PD-L1 Monoclonal Antibodies Research Articles

Concordance between PD-L1 assays 28-8 and SP263 and their respective scoring algorithms in procured upper gastrointestinal adenocarcinoma samples.

479 Background: PD-L1 is being studied as a predictive immunohistochemical (IHC) biomarker for gastroesophageal junction (GEJ), gastric (GC), and esophageal (EAC) adenocarcinomas, and anti-PD-(L)1 therapies are used to treat them. Here, we compare the VENTANA PD-L1 (SP263) IHC assay and its tumor area positivity (TAP) algorithm with the clinically validated Agilent PD-L1 IHC 28-8 pharmDX combined positive score (CPS) algorithm in GEJ, GC, and EAC samples. The degree of concordance between SP263 TAP ≥ 5% and 28-8 CPS ≥ 5 is important for interpreting real-world settings and emerging clinical trial data. Methods: GEJ, GC, and EAC tumor samples procured from company-sponsored clinical trials (NCT02545504, NCT02862535, NCT02864381) and external vendors with informed consent were analyzed 4 ways: SP263 TAP, SP263 CPS, 28-8 TAP, and 28-8 CPS. Readouts were evaluated by a single pathologist and were analyzed with Pearson correlation coefficients. Results: 286 patient samples were analyzed (GEJ, n = 106; GC, n = 88; EAC, n = 92). The agreement among the SP263 TAP ≥ 5% and 28-8 CPS ≥ 5 prevalence is shown in the Table. The overall correlation coefficient between 28-8 CPS and SP263 TAP was high ( R = 0.95; P < 2.2 × 10 −16 ). In addition, when applying the same scoring algorithm to both assays (SP263 TAP vs 28-8 TAP or SP263 CPS vs 28-8 CPS), the correlation coefficients remained high ( R = 0.97; P < 2.2 × 10 −16 ). When both algorithms were applied to the same IHC assay (SP263 TAP vs SP263 CPS or 28-8 TAP vs 28-8 CPS), the correlation coefficients were also high ( R = 0.98; P < 2.2 × 10 −16 ). Conclusions: In this controlled experiment the PD-L1 assays 28-8 and SP263 concordance was high. The scoring algorithms for GEJ, GC, and EAC samples were observed as highly correlated; minor differences were likely driven by the distinct PD-L1 monoclonal antibody clones utilized in the IHC assays. These data suggest that the 2 assays are comparable for evaluating PD-L1 expression at the TAP ≥ 5% and CPS ≥ 5 cutoffs. Clinical trial information: NCT02545504 , NCT02862535 , NCT02864381 . Concordance of SP263 TAP ≥ 5% with 28-8 CPS ≥ 5. Positive percentage agreement: 0.96Negative percentage agreement: 0.95Overall percentage agreement: 0.95 28-8 CPS ≥ 5: Positive 28-8 CPS ≥ 5: Negative SP263 TAP ≥ 5%: Positive 116 9 SP263 TAP ≥ 5%: Negative 5 156

Multiplex immunohistochemistry to explore the tumor immune microenvironment in HCC patients with different GPC3 expression

ObjectivesGPC3 has been recognized as a promising target for immunotherapy in hepatocellular carcinoma (HCC). However, the GPC3-targeted immunotherapies have shown limited therapeutic efficacy. The use of anti-PD-1/PD-L1 monoclonal antibodies in HCC treatment is considerably constrained. Furthermore, there is still a notable lack of understanding concerning the immune landscape in HCC, especially regarding varied GPC3 expression levels. Therefore, thorough exploration of the intricate tumor immune microenvironment at different GPC3 expression levels is essential for guiding and improving HCC treatment strategies.MethodsSixty patients with HCC were enrolled in this study, receiving a first-line treatment that combined anti-angiogenesis targeted drugs and immunotherapy. Immunohistochemistry was used to assess the levels of GPC3 expression. Multiple immunohistochemical markers, such as CD8, PD-1, LAG3, TIGIT, TIM-3, CD103, Claudin18.2, PD-L1, CD4, Foxp3, CD68, CD163, GPC3, CD11C, CD14, CD66b, and HLA-DR, were used to characterize the immune microenvironment and spatial distribution of immune cells in HCC tumors with different levels of GPC3 expression. Cell expression levels and spatial distribution were determined by fluorescence staining and subsequent analysis of fluorescence intensity using the Panoramic Pathology Workstation (Pano ATLAS). This approach facilitated a detailed examination of cell characteristics and spatial information within the samples.ResultsBased on the result of GPC3 immunohistochemical analysis, patients with strong positive GPC3 expression were classified as high GPC3 expression, while the others were classified as low GPC3 expression. Patients in the low GPC3 expression group had longer overall survival (OS) than in the high group (P = 0.003, HR = 2.9240). Further exploration of the immune microenvironment based on different GPC3 expression levels revealed that in high GPC3 expression group, the proportions of CD8+ T cells(P = 0.0435), TIM-3+ T cells(P = 0.0447), CD103+CD8+ tissue-resident T cells(P = 0.0410), CD11C+CD14−DC cells(P = 0.0497), CD11C+HLA-DR−DC cells(P = 0.0309), CD11C+CD14−HLA-DR−DC cells(P = 0.0233), and CD11C+CD14−CD66b−DC cells(P = 0.0474) were all higher compared to low expression group. At spatial distances of 10 μm, 20 μm, and 30 μm, the levels of CD8+ T cells were higher in the high expression group compared to the low expression group (high vs. low: P = 0.0281, P = 0.0236, P = 0.0220).ConclusionsMultiple immunohistochemistry is a powerful technique for exploring the intricate immune microenvironment of hepatocellular carcinoma, enabling the precise identification of diverse cell subsets and their spatial distribution within the tumor microenvironment. This methodology provides valuable insights into the complex interactions and spatial organization of immune cells in the context of hepatocellular carcinoma progression. Low GPC3 expression in HCC patients indicates potential benefits from combined targeted and immunotherapy. Different levels of GPC3 expression levels can predict the effectiveness of targeted combination immunotherapy in HCC patients. Additionally, different GPC3 expression patterns in HCC patients correspond to unique tumor immune microenvironments, which have implications for guiding HCC treatment approaches.

