Patent Application
20210107979
This disclosure relates to DLL3 binding agents and chimeric antigen receptors (CARs) comprising an antigen binding molecule which binds to DLL3, polynucleotides encoding the same, and methods of treating a cancer in a patient using the same.
This application is being filed electronically via EFS-Web and includes an electronically submitted sequence listing in .txt format. The .txt file contains a sequence listing entitled “AT-019_03 US_SL” created on Feb. 4, 2020, and having a size of 1,026,798 bytes. The sequence listing contained in this .txt file is part of the specification and is incorporated herein by reference in its entirety.
Small cell lung cancer (SCLC) is an aggressive form of lung cancer with a poor prognosis and limited therapeutic options. SCLC represents about 10-15% of all new diagnosed lung cancers. The American Cancer Society estimates that about 234,000 new cases of lung cancer will be diagnosed in 2018. Estimated 5-year relative survival rates for SCLC are 31% (for stage I), 19% (for stage II), 8% (for stage III) and 2% (for stage IV). Survival rates for SCLC have remained low for several decades in a large part due to the lack of new therapies to combat this form of lung cancer. Conventional therapeutic treatments for cancer include chemotherapy and radiotherapy. Patients typically respond well to the current front-line therapy, which includes etoposide and cisplatin, but invariably quickly relapse with chemoresistant disease. Prognosis in the relapsed refractory setting is extremely poor, with rapid disease progression and short median survival of less than six months. There remains therefore a great need to develop more targeted and potent therapies for proliferative disorders.
Adoptive transfer of immune cells genetically modified to recognize malignancy-associated antigens is showing promise as a new approach to treating cancer (see, e.g., Brenner et al., Current Opinion in Immunology, 22(2): 251-257 (2010); Rosenberg et al., Nature Reviews Cancer, 8(4): 299-308 (2008)) Immune cells can be genetically modified to express chimeric antigen receptors (CARs), fusion proteins comprised of a DLL3 antigen recognition moiety and T cell activation domains (see, e.g., Eshhar et al., Proc. Natl. Acad. Sci. USA, 90(2): 720-724 (1993), and Sadelain et al., Curr. Opin. Immunol, 21(2): 215-223 (2009)) Immune cells that contain CARs, e.g., CAR-T cells (CAR-Ts), are engineered to endow them with antigen specificity while retaining or enhancing their ability to recognize and kill a target cell.
DLL3 is a non-canonical Notch ligand, functioning in a cell autonomous manner to inhibit Notch signaling, thus blocking cell to cell interactions and internalization of Notch in the target cell. Delta-like ligand 3 (DLL3) is an SCLC tumor marker and has been found to be associated with cancer stem cells. Other indications that implicate DLL3 include melanoma, low grade gliomas, glioblastoma, medullary thyroid cancer, carcinoids, dispersed neuroendocrine tumors in the pancreas, bladder and prostate, testicular cancer, and lung adenocarcinomas with neuroendocrine features. There is a need for treatments for cancer and in particular malignancies involving aberrant expression of DLL3. Provided herein are methods and compositions addressing this need.
Provided herein are chimeric antigen receptors (CARs) comprising a DLL3 antigen binding domain that specifically binds to DLL3; and immune cells comprising these DLL3-specific CARs, e.g., CAR-T cells. Also provided are methods of making and using these DLL3-specific CARs, and immune cells comprising these DLL3-specific CARs. The DLL-3 targeting CAR T cells described herein demonstrate good transduction efficiency, in vitro phenotype and potent in vitro and in vivo anti-tumor activity.
In one aspect, the present disclosure provides a chimeric antigen receptor comprising an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and wherein the antigen binding domain comprises at least one of: (a) a variable heavy chain CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs 1, 10, 19, 28, 37, 46, 55, 64, 73, 82, 91, 100, 109, 118, 127, 136, 145, 154, 163, 172, 181, 190, 199, 208, 217, 226, 235, 244, 253, 262, 271, 280, 289, 298, 307, 316, 325, 334, 343, 352, 361, 370, 379, 388, 397, 406, 415, 424, 433, 442, 451, and 460; (b) a variable heavy chain CDR2 comprising an amino acid sequence selected from the group consisting of SEQ NOs: 2, 11, 20, 38, 47, 56, 65, 74, 83, 92, 101, 110, 119, 128, 137, 146, 155, 164, 173, 182, 191, 200, 209, 218, 227, 236, 245, 254, 263, 272, 281, 290, 299, 308, 317, 326, 335, 344, 353, 362, 371, 380, 389, 398, 407, 416, 425, 434, 443, 452, 461, and 695; (c) a variable heavy chain CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs 3, 12, 21, 30, 39, 48, 57, 66, 75, 84, 93, 102, 111, 120, 129, 138, 147, 156, 165, 174, 183, 192, 201, 210, 219, 228, 237, 246, 255, 264, 273, 282, 291, 300, 309, 318, 327, 336, 345, 354, 363, 372, 381, 390, 399, 408, 417, 426, 435, 444, 453, and 462; (d) a variable light chain CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 13, 22, 31, 40, 49, 58, 67, 85, 94, 103, 112, 121, 130, 139, 148, 157, 166, 175, 184, 193, 202, 211, 220, 229, 238, 247, 256, 265, 274, 283, 292, 301, 310, 319, 328, 337, 346, 355, 364, 373, 382, 391, 400, 409, 418, 427, 436, 445, 454, 463, and 696; (e) a variable light chain CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 5, 14, 23, 32, 41, 50, 59, 68, 77, 86, 95, 104, 113, 122, 131, 140, 149, 158, 167, 176, 185, 194, 203, 212, 221, 230, 239, 248, 257, 266, 275, 284, 293, 302, 311, 320, 329, 338, 347, 356, 365, 374, 383, 392, 401, 410, 419, 428, 437, 446, 455, and 464; and (f) a variable light chain CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 15, 24, 33, 42, 51, 60, 69, 78, 87, 96, 105, 114, 123, 132, 141, 150, 159, 168, 177, 186, 195, 204, 213, 222, 231, 240, 249, 258, 267, 276, 285, 294, 303, 312, 321, 330, 339, 348, 357, 366, 375, 384, 393, 402, 411, 420, 429, 438, 447, 456, and 465.
In another aspect, the present disclosure provides a chimeric antigen receptor comprising an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and wherein the antigen binding domain comprises: (a) a variable heavy chain CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 10, 19, 28, 37, 46, 55, 64, 73, 82, 91, 100, 109, 118, 127, 136, 145, 154, 163, 172, 181, 190, 199, 208, 217, 226, 235, 244, 253, 262, 271, 280, 289, 298, 307, 316, 325, 334, 343, 352, 361, 370, 379, 388, 397, 406, 415, 424, 433, 442, 451, and 460; (b) a variable heavy chain CDR2 comprising an amino acid sequence selected from the group consisting of SEQ NOs: 2, 11, 20, 38, 47, 56, 65, 74, 83, 92, 101, 110, 119, 128, 137, 146, 155, 164, 173, 182, 191, 200, 209, 218, 227, 236, 245, 254, 263, 272, 281, 290, 299, 308, 317, 326, 335, 344, 353, 362, 371, 380, 389, 398, 407, 416, 425, 434, 443, 452, and 695461; and (c) a variable heavy chain CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 12, 21, 30, 39, 48, 57, 66, 75, 84, 93, 102, 111, 120, 129, 138, 147, 156, 165, 174, 183, 192, 201, 210, 219, 228, 237, 246, 255, 264, 273, 282, 291, 300, 309, 318, 327, 336, 345, 354, 363, 372, 381, 390, 399, 408, 417, 426, 435, 444, 453, and 462.
In one aspect, the present disclosure provides a chimeric antigen receptor comprising an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and wherein the antigen binding domain comprises: (a) a variable light chain CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 13, 22, 31, 40, 49, 58, 67, 85, 94, 103, 112, 121, 130, 139, 148, 157, 166, 175, 184, 193, 202, 211, 220, 229, 238, 247, 256, 265, 274, 283, 292, 301, 310, 319, 328, 337, 346, 355, 364, 373, 382, 391, 400, 409, 418, 427, 436, 445, 454, 463, and 696; (b) a variable light chain CDR2 comprising an amino acid sequence selected from the group consisting of SEQ NOs: 5, 14, 23, 32, 41, 50, 59, 68, 77, 86, 95, 104, 113, 122, 131, 140, 149, 158, 167, 176, 185, 194, 203, 212, 221, 230, 239, 248, 257, 266, 275, 284, 293, 302, 311, 320, 329, 338, 347, 356, 365, 374, 383, 392, 401, 410, 419, 428, 437, 446, 455, and 464; and (c) a variable light chain CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 15, 24, 33, 42, 51, 60, 69, 78, 87, 96, 105, 114, 123, 132, 141, 150, 159, 168, 177, 186, 195, 204, 213, 222, 231, 240, 249, 258, 267, 276, 285, 294, 303, 312, 321, 330, 339, 348, 357, 366, 375, 384, 393, 402, 411, 420, 429, 438, 447, 456, and 465.
In another aspect, the present disclosure provides a chimeric antigen receptor comprising an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and wherein the antigen binding domain comprises at least one of: (a) a variable heavy chain comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 7, 16, 25, 34, 43, 52, 61, 70, 79, 88, 97, 106, 115, 124, 133, 142, 151, 160, 169, 178, 187, 196, 205, 214, 223, 232, 241, 250, 259, 268, 277, 286, 295, 304, 313, 322, 331, 340, 349, 358, 367, 376, 385, 394, 403, 412, 421, 430, 439, 448, 457, 466; and (b) a variable light chain comprising an amino acid sequence selected from the group consisting of SEQ NOs: 8, 17, 26, 35, 44, 53, 62, 71, 80, 89, 98, 107, 116, 125, 134, 143, 152, 161, 170, 179, 188, 197, 206, 215, 224, 233, 242, 251, 260, 269, 278, 287, 296, 305, 314, 323, 332, 341, 350, 359, 368, 377, 386, 395, 404, 413, 422, 431, 440, 449, 458, and 467, wherein the variable heavy chain and the variable light chain is linked by at least one linker.
In a further aspect, the present disclosure provides a chimeric antigen receptor comprising an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and wherein the antigen binding domain comprises: (a) a variable heavy chain comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 7, 16, 25, 34, 43, 52, 61, 70, 79, 88, 97, 106, 115, 124, 133, 142, 151, 160, 169, 178, 187, 196, 205, 214, 223, 232, 241, 250, 259, 268, 277, 286, 295, 304, 313, 322, 331, 340, 349, 358, 367, 376, 385, 394, 403, 412, 421, 430, 439, 448, 457, and 466; and (b) a variable light chain comprising an amino acid sequence selected from the group consisting of SEQ NOs: 8, 17, 26, 35, 44, 53, 62, 71, 80, 89, 98, 107, 116, 125, 134, 143, 152, 161, 170, 179, 188, 197, 206, 215, 224, 233, 242, 251, 260, 269, 278, 287, 296, 305, 314, 323, 332, 341, 350, 359, 368, 377, 386, 395, 404, 413, 422, 431, 440, 449, 458, and 467, wherein the variable heavy chain and the variable light chain is linked by at least one linker.
In one aspect, the present disclosure provides a chimeric antigen receptor comprising an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and wherein the antigen binding domain comprises a sequence selected from the group consisting of those scFvs presented in Table 1d.
In another aspect, the present disclosure provides, a chimeric antigen receptor that specifically binds to DLL3, wherein the chimeric antigen receptor comprises an amino acid sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 482 to 533 and 632-683. In some embodiments, the chimeric antigen receptor comprises an amino acid sequence of any one of SEQ ID NOs: 482 to 533 and 632-683.
In some embodiments, the present disclosure provides, a chimeric antigen receptor that specifically binds to DLL3, wherein the chimeric antigen receptor comprises an amino acid sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 482 to 533 and 632-683, with or without a signal sequence. In some embodiments, the chimeric antigen receptor comprises an amino acid sequence of any one of SEQ ID NOs: 482 to 533 and 632-683, with or without a signal sequence.
In some embodiments, the intracellular domain of the chimeric antigen receptor comprises at least one costimulatory domain.
In some embodiments, the costimulatory domain of the chimeric antigen receptor is a signaling region of CD28, OX-40, 4-1BB/CD137, CD2, CD7, CD27, CD30, CD40, programmed death-1 (PD-1), inducible T cell costimulator (ICOS), lymphocyte function-associated antigen-1 (LFA-1 (CD1 1a/CD18), CD3 gamma, CD3 delta, CD3 epsilon, CD247, CD276 (B7-H3), LIGHT, (TNFSF14), NKG2C, Ig alpha (CD79a), DAP-10, Fc gamma receptor, MHC class I molecule, TNF receptor proteins, an Immunoglobulin protein, cytokine receptor, integrins, Signaling Lymphocytic Activation Molecules (SLAM proteins), activating NK cell receptors, BTLA, a Toll ligand receptors, ICAM-1, B7-H3, CDS, ICAM-1, GITR, BAFFR, LIGHT, HVEM (LIGHTR), KIRDS2, SLAMF7, NKp80 (KLRF1), NKp44, NKp30, NKp46, CD19, CD4, CD8alpha, CD8beta, IL-2R beta, IL-2R gamma, IL-7R alpha, ITGA4, VLA1, CD49a, ITGA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD1 1d, ITGAE, CD103, ITGAL, CD1 1a, LFA-1, ITGAM, CD1 1b, ITGAX, CD1 1c, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, NKG2D, TNFR2, TRANCE/RANKL, DNAMI (CD226), SLAMF4 (CD244, 2B4), CD84, CD96 (Tactile), CEACAM1, CRT AM, Ly9 (CD229), CD160 (BY55), PSGL1, CD100 (SEMA4D), CD69, SLAMF6 (NTB-A, Ly108), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD162), LTBR, LAT, GADS, SLP-76, PAG/Cbp, CD19a, a ligand that specifically binds with CD83, or any combination thereof.
In some embodiments, the costimulatory domain comprises a signaling region of CD28.
In some embodiments, the CD28 costimulatory domain comprises SEQ ID NO: 550.
In some embodiments, the costimulatory domain comprises a signaling region of 4-1BB/CD137.
In some embodiments, the 4-1BB/CD137 costimulatory domain comprises SEQ ID NO: 480.
In some embodiments, the intracellular domain comprises at least one activating domain.
In some embodiments, the activating domain comprises CD3.
In some embodiments, the CD3 comprises CD3 zeta.
In some embodiments, the CD3 zeta comprises SEQ ID NO: 481.
In some embodiments, the chimeric antigen receptor is encoded by the polynucleotide sequence of any one of SEQ ID NOs: 571-621 and 631.
In some embodiments, the chimeric antigen receptor further comprises a safety switch.
In some embodiments, the safety switch comprises a CD20 mimotope or a QBEND-10 epitope.
In some embodiments, the safety switch comprises one or more CD20 mimotopes or one or more QBEND-10 epitopes, or combinations thereof.
In some embodiments, the chimeric antigen receptor comprises one or more safety switch in the format of QR3, SR2, RSR, or R2S.
In some embodiments, the chimeric antigen receptor comprises the amino acid sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 622-628, 474-476, 565, and 684-694.
In some embodiments, the chimeric antigen receptor comprises the amino acid sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 622-628, 474-476, 565, and 684-694, with or without a signal sequence.
In some aspects, the present disclosure provides an isolated polynucleotide encoding any one of the chimeric antigen receptors described herein.
In another aspect, the present disclosure provides a vector comprising the polynucleotide encoding any one of the chimeric antigen receptors described herein.
In some embodiments, the vector is a retroviral vector, a DNA vector, a plasmid, a RNA vector, an adenoviral vector, an adenovirus associated vector, a lentiviral vector, or any combination thereof.
In another aspect, the present disclosure provides an engineered immune cell expressing a chimeric antigen receptors described herein.
In some aspects, the present disclosure provides an engineered immune cell expressing the polynucleotide or vector encoding any one of the chimeric antigen receptors described herein.
In some embodiments, the engineered immune cell is a T cell, tumor infiltrating lymphocyte (TIL), NK cell, TCR-expressing cell, dendritic cell, or NK-T cell.
In some embodiments, the engineered immune cell is an autologous T cell.
In some embodiments, the engineered immune cell is an allogeneic T cell.
In some embodiments, the engineered immune cell is TCR (e.g., TCRα, TCRβ) knocked out.
In one aspect, the present disclosure provides a pharmaceutical composition comprising the engineered immune cell expressing a chimeric antigen receptors described herein.
In some aspects, the present disclosure provides a method of treating a disease or disorder in a subject in need thereof comprising administering to the subject the engineered immune cell or the pharmaceutical composition comprising the engineered immune cell expressing a chimeric antigen receptors described herein.
In some embodiments, the disease or disorder is cancer.
In some embodiments, the disease or disorder is small cell lung cancer.
In some aspects, the present disclosure provides an article of manufacture comprising the engineered immune cell or the pharmaceutical composition comprising the engineered immune cell expressing a chimeric antigen receptors described herein.
In some aspects, the present disclosure provides an anti-DLL3 binding agent disclosed herein.
In some embodiments, the anti-DLL3 binding agent is an antibody, an antibody conjugate, or an antigen-binding fragment thereof, optionally, a F(ab′)2 fragment, a Fab′ fragment, a Fab fragment, a Fv fragment, a scFv fragment, a dsFv fragment, or a dAb fragment.
In some embodiments, the binding agent is a monoclonal antibody comprising an IgG constant region.
In some embodiments, the anti-DLL3 binding agent comprises a variable heavy (VH) chain sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to a VH sequence provided in Table 1b.
In some embodiments, the anti-DLL3 binding agent comprises a variable light (VL) chain sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to a VL sequence provided in Table 1c.
In some embodiments, the anti-DLL3 binding agent comprises a sequence that is at least about 80%, 85%, 90%, 95%, 96%, 98%, 99% or 100% identical to an scFv sequence presented in Table 1d.
In some embodiments, the anti-DLL3 binding agent is a fusion protein comprising a scFv fragment fused to an Fc constant region.
In some aspects, the present disclosure provides a pharmaceutical composition comprising the anti-DLL3 binding agent disclosed herein and a pharmaceutically acceptable excipient.
In some aspects, the present disclosure provides a method of treating a disease or disorder in a subject in need thereof comprising administering to the subject an anti-DLL3 binding agent, or a pharmaceutical composition comprising the anti-DLL3 binding agent, as disclosed herein.
In some embodiments, the disease or disorder is cancer.
In some embodiments, the disease or disorder is small cell lung cancer.
Provided herein are DLL3-specific antibodies and chimeric antigen receptors (CARs). The DLL-3 specific CARs described herein, comprise an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3, and polynucleotides encoding these CARs. Also provided are immune cells comprising these DLL3-specific CARs, e.g., CAR-T cells, and pharmaceutical compositions comprising these immune cells. Methods of making and using these DLL3-specific CARs and immune cells comprising these DLL3-specific CARs are also disclosed, e.g., for the treatment of cancer.
The present disclosure provides DLL-3 binding agents (e.g., molecules comprising a DLL3 antigen binding domain, DLL-3 antibodies or fragments thereof), that specifically bind to DLL-3. As used herein, the term “antibody” refers to a polypeptide that includes canonical immunoglobulin sequence elements sufficient to confer specific binding to a particular target antigen (e.g., DLL-3). As is known in the art, intact antibodies as produced in nature are approximately 150 kD tetrameric agents comprised of two identical heavy chain polypeptides (about 50 kD each) and two identical light chain polypeptides (about 25 kD each) that associate with each other into what is commonly referred to as a “Y-shaped” structure. Each heavy chain is comprised of at least four domains (each about 110 amino acids long)—an amino-terminal variable (VH) domain (located at the tips of the Y structure), followed by three constant domains: CH1, CH2, and the carboxy-terminal CH3 (located at the base of the Y's stem). A short region, known as the “switch”, connects the heavy chain variable and constant regions. The “hinge” connects CH2 and CH3 domains to the rest of the antibody. Two disulfide bonds in this hinge region connect the two heavy chain polypeptides to one another in an intact antibody. Each light chain is comprised of two domains—an amino-terminal variable (VL) domain, followed by a carboxy-terminal constant (CL) domain, separated from one another by another “switch”. Those skilled in the art are well familiar with antibody structure and sequence elements, recognize “variable” and “constant” regions in provided sequences, and understand that there may be some flexibility in definition of a “boundary” between such domains such that different presentations of the same antibody chain sequence may, for example, indicate such a boundary at a location that is shifted one or a few residues relative to a different presentation of the same antibody chain sequence.
