PD-1 Blockade Treatment Research Articles

PD-1 blockade treatment in melanoma: Mechanism of response and tumor-intrinsic resistance.

Malignant melanoma is characterized by high immunogenicity, genetic heterogeneity, and diverse pathological manifestations, affecting both skin and mucosa over the body. Pembrolizumab and nivolumab, both anti-PD-1 monoclonal antibodies, were approved by the US FDA for unresectable or metastatic melanoma in 2011 and 2014, respectively, with enduring and transformative outcomes. Despite marked clinical achievements, only a subset of patients manifested a complete response. Approximately 55% of melanoma patients exhibited primary resistance to PD-1 antibodies, with nearly 25% developing secondary resistance within 2 years of treatment. Thus, there is a critical need to comprehensively elucidate the mechanisms underlying the efficacy and resistance to PD-1 blockade. This review discusses the fundamental mechanisms of PD-1 blockade, encompassing insights from T cells and B cells, and presents resistance to anti-PD-1 with a particular focus on tumoral-intrinsic mechanisms in melanoma.

Gold Nano Frameworks with Mesopores for Synergistic Immune-Thermal Therapy in Hepatic Carcinoma: A Paradigm Shift in Immune Checkpoint Blockade.

Immune checkpoint blockade (ICB) therapy, while showing promise in various cancers, exhibits limited effectiveness in hepatic carcinoma due to the tumor's immunosuppressive microenvironment (TME) and challenges associated with immune cell infiltration. Efforts to transform the "cold" TME into an "inflamed" state, notably through chemo-immunotherapy, have sparked interest due to their potential to induce immunogenic cell death and augment the infiltration of cytotoxic T lymphocytes (CTLs). Nonetheless, the efficacy of chemo-immunotherapy is often compromised by suboptimal pharmacokinetics, poor tumor accumulation, and off-target toxicity. Herein, in response, we introduce an innovative, milder thermal therapeutic approach leveraging gold nano frameworks with mesopores for the targeted delivery of the immunostimulant imiquimod and NIR-II photothermal therapy. This strategy employs targeted molecule modifications to ensure precise tumor targeting, guided by photoacoustic imaging. Subsequent to mild thermal treatment, there is a release of immunogenic proteins (CRT and HSP90), enhancing tumor immunogenicity. Assisted by imiquimod, substantial CTL infiltration occurs, accompanied by pro-inflammatory factor release (TNF-α, IL-6), transforming M2 macrophages into the M1 phenotype. Ultimately, the proposed strategy combines PD-L1/PD-1 blockade, imiquimod and mild thermal treatment to synergistically enhance tumor immunogenicity, remodel the TME, and restrain hepatic carcinoma, making strides in ICB synergistic immune-thermal therapy.

Identification of JUN gene and cellular microenvironment in response to PD-1 blockade treatment in lung cancer patients via single-cell RNA sequencing.

Exploring the molecular mechanisms of PD-1/PDL-1 blockade for non-small cell lung cancer (NSCLC) would facilitate understanding for tumor microenvironment (TME) and development of individualized medicine. To date, biomarkers of response to PD-1 blockade therapy were still limited. In this study, we hypothesize that cell type in the tumor microenvironment can influence the effect of PD-1 blockade immunotherapy through specific genes. Therefore, we re-analyze the single-cell RNA sequencing data and validation in tissue from lung adenocarcinoma patients. Dynamic changes of cellular subpopulation were observed after anti-PD-1 immunotherapy among TMEs between primary/metastasis or good/poor response patients. Non-exhausted CD8 T cells and dysregulated genes were observed in responsing patients from PD-1 blockade therapy. Among all changed genes, JUN, involved in PD-1 blockade immunotherapy pathway, and could be considered as a PD-1 responsing biomarker.