PD-L1 monoclonal antibody alleviated MI injury of left ventricular function via modulating CD47/SHP2/SIRPα/SYK/FcγR signalings in tumor associated macrophages

To investigate how PD-L1 monoclonal antibodies (mAbs) affect the left ventricular function in mice with myocardial infarction (MI) and through what mechanisms they exert their effects. In vivo experiments were conducted using 27 female BALB/c mice, which were divided equally into 3 groups. Cardiac function was assessed by ultrasound. Heart tissue and breast cancer tumor samples were isolated, and the content of cGAMP was measured using LC-MS/MS. The extent of myocardial infarction was evaluated by Masson staining. In vitro experiments involved dividing macrophages, treated with different inducers, into 8 groups. Protein expression levels in each group were analyzed by Western blotting, and the macrophages were transplanted into experimental mice for observation. In the in vivo experiments, ultrasound examination showed that PD-L1 mAb improved cardiac function in mice with breast cancer and MI. Both cGAMP content measurement and Masson staining results indicated that PD-L1 mAb had a therapeutic effect on mice with breast cancer and MI, improving the infarct condition and slowing tumor progression. In vitro Western blotting analysis revealed that PD-L1 mAb can modulate the CD47/SHP2/SIRPα/SYK/FcγR signaling pathway, thereby affecting breast cancer. Treatment with a STING inhibitor significantly reduced the cGAMP effect, leading to improved left ventricular function in mice with MI. PD-L1 monoclonal antibodies improve left ventricular function in mice with myocardial infarction by modulating the CD47/SHP2/SIRPα/SYK/FcγR signaling pathway in tumor-associated macrophages and inhibiting the expression of cGAMP.

Discovery of an theranostic functional mAb for visualizing the sensitivity and effectiveness of PD-L1 checkpoint therapy

To address the challenges of inconsistent efficacy, low sensitivity, and subjective screening methods faced by PD-L1-targeted immune checkpoint therapies in the clinic. We propose to construct a therapeutic functional monoclonal antibody with tracking capability using tetrazolium-based bioorthogonal reaction turn-on fluorescence technology, focusing on the molecular biomarker PD-L1 for easy visualisation of therapeutic response. This therapeutic monoclonal antibody enables bioorthogonal reaction turn-on fluorescence to monitoring of tumors with varying degrees of PD-L1 expression, while preserving the activity of the PDL1 monoclonal antibody and improve the immune activation rate and achieve efficient anti-tumor effects. In conclusion, our proposed family of bio-orthogonal reaction-driven fluorescence turn-on methods can be used to identify therapeutic bifunctional monoclonal antibodies to PD-L1, which can be employed alongside the screening of PD-L1 antibodies for therapeutic effects.Abbreviations: CRT, Calreticulin; DCs, Dendritic cells; ELISA, Enzyme-linked immunosorbent assay; IFN-γ, Interferon-γ; IL-2, Interleukin-2; IHC, Immunohistochemistry; WB, Western blot.

Generation, Characterization, and Preclinical Studies of a Novel NKG2A-Targeted Antibody BRY805 for Cancer Immunotherapy.

Immuno-oncology has revolutionized cancer treatment, with NKG2A emerging as a novel target for immunotherapy. The blockade of NKG2A using the immune checkpoint inhibitor (ICI) monalizumab has been shown to enhance the responses of both NK cells and CD8+ T cells. However, monalizumab has demonstrated limited efficacy in in vitro cytotoxic assays and clinical trials. In our study, we discovered and characterized a novel anti-NKG2A antibody, BRY805, which exhibits high specificity for the human CD94/NKG2A heterodimer complex and does not bind to the activating NKG2C receptor. In vitro cytotoxicity assays demonstrated that BRY805 effectively activated NK92 cells and primary NK cells, thereby enhancing the cytotoxic activity of effector cells against cancer cells overexpressing HLA-E, with significantly greater efficacy compared to monalizumab. Furthermore, BRY805 exhibited synergistic antitumor activity when combined with PD-L1 monoclonal antibodies. In a mouse xenograft model, BRY805 showed superior tumor control relative to monalizumab and demonstrated a favorable safety profile in non-human primate studies.

