis, discoid lupus erythematosus, Dressler's syndrome group, drug-induced lupus, eczema, endometriosis, eosinophilic fasciitis, eosinophilic gastroenteritis, eosinophilic pneumonia, epidermolysis bullosa acquisita, erythema nodosum, erythroblastosis fetalis, essential mixed cryoglobulinemia, Evans syndrome, fibrodysplasia ossificans progressiva, fibrosing alveolitis (or idiopathic pulmonary fibrosis), gastritis, gastrointestinal ulcers, glomerulonephritis, Goodpasture syndrome, Hashimoto's encephalopathy, Hashimoto's thyroiditis, Henoch-Schönlein purpura, herpes gestationis Other names: pemphigoid gestationis, hidradenitis suppurativa, Hughes-Stovin syndrome, hypogammaglobulinemia, idiopathic inflammatory demyelinating disease, idiopathic pulmonary fibrosis, idiopathic thrombocytopenic purpura, IgA nephropathy, inclusion body myositis, interstitial cystitis, juvenile idiopathic arthritis Other names: juvenile rheumatoid arthritis, Kawasaki disease, Lambert-Eaton myasthenic syndrome, leukocytoclastic vasculitis, lichen planus, lichen sclerosus, linear IgA disease, lupoid hepatitisAutoimmune hepatitis, Majeed syndrome, microscopic colitis, microscopic polyangiitis, Miller-Fisher syndrome, mixed connective tissue disease, morphea, and Mucher-Habermann disease. Acute pityriasis lichenoides, multiple sclerosis, myasthenia gravis, myositis, Meniere's disease, narcolepsy, neuromyelitis optica, neuromyotonia, ophthalmic cicatricial pemphigoid, opsoclonus-myoclonus syndrome, Ord's thyroiditis, relapsing rheumatoid arthritis, PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection), paraneoplastic cerebellar degeneration, paroxysmal nocturnal hemoglobinuria (PNH), Parry-Romberg syndrome, pars planitis, Parsonage-Turner syndrome, pemphigus vulgaris, perivenous encephalomyelitis, pernicious anemia, POEMS syndrome, polyarteritis nodosa, polymyalgia rheumatica, polymyositis, primary biliary cirrhosis, primary sclerosing cholangitis, progressive These include: inflammatory neuropathy, pure red cell aplasia, pyoderma gangrenosum, Rasmussen's encephalitis, Raynaud's phenomenon, Reiter's syndrome, relapsing polychondritis, restless legs syndrome, retroperitoneal fibrosis, rheumatic fever, schizophrenia, Schmidt's syndrome, Schnitzler's syndrome, scleritis, serum sickness, Sjögren's syndrome, spondyloarthropathy, stiff-person syndrome, Still's disease, subacute bacterial endocarditis (SBE), Susac's syndrome, Sweet's syndrome, Sydenham's chorea, sympathetic ophthalmia, Takayasu's arteritis, temporal arteritis, thrombocytopenia, Tolosa-Hunt syndrome, transverse myelitis, ulcerative colitis, undifferentiated spondyloarthropathy, urticarial vasculitis, vitiligo, and Wegener's granulomatosis.

[0168] V. Combination Therapy The anti-BTLA antibodies described herein can be used in combination with additional therapeutic agents to treat cancer or autoimmune disorders.

[0169] Exemplary therapeutic agents that may be used as part of a combination therapy to treat cancer include, for example, radiation, mitomycin, tretinoin, ribomustine, gemcitabine, vincristine, etoposide, cladribine, mitobronitol, methotrexate, doxorubicin, carboquone, pentostatin, nitracrine, zinostatin, cetrorelix, letrozole, raltitrexed, daunorubicin, fadrozole, fotemustine, thymalfasin, sobuzoxane, nedaplatin, cytarabine, bicalutamide, vinorelbine, vesnarinone, aminoglutethimide, amsacrine, proglucan, ribosomal ... , elliptinium acetate, ketanserin, doxifluridine, etretinate, isotretinoin, streptozocin, nimustine, vindesine, flutamide, drogenil, butocin, carmofur, razoxane, sizofiran, carboplatin, mitolactol, tegafur, ifosfamide, prednimustine, picibanil, levamisole, teniposide, improsulfan, enocitabine, lisuride, oxymetholone, tamoxifen, progesterone, mepitiostane, epithiostanol, formestane, interferon-alpha, interferon-2 Included are alpha, interferon-beta, interferon-gamma, colony-stimulating factor-1, colony-stimulating factor-2, denileukin diftitox, interleukin-2, luteinizing hormone-releasing factor and variations of the aforementioned agents that may exhibit differential binding to their cognate receptors and increased or decreased serum half-lives.

