PD-L1 and VEGF dual blockade enhances anti-tumor effect on brain metastasis in hematogenous metastasis model.

Immunotherapy improves survival outcomes in cancer patients, but there is still an unmet clinical need in the treatment of brain metastases. Here, we used a mouse model to investigate the antitumor effect of programmed death-ligand 1 (PD-L1) and vascular endothelial growth factor (VEGF) dual blockade on metastatic brain tumors and evaluated immune responses during treatment. After establishing hematogenous brain metastasis by transplanting murine bladder carcinoma MBT2 cells stably expressing secNLuc reporter via the internal carotid artery of C3H/HeNCrl mice, we observed the formation of metastases not only in the brain parenchyma but also in the ventricles. The observed pathological areas showed that metastases in the ventricle were histologically larger than that in the brain parenchyma. Regarding the total tumor burden in the whole brain as revealed by Nluc activities, the combination of anti-PD-L1 antibody and anti-VEGF antibody showed a stronger anti-tumor effect than each single agent. Anti-PD-L1 antibody alone enhanced CD8+ T cell priming in regional lymph nodes, increased the proportion of activated CD8+ T cells in whole brain, and increased the density of CD8+ cells in the brain parenchyma. Furthermore, anti-VEGF antibody alone decreased microvessel density (MVD) in ventricular metastases, and the combination treatment increased intratumoral CD8+ cell density in the brain parenchyma and ventricular metastases. These results suggest that PD-L1 blockade enhanced cancer immunity not only in brain metastases lesions but also in the regional lymph nodes of the metastases, and that the addition of VEGF blockade increased the antitumor effect by increasing the infiltration of activated CD8+ T cell and decreasing MVD.

Prognostic Significance of Plasma Neutrophil Extracellular Trap Levels in Patients with Non-Small Cell Lung Cancer Treated with Immune Checkpoint Inhibitors.

Neutrophil extracellular traps (NETs) released from neutrophils are related to cancer progression. However, the relationship between the therapeutic effects of immune checkpoint inhibitors (ICIs) such as anti-PD-1 and anti-PD-L1 antibodies and plasma NET concentration in patients with non-small cell lung cancer (NSCLC) is poorly understood. In this study, concentrations of citrullinated histone H3 (CitH3), a surrogate marker of NETs, in plasma before/after treatment were examined in patients with advanced or recurrent NSCLC undergoing ICI treatment (n = 185). The clinical significances of NET levels before/after treatment and posttreatment changes were statistically evaluated. As a result, multivariate Cox analysis showed that high NET levels before treatment were statistically significant predictors of unfavorable overall survival (OS; p < 0.001, HR 1.702, 95% CI 1.356-2.137) and progression-free survival (PFS; p < 0.001, HR 1.566, 95% CI 1.323-1.855). The Kaplan-Meier curves showed significant separation between the high- and low-NET groups in OS (p = 0.002) and PFS (p < 0.001). Additionally, high NET levels after treatment were also significantly associated with worse OS (p < 0.001) and PFS (p < 0.001) by multivariate Cox analysis. Notably, the pretreatment NET levels were significantly correlated with the plasma levels of NET-related inflammatory cytokines, such as IL-6 and IL-8, and with NET-related gene expression and immune-suppressive profile in peripheral blood mononuclear cells. Our findings suggest that NETs released from activated neutrophils might reduce the clinical efficacy of ICIs in patients with NSCLC.

Model-informed drug development of envafolimab, a subcutaneously injectable PD-L1 antibody, in patients with advanced solid tumors.

