Patent Application
20200306375
Recent examples of chimeric antigen receptor (CAR) T cell directed to solid tumors have been clinical (or even preclinical) failures. The invention described herein presents solutions for solid tumor and other oncology indications.
Cellular therapeutics that are introduced into cancer patients and traffic into tumor microenvironments encounter multiple barriers that limit their efficacy. These barriers include, but are not limited to: cellular anergy, intrinsic cell death, suboptimal cell trafficking, limited proliferation, limited effector function, poor “take” (survival, persistence and differentiation), active exclusion from tumors, persistent immunosuppression in the tumor microenvironment, and tumor-induced cell death. Almost all attempts to date to overcome these limitations require non-physiological manipulation of the cellular therapeutic both in vitro and in vivo. The efficacy of cellular therapeutics is therefore broadly hindered by both intrinsic and extrinsic factors.
Targeting solid tumors presents an additional set of challenges to overcome, for example, their overall lesser sensitivity to T cell mediated cytotoxicity, a microenvironment with differing immunosuppressive mechanisms between tumor types, and a lack of target antigens with favorable expression profiles. Additionally, solid tumors are heavily fortified against cellular therapeutic attack as they deploy an impenetrable extracellular matrix, hypoxia, and acidic pH. Despite the vast number of targets that have been investigated, only a small number are tumor-specific (e.g., expression is restricted to the tumor cell) and this finding, as such, illustrates the difficulty and the need to discover an effective solution for eliminating or reducing the tumor. Yet another problem for targeting tumors is the heterogeneity of the tumor cells which express different antigens and different levels of antigens. The invention described herein addresses these problems and provides additional benefits as well.
The present invention is based, at least in part, upon the introduction of cellular therapy targets into cancer cells (e.g., tumor cells such as solid tumor cells) such that they are more susceptible to effector cells that can eliminate and/or reduce the cancer cells. As further detailed herein, cancer cells (e.g., tumors) can be transduced with fusion proteins. Such fusion proteins consist of a binding component fused to a target component. For example, the fusion protein can be (i) an antibody or antibody fragment which binds to one or more tumor-associated antigens (TAA) or tumor-specific antigens (TSA), fused to (ii) a target for cellular therapy, e.g. CD19; a cytokine-target fusion; a bi-specific T-cell engager (BiTE); or an anti-idiotype peptide or antibody or fragment thereof. They can also be transduced with CD19 variants (or mutants). These fusion proteins or variants (or mutants) can be secreted by the tumor cells and/or permeate the tumor microenvironment.
Accordingly, in one aspect, the invention provides for recombinant vectors encoding an antibody or antibody fragment to a tumor-associated antigens (TAA) or tumor-specific antigens (TSA) and a therapeutic agent, as a fusion protein. In other embodiments, the therapeutic agent is selected from the group consisting of a cytokines, peptides (e.g. anti-idiotype peptides), proteins, antibodies (e.g, anti-idiotype antibodies), antibody fragments, T-cellengager and NK-cell engager. In other embodiments, the tumor antigen is selected from the group consisting of glioma-associated antigen, carcinoembryonic antigen (CEA), β-human chorionic gonadotropin, alphafetoprotein (AFP), lectin-reactive AFP, thyroglobulin, RAGE-1, MN-CA IX, human telomerase reverse transcriptase, RU1 , RU2 (AS), intestinal carboxyi esterase, mut hsp70-2, M-CSF, prostase, prostate-specific antigen (PSA), PAP, NY-ESO- 1, LAGE-la, p53, prostein, PSMA, Her2/neu, survivin and telomerase, prostate-carcinoma tumor antigen- 1 (PCTA-1), MAGE, ELF2M, neutrophil elastase, ephrinB2, CD22, insulin growth factor (IGF)-I, IGF-II, IGF-I receptor and mesothelin, EphA2, HER2, GD2, Glypican-3, 5T4, 8H9, αvβ6 integrin, BCMA, B7-H3, B7-H6, CAIX, CA9, CD19, CD20, CD22, kappa light chain, CD30, CD33, CD38, CD44, CD44v6, CD44v7/8, CD70, CD123, CD138, CD171, CEA, CSPG4, EGFR, EGFRvIII, EGP2, EGP40, EPCAM, ERBB3, ERBB4, ErbB3/4, FAP, FAR, FBP, fetal AchR, Folate Receptor a, GD2, GD3, HLA-Al MAGE Al, HLA-A2, ILI IRa, IL13Ra2, KDR, Lambda, Lewis-Y, MCSP, Mesothelin, Mucl, MucI6, NCAM, NKG2D ligands, NY-ESO-1, PRAME, PSCA, PSC1, PSMA, ROR1, SURVIVIN, TAG72, TEM1, TEM8, VEGRR2, carcinoembryonic antigen, HMW-MAA, and VEGF receptors.
In other embodiments, the cytokine is capable of being secreted by a tumor cell comprising said vector. In other embodiments, the vector is a viral vector. In other embodiments, the vector integrates into the genome of a cancer cell. In other embodiments, the therapeutic agent is an antigen for a chimeric antigen receptor (CAR). In other embodiments, the therapeutic agent is an antigen for a T cell receptor (TCR). In other embodiments, the therapeutic agent is an antigen for an ADC antibody, ADCC antibody, and/or a radiotherapeutic antibody.
In some embodiments the therapeutic agent is an “anti-idiotype” peptide. In some embodiments, the therapeutic agent is an anti-idiotype” peptide that binds an antigen binding receptor of one or more additional cellular therapeutics (e.g., an scFv of a CAR-T cell). In some embodiments, an anti-idiotype peptide that binds an antigen binding receptor of one or more additional cellular therapeutics binds one or more CDRs of an antigen binding receptor (e.g., an scFv of a CAR-T cell).
In other embodiments, the therapeutic agent is an anti-idiotype antibody or fragment thereof. In some embodiments, the therapeutic agent is an anti-idiotype antibody or fragment that binds an antigen binding portion of one or more cellular therapeutics (e.g., an scFv of a CAR-T cell). For example, in some embodiments, the therapeutic agent is an anti-idiotype antibody or fragment (e.g., scFv) that binds to a B-cell specific marker antigen binding portion (e.g., a CAR that binds CD19, CD20, CD21, CD22, CD24, CD79a, CD79b, ROR1, or BCMA) of a CAR-T cell. Additionally, for example, in some embodiments, the therapeutic agent is an anti-idiotype antibody or fragment (e.g., scFv) that binds an anti-CD19 antibody or fragment (e.g., an anti-CD19 antibody (e.g., anti-CD19 scFv) expressed by a CAR-T cell). In other embodiments, the therapeutic agent is an immunostimulatory cytokine or molecule selected from the group consisting of TLR agonists, PAMP, DAMP and other stimulators. In other embodiments, the therapeutic agent is a peptide with immunomodulatory or anti-tumor properties.
In other embodiments, the TAA or TSA and therapeutic agent are expressed as a fusion protein. In other embodiments, the TAA or TSA is selected from the group consisting of a glioma-associated antigen, carcinoembryonic antigen (CEA), β-human chorionic gonadotropin, alphafetoprotein (AFP), lectin-reactive AFP, thyroglobulin, RAGE-1 , MN-CA IX, human telomerase reverse transcriptase, RU1 , RU2 (AS), intestinal carboxyi esterase, mut hsp70-2, M-CSF, prostase, prostate-specific antigen (PSA), PAP, NY-ESO- 1 , LAGE-la, p53, prostein, PSMA, Her2/neu, survivin and telomerase, prostate-carcinoma tumor antigen- 1 (PCTA-1), MAGE, ELF2M, neutrophil elastase, ephrinB2, CD22, insulin growth factor (IGF)-I, IGF-II, IGF-I receptor and mesothelin, EphA2, HER2, GD2, Glypican-3, 5T4, 8H9, αvβ6 integrin, BCMA, B7-H3, B7-H6, CAIX, CA9, CD19, CD20, CD22, kappa light chain, CD30, CD33, CD38, CD44, CD44v6, CD44v7/8, CD70, CD123, CD138, CD171, CEA, CSPG4, EGFR, EGFRvIII, EGP2, EGP40, EPCAM, ERBB3, ERBB4, ErbB3/4, FAP, FAR, FBP, fetal AchR, Folate Receptor a, GD2, GD3, HLA-Al MAGE AI, HLA-A2, ILl IRa, IL13Ra2, KDR, Lambda, Lewis-Y, MCSP, Mesothelin, Mucl, Mucl6, NCAM, NKG2D ligands, NY-ESO-1, PRAME, PSCA, PSC1, PSMA, ROR1, SURVIVIN, TAG72, TEM1, TEM8, VEGRR2, carcinoembryonic antigen, HMW-MAA, and VEGF receptors
In other aspects, the invention provides for recombinant vectors encoding a cytokine to a tumor expressed cytokine receptor and a therapeutic agent as a fusion protein. In some embodiments, the cytokine receptor is a type I receptor or a type II receptor.
In other aspects, the invention provides for recombinant tumor cells comprising a vector as described above and herein. In some embodiments, the tumor cell expresses one or more fusion proteins.
In other aspects, the invention provides for methods of producing a recombinant tumor cell capable of expressing a fusion protein comprising an antibody or antibody fragment to a tumor-associated antigens (TAA) or tumor-specific antigens (TSA) and a therapeutic agent, said method comprising (a) introducing a vector as described above and herein into a tumor cell; and (b) culturing the tumor cell such that the vector is transduced into the tumor cell. In some embodiments, the vector and/or its components integrate in the tumor cells' genome. In some embodiments, the TAA or TSA is selected from the group consisting of glioma-associated antigen, carcinoembryonic antigen (CEA), β-human chorionic gonadotropin, alphafetoprotein (AFP), lectin-reactive AFP, thyroglubilin, RAGE-1 , MN-CA IX, human telomerase reverse transcriptase, RU1 , RU2 (AS), intestinal carboxyiesterase, mut hsp70-2, M-CSF, prostase, prostate-specific antigen (PSA), PAP, NY-ESO- 1 , LAGE-la, p53, prostein, PSMA, Her2/neu, survivin and telomerase, prostate-carcinoma tumor antigen- 1 (PCTA-1), MAGE, ELF2M, neutrophil elastase, ephrinB2, CD22, insulin growth factor (IGF)-I, IGF-II, IGF-I receptor and mesothelin, EphA2, HER2, GD2, Glypican-3, 5T4, 8H9, αvβ6 integrin, BCMA, B7-H3, B7-H6, CAIX, CA9, CD19, CD20, CD22, kappa light chain, CD30, CD33, CD38, CD44, CD44v6, CD44v7/8, CD70, CD123, CD138, CD171, CEA, CSPG4, EGFR, EGFRvIII, EGP2, EGP40, EPCAM, ERBB3, ERBB4, ErbB3/4, FAP, FAR, FBP, fetal AchR, Folate Receptor a, GD2, GD3, HLA-Al MAGE AI, HLA-A2, ILl IRa, IL13Ra2, KDR, Lambda, Lewis-Y, MCSP, Mesothelin, Mucl, Mucl6, NCAM, NKG2D ligands, NY-ESO-1, PRAME, PSCA, PSC1, PSMA, ROR1, SURVIVIN, TAG72, TEM1, TEM8, VEGRR2, carcinoembryonic antigen, HMW-MAA, and VEGF receptors. In some embodiments, the TAA or TSA is an antigen for a chimeric antigen receptor (CAR). In some embodiments, the TAA or TSA is an antigen for a T cell receptor (TCR). In some embodiments, the therapeutic agent is an antigen for an ADC antibody, ADCC antibody, and/or a radiotherapeutic antibody. In other embodiments, the therapeutic agent is an anti-idiotype antibody or fragment thereof as described herein In some embodiments, the therapeutic agent is an immunostimulatory cytokine or molecule selected from the group consisting of TLR agonists, PAMP, DAMP and other stimulators. In some embodiments, the therapeutic agent is a peptide with immunomodulatory or anti-tumor properties.
In other aspects, the invention provides for methods of treating cancer in an individual in need thereof comprising administering a composition comprising a vector as described above and herein. In some embodiments, a fusion protein is expressed. In other embodiments, the cancer cell expresses a therapeutic agent that increases immune response against the cancer cell. In some embodiments, the cancer cell expresses one or more proteins or peptides that are capable of being recognized by or that recognize a CAR. In some embodiments, the cancer cell express one or more protein or peptide antigens that is capable of being recognized by a TCR. In some embodiments, the cancer cell express one or more fusion proteins containing therapeutic agents capable of being recognized by immune cells in the individual. In some embodiments, the method further comprises administration of CART cells to the individual.
The present invention is based, at least in part, upon the introduction of cellular therapy targets into solid tumor cells. Tumor cells can be transduced with fusion proteins such that the fusion proteins are secreted by the tumor cells and released to the tumor microenvironment to combat the tumor.
