anti-PD1 Antibody Research Articles

First-in-human phase 1 dose-escalation results with livmoniplimab, an antibody targeting the GARP:TGF-ß1 complex, as monotherapy and in combination with the anti–PD-1 antibody budigalimab in patients with advanced solid tumors

BackgroundTransforming growth factor (TGF)-ß1 is a pleiotropic cytokine that can promote tumor growth and suppress antitumor immune responses. Latent TGF-ß1 associates with glycoprotein-A repetition predominant (GARP) on the surface of regulatory T cells prior to its activation and release. Livmoniplimab is a monoclonal antibody (mAb) that binds the GARP:TGF-ß1 complex to inhibit activation and release of TGF-ß1. It is in clinical development in combination with budigalimab, an anti-programmed cell death protein 1 Fc-modified mAb. The first-in-human, phase 1, dose-escalation results are presented herein (ClinicalTrials.gov: NCT03821935).MethodsThe dose-escalation phase enrolled adult patients with advanced solid tumors. Patients received escalating doses of livmoniplimab ranging from 3mg to 1500mg, once every 2 weeks (Q2W), as monotherapy or in combination with a 500mg fixed dose of budigalimab Q4W. The primary objective of the dose escalation was to determine the recommended phase 2 dose. Secondary objectives were to assess safety and pharmacokinetics (PK), and exploratory objectives included evaluating preliminary efficacy.ResultsFifty-seven patients enrolled in the dose escalation: 23 in monotherapy cohorts and 34 in combination therapy cohorts. Dose-limiting toxicities were limited, no maximum tolerated dose was reached, and the maximum administered dose of 1500mg was selected for dose expansion. The most common adverse events reported in monotherapy-treated patients were fatigue, anemia, and nausea, and those in combination therapy-treated patients were pruritus, fatigue, nausea, and anemia. Livmoniplimab exhibited dose-proportional PK, and peripheral blood biomarker data demonstrated saturation of the GARP:TGF-ß1 complex on platelets at livmoniplimab doses within the linear PK range. No objective tumor responses were observed in the monotherapy dose escalation. However, the objective response rate was 15% in the combination dose escalation, with a median response duration of 8.4 months.ConclusionLivmoniplimab was well-tolerated as monotherapy and in combination with budigalimab in the dose-escalation phase. Encouraging preliminary efficacy was demonstrated in the combination dose escalation in heavily pretreated patients, supporting further development of this novel drug combination in patients with advanced solid tumors.

Combining a WT1 Vaccine (Galinpepimut-S) with Checkpoint Inhibition (Nivolumab) in Patients with WT1-Expressing Diffuse Pleural Mesothelioma (DPM): A Phase I Study

IntroductionWilms’ tumor suppressor protein (WT1) often presents on the surface of diffuse pleural mesotheliomas (DPMs) and is an ideal therapeutic target. Galinpepimut-S (GPS), a tetravalent, non-HLA restricted, heteroclitic WT1-specific peptide vaccine was safe and effective in early phase clinical trials and upregulates T cell suppressive programmed death-ligand 1 (PD-L1) in the tumor microenvironment of other malignancies. A randomized phase II 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 I 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 2 doses of GPS followed by 6 doses of GPS with intravenous nivolumab every 2 weeks, and up to 6 additional cycles until disease progression or unacceptable toxicity. ResultsTen patients were treated; 70% experienced mostly mild treatment-related adverse events; 2 experienced a grade ≥3 adverse event. Three (30%) of 10 patients demonstrated vaccine-specific T-cell responses. There were no partial responses; 3 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 demonstrated a tolerable toxicity profile and induced immune responses in a subset of patients, but initial response and survival benefit were limited possibly due to the small sample size.

