AU2020203550A1

AU2020203550A1 - Central Memory T Cells for Adoptive T Cell Therapy

Info

Publication number: AU2020203550A1
Application number: AU2020203550A
Authority: AU
Inventors: Christine E. BROWN; Stephen J. Forman
Original assignee: City of Hope
Current assignee: City of Hope
Priority date: 2014-09-19
Filing date: 2020-05-29
Publication date: 2020-06-18
Also published as: AU2023202826A1; AU2015317316A1

Abstract

Chimeric transmembrane immunoreceptors (CAR) which include an extracellular domain that includes IL-13 or a variant thereof that binds interleukin-13Ra2 (IL13Ra2), a transmembrane region, a costimulatory domain and an intracellular signaling domain are described.

Description

Central Memory T Cells for Adoptive T Cell Therapy

BACKGROUND

[001] Tumor-specific T cell based immunotherapies, including therapies employing engineered T cells, have been investigated for anti-tumor treatment. In some cases the T cells used in such therapies do not remain active in vivo for a long enough period. In some cases, the tumor-specificity of the T cells is relatively low. Therefore, there is a need in the art for tumor-specific cancer therapies with longer term anti-tumor functioning.

[002] Adoptive T cell therapy (ACT) utilizing chimeric antigen receptor (CAR) engineered T cells may provide a safe and effective way to reduce recurrence rates of MG, since CAR T cells can be engineered to specifically recognize antigenically-distinct tumor populations (Cartellieri et al. 2010 J Biomed Biotechnol 2010:956304; Ahmed et al. 2010 Clin Cancer Res 16:474; Sampson et al. 2014 Clin Cancer Res 20:972; Brown et al. 2013 Clin Cancer Res 2012 18:2199; Chow et al. 2013 Mol Ther 21:629), and T cells can migrate through the brain parenchyma to target and kill infiltrative malignant cells (Hong et al. 2010 Clin Cancer Res 16:4892; Brown et al. 2007 J Immunol 179:3332; Hong et al. 2010 Clin Cancer Res 16:4892; Yaghoubi 2009 Nat Clin PRact Oncol 6:53). Preclinical studies have demonstrated that IL 13Ra2-targeting CAR+ T cells exhibit potent major histocompatibility complex (MHC)-independent, IL13Ra2-specific cytolytic activity against both stem-like and differentiated glioma cells, and induce regression of established glioma xenografts in vivo (Kahlon et al. 2004 Cancer Res 64:9160; Brown et al. 2012 Clin Cancer Res 18:2199).

SUMMARY

[003] Described herein are cell populations that comprise central memory T cells (Tern). The cell populations include both CD4+ T cells and CD8+ T cells. The cells in the cell populations are useful for expressing chimeric transmembrane immunoreceptors (chimeric antigen receptors or “CARs”) which comprise an extracellular domain (e.g., an

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2020203550 29 May 2020 scFv that binds to a selected target), a transmembrane region and an intracellular signaling domain, e.g., an intracellular domain that includes the signaling domain from the zeta chain of the human CD3 complex (6Ό3ζ) and one or more costimulatory domains, e.g., a 4-1BB costimulatory domain. The extracellular domain enables the CAR, when expressed on the surface of a T cell, to direct T cell activity to those cells expressing a target recognized by the extracellular domain. The inclusion of a costimulatory domain, such as the 4-IBB (CD 137) costimulatory domain in series with CD3ζ in the intracellular region enables the T cell to receive co-stimulatory signals.

[004] The Tern cells described herein, for example, patient-specific, autologous or allogenic Tern cells can be engineered to express a desired CAR and the engineered cells can be expanded and used in ACT. The population of Tcm cells are CD45RO+CD62L and include CD4+ and CD8+ cells.

[005] In various embodiments: the population of human T cells comprise a vector expressing a chimeric antigen receptor; the population of human central memory T cells (Tcm cells ) comprise at least 10% CD4+ cells and at least 10% CD8+ cells (e.g., at least 20%, 30%, 40%, 50% 60%, 70%, 80% of the cells are Tcm cells; at least 15%, 20%, 25%, 30%, 35% of the Tcm cells are CD4+ and at least 15%, 20%, 25%, 30%, 35% of the Tcm cells are CD8+ cells).

[006] Also described is a method of treating cancer in a patient comprising administering a population of autologous or allogeneic human T cells (e.g., autologous or allogenic T cells comprising Tcm cells, e.g., at least 20%, 30%, 40%, 50% 60%, 70%, 80% of the cells are Tcm cells; at least 15%, 20%, 25%, 30%, 35% of the Tcm cells are CD4+ and at least 15%, 20%, 25%, 30%, 35% of the Tcm cells are CD8+ cells) transduced by a vector comprising an expression cassette encoding a chimeric antigen receptor.

[007] Described herein a population of human T cells of transduced with a vector expressing a chimeric antigen receptor wherein at least 50% of the transduced human T cells are central memory T cells. In various embodiments: at least 10% of the transduced cells central memory T cells are CD4+; at least 10% of the transduced central memory T

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2020203550 29 May 2020 cells are CD8+; at leastl5% of the central memory T cells are CD4+ and at least 15% are CD8+; and at least 50% of the transduced human T cells are CD4+/CD8+/CD62L+.

[008] Also described herein is a population of human T cells of transduced with a vector expressing a chimeric antigen receptor wherein: at least 50% of the transduced human T cells are CD45R0+, CD62L+ and CD45Ra-, at least 10% of the cells are CD4+ and at least 10% of the cells are CD4+. In various embodiments: at least 10% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD4+ and at least 10% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD8+; and at least 15% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD4+ and at least 15% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD4+.

[009] Also described is a method of treating cancer comprising administering to a patient in need thereof a pharmaceutical composition comprising the central memory T cells described herein. The T cells can be autologous to the patient or are allogenic to the patient.

[0010] Also described is a method for preparing a population central memory T cells comprising: obtaining a population of T cells from a human subject; depleting the population of T cells for cells that express CD25, cells that express CD 14, and cells that express CD45+ to prepared a depleted T cell population; enriching the depleted T cell population for cells expressing CD62L, thereby preparing a population of central memory T cells, wherein the method does not comprising a step of depleting a cell population for cells expressing CD4 and does not comprising a step of depleting a cell population of cells expressing CD8+. In various embodiments: at least 50% (e.g., at least 60%, 70%, 80%, 90% or 95%) of the cells in the population central memory T cells are CD45R0+, CD62L+ and CD45Ra-, at least 10% of the cells are CD4+ and at least 10% of the cells are CD4+; at least 50% (e.g., at least 60%, 70%, 80%, 90% or 95%) of the cells in the population central memory T cells are CD45R0+, CD62L+ and CD45Ra-, at least 15% of the cells are CD4+ and at least 15% of the cells are CD4+; at least 50% of the cells in the population central memory T cells are CD45R0+, CD62L+ and CD45Ra-, at least 20% (e.g., at least 30%, 40% or 50%) of the cells are CD4+ and at least 20% (e.g., at least

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30%, 40% or 50%) of the cells are CD4+. The method can further comprise stimulating the population of central memory T cells (e.g., by contacting the population of central memory T cells with CD3 and/or CD28); can comprise transducing the cells with a vector expressing a recombinant protein to create a population of genetically modified central memory T cells; and can comprise expanding the population of generically modified central memory T cells (e.g., of expanding the population of generically modified central memory T cells by exposing the cells to one or both of IL-2 and IL-15.

DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a schematic depiction of IL13(E13Y)-zetakine CAR (Left) composed of the IL13Ra2-specific human IL-13 variant (huIL-13(E13Y)), human IgG4 Fc spacer (huy4F_c), human CD4 transmembrane (huCD4 tm), and human 6Ό3ζ chain cytoplasmic (1ηι6Ό3ζ cyt) portions as indicated. Also depicted is a ΙΕ13(Ε())ΒΒζ CAR which is the same as the IL13(E13Y)-zetakine with the exception of the two point mutations, L235E and N297Q indicated in red, that are located in the CH2 domain of the IgG4 spacer, and the addition of a costimulatory 4-IBB cytoplasmic domain (4-IBB cyt).

[0012] Figures 2A-C depict certain vectors an open reading frames. A is a diagram of the cDNA open reading frame of the 2670 nucleotide IL13(EQ)BBZ-T2ACD19t construct, where the IL13Ra2-specific ligand IL13(E13Y), IgG4(EQ) Fc hinge, CD4 transmembrane, 4-IBB cytoplasmic signaling, three-glycine linker, and 6Ό3ζ cytoplasmic signaling domains of the IL13(EQ)BBZ CAR, as well as the T2A ribosome skip and truncated CD 19 sequences are indicated. The human GM-CSF receptor alpha and CD 19 signal sequences that drive surface expression of the ILI 3(Ε(/))ΒΒζ CAR and CD19t are also indicated. B is a diagram of the sequences flanked by long terminal repeats (indicated by ‘R’) that will integrate into the host genome. C is a map of the IL 13(EQ)BBZ-T2A-CD 19t_epHIV7 plasmid.

[0013] Figure 3 depicts the construction of pHIV7.

[0014] Figure 4 depicts the elements of pHIV7.

[0015] Figure 5 depicts a production scheme for ΙΕ13(Ε())ΒΒζ/ΕΟ19ΐ+ Tcm.

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[0016] Figures 6A-C depicts the results of flow cytometric analysis of surface transgene and T cell marker expression. IL13(EQ)BE^/CD19t+ Tcm HD006.5 and HD187.1 were co-stained with anti-IL13-PE and anti-CD8-FITC to detect CD8+ CAR+ and CD4+ (i.e., CD8 negative) CAR+ cells (A), or anti-CD19-PE and anti-CD4-FITC to detect CD4+ CD19t+ and CD8+ (i.e., CD4 negative) CAR+ cells (Β). ΙΕ13(Ερ)ΒΒζ/εϋ19ΐ+ Tcm HD006.5 and HD187.1 stained with fluorochromeconjugatedanti-CD3, TCR, CD4, CD8, CD62L and CD28 (grey histograms) or isotype controls (black histograms) (C). In all cases the percentages based on viable lymphocytes (DAPI negative) stained above isotype.

[0017] Figures 7A-B depict the in vitro functional characterization of IL13Ra2-specific effector function of IL13(EQ)BBZ+ Tcm. IL13(EQ)BBZ/CD19t+ Tcm HD006.5 and HD187.1 were used as effectors in a 6-hour ⁵¹Cr release assay using a 10:1 E:T ratio based on CD19t expression. The IL 13Ra2-positive tumor targets were K562 engineered to express IL13Ra2 (K562-IL13Ra2) and primary glioma line PBT030-2, and the IL 13Ra2-negative tumor target control was K562 parental line (A).

IL13(EQ)BBZ/CD19t+ Tcm HD006.5 and HD187.1 were evaluated for antigendependent cytokine production following overnight co-culture at a 10:1 E:T ratio with IL 13Ra2-positive and negative targets. Cytokine levels were measured using the BioPlex Pro Human Cytokine TH1/TH2 Assay kit and INF-γ are reported (B).

[0018] Figures 8A-C depict the result of studies demonstrating the regression of established glioma tumor xenografts after adoptive transfer of IL13(EQ)BB^CD19t+ Tcm. EGFP-ffLuc+ PBT030-2 tumor cells (1 x 10⁵) were stereotactically implanted into the right forebrain of NSG mice. On day 5, mice received either 2xl0⁶ΙΕ13(Ερ)ΒΒζ/Οϋ19ΐ+ Tcm (l.lxlO⁶ CAR+; n=6), 2xl0⁶ mock TCM (no CAR; n=6) or PBS (n=6). Representative mice from each group showing relative tumor burden using Xenogen Living Image (A). Quantification of ffLuc flux (photons/sec) shows that IL13(EQ)BBζ/CD19t+ Tcm induce tumor regression as compared to mock-transduced Tcm and PBS (#p<0.02, *p<0.001, repeated measures ANOVA) (B). Kaplan Meier survival curve (n=6 per group) demonstrating significantly improved survival (p=0.0008; log-rank test) for mice treated with IL13(EQ)BBζ/CD19t+ Tcm (C)

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[0019] Figures 9A-C depict the results of studies comparing ant-tumor efficacy of IL13(EQ)BBZ Tcm and IL13-zetakine CTL clones. EGFP-ffLuc+ PBT030-2 TSs (lx 10⁵) were stereotactically implanted into the right forebrain of NSG mice. On day 8, mice received either 1.6xl0⁶ mock Tcm (no CAR), 1.0^χ10⁶ CAR+ ΙΕ13(Ε())ΒΒζ Tcm (1.6xl0⁶ total T cells; 63% CAR), l.OxlO⁶ IL13-zetakine CD8+ CTL cl. 2D7 (clonal CAR+), or no treatment (n=6 per group). Representative mice from each group showing relative tumor burden using Xenogen Living Image (A). Linear regression lines of natural log of ffLuc flux (photons/sec) over time, P-values are for group by time interaction comparisons (B). Kaplan Meier survival analysis (n= 6 per group) demonstrate significantly improved survival (p=0.02; log-rank test) for mice treated with ΙΕ13(Ε())ΒΒζ Tcm as compared to IL13-zetakine CD8+ CTL cl. 2D7 (C).

[0020] Figures 10A-C depict the results of studies comparing ant-tumor efficacy of ΙΕ13(Ερ)ΒΒζ Tcm and IL13-zetakine CTL clones. EGFP-ffLuc+PBT030-2 TSs (lx 10⁵) were stereotactically implanted into the right forebrain of NSG mice. On day 8, mice received either 1.3xl0⁶ mock Tcm (no CAR; n=6), 1.0, 0.3 or O.lxlO⁶ CAR+ ΙΕ13(Ερ)ΒΒζ Tcm (78% CAR+; n=6-7), 1.0, 0.3 or O.lxlO⁶ IL13-zetakine CD8+ CTL cl. 2D7 (clonal CAR+; n=6-7), or no treatment (n=5). Xenogen imaging of representative mice from each group showing relative tumor burden (A). Linear regression lines of natural log of ffLuc flux (photons/sec) shows that ILI 3(Εζ))ΒΒζ Tcm achieve superior tumor regression as compared to first-generation IL13-zetakine CTL cl. 2D7, mock Tcm and tumor only (B). Average flux per group at day 27 post tumor injection demonstrating that the O.lxlO⁶ ΙΕ13(Ε())ΒΒζ Tcm dose outperforms the ten-fold higher l.OxlO⁶ dose of IL13-zetakine CD8+ CTL cl. 2D7 (p = 0.043; Welch two sample t- test) (C).

