A human CD137xPD-L1 bispecific antibody promotes anti-tumor immunity via context-dependent T cell costimulation and checkpoint blockade
2021; 12 (1): 4445
Immune checkpoint inhibitors demonstrate clinical activity in many tumor types, however, only a fraction of patients benefit. Combining CD137 agonists with these inhibitors increases anti-tumor activity preclinically, but attempts to translate these observations to the clinic have been hampered by systemic toxicity. Here we describe a human CD137xPD-L1 bispecific antibody, MCLA-145, identified through functional screening of agonist- and immune checkpoint inhibitor arm combinations. MCLA-145 potently activates T cells at sub-nanomolar concentrations, even under suppressive conditions, and enhances T cell priming, differentiation and memory recall responses. In vivo, MCLA-145 anti-tumor activity is superior to immune checkpoint inhibitor comparators and linked to recruitment and intra-tumor expansion of CD8 + T cells. No graft-versus-host-disease is observed in contrast to other antibodies inhibiting the PD-1 and PD-L1 pathway. Non-human primates treated with 100 mg/kg/week of MCLA-145 show no adverse effects. The conditional activation of CD137 signaling by MCLA-145, triggered by neighboring cells expressing >5000 copies of PD-L1, may provide both safety and potency advantages.
View details for DOI 10.1038/s41467-021-24767-5
View details for Web of Science ID 000679964000015
View details for PubMedID 34290245
View details for PubMedCentralID PMC8295259
Addition of anti-TIM3 or anti-TIGIT Antibodies to anti-PD1 Blockade Augments Human T cell Adoptive Cell Transfer
2021; 10 (1): 1873607
PD1 blockade to reinvigorate T cells has become part of standard of care for patients with NSCLC across disease stages. However, the majority of patients still do not respond. One potential mechanism of resistance is increased expression of other checkpoint inhibitory molecules on T cells leading to their suppression; however, this phenomenon has not been well studied in tumor-reactive, human T cells. The purpose of this study was to evaluate this compensatory mechanism in a novel model using human effector T cells infiltrating and reactive against human lung cancer. Immunodeficient mice with flank tumors established from a human lung cancer cell line expressing the NYESO1 antigen were treated with activated human T cells expressing a TCR reactive to NYESO1 (Ly95) with or without anti-PD1 alone and with combinations of anti-PD1 plus anti-TIM3 or anti-TIGIT. A month later, the effect on tumor growth and the phenotype and ex vivo function of the TILs were analyzed. Anti-PD1 and Ly95 T cells led to greater tumor control than Ly95 T cells alone; however, tumors continued to grow. The ex-vivo function of PD1-blocked Ly95 TILs was suppressed and was associated with increased T cell expression of TIM3/TIGIT. Administering combinatorial blockade of PD1+ TIM3 or PD1+ TIGIT with Ly95 T cells led to greater tumor control than blocking PD1 alone. In our model, PD1 blockade was suboptimally therapeutic alone. The effect of TIM3 and TIGIT was upregulated on T cells in response to PD1 blockade and anti-tumor activity could be enhanced when these inhibitory receptors were also blocked with antibodies in combination with anti-PD1 therapy.
View details for DOI 10.1080/2162402X.2021.1873607
View details for Web of Science ID 000612075500001
View details for PubMedID 33537176
View details for PubMedCentralID PMC7833767
Neoadjuvant Gene Mediated Cytotoxic Immunotherapy for Non-Small Cell Lung Cancer - Safety and Immunologic Activity.
Molecular therapy : the journal of the American Society of Gene Therapy
Gene-mediated cytotoxic immunotherapy (GMCI) is an immuno-oncology approach involving local delivery of a replication-deficient adenovirus expressing Herpes simplex thymidine kinase (AdV-tk) followed by anti-herpetic prodrug activation that promotes immunogenic tumor cell death, antigen presenting cell activation, and T cell stimulation. This Phase I dose escalation pilot trial assessed bronchoscopic delivery of AdV-tk in patients with suspected lung cancer who were candidates for surgery. A single intra-tumoral AdV-tk injection in three dose cohorts (maximum 1012 viral particles) was performed during diagnostic staging, followed by a 14 day course of the prodrug valacyclovir, and subsequent surgery one week later. Twelve patients participated after appropriate informed consent. Vector-related adverse events were minimal. Immune biomarkers were evaluated in tumor and blood before and after GMCI. Significantly increased infiltration of CD8+ T cells was found in resected tumors. Expression of activation, inhibitory, and proliferation markers, such as HLA-DR, CD38, Ki67, PD1, CD39, and CTLA-4, were significantly increased in both the tumor and peripheral CD8+ T-cells. Thus, intratumoral AdV-tk injection into NSCLC proved safe, feasible, and effectively induced CD8+ T cell activation. These data provide a foundation for additional clinical trials of GMCI for lung cancer patients with potential benefit if combined with other immune therapies.