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. 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”. Intact antibody tetramers are composed 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 disclosure include glycosylated Fc domains, including Fc domains with modified or engineered such glycosylation. For purposes of the present disclosure, 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 fully human, or 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 disclosure is in a format selected from, but not limited to, intact IgG, IgE and IgM, anti-idiotype antibodies, bi- or multi-specific antibodies (e.g., Zybodies®, etc), single chain Fvs, polypeptide-Fc fusions, Fabs, cameloid antibodies, masked antibodies (e.g., Probodies®), Small Modular ImmunoPharmaceuticals (“SMIPsTM”), single chain or Tandem diabodies (TandAb®), VHHs, Anticalins®, Nanobodies®, minibodies, BiTE®s, ankyrin repeat proteins or DARPINs®, Avimers®, a DART, a TCR-like antibody, Adnectins®, Affilins®, Trans-bodies®, Affibodies®, a TrimerX®, MicroProteins, Fynomers®, Centyrins®, and a KALBITOR®. 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.)).
As used herein, an “antibody fragment” includes a portion of an intact antibody, such as, for example, the antigen-binding or variable region of an antibody. Examples of antibody fragments include Fab, Fab′, F(ab′)2, and Fv fragments; triabodies; tetrabodies; linear antibodies; single-chain antibody molecules; and multi-specific antibodies formed from antibody fragments. For example, antibody fragments include isolated fragments, “Fv” fragments (consisting of the variable regions of the heavy and light chains), recombinant single chain polypeptide molecules in which light and heavy chain variable regions are connected by a peptide linker (“ScFv proteins”), and minimal recognition units consisting of the amino acid residues that mimic the hypervariable region. In many embodiments, an antibody fragment contains sufficient sequence of the parent antibody of which it is a fragment that it binds to the same antigen as does the parent antibody; in some embodiments, a fragment binds to the antigen with a comparable affinity to that of the parent antibody and/or competes with the parent antibody for binding to the antigen. Examples of antigen binding fragments of an antibody include, but are not limited to, Fab fragment, Fab′ fragment, F(ab′)2 fragment, scFv fragment, Fv fragment, dsFv diabody, dAb fragment, Fd′ fragment, Fd fragment, and an isolated complementarity determining region (CDR) region. An antigen binding fragment of an antibody may be produced by any means. For example, an antigen binding fragment of an antibody may be enzymatically or chemically produced by fragmentation of an intact antibody and/or it may be recombinantly produced from a gene encoding the partial antibody sequence. Alternatively or additionally, antigen binding fragment of an antibody may be wholly or partially synthetically produced. An antigen binding fragment of an antibody may optionally comprise a single chain antibody fragment. Alternatively or additionally, an antigen binding fragment of an antibody may comprise multiple chains which are linked together, for example, by disulfide linkages. An antigen binding fragment of an antibody may optionally comprise a multimolecular complex. A functional antibody fragment typically comprises at least about 50 amino acids and more typically comprises at least about 200 amino acids.
As used herein, “antigen” means a molecule that provokes an immune response; and/or an agent that binds to a T cell receptor (e.g., when presented by an MHC molecule) or to an antibody or antibody fragment. In some embodiments, an antigen elicits a humoral response (e.g., including production of antigen-specific antibodies); in some embodiments, an antigen elicits a cellular response (e.g., involving T-cells whose receptors specifically interact with the antigen). In some embodiments, an antigen binds to an antibody and may or may not induce a particular physiological response in an organism. In general, an antigen may be or include any chemical entity such as, for example, a small molecule, a nucleic acid, a polypeptide, a carbohydrate, a lipid, a polymer (in some embodiments other than a biologic polymer (e.g., other than a nucleic acid or amino acid polymer)) etc. In some embodiments, an antigen is or comprises a polypeptide. In some embodiments, an antigen is or comprises a glycan. Those of ordinary skill in the art will appreciate that, in general, an antigen may be provided in isolated or pure form, or alternatively may be provided in crude form (e.g., together with other materials, for example in an extract such as a cellular extract or other relatively crude preparation of an antigen-containing source), or alternatively may exist on or in a cell. In some embodiments, an antigen is a recombinant antigen.
Idiotope: As used herein, the term “idiotope” refers to a unique antigenic determinant (epitope) of a variable region of an antibody, or antigen binding portion.
Idiotype: As used herein the term “idiotype” refers to a set of idiotopes of a particular antibody, or antigen binding portion.
The term, “autologous” refers to any material derived from the same individual to which it is later re-introduced into the individual.
The term “cell therapy antigen” as used herein is meant to refer to one or more antigens (that are genetically engineered or naturally occurring) that can be recognized by effector cells (e.g., genetically engineered CAR T cell or genetically engineered or naturally occurring TCR). An antigen that is expressed on tumors (i.e., “tumor-associated antigen” or TAA) is one type of cell therapy antigen. An antigen that is expressed selectively on tumors (i.e., “tumor-selective antigen” or TSA) is also a type of cell therapy antigen. An antigen can also be expressed on tumor cells through therapeutic intervention, for example, by transducing tumor cells, in vivo, with genetic materials of the present invention, as described herein.
As used herein, the term “fusion protein” generally refers to a polypeptide including at least two segments, each of which shows a high degree of amino acid identity to a peptide moiety that (1) occurs in nature, and/or (2) represents a functional domain of a polypeptide. Typically, a polypeptide containing at least two such segments is considered to be a fusion protein if the two segments are moieties that (1) are not included in nature in the same peptide, and/or (2) have not previously been linked to one another in a single polypeptide, and/or (3) have been linked to one another through action of the hand of man.
The term “promoter” refers to a region of a DNA sequence that directs expression of genes. The promoter is typically upstream from the start of transcription start site and is involved in recognition and binding of RNA polymerase and other transcription machinery (e.g., other proteins) to initiate transcription of a polynucleotide sequence.
The term “solid tumor” is meant as an abnormal mass that usually does not contain cysts or liquid areas. Solid tumors can be benign or malignant. Different types of solid tumors are named for the types of cells that form them (such as sarcomas, carcinomas, and lymphomas). Examples of solid tumors such as sarcomas and carcinoma, include fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteosarcoma, and other sarcomas, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, lymphoid malignancy, pancreatic cancer, breast cancer, lung cancers, ovarian cancer, prostate cancer, hepatocellular carcinoma, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, medullary thyroid carcinoma, papillary thyroid carcinoma, pheochromocytomas sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, Wilms' tumor, cervical cancer, testicular tumor, seminoma, bladder carcinoma, melanoma, and CNS tumors (such as a glioma (such as brainstem glioma and mixed gliomas), glioblastoma (also known as glioblastoma multiforme) astrocytoma, CNS lymphoma, germinoma, medulloblastoma, Schwannoma craniopharyogioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, menangioma, neuroblastoma, retinoblastoma and brain metastases.
An “individual” or “subject” can be a vertebrate, a mammal, or a human. Mammals include, but are not limited to, farm animals, sport animals, pets, primates, mice and rats. In one aspect, a subject is a human. An “individual” or “subject” can be a “patient” (e.g., under the care of a physician) but in some cases, an individual or subject is not a patient.
“Pseudoviruses” or “papilloma pseudoviruses” or “papillomavirus gene transfer vectors” refer to one or more papillomavirus capsid proteins that assemble and package heterologous nucleic acids (e.g., DNA) with or without viral nucleic acids (e.g., DNA) into infectious particles. The methods used to produce papilloma pseudoviruses are known in the art and are described, for example, in U.S. Pat. Nos. 6,599,739, 7,205,126, and 6,416,945; and in Buck and Thomspon, Production of Papillomavirus-Based Gene Transfer Vectors. Current Protocols in Cell Biology 26.1.1-26.1.19, December 2007, all of which are incorporated by reference.
The term “T cell receptor” or “TCR” refers to a heterodimeric receptor found on the surface of T lymphocytes. TCRs are antigen-specific molecules that are responsible for recognizing antigenic peptides of the major histocompatibility complex (MHC) on the surface of antigen presenting cells (APCs), or any other nucleated cell. They are members of the immunoglobulin superfamily, and typically consist of two chains; alpha (α) and beta (β), while a small subset of TCRs are formed by variable gamma (γ) and delta (δ) chains. The chains pair on the surface of a T cell to form a heterodimeric receptor.
The term “transfected” or “transformed” or “transduced” is defined as a process by which exogenous nucleic acid is transferred or introduced into the host cell. A “transfected” or “transformed” or “transduced” cell is one which has been transfected, transformed or transduced with exogenous nucleic acid. The cell includes the primary subject cell and its progeny. In some embodiments, the host cell is a cancer cell, for example a tumor cell such as solid tumor cell.
The term “tropism” refers to the movement or targeting of a viral vector towards a receptor.
A “vector” is a composition which comprises an isolated nucleic acid, and which can be used to deliver the isolated nucleic acid to the interior of a cell. Numerous vectors are known in the art including, but not limited to, linear polynucleotides, polynucleotides associated with ionic or amphiphilic compounds, plasmids, and viruses. Thus, the term “vector” includes an autonomously replicating plasmid or a virus. The term should also be construed to include non-plasmid and non-viral compounds which facilitate transfer of nucleic acid into cells, such as, for example, polylysine compounds, liposomes, and the like. Examples of viral vectors include, but are not limited to, adenoviral vectors, adeno-associated virus and phage vectors (AAVP), retroviral vectors, human papilloma virus (HPV) pseudovirus vectors, and the like.
The invention provides for compositions that can be used for introduction of fusion proteins into cancer cells (e.g., tumor cells) that will make the cancer cells more susceptible for destruction by either an individual's immune system and/or additional therapeutic agents. Compositions can include, but are not limited to, vectors and various constructs described herein, host cells (including tumor cells) containing such vectors and/or constructs, host cells expressing or capable of expressing these vectors and/or constructs, kits containing the vectors, constructs, instructions, and/or reagents and the like.
Cancer cells (e.g., tumors) can be transduced with fusion proteins. As the fusion proteins are expressed (and/or secreted), the proteins can also permeate the tumor microenvironment. Non-limiting examples of fusion proteins contemplated by the invention include: antibody fusions so that the antibody or antibody fragment binds to one or more tumor-associated antigens (TAA) or tumor-specific antigens (TSA), cytokine target fusions, bi-specific T-cell engagers (BITES) or CD19 variants. In some embodiments, a fusion protein includes an antibody or fragment that binds a tumor antigen described herein, and an anti-idiotype antibody or fragment.
The nucleic acid sequences coding the desired gene of interest can be cloned into a number of types of vectors. For example, the nucleic acid can be cloned into a plasmid, a phagemid, a phage derivative, an animal virus, and a cosmid. Other vectors can include expression vectors, replication vectors, probe generation vectors, sequencing vectors, and viral vectors. In other examples, the vector can be a foamy viral (FV) vector, a type of retroviral vector made from spumavirus. Viral vector design and technology is well known in the art as described in Sambrook et al, (Molecular Cloning: A Laboratory Manual, 2001), and in other virology and molecular biology manuals.
Transfer of nucleic acid to a cell for gene-modification of the cell in order for the cell to express a gene of interest is widely performed via transduction (e.g., viral transduction). The nucleic acid sequence coding for the desired gene of interest or portion thereof (e.g., tumor associated antigen) can be obtained using recombinant methods known in the art. Exemplary methods include screening libraries from cells expressing the gene, deriving the gene from a vector, or isolating directly from cells and tissues. These methods are performed using standard techniques. In other embodiments, the gene of interest can be produced synthetically rather than cloned. Gene delivery methods are well-known in the art, for example, U.S. Pat. No. 5,399,346.
Viruses are highly efficient at nucleic acid delivery to specific cell types, while often avoiding detection by the infected host immune system. These features make certain viruses attractive candidates as vehicles for introduction of cellular therapy targets into cancer cells, e.g., solid tumor cells. A number of viral based systems have been developed for gene transfer into mammalian cells. Examples of viral vectors include, but are not limited to, retroviruses, adenoviruses, adeno-associated viruses, herpes viruses, lentiviruses, poxviruses, herpes simplex 1 virus, herpes virus, oncoviruses (e.g., murine leukemia viruses), and the like. In general, a suitable vector contains an origin of replication functional in at least one organism, a promoter sequence, convenient restriction endonuclease sites, and one or more selectable markers, (e.g., WO 01/96584; WO 01/29058; and U.S. Pat. No. 6,326,193).
Lentiviral and Retroviral transduction can be enhanced by the addition of polybrene (SantaCruz sc-134220; Millipore TR-1003-G; Sigma 107689), a cationic polymer (also known as hexamehtrine bromide) that is used to increase the efficiency of the retrovirus transduction.