[0021] Figure 11 depicts the results of studies demonstrating ΙΜ3(Εζ))ΒΒζ Tcm display improved persistence compared IL13-zetakine CTL clones. CD3 immunohistochemistry evaluating T cell persistence at the tumor site 7-days post T cell infusion. Significant numbers of T cells are detected for ΙΜ3(Εζ))ΒΒζ Tcm (top panel). By contrast, very few viable CD3+ IL13-zetakine T cells are detected (bottom panel).

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[0022] Figures 12A-D depict the results of experiments comparing route of CAR+ T cell delivery (i.e. versus i.v.) for large established tumors. EGFP-ffLuc+ PBT030-2 TSs (IxlO⁵) were implanted into the right forebrain of NSG mice. On days 19 and 26, mice were injected i.v. through the tail vein with either 5xl0⁶ CAR+ ILI 3(ΕΟ)ΒΒζ+ Tern (11.8xl0⁶ total cells; n=4), or mock Tern (11.8xl0⁶ cells; n=4). Alternatively, on days 19, 22, 26 and 29 mice were injected i.e. with either IxlO⁶ CAR+ ΙΕ13(Ε())ΒΒζ+ Tern (2.4xl0⁶ total cells; n=4), or mock Tern (2.4xl0⁶ cells; n=5). Average ffLuc flux (photons/sec) over time shows that i.e. delivered ILI 3(ΕΟ)ΒΒζ Tern mediates tumor regression of day 19 tumors. By comparison, i.v. delivered T cells do not shown reduction in tumor burden as compared to untreated or mock Tern controls (A). Kaplan Meier survival curve demonstrates improved survival for mice treated i.e. IL13(EQ)BBZ Tern as compared to mice treated with i.v. administered CAR+ Tern (p = 0.0003 log rank test) (B). Representative H&E and CD3 IHC of mice treated i.v. (C) versus i.e. (D) with IL13(EQ)BBZ+ Tern. CD3+ T cells were only detected in the i.e. treated group, with no CD3+ cells detected in the tumor or surrounding brain parenchyma for i.v. treated mice.

[0023] Figures 13A-B depict the results of studies showing that CAR+ T cell injected intracranially, either intratumoral (i.c.t.) or intraventricular (i.c.v.), can traffic to tumors on the opposite hemisphere. EGFP-ffLuc+ PBT030-2 TSs (fxf05) were stereotactically implanted into the right and left forebrains of NSG mice. On day 6, mice were injected i.e. at the right tumor site with 1.0x106 ΙΕ13(Ε())ΒΒζ+ Tern (1.6x106 total cells; 63% CAR; n=4). Schematic of multifocal glioma experimental model (A). CD3 IHC showing T cells infiltrating both the right and left tumor sites (B).

[0024] Figure 14 depicts the amino acid sequence of ΙΕί3(Ε())ΒΒζ/ΟΟί9ΐ+ (SEQ ID NO:10).

[0025] Figure 15 depicts a sequence comparison of IL13(EQ)41BBζ[IL13{EQ}41BBζ T2A-CD19t_epHIV7; pF02630] (SEQ ID NO: 12) and CD19Rop_epHIV7 (pJO 1683) (SEQ ID NO: 13).

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DETAILED DESCRIPTION

[0026] A Tcm cell population that includes CD4+ cells and CD8+ cells (“Tcm CD4+/CD8+” cell population) is described below. The cells of the Tcm CD4+/CD8+ cell population can be activated with anti-CD3/CD28 and transduced with, for example, a SIN lentiviral vector that directs the expression of a CAR to create genetically modified cells. The activated/genetically modified cells can be expanded in vitro with IL-2/IL-15 and then used or cryopreserved and used later. Described is an example of the use of Tcm CD4+/CD8+ cell population to express a CAR targeted to IL13Ra2.

[0027] The CAR used in the examples below is referred to as ΙΕ13(Ε())ΒΒζ. This CAR includes a variety of important features including: a IL13a2 ligand having an amino acid change that improves specificity of biding to IL13a2; the domain of CD137 (4-1BB) in series with CD3ζ to provide beneficial costimulation; and an IgG4 Fc region that is mutated at two sites within the CH2 region (L235E; N297Q) in a manner that reduces binding by Fc receptors (FcRs). This CAR and others can be produced using a vector in which the CAR open reading frame is followed by a T2A ribosome skip sequence and a truncated CD 19 (CD19t), which lacks the cytoplasmic signaling tail (truncated at amino acid 323). In this arrangement, co-expression of CD19t provides an inert, nonimmunogenic surface marker that allows for accurate measurement of gene modified cells, and enables positive selection of gene-modified cells, as well as efficient cell tracking and/or imaging of the therapeutic T cells in vivo following adoptive transfer. Coexpression of CD19t provides a marker for immunological targeting of the transduced cells in vivo using clinically available antibodies and/or immunotoxin reagents to selectively delete the therapeutic cells, and thereby functioning as a suicide switch.

[0028] Gliomas, express IL13 receptors, and in particular, high-affinity IL13 receptors. However, unlike the IL 13 receptor, glioma cells overexpress a unique IL13Ra2 chain capable of binding IL 13 independently of the requirement for IL4R3 or yc44. Like its homolog IL4, IL13 has pleotropic immunoregulatory activity outside the CNS. Both IL 13 and IL4 stimulate IgE production by B lymphocytes and suppress pro-inflammatory cytokine production by macrophages.

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[0029] Detailed studies using autoradiography with radiolabeled IL 13 have demonstrated abundant IL 13 binding on nearly all malignant glioma tissues studied. This binding is highly homogeneous within tumor sections and in single cell analysis. However, molecular probe analysis specific for IL13Ra2 mRNA did not detect expression of the glioma-specific receptor by normal brain elements and autoradiography with radiolabeled IL 13 also could not detect specific IL 13 binding in the normal CNS. These studies suggest that the shared I LI 3 Ret 1/1 Ε4β/γο receptor is not expressed detectably in the normal CNS. Therefore, IL13Ra2 is a very specific cell-surface target for glioma and is a suitable target for a CAR designed for treatment of a glioma.

[0030] Binding of IL 13-based therapeutic molecules to the broadly expressed

I LI 3 Ret 1/1 Η4β/γο receptor complex, however, has the potential of mediating undesired toxicities to normal tissues outside the CNS, and thus limits the systemic administration of these agents. An amino acid substitution in the IL 13 alpha helix A at amino acid 13 of tyrosine for the native glutamic acid selectively reduces the affinity of IL 13 to the I LI 3 Ret 1/1 Ε4β/γο receptor. Binding of this mutant (termed IL13(E13Y)) to IL13Ra2, however, was increased relative to wild-type IL13. Thus, this minimally altered IL 13 analog simultaneously increases IL13's specificity and affinity for glioma cells. Therefore, CAR described herein include an IL 13 containing a mutation (E to Y or E to some other amino acid such as K or R or L or V) at amino acid 13 (according to the numbering of Debinski et al. 1999 Clin Cancer Res 5:3143s). IL13 having the natural sequence also may be used, however, and can be useful, particularly in situations where the modified T cells are to be locally administered, such as by injection directly into a tumor mass.