Predictive value of circulating immune cell changes in response to PD-1 blockade and TKI therapy in patients with hepatocellular carcinoma

Purpose: This study investigated the dynamic changes in circulating immune cells following immune checkpoint inhibitors (ICIs), tyrosine kinase inhibitors (TKIs), and interventional therapy in hepatocellular carcinoma (HCC).Methods: HCC patients undergoing transarterial chemoembolization (TACE), TKI, and ICI treatment were included in the treatment group. Peripheral blood samples were collected from these patients before each cycle of PD-1 blockade treatment. Flow cytometry analysis was conducted to assess the composition of peripheral immune cells and identify PD-1-expressing T cells.Results: The treatment group showed a median time-to-tumor progression (TTP) of 8 months and an overall survival (OS) of 19 months. In comparison, the control group had 6 months and 15 months respectively. These differences were statistically significant (P = 0.029 for TTP and P = 0.020 for OS). In HCC patients receiving Lenvatinib, more circulating natural killer (NK) cells were noted. After 1–2 cycles of PD-1 antibody treatment, a general decline in the proportion of circulating PD-1+T cells was found, indicating individual variations in response.Conclusion: Circulating immune cells have the potential to serve as indicators of the response to immunotherapy, providing a means to monitor dynamic changes and optimize treatment for HCC.

The single cell immunogenomic landscape after neoadjuvant immunotherapy combined chemotherapy in esophageal squamous cell carcinoma

Neoadjuvant immunotherapy represents promising strategy in the treatment of esophageal squamous cell carcinoma (ESCC). However, the mechanisms underlying its impact on treatment sensitivity or resistance remain a subject of controversy. In this study, we conducted single-cell RNA and T/B cell receptor (scTCR/scBCR) sequencing of CD45+ immune cells on samples from 10 patients who received neoadjuvant immunotherapy and chemotherapy. We also validated our findings using multiplexed immunofluorescence and analyzed bulk RNA-seq from other cohorts in public database. By integrating analysis of 87357 CD45+ cells, we found GZMK + effector memory T cells (Tem) were relatively enriched and CXCL13+ exhausted T cells (Tex) and regulator T cells (Treg) decreased among responders, indicating a persistent anti-tumor memory process. Additionally, the enhanced presence of BCR expansion and somatic hypermutation process within TNFRSF13B + memory B cells (Bmem) suggested their roles in antigen presentation. This was further corroborated by the evidence of the T-B co-stimulation pattern and CXCL13-CXCR5 axis. The complexity of myeloid cell heterogeneity was also particularly pronounced. The elevated expression of S100A7 in ESCC, as detected by bulk RNA-seq, was associated with an exhausted and immunosuppressive tumor microenvironment. In summary, this study has unveiled a potential regulatory network among immune cells and the clonal dynamics of their functions, and the mechanisms of exhaustion and memory conversion between GZMK + Tem and TNFRSF13B + Bmem from antigen presentation and co-stimulation perspectives during neoadjuvant PD-1 blockade treatment in ESCC.

Analysis of efficacy and safety for the combination of regorafenib and PD-1 inhibitor in advanced hepatocellular carcinoma: A real-world clinical study

Background and aimsHepatocellular carcinoma (HCC) is a prevalent and deadly disease with limited treatment options. Regorafenib, a tyrosine kinase inhibitor, has shown promise in HCC treatment but faces limitations as a monotherapy. Combining regorafenib with PD-1 inhibitor may improve efficacy and survival outcomes for patients. This retrospective analysis was conducted to explore its efficacy and safety, providing reference experience for better application of this combination therapy. MethodsThis retrospective single-center study evaluated the efficacy and safety of combining regorafenib with PD-1 blockade for patients with HCC. Efficacy was evaluated according to the RECIST 1.1 evaluation criteria. Safety was assessed using CTCAE 4.0. Data was analyzed to compare survival status in different subgroups. ResultsGenerally, there were 76 patients with HCC elected to receive the regorafenib plus PD-1 blockade treatment during the study period. The objective response rate was 21.1% (n = 16), and the disease control rate was 56.6% (n = 43). Median progression-free survival (PFS) was 6.8 months, and median overall survival had not yet been reached. All patients suffered of at least 1 adverse event. Grade ≥3 adverse events occurred in 31.6% of patients (n = 24), with the most common being hand-foot syndrome, decreased appetite, and abdominal distension. Subgroup analyses showed no significant differences in PFS based on cirrhosis status or previous treatment lines. ConclusionWith manageable safety, regorafenib combined PD-1 inhibitor could bring survival benefits for advanced HCC who have received systemic treatment. Further, the Cox analysis showed that HBV infection, metastasis, etc. did not have significant effects on the survival benefits.