For example, retroviruses provide a platform for gene delivery systems. Retroviruses are enveloped viruses that belong to the viral family Retroviridae. Once in a host's cell, the virus replicates by using a viral reverse transcriptase enzyme to transcribe its RNA into DNA. The retroviral DNA replicates as part of the host genome, and is referred to as a provirus. A selected gene can be inserted into a vector and packaged in retroviral particles using techniques known in the art. The recombinant virus can then be isolated and delivered to cells of the subject either in vivo or ex vivo. A number of retroviral systems are known in the art, for example See U.S. Pat Nos. 5,994,136, 6,165,782, and 6,428,953.
Retroviruses include the genus of Alpharetrovirus (e.g., avian leukosis virus), the genus of Betaretrovirus; (e.g., mouse mammary tumor virus) the genus of Deltaretrovirus (e.g., bovine leukemia virus and human T-lymphotropic virus), the genus of Epsilonretrovirus (e.g., Walleye dermal sarcoma virus), and the genus of Lentivirus.
In other embodiments, the retrovirus is a lentivirus a genus of viruses of the Retroviridae family, characterized by a long incubation period. Lentiviruses are unique among the retroviruses in being able to infect non- dividing cells; they can deliver a significant amount of genetic information into the DNA of the host cell, so they are one of the most efficient methods of a gene delivery vector. Lentiviral vectors have an advantage to other viral vectors in that they can transduce non-proliferating cells and show low immunogenicity. In some examples, the lentivirus includes, but is not limited to human immunodeficiency viruses (HIV-1 and HIV-2), simian immunodeficiency virus (S1V), feline immunodeficiency virus (FIV), equine infections anemia (EIA), and visna virus. Vectors derived from lentiviruses offer the means to achieve significant levels of gene transfer in vivo.
In embodiments, the vector is an adenovirus vector. Adenoviruses are a large family of viruses containing double stranded DNA. They replicate the DNA of the host cell, while using the host's cell machinery to synthesize viral RNA DNA and proteins. Adenoviruses are known in the art to affect both replicating and non-replicating cells, to accommodate large transgenes, and to code for proteins without integrating into the host cell genome.
In some embodiments, an AAVP vector is used. The AAVP vector is a hybrid of prokaryotic-eukaryotic vectors, which are chimeras of genetic cis-elements of recombinant adeno-associated virus and phage. An AAVP combines selected elements of both phage and AAV vector systems, providing a vector that is simple to produce in bacteria with no packaging limit, while allowing infection of mammalian cells combined with integration into the host chromosome. Vectors containing many of the appropriate elements are commercially available, and can be further modified by standard methodologies to include the necessary sequences. Among other things, AAVPs do not require helper viruses or trans-acting factors. In addition, the native tropism of AAV for mammalian cells is eliminated since there is not AAV capsid formation. Other methods and details are in U.S. Pat. No. 8,470,528 and Hajitou A. et al., Cell, 125: 358-398, both of which are incorporated herein by reference.
In other aspects, a human papilloma (HPV) pseudovirus is used. Recent studies have shown that DNA plasmids can be packaged into papillomavirus L1 and L2 capsid protein to generate pseudovirion that can efficiently deliver DNA. The encapsulation protects the DNA from nucleases and provides a targeted delivery with great stability. Many of the safety concerns associated with the use of viral vectors are mitigated with the HPV pseudoviros because its construct is different from the natural HPV viral genome. Other methods and examples are in Hung, C., et al., Plos One, 7:7(e40983); 2012, U.S. Pat. No. 8,394,411, and Kines, R., et al Int J of Cancer, 2015, all of which are incorporated herein by reference.
In some aspects, an oncolytic virus is used. Oncolytic virus therapy selectively replicates the virus in cancer cells, and subsequently spreads within a tumor without affecting normal tissue. Alternatively, the oncolytic virus preferentially infects and kills cells without causing damage to normal tissues. Oncolytic viruses are also effective at inducing immune responses to themselves as well as to the infected tumor cell. Typically, oncolytic viruses fall into two classes: (I) viruses that naturally replicate preferentially in cancer cells and are nonpathogenic in humans. Exemplary class (I) oncolytic viruses include autonomous parvoviruses, myxoma virus (poxvirus), Newcastle disease virus (NDV; paramyxovirus), reovirus, and Seneca valley virus (picornavirus). A second class (II), include viruses that are genetically manipulated for use as vaccine vectors, including measles virus (paramyxovirus), poliovirus (picornavirus), and vaccinia virus (poxvirus). Additionally, oncolytic viruses may include those genetically engineered with mutations/deletions in genes required for replication in normal but not in cancer cells including adenovirus, herpes simplex virus, and vesicular stomatitis virus. Oncolytic viruses can be used as a viral transduction method due to their low probability of genetic resistance because they can target multiple pathways and replicate in a tumor-selective method. The viral dose within the tumor can increase with time due to in situ viral amplification (as compared to small molecule therapies which decrease with time), and safety features can be built in (i.e., drug and immune sensitivity).
In some aspects of the invention, the nucleic acids encoding cellular therapy target(s) or tumor-associated antigen(s) are integrated as part of the tumor cells' genetic makeup. Without being bound by theory, integration of the nucleic acid encoding cellular therapy target(s) can be helpful in that as the tumor cell replicates, progeny tumor cells would express the cellular therapy target(s) and, as such, be susceptible to the effector cells and other therapeutic agents (including combination therapy agents). It follows that in some indications, such as metastatic disease, the state of rapid tumor cell proliferation becomes useful in propagating the therapeutics of the present invention.
In one embodiment, integration can be achieved by using viruses that naturally integrate into the host cell. Integration is a crucial step in replication of retroviruses as it is a virus genome that has been integrated into the DNA of a host cell. Integration is not part of the viral replication cycle, but it can occasionally occur. The virus does not directly make new DNA copies of itself while integrated into the host genome; alternatively, it is passively replicated along with the host genome and passed on to the original cell's offspring. Integration of the viral DNA results in permanent insertion of the viral genome into the host chromosomal DNA, referred as a provirus in the case of retroviruses.
In other embodiments, integration can be achieved by commercially available kits, including the CompoZr® Targeted Integration Kit which is designed to integrate a gene of interest into the adeno-associated virus integration site 1 (AAVS1) on human chromosome 19.
In addition to the expression of TAA, the cancer cells (e.g., solid tumor cells) can be engineered so that they also express one or more fusion proteins of an antibody or antibody fragment (e.g., scFv) coupled to an antigen that an effector cell will recognize. The antibody or antibody fragment recognizes the tumor cell and binds and presents the antigen for an effector cell to recognize. In one non-limiting example, a solid tumor cell can be transduced with a fusion protein that includes an anti-tumor TAA scFv that binds to a tumor cell, and also part or all of the human CD19 protein. The scFv portion binds to the tumor cell and the CD19 is presented to effector cells for them to target the tumor cell and destroy the tumor cell.
In another embodiment, the cancer cells (e.g., solid tumor cells) can be engineered so that they also express one or more fusion proteins of an antibody or antibody fragment (e.g., scFv) coupled to an anti-idiotype antibody that will recognize an effector cell. The antibody or antibody fragment recognizes the tumor cell and binds and presents the anti-idiotype antibody that binds an antigen binding portion of one or more cellular therapeutics (e.g., and scFv of a CAR-T cell). In one non-limiting example, a solid tumor cell can be transduced with a fusion protein that is an “scFv/anti-idiotype scFv” fusion protein that includes (i) an scFv that binds a tumor antigen (as described herein) at the N-terminus and (ii) an anti-idiotype scFv that binds to an antigen binding portion at the C-terminus. In some embodiments, a fusion protein is an “anti-idiotype scFv/scFv” fusion protein that includes (i) an anti-idiotype scFv that binds to an antigen binding portion at the N-terminus, and (ii) an scFv that binds a tumor antigen (as described herein) at the C-terminus.
In some such embodiments, after being expressed, such fusion protein is secreted from a tumor and can bind on or near a tumor cell via its anti-tumor antibody or fragment (e.g., scFv). Upon subsequent treatment with an additional cellular therapeutic (e.g., CAR-T cell), the fusion protein (bound to a tumor antigen) binds to such additional cellular therapeutic via its idiotope-binding protein (e.g., via its anti-idiotype antibody that recognizes an antigen binding receptor of a CAR-T cell). In some embodiments the antigen binding receptor binds a B cell specific marker. In some embodiments, a B cell specific marker is a B cell antigen. In some embodiments, a B cell specific marker is a neoantigen and/or an antigen expressed by a B cell lineage cancer cell. For example, a fusion protein can include (i) an scFv that binds to a tumor antigen and (ii) an anti-idiotype antibody (e.g., anti-idiotype scFv) that binds to a B-cell antigen binding domain (e.g., a CAR that binds CD19, CD20, CD21, CD22, CD24, CD79a, CD79b, ROR1, or BCMA) of a CAR-T cell. Additionally, for example, a fusion protein can include (i) an scFv that binds to a tumor antigen and (ii) an anti-idiotype antibody (e.g., anti-idiotype scFv) that binds to an anti-CD19 scFv on a CD19 CAR-T cell.
Genes productively introduced into tumor cells will provide improved cellular therapeutic activity by addressing or circumventing critical barriers to efficacy. These genes will improve therapeutic efficacy by “propagating” the anti-tumor response, optimize cytokine support in the local environment, reverse local immunosuppression, improve cellular effector functions, and promote cellular access to tumors. Any gene can be included in an expressed construct as described herein, and the present disclosure is not limited to any particular gene. Exemplary, non-limiting types of genes that can be included as cellular therapy targets include, e.g., targets for additional cellular therapeutics, polypeptide antigens, antibodies, cytokines, agents targeting tumor microenvironment, and agents supporting immune cell growth/proliferation.
An expressed gene contains a promotor with its associated elements, and a gene sequence. An expressed gene contains three essential characteristics: 1) an optimal promoter for expression in the tumor cell, 2) an optimal expressed gene sequence, and 3) an optimized expression pattern with defined kinetics. A set of promoters is developed to drive diverse expression patterns. Examples include; rapid and sustained expression, measured in days, or rapid but reversible expression, or delayed expression. Also, the level of expression can be modified by selective use of regulatory and promoter elements. Such methods are well understood, for example, E.D. Papadakis, et al., Current Gene Therapy, 4: 89-113 (incorporated herein by reference).
The invention provides for compositions and methods for treating cancer by engineering a system whereby the cancer cells (e.g., tumor cells or solid tumor cells) secrete fusion proteins that include TAA or TSA and a therapeutic agent. An individual having cancer or suspected of having cancer can be given a composition that allows for the in vivo transduction of their cancer cells. The administration can be by any means, including, but not limited to intravenously, systemically, intramuscularly, intraperitonally, or intra-tumoral injection.
In some embodiments, the cell therapy antigen that is expressed on local tumor cells following transduction and secretion of fusion proteins is recognized by the effector cells, and can comprise a tumor associated antigen (TAA). In one embodiment, TAA expression can be restricted to the tumor cell population alone, expressed by all tumor cells, and expressed on the tumor cell surface. Other antigens are overexpressed on tumor cells, but may be found on normal cells at lower levels of expression and thus are tumor-selective antigens (TSA). In addition, some tumor antigens arise as “passenger mutations”, i.e. are non-essential antigens expressed by tumor cells that have defective control over DNA repair, thus accumulating mutations in diverse proteins. Some tumor antigens are proteins that are produced by tumor cells that elicit an immune response; particularly T-cell mediated immune responses. Tumor-specific molecules that may be targeted by cellular therapy targets may include tumor associated antigens well known in the art and can include, for example, a glioma-associated antigen, carcinoembryonic antigen (CEA), β-human chorionic gonadotropin, alphafetoprotein (AFP), lectin-reactive AFP, thyroglobulin, RAGE-1 , MN-CA IX, human telomerase reverse transcriptase, RU1 , RU2 (AS), intestinal carboxyi esterase, mut hsp70-2, M-CSF, prostase, prostate-specific antigen (PSA), PAP, NY-ESO- 1 , LAGE-la, p53, prostein, PSMA, Her2/neu, survivin and telomerase, prostate-carcinoma tumor antigen- 1 (PCTA-1), MAGE, ELF2M, neutrophil elastase, ephrinB2, CD22, insulin growth factor (IGF)-I, IGF-II, IGF-I receptor and mesothelin. The application of technologies, including next generation sequencing (NGS) of tumor genomes and exomes, and high-sensitivity mass spectrometry (protein sequencing) analysis of the tumor proteome, is continuing to identify novel TAA and TSA antigens of use for this invention.
NGS is a method of high-throughput sequencing that performs massively parallel sequencing, during which millions of fragments of DNA from a single sample are sequenced in unison. NGS facilitates high-throughput sequencing, which allows an entire genome to be sequenced in less than one day. The creation of NGS platforms has made sequencing accessible to more labs, rapidly increasing the amount of research and clinical diagnostics being performed with nucleic acid sequencing, and thus have revolutionized genomics and molecular biology. Some NGS technologies include Illumina (Solexa) sequencing, Roche 454 sequencing, Ion torrent: proton/PGM sequencing, and SOLiD sequencing.