[0031] The CAR described herein can be produced by any means known in the art, though preferably it is produced using recombinant DNA techniques. Nucleic acids encoding the several regions of the chimeric receptor can be prepared and assembled into a complete coding sequence by standard techniques of molecular cloning known in the art (genomic library screening, PCR, primer-assisted ligation, site-directed mutagenesis, etc.) as is convenient. The resulting coding region is preferably inserted into an

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2020203550 29 May 2020 expression vector and used to transform a suitable expression host cell line, preferably a T lymphocyte cell line, and most preferably an autologous T lymphocyte cell line.

Example 1: Construction and Structure of an IL13Ra2-specific CAR

[0032] The structure of a useful IL13Ra2-specific CAR is described below. The codon optimized CAR sequence contains a membrane-tethered IL-13 ligand mutated at a single site (E13Y) to reduce potential binding to IL13Ral, an IgG4 Fc spacer containing two mutations (L235E; N297Q) that greatly reduce Fc receptor-mediated recognition models, a CD4 transmembrane domain, a costimulatory 4-IBB cytoplasmic signaling domain, and a CD3ζ cytoplasmic signaling domain. A T2A ribosome skip sequence separates this ILI3(Έ<9)ΒΒζ CAR sequence from CD19t, an inert, non-immunogenic cell surface detection/selection marker. This T2A linkage results in the coordinate expression of both ΙΕ13(Ε())ΒΒζ and CD19t from a single transcript. Figure 1A is a schematic drawing of the 2670 nucleotide open reading frame encoding the IL13(EQ)BBZ-T2ACD19t construct. In this drawing, the IL13Ra2-specific ligand IL13(E13Y), IgG4(EQ) Fc, CD4 transmembrane, 4-IBB cytoplasmic signaling, three-glycine linker, and CD3ζ cytoplasmic signaling domains of the IL13(EQ)BBZ CAR, as well as the T2A ribosome skip and truncated CD 19 sequences are all indicated. The human GM-CSF receptor alpha and CD 19 signal sequences that drive surface expression of the IL13(EQ)BBZ CAR and CD19t are also indicated. Thus, the IL13(EQ)BBZ-T2ACD19t construct includes a IL13Ra2-specific, hinge-optimized, costimulatory chimeric immunoreceptor sequence (designated IL13(EQ)BBZ), a ribosome-skip T2A sequence, and a CD19t sequence.

[0033] The IL13(EQ)BBZ sequence was generated by fusion of the human GM-CSF receptor alpha leader peptide with IL13(E13Y) ligand 5 L235E/N297Q-modified IgG4 Fc hinge (where the double mutation interferes with FcR recognition), CD4 transmembrane, 4-IBB cytoplasmic signaling domain, and CD3ζ cytoplasmic signaling domain sequences. This sequence was synthesized de novo after codon optimization. The T2A sequence was obtained from digestion of a T2A-containing plasmid. The CD19t sequence was obtained from that spanning the leader peptide sequence to the transmembrane components (i.e., basepairs 1-972) of a CD19-containing plasmid. All three fragments, 1)

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IL13(EQ)BBZ, 2) T2A, and 3) CD19t, were cloned into the multiple cloning site of the epHIV7 lentiviral vector. When transfected into appropriate cells, the vector integrates the sequence depicted schematically in Figure IB into the host cells genome. Figure 1C provides a schematic drawing of the 9515 basepair IL13(EQ)BBZ-T2A-CD19t _epHIV7 plasmid itself.

[0034] As shown schematically in Figure 2, IL13(EQ)BBZ CAR differs in several important respects from a previously described IL13Ra2-specific CAR referred to as IL13(E13Y)-zetakine (Brown et al. 2012 Clinical Cancer Research 18:2199). The IL13(E13Y)-zetakine is composed of the IL13Ra2-specific human IL-13 mutein (huIL13(E13Y)), human IgG4 Fc spacer (huy4Fc), human CD4 transmembrane (huCD4 tm), and human 6Ό3ζ chain cytoplasmic (1ηι6Ό3ζ cyt) portions as indicated. In contrast, the ΙΕ13(ΕΡ)ΒΒζ ) has two point mutations, L235E and N297Q that are located in the CH2 domain of the IgG4 spacer, and a costimulatory 4-IBB cytoplasmic domain (4-IBB cyt).

Example 2: Construction and Structure of epHIV7 used for Expression of an IL13Ra2-specific CAR

[0035] The pHIV7 plasmid is the parent plasmid from which the clinical vector IL13(EQ)BBZ-T2A-CD19t_epHIV7 was derived in the T cell Therapeutics Research Laboratory (TCTRL) at City of Hope (COH). The epHIV7 vector used for expression of the CAR was produced from pHIV7 vector. Importantly, this vector uses the human EFl promoter to drive expression of the CAR. Both the 5' and 3' sequences of the vector were derived from pv653RSN as previously derived from the HXBc2 provirus. The polypurine tract DNA flap sequences (cPPT) were derived from HIV-1 strain pNL4-3 from the NIH AIDS Reagent Repository. The woodchuck post-transcriptional regulatory element (WPRE) sequence was previously described.

[0036] Construction of pHIV7 is schematically depicted in Figure 3. Briefly, pv653RSN, containing 653 bp from gag-pol plus 5’ and 3’ long-terminal repeats (LTRs) with an intervening SL3-neomycin phosphotransferase gene (Neo), was subcloned into pBluescript, as follows: In Step 1, the sequences from 5’ LTR to rev-responsive element

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2020203550 29 May 2020 (RRE) made p5’HIV-l 51, and then the 5' LTR was modified by removing sequences upstream of the TATA box, and ligated first to a CMV enhancer and then to the SV40 origin of replication (p5'HIV-2). In Step 2, after cloning the 3' LTR into pBluescript to make p3’HIV-l, a 400-bp deletion in the 3' LTR enhancer/promoter was made to remove cis-regulatory elements in HIV U3 and form p3'HIV-2. In Step 3, fragments isolated from the p5'HIV-3 and p3'HIV-2 were ligated to make pHIV-3. In Step 4, the p3'HIV-2 was further modified by removing extra upstream HIV sequences to generate p3’HIV-3 and a 600-bp BamHI-Sall fragment containing WPRE was added to p3’HIV-3 to make the p3'HIV-4. In Step 5, the pHIV-3 RRE was reduced in size by PCR and ligated to a 5’ fragment from pHIV-3 (not shown) and to the p3’HIV-4, to make pHIV-6. In Step 6, a 190-bp Bglll-BamHI fragment containing the cPPT DNA flap sequence from HIV-1 pNL4-3 (55) was amplified from pNL4-3 and placed between the RRE and the WPRE sequences in pHIV6 to make pHIV-7. This parent plasmid pHIV7-GFP (GFP, green fluorescent protein) was used to package the parent vector using a four-plasmid system.

[0037] A packaging signal, psi ψ, is required for efficient packaging of viral genome into the vector. The RRE and WPRE enhance the RNA transcript transport and expression of the transgene. The flap sequence, in combination with WPRE, has been demonstrated to enhance the transduction efficiency of lentiviral vector in mammalian cells.