BACKGROUND AND OBJECTIVES: Envafolimab is the first and only globally approved subcutaneously injectable PD-L1 antibody for the treatment of instability-high (MSI-H) or DNA mismatch repair deficient (dMMR) advanced solid tumors in adults, including those with advanced colorectal cancer that has progressed after treatment with a fluoropyrimidine, oxaliplatin, and irinotecan. The aim of this investigation was to examine the pharmacokinetic and exposure-response (E-R) profile of envafolimab in patients with solid tumors to support the approval of fixed and alternative dose regimens. METHODS: In this study, a population pharmacokinetic (PopPK) modeling approach will be employed to quantitatively evaluate intrinsic and extrinsic covariates. Additionally, PopPK-estimated exposure parameters were used to evaluate E-R relationship for safety and efficacy to provide a theoretical basis for recommending optimal treatment regimens. Simulations were performed on the dosing regimens of body weight-based regimen of 2.50 mg/kg QW, fixed dose 150 mg QW, and 300 mg Q2W for the selection of alternative dosing regimens. Data from 4 clinical studies (NCT02827968, NCT03101488, NCT03248843, and NCT03667170) were utilized. RESULTS: The PopPK dataset comprised 182 patients with 1810 evaluable envafolimab concentration records. Finally, a one-compartment model incorporating first-order absorption, first-order linear elimination, and time-dependent elimination according to an Emax function was found to accurately describe the concentration-time data of envafolimab in patients with advanced solid tumors. Creatinine clearance and country were identified as statistically significant factors affecting clearance, but had limited clinical significance. A relative flat exposure-response relationship was observed between early measures of safety and efficacy to verify that no dose adjustment is required. Simulation results indicated that 2.50 mg/kg QW, 150 mg QW, and 300 mg Q2W regimen yield similar steady-state exposure. CONCLUSIONS: No statistically significant difference was observed between weight-based and fixed dose regimens. Model-based simulation supports the adoption of a 150 mg weekly or 300 mg biweekly dosing regimen of envafolimab in the solid tumor population, as these schedules effectively balance survival benefits and safety risks.

Recombinant human adenovirus type 5 promotes anti-tumor immunity via inducing pyroptosis in tumor endothelial cells.

Recombinant human type 5 adenovirus (H101) is an oncolytic virus used to treat nasopharyngeal carcinoma. Owing to the deletion of the E1B-55kD and E3 regions, H101 is believed to selectively inhibit nasopharyngeal carcinoma. Whether H101 inhibits other type of tumors via different mechanisms remains unclear. In this study we investigated the effects of H101 on melanomas. We established B16F10 melanoma xenograft mouse model, and treated the mice with H101 (1 × 108 TCID50) via intratumoral injection for five consecutive days. We found that H101 treatment significantly inhibited B16F10 melanoma growth in the mice. H101 treatment significantly increased the infiltration of CD8+ T cells and reduced the proportion of M2-type macrophages. We demonstrated that H101 exhibited low cytotoxicity against B16F10 cells, but the endothelial cells were more sensitive to H101 treatment. H101 induced endothelial cell pyroptosis in a caspase-1/GSDMD-dependent manner. Furthermore, we showed that the combination of H101 with the immune checkpoint inhibitor PD-L1 antibody (10 mg/kg, i.p., every three days for three times) exerted synergic suppression on B16F10 tumor growth in the mice. This study demonstrates that, in addition to oncolysis, H101 inhibits melanoma growth by promoting anti-tumor immunity and inducing pyroptosis of vascular endothelial cells.

Combination therapy with probiotics and anti-PD-L1 antibody synergistically ameliorates sepsis in mouse model.

The study investigated the protective effects and mechanisms of probiotics in conjunction with an anti-PD-L1 antibody on the immune functions of septic mice. Sixty-four mice were assigned to sepsis groups receiving vehicle, probiotics, and anti-PD-L1 antibody individually or in combination, with healthy mice as controls. Sepsis was induced by cecal ligation and puncture (CLP), followed by intraperitoneal Lipopolysaccharide (LPS) injection. Blood and tissues were collected one day post-injection for detecting inflammation-related cytokines, Treg, PI3K/Akt pathway-related protein expression, and lung tissue pathology. The survival time of the remaining ten mice was recorded over seven days. Compared to healthy mice, septic mice given PBS exhibited significantly different serum levels of IL-6, IL-8, IL-17, IL-10, and IFN-γ (all p < 0.001). Treatment with anti-PD-L1 antibody combined with probiotics significantly increased the 7-day survival rate in septic mice, accompanied by decreased pro-inflammatory cytokines, increased anti-inflammatory cytokines, improved oxidative stress, reduced lung injury, and enhanced Th17/Treg balance. This combined therapy demonstrated superior efficacy compared to antibodies or probiotics alone. Additionally, it facilitated peripheral blood polymorphonuclear neutrophil apoptosis, enhancing protection by blocking PD-L1 function and inhibiting PI3K-dependent AKT phosphorylation. In conclusion, combining probiotics with an anti-PD-L1 antibody enhances protective effects in septic mice by reducing serum inflammatory factors, promoting neutrophil apoptosis, regulating Th17/Treg balance, and inhibiting the PI3K/Akt pathway.