Abstract 2876: Spatial immune cell atlas predicts the sensitivity to neoadjuvant PD-1 blockade treatment combined with radiotherapy in resectable esophageal squamous cell carcinoma

Abstract Combination of radiotherapy and immunotherapy in neoadjuvant treatment seems a promising approach in resectable esophageal squamous cell squamous (ESCC). The clinical study of radiotherapy combined with PD-1 blockade therapy for neoadjuvant treatment of resectable ESCC shows good result. In order to investigate the underlying mechanism of the effectiveness of radiotherapy combined with immunotherapy in ESCC, we collected the pre and post neoadjuvant therapy samples from 5 responders and 5 non-responders ESCC patients and performed multiplexed tissue imaging using 28 markers. Using the detection measurements exported from QuPath, we performed the unsupervised clustering with Seurat and defined 20 cell types. Scimap was used to calculate the distance between different cell types. We found that CD4+ T, CD8+ T, cytotoxic CD8+ T cells and M1 macrophages showed an increase after treatment in both responders and non-responders. Tregs were decreased after neoadjuvant treatment in responder while there was no significant decrease in non-responder. And the distance between Tregs and cancer cells were increased in responders. Collectively, we provide an approach for investigating the underlying mechanism of the sensitivity to neoadjuvant PD-1 blockade treatment combined with radiotherapy in resectable ESCC using spatial multiplexed imaging. Citation Format: Xiaoyang Yin, Kailun Xu, Shu Zheng, Baosheng Li. Spatial immune cell atlas predicts the sensitivity to neoadjuvant PD-1 blockade treatment combined with radiotherapy in resectable esophageal 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 2876.

Efficacy of PD-1 checkpoint inhibitor therapy in melanoma and beyond: are peripheral T cell phenotypes the key?

Immunotherapy treatment strategies have proven effective in a limited portion of patients, where identifying responders from non-responders to treatment remains a challenge. While some indications can be drawn from invasive biopsies, we need more accessible methods for predicting response and better correlates of response prior to starting therapy. Recent work has identified differences in immune composition at baseline in peripheral blood from melanoma patients responding to PD-1 blockade treatment. Through flow cytometric analysis of T cell receptors, phenotypical features of CD8+ and CD4+ T cells and Tregs could allow for the stratification of treatment response. Analysing T cells within peripheral blood could potentially allow for the stratification of PD-1 treatment response prior to therapy in different cancer settings.

Immunohistochemical Expression of Programmed Death Ligand-1 and CD-8 in Glioblastoma