[0038] The helper functions, required for production of the viral vector), are divided into three separate plasmids to reduce the probability of generation of replication competent lentivirus via recombination: 1) pCgp encodes the gag/pol protein required for viral vector assembly; 2) pCMV-Rev2 encodes the Rev protein, which acts on the RRE sequence to assist in the transportation of the viral genome for efficient packaging; and 3) pCMV-G encodes the glycoprotein of the vesiculo-stomatitis virus (VSV), which is required for infectivity of the viral vector.

[0039] There is minimal DNA sequence homology between the pHIV7 encoded vector genome and the helper plasmids. The regions of homology include a packaging signal region of approximately 600 nucleotides, located in the gag/pol sequence of the pCgp helper plasmid; a CMV promoter sequence in all three helper plasmids; and a RRE

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2020203550 29 May 2020 sequence in the helper plasmid pCgp. It is highly improbable that replication competent recombinant virus could be generated due to the homology in these regions, as it would require multiple recombination events. Additionally, any resulting recombinants would be missing the functional LTR and tat sequences required for lentiviral replication.

[0040] The CMV promoter was replaced by the EFla-HTLV promoter (EFlp), and the new plasmid was named epHIV7 (Figure 4). The EFlp has 563 bp and was introduced into epHIV7 using Nrul and Nhel, after the CMV promoter was excised.

[0041] The lentiviral genome, excluding gag/pol and rev that are necessary for the pathogenicity of the wild-type virus and are required for productive infection of target cells, has been removed from this system. In addition, the IL13(EQ)BBZT2ACD19t_epHIV7 vector construct does not contain an intact 3’LTR promoter, so the resulting expressed and reverse transcribed DNA proviral genome in targeted cells will have inactive LTRs. As a result of this design, no HIV-I derived sequences will be transcribed from the provirus and only the therapeutic sequences will be expressed from their respective promoters. The removal of the LTR promoter activity in the SIN vector is expected to significantly reduce the possibility of unintentional activation of host genes (56). Table 4 summarizes the various regulator elements present in IL13(EQ)BBZT2ACD19t_epHIV7.

Table 4 Functional elements of IL13(EQ)41BBZ-T2A-CD19t_epHIV7
Regulatory Elements and Genes	Location (Nucleotide Numbers)	Comments
U5	87-171	5 ’ Unique sequence
psi	233-345	Packaging signal
RRE	957-1289	Rev-responsive element
flap	1290-1466	Contains polypurine track sequence and central termination sequence to facilitate nuclear import of pre-integration complex
EFlp Promoter	1524-2067	EFl-alpha Eukaryotic Promoter sequence driving expression of CD19Rop
IL13-IgG4 (EQ)41BB-Zeta-T2A-	2084-4753	Therapeutic insert

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Table 4 Functional elements of IL13(EQ)41BBZ-T2A-CD19t_epHIV7
Regulatory Elements and Genes	Location (Nucleotide Numbers)	Comments
CD19t
WPRE	4790-5390	Woodchuck hepatitis virus derived regulatory element to enhance viral RNA transportation
delU3	5405-5509	3’ U3 with deletion to generate SIN vector
R	5510-5590	Repeat sequence within LTR
U5	5591-5704	3’ U5 sequence in LTR
Amp^R	6540-7398	Ampicillin-resistance gene
CoEl ori	7461-8342	Replication origin of plasmid
SV40 ori	8639-8838	Replication origin of SV40
CMV promoter	8852-9451	CMV promoter to generate viral genome RNA
R	9507-86	Repeat sequence within LTR

Example 3: Production of Vectors for Transduction of Patient T Cells

[0042] For each plasmid (IL13(EQ)BBZ-T2A-CD19t_epHIV7; pCgp; pCMV-G; and pCMV-Rev2), a seed bank is generated, which is used to inoculate the fermenter to produce sufficient quantities of plasmid DNA. The plasmid DNA is tested for identity, sterility and endotoxin prior to its use in producing lentiviral vector.

[0043] Briefly, cells were expanded from the 293T working cell (WCB), which has been tested to confirm sterility and the absence of viral contamination. A vial of 293T cells from the 293T WCB was thawed. Cells were grown and expanded until sufficient numbers of cells existed to plate an appropriate number of 10 layer cell factories (CFs) for vector production and cell train maintenance. A single train of cells can be used for production.

[0044] The lentiviral vector was produced in sub-batches of up to 10 CFs. Two subbatches can be produced in the same week leading to the production of approximately 20 L of lentiviral supematant/week. The material produced from all sub-batches were pooled during the downstream processing phase, in order to produce one lot of product. 293T cells were plated in CFs in 293T medium (DMEM with 10% FBS). Factories were placed

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2020203550 29 May 2020 in a 37°C incubator and horizontally leveled in order to get an even distribution of the cells on all the layers of the CF. Two days later, cells were transfected with the four lentiviral plasmids described above using the CaPO4 method, which involves a mixture of Tris:EDTA, 2M CaC12, 2X HBS, and the four DNA plasmids. Day 3 after transfection, the supernatant containing secreted lentiviral vectors was collected, purified and concentrated. After the supernatant was removed from the CFs, End-of-Production Cells were collected from each CF. Cells were trypsinized from each factory and collected by centrifugation. Cells were resuspended in freezing medium and cryopreserved. These cells were later used for replication-competent lentivirus (RCL) testing.

[0045] To purify and formulate vectors crude supernatant was clarified by membrane filtration to remove the cell debris. The host cell DNA and residual plasmid DNA were degraded by endonuclease digestion (Benzonase®). The viral supernatant was clarified of cellular debris using a 0.45 pm filter. The clarified supernatant was collected into a preweighed container into which the Benzonase® is added (final concentration 50 U/mL). The endonuclease digestion for residual plasmid DNA and host genomic DNA as performed at 37°C for 6 h. The initial tangential flow ultrafiltration (TFF) concentration of the endonuclease-treated supernatant was used to remove residual low molecular weight components from the crude supernatant, while concentrating the virus -20 fold. The clarified endonuclease-treated viral supernatant was circulated through a hollow fiber cartridge with a NMWCO of 500 kD at a flow rate designed to maintain the shear rate at -4,000 sec-1 or less, while maximizing the flux rate. Diafiltration of the nuclease-treated supernatant was initiated during the concentration process to sustain the cartridge performance. An 80% permeate replacement rate was established, using 4% lactose in PBS as the diafiltration buffer. The viral supernatant was brought to the target volume, representing a 20-fold concentration of the crude supernatant, and the diafiltration was continued for 4 additional exchange volumes, with the permeate replacement rate at 100%.