An alternative method for identifying tumor specific antigens is direct protein sequencing. Protein sequencing of enzymatic digests using multidimensional MS techniques (MSn) including tandem mass spectrometry (MS/MS)) can also be used to identify antigens. Such proteomic approaches permit rapid, highly automated analysis (See, e.g., K. Gevaert and J. Vandekerckhove, Electrophoresis 21: 1145- 1154 (2000, incorporated herein by reference)). Furthermore, high-throughput methods for de novo sequencing of unknown proteins may be used to analyze the proteome of a patient's tumor to identify expressed antigens. For example, meta shotgun protein sequencing may be used to identify expressed antigens (See e.g., Guthals et al. (2012), Molecular and Cellular Proteomics 11(10): 1084-96, incorporated herein by reference).
Non-limiting examples of tumor antigens that can used include EphA2, HER2, GD2, Glypican-3, 5T4, 8H9, αvβ6 integrin, BCMA, B7-H3, B7-H6, CAIX, CA9, CD19, CD20, CD22, kappa light chain, CD30, CD33, CD38, CD44, CD44v6, CD44v7/8, CD70, CD123, CD138, CD171, CEA, CSPG4, EGFR, EGFRvIII, EGP2, EGP40, EPCAM, ERBB3, ERBB4, ErbB3/4, FAP, FAR, FBP, fetal AchR, Folate Receptor a, GD2, GD3, HLA-Al MAGE Al, HLA-A2, ILl IRa, IL13Ra2, KDR, Lambda, Lewis-Y, MCSP, Mesothelin, Mucl, Mucl6, NCAM, NKG2D ligands, NY-ESO-1, PRAME, PSCA, PSC1, PSMA, ROR1, SURVIVIN, TAG72, TEM1, TEM8, VEGRR2, carcinoembryonic antigen, HMW-MAA, and VEGF receptors. Other exemplary antigens that can be used are antigens that are present with in the extracellular matrix of tumors, such as oncofetal variants of fibronectin, tenascin, or necrotic regions of tumors.
Additional tumor-selective molecules can be used include any membrane protein or biomarker that is expressed or overexpressed in tumor cells including, but not limited to, integrins (e.g., integrin αbβ3, α5β1), EGF Receptor Family (e.g., EGFR2, Erbb2/HER2/neu, Erbb3, Erbb4), proteoglycans (e.g., heparan sulfate proteoglycans), disialogangliosides (e.g., GD2, GD3), B7-H3 (aka CD276), cancer antigen 125 (CA- 125), epithelial cell adhesion molecule (EpCAM), vascular endothelial growth factor receptors 1 and 2 (VEGFR-1 , VEGFR-2), CD52, carcinoembryonic antigen (CEA), tumor associated glycoproteins (e.g., TAG-72), cluster of differentiation 19 (CD19), CD20, CD22, CD30, CD33, CD40, CD44, CD74, CD152, mucin 1 (M UC1), tumor necrosis factor receptors (e.g., TRAIL-R2), insulin-like growth factor receptors, folate receptor a, transmembrane glycoprotein NMB (GPNMB), C-C chemokine receptors (e.g., CCR4), prostate specific membrane antigen (PSMA), recepteur d'origine nantais (RON) receptor, cytotoxic T-lymphocyte antigen 4 (CTLA4), and other tumor specific receptors or antigens.
As exemplified by the non-limiting examples of TAA and TSA targets recited herein, there is a large and diverse selection of antigens to which one of skill in the art can direct the transduced and expressed therapeutics described herein. For example, the therapeutics might comprise a secreted fusion protein that contains a scFv antigen binding domain (e.g. anti-MUC16, anti-CEA, anti-PSMA) fused to the target antigen (e.g. CD19) that can be recognized by a CAR T cell. In this embodiment, the secreted fusion protein has two functional domains, the scFv that binds to the target tumor cell surface, and the CD19 protein domain that is presented as a target for the CAR T cell (
Further, multiple genes can be encoded in a single CAR expression construct by using, for example, in frame or independent IRES initiation sites for individual elements. Alternatively, inducible methods have been described, whereby the application of a small molecule can induce or block expression of one or more CAR elements. A wide variety of such methods are disclosed, such as inhibitory CARs, costimulatory CARs, “cideCARs”, on switches and others, the use of which can further modify or alter the activity of CART cells (see Baas, T. SciBX 7(25); doi:10.1038/scibx.2014.725).
In other embodiments, the transduced tumor cells secrete fusion proteins that are targeted by antibody-drug conjugates that are known and include, e.g., brentuximab vedotin (ADCETRIS, Seattle Genetics); trastuzumab emtansine (Roche); Gemtuzumab ozogamicin (Pfizer); CMC-544; SAR3419; CDX-011; PSMA-ADC; BT-062; CD30, HER2, and IMGN901 (see, e.g., Sassoon et al., Methods Mol. Biol. 1045:1-27 (2013); Bouchard et al., Bioorganic Med. Chem. Lett. 24: 5357-5363 (2014)). In other embodiments, the transduced tumor cells secrete fusion proteins which can be targeted by antibodies having antibody dependent cellular cytotoxicity function such as those recognized by rituximab, ocrelizumab, ipilimumab, cituximab, erbitux and many others. Accordingly, in some embodiments, a nucleic acid encoding a polypeptide antigen as part of the fusion protein that binds to one or more of such known antibody-drug conjugates can be included in as a cellular therapy target described herein.
In some embodiments, the tumor and/or tumor microenvironment is transduced with a cytokine fusion protein, e.g., a fusion protein of a cytokine (e.g., an anti-tumor cytokine) and a target for one or more additional cellular therapeutics described herein (e.g., a CAR-T target). Exemplary cytokines may bind to the tumors, and present the tumor with the cytokine. For example, some contemplated targets include CD19, CD20, CD21, CD22, CD24, and BCMA. Such a cellular therapy can provide both a target for one or more additional cellular therapeutics (e.g., a CAR-T target) and a stimulatory cytokine at a tumor surface. For example, an expressed and/or secreted construct can encode a cytokine-CD19 fusion protein, or a fusion of a cytokine and a CD19 fragment, e.g., a CD19 fragment to which a CD19- CAR-T cell binds. In some embodiments, a CD19 fragment is a CD19 IgC domain. Without wishing to be bound by theory, a single expressed construct encoding such a fusion protein advantageously allows a cellular therapeutic to be genetically engineered using a minimal (e.g., a single) transgene. An additional benefit of using cytokine fusion proteins is to utilize their tight binding to their receptors, in addition to the cytokine functional effect.
In some embodiments, one or more cytokines secreted as part of a cytokine fusion protein bind to cells at high affinity (e.g., KD of about 10−7, 10−8, 10−9, 10−10, 10−11, or less) and/or have low internalization rates (e.g., less than about 10, 102, 103, 104, or 105 cytokine molecules per cell per day). Binding affinity and internalization rates of various cytokines are known in the art and/or can be measured using known methods.
In some embodiments, the recombinant tumor described herein encodes, as a fusion protein as described herein, one or more pro-immune response agents, e.g., one or more cytokines used in cancer therapy. Non-limiting, exemplary cytokines that can be included include, e.g., IFNα, IFNβ, IFNγ, IL-1, IL-2, IL-7, IL-12, IL-15, IL-21, IL-36, TNF, LTα, GM-CSF, G-CSF, a TLR agonist, and an immune checkpoint antibody fragment.
Known problems associated with cytokine therapy include, e.g., high dose requirements, toxicity, and limited efficacy. Thus, in some embodiments, expressed constructs are used to deliver one or more cytokines at a specific site and/or at a specific dose (e.g., to reduce or eliminate one or more risks associated with cytokine therapy).
In some embodiments, expression of a cytokine (e.g., an immunostimulatory cytokine) at or near a surface of a tumor induces an immune response to the tumor. In some embodiments, an expressed cytokine fusion protein can be a target for one or more additional cellular therapeutics (e.g., one or more additional CAR-T cells). In some embodiments, secretion of a cytokine fusion protein near a surface of a tumor induces an immune response to the tumor and is also used as a target for one or more additional cellular therapeutics (e.g., one or more additional CAR-T cells). An example is an Interferon alpha cytokine fused to the CD19 protein domain recognized by a CAR T cell with CD19 reactivity. The IFNalpha molecule binds with high affinity to interferon receptors on or near the tumor cell, thus supporting cellular therapeutic activity directed to CD19. In another example, the interferon alpha cytokine is fused to a scFV that recognizes a TAA or a TSA on the same tumor cell type, thus binding back on to the cell and surrounding cells, and inducing or supporting an IFNalpha-driven immune response.
For example, release of IL-21 can be used to induce expansion and/or effector differentiation of CD8+ T cells and/or support NK cell activation and cytolytic activity. In one exemplary method, an expressed construct encodes IL-21. Upon binding of a scFv directed an antigen on a tumor cell, a cellular therapeutic described herein exhibits prolonged release of IL-21. Exemplary cellular therapeutics include, e.g., CAR-T cells, CAR-NK cells, TCR-T cells, TIL cells, allogenic NK cells, and autologous NK cells.
In another exemplary method, induced release of IL-15 fusion proteins can be used to support NK cell expansion and/or to recruit NK cells to promulgate an anti-tumor response and to support the survival and expansion of cellular therapeutics. Exemplary cellular therapeutics include, e.g., CAR-T cells, CAR-NK cells, TCR-T cells, TIL cells, allogenic NK cells, and autologous NK cells. In this example a scFv that recognizes a TAA or a TSA on the target tumor cell type binds, and presents IL-15 in the local environment. In a further exemplification, of relevance to all of the cytokine examples proposed, the secreted fusion protein is trifunctional, having a scFV that recognizes a TAA or a TSA on the target tumor cell type, a cytokine encoded into a beta loop or beta strand within the heavy or light chain variable region that is not engaged in antigen binding, and expressing a target antigen for the binding of a cellular therapeutic. The utilization of CDRs within the heavy and light variable domains of a scFv is readily determined from the sequence of the CDR as well as through the use of databases that indicate which residues are involved in antigen engagement and which are not involved but are otherwise solvent exposed, i.e. useful for expression of an encoded sequence such as a cytokine.
In some examples, the recombinant tumor cells can express, as part of a fusion protein, scFv or TCR that may be fused to cell recruiting moieties (e.g., anti-CD3, anti-CD16, or an anti-idiotype antibody or fragment). In other embodiments, bispecific T cell engager (BiTE®) technology is utilized to help engage the body's endogenous T cells and to target cancer cells that have been engineered to express one or more TAA's. The antibody constructs of the BiTE® technology are constructed by genetically linking the minimal binding domains of monoclonal antibodies for TAA or tumor-associated surface antigens and for the T cell receptor-associated molecule, onto a single polypeptide chain. One antibody is specific for a selected surface antigen on a targeted tumor cell, and the other antibody is specific for moiety (e.g., CD3), tied to the T-cell receptor complex on the surface of T cells. The BiTE® technology binds polyclonal cytotoxic T cells and targeted malignant cells.
In some embodiments, a target for one or more additional cellular therapeutics is or comprises a polypeptide antigen. The polypeptide antigen to be expressed by an expressed construct, and is not limited to any particular polypeptide or portion thereof, provided that an additional cellular therapeutic (e.g., CAR-T cell) can be engineered to recognize and bind to such polypeptide target. In some embodiments, the polypeptide target is a polypeptide that is not a tumor-associated antigen. In some embodiments, the target is a tumor antigen, e.g., BCMA, CD19, CD20, CD22, ROR1, mesothelin, CD33/IL3Ra, c-Met, PSMA, Glycolipid F77, EGFRvIII, GD-2, NY-ESO-1 TCR, or MAGE A3 TCR.
In some embodiments, the tumor and/or tumor microenvironment is transduced with a fusion protein comprising (i) an antibody or antigen-binding fragment thereof that binds to a tumor antigen described herein and (ii) an “anti-idiotype” peptide that binds an antigen binding receptor of one or more additional cellular therapeutics (e.g., an scFv of a CAR-T cell). In some embodiments, an anti-idiotype peptide that binds an antigen binding receptor of one or more additional cellular therapeutics binds one or more CDRs of an antigen binding receptor (e.g., an scFv of a CAR-T cell). In some embodiments, a fusion protein includes (i) an scFv that binds a tumor antigen (as described herein) at the N-terminus and (ii) an anti-idiotype peptide that binds to an antigen binding receptor (described herein) at the C-terminus. In some embodiments, a fusion protein includes (i) an anti-idiotype peptide that binds to an antigen binding receptor (described herein) at the N-terminus, and (ii) an scFv that binds a tumor antigen (as described herein) at the C-terminus.