The assignment of amino acids to each of the framework, CDR, and variable domains is typically in accordance with numbering schemes of Kabat numbering (see, e.g., Kabat et al. in Sequences of Proteins of Immunological Interest, 5th Ed., NIH Publication 91-3242, Bethesda Md. 1991), Chothia numbering (see, e.g., Chothia & Lesk, (1987), J Mol Biol 196: 901-917; Al-Lazikani et al., (1997) J Mol Biol 273: 927-948; Chothia et al., (1992) J Mol Biol 227: 799-817; Tramontano et al., (1990) J Mol Biol 215(1): 175-82; and U.S. Pat. No. 7,709,226), contact numbering, or the AbM scheme (Antibody Modeling program, Oxford Molecular).
Accordingly, in some embodiments, the CDRs of the DLL3 binding agents presented herein are numbered according to the Kabat numbering scheme. In other embodiments, the CDRs of the DLL3 binding agents presented herein are numbered according to the Chothia numbering scheme. In other embodiments, the CDRs of the DLL3 binding agents presented herein are numbered according to the contact numbering scheme. In other embodiments, the CDRs of the DLL3 binding agents presented herein are numbered according to the AbM numbering scheme.
Intact antibody tetramers are comprised of two heavy chain-light chain dimers in which the heavy and light chains are linked to one another by a single disulfide bond; two other disulfide bonds connect the heavy chain hinge regions to one another, so that the dimers are connected to one another and the tetramer is formed. Naturally-produced antibodies are also glycosylated, typically on the CH2 domain. Each domain in a natural antibody has a structure characterized by an “immunoglobulin fold” formed from two beta sheets (e.g., 3-, 4-, or 5-stranded sheets) packed against each other in a compressed antiparallel beta barrel. Each variable domain contains three hypervariable loops known as “complement determining regions” (CDR1, CDR2, and CDR3) and four somewhat invariant “framework” regions (FR1, FR2, FR3, and FR4). When natural antibodies fold, the FR regions form the beta sheets that provide the structural framework for the domains, and the CDR loop regions from both the heavy and light chains are brought together in three-dimensional space so that they create a single hypervariable antigen binding site located at the tip of the Y structure. The Fc region of naturally-occurring antibodies binds to elements of the complement system, and also to receptors on effector cells, including for example effector cells that mediate cytotoxicity. As is known in the art, affinity and/or other binding attributes of Fc regions for Fc receptors can be modulated through glycosylation or other modification. In some embodiments, antibodies produced and/or utilized in accordance with the present invention include glycosylated Fc domains, including Fc domains with modified or engineered such glycosylation.
For purposes of the present invention, in certain embodiments, any polypeptide or complex of polypeptides that includes sufficient immunoglobulin domain sequences as found in natural antibodies can be referred to and/or used as an “antibody”, whether such polypeptide is naturally produced (e.g., generated by an organism reacting to an antigen), or produced by recombinant engineering, chemical synthesis, or other artificial system or methodology. In some embodiments, an antibody is polyclonal; in some embodiments, an antibody is monoclonal. In some embodiments, an antibody has constant region sequences that are characteristic of mouse, rabbit, primate, or human antibodies. In some embodiments, antibody sequence elements are humanized, primatized, chimeric, etc, as is known in the art.
Moreover, the term “antibody” as used herein, can refer in appropriate embodiments (unless otherwise stated or clear from context) to any of the art-known or developed constructs or formats for utilizing antibody structural and functional features in alternative presentation. For example, in some embodiments, an antibody utilized in accordance with the present invention is in a format selected from, but not limited to, intact IgA, IgG, IgE or IgM antibodies; bi- or multi-specific antibodies (e.g., Zybodies®, etc); antibody fragments such as Fab fragments, Fab′ fragments, F(ab′)2 fragments, Fd′ fragments, Fd fragments, and isolated CDRs or sets thereof; single chain Fvs; polypeptide-Fc fusions; single domain antibodies (e.g., shark single domain antibodies such as IgNAR or fragments thereof); cameloid antibodies; masked antibodies (e.g., Probodies®); Small Modular ImmunoPharmaceuticals (“SMIPs™); single chain or Tandem diabodies (TandAb®); VHHs; Anticalins®; Nanobodies® minibodies; BiTE®s; ankyrin repeat proteins or DARPINs®; Avimers®; DARTs; TCR-like antibodies; Adnectins®; Affilins®; Trans-Bodies®; Affibodies®; TrimerX®; MicroProteins; Fynomers®, Centyrins®; and KALBITOR®s. In some embodiments, an antibody may lack a covalent modification (e.g., attachment of a glycan) that it would have if produced naturally. In some embodiments, an antibody may contain a covalent modification (e.g., attachment of a glycan, a payload (e.g., a detectable moiety, a therapeutic moiety, a catalytic moiety, etc), or other pendant group (e.g., poly-ethylene glycol, etc).
Antibodies include antibody fragments. Antibodies also include, but are not limited to, polyclonal monoclonal, chimeric dAb (domain antibody), single chain, Fab, Fa, F(ab)2 fragments, scFvs, and Fab expression libraries. An antibody may be a whole antibody, or immunoglobulin, or an antibody fragment.
As detailed above, whole antibodies consist of two pairs of a “light chain” (LC) and a “heavy chain” (HC) (such light chain (LC)/heavy chain pairs are abbreviated herein as LC/HC). The light chains and heavy chains of such antibodies are polypeptides consisting of several domains. In a whole antibody, each heavy chain comprises a heavy chain variable region (abbreviated herein as HCVR or VH) and a heavy chain constant region. The heavy chain constant region comprises the heavy chain constant domains CH1, CH2 and CH3 (antibody classes IgA, IgD, and IgG) and optionally the heavy chain constant domain CH4 (antibody classes IgE and IgM). Each light chain comprises a light chain variable domain VL and a light chain constant domain CL. The variable domains VH and VL can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4 (Janeway, C. A., Jr, et al, (2001). Immunobiology, 5th ed., Garland Publishing; and Woof, J., Burton, D., Nat Rev Immunol 4 (2004) 89-99). The two pairs of heavy chain and light chain (HC/LC) are capable of specifically binding to the same antigen. Thus said whole antibody is a bivalent, monospecific antibody. Such “antibodies” include e.g., mouse antibodies, human antibodies, chimeric antibodies, humanized antibodies and genetically engineered antibodies (variant or mutant antibodies) as long as their characteristic properties are retained. In some embodiments, antibodies or binding agents are humanized antibodies, especially as recombinant human or humanized antibodies.
In some embodiments, the antibody or binding agent can be “symmetrical.” By “symmetrical” is meant that the antibody or binding agent has the same kind of Fv regions (e.g., the antibody has two Fab regions). In some embodiments, the antibody or binding agent can be “asymmetrical.” By “asymmetrical” is meant that the antibody or binding agent has at least two different kinds of Fv regions (e.g., the antibody has: Fab and scFv regions, Fab and scFv2 regions, or Fab-VHH regions). Various asymmetrical antibody or binding agent architectures are known in the art (Brinkman and Kontermann et al. 2017 Mabs (9)(2): 182-212).
As used herein, the term “antibody agent” refers to an agent that specifically binds to a particular antigen. In some embodiments, the term encompasses any polypeptide or polypeptide complex that includes immunoglobulin structural elements sufficient to confer specific binding. Exemplary antibody agents include, but are not limited to monoclonal antibodies or polyclonal antibodies. In some embodiments, an antibody agent may include one or more constant region sequences that are characteristic of mouse, rabbit, primate, or human antibodies. In some embodiments, an antibody agent may include one or more sequence elements are humanized, primatized, chimeric, etc, as is known in the art. In many embodiments, the term “antibody agent” is used to refer to one or more of the art-known or developed constructs or formats for utilizing antibody structural and functional features in alternative presentation. For example, an antibody agent utilized in accordance with the present invention is in a format selected from, but not limited to, intact IgA, IgG, IgE or IgM antibodies; bi- or multi-specific antibodies (e.g., Zybodies, etc); antibody fragments such as Fab fragments, Fab′ fragments, F(ab′)2 fragments, Fd′ fragments, Fd fragments, and isolated CDRs or sets thereof; single chain Fvs; polypeptide-Fc fusions; single domain antibodies (e.g., shark single domain antibodies such as IgNAR or fragments thereof); cameloid antibodies; masked antibodies (e.g., Probodies®); Small Modular ImmunoPharmaceuticals (“SMIPs™); single chain or Tandem diabodies (TandAb®); VHHs; Anticalins®; Nanobodies® minibodies; BiTE®s; ankyrin repeat proteins or DARPINs®; Avimers; DARTs; TCR-like antibodies; Adnectins®; Affilins®; Trans-Bodies®; Affibodies®; TrimerX®; MicroProteins; Fynomers, Centyrins; and KALBITOR®s.
In some embodiments, an antibody may lack a covalent modification (e.g., attachment of a glycan) that it would have if produced naturally. In some embodiments, an antibody may contain a covalent modification (e.g., attachment of a glycan, a payload [e.g., a detectable moiety, a therapeutic moiety, a catalytic moiety, etc], or other pendant group [e.g., poly-ethylene glycol, etc.]. In many embodiments, an antibody agent is or comprises a polypeptide whose amino acid sequence includes one or more structural elements recognized by those skilled in the art as a complementarity determining region (CDR); in some embodiments, an antibody agent is or comprises a polypeptide whose amino acid sequence includes at least one CDR (e.g., at least one heavy chain CDR and/or at least one light chain CDR) that is substantially identical to one found in a reference antibody In some embodiments, an antibody agent is or comprises a polypeptide whose amino acid sequence includes structural elements recognized by those skilled in the art as an immunoglobulin variable domain. In some embodiments, an antibody agent is a polypeptide protein having a binding domain which is homologous or largely homologous to an immunoglobulin-binding domain.
An antibody or antigen binding molecule encoded of the present invention can be single chained or double chained. In some embodiments, the antibody or antigen binding molecule is single chained. In certain embodiments, the antigen binding molecule is selected from the group consisting of an scFv, a Fab, a Fab′, a Fv, a F(ab)2, a dAb, and any combination thereof.
In some embodiments, an anti-DLL-3 antibody agent is isolated. In some embodiments, an antibody agent can be purified to greater than 95% or 99% purity as determined by, for example, electrophoretic (e.g., SDS-PAGE, isoelectric focusing (IEF), capillary electrophoresis) or chromatographic (e.g., ion exchange or reverse phase HPLC) (See, e.g., Flatman et al., J. Chromatogr., B 848:79-87 (2007)). In some aspects, the present disclosure provides a composition comprising a DLL-3 binding agent (e.g., a DLL3 specific antibody) and a pharmaceutically acceptable carrier.
In some embodiments, an anti-DLL-3 antibody agent comprises an Fc. Fc domains can interact with cell surface receptors which can allow antibodies to activate the immune system. In IgG, IgA and IgD antibody isotypes, a Fc region is composed of two identical protein fragments, derived from the second and third constant domains of the antibody's two heavy chains; IgM and IgE Fc regions contain three heavy chain constant domains (CH domains 2-4) in each polypeptide chain. The Fc regions of IgG may bear a highly conserved N-glycosylation site (N297). Glycosylation of the Fc fragment may be essential for Fc receptor-mediated activity. The N-glycans attached to this site can predominantly be core-fucosylated diantennary structures of the complex type.
While the constant regions of the light and heavy chains may not be directly involved in binding of the antibody to an antigen, the constant regions can influence the orientation of the variable regions. The constant regions can also exhibit various effector functions, such as participation in antibody-dependent complement-mediated lysis or antibody-dependent cellular toxicity via interactions with effector molecules and cells.
The disclosed anti-DLL-3 antibody agents can be antibodies of any isotype, including isotype IgA, isotype IgD, isotype IgE, isotype IgG, or isotype IgM. In some embodiments, an anti-DLL-3 antibody contains a IgG1, IgG2, IgG3, or IgG4 constant domain.
Provided herein are DLL3 binding agents (e.g., antibodies) that can bind to various regions or domains of the DLL3 target. The epitope can be, for example, contiguous amino acids of the DLL3 target (linear or contiguous epitope) or come together from two or more non-contiguous regions of the DLL3 target (conformational, non-linear, discontinuous, or non-contiguous epitope). The epitope to which the DLL3 antigen binding domain binds can be determined by various assays, e.g., NMR spectroscopy, X-ray diffraction crystallography studies, ELISA assays, hydrogen/deuterium exchange coupled with mass spectrometry (e.g., liquid chromatography electrospray mass spectrometry), array-based oligo-peptide scanning assays, flow cytometry, and/or mutagenesis mapping (e.g., site-directed mutagenesis mapping).
Representative DLL3 regions or domains are shown in
In some embodiments, the DLL3 binding agent comprises a variable heavy chain (VH), wherein the amino acid sequence of the VH is selected from the VH sequences presented in Table 1b. In some embodiments, an anti-DLL-3 binding agent comprises an immunoglobulin heavy chain having at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) sequence identity to an amino acid sequence presented in Table 1b.
In some embodiments, the DLL3 binding agent comprises a variable light chain (VL), wherein the amino acid sequence of the VL is selected from the VL sequences presented in Table 1c. In some embodiments, an anti-DLL-3 binding agent comprises an immunoglobulin light chain having at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) sequence identity to an amino acid sequence presented in Table 1c.
Provided herein are DLL3 binding agents (e.g., antibodies), wherein the DLL3 antigen binding domain comprises a variable heavy chain (VH) and a variable light chain, wherein the amino acid sequence of the VH is selected from the VH sequences presented in Table 1b; and the amino acid sequence of the VL is selected from the VL sequences presented in Table 1c.
In some embodiments, the DLL-3 binding agent comprises a heavy chain CDR1, CDR2, and CDR3. In some embodiments, the heavy chain CDR1, CDR2, and CDR3 sequences are selected from the heavy chain CDRs presented in Table 1e.
In some embodiments, the DLL-3 binding agent comprises a light chain CDR1, CDR2, and CDR3. In some embodiments, the light chain CDR1, CDR2, and CDR3 sequences are selected from the light chain CDRs presented in Table 1f.
The disclosure encompasses modifications to the DLL3 antibody agents comprising the sequences shown in Tables 1b to 1e, including functionally equivalent DLL3 antibody agents having modifications which do not significantly affect their properties and variants which have enhanced or decreased activity and/or affinity. For example, the amino acid sequence may be mutated to obtain a DLL3 antigen binding agent with a desired binding affinity to DLL3. Modification of polypeptides is routine practice in the art and need not be described in detail herein. Examples of modified polypeptides include polypeptides with conservative substitutions of amino acid residues, one or more deletions or additions of amino acids which do not significantly deleteriously change the functional activity, or which mature (enhance) the affinity of the polypeptide for its ligand, or use of chemical analogs.
Amino acid sequence insertions include amino- and/or carboxyl-terminal fusions ranging in length from one residue to polypeptides containing a hundred or more residues, as well as intrasequence insertions of single or multiple amino acid residues. Examples of terminal insertions include an antibody with an N-terminal methionyl residue or the antibody fused to an epitope tag. Other insertional variants of the antibody molecule include the fusion to the N- or C-terminus of the antibody of an enzyme or a polypeptide which increases the half-life of the antibody in the blood circulation.
Substitution variants have at least one amino acid residue in the antigen binding domain removed and a different residue inserted in its place. In some embodiments, sites of interest for substitutional mutagenesis include the hypervariable regions/CDRs, but FR alterations are also contemplated. Conservative substitutions are shown in Table 2 under the heading of “conservative substitutions.” If such substitutions result in a change in biological activity, then more substantial changes, denominated “exemplary substitutions” in Table 2, or as further described below in reference to amino acid classes, may be introduced and the products screened.
i. Antibody Fragments
In one aspect, an anti-DLL-3 antibody agent according to any of the above embodiments can be an antibody fragment. An antibody fragment comprises a portion of an intact antibody, such as the antigen binding or variable region of the intact antibody. Antibody fragments include, but are not limited to, Fab, Fab′, Fab′-SH, F(ab′)2, Fv, diabody, linear antibodies, multispecific formed from antibody fragments antibodies and scFv fragments, and other fragments described below. In some embodiments, the antibody is a full length antibody, e.g., an intact IgG1 antibody or other antibody class or isotype as described herein. (See, e.g., Hudson et al., Nat. Med., 9: 129-134 (2003); Pluckthun, The Pharmacology of Monoclonal Antibodies, vol. 113, pp. 269-315 (1994); Hollinger et al., Proc. Natl. Acad. Sci. USA, 90: 6444-6448 (1993); WO93/01161; and U.S. Pat. Nos. 5,571,894, 5,869,046, 6,248,516, and 5,587,458). A full length antibody, intact antibody, or whole antibody is an antibody having a structure substantially similar to a native antibody structure or having heavy chains that contain an Fc region as defined herein. Antibody fragments can be made by various techniques, including but not limited to proteolytic digestion of an intact antibody as well as production by recombinant host cells (e.g., E. coli or phage), as known in the art.
An Fv antibody fragment comprises a complete antigen-recognition and antigen-binding site. This fragment may comprise a dimer of one heavy- and one light-chain variable region domain in tight, non-covalent association. From the folding of these two domains emanate six hypervariable loops (three loops each from the H and L chain) that contribute the amino acid residues for antigen binding and confer antigen binding specificity to the antibody. However, even a single variable region (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen, although at a lower affinity than the entire binding site.
A diabody is a small antibody fragment prepared by constructing an sFv fragment with a short linker (e.g., about 5-10 residues) between the VH and VL domains such that interchain but not intra-chain pairing of the V domains is achieved, resulting in a bivalent fragment. Bispecific diabodies are heterodimers of two crossover sFv fragments in which the VH and VL domains of the two antibodies are present on different polypeptide chains (See, e.g., EP 404,097; WO 93/11161; and Hollinger et al, Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993)).
Domain antibodies (dAbs), which can be produced in fully human form, are the smallest known antigen-binding fragments of antibodies, ranging from about 11 kDa to about 15 kDa. DAbs are the robust variable regions of the heavy and light chains of immunoglobulins (VH and VL, respectively). They are highly expressed in microbial cell culture, show favorable biophysical properties including, for example, but not limited to, solubility and temperature stability, and are well suited to selection and affinity maturation by in vitro selection systems such as, for example, phage display. dAbs are bioactive as monomers and, owing to their small size and inherent stability can be formatted into larger molecules to create drugs with prolonged serum half-lives or other pharmacological activities. (See, e.g., WO9425591 and US20030130496).
Fv and scFv are the species have intact combining sites that are devoid of constant regions. Thus, they may be suitable for reduced nonspecific binding during in vivo use. A single-chain Fv (sFv or scFv) is an antibody fragment that comprises the VH and VL antibody domains connected into a single polypeptide chain. The sFv polypeptide can further comprise a polypeptide linker between the VH and VL domains that enable the sFv to form the desired structure for antigen binding (See, e.g., Pluckthun, The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds., Springer-Verlag, New York, pp. 269-315 (1994); Borrebaeck 1995, infra. scFv fusion proteins can be constructed to yield fusion of an effector protein at either the amino or the carboxy terminus of an sFv. The antibody fragment also can be a “linear antibody (See, e.g., U.S. Pat. No. 5,641,870). Such linear antibody fragments can be monospecific or bispecific. Exemplary DLL3 specific scFvs are provided in Table 1d.
