RESUMO
To enhance the therapeutic index of T-cell engagers (TCEs), we engineered masked, precision-activated TCEs (XPAT proteins), targeting a tumor antigen (human epidermal growth factor receptor 2 (HER2) or epidermal growth factor receptor (EGFR)) and CD3. Unstructured XTEN polypeptide masks flank the N and C termini of the TCE and are designed to be released by proteases in the tumor microenvironment. In vitro, unmasked HER2-XPAT (uTCE) demonstrates potent cytotoxicity, with XTEN polypeptide masking providing up to 4-log-fold protection. In vivo, HER2-XPAT protein induces protease-dependent antitumor activity and is proteolytically stable in healthy tissues. In non-human primates, HER2-XPAT protein demonstrates a strong safety margin (>400-fold increase in tolerated maximum concentration versus uTCE). HER2-XPAT protein cleavage is low and similar in plasma samples from healthy and diseased humans and non-human primates, supporting translatability of stability to patients. EGFR-XPAT protein confirmed the utility of XPAT technology for tumor targets more widely expressed in healthy tissues.
Assuntos
Neoplasias , Linfócitos T , Animais , Humanos , Antígenos de Neoplasias/metabolismo , Receptores ErbB , Imunoterapia/efeitos adversos , Neoplasias/tratamento farmacológico , Microambiente Tumoral , Complexo CD3/metabolismoRESUMO
T cell-engaging bispecific antibodies (TCB) are highly potent therapeutics that can recruit and activate cytotoxic T cells to stimulate an antitumor immune response. However, the development of TCBs against solid tumors has been limited by significant on-target toxicity to normal tissues. Probody therapeutics have been developed as a novel class of recombinant, protease-activated antibody prodrugs that are "masked" to reduce antigen binding in healthy tissues but can become conditionally unmasked by proteases that are preferentially active in the tumor microenvironment (TME). Here, we describe the preclinical efficacy and safety of CI107, a Probody TCB targeting EGFR and CD3. In vitro, the protease-activated, unmasked CI107 effectively bound EGFR and CD3 expressed on the surface of cells and induced T-cell activation, cytokine release, and cytotoxicity toward tumor cells. In contrast, dually masked CI107 displayed a >500-fold reduction in antigen binding and >15,000-fold reduction in cytotoxic activity. In vivo, CI107 potently induced dose-dependent tumor regression of established colon cancer xenografts in mice engrafted with human peripheral blood mononuclear cells. Furthermore, the MTD of CI107 in cynomolgus monkeys was more than 60-fold higher than that of the unmasked TCB, and much lower levels of toxicity were observed in animals receiving CI107. Therefore, by localizing activity to the TME and thus limiting toxicity to normal tissues, this Probody TCB demonstrates the potential to expand clinical opportunities for TCBs as effective anticancer therapies for solid tumor indications. SIGNIFICANCE: A conditionally active EGFR-CD3 T cell-engaging Probody therapeutic expands the safety window of bispecific antibodies while maintaining efficacy in preclinical solid tumor settings.
Assuntos
Anticorpos Biespecíficos , Complexo CD3 , Neoplasias do Colo , Receptores ErbB , Animais , Humanos , Camundongos , Anticorpos Biespecíficos/uso terapêutico , Complexo CD3/antagonistas & inibidores , Neoplasias do Colo/terapia , Receptores ErbB/antagonistas & inibidores , Leucócitos Mononucleares/metabolismo , Peptídeo Hidrolases/metabolismo , Microambiente Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Immune-checkpoint blockade has revolutionized cancer treatment. However, most patients do not respond to single-agent therapy. Combining checkpoint inhibitors with other immune-stimulating agents increases both efficacy and toxicity due to systemic T-cell activation. Protease-activatable antibody prodrugs, known as Probody therapeutics (Pb-Tx), localize antibody activity by attenuating capacity to bind antigen until protease activation in the tumor microenvironment. Herein, we show that systemic administration of anti-programmed cell death ligand 1 (anti-PD-L1) and anti-programmed cell death protein 1 (anti-PD-1) Pb-Tx to tumor-bearing mice elicited antitumor activity similar to that of traditional PD-1/PD-L1-targeted antibodies. Pb-Tx exhibited reduced systemic activity and an improved nonclinical safety profile, with markedly reduced target occupancy on peripheral T cells and reduced incidence of early-onset autoimmune diabetes in nonobese diabetic mice. Our results confirm that localized PD-1/PD-L1 inhibition by Pb-Tx can elicit robust antitumor immunity and minimize systemic immune-mediated toxicity. These data provide further preclinical rationale to support the ongoing development of the anti-PD-L1 Pb-Tx CX-072, which is currently in clinical trials.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígeno B7-H1/uso terapêutico , Imunoterapia/métodos , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/farmacologia , Antígeno B7-H1/farmacologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Humanos , Camundongos , Microambiente TumoralRESUMO