Efficacy and Safety of Anti-Programmed Cell Death Protein 1/Programmed Death-Ligand 1 Antibodies Plus Chemotherapy as First-Line Treatment for NSCLC in the People's Republic of China: a Systematic Review and Meta-Analysis.

Introduction: The available approved anticancer drugs for Chinese patients are relatively limited because of China's low participation rate in international clinical trials. Therefore, a focus on approved anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) drugs in China is needed. This study aims to assess the heterogeneity of anti-PD-1/PD-L1 antibodies manufactured in China (domestic PD-1/PD-L1) and overseas (imported PD-1/PD-L1) when combined with chemotherapy as the first-line treatment of NSCLC. Methods: A systematic search was performed using PubMed, EMBASE, and Cochrane Library of publications up to July 13, 2023. Meta-analysis was applied to compare the efficacy and safety profile between anti-PD-1/PD-L1 antibodies plus chemotherapy (PD-1/PD-L1+Chemo) and chemotherapy alone using STATA software. Pooled hazard ratios for progression-free survival and overall survival, odds ratios for objective response rate, and incidence rate of grade greater than or equal to three treatment-related adverse events with 95% confidence intervals were calculated in the domestic group and imported group by a random-effects model, and the heterogeneity between the two estimates was assessed. Results: There were 14 eligible clinical studies with a total of 3951 patients involved in this analysis, including eight studies of domestic PD-1/PD-L1+Chemo and six studies of imported PD-1/PD-L1+Chemo. The study revealed that there was no significant difference between domestic and imported PD-1/PD-L1+Chemo in overall survival (p = 0.80), progression-free survival (p = 0.53), and incidence rate of grade greater than or equal to three treatment-related adverse events (p = 0.10). Nevertheless, the objective response rate of imported PD-1/PD-L1+Chemo was significantly higher than that of domestic PD-1/PD-L1+Chemo (p = 0.03). Conclusions: Domestic anti-PD-1/PD-L1 antibodies plus chemotherapy were found to have comparable efficacy and safety to those combined with imported anti-PD-1/PD-L1 antibodies based on current evidence.

Anti-PD-L1 antibody retains antitumour effects while mitigating immunotherapy-related colitis in bladder cancer-bearing mice after CT-mediated intratumoral delivery.

Drug local delivery system that directly supply anti-cancer drugs to the tumor microenvironment (TME) results in excellent tumor control and minimizes side effects associated with the anti-cancer drugs. Immune checkpoint inhibitors (ICIs) have been the mainstay of cancer immunotherapy. However, the systemic administration of ICIs is accompanied by considerable immunotherapy-related toxicity. To explore whether an anti-PD-L1 antibody administered locally via a sustained-release gel-forming carrier retains its effective anticancer function while causing fewer colitis-like side effects, CT, a previously reported depot system, was used to locally deliver an anti-PD-L1 antibody together with curcumin to the TME in bladder cancer-bearing ulcerative colitis model mice. We showed that CT-mediated intratumoral coinjection of an anti-PD-L1 antibody and curcumin enabled sustained release of both the loaded anti-PD-L1 antibody and curcumin, which contributed to substantial anticancer effects with negligible side effects on the colons of the UC model mice. However, although the anti-PD-L1 antibody administered systemically synergized with the CT-mediated intratumoral delivery of curcumin in inhibiting tumour growth, colitis was significantly worsened by intraperitoneal administration of anti-PD-L1 antibody. These findings suggested that CT is a promising agent for the local delivery of anticancer drugs, as it can allow effective anticancer functions to be retained while sharply reducing the adverse side effects associated with the systemic administration of these drugs.