[0046] Further concentration of the viral product was accomplished by using a high speed centrifugation technique. Each sub-batch of the lentivirus was pelleted using a

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Sorvall RC-26 plus centrifuge at 6000 RPM (6,088 RCF) at 6oC for 16-20 h. The viral pellet from each sub-batch was then reconstituted in a 50 mL volume with 4% lactose in PBS. The reconstituted pellet in this buffer represents the final formulation for the virus preparation. The entire vector concentration process resulted in a 200-fold volume reduction, approximately. Following the completion of all of the sub-batches, the material was then placed at -80oC, while samples from each sub-batch were tested for sterility. Following confirmation of sample sterility, the sub-batches were rapidly thawed at 37oC with frequent agitation. The material was then pooled and manually aliquoted in the Class II Type A/B3 biosafety cabinet in the viral vector suite. A fill configuration of 1 mL of the concentrated lentivirus in sterile USP class 6, externally threaded O-ring cryovials was used. Center for Applied Technology Development (CATD)’s Quality Systems (QS) at COH released all materials according to the Policies and Standard Operating Procedures for the CBG and in compliance with current Good Manufacturing Practices (cGMPs).

[0047] To ensure the purity of the lentiviral vector preparation, it was tested for residual host DNA contaminants, and the transfer of residual host and plasmid DNA. Among other tests, vector identity was evaluated by RT-PCR to ensure that the correct vector is present. All release criteria were met for the vector intended for use in this study.

Example 4: Preparation of a Tcm CD4+/CD8+ Cell Population Suitable for Use in ACT

[0048] An outline of the manufacturing strategy for a Tcm CD4+/CD8+ cell population is depicted in Figure 8 (Manufacturing schema for IL13(EQ)BBζ/CD19t+ Tcm). Specifically, apheresis products obtained from consented research participants are ficolled, washed and incubated overnight. Cells are then depleted of monocyte, regulatory T cell and naive T cell populations using GMP grade anti-CD14, anti-CD25 and antiCD45RA reagents (Miltenyi Biotec) and the CliniMACS™ separation device. Following depletion, negative fraction cells are enriched for CD62L+ Tcm cells using DREG56biotin (COH clinical grade) and anti-biotin microbeads (Miltenyi Biotec) on the

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CliniMACSTM separation device. The cells are not depleted for CD4+ cells or for CD8+ cells.

[0049] Following enrichment, Tcm CD4+/CD8+ cells are formulated in complete XVivol5 plus 50 lU/mL IL-2 and 0.5 ng/mL IL-15 and transferred to a Teflon cell culture bag, where they are stimulated with Dynal ClinEx™ Vivo CD3/CD28 beads. Up to five days after stimulation, cells are transduced with a desired vector expressing a CAR (e.g., IL13(EQ)BBZ-T2A-CD19t_epHIV7 lentiviral vector) at a multiplicity of infection (MOI) of, for example, 1.0 to 0.3. Cultures are maintained for up to 42 days with addition of complete X-Vivol5 and IL-2 and IL-15 cytokine as required for cell expansion (keeping cell density between 3xl0⁵ and 2xl0⁶ viable cells/mL, and cytokine supplementation every Monday, Wednesday and Friday of culture). Cells typically expand to approximately 10⁹ cells under these conditions within 21 days. At the end of the culture period cells are harvested, washed twice and formulated in clinical grade cryopreservation medium (Cryostore CS5, BioLife Solutions).

[0050] On the day(s) of T cell infusion, the cryopreserved and released product is thawed, washed and formulated for re-infusion. The cryopreserved vials containing the released cell product are removed from liquid nitrogen storage, thawed, cooled and washed with a PBS/2% human serum albumin (HSA) Wash Buffer. After centrifugation, the supernatant is removed and the cells resuspended in a Preservative-Free Normal Saline (PENS)/ 2% HSA infusion diluent. Samples are removed for quality control testing.

[0051] Two qualification runs on cells procured from healthy donors were performed using the manufacturing platform described above. Each preclinical qualification run product was assigned a human donor (HD) number - HD006.5 and HD 187.1. Importantly, as shown in Table 5, these qualification runs expanded >80 fold within 28 days and the expanded cells expressed the IL13(EQ)BBy/CD19t transgenes.

Table 5: Summary of Expression Data from Pre-clinical Qualification Run Product

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Cell Product	CAR	CD19	CD4+	CD8+	Fold Expansion
HD006.5	20%	22%	24%	76%	84-fold (28 days)
Hdl87.1	18%	25%	37%	63%	259-fold (28 days)

Example 5: Flow cytometric analysis of surface transgene and T cell marker expression in ILl 3(EQ)BBy/CD 19t+T(\i

[0052] The two preclinical qualification run products described in Example 4 were used in pre-clinical studies to as described below. Figures 6A-C depict the results of flow cytometric analysis of surface transgene and T cell marker expression.

IL13(EQ)BBY/CD19t+ Tcm HD006.5 and HD187.1 were co-stained with anti-IL13-PE and anti-CD8-FITC to detect CD8+ CAR+ and CD4+ (i.e., CD8 negative) CAR+ cells (Figure 6A), or anti-CD19-PE and anti-CD4-FITC to detect CD4+ CD19t+ and CD8+ (i.e., CD4 negative) CAR+ cells (Figure 6B). IL13(EQ)BBY/CD19t+ Tcm HD006.5 and HD187.1 were stained with fhiorochrome-conjugated anti-CD3, TCR, CD4, CD8, CD62L and CD28 (grey histograms) or isotype controls (black histograms). (Figure 6C). In each of Figures 6A-C, the percentages indicated are based on viable lymphocytes (DAPI negative) stained above isotype.

Example 6: Effector Activity of IL13(EQ)BBY/CD19t+ Tcm

[0053] The effector activity of ILl 3(Ε6))ΒΒζ/6Ό 19t+ Tcm was assessed and the results of this analysis are depicted in Figures 7A-B. Briefly, IL13(EQ)BBY/CD19t+ Tcm HD006.5 and HD187.1 were used as effectors in a 6-hour 51Cr-release assay using a 10E:lT ratio based on CD19t expression. The IL 13Ra2-positive tumor targets were K562 engineered to express IL13Ra2 (K562-IL13Ra2) and primary glioma line PBT030-2, and the IL 13Ra2-negative tumor target control was the K562 parental line (Figure 7A). IL13(EQ)BBY/CD19t+ HD006.5 and HD187.1 were evaluated for antigen-dependent cytokine production following overnight co-culture at a 10E:lT ratio with the same IL 13Ra2-positive and negative targets as described in above. Cytokine levels were

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2020203550 29 May 2020 measured using the Bio-Plex Pro Human Cytokine TH1/TH2 Assay kit and INF-γ levels are depicted (Figure 7B).

Example 7: In vivo Anti-tumor Activity of IL1 3(EQ)BBy/CD 19t+ Tcm

[0054] The studies described below demonstrate that IL13(EQ)BBY/CD19t+ Tcm exhibit anti-tumor efficacy in in vivo mouse models. Specifically, we have evaluated the antitumor potency of IL13(EQ)BBY/CD19t+ Tcm against the IL13Ra2+ primary low-passage glioblastoma tumor sphere line PBT030-2, which has been engineered to express both EGFP and firefly luciferase (ffLuc) reporter genes (PBT030-2 EGFP:ffLuc) (6). A panel of primary lines (PBT) from patient glioblastoma specimens grown as tumor spheres (TSs) in serum-free media. These expanded TS lines exhibit stem cell-like characteristics, including expression of stem cell markers, multilineage differentiation and capacity to initiate orthotopic tumors in immunocompromised mice (NSG) at low cell numbers. The PBT030-2 EGFP:ffLuc TS-initiated xenograft model (O.lxlO⁶ cells; 5 day engraftment) has been previously used to evaluate in vivo anti-tumor activity in NSG mice of IL13Ra2-specific CAR expressing T cells, whereby three injections of 2xl0⁶ cytolytic T lymphocytes (CTLs) over a course of 2 weeks were shown to reduce tumor growth. However, in those experiments the majority of the PBT030-2 tumors eventually recurred. By comparison, a single injection of IL13(EQ)BBY/CD19t+ Tcm (l.lxlO⁶ CAR+ Tcm; 2xl0⁶ total TCM) exhibited robust anti-tumor activity against PBT030-2 EGFP:ffLuc TSinitiated tumors (O.lxlO⁶ cells; 5 day engraftment) as shown in Figures 8A-C. As compared to NSG mice treated with either PBS or mock transduced Tcm (no CAR), IL13(EQ)BBY/CD19t+ Tcm significantly reduce ffLuc flux (p < 0.001 at >18-days) and significantly improve survival (p = 0.0008).