Costimulation via CD137 (4-1BB) enhances antitumor immunity mediated by cytotoxic T lymphocytes. Anti-CD137 agonist antibodies elicit mild liver inflammation in mice, and the maximum tolerated dose of Urelumab, an anti-human CD137 agonist monoclonal antibody, in the clinic was defined by liver inflammation-related side effects. A protease-activated prodrug form of the anti-mouse CD137 agonist antibody 1D8 (1D8 Probody therapeutic, Pb-Tx) was constructed and found to be selectively activated in the tumor microenvironment. This construct, which encompasses a protease-cleavable linker holding in place a peptide that masks the antigen binding site, exerted antitumor effects comparable to the unmodified antibody but did not result in liver inflammation. Moreover, it efficaciously synergized with both PD-1 blockade and adoptive T-cell therapy. Surprisingly, minimal active Pb-Tx reached tumor-draining lymph nodes, and regional lymphadenectomy did not abrogate antitumor efficacy. By contrast, S1P receptor-dependent recirculation of T cells was absolutely required for efficacy. The preferential cleavage of the anti-CD137 Pb-Tx by tumor proteases offers multiple therapeutic opportunities, including neoadjuvant therapy, as shown by experiments in which the Pb-Tx is given prior to surgery to avoid spontaneous metastases.
Assuntos
Antineoplásicos/toxicidade , Antineoplásicos/uso terapêutico , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Humanos , Imunoterapia , Inflamação/patologia , Fígado/patologia , Neoplasias Pulmonares/secundário , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Camundongos , Terapia Neoadjuvante , Peptídeo Hidrolases/metabolismoRESUMO
PD-1 (programmed cell death-1) is the central inhibitory receptor regulating CD8 T cell exhaustion during chronic viral infection and cancer. Interestingly, PD-1 is also expressed transiently by activated CD8 T cells during acute viral infection, but the role of PD-1 in modulating T cell effector differentiation and function is not well defined. To address this question, we examined the expression kinetics and role of PD-1 during acute lymphocytic choriomeningitis virus (LCMV) infection of mice. PD-1 was rapidly up-regulated in vivo upon activation of naive virus-specific CD8 T cells within 24 h after LCMV infection and in less than 4 h after peptide injection, well before any cell division had occurred. This rapid PD-1 expression by CD8 T cells was driven predominantly by antigen receptor signaling since infection with a LCMV strain with a mutation in the CD8 T cell epitope did not result in the increase of PD-1 on antigen-specific CD8 T cells. Blockade of the PD-1 pathway using anti-PD-L1 or anti-PD-1 antibodies during the early phase of acute LCMV infection increased mTOR signaling and granzyme B expression in virus-specific CD8 T cells and resulted in faster clearance of the infection. These results show that PD-1 plays an inhibitory role during the naive-to-effector CD8 T cell transition and that the PD-1 pathway can also be modulated at this stage of T cell differentiation. These findings have implications for developing therapeutic vaccination strategies in combination with PD-1 blockade.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Ativação Linfocitária , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Receptor de Morte Celular Programada 1/imunologia , Animais , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/genética , Feminino , Coriomeningite Linfocítica/genética , Camundongos , Receptor de Morte Celular Programada 1/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologiaRESUMO
This report is a summary of 'New Cancer Immunotherapy Agents in Development' program, which took place in association with the 31st Annual Meeting of the Society for Immunotherapy of Cancer (SITC), on November 9, 2016 in National Harbor, Maryland. Presenters gave brief overviews of emerging clinical and pre-clinical immune-based agents and combinations, before participating in an extended panel discussion with multidisciplinary leaders, including members of the FDA, leading academic institutions and industrial drug developers, to consider topics relevant to the future of cancer immunotherapy.