Nanoparticles Encapsulated in Red Blood Cell Membranes for Near-Infrared Second Window Imaging-Guided Photothermal-Enhanced Immunotherapy on Tumors.

Photothermal therapy (PTT), which uses the high thermal conversion ability of photothermal agents to ablate tumor cells at high temperatures, has gained significant attention because it has the advantages of high selectivity and specificity, precise targeting of tumor sites, and low invasiveness and trauma. However, PTT guided by the NIR-I has limitations in tissue penetration depth, resulting in limited imaging monitoring and therapeutic effects on deep-seated tumor tissues. Moreover, nanoparticles are easily cleared by the immune system and difficult to passively target tumor sites during the process of treatment. To address these issues, we prepared nanoparticles using NIR-II dyes IR1048 and DSPE-PEG-OH and further encapsulated them in red blood cell membranes derived from mice. These biomimetic nanoparticles, called RDIR1048, showed reduced clearance by the immune system and had long circulation characteristics. They effectively accumulated at tumor sites, and strong fluorescence could still be observed at the tumor site 96 h after administration. Furthermore, through mouse thermal imaging experiments, we found that RDIR1048 exhibited good PTT ability. When used in combination with an immune checkpoint inhibitor, anti-PD-L1 antibodies, it enhanced the immunogenic cell death of tumor cells caused by PTT and improved the therapeutic effect of immunotherapy, which demonstrated good therapeutic efficacy in the treatment of tumor-bearing mice. This study provides a feasible basis for the future development of NIR-II nanoparticles with long circulation properties.

Clinical Efficacy of Programmed Cell Death Ligand 1 Antibody in Treatment of Extranodal Natural Killer/T-Cell Lymphoma With Hemophagocytic Lymphohistiocytosis.

Extranodal natural killer/T-cell lymphoma-associated hemophagocytic lymphohistiocytosis (ENKTCL-LAHS) is a rare disease with poor prognosis. Currently, there are no well-established treatments for LAHS. Almost 50% of patients experience relapsed or refractory disease to anti-hemophagocytic lymphohistiocytosis (HLH) treatment, and the regimen for salvage therapy is limited. We report a case of ENKTCL-LAHS that was successfully treated with a programmed cell death ligand 1 (PD-L1) antibody (sugemalimab) alone and provide a literature review on existing ENKTCL-LAHS treatment options. A 31-year-old man with relapsed ENKTCL complicated by HLH was admitted to our hospital. Following the administration of the PD-L1 antibody sugemalimab, fever was resolved, Epstein-Barr virus (EBV) DNA copy number was negative, and HLH-related blood biochemical markers were decreased in the patient. Consequently, the patient achieved complete remission with a progression-free time (PFS) of 44 months. The prognosis of ENKTCL-LAHS is extremely poor, and the clinical treatment of ENKTCL-HLH is challenging. No previous reports exist regarding the use of PD-L1 antibodies in ENKTCL-LAHS treatment. This study is the first to report a patient with ENKTCL-LAHS treated with the PD-L1 antibody alone, who achieved a long PFS of 44 months. Our results suggest the effectiveness and safety of sugemalimab in the treatment of ENKTCL-LAHS; however, more clinical cases are required for validation. The PD-L1 antibody presents a novel treatment option for patients with ENKTCL-LAHS and warrants further clinical promotion.

Dual immunotherapy in advanced or metastatic non-small cell lung cancer: A network meta-analysis.