Myeloid subsets impede the efficacy of anti-PD1 therapy in patients with advanced gastric cancer (WJOG10417GTR study).

Gastric cancer (GC) is one of the most common and deadly malignant diseases worldwide. Despite revolutionary advances, the therapeutic efficacy of anti-PD1/PDL1 monoclonal antibodies in advanced GC is still low due to the emergence of innate and acquired resistance to treatment. Myeloid cells represent the majority of human immune cells. Therefore, their increase, decrease, and abnormality could have a significant impact on the patient's immune system and the progression of cancer, and reprogramming, inhibiting, and eliminating the tumor-supportive types may improve the immunological situation and efficacy of immunotherapy. However, the significance of myeloid cells in anti-PD1/PDL1 therapy remains unclear in GC. In the WJOG10417GTR study on GC, we sought to identify myeloid determinants that could predict anti-PD1 therapeutic efficacy and also serve as potential therapeutic targets. We collected tumor tissues and peripheral blood from 96 patients with advanced GC before and 1 month after anti-PD1 nivolumab monotherapy, and the isolated whole leucocytes were analyzed by flow cytometry for various immune cell populations, including many myeloid subsets. Then, the relationship between the cellular levels and progression-free survival (PFS) or overall survival (OS) was statistically analyzed. We found that high levels of several myeloid subsets expressing molecules that have been targeted in drug discovery but not yet approved for clinical use were significantly associated with shorter PFS/OS as compared with low levels: PDL1+ and CTLA4+ myeloid subsets within tumors at baseline, PDL1+, B7H3+ and CD115+ myeloid subsets in peripheral blood at baseline, and LAG3+, CD155+ and CD115+ myeloid subsets in peripheral blood at post-treatment. This study revealed that these myeloid subsets are significant risk factors in nivolumab therapy for advanced GC. Targeting them may be useful as diagnostic biomarkers to predict potential anti-PD1 therapeutic efficacy, and also as therapeutic targets for accelerating the development of new drugs to improve clinical outcomes in immunotherapy for GC.

O-GlcNAcylation of enolase 1 serves as a dual regulator of aerobic glycolysis and immune evasion in colorectal cancer

Aerobic glycolysis and immune evasion are two key hallmarks of cancer. However, how these two features are mechanistically linked to promote tumor growth is not well understood. Here, we show that the glycolytic enzyme enolase-1 (ENO1) is dynamically modified with an O-linked β-N-acetylglucosamine (O-GlcNAcylation), and simultaneously regulates aerobic glycolysis and immune evasion via differential glycosylation. Glycosylation of threonine 19 (T19) on ENO1 promotes its glycolytic activity via the formation of active dimers. On the other hand, glycosylation of serine 249 (S249) on ENO1 inhibits its interaction with PD-L1, decreases association of PD-L1 with the E3 ligase STUB1, resulting in stabilization of PD-L1. Consequently, blockade of T19 glycosylation on ENO1 inhibits glycolysis, and decreases cell proliferation and tumor growth. Blockade of S249 glycosylation on ENO1 reduces PD-L1 expression and enhances T cell-mediated immunity against tumor cells. Notably, elimination of glycosylation at both sites synergizes with PD-L1 monoclonal antibody therapy to promote antitumor immune response. Clinically, ENO1 glycosylation levels are up-regulated and show a positive correlation with PD-L1 levels in human colorectal cancers. Thus, our findings provide a mechanistic understanding of how O-GlcNAcylation bridges aerobic glycolysis and immune evasion to promote tumor growth, suggesting effective therapeutic opportunities.

Perioperative immunotherapy for non-small cell lung cancer: consensus and controversy (2024 edition)

Lung cancer is the malignant tumour with the highest morbidity and mortality rate in China, among which non-small cell lung cancer (NSCLC) is the main pathological type of lung cancer, accounting for about 80% to 85%. Radial surgery is the standard treatment for early-stage NSCLC, but postoperative recurrence is an inevitable problem in clinical practice. Adding perioperative chemotherapy to surgery can only increase the 5-year overall survival rate by about 5%. There is an urgent need for better systemic treatments. In recent years, immunotherapeutic drugs, represented by PD-1/PD-L1 monoclonal antibodies, have brought breakthroughs from subsequent-line treatment to front-line treatment for NSCLC. Several Phase III studies on perioperative immunotherapy have shown that adding immunotherapy during the neoadjuvant and adjuvant treatment can significantly improve survival outcomes for patients, leading to the development of a new standard treatment for resectable NSCLC. In January 2024, the first PD-1 monoclonal antibodies (Toripalimab) were approved for perioperative treatment of NSCLC in China, starting a new era of perioperative immunotherapy. At present, there is still a lack of unified consensus on the application of perioperative immunotherapy at all levels of medical institutions. In order to privide diagnostic and treatment guidance for clinicians, promote the standardization of clinical practice for immunotherapy in resectable NSCLC, and clarify the controversial opinions regarding perioperative immunotherapy, Lung Cancer Expert Committee of the Chinese Anti-Cancer Association, Chinese Thoracic Oncology Group, Lung Cancer Expert Committee of the Chinese Medical Association Oncology Society jointly published this Consensus and Controversy to provide a guidance for the standardized management of perioperative immunotherapy for NSCLC.

