anti-PD1 Antibody Research Articles

Prognostic and predictive factors in patients with metastatic gastric cancer treated with immune checkpoint inhibitors

Introduction. Microsatellite instability, PD-L1 CPS expression, high tumor mutational burden (TMB), and the presence of Epstein-Barr virus are the main tumor predictors of the response to immunotherapy in patients with metastatic gastric cancer (mGC). However, selecting patients for immunotherapy in mGC seems challenging due the lack of an optimal cut-off for PD-L1 CPS expression in microsatellite-stable gastric adenocarcinomas, significant benefit from anti-PD-L1 inhibitors in late-line treatment, and inaccessibility of Epstein-Barr virus and TMB determination in real clinical practice.Aim. The aim of our study is to determine prognostic and predictive biomarkers of patients, who received ICIs for mGC.Materials and methods. Our study included patients with mGC treated with anti-PD1 antibodies between 2018 and 2023 in five oncology centers in Moscow. Variables with p <0.05 obtained from a univariate analysis, were selected to perform multivariate analysis. According to the number of prognostic factors, patients were stratified into two groups with favorable and unfavorable prognosis. The optimal cut-off of the neutrophil-lymphocyte ratio (NLR) to predict of the efficacy of immunotherapy was determined using ROC analysis. The Kaplan–Meier method was performed to analyze survival curves of patients according to prognostic groups and NLR levels and the log-rank-test was used to compare the differences. Statistics was performed using the IBM SPSS v. 22 and PRISM 10.Results. Between January 1, 2018 and February 28, 2023, 122 patients with mGC who received ICIs were included. NLR was analyzed in 71 (58 %) patients out of 122. The median NLR was 2.36 (0.41–10.00). The cut-off of NLR for predicting mortality was 1.8 (AUC 0.81, p <0.001). The median of PFS and OS in patients with high NLR (NLR ≥1.8) were 2 and 4 months, respectively; mOS and mPFS in the low NLR group were not achieved (p <0.001). Eight factors were statistically significant in univariate analysis of patients with MSS: ECOG status (0–1 and 2–3), signet-ring cell histology, primary tumor, the number of organs with metastases (1–2 and 3 or more), ascites, pain, the line of immunotherapy (I–II and III–IV) and N LR level. Multivariate analyses revealed the presence of ascites (p = 0.001), immunotherapy administration in III– IV lines (p = 0.02), and NLR≥1.8 (p = 0.004) were independent prognostic factors for OS. Each factor was assigned with a score from 1 to 2, depending on its significance: presence of ascites – 2 points, high NLR – 2 points, III–IV line of immunotherapy – 1 point. Patients were stratified into two prognostic groups according to the number of prognostic factors – the group with favorable prognosis (0–2 points, n = 20) and unfavorable prognosis (3–5 points, n = 22). The mOS of patients with favorable and unfavorable prognosis was 6 months and 3 months, respectively (p = 0.048).Conclusion. Ascites, NLR level of ≥1.8 and administration of ICIs in late setting are associated with low efficacy of immunotherapy in patients with MSS mGC. Further research should be planned including more patients and those who did not receive ICIs to determine the prognostic significance of our model.

Convection-enhanced delivery of [177Lu]Lu-labeled gold nanoparticles combined with anti-PD1 checkpoint immunotherapy improves the survival of immunocompetent C57BL/6J mice with orthotopic GL261 murine glioma tumors