Background Glioblastoma (GBM) is the most common and most aggressive primary malignant brain tumor in adults. It is characterized by its extremely poor prognosis despite the available treatment strategies. Immune evasion is described in Glioblastoma via the PD-L1/ PD-1 interaction. Programmed death ligand 1 (PD-L1) is a cell surface ligand expressed on the surface of several tumors including GBM and its receptor is the PD-1 (Programmed deasth-1). Other malignant tumors including melanoma and non-small cell lung cancer, showed promising results using PD-L1/PD1 blockade treatment strategies where PD-L1 was described as a potential predictive biomarker for patient selection in these tumors. In our study we will shed the light on the expression and role of PD-L1 in glioblastoma, the presence of tumor infiltrating lymphocytes (TILs) and its interaction with PD-L1 in glioblastoma. The role of PD-L1, CD-8+ TILs, other clinicopathologic parameters and patient’s survival will be also discussed in relation to glioblastoma. Methods Paraffin embedded tissue blocks of thirty cases of GBN were retrieved, slides were prepared and stained via Hx& E for evaluation and confirmation of diagnosis according to the CNS WHO 2016. Immunohistochemistry using PD-L1 and CD-8 was performed on the 30 glioblastoma cases. Interpretation of the results and correlation between the expression of both markers and the clinicopathologic parameters was also done. Furthermore, survival analysis was done to correlate overall survival and progression free survival of the glioblastoma cases to the expression of PD-L1 and CD-8 markers and also the clinicopathologic parameters available. Results Diffuse/fibrillary PD-L1 was expressed in all cases (30/30) with variable percentages (16.7% in ≤ 25% of cases 5/30, 33.3% in > 25%- ≤ 50% of cases10/30, 16.7% in > 50%- ≤ 75% of cases 5/30 and 33.3% in > 75% of cases 10/30). The mean value of Diffuse/fibrillary PD-L1 expression was 57.6%. Membranous PD-L1 was expressed in 6/30 of the cases. TILs were set into two groups according to Han et al 2014; low infiltration group 17/30 (56.7%) of cases and high infiltration group 13/30 (43.3%) of cases. Expression of CD-8 was 10% (median percentage) and 14.3% (mean percentage). PD-L1 and CD-8 correlation was statistically significant (P 0.001) where high PD-L1 expression is associated with low CD-8 expression. PD-L1 expression was associated with worse overall survival (0.001) and worse progression free survival (P 0.026). CD-8expression did not affect the outcome. Correlation of age, sex, tumor site and laterality to outcome were statistically insignificant. In the results of our study PD-L1 expression was the only independent factor that affected the prognosis according to Cox variate analysis. Conclusion The incidence of PD-L1 expression in GBM patients is robust. Higher expression of PD-L1 is associated with lower TILs expression and worse prognosis.

Tertiary Lymphoid Structure Raises Survival and Immunotherapy in HPV− HNSCC

Immune checkpoint blockade (ICB) targeting PD-1/PD-L1 has been used for the treatment of head and neck squamous cell carcinoma (HNSCC). However, the overall response rate to ICB therapy for HNSCC remains less than 20%. It has recently been reported that the appearance of tertiary lymphoid structures (TLSs) in tumor tissue is correlated with better prognosis and response to ICB treatment. Here, we demonstrated an immune classification for the tumor microenvironment (TME) of HNSCC by analyzing The Cancer Genome Atlas (TCGA)–HNSCC data set and found that immunotype D with TLS enrichment had a better prognosis and response to ICB treatment. Furthermore, we observed that TLSs were present in a part of tumor samples of human papillomavirus (HPV) infection negative HNSCC (HPV− HNSCC) and were associated with the densities of dendritic cell (DC)–LAMP+ DCs, CD4+ T cells, CD8+ T cells, and progenitor T cells in TME. We established an HPV− HNSCC mouse model with TLS-enriched TME by overexpressing LIGHT in a mouse HNSCC cell line. We found that the induction of TLS formation enhanced the response to PD-1 blockade treatment in the HPV− HNSCC mouse model, accompanied by increases in DCs and progenitor exhausted CD8+ T cells in the TME. Elimination of CD20+ B cells attenuated the therapeutic effect of PD-1 pathway blockade in TLS+ HPV− HNSCC mouse models. These results indicate that TLSs contribute to the favorable prognosis and antitumor immunity of HPV− HNSCC. Inducing TLS formation in HPV− HNSCC tumors is a potential therapeutic method for improving the ICB response rate in patients with HPV− HNSCC.