A random forest model to predict the efficacy of anti-PD-1/PD-L1 monoclonal antibody in lung adenocarcinoma.

e20558 Background: Not all patients with lung adenocarcinoma (LUAD) could benefit from anti-PD-1/PD-L1 monoclonal antibody therapy, and existing biomarkers cannot explain all clinical benefits. Therefore, an effective model to predict the efficacy of anti-PD-1/PD-L1 monoclonal antibody is necessary. Methods: DNA methylation sequencing was used in LUAD patients’ FFPE samples, who received anti-PD-1/PD-L1 monoclonal antibody. The DNA methylation level of each gene was transformed into binary format according to its median value. The progression-free survival (PFS) was defined as the duration from the beginning of anti-PD-1/PD-L1 monoclonal antibody therapy to disease progression or death. Patients were randomly divided into training cohort (70%) and test cohort (30%). In the training cohort, uni-Cox regression was used to estimate the value in predicting PFS, and LASSO-Cox regression was performed to screened genes to build random forest model. The accuracy of this random forest model was validated in the test cohort. Finally, DNA methylation data were used to calculated the risk score of patients in the TCGA-LUAD cohort, and GSEA and GSVA were employed in RNA data to explore the mechanism and explain the efficacy of the prediction model. Results: In this study, 40 patients with LUAD were enrolled, and the median PFS of them was 7.57 months. A total of 29 genes with P < 0.05 and C-index > 0.7 were selected to perform LASSO-Cox regression, and 13 genes ( BTBD7, CAD, FBXL20, FKBP7, HBP1, IGFBP3, RAB5B, RASGRP1, RNF8, SOHLH1, TMEM223, UHRF1 and WWC2) were used to build prediction model. The C-index of risk score from this model was 0.96 and 0.93 in the training and test cohort, respectively. Patients were divided into the high and low risk groups according to the median risk score, and the median PFS of the high risk group was shorter than that of the low risk group (training cohort: 3.05 vs. 10.89 months, P < 0.01, HR = 2.51, 95% CI: 1.50-4.22; test cohort: 1.64 vs. 11.31 months, P = 0.03, HR = 1.80, 95% CI: 1.04-3.14). In the low and high risk group of the TCGA-LUAD cohort, there were 92.2% (388/421) and 0.5% (2/421) significant enriched ( P < 0.05 and FDR < 0.25) immunity-related pathways from results of GSEA, respectively, meanwhile 94.3% (397/421) and 1.9% (8/421) significant enriched immunity-related pathways from results of GSVA, respectively. Therefore, the lower risk score of this random forest model accompanied with the higher activation of immunity-related pathways which might help anti-PD-1/PD-L1 monoclonal antibody to express better efficacy. Conclusions: A random forest model based on DNA methylation data was constructed and showed a potential value in predicting the PFS of anti-PD-1/PD-L1 monoclonal antibody therapy in LUADs, and the risk score of this model is negatively correlated to the activation of immunity-related pathways, which could help to identify LUAD patients that would benefit from immunotherapy.

A single-arm, open-label phase II clinical trial of SHR-1210 (camrelizumab) in combination with nimotuzumab in the second-line treatment of advanced esophageal squamous cell carcinoma.

e16007 Background: The prognosis of advanced esophageal cancer is bleak, and the current first-line regimen based on paclitaxel, cisplatin and fluorouracil (TPF) with an effective rate is about 30%. The second-line treatment regimen based on anti-PD-1/PD-L1 monoclonal antibodies obtained median overall survival (mOS) 10.8 months in phase I-II clinical trials, but a large proportion of patients (pts) still do not respond to this therapy. Additionally, nimotuzumab in the previous Cuba phase 2 study had a good disease control rate (DCR) combined with PF regimen. So, we conducted the study to evaluate the new combination modality efficacy and treatment-related adverse events (safety). The primary endpoints was ORR, and the secondary endpoints included overall survival (OS), DCR, progression-free survival (PFS), duration of response (DoR), time to response (TTR), 9-month and 12-month survival rate, as well as safety. Methods: According to the relevant literature, the second-line treatment for ORR is about 15%, and the efficacy of camrelizumab combined with nimotuzumab is expected to be 35%, alpha=0.05. A total of 38 cases were enrolled in the two-stage Simon method, with a bilateral α value of 5% and a test efficiency of 90%. In the first phase, 23 pts were enrolled 15 pts in the second stage. If 9 or more pts reached CR/PR. The trial is considered successful. The dropout rate of 10% was calculated, and a total of 42 pts were enrolled. Results: In this phase 2 study, a total of 41 pts were administered. One case was lost to follow-up. The mean age was 45 years (range, 42-77). The results of the intention-to-treat analysis showed that the ORR was 36% (15/42). The mOS was 12.62 months with median follow-up 8.28 months. The 9-month and 12-month survival rates were 84% and 51%, respectively. The DCR was 81% (34/42). Median PFS was 9.89 months with median follow-up 9.17 months. In terms of safety, the incidence of TEAEs was 60% (25/42), of which 71% (30/42) had adverse events below grade 3 and 26% (11/42) had adverse events above grade 3 including 0 case related to nimotuzumab and 4 cases related to camrelizumab. The overall incidence of adverse drug reactions grade 3 or above was 10% (4/42), of which 0 case related to nimotuzumab and 4 cases related to camralizumab. Conclusions: The combination of camrelizumab and nimotuzumab in the second-line treatment of advanced esophageal squamous cell carcinoma showed a trend benefit for ORR and OS with a controllable toxicity.

