Immunoreceptor Tyrosine-based Inhibitory Motif Domain Research Articles

A phase 3, randomized study of adjuvant rilvegostomig plus chemotherapy in resected biliary tract cancer: ARTEMIDE-Biliary01.

TPS4199 Background: Biliary tract cancer (BTC) is a rare but aggressive heterogenous group of gastrointestinal cancers that arise from the intra- or extrahepatic bile ducts (cholangiocarcinoma [CCA]) or the gallbladder (GBC). In early-stage disease following curative resection, adjuvant chemotherapy with a fluoropyrimidine- or gemcitabine-based regimen is usually recommended, however, recurrence rates remain high (e.g. in the BILCAP study, 5-year recurrence-free survival with adjuvant capecitabine was 34%). Immunotherapy is efficacious as adjuvant therapy in other cancer types. Results from the TOPAZ-1 and KEYNOTE-966 studies support combining immunotherapy and chemotherapy in advanced BTC, including in locally advanced non-metastatic disease. Furthermore, dual inhibition of programmed cell death-1 (PD-1) or programmed cell death ligand-1 (PD-L1) and the novel immune checkpoint, T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), has shown promising results across multiple tumor types without major increases in high-grade toxicity compared with PD-1 or PD-L1 inhibition alone. Rilvegostomig is an anti-PD-1/-TIGIT bi-specific monoclonal antibody that appears active and well tolerated in non-small-cell lung cancer. ARTEMIDE-Biliary01 will investigate the efficacy of rilvegostomig plus standard of care adjuvant chemotherapy in patients with BTC after curative intent resection. Methods: ARTEMIDE-Biliary01 (NCT06109779) is a Phase 3, randomized, double-blind, placebo-controlled, multicenter, global study to assess the efficacy and tolerability of rilvegostomig IV every three weeks versus placebo in combination with investigator's choice of chemotherapy (capecitabine, S-1 [tegafur/gimeracil/oteracil] or gemcitabine/cisplatin) as adjuvant treatment in patients with BTC after curative intent resection. This study will enroll approximately 750 adults with histologically confirmed adenocarcinoma of the biliary tract (intrahepatic or extrahepatic CCA or muscle-invasive GBC) after macroscopically complete resection (R0 or R1) and an ECOG PS of 0–1. Key exclusion criteria include locally advanced, unresectable, or metastatic disease at initial diagnosis and any anti-cancer therapy for BTC prior to surgery. The primary endpoint is recurrence-free survival, and the key secondary endpoint is overall survival. Additional endpoints include progression-free survival following recurrence, patient-reported tolerability, and safety. Enrollment has begun, and approximately 200 sites will be recruiting globally across Asia, Australia, Europe, North America, and South America. Clinical trial information: NCT06109779 .

Probing the Immunoreceptor Tyrosine-Based Inhibition Motif Interaction Protein Partners with Proteomics.

Phosphorylation of tyrosine is the basic mode of protein function and signal transduction in organisms. This process is regulated by protein tyrosine kinases (PTKs) and protein tyrosinases (PTPs). Immunoreceptor tyrosine-based inhibition motif (ITIM) has been considered as regulating the PTP activity through the interaction with the partner proteins in the cell signal pathway. The ITIM sequences need to be phosphorylated first to active the downstream signaling proteins. To explore potential regulatory mechanisms, the ITIM sequences of two transmembrane immunoglobulin proteins, myelin P0 protein-related protein (PZR) and programmed death 1 (PD-1), were analyzed to investigate their interaction with proteins involved in regulatory pathways. We discovered that phosphorylated ITIM sequences can selectively interact with the tyrosine phosphatase SHP2. Specifically, PZR-N-ITIM (pY) may be critical in the interaction between the ITIM and SH2 domains of SHP2, while PD1-C-ITSM (pY) may play a key role in the interaction between the ITIM and SH2 domains of SHP2. Quite a few proteins were identified containing the SH2 domain, exhibiting phosphorylation-mediated interaction with PZR-ITIM. In this study, 14 proteins with SH2 structural domains were identified by GO analysis on 339 proteins associated to the affinity pull-down of PZR-N-ITIM (pY). Through the SH2 domains, these proteins may interact with PZR-ITIM in a phosphorylation-dependent manner.