IntroductionOur objective was to study convection enhanced delivery (CED) of 177Lu-labeled metal chelating polymer (MCP) conjugated to gold nanoparticles ([177Lu]Lu-MCP-AuNP) alone or combined with anti-PD1 immune checkpoint inhibition (ICI) for improving the survival of immunocompetent C57BL/6J mice with orthotopic GL261 murine glioma tumors. MethodsC57BL/6J mice with GL261 tumors were treated with [177Lu]Lu-MCP-AuNP (0.8 or 2.7 MBq; 4 × 1011 AuNP) alone or combined with anti-PD1 antibodies (200 μg i.p. every 2 d × 3 doses). Control mice received normal saline, non-radioactive MCP-AuNP or anti-PD1 antibodies. Kaplan-Meier median survival was estimated. T-cell infiltration into the brain was probed by flow cytometry. Toxicity was assessed by monitoring body weight and cognitive function tests [Object Location Test (OLT) and Novel Object Recognition Test (NORT)] and T2-weighted MRI of the brain, overall health and ex vivo histopathological examination of the brain. ResultsTreatment with [177Lu]Lu-MCP-AuNP (0.8 MBq) significantly increased median survival compared to MCP-AuNP (29 vs. 25 d; P = 0.007) or normal saline-treated mice (24 d; P < 0.001). Combining [177Lu]Lu-MCP-AuNP (0.8 MBq) with anti-PD1 antibodies increased median survival to 32 d (P < 0.0001 vs. normal saline). Increasing the mean amount of [177Lu]Lu-MCP-AuNP to 2.7 MBq and combining with anti-PD1 antibodies extended survival to at least 218 d in 5/9 mice. Increased CD8+ cytotoxic T-cells and decreased CD4+ helper T-cells were found in the brain vs. normal saline-treated mice. No weight loss (>20 %) was observed for treated or control mice. There was no change in cognitive function in mice treated with [177Lu]Lu-MCP-AuNP (0.8 MBq) alone or combined with anti-PD1 antibodies assessed by the OLT or NORT. T2-weighted MRI in mice treated with 2.7 MBq [177Lu]Lu-MCP-AuNP combined with anti-PD1 antibodies revealed edema, gliosis and ex vacuo dilatation of the ventricle proximal to the site of infusion. Histopathological examination of the brain revealed dilatation of the ventricle and gliosis proximal to the site of infusion but no radiation necrosis. MRI and histological analysis did not reveal tumor in the brain of these mice. Mice treated with 2.7 MBq [177Lu]Lu-MCP-AuNP combined with anti-PD1 antibodies did not demonstrate overall deleterious health effects. ConclusionsWe conclude that CED of [177Lu]Lu-MCP-AuNP combined with anti-PD1 checkpoint immunotherapy improved the survival of immunocompetent C67BL/6J mice with GL261 glioma tumors in the brain. Higher administered amounts of [177Lu]Lu-MCP-AuNP (2.7 MBq vs. 0.8 MBq) were most effective and yielded long-term survival. Advances in knowledge and implications for patient careThis study demonstrates that combining a locally-infused radiation nanomedicine, [177Lu]Lu-MCP-AuNP and anti-PD1 checkpoint immunotherapy improved the survival of mice with glioma tumors in the brain. In the future, this treatment may be useful to treat residual tumor at the surgical margins in patients with GBM to prevent local recurrence and improve survival.

Persistence of activated anti-mesothelin hYP218 chimeric antigen receptor T cells in the tumour is associated with efficacy in gastric and colorectal carcinomas.

Patients with advanced gastric and colorectal cancers have limited treatment options. Since mesothelin is highly expressed in these tumour types, we evaluated the therapeutic benefits of anti-mesothelin hYP218 CAR T cells alone, and in combination with anti-PD1 antibody, pembrolizumab. GEPIA analysis was performed using human gastric (n=408) and colon cancer tumours (n=275) in TCGA database, to evaluate mRNA expression of mesothelin, compared to normal tissues. Mesothelin expression in gastric and colorectal cancer cell-lines (n=5) was analysed using flow cytometry. In vitro efficacy by hYP218 CAR T cells was tested by cytotoxicity and cytokine release assays. In vivo anti-tumour efficacy of hYP218 CAR T cells alone, and in combination with pembrolizumab, was evaluated in NSG mice bearing human gastric (HGC27) and colorectal (SW48) tumour xenografts. Additionally, hYP218 CAR-T cell persistence, activation and exhaustion marker-expression were studied. Mesothelin expression was significantly higher in gastric and colon cancer biopsies compared to normal tissues (p<.005). Mesothelin expression in gastric and colon cancer cell lines ranged from 10000 to 70000 molecules per cell. hYP218 CAR T cells demonstrated strong cytotoxic activity at low effector to target ratio, ranging from 0.24 to 1.0. In NSG mouse-models, hYP218 CAR T cells demonstrated anti-tumour efficacy and persisted in the tumour microenvironment in a functional state at day 40 posttreatment with expression of activation markers CD39 and CD69, increased production of IFN-γ and TNF-α and ability to kill tumour cells in vitro when isolated from tumours. There was increased PD1 expression. In combination with pembrolizumab, hYP218 CAR T cells led to slower tumour growth in NSG mice bearing large but not small HGC27 tumours. Anti-tumour efficacy of hYP218 CAR T cells is due to increased accumulation of activated CAR T cells in the tumour and combination with pembrolizumab resulted in improvement in anti-tumour activity of large established tumours. HIGHLIGHTS: Mesothelin expression is significantly higher in gastric and colorectal cancers than normal tissues. hYP218 CAR T cells demonstrate strong anti-tumour activity against mesothelin-positive gastric and colorectal carcinomas. Activated hYP218 CAR T cells persist in the tumour microenvironment and retain their cytotoxic activity. Addition of pembrolizumab in larger tumours enhance CAR T cell efficacy.