[0055] Briefly, EGFP-ffLuc+ PBT030-2 tumor cells (lx 10⁵) were stereotactically implanted into the right forebrain of NSG mice. On day 5, mice received either 2xl0⁶IL13(EQ)BBY/CD19t+ Tcm (1.1x106 CAR+; n=6), 2xl0⁶ mock Tcm (no CAR; n=6) or PBS (n=6). Figure 8A depicts representative mice from each group showing relative tumor burden using Xenogen Living Image. Quantification of ffLuc flux (photons/sec) shows that IL13(EQ)BBζ/CD19t-l- Tcm induce tumor regression as compared to mock19

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2020203550 29 May 2020 transduced Tcm and PBS (#p<0.02, *p<0.001, repeated measures ANOVA) (Figure 8B). As shown in Figure 8C, a Kaplan Meier survival curve (n=6 per group) demonstrates significantly improved survival (p=0.0008; log-rank test) for mice treated with IL13(EQ)BBy/CD19t+ Tcm.

Example 8: Comparison of ΙΕ13(ΕΟ)ΒΒζ+ Tcm and Non-Tcm IL13-zetakine CD8+ CTL Clones in Antitumor Efficacy and T cell Persistence

[0056] The studies described below compare ILI3(Ε<3)ΒΒζ+ Tcm and a previously created IL13Ra2-specific human CD8+ CTLs (IL13-zetakine CD8+ CTL (described in Brown et al. 2012 Clin Cancer Res 18:2199 and Kahlon et al. 2004 Cancer Res 64:9160). The IL13-zetakine uses a 6 Ό3ζ stimulatory domain, lacks a co-stimulatory domain and uses the same IL13 variant as ΙΕ13(Ε())ΒΒζ+.

[0057] A panel of primary lines (PBT) from patient glioblastoma specimens grown as tumor spheres (TSs) in serum-free media was generated (Brown et al. 2012 Clin Cancer Res 18:2199; Brown et al. 2009 Cancer Res 69:8886). These expanded TS lines exhibit stem cell-like characteristics, including expression of stem cell markers, multi-lineage differentiation and capacity to initiate orthotopic tumors in immunocompromised mice (NSG) at low cell numbers. The IL13Ra2+ primary low-passage glioblastoma TS line PBT030-2, which has been engineered to express both EGFP and firefly luciferase (ffLuc) reporter genes (PBT030-2 EGFP:ffLuc) (Brown et al. 2012 Clin Cancer Res 18:2199) was used for the experiments outlined below.

[0058] First, a single dose (IxlO⁶ CAR T cells) of ΙΕ13(Ε())ΒΒζ+ Tcm product was compared to IL13-zetakine CD8+ CTL clones evaluated against day 8 PBT030-2 EGFP:ffuc TS-initiated xenografts (O.lxlO⁶ cells). While both IL13Ra2-specific CAR T cells (IL13-zetakine CTL and ILI3(Ε6))ΒΒζ Tcm) demonstrated antitumor activity against established PBT030-2 tumors as compared to untreated and mock Tcm (CARnegative) controls (Figures 9A and 9B), IL13(EQ)BBZ+ Tcm mediated significantly improved survival and durable tumor remission with mice living >150 days as compared to our first-generation IL13-zetakine CD8+ CTL clones (Figure 9C).

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[0059] To further compare the therapeutic effectiveness of these two IL13Ra2-CAR T cell products, a dose titration of 1.0, 0.3 and O.lxlO⁶ CAR T cells against day 8 PBT0302 EGFP:ffuc TS-initiated tumors was performed (Figures 10A-C). The highest dose (IxlO⁶) of IL13-zetakine CD8+ CTL cl. 2D7 mediated antitumor responses as measured by Xenogen flux in 3 of 6 animals (Figure 10C), but no significant antitumor responses were observed at lower CAR T cell doses. By comparison, injection of ΙΕΙ3(Εζ))ΒΒζ+ Tern product mediated complete tumor regression in the majority of mice at all dose levels, including treatment with as few as O.lxlO⁶ CAR T cells. These data demonstrate that ILI3(Εζ))ΒΒζ+ Tern is at least 10-fold more potent than IL13-zetakine CD8+ CTL clones in antitumor efficacy. The improved anti-tumor efficacy of is due to improved T cell persistence in the tumor microenvironment. Evaluation of CD3+ T cells 7-days post i.e. injection revealed significant numbers of ILI 3(Εζ))ΒΒζ+ Tern in the tumor microenvironment, whereas very few first-generation IL 13-zeta CTLs were present (Figure 11).

Example 9: Comparison of CAR T cell delivery route for treatment of large TSinitiated PBT tumors

[0060] Described below are studies that compare the route of delivery, intraveneous (i.v.) or intracranial (i.e.), on antitumor activity against invasive primary PBT lines. In pilot studies (data not shown), it was unexpectedly observed that i.v. administered ILI 3(Εζ))ΒΒζ+ Tern provided no therapeutic benefit as compared to PBS for the treatment of small (day 5) PBT030-2 EGFP:ffLuc tumors. This is in contrast to the robust therapeutic efficacy observed with i.e. administered CAR+ T cells. Reasoning that day 5 PBT030-2 tumors may have been too small to recruit therapeutic T cells from the periphery, a comparison was made of i.v. versus i.e. delivery against larger day 19 PBT030-2 EGFP:ffLuc tumors. For these studies, PBT030-2 engrafted mice were treated with either two i.v. infusions (5 x 10⁶ CAR+ Tern; days 19 and 26) or four i.e. infusions (1 x 10⁶ CAR+ Tern; days 19, 22, 26 and 29) of IL13(EQ)BBZ+ Tern, or mock Tern (no CAR). Here too no therapeutic benefit as monitored by Xenogen imaging or KaplanMeier survival analysis for i.v. administered CAR+ T cells (Figures 12A and 12B). In contrast, potent antitumor activity was observed for i.e. administered ILI3(Εζ))ΒΒζ+

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Tcm (Figures 12A-B). Next, brains from a cohort of mice 7 days post T cell injection were harvested and evaluated for CD3+ human T cells by IHC. Surprisingly, for mice treated i.v. with either mock Tcm or ILI3(EQ)BEfy Tcm there were no detectable CD3+ human T cells in the tumor or in others mouse brain regions where human T cells typically reside (i.e. the leptomeninges) (Figure 12C), suggesting a deficit in tumor tropism. This is in contrast to the significant number of T cells detected in the i.e. treated mice (Figure 12D).