IR-780 Dye-based Targeting of Cancer-associated Fibroblasts Improves Cancer Immunotherapy by Increasing Intra-tumoral T Lymphocytes Infiltration.

Immune-checkpoint inhibitors (ICIs) against programmed death (PD)-1/PD-L1 pathway immunotherapy have been demonstrated to be effective in only a subset of patients with cancer, while the rest may exhibit low response or may develop drug resistance after initially responding. Previous studies have indicated that extensive collagen-rich stroma secreted by cancer-associated fibroblasts (CAFs) within the tumor microenvironment is one of the key obstructions of the immunotherapy for some tumors by decreasing the infiltrating cytotoxic T cells. However, there is still a lack of effective therapeutic strategies to control the extracellular matrix by targeting CAFs. The enhanced uptake of IR-780 by CAFs was assessed by using in vivo or ex vivo nearinfrared fluorescence imaging, confocal NIR fluorescent imaging, and CAFs isolation testing. The fibrotic phenotype down-regulation effects and in vitro CAFs killing effect of IR-780 were tested by qPCR, western blot, and flow cytometry. The in vivo therapeutic enhancement of anti-PD-L1 by IR-780 was evaluated on EMT6 and MC38 subcutaneous xenograft mice models. IR-780 has been demonstrated to be preferentially taken up by CAFs and accumulate in the mitochondria. Further results identified low-dose IR-780 to downregulate the fibrotic phenotype, while high-dose IR-780 could directly kill both CAFs and EMT6 cells in vitro. Moreover, IR-780 significantly inhibited extracellular matrix (ECM) protein deposition in the peri-tumoral stroma on subcutaneous EMT6 and MC38 xenografts, which increased the proportion of tumor-infiltrating lymphocytes (TILs) in the deep tumor and further promoted anti-PD-L1 therapeutic efficacy. This work provides a unique strategy for the inhibition of ECM protein deposition in the tumor microenvironment by targeted regulating of CAFs, which destroys the T cell barrier and further promotes tumor response to PD-L1 monoclonal antibody. IR-780 has been proposed as a potential therapeutic small-molecule adjuvant to promote the effect of immunotherapy.

Abstract PO1-19-10: Durvalumab + datopotamab deruxtecan in patients with PD-L1 positive advanced/metastatic triple-negative breast cancer: Arm 8 of the phase 1b/2, open label, platform BEGONIA study

Abstract Background: Patients (pts) with advanced/metastatic triple-negative breast cancer (a/mTNBC) have limited treatment options and poor prognosis. Immune checkpoint inhibitors combined with chemotherapy is the standard of care for pts with PD-L1 positive tumors; still, most pts progress within a year, highlighting a need for new treatments. BEGONIA is an ongoing Simon 2-stage, multicenter, multi-arm platform study evaluating the safety and efficacy of durvalumab (D), an anti–PD-L1 monoclonal antibody, with or without paclitaxel, in combination with novel oncology therapies as first-line treatment for a/mTNBC (NCT03742102). Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate (ADC) consisting of a humanized anti-trophoblast cell surface antigen 2 (TROP2) IgG1 monoclonal antibody linked to a topoisomerase I inhibitor payload via a plasma stable, tumor selective, tetrapeptide-based cleavable linker. TROP2 is broadly expressed on breast and other epithelial tumors and Dato-DXd monotherapy showed antitumor activity in heavily pretreated mTNBC pts (Bardia SABCS 2022 P6-10-03). Pts treated with Dato-DXd+D in Arm 7 of BEGONIA showed a 74% objective response rate (ORR) with median 7.2 months follow-up (Schmid SABCS 2022 PD11-09). Although responses were observed in both PD-L1–high and –low-expressing tumors, most pts (87%) had PD-L1–low-expressing tumors. In Arm 8 of BEGONIA, pts determined to have PD-L1 positive tumors by pre-existing/local testing will be recruited and treated with Dato-DXd+D to evaluate efficacy and safety in a PD-L1–high population. Methods: Eligible female pts are aged ≥18 years with untreated unresectable, locally advanced or mTNBC; ≥6 months between completion of treatment for earlier-stage breast cancer and recurrence of distant disease; ≥12 months since prior taxane therapy; ECOG PS 0/1; adequate organ function; and ≥1 nonirradiated measurable lesion. For inclusion in Arm 8, a PD-L1 positive tumor as determined by local immunohistochemistry (IHC) testing is required (either pre-existing or obtained during prescreening). Exclusion criteria for Arm 8 are clinically significant corneal disease; history or suspicion of interstitial lung disease/pneumonitis; underlying pulmonary disorder; prior exposure to immune-mediated therapy; or prior treatment with an ADC containing a topoisomerase I inhibitor. Arm 8 will evaluate Dato-DXd (6 mg/kg) + D (1120 mg) given intravenously every 3 weeks until disease progression or unacceptable toxicity. Tumors will be assessed per RECIST v1.1 every 6 weeks for 48 weeks, then every 12 weeks thereafter. A safety run-in will not occur for Arm 8, as Dato-DXd+D was evaluated in Arm 7 and was tolerable with no DLTs reported. Part 1 of Arm 8 will enroll 30 pts. The primary endpoint of Part 1 is safety and tolerability. A futility analysis will be performed with an option to expand Arm 8 to Part 2, where an additional 27 pts will be enrolled if expansion criteria are met. The primary endpoint for Part 2 is ORR. Secondary endpoints include ORR (Part 1 only), testing for antidrug antibodies and treatment pharmacokinetics (Part 1 only), duration of response (DoR), progression-free survival (PFS), and overall survival (OS). ORR will be summarized with descriptive statistics and 95% Clopper-Pearson confidence intervals. Kaplan-Meier analysis will be used for DoR, PFS, and OS. All tumor response and survival endpoints will be based on investigator assessments. Additional PD-L1 testing with the VENTANA PD-L1 (SP263) Assay will be performed on pretreatment tumor samples; high expression is defined as ≥10% of the tumor area populated by PD-L1–expressing tumor or immune cells. TROP2 expression will be assessed by IHC. Enrollment is ongoing. Funding: AstraZeneca/Daiichi Sankyo Citation Format: Peter Schmid, Cynthia Ma, Robert Huisden, Ross Stewart, Katrin Heider, Petra Vuković, Neelima Denduluri. Durvalumab + datopotamab deruxtecan in patients with PD-L1 positive advanced/metastatic triple-negative breast cancer: Arm 8 of the phase 1b/2, open label, platform BEGONIA study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-19-10.