Objectives: Recently, there has been extensive research on dual immunotherapy for advanced or metastatic non-small cell lung cancer (NSCLC), yet a comprehensive evaluation is lacking. This study aimed to rank the available treatment options and assess the efficacy and safety of dual immunotherapy regimens through the implementation of a Bayesian network meta-analysis (NMA). Materials and methods: A thorough search was conducted to recognize eligible randomized controlled trials (RCTs) on March 20, 2023. Overall survival (OS), progression-free survival (PFS), treatment-related adverse events (TRAEs) and grade ≥3 TRAEs were evaluated to identify the efficacy and safety of dual immunotherapy regimens. The surface under the cumulative ranking curve (SUCRA) and P score were employed to rank the treatments. Results: Eleven clinical trials involving six different regimens were included in this study. The combination of anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) antibodies with anti-T-cell immunoglobulin and ITIM domain (TIGIT) antibodies emerged as the most promising regimen for improving OS and PFS, followed by anti-PD-1/PD-L1 + anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) + chemotherapy treatment and anti-PD-1/PD-L1 + anti-CTLA-4 treatment. The forest plots demonstrated that these three regimens were all superior to chemotherapy. The above results were observed in both unselected treatment line and first-line settings. The least likely to be associated with TRAEs and grade ≥3 TRAEs were respectively anti-CTLA-4 treatment and anti-PD-1/PD-L1 + anti-TIGIT treatment, with anti-PD-1/PD-L1 + anti-CTLA-4 + chemotherapy treatment to be the worst. Conclusions: This NMA validated the promising efficacy and safety of dual immunotherapy in advanced or metastatic NSCLC. Among them, anti-PD-1/PD-L1 + anti-TIGIT regimen emerges as a highly potential therapeutic approach. Ongoing research efforts should focus on improving treatment regimens, identifying biomarkers, and managing TRAEs to optimize the patient benefits of dual immunotherapy.

Bio-responsive Au-miR-183 inhibitor enhances immunotherapy in hepatocellular carcinoma by inducing immunogenic cell death.

The treatment of advanced hepatocellular carcinoma (HCC) is limited, and immunotherapy is the current research focus of multi-disciplinary collaborative comprehensive treatment of HCC. Herein, we constructed a bio-responsive Au-miR-183 inhibitor (Au@miR-183i) delivery system targeting liver cancer stem cells (LCSCs), and adopted the strategy of combining αPD-L1 immunotherapy. The multifunctional Au@miR-183i nanocomplexes (NCs), which self-assemble based on the tumor microenvironment, consume NADPH and H2O2, leading to redox homeostasis disturbance, ROS accumulation, regulation of the LCSC niche, and induction of stemness regression. Moreover, self-assembled Au@miR-183i NCs specifically target the delivery of miR-183i to LCSCs, triggering the immunogenic cell death (ICD) effect, promoting the maturation of dendritic cells, inducing infiltration of CD8+ T cells, and facilitating the transformation of 'cold' tumors into 'hot' tumors. More importantly, consistent with the results in vitro, Au@miR-183i NCs demonstrated effective tumor targeting and strong ICD induction in vivo, assisted in enhancing αPD-L1 immunotherapy, and activated a robust systemic anti-tumor immune response in tumor-bearing mouse models. Overall, we provide a simple and universal therapeutic strategy by constructing a multifunctional bio-responsive Au@miR-183i NCs delivery system with LCSC targeting capability. Furthermore, nanocomplex-based ICD inducers have great promise in enhancing anti-tumor immunity and the PD-1/PD-L1 blocking efficacy in HCC, which provides a theoretical basis for effectively eliminating LCSCs and achieving a high-efficiency synergistic treatment strategy for HCC.

Imaging diagnosis and efficacy monitoring by [89Zr]Zr-DFO-KN035 immunoPET in patients with PD-L1-positive solid malignancies.