[0170] An additional class of agents that can be used as part of a combination therapy to treat cancer are immune checkpoint inhibitors. Exemplary immune checkpoint inhibitors include agents that inhibit one or more of (i) cytotoxic T-lymphocyte-associated antigen 4 (CTLA4), (ii) programmed cell death protein 1 (PD1), (iii) PDL1, (iv) LAG3, (v) B7-H3, (vi) B7-H4, and (vii) TIM3, such as ipilimumab, nivolumab, pembrolizumab, avelumab, durvalumab, and atezolizumab.

[0171] Still other agents that can be used as part of a combination therapy to treat cancer are monoclonal antibodies that target non-checkpoint targets (e.g., herceptin) and non-cytotoxic agents (e.g., tyrosine kinase inhibitors).

[0172] Further categories of anti-cancer drugs include, for example: (i) ALK inhibitors, ATR inhibitors, A2A antagonists, base excision repair inhibitors, Bcr-Abl tyrosine kinase inhibitors, Bruton's tyrosine kinase inhibitors, CDC7 inhibitors, CHK1 inhibitors, cyclin-dependent kinase inhibitors, DNA-PK inhibitors, inhibitors of both DNA-PK and mTOR, DNMT1 inhibitors, DNMT1 inhibitors plus 2-chloro-deoxyadenosine, HDAC inhibitors, hedgehog signaling pathway inhibitors, IDO inhibitors, JAK inhibitors, mTOR inhibitors, MEK inhibitors (ii) an inhibitor selected from a tumor necrosis factor (MTF) inhibitor, a MELK inhibitor, an MTH1 inhibitor, a PARP inhibitor, a phosphoinositide 3-kinase inhibitor, an inhibitor of both PARP1 and DHODH, a proteasome inhibitor, a topoisomerase-II inhibitor, a tyrosine kinase inhibitor, a VEGFR inhibitor, and a WEE1 inhibitor; (ii) an agonist of OX40, CD137, CD40, GITR, CD27, HVEM, TNFRSF25, or ICOS; and (iii) a cytokine selected from IL-12, IL-15, GM-CSF, and G-CSF.

[0173] The antibodies of the invention may also be used as an adjunct to surgical removal of cancer from its primary focus.

[0174] Exemplary therapeutic agents that may be used as part of a combination therapy with an anti-BTLA antibody disclosed herein to treat, delay the progression of, prevent the recurrence of, or alleviate the symptoms of an autoimmune or inflammatory disorder include any anti-inflammatory and / or immunosuppressive therapy known in the art and described herein. In some embodiments, the anti-inflammatory and / or immunosuppressive therapy includes, but is not limited to, methotrexate, cyclosporine A (including, for example, cyclosporine microemulsion), tacrolimus, corticosteroids, statins, interferon beta, nonsteroidal anti-inflammatory drugs, and 6-MP (also known as mercaptopurine, 6-mercaptopurine, or Purinethol).

[0175] In some embodiments, anti-inflammatory and / or immunosuppressive therapies for combination with the anti-BTLA antibodies disclosed herein include, but are not limited to, TOPK inhibitors (e.g., OTS964 ((R)-9-(4-(1-(dimethylamino)propan-2-yl)phenyl)-8-hydroxy-6-methylthieno[2,3-c]quinolin-4(5H)-one) (Oncotherapy Science), tyrosine kinase inhibitors (e.g., axitinib, dasatinib, icotinib), topoisomerase inhibitors (e.g., topotecan), sphingosine-1-phosphate receptor agonists (e.g., fingolimod, KRP-203), anti-T cell immunoglobulins (e.g., AtGam), anti-IL-2 receptor antibodies (e.g., daclizumab), amide (CTX), ifosfamide (IFO), adriamycin (ADM), daunorubicin (DNR), vincristine (VCR), vinblastine (VBL), etoposide These include poside (VP16), Vermeer (Vumon), carboplatin (CBP), tacrolimus, sirolimus, everolimus, azathioprine, brequinar, leflunomide, LEA-29Y, anti-CD3 antibodies (e.g., OKT3), aspirin, B7-CD28 blocking molecules (e.g., belatacept, abatacept), CD40-CD154 blocking molecules (anti-CD40 antibodies), acetaminophen, ibuprofen, naproxen, piroxicam, and anti-inflammatory steroids (e.g., prednisolone or dexamethasone).

[0176] In some embodiments, anti-inflammatory and / or immunosuppressive therapies for combination with the anti-BTLA antibodies disclosed herein include ablation of autoimmune cells, for example, by administration of TNF-alpha, CFA, interleukin-1 (IL-1), proteasome inhibitors, NFκB inhibitors, anti-inflammatory drugs, tissue plasminogen activator (TPA), lipopolysaccharide, ultraviolet light, and intracellular mediators of the TNF-alpha signaling pathway. Such agents induce apoptosis of autoreactive lymphocytes by disrupting pathways downstream of TNF-alpha receptor signaling or by acting downstream of TNF-alpha receptor binding (Baldwin et al., Ann. Rev. Immunol. (1996) 12:141; Baltimore, Cell (1996) 87:13).