Abstract CT053: Exploration of potential biomarkers correlated with efficacy of ociperlimab (anti-TIGIT) plus tislelizumab (anti-PD-1) in 1L PD-L1+ non-small cell lung cancer (NSCLC)

Abstract Background: PD-L1 expression was associated with anti-immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) + anti-PD-(L)1 treatment, in which a high PD-L1 subgroup showed improved efficacy. We investigated if anti-TIGIT mechanism of action (MOA)-related markers were associated with the efficacy of ociperlimab + tislelizumab in Cohort 3 (1L PD-L1+ NSCLC) of the phase 1/1b AdvanTIG-105 trial (NCT04047862) and evaluated a potential patient-enrichment strategy based on tumor tissue gene expression profile (GEP). Methods: Tumor tissue GEP was tested using TruSeq RNA Access technology. Ventana SP263 PD-L1 immunohistochemistry (IHC) assay was used to evaluate PD-L1 expression. Median progression-free survival (mPFS) by investigator was calculated descriptively by Kaplan-Meier methodology. 95% confidence intervals for mPFS were generated using the Brookmeyer method. The primary inferential PFS comparison used unstratified log-rank test with 2-sided descriptive P-values. Results: At data cutoff (Feb 2, 2023), 24 of 45 patients had GEP results. Anti-TIGIT MOA-related genes and signatures correlated with ociperlimab + tislelizumab treatment response. Patients with high (H) vs low (L) expression of TIGIT, CD226, CCR8, or a tumor-associated macrophage (TAM) signature had significantly longer mPFS (Table). Dual biomarkers combining both anti-PD-L1 (PD-L1 IHC) and one of the anti-TIGIT MOA-related factors (TIGIT, CCR8, TAM signature GEP) identified subgroups of PD-L1 H + TIGIT MOA-related factor H patients with improved PFS vs other subgroups (Table). A highly overlapped PD-L1 H + TIGIT H + CCR8 H + TAM signature H patient population was observed in dual biomarker analyses. Conclusions: Anti-TIGIT MOA-related genes and signatures correlated with efficacy in ociperlimab + tislelizumab-treated 1L PD-L1+ NSCLC. Combining anti-TIGIT MOA-related factors with PD-L1 expression identified a subgroup of patients with improved efficacy. TABLE 1. NAND Table. Efficacy Analyses in Patient Subgroups TIGITa CD226b CCR8b TAMb Subgroup H L H L H L H L n 8 16 12 12 12 12 12 12 mPFS, months (95% CI) NR (2.6, NR) 5.26 (2.07, 11.86) NR (4.21, NR) 4.68 (1.41, 15.05) 15.21 (2.6, NR) 4.7 (1.71, 7.16) 15.21 (4.21, NR) 4.17 (1.71, 5.45) PFS, P-value 0.0326 0.0327 0.0131 0.0153 PD-L1c + TIGITb PD-L1c + CCR8b PD-L1c + TAMb Subgroup TIGITHPD-L1H TIGITHPD-L1L TIGITLPD-L1H TIGITL PD-L1L CCR8HPD-L1H CCR8HPD-L1L CCR8LPD-L1H CCR8L PD-L1L TAMHPD-L1H TAMHPD-L1L TAMLPD-L1H TAML PD-L1L n 8 4 8 4 11 1 5 7 9 3 7 5 mPFS, months (95% CI) NR (1.41,NR) 4.76 (2.6,NR) 8.62 (2.07,NR) 2.94 (1.25,NR) NR (1.41,NR) 2.6 (NR,NR) 5.19 (2.07,NR) 4.21 (1.25,7.16) 23.89 (1.41,NR) 5.32 (4.21,NR) 5.29 (2.07,NR) 2.6 (1.25,NR) Cutoff: aTop 1/3; bMedian; cTC≥25% Citation Format: Se Hyun Kim, Jiayuan Zhang, Wei Tan, Han Yan, Tian Tian, Hao Zheng, Ziqi Zhou, Ruihua Wang, Yun Zhang, Zhirong Shen, Hye Ryun Kim, Diansheng Zhong, Shun Lu. Exploration of potential biomarkers correlated with efficacy of ociperlimab (anti-TIGIT) plus tislelizumab (anti-PD-1) in 1L PD-L1+ non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT053.

Differential Immunoexpression of Inhibitory Immune Checkpoint Molecules and Clinicopathological Correlates in Keratoacanthoma, Primary Cutaneous Squamous Cell Carcinoma and Metastases.