An Update on Access to Novel Treatment for Metastatic Melanoma in Europe — A 2024 Survey of the European Melanoma Registry and the European Association of Dermato-Oncology

Advances in cancer treatments have significantly improved their effectiveness, yet access to first-line therapies remains limited. A 2017 survey revealed that over 25% of metastatic melanoma patients in Europe lacked access to recommended therapies. To address this, the European Association of Dermato-Oncology and the European Melanoma Registry conducted a follow-up study on the registration and reimbursement of first-line treatments.A web-based survey using LimeSurvey was distributed to melanoma experts across 27 European countries from February to April 2022 and updated from February to April 2024. The questionnaire covered the percentage of patients receiving recommended treatments, as well as treatment authorization and reimbursement dates for systemic and adjuvant therapies.There has been significant improvement in the registration and reimbursement of BRAFi/MEKi, anti-PD1, and anti-PD1/anti-CTLA4 therapies, increasing from 48%, 63%, and 37% in 2017 to 96%, 96%, and 78% in 2024, respectively. Despite these gains, restrictions persist. Anti-PD1/anti-CTLA4 combination immunotherapy is still not available without restrictions in 48% of the surveyed countries. The nivolumab/relatlimab combination is licensed only for PDL-1-negative melanoma and reimbursed in seven countries of Europe. Tebentafusp is reimbursed in 12 countries and talimogene laherpervec in 6. In 2024, adjuvant treatments for stage III melanoma are reimbursed in 22 countries for dabrafenib/trametinib and 24 of 27 for anti-PD1 antibodies. Pembrolizumab and nivolumab are reimbursed in 16 and 8 countries, respectively, for stage IIB/IIC disease.While there have been improvements in the reimbursement of metastatic melanoma treatments in Europe, challenges and discrepancies remain. Further efforts at European and global levels are needed to harmonize and enhance access to cancer medicines.

Visualizing Immune Checkpoint Inhibitors Derived Inflammation in Atherosclerosis.

Immune checkpoint inhibitor (ICI) usage has resulted in immune-related adverse events in patients with cancer, such as accelerated atherosclerosis. Of immune cells involved in atherosclerosis, the role of CCR2+ (CC motif chemokine receptor 2-positive) proinflammatory macrophages is well documented. However, there is no noninvasive approach to determine the changes of these cells in vivo following ICI treatment and explore the underlying mechanisms of immune-related adverse events. Herein, we aim to use a CCR2 (CC motif chemokine receptor 2)-targeted radiotracer and positron emission tomography (PET) to assess the aggravated inflammatory response caused by ICI treatment in mouse atherosclerosis models and explore the mechanism of immune-related adverse events. Apoe-/- mice and Ldlr-/- mice were treated with an ICI, anti-PD1 (programmed cell death protein 1) antibody, and compared with those injected with either isotype control IgG or saline. The radiotracer 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-ECL1i (extracellular loop 1 inverso) was used for PET imaging of CCR2+ macrophages. Atherosclerotic arteries were collected for molecular characterization. CCR2 PET revealed significantly higher radiotracer uptake in both Apoe-/- and Ldlr-/- mice treated with anti-PD1 compared with the control groups. The increased expression of CCR2+ cells in Apoe-/- and Ldlr-/- mice was confirmed by immunostaining and flow cytometry. Single-cell RNA sequencing revealed elevated expression of CCR2 in myeloid cells. Mechanistically, IFNγ (interferon gamma) was essential for aggravated inflammation and atherosclerotic plaque progression following anti-PD1 treatment. Accelerated atherosclerotic plaque inflammation triggered by anti-PD1 treatment can be noninvasively detected by 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-ECL1i PET. Aggravated plaque inflammation is time- and dose-dependent and predominately mediated by IFNγ signaling. This study warrants further investigation of CCR2 PET as a noninvasive approach to visualize atherosclerotic plaque inflammation and explore the underlying mechanism following ICI treatment.

Monoclonal antibody targeting CEACAM1 enhanced the response to anti-PD1 immunotherapy in non-small cell lung cancer

Carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1), an extensively studied cell surface molecule, mainly expressed by certain epithelial, endothelial, lymphoid and myeloid cells, and is an attractive target for cancer immunotherapy. Here, to investigate the anti-tumor effects and mechanisms of CEACAM1 antibody, we prepared the antibody and explored its anti-tumor effects on Non-small Cell Lung Cancer (NSCLC) in vitro and in vivo. Firstly, antigen of human CEACAM1 recombinant protein was immunized on BALB/c mice and the high-affinity mouse anti-human monoclonal antibody 3C11 was selected by hybridoma technique. Next, ELISA was applied to detect the blocking effects of 3C11 on CEACAM1-CEACAM1 and CEACAM1-CEACAM5. Then, cell assays and ELISA were used to evaluate the role of 3C11 in blocking CEACAM1-CEACAM1 immunosuppressive signal transduction between dendritic cells (DCs) and T cells or natural killer cells (NK) and tumor cells. Finally, the synergistic anti-tumor effect of 3C11 combined with anti-PD-1 antibody was evaluated through cell stimulation assays and NCI-H358-induced tumor models in mice. The results showed the EC50 of 3C11 binding to NCI-H358 or exhausted T cells were 0.04971 μg/mL and 0.03475 μg/mL, respectively. 3C11 activated the exhausted T cells and enhanced the killing effect of NK by blocking CEACAM1-CEACAM1. In addition, the combination of 3C11 and anti-PD1 antibody produced synergistic anti-tumor effect on NSCLC. Its improved tumor growth inhibition value (TGI) of anti-PD-1 from 18 % to 85 % in vivo. These findings suggest that 3C11 can be considered an effective immunotherapy drug for NSCLC.