Circular RNA in liquid biopsy as biomarkers toward precision medicine

Circular RNA in liquid biopsy as biomarkers toward precision medicine

A real-world retrospective study of incidence and associated factors of endocrine adverse events related to PD-1/PD-L1 inhibitors.

The adverse events (AEs) related to immune checkpoint inhibitors (ICIs) have been mostly described in clinical trials, however, such trials are restricted to selection criteria and the results cannot wholly represent the real-world setting. We aimed to evaluate the real-world endocrine AEs associated with programmed death receptor-1/programmed death ligand-1 (PD-1/PD-L1) inhibitors in Chinese population. This retrospective study included cancer patients who were treated with PD-1/PD-L1 inhibitors between January 2018 and December 2020 at Xinqiao Hospital, the Third Military Medical University. The information of 581 patients was reviewed, and data on clinical characteristics, PD-1/PD-L1 use, occurrence of endocrine AEs, and response to PD-1 blockade treatment were collated. The definition of endocrine AEs relied on diagnostic tests. Fisher's exact test or Pearson's chi-squared test was used to analyze the associations between endocrine variables and several categorical variables. Multivariate analyses were performed using a logistic regression model. Endocrine AEs were observed in 116 of the 581 patients (20.0%). The median time to onset of endocrine AEs was approximately 12 weeks. Pembrolizumab was associated with a significantly higher incidence of endocrine AEs compared to other anti-PD-1 agents (38.5%; P=0.0002); PD-1/PD-L1 inhibitor treatment combined with antiangiogenic therapy or with two other therapies (chemotherapy and antiangiogenic therapy) was associated with a significantly increased occurrence of endocrine AEs, compared to PD-1 blockade treatment alone (41.2%; P=0.015), both based on multivariate analysis. Patients who developed endocrine AEs had significantly higher overall response rates (ORRs; 33.3% vs. 23.1%, P=0.045) and disease control rates (DCRs; 91.1% vs. 79.1%, P=0.008) compared to patients without endocrine AEs. In multivariate analysis, endocrine AEs remained an independent factor for both ORR (OR: 1.764, 95% CI: 1.052-2.957, P=0.031) and DCR (OR: 2.896, 95% CI: 1.324-6.332, P=0.008) after adjusting for the confounding factors. A real-world Chinese population receiving PD-1/PD-L1 treatment, pembrolizumab administrated and triple therapy treatment modalities had a higher incidence of endocrine AEs. Patients who developed endocrine AEs demonstrated a favorable response to PD-l blockade treatment.

Stratification of PD-1 blockade response in melanoma using pre- and post-treatment immunophenotyping of peripheral blood.

Efficacy of checkpoint inhibitor therapies in cancer varies greatly, with some patients showing complete responses while others do not respond and experience progressive disease. We aimed to identify correlates of response and progression following PD-1-directed therapy by immunophenotyping peripheral blood samples from 20 patients with advanced malignant melanoma before and after treatment with the PD-1 blocking antibody pembrolizumab. Our data reveal that individuals responding to PD-1 blockade were characterised by increased CD8 T cell proliferation following treatment, while progression was associated with an increase in CTLA-4-expressing Treg. Remarkably, unsupervised clustering analysis of pre-treatment T cell subsets revealed differences in individuals that went on to respond to PD-1 blockade compared to individuals that did not. These differences mapped to expression of the proliferation marker Ki67 and the costimulatory receptor CD28 as well as the inhibitory molecules 2B4 and KLRG1. While these results require validation in larger patient cohorts, they suggest that flow cytometric analysis of a relatively small number of T cell markers in peripheral blood could potentially allow stratification of PD-1 blockade treatment response prior to therapy initiation.

Chloroquine treatment influences immunologicalmemory through the PD-1/PD-L1 pathway during the initiation of Plasmodium chabaudi infection.