One of skill in the art will recognize that several methods can be used to identify peptides that bind to antibodies or fragments thereof (e.g., scFvs or CDRs). Exemplary methods include screening or panning peptide libraries. For example, peptides that bind rituximab, an anti-CD20 antibody, have been identified (Klein et al. mABs 5:1, 22-33 January/February 2013; Philip et al. Blood. 2014 Aug 21;124(8):1277-87; Perosa et al. J Immunol 2007; 179: 7967-7974; Perosa et al. Blood. 2006 Feb 1;107(3):1070-7). In some embodiments, peptides that bind antibodies can be identified through the use of phage display libraries (see, e.g., Smith Science. 1985 Jun 14;228(4705):1315-7; Scott et al. Science. 1990 Jul 27;249(4967):386-90; Mintz et al. Nat Biotechnol. 2003 Jan;21(1):57-63; Spatola et al. Anal Chem. 2013; Rojas et al. MAbs. 2014;6(6):1368-76; Wang et al. Oncotarget. 2016 Nov 15;7(46):75293-75306; He et al. Virology Journal 2012, 9:217; Li et al. PLoS One. 2016 May 18;11(5):e0147361; de Oliveira-Junior et al. Biomed Res Int. 2015;2015:267989). In some embodiments, peptides that bind antibodies can be identified through screens of peptide libraries displayed on organisms other than phage (for example bacteria, see, e.g., US Pat. 9,309,510). In some embodiments, peptides that bind antibodies can be identified through other peptide libraries, for example, soluble peptide libraries (e.g., positional scanning libraries; see, for example, Pinilla et al. Biochem J. (1994) 301, 847-853), DNA-encoded cyclic libraries, etc. Any of such peptides can be used as an “anti-idiotype” peptide in methods and constructs described herein.
In some embodiments, after being expressed, such fusion protein is secreted from a transduced cell and can bind on or near a tumor cell via its anti-tumor antibody or fragment (e.g., scFv). Upon subsequent treatment with an additional cellular therapeutic (e.g., CAR-T cell), the fusion protein (bound to a tumor antigen) binds to such additional cellular therapeutic via its anti-idiotype peptide (e.g., that recognizes an antigen binding receptor of a CAR-T cell). For example, a fusion protein can include (i) an scFv that binds to a tumor antigen and (ii) an anti-idiotype peptide that binds to a B-cell specific marker binding domain (e.g., a CAR that binds CD19, CD20, CD21, CD22, CD24, CD79a, CD79b, ROR1, or BCMA) of a CAR-T cell. In some embodiments, a fusion protein can include (i) an scFv that binds to a tumor antigen and (ii) an anti-idiotype peptide that binds to an anti-CD19 scFv on a CD19 CAR-T cell.
In some embodiments, the tumor and/or tumor microenvironment is transduced with a fusion protein comprising (i) an antibody or antigen-binding fragment thereof that binds to a tumor antigen described herein and (ii) an anti-idiotype antibody or fragment that binds an antigen binding portion of one or more additional cellular therapeutics (e.g., an scFv of a CAR-T cell). In some embodiments, a fusion protein is an “scFv/anti-idiotype scFv” fusion protein that includes (i) an scFv that binds a tumor antigen (as described herein) at the N-terminus and (ii) an anti-idiotype scFv that binds to an antigen binding portion at the C-terminus. In some embodiments, a fusion protein is an “anti-idiotype scFv/scFv” fusion protein that includes (i) an anti-idiotype scFv that binds to an antigen binding portion at the N-terminus, and (ii) an scFv that binds a tumor antigen (as described herein) at the C-terminus.
In some such embodiments, after being expressed, such fusion protein is secreted from a tumor and can bind on or near a tumor cell via its anti-tumor antibody or fragment (e.g., scFv). Upon subsequent treatment with a cellular therapeutic (e.g., CAR-T cell), the fusion protein (bound to a tumor antigen) binds to such cellular therapeutic via its idiotope-binding protein (e.g., via its anti-idiotype antibody that recognizes an antigen binding portion of a CAR-T cell).=In some embodiments the antigen binding receptor binds a B cell specific marker. In some embodiments, a B cell specific marker is a B cell antigen. In some embodiments, a B cell specific marker is a neoantigen and/or an antigen expressed by a B cell lineage cancer cell. For example, a fusion protein can include (i) an scFv that binds to a tumor antigen and (ii) an anti-idiotype antibody (e.g., anti-idiotype scFv) that binds to a B-cell specific marker binding domain (e.g., a CAR that binds CD19, CD20, CD21, CD22, CD24, CD79a, CD79b, ROR1, or BCMA) of a CAR-T cell. In some embodiments, a fusion protein can include (i) an scFv that binds to a tumor antigen and (ii) an anti-idiotype antibody (e.g., anti-idiotype scFv) that binds to an anti-CD19 scFv on a CD19 CAR-T cell.
Anti-idiotype antibodies are specific antibodies that can bind to the CDR sequences within a specific antibody of an antibody's scFv. Anti-idiotype antibodies can be characterized by their binding. Type 1 anti-idiotype antibodies bind to the CDRs of a target antibody variable domain in such a manner as to inhibit, disrupt or neutralize the activity of the target antibody, i.e., its ability to bind antigen. Type 2 anti-idiotype antibodies bind to the CDRs of the target antibody variable domains in such a manner as to be able to bind even when the antibody is bound to antigen. Thus Type 2 antibodies are not defined by their ability to inhibit or neutralize antigen binding. A Type 3 anti-idiotype antibody only binds a target antibody when is bound to antigen.
Anti-idiotype antibodies are known in the art, and any such antibody is useful in compositions and methods described herein. One example of a specific anti-idiotype antibody specific for an antibody scFv is antibody 136.20.1, which recognizes the scFv domain of the mouse anti-human antibody FMC63 (see, e.g., Jena B, et al. (2013) Chimeric Antigen Receptor (CAR)-Specific Monoclonal Antibody to Detect CD19-Specific T Cells in Clinical Trials. PLoS ONE 8(3): e57838; US 2016/0096902). The 136.20.1 antibody and its domains (e.g., the scFv domain), have been used to detect the FMC63 VH/VL pair, or scFv, e.g., as displayed on the surface of a CAR T cell. However, the 136.20.1 antibody has not previously been presented to an FMC63-based CAR T cell as a means of triggering CAR T activity. Indeed, in the scFv or similar monovalent format, 136.20.1 antibody triggering CART activity would not be expected. It has been shown that 136.20.1 binds to the antigen (CD19) recognition site of FMC63, since at concentrations above 5μg/mI136.20.1 inhibits binding of the FMC63 CART cell to CD19.
Another example is an anti-idiotype antibody that recognizes an anti-human CD22 scFv (as described in, e.g., Zhoa et al. 2014. Generation of Anti-Idiotype scFv for Pharmacokinetic Measurement in Lymphoma Patients Treated with Chimera Anti-CD22 Antibody SM03. PLoS ONE 9(5): e96697; US 2015/0175711). One such antibody is an anti-idiotype single-chain Fv (scFv) antibody specific for the murine (RFB4), chimeric (SM03) and humanized (SM06) versions of an anti-CD22 antibody that has the characteristics of a Type 1 anti-idiotypic antibody, that is, it binds specifically to the CDRs of the named anti-CD22 antibodies and inhibits the binding of the named antibodies to human CD22 protein. A Type 2 idiotypic antibody that specifically recognizes rituximab (a mouse-derived antibody to human CD20) has also been described (see Cragg et al. (2004) An anti-idiotype antibody capable of binding rituximab on the surface of lymphoma cells. Blood 104: 2540-2542).
Other examples include anti-idiotypic antibodies described by Dunn & Kehry in US 2013/0330323 A1. Other examples include myriad anti-idiotypic antibodies published and described. Other examples include novel anti-idiotypic antibodies as discovered in directed screening campaigns using the target antibody or scFv protein as immunogen or screening reagent.
In some embodiments, the tumor and/or tumor microenvironment is transduced with a fusion protein comprising an antibody (or antigen-binding fragment thereof, e.g., secreted scFv or other antibody formats) and a target for one or more additional cellular therapeutics (e.g., a CAR-T target). An antibody (or fragment) can be selected to bind, e.g., to a tumor antigen (e.g., a tumor antigen described herein), and its fusion partner can include a target for one or more additional cellular therapeutics. Such antibodies (or antigen-binding fragments) include, e.g., a monoclonal antibody (mAb), including, for example, scFv and full length mAbs, a VHH domain, a diabody, a nanobody, etc. In one example, a construct encodes a secreted fusion protein consisting of a mAb (e.g., an anti-tumor associated antigen mAb or antigen-binding fragment) and CD19 or a fragment thereof (e.g., a CD19 Ig domain). In some embodiments, an antibody (or fragment) binds to an antigen expressed on several types of cells. In some embodiments, an antibody (or fragment) binds to a tumor-selective antigen. In some embodiments, an antibody (or fragment) binds to a tumor-selective, but not specific, antigen. In some embodiments, an antibody (or fragment) binds to a tumor antigen associated with a hematologic malignancy. In some embodiments, an antibody (or fragment) binds to a tumor antigen associated with a solid tumor. In some embodiments, an antibody (or fragment) binds to one or more of BCMA, CD19, CD20, CD22, ROR1, mesothelin, CD33/IL3Ra, c-Met, PSMA, Glycolipid F77, EGFRvIII, GD-2, NY-ESO-1 TCR, and MAGE A3 TCR.
The target, which is placed on the tumor cells, can be CD19. Other B cell targets can be used, including but not limited to CD20, CD21, CD22, CD23, CD24, CD72, CD79a, CD79b, and BCMA. These B cell targets have particular advantages as CAR T cell targets, along with the list of other targets. In addition, the target can include CD30, Her 2, a target for ADC's or radioimmunotherapy (e.g., a monoclonal antibody carrying a radioisotope).
Peptides that Inhibit Local (e.g., Tumor Microenvironment) Factors
In some embodiments, peptides (e.g., polypeptides and fragments thereof) that inhibit local factors can be expressed as a fusion protein by the tumor cell. Nucleic acids coding for these peptides can be engineered as described herein and/or by any method known to one of skill in the art such that the peptide(s) are expressed. Non-limiting examples include TGFbeta, adenosine receptor 2, vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), indoleamine 2,3-dioxygenase 1 (ID01), and matrix metalloproteinases (MMPs)).
CD19 is a 95 kd transmembrane glycoprotein belonging to the Ig superfamily and includes two extracellular C2-type Ig domains (see, e.g., Tedder Nature Rev. Rheum. 5:572-577 (2009); Wang et al., Exp. Hematol. Oncol. 2012 Nov 29;1(1):36. doi: 10.1186/2162-3619-1-36.)). In some embodiments, one or both of the C2-type Ig domains are used as scaffolds for mutagenesis, and CD19 variants (e.g., CD19 or a portion thereof that include one or more mutations within one or both C2-type Ig domains) can be screened and selected for binding to a target antigen described herein.
The nucleotide sequence of human CD19 is known (see Genbank Accession No. M84371.1). To provide variant nucleic acid sequences that encode CD19 variants that bind a particular antigen, a number of methods known in the art may be utilized. In some embodiments, a screening procedure is used that enables identification and/or isolation of nucleic acids that encode CD19 variants that bind a particular antigen. Exemplary methods include a so-called biopanning step, known from technologies such as phage display (Kang, A. S. et al. 1991. Proc Natl Acad Sci USA 88, 4363-4366), ribosome display (Schaffitzel, C. et al. 1999. J. Immunol. Methods 231, 119-135), DNA display (Cull, M. G. et al. 1992. Proc Natl Acad Sci USA 89, 1865-1869), RNA-peptide display (Roberts, R. W., Szostak, J. W., 1997. Proc Natl Acad Sci USA 94, 12297-12302), covalent display (WO 98/37186), bacterial surface display (Fuchs, P. et al. 1991. Biotechnology 9, 1369-1372), yeast surface display (Boder, E. T., Wittrup, K. D., 1997. Nat Biotechnol 15, 553-557) and eukaryotic virus display (Grabherr, R., Ernst, W., 2001. Comb. Chem. High Throughput. Screen. 4, 185-192). FACS and magnetic bead sorting are also applicable for enrichment (panning) purposes using labeled antigen. Immunodetection assays such as ELISA (Dreher, M. L. et al. 1991. J. Immunol. Methods 139, 197-205) and ELISPOT (Czerkinsky, C. C. et. al. 1983. J Immunol Methods. 65, 109-21) can also be used either following a biopanning step or alone.