8439 Targeting Interferon Gamma-Mediated CXCL16-CXCR6 Chemokine-Receptor Interactions As A Strategy To Prevent Immune Checkpoint Inhibitor Autoimmune Diabetes

Abstract Disclosure: S. Wang: None. N. Huang: None. J.G. Ortega: None. J. Lee: None. K. Kimbrell: None. J. Nguyen: None. J. Olay: None. E. McCarthy: None. E. Peluso: None. H. Chen: None. M.G. Lechner: None. Autoimmune diabetes mellitus is a rare but life-threatening side effect of immune checkpoint inhibitor (ICI) cancer therapy. Checkpoint inhibitors increase immune activation by blocking regulatory molecules on T cells, including programmed death protein (PD1). As a result of this heightened immune activation, patients can develop autoimmunity in healthy tissues, known as immune related adverse events (IRAEs). ICI-associated diabetes mellitus (ICI-T1DM) is an IRAE that results in autoimmune destruction of insulin-producing pancreatic beta-cells. Patients with ICI-T1DM require life-long insulin therapy and more than half present initially with diabetic ketoacidosis. Unfortunately, the mechanism of this IRAE is not fully understood. Anti-PD1 antibody treatment (10mg/kg/dose, twice weekly, i.p.) of male and female non-obese diabetic (NOD) mice leads to autoimmune infiltrates in multiple tissues, including accelerated insulitis and DM. Single cell RNA sequencing of islet infiltrating immune cells from ICI-treated mice previously showed a role for CD8+ T cells and cytokine interferon gamma (IFNγ) in the development of ICI-T1DM. Using CellChat to perform receptor-ligand interaction analysis of these data, we identified both CD8+ and CD4+ T cells as the primary source of IFNγ in immune infiltrates and islet myeloid cells as the primary target. Furthermore, CellChat analysis showed increased receptor-ligand interactions between T cell receptor CXCR6 and its chemokine CXCL16, as well as CXCR3 and chemokines CXCL9 and CXCL10. In vitro IFNγ stimulation of myeloid cells induced strong expression of CXCL16, 9, and 10, suggesting a potential mechanism by which effector T cells are recruited to islets during ICI therapy. Immunophenotyping of islet-infiltrating immune cells indeed showed increased IFNγ+CXCR6+ effector CD8+ cells in anti-PD1 treated mice compared to isotype-treated controls. Moreover, these IFNγ+CXCR6+CD8+ T cells stained positively for the NRP-V7 mimotope tetramer, a known antigen for CD8+ T cells in spontaneous autoimmune diabetes in NOD mice, suggesting this as an antigen-specific population contributing to the immunopathogenesis of ICI-T1DM. Finally, genetic deletion of CXCR6 in NOD mice delayed the onset of autoimmune diabetes during anti-PD1 treatment in female (p=0.0162) but not male mice (p=0.3656). In summary, these data further elucidate the cellular mechanisms by which IFNγ and chemokine signaling pathways drive the development of ICI-T1DM and identify the CXCR6-CXCL16 axis as a potential therapeutic target to prevent this IRAE in checkpoint inhibitor-treated cancer patients. Presentation: 6/2/2024

Combining a WT1 Vaccine (Galinpepimut-S) With Checkpoint Inhibition (Nivolumab) in Patients With WT1–Expressing Diffuse Pleural Mesothelioma: A Phase 1 Study

IntroductionWT1 often presents on the surface of diffuse pleural mesotheliomas (DPMs) and is an ideal therapeutic target. Galinpepimut-S (GPS), a tetravalent, non–human leukocyte antigen–restricted, heteroclitic WT1–specific peptide vaccine was safe and effective in early phase clinical trials and upregulates T-cell suppressive programmed death-ligand 1 in the tumor microenvironment of other malignancies. A randomized phase 2 study of adjuvant GPS in patients with DPM trended toward improved median overall survival. MethodsTo further enhance immunogenicity, we combined GPS with nivolumab, an anti-PD1 monoclonal antibody, in an open-label, single-center phase 1 study, examining tolerability and immunogenicity in patients with previously treated DPM. We enrolled patients with progressive or recurrent DPM treated with at least one course of pemetrexed-based chemotherapy. Patients received two doses of GPS followed by six doses of GPS with intravenous nivolumab every 2 weeks, and up to six additional cycles until disease progression or unacceptable toxicity. ResultsTen patients were treated; 70% experienced mostly mild treatment-related adverse events; two experienced a grade 3 or higher adverse event. Three of the 10 patients (30%) reported vaccine-specific T-cell responses. There were no partial responses; three patients had prolonged stable disease with up to 17% decrease in tumor volume. Median progression-free survival was 3.9 months and the median overall survival was 7.4 months. ConclusionsCoadministration of GPS and nivolumab reported a tolerable toxicity profile and induced immune responses in a subset of patients, but initial response and survival benefit were limited possibly owing to the small sample size.

