ALK5/VEGFR2 dual inhibitor TU2218 alone or in combination with immune checkpoint inhibitors enhances immune-mediated antitumor effects.

Transforming growth factor ß (TGFß) is present in blood of patients who do not respond to anti-programmed cell death (ligand) 1 [PD-(L)1] treatment, and through synergy with vascular endothelial growth factor (VEGF), it helps to create an environment that promotes tumor immune evasion and immune tolerance. Therefore, simultaneous inhibition of TGFß/VEGF is more effective than targeting TGFß alone. In this study, the dual inhibitory mechanism of TU2218 was identified through in vitro analysis mimicking the tumor microenvironment, and its antitumor effects were analyzed using mouse syngeneic tumor models. TU2218 directly restored the activity of damaged cytotoxic T lymphocytes (CTLs) and natural killer cells inhibited by TGFß and suppressed the activity and viability of regulatory T cells. The inactivation of endothelial cells induced by VEGF stimulation was completely ameliorated by TU2218, an effect not observed with vactosertib, which inhibits only TGFß signaling. The combination of TU2218 and anti-PD1 therapy had a significantly greater antitumor effect than either drug alone in the poorly immunogenic B16F10 syngeneic tumor model. The mechanism of tumor reduction was confirmed by flow cytometry, which showed upregulated VCAM-1 expression in vascular cells and increased influx of CD8 + CTLs into the tumor. As another strategy, combination of anti-CTLA4 therapy and TU2218 resulted in high complete regression (CR) rates in CT26 and WEHI-164 tumor models. In particular, immunological memory generated by the combination of anti-CTLA4 and TU2218 in the CT26 model prevented the development of tumors after additional tumor cell transplantation, suggesting that the TU2218-based combination has therapeutic potential in immunotherapy.

Therapeutic approaches and novel antifibrotic agents in renal fibrosis: A comprehensive review.

Renal fibrosis (RF) is one of the underlying pathological conditions leading to progressive loss of renal function and end-stage renal disease (ESRD). Over the years, various therapeutic approaches have been explored to combat RF and prevent ESRD. Despite significant advances in understanding the underlying molecular mechanism(s), effective therapeutic interventions for RF are limited. Current therapeutic strategies primarily target these underlying mechanisms to halt or reverse fibrotic progression. Inhibition of transforming growth factor-ß (TGF-ß) signaling, a pivotal mediator of RF has emerged as a central strategy to manage RF. Small molecules, peptides, and monoclonal antibodies that target TGF-ß receptors or downstream effectors have demonstrated potential in preclinical models. Modulating the renin-angiotensin system and targeting the endothelin system also provide established approaches for controlling fibrosis-related hemodynamic changes. Complementary to pharmacological strategies, lifestyle modifications, and dietary interventions contribute to holistic management. This comprehensive review aims to summarize the underlying mechanisms of RF and provide an overview of the therapeutic strategies and novel antifibrotic agents that hold promise in its treatment.

De novo Antineoplastic Drug Design to Suppress Head, Neck and Oral Cancer using Theoretical Organic and Biochemistry via Comprehensive Molecular Docking and Dynamics.

OBJECTIVE: A de novo antineoplastic drug was planned to suppress and modulate the Head, Neck, and Oral Cancer. METHODS: Using the computational software tools including molecular docking, molecular dynamics (MD), and post-molecular dynamics bond contact analyses, it has been shown that the new drug called ''Innovative Head, Neck, and Oral Cancer Suppressor'', or simply abbreviated as "IHNOCS" is very effective in terms of suppressing and co-modulating TGF-ß and KRTAP2-3 together. RESULT: The drug suppresses the KRTAP2-3 protein activity while also holding onto TGF-ß and modulating it to slow down and halt the metastasis. CONCLUSION: We have effectively created a novel medication using principles of theoretical chemistry, biochemistry, pharmaceutical chemistry and organic chemistry and organic chemistry to inhibit Head, Neck, and Oral Cancer. This medication should further undergo experimental testing in various stages, including in vitro, in vivo, and human clinical phases. It exhibits significant effectiveness in inhibiting the progression of cancer by simultaneously targeting TGF-ß and KRTAP2-3, thereby impeding metastasis and suppressing the disease.