Assuntos
Vacinas Anticâncer/uso terapêutico , Imunoterapia , Neoplasias/tratamento farmacológico , Microambiente Tumoral/imunologia , Vacinas Anticâncer/imunologia , Humanos , Neoplasias/imunologia , Microambiente Tumoral/efeitos dos fármacosRESUMO
Expression of PD-L1, the ligand for T-cell inhibitory receptor PD-1, is one key immunosuppressive mechanism by which cancer avoids eradication by the immune system. Therapeutic use of blocking antibodies to PD-L1 or its receptor PD-1 has produced unparalleled, durable clinical responses, with highest likelihood of response seen in patients whose tumour or immune cells express PD-L1 before therapy. The significance of PD-L1 expression in each cell type has emerged as a central and controversial unknown in the clinical development of immunotherapeutics. Using genetic deletion in preclinical mouse models, here we show that PD-L1 from disparate cellular sources, including tumour cells, myeloid or other immune cells can similarly modulate the degree of cytotoxic T-cell function and activity in the tumour microenvironment. PD-L1 expression in both the host and tumour compartment contribute to immune suppression in a non-redundant fashion, suggesting that both sources could be predictive of sensitivity to therapeutic agents targeting the PD-L1/PD-1 axis.
Assuntos
Anticorpos Bloqueadores/farmacologia , Antígeno B7-H1/imunologia , Neoplasias/imunologia , Microambiente Tumoral/imunologia , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Linhagem Celular Tumoral , Humanos , Camundongos Knockout , Neoplasias/tratamento farmacológico , Neoplasias/genética , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/genéticaRESUMO
Targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) can induce regression of tumors bearing activating mutations in the Ras pathway but rarely leads to tumor eradication. Although combining MEK inhibition with T-cell-directed immunotherapy might lead to more durable efficacy, T cell responses are themselves at least partially dependent on MEK activity. We show here that MEK inhibition did profoundly block naive CD8(+) T cell priming in tumor-bearing mice, but actually increased the number of effector-phenotype antigen-specific CD8(+) T cells within the tumor. MEK inhibition protected tumor-infiltrating CD8(+) T cells from death driven by chronic TCR stimulation while sparing cytotoxic activity. Combining MEK inhibition with anti-programmed death-ligand 1 (PD-L1) resulted in synergistic and durable tumor regression even where either agent alone was only modestly effective. Thus, despite the central importance of the MAP kinase pathway in some aspects of T cell function, MEK-targeted agents can be compatible with T-cell-dependent immunotherapy.
Assuntos
Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/imunologia , Carcinoma/terapia , Neoplasias do Colo/terapia , Imunoterapia , Animais , Anticorpos Monoclonais/administração & dosagem , Apoptose , Azetidinas/administração & dosagem , Azetidinas/farmacologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Carcinoma/imunologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias do Colo/imunologia , Sinergismo Farmacológico , Tratamento Farmacológico , Quimioterapia Combinada , MAP Quinases Reguladas por Sinal Extracelular , Humanos , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Terapia de Alvo Molecular , Transplante de Neoplasias , Piperidinas/administração & dosagem , Piperidinas/farmacologiaRESUMO
UNLABELLED: Pancreas ductal adenocarcinoma (PDAC) has one of the worst 5-year survival rates of all solid tumors, and thus new treatment strategies are urgently needed. Here, we report that targeting Bruton tyrosine kinase (BTK), a key B-cell and macrophage kinase, restores T cell-dependent antitumor immune responses, thereby inhibiting PDAC growth and improving responsiveness to standard-of-care chemotherapy. We report that PDAC tumor growth depends on cross-talk between B cells and FcRγ(+) tumor-associated macrophages, resulting in T(H)2-type macrophage programming via BTK activation in a PI3Kγ-dependent manner. Treatment of PDAC-bearing mice with the BTK inhibitor PCI32765 (ibrutinib) or by PI3Kγ inhibition reprogrammed macrophages toward a T(H)1 phenotype that fostered CD8(+) T-cell cytotoxicity, and suppressed PDAC growth, indicating that BTK signaling mediates PDAC immunosuppression. These data indicate that pharmacologic inhibition of BTK in PDAC can reactivate adaptive immune responses, presenting a new therapeutic modality for this devastating tumor type. SIGNIFICANCE: We report that BTK regulates B-cell and macrophage-mediated T-cell suppression in pancreas adenocarcinomas. Inhibition of BTK with the FDA-approved inhibitor ibrutinib restores T cell-dependent antitumor immune responses to inhibit PDAC growth and improves responsiveness to chemotherapy, presenting a new therapeutic modality for pancreas cancer.