Beyond established anti-programmed cell death protein 1/programmed cell death ligand 1 immunotherapy, T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) and its ligand CD155 are promising novel inhibitory immune checkpoint targets in human malignancies. Yet, in cutaneous squamous cell carcinoma, evidence on the collective expression patterns of these inhibitory immune checkpoints is scarce. Complete tumour sections of 36 cutaneous squamous cell carcinoma, 5 cutaneous metastases and 9 keratoacanthomas, a highly-differentiated, squamoproliferative tumour, with disparately benign biologic behaviour, were evaluated by immunohistochemistry for expression of programmed cell death ligand 1 (Tumor Proportion Score, Immune Cell Score), TIGIT, CD155 and CD8+ immune infiltrates. Unlike keratoacanthomas, cutaneous squamous cell carcinoma displayed a strong positive correlation of programmed cell death ligand 1 Tumor Proportion Score and CD115 expression (p < 0.001) with significantly higher programmed cell death ligand 1 Tumor Proportion Score (p < 0.001) and CD155 expression (p < 0.01) in poorly differentiated G3-cutaneous squamous cell carcinoma compared with keratoacanthomas. TIGIT+ infiltrates were significantly increased in programmed cell death ligand 1 Immune Cell Score positive primary tumours (p = 0.05). Yet, a strong positive correlation of TIGIT expression with CD8+ infiltrates was only detected in cutaneous squamous cell carcinoma (p < 0.01), but not keratoacanthomas. Providing a comprehensive overview on the collective landscape of inhibitory immune checkpoint expression, this study reveals associations of novel inhibitory immune checkpoint with CD8+ immune infiltrates and tumour differentiation and highlights the TIGIT/CD155 axis as a potential new target for cutaneous squamous cell carcinoma immunotherapy.

T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain as a promising immune checkpoint target for the treatment of SLE.

Immune checkpoints (ICs) play a pivotal role in orchestrating immune regulation, crucial for the maintenance of immune tolerance and prevention of autoimmune diseases. One noteworthy example among these immune regulators is T cell immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT). The TIGIT pathway's inhibition or the absence of TIGIT has been linked to the hyperactivation and excessive proliferation of T cells, rendering individuals more susceptible to autoimmune diseases and exacerbating inflammatory responses. Conversely, the activation of TIGIT has exhibited promising outcomes in ameliorating autoimmune disorders, as observed in murine models of systemic lupus erythematosus (SLE). Consequently, a judicious exploration of the co-inhibitory axis appears warranted for the effective management of pathogenic immune responses in SLE. In light of compelling evidence, this review undertakes a comprehensive examination of TIGIT's characteristics within the context of autoimmunity, offering insights into its potential as a therapeutic target for SLE.

Essential role of CD155 glycosylation in functional binding to DNAM-1 on natural killer cells.

The cluster of differentiation 155 (CD155) is highly expressed on tumor cells and augments or inhibits the cytotoxic activities of natural killer (NK) cells and T cells through its receptor ligands DNAX accessory molecule 1 (DNAM-1) and T-cell immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), respectively. Although CD155 is heavily glycosylated, the role of glycosylation of CD155 in the cytotoxic activity of effector lymphocytes remains unknown. Here, we show that the N-linked glycosylation at residue 105 (N105 glycosylation) in the first Ig-like domain of CD155 is involved in the binding of CD155 to both DNAM-1 and TIGIT. The N105 glycosylation also plays an essential role to induce signaling in both DNAM-1 and TIGIT reporter cells. Moreover, we show that the N105 glycosylation of CD155 contributes preferentially to the DNAM-1-mediated activating signal over the TIGIT-mediated inhibitory signal in NK cells. Our results demonstrated the important role of the N105 glycosylation of CD155 in DNAM-1 and TIGIT functions and shed new light on the understanding of tumor immune responses.

Combination of oligo-fractionated irradiation with nivolumab can induce immune modulation in gastric cancer

BackgroundTumor-associated antigen (TAA)-specific CD8(+) T cells are essential for nivolumab therapy, and irradiation has been reported to have the potential to generate and activate TAA-specific CD8(+) T cells. However, mechanistic...

Combining TIGIT blockade with IL-15 stimulation is a promising immunotherapy strategy for lung adenocarcinoma.