Abstract 2358: YH41723 (IMC-202), a Novel TIGITxPD-L1 bispecific antibody, leads to potent anti-tumor immunity through T cell engaging and T/NK cell activation

Abstract Immune checkpoint inhibitors (ICIs) have been making innovative advances in current cancer therapy. In particular, the PD-L1/PD-1 blockades changed the paradigm of anti-cancer treatment, showing high efficiency compared to conventional therapy. However, drug resistance has been observed in many patients receiving PD-1/PD-L1 monoclonal antibodies (mAbs), and there are still many limitations in restoring T cell. To overcome this, various ICI targets including T cell immunoreceptor with Ig and ITIM domain (TIGIT) are being studied. TIGIT is a T cell co-inhibitory receptor, highly expressed on regulatory T (Treg) cells and memory T cells and natural killer (NK) cells. In combination with PD-1/PD-L1 inhibition, the activation of CD226 through the blocking of TIGIT/PVR ligation is important for T cell activation. In this study, we demonstrated the synergistic effect that can be obtained by simultaneously blocking of PD-L1 and TIGIT and effect of T cell engager function using TIGITxPD-L1 bispecific antibody (BsAb). We generated an anti-TIGITxPD-L1 BsAb, YH41723 (IMC-202), with Fc-engineering to enhance the effector function. In order to confirm superior efficacy of YH41723 compared to combination of two monoclonal antibodies, PD-L1 mAb+TIGIT mAb, we verified the CD8+ T cell-mediated tumor killing effect by T cell engager function of YH41723. We also observed strong antibody-dependent cell-mediated cytotoxicity (ADCC) effect of YH41723 against various cancer cell lines. In addition, YH41723 showed superior anti-tumor efficacy than combination treatment in NK cell-mediated tumor killing assay. We further confirmed the significant Treg cell depletion efficacy of YH41723 in vitro compared to combination. We tested in vivo anti-cancer efficacy of YH41723 in hPD-L1 KI CT26 with BALB/c-H/K-dKO mouse models (B cell-deficient mice). As a result, YH41723 showed superior tumor growth inhibition effect compared with anti-PD-L1 mAb and anti-TIGIT mAb combination. Even, 7 of 8 mice showed complete regression in 30 mg/kg dosing group. 60 days after the last administration, we further performed tumor re-challenge test. The tumor-free state of tumor re-challenged mice was sustained, indicating that the immune memory was generated by YH41723. Taken together, YH41723 showed strong efficacy in NK/T cell activation and Treg depletion in vitro and excellent anti-tumor efficacy in vivo, supporting that YH41723 as an effective anti-cancer immunotherapy and combination candidate with other ICIs. Citation Format: Min Hyeok Jee, Young Bong Park, Byeong-Yun An, Hee Ra Jung, Eunjung Lee, Jun Hwan Kim, Ji Eun Park, Ji Young Yoon, Seung Mi Jeong, Yang Kyun Ryu, Sung Ho Kim, Heung Tae Kim, Se-Woong Oh, Yeol Hong Kim. YH41723 (IMC-202), a Novel TIGITxPD-L1 bispecific antibody, leads to potent anti-tumor immunity through T cell engaging and T/NK cell activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2358.