Thus, in some embodiments, an inducible construct described herein encodes a CD19 variant (or fragment), either alone or as part of a fusion protein described herein. For example, an inducible construct described herein can encode a CD19 variant (or fragment) selected to bind to a tumor agent and which, upon expression, can bind to the tumor antigen and that itself can be a target for an additional cellular therapeutic (e.g., a CAR-T cell that binds CD19). In some embodiments, an inducible construct described herein encodes a CD19 variant that includes a C2-type Ig domain variant selected to bind a tumor antigen. Upon expression of the CD19 variant, the C2-type Ig domain binds to the tumor antigen on a tumor cell. Subsequently, treatment with (e.g., administration to a subject of) a CAR-T cell that recognizes CD19 kills the tumor cell to which the CD19 variant is bound. In some embodiments, an inducible construct described herein encodes a CD19 variant that includes variants of both C2-type Ig domains, each of which is selected to bind a tumor antigen (e.g., different epitopes of the tumor antigen). Upon expression of the CD19 variant, the C2-type Ig domains bind to the tumor antigen on a tumor cell. Subsequently, treatment with (e.g., administration to a subject of) a CAR-T cell that recognizes CD19 kills the tumor cell to which the CD19 variant is bound.
In some embodiments, a CD19 variant selected for binding to a target antigen is included in a fusion protein. For example, a CD19 variant that includes a C2-type Ig domain variant selected to bind a tumor antigen can be fused to an antibody or fragment thereof that also binds to the tumor antigen (e.g., to a different epitope on the tumor antigen). Exemplary fusion proteins include, e.g., CD19 variant/scFv fusion proteins and CD19 variant/VHH fusion proteins. An inducible construct described herein can encode such a CD19 variant/antibody fusion protein and upon expression, the CD19 variant and the antibody of the fusion protein bind to the tumor antigen on a tumor cell. Subsequently, treatment with (e.g., administration to a subject of) a CAR-T cell that recognizes CD19 kills the tumor cell to which the CD19 variant/antibody fusion protein is bound. In some embodiments, as described herein, the CD19 scaffold genes that are useful in the context of inducible expression will also be useful when modified for the production in vitro of soluble, purified fusion proteins. Additional, non-limiting examples of fusion proteins that include CD19 variants (or fragment) as a scaffold include, e.g., CD19 variant /cytokine fusion proteins and CD19 variant/TLR agonist fusion proteins.
Additional, non-limiting examples of fusion proteins that include CD19 (or fragment) as a scaffold include, e.g., CD19-cytokine fusion proteins, CD19-TLR agonist fusion proteins. Other B cell restricted cell surface markers which contain immunoglobulin-like domains include CD22, CD79a and CD79b. These Ig domains can also be mutagenized to generate variants binding TAA's and TSA's.
In some embodiments, a CD19 variant selected for binding to a target antigen is included in a fusion protein with an anti-idiotype antibody or fragment described herein. For example, a CD19 variant that includes an ECD variant or C2-type Ig domain variant selected to bind a tumor antigen can be fused to an anti-idiotype antibody or fragment thereof that binds to an antibody or portion on a cellular therapeutic, e.g., CAR-T cell. An expression construct described herein can encode such a CD19 variant/anti-idiotype antibody fusion protein and upon expression, the CD19 variant of the fusion protein binds to the tumor antigen on a tumor cell. Subsequently, treatment with (e.g., administration to a subject of) a CAR-T cell that expresses an antibody or fragment recognized by the anti-idiotype antibody or fragment kills the tumor cell to which the CD19 variant/anti-idiotype antibody fusion protein is bound. In some embodiments, an expression construct described herein can encode one or more CD19 variants. For example, in some embodiments, a first CD19 variant that includes an ECD variant or C2-type Ig domain variant selected to bind a tumor antigen can be fused to a second CD19 variant that includes an ECD variant or C2-type Ig domain variant selected to bind an antibody or fragment expressed on a cellular therapeutic (e.g., CAR-T cell).
In some embodiments, a CD19 variant selected for binding to a target antigen is included in a fusion protein with an anti-idiotype peptide that binds an antigen binding receptor of one or more additional cellular therapeutics as described herein. For example, a CD19 variant that includes an ECD variant or C2-type Ig domain variant selected to bind a tumor antigen can be fused to an anti-idiotype peptide that binds to an antibody or portion on a cellular therapeutic, e.g., CAR-T cell. An expression construct described herein can encode such a CD19 variant/anti-idiotype peptide fusion protein and upon expression, the CD19 variant of the fusion protein binds to the tumor antigen on a tumor cell. Subsequently, treatment with (e.g., administration to a subject of) a CAR-T cell that expresses an antibody or fragment recognized by the anti-idiotype peptide kills the tumor cell to which the CD19 variant/anti-idiotype peptide fusion protein is bound.
The below Table 1 presents a non-comprehensive list of certain human polypeptide antigens targeted by known, available antibody agents, and notes certain cancer indications for which the antibody agents have been proposed to be useful:
Accordingly, a cellular therapeutic that targets an expressed construct encoding a polypeptide antigen can be used in combination with one or more of these (or other) known antibodies.
Exemplary amino acid and nucleotide sequences of the disclosure are listed in the following Table:
The following examples are provided for illustrative purposes only and are not intended to limit the invention in any manner.
Cytokine support for cancer therapeutics has a long history (e.g. the systemic use of TNF, LTa, IFNs and IL-2). Inherent problems with systemic cytokine therapy include high dosage requirement, minimal efficacy, and toxicity (lethal in the case of TNF and LTa). Such toxicity limits the use of IL-12 and IL-15.
For example, systemic recombinant IL-12 induced multiple serious adverse effects, including renal and systemic toxicity. High-dose levels were linked to temporary immune suppression, which would be unfavorable for effective immunotherapy. (See, Leonard et al., Blood 1997;90:2541-8, and Colombo, MP et al., CytokineGrowth Factor Rev 2002;13:155-68, incorporated herein by reference. The majority of systemic IL-12 trials were associated with toxic adverse events and limited efficacy, since the cytokine did not reach the tumor site(s) in sufficient concentration (S Tugues, et al., 2015 Cell Death Differ 22: 237-246, incorporated herein by reference.
Recombinant IL-15 induces NK and CD8 cell mediated toxicities. Dose-limiting toxicities observed in patients receiving rIL-15 included grade 3 hypotension, thrombocytopenia, and elevations of ALT and AST, resulting in a suboptimal maximum-tolerated dose, having minimal clinical efficacy. (See, Conlon, K., et al., J. of Clinical Oncology Jan 1, 2015: 74-82, incorporated herein by reference).
These and similar studies illustrate the dose-limiting toxicity and minimal efficacy associated with the uncontrolled administration and systemic distribution of cytokines. Accordingly, an individual with cancer or suspected of having cancer (e.g., tumor) is administered with a composition that allows for the direct transduction of the tumor cells so that a fusion protein of a cytokines and a target. The administration can be intravenously or intra-tumorally.
CART cells, CAR NK cells, TCR T cells, TIL, allogeneic NK cells and autologous NK cells are engineered for prolonged release of IL-21 as a cytokine fusion protein with TAA. Expansion and effector differentiation is induced in CD8+ T cells, and NK cell activation and cytolytic activity is supported.
Engagement of activation signals rapidly secretes IL-15 under the control of the TNF promoter, which supports NK cell expansion (e.g., CAR NK, allogeneic NK cells, and autologous NK cells) or recruits NK cell promulgation in an anti-tumor response (e.g., CAR T, TCR, TIL). Alternatively, various combinations of cytokines expressed and promoters are used, and are expressed in a suitable manner (IL-2, IL-12, IL-36g, IFNg) as a fusion protein.
Sustained local production of an anti-TAA scFv antibody fused to IL-12 recruits immune cells to support and expand the anti-tumor immune response triggered by engagement with the CAR T cell or other cellular therapeutic.
The target is the polypeptide sequence, protein domain or domains recognized by the ADC, which is an antibody coupled to a toxin. ADC targets are the HER2 receptor, the CD30 cell surface protein, folate receptor alpha, and CD19, among many others.
The targeting method utilizes an scFv antibody or fragment thereof, and is fused to an antibody-drug conjugate target. Alternatively, a secreted heterodimer TCR alpha/beta or gamma/delta chain targeting method is used. Example antibody-drug conjugate target includes CD30, HER2, or ADCC antibody targets.
A “pro-immune response agent” is any agent capable of stimulating the immune response by stimulation cells comprising the immune response cell populations. Agents that stimulate immune responses directly include cytokines, the “danger signals” (DAMPs, PAMPs, TLR agonists etc.), agonist antibodies or ligands (e.g. anti-4-1BB, CD4OL, B7-1, and many others), inhibitors of immunosuppressive signals (antagonists of PD-1, PD-L1, CTLA4, Lag-3, TIM-3, ID01, adenosine receptor, TGFbeta, and many others)
The targeting method utilizes a scFv antibody (or fragment thereof), alternatively, the targeting method is a secreted heterodimer TCR alpha/beta or gamma/delta chain. In both targeting methods, the pro-immune response agent includes IL-2, IFNalpha, IL-12, IL-15, IL-21, any TLR agonist and any immune checkpoint antibody (or fragment thereof).
Another method for recruitment of immune effector cells is the development of bispecific T-cell Engagers (e.g. BiTEs) which consist of two scFvs connected by a linker. One arm is an anti-TAA scFv, and the second scFv binds to the CD3 subunit of the TCR complex and therefore triggers T cell activation. Importantly, BiTEs and related molecules (DARTS, diabodies, fCabs etc) elicit repeated rounds of tumor cell lysis by T cells at very low effector/ target (E/T) cell ratios. The cytotoxicity is mediated by membrane perforation and subsequent induction of granzymes and apoptosis, exactly the type of killing that one wished to elicit: in the anti-tumor setting. Normally, the affinity of the anti-TAA scFv tumor-associated antigen is much higher than that directed against CD3—this enforces specificity for the targeted tumor. Many BiTEs have been generated, including BiTEs that target CD19, EpCAM, HER2, carcinoembryonic antigen (CEA), ephrin A2 (EphA2), CD33, and melanoma-associated chondroitin sulfate proteoglycan (MCSP). Other BiTEs that are in clinical studies are composed of EpCAM, prostate-specific membrane antigen (PSNIA), or CEA-binding molecules combined with CD3-binding modules.
In some examples, the targeting method utilizes an scFv antibody (or fragment thereof), alternatively, the targeting method includes a secreted heterodimer TCR alpha/beta or gamma/delta chain. In both targeting methods, the cell recruiting moiety is fused to anti-CD16. In alternative examples, the cell recruiting moiety is fused to an anti-CD3 moiety, and utilizes the BITE® technology described herein.
HPV pseudovirus comprising an ScFv-CD19 fusion protein is injected IV to transduce tumor cells in a xenograft mouse model of breast cancer expressing Her2. The transduced tumors secrete the ScFv-CD19 fusion protein, resulting in coating of tumor cells with the ScFv-Cd19 fusion protein via ScFv binding to Her2. Addition of CD19-directed CAR T cells kills the tumor cells coated with CD19. CAR T cells directed to CD19 are made by standard methods.
A chimeric AAV/phage virus is injected IV to transduce tumor cells in a xenograft mouse model of breast cancer expressing Her2. The transduced tumors secrete the ScFv-CD19 fusion protein, resulting in coating of tumor cells with the ScFv-CD19 fusion protein via ScFv binding to Her2. Addition of CD19-directed CAR T cells kills the tumor cells coated with CD19. The generation of CD19 directed CAR T cells is well established.
HPV pseudovirus comprising an ScFv-CD30 fusion protein is injected IV to transduce tumor cells in a xenograft mouse model of breast cancer expressing Her2. The transduced tumors secrete the ScFv-CD30 fusion protein, resulting in coating of tumor cells with the ScFv-CD30 fusion protein via ScFv binding to Her2. Addition of CD30-directed antibody-drug conjugate (ADC) kills the tumor cells coated with CD30.Adcetris is a commercially available ADC from Seattle Genetics.
The present Example demonstrates expression of fusion proteins from cells transduced with AAV viral particles encoding fusion proteins. Further, the present example demonstrates that the expressed fusion proteins are capable of being bound by the anti-CD19 antibody FMC63 and detected by an anti-His antibody binding to the C-terminal His tag. Once expressed the fusion proteins are able to activate CAR19 T cells in the presence of cells that are CD19 negative.
The following table lists the various constructs tested in this example:
A 12 well plate was seeded with either A431 or 293T cells around 4×10e5 cells/well in DMEM+10% FBS media. The following day, one well was counted to get an accurate count for the viral infections. Cells were infected with a multiplicity of infection (MOI) of 1×106 or 5×106. AAV2 viral particles were made by Vigene (Rockville, Md.). The viral particles were generated from plasmids where the inserts containing the CD19 D1+D2-scFv-His sequences were cloned into pAV-FH. The viral particles AAV-1 (CD19-D1+2-Trastuzumab scFv (VH/VL), SEQ ID NO:113), AAV-3 (CD19 D1+D2-MOC31 scFv (VH/VL), SEQ ID NO:114), AAV-5 (CD19 D1+D2-LY2875358 scFv (VH/VL), SEQ ID NO:115) and AAV-7 (CD19 D1+D2-Panitumumab scFv (VH/VL), SEQ ID NO:116) had titers of 8.39×1013, 1.51×1014, 3.03×1014 and 2.13×1014 GC/ml, respectively. Infections were done in 0.6ml/well DMEM+2% FBS where the virus was added directly into the media. Different concentrations of virus were used from 10 μl (aka “104” or “10e4”) to 5×106 (aka “5×106” or “5×10e6”). The following day, the media was changed to DMEM+10%FBS and the incubation continued for 3 or 6 days.