View details for DOI 10.1016/j.ymthe.2020.11.001
View details for PubMedID 33160076
Phenotypic and functional analysis of malignant mesothelioma tumor-infiltrating lymphocytes
2019; 8 (9): e1638211
Given the growing interest and promising preliminary results of immunotherapy in malignant pleural mesothelioma (MPM), it has become important to more fully understand the immune landscape in this tumor. This may be especially relevant in deciding who might benefit most from checkpoint blockade or agonist antibody therapy. Since the phenotype of tumor infiltrating lymphocytes (TILs) in MPM has not been fully described and their function has not been carefully assessed, we collected fresh tumor and blood from 22 patients undergoing surgical resection and analysed single cell suspensions by flow cytometry. The functionality of TILs was assessed by measurement of cytokine expression (IFN-γ) following overnight stimulation ex vivo. Results showed low numbers of CD8+ TILs whose function was either moderately or severely suppressed. The degree of TIL hypofunction did not correlate with the presence of co-existing macrophages or neutrophils, nor with expression of the inhibitory receptors PD-1, CD39 and CTLA-4. Hypofunction was associated with higher numbers of CD4 regulatory T cells (Tregs) and with expression of the inhibitory receptor TIGIT. On the other hand, presence of tissue-resident memory (Trm) cells and expression of TIM-3 on CD8+ cells were positively associated with cytokine production. However, Trm function was partially suppressed when the transcription factor Eomesodermin (Eomes) was co-expressed. Understanding the function of TILs in malignant mesothelioma may have clinical implications for immunotherapy, especially in choosing the best immunotherapy targets. Our data suggests that Treg cell blocking agents or TIGIT inhibitor antibodies might be especially valuable in these patients.
View details for DOI 10.1080/2162402X.2019.1638211
View details for Web of Science ID 000476282000001
View details for PubMedID 31428531
View details for PubMedCentralID PMC6685523
Function of Human Tumor-Infiltrating Lymphocytes in Early-Stage Non-Small Cell Lung Cancer
CANCER IMMUNOLOGY RESEARCH
2019; 7 (6): 896–909
Cancer progression is marked by dysfunctional tumor-infiltrating lymphocytes (TIL) with high inhibitory receptor (IR) expression. Because IR blockade has led to clinical responses in some patients with non-small cell lung cancer (NSCLC), we investigated how IRs influenced CD8+ TIL function from freshly digested early-stage NSCLC tissues using a killing assay and intracellular cytokine staining after in vitro T-cell restimulation. Early-stage lung cancer TIL function was heterogeneous with only about one third of patients showing decrements in cytokine production and lytic function. TIL hypofunction did not correlate with clinical factors, coexisting immune cells (macrophages, neutrophils, or CD4+ T regulatory cells), nor with PD-1, TIGIT, TIM-3, CD39, or CTLA-4 expression. Instead, we found that the presence of the integrin αeβ7 (CD103), characteristic of tissue-resident memory cells (TRM), was positively associated with cytokine production, whereas expression of the transcription factor Eomesodermin (Eomes) was negatively associated with TIL function. These data suggest that the functionality of CD8+ TILs from early-stage NSCLCs may be influenced by competition between an antitumor CD103+ TRM program and an exhaustion program marked by Eomes expression. Understanding the mechanisms of T-cell function in the progression of lung cancer may have clinical implications for immunotherapy.
View details for DOI 10.1158/2326-6066.CIR-18-0713
View details for Web of Science ID 000470290200006
View details for PubMedID 31053597
View details for PubMedCentralID PMC6548666
CAR T Cells for Solid Tumors: New Strategies for Finding, Infiltrating, and Surviving in the Tumor Microenvironment
FRONTIERS IN IMMUNOLOGY
2019; 10: 128
Chimeric antigen receptor (CAR) T cells, T cells that have been genetically engineered to express a receptor that recognizes a specific antigen, have given rise to breakthroughs in treating hematological malignancies. However, their success in treating solid tumors has been limited. The unique challenges posed to CAR T cell therapy by solid tumors can be described in three steps: finding, entering, and surviving in the tumor. The use of dual CAR designs that recognize multiple antigens at once and local administration of CAR T cells are both strategies that have been used to overcome the hurdle of localization to the tumor. Additionally, the immunosuppressive tumor microenvironment has implications for T cell function in terms of differentiation and exhaustion, and combining CARs with checkpoint blockade or depletion of other suppressive factors in the microenvironment has shown very promising results to mitigate the phenomenon of T cell exhaustion. Finally, identifying and overcoming mechanisms associated with dysfunction in CAR T cells is of vital importance to generating CAR T cells that can proliferate and successfully eliminate tumor cells. The structure and costimulatory domains chosen for the CAR may play an important role in the overall function of CAR T cells in the TME, and "armored" CARs that secrete cytokines and third- and fourth-generation CARs with multiple costimulatory domains offer ways to enhance CAR T cell function.
View details for DOI 10.3389/fimmu.2019.00128
View details for Web of Science ID 000457800800001
View details for PubMedID 30804938
View details for PubMedCentralID PMC6370640