Abstract 4040: Hypoxia-induced HIF-1α/USP3 pathway promoting immune escape in lung squamous cell carcinoma

Abstract Background: Immune escape poses a significant mechanism for tumor progress as well as enormous challenge for the treatment of lung squamous cell carcinoma (LUSC). The close association between hypoxic environments and tumor immune escape, with PD-L1 serving as a key marker, has garnered considerable attention. This study aims to delve into the molecular mechanisms underlying the regulation of PD-L1 deubiquitination by the hypoxia-induced HIF-1α/USP3 pathway, shedding light on the immune escape mechanisms in LUSC. Methods: NSCLC cells were cultured under hypoxia condition and the expression of USP3, HIF-1α and PD-L1 were measured by Western blot. Chromatin Immunoprecipitation (ChIP) and Co-immunoprecipitation (CO-IP) were employed to elucidate the direct regulatory mechanisms of the HIF-1α/USP3 pathway in PD-L1 deubiquitination. In vitro T cell-mediated killing assays was used to investigate the functional roles of USP3 in antitumor immunity in NSCLC. Results: We demonstrated that hypoxia score was increased in LUSC and negatively correlated with CD8+ T cell infiltration. Hypoxia as a major factor triggering LUSC cell immunosuppression and against T cell surveillance via stabilization of PD-L1. Mechanistically, USP3, induced by HIF-1α, is required for hypoxia-mediated PD-L1 stabilization in LUSC cells. USP3 inhibits the ubiquitination and degradation of PD-L1. The combination of USP3 inhibitors with PD-1/PD-L1 monoclonal antibodies significantly enhances the anti-LUSC effect, possibly through promoting the infiltration of CD8+ T and NK cells. Conclusion: This research unveils a novel mechanism by which hypoxia, through the HIF-1α/USP3 pathway, regulates PD-L1 deubiquitination, thereby promoting immune escape in LUSC. Furthermore, our study provides a new strategy involving USP3 inhibitors in combination with PD-1/PD-L1 monoclonal antibodies, offering novel insights for molecular targeted therapy and reversal of drug resistance in LUSC. Citation Format: Xiuwen Zhang, Hua Huang, Chen Ding, Chen Chen, Yongwen Li, Hongyu Liu, Chen Jun. Hypoxia-induced HIF-1α/USP3 pathway promoting immune escape in lung squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4040.

Sokotrasterol Sulfate Suppresses IFN-γ-Induced PD-L1 Expression by Inhibiting JAK Activity.

PD-1/PD-L1 monoclonal antibodies exhibit promising therapeutic effectiveness in multiple cancers. However, developing a simple and efficient non-antibody treatment strategy using the PD-1/PD-L1 signaling pathway still remains challenging. In this study, we developed a flow cytometry assay to screen bioactive compounds with PD-L1 inhibitory activity. A total of 409 marine natural products were screened, and sokotrasterol sulfate (SKS) was found to efficiently suppress the IFN-γ-induced PD-L1 expression. SKS sensitizes the tumor cells to antigen-specific T-cell killing in the T cell-tumor cell coculture system. Mechanistically, SKS directly targeted Janus kinase (JAK) to inhibit the downstream activation of signal transducer and activator of transcription (STAT) and the subsequent transcription of PDL1. Our findings highlight the immunological role of SKS that may act as a basis for a potential immunotherapeutic agent.

LAPTM4B-mediated hepatocellular carcinoma stem cell proliferation and MDSC migration: implications for HCC progression and sensitivity to PD-L1 monoclonal antibody therapy

In hepatocellular carcinoma (HCC), immunotherapy is vital for advanced-stage patients. However, diverse individual responses and tumor heterogeneity have resulted in heterogenous treatment outcomes. Our mechanistic investigations identified LAPTM4B as a crucial gene regulated by ETV1 (a transcription factor), especially in liver cancer stem cells (LCSCs). The influence of LAPTM4B on LCSCs is mediated via the Wnt1/c-Myc/β-catenin pathway. CXCL8 secretion by LAPTM4B drove myeloid-derived suppressor cell (MDSC) migration, inducing unfavorable patient prognosis. LAPTM4B affected PD-L1 receptor expression in tumor microenvironment and enhanced tumor suppression induced by PD-L1 monoclonal antibodies in HCC patients. LAPTM4B up-regulation is correlated with adverse outcomes in HCC patients, sensitizing them to PD-L1 monoclonal antibody therapy.

Efficacy and safety of the combination of cisplatin plus nab-paclitaxel and nivolumab with radiotherapy after maximal tumor resection in non-metastatic muscle invasive bladder cancer (CNN-BC trial).