Self-Tumor Antigens in Solid Tumors Turned into Vaccines by α-gal Micelle Immunotherapy.

A major reason for the failure of the immune system to detect tumor antigens (TAs) is the insufficient uptake, processing, and presentation of TAs by antigen-presenting cells (APCs). The immunogenicity of TAs in the individual patient can be markedly increased by the in situ targeting of tumor cells for robust uptake by APCs, without the need to identify and characterize the TAs. This is feasible by the intra-tumoral injection of α-gal micelles comprised of glycolipids presenting the carbohydrate-antigen "α-gal epitope" (Galα1-3Galβ1-4GlcNAc-R). Humans produce a natural antibody called "anti-Gal" (constituting ~1% of immunoglobulins), which binds to α-gal epitopes. Tumor-injected α-gal micelles spontaneously insert into tumor cell membranes, so that multiple α-gal epitopes are presented on tumor cells. Anti-Gal binding to these epitopes activates the complement system, resulting in the killing of tumor cells, and the recruitment of multiple APCs (dendritic cells and macrophages) into treated tumors by the chemotactic complement cleavage peptides C5a and C3a. In this process of converting the treated tumor into a personalized TA vaccine, the recruited APC phagocytose anti-Gal opsonized tumor cells and cell membranes, process the internalized TAs and transport them to regional lymph-nodes. TA peptides presented on APCs activate TA-specific T cells to proliferate and destroy the metastatic tumor cells presenting the TAs. Studies in anti-Gal-producing mice demonstrated the induction of effective protection against distant metastases of the highly tumorigenic B16 melanoma following injection of natural and synthetic α-gal micelles into primary tumors. This treatment was further found to synergize with checkpoint inhibitor therapy by the anti-PD1 antibody. Phase-1 clinical trials indicated that α-gal micelle immunotherapy is safe and can induce the infiltration of CD4+ and CD8+ T cells into untreated distant metastases. It is suggested that, in addition to converting treated metastases into an autologous TA vaccine, this treatment should be considered as a neoadjuvant therapy, administering α-gal micelles into primary tumors immediately following their detection. Such an immunotherapy will convert tumors into a personalized anti-TA vaccine for the period prior to their resection.

Higher Nodal expression is often associated with poorer survival in patients diagnosed with melanoma and treated with anti-PD1 therapy.

Advanced melanoma is considered the most aggressive and deadly form of skin cancer whose incidence has been rising over the past three decades. In the absence of treatment, the median overall survival for advanced-stage metastatic disease is less than 6months. Although most melanomas detected at an early stage can be cured with surgery, a subset of these eventually metastasize. Therefore, a critical need exists to identify unique molecular features that would be predictive of long-term outcome and response to specific therapies. Recent promising therapeutic regimens have included the use of immune checkpoint inhibitors, such as anti-PD1 antibodies. However, the ability to identify responders and non-responders to this therapy remains elusive. To address this challenge at the molecular level, previously our laboratory identified the emergence of a stem cell phenotype associated with advanced melanoma and other aggressive forms of cancer. Underlying this phenotype is the aberrant re-expression of the embryonic morphogen "Nodal". Particularly noteworthy, we have observed Nodal to remain in advanced tumors of non-responders to standard-of-care therapies (i.e., BRAFi). This pilot study is the first proof-of-principle attempt to predict treatment response survival outcome in a small cohort of melanoma patients receiving anti-PD1 immune checkpoint inhibitor therapy - based on their Nodal expression profile. Using advanced multiplex immunohistochemistry-based digital pathology, the major finding of this preliminary study indicates that higher Nodal expression is often associated with poorer overall survival after anti-PD1 therapy, reaching nearly statistical relevance.

Directed protein engineering identifies a human TIM-4 blocking antibody that enhances anti-tumor response to checkpoint inhibition in murine colon carcinoma

Abstract Background T-cell immunoglobulin and mucin domain containing molecule-4 (TIM-4) is a scavenger receptor best known for its role in recognizing dying cells. TIM-4 orchestrates phagocytosis allowing for cellular clearance of apoptotic cells, termed efferocytosis. It was previously shown that TIM-4 directly interacts with AMPKα1, activating the autophagy pathway, leading to degradation of ingested tumors, and effectively reducing antigen presentation. Methods This study sought to identify a novel human TIM-4 antibody that can prevent phagocytosis of tumor cells thereby allowing for more antigen presentation resulting in anti-tumor immunological response. Using phage display panning directed against human TIM-4, we engineered a novel human TIM-4 antibody (SKWX301). Combination of in vitro phagocytosis assays and cell viability assays were used to test functionality of SKWX301. To examine the effect of SKWX301 in mouse models, we employed a syngeneic mouse model. CT26 cells were subcutaneously injected into BALB/c mice and tumor growth and mouse survival were analyzed. Results SKWX301can prevent human macrophage phagocytosis of cancer cells in vitro. Combination of low dose SKWX301 and anti-PD1 antibody significantly inhibited tumor growth and increased overall survival in mice. This demonstrates that SKWX301 is effective in both human in vitro models and mouse in vivo models. Conclusion Our study has demonstrated a rapid antibody discovery approach and identified a novel human TIM-4 antibody that can serve as a therapeutic for antitumor immunity to improve cancer therapy.