In some embodiments, the DLL3 antigen binding domain comprises a scFv comprising a light chain variable (VL) region and the heavy chain variable (VH) region of a DLL3-specific monoclonal antibody joined by a flexible linker. Single chain variable region fragments may be made by linking light and/or heavy chain variable regions by using a linking peptide An example of a linking peptide is the GS linker having the amino acid sequence (GGGGS)x wherein x is 1, 2, 3, 4, or 5 (SEQ ID NO: 470). In some embodiments, x is 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or any integer less than about 20. In some embodiments, the linker is (GGGGS)4 (SEQ ID NO: 478). In general, linkers can be short, flexible polypeptides, which in some embodiments are comprised of about 20 or fewer amino acid residues. Linkers can in turn be modified for additional functions, such as attachment of drugs or attachment to solid supports. The single chain variants can be produced either recombinantly or synthetically. For synthetic production of scFv, an automated synthesizer can be used. For recombinant production of scFv, a suitable plasmid containing polynucleotide that encodes the scFv can be introduced into a suitable host cell, either eukaryotic, such as yeast, plant, insect or mammalian cells, or prokaryotic, such as E. coli. Polynucleotides encoding the scFv of interest can be made by routine manipulations such as ligation of polynucleotides. The resultant scFv can be isolated using standard protein purification techniques known in the art.
In exemplary embodiments, provided herein are DLL3 antigen binding domains comprising: a VH region comprising a VH CDR1, VH CDR2, and VH CDR3 of the VH sequence shown in Table 1b and/or a VL region comprising VL CDR1, VL CDR2, and VL CDR3 of the VL sequence shown in Table 1c. In some embodiments, the VH and VL are linked together by a linker. In some embodiments the linker comprises the amino acid sequence GGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 478). In some embodiments the linker may be encoded by a DNA sequence comprising GGCGGTGGAGGCTCCGGAGGGGGGGGCTCTGGCGGAGGGGGCTCC (SEQ ID NO: 564). In some embodiments, the linker may be encoded by a DNA sequence comprising ggcggcggcggctctggaggaggaggcagcggcggaggaggctccggaggcggcggctct (SEQ ID NO: 630). In some embodiments the linker comprises the amino acid sequence GGGGSGGGGSGGGGS (SEQ ID NO: 534). In some embodiments the linker is a scFv Whitlow linker, which may comprise the amino acid sequence GSTSGSGKPGSGEGSTKG (SEQ ID NO: 535). The scFv Whitlow linker may be encoded by a DNA sequence comprising GGGTCTACATCCGGCTCCGGGAAGCCCGGAAGTGGCGAAGGTAGTACAAAGGGG (SEQ ID NO: 566). In some embodiments, the VH and VL sequences of the scFv's disclosed can be oriented with the VH sequence being located at the N-terminus of the scFv and followed by a linker and then the VL sequence, while in other embodiments the scFv can be oriented with the VL sequence at the N-Terminus and followed by a linker and then the VH sequence.
ii. Chimeric and Humanized Antibodies
In some embodiments, an anti-DLL-3 antibody agent is or comprises a monoclonal antibody, including a chimeric, humanized or human antibody.
In some embodiments, an anti-DLL-3 antibody agent provided herein can be a chimeric antibody (See, e.g., U.S. Pat. No. 4,816,567; and Morrison et al., Proc. Natl. Acad. Sci. USA, 81: 6851-6855 (1984)). A chimeric antibody can be an antibody in which a portion of the heavy and/or light chain is derived from a particular source or species, while the remainder of the heavy and/or light chain is derived from a different source or species. In one example, a chimeric antibody can comprise a non-human variable region (e.g., a variable region derived from a mouse, rat, hamster, rabbit, or non-human primate, such as a monkey) and a human constant region. In a further example, a chimeric antibody can be a “class switched” antibody in which the class or subclass has been changed from that of the parent antibody. Chimeric antibodies include antigen-binding fragments thereof.
In some embodiments, a chimeric antibody can be a humanized antibody (See, e.g., Almagro and Fransson, Front. Biosci., 13: 1619-1633 (2008); Riechmann et al., Nature, 332:323-329 (1988); Queen et al., Proc. Natl Acad. Sci. USA 86: 10029-10033 (1989); U.S. Pat. Nos. 5,821,337, 7,527,791, 6,982,321, and 7,087,409; Kashmiri et al., Methods 36:25-34 (2005); Padlan, Mol. Immunol, 28:489-498 (1991); Dall'Acqua et al., Methods, 36:43-60 (2005); Osbourn et al., Methods, 36:61-68 (2005); and Klimka et al., Br. J. Cancer, 83:252-260 (2000)). A humanized antibody is a chimeric antibody comprising amino acid residues from non-human hypervariable regions and amino acid residues from human FRs. In certain embodiments, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the hypervariable regions (e.g., CDRs) correspond to those of a non-human antibody, and all or substantially all of the FRs correspond to those of a human antibody. A humanized antibody optionally may comprise at least a portion of an antibody constant region derived from a human antibody.
A non-human antibody can be humanized to reduce immunogenicity to humans, while retaining the specificity and affinity of the parental non-human antibody. A humanized antibody can comprise one or more variable domains comprising one or more CDRs, or portions thereof, derived from a non-human antibody. A humanized antibody can comprise one or more variable domains comprising one or more FRs, or portions thereof, derived from human antibody sequences. A humanized antibody can optionally comprise at least a portion of a human constant region. In some embodiments, one or more FR residues in a humanized antibody are substituted with corresponding residues from a non-human antibody (e.g., the antibody from which the CDR residues are derived), to restore or improve antibody specificity or affinity.
Human framework regions that may be used for humanization include but are not limited to: framework regions selected using a “best-fit” method; framework regions derived from the consensus sequence of human antibodies of a particular subgroup of light or heavy chain variable regions; human mature (somatically mutated) framework regions or human germline framework regions; and framework regions derived from screening FR libraries (See, e.g., Sims et al., J. Immunol, 151:2296 (1993); Carter et al., Proc. Natl. Acad. Sci. USA, 89:4285 (1992); Presta et al., J. Immunol, 151:2623 (1993); Baca et al., J. Biol. Chem., 272: 10678-10684 (1997); and Rosok et al., J. Biol. Chem., 271:22611-22618 (1996)).
iii. Human Antibodies
In some embodiments, an anti-DLL-3 antibody agent provided herein is a human antibody. Human antibodies can be produced using various techniques known in the art (See, e.g., van Dijk and van de Winkel, Curr. Opin. Pharmacol, 5: 368-74 (2001); and Lonberg, Curr. Opin. Immunol, 20:450-459 (2008)). A human antibody can be one which possesses an amino acid sequence which corresponds to that of an antibody produced by a human or a human cell or derived from a non-human source that utilizes human antibody repertoires or other human antibody-encoding sequences. This definition of a human antibody specifically excludes a humanized antibody comprising non-human antigen-binding residues. Human antibodies may be prepared by administering an immunogen (e.g., a DLL-3 protein) to a transgenic animal that has been modified to produce intact human antibodies or intact antibodies with human variable regions in response to antigenic challenge (See, e.g., Lonberg, Nat. Biotech., 23: 1117-1125 (2005); U.S. Pat. Nos. 6,075,181, 6,150,584, 5,770,429, and 7,041,870; and U.S. Pat. App. Pub. No. US 2007/0061900) Human variable regions from intact antibodies generated by such animals may be further modified, e.g., by combining with a different human constant region.
Human antibodies can also be made by hybridoma-based methods. For example, human antibodies can be produced from human myeloma and mouse-human heteromyeloma cell lines, using human B-cell hybridoma technology, and other methods (See, e.g., Kozbor, J. Immunol, 133: 3001 (1984); Brodeur et al., Monoclonal Antibody Production Techniques and Applications, pp. 51-63 (1987); Boerner et al., J. Immunol, 147: 86 (1991); Li et al., Proc. Natl. Acad. Sci. USA, 103:3557-3562 (2006); U.S. Pat. No. 7,189,826; Ni, Xiandai Mianyixue, 26(4): 265-268 (2006); Vollmers and Brandlein, Histology and Histopathology, 20(3): 927-937 (2005); and Vollmers and Brandlein, Methods and Findings in Experimental and Clinical Pharmacology, 27(3): 185-91 (2005)). Human antibodies may also be generated by isolating Fv clone variable domain sequences selected from human-derived phage display libraries. Such variable domain sequences may then be combined with a desired human constant region.
Modifications of the oligosaccharide in an antibody can be made, for example, to create antibody variants with certain improved properties. For example, antibody glycosylation variants can have improved CDC function. In some embodiments, the present disclosure can contemplate an antibody variant that possesses some but not all effector functions, which make it a desirable candidate for applications in which the half-life of the antibody in vivo is important yet certain effector functions (such as complement) are unnecessary or deleterious. In vitro and/or in vivo cytotoxicity assays can be conducted to confirm the reduction/depletion of CDC activities.
iv. Antibody Derivatives
In some embodiments, an antibody agent provided herein may be further modified to contain additional nonproteinaceous moieties that are known in the art and readily available. The moieties suitable for derivatization of the antibody can include but are not limited to water soluble polymers. Non-limiting examples of water soluble polymers can include, but are not limited to, polyethylene glycol (PEG), copolymers of ethylene glycol/propylene glycol, carboxymethylcellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone, poly-1,3-dioxolane, poly-1,3,6-trioxane, ethyl ene/maleic anhydride copolymer, polyaminoacids (either homopolymers or random copolymers), and dextran or poly(n-vinyl pyrrolidone)polyethylene glycol, polypropylene glycol homopolymers, polypropylene oxide/ethylene oxide co-polymers, polyoxyethylated polyols (e.g., glycerol), polyvinyl alcohol, and mixtures thereof. Polyethylene glycol propionaldehyde may have advantages in manufacturing due to its stability in water.
The polymer may be of any molecular weight, and may be branched or unbranched. The number of polymers attached to the antibody may vary, and if two or more polymers are attached, they can be the same or different molecules.
In some embodiments, conjugates of an antibody and nonproteinaceous moiety that may be selectively heated by exposure to radiation are provided. In some embodiments, the nonproteinaceous moiety can be a carbon nanotube (See, e.g., Kam et al., Proc. Natl. Acad. Sci. USA, 102: 11600-11605 (2005)). The radiation may be of any wavelength, and can include, but is not limited to, wavelengths that do not harm ordinary cells, but which heat the nonproteinaceous moiety to a temperature at which cells proximal to the antibody-nonproteinaceous moiety are killed.
A DLL3 binding agent (e.g., a molecule comprising an antigen binding domain) is said to “specifically bind” its target antigen (e.g., human, cyno or mouse DLL3) when the dissociation constant (Kd) is ˜1 nM. The antigen binding domain specifically binds antigen with “high affinity” when the Kd is 1-5 nM, and with “very high affinity” when the Kd is 0.1-0.5 nM. In one embodiment, the antigen binding domain has a Kd of ˜1 nM. In one embodiment, the off-rate is <1×10−5. In other embodiments, the antigen binding domains will bind to human DLL3 with a Kd of between about 1×10−7 M and 1×10−12 M, and in yet another embodiment the antigen binding domains will bind with a Kd between about 1×10−5 M and 1×10−12 M.
As provided herein, the antigen binding domains of the present disclosure specifically bind mammalian DLL3 (e.g., human DLL3, cyno DLL3 or mouse DLL3). In certain embodiments, a DLL3 antigen binding domain of the present disclosure binds mammalian DLL3 with a Kd of less than 1×10−6 M, less than 1×10−7 M, less than 1×10−8 M, or less than 1×10−9 M. In one particular embodiment, the DLL3 antigen binding domains binds mammalian DLL3 (e.g., human DLL3, cyno DLL3 or mouse DLL3) with a Kd of less than 1×10−7 M. In another embodiment, the DLL3 antigen binding domains binds mammalian DLL3 (e.g., human DLL3, cyno DLL3 or mouse DLL3) with a Kd of less than 1×10−8 M. In some embodiments, the DLL3 antigen binding domains binds mammalian DLL3 (e.g., human DLL3, cyno DLL3) with a Kd of about 1×10−7M, about 2×10−7 M, about 3×10−7 M, about 4×10−7M, about 5×10−7 M, about 6×10−7 M, about 7×10−7 M, about 8×10−7 M, about 9×10−7 M, about 1×10−8 M, about 2×10−8 M, about 3×10−8 M, about 4×10−8 M, about 5×10−8 M, about 6×10−8 M, about 7×10−8 M, about 8×10−8 M, about 9×10−8 M, about 1×10−9 M, about 2×10−9 M, about 3×10−9 M, about 4×10−9 M, about 5×10−9 M, about 6×10−9 M, about 7×10−9 M, about 8×10−9 M, about 9×10−9 M, about 1×10−10 M, or about 5×10−10 M. In certain embodiments, the Kd is calculated as the quotient of Koff/Kon, and the Kon and Koff are determined using a monovalent antibody, such as a Fab fragment, as measured by, e.g., BIAcore® surface plasmon resonance technology. In other embodiments, the Kd is calculated as the quotient of Koff/Kon, and the Kon and Koff are determined using a bivalent antibody, such as a Fab fragment, as measured by, e.g., BIAcore® surface plasmon resonance technology.
In some embodiments, the DLL3 antigen binding domain binds mammalian DLL3 (e.g., human DLL3, cyno DLL3 or mouse DLL3) with an association rate (kon) of less than 1×10−4 M4 s-1, less than 2×10−4 M4 less than 3×10−4 M4 s-1, less than 4×10−4 M4 s-1, less than 5×10−4 M4 s-1, less than 7×10−4 M4 s-1, less than 8×10−4 M4 s-1, less than 9×10−4 M4 s-1, less than 1×10−5 M4 s-1, less than 2×10−5 M4 s-1, less than 3×10−5 M4 s-1, less than 4×10−5 M4 s-1, less than 5×10−5 M4 s-1, less than 6×10−5 M4 s-1, less than 7×10−5 M4 s-1, less than 8×10−5 M4 s-1, less than 9×10−5 M4 s-1, less than 1×10−6 M4 s-1, less than 2×10−6 M4 s-1, less than 3×10−6 M4 s-1, less than 4×10−6 M4 s-1, less than 5×10−6 M4 s-1, less than 6×10−6 M4 s-1, less than 7×10−6 M4 s-1, less than 8×10−6 M4 s-1, less than 9×10−6 M4 s-1, or less than 1×10−7 M4 s-1. In certain embodiments, the kon is determined using a monovalent antibody, such as a Fab fragment, as measured by, e.g., BIAcore® surface plasmon resonance technology. In other embodiments, the kon is determined using a bivalent antibody as measured by, e.g., BIAcore® surface plasmon resonance technology.
In some embodiments, the DLL3 antigen binding domain binds mammalian DLL3 (e.g., human DLL3, cyno DLL3 or mouse DLL3) with an dissociation rate (koff) of less than 1×10−2 s−1, less than 2×10−2 s−1, less than 3×10−2 s−1, less than 4×10−2 s−1, less than 5×10−2 s−1, less than 6×10−2 s−1, less than 7×10−2 s−1, less than 8×10−2 s−1, less than 9×10−2 s−1, less than 1×10−3 s−1, less than 2×10−3 s−1, less than 3×10−3 s−1, less than 4×10−3 s−1, less than 5×10−3 s−1, less than 6×10−3 s−1, less than 7×10−3 s−1, less than 8×10−3 s−1, less than 9×10−3 s−1, less than 1×10−4 s−1, less than 2×10−4 s−1, less than 3×10−4 s−1, less than 4×10−4 s−1, less than 5×10−4 s−1, less than 6×10−4 s−1 less than 7×10−4 s−1, less than 8×10−4 s−1, less than 9×10−4 s−1, less than 1×10−5 s−1, or less than 5×10−4 s−1. In certain embodiments, the koff is determined using a monovalent antibody, such as a Fab fragment, as measured by, e.g., BIAcore® surface plasmon resonance technology. In other embodiments, the koff is determined using a bivalent antibody as measured by, e.g., BIAcore® surface plasmon resonance technology.
As used herein, chimeric antigen receptors (CARs) are proteins that specifically recognize target antigens (e.g., target antigens on cancer cells). When bound to the target antigen, the CAR may activate the immune cell to attack and destroy the cell bearing that antigen (e.g., the cancer cell). CARs may also incorporate costimulatory or signaling domains to increase their potency. See Krause et al., J. Exp. Med., Volume 188, No. 4, 1998 (619-626); Finney et al., Journal of Immunology, 1998, 161: 2791-2797, Song et al., Blood 119:696-706 (2012); Kalos et al., Sci. Transl. Med. 3:95 (2011); Porter et al., N Engl. J. Med. 365:725-33 (2011), and Gross et al., Annu. Rev. Pharmacol. Toxicol. 56:59-83 (2016); U.S. Pat. Nos. 7,741,465, and 6,319,494.
Chimeric antigen receptors described herein comprise an extracellular domain, a transmembrane domain, and an intracellular domain, wherein the extracellular domain comprises a DLL3 antigen binding domain that specifically binds to DLL3. In some embodiments, the DLL-3 specific CAR comprises the following elements from 5′ to 3′: a signal sequence, a DLL3 antigen binding domain (e g, an anti-DLL3 scFv), a hinge and transmembrane region, and one or more successive signaling domains. In certain embodiments, the DLL-3 specific CAR comprises the following elements from 5′ to 3′: a CD8α signal sequence, a DLL3 scFv comprising a DLL3 variable heavy chain and/or variable light chain described herein, a CD8α hinge and transmembrane region, a 41BB cytoplasmic signaling domain, and a CD3ζ cytoplasmic signaling domain. (
In some embodiments, the DLL-3 specific CARs further comprise a safety switches and/or monoclonal antibody specific-epitope.
a. Antigen Binding Domain
As discussed above, the DLL3 CARs described herein comprise an antigen binding domain. An “antigen binding domain” as used herein means any polypeptide that binds a specified target antigen, for example the specified target antigen can be the DLL3 (DLL-3) protein or fragment thereof (referred to interchangeably herein as a “DLL3 antigen”, “DLL3 target antigen”, or “DLL3 target”). In some embodiments, the antigen binding domain binds to a DLL3 antigen on a tumor cell. In some embodiments, the antigen binding domain binds to a DLL3 antigen on a cell involved in a hyperproliferative disease.
In some embodiments, the antigen binding domain comprises a variable heavy chain, variable light chain, and/or one or more CDRs described herein. In some embodiments, the antigen binding domain is a single chain variable fragment (scFv), comprising light chain CDRs CDR1, CDR2 and CDR3, and heavy chain CDRs CDR1, CDR2 and CDR3.
In some embodiments, DLL-3 specific CARs comprise a VH shown in Table 1b. In some embodiments, DLL-3 specific CARs comprise a VL shown in Table 1c. In some embodiments, DLL-3 specific CARs comprise a heavy chain CDR1, CDR2, CDR3 shown in Table 1e. In some embodiments, DLL-3 specific CARs comprise a light chain CDR1, CDR2, CDR3 shown in Table 1f.
Variants of the antigen binding domains (e.g., variants of the CDRs, VH and/or VL) are also within the scope of the disclosure, e.g., variable light and/or variable heavy chains that each have at least 70-80%, 80-85%, 85-90%, 90-95%, 95-97%, 97-99%, or above 99% identity to the amino acid sequences of the antigen binding domain sequences described herein. In some instances, such molecules include at least one heavy chain and one light chain, whereas in other instances the variant forms contain two variable light chains and two variable heavy chains (or subparts thereof). A skilled artisan will be able to determine suitable variants of the antigen binding domains as set forth herein using well-known techniques. In certain embodiments, one skilled in the art can identify suitable areas of the molecule that may be changed without destroying activity by targeting regions not believed to be important for activity.
In certain embodiments, the polypeptide structure of the antigen binding domains is based on antibodies, including, but not limited to, monoclonal antibodies, bispecific antibodies, minibodies, domain antibodies, synthetic antibodies (sometimes referred to herein as “antibody mimetics”), chimeric antibodies, humanized antibodies, human antibodies, antibody fusions (sometimes referred to herein as “antibody conjugates”), and fragments thereof, respectively. In some embodiments, the antigen binding domain comprises or consists of avimers.
A DLL3 antigen binding domain is said to be “selective” when it binds to one target more tightly than it binds to a second target.
In some embodiments, the DLL3 antigen binding domain is a scFv. In some embodiments, the DLL3 specific CAR comprises an scFv provided in Table 1d.