[0177] In some embodiments, the anti-BTLA antibodies disclosed herein are used in conjunction with surgical methods to treat or otherwise alleviate autoimmune diseases.

[0178] For example, anti-BTLA antibodies acting as BTLA agonists may be combined with any existing treatment for multiple sclerosis, such as corticosteroids (e.g., oral prednisone and intravenous methylprednisolone), plasmapheresis, ocrelizumab, beta interferon, glatiramer acetate, dimethyl fumarate, fingolimod, feriflunomide, natalizumab, alemtuzumab, and / or mitoxantrone, to treat the symptoms of multiple sclerosis, slow the progression of multiple sclerosis, prevent relapses of multiple sclerosis, or alleviate the symptoms of multiple sclerosis.

[0179] The amounts of the antibody and additional therapeutic agent and the relative timing of administration can be selected to achieve a desired combined therapeutic effect. For example, when administering a combination therapy to a patient in need of such administration, the therapeutic agents in the combination, or pharmaceutical compositions or compositions containing the therapeutic agents, can be administered in any order, e.g., sequentially, simultaneously, together, contemporaneously, etc. Furthermore, for example, a polyspecific binding protein can be administered during the time that the additional therapeutic agent exerts its prophylactic or therapeutic effect, or vice versa.

[0180] VI. Pharmaceutical Compositions and Administration The present disclosure also features pharmaceutical compositions / formulations containing a therapeutically effective amount of an anti-BTLA antibody described herein. The compositions can be formulated for use in various drug delivery systems. One or more physiologically acceptable excipients or carriers can also be included in the composition for appropriate formulation. Suitable formulations for use in the present disclosure can be found in Remington's Pharmaceutical Sciences, Mack Publishing Company, Philadelphia, Pa., 17th ed., 1985. For a brief review of methods for drug delivery, see, for example, Langer (Science 249:1527-1533, 1990).

[0181] The antibodies of the present disclosure may be present in a lyophilized formulation or a liquid aqueous pharmaceutical formulation. Aqueous carriers of interest herein are those that are pharmaceutically acceptable (safe and non-toxic for human administration) and useful for preparing liquid formulations. Exemplary carriers include sterile water for injection (SWFI), bacteriostatic water for injection (BWFI), pH buffers (e.g., phosphate-buffered saline), sterile saline, Ringer's solution, or dextrose solution.

[0182] The antibody of the present disclosure can be present in a lyophilized formulation comprising a protein and a lyoprotectant. The lyoprotectant can be a sugar, for example, a disaccharide. In certain embodiments, the lyoprotectant is sucrose or maltose. The lyophilized formulation can also include one or more buffers, surfactants, bulking agents, and / or preservatives.

[0183] The actual dosage level of the active ingredient in the pharmaceutical compositions of the present invention may be varied to obtain an amount of active ingredient that is not toxic to the patient and is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration. A range of 0.1 mg to 1 g of active antibody may be administered per dose to an adult, and preferably 0.5 mg to 500 mg. Alternatively, the patient's dose may be adjusted to the patient's approximate body weight or surface area. Other factors determining the appropriate dose may include the disease or condition being treated or prevented, the severity of the disease, the route of administration, and the patient's age, sex, and medical condition. Further refinement of the calculations necessary to determine the appropriate dose for treatment is routinely performed by those skilled in the art, particularly in light of the dosage information and assays disclosed herein. Doses may also be determined through the use of known assays that are used in conjunction with appropriate dose-response data to determine dosage. Doses for individual patients may be adjusted while monitoring disease progression. Blood levels of the targetable construct or complex in the patient may be measured to determine whether the dose needs to be adjusted to reach or maintain an effective concentration. Pharmacogenomics may be used to determine which targetable constructs and / or complexes, and their dosages, are most likely to be effective for a given individual (Schmitz et al., Clinica Chimica Acta 308: 43-53, 2001; Steimer et al., Clinica Chimica Acta 308: 33-41, 2001).

[0184] Doses may be given one or more times daily, weekly, monthly, or yearly, or even once every 2 to 20 years. Those skilled in the art can easily estimate dosing repetition rates based on measurements of residence time and concentration of the targetable construct or complex in bodily fluids or tissues. Administration of the present invention can be intravenous, intraarterial, intraperitoneal, intramuscular, subcutaneous, intrapleural, intrathecal, or intracavity, by perfusion through a catheter or by direct intralesional injection. It can be administered one or more times daily, one or more times weekly, one or more times monthly, and one or more times yearly. [Example]

[0185] Having now generally described the invention, it will be more clearly understood by reference to the following examples, which are included solely for the purpose of illustrating certain aspects and embodiments of the invention and are not intended to limit the invention.