Efficacy of anti PD-1 therapy in children and adolescent melanoma patients (MELCAYA study)

BackgroundData on the efficacy and safety of anti PD-1 antibodies in children and adolescents (CA) with melanoma are lacking. The aim of this study was to determine outcomes of CA melanoma patients receiving anti PD-1 antibodies. MethodsMelanoma patients ≤18 years treated with anti PD-1 were retrospectively retrieved from 15 academic centers. Information on histopathological diagnosis, surgical treatment, systemic therapy, objective response rate (ORR), safety profile was collected. Progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier method. ResultsBetween April 2016 and March 2024, 99 patients treated with systemic therapy were retrieved, 81 treated with anti PD-1 therapy. Median age was 14 years (range 2–18 years), 37 pts were ≤12 yrs. Overall, 38 CA patients received anti PD-1 in adjuvant setting, and the 3-year PFS and OS were 70.6 % and 81.1 %, respectively. Two patients received anti-PD-1 based neoadjuvant treatment, both had a pathologic complete response and remain disease free. Fifty-six received a systemic therapy for advanced disease and among them, 43 received anti PD-1-based therapy for advanced disease in 1st line, while 12 and 5 pts received a 2nd and 3rd line, respectively. Among patients receiving a 1st line therapy with anti PD-1 monotherapy the ORR was 25 %, and the 3-year OS was 34 %. Toxicities were consistent with previous studies in adult melanoma patients. ConclusionsOur study provides the first evidence of efficacy of anti PD-1 in CA melanoma patients and supports the use of anti PD-1 therapy in pts ≤18 years, included those <12 years.

Sintilimab in combination with stereotactic body radiotherapy and granulocyte-macrophage colony-stimulating factor in metastatic non-small cell lung cancer: The multicenter SWORD phase 2 trial

This single-arm, multicenter, phase 2 trial (NCT04106180) investigated the triple combination of sintilimab (anti-PD1 antibody), stereotactic body radiotherapy (SBRT) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in metastatic non-small cell lung cancer (NSCLC). With a median follow-up of 32.1 months, 18 (36.7%, 90% CI 25.3%–49.5%) of the 49 evaluable patients had an objective response, meeting the primary endpoint. Secondary endpoints included out-of-field (abscopal) response rate (ASR), progression-free survival (PFS), overall survival (OS), and treatment-related adverse events (TRAEs). The ASR was 30.6% (95% CI 18.3%–45.4%). The median PFS and OS were 5.9 (95% CI 2.5–9.3) and 18.4 (95% CI 9.7–27.1) months, respectively. Any grade and grade 3 TRAEs occurred in 44 (86.3%) and 6 (11.8%) patients, without grade 4–5 TRAEs. Moreover, in pre-specified biomarker analyses, SBRT-induced increase of follicular helper T cells (Tfh) in unirradiated tumor lesions and patient’s blood, as well as of circulating IL-21 levels, was found associated with improved prognosis. Taken together, the triple combination therapy was well tolerated with promising efficacy and Tfh may play a critical role in SBRT-triggered anti-tumor immunity in metastatic NSCLC.

Assessment of baseline CCL19+ dendritic cell infiltration for predicting responses to immunotherapy in lung adenocarcinoma patients

To explore the correlation of baseline CCL19+ dendritic cell (CCL19+ DC) infiltration in lung adenocarcinoma microenvironment with immunotherapy efficacy and CD8+ T cell infiltration. We retrospectively analyzed the data of patients with lung adenocarcinoma hospitalized at First Affiliated Hospital of Henan University of Science and Technology from January, 2020 to December, 2023, and collected tissue samples from 96 patients undergoing immunotherapy for assessing CCL19+ DC and CD8+ T cell infiltration using immunofluorescence assay. We evaluated the predictive value of baseline CCL19+ DCs for patient responses to immunotherapy using receiver-operating characteristics (ROC) curves and analyzed the correlations of baseline CCL19+ DC expression with immunotherapy efficacy and CD8+ T cell and cytotoxic T lymphocyte (CTL) infiltrations. In co-culture systems of lung adenocarcinoma PC9 cells, CD8+ T cells and DCs (overexpressing CCL19 with or without anti PD-1 antibody treatment), the expressions of granzyme B, perforin, IFN-γ, and Ki-67 in T cells were analyzed using flow cytometry. The patients with partial or complete remission following immunotherapy had a significantly higher baseline CCL19+ DC infiltration level in lung adenocarcinoma tissues than those with poor responses. CCL19+ DC infiltration had an area under ROC curve of 0.785, a sensitivity of 75.6%, and a specificity of 62.8% for predicting immunotherapy efficacy. The expression of CD8+ T cell surface molecules Granzyme B (P<0.01), Perforin (P<0.01), IFN-γ (P<0.01) and Ki-67 (P<0.001) in patients with high expression of CCL19+ DC were higher than those in patients with low expression of CCL19+ DC. The baseline CCL19+ DC infiltration level was positively correlated with immunotherapy efficacy (P=0.003), CTL infiltration of (r=0.6657, P<0.001) and CD8+ T cell infiltration (P=0.007). In the co-cultured cells, CCL19 overexpression combined with anti-PD1 treatment of the DCs more strongly enhanced cytotoxicity and proliferation of CD8+ T lymphocytes than either of the single treatments (P<0.01 or 0.001). The baseline CCL19+ DC infiltration level in lung adenocarcinoma microenvironment is positively correlated with immunotherapy efficacy and CTL infiltration and can thus predict the response to immunotherapy.