TPS723 Background: The therapeutic gold standard for muscle invasive bladder cancer (MIBC) is radical cystectomy (RC) preceded by neoadjuvant chemotherapy when appropriate. However, RC is a major surgery procedure with 13% rate of severe complication and a perioperative mortality rate of about 1.5 - 5 %. Trimodal therapy (TMT) is a “bladder sparing” option alternative to RC. TMT consists of complete transurethral bladder tumor resection (TURBT) followed by a combination of systemic chemotherapy and locoregional radiotherapy (RT), with the option of “salvage” cystectomy in case of local treatment failure. Immunotherapy with anti-PD1/PD-L1 monoclonal antibody significantly improves survival of metastatic BC patients, and it seems to potentiate the activity of RT without increased toxicity. Therefore, we investigate the role of a multimodal TMT strategy to increase the disease-free survival (DFS) and avoid or delay RC in non-metastatic MIBC pts. Methods: CNN-BC trial (NCT05203913) is a phase 2, open-label, mono-institutional study evaluating the activity and safety of TMT with cisplatin, nab-paclitaxel and nivolumab as systemic therapy in non-metastatic MIBC pts. Eligible pts should have undergone complete TURBT with diagnosis of T2-T3 N0M0 urothelial carcinoma, and no evidence of lymph nodes or metastatic disease at FDG-PET within 6 weeks from the start of treatments. TMT consists of nivolumab (480 mg IV every 4 weeks for a total of 13 doses), weekly nab-paclitaxel (60mg/m2) plus cisplatin (20mg/m2) administered concurrently with RT (60Gy in 25 fractions over 5 weeks on original bladder tumor, plus a concomitant boost of 50Gy in 25 fractions on whole bladder and pelvic nodes). The primary endpoint is the 1-year DFS rate, defined as the rate of survival free of recurrence in pelvic nodes or bladder, or appearance of distant metastases. Secondary endpoints include: the rate of pts who require salvage cystectomy, the rate of locoregional complete response (CR) and of locoregional DFS, median DFS, safety, and quality of life. Exploratory biomarkers analysis will be performed. The trial is actively recruiting. Clinical trial information: NCT05203913 .

Inflammation-Driven Nanohitchhiker Enhances Postoperative Immunotherapy by Alleviating Prostaglandin E2-Mediated Immunosuppression.

Inflammation contributes to the immunosuppressive microenvironment and leads to the recurrence of surgically resected tumors. The COX-2/PGE2 axis is considered a key player in shaping the immunosuppression microenvironment. However, targeted modulation of the postoperative tumor microenvironment is challenging. To specifically curb the inflammation and alleviate immunosuppression, here, we developed a PGE2 inhibitor celecoxib (CXB)-loaded bionic nanoparticle (CP@CM) coated with activated murine vascular endothelial cell (C166 cells) membrane to target postoperative melanoma and inhibit its recurrence. CP@CM adhered to inflammatory white blood cells (WBCs) through the adhesion molecules, including ICAM-1, VCAM-1, E-selectin, and P-selection, expressed on the surface of C166 cells. Leveraging the natural tropism of the WBC to the inflammatory postoperative tumor site, CP@CM efficiently targeted postoperative tumors. In melanoma postoperative recurrence models, CXB significantly reduced PGE2 secretion and the recruitment of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Treg) by inhibiting the activity of COX-2. This was followed by an increase in the infiltration of CD8+ T cells and CD4+ T cells in tumor tissues. Additionally, the immune responses were further enhanced by combining a PD-L1 monoclonal antibody. Ultimately, this immunotherapeutic strategy reversed the tumor immunosuppressive microenvironment and inhibited tumor recurrence, demonstrating a promising potential for postoperative immunotherapy for melanoma.

Enhancing cancer care with improved checkpoint inhibitors: a focus on PD-1/PD-L1.

The emergence of checkpoint inhibitors targeting the PD-1/PD-L1 axis marks a paradigm shift in cancer therapy, offering a novel avenue for enhancing patient outcomes. This review examines the structural and functional dynamics of PD-1 and PD-L1 while exploring the clinical implications of current PD-1/PD-L1 monoclonal antibodies. Highlighting recent advancements, this paper delves into the promising results from combination therapies that present a multifaceted attack on tumor progression. Despite the success observed across various cancer types, challenges such as immune resistance remain. Future considerations are discussed with an emphasis on the need for further clinical studies, aiming to refine and broaden the curative potential of PD-1/PD-L1 inhibitors in oncology. This review postulates that ongoing research and innovative approaches could significantly enhance cancer care, making immunotherapy an even more central strategy in the fight against cancer. See also the graphical abstract(Fig. 1).

Immunotherapy, targeted therapy, and their cross talks in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a challenging malignancy with limited treatment options beyond surgery and chemotherapy. Recent advancements in targeted therapies and immunotherapy, including PD-1 and PD-L1 monoclonal antibodies, have shown promise, but their efficacy has not met expectations. Biomarker testing and personalized medicine based on genetic mutations and other biomarkers represent the future direction for HCC treatment. To address these challenges and opportunities, this comprehensive review discusses the progress made in targeted therapies and immunotherapies for HCC, focusing on dissecting the rationales, opportunities, and challenges for combining these modalities. The liver's unique physiology and the presence of fibrosis in many HCC patients pose additional challenges to drug delivery and efficacy. Ongoing efforts in biomarker development and combination therapy design, especially in the context of immunotherapies, hold promise for improving outcomes in advanced HCC. Through exploring the advancements in biomarkers and targeted therapies, this review provides insights into the challenges and opportunities in the field and proposes strategies for rational combination therapy design.