Potential of αvß6 and αvß1 integrin inhibition for treatment of idiopathic pulmonary fibrosis.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease of unknown cause with a dismal prognosis. Nintedanib and Pirfenidone are approved worldwide for the treatment of IPF, but they only slow the rate of functional decline and disease progression. Therefore, there is an urgent need for more efficacious and better tolerated drugs. AREAS COVERED: αvß6 and αvß1 are two integrins overexpressed in fibrotic tissue, which play a critical role in the development of lung fibrosis. They act by converting transforming growth factor (TGF)-ß, one of the most important profibrotic cytokine, in its active form. Here, we summarize and critically discuss the potential of a dual αvß6/αvß1 integrin inhibitor for the treatment of IPF. EXPERT OPINION: Bexotegrast, a dual αvß6/αvß1 integrin inhibitor, has the potential to slow or even halt disease progression in IPF. Indeed, the strong pre-clinical rationale and promising early phase clinical trial data have raised expectations.

Structure, unique biological properties, and mechanisms of action of transforming growth factor ß.

Transforming growth factor ß (TGF-ß) is a ubiquitous molecule that is extremely conserved structurally and plays a systemic role in human organism. TGF-ß is a homodimeric molecule consisting of two subunits joined through a disulphide bond. In mammals, three genes code for TGF-ß1, TGF-ß2, and TGF-ß3 isoforms of this cytokine with a dominating expression of TGF-ß1. Virtually, all normal cells contain TGF-ß and its specific receptors. Considering the exceptional role of fine balance played by the TGF-ß in anumber of physiological and pathological processes in human body, this cytokine may be proposed for use in medicine as an immunosuppressant in transplantology, wound healing and bone repair. TGFb itself is an important target in oncology. Strategies for blocking members of TGF-ß signaling pathway as therapeutic targets have been considered. In this review, signalling mechanisms of TGF-ß1 action are addressed, and their role in physiology and pathology with main focus on carcinogenesis are described.

TGFß in Pancreas and Colorectal Cancer: Opportunities to Overcome Therapeutic Resistance.

TGFß is a pleiotropic signaling pathway that plays a pivotal role in regulating a multitude of cellular functions. TGFß has a dual role in cell regulation where it induces growth inhibition and cell death; however, it can switch to a growth-promoting state under cancerous conditions. TGFß is upregulated in colorectal cancer and pancreatic cancer, altering the tumor microenvironment and immune system and promoting a mesenchymal state. The upregulation of TGFß in certain cancers leads to resistance to immunotherapy, and attempts to inhibit TGFß expression have led to reduced therapeutic resistance when combined with chemotherapy and immunotherapy. Here, we review the current TGFß inhibitor drugs in clinical trials for pancreatic and colorectal cancer, with the goal of uncovering advances in improving clinical efficacy for TGFß combinational treatments in patients. Furthermore, we discuss the relevance of alterations in TGFß signaling and germline variants in the context of personalizing treatment for patients who show lack of response to current therapeutics.

Discovery of Sophoridine α-Aryl Propionamide Derivative ZM600 as a Novel Antihepatic Fibrosis Agent.

Hepatic stellate cells (HSCs) activation is a key event in the development of liver fibrosis, and blockage of the activation of HSCs has been shown to alleviate liver fibrosis. Sophoridine, a bioactive alkaloid found in many Chinese herbs, exhibits a broad spectrum of pharmacological effects, but its activities are not strong. In this study, a series of structurally modified derivatives of sophoridine were designed and synthesized. Among them, sophoridine α-aryl propionamide derivative ZM600 displayed a significant inhibitory effect on the activation of HSCs. The in vivo experiment demonstrated that ZM600 markedly ameliorated carbon tetrachloride (CCl4) and bile duct ligation (BDL)-induced liver fibrosis with a significant improvement of extracellular matrix deposition. Mechanism investigations revealed that ZM600 specifically inhibited the activation of NF-κB, PI-3K/AKT, and TGF-ß/Smads signaling pathways. These results suggest that ZM600 has a protective effect on liver fibrosis, which provides a new candidate for the treatment of liver fibrosis.