In some embodiments, the DLL3 specific CAR comprises a leader or signal peptide; in some embodiments the leader peptide comprises an amino acid sequence that is at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identical to the amino acid sequence MALPVTALLLPLALLLHAARP (SEQ ID NO: 477). In some embodiments, the leader peptide comprises the amino acid sequence of SEQ ID NO: 477. In some embodiments, the leader peptide is encoded by a nucleic acid sequence comprising:
In other embodiments, the disclosure relates to isolated polynucleotides encoding any one of the DLL3 antigen binding domains described herein. In some embodiments, the disclosure relates to isolated polynucleotides encoding a DLL3 CAR described in Table 10. Also provided herein are vectors comprising the polynucleotides, and methods of making the same.
b. Safety Switches and Monoclonal Antibody Specific-Epitopes
It will be appreciated that adverse events may be minimized by transducing the immune cells (containing one or more CARs) with a suicide gene. It may also be desired to incorporate an inducible “on” or “accelerator” switch into the immune cells. Suitable techniques include use of inducible caspase-9 (U.S. Appl. 2011/0286980) or a thymidine kinase, before, after or at the same time, as the cells are transduced with the CAR construct of the present disclosure. Additional methods for introducing suicide genes and/or “on” switches include TALENS, zinc fingers, RNAi, siRNA, shRNA, antisense technology, and other techniques known in the art.
In accordance with the disclosure, additional on-off or other types of control switch techniques may be incorporated herein. These techniques may employ the use of dimerization domains and optional activators of such domain dimerization. These techniques include, e.g., those described by Wu et al., Science 2014 350 (6258) utilizing FKBP/Rapalog dimerization systems in certain cells, the contents of which are incorporated by reference herein in their entirety. Additional dimerization technology is described in, e.g., Fegan et al. Chem. Rev. 2010, 110, 3315-3336 as well as U.S. Pat. Nos. 5,830,462; 5,834,266; 5,869,337; and 6,165,787, the contents of which are also incorporated by reference herein in their entirety. Additional dimerization pairs may include cyclosporine-A/cyclophilin, receptor, estrogen/estrogen receptor (optionally using tamoxifen), glucocorticoids/glucocorticoid receptor, tetracycline/tetracycline receptor, vitamin D/vitamin D receptor. Further examples of dimerization technology can be found in e.g., WO 2014/127261, WO 2015/090229, US 2014/0286987, US2015/0266973, US2016/0046700, U.S. Pat. No. 8,486,693, US 2014/0171649, and US 2012/0130076, the contents of which are further incorporated by reference herein in their entirety.
In some embodiments, the CAR-immune cell (e.g., CAR-T cell) of the disclosure comprises a polynucleotide encoding a suicide polypeptide, such as for example RQR8. See, e.g., WO2013153391A, which is hereby incorporated by reference in its entirety. In CAR-immune cell (e.g., CAR-T cell) cells comprising the polynucleotide, the suicide polypeptide is expressed at the surface of a CAR-immune cell (e.g., CAR-T cell). In some embodiments, the suicide polypeptide comprises the amino acid sequence shown in SEQ ID NO: 552:
The suicide polypeptide may also comprise a signal peptide at the amino terminus—for example, MGTSLLCWMALCLLGADHADA (SEQ ID NO: 553). In some embodiments, the suicide polypeptide comprises the amino acid sequence shown in SEQ ID NO: 554, which includes the signal sequence of SEQ ID NO: 553:
When the suicide polypeptide is expressed at the surface of a CAR-immune cell (e.g., CAR-T cell), binding of rituximab to the R epitopes of the polypeptide causes lysis of the cell. More than one molecule of rituximab may bind per polypeptide expressed at the cell surface. Each R epitope of the polypeptide may bind a separate molecule of rituximab. Deletion of DLL3-specific CAR-immune cell (e.g., CAR-T cell) may occur in vivo, for example by administering rituximab to a patient. The decision to delete the transferred cells may arise from undesirable effects being detected in the patient which are attributable to the transferred cells, such as for example, when unacceptable levels of toxicity are detected.
In some embodiments, a suicide polypeptide is expressed on the surface of the cell. In some embodiments, a suicide polypeptide is included in the CAR construct. In some embodiments, a suicide polypeptide is not part of the DLL3 CAR construct.
In some embodiments, the extracellular domain of any one of the DLL3-specific CARs disclosed herein may comprise one or more epitopes specific for (i.e., specifically recognized by) a monoclonal antibody. These epitopes are also referred to herein as mAb-specific epitopes. Exemplary mAb-specific epitopes are disclosed in International Patent Publication No. WO 2016/120216, which is incorporated herein in its entirety. In these embodiments, the extracellular domain of the CARs comprise antigen binding domains that specifically bind to DLL3 and one or more epitopes that bind to one or more monoclonal antibodies (mAbs). CARs comprising the mAb-specific epitopes can be single-chain or multi-chain.
The inclusion of epitopes specific for monoclonal antibodies in the extracellular domain of the CARs described herein allows sorting and depletion of engineered immune cells expressing the CARs. In some embodiments, this feature also promotes recovery of endogenous DLL3-expressing cells that were depleted by administration of engineered immune cells expressing the CARs. In some embodiments, allowing for depletion provides a safety switch in case of deleterious effects, e.g., upon administration to a subject.
Accordingly, in some embodiments, the present disclosure relates to a method for sorting and/or depleting the engineered immune cells endowed with the CARs comprising mAb-specific epitopes and a method for promoting recovery of endogenous DLL3-expressing cells.
Several epitope-monoclonal antibody couples can be used to generate CARs comprising monoclonal antibody specific epitopes; in particular, those already approved for medical use, such as CD20 epitope/rituximab as a non-limiting example.
The disclosure also encompasses methods for sorting the engineered immune cells endowed with the DLL3-specific CARs expressing the mAb-specific epitope(s) and therapeutic methods where the activation of the engineered immune cells endowed with these CARs is modulated by depleting the cells using an antibody that targets the external ligand binding domain of said CARs. Table 4 provides exemplary mimotope sequences that can be inserted into the extracellular domains of any one of the CARs of the disclosure.
In some embodiments, the extracellular binding domain of the CAR comprises the following sequence:
c. Hinge Domain
The extracellular domain of the CARs of the disclosure may comprise a “hinge” domain (or hinge region). The term generally to any polypeptide that functions to link the transmembrane domain in a CAR to the extracellular antigen binding domain in a CAR. In particular, hinge domains can be used to provide more flexibility and accessibility for the extracellular antigen binding domain.
A hinge domain may comprise up to 300 amino acids—in some embodiments 10 to 100 amino acids or in some embodiments 25 to 50 amino acids. The hinge domain may be derived from all or part of naturally occurring molecules, such as from all or part of the extracellular region of CD8, CD4, CD28, 4-1BB, or IgG (in particular, the hinge region of an IgG; it will be appreciated that the hinge region may contain some or all of a member of the immunoglobulin family such as IgG1, IgG2, IgG3, IgG4, IgA, IgD, IgE, IgM, or fragment thereof), or from all or part of an antibody heavy-chain constant region. Alternatively, the A domain may be a synthetic sequence that corresponds to a naturally occurring A sequence or may be an entirely synthetic A sequence. In some embodiments said A domain is a part of human CD8α chain (e.g., NP_001139345.1). In another particular embodiment, said hinge and transmembrane domains comprise a part of human CD8α chain. In some embodiments, the hinge domain of CARs described herein comprises a subsequence of CD8a, CD28, an IgG1, IgG4, PD-1 or an FcγRIIIα, in particular the hinge region of any of an CD8a, CD28, an IgG1, IgG4, PD-1 or an FcγRIIIα. In some embodiments, the hinge domain comprises a human CD8α hinge, a human IgG1 hinge, a human IgG4, a human PD-1 or a human FcγRIIIα hinge. In some embodiments the CARs disclosed herein comprise a scFv, CD8α human hinge and transmembrane domains, the CD3ζ signaling domain, and 4-1BB signaling domain. Table 5 provides amino acid sequences for exemplary hinges provided herein.
In certain embodiments, the hinge region comprises an amino acid sequence that is at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% identical to the extracellular domain amino acid sequences set forth herein in Table 5.
d. Transmembrane Domain
The CARs of the disclosure are designed with a transmembrane domain that is fused to the extracellular domain of the CAR. It can similarly be fused to the intracellular domain of the CAR. In some instances, the transmembrane domain can be selected or modified by amino acid substitution to avoid binding of such domains to the transmembrane domains of the same or different surface membrane proteins to minimize interactions with other members of the receptor complex. In some embodiments, short linkers may form linkages between any or some of the extracellular, transmembrane, and intracellular domains of the CAR.
Suitable transmembrane domains for a CAR disclosed herein have the ability to (a) be expressed at the surface an immune cell such as, for example without limitation, a lymphocyte cell, such as a T helper (Th) cell, cytotoxic T (Tc) cell, T regulatory (Treg) cell, or Natural killer (NK) cells, and/or (b) interact with the extracellular antigen binding domain and intracellular signaling domain for directing the cellular response of an immune cell against a target cell.
The transmembrane domain may be derived either from a natural or from a synthetic source. Where the source is natural, the domain may be derived from any membrane-bound or transmembrane protein.
Transmembrane regions of particular use in this disclosure may be derived from (comprise, or correspond to) CD28, OX-40, 4-1BB/CD137, CD2, CD7, CD27, CD30, CD40, programmed death-1 (PD-1), inducible T cell costimulator (ICOS), lymphocyte function-associated antigen-1 (LFA-1, CD1-1a/CD18), CD3 gamma, CD3 delta, CD3 epsilon, CD247, CD276 (B7-H3), LIGHT, (TNFSF14), NKG2C, Ig alpha (CD79a), DAP-10, Fc gamma receptor, MHC class 1 molecule, TNF receptor proteins, an Immunoglobulin protein, cytokine receptor, integrins, Signaling Lymphocytic Activation Molecules (SLAM proteins), activating NK cell receptors, BTLA, a Toll ligand receptors, ICAM-1, B7-H3, CDS, ICAM-1, GITR, BAFFR, LIGHT, HVEM (LIGHTR), KIRDS2, SLAMF7, NKp80 (KLRF1), NKp44, NKp30, NKp46, CD19, CD4, CD8alpha, CD8beta, IL-2R beta, IL-2R gamma, IL-7R alpha, ITGA4, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD1 1d, ITGAE, CD103, ITGAL, CD1 1a, LFA-1, ITGAM, CD1 1b, ITGAX, CD1 1c, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, NKG2D, TNFR2, TRANCE/RANKL, DNAM1 (CD226), SLAMF4 (CD244, 2B4), CD84, CD96 (Tactile), CEACAM1, CRT AM, Ly9 (CD229), CD160 (BY55), PSGL1, CD100 (SEMA4D), CD69, SLAMF6 (NTB-A, Ly108), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD162), LTBR, LAT, GADS, SLP-76, PAG/Cbp, CD19a, a ligand that specifically binds with CD83, or any combination thereof.
As non-limiting examples, the transmembrane region can be a derived from, or be a portion of a T cell receptor such as α, β, γ or δ, polypeptide constituting CD3ζ complex, IL-2 receptor p55 (α chain), p75 (β chain) or γ chain, subunit chain of Fc receptors, in particular Fcγ receptor III or CD proteins. Alternatively, the transmembrane domain can be synthetic and can comprise predominantly hydrophobic residues such as leucine and valine. In some embodiments said transmembrane domain is derived from the human CD8α chain (e.g., NP_001139345.1).
In some embodiments, the transmembrane domain in the CAR of the disclosure is a CD8α transmembrane domain. In some embodiments, the transmembrane domain in the CAR of the disclosure is a CD8α transmembrane domain comprising the amino acid sequence IYIWAPLAGTCGVLLLSLVIT (SEQ ID NO: 549). In some embodiments, the CD8α transmembrane domain comprises the nucleic acid sequence that encodes the transmembrane amino acid sequence of SEQ ID NO: 549. In some embodiments, the hinge and transmembrane domain in the CAR of the disclosure is a CD8α hinge and transmembrane domain comprising the amino acid sequence of SEQ ID NO: 479.
In some embodiments, the transmembrane domain in the CAR of the disclosure is a CD28 transmembrane domain. In some embodiments, the transmembrane domain in the CAR of the disclosure is a CD28 transmembrane domain comprising the amino acid sequence of FWVLVVVGGVLACYSLLVTVAFIIFWV (SEQ ID NO: 550). In some embodiments, the CD28 transmembrane domain comprises the nucleic acid sequence that encodes the transmembrane amino acid sequence of SEQ ID NO: 550.
e. Intracellular Domain
The intracellular (cytoplasmic) domain of the CARs of the disclosure can provide activation of at least one of the normal effector functions of the immune cell comprising the CAR, e.g., Signal 1/activation and/or Signal 2/costimulation. Effector function of a T cell, for example, may refer to cytolytic activity or helper activity, including the secretion of cytokines. In some embodiments, an activating intracellular signaling domain for use in a CAR can be the cytoplasmic sequences of, for example without limitation, the T cell receptor and co-receptors that act in concert to initiate signal transduction following antigen receptor engagement, as well as any derivative or variant of these sequences and any synthetic sequence that has the same functional capability.
It will be appreciated that suitable (e.g., activating) intracellular domains include, but are not limited to signaling domains derived from (or corresponding to) CD3 zeta, CD28, OX-40, 4-1BB/CD137, CD2, CD7, CD27, CD30, CD40, programmed death-1 (PD-1), inducible T cell costimulator (ICOS), lymphocyte function-associated antigen-1 (LFA-1, CD1-1a/CD18), CD3 gamma, CD3 delta, CD3 epsilon, CD247, CD276 (B7-H3), LIGHT, (TNFSF14), NKG2C, Ig alpha (CD79a), DAP-10, Fc gamma receptor, MHC class 1 molecule, TNF receptor proteins, an Immunoglobulin protein, cytokine receptor, integrins, Signaling Lymphocytic Activation Molecules (SLAM proteins), activating NK cell receptors, BTLA, a Toll ligand receptors, ICAM-1, B7-H3, CDS, ICAM-1, GITR, BAFFR, LIGHT, HVEM (LIGHTR), KIRDS2, SLAMF7, NKp80 (KLRF1), NKp44, NKp30, NKp46, CD19, CD4, CD8alpha, CD8beta, IL-2R beta, IL-2R gamma, IL-7R alpha, ITGA4, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD1 1d, ITGAE, CD103, ITGAL, CD1 1a, LFA-1, ITGAM, CD1 1b, ITGAX, CD1 1c, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, NKG2D, TNFR2, TRANCE/RANKL, DNAM1 (CD226), SLAMF4 (CD244, 2B4), CD84, CD96 (Tactile), CEACAM1, CRT AM, Ly9 (CD229), CD160 (BY55), PSGL1, CD100 (SEMA4D), CD69, SLAMF6 (NTB-A, Ly108), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD162), LTBR, LAT, GADS, SLP-76, PAG/Cbp, CD19a, a ligand that specifically binds with CD83, or any combination thereof.
The intracellular domains of the CARs of the disclosure may incorporate, in addition to the activating domains described above, costimulatory signaling domains (interchangeably referred to herein as costimulatory molecules) to increase their potency. Costimulatory domains can provide a signal in addition to the primary signal provided by an activating molecule as described herein.
It will be appreciated that suitable costimulatory domains within the scope of the disclosure can be derived from (or correspond to) for example, CD28, OX40, 4-1BB/CD137, CD2, CD3 (alpha, beta, delta, epsilon, gamma, zeta), CD4, CD5, CD7, CD9, CD16, CD22, CD27, CD30, CD 33, CD37, CD40, CD 45, CD64, CD80, CD86, CD134, CD137, CD154, PD-1, ICOS, lymphocyte function-associated antigen-1 (LFA-1 (CD1 1a/CD18), CD247, CD276 (B7-H3), LIGHT (tumor necrosis factor superfamily member 14; TNFSF14), NKG2C, Ig alpha (CD79a), DAP-10, Fc gamma receptor, MHC class I molecule, TNFR, integrin, signaling lymphocytic activation molecule, BTLA, Toll ligand receptors, ICAM-1, B7-H3, CDS, ICAM-1, GITR, BAFFR, LIGHT, HVEM (LIGHTR), KIRDS2, SLAMF7, NKp80 (KLRF1), NKp44, NKp30, NKp46, CD19, CD4, CD8alpha, CD8beta, IL-2R beta, IL-2R gamma, IL-7R alpha, ITGA4, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD1-1d, ITGAE, CD103, ITGAL, CD1-1a, LFA-1, ITGAM, CD1-1b, ITGAX, CD1-1c, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, NKG2D, TNFR2, TRANCE/RANKL, DNAM1 (CD226), SLAMF4 (CD244, 2B4), CD84, CD96 (Tactile), CEACAM1, CRT AM, Ly9 (CD229), CD160 (BY55), PSGL1, CD100 (SEMA4D), CD69, SLAMF6 (NTB-A, Ly108), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD162), LTBR, LAT, GADS, SLP-76, PAG/Cbp, CD19a, CD83 ligand, or fragments or combinations thereof. It will be appreciated that additional costimulatory molecules, or fragments thereof, not listed above are within the scope of the disclosure.
In some embodiments, the intracellular/cytoplasmic domain of the CAR can be designed to comprise the 41BB/CD137 domain by itself or combined with any other desired intracellular domain(s) useful in the context of the CAR of the disclosure. The complete native amino acid sequence of 41BB/CD137 is described in NCBI Reference Sequence: NP_001552.2. The complete native 41BB/CD137 nucleic acid sequence is described in NCBI Reference Sequence: NM_001561.5.
In some embodiments, the intracellular/cytoplasmic domain of the CAR can be designed to comprise the CD28 domain by itself or combined with any other desired intracellular domain(s) useful in the context of the CAR of the disclosure. The complete native amino acid sequence of CD28 is described in NCBI Reference Sequence: NP_006130.1. The complete native CD28 nucleic acid sequence is described in NCBI Reference Sequence: NM_006139.1.
In some embodiments, the intracellular/cytoplasmic domain of the CAR can be designed to comprise the CD3 zeta domain by itself or combined with any other desired intracellular domain(s) useful in the context of the CAR of the disclosure. In some embodiments, the intracellular signaling domain of the CAR can comprise the CD3 signaling domain which has amino acid sequence with at least about 70%, at least 80%, at least 90%, 95%, 97%, or 99% sequence identity with an amino acid sequence shown in SEQ ID NO: 481 in Table 7. For example, the intracellular domain of the CAR can comprise a CD3 zeta chain portion and a portion of a costimulatory signaling molecule. The intracellular signaling sequences within the intracellular signaling portion of the CAR of the disclosure may be linked to each other in a random or specified order. In some embodiments, the intracellular domain is designed to comprise the activating domain of CD3 zeta and a signaling domain of CD28. In some embodiments, the intracellular domain is designed to comprise the activating domain of CD3 zeta and a costimulatory/signaling domain of 4-1BB.
In some embodiments, the 4-1BB (intracellular domain) comprises the amino acid sequence KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL (SEQ ID NO: 480). In some embodiments, the 4-1BB (intracellular domain) is encoded by the nucleic acid sequence:
In some embodiments, the intracellular domain in the CAR is designed to comprise a portion of CD28 and CD3 zeta, wherein the intracellular CD28 comprises the nucleic acid sequence set forth in SEQ ID NO: 567.
In some embodiments, the intracellular domain in the CAR is designed to comprise the amino acid sequence RSKRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAYRS (SEQ ID NO: 551). The CD3 zeta amino acid sequence may comprise SEQ ID NO: 481 or 469 and the nucleic acid sequence may comprise SEQ ID NO: 569:
In some embodiments the intracellular signaling domain of the CAR of the disclosure comprises a domain of a co-stimulatory molecule. In some embodiments, the intracellular signaling domain of a CAR of the disclosure comprises a part of co-stimulatory molecule selected from the group consisting of fragment of 4-1BB (GenBank: AAA53133) and CD28 (NP_006130.1). In some embodiments, the intracellular signaling domain of the CAR of the disclosure comprises amino acid sequence which comprises at least 70%, at least 80%, at least 90%, 95%, 97%, or 99% sequence identity with an amino acid sequence shown in SEQ ID NO: 480 and SEQ ID NO: 551. In some embodiments, the intracellular signaling domain of the CAR of the disclosure comprises amino acid sequence which comprises at least 70%, at least 80%, at least 90%, 95%, 97%, or 99% sequence identity with an amino acid sequence shown in SEQ ID NO: 480 and/or at least 70%, at least 80%, at least 90%, 95%, 97%, or 99% sequence identity with an amino acid sequence shown in SEQ ID NO: 551.