A β-1,3/1,6-glucan enhances anti-tumor effects of PD1 antibody by reprogramming tumor microenvironment

Checkpoint blockades have emerged as a frontline approach in cancer management, designed to enhance the adaptive immune response against tumors. However, its clinical efficacy is limited to a narrow range of tumor types, which necessitates the exploration of novel strategies that target another main branch of the immune system. One such potential strategy is the therapeutic modulation of pattern recognition receptors (PRRs) pathways in innate immune cells, which have shown promise in tumor eradication. Previously, a β-1,3/1,6-glucan with high purity from Durvillaea antarctica (BG136) was reported by our group to exhibit pan-antitumor effects. In the current study, we systemically studied the antitumor activity of BG136 in combination with anti-PD1 antibody in MC38 syngeneic tumor model in vivo. Integrated transcriptomic and metabolomic analyses suggested that BG136 enhanced the antitumor immunity of anti-PD1 antibody by reprogramming the tumor microenvironment to become more proinflammatory. In addition, an increase in innate and adaptive immune cell infiltration and activation, enhanced lipid metabolism, and a decrease in ascorbate and aldarate metabolism were also found. These findings provide mechanistic insights that support the potent antitumor efficacy of BG136 when combined with immune checkpoint inhibitor antibodies.

Remodeling the hepatic immune microenvironment and demolishing T cell traps to enhance immunotherapy efficacy in liver metastasis

Immune checkpoint inhibitors (ICIs) exhibit compromised therapeutic efficacy in many patients with advanced cancers, particularly those with liver metastases. Much of this incapability can be ascribed as an irresponsiveness resulting from the “cold” hepatic tumor microenvironment that acts as T cell “traps” for which there currently lack countermeasures. We report a novel nanomedicine that converts the hepatic immune microenvironment to a “hot” phenotype by targeting hepatic macrophage-centric T cell elimination. Using the nanomedicine, composed of KIRA6 (an endothelium reticulum stress inhibitor), α-Tocopherol nanoemulsions, and anti-PD1 antibodies, we found its potency in murine models of orthotopic colorectal tumors and hepatic metastases, restoring immune responses and enhancing anti-tumor effects. A post-treatment scrutiny of the immune microenvironment landscape in the liver reveals repolarization of immunosuppressive hepatic macrophages, upregulation of Th1-like effector CD4+ T cells, and rejuvenation of dendritic cells along with CD8+ T cells. These findings suggest adaptations of liver-centric immune milieu modulation strategies to improve the efficacy of ICIs for a variety of “cold” tumors and their liver metastases.

Genome-wide CRISPR screening identifies tyrosylprotein sulfotransferase-2 as a target for augmenting anti-PD1 efficacy

BackgroundImmune checkpoint therapy (ICT) provides durable responses in select cancer patients, yet resistance remains a significant challenge, prompting the exploration of underlying molecular mechanisms. Tyrosylprotein sulfotransferase-2 (TPST2), known for its role in protein tyrosine O-sulfation, has been suggested to modulate the extracellular protein-protein interactions, but its specific role in cancer immunity remains largely unexplored.MethodsTo explore tumor cell-intrinsic factors influencing anti-PD1 responsiveness, we conducted a pooled loss-of-function genetic screen in humanized mice engrafted with human immune cells. The responsiveness of cancer cells to interferon-γ (IFNγ) was estimated by evaluating IFNγ-mediated induction of target genes, STAT1 phosphorylation, HLA expression, and cell growth suppression. The sulfotyrosine-modified target gene of TPST2 was identified by co-immunoprecipitation and mass spectrometry. The in vivo effects of TPST2 inhibition were evaluated using mouse syngeneic tumor models and corroborated by bulk and single-cell RNA sequencing analyses.ResultsThrough in vivo genome-wide CRISPR screening, TPST2 loss-of-function emerged as a potential enhancer of anti-PD1 treatment efficacy. TPST2 suppressed IFNγ signaling by sulfating IFNγ receptor 1 at Y397 residue, while its downregulation boosted IFNγ-mediated signaling and antigen presentation. Depletion of TPST2 in cancer cells augmented anti-PD1 antibody efficacy in syngeneic mouse tumor models by enhancing tumor-infiltrating lymphocytes. RNA sequencing data revealed TPST2’s inverse correlation with antigen presentation, and increased TPST2 expression is associated with poor prognosis and altered cancer immunity across cancer types.ConclusionsWe propose TPST2’s novel role as a suppressor of cancer immunity and advocate for its consideration as a therapeutic target in ICT-based treatments.