T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an immune checkpoint molecule that suppresses CD8+ T-cell function in cancer. However, the expression profile and functional significance of TIGIT in the immune microenvironment of lung adenocarcinoma (LUAD) remain elusive. Interleukin (IL)-15 has emerged as a promising candidate for enhancing CD8+ T-cell mediated tumour eradication. Exploring therapeutic strategies that combine IL-15 with TIGIT blockade in LUAD is warranted. We investigated the regulatory network involving coinhibitory TIGIT and CD96, as well as costimulatory CD226 in LUAD using clinical samples. The potential role of TIGIT in regulating the pathogenesis of LUAD was addressed through a murine model with transplanted tumours constructed in Tigit-/- mice. The therapeutic strategy that combines TIGIT blockade with IL-15 stimulation was verified using a transplanted tumour murine model and a patient-derived organoid (PDO) model. The frequency of TIGIT+ CD8+ T cells was significantly increased in LUAD. Increased TIGIT expression indicated poorer prognosis in LUAD patients. Furthermore, the effector function of TIGIT+ CD8+ tumour-infiltrating lymphocytes (TILs) was impaired in LUAD patients and TIGIT inhibited antitumour immune response of CD8+ TILs in tumour-bearing mice. Mechanistically, IL-15 enhanced the effector function of CD8+ TILs but stimulated the expression of TIGIT on CD8+ TILs concomitantly. The application of IL-15 combined with TIGIT blockade showed additive effects in enhancing the cytotoxicity of CD8+ TILs and thus further increased the antitumour immune response in LUAD. Our findings identified TIGIT as a promising therapeutic target for LUAD. LUAD could benefit more from the combined therapy of IL-15 stimulation and TIGIT blockade.

Synthetic studies on the extracellular domain of the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) using Trt-K10 solubilizing tags

The T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an inhibitory immunoreceptor expressed on lymphocytes that serves as a promising target for cancer immunotherapy. In this study, facile synthetic protocols to produce the extracellular domain of TIGIT were investigated for applications of TIGIT in mirror-image screening. During the synthesis via sequential native chemical ligations, we encountered problems with significantly poor solubility of the ligated products. Introducing trityl-type solubilizing auxiliaries, which also functioned as temporary protecting groups for cysteine residues, facilitated a flexible order of ligations and efficient purification protocols. After refolding under appropriate conditions, the synthetic TIGIT showed a sufficient affinity toward its target ligand CD155.

Immune checkpoint inhibitors as potential therapy for reverting T-cell exhaustion and reverting HIV latency in people living with HIV.

The immune system of people living with HIV (PLWH) is persistently exposed to antigens leading to systemic inflammation despite combination antiretroviral treatment (cART). This inflammatory milieu promotes T-cell activation and exhaustion. Furthermore, it produces diminished effector functions including loss of cytokine production, cytotoxicity, and proliferation, leading to disease progression. Exhausted T cells show overexpression of immune checkpoint molecules (ICs) on the cell surface, including programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), and lymphocyte activation gene-3 (LAG-3). The ICs also play a crucial role in T-cell exhaustion by reducing the immune response to cancer antigens. Immunotherapy based on immune checkpoint inhibitors (ICIs) has changed the management of a diversity of cancers. Additionally, the interest in exploring this approach in the setting of HIV infection has increased, including AIDS-defining cancers and non-AIDS-defining cancers in PLWH. To date, research on this topic suggests that ICI-based therapies in PLWH could be a safe and effective approach. In this review, we provide an overview of the current literature on the potential role of ICI-based immunotherapy not only in cancer remission in PLWH but also as a therapeutic intervention to restore immune response against HIV, revert HIV latency, and attain a functional cure for HIV infection.

The identification of a PTEN-associated gene signature for the prediction of prognosis and planning of therapeutic strategy in endometrial cancer.