In exemplary embodiments, a CAR of the disclosure comprises, from N-terminus to C-terminus: a (cleavable) CD8α signal sequence, a DLL3 scFv, a CD8α hinge and transmembrane region, a 4-1BB cytoplasmic (costimulatory) signaling domain, and a CD3ζ cytoplasmic (stimulatory) signaling domain.
a. Immune Cells
Provided herein are engineered immune cells expressing the CARs of the disclosure (e.g., CAR-T cells).
In some embodiments, an engineered immune cell comprises a population of CARs, each CAR comprising different extracellular antigen-binding domains. In some embodiments, an immune cell comprises a population of CARs, each CAR comprising the same extracellular antigen-binding domains.
The engineered immune cells can be allogeneic or autologous.
In some embodiments, the engineered immune cell is a T cell (e.g., inflammatory T lymphocyte, cytotoxic T lymphocyte, regulatory T lymphocyte (Treg), helper T lymphocyte, tumor infiltrating lymphocyte (TIL)), natural killer T cell (NKT), TCR-expressing cell, dendritic cell, killer dendritic cell, a mast cell, or a B-cell. In some embodiments, the cell can be derived from the group consisting of CD4+T-lymphocytes and CD8+T-lymphocytes. In some exemplary embodiments, the engineered immune cell is a T cell. In some exemplary embodiments, the engineered immune cell is a gamma delta T cell. In some exemplary embodiments, the engineered immune cell is a macrophage. In some exemplary embodiments, the engineered immune cell is a natural killer (NK) cell.
In some embodiments, the engineered immune cell can be derived from, for example without limitation, a stem cell. The stem cells can be adult stem cells, non-human embryonic stem cells, more particularly non-human stem cells, cord blood stem cells, progenitor cells, bone marrow stem cells, induced pluripotent stem cells, totipotent stem cells or hematopoietic stem cells.
In some embodiments, the cell is obtained or prepared from peripheral blood. In some embodiments, the cell is obtained or prepared from peripheral blood mononuclear cells (PBMCs). In some embodiments, the cell is obtained or prepared from bone marrow. In some embodiments, the cell is obtained or prepared from umbilical cord blood. In some embodiments, the cell is a human cell.
In some embodiments, the cell is transfected or transduced by the nucleic acid vector using a method selected from the group consisting of electroporation, sonoporation, biolistics (e.g., Gene Gun), lipid transfection, polymer transfection, nanoparticles, viral transfection (e.g., retrovirus, lentivirus, AAV) or polyplexes.
In some embodiments, the engineered immune cells expressing at their cell surface membrane a DLL3-specific CAR of the disclosure comprise a percentage of stem cell memory and central memory cells greater than 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%. In some embodiments, the engineered immune cells expressing at their cell surface membrane a DLL3-specific CAR of the disclosure comprise a percentage of stem cell memory and central memory cells of about 10% to about 100%, about 10% to about 90%, about 10% to about 80%, about 10% to about 70%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 10% to about 30%, about 10% to about 20%, about 15% to about 100%, about 15% to about 90%, about 15% to about 80%, about 15% to about 70%, about 15% to about 60%, about 15% to about 50%, about 15% to about 40%, about 15% to about 30%, about 20% to about 100%, about 20% to about 90%, about 20% to about 80%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40%, about 20% to about 30%, about 30% to about 100%, about 30% to about 90%, about 30% to about 80%, about 30% to about 70%, about 30% to about 60%, about 30% to about 50%, about 30% to about 40%, about 40% to about 100%, about 40% to about 90%, about 40% to about 80%, about 40% to about 70%, about 40% to about 60%, about 40% to about 50%, about 50% to about 100%, about 50% to about 90%, about 50% to about 80%, about 50% to about 70%, about 50% to about 60%, about 60% to about 100%, about 60% to about 90%, about 60% to about 80%, about 60% to about 70%, about 70% to about 90%, about 70% to about 80%, about 80% to about 100%, about 80% to about 90%, about 90% to about 100%, about 25% to about 50%, about 75% to about 100%, or about 50% to about 75%.
In some embodiments, the immune cell is an inflammatory T-lymphocyte that expresses any one of the CARs described herein. In some embodiments, the immune cell is a cytotoxic T-lymphocyte that expresses any one of the CARs described herein. In some embodiments, the immune cell is a regulatory T-lymphocyte that expresses any one of the CARs described herein. In some embodiments, the immune cell is a helper T-lymphocyte that expresses any one of the CARs described herein.
Prior to expansion and genetic modification, a source of cells can be obtained from a subject through a variety of non-limiting methods. Cells can be obtained from a number of non-limiting sources, including peripheral blood mononuclear cells, bone marrow, lymph node tissue, cord blood, thymus tissue, tissue from a site of infection, ascites, pleural effusion, spleen tissue, and tumors. In some embodiments, any number of T cell lines available and known to those skilled in the art, may be used. In some embodiments, cells can be derived from a healthy donor, from a patient diagnosed with cancer or from a patient diagnosed with an infection. In some embodiments, cells can be part of a mixed population of cells which present different phenotypic characteristics.
Also provided herein are cell lines obtained from a transformed immune cell (e.g., T-cell) according to any of the above-described methods. Also provided herein are modified cells resistant to an immunosuppressive treatment. In some embodiments, an isolated cell according to the disclosure comprises a polynucleotide encoding a CAR.
The immune cells of the disclosure can be activated and expanded, either prior to or after genetic modification of the immune cells, using methods as generally known. Generally, the engineered immune cells of the disclosure can be expanded, for example, by contacting with an agent that stimulates a CD3 TCR complex and a costimulatory molecule on the surface of the T-cells to create an activation signal for the T cell. For example, chemicals such as calcium ionophore A23187, phorbol 12-myristate 13-acetate (PMA), or mitogenic lectins like phytohemagglutinin (PHA) can be used to create an activation signal for the T cell.
In some embodiments, T cell populations may be stimulated in vitro by contact with, for example, an anti-CD3 antibody such as an OKT3 antibody, or antigen-binding fragment thereof, or an anti-CD2 antibody immobilized on a surface, or by contact with a protein kinase C activator (e.g., bryostatin) in conjunction with a calcium ionophore. For co-stimulation of an accessory molecule on the surface of the T cells, a ligand that binds the accessory molecule is used. For example, a population of T cells can be contacted with an anti-CD3 antibody (e.g., an OKT3 antibody) and an anti-CD28 antibody, under conditions appropriate for stimulating proliferation of the T cells. The anti-CD3 antibody and an anti-CD28 antibody can be disposed on a bead, such as a plastic or magnetic bead, or plate or other substrate. Conditions appropriate for T cell culture include an appropriate media (e.g., Minimal Essential Media or RPMI Media 1640 or, X-vivo 15, (Lonza)) that may contain factors necessary for proliferation and viability, including serum (e.g., fetal bovine or human serum), interleukin-2 (IL-2), insulin, IFN-γ, IL-4, IL-7, GM-CSF, IL-10, IL-2, IL-15, TGFbeta, and TNF, or any other additives for the growth of cells known to the skilled artisan. Other additives for the growth of cells include, but are not limited to, surfactant, plasmanate, and reducing agents such as N-acetyl-cysteine and 2-mercaptoethanoi. Media can include RPMI 1640, A1M-V, DMEM, MEM, a-MEM, F-12, X-Vivo 15, and X-Vivo 20, Optimizer, with added amino acids, sodium pyruvate, and vitamins, either serum-free or supplemented with an appropriate amount of serum (or plasma) or a defined set of hormones, and/or an amount of cytokine(s) sufficient for the growth and expansion of T cells (e.g., IL-7 and/or IL-15). Antibiotics, e.g., penicillin and streptomycin, are included only in experimental cultures, not in cultures of cells that are to be infused into a subject. The target cells are maintained under conditions necessary to support growth, for example, an appropriate temperature (e.g., 37° C.) and atmosphere (e.g., air plus 5% CO2). T cells that have been exposed to varied stimulation times may exhibit different characteristics. In some embodiments, the cells of the disclosure can be expanded by co-culturing with tissue or cells. The cells can also be expanded in vivo, for example in the subject's blood after administering the cell into the subject.
In some embodiments, an engineered immune cell according to the present disclosure may comprise one or more disrupted or inactivated genes. In some embodiments, an engineered immune cell according to the present disclosure comprises one disrupted or inactivated gene selected from the group consisting of CD52, DLL3, GR, PD-1, CTLA-4, LAG3, TIM3, BTLA, BY55, TIGIT, B7H5, LAIR1, SIGLEC10, 2B4, HLA, TCRα and TCRβ and/or expresses a CAR, a multi-chain CAR and/or a pTa transgene. In some embodiments, an isolated cell comprises polynucleotides encoding polypeptides comprising a multi-chain CAR. In some embodiments, the isolated cell according to the present disclosure comprises two disrupted or inactivated genes selected from the group consisting of: CD52 and GR, CD52 and TCRα, CDR52 and TCRβ, DLL3 and CD52, DLL3 and TCRα, DLL3 and TCRβ, GR and TCRα, GR and TCRβ, TCRα and TCRβ, PD-1 and TCRα, PD-1 and TCRβ, CTLA-4 and TCRα, CTLA-4 and TCRβ, LAG3 and TCRα, LAG3 and TCRβ, TIM3and TCRα, Tim3 and TCRβ, BTLA and TCRα, BTLA and TCRβ, BY55 and TCRα, BY55 and TCRβ, TIGIT and TCRα, TIGIT and TCRβ, B7H5 and TCRα, B7H5 and TCRβ, LAIR1 and TCRα, LAIR1 and TCRβ, SIGLEC10 and TCRα, SIGLEC10 and TCRβ, 2B4 and TCRα, 2B4 and TCRβ and/or expresses a CAR, a multi-chain CAR and a pTα transgene. In some embodiments the method comprises disrupting or inactivating one or more genes by introducing into the cells a endonuclease able to selectively inactivate a gene by selective DNA cleavage. In some embodiments the endonuclease can be, for example, a zinc finger nuclease (ZFN), megaTAL nuclease, meganuclease, transcription activator-like effector nuclease (TALE-nuclease/TALEN), or CRISPR (e.g., Cas9) endonuclease.
In some embodiments, TCR is rendered not functional in the cells according to the disclosure by disrupting or inactivating TCRα gene and/or TCRβ gene(s). In some embodiments, a method to obtain modified cells derived from an individual is provided, wherein the cells can proliferate independently of the major histocompatibility complex (MHC) signaling pathway. Modified cells, which can proliferate independently of the MHC signaling pathway, susceptible to be obtained by this method are encompassed in the scope of the present disclosure. Modified cells disclosed herein can be used in for treating patients in need thereof against Host versus Graft (HvG) rejection and Graft versus Host Disease (GvHD); therefore in the scope of the present disclosure is a method of treating patients in need thereof against Host versus Graft (HvG) rejection and Graft versus Host Disease (GvHD) comprising treating said patient by administering to said patient an effective amount of modified cells comprising disrupted or inactivated TCRα and/or TCRβ genes.
In some embodiments, the immune cells are engineered to be resistant to one or more chemotherapy drugs. The chemotherapy drug can be, for example, a purine nucleotide analogue (PNA), thus making the immune cell suitable for cancer treatment combining adoptive immunotherapy and chemotherapy. Exemplary PNAs include, for example, clofarabine, fludarabine, cyclophosphamide, and cytarabine, alone or in combination. PNAs are metabolized by deoxycytidine kinase (dCK) into mono-, di-, and tri-phosphate PNA. Their tri-phosphate forms compete with ATP for DNA synthesis, act as pro-apoptotic agents, and are potent inhibitors of ribonucleotide reductase (RNR), which is involved in trinucleotide production. Provided herein are DLL3-specific CAR-T cells comprising a disrupted or inactivated dCK gene. In some embodiments, the dCK knockout cells are made by transfection of T cells using polynucleotides encoding specific TAL-nuclease directed against dCK genes by, for example, electroporation of mRNA. The dCK knockout DLL3-specific CAR-T cells are resistant to PNAs, including for example clorofarabine and/or fludarabine, and maintain T cell cytotoxic activity toward DLL3-expressing cells.
In some embodiments, isolated cells or cell lines of the disclosure can comprise a pTα or a functional variant thereof. In some embodiments, an isolated cell or cell line can be further genetically modified by disrupting or inactivating the TCRα gene.
The disclosure also provides engineered immune cells comprising any of the CAR polynucleotides described herein. In some embodiments, a CAR can be introduced into an immune cell as a transgene via a plasmid vector. In some embodiments, the plasmid vector can also contain, for example, a selection marker which provides for identification and/or selection of cells which received the vector.
CAR polypeptides may be synthesized in situ in the cell after introduction of polynucleotides encoding the CAR polypeptides into the cell. Alternatively, CAR polypeptides may be produced outside of cells, and then introduced into cells. Methods for introducing a polynucleotide construct into cells are known in the art. In some embodiments, stable transformation methods (e.g., using a lentiviral vector) can be used to integrate the polynucleotide construct into the genome of the cell. In other embodiments, transient transformation methods can be used to transiently express the polynucleotide construct, and the polynucleotide construct not integrated into the genome of the cell. In other embodiments, virus-mediated methods can be used. The polynucleotides may be introduced into a cell by any suitable means such as for example, recombinant viral vectors (e.g., retroviruses, adenoviruses), liposomes, and the like. Transient transformation methods include, for example without limitation, microinjection, electroporation or particle bombardment. Polynucleotides may be included in vectors, such as for example plasmid vectors or viral vectors.
In some embodiments, isolated nucleic acids are provided comprising a promoter operably linked to a first polynucleotide encoding a DLL3 antigen binding domain, at least one costimulatory molecule, and an activating domain. In some embodiments, the nucleic acid construct is contained within a viral vector. In some embodiments, the viral vector is selected from the group consisting of retroviral vectors, murine leukemia virus vectors, SFG vectors, adenoviral vectors, lentiviral vectors, adeno-associated virus (AAV) vectors, Herpes virus vectors, and vaccinia virus vectors. In some embodiments, the nucleic acid is contained within a plasmid.
b. Methods of Making
Provided herein are methods of making the CARs and the CAR-containing immune cells of the disclosure.
A variety of known techniques can be utilized in making the polynucleotides, polypeptides, vectors, antigen binding domains, immune cells, compositions, and the like according to the disclosure.
Prior to the in vitro manipulation or genetic modification of the immune cells described herein, the cells may be obtained from a subject. The cells expressing a DLL3 CAR may be derived from an allogenic or autologous process.
i. Source Material
In some embodiments, the immune cells comprise T cells. T cells can be obtained from a number of sources, including peripheral blood mononuclear cells (PBMCs), bone marrow, lymph nodes tissue, cord blood, thymus tissue, tissue from a site of infection, ascites, pleural effusion, spleen tissue, and tumors. In certain embodiments, T cells can be obtained from a unit of blood collected from the subject using any number of techniques known to the skilled person, such as FICOLL™ separation.
Cells may be obtained from the circulating blood of an individual by apheresis. The apheresis product typically contains lymphocytes, including T cells, monocytes, granulocytes, B cells, other nucleated white blood cells, red blood cells, and platelets. In certain embodiments, the cells collected by apheresis may be washed to remove the plasma fraction, and placed in an appropriate buffer or media for subsequent processing.
In certain embodiments, T cells are isolated from PBMCs by lysing the red blood cells and depleting the monocytes, for example, using centrifugation through a PERCOLL™ gradient. A specific subpopulation of T cells, (e.g., CD28+, CD4+, CDS+, CD45RA−, CD45RO+, CDS+, CD62−, CD95−, CD95+, IL2RP+, IL2Rβ−, CCR7+, CCR7−, CDL−, CD62L+ and combinations thereof) can be further isolated by positive or negative selection techniques known in the art. In one example the subpopulation of T cells is CD45RA+, CD95−, IL-2Rβ−, CCR7+, CD62L+. In one example the subpopulation of T cells is CD45RA+, CD95+, IL-2Rβ+, CCR7+, CD62L+. In one example the subpopulation of T cells is CD45RO+, CD95+, IL-2Rβ+, CCR7+, CD62L+. In one example the subpopulation of T cells is CD45RO+, CD95+, IL-2Rβ+, CCR7-, CD62L-. In one example the subpopulation of T cells is CD45RA+, CD95+, IL-2Rβ+, CCR7−, CD62L−. For example, enrichment of a T cell population by negative selection can be accomplished with a combination of antibodies directed to surface markers unique to the negatively selected cells. One method for use herein is cell sorting and/or selection via negative magnetic immunoadherence or flow cytometry that uses a cocktail of monoclonal antibodies directed to cell surface markers present on the cells negatively selected. For example, to enrich for CD4+ cells by negative selection, a monoclonal antibody cocktail typically includes antibodies to CD14, CD20, CD11b, CD16, HLA-DR, and CD8. Flow cytometry and cell sorting may also be used to isolate cell populations of interest for use in the present disclosure.
PBMCs may be used directly for genetic modification with the immune cells (such as CARs or TCRs) using methods as described herein. In certain embodiments, after isolating the PBMCs, T lymphocytes can be further isolated and both cytotoxic and helper T lymphocytes can be sorted into naive, memory, and effector T cell subpopulations either before or after genetic modification and/or expansion.
In some embodiments, CD8+ cells are further sorted into naive, stem cell memory, central memory, and effector cells by identifying characteristic cell surface antigens that are associated with each of these types of CD8+ cells. In some embodiments, the expression of phenotypic markers of central memory T cells include CD45RO, CD62L, CCR7, CD28, CD3, and CD127 and are negative for granzyme B. In some embodiments, stem cell memory T cells are CD45RO−, CD62L+, CD8+ T cells. In some embodiments, central memory T cells are CD45RO+, CD62L+, CD8+ T cells. In some embodiments, effector T cells are negative for CD62L, CCR7, CD28, and CD127, and positive for granzyme B and perforin.
In certain embodiments, CD4+ T cells are further sorted into subpopulations. For example, CD4+T helper cells can be sorted into naive, central memory, and effector cells by identifying cell populations that have characteristic cell surface antigens.
iii. Stem Cell-Derived Immune Cells
In some embodiments, the immune cells may be derived from stem cells, such as a progenitor cell, a bone barrow stem cell, an inducible pluripotent stem cell, an iPSC, a hematopoietic stem cell, and a mesenchymal stem cell. iPS cells and other types of stem cells may be cultivated immortal cell lines or isolated directly from a patient. Various methods for isolating, developing, and/or cultivating stem cells are known in the art and may be used to practice the present invention.
In some embodiments, the immune cell is an induced pluripotent stem cell (iPSC) derived from a reprogrammed T-cell. In some embodiments, the source material may be an induced pluripotent stem cell (iPSC) derived from a T cell or non-T cell. The source material may alternatively be a B cell, or any other cell from peripheral blood mononuclear cell isolates, hematopoietic progenitor, hematopoietic stem cell, mesenchymal stem cell, adipose stem cell, or any other somatic cell type.
ii. Genetic Modification of Isolated Cells
The immune cells, such as T cells, can be genetically modified following isolation using known methods, or the immune cells can be activated and expanded (or differentiated in the case of progenitors) in vitro prior to being genetically modified. In some embodiments, the isolated immune cells are genetically modified to reduce or eliminate expression of endogenous TCRα and/or CD52. In some embodiments, the cells are genetically modified using gene editing technology (e.g., CRISPR/Cas9, CRISPR/CAS12, a zinc finger nuclease (ZFN), a TALEN, a MegaTAL, a meganuclease) to reduce or eliminate expression of endogenous proteins (e.g., TCRα and/or CD52). In another embodiment, the immune cells, such as T cells, are optionally further genetically modified with the chimeric antigen receptors described herein (e.g., transduced with a viral vector comprising one or more nucleotide sequences encoding a CAR) and then are activated and/or expanded in vitro.