Expression analysis was examined in the supernatant using an ELISA where anti-CD19 FMC63 was used for capture and anti-His used for detection. Briefly, 96 well plates (Pierce, Cat# 15041) were coated with 1.0 μg/ml reagent in 0.1 M carbonate, pH 9.5 for O/N at 4C. The plates were then blocked with 0.3% nonfat dry milk (NFD) in TBS (200 μl/well) for 1 hr at RT. Plates were then washed 3× with wash buffer (1× TBST: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). Titrations were performed from undiluted cell culture supernatant or purified protein at 1.0 μg/ml with serial 3× dilutions, 100 μl per well and incubate for 1h at RT. Dilution buffer is 1% BSA in 1× TBS (0.1 M Tris, 0.5 M NaCl) followed by washing 3× with wash buffer. Secondary reagents were added (if needed) such as Biotinylated-reagents at 1 μg/ml concentration at RT for 1 hour. HRP-conjugated reagents were added at 1:2000, applied 100 μl per well, incubated at RT in dark for 1 hr. 100 μl 1-Step Ultra TMB-ELISA (Thermo Fisher, Prod#34028) was added per well. Plates were read at 405 nm when color had developed.
An aliquot of the XTT reagent and the activation reagent was rapidly thawed at 37oC prior to use. 0.1 ml of activation reagent was then added to 5.0 ml of the XTT reagent. 50 μl of the activated—XTT solution was then added to each well. The plate was placed in the cell culture incubator for 2-4 hours and monitored for color development. The absorbance of the plate was read at wavelength 450 nm. The % cell death (aka cytotoxicity) was calculated as follows:
killing=[1-OD(experimental wells-corresponding number of T cells)/OD (tumor cells without T cell-medium)]×100
A 96 well plate (Pierce, product #15041) was coated with 1.0 μg/ml mouse anti-human IFNγ (BD Pharmingen, Cat# 551221) in 0.1 M carbonate buffer, pH 9.5, overnight at 4° C. The plate was blocked with 0.3% non-fat dry milk solution in tris-buffered saline (TBS) using 200 μl/well for 1 hour at room temperature. The plate was washed x3 with wash buffer (1× TBS/Tween: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). 100 μl culture supernatant from the 24 hour or 48 hour culture plates (see above) were added to the ELISA plate. A titration of recombinant human IFNγ (Thermo Fisher, Cat# RIFNG100) was also performed in the same plate from 300 ng/ml with serial 3× dilutions to 2 pg/ml to generate a standard curve. The plate was then incubated for 1 hour at room temperature. The dilution buffer was 1× TBS (0.1 M Tris, 0.5 M NaCl) plus 1% BSA. The plate was washed x3 with wash buffer. Biotinylated mouse anti-human IFNγ (BD Pharmingen, Cat# 554550) was added at 1 μg/ml concentration and the plate was incubated at room temperature for 1 hour. The plate was washed again x3 with wash buffer. HRP-conjugated Streptavidin (Thermo Fisher, Cat# 21130) was added at a 1:2000 dilution from the stock, with 100 μl added per well. The plate was then incubated at room temperature for 1 hour in the dark. The plate was washed again x3 with wash buffer. 100 μl per well of 1-Step Ultra TMB-ELISA development solution (Thermo Fisher, Cat #34028) was added per well. The plate was read at wavelength 405 nm when color developed sufficiently.
Construction and Expression of Trastuzumab scFv-Anti-Id Fusion Proteins
This example illustrates that an anti-idiotype scFv (136.20.1 scFv, which recognizes the scFv domain of the mouse anti-human antibody FMC63 (see, e.g., Jena B, et al. (2013) Chimeric Antigen Receptor (CAR)-Specific Monoclonal Antibody to Detect CD19-Specific T Cells in Clinical Trials. PLoS ONE 8(3): e57838; US 2016/0096902))can be fused to scFvs that bind to HER2, an antigen expressed on solid tumors and their metastases, e.g., the anti-Her2 scFv that is derived from trastuzumab/hu4D5v8 (e.g. from PDB database (1N8Z) and the Drug Bank database (AC. DB00072), see also Cho HS, Mason K, Ramyar KX, Stanley AM, Gabelli SB, Denney DW, Jr, et al. Structure of the extracellular region of HER2 alone and in complex with the Herceptin Fab. Nature. 2003;421:756-760), or of other anti-Her2 scFvs whether known in the art or newly discovered.
Trastuzumab scFv/anti-Id scFv fusion proteins containing 136.20.1 anti-idiotype scFv and trastuzumab scFv is created using the coding sequences for each scFv, with an appropriate signal sequence, linked together using G4S or other robust linker sequences as needed to allow each VH/VL pair to fold, and also to retain the structural integrity of each scFv by preventing interaction between the two scFv, using methods well known in the art.
The trastuzumab scFv-anti-Id scFv fusion proteins are produced in a variety of configurations, where each scFv is provided in tandem as a VH/VL pair, and in the N- or C-terminal position. For example, trastuzumab scFv-anti-Id scFv fusion proteins include N-terminal 136.20.1 scFv (VH/VL or VL/VH) and C-terminal trastuzumab scFv (VH/VL or VL-VH) and also N-terminal trastuzumab scFv (VH/VL or VL/VH) and C-terminal 136.20.1 scFv (VH/VL or VL/VH).
A His-tag is used to monitor protein expression. The His-tag is N-terminal or C-terminal in placement. A FLAG-tag is used as needed. A biotin label is used as needed. Other tags and labels are used as needed.
The assembled sequences are cloned into expression systems for analysis. For example, the sequences are cloned into the pcDNA-1 vector. The cloned sequences are expressed in mammalian cells. For example, 293T cells are transfected using vector DNA and Lipofectamine 2000® (Invitrogen). Some transfections are for temporary protein production (transient) while some are for cell line development (stable). Optimized sequences are cloned into retroviral, lentiviral or mRNA systems suitable for large scale transduction of human T cells. Protein expression level and quality is determined by Western blot analyses, immunoprecipitation, ELISA analyses, chromatography and/or additional methods as needed.
Trastuzumab scFv-Anti-Id Fusion Proteins are Recognized by FMC63 and by HER2
The ability of the trastuzumab scFv-anti-Id scFv fusion proteins to bind to the distinct ligands is determined using a variety of methods to demonstrate specific binding. ELISA plates are coated with FMC63 antibody or with streptavidin/biotinylated-HER2 to bind to 136.20.1 scFv and trastuzumab scFv, respectively. After binding is allowed to occur, the plates are gently washed to remove unbound materials. Anti-HIS-antibody coupled to horseradish peroxidase (HRP) is used to detect the bound fusion protein. In another iteration, an ELISA plate is coated with anti-HIS antibody to capture the fusion protein, and biotinylated HER2/streptavidin-HRP is used to detect. In another iteration, the ELISA plates is coated with FMC63 antibody and biotinylated HER2/streptavidin-HRP is used to detect. Other iterations are utilized as needed. The ELISAs are used to monitor expression of transient transfections, stable transfections, and cell transductions.
Trastuzumab scFv-Anti-Id Fusion Proteins Bind to HER2 Positive BT474 Cells
The trastuzumab scFv-anti-Id scFv fusion proteins are shown to bind to target (HER2 positive) tumor cells using standard techniques known in the art, e.g. flow cytometry, ELISA, etc. Trastuzumab scFv-anti-Id scFv fusion proteins are incubated with BT474 cells or other human tumor cells or cell lines that are HER2-positive. After incubation the cells are gently washed to remove unbound materials. The bound trastuzumab scFv-anti-Id scFv fusion proteins are detected using fluorescently labeled anti-HIS antibody or FMC63 antibody.
CAR19 T Cells are Redirected to HER2 Positive Tumor Cells via the Trastuzumab scFv-Anti-Id Fusion Protein, and in a Manner that Successfully Activates the CAR19 T Cells so that they lyse the Tumor Cells
Trastuzumab scFv-anti-Id scFv fusion proteins are shown to induce CAR T cell activity using cytokine release and cytotoxicity assays. Trastuzumab scFv-anti-Id scFv fusion proteins are incubated with BT474 cells or other human tumor cells or cell lines that are HER2-positive. Trastuzumab scFv-anti-Id scFv fusion proteins are in the form of a soluble purified protein, or are in a cell culture supernatant, or are secreted from a cell in the culture, for example a CAR T cell that has an FMC63-based CAR domain. FMC63-based CAR T cells are added to the culture if they are not already present. The coculture is allowed to incubate, for example between 4 hours and 72 hours. At an optimal time, supernatants are collected for ELISA analyses, for example, for IL-2 and IFN-gamma. At an optimal time the cells are analyzed using a cytotoxicity assay, for example an XTT assay. The assays demonstrate that trastuzumab scFv-anti-Id scFv fusion proteins redirect FMC63 based CART cells to lyse target HER2-positive tumors cells, causing their cytotoxicity.
Construction and Expression of Various scFv-Anti-Id Fusion Proteins
The scFv from the 136.20.1 anti-idiotype antibody recognizing FMC63 can be fused to many other scFv directed to diverse tumor antigens and investigated for functionality in the same manner as the trastuzumab scFv fusion. In another example, the 136.20.1 scFv is fused to a tumor targeting scFv, for example an scFv that targets CD20, an antigen that is expressed on B cell malignancies, e.g., the anti-CD20 scFv as is disclosed as a component of SEQ ID NO: 65, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 125, or SEQ ID NO: 126 or other variations of the anti-CD20 scFv or of other anti-CD20 scFvs whether known in the art or newly discovered. In a further example, the 136.20.1 anti-idiotype scFv is fused to an scFv that targets BCMA, an antigen that is expressed on plasma cell malignancies including multiple myeloma, e.g. the anti-BCMA scFv as is disclosed as a component of SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 119, or SEQ ID NO: 120 or other variations of this anti-BCMA scFv or of other anti-BCMA scFvs whether known in the art or newly discovered. In another example, the 136.20.1 anti-idiotype scFv is fused to a tumor targeting scFv, for example, an scFv that targets EGFR, an antigen expressed on solid tumors and their metastases, e.g., the anti-EGFR scFv that is disclosed within SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 54, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 88, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, or other variations of the anti-EGFR scFv or of other anti-EGFR scFvs whether known in the art or newly discovered.
A 12 well plate is seeded with either A431 or 293T cells around 4×10e5 cells/well in DMEM+10% FBS media. The following day, one well is counted to get an accurate count for the viral infections. Cells are infected with a multiplicity of infection (MOI) of 1×106 or 5×106. AAV2 viral particles are made by Vigene (Rockville, MD). The viral particles are generated from plasmids where the inserts containing sequences encoding the scFv-anti-Id fusion proteins (that include a HIS tag on the scFv) are cloned into pAV-FH. The viral particles are titered using standard methods. Infections are done in 0.6ml/well DMEM+2% FBS where the virus is added directly into the media. Different concentrations of virus are used from approx 104 (aka “104” or “10e4”) to 5×106 (aka “5×106” or “5×10e6”). The following day, the media is changed to DM EM+10%FBS and the incubation continued for 3 or 6 days.
Expression analysis is examined in the supernatant using an ELISA where anti-CD19 FMC63 is used for capture and anti-His used for detection. Briefly, 96 well plates (Pierce, Cat# 15041) are coated with 1.0 μg/ml reagent in 0.1 M carbonate, pH 9.5 for O/N at 4C. The plates are then blocked with 0.3% nonfat dry milk (NFD) in TBS (200 μl/well) for 1 hr at RT. Plates are then washed 3× with wash buffer (1× TBST: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). Titrations are performed from undiluted cell culture supernatant or purified protein at 1.0 μg/ml with serial 3× dilutions, 100 μl per well and incubated for 1h at RT. Dilution buffer is 1% BSA in 1× TBS (0.1 M Tris, 0.5 M NaCl) followed by washing 3× with wash buffer. Secondary reagents are added (if needed) such as Biotinylated-reagents at 1 μg/ml concentration at RT for 1 hour. HRP-conjugated reagents are added at 1:2000, applied 100 μl per well, incubated at RT in dark for 1 hr. 100 μl 1-Step Ultra TMB-ELISA (Thermo Fisher, Prod#34028) is added per well. Plates are read at 405 nm when color has developed. The expressed fusion proteins are capable of being bound by the anti-CD19 antibody FMC63 and detected by an anti-His antibody.