Rationale: Although programmed death-ligand 1 (PD-L1) inhibitors have achieved efficacy in cancer therapy, their response rate is low. Differences in the prognosis of patients with cancer under anti-PD-L1 treatment are related to the PD-L1 level in tumors. Accurate PD-L1 detection can optimize the accuracy of tumor immunotherapy and avoid ineffective clinical diagnosis and treatments. Methods: We investigated the imaging efficiency and therapy monitoring capacity of [89Zr]Zr-DFO-KN035 immunoPET for tumors. We labeled the monodomain anti-PD-L1 antibody KN035 with the radionuclide zirconium-89 and used this tracer for PET imaging. [89Zr]Zr-DFO-KN035 uptakes in patients with PD-L1-positive tumors, including primary and metastatic tumors, as well as in normal tissues, were comparatively assessed by using positron emission tomography/computed tomography imaging. Results: In PD-L1-positive patients, [89Zr]Zr-DFO-KN035 was sensitive in tumor-targeting imaging and could detect multiple metastatic foci, including multiple bone metastases (tumor-to-muscle ratios of 7.102 and 6.118 at 55 and 120 h, respectively) and lymph-node metastases (tumor-to-muscle ratios of 11.346 and 6.542 at 55 and 120 h, respectively). The needed radioactive dose of [89Zr]Zr-DFO-KN035 (55.5-92.5 MBq) used in this study was considerably lower than that of [18F]FDG (370-555 MBq). [89Zr]Zr-DFO-KN035 monitored and predicted the site of adverse reactions in antitumor immunotherapy. Moreover, after antitumor treatment, [89Zr]Zr-DFO-KN035 enabled observational imaging for therapeutic efficacy evaluation, which can help predict patient prognosis. Conclusion: [89Zr]Zr-DFO-KN035 can be used for the diagnosis and therapy monitoring of PD-L1-positive tumors and provide noninvasive and comprehensive observations for tumor diagnostic imaging, prognosis prediction, and efficacy evaluation.

PET Imaging of Peptide Probe Al[18F]F-NOTA-PCP1 for Monitoring the Engagement of PD-L1 Antibodies in Tumors.

Immune checkpoint inhibitors (ICIs) are a powerful treatment modality for various types of cancer. The effectiveness of ICIs is intimately connected to the binding status of antibodies to receptors. However, validated means to accurately evaluate target specificity and predict antibody efficacy in vivo are lacking. A novel peptide-based probe called Al[18F]F-NOTA-PCP1 was developed and validated for its specificity to PD-L1 in A549, U87MG, GL261, and GL261-iPDL1 cell lines, as well as in xenograft models. Then the probe was used in PET/CT scans to determine the binding status of PD-L1 antibodies (atezolizumab, avelumab, and durvalumab) in U87MG xenograft model mice. Moreover, Al[18F]F-NOTA-PCP1 was used to evaluate the impact of different treatment times and doses. Al[18F]F-NOTA-PCP1 PET/CT can be used to evaluate the interaction between PD-L1 and antibodies to determine the effectiveness of immunotherapy. By quantifying target engagement, the probe has the potential to predict the efficacy of immunotherapy and optimize the dose and treatment schedules for PD-L1 immunotherapy. This imaging agent could be a valuable tool in guiding personalized treatment strategies and improving cancer patient outcomes.

Using anti-PD-L1 antibody conjugated gold nanoshelled poly (Lactic-co-glycolic acid) nanocapsules loaded with doxorubicin: A theranostic agent for ultrasound imaging and photothermal/chemo combination therapy of triple negative breast cancer.