Methods for activating and expanding T cells are known in the art and are described, for example, in U.S. Pat. Nos. 6,905,874; 6,867,041; 6,797,514; and PCT WO2012/079000, the contents of which are hereby incorporated by reference in their entirety. Generally, such methods include contacting PBMC or isolated T cells with a stimulatory molecule and a costimulatory molecule, such as anti-CD3 and anti-CD28 antibodies, generally attached to a plastic or magnetic bead or other surface, in a culture medium with appropriate cytokines, such as IL-2. Anti-CD3 and anti-CD28 antibodies attached to the same bead serve as a “surrogate” antigen presenting cell (APC). One example is the Dynabeads® system, which is a CD3/CD28 activator/stimulator system for physiological activation of human T cells. In other embodiments, the T cells may be activated and stimulated to proliferate with feeder cells and appropriate antibodies and cytokines using methods such as those described in U.S. Pat. Nos. 6,040,177; 5,827,642; and WO2012129514, the contents of which are hereby incorporated by reference in their entirety.
Certain methods for making the constructs and engineered immune cells of the disclosure are described in PCT application PCT/US15/14520, the contents of which are hereby incorporated by reference in their entirety.
It will be appreciated that PBMCs can further include other cytotoxic lymphocytes such as NK cells or NKT cells. An expression vector carrying the coding sequence of a chimeric receptor as disclosed herein can be introduced into a population of human donor T cells, NK cells or NKT cells. Successfully transduced T cells that carry the expression vector can be sorted using flow cytometry to isolate CD3 positive T cells and then further propagated to increase the number of these CAR expressing T cells in addition to cell activation using anti-CD3 antibodies and IL-2 or other methods known in the art as described elsewhere herein. Standard procedures are used for cryopreservation of T cells expressing the CAR for storage and/or preparation for use in a human subject. In one embodiment, the in vitro transduction, culture and/or expansion of T cells are performed in the absence of non-human animal derived products such as fetal calf serum and fetal bovine serum. In an embodiment, cryopreservation can comprise freezing in a suitable medium, such as CryoStor® CS10, CryoStor® CS2 or CryoStor® CS5 (BioLife Solutions).
For cloning of polynucleotides, the vector may be introduced into a host cell (an isolated host cell) to allow replication of the vector itself and thereby amplify the copies of the polynucleotide contained therein. The cloning vectors may contain sequence components generally include, without limitation, an origin of replication, promoter sequences, transcription initiation sequences, enhancer sequences, and selectable markers. These elements may be selected as appropriate by a person of ordinary skill in the art. For example, the origin of replication may be selected to promote autonomous replication of the vector in the host cell.
In certain embodiments, the present disclosure provides isolated host cells containing the vector provided herein. The host cells containing the vector may be useful in expression or cloning of the polynucleotide contained in the vector. Suitable host cells can include, without limitation, prokaryotic cells, fungal cells, yeast cells, or higher eukaryotic cells such as mammalian cells, and more specifically human cells.
The vector can be introduced to the host cell using any suitable methods known in the art, including, without limitation, DEAE-dextran mediated delivery, calcium phosphate precipitate method, cationic lipids mediated delivery, liposome mediated transfection, electroporation, microprojectile bombardment, receptor-mediated gene delivery, delivery mediated by polylysine, histone, chitosan, and peptides. Standard methods for viral transfection and transformation of cells for expression of a vector of interest are well known in the art. In a further embodiment, a mixture of different expression vectors can be used in genetically modifying a donor population of immune effector cells wherein each vector encodes a different CAR as disclosed herein. The resulting transduced immune effector cells form a mixed population of engineered cells, with a proportion of the engineered cells expressing more than one different CARs.
In one embodiment, the disclosure provides a method of storing genetically engineered cells expressing CARs which target a DLL3 protein. In an embodiment this involves cryopreserving the immune cells such that the cells remain viable upon thawing. In an embodiment, cryopreservation can comprise freezing in a suitable medium, such as CryoStor® CS10, CryoStor® CS2 or CryoStor® CS5 (BioLife Solutions). A fraction of the immune cells expressing the CARs can be cryopreserved by methods known in the art to provide a permanent source of such cells for the future treatment of patients afflicted with a malignancy. When needed, the cryopreserved transformed immune cells can be thawed, grown and expanded for more such cells.
In some embodiments, the cells are formulated by first harvesting them from their culture medium, and then washing and concentrating the cells in a medium and container system suitable for administration (a “pharmaceutically acceptable” carrier) in a treatment-effective amount. Suitable infusion media can be any isotonic medium formulation, typically normal saline, Normosol™ R (Abbott) or Plasma-Lyte™ A (Baxter), but also 5% dextrose in water or Ringer's lactate can be utilized. The infusion medium can be supplemented with human serum albumin.
iv. Allogeneic CAR T Cells
In brief, the process for manufacturing allogeneic CAR T therapy, or AlloCARs™ involves harvesting healthy, selected, screened and tested T cells from healthy donors. Allogeneic T cells are gene editing to reduce the risk of graft versus host disease (GvHD) and to prevent allogeneic rejection. A selected T cell receptor gene (e.g., TCRα, TCRβ) is knocked out to avoid GvHD. The CD52 gene can also be knocked out to render the CAR T product resistant to anti-CD52 antibody treatment. Anti-CD52 antibody treatment can therefore be used to lymphodeplete the host immune system and allow the CAR T cells to stay engrafted to achieve full therapeutic impact. Next, the T cells are engineered to express CARs, which recognize certain cell surface proteins (e.g., DLL-3) that are expressed in hematologic or solid tumors. The engineered T cells then undergo a purification step and are ultimately cryopreserved in vials for delivery to patients.
v. Autologous CAR T cells
Autologous chimeric antigen receptor (CAR) T cell therapy, involves collecting a patient's own cells (e.g., white blood cells, including T cells) and genetically engineering the T cells to express CARs that recognize a target antigen expressed on the cell surface of one or more specific cancer cells and kill cancer cells. The engineered cells are then cryopreserved and subsequently administered to the patient from which the cells were removed for engineering.
The disclosure comprises methods for treating or preventing a condition associated with undesired and/or elevated DLL3 levels in a patient, comprising administering to a patient in need thereof an effective amount of at least one CAR, or immune-cell comprising a CAR disclosed herein.
Methods are provided for treating diseases or disorders, including cancer. In some embodiments, the disclosure relates to creating a T cell-mediated immune response in a subject, comprising administering an effective amount of the engineered immune cells of the present application to the subject. In some embodiments, the T cell-mediated immune response is directed against a target cell or cells. In some embodiments, the engineered immune cell comprises a chimeric antigen receptor (CAR). In some embodiments, the target cell is a tumor cell. In some aspects the disclosure comprises a method for treating or preventing a malignancy, said method comprising administering to a subject in need thereof an effective amount of at least one isolated antigen binding domain described herein. In some aspects, the disclosure comprises a method for treating or preventing a malignancy, said method comprising administering to a subject in need thereof an effective amount of at least one immune cell, wherein the immune cell comprises at least one chimeric antigen receptor, and/or isolated antigen binding domain as described herein. The CAR containing immune cells of the disclosure can be used to treat malignancies involving aberrant expression of DLL3. In some embodiments, CAR containing immune cells of the disclosure can be used to treat such malignancies as small cell lung cancer, melanoma, low grade gliomas, glioblastoma, medullary thyroid cancer, carcinoids, dispersed neuroendocrine tumors in the pancreas, bladder and prostate, testicular cancer, and lung adenocarcinomas with neuroendocrine features. In exemplary embodiments, the CAR-containing immune cells, e.g., the anti-DLL3 CAR-T cells of the disclosure, are used to treat small cell lung cancer.
Also provided are methods for reducing the size of a tumor in a subject, comprising administering to the subject an engineered cell of the present disclosure to the subject, wherein the cell comprises a chimeric antigen receptor comprising a DLL3 antigen binding domain and binds to a DLL3 antigen on the tumor.
In some embodiments, the subject has a solid tumor, or a blood malignancy such as lymphoma or leukemia. In some embodiments, the engineered cell is delivered to a tumor bed, such as a tumor bed found in small cell lung cancer. In some embodiments, the cancer is present in the bone marrow of the subject. In some embodiments, the engineered cells are autologous immune cells, e.g., autologous T cells. In some embodiments, the engineered cells are allogeneic immune cells, e.g., allogeneic T cells. In some embodiments, the engineered cells are heterologous immune cells, e.g., heterologous T cells. In some embodiments, the engineered cells are transfected or transduced ex vivo. As used herein, the term “in vitro cell” refers to any cell that is cultured ex vivo.
A “therapeutically effective amount,” “effective dose,” “effective amount,” or “therapeutically effective dosage” of a therapeutic agent, e.g., engineered CART cells, is any amount that, when used alone or in combination with another therapeutic agent, protects a subject against the onset of a disease or promotes disease regression evidenced by a decrease in severity of disease symptoms, an increase in frequency and duration of disease symptom-free periods, or a prevention of impairment or disability due to the disease affliction. The ability of a therapeutic agent to promote disease regression can be evaluated using a variety of methods known to the skilled practitioner (e.g., a physician or clinician), such as in human subjects during clinical trials, in animal model systems predictive of efficacy in humans, or by assaying the activity of the agent in in vitro assays.
The terms “patient” and “subject” are used interchangeably and include human and non-human animal subjects as well as those with formally diagnosed disorders, those without formally recognized disorders, those receiving medical attention, those at risk of developing the disorders, etc.
The term “treat” and “treatment” includes therapeutic treatments, prophylactic treatments, and applications in which one reduces the risk that a subject will develop a disorder or other risk factor. Treatment does not require the complete curing of a disorder and encompasses embodiments in which one reduces symptoms or underlying risk factors. The term “prevent” does not require the 100% elimination of the possibility of an event. Rather, it denotes that the likelihood of the occurrence of the event has been reduced in the presence of the compound or method.
Desired treatment total amounts of cells in the composition comprise at least 2 cells (for example, at least one CD8+ T cell and at least one CD4+ T cell, or two CD8+ T cells, or two CD4+ T cells) or is more typically greater than 102 cells, and up to 106, up to and including 108 or 109 cells and can be 1010 or 1012 or more cells. The number of cells will depend upon the desired use for which the composition is intended, and the type of cells included therein. The density of the desired cells is typically greater than 106 cells/ml and generally is greater than 107 cells/ml, generally 108 cells/ml or greater. The clinically relevant number of immune cells can be apportioned into multiple infusions that cumulatively equal or exceed 105, 106, 107, 108, 109, 1010, 1011, or 1012 cells. In some aspects of the present disclosure, particularly since all the infused cells will be redirected to a particular target antigen (e.g., DLL3), lower numbers of cells, in the range of 106/kilogram (106-1011 per patient) may be administered. CAR treatments may be administered multiple times at dosages within these ranges. The cells may be autologous, allogeneic, or heterologous to the patient undergoing therapy.
In some embodiments, the therapeutically effective amount of the CAR T cells is about 1×105 cells/kg, about 2×105 cells/kg, about 3×105 cells/kg, about 4×105 cells/kg, about 5×105 cells/kg, about 6×105 cells/kg, about 7×105 cells/kg, about 8×105 cells/kg, about 9×105 cells/kg, 2×106 cells/kg, about 3×106 cells/kg, about 4×106 cells/kg, about 5×106 cells/kg, about 6×106 cells/kg, about 7×106 cells/kg, about 8×106 cells/kg, about 9×106 cells/kg, about 1×107 cells/kg, about 2×107 cells/kg, about 3×107 cells/kg, about 4×107 cells/kg, about 5×107 cells/kg, about 6×107 cells/kg, about 7×107 cells/kg, about 8×107 cells/kg, or about 9×107 cells/kg.
In some embodiments, target doses for CAR+/CAR-T+ cells range from about 1×106 to about 1×1010 cells/kg, for example about 1×106 cells/kg, about 1×107 cells/kg, about 1×108 cells/kg, about 1×109 cells/kg or about 1×1010 cells/kg. It will be appreciated that doses above and below this range may be appropriate for certain subjects, and appropriate dose levels can be determined by the healthcare provider as needed. Additionally, multiple doses of cells can be provided in accordance with the disclosure.
In some aspects the disclosure comprises a pharmaceutical composition comprising at least one antigen binding domain as described herein and a pharmaceutically acceptable excipient. In some embodiments, the pharmaceutical composition further comprises an additional active agent.
The CAR expressing cell populations of the present disclosure may be administered either alone, or as a pharmaceutical composition in combination with diluents and/or with other components such as IL-2 or other cytokines or cell populations. Pharmaceutical compositions of the present disclosure may comprise a CAR expressing cell population, such as T cells, as described herein, in combination with one or more pharmaceutically or physiologically acceptable carriers, diluents or excipients. Such compositions may comprise buffers such as neutral buffered saline, phosphate buffered saline and the like; carbohydrates such as glucose, mannose, sucrose or dextrans, mannitol; proteins; polypeptides or amino acids such as glycine; antioxidants; chelating agents such as EDTA or glutathione; adjuvants (e.g., aluminum hydroxide); and preservatives. Compositions of the present disclosure are preferably formulated for intravenous administration.
The pharmaceutical compositions (solutions, suspensions or the like), may include one or more of the following: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer's solution, isotonic sodium chloride, fixed oils such as synthetic mono- or diglycerides which may serve as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. For therapeutic applications, an injectable pharmaceutical composition is preferably sterile.
In some embodiments, upon administration to a patient, engineered immune cells expressing at their cell surface any one of the DLL3-specific CARs described herein may reduce, kill or lyse endogenous DLL3-expressing cells of the patient. In one embodiment, a percentage reduction or lysis of DLL3-expressing endogenous cells or cells of a cell line expressing DLL3 by engineered immune cells expressing any one of the DLL3-specific CARs described herein is at least about or greater than 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%. In one embodiment, a percentage reduction or lysis of DLL3-expressing endogenous cells or cells of a cell line expressing DLL3 by engineered immune cells expressing any one of the DLL3-specific CARs described herein is about 5% to about 95%, about 10% to about 95%, about 10% to about 90%, about 10% to about 80%, about 10% to about 70%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 20% to about 90%, about 20% to about 80%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, about 25% to about 75%, or about 25% to about 60%. In one embodiment, the endogenous DLL3-expressing cells are endogenous DLL3-expressing bone marrow cells.
In one embodiment, the percent reduction or lysis of target cells, e.g., a cell line expressing DLL3, by engineered immune cells expressing at their cell surface membrane a DLL3-specific CAR of the disclosure can be measured using the assay disclosed herein.
The methods can further comprise administering one or more chemotherapeutic agents to a patient prior to administering the engineered cells provided herein. In certain embodiments, the chemotherapeutic agent is a lymphodepleting (preconditioning) chemotherapeutic. For example, methods of conditioning a patient in need of a T cell therapy comprising administering to the patient specified beneficial doses of cyclophosphamide (between 200 mg/m2/day and 2000 mg/m2/day, about 100 mg/m2/day and about 2000 mg/m2/day; e.g., about 100 mg/m2/day, about 200 mg/m2/day, about 300 mg/m2/day, about 400 mg/m2/day, about 500 mg/m2/day, about 600 mg/m2/day, about 700 mg/m2/day, about 800 mg/m2/day, about 900 mg/m2/day, about 1000 mg/m2/day, about 1500 mg/m2/day or about 2000 mg/m2/day) and specified doses of fludarabine (between 20 mg/m2/day and 900 mg/m2/day, between about 10 mg/m2/day and about 900 mg/m2/day; e.g., about 10 mg/m2/day, about 20 mg/m2/day, about 30 mg/m2/day, about 40 mg/m2/day, about 40 mg/m2/day, about 50 mg/m2/day, about 60 mg/m2/day, about 70 mg/m2/day, about 80 mg/m2/day, about 90 mg/m2/day, about 100 mg/m2/day, about 500 mg/m2/day or about 900 mg/m2/day). An exemplary dosing regimen involves treating a patient comprising administering daily to the patient about 300 mg/m2/day of cyclophosphamide in combination or before or after administering about 30 mg/m2/day of fludarabine for three days prior to administration of a therapeutically effective amount of engineered T cells to the patient.
In some embodiments, notably in the case when the engineered cells provided herein have been gene edited to eliminate or minimize surface expression of CD52, lymphodepletion further comprises administration of an anti-CD52 antibody, such as alemtuzumab. In some embodiments, the CD52 antibody is administered at a dose of about 1-20 mg/day IV, e.g., about 13 mg/day IV for 1, 2, 3 or more days. The antibody can be administered in combination with, before, or after administration of other elements of a lymphodepletion regime (e.g., cyclophosphamide and/or fludarabine).
In other embodiments, the antigen binding domain, transduced (or otherwise engineered) cells and the chemotherapeutic agent are administered each in an amount effective to treat the disease or condition in the subject.
In certain embodiments, compositions comprising CAR-expressing immune effector cells disclosed herein may be administered in conjunction with any number of chemotherapeutic agents. Examples of chemotherapeutic agents include alkylating agents such as thiotepa and cyclophosphamide (CYTOXAN™); alkyl sulfonates such as busulfan, improsulfan and piposulfan; aziridines such as benzodopa, carboquone, meturedopa, and uredopa; ethylenimines and methylamelamines including altretamine, triethylenemelamine, trietylenephosphoramide, triethylenethiophosphaoramide and trimethylolomelamine resume; nitrogen mustards such as chlorambucil, chlornaphazine, cholophosphamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novembichin, phenesterine, prednimustine, trofosfamide, uracil mustard; nitrosureas such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine, ranimustine; antibiotics such as aclacinomysins, actinomycin, authramycin, azaserine, bleomycins, cactinomycin, calicheamicin, carabicin, carminomycin, carzinophilin, chromomycins, dactinomycin, daunorubicin, detorubicin, 6-diazo-5-oxo-L-norleucine, doxorubicin, epirubicin, esorubicin, idarubicin, marcellomycin, mitomycins, mycophenolic acid, nogalamycin, olivomycins, peplomycin, potfiromycin, puromycin, quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexate and 5-fluorouracil (5-FU); folic acid analogues such as denopterin, methotrexate, pteropterin, trimetrexate; purine analogs such as fludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidine analogs such as ancitabine, azacitidine, 6-azauridine, carmofur, cytarabine, dideoxyuridine, doxifluridine, enocitabine, floxuridine, 5-FU; androgens such as calusterone, dromostanolone propionate, epitiostanol, mepitiostane, testolactone; anti-adrenals such as aminoglutethimide, mitotane, trilostane; folic acid replenisher such as frolinic acid; aceglatone; aldophosphamide glycoside; aminolevulinic acid; amsacrine; bestrabucil; bisantrene; edatraxate; defofamine; demecolcine; diaziquone; elformithine; elliptinium acetate; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidamine; mitoguazone; mitoxantrone; mopidamol; nitracrine; pentostatin; phenamet; pirarubicin; podophyllinic acid; 2-ethylhydrazide; procarbazine; PSK®; razoxane; sizofiran; spirogermanium; tenuazonic acid; triaziquone; 2, 2′,2″-trichlorotriethylamine; urethan; vindesine; dacarbazine; mannomustine; mitobronitol; mitolactol; pipobroman; gacytosine; arabinoside (“Ara-C”); cyclophosphamide; thiotepa; taxoids, e.g., paclitaxel (TAXOL™, Bristol-Myers Squibb) and doxetaxel (TAXOTERE®, Rhone-Poulenc Rorer); chlorambucil; gemcitabine; 6-thioguanine; mercaptopurine; methotrexate; platinum analogs such as cisplatin and carboplatin; vinblastine; platinum; etoposide (VP-16); ifosfamide; mitomycin C; mitoxantrone; vincristine; vinorelbine; navelbine; novantrone; teniposide; daunomycin; aminopterin; xeloda; ibandronate; CPT-11; topoisomerase inhibitor RF 52000; difluoromethylomithine (DMFO); retinoic acid derivatives such as Targretin™ (bexarotene), Panretin™, (alitretinoin); ONTAK™ (denileukin diftitox); esperamicins; capecitabine; and pharmaceutically acceptable salts, acids or derivatives of any of the above. Also included in this definition are anti-hormonal agents that act to regulate or inhibit hormone action on tumors such as anti-estrogens including for example tamoxifen, raloxifene, aromatase inhibiting 4(5)-imidazoles, 4-hydroxytamoxifen, trioxifene, keoxifene, LY117018, onapristone, and toremifene (Fareston); and anti-androgens such as flutamide, nilutamide, bicalutamide, leuprolide, and goserelin; and pharmaceutically acceptable salts, acids or derivatives of any of the above. Combinations of chemotherapeutic agents are also administered where appropriate, including, but not limited to CHOP, i.e., Cyclophosphamide (Cytoxan®), Doxorubicin (hydroxydoxorubicin), Vincristine (Oncovin®), and Prednisone.