Endometrial cancer (EC) is one of the most common malignancies among women. To improve the prognosis and treatment of EC, finding out a phosphatase and tensin homolog deleted on chromosome 10 (PTEN)-associated prognostic signature would be beneficial. EC clinical data, genetic mutation data, and transcriptome data were downloaded from The Cancer Genome Atlas (TCGA) database. To clarify the specific PTEN-associated signature, cox regression analyses were performed. The clinical value of the selected signature on the overall survival (OS) and the secretoglobin family 2A member 1 (SCGB2A1)-independent analysis, immune and functional analysis were investigated respectively. Five hundred and fourteen EC samples were screened and PTEN mutation occupied 57%. Enrichment analysis indicated that mutant-type PTEN was enriched for pathways related to the upregulated human T-cell leukemia virus-1 (HTLV-1) infection and estrogen signaling pathway. SCGB2A1 was identified by cox regression analysis. Immune analysis exhibited significant immune infiltration with higher expression of T cells, B cells, and macrophage groups. Immune-checkpoint transcripts CD274 molecule (CD274), and cytotoxic T-lymphocyte associated protein 4 (CTLA4), hepatitis A virus cellular receptor 2 (HAVCR2), lymphocyte activation gene 3 (LAG3), programmed cell death 1 (PDCD1), PDCD1 ligand 2 (PDCD1LG2), T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), and sialic acid binding immunoglobulin like lectin 15 (SIGLEC15) were discovered statistically different. In addition, the low-SCGB2A1 group had worse OS than the high-SCGB2A1 group. SCGB2A1 showed significant area under the curve (AUC) values in a time-dependent receiver operating characteristic (ROC) analysis. Prevalence of microsatellite instability (MSI) was detected and SCGB2A1 showed a negative correlation with EC. Immune checkpoint blockade (ICB) response indicated a worse immune response in the low-SCGB2A1 group. The distribution of one-class linear regression (OCLR) scores reflected the negative correlation between messenger RNA expression-based stemness index (mRNAsi) and prognostic gene expression. Furthermore, several SCGB2A1-related signaling pathways in EC were identified. SCGB2A1 is a prognostic immunometabolic signature for patients with EC, which may help improve the prognosis and therapeutic effect.

Weak SARS-CoV-2-specific responses of TIGIT-expressing CD8 + T cells in people living with HIV after a third dose of a SARS-CoV-2 inactivated vaccine.

T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), an inhibitory receptor expressed on T cells, plays a dysfunctional role in antiviral infection and antitumor activity. However, it is unknown whether TIGIT expression on T cells influences the immunological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccines. Forty-five people living with HIV (PLWH) on antiretroviral therapy (ART) for more than two years and 31 healthy controls (HCs), all received a third dose of a SARS-CoV-2 inactivated vaccine, were enrolled in this study. The amounts, activation, proportion of cell subsets, and magnitude of the SARS-CoV-2-specific immune response of TIGIT + CD4 + and TIGIT + CD8 + T cells were investigated before the third dose but 6 months after the second vaccine dose (0W), 4 weeks (4W) and 12 weeks (12W) after the third dose. Compared to that in HCs, the frequency of TIGIT + CD8 + T cells in the peripheral blood of PLWH increased at 12W after the third dose of the inactivated vaccine, and the immune activation of TIGIT + CD8 + T cells also increased. A decrease in the ratio of both T naïve (T N ) and central memory (T CM ) cells among TIGIT + CD8 + T cells and an increase in the ratio of the effector memory (T EM ) subpopulation were observed at 12W in PLWH. Interestingly, particularly at 12W, a higher proportion of TIGIT + CD8 + T cells expressing CD137 and CD69 simultaneously was observed in HCs than in PLWH based on the activation-induced marker assay. Compared with 0W, SARS-CoV-2-specific TIGIT + CD8 + T-cell responses in PLWH were not enhanced at 12W but were enhanced in HCs. Additionally, at all time points, the SARS-CoV-2-specific responses of TIGIT + CD8 + T cells in PLWH were significantly weaker than those of TIGIT - CD8 + T cells. However, in HCs, the difference in the SARS-CoV-2-specific responses induced between TIGIT + CD8 + T cells and TIGIT - CD8 + T cells was insignificant at 4W and 12W, except at 0W. TIGIT expression on CD8 + T cells may hinder the T-cell immune response to a booster dose of an inactivated SARS-CoV-2 vaccine, suggesting weakened resistance to SARS-CoV-2 infection, especially in PLWH. Furthermore, TIGIT may be used as a potential target to increase the production of SARS-CoV-2-specific CD8 + T cells, thereby enhancing the effectiveness of vaccination.

AdvanTIG-105: a phase I dose escalation study of the anti-TIGIT monoclonal antibody ociperlimab in combination with tislelizumab in patients with advanced solid tumors

BackgroundOciperlimab, a novel, humanized monoclonal antibody (mAb), binds to T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) with high affinity and specificity. Tislelizumab is an anti-programmed cell...