Novel quinazoline sulfonamide-based scaffolds modulate methicillin-resistant Staphylococcus aureus (MRSA) pneumonia in immunodeficient irradiated model: Regulatory role of TGF-ß.

A library of new quinazoline pharmacophores bearing benzenesulfonamide moiety was designed and synthesized. Compounds 3a-n were screened for their in vitro antimicrobial activity against eight multidrug-resistant clinical isolates. Compounds 3d and 3n exhibited prominent antibacterial activity, specifically against MRSA. After exhibiting relative in vitro and in vivo safety, compound 3n was selected to assess its anti-inflammatory activity displaying promising COX-2 inhibitory activity compared to Ibuprofen. In vivo experimental MRSA pneumonia model was conducted on immunodeficient (irradiated) mice to reveal the antimicrobial and anti-inflammatory responses of compound 3n compared to azithromycin (AZ). Treatment with compound 3n (10 and 20 mg/kg) as well as AZ resulted in a significant decrease in bacterial counts in lung tissues, suppression of serum C-reactive protein (CRP), lung interleukin-6 (IL-6), myeloperoxidase activity (MPO) and transforming growth factor-ß (TGF-ß). Compound 3n showed a non-significant deviation of lung TGF-ß1 from normal values which in turn controlled the lung inflammatory status and impacted the histopathological results. Molecular docking of 3n showed promising interactions inside the active sites of TGF-ß and COX-2. Our findings present a new dual-target quinazoline benzenesulfonamide derivative 3n, which possesses significant potential for treating MRSA-induced pneumonia in an immunocompromised state.

Safety, pharmacokinetics, pharmacodynamics, and antitumor activity of SAR439459, a TGFß inhibitor, as monotherapy and in combination with cemiplimab in patients with advanced solid tumors: Findings from a phase 1/1b study.

SAR439459 (SAR'459), a "second-generation" human anti-transforming growth factor beta (TGFß) monoclonal antibody, enhances the activity of immune checkpoint inhibitors. In this phase I/Ib study, we evaluated the safety, pharmacokinetics (PK), pharmacodynamics, and antitumor activity of SAR'459 ± cemiplimab (intravenous) in patients with advanced solid tumors. Increasing doses of SAR'459 were administered every 2 or 3 weeks (Q2W, Q3W) alone (Part 1A) or with 3 mg/kg cemiplimab Q2W or 350 mg Q3W (Part 1B). In Part 2A (dose expansion), melanoma patients were randomly (1:1) administered 22.5 or 7.5 mg/kg SAR'459. In Part 2B (dose expansion), 22.5 mg/kg SAR'459 and 350 mg cemiplimab Q3W were administered. The primary end points were maximum tolerated dose (MTD) or maximum administered dose (MAD; Part 1), preliminary antitumor activity (Part 2B), and optimal monotherapy dose (Part 2A). Twenty-eight and 24 patients were treated in Parts 1A and 1B, respectively; MTD was not reached, MAD was 15 (Q2W) and 22.5 mg/kg (Q3W) alone and in combination, respectively. Fourteen and 95 patients, including 14 hepatocellular carcinoma (HCC) patients, were treated in Parts 2A and 2B, respectively. The population PK model yielded satisfactory goodness-of-fit plots and adequately described the observed data by a two-compartment PK model with linear elimination. Objective responses were not observed in Parts 1 and 2A. In Part 2B, objective response rate was 8.4% and 7.1% across tumor types and the HCC cohort, respectively. The most frequent treatment-emergent adverse effects were hemorrhagic events (43.5%), keratoacanthoma (6.8%), and skin neoplasms (6.2%). Fatal bleeding occurred in 21.4% HCC patients despite the implementation of mitigation measures. SAR'459 monotherapy and combination with cemiplimab appeared relatively safe and tolerable in limited number of patients in dose escalation. However, the study was discontinued due to the unclear efficacy of SAR'459 and bleeding risk, particularly in HCC patients.

Moscatilin Reverses EMT Progression and its Resulting Enhanced Invasion and Migration by Affecting the TGF-ß Signaling Pathway in Bladder Cancer.