[0186] [Example 1] Anti-BTLA antibodies bind to recombinant BTLA Binding of anti-BTLA antibodies to human or cynomolgus monkey BTLA was assayed by ELISA. Plates (384 wells) were coated with 20 μl BTLA(ECD)-HIS (1 μg / ml) overnight at 4°C. The wells were then washed with PBS and blocked with 55 μl blocking buffer for 1 hour at room temperature. The wells were then washed with PBS, and the anti-BTLA antibodies of the present invention, as well as the anti-BTLA antibodies 4C7 and 8D5 (described in U.S. Patent No. 8,563,694), and a human IgG control were added to the wells at various concentrations (67, 22, 7.4, 2.5, 0.8, 0.3, 0.09, 0.03, 0.01, 0.004, and 0.001 nM) and incubated for 1 hour at room temperature. The wells were then washed with PBS, and 20 μl of diluted HRP-conjugated secondary anti-human IgG antibody was then added to the wells and incubated at room temperature for 45 minutes. After removing excess HRP-conjugated secondary antibody, substrate solution was added to the wells to generate a chemiluminescent signal. Photon emission was determined using an Omegastar plate reader, and relative light units (RLU) were calculated. Figure 1 shows an exemplary binding profile of anti-BTLA antibody 13-F7A to human BTLA, compared with the 4C7 and 8D5 antibodies. Human IgG was used as a negative control. Table 4 summarizes the binding EC50 of various anti-BTLA antibodies to human and cynomolgus monkey BTLA, as measured by ELISA.

[0187] [Table 4]

[0188] [Example 2] Anti-BTLA antibodies bind to BTLA expressed on cells HEK293 cells expressing human or cynomolgus BTLA were used to evaluate the binding of anti-BTLA antibodies to BTLA. Various concentrations of anti-BTLA antibodies (67, 22, 7.4, 2.5, 0.8, 0.3, 0.09, 0.03, 0.01, 0.004, and 0.001 nM) were incubated with the cells for 1 hour at room temperature. A fluorophore-conjugated anti-human IgG secondary antibody was then added, and the cells were analyzed by flow cytometry. Figures 2A-2B show an exemplary binding profile of anti-BTLA antibody 13-F7A to HEK293 cells expressing human or cynomolgus BTLA. Compared to control HEK293 cells (Figure 2C), 13-F7A binds to both human BTLA and cynomolgus BTLA. Table 5 summarizes the binding EC50 of various anti-BTLA antibodies to human and cynomolgus BTLA, as measured by FACS.

[0189] [Table 5]

[0190] [Example 3] Anti-BTLA antibodies inhibit the BTLA / HVEM interaction An ELISA-based biofunctional assay was used to assay the effect of anti-BTLA antibodies on BTLA / HVEM interaction. Each well of a 384-well ELISA plate was coated with 20 μl of 5 μg / ml human HVEM-rat IgG2a for 1 hour at 37°C (or overnight at 4°C). After coating, the plate was washed twice with washing solution (PBS containing 0.05% Tween-20) in a Molecular Devices Aquamax2000 plate washer and then blocked with blocking solution (PBS containing 3% BSA) for 1 hour at room temperature (RT). During the blocking step, 1 μg / ml human BTLA-human Fc or 0.5 μg / ml cynomolgus BTLA-human Fc was mixed with anti-BTLA antibodies, 4C7, 8D5, or a human IgG2 control at various concentrations (67, 22, 7.4, 2.5, 0.8, 0.3, 0.09, 0.03, 0.01, 0.004, and 0.001 nM). After the blocking step, the plate was washed twice with a plate washer. 20 μl of the protein / antibody mixture was then added to the plate and incubated for 1 hour at room temperature. Unbound material was discarded, and the plate was washed four times with a plate washer. 20 μl of secondary antibody (anti-human Fc-HRP) was then added to each well and incubated for 45 minutes at room temperature. Unbound material was discarded, and the plate was washed eight times with a plate washer. Twenty microliters of chemiluminescent substrate was then added to each well, luminescence was read at a gain of 3600, and relative light units (RLU) were calculated. Figure 3 shows an exemplary profile for anti-BTLA antibody 13-F7A. 13-F7A inhibited human BTLA interaction with human HVEM to a similar extent as 4C7. However, 8D5 and the human IgG control had little effect on the interaction between human BTLA and HVEM. Table 6 summarizes the IC50 values ​​for different anti-BTLA antibodies that inhibit the interaction between human BTLA and HVEM, as well as the interaction between cynomolgus monkey BTLA and HVEM.

[0191] [Table 6]

[0192] [Example 4] Anti-BTLA antibodies bind to BTLA with high affinity The binding affinity of anti-BTLA antibodies to human and cynomolgus BTLA was measured by Bio-Layer Interferometry (Octet® system from ForteBIO). 10 μg / ml of each anti-BTLA antibody was immobilized on a biosensor chip surface via anti-human-Fc (AHC) capture. Human or cynomolgus BTLA was diluted in PBS and loaded in 3-fold serial dilutions at concentrations from 166.7 nM to 6.17 nM. Binding curves were fitted to a 1:1 interaction model using the analysis software provided by the Octet® system. Figure 4 shows exemplary association and dissociation curves between anti-BTLA antibody 13-F7A and different concentrations of human BTLA (166.7 nM, 55.6 nM, 18.5 nM, and 6.17 nM). Table 7 shows the binding dissociation constants (K ) for different anti-BTLA antibodies to human and cynomolgus BTLA measured by Bio-Layer Interferometry. D ) is shown below.