Clinical significance of the expression of FOXP3 and TIGIT in Merkel cell carcinoma

The pathogenesis of 80% of Merkel cell carcinoma (MCC) cases is associated with Merkel cell polyomavirus (MCPyV). Forkhead helix transcription factor P3 (FOXP3) and the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT)–CD155 pathway, which are targets for immunotherapy, were assessed as prognostic factors of MCC. We analyzed mRNA expression data of 111 patients with MCC and performed immunohistochemical analysis to detect the expression of programmed death ligand 1 (PD-L1), CD8, FOXP3, TIGIT, and CD155 in 65 cases of MCC. In CD8 and FOXP3 immunostaining, the number of expressing-infiltrating cells was determined by dividing the region into tumor center and invasive front areas. FOXP3 expression was evaluated separately in cells with high and low intensities. Aberrant TIGIT expression and weak CD155 staining were observed in MCC cells. CD8- and FOXP3-positive cell infiltrations were higher in the invasive front than in the tumor center. Multivariate Cox hazard analysis revealed that high infiltration of cells with low-intensity FOXP3 expression in the invasive front is a favorable prognostic factor (p = 0.025). Thus, targeting TIGIT–CD155 signaling and FOXP3 as well as PD-L1 may be a therapeutic strategy for MCC.

AdvanTIG-105: Phase 1b dose-expansion study of ociperlimab (OCI) + tislelizumab (TIS) with chemotherapy (chemo) in patients (pts) with stage IV gastric/gastroesophageal adenocarcinoma (GC/GEJC).

31 Background: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) inhibitor in combination with an anti-programmed cell death protein 1 (PD-1) antibody has shown antitumor activity in solid tumors. AdvanTIG-105 (NCT04047862) is a phase 1/1b open-label study designed to assess the safety and preliminary antitumor activity of OCI, an anti-TIGIT monoclonal antibody (mAb), + TIS, an anti-PD-1 mAb, in pts with unresectable, locally advanced or metastatic solid tumors. In the dose-escalation part, OCI + TIS was well tolerated with preliminary antitumor activity observed, and the recommended phase 2 dose (RP2D) of OCI 900 mg intravenously (IV) every three weeks (Q3W) + TIS 200 mg IV Q3W was established. We report results from the dose-expansion part (GC/GEJC Cohort 9) of the AdvanTIG-105 study. Methods: Eligible pts had histologically/cytologically confirmed stage IV GC/GEJC. Pts were excluded if they had squamous cell, undifferentiated or other histological types of GC, had GC/GEJC with positive HER2 expression, or if they had received any prior therapy for metastatic disease. Pts received either the RP2D of OCI + TIS with oxaliplatin + capecitabine Q3W for 6 cycles (C), followed by maintenance therapy with the RP2D of OCI + TIS, + capecitabine Q3W, or the RP2D of OCI + TIS with cisplatin + 5-fluorouracil Q3W for 6 C. Treatment continued until disease progression, intolerable toxicity, or withdrawal of consent. The primary endpoint was investigator-assessed overall response rate (ORR) per RECIST v1.1. Secondary endpoints included progression-free survival (PFS), duration of response (DoR), disease control rate (DCR) per RECIST v1.1, and safety. Results: As of September 29, 2022, 60 pts with a median age of 61.5 years (range 35-82) were enrolled; 59 were efficacy evaluable. Median study follow-up was 31.1 weeks (range 1.4-78.4). ORR was 50.8% (95% CI: 37.5, 64.1); DCR was 84.7% (95% CI: 73.0, 92.8) with a median DoR of 8.1 months (95% CI: 4.5, not evaluable [NE]). Median PFS was 8.2 months (95% CI: 5.8, NE). In a subgroup analysis, ORR in pts with PD-L1 tumor area positivity (TAP) score ≥5% (n=27) was 59.3% (95% CI: 38.8, 77.6), and 50.0% (95% CI: 30.7, 69.4) in pts with PD-L1 TAP &lt;5% (n=28). All 60 pts reported ≥1 treatment-emergent adverse event (TEAE), the most common being anemia (43.3%) and platelet count decreased (41.7%). In total, 43 pts (71.7%) had ≥grade 3 TEAEs and 28 (46.7%) had serious adverse events. TEAEs leading to discontinuation of TIS and OCI occurred in 5 (8.3%) pts. TEAEs led to death in 2 (3.3%) pts; one event (neutropenic sepsis) was related to chemo, while the other (pulmonary embolism) was not treatment related. Conclusions: OCI 900 mg + TIS 200 mg + chemo was generally well tolerated and showed encouraging antitumor activity in pts with stage IV GC/GEJC. Clinical trial information: NCT04047862 .