In some embodiments, the chemotherapeutic agent is administered at the same time or within one week after the administration of the engineered cell, polypeptide, or nucleic acid. In other embodiments, the chemotherapeutic agent is administered from about 1-7 days, about 1 to about 4 weeks or from about 1 week to about 1 month, about 1 week to about 2 months, about 1 week to about 3 months, about 1 week to about 6 months, about 1 week to about 9 months, or about 1 week to about 12 months after the administration of the engineered cell, polypeptide, or nucleic acid. In other embodiments, the chemotherapeutic agent is administered at least 1 month before administering the cell, polypeptide, or nucleic acid. In some embodiments, the methods further comprise administering two or more chemotherapeutic agents.
A variety of additional therapeutic agents may be used in conjunction with the compositions described herein. For example, potentially useful additional therapeutic agents include PD-1 inhibitors such as nivolumab (Opdivo®), pembrolizumab (Keytruda®), pembrolizumab, pidilizumab, and atezolizumab.
Additional therapeutic agents suitable for use in combination with the disclosure include, but are not limited to, ibrutinib (Imbruvica®), ofatumumab (Arzerra®, rituximab (Rituxan®), bevacizumab (Avastin®), trastuzumab (Herceptin®), trastuzumab emtansine (KADCYLA®, imatinib (Gleevec®), cetuximab (Erbitux®, panitumumab) (Vectibix®), catumaxomab, ibritumomab, ofatumumab, tositumomab, brentuximab, alemtuzumab, gemtuzumab, erlotinib, gefitinib, vandetanib, afatinib, lapatinib, neratinib, axitinib, masitinib, pazopanib, sunitinib, sorafenib, toceranib, lestaurtinib, axitinib, cediranib, lenvatinib, nintedanib, pazopanib, regorafenib, semaxanib, sorafenib, sunitinib, tivozanib, toceranib, vandetanib, entrectinib, cabozantinib, imatinib, dasatinib, nilotinib, ponatinib, radotinib, bosutinib, lestaurtinib, ruxolitinib, pacritinib, cobimetinib, selumetinib, trametinib, binimetinib, alectinib, ceritinib, crizotinib, aflibercept,adipotide, denileukin diftitox, mTOR inhibitors such as Everolimus and Temsirolimus, hedgehog inhibitors such as sonidegib and vismodegib, CDK inhibitors such as CDK inhibitor (palbociclib).
In some embodiments, the composition comprising CAR-containing immune cells may be administered with a therapeutic regimen to prevent or reduce cytokine release syndrome (CRS) or neurotoxicity. The therapeutic regimen to prevent cytokine release syndrome (CRS) or neurotoxicity may include lenzilumab, tocilizumab, atrial natriuretic peptide (ANP), anakinra, iNOS inhibitors (e.g., L-NIL or 1400 W). In additional embodiments, the composition comprising CAR-containing immune cells can be administered with an anti-inflammatory agent. Anti-inflammatory agents or drugs include, but are not limited to, steroids and glucocorticoids (including betamethasone, budesonide, dexamethasone, hydrocortisone acetate, hydrocortisone, hydrocortisone, methylprednisolone, prednisolone, prednisone, triamcinolone), nonsteroidal anti-inflammatory drugs (NSAIDS) including aspirin, ibuprofen, naproxen, methotrexate, sulfasalazine, leflunomide, anti-TNF medications, cyclophosphamide and mycophenolate. Exemplary NSAIDs include ibuprofen, naproxen, naproxen sodium, Cox-2 inhibitors, and sialylates. Exemplary analgesics include acetaminophen, oxycodone, tramadol of proporxyphene hydrochloride. Exemplary glucocorticoids include cortisone, dexamethasone, hydrocortisone, methylprednisolone, prednisolone, or prednisone. Exemplary biological response modifiers include molecules directed against cell surface markers (e.g., CD4, CD5, etc.), cytokine inhibitors, such as the TNF antagonists, (e.g., etanercept (ENBREL®), adalimumab (HUMIRA®) and infliximab (REMICADE®), chemokine inhibitors and adhesion molecule inhibitors. The biological response modifiers include monoclonal antibodies as well as recombinant forms of molecules. Exemplary DMARDs include azathioprine, cyclophosphamide, cyclosporine, methotrexate, penicillamine, leflunomide, sulfasalazine, hydroxychloroquine, Gold (oral (auranofin) and intramuscular) and minocycline.
In certain embodiments, the compositions described herein are administered in conjunction with a cytokine. Examples of cytokines are lymphokines, monokines, and traditional polypeptide hormones. Included among the cytokines are growth hormones such as human growth hormone, N-methionyl human growth hormone, and bovine growth hormone; parathyroid hormone; thyroxine; insulin; proinsulin; relaxin; prorelaxin; glycoprotein hormones such as follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), and luteinizing hormone (LH); hepatic growth factor (HGF); fibroblast growth factor (FGF); prolactin; placental lactogen; mullerian-inhibiting substance; mouse gonadotropin-associated peptide; inhibin; activin; vascular endothelial growth factor; integrin; thrombopoietin (TPO); nerve growth factors (NGFs) such as NGF-beta; platelet-growth factor; transforming growth factors (TGFs) such as TGF-alpha and TGF-beta; insulin-like growth factor-I and -II; erythropoietin (EPO); osteoinductive factors; interferons such as interferon-alpha, beta, and -gamma; colony stimulating factors (CSFs) such as macrophage-CSF (M-CSF); granulocyte-macrophage-CSF (GM-CSF); and granulocyte-CSF (G-CSF); interleukins (ILs) such as IL-1, IL-1alpha, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12; IL-15, IL-21 a tumor necrosis factor such as TNF-alpha or TNF-beta; and other polypeptide factors including LIF and kit ligand (KL). As used herein, the term cytokine includes proteins from natural sources or from recombinant cell culture, and biologically active equivalents of the native sequence cytokines.
In some embodiments, provided are methods for in vitro sorting of a population of immune cells, wherein a subset of the population of immune cells comprises engineered immune cells expressing any one of the DLL3-specific CARs comprising epitopes specific for monoclonal antibodies (e.g., exemplary mimotope sequences). The method comprises contacting the population of immune cells with a monoclonal antibody specific for the epitopes and selecting the immune cells that bind to the monoclonal antibody to obtain a population of cells enriched in engineered immune cells expressing the DLL3-specific CAR.
In some embodiments, said monoclonal antibody specific for said epitope is optionally conjugated to a fluorophore. In this embodiment, the step of selecting the cells that bind to the monoclonal antibody can be done by Fluorescence Activated Cell Sorting (FACS).
In some embodiments, said monoclonal antibody specific for said epitope is optionally conjugated to a magnetic particle. In this embodiment, the step of selecting the cells that bind to the monoclonal antibody can be done by Magnetic Activated Cell Sorting (MACS).
In some embodiments, the mAb used in the method for sorting immune cells expressing the CAR is chosen from alemtuzumab, ibritumomab tiuxetan, muromonab-CD3, tositumomab, abciximab, basiliximab, brentuximab vedotin, cetuximab, infliximab, rituximab, bevacizumab, certolizumab pegol, daclizumab, eculizumab, efalizumab, gemtuzumab, natalizumab, omalizumab, palivizumab, ranibizumab, tocilizumab, trastuzumab, vedolizumab, adalimumab, belimumab, canakinumab, denosumab, golimumab, ipilimumab, ofatumumab, panitumumab, QBEND-10 and/or ustekinumab. In some embodiments, said mAb is rituximab. In another embodiment, said mAb is QBEND-10.
In some embodiments, the population CAR-expressing immune cells obtained when using the method for in vitro sorting CAR-expressing immune cells described above, comprises at least 70%, 75%, 80%, 85%, 90%, 95% of CAR-expressing immune cells. In some embodiments, the population of CAR-expressing immune cells obtained when using the method for in vitro sorting CAR-expressing immune cells, comprises at least 85% CAR-expressing immune cells.
In some embodiments, the population of CAR-expressing immune cells obtained when using the method for in vitro sorting CAR-expressing immune cells described above shows increased cytotoxic activity in vitro compared with the initial (non-sorted) cell population. In some embodiments, said cytotoxic activity in vitro is increased by 10%, 20%, 30% or 50%. In some embodiments, the immune cells are T-cells.
In some embodiments, the mAbs are previously bound onto a support or surface. Non-limiting examples of solid support may include a bead, agarose bead, a plastic bead a magnetic bead, a plastic welled plate, a glass welled plate, a ceramic welled plate, a column, or a cell culture bag.
The CAR-expressing immune cells to be administered to the recipient may be enriched in vitro from the source population. Methods of expanding source populations may include selecting cells that express an antigen such as CD34 antigen, using combinations of density centrifugation, immuno-magnetic bead purification, affinity chromatography, and fluorescent activated cell sorting.
Flow cytometry is may be used to quantify specific cell types within a population of cells. In general, flow cytometry is a method for quantitating components or structural features of cells primarily by optical means. Since different cell types can be distinguished by quantitating structural features, flow cytometry and cell sorting can be used to count and sort cells of different phenotypes in a mixture.
A flow cytometry analysis involves two primary steps: 1) labeling selected cell types with one or more labeled markers, and T) determining the number of labeled cells relative to the total number of cells in the population. In some embodiments, the method of labeling cell types includes binding labeled antibodies to markers expressed by the specific cell type. The antibodies may be either directly labeled with a fluorescent compound or indirectly labeled using, for example, a fluorescent-labeled second antibody which recognizes the first antibody.
In a some embodiments, the method used for sorting T cells expressing CAR is the Magnetic-Activated Cell Sorting (MACS). Magnetic-activated cell sorting (MACS) is a method for separation of various cell populations depending on their surface antigens (CD molecules) by using superparamagnetic nanoparticles and columns. MACS may be used to obtain a pure cell population. Cells in a single-cell suspension may be magnetically labeled with microbeads. The sample is applied to a column composed of ferromagnetic spheres, which are covered with a cell-friendly coating allowing fast and gentle separation of cells. The unlabeled cells pass through while the magnetically labeled cells are retained within the column. The flow-through can be collected as the unlabeled cell fraction. After a washing step, the column is removed from the separator, and the magnetically labeled cells are eluted from the column.
Detailed protocol for the purification of specific cell population such as T-cell can be found in Basu S et al. (2010). (Basu S, Campbell H M, Dittel B N, Ray A. Purification of specific cell population by fluorescence activated cell sorting (FACS). J Vis Exp. (41): 1546).
In some aspects the present disclosure provides a method for depleting DLL3 specific CAR-expressing immune cells by in vivo depletion. in vivo depletion may include the administration of a treatment (e.g., a molecule that binds an epitope on the CAR) to a mammalian organism aiming to stop the proliferation of the CAR-expressing immune cells by inhibition or elimination.
One aspect of the invention is related to a method for in vivo depleting an engineered immune cell expressing a DLL3 CAR comprising a mAb specific epitope, comprising contacting said engineered immune cell or said CAR-expressing immune cell with at least one epitope-specific mAb. Another aspect of the invention relates to a method for in vivo depleting CAR-expressing immune cell which comprises a chimeric scFv (e.g., formed by insertion of a mAb-specific epitope) by contacting said engineered immune cell with epitope-specific antibodies. In some embodiments, the immune cells are T-cells and/or the antibodies are monoclonal.
According to one embodiment, the in vivo depletion of the immune engineered cells is performed on engineered immune cells which has been previously sorted using the in vitro method of the present invention. In this case, the same infused mAb may be used. In some embodiments, the mAb-specific antigen is CD20 antigen and the epitope-specific mAb is rituximab. In some embodiments, the invention relates to a method for in vivo depleting an engineered immune cell expressing a CAR comprising an mAb-specific epitope (CAR-expressing immune cell) in a patient comprising contacting said CAR-expressing immune cell with at least one epitope-specific mAb.
In some embodiments, the step of contacting said engineered immune cell or said CAR-expressing immune cell with at least one epitope-specific mAb comprises infusing the patient with epitope-specific mAb (e.g., rituximab). In some embodiments, the amount of epitope-specific mAb administered to the patient is sufficient to eliminate at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the CAR-expressing immune cell in the patient.
In some embodiments, the step of contacting said engineered immune cell or said CAR-expressing immune cell with at least one epitope-specific mAb comprises infusing the patient with about 375 mg/m2 of rituximab, once or several times. In some embodiments, the mAb (e.g., rituximab) is administered once weekly.
In some embodiments, when immune cells expressing a CAR comprising an mAb-specific epitope (CAR-expressing immune cells) are depleted in a complement dependent cytotoxicity (CDC) assay using epitope-specific mAb, the amount of viable CAR-expressing immune cells decreases. In some embodiments, the amount of viable CAR-expressing immune cells decreases by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%. In some embodiments, said mAb-specific epitope is a CD20 epitope or mimotope and/or the epitope-specific mAb is rituximab.
In certain embodiments, the in vivo depletion of CAR-engineered immune cells is performed by infusing bi-specific antibodies. By definition, a bispecific monoclonal antibody (BsAb) is an artificial protein that is composed of fragments of two different monoclonal antibodies and consequently binds to two different types of antigen. These BsAbs and their use in immunotherapy have been reviewed in Muller D and Kontermann R. E. (2010) Bispecific Antibodies for Cancer Immunotherapy, BioDrugs 24 (2): 89-98.
According to another particular embodiment, the infused bi-specific mAb is able to bind both the mAb-specific epitope borne on engineered immune cells expressing the chimeric scFv and to a surface antigen on an effector and cytotoxic cell (e.g., immune cells such as lymphocytes, macrophages, dendritic cells, natural killer cells (NK Cell), cytotoxic T lymphocytes (CTL)). By doing so, the depletion of engineered immune cells triggered by the BsAb may occur through antibody-dependent cellular cytotoxicity (ADCC). (Deo Y M, Sundarapandiyan K, Keler T, Wallace P K, and Graziano R F, (2000), Journal of Immunology, 165 (10):5954-5961]).
In some embodiments, a cytotoxic drug is coupled to the epitope-specific mAbs which may be used to deplete CAR-expressing immune cells. By combining targeting capabilities of monoclonal antibodies with the cancer-killing ability of cytotoxic drugs, antibody-drug conjugate (ADC) allows a sensitive discrimination between healthy and diseased tissue when compared to the use of the drug alone. Market approvals were received for several ADCs; the technology for making them—particularly on linkers—are described in (Payne, G. (2003) Cancer Cell 3:207-212; Trail et al (2003) Cancer Immunol. Immunother. 52:328-337; Syrigos and Epenetos (1999) Anticancer Research 19:605-614; Niculescu-Duvaz and Springer (1997) Adv. Drug Del. Rev. 26:151-172; U.S. Pat. No. 4,975,278).
In some embodiments, the epitope-specific mAb to be infused is conjugated beforehand with a molecule able to promote complement dependent cytotoxicity (CDC). Therefore, the complement system helps or complements the ability of antibodies to clear pathogens from the organism. When stimulated an activation cascade is triggered as a massive amplification of the response and activation of the cell-killing membrane attack complex. Different molecule may be used to conjugate the mAb, such as glycans (Courtois, A, Gac-Breton, S., Berthou, C, Guezennec, J., Bordron, A. and Boisset, C. (2012), Complement dependent cytotoxicity activity of therapeutic antibody fragments may be acquired by immunogenic glycan coupling, Electronic Journal of Biotechnology ISSN: 0717-3458; http://www.ejbiotechnology.info DOI: 10.2225/vol15-issue5).
The present application provides kits comprising any one of the DLL3 containing CARs or DLL3 CAR containing immune cells described herein, and pharmaceutical compositions of the same. In an embodiment of a kit the engineered CAR cells are frozen in a suitable medium, such as CryoStor® CS10, CryoStor® CS2 or CryoStor® CS5 (BioLife Solutions).
In some exemplary embodiments, a kit of the disclosure comprises allogeneic DLL3 CAR-containing T-cells and a CD52 antibody for administering to the subject a lymphodepletion regiment and a CAR-T regimen.
The present application also provides articles of manufacture comprising any one of the therapeutic compositions or kits described herein. Examples of an article of manufacture include vials (e.g., sealed vials).
The monoclonal antibodies to be used in accordance with the invention may be made by the hybridoma method first described by Kohler and Milstein, Nature 256:495, 1975, or may be made by recombinant DNA methods such as described in U.S. Pat. No. 4,816,567. Anti-DLL3 antibodies were first screened in Flag-DLL3 (adipogen) ELISA and then screened in FACS to determine binding to HEK-293T cells with or without human DLL3 expression.
To test if the DLL3 specific antibodies can recognize cells that express endogenous DLL3, DMS 273 (Sigma, cat #95062830), DMS 454 (Sigma, cat #95062832), and SHP-77 (ATCC, cat # CRL-2195) cells were stained with 2 ug/ml of purified DLL3 antibodies with mouse IgG2A backbone (mIgG2a) or control mIgG2a antibody in PBS supplemented with 1% BSA. Bound DLL3 antibodies were detected with PE labelled anti-mouse IgG antibody (Biolegend, cat #405307). The samples were analyzed by flow cytometry. Representative images showing binding of DLL3 antibodies to DMS 273, DMS 454 and SHP-77 cells are included in
This example determines the binding kinetics and affinity of various anti-DLL3 antibodies at 37° C. as both full-length monoclonal antibodies (IgG) and scFvs toward human, cynomolgus monkey (cyno) and mouse DLL3. For the scFvs, the variable regions of the anti-DLL3 antibodies derived from their respective hybridoma were cloned flanking a (GGGGS)3 (SEQ ID NO: 472) or (GGGGS)4 (SEQ ID NO: 478) linker followed by part of the hinge and Fc from a modified human IgG2 sequence resulting in a scFv-Fc fusion which was expressed using Expi293. The extracellular domain (ECD) from human, cyno and mouse DLL3 was fused with a C-terminal 8×His epitope tag (SEQ ID NO: 473) and Avi tag, expressed using Expi293 then purified by immobilized metal affinity chromatography (IMAC) followed by size exclusion chromatography (SEC).
The antibody binding kinetics were determined by surface plasmon resonance (Biacore™ surface plasmon resonance (SPR) system, GE Healthcare Bio-Sciences, Pittsburgh Pa.). The antibodies diluted in HBS-T+ running buffer (0.01 M HEPES pH 7.4, 0.15 M NaCl, 0.05% v/v Tween20, 1 mg/mL BSA) were captured on a CM4 chip immobilized with an antibody specific for the anti-DLL3 antibody constant domains. Purified DLL3 was serially diluted into HBS-T+, injected for 2 min at 30 uL/min and a dissociation time of 10 min then the surface regenerated with either 10 mM Glycine-HCl pH 1.7 or phosphoric acid between injections. Kinetic association rates (kon) and dissociation rates (koff) are obtained simultaneously by fitting the data globally to a 1:1 Langmuir binding model (Karlsson, R. Roos, H. Fagerstam, L. Petersson, B. (1994). Methods Enzymology 6. 99-110) using the BIAevaluation program. Equilibrium dissociation constant (Kd) values are calculated as koff/kon.
The kinetics and affinity parameters for tested anti-DLL3 antibodies are shown in Table 8. Specifically, Table 8 shows the affinity of anti-DLL3 antibodies (either as IgG or scFv-Fc fusion) to human, cyno and mouse DLL3. The last column shows which extracellular domain of human DLL3 each of anti-DLL3 antibodies recognizes
A panel of CHO cells expressing full length and a variety of truncated human DLL3 were used to determine which domain each DLL3 targeting antibody recognizes. The extracellular domain of human DLL3 can be subdivided into different sub-domains that are defined by the following amino acid positions: Signal peptide: 1-26; N-terminus (N-ter): 27-175; DSL: 176-215; EGF1:215-249; EGF2:274-310; EGF3:312-351; EGF4:353-389; EGF5: 391-427; and EGF6: 429-465.