[0193] [Table 7]

[0194] [Example 5] Anti-BTLA antibodies regulate T cell function The effect of anti-BTLA antibodies on T cell function was assayed. Peripheral blood mononuclear cells (PBMCs) were isolated from heparinized whole blood of human donors by density gradient centrifugation. PBMCs were cultured at 1 × 10 in complete RPMI 1640 (RPMI 1640, 10% FCS, l-glutamine, penicillin, and streptomycin). 6The cells were resuspended at 100 μl / ml and seeded into a 96-well cell culture cluster plate. 1 ng / ml Staphylococcal enterotoxin B (SEB) was added to each well along with each anti-BTLA antibody. The cells were incubated at 37°C and 5% CO2 for 48 hours, and the supernatant was collected. IL-2 concentrations in the supernatant were measured by ELISA using an anti-IL2 capture antibody (R&D Systems MAB602).

[0195] Figures 5A-5F show dose-response curves of IL-2 release from primary T cells in the presence of different anti-BTLA antibodies and SEB. Human IgG2 and IgG4 were used as controls for the assay because, in this example, the anti-BTLA antibodies contain the Fc domain from human IgG2, and 8D5 and 4C7 each contain the Fc domain from human IgG4. The anti-BTLA antibodies 16-I20A, 15-C19A, and 16-H16A increased SEB-induced IL-2 secretion by T cells and therefore acted as BTLA antagonists. In addition, they exhibited higher maximal antagonist activity compared to the 4C7 antibody. The EC50 of each antibody tested was calculated, and 16-I20A exhibited a similar EC50, i.e., potency in antagonizing T cell function, compared to the 4C7 antibody. The anti-BTLA antibodies 12-I8A, 8-M23A, and 13-F7A inhibited SEB-induced IL-2 secretion by T cells and thus acted as BTLA agonists.

[0196] Incorporation by Reference The entire disclosure of each of the patent documents and scientific articles referenced herein is incorporated by reference for all purposes.

[0197] equivalent The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Accordingly, the foregoing embodiments are considered to be illustrative in all respects and not limiting of the invention described herein. The scope of the invention is, therefore, indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:1 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:2; b) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:3 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:4; c) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:5 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:6; d) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:7 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:8; e) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:9 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:10; f) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:11 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:12; g) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 13 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 14; h) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 15 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 16; i) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 17 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 18; j) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20; k) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:22; l) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:23 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:24; m) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:26; n) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:29 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:30; o) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:31 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:32; p) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 33 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 34; q) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 36; r) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:37 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:38; s) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 39 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 40; or t) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 41 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 42 An antibody comprising:

2. a) a vhCDR1 comprising SEQ ID NO:47, a vhCDR2 comprising SEQ ID NO:48, a vhCDR3 comprising SEQ ID NO:49, a vlCDR1 comprising SEQ ID NO:50, a vlCDR2 comprising SEQ ID NO:51, and a vlCDR3 comprising SEQ ID NO:52; b) a vhCDR1 comprising SEQ ID NO:53, a vhCDR2 comprising SEQ ID NO:54, a vhCDR3 comprising SEQ ID NO:55, a vlCDR1 comprising SEQ ID NO:56, a vlCDR2 comprising SEQ ID NO:57, and a vlCDR3 comprising SEQ ID NO:58; c) a vhCDR1 comprising SEQ ID NO:59, a vhCDR2 comprising SEQ ID NO:60, a vhCDR3 comprising SEQ ID NO:61, a vlCDR1 comprising SEQ ID NO:62, a vlCDR2 comprising SEQ ID NO:63, and a vlCDR3 comprising SEQ ID NO:64; d) a vhCDR1 comprising SEQ ID NO:65, a vhCDR2 comprising SEQ ID NO:66, a vhCDR3 comprising SEQ ID NO:67, a vlCDR1 comprising SEQ ID NO:68, a vlCDR2 comprising SEQ ID NO:69, and a vlCDR3 comprising SEQ ID NO:70; e) vhCDR1 comprising SEQ ID NO:71, vhCDR2 comprising SEQ ID NO:72, vhCDR3 comprising SEQ ID NO:73, vlCDR1 comprising SEQ ID NO:74, vlCDR2 comprising SEQ ID NO:75, and vlCDR3 comprising SEQ ID NO:76; f) vhCDR1 comprising SEQ ID NO:77, vhCDR2 comprising SEQ ID NO:78, vhCDR3 comprising SEQ ID NO:79, vlCDR1 comprising SEQ ID NO:80, vlCDR2 comprising SEQ ID NO:81, and vlCDR3 comprising SEQ ID NO:82; g) vhCDR1 comprising SEQ ID NO:83, vhCDR2 comprising SEQ ID NO:84, vhCDR3 comprising SEQ ID NO:85, vlCDR1 comprising SEQ ID NO:86, vlCDR2 comprising SEQ ID NO:87, and vlCDR3 comprising SEQ ID NO:88; h) vhCDR1 comprising SEQ ID NO:89, vhCDR2 comprising SEQ ID NO:90, vhCDR3 comprising SEQ ID NO:91, vlCDR1 comprising SEQ ID NO:92, vlCDR2 comprising SEQ ID NO:93, and vlCDR3 comprising SEQ ID NO:94; i) vhCDR1 comprising SEQ ID NO:95, vhCDR2 comprising SEQ ID NO:96, vhCDR3 comprising SEQ ID NO:97, vlCDR1 comprising SEQ ID NO:98, vlCDR2 comprising SEQ ID NO:99, and vlCDR3 comprising SEQ ID NO:100; j) vhCDR1 comprising SEQ ID NO: 101, vhCDR2 comprising SEQ ID NO: 102, vhCDR3 comprising SEQ ID NO: 103, vlCDR1 comprising SEQ ID NO: 104, vlCDR2 comprising SEQ ID NO: 105, and vlCDR3 comprising SEQ ID NO: 106; k) vhCDR1 comprising SEQ ID NO: 107, vhCDR2 comprising SEQ ID NO: 108, vhCDR3 comprising SEQ ID NO: 109, vlCDR1 comprising SEQ ID NO: 110, vlCDR2 comprising SEQ ID NO: 111, and vlCDR3 comprising SEQ ID NO: 112; l) vhCDR1 comprising SEQ ID NO: 113, vhCDR2 comprising SEQ ID NO: 114, vhCDR3 comprising SEQ ID NO: 115, vlCDR1 comprising SEQ ID NO: 116, vlCDR2 comprising SEQ ID NO: 117, and vlCDR3 comprising SEQ ID NO: 118; m) vhCDR1 comprising SEQ ID NO: 119, vhCDR2 comprising SEQ ID NO: 120, vhCDR3 comprising SEQ ID NO: 121, vlCDR1 comprising SEQ ID NO: 122, vlCDR2 comprising SEQ ID NO: 123, and vlCDR3 comprising SEQ ID NO: 124; n) vhCDR1 comprising SEQ ID NO: 131, vhCDR2 comprising SEQ ID NO: 132, vhCDR3 comprising SEQ ID NO: 133, vlCDR1 comprising SEQ ID NO: 134, vlCDR2 comprising SEQ ID NO: 135, and vlCDR3 comprising SEQ ID NO: 136; o) a vhCDR1 comprising SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO: 142; p) vhCDR1 comprising SEQ ID NO: 143, vhCDR2 comprising SEQ ID NO: 144, vhCDR3 comprising SEQ ID NO: 145, vlCDR1 comprising SEQ ID NO: 146, vlCDR2 comprising SEQ ID NO: 147, and vlCDR3 comprising SEQ ID NO: 148; q) a vhCDR1 comprising SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO: 154; r) a vhCDR1 comprising SEQ ID NO: 155, a vhCDR2 comprising SEQ ID NO: 156, a vhCDR3 comprising SEQ ID NO: 157, a vlCDR1 comprising SEQ ID NO: 158, a vlCDR2 comprising SEQ ID NO: 159, and a vlCDR3 comprising SEQ ID NO: 160; s) a vhCDR1 comprising SEQ ID NO: 161, a vhCDR2 comprising SEQ ID NO: 162, a vhCDR3 comprising SEQ ID NO: 163, a vlCDR1 comprising SEQ ID NO: 164, a vlCDR2 comprising SEQ ID NO: 165, and a vlCDR3 comprising SEQ ID NO: 166; or t) vhCDR1 comprising SEQ ID NO: 167, vhCDR2 comprising SEQ ID NO: 168, vhCDR3 comprising SEQ ID NO: 169, vlCDR1 comprising SEQ ID NO: 170, vlCDR2 comprising SEQ ID NO: 171, and vlCDR3 comprising SEQ ID NO: 172 An antibody comprising:

3. The antibody of claim 1 or 2, which binds to human and / or cynomolgus monkey BTLA.

4. a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:22; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:31 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:32; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:36; vhCDR1 comprising SEQ ID NO:107, vhCDR2 comprising SEQ ID NO:108, vhCDR3 comprising SEQ ID NO:109, vlCDR1 comprising SEQ ID NO:110, vlCDR2 comprising SEQ ID NO:111, and vlCDR3 comprising SEQ ID NO:112; vhCDR1 comprising SEQ ID NO: 137, vhCDR2 comprising SEQ ID NO: 138, vhCDR3 comprising SEQ ID NO: 139, vlCDR1 comprising SEQ ID NO: 140, vlCDR2 comprising SEQ ID NO: 141, and vlCDR3 comprising SEQ ID NO: 142; or vhCDR1 comprising SEQ ID NO: 149, vhCDR2 comprising SEQ ID NO: 150, vhCDR3 comprising SEQ ID NO: 151, vlCDR1 comprising SEQ ID NO: 152, vlCDR2 comprising SEQ ID NO: 153, and vlCDR3 comprising SEQ ID NO: 154; The antibody of claim 1 or 2, which acts as a BTLA antagonist and blocks BTLA binding to HVEM and HVEM-mediated inhibition of T cell function.