Growing evidence describes the host immune response mechanism involved in malaria. Despite the spread of drug resistance, chloroquine (CQ) remains the main antimalarial drug in most countries in Latin America and Asia. Studies have indicated an immunomodulatory activity of CQ, however, the potential implications for CQ on immunological memory recognizing the malaria parasite are still being elucidated. Our study suggests that CQ treatment significantly delayed the initiation of parasitemia during infection of mice with the rodent malaria parasite, Plasmodium chabaudi (P.c.). Additionally, there was a decrease in T follicular helper cells (Tfh), CD4+ effector memory T cells, memory B cells (MBC), IgG2a memoryB cells, along with IgG2a plasma cells; while antibody production was not affected atthe observation time points. After PD-1 blockade and CQ treatment, no reductions in the numbers of CD4+ effector memory T cells, MBC, and IgG2a memoryB cells were observed compared with the P.c. group. Therefore, CQ might regulate immunological memory via the PD-1/PD-L1 signaling pathway. Compared with antibody secretion, the inhibition of CQ on immune memory cells was a more sensitive indicator.

Prospective assessment using 18F-FDG PET/CT as a novel predictor for early response to PD-1 blockade in non-small-cell lung cancer

Anti-programmed death-1 (PD-1) blockade is a standard treatment for advanced non-small-cell lung cancer (NSCLC). However, no appropriate modality exists for monitoring its therapeutic response immediately after initiation. Therefore, we aimed to elucidate the clinical relevance of 18F-FDG PET/CT versus CT in predicting the response to PD-1 blockade in the early phase. This prospective study included a total of 54 NSCLC patients. 18F-FDG PET/CT was performed at 4 weeks and 9 weeks after PD-1 blockade monotherapy. Maximum standardized uptake values (SULmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated. Among all patients, partial metabolic response and progressive metabolic disease after PD-1 blockade were observed in 35.2% and 11.1% on SULmax, 22.2% and 51.8% on MTV, and 27.8% and 46.3% on TLG, respectively, whereas a partial response (PR) and progressive disease (PD), respectively, based on RECIST v1.1 were recognized in 35.2% and 35.2%, respectively. The predictive probability of PR (MTV: 57.9% vs. 21.1%, p = 0.044; TLG: 63.2% vs. 21.1%, p = 0.020) and PD (MTV: 78.9% vs. 47.3%, p = 0.002; TLG: 73.7% vs. 21.1%, p = 0.007) detected based on RECIST at 4 weeks after PD-1 blockade initiation was significantly higher using MTV or TLG on 18F-FDG uptake than on CT. Multivariate analysis revealed that metabolic response by MTV or TLG at 4 weeks was an independent factor for response to PD-1 blockade treatment. Metabolic assessment by MTV or TLG was superior to morphological changes on CT for predicting the therapeutic response and survival at 4 weeks after PD-1 blockade.

Feasibility and Tolerance of Apatinib plus PD-1 Inhibitors for Previously Treated Advanced Gastric Cancer: A Real-World Exploratory Study.