To generate truncated DLL3 proteins used for epitope mapping, the sequences of the respective 8 extracellular domains (signal peptide plus N-terminus, DSL, EGF1, EGF2, EGF3, EGF4, EGF5 and EGF6) of human DLL3 were deleted one by one from the antigen, starting from the N-terminus. Table 6 shows the truncated DLL3 proteins that were generated (also see
To establish CHO cells expressing full length and truncated human DLL3 with an N-terminal HA tag, the coding sequences for full length human DLL3 (SEQ ID NO: 556; GeneBank record NM_016941) and the 7 HA-tagged truncated human DLL3 (SEQ ID NOs: 557 to 563) were cloned into pLVX-SFFV-Puro-P2A-TetO3G vector (Clontech). A lentivirus encoding either the full length or truncated human DLL3s were generated by co-transfecting 293T cells with the pLVX-SFFV-Puro-P2A-TetO3G vectors with psPAX2 and pMD2G vectors. Two days after transfection, supernatant containing viral particles were collected and used to transduce CHO cells together with 5 ug/ml of polybrene.
The expression of full length and truncated DLL3 was verified in a FACS assay using PE conjugated anti-HA antibody (Biolegend, cat #901518). As negative control, cells were incubated with isotype-matched and PE-labelled antibody (Biolegend, cat #400111) instead of anti-HA antibody. The bottom panel of
CHO cells expressing full length and truncated DLL3 were stained with hybridoma supernatant or purified DLL3 antibodies in PBS+1% BSA. Bound DLL3 antibodies were detected with PE labelled anti-mouse IgG antibody (Biolegend, cat #405307). The samples were analyzed by flow cytometry. The binding domain for each clone was determined using the panel of CHO expressing full length or truncated DLL3 described in Example 2. Flow cytometry analysis demonstrated that, for example, if a clone binds to all truncated proteins including EGF3 but not to any truncated protein without EGF3, then such clone recognizes EGF3. As shown in the representative images in
This example describes the construction of anti-DLL3 chimeric antigen receptors (CARs).
The anti-DLL3 antibodies listed in Table 1a were reformatted to CARs. The amino acid sequences of the heavy chain variable regions and light chain variable regions of these antibodies (Table 1b and Table 1c) were used to design single chain variable fragments (scFvs) (Table 1d) having the following general structure: heavy chain variable region--linker--light chain variable region. The linker had the following amino acid sequences GGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 478).
Protein sequences encoding chimeric antigen receptor were designed to contain the following elements from 5′ to 3′ (
A schematic of the CAR structure is set forth in
To generate DLL3 CAR-T cells, PBMCs were first purified from buffy coat samples using Ficoll gradient density medium (Ficoll Paque PLUS/GE Healthcare Life Sciences). T cells were purified from PBMCs using a commercially available T cell isolation kit (Miltenyi Biotec, Cat #130-096-535). Alternatively, primary human T cells can be directly purified from LeukoPak (StemCell Technologies).
To make lentivirus encoding DLL3 CARs, HEK-293T cells were plated at 0.4 million cells per mL in 2 mL of DMEM (Gibco) supplemented with 10% FBS (Hyclone or JR Scientific) per well of a 6-well plate on Day 0. On Day 1, the lentivirus was prepared by mixing together lentiviral packaging vectors 1.5 ug psPAX2, 0.5 ug pMD2G, and 0.5 ug of the appropriate transfer CAR vector in 250 uL Opti-MEM (Gibco) per well of the 6-well plate (“DNA mix”). 10 uL Lipofectamine 2000 (Invitrogen) in 250 uL Opti-MEM was incubated at room temperature for 5 minutes and then added to the DNA mix. The mixture was incubated at room temperature for 20 minutes and the total volume of 500 uL was slowly added to the sides of the wells containing HEK-293T. Purified T cells were activated in X-Vivo-15 medium (Lonza) supplemented with 100 IU/mL human IL-2 (Miltenyi Biotec), 10% FBS (Hyclone), and human T TransAct (Miltenyi Biotec, Cat #130-111-160, 1:100 dilution). On Day 2, the media from each well of the 6-well plate was replaced with 2 mL per well of T cell transduction media, i.e., X-Vivo-15 supplemented with 10% FBS. On Day 3, T cells were resuspended at 0 5 million cells per mL in 1 mL of T cell transduction media per well of a Grex-24 plate (Wilson Wolf, cat #80192M). The lentiviral supernatants from HEK293T cells were harvested and passed through a 0.45 micron filter (EMD Millipore) to remove cell debris, and then added to the T cells along with 100 IU/mL human IL-2. On Day 5, 4.5 mL of T cell expansion media, i.e., X-Vivo-15 supplemented with 5% human AB serum (Gemini Bio) was added to each well of a Grex-24 plate. On Day 9 and Day 13, transduction efficiency was determined by detecting the percentage of T cells that recognize recombinant DLL3 (Adipogen) using flow cytometry. Cells were expanded into larger flasks or G-Rex vessels (Wilson Wolf) as needed using T cell expansion media. On Day 14, DLL3 CAR-T cells were cryopreserved. Percentage of cells stained with recombinant DLL3 was normalized across clones right before cryopreservation.
To determine the percentage of T cells that were successfully transduced with DLL3 CAR, T cells were first incubated with 1 ug/ml Flag tagged recombinant DLL3 (Adipogen) in PBS+1% BSA for 20 minutes at 4 C. Then cells were washed with PBS+1% BSA, stained with PE labelled anti-Flag antibodies (Biolegend, Cat #637310) and analyzed using flow cytometry.
Examples of DLL3 CAR-T cells are shown in
This example describes experiments used to determine the specificity and in vitro activity of CARs for DLL3.
SHP-77, WM266.4, DMS 454 and DMS 273 are DLL3+ cells lines that were purchased from ATCC or Sigma. HEK-293T is a DLL3 negative cell line. To express human DLL3 in HEK-293T, lentivirus encoding full length human DLL3 was used to transduce HEK-293T cells.
To test DLL3-specific killing, firefly luciferase expressing HEK-293T cells with or without human DLL3 expression were then plated at a seeding density of 5,000 cells per well in 96-well assay plates (Costar). DLL3 CAR-T cells were thawed and added to plated HEK-293T cells with or without human DLL3 expression at effector:target (E:T) ratio ranging from 1:9 to 9:1 in T cell expansion media, i.e., X-Vivo-15 supplemented with 5% human AB serum (Gemini Bio). Cell viability was measured after 72 hours using one-glo assay kit (Promega). Representative DLL3 CAR-T cells demonstrated potent killing on HEK-293T-DLL3 cells but did not show detectable activity in HEK-293T parental cells (
To test the cytotoxic activity of DLL3 CAR-T cells against cell lines that express endogenous DLL3, DLL3 CAR-T cells were incubated with firefly luciferase labelled DLL3+ SHP-77, WM266.4, DMS 454 or DMS 273 cells at effector:target (E:T) ratio ranting from 1:9 to 9:1 in T cell expansion media, i.e., X-Vivo-15 supplemented with 5% human AB serum (Gemini Bio). Cell viability was measured after 72 hours using one-glo assay kit (Promega). Each condition was assayed in 3 replicates. Average percentage of live cells and standard deviation were plated (
To measure cytokines secreted from DLL3 CAR-T cells, DLL3 CAR-T cells were incubated with DLL3+ SHP-77 cells at effector:target (E:T) ratio of 1:1 or 1:9 in T cell expansion media, i.e., X-Vivo-15 supplemented with 5% human AB serum (Gemini Bio). 24 hours later, tissue culture supernatant was collected and the levels of 3 cytokines [interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-2] in the supernatants were measured using human proinflammatory tissue culture 9-plex assay (MSD) following manufacturer's protocol.
A serial killing assay involves repeated exposure of CAR-T cells to their target causing the CAR-T cells to undergo proliferation and in certain cases, differentiation and exhaustion. This assay was used to select optimal clones with high target cell lysis and proliferative abilities after several rounds of exposure to target cells.
One the first day of the assay, 5,000 firefly luciferase labelled WM266.4, DMS 454 or DMS 273 cells that are known to express DLL3 were seeded in 96-well plates with white wall and flat clear bottom in 100 ul X-Vivo-15 medium with 5% of human serum. After target cells attached to the bottom of the plates, DLL3 CAR-T cells were thawed and added to plated target cells at an effector:target (E:T) ratio of 1:1 in X-VIVO medium with 5% of human serum. Every 2 days thereafter, 100 μl medium containing DLL3 CAR-T cells were transferred to freshly plated target cells and percentage lysis of previously plated target cells were determined using one-glo assay system or CellTiter-glo system (Promega). Each condition was assayed in 3 to 6 replicates. Average percentage of lysis and standard deviation were plated (
To test the anti-tumor activity of DLL3 CAR-T cells, SHP-77 tumor bearing NSG mice were used. SHP-77 cells were obtained from a frozen stock vial, thawed and counted according to standard procedure. Cells were diluted to 50×106 viable cells/mL in complete growth medium (RPMI+10% FBS). Cell suspension was kept on ice until implantation Immediately before implanting, cells were mixed 1:1 with BD Matrigel Matrix (cat #354234) and 200 μL of cells/matrigel suspension containing 5×106 SHP-77 cells was injected per mouse subcutaneously. Tumor growth was monitored by caliper measurements using a digital caliper starting from Day 5 post-implantation. Tumor size was calculated using the formula Tumor volume=(width{circumflex over ( )}2×length/2). Mice were randomized into groups of 5 based on tumor volume about two weeks post-implantation. Average tumor volume per group was 314 mm3 or less. One day after mice were randomized, Non-transduced T cells and DLL3 CAR-T cells were thawed and counted according to standard procedure. Cells were resuspended in RPMI+10% FBS and injected at doses 2 or 5 million CAR+ cells/mouse by tail vein IV injection in a volume of 200 uL/mouse. Tumors continued to be monitored every 3-4 days until the end of the study. 26C8 and 10G1-K DLL3 CAR-T cells induced tumor inhibition in a dose dependent manner (
To test anti-tumor activity of DLL3 CAR-T cells in models that show metastasis similar to human disease, SHP-77 tumors were established with tail vein injection. Tumors were observed in lung, liver, brain, kidney and spleen. Specifically, SHP-77 cells were thawed and diluted to 40×106 viable cells/mL in complete growth medium (RPMI+10% FBS). Cell suspension was kept on ice until implantation and 200 uL of cell suspension was injected per mouse by tail vein IV. On day 7 post-implantation, 200 uL Luciferin (15 mg/mL) was injected and tumor growth was monitored by IVIS imaging., Mice were randomized into groups of 5 based on Total Flux on Day 11 post-implantation. On Day 12 post-implantation, CAR-Ts were thawed and counted according to standard procedure. Cells were resuspended in RPMI+10% FBS and injected at 2 or 7 million CAR+ cells per mouse by tail vein IV injection in a volume of 200 uL per mouse. Tumors continued to be monitored every 3-4 days until the end of the study. As shown in
This example describes the construction, expression and cytotoxic activity of anti-DLL3 CAR with safety switch. The anti-DLL3 CARs in Table 6 were reformatted to include different safety switches structures listed below (Table 8).
Protein sequences encoding anti-DLL3 CAR constructs including a safety switch are shown in Table 9. Exemplary safety switch constructs may comprise the CD8α signal sequence (SEQ ID NO: 477), an anti-DLL3 scFv described herein, CD20 mimotope (SEQ ID NO: 536), QBEND-10 epitope (SEQ ID NO: 544), hinge and transmembrane regions of the human CD8α molecule (SEQ ID NO: 479), the cytoplasmic portion of the 4-1BB molecule (SEQ ID NO: 291) and the cytoplasmic portion of the CD3ζ molecule (SEQ ID NO: 292).
CAR-Ts were generated using methods described in Example 5 and their cytotoxic activity were examined using methods described in Example 7.
Small cell lung cancer PDX models were purchased from Crown Bioscience. To examine DLL3 expression of cell surface, frozen vials of PDX models were thawed and 200,000 cells were used for each staining sample. The expression of DLL3 was verified in a FACS assay using PE conjugated anti-DLL3 antibody. Brilliant violet 421 conjugated anti-human CD45 and anti-mouse CD45 antibodies were added in the same staining sample to exclude human and mouse lymphocytes.
In order to deplete or turn off CAR T cells in the event of unwanted activity, a rituximab off-switch was developed by insertion of rituximab mimotopes at varying location in the extracellular region of the CARs as described in Example 9. Complement-dependent cytotoxicity assay was used to evaluate rituximab-dependent in vitro depletion of DLL3 CAR-T cells. In this assay, frozen CAR-T cells were thawed and 1×105 cells were incubated in RPMI 1640 medium supplemented with 10% FBS in 96-well plates. Cells were incubated for 3 hours in the absence or presence of 25% baby rabbit complement (Cedarlane, CL3441-S) and rituximab antibodies (produced in-house; 100 mg/mL). Cells were stained with recombinant DLL3 (Adipogen) and cytotoxicity was analyzed by flow cytometry.
To test the anti-tumor activity of DLL3 CAR-T cells with a safety switch, SHP-77 tumor bearing NSG mice were used. SHP-77 cells were thawed from a frozen vial, counted and diluted. 50×106 viable cells/mL in RPMI medium/matrigel suspension was injected per mouse subcutaneously. Tumor growth was monitored by caliper measurements using a digital caliper starting from Day 5 post-implantation. Tumor size was calculated using the formula Tumor volume=(width{circumflex over ( )}2×length/2). Mice were randomized into groups of 8 based on tumor volume about 14 days post-implantation. Average tumor volume per group was 178 mm3. On the same day after mice were randomized, Non-transduced T cells and DLL3 CAR-T cells were thawed and counted according to standard procedure. Cells were resuspended in RPMI at 5×106 CAR+ cells/mouse by tail vein IV injection in a volume of 200 uL/mouse. Tumors continued to be monitored every 3-4 days until the end of the study. All groups of DLL3 CAR-T cells with safety switch induced significant tumor inhibition and complete or near complete elimination of detectable tumor by Day 50 (
To test anti-tumor activity of DLL3 CAR-T cells in models that show metastasis like human disease, DMS 273 small cell lung tumors expressing exogenous DLL3 (DMS 273-DLL3) were established with tail vein injection. Specifically, DMS 273-DLL3 cells were thawed and diluted to 5×105 viable cells/mL in RPMI medium. 200 uL of cell suspension was injected per mouse by tail vein IV. On day 3 post-implantation, mice were randomized into groups of 9. On the same day, DLL3 CAR-Ts were thawed, counted and resuspended in RPMI medium at 5×106 CAR+ cells per mouse by tail vein IV injection in a volume of 200 uL per mouse. Tumors continued to be monitored every 3-4 days using IVIS imaging system until the end of the study. As shown in
DLL3 RNA has been reported in human brain and pituitary (GTex). Similarly, mouse DLL3 RNA has also been reported in pituitary (Bio-GPS). To understand DLL3 RNA expression in mouse brain, brains from three NSG mice were fixed in 10% neutral buffered formalin (NBF), embedded, serially sectioned at 4-6 microns, and analyzed in an RNAscope®LS Red ISH assay (ACDBio). DLL3 RNA was detected at low levels in brain samples of NSG mice.
To understand the potential toxicity liabilities of DLL3 RNA expression in the brain and pituitary, non-transduced T cells, 8×106 10 G1-K DLL3 CAR-T cells, or 8×106 2 G1 DLL3 CAR-T cells were IV injected into NSG mice. Seven days after injection, spleens, brains and pituitaries were harvested, fixed in 10% NBF, embedded, serially sectioned at 4-6 microns, and stained with anti-human CD3 antibody (Abcam, ab52959, 1:500 dilution) to detect human T cells by immunohistochemistry. Although T cells were detected in spleens from all animals, they were not detected in brain or pituitary samples (
To further evaluate potential brain and pituitary toxicity liabilities, DLL3 CAR-T cells were injected into NSG mice bearing subcutaneous LN229 tumors that express exogenous mouse DLL3 (LN229-mDLL3). In this model, activation of CAR-T by tumor cells may lead to increased sensitivity and activity against potential DLL3-expressing normal tissues. The experiment design is shown in
On day 49, when animals that received DLL3 CAR-T cells were tumor free, brain tissues from animals were fixed in 10% NBF and embedded to reveal the ventricular system, including the lateral, third and fourth ventricles, such that the three sections were placed into a single block that was serially sectioned at 4-6 microns, and stained with hematoxylin and eosin (H&E) or stained to detect human-specific CD3 (hCD3) by immunohistochemistry. Pituitary glands were fixed in 10% NBF, processed and stained with H&E or immunohistochemically stained to demonstrate hCD3. The H&E slides were examined microscopically and histopathologic findings were scored by a pathologist using a standard system. Administration of DLL3 CAR-T cells resulted in abundant hCD3-staining T cells in the pituitary pars intermedia and nervosa with relatively few T cells in the pars distalis (
To promote T cell infiltration into the brain and further understand potential brain toxicity, NSG mice bearing intracranial LN229 tumors that express exogenous mouse DLL3 and human EGFRvIII (LN229-mDLL3-vIII) were used. The experiment design is shown in
On day 22, animals that received non-transduced T cells or 10G1-K DLL3 CAR-T cells had rare/sparse hCD45 staining T cells in the brain or pituitary gland (data not shown). On the other hand, for animals treated with EGFRvIII CAR-T cells, hCD45+ staining ranged from rare/sparse to moderately low or moderate-to-moderately high in areas of infiltrate/gliosis or glioma, consistent with anti-tumor activity in this group (data not shown). On day 38, animals that received non-transduced T cells or EGFRvIII CAR-T cells had rare/sparse hCD45+ staining in the brain and pituitary gland. Animals that received 10G1-K DLL3 CAR-T cells had minimal or mild mononuclear cell infiltrate in the pituitary gland, primarily in the pars intermedia and nervosa (
To directly test whether the DLL3 CARTs are active against the pituitary, mouse pituitaries from NSG mice were harvested under aseptic conditions for in vitro analysis. Tissues were dissociated by 3 rounds of incubations at 37 C in 1 mL dissociation mix [5 mL DMEM, high glucose, GlutaMax (Gibco, cat #10564), 50 uL Enzyme H, 5 uL Enzyme R, 6.25 uL Enzyme A (Miltenyi tumor dissociation kit #130-095-929)] followed by mechanical dissociation using trituration. Single cells were transferred to complete medium (DMEM, high glucose, GlutaMax, 20%, 1× Insulin-Transferrin-Selenium Solution, 1×MEM Non-Essential Amino Acids, 1× Penicillin-Streptomycin) and pooled following each round. Cells were pelleted and treated with ACK lysis buffer for 3 min at RT, followed by neutralization in complete medium. The cell suspension was filtered through a 70u filter and centrifuged to remove buffer. Cells were counted and plated in 96-well plate in complete medium at 5×104 cells per well and let to recover for 3 days before CAR-T cells were added. At the time CAR-T cells are added, the expected target density is 1×104 cells per well. For controls, DLL3+ cells (DMS-273) and DLL3− cells (293T) were plated at the same densities. 10G1-K and 2G1 DLL3 CAR-T cells were added at E:T=9:1, 3:1, and 1:1 and co-cultured with targets for 3 days. At the end of 3 day co-culture, the media was separated from the wells and centrifuged to pellet out the T cells. The target cells were treated with 50 uL/well Cell Titer Glo (Promega, G7570) for 10 minutes and analyzed in SpectraMax plate reader for cytotox readout.
The present application claims the benefit of priority to U.S. Provisional Application No. 62/812,585, filed Mar. 1, 2019; and U.S. Provisional Application No. 62/969,976, filed Feb. 4, 2020, the contents of all of which are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 62969976 | Feb 2020 | US | |
| 62812585 | Mar 2019 | US |