Triple negative breast cancer (TNBC) has the worst prognosis of all breast cancers, and it is difficult to progress through traditional chemotherapy. Therefore, the treatment of TNBC urgently requires agents with effective diagnostic and therapeutic capabilities. In this study, we obtained programmed death-ligand 1 (PD-L1) antibody conjugated gold nanoshelled poly(lactic-co-glycolic acid) (PLGA) nanocapsules (NCs) encapsulating doxorubicin (DOX) (DOX@PLGA@Au-PD-L1 NCs). PLGA NCs encapsulating DOX were prepared by a modified single-emulsion oil-in-water (O/W) solvent evaporation method, and gold nanoshells were formed on the surface by gold seed growth method, which were coupled with PD-L1 antibodies by carbodiimide method. The fabricated DOX@PLGA@Au-PD-L1 NCs exhibited promising contrast enhancement in vitro ultrasound imaging. Furthermore, DOX encapsulated in NCs displayed good pH-responsive and photo-triggered drug release properties. After irradiating 200 µg/mL NCs solution with a laser for 10 min, the solution temperature increased by nearly 23°C, indicating that the NCs had good photothermal conversion ability. The targeting experiments confirmed that the NCs had specific target binding ability to TNBC cells overexpressing PD-L1 molecules. Cell experiments exhibited that the agent significantly reduced the survival rate of TNBC cells through photochemotherapy combination therapy. As a multifunctional diagnostic agent, DOX@PLGA@Au-PD-L1 NCs could be used for ultrasound targeted contrast imaging and photochemotherapy combination therapy of TNBC cells, providing a promising idea for early diagnosis and treatment of TNBC.

Development and characterization of mouse anti-canine PD-L1 monoclonal antibodies and their expression in canine tumors by immunohistochemistry in vitro.

Immune escape is the hallmark of carcinogenesis. This widely known mechanism is the overexpression of immune checkpoint ligands, such as programmed cell death protein 1 and programmed death-ligand 1 (PD-1/PD-L1), leading to T cell anergy. Therefore, cancer immunotherapy with specific binding to these receptors has been developed to treat human cancers. Due to the lack of cross-reactivity of these antibodies in dogs, a specific canine PD-1/PD-L1 antibody is required. The aim of this study is to develop mouse anti-canine PD-L1 (cPD-L1) monoclonal antibodies and characterize their in vitro properties. Six mice were immunized with recombinant cPD-L1 with a fusion of human Fc tag. The hybridoma clones that successfully generated anti-cPD-L1 antibodies and had neutralizing activity were selected for monoclonal antibody production. Antibody properties were tested by immunosorbent assay, surface plasmon resonance, and immunohistochemistry. Four hybridomas were effectively bound and blocked to recombinant cPD-L1 and cPD-1-His-protein, respectively. Candidate mouse monoclonal antibodies worked efficiently on formalin-fixed paraffin-embedded tissues of canine cancers, including cutaneous T-cell lymphomas, mammary carcinomas, soft tissue sarcomas, squamous cell carcinomas, and malignant melanomas. However, functional assays of these anti-cPD-L1 antibodies need further investigation to prove their abilities as therapeutic drugs in dogs as well as their applications as prognostic markers.

A Phase Ib Study of Durvalumab (MEDI4736) in Combination with Carbon-Ion Radiotherapy and Weekly Cisplatin for Patients with Locally Advanced Cervical Cancer (DECISION Study): The Early Safety and Efficacy Results.

We conducted a phase Ib study to examine the safety of a combination of carbon-ion RT (CIRT) with durvalumab (MEDI4736; AstraZeneca) in patients with locally advanced cervical cancer. This was an open-label, single-arm study with a modified 3 + 3 design. Patients with newly diagnosed histologically proven locally advanced cervical cancer were enrolled. All patients received 74.4 Gy of CIRT in 20 fractions and concurrent weekly cisplatin (chemo-CIRT) at a dose of 40 mg/m2. Durvalumab was administered (1500 mg/body) at weeks two and six. The primary endpoint was the incidence of adverse events (AEs) and serious AEs (SAEs), including dose-limiting toxicity (DLT). All three enrolled patients completed the treatment without interruption. One patient developed hypothyroidism after treatment and was determined to be an SAE. No other SAEs were observed. The patient recovered after levothyroxine sodium hydrate treatment. None of the AEs, including hypothyroidism, were associated with DLT in the present study. All three patients achieved complete responses within the CIRT region concerning treatment efficacy. This phase 1b trial demonstrates the safety of combining chemo-CIRT and durvalumab for locally advanced cervical cancer in the early phase. Further research is required as only three patients were included in this study.

A PD-L1 Antibody-Conjugated PAMAM Dendrimer Nanosystem for Simultaneously Inhibiting Glycolysis and Promoting Immune Response in Fighting Breast Cancer.