BACKGROUND: Bladder cancer metastasis is an essential process in the progression of muscle-invasive bladder cancer. EMT plays a crucial role in facilitating the spread of cancer cells. Identifying compounds that can inhibit these abilities of cancer cells is a significant international endeavor. OBJECTIVE: To explore the migration and invasion effect of Moscatilin on the bladder and clarify the mechanism of action Methods: The anti-bladder cancer effect of Moscatilin was observed by a cell proliferation experiment. The migration and invasion of bladder cancer cells inhibited by Moscatilin were detected by Transwell and Wound healing. The effects of Moscatilin on EMT-related proteins E-cadherin, N-cadherin, Snail1, Vimentin, and TGF-ß signaling pathways were detected by Western blot, and nucleic acid levels were verified by qPCR. RESULTS: Our study revealed that Moscatilin reduced the viability of bladder cancer cells in vitro and impeded their migration and invasion in experimental settings. Furthermore, we observed that Moscatilin decreased the activation levels of active proteins, specifically Smad3, Samd2, and MMP2. Additionally, we found that moscatilin significantly reduced the expression level of TGF-ß and was also capable of reversing the overexpression effect of TGF-ß. Treatment with Moscatilin also led to significant inhibition of interstitial cell markers Ncadherin and Snail1, which are associated with EMT. CONCLUSION: These findings indicate that Moscatilin impedes the migration and invasion of bladder cancer cells by influencing cell survival, modulating TGF-ß/Smad signaling, and inhibiting EMT.

Corneal fibrosis: From in vitro models to current and upcoming drug and gene medicines.

Fibrotic diseases are characterised by myofibroblast differentiation, uncontrolled pathological extracellular matrix accumulation, tissue contraction, scar formation and, ultimately tissue / organ dysfunction. The cornea, the transparent tissue located on the anterior chamber of the eye, is extremely susceptible to fibrotic diseases, which cause loss of corneal transparency and are often associated with blindness. Although topical corticosteroids and antimetabolites are extensively used in the management of corneal fibrosis, they are associated with glaucoma, cataract formation, corneoscleral melting and infection, imposing the need of far more effective therapies. Herein, we summarise and discuss shortfalls and recent advances in in vitro models (e.g. transforming growth factor-ß (TGF-ß) / ascorbic acid / interleukin (IL) induced) and drug (e.g. TGF-ß inhibitors, epigenetic modulators) and gene (e.g. gene editing, gene silencing) therapeutic strategies in the corneal fibrosis context. Emerging therapeutical agents (e.g. neutralising antibodies, ligand traps, receptor kinase inhibitors, antisense oligonucleotides) that have shown promise in clinical setting but have not yet assessed in corneal fibrosis context are also discussed.

Targeting the TGF-ß signaling pathway: an updated patent review (2021-present).

INTRODUCTION: The TGF-ß signaling pathway is a complex network that plays a crucial role in regulating essential biological functions and is implicated in the onset and progression of multiple diseases. This review highlights the recent advancements in developing inhibitors targeting the TGF-ß signaling pathway and their potential therapeutic applications in various diseases. AREA COVERED: The review discusses patents on active molecules related to the TGF-ß signaling pathway, focusing on three strategies: TGF-ß activity inhibition, blocking TGF-ß receptor binding, and disruption of the signaling pathway using small molecule inhibitors. Combination therapies and the development of fusion proteins targeting multiple pathways are also explored. The literature search was conducted using the Cortellis Drug Discovery Intelligence database, covering patents from 2021 onwards. EXPERT OPINION: The development of drugs targeting the TGF-ß signaling pathway has made significant progress in recent years. However, addressing challenges such as specificity, systemic toxicity, and patient selection is crucial for their successful clinical application. Targeting the TGF-ß signaling pathway holds promise as a promising approach for the treatment of various diseases.

Computational Exploration of Naturally Occurring Flavonoids as TGF-ß Inhibitors in Breast Cancer: Insights from Docking and Molecular Dynamics Simulations and In-vitro Cytotoxicity Study.