Background Apatinib is established to be the standard of care as third-line therapy for patients with previously treated advanced gastric cancer (GC). Programmed cell death protein 1 (PD-1) blockades also exhibited promising efficacy and safety for patients with treatment-refractory advanced GC. Objective This study was to explore the feasibility and tolerance of apatinib plus PD-1 inhibitors for patients with previously treated advanced GC. Methods This study was performed as a real-world study; patients with advanced GC who were treated with previous systemic chemotherapy were screened retrospectively. Eligible patients were administered with apatinib combined with PD-1 blockade treatment. Efficacy of the patients was assessed with the change of target lesion using radiological evidence according to RECIST 1.1 criteria, and follow-up was carried out regularly. A safety profile was collected and documented during the combination treatment. Univariate analysis based on baseline characteristic subgroup was implemented in univariate analysis to identify the potential factor that might contribute to progression-free survival (PFS). Results Between August 2018 and October 2021, a total of 39 patients with advanced GC or gastroesophageal junction adenocarcinoma participated in this study consecutively and all the patients were available for efficacy and safety assessment. The best overall response during apatinib plus PD-1 blockade administration exhibited that PR was observed in 8 patients, SD was noted in 19 patients, and PD was found in 12 patients, which yielded an ORR of 20.5% (95% CI: 9.3%-36.5%), and DCR was 69.2% (95% CI: 52.4%-83.0%). Furthermore, the relatively enough follow-up had resulted in the mature PFS and overall survival (OS) data, suggesting that the median PFS of the 39 patients with advanced GC was 3.9 months (95% CI: 2.74-5.06). Additionally, the median OS of the 39 patients with advanced GC was 7.8 months (95% CI: 4.82-10.78). Furthermore, the most common adverse reactions of the 39 patients who received apatinib plus PD-1 blockades treatment were fatigue (61.5%), nausea and vomiting (56.4%), diarrhea (48.7%), hypertension (46.2%), hand-foot syndrome (38.5%), and rash (28.2%). Furthermore, performance status was independently associated with PFS of apatinib plus PD-1 inhibitor combination administration in baseline characteristic subgroup analysis. Conclusion Apatinib plus PD-1 inhibitors exhibited promising effectiveness and acceptable tolerance for previously treated advanced GC preliminarily. And this conclusion should be confirmed in clinical trials in the future.

A Patient With Failed Liver Transplantation After the Use of PD-1 Blockade Combined With Lenvaxen.

Hepatocellular carcinoma (HCC) is a common malignant tumor with high extent of invasiveness. Its invasion process is closely related to complex tumor microenvironment and microvascular characteristics. Recently, immune combined targeted therapy has been applied to patients, combination therapy program with better effect needs to be explored. Atezolizumab combined Bevacizumab regimen in phase III clinical trial IMbrave150 was approved by U.S. Federal Drug Administration (FDA) for HCC treatment. This program is mostly used for liver malignant tumors have failed other treatments. Patients in terminal stage, overall curative has an unsatisfactory effect, survival time of patients is limited. Therefore, seeking best plan for combined treatment to improve patient's life quality and survival rate are still one of the most important clinical difficulties. This report describes a 37-year-old male who suffered from HCC repeatedly relapsed after hepatectomy. The patient received transcatheter arterial chemoembolization (TACE), microwave ablation (MWA), targeted therapy, and other combined treatments, all showed poor treatment effects. He received liver transplantation (LT) after receiving PD-1 blockade combined targeted therapy, eventually died due to severe immune rejection. It's first case of an allogeneic liver transplantation patient who received PD-1 blockade and Lenvaxen combined therapy. PD-1 blockade treatment and clinical observations of this case were summarized.

Accumulation of dysfunctional tumor-infiltrating PD-1+ DCs links PD-1/PD-L1 blockade immunotherapeutic response in cervical cancer

ABSTRACT Various predictive biomarkers are needed to select candidates for optimal and individualized treatments. Tumor‐infiltrating immune cells have gained increasing interest in cancer research for the prediction of therapeutic response and survival. However, the role of dendritic cells (DCs) in PD-1 blockade immunotherapy remains unclear. In this study, we identified a population of PD-1+ DCs in the tumor microenvironment (TME) of cervical cancer (CC). The accumulation of PD-1+ DCs in cervical tumors was correlated with advanced stages, elevated preoperative squamous cell carcinoma antigen levels and lymph-vascular space invasion. PD-1 expression was induced on activated tumor-associated DCs (TADCs) in vitro compared with their resting counterparts. This PD-1+ DC population was characterized by reduced secretion of cytokines (IL-12, TNF-α, and IL-1β) and dysfunctional induction of T cell proliferation and cytotoxic reaction. PD-1 blockade significantly reinvigorated PD-1+ DCs to release IL-12, TNF-α, and IL-1β compared with PD-1- DCs. TILs from samples with higher PD-1+ DC infiltration could be induced to achieve a greater killing effect of PD-1 blockade treatment. Our findings suggested a role for PD-1+ DCs in immune surveillance dysfunction and CC progression. PD-1+ DC density in the TME may serve as a diagnostic factor for predicting the optimal beneficiaries of PD-1/PD-L1 blockade immunotherapy in CC.