TIGIT immune checkpoint blockade enhances immunity of human peripheral blood NK cells against castration-resistant prostate cancer

Castration-resistant prostate cancer (CRPC) patients have a 14-month median survival, emphasizing the need for alternative treatments. Previously, we demonstrated that expanded high-dose natural killer (NK) cells derived from human peripheral blood exhibit therapeutic efficacy against CRPC. However, which immune checkpoint blockade promotes NK cell antitumor immunity against CRPC remains unknown. Here, we explored immune checkpoint molecule expression in NK and CRPC cells during their interactions, and identified that the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) monoclonal antibody (mAb), vibostolimab, significantly enhanced NK cell cytotoxicity against CRPC cells and cytokine production in vitro, demonstrated by upregulation of degranulation marker CD107a and Fas-ligand (Fas-L) and increased interferon-gamma (IFN-γ) and tumor necrosis factor-alpha secretion. TIGIT blockade increased Fas-L expression and IFN-γ production via the NF-κB signaling pathway and restored degranulation via the mitogen-activated protein kinase ERK (extracellular signal-regulated kinase) kinase/ERK pathway in activated NK cells. Vibostolimab significantly enhanced NK cell antitumor effects against CRPC in two xenograft mouse models. Vibostolimab also increased T cell chemotaxis induced by activated NK cells in vitro and in vivo. Overall, blocking TIGIT/CD155 signaling enhances the antitumor effect of expanded NK cells against CRPC; this finding supports the translational application of TIGIT mAb and NK cell combination strategies from bench to bedside for CRPC treatment.

TIGIT is a key inhibitory checkpoint receptor in lymphoma

BackgroundPD-1 checkpoint blockade therapy (CBT) has greatly benefited patients with select solid tumors and lymphomas but has limited efficacy against diffuse large B-cell lymphoma (DLBCL). Because numerous inhibitory checkpoint receptors...

AdvanTIG-105: A phase 1b dose-expansion study of ociperlimab (OCI) + tislelizumab (TIS) with chemotherapy (chemo) in patients (pts) with stage IV gastric/gastroesophageal adenocarcinoma (GC/GEJC).

4028 Background: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) inhibitor in combination with an anti-programmed cell death protein 1 (PD-1) antibody has shown antitumor activity in solid tumors. AdvanTIG-105 (NCT04047862) is a phase 1/1b open-label study designed to assess the safety and preliminary antitumor activity of OCI, an anti-TIGIT monoclonal antibody (mAb), + TIS, an anti-PD-1 mAb, in pts with unresectable, locally advanced or metastatic solid tumors. In the dose-escalation part, OCI + TIS was well tolerated with preliminary antitumor activity observed, and the recommended phase 2 dose (RP2D) of OCI 900 mg intravenously (IV) every three weeks (Q3W) + TIS 200 mg IV Q3W was established. We report results from the dose-expansion part (GC/GEJC Cohort 9) of the AdvanTIG-105 study. Methods: Eligible pts had histologically/cytologically confirmed stage IV GC/GEJC. Pts were excluded if they had squamous cell, undifferentiated or other histological types of GC, had GC/GEJC with positive HER2 expression, or if they had received any prior therapy for metastatic disease. Pts received either the RP2D of OCI + TIS with oxaliplatin + capecitabine Q3W for 6 cycles (C), followed by maintenance therapy with the RP2D of OCI + TIS, + capecitabine Q3W, or the RP2D of OCI + TIS with cisplatin + 5-fluorouracil Q3W for 6 C. Treatment continued until disease progression, intolerable toxicity, or withdrawal of consent. The primary endpoint was investigator-assessed overall response rate (ORR) per RECIST v1.1. Secondary endpoints included progression-free survival (PFS), duration of response (DoR), disease control rate (DCR) per RECIST v1.1, and safety. Results: As of September 29, 2022, 60 pts with a median age of 61.5 years (range 35-82) were enrolled; 59 were efficacy evaluable. Median study follow-up was 31.1 weeks (range 1.4-78.4). ORR was 50.8% (95% CI: 37.5, 64.1); DCR was 84.7% (95% CI: 73.0, 92.8) with a median DoR of 4.6 months (95% CI: 3.9, 7.1). Median PFS was 8.2 months (95% CI: 5.8, not evaluable). In a subgroup analysis, ORR in pts with PD-L1 tumor area positivity (TAP) score ≥5% (n = 27) was 59.3% (95% CI: 38.8, 77.6), and 50.0% (95% CI: 30.7, 69.4) in pts with PD-L1 TAP &lt; 5% (n = 28). All 60 pts reported ≥1 treatment-emergent adverse event (TEAE), the most common being anemia (43.3%) and platelet count decreased (41.7%). In total, 43 pts (71.7%) had ≥grade 3 TEAEs and 28 (46.7%) had serious adverse events. TEAEs leading to discontinuation of TIS and OCI occurred in 5 (8.3%) pts. TEAEs led to death in 2 (3.3%) pts; one event (neutropenic sepsis) was related to chemo, while the other (pulmonary embolism) was not treatment related. Conclusions: OCI 900 mg + TIS 200 mg + chemo was generally well tolerated and showed encouraging antitumor activity in pts with stage IV GC/GEJC. Clinical trial information: NCT04047862 .