Breast cancer is a global health concern, demanding innovative treatments. Targeting the Transforming Growth Factor-beta (TGF-ß) signaling pathway, pivotal in breast cancer, is a promising approach. TGF-ß inhibits proliferation via G1 phase cell cycle arrest, acting as a suppressor initially, but in later stages, it promotes progression by enhancing motility, invasiveness, and metastasis formation. This study explores naturally occurring flavonoids' interactions with TGF-ß. Using molecular docking against the protein's crystal structure (PDB Id: 1PY5), Gossypin showed the highest docking score and underwent molecular dynamics simulation, revealing complex flexibility and explaining how flavonoids impede TGF-ß signaling in breast cancer. ADMET predictions adhered to Lipinski's rule of Five. Insights into flavonoid-TGF-ß binding offer a novel angle for breast cancer treatment. Flavonoids having a good docking score like gossypin, morin, luteolin and taxifolin shown potent cytotoxic effect on breast cancer cell line, MCF-7. Understanding these interactions could inspire flavonoid-based therapies targeting TGF-ß to halt breast cancer growth. These findings pave the way for personalized, targeted breast cancer therapies, offering hope against this formidable disease.

Single dual-specific anti-PD-L1/TGF-ß antibody synergizes with chemotherapy as neoadjuvant treatment for pancreatic ductal adenocarcinoma: a preclinical experimental study.

AIMS: Chemotherapy resistance is an important cause of neoadjuvant therapy failure in pancreatic ductal adenocarcinoma (PDAC). BiTP (anti-PD-L1/TGF-ß bispecific antibody) is a single antibody that can simultaneously and dually target transforming growth factor-beta (TGF-ß) and programmed cell death ligand 1 (PD-L1). We attempted in this study to investigate the efficacy of BiTP in combination with first-line chemotherapy in PDAC. METHODS: Preclinical assessments of BiTP plus gemcitabine and nab-paclitaxel were completed through a resectable KPC mouse model (C57BL/6J). Spectral flow cytometry, tissue section staining, enzyme-linked immunosorbent assays, Counting Kit-8, transwell, and Western blot assays were used to investigate the synergistic effects. RESULTS: BiTP combinatorial chemotherapy in neoadjuvant settings significantly downstaged PDAC tumors, enhanced survival, and had a higher resectability for mice with PDAC. BiTP was high affinity binding to targets and reverse chemotherapy resistance of PDAC cells. The combination overcame immune evasion through reprogramming tumor microenvironment via increasing penetration and function of T cells, natural killer cells, and dendritic cells and decreasing the function of immunosuppression-related cells as regulatory T cells, M2 macrophages, myeloid-derived suppressor cells, and cancer-associated fibroblasts. CONCLUSION: Our results suggest that the BiTP combinatorial chemotherapy is a promising neoadjuvant therapy for PDAC.

Biomarker and pharmacodynamic activity of the transforming growth factor-beta (TGFß) inhibitor SAR439459 as monotherapy and in combination with cemiplimab in a phase I clinical study in patients with advanced solid tumors.

SAR439459, a 'second-generation' human anti-transforming growth factor-beta (TGFß) monoclonal antibody, inhibits all TGFß isoforms and improves the antitumor activity of anti-programmed cell death protein-1 therapeutics. This study reports the pharmacodynamics (PD) and biomarker results from phase I/Ib first-in-human study of SAR439459 ± cemiplimab in patients with advanced solid tumors (NCT03192345). In dose-escalation phase (Part 1), SAR439459 was administered intravenously at increasing doses either every 2 weeks (Q2W) or every 3 weeks (Q3W) with cemiplimab IV at 3 mg/kg Q2W or 350 mg Q3W, respectively, in patients with advanced solid tumors. In dose-expansion phase (Part 2), patients with melanoma received SAR439459 IV Q3W at preliminary recommended phase II dose (pRP2D) of 22.5/7.5 mg/kg or at 22.5 mg/kg with cemiplimab 350 mg IV Q3W. Tumor biopsy and peripheral blood samples were collected for exploratory biomarker analyses to assess target engagement and PD, and results were correlated with patients' clinical parameters. SAR439459 ± cemiplimab showed decreased plasma and tissue TGFß, downregulation of TGFß-pathway activation signature, modulation of peripheral natural killer (NK) and T cell expansion, proliferation, and increased secretion of CXCL10. Conversion of tumor tissue samples from 'immune-excluded' to 'immune-infiltrated' phenotype in a representative patient with melanoma SAR439459 22.5 mg/kg with cemiplimab was observed. In paired tumor and plasma, active and total TGFß1 was more consistently elevated followed by TGFß2, whereas TGFß3 was only measurable (lower limit of quantitation ≥2.68 pg/mg) in tumors. SAR439459 ± cemiplimab showed expected peripheral PD effects and TGFß alteration. However, further studies are needed to identify biomarkers of response.