5. a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:26; a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:29 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:30; vhCDR1 comprising SEQ ID NO:101, vhCDR2 comprising SEQ ID NO:102, vhCDR3 comprising SEQ ID NO:103, vlCDR1 comprising SEQ ID NO:104, vlCDR2 comprising SEQ ID NO:105, and vlCDR3 comprising SEQ ID NO:106; vhCDR1 comprising SEQ ID NO: 119, vhCDR2 comprising SEQ ID NO: 120, vhCDR3 comprising SEQ ID NO: 121, vlCDR1 comprising SEQ ID NO: 122, vlCDR2 comprising SEQ ID NO: 123, and vlCDR3 comprising SEQ ID NO: 124; or vhCDR1 comprising SEQ ID NO: 131, vhCDR2 comprising SEQ ID NO: 132, vhCDR3 comprising SEQ ID NO: 133, vlCDR1 comprising SEQ ID NO: 134, vlCDR2 comprising SEQ ID NO: 135, and vlCDR3 comprising SEQ ID NO: 136; The antibody of claim 1 or 2, which acts as a BTLA agonist and inhibits pro-inflammatory T cell function.

6. The antibody of claim 1 , comprising a constant region having an amino acid sequence that is at least 90% identical to human IgG.

7. The antibody of claim 6, wherein the human IgG is selected from the group consisting of IgG1, IgG2, IgG3 and IgG4.

8. The antibody of claim 7, wherein the IgG is IgG2.

9. A nucleic acid composition encoding an antibody according to any one of claims 1 to 8.

10. a) a first nucleic acid comprising SEQ ID NO:185 and a second nucleic acid comprising SEQ ID NO:186; b) a first nucleic acid comprising SEQ ID NO: 187 and a second nucleic acid comprising SEQ ID NO: 188; c) a first nucleic acid comprising SEQ ID NO: 189 and a second nucleic acid comprising SEQ ID NO: 190; d) a first nucleic acid comprising SEQ ID NO: 191 and a second nucleic acid comprising SEQ ID NO: 192; e) a first nucleic acid comprising SEQ ID NO: 193 and a second nucleic acid comprising SEQ ID NO: 194; f) a first nucleic acid comprising SEQ ID NO: 195 and a second nucleic acid comprising SEQ ID NO: 196; g) a first nucleic acid comprising SEQ ID NO:197 and a second nucleic acid comprising SEQ ID NO:198; h) a first nucleic acid comprising SEQ ID NO: 199 and a second nucleic acid comprising SEQ ID NO: 200; i) a first nucleic acid comprising SEQ ID NO:201 and a second nucleic acid comprising SEQ ID NO:202; j) a first nucleic acid comprising SEQ ID NO: 203 and a second nucleic acid comprising SEQ ID NO: 204; k) a first nucleic acid comprising SEQ ID NO:205 and a second nucleic acid comprising SEQ ID NO:206; l) a first nucleic acid comprising SEQ ID NO:207 and a second nucleic acid comprising SEQ ID NO:208; m) a first nucleic acid comprising SEQ ID NO:209 and a second nucleic acid comprising SEQ ID NO:210; n) a first nucleic acid comprising SEQ ID NO:211 and a second nucleic acid comprising SEQ ID NO:212; o) a first nucleic acid comprising SEQ ID NO:213 and a second nucleic acid comprising SEQ ID NO:214; p) a first nucleic acid comprising SEQ ID NO:215 and a second nucleic acid comprising SEQ ID NO:216; q) a first nucleic acid comprising SEQ ID NO:217 and a second nucleic acid comprising SEQ ID NO:218; r) a first nucleic acid comprising SEQ ID NO:219 and a second nucleic acid comprising SEQ ID NO:220; s) a first nucleic acid comprising SEQ ID NO:221 and a second nucleic acid comprising SEQ ID NO:222; t) a first nucleic acid comprising SEQ ID NO: 223 and a second nucleic acid comprising SEQ ID NO: 224; or u) a first nucleic acid comprising SEQ ID NO: 225 and a second nucleic acid comprising SEQ ID NO: 226 The nucleic acid composition of claim 9 .

11. 11. An expression vector composition comprising the nucleic acid composition of claim 10, wherein the first nucleic acid is contained in a first expression vector and the second nucleic acid is contained in a second expression vector.

12. 11. An expression vector composition comprising the nucleic acid composition of claim 10, wherein the first nucleic acid and the second nucleic acid are contained in a single expression vector.