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

Real-World efficiency of pembrolizumab in metastatic melanoma patients following adjuvant anti-PD1 treatment

BackgroundPostoperative treatment of patients with either BRAF/MEK inhibitors or anti-PD1 antibodies in the adjuvant setting results in improved recurrence free survival and has therefore become a standard of care for most patients with resected stage III melanoma. For patients who need systemic treatment after failure of adjuvant immune checkpoint inhibitors, there is insufficient evidence regarding efficacy of a retreatment with anti-PD1 antibodies. MethodsFrom the European Melanoma Treatment Registry (EUMelaReg) we have identified 74 patients and evaluated the clinical characteristics and outcome of anti-PD1 retreatment with pembrolizumab in these patients. The primary objectives were overall response rate and progression-free survival stratified by type of recurrence, i.e. whether recurrence occurred while on adjuvant anti-PD1, or later during follow up. In addition, the analysis was stratified for patients, who terminated adjuvant treatment early due to side effects. ResultsThe ORR of pembrolizumab retreatment in 1st line after recurrence (n=51) was 37.3%, which did not differ significantly between type of recurrence (40.9% in early vs. 34.5% in late recurrence). Patients who discontinued adjuvant anti-PD1 for toxicity had a higher ORR (52.9%) compared to patients who completed the treatment (37.5%) or discontinued due to disease progression (23.1%). PFS in 1st line retreatment was comparable between the groups with a median PFS (95% CI) of 7.4 (2.3-NR) months and 6.1 (3.4-13.1) months in early and late recurrence, respectively. ConclusionRetreatment with pembrolizumab may be a valuable treatment option after failure of adjuvant immunotherapy, in particular in patients who have stopped adjuvant treatment for side effects.

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.

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.

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.

Treatment approaches for older Hodgkin lymphoma patients.

Hodgkin lymphoma (HL) occurs at two age peaks around 25 and 60 years of age. Due to varying fitness and co-morbidities older patients are a heterogeneous group that has relatively poor treatment outcomes. The evolving therapeutic landscape for older HL is summarized herein. Due to lack of data from larger trials and approval of novel drugs, first-line treatment of limited-stage HL (i.e. early-stage favourable and unfavourable) remains largely A(B)VD and radiotherapy based. For patients with advanced-stage HL, the anti-CD30 antibody-drug conjugate brentuximab vedotin is approved in combination with AVD chemotherapy (BV-AVD). Due to toxicities such as febrile neutropenia or polyneuropathy and lack of improvement in progression-free and overall survival in the older subgroup, fully concomitant BV-AVD is however not used widely. More recently, promising early data was reported with the combination of nivolumab and AVD (N-AVD) in patients >60 years with advanced-stage HL. Second-line treatment depends on fitness and might include high-dose chemotherapy and autologous stem-cell transplantation for selected patients. For unfit or multiply relapsed patients, anti-PD1 antibodies are the preferred treatment option. The increasing number of older HL patients constitutes a therapeutic challenge despite recent advances and the increased usage of targeted agents.

A novel biomimetic nanoplasmonic sensor for rapid and accurate evaluation of checkpoint inhibitor immunotherapy.

Immune checkpoint inhibitors (ICIs) emerged as promising immunotherapies for cancer treatment, harnessing the patient's immune system to fight and eliminate tumor cells. However, despite their potential and proven efficacies, checkpoint inhibitors still face important challenges such as the tumor heterogeneity and resistance mechanisms, and the complex in vitro testing, which limits their widespread applicability and implementation to treat cancer. To address these challenges, we propose a novel analytical technique utilizing biomimetic label-free nanoplasmonic biosensors for rapid and reliable screening and evaluation of checkpoint inhibitors. We have designed and fabricated a low-density nanostructured plasmonic sensor based on gold nanodisks that enables the direct formation of a functional supported lipid bilayer, which acts as an artificial cell membrane for tumor ligand immobilization. With this biomimetic scaffold, our biosensing approach provides real-time, highly sensitive analysis of immune checkpoint pathways and direct assessment of the blocking effects of monoclonal antibodies in less than 20min/test. We demonstrate the accuracy of our biomimetic sensor for the study of the programmed cell death protein 1 (PD1) checkpoint pathway, achieving a limit of detection of 6.7ng/mL for direct PD1/PD-L1 interaction monitoring. Besides, we have performed dose-response inhibition curves for an anti-PD1 monoclonal antibody, obtaining a half maximal inhibitory concentration (IC50) of 0.43nM, within the same range than those obtained with conventional techniques. Our biomimetic sensor platform combines the potential of plasmonic technologies for rapid label-free analysis with the reliability of cell-based assay in terms of ligand mobility. The biosensor is integrated in a compact user-friendly device for the straightforward implementation in biomedical and pharmaceutical laboratories.