Oxadiazole Derivatives of Diclofenac as an Anti-proliferative Agent for B-cell Non-Hodgkin Lymphoma: An In vitro and In Silico Studies.

BACKGROUND: Non-Hodgkin lymphoma of B cell origin is the common type of lymphoma- related malignancy with poor response rate with conventional front-line therapies. AIM: The aim of the present study was to investigate the potential of new anti-inflammatory oxadiazole derivatives of Diclofenac as an anti-lymphoma agent through in vitro and in silico approaches. METHODS: Anti-lymphoma potential was evaluated by alamar blue technique. MTT assay employed for cytotoxicity. Gene and protein expression studies was performed by qRT-PCR and ELISA respectively. Docking studies was performed by using MOE program. RESULTS: Among five diclofenac derivatives, (II) showed promising anti-lymphoma effects, where it inhibited the expression of BCL-2, p-38 MAPK and TGF-ß in both follicular and Burkitt's lymphoma cells and was non-toxic against normal human fibroblast cells. The in silico studies against BCL-2 revealed that the unsubstituted Sulphur group in (II) is involved in the crucial interactions with the binding site residue. CONCLUSION: The compound (II) can be a potential therapeutic candidate for B-cell non-Hodgkin lymphoma and deserves further development as a novel anti-lymphoma agent.

TGF-ß inhibitor treatment of H2O2-induced cystitis models provides biochemical mechanism for elucidating interstitial cystitis/painful bladder syndrome patients.

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic disease for which no effective treatment is available. Transforming growth factor-ß (TGF-ß) is thought to be involved in the pathogenesis of IC/PBS, and previous studies have suggested that administrations of a TGF-ß inhibitor significantly ameliorated IC/PBS in a mouse model. However, the molecular mechanisms underlying the therapeutic effect of a TGF-b inhibitor on IC/PBS has not been comprehensively analyzed. TGF-ß has a variety of actions, such as regulation of immune cells and fibrosis. In our study, we induced IC/PBS-like disease in mice by an intravesical administration of hydrogen peroxide (H2O2) and examined the effects of three TGF-ß inhibitors, Repsox, SB431542, and SB505124, on the urinary functions as well as histological and gene expression profiles in the bladder. TGF-ß inhibitor treatment improved urinary function and histological changes in the IC/PBS mouse model, and SB431542 was most effective among the TGF-ß inhibitors. In our present study, TGF-ß inhibitor treatment improved abnormal enhancement of nociceptive mechanisms, immunity and inflammation, fibrosis, and dysfunction of bladder urothelium. These results show that multiple mechanisms are involved in the improvement of urinary function by TGF-ß inhibitor.

Microcystin-LR prenatal exposure drives preeclampsia-like changes in mice by inhibiting the expression of TGF-ß and VEGFA.

Microcystin-leucine-arginine (MC-LR) is widespread in the water and food, which has suspected to be associated with adverse pregnancy outcomes. In the present study, we aim to assess the interaction between MC-LR exposure and preeclampsia development and elucidate the molecular events involved. After exposure to MC-LR during pregnancy, the mice developed hypertension and proteinuria, the typical symptoms of preeclampsia. This was associated with decreased invasiveness of placental trophoblast and vascular dysplasia caused by MC-LR through down-regulating VEGFA and TGF-ß expression via AKT/m-TOR/HIF-1α pathway. In addition, this conclusion has been confirmed in a case-control study. Significantly, the addition of Deferoxamine (DFM), a phosphorylated serine-threonine protein kinases (p-AKT) specific agonist, can antagonize the inhibitory effect of MC-LR on the expression of related proteins, which further ameliorate the migration and invasion ability of HTR-8/Svneo cells. To sum up, our study revealed the pathologic mechanism by which MC-LR lead to preeclampsia and emphasized the importance of pregnancy management.