13. A host cell comprising the expression vector composition of claim 11 or 12.

14. 14. A method of making an antibody, comprising culturing the host cell of claim 13 under conditions in which the antibody is expressed, and recovering the antibody.

15. A composition comprising an antibody according to any one of claims 1 to 8 and a pharma- ceutically acceptable carrier or diluent.

16. A method for modulating an immune response in a subject, comprising administering to the subject an effective amount of an antibody described in any one of claims 1 to 8, or a composition described in claim 15.

17. 17. The method of claim 16, which stimulates an immune response in a subject, comprising administering to the subject an effective amount of an antibody of any one of claims 1 to 8, or a composition of claim 15, wherein the antibody acts as a BTLA antagonist.

18. The method of claim 17, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:21 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:22; and / or a vhCDR1 comprising SEQ ID NO:107, a vhCDR2 comprising SEQ ID NO:108, a vhCDR3 comprising SEQ ID NO:109, a vlCDR1 comprising SEQ ID NO:110, a vlCDR2 comprising SEQ ID NO:111, and a vlCDR3 comprising SEQ ID NO:

112.

19. The method of claim 17, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 31 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 32; and / or a vhCDR1 comprising SEQ ID NO: 137, a vhCDR2 comprising SEQ ID NO: 138, a vhCDR3 comprising SEQ ID NO: 139, a vlCDR1 comprising SEQ ID NO: 140, a vlCDR2 comprising SEQ ID NO: 141, and a vlCDR3 comprising SEQ ID NO:

142.

20. The method of claim 17, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 35 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 36; and / or a vhCDR1 comprising SEQ ID NO: 149, a vhCDR2 comprising SEQ ID NO: 150, a vhCDR3 comprising SEQ ID NO: 151, a vlCDR1 comprising SEQ ID NO: 152, a vlCDR2 comprising SEQ ID NO: 153, and a vlCDR3 comprising SEQ ID NO:

154.

21. 17. The method of claim 16, which suppresses an immune response in a subject, comprising administering to the subject an effective amount of an antibody of any one of claims 1 to 8, or a composition of claim 15, wherein the antibody acts as a BTLA agonist.

22. The method of claim 21, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 19 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 20; and / or a vhCDR1 comprising SEQ ID NO: 101, a vhCDR2 comprising SEQ ID NO: 102, a vhCDR3 comprising SEQ ID NO: 103, a vlCDR1 comprising SEQ ID NO: 104, a vlCDR2 comprising SEQ ID NO: 105, and a vlCDR3 comprising SEQ ID NO:

106.

23. The method of claim 21, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:25 and a light chain variable region comprising the amino acid sequence of SEQ ID NO:26; and / or a vhCDR1 comprising SEQ ID NO:119, a vhCDR2 comprising SEQ ID NO:120, a vhCDR3 comprising SEQ ID NO:121, a vlCDR1 comprising SEQ ID NO:122, a vlCDR2 comprising SEQ ID NO:123, and a vlCDR3 comprising SEQ ID NO:

124.

24. The method of claim 21, wherein the antibody comprises a heavy chain variable region comprising an amino acid sequence at least 90% identical to SEQ ID NO:29 and a light chain variable region comprising an amino acid sequence at least 90% identical to SEQ ID NO:30; and / or a vhCDR1 comprising SEQ ID NO:131, a vhCDR2 comprising SEQ ID NO:132, a vhCDR3 comprising SEQ ID NO:133, a vlCDR1 comprising SEQ ID NO:134, a vlCDR2 comprising SEQ ID NO:135, and a vlCDR3 comprising SEQ ID NO:

136.

25. A method for treating cancer in a subject, comprising administering to the subject an effective amount of an antibody described in any one of claims 1 to 8, or a composition described in claim 15, wherein the antibody acts as a BTLA antagonist.

26. 26. The method of claim 25, wherein the cancer upregulates HVEM.

27. 27. The method of claim 25 or 26, wherein the subject has high levels of BTLA on T cells.

28. 28. The method of any one of claims 25 to 27, wherein the cancer is gastric cancer.

29. 29. The method of any one of claims 25 to 28, wherein the antibody is combined with one or more additional therapeutic agents to treat cancer.

30. 30. The method of claim 29, wherein the additional therapeutic agent is another immune checkpoint inhibitor.

31. 31. The method of claim 30, wherein the other immune checkpoint inhibitor is selected from the group consisting of ipilimumab, nivolumab, pembrolizumab, avelumab, durvalumab, and atezolizumab.

32. A method for treating an autoimmune disease in a subject, comprising administering to the subject an effective amount of an antibody described in any one of claims 1 to 8, or a composition described in claim 15, wherein the antibody acts as a BTLA agonist.

33. 33. The method of claim 32, wherein the subject expresses low levels of HVEM on autoreactive T cells present at sites where autoimmune disease occurs.

34. 34. The method of claim 32 or 33, wherein the autoimmune disease is multiple sclerosis.

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