Breast cancer is the most frequent malignancy affecting women, yet current therapeutic strategies remain ineffective for patients with late-stage or metastatic disease. Here an effective strategy is reported for treating metastatic breast cancer. Specifically, a self-assembling dendrimer nanosystem decorated with an antibody against programmed cell death ligand 1 (PD-L1) is established for delivering a small interfering RNA (siRNA) to target 3-phosphoinositide-dependent protein kinase-1 (PDK1), a kinase involved in cancer metabolism and metastasis. This nanosystem, named PPD, is designed to target PD-L1 for cancer-specific delivery of the siRNA to inhibit PDK1 and modulate cancer metabolism while promoting programmed cell death 1 (PD-1)/PD-L1 pathway-based immunotherapy. Indeed, PPD effectively generates simultaneous inhibition of PDK1-induced glycolysis and the PD-1/PD-L1 pathway-related immune response, leading to potent inhibition of tumor growth and metastasis without any notable toxicity in tumor-bearing mouse models. Collectively, these results highlight the potential use of PPD as an effective and safe tumor-targeting therapy for breast cancer. This study constitutes a successful proof of principle exploiting the intrinsic features of the tumor microenvironment and metabolism alongside a unique self-assembling dendrimer platform to achieve specific tumor targeting and siRNA-based gene silencing in combined and precision cancer therapy.

IL-36α inhibits melanoma by inducing pro-inflammatory polarization of macrophages.

Interleukin-36α (IL-36α) is essential for various inflammatory conditions, such as psoriasis and rheumatoid arthritis, whereas its role in tumor immunity is unclear. In this study, it was demonstrated that IL-36α could activate the NF-κB and MAPK signaling pathways in macrophages, leading to the expression of IL-1ß, IL-6, TNF-α, CXCL1, CXCL2, CXCL3, CXCL5 and iNOS. Importantly, IL-36α has significant antitumor effects, altering the tumor microenvironment and promoting the infiltration of MHC IIhigh macrophages and CD8+ T cells while decreasing the levels of monocyte myeloid-derived suppressor cells, CD4+ T cells and regulatory T cells. This ultimately results in the inhibition of tumor growth and migration. Furthermore, IL-36α synergized with the PD-L1 antibody increased the immune cells infiltration and enhanced the anti-tumor effect of the PD-L1 antibody on melanoma. Collectively, this study reveals a new role for IL-36α in promoting anti-tumor immune responses in macrophages and suggests its potential for cancer immunotherapy.

Enhanced Systemic Antitumour Immunity by Hypofractionated Radiotherapy and Anti-PD-L1 Therapy in Dogs with Pulmonary Metastatic Oral Malignant Melanoma.

Although immune checkpoint inhibitors (ICIs), such as the anti-programmed death-ligand 1 (PD-L1) antibody, have been developed for the treatment of canine malignant melanoma, desirable clinical efficacies have not been achieved. Recent studies in humans have suggested that radiation therapy (RT) combined with ICIs induces robust systemic antitumour immunity in patients with cancer. This study retrospectively examined the therapeutic efficacy of combination therapy (hypofractionated RT and anti-PD-L1 antibody [c4G12]) in dogs with pulmonary metastatic oral malignant melanoma. The intrathoracic clinical benefit rate (CBR)/median overall survival (OS) in the no RT (n = 20, free from the effect of RT), previous RT (n = 9, received RT ≤8 weeks prior to the first c4G12 dose), and concurrent RT (n = 10, c4G12 therapy within ±1 week of the first RT fraction) groups were 10%/185 days, 55.6%/283.5 days (p < 0.05 vs. no RT group), and 20%/129 days (p > 0.05 vs. no RT group), respectively. The adverse events were considered to be tolerable in the combination therapy. Thus, hypofractionated RT before the initiation of c4G12 therapy can be an effective approach for enhancing the therapeutic efficacy of immunotherapy, with acceptable safety profiles. Further prospective clinical studies are required to confirm the findings of this study.