Exploratory study of an anti-PD-L1/TGF-ß antibody, TQB2858, in patients with refractory or recurrent osteosarcoma and alveolar soft part sarcoma: a report from Chinese sarcoma study group (TQB2858-Ib-02).

BACKGROUND: Novel and effective immunotherapies are required for refractory or recurrent sarcomas. Transforming growth factor-beta (TGF-ß) is a diverse regulatory and fibrogenic protein expressed in multiple sarcoma tumors that promotes epithelial-mesenchymal transition and excessive deposition of extracellular matrix. This study evaluated the efficacy and safety of the anti-PD-L1/TGF-ß antibody TQB2858 in patients with refractory osteosarcoma and alveolar soft part sarcoma (ASPS). METHODS: This single-arm phase 1b exploratory study included patients with refractory osteosarcoma or ASPS who had previously undergone at least two lines of systemic therapy. Patients were administered 1200 mg of TQB2858 once every 3 weeks. The primary endpoint was objective response rate (ORR), with null and alternative hypotheses of ORR ≤5% and ≥20%, respectively. Exploratory biomarker analyses using immunohistochemistry (IHC) staining (for PD-L1 and TGF-ß) were performed on pre-treatment tumor samples. RESULTS: Eleven eligible patients were included in this study. TQB2858 did not demonstrate evidence of efficacy as 0/5 osteosarcomas had any objective response, while 2/6 ASPS showed a partial response. The median progression-free survivals were 1.51 (1.38, Not Evaluable) and 2.86 (1.38, Not Evaluable) months for the osteosarcoma and ASPS groups, respectively. None of the administered cycles met the criteria for unacceptable toxicity. Other Grade 3 toxicities included abnormal liver function and elevation of γ-glutamyl transferase. IHC analysis revealed that functional enrichment in the TGF-ß pathway or PD-L1 was not associated with treatment outcomes. CONCLUSIONS: The combination of PD-L1 and TQB2858 did not significantly improve the ORR in patients with recurrent osteosarcoma. However, it improved immunogenic responses in ASPS, even after progression upon anti-PD-1/PD-L1 therapy, with an acceptable safety profile. IHC profiling with pathway enrichment analysis may not have any predictive value for survival outcomes. TRIAL REGISTRATION: Prospectively registered in the Ethical Review Committee of Peking University People's Hospital. The trial registration number is 2021PHA105-001 and 2021PHA140-001 and the registration date was March 2, 2022. CLINICALTRIALS: gov Identifier CTR20213001 and CTR20220390.

Combined PD-L1/TGFß blockade allows expansion and differentiation of stem cell-like CD8 T cells in immune excluded tumors.

TGFß signaling is associated with non-response to immune checkpoint blockade in patients with advanced cancers, particularly in the immune-excluded phenotype. While previous work demonstrates that converting tumors from excluded to inflamed phenotypes requires attenuation of PD-L1 and TGFß signaling, the underlying cellular mechanisms remain unclear. Here, we show that TGFß and PD-L1 restrain intratumoral stem cell-like CD8 T cell (TSCL) expansion and replacement of progenitor-exhausted and dysfunctional CD8 T cells with non-exhausted T effector cells in the EMT6 tumor model in female mice. Upon combined TGFß/PD-L1 blockade IFNγhi CD8 T effector cells show enhanced motility and accumulate in the tumor. Ensuing IFNγ signaling transforms myeloid, stromal, and tumor niches to yield an immune-supportive ecosystem. Blocking IFNγ abolishes the anti-PD-L1/anti-TGFß therapy efficacy. Our data suggest that TGFß works with PD-L1 to prevent TSCL expansion and replacement of exhausted CD8 T cells, thereby maintaining the T cell compartment in a dysfunctional state.