An aliquot of the XTT reagent and the activation reagent is rapidly thawed at 37° C. prior to use. 0.1 ml of activation reagent is then added to 5.0 ml of the XTT reagent. 50 μl of the activated—XTT solution is then added to each well. The plate is placed in the cell culture incubator for 2-4 hours and monitored for color development. The absorbance of the plate is read at wavelength 450 nm. The % cell death (aka cytotoxicity) is calculated as follows:
% killing=[1-OD(experimental wells-corresponding number of T cells)/OD (tumor cells without T cell-medium)]×100
Expressed fusion proteins are capable of directing CAR19 T cell activation and cytotoxicity upon incubation of supernatant with CAR19 T cells and BT474 cells.
A 96 well plate (Pierce, product #15041) is coated with 1.0 μg/ml mouse anti-human IFNγ (BD Pharmingen, Cat# 551221) in 0.1 M carbonate buffer, pH 9.5, overnight at 4° C. The plate is blocked with 0.3% non-fat dry milk solution in tris-buffered saline (TBS) using 200 μl/well for 1 hour at room temperature. The plate is washed x3 with wash buffer (1× TBS/Tween: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). 100 μl culture supernatant from the 24 hour or 48 hour culture plates (see above) are added to the ELISA plate. A titration of recombinant human IFNγ (Thermo Fisher, Cat# RIFNG100) is also performed in the same plate from 300 ng/ml with serial 3× dilutions to 2 pg/ml to generate a standard curve. The plate is then incubated for 1 hour at room temperature. The dilution buffer is 1× TBS (0.1 M Tris, 0.5 M NaCl) plus 1% BSA. The plate is washed x3 with wash buffer. Biotinylated mouse anti-human IFNγ (BD Pharmingen, Cat# 554550) is added at 1 μg/ml concentration and the plate is incubated at room temperature for 1 hour. The plate is washed again x3 with wash buffer. HRP-conjugated Streptavidin (Thermo Fisher, Cat# 21130) is added at a 1:2000 dilution from the stock, with 100 μl added per well. The plate is then incubated at room temperature for 1 hour in the dark. The plate is washed again x3 with wash buffer. 100 μl per well of 1-Step Ultra TMB-ELISA development solution (Thermo Fisher, Cat #34028) is added per well. The plate is read at wavelength 405 nm when color has developed sufficiently. Expressed fusion proteins are capable of inducing IFNγ upon incubation of supernatant with CAR19 T cells and BT474 cells.
The following table lists the various constructs tested in this example:
The amino sequence for the variable heavy and light chains for the anti-FMC63 antibody, 136.20.1, was obtained from Cooper et al. patent WO2014190273 Al. The sequences were back translated and used to generate the full antibody chains. For the heavy chain, the sequence of the leader and constant domains were obtained from a murine IgG2a antibody (UniProt P01863). For the kappa light chain, the signal sequence and constant domains were obtained from Uniprot P01863. The nucleotide sequence of the anti-CD19 FMC63 CAR heavy chain (SEQ ID NO: 319; construct #151) and light chain (SEQ ID NO: 320; construct #152) were chemically synthesized by GenScript and cloned into the vector pcDNA3.1(+) (#151) or pcDNA3.1(+)hygro (#152). Equal amounts of the plasmids were co-transfected into 293T cells using lipofectamine 2000 (Invitrogen/Thermo Fisher Prod#11668019) following the manufacturers instructions; supernatants were harvested after 48hr. For the large-scale transfections, 293T cells were seeded into T175 flasks and transfected with lipofectamine 2000, as above, when the cells reached about 80% confluency. Cells were cultured in bovine FBS with low serum IgG (VWR). Supernatants were harvested every 3-4 days.
A 96 well plate (Pierce, Cat# 15041) was coated with 1.0 ug/ml goat anti-mlgG in 0.1 M carbonate, pH 9.5 for O/N at 4C. The plate was blocked with 0.3% non-fat milk in Tris buffered saline (TBS 0.1 M Tris, 0.5 M NaCl) (200 ul/well) for 1 hr at RT. Then washed 3× with wash buffer (1× TBST: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). The cell culture sup was titrated from 50× dilution down with 3× dilutions,100 ul was added per well and incubated for 1h at RT. Dilution buffer is 1% BSA in 1× TBS. The plate was washed 3× with wash buffer then 100 ul per well HRP-goat anti-mlgG at 1:2000 was applied and incubated at RT in dark for 1 hr. Then 100 ul of 1-Step Ultra TMB-ELISA from Thermo Fisher, Prod#34028 was added per well and the plate was read at 405 nm when color developed.
CAR expression
293T cells were transfected with an anti-CD19 FMC63 CAR vector (SEQ ID NO: 317; construct #140). The CAR sequence (FMC63 VL-VH-Flag-CD28 linker/transmembrane/intracellular domain (ICD)-4-1BB ICD-CD3z ICD) was synthesized by ProMab Biotechnologies. The CAR insert was then cloned into a modified form of the System Biosciences vector pCDH-EF1a to generate construct #140 (SEQ ID NO: 317). The vector were transiently transfected into 293T cells using 2.5ug of DNA and 10 ul of lipofectamine 2000 (Invitrogen/Thermo Fisher). After ˜48hrs, the cells were harvested and resuspended in FACS buffer (1%I3SA, 0.1% sodium azide in PBS). CAR transfected cells (2.5×10{circumflex over ( )}5) were incubated with anti-Flag (1 ug/test) for 30 min at 4° C., spun and washed twice with FACS buffer, then followed by incubation with anti-rabbit IgG-APC for 30 min at 4° C. Cells were spun and washed as above, then fixed with 1% PFA in PBS. Fixed cells were analyzed on Accuri 6 for CAR expression (Flag positive).
Cells transfected with construct #140 (SEQ ID NO: 317) (2.5×10{circumflex over ( )}5 in 50 ul) were incubated with 50 u1 sup or purified (5 ug/ml as final conc.) protein of constructs#151/#152 (SEQ ID NO: 319/ SEQ ID NO: 320) for 30 min at 4° C., spun and washed twice with FACS buffer. This was followed by another incubation with anti-mouse Fc gamma-PE for 30 min at 4° C. Cells were spun and washed as above, and fixed with 1% PFA in PBS. Fixed cells were analyzed on Accuri 6 for CAR expression binding (PE positive).
Constructs were generated to express the anti-FMC63 scFv-Trastuzumab scFv fusion proteins with two orientations of the heavy and light variable domains of anti-FMC63. Construct #171 (SEQ ID NO: 121) contains anti-FMC63 VH-linker-VL-linker-Trastuzumab scFv-His and construct #172 (SEQ ID NO: 122) contains the anti-FMC63 in the VL-linker-VH arrangement. The sequences were chemically synthesized by GenScript and cloned into pcDNA3.1(+) hygro. Supernatants containing the bispecific scFvs were produced by transfecting 293T cells using lipofectamine 2000 (Invitrogen/Thermo Fisher). The supernatants were harvested after 72hrs by spinning for 3 min at 12k rpm at 4C.
A 96 well plate (Pierce, Cat# 15041) was coated with 1.0 ug/ml Her2-hFc (plate#1) (Acrobiosystems, Cat#HE2-H5253) or FMC63 (plate#2) (NOVUS, Cat#NBP2-527160) in 0.1 M carbonate, pH 9.5 for O/N at 4C. The plates were blocked with 0.3% non-fat milk in TBS (200 ul/well) for 1 hr at RT. The plate was washed 3× with wash buffer (1× TBST: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). The cell culture sup was titrated from no dilution down with 3 fold dilutions; the purified construct #42 protein (LakePharma) was started with 1 ug/ml down with 3 fold dilutions. Next, 100 ul was added per well and incubated for 1h at RT. Dilution buffer is 1% BSA in 1× TBS (0.1 M Tris, 0.5 M NaCl). The plates were washed 3× with wash buffer. For the plate#1, 100 ul of 1 ug/ml FMC63 was added to each well for 1 hr at RT and followed by 100 ul HRP-anti-mlgG at 1:2000. For plate#2, 100 ul HRP-anti-his at 1:2000 was applied per well and incubated for 1 hr at RT. For the final step, 100 ul 1-Step Ultra TMB-ELISA from Thermo Fisher, Prod#34028 was added per well and plates were read at 405 nm when color developed.
Supernatant (100u1) from 293T cells, transfected with constructs #171 or #172, was incubated with 50u1 (2×10e5) SKOV-3 luciferase cells (Cell Biolabs, Inc. #AKR232) on ice for 30 min. The samples were spun, washed 2× with FACS buffer (1%BSA, 0.1% sodium azide in PBS) and then incubated with anti-His tag-PE (5ul/sample, R&D systems #IC050P) on ice for 30 min. The cells were spun, washed 2× with FACS buffer and fixed with 1% PFA in PBS. Fixed cells were analyzed on Accuri 6 for anti-id-Trastuzumab scFv-His binding. The presence of Her2 on the SKOV-3 cells was determined by staining 2×10e5 cells with 1u1/sample anti-Her2 (Novus #NBP2-33064PE) for 30 min on ice, spun, washed 2× with FACS buffer, fixed and read as above. An anti-murine IgG2a-PE antibody 1u1/test (Thermo Fisher #SA1-120-82) was used as a control.
Supernatant from cells transfected with #171 (concentration=0.15ug/ml), starting at 0.075ug/ml was titrated down in 3× serial dilution in RPMI +10%FBS (no antibiotics) medium for 8 points. Five replicates were done per dilution. SKOV3-Her2-Luc cells were seeded at 1×10e4/100u1 RPMI +10% FBS (no antibiotics)/well in a solid white plate. The cells were allowed to settle for ˜2hrs and then spun out and the supernatant removed. Next 50 ul of the 3× serial diluted #171 containing supernatant was added to SKOV3 cells. Then, 50 ul of CAR T cells #150 (SEQ ID NO:318) (5×10e4) was added (5 CART: 1 SKOV3 ratio) and the plate was incubated at 37° C. for 48hr. The sup was collected and the cells washed 2× with PBS. 20 ul 1× lysis buffer from Luciferase assay system kit, Promega, Fisher CAT# PR-E1500 was added into plate. The plate was placed into the luminometer with injector (Glomax Multi Detection System form Promega). The injector adds 100 ul of Luciferase assay reagent per well, then the well is read immediately. The plate is advanced to the next well for a repeat of the inject-then-read process.The % killing was determined for each concentration by dividing it by the RLU (relative luciferase units) of the target cells only using the equation 1-RLU sample/RLU target cell x 100%.
A 96 well plate (Pierce, Cat# 15041) was coated with 2.0 ug/ml anti-INFg NlB42 (BD Pharmingen, cat#551221 through Fisher) at 100 ul in 0.1 M carbonate, pH9.5 for O/N at 4C. The plate was then blocked with 0.3% NF milk in TBS (200 ul/well) for 1 hr at RT and wash 3× with wash buffer 200 ul/well (1× TBST: 0.1 M Tris, 0.5 M NaCl, 0.05% Tween20). Next, 100 ul cell culture sup were transferred on the plate from the killing assay post 24 h and 48 h on to the plate and incubated for 1 h at RT. The interferon gamma (INFg) standard (recombinant human interferon gamma from Thermo Fisher, cat#RIFNG100) was prepared at starting concentration at 0.1 ug/ml and 3× series dilution to 1pg/ml and then 100 ul was added per well and incubated for 1h at RT. The dilution buffer is 1% BSA in 1× TBS (0.1 M Tris, 0.5 M NaCl). The plate was then washed 3× with wash buffer and biotinylated-mouse anti-human INFg (BD Pharmingen, cat# 554550 through Fisher) was added at 1 ug/ml concentration at RT for 1 hour. The plate was washed 3× with wash buffer and HRP-conjugated SA (Pierce high sensitivity Streptavidin-HRP: Thermo Fisher, Cat# 21130) was added at 1:2000; it was applied at 100 ul per well and incubated at RT in the dark for 1 hr. The plate was washed again 3× with wash buffer and 100 ul 1-Step Ultra TMB-ELISA from Thermo Fisher, Prod#34028 was added per well. The plate was read at 405 nm when the color developed.
The results of the luciferase release killing assay are shown in
The specificity of redirected killing by Trastuzumab scFv/anti-ld scFv fusion proteins is further demonstrated by comparison to control protiens lacking an anti-Id scFv portion.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. The scope of the present invention is not intended to be limited to the above Description, but rather is as set forth in the following claims:
This application claims priority to each of U.S. Provisional Patent Application Nos. 62/462,108 filed Feb. 22, 2017; and 62/541,409 filed Aug. 4, 2017, the entire contents of each of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US18/19266 | 2/22/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62541409 | Aug 2017 | US | |
| 62462108 | Feb 2017 | US |