Assuntos
Comunicação Celular/imunologia , Sistema Imunitário/citologia , Sistema Imunitário/patologia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/metabolismo , Proteínas Tirosina Quinases/metabolismo , Tirosina Quinase da Agamaglobulinemia , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Humanos , Leucócitos/imunologia , Leucócitos/metabolismo , Ativação de Macrófagos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Células Mieloides/imunologia , Células Mieloides/metabolismo , Neoplasias Pancreáticas/genética , Receptores de IgG/metabolismo , Transdução de SinaisRESUMO
Tumors constitute highly suppressive microenvironments in which infiltrating T cells are "exhausted" by inhibitory receptors such as PD-1. Here we identify TIGIT as a coinhibitory receptor that critically limits antitumor and other CD8(+) T cell-dependent chronic immune responses. TIGIT is highly expressed on human and murine tumor-infiltrating T cells, and, in models of both cancer and chronic viral infection, antibody coblockade of TIGIT and PD-L1 synergistically and specifically enhanced CD8(+) T cell effector function, resulting in significant tumor and viral clearance, respectively. This effect was abrogated by blockade of TIGIT's complementary costimulatory receptor, CD226, whose dimerization is disrupted upon direct interaction with TIGIT in cis. These results define a key role for TIGIT in inhibiting chronic CD8(+) T cell-dependent responses.
Assuntos
Antígenos de Diferenciação de Linfócitos T/metabolismo , Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Neoplasias/imunologia , Receptores Imunológicos/metabolismo , Animais , Linfócitos T CD8-Positivos/metabolismo , Células CHO , Linhagem Celular Tumoral , Cricetulus , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Humanos , Coriomeningite Linfocítica/patologia , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/patologia , Multimerização Proteica , RatosRESUMO
Clinical results from the latest strategies for T-cell activation in cancer have fired interest in combination immunotherapies that can fully engage T-cell immunity. In this study, we describe a trastuzumab-based bispecific antibody, HER2-TDB, which targets HER2 and conditionally activates T cells. HER2-TDB specifically killed HER2-expressing cancer cells at low picomolar concentrations. Because of its unique mechanism of action, which is independent of HER2 signaling or chemotherapeutic sensitivity, HER2-TDB eliminated cells refractory to currently approved HER2 therapies. HER2-TDB exhibited potent antitumor activity in four preclinical model systems, including MMTV-huHER2 and huCD3 transgenic mice. PD-L1 expression in tumors limited HER2-TDB activity, but this resistance could be reversed by anti-PD-L1 treatment. Thus, combining HER2-TDB with anti-PD-L1 yielded a combination immunotherapy that enhanced tumor growth inhibition, increasing the rates and durability of therapeutic response.
Assuntos
Anticorpos Biespecíficos/imunologia , Ativação Linfocitária , Receptor ErbB-2/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Biespecíficos/farmacologia , Anticorpos Monoclonais Humanizados/farmacologia , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Ratos , Ratos Sprague-Dawley , TrastuzumabRESUMO
B cells foster squamous cell carcinoma (SCC) development through deposition of immunoglobulin-containing immune complexes in premalignant tissue and Fcγ receptor-dependent activation of myeloid cells. Because human SCCs of the vulva and head and neck exhibited hallmarks of B cell infiltration, we examined B cell-deficient mice and found reduced support for SCC growth. Although ineffective as a single agent, treatment of mice bearing preexisting SCCs with B cell-depleting αCD20 monoclonal antibodies improved response to platinum- and Taxol-based chemotherapy. Improved chemoresponsiveness was dependent on altered chemokine expression by macrophages that promoted tumor infiltration of activated CD8(+) lymphocytes via CCR5-dependent mechanisms. These data reveal that B cells, and the downstream myeloid-based pathways they regulate, represent tractable targets for anticancer therapy in select tumors.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfócitos B/imunologia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/imunologia , Macrófagos/imunologia , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Células CHO , Carcinoma de Células Escamosas/patologia , Cricetulus , Feminino , Humanos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Camundongos , Camundongos Transgênicos , Neoplasias/patologia , Compostos Organoplatínicos/administração & dosagem , Paclitaxel/administração & dosagem , Fenótipo , Microambiente Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The aim of T-cell-based immune therapy for cancer has been to generate durable clinical benefit for patients. Following a generation of therapies that largely showed minimal activity, substantial toxicity, and no biomarkers to identify which patients benefit from treatment, early studies are showing signs that programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) inhibitors are highly active. Preclinical and early data from clinical studies suggest that targeting this pathway can induce durable clinical responses in patients in a variety of tumor types, including lung and colon cancer. Furthermore, correlations with tumor PD-L1 expression may enable selection of patients most likely to benefit from treatment. The emerging data not only offer the hope of better cancer therapy but also provide evidence that changes our understanding of how the host immune system interacts with human cancer.