Upregulation of LAG3 modulates the immune imbalance of CD4+ T-cell subsets and exacerbates disease progression in patients with alveolar echinococcosis and a mouse model.

Infection with the cestode Echinococcus multilocularis (E. multilocularis) causes alveolar echinococcosis (AE), a tumor-like disease predominantly affecting the liver but able to spread to any organ. T cells develop functional defects during chronic E. multilocularis infection, mostly due to upregulation of inhibitory receptors such as T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) and programmed death-1 (PD-1). However, the role of lymphocyte activation gene-3 (LAG3), an inhibitory receptor, in AE infection remains to be determined. Here, we discovered that high expression of LAG3 was mainly found in CD4+ T cells and induced regulatory T cells (iTregs) in close liver tissue (CLT) from AE patients. In a mouse model of E. multilocularis infection, LAG3 expression was predominantly found in T helper 2 (Th2) and Treg subsets, which secreted significantly more IL-4 and IL-10, resulting in host immune tolerance and disease progression at a late stage. Furthermore, LAG3 deficiency was found to drive the development of effector memory CD4+ T cells and enhance the type 1 CD4+ T-cell immune response, thus inhibiting metacestode growth in vivo. In addition, CD4+ T cells from LAG3-deficient mice produced more IFN-γ and less IL-4 when stimulated by E. multilocularis protoscoleces (EmP) antigen in vitro. Finally, adoptive transfer experiments showed that LAG3-knockout (KO) CD4+ T cells were more likely to develop into Th1 cells and less likely to develop into Tregs in recipient mice. Our work reveals that high expression of LAG3 accelerates AE disease progression by modulating the immune imbalance of CD4+ T-cell subsets. These findings may provide a novel immunotherapeutic strategy against E. multilocularis infection.

In Situ STING-Activating Nanovaccination with TIGIT Blockade for Enhanced Immunotherapy of Anti-PD-1-Resistant Tumors.

Immunotherapies comprising programmed cell death protein 1/PD ligand 1 (PD-1/PD-L1) immune checkpoint inhibitors are effective cancer treatments. However, the low response rate and immunoresistance resulting from alternative immune checkpoint upregulation and inefficient immune stimulation by T cells are problematic. The present report describes a biomimetic nanoplatform that simultaneously blocks the alternative T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) checkpoint and activates the stimulator of interferon genes (STING) signaling pathway in situ for enhanced antitumor immunity. The nanoplatform is engineered by fusing a red blood cell membrane with glutathione-responsive liposome-encapsulated cascade-activating chemoagents (β-lapachone and tirapazamine), and anchoring them with a detachable TIGIT block peptide (named as RTLT). In the tumor environment, the peptide is spatiotemporally released to reverse T-cell exhaustion and restore antitumor immunity. The cascade activation of chemotherapeutic agents causes DNA damage and inhibits the repair of double-stranded DNA, which induces robust in situ STING activation for an efficient immune response. The RTLT inhibits anti-PD-1-resistant tumor growth, and prevents tumor metastasis and recurrence in vivo by inducing antigen-specific immune memory. This biomimetic nanoplatform thus provides a promising strategy for in situ cancer vaccination.