[0061] Tumor derived cytokines, particularly MCP-1/CCL2, are important in recruiting T cells to the tumor. Thus, PBT030-2 tumor cells were evaluated and it was found that this line produces high levels of MCP-1/CCL2 comparable to U251T cells (data not shown), a glioma line previously shown to attract i.v. administered effector CD8+ T cells to i.e. engrafted tumors. Malignant gliomas are highly invasive tumors and are often multifocal in presentation. The studies described above establish that IL13BBZ Tcm can eliminate infiltrated tumors such as PBT030-2, and mediate long-term durable antitumor activity. The capacity of intracranially delivered CAR T cells to traffic to multifocal disease was also examined. For this study PBT030-2 EGFP:ffLuc TSs were implanted in both the left and right hemispheres (Figure 13A) and CAR+ T cells were injected only at the right tumor site. Encouragingly, for all mice evaluated (n=3) we detected T cells by CD3 IHC 7-days post T cell infusion both at the site of injection (i.e. right tumor), as well within the tumor on the left hemisphere (Figure 13B). These findings provide evidence that CAR+ T cells are able to traffic to and infiltrate tumor foci at distant sites. Similar findings were also observed in a second tumor model using the U25 IT glioma cell line (data not shown).

Example 10: ΙΕ13(ΕΟ)ΒΒζ/ΟΡ19ί Sequences

[0062] The complete amino acid sequence of ILI 3(Ε0)ΒΒζ/ΟΟ 19t is depicted in Figure 17. The entire sequence (SEQ ID NO:1) includes: a 22 amino acid GMCSF signal peptide (SEQ ID NOG), a 112 amino acid IL-13 sequence (SEQ ID NOG; amino acid substitution E13Y shown in bold); a 229 amino acid IgG4 sequence (SEQ ID NO:4; with amino acid substitutions L235E and N297Q shown in bold); a 22 amino acid CD4

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2020203550 29 May 2020 transmembrane sequence (SEQ ID NO:5); a 42 amino acid 4-1BB sequence (SEQ ID NO:6); a 3 amino acid Gly linker; a 112 amino acid Οϋ3ζ sequence (SEQ ID NO:7); a 24 amino acid T2A sequence (SEQ ID NO:8); and a 323 amino acid CD19t sequence (SEQ ID NOG).

[0063] The mature chimeric antigen receptor sequence (SEQ ID NO:10) includes: a 112 amino acid IL-13 sequence (SEQ ID NOG; amino acid substitution E13Y shown in bold); a 229 amino acid IgG4 sequence (SEQ ID NO:4; with amino acid substitutions L235E and N297Q shown in bold); at 22 amino acid CD4 sequence (SEQ ID NOG); a 42 amino acid 4-1BB sequence (SEQ ID NO:6); a 3 amino acid Gly linker; and a 112 amino acid Οϋ3ζ sequence (SEQ ID NO:7). Within this CAR sequence (SEQ ID NO: 10) is the IL-13/IgG4/CD4t/41-BB sequence (SEQ ID NO:11), which includes: a 112 amino acid IL-13 sequence (SEQ ID NOG; amino acid substitution E13Y shown in bold); a 229 amino acid IgG4 sequence (SEQ ID NOG; with amino acid substitutions L235E and N297Q shown in bold); at 22 amino acid CD4 sequence (SEQ ID NOG); and a 42 amino acid 4-1BB sequence (SEQ ID NOG). The IL13/IgG4/CD4t/4-lBB sequence (SEQ ID NO: 11) can be joined to the 112 amino acid Οϋ3ζ sequence (SEQ ID NOG) by a linker such as a Gly Gly Gly linker. The CAR sequence (SEQ ID NO :10) can be preceded by a 22 amino acid GMCSF signal peptide (SEQ ID NOG). Figure 18 depicts a comparison of the sequences of ΙΕ13^)41ΒΒζ[ΙΕ13^}41ΒΒζ T2A-CD19t_epHIV7; pF02630] (SEQ ID NO:12) and CD19Rop_epHIV7 (pJO 1683) (SEQ ID NO: 13).

Claims

1. The population of human T cells of transduced with a vector expressing a chimeric antigen receptor wherein at least 50% of the transduced human T cells are central memory T cells.

2. The population of human T cells of claim 1 wherein at least 10% of the transduced cells central memory T cells are CD4+.

3. The population of human T cells of claim 1 wherein at least 10% of the transduced central memory T cells are CD8+.

4. The population of human T cells of claim 1 wherein at least 15% of the central memory T cells are CD4+ and at least 15% are CD8+.

5. The population of human T cells of claim 1 wherein at least 50% of the transduced human T cells are CD4+/CD8+/CD62L+.

6. A population of human T cells of transduced with a vector expressing a chimeric antigen receptor wherein: at least 50% of the transduced human T cells are CD45R0+, CD62L+ and CD45Ra-, at least 10% of the cells are CD4+ and at least 10% of the cells are CD4+.

7. The population of human T cells of claim 6 wherein at least 10% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD4+ and at least 10% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD8+.

8. The population of human T cells of claim 6 wherein at least 15% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD4+ and at least 15% of the cells that are CD45R0+, CD62L+ and CD45Ra- are also CD4+.

9. A method of treating cancer comprising administering to a patient in need thereof a pharmaceutical composition comprising the human T cells of any of claims 1-8.

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10. The method of claim 9 wherein the population of human T cells are autologous to the patient.

11. The method of claim 9 wherein the population of human T cells are allogenic to the patient.

12. A method for preparing a population central memory T cells comprising: obtaining a population of T cells from a human subject; depleting the population of T cells for cells that express CD25, cells that express CD 14, and cells that express CD45+ to prepared a depleted T cell population; enriching the depleted T cell population for cells expressing CD62L, thereby preparing a population of central memory T cells, wherein the method does not comprising a step of depleting a cell population for cells expressing CD4 and does not comprising a step of depleting a cell population of cells expressing CD8+.

13. The method of claim 12 wherein at least 50% of the cells in the population central memory T cells are CD45R0+, CD62L+ and CD45Ra-, at least 10% of the cells are CD4+ and at least 10% of the cells are CD4+.

14. The method of claim 12 wherein at least 50% of the cells in the population central memory T cells are CD45R0+, CD62L+ and CD45Ra-, at least 15% of the cells are CD4+ and at least 15% of the cells are CD4+.

15. The method of claim 12 wherein at least 50% of the cells in the population central memory T cells are CD45R0+, CD62L+ and CD45Ra-, at least 20% of the cells are CD4+ and at least 20% of the cells are CD4+.

16. The method of claim 12 further comprising stimulating the population of central memory T cells

17. The method of claim 16 comprising contacting the population of central memory T cells with CD3 and/or CD28.

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18. The method of claim 16 further comprising transducing the cells with a vector expressing a recombinant protein to create a population of genetically modified central memory T cells.

19. The method of claim 19 further comprising expanding the population of generically modified central memory T cells.

20. The method of claim 19 wherein the step of expanding the population of generically modified central memory T cells comprising exposing the cells to one or both of IL-2 and IL-15.