Relationship Between PD-L1, PD-1, CD8 and Clinicopathological Factors in Primary SCCs.

Squamous cell carcinoma of the skin (SCCs) is the second most common skin cancer, with continuously increasing incidence. Programmed cell death ligand 1 (PD-L1), programmed cell death 1 receptor (PD-1), and CD8 expression in primary SCCs have not been described in many studies. We investigated the association between PD-L1, PD-1, CD8, and clinicopathological prognostic factors for recurrence, metastasis, and mortality of SCCs. Immunohistochemically stained sections of 100 primary SCCs divided into two groups according to diameter of the tumors (<20 mm and >20 mm) were assessed. Recombinant rabbit anti-PD-L1 antibody [SP142] - C-terminal, rabbit monoclonal anti-PD1 antibody [NAT105], and FLEX Mono Mo A-Hu CD8, cl C8/144B, RTU were used. We did not establish statistically significant differences between PD-L1, PD-1, CD8 expression, and high-risk clinicopathological features - tumor size >20 mm, depth >6 mm, poor tumor cell differentiation, perineural/lymphovascular invasion, low/absent lymphocyte stromal reaction. In primary SCCs, the expression of PD-L1, PD-1, and CD8 are not associated with high-risk clinicopathological factors. We suggest that these immunohistochemical markers are more significant in advanced cases and metastatic tissues.

MS-20 enhances the gut microbiota-associated antitumor effects of anti-PD1 antibody

ABSTRACT Cancer immunotherapy has been regarded as a promising strategy for cancer therapy by blocking immune checkpoints and evoking immunity to fight cancer, but its efficacy seems to be heterogeneous among patients. Manipulating the gut microbiota is a potential strategy for enhancing the efficacy of immunotherapy. Here, we report that MS-20, also known as “Symbiota®”, a postbiotic that comprises abundant microbial metabolites generated from a soybean-based medium fermented with multiple strains of probiotics and yeast, inhibited colon and lung cancer growth in combination with an anti-programmed cell death 1 (PD1) antibody in xenograft mouse models. Mechanistically, MS-20 remodeled the immunological tumor microenvironment by increasing effector CD8+ T cells and downregulating PD1 expression, which were mediated by the gut microbiota. Fecal microbiota transplantation (FMT) from mice receiving MS-20 treatment to recipient mice increased CD8+ T-cell infiltration into the tumor microenvironment and significantly improved antitumor activity when combined with anti-PD1 therapy. Notably, the abundance of Ruminococcus bromii, which increased following MS-20 treatment, was positively associated with a reduced tumor burden and CD8+ T-cell infiltration in vivo. Furthermore, an ex vivo study revealed that MS-20 could alter the composition of the microbiota in cancer patients, resulting in distinct metabolic pathways associated with favorable responses to immunotherapy. Overall, MS-20 could act as a promising adjuvant agent for enhancing the efficacy of immune checkpoint-mediated antitumor therapy.

Immunotherapy for endometrial cancer.

Advanced recurrent endometrial cancer (EC) has a poor prognosis and new treatment options are needed. In 2013, EC was classified by genomic analysis into four groups: the POLE ultra-mutated group, the MSI-high hypermutated group (MSI-H), the copy number low group, and the copy number high group. The prognosis differs based on the classification, which should enable the individualization of treatment. The MSI-H and POLE types can induce PD-L1 expression in cancer cells. Among the gynecological cancers, EC exhibits the highest levels of PD-1 and PD-L1 expression and has the highest proportion of MSI-H. Thus, an immune checkpoint inhibitor (ICI) is expected to be effective. The first ICI to show efficacy in recurrent EC was the anti-PD1 antibody pembrolizumab, which exhibited efficacy in MSI-H EC. The combination of pembrolizumab and the multi-kinase inhibitor lenvatinib significantly prolongs OS/PFS compared with single-agent chemotherapy in previously treated recurrent EC, regardless of MSI status. ICIs are now moving from second-line and beyond to first-line treatment regimens. The efficacy of paclitaxel plus carboplatin (TC) and ICI combinations compared with TC have been demonstrated, including an ongoing Phase III trial comparing chemotherapy with the combination of pembrolizumab and lenvatinib. Although ICIs are becoming the mainstay of EC, they cause systemic inflammatory side effects known as irAEs. The incidence of irAEs is higher for combination therapy with CT or lenvatinib compared with ICI therapy alone. Even though they are rarely fatal, irAEs should be addressed promptly.