Abstract 1657: Tumor selective immunotherapy to overcome checkpoint blockade resistance

Abstract Most patients are resistant to PD-1/PD-L1 blockade therapy but mechanisms are not well defined. Defective innate sensing limits reactivation of T cells after the blockade. Patients with well-established solid tumors often generate complicated immunosuppressive networks and are generally refractory to immunotherapy. NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase elevated (more than 100-fold) in most solid cancers and has emerged as a promising target for direct tumor-killing. Here, we demonstrate that novel NQO1 targeting drug-Isobutyldeoxynyboquinone (IB-DNQ) causes tumor-selective innate sensing leading to T cell dependent tumor suppression. IB-DNQ treatment increases PD-L1 expression in the tumor microenvironment. Upregulated PD-L1 within TME contributes to tumor relapse and provides therapeutic window for combination therapy of IB-DNQ with immune checkpoint blockade. We demonstrate that IB-DNQ or PD-1 blockade treatment alone leads to tumor rejection in mice bearing small but not large established tumors. However, combination therapy of IB-DNQ with anti-PD-L1 eradicates well-established and checkpoint blockade refractory tumors. Citation Format: Lingxiang Jiang, Paul J. Hergenrother, Xiumei Huang. Tumor selective immunotherapy to overcome checkpoint blockade resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1657.

Serum Metabolite Biomarkers Predictive of Response to PD-1 Blockade Therapy in Non-Small Cell Lung Cancer.

Background: Despite remarkable success of immunotherapies with checkpoint blockade antibodies targeting programmed cell death protein 1 (PD-1), the majority of patients with non-small-cell lung cancer (NSCLC) have yet to receive durable benefits. We used the metabolomic profiling of early on-treatment serum to explore predictors of clinical outcomes of anti-PD-1 treatment in patients with advanced NSCLC. Methods: We recruited 74 Chinese patients who had stage IIIB/IV NSCLC-proven tumor progression and were treated with PD-1 inhibitor. The study was comprised of a discovery cohort of patients treated with nivolumab and two validation cohorts of patients receiving tislelizumab or nivolumab. Serum samples were collected 2–3 weeks after the first infusion of PD-1 inhibitor. Metabolomic profiling of serum was performed using ultrahigh performance lipid chromatograph-mass spectrometry. The serum metabolite biomarkers were identified using an integral workflow of nontargeted metabolomic data analysis. Results: A serum metabolite panel consisting of hypoxanthine and histidine was identified and validated as a predictor of response to PD-1 blockade treatment in patients with advanced NSCLC. High levels of both hypoxanthine and histidine in early on-treatment serum were associated with improved progression-free survival [hazard ratio (HR) = 0.078, 95% confidence interval (CI), 0.027–0.221, p < 0.001] and overall survival (HR = 0.124, 95% CI, 0.039–0.397, p < 0.001) in the discovery cohort. The serum metabolite panel showed a high sensitivity and specificity in distinguishing responders and non-responders in the validation cohorts 1 and 2, with an area under the receiver-operating characteristic curve of 0.933 and 1.000, respectively. High levels of serum hypoxanthine and histidine were correlated with improved progression-free survival in the validation cohort 1 (HR = 0.137, 95% CI, 0.040–0.467, p = 0.001) and in the validation cohort 2 (HR = 0.084, 95% CI, 0.009–0.762, p = 0.028). Conclusion: Our results revealed that hypoxanthine and histidine in early on-treatment serum are predictive biomarkers of response to PD-1 blockade therapy in patients with advanced NSCLC. The serum biomarker panel would enable early identification of NSCLC patients who may benefit from PD